DAQ-2024-011734

Small Source Registration

DAQE-EN162350001-24

{{$d1 }}

Jessica Bonsall
48forty Solutions, LLC
11740 Katy Freeway, Suite 1200
Houston, TX 77079
[e-mail]

Dear Ms. Bonsall:

Re: Request for Evaluation of Compliance with Rule R307-401-9, UAC: Small Source Exemption
Project Fee Code: N162350001

On October 1, 2024, the Division of Air Quality (DAQ) received your request for a small source
exemption for the 48forty Solutions, LLC Tooele Wood Pallet Repair and Recycling Facility. The source
is located at 1820 West G Avenue, Building 641 in Tooele, Tooele County. The DAQ has determined the
small source exemption applies to the source, as long as the equipment and associated processes operate
as specified in the registration request. According to your application, the facility will not process more
than 3,744 pallets per day and will not burn more than 2,900 tons of wood per year in the air curtain
incinerator.

The small source exemption does not exempt a source from complying with other applicable federal,
state, and local regulations and the current Utah Administrative Code. Based on the emissions that you
submitted to DAQ with your registration request, the 48forty Solutions, LLC Tooele Wood Pallet Repair
and Recycling Facility is not required to obtain an approval order under R307-401. If you change your
operation such that there is an increase in emissions, we recommend that you notify us, as an approval
order may be required.

As authorized by the Utah Legislature, the fee for issuing this small source exemption is a one-time filing
fee in addition to the actual time spent by the review engineer and all other staff on the project. Payment
should be sent to DAQ upon receipt of the invoice.
195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144820 • Salt Lake City, UT 84114-4820
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

SPENCER J. COX
Governor
DEIDRE HENDERSON
Lieutenant Governor

Department of
Environmental Quality

Kimberly D. Shelley
Executive Director

DIVISION OF AIR QUALITY
Bryce C. Bird
Director

, 3 " * " / Þ Û Ù Û Ý
DAQE-EN162350001-24
Page 2
Thank you for registering your source with the DAQ. If you have any additional questions, please contact
Lucia Mason at [phone] or [e-mail].

Sincerely,

Bryce C. Bird
Director

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Alan D. Humpherys, Manager
New Source Review Section

BCB:ADH:LM:jg

{{#d1=date1_es_:signer1:date:format(date, "mmmm d, yyyy")}} {{#s=Sig_es_:signer1:signature}}
Site #:16235
Facility Type:Wood palate repair and recycling facility
UTM Northing:
UTM Easting:
Kiln Heater - Propane-fired
(Rating: 0.85 MMBtu/hr)Kiln - Wood Offgas
Exempt Yes No
NOX 0.113
CO 0.065
PM10 0.00609
PM2.5 0.00609
VOC 0.0002 1.82E+00
SO2 0.0087
HAP 0.0015 0.11
Notes
Exempt via R307-401-10, supplys
heat to the kiln
1,3-Butadiene
2-Methylnaphthalene 3.74E-05
3-Methylchloranthrene 2.81E-06
7,12-Dimethylbenz(a)anthracene 2.50E-05
Acenaphthene 2.81E-06
Acenaphthylene 2.81E-06
Acetaldehyde 33
Acetophenone
Acrolein 3
Anthracene 3.74E-06
Antimony Unlisted Compounds (component of SBC)
Arsenic 3.12E-04
Benz(a)anthracene 2.81E-06
Benzene
Benzene 3.28E-03
Benzo(a)pyrene 1.87E-06
Benzo(b)fluoranthene 2.81E-06
Benzo(g,h,i)perylene 1.87E-06
Benzo(k)fluoranthene 2.81E-06
Beryllium 1.87E-05
Cadmium 1.72E-03
Carbon tetrachloride
Chlorine
Chlorobenzene
Chloroform
Chromic acid (VI) (component of solCR6 and CRC)
Chromium 2.18E-03
Chrysene 2.81E-06
Cobalt 1.31E-04
Di(2-ethylhexyl)phthalate (DEHP)
Dibenz(a,h)anthracene
Criteria Pollutants An
HAP Annual Em
Dibenzo(a,h)anthracene 1.87E-06
Dichlorobenzene 1.87E-03
Dinitrophenol, 2,4-
Ethyl benzene
Ethylene dichloride (1,2-dichloroethane)
Fluoranthene 4.68E-06
Fluorene 4.37E-06
Formaldehyde 1.17E-01 10
Hexachlorodibenzo-p-dioxin 1,2,3,6,7,8
Hexane 2.81E+00
Hydrogen chloride (hydrochloric acid)
Indeno(1,2,3-cd)pyrene 2.81E-06
Lead Unlisted Compounds (component of PBC)
Manganese 5.93E-04
Mercury 4.06E-04
Methanol 176
Methyl bromide (bromomethane)
Methyl chloride (chloromethane)
Methyl chloroform (1,1,1 trichloroethane)
Methyl ethyl ketone
Methylene chloride (dichloromethane)
Naphthalene 9.52E-04
Nickel 3.28E-03
Nitrophenol, 4-
Pentachlorophenol
Perchloroethylene (tetrachloroethylene)
Phenanathrene 2.65E-05
Phenanthrene
Phenol
Phosphorus Metal, Yellow or White
Polychlorinated biphenyls
Polycyclic Organic Matter
Propionaldehyde 1
Propylene dichloride (1,2 dichloropropane)
Pyrene 7.80E-06
Selenium 3.74E-05
Styrene
Tetrachlorodibenzo-p-dioxin, 2,3,7,8-
Toluene 5.30E-03
Trichloroethylene
Trichlorophenol, 2,4,6-
Vinyl chloride
Xylenes
Table Saws for
Wood Cutting
ACI Aucillary Diesel
Engine
Air Curtain
Incinerator (ACI)
Blochar Ash
Handling Total
No No No No
2.147 1.45 3.60
0.463 3.77 4.23
0.10 0.152 1.885 0.02 2.16
0.05 0.152 1.595 0.01 1.81
0.174 1.305 3.30
0.001 0.145 0.15
1.9E-03 0.51 0.62
Tier 4 Final Certified,
part of ACI
3.79E-02 0.0
0.0
0.0
0.0
1.38E-03 0.0
4.91E-03 0.0
7.44E-01 21.663 55.8
0.00008352 0.0
8.97E-02 104.4 107.1
1.81E-03 0.0
0.20619 0.2
0.5742 0.6
1.63E-03 0.0
9.05E-01 0.9
109.62 109.6
1.82E-04 0.06786 0.1
9.61E-05 0.0
4.74E-04 0.0
1.50E-04 0.0
0.02871 0.0
0.10701 0.1
1.1745 1.2
20.619 20.6
0.8613 0.9
0.7308 0.7
0.09135 0.1
0.45675 0.5
3.42E-04 0.0
0.16965 0.2
0.0012267 0.0
5.65E-04 0.0
nnual Emissions (tpy)
missions (lb/year)
0.0
0.0
0.004698 0.0
0.8091 0.8
0.7569 0.8
7.38E-03 0.0
2.83E-02 0.0
1.14E+00 114.84 125.6
4.6719E-07 0.0
0.0
495.9 495.9
3.64E-04 0.0
1.2528 1.3
41.76 41.8
0.09135 0.1
0.3915 0.4
0.6003 0.6
0.8091 0.8
0.14094 0.1
7.569 7.6
8.22E-02 2.5317 2.6
0.8613 0.9
0.002871 0.0
0.0013311 0.0
0.9918 1.0
0.0
2.85E-02 0.0
1.3311 1.3
0.7047 0.7
0.000212715 0.0
3.2625 3.3
1.5921 2.6
0.8613 0.9
4.64E-03 0.0
0.07308 0.1
49.59 49.6
2.2446E-07 0.0
3.97E-01 24.012 24.4
0.783 0.8
0.0005742 0.0
0.4698 0.5
2.76E-01 0.6525 0.9
Exempt:
Yes
No
(must be less than 1 tpy)
Equipment Details *Liquified Petroleum Gas (aka Propane)
Rating 1 MMBtu/hour *Supplys heat to the kiln
Operational Hours 1,872 hours/year
Sulfur Content 0.18 gr/100 ft3
Fuel Propane
Criteria Pollutant
Concentration
(ppm)
Emission
Factor
(lb/10^3 gal)
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)Reference
NOX 13 0.12 0.11
CO 7.5 0.07 0.07
PM10 0.7 0.01 0.01
PM2.5 0.7 0.01 0.01
SO2 0.018 0.00 0.00
VOC 1.0 0.01 0.01HAP0.00 0.00 See Below
Green House Gas Pollutant
Global
Warming
Potential
Emission
Factor
(lb/10^3 gal)
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)Reference
CO2 (mass basis)1 12,500 116 109
Methane (mass basis)25 0.2 0.00 0.00
N2O (mass basis)298 0.9 0.01 0.01
CO2e 111
Hazardous Air Pollutant
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)Reference
2-Methylnaphthalene 2.40E-05 2.00E-08 1.87E-083-Methylchloranthrene 1.80E-06 1.50E-09 1.40E-09
7,12-Dimethylbenz(a)anthracene 1.60E-05 1.33E-08 1.25E-08
Acenaphthene 1.80E-06 1.50E-09 1.40E-09
Acenaphthylene 1.80E-06 1.50E-09 1.40E-09
Anthracene 2.40E-06 2.00E-09 1.87E-09Benz(a)anthracene 1.80E-06 1.50E-09 1.40E-09Benzene2.10E-03 1.75E-06 1.64E-06
Benzo(a)pyrene 1.20E-06 1.00E-09 9.36E-10
Benzo(b)fluoranthene 1.80E-06 1.50E-09 1.40E-09
Benzo(g,h,i)perylene 1.20E-06 1.00E-09 9.36E-10
Benzo(k)fluoranthene 1.80E-06 1.50E-09 1.40E-09Chrysene1.80E-06 1.50E-09 1.40E-09Dibenzo(a,h)anthracene 1.20E-06 1.00E-09 9.36E-10
Dichlorobenzene 1.20E-03 1.00E-06 9.36E-07
Fluoranthene 3.00E-06 2.50E-09 2.34E-09
Fluorene 2.80E-06 2.33E-09 2.18E-09
Formaldehyde 7.50E-02 6.25E-05 5.85E-05Hexane1.80E+00 1.50E-03 1.40E-03Indeno(1,2,3-cd)pyrene 1.80E-06 1.50E-09 1.40E-09
Naphthalene 6.10E-04 5.08E-07 4.76E-07
Phenanathrene 1.70E-05 1.42E-08 1.33E-08
Pyrene 5.00E-06 4.17E-09 3.90E-09
Toluene 3.40E-03 2.83E-06 2.65E-06Arsenic2.00E-04 1.67E-07 1.56E-07Beryllium1.20E-05 1.00E-08 9.36E-09
Cadmium 1.10E-03 9.17E-07 8.58E-07
Chromium 1.40E-03 1.17E-06 1.09E-06
Cobalt 8.40E-05 7.00E-08 6.55E-08
Manganese 3.80E-04 3.17E-07 2.96E-07Mercury2.60E-04 2.17E-07 2.03E-07Nickel2.10E-03 1.75E-06 1.64E-06
Selenium 2.40E-05 2.00E-08 1.87E-08
LPG-Fired Boilers & Heaters
AP-42 Table 1.5-1
&Table A-1 to
Subpart A of Part 98
Manufacturer Data
or AP-42 Table 1.5-1
No HAP data in AP-42 Chapter 1.5.
AP-42 Table 1.4-3
and
Table 1.4-4
used to generate
HAP data in this section.
Emission Factor(lb/10^6 scf)
Page 7 of 38 Version 1.0
November 29, 2018
Kiln Heater (Wood Offgas) *Heated by LPG Heater
Throughput 208000 pallets/year *Based on typical pallets per year (different from
Pallet Weight 40.1 lbs/pallet
Board ft Weight 2.6 lbs/board ft
Throughput Converted 3208 Mbf/year
Usage (hours)6 hours/day *conservative estimate according to NOI
Usage (hours)8760 hours/year
Pollutants
Emission Factor
(lb/Mbf)Emissions (tpy)
VOC 1.1352 2 * EPA Region 10 HAP and VOC Emission Fact
HAPs
Emission Factor
(lb/Mbf)
Emissions
(lb/year)Mbf = thousand board feed
Acetaldehyde 0.0104 33
Acrolein 0.0008 3
Formaldehyde 0.003 10
Methanol 0.055 176
Propionaldehyde 0.0003 1
Dungan Source
https://www.epa.gov/system/files/documents/2021-07/epa-region-10-lumber-drying-ef-january-2021.pdf
mbf = thousand board feet
m table saws which are based on max potential)
ors for Lumber Drying, January 2021
1.60E-06
Old Source (Wood P
https://www.epa.gov/s
roducts in the Waste Stream - Characterization and Combustion Emissions)
Tabel Saws (Fugitive)
Throughput 3744 pallets/day
Pallet Weight 40.1 lbs/pallet
Operating Time 312 days/year
Throughput 23421 tons wood/year *Production scaled up to 24/7,
Control Efficency 95.00% *"Enclosed building 95% contro
Pollutants
Emission Factor (lb
VOC/ton Wood)Emissions (tpy)
PM10 0.175 0.10 *Emission factors based on US
PM2.5 0.088 0.05
conservative assumption that every potential pallet to the site goes to the saw room to be trimmed
SEPA Memorandum dated May 08, 2014 re: Particulate Matter Potential to Emit at Sawmills, Excluding Boilers,
Located inPacific Northwest Indian Country
Equipment Details
Rating 74 hp = (55.3 kw)
Operational Hours 1,872 hours/year
Sulfur Content 15 ppm or 0.0015%
Criteria Pollutant
Emission
Standards
(g/hp-hr)
Emission Factor
(lb/hp-hr)
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)
NOX 0.031 2.29 2.15
CO 6.68E-03 0.49 0.46
PM10 2.20E-03 0.16 0.15
PM2.5 2.20E-03 0.16 0.15
VOC 2.51E-03 0.19 0.17
SO2 1.21E-05 0.00 0.00
HAP 0.00 0.00
Green House Gas Pollutant
Global
Warming
Potential
Emission Factor
(lb/hp-hr)
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)
CO2 (mass basis)1 1.15 85 80
Methane (mass basis)25 0 0CO2e80
Hazardous Air Pollutant
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)
Benzene 9.33E-04 4.83E-04 4.52E-04
Toluene 4.09E-04 2.12E-04 1.98E-04
Xylenes 2.85E-04 1.48E-04 1.38E-04
1,3-Butadiene 3.91E-05 2.03E-05 1.90E-05
Formaldehyde 1.18E-03 6.11E-04 5.72E-04
Acetaldehyde 7.67E-04 3.97E-04 3.72E-04
Acrolein 9.25E-05 4.79E-05 4.48E-05
Naphthalene 8.48E-05 4.39E-05 4.11E-05
Acenaphthylene 5.06E-06 2.62E-06 2.45E-06
Acenaphthene 1.42E-06 7.36E-07 6.88E-07
Fluorene 2.92E-05 1.51E-05 1.42E-05
Phenanthrene 2.94E-05 1.52E-05 1.43E-05
Anthracene 1.87E-06 9.69E-07 9.07E-07
Fluoranthene 7.61E-06 3.94E-06 3.69E-06
Pyrene 4.78E-06 2.48E-06 2.32E-06
Benz(a)anthracene 1.68E-06 8.70E-07 8.15E-07
Chrysene 3.53E-07 1.83E-07 1.71E-07
Benzo(b)fluoranthene 9.91E-08 5.13E-08 4.80E-08
Benzo(k)fluoranthene 1.55E-07 8.03E-08 7.52E-08
Benzo(a)pyrene 1.88E-07 9.74E-08 9.12E-08
Indeno(1,2,3-cd)pyrene 3.75E-07 1.94E-07 1.82E-07
Dibenz(a,h)anthracene 5.83E-07 3.02E-07 2.83E-07
Benzo(g,h,l)perylene 4.89E-07 2.53E-07 2.37E-07
Emission Factor
(lb/MMBtu)
Diesel-Fired Engines
Emergency Engines should
equal 100 hours of
operation per year
9.48E-09
7,000 BTU/hp-hr
*Tier 4 Final Certification, part of ACI S220E
Table 3.3-1
<600 hp
lb/hp-hr lb/hr Ton/year Check
Nox - Uncontrolled 0.031 2.29 2.15 Match
Reference Nox - Controlled
CO 6.68E-03 0.49 0.46 Match
SO2 2.05E-03 0.15 0.14
PM10 2.20E-03 0.16 0.15 Match
CO2 1.15E+00 85 80 Match
Aldehydes 4.63E-04 Not used, included in HAP below.
AP-42 Table 3.4-1 TOC 2.51E-03 0.19 0.17
See Below VOC 2.51E-03 0.19 0.17 Match
Methane Match
Reference Exhaust 2.47E-03
Evaporative 0.00
Crankcase 4.41E-05
Refueling 0.00
Reference HAP
Table 3.3-2
<600 hp
(lb/MMBtu)lb/hp-hr lb/hr Ton/year
Benzene 9.33E-04 6.53E-06 4.83E-04 4.52E-04
Toluene 4.09E-04 2.86E-06 2.12E-04 1.98E-04
Xylenes 2.85E-04 2.00E-06 1.48E-04 1.38E-04
1,3-Butadiene 3.91E-05 2.74E-07 2.03E-05 1.90E-05
Formaldehyde 1.18E-03 8.26E-06 6.11E-04 5.72E-04
Acetaldehyde 7.67E-04 5.37E-06 3.97E-04 3.72E-04
Acrolein 9.25E-05 6.48E-07 4.79E-05 4.48E-05
Naphthalene 8.48E-05 5.94E-07 4.39E-05 4.11E-05
Acenaphthylene 5.06E-06 3.54E-08 2.62E-06 2.45E-06
Acenaphthene 1.42E-06 9.94E-09 7.36E-07 6.88E-07
Fluorene 2.92E-05 2.04E-07 1.51E-05 1.42E-05
Phenanthrene 2.94E-05 2.06E-07 1.52E-05 1.43E-05
Anthracene 1.87E-06 1.31E-08 9.69E-07 9.07E-07
Fluoranthene 7.61E-06 5.33E-08 3.94E-06 3.69E-06
Pyrene 4.78E-06 3.35E-08 2.48E-06 2.32E-06
Benz(a)anthracene 1.68E-06 1.18E-08 8.70E-07 8.15E-07
Chrysene 3.53E-07 2.47E-09 1.83E-07 1.71E-07
Benzo(b)fluoranthene 9.91E-08 6.94E-10 5.13E-08 4.80E-08
Benzo(k)fluoranthene 1.55E-07 1.09E-09 8.03E-08 7.52E-08
Benzo(a)pyrene 1.88E-07 1.32E-09 9.74E-08 9.12E-08
Indeno(1,2,3-cd)pyrene 3.75E-07 2.63E-09 1.94E-07 1.82E-07
Dibenz(a,h)anthracene 5.83E-07 4.08E-09 3.02E-07 2.83E-07
Benzo(g,h,l)perylene 4.89E-07 3.42E-09 2.53E-07 2.37E-07
AP-42 Table 3.3-2,
Table 3.4-3, &
Table 3.4-4
(1,3-Butadiene will
not popluate if the
engine size is greater
than 600 hp. AP-42
does not list 1,3-
Butadiene for engines
greater than 600 hp.)

Manufacturer Data,
AP-42 Table 3.3-1,
& Table 3.4-1
AP-42 Table 3.3-1
& Table 3.4-1
EF x S lb/hp-hr lb/hr Ton/year Check
0.024 1.78 1.66
0.013 0.96 0.90
5.50E-03 0.41 0.38
8.09E-03 1.21E-05 0.00 0.00 Match Used>600 hp to allow for sulfur co
0.0007 0.05 0.05 Table 3.3-1 does not allow for a s
1.16 86 80 To be more representatvie, Table
7.05E-04 0.05 0.05 for engines >600 hp, TOC is 91%
91%6.42E-04 0.05 0.04
9%6.35E-05 0.00 0.00
Check
Table 3.4-3
>600 hp
(lb/MMBtu)lb/hp-hr lb/hr Ton/year Check
Match 7.76E-04 5.43E-06 4.02E-04 3.76E-04
Match 2.81E-04 1.97E-06 1.46E-04 1.36E-04
Match 1.93E-04 1.35E-06 1.00E-04 9.36E-05
Match
Match 7.89E-05 5.52E-07 4.09E-05 3.83E-05
Match 2.52E-05 1.76E-07 1.31E-05 1.22E-05
Match 7.88E-06 5.52E-08 4.08E-06 3.82E-06
Match 1.30E-04 9.10E-07 6.73E-05 6.30E-05
Match 9.23E-06 6.46E-08 4.78E-06 4.48E-06
Match 4.68E-06 3.28E-08 2.42E-06 2.27E-06
Match 1.28E-05 8.96E-08 6.63E-06 6.21E-06
Match 4.08E-05 2.86E-07 2.11E-05 1.98E-05
Match 1.23E-06 8.61E-09 6.37E-07 5.96E-07
Match 4.03E-06 2.82E-08 2.09E-06 1.95E-06
Match 3.71E-06 2.60E-08 1.92E-06 1.80E-06
Match 6.22E-07 4.35E-09 3.22E-07 3.02E-07
Match 1.53E-06 1.07E-08 7.93E-07 7.42E-07
Match 1.11E-06 7.77E-09 5.75E-07 5.38E-07
Match 2.18E-07 1.53E-09 1.13E-07 1.06E-07
Match 2.57E-07 1.80E-09 1.33E-07 1.25E-07
Match 4.14E-07 2.90E-09 2.14E-07 2.01E-07
Match 3.46E-07 2.42E-09 1.79E-07 1.68E-07
Match 5.56E-07 3.89E-09 2.88E-07 2.70E-07
Table 3.4-1
>600 hp
e 3.4-1 was used for all engine sizes.
Air Curtain Incinerator (ACL) *Also known as trench co
Throughput 2900 tons/year
Max Rated Capacity 7 tons wood waste/hr
Criteria Pollutant
Table 1 (Vegitative Debris):
Emission Factor
(lb/ton wood waste)
Table 1 (Vegitative
Debris): Emissions
(tpy)
NOX 1.6 2.3
CO 6.9 10.0
PM10 (PM for AP-42)7.7 11.2
PM2.5
VOC 0.41 0.6
SO2 4.90E-01 0.7
HAP
*AP-42 Tabel 1.6-4 EMISSIONFACTORS FOR TRACE E
HAPs
Emission Factor
(lb/MMBtu)
Emissions
(lb/year)
Acetaldehyde (TH)8.30E-04 21.7
Acetophenone (H)3.20E-09 0.0
Acrolein (TH)4.00E-03 104.4
Antimony Unlisted Compounds (component 7.90E-06 0.2
Arsenic Unlisted Compounds (component of 2.20E-05 0.6
Benzene (TH)4.20E-03 109.6
Benzo(a)pyrene (T)2.60E-06 0.1
Beryllium Metal (unreacted) (component of B 1.10E-06 0.0
Cadmium Metal (unreacted) (component of 4.10E-06 0.1
Carbon tetrachloride (TH)4.50E-05 1.2
Chlorine (TH)7.90E-04 20.6
Chlorobenzene (TH)3.30E-05 0.9
Chloroform (TH)2.80E-05 0.7
Chromium Unlisted Cmpds(H)(add w/chrom 1.75E-05 0.5
Chromic acid (VI) (component of solCR6 an 3.50E-06 0.1
Cobalt Unlisted Compounds (component of 6.50E-06 0.2
Dinitrophenol, 2,4- (H)1.80E-07 0.0
Di(2-ethylhexyl)phthalate (DEHP) (TH)4.70E-08 0.0
Ethyl benzene (H)3.10E-05 0.8
Ethylene dichloride (1,2-dichloroethane) (TH 2.90E-05 0.8
Formaldehyde (TH)4.40E-03 114.8
Hexachlorodibenzo-p-dioxin 1,2,3,6,7,8 (TH 1.79E-11 0.0
Hydrogen chloride (hydrochloric acid) (TH)1.90E-02 495.9
Lead Unlisted Compounds (component of P 4.80E-05 1.3
Manganese Unlisted Compounds (compone 1.60E-03 41.8
Mercury, vapor (component of HGC)(T/H)3.50E-06 0.1
Methyl bromide (H) (bromomethane)1.50E-05 0.4
Methyl chloride (H) (chloromethane)2.30E-05 0.6
Methyl chloroform (TH) (1,1,1 trichloroethan 3.10E-05 0.8
Methyl ethyl ketone (T)5.40E-06 0.1
Methylene chloride (TH) (dichloromethane)2.90E-04 7.6
Naphthalene (H)9.70E-05 2.5
Nickel metal (Component of 373024/NIC) (T 3.30E-05 0.9
Nitrophenol, 4- (H)1.10E-07 0.0
Pentachlorophenol (TH)5.10E-08 0.0
Perchloroethylene (tetrachloroethylene) (TH 3.80E-05 1.0
Phenol (TH)5.10E-05 1.3
Phosphorus Metal, Yellow or White (H)2.70E-05 0.7
Polychlorinated biphenyls (TH)8.15E-09 0.0
Polycyclic Organic Matter (H)1.25E-04 3.3
Propionaldehyde (H)6.10E-05 1.6
Propylene dichloride (H) (1,2 dichloropropan 3.30E-05 0.9
Selenium compounds (H)2.80E-06 0.1
Styrene (TH)1.90E-03 49.6
Tetrachlorodibenzo-p-dioxin, 2,3,7,8- (TH)8.60E-12 0.0
Toluene (TH)9.20E-04 24.0
Trichloroethylene (TH)3.00E-05 0.8
Trichlorophenol, 2,4,6- (H)2.20E-08 0.0
Vinyl chloride (TH)1.80E-05 0.5
Xylene (TH)2.50E-05 0.7
* Highest HAP (Hydrogen chloride (hydrochl 1.90E-02 495.9
* Total HAPs 3.88E-02 1013.3
A. AirBurners Operating Manual
ombustors
* how did they get this?
*A. AirBurners Operating Manual, S220E
Table 2 (Agricultural Sources
and Forest Vegitation):
(lb/ton wood waste)
Table 2 (Agricultural Sources and
Forest Vegitation): Emissions
(typ)
AP-42, Table 2.1-12:
Emission Factor
(lb/ton wood waste)
1 1.45 4
2.6 3.77
1.3 1.89 13
1.1 1.60
0.9 1.31
0.1 0.15 0.1
*PM2.5 from Table 1
ELEMENTS FROM WOOD RESIDUE COMBUSTION, same as NCDEQ's emission estimation sp
1.08E-02
Trench combustors https://www3.epa.gov/ttnchie
Heating Value of Wood Waste 4500 Btu/lb wood waste *AP-42 Section 1.6
9 MMBtu/ton
AP-42 Emissions:
(tpy)
5.8 AP-42, 2.1 Refuse Combustion, https://www3.epa.gov/
18.85
0.145
preadsheet for wood waste combustion, rev. L (revised September 3, 2019)
e1/ap42/ch02/final/c02s01.pdf
/ttnchie1/ap42/ch02/final/c02s01.pdf
Biochar Ash Handling (Fugitive)
Ash percentage 3.00%
Max Rated Capacity 7 tons wood waste/hr
Throughput 0.21 tons ash/hr
Usage (hours)1872 hours/year
Pollutants
Emission Factor (lb
VOC/ton Ash)Emissions (tpy)
PM10 0.11 0.02
PM2.5 0.04 0.01
A. Ash Content, "Emissions from Wood-Fired Combustion Equipment"
*B. Emission factors converted
Emissions from a Dry Coal Fly a
https://www3.epa.gov/ttnchie1/c
*A. Ash percentage of 3% cons
Fired Combustion Equipment" r
2008. Available at: https://www2
paperwood/emissions_report_0
PM10 53 g/Mg
PM2.5 19 g/Mg
B. PM10 and PM2.5 Emission Factors, "Fugitive Emissions from a Dry Co
d from the below emission factors for PM10 and PM2.5 (g/Mg of ash), from Table 1 of "Fugitive
ash Storage Pile (2012)" Available at:
conference/ei20/session5/smueller.pdf. Assuming PM = PM10.
servatively assumed from maximum ash content present in Table 2 of "Emissions from Wood-
report prepared by Envirochem Services Inc. for the Ministry of Environment dated June 30,
2.gov.bc.ca/assets/gov/environment/wastemanagement/industrial-waste/industrial-waste/pulp-
08.pdf
oal Fly ash Storage Pile (2012)"
Lucia Mason <[e-mail]>
SSE Peer Review, 16235: 48forty Solutions, LLC- Tooele Wood Pallet Facility
5 messages
Lucia Mason <[e-mail]>Tue, Oct 29, 2024 at 8:07 AM
To: Christine Bodell <[e-mail]>
Hi Christine,
Could you peer review this Small Source Exemption for 48forty? Let me know if you have any questions.
Thanks,
Lucia
SSE, 16235 0001: 48forty Solutions, LLC- Tooele Woo…
#1 PEER, EN162350001.rtf
809K
Christine Bodell <[e-mail]>Tue, Oct 29, 2024 at 8:46 PM
To: Lucia Mason <[e-mail]>
Lucia,
Great job on being so thorough in estimating the site's PTE. I have attached my minor edits.
What was the rationale for not using the AP-42 factors for the air curtain incinerator?
Thanks,
Christine
[Quoted text hidden]
#1 PEER, EN162350001_CB.rtf
811K
Lucia Mason <[e-mail]>Wed, Oct 30, 2024 at 4:51 PM
11/4/24, 7:59 AM State of Utah Mail - SSE Peer Review, 16235: 48forty Solutions, LLC- Tooele Wood Pallet Facility
https://mail.google.com/mail/u/0/?ik=509389cc4c&view=pt&search=all&permthid=thread-a:r-2596458072640655331&simpl=msg-a:r-2059400790995112438&simpl=msg-f:1814305361778137564&simpl…1/2
To: Christine Bodell <[e-mail]>
Hi Christine,
Thanks for the edits. I've attached an updated copy of the SSE letter.
The emission factors in AP-42 were found using a pilot-scale trench incinerator in 1968. The document the source used compares emission factors from a number
of more recent tests that feature full scale air curtain incinerators. Additionally, the PM emission factor listed in AP-42 for trench incinerators is higher than the AP-42
open burning PM emission factor for ponderosa pine (pine is a common wood for pallets). Air curtain incinerators are definitely considered cleaner than open
burning so this comparison casts doubt on the credibility of the AP-42 trench incinerator test.
I attached the document the source pulled their emission factors if you're interested. Let me know if you have any questions.
Enjoy New Orleans and happy Halloween!!
Lucia
[Quoted text hidden]
2 attachments
CA SJV APCD_ACI Emission Factors Determination_042017.pdf
661K
#2 PEER, EN162350001.rtf
810K
Christine Bodell <[e-mail]>Sat, Nov 2, 2024 at 2:32 PM
To: Lucia Mason <[e-mail]>
Hello Lucia,
Thank you for the explanation. I agree with your approach. Great job and I have signed off.
Best,
Christine
[Quoted text hidden]
Lucia Mason <[e-mail]>Mon, Nov 4, 2024 at 7:23 AM
To: Christine Bodell <[e-mail]>
Thank you!
[Quoted text hidden]
11/4/24, 7:59 AM State of Utah Mail - SSE Peer Review, 16235: 48forty Solutions, LLC- Tooele Wood Pallet Facility
https://mail.google.com/mail/u/0/?ik=509389cc4c&view=pt&search=all&permthid=thread-a:r-2596458072640655331&simpl=msg-a:r-2059400790995112438&simpl=msg-f:1814305361778137564&simpl…2/2
10/96 Solid Waste Disposal 2.1-1
2.1 Refuse Combustion
Refuse combustion involves the burning of garbage and other nonhazardous solids, commonly
called municipal solid waste (MSW). Types of combustion devices used to burn refuse include single
chamber units, multiple chamber units, and trench incinerators.
2.1.1 General1-3
As of January 1992, there were over 160 municipal waste combustor (MWC) plants operating in
the United States with capacities greater than 36 megagrams per day (Mg/day) (40 tons per day [tpd]), with
a total capacity of approximately 100,000 Mg/day (110,000 tpd of MSW).1 It is projected that by 1997,
the total MWC capacity will approach 150,000 Mg/day (165,000 tpd), which represents approximately
28 percent of the estimated total amount of MSW generated in the United States by the year 2000.
Federal regulations for MWCs are currently under 3 subparts of 40 CFR Part 60. Subpart E
covers MWC units that began construction after 1971 and have capacities to combust over 45 Mg/day
(50 tpd) of MSW. Subpart Ea establishes new source performance standards (NSPS) for MWC units
which began construction or modification after December 20, 1989 and have capacities over 225 Mg/day
(250 tpd). An emission guideline (EG) was established under Subpart Ca covering MWC units which
began construction or modification prior to December 20, 1989 and have capacities of greater than
225 Mg/day (250 tpd). The Subpart Ea and Ca regulations were promulgated on February 11, 1991.
Subpart E includes a standard for particulate matter (PM). Subparts Ca and Ea currently establish
standards for PM, tetra- through octa- chlorinated dibenzo-p-dioxin/chlorinated dibenzofurans
(CDD/CDF), hydrogen chloride (HCl), sulfur dioxide (SO2), nitrogen oxides (NOx) (Subpart Ea only), and
carbon monoxide (CO). Additionally, standards for mercury (Hg), lead (Pb), cadmium (Cd), and NOx (for
Subpart Ca) are currently being considered for new and existing facilities, as required by Section 129 of the
Clean Air Act Amendments (CAAA) of 1990.

In addition to requiring revisions of the Subpart Ca and Ea regulations to include these additional
pollutants, Section 129 also requires the EPA to review the standards and guidelines for the pollutants
currently covered under these subparts. It is likely that the revised regulations will be more stringent. The
regulations are also being expanded to cover new and existing MWC facilities with capacities of
225 Mg/day (250 tpd) or less. The revised regulations will likely cover facilities with capacities as low as
18 to 45 Mg/day (20 to 50 tpd). These facilities are currently subject only to State regulations.
2.1.1.1 Combustor Technology -
There are 3 main classes of technologies used to combust MSW: mass burn, refuse-derived fuel
(RDF), and modular combustors. This section provides a general description of these 3 classes of
combustors. Section 2.1.2 provides more details regarding design and operation of each combustor class.
With mass burn units, the MSW is combusted without any preprocessing other than removal of
items too large to go through the feed system. In a typical mass burn combustor, refuse is placed on a
grate that moves through the combustor. Combustion air in excess of stoichiometric amounts is
supplied both below (underfire air) and above (overfire air) the grate. Mass burn combustors are usually
erected at the site (as opposed to being prefabricated at another location), and range in size from 46 to
900 Mg/day (50 to 1,000 tpd) of MSW throughput per unit. The mass burn combustor category can be
divided into mass burn waterwall (MB/WW), mass burn rotary waterwall combustor (MB/RC), and mass
burn refractory wall (MB/REF) designs. Mass burn waterwall designs have water-filled tubes in the
furnace walls that are used to recover heat for production of steam and/or electricity. Mass burn rotary
2.1-2 EMISSION FACTORS 10/96
waterwall combustors use a rotary combustion chamber constructed of water-filled tubes followed by a
waterwall furnace. Mass burn refractory designs are older and typically do not include any heat recovery.
Process diagrams for a typical MB/WW combustor, a MB/RC combustor, and one type of MB/REF
combustor are presented in Figure 2.1-1, Figure 2.1-2, and Figure 2.1-3, respectively.
Refuse-derived fuel combustors burn processed waste that varies from shredded waste to finely
divided fuel suitable for co-firing with pulverized coal. Combustor sizes range from 290 to 1,300 Mg/day
(320 to 1,400 tpd). A process diagram for a typical RDF combustor is shown in Figure 2.1-4. Waste
processing usually consists of removing noncombustibles and shredding, which generally raises the heating
value and provides a more uniform fuel. The type of RDF used depends on the boiler design. Most boilers
designed to burn RDF use spreader stokers and fire fluff RDF in a semi-suspension mode. A subset of the
RDF technology is fluidized bed combustors (FBC).
Modular combustors are similar to mass burn combustors in that they burn waste that has not been
pre-processed, but they are typically shop fabricated and generally range in size from 4 to 130 Mg/day
(5 to 140 tpd) of MSW throughput. One of the most common types of modular combustors is the starved
air or controlled air type, which incorporates two combustion chambers. A process diagram of a typical
modular starved-air (MOD/SA) combustor is presented in Figure 2.1-5. Air is supplied to the primary
chamber at sub-stoichiometric levels. The incomplete combustion products (CO and organic compounds)
pass into the secondary combustion chamber where additional air is added and combustion is completed.
Another type of modular combustor design is the modular excess air (MOD/EA) combustor which consists
of 2 chambers as with MOD/SA units, but is functionally similar to mass burn units in that it uses excess
air in the primary chamber.
2.1.2 Process Description4
Types of combustors described in this section include:
-Mass burn waterwall,
-Mass burn rotary waterwall,
-Mass burn refractory wall,
-Refuse-derived fuel-fired,
-Fluidized bed,
-Modular starved air, and
-Modular excess air.
10
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6
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Figure 2.1-1. Typical mass burn waterfall combustor.
2.
1
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4
EM
I
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S
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F
A
C
T
O
R
S
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Figure 2.1-2. Simplified process flow diagram for a rotary waterwall combustor.
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6
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D
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Figure 2.1-3. Mass burn refractory wall combustor with grate/rotary kiln.
2.
1
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6
EM
I
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S
I
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N

F
A
C
T
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R
S
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Figure 2.1-4. Typical RDF-fired spreader stoker boiler.
10
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So
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W
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D
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p
o
s
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2.
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7
Figure 2.1-5. Typical modular starved-air combustor with transfer rams.
2.1-8 EMISSION FACTORS 10/96
2.1.2.1 Mass Burn Waterwall Combustors -
The MB/WW design represents the predominant technology in the existing population of large
MWCs, and it is expected that over 50 percent of new units will be MB/WW designs. In MB/WW units,
the combustor walls are constructed of metal tubes that contain circulating pressurized water used to
recover heat from the combustion chamber. In the lower actively burning region of the chamber where
corrosive conditions may exist, the walls are generally lined with castable refractory. Heat is also
recovered in the convective sections (i. e., superheater, economizer) of the combustor.
With this type of system, unprocessed waste (after removal of large, bulky items) is delivered by an
overhead crane to a feed hopper, which conveys the waste into the combustion chamber. Earlier MB/WW
designs utilized gravity feeders, but it is now more typical to feed by means of single or dual hydraulic
rams.
Nearly all modern MB/WW facilities utilize reciprocating grates or roller grates to move the waste
through the combustion chamber. The grates typically include 3 sections. On the initial grate section,
referred to as the drying grate, the moisture content of the waste is reduced prior to ignition. The second
grate section, referred to as the burning grate, is where the majority of active burning takes place. The
third grate section, referred to as the burnout or finishing grate, is where remaining combustibles in the
waste are burned. Smaller units may have only 2 individual grate sections. Bottom ash is discharged from
the finishing grate into a water-filled ash quench pit or ram discharger. From there, the moist ash is
discharged to a conveyor system and transported to an ash load-out or storage area prior to disposal. Dry
ash systems have been used in some designs, but their use is not widespread.
Combustion air is added from beneath the grate by way of underfire air plenums. The majority of
MB/WW systems supply underfire air to the individual grate sections through multiple plenums, which
enhance the ability to control burning and heat release from the waste bed. Overfire air is injected through
rows of high-pressure nozzles located in the side walls of the combustor to oxidize fuel-rich gases evolved
from the bed and complete the combustion process. Properly designed and operated overfire air systems
are essential for good mixing and burnout of organics in the flue gas. Typically, MB/WW MWCs are
operated with 80 to 100 percent excess air.
The flue gas exits the combustor and passes through additional heat recovery sections to one
or more air pollution control devices (APCD). The types of APCDs that may be used are discussed in
Section 2.1.4.
2.1.2.2 Mass Burn Rotary Waterwall Combustors -
A more unique mass burn design is the MB/RC. Plants of this design range in size from 180 to
2,400 Mg/day (200 to 2,700 tpd), with typically 2 or 3 units per plant. This type of system uses a rotary
combustion chamber. Following pre-sorting of objects too large to fit in the combustor, the waste is ram
fed to the inclined rotary combustion chamber, which rotates slowly, causing the waste to advance and
tumble as it burns. Underfire air is injected through the waste bed, and overfire air is provided above the
waste bed. Bottom ash is discharged from the rotary combustor to an afterburner grate and then into a wet
quench pit. From there, the moist ash is conveyed to an ash load-out or storage area prior to disposal.
Approximately 80 percent of the combustion air is provided along the rotary combustion chamber
length, with most of the air provided in the first half of the chamber. The rest of the combustion air is
supplied to the afterburner grate and above the rotary combustor outlet in the boiler. The MB/RC operates
at about 50 percent excess air, compared with 80 to 100 percent for typical MB/WW firing systems.
Water flowing through the tubes in the rotary chamber recovers heat from combustion. Additional heat
recovery occurs in the boiler waterwall, superheater, and economizer. From the economizer, the flue gas is
10/96 Solid Waste Disposal 2.1-9
typically routed to APCDs.
2.1.2.3 Mass Burn Refractory Wall Combustors -
Prior to 1970 there were numerous MB/REF MWCs in operation. The purpose of these plants
was to achieve waste reduction; energy recovery was generally not incorporated in their design. Most of
the roughly 25 MB/REF plants that still operate or that were built in the 1970s and 1980s use electrostatic
precipitators (ESPs) to reduce PM emissions, and several have heat recovery boilers. Most MB/REF
combustors have unit sizes of 90 to 270 Mg/day (100 to 300 tpd). It is not expected that additional plants
of this design will be built in the United States.

The MB/REF combustors comprise several designs. One design involves a batch-fed upright
combustor, which may be cylindrical or rectangular in shape. A second design is based on a rectangular
combustion chamber with a traveling, rocking, or reciprocating grate. This type of combustor is
continuously fed and operates in an excess air mode. If the waste is moved on a traveling grate, it is not
sufficiently aerated as it advances through the combustor. As a result, waste burnout or complete
combustion is inhibited by fuel bed thickness, and there is considerable potential for unburned waste to be
discharged into the bottom ash pit. Rocking and reciprocating grate systems stir and aerate the waste bed
as it advances through the combustion chamber, thereby improving contact between the waste and
combustion air and increasing the burnout of combustibles. The system generally discharges the ash at the
end of the grate to a water quench pit for collection and disposal in a landfill.
Because MB/REF combustors do not contain a heat transfer medium (such as the waterwalls that
are present in modern energy recovery units), they typically operate at higher excess air rates (150 to
300 percent) than MB/WW combustors (80 to 100 percent). The higher excess air levels are required to
prevent excessive temperatures, which can result in refractory damage, slagging, fouling, and corrosion
problems. One adverse effect of higher excess air levels is the potential for increased carryover of PM
from the combustion chamber and, ultimately, increased stack emission rates. High PM carryover may
also contribute to increased CDD/CDF emissions by providing increased surface area for downstream
catalytic formation to take place. A second problem is the potential for high excess air levels to quench
(cool) the combustion reactions, preventing thermal destruction of organic species.
An alternate, newer MB/REF combustor is the Volund design (Figure 2.1-3 presents this MB/REF
design). This design minimizes some of the problems of other MB/REF systems. A refractory arch is
installed above the combustion zone to reduce radiant heat losses and improve solids burnout. The
refractory arch also routes part of the rising gases from the drying and combustion grates through a gas by-
pass duct to the mixing chamber. There the gas is mixed with gas from the burnout grate or kiln. Bottom
ash is conveyed to an ash quench pit. Volund MB/REF combustors operate with 80 to 120 percent excess
air, which is more in line with excess air levels in the MB/WW designs. As a result, lower CO levels and
better organics destruction are achievable, as compared to other MB/REF combustors.
2.1.2.4 Refuse-derived Fuel Combustors -
Refuse-derived fuel combustors burn MSW that has been processed to varying degrees, from
simple removal of bulky and noncombustible items accompanied by shredding, to extensive processing to
produce a finely divided fuel suitable for co-firing in pulverized coal-fired boilers. Processing MSW to
RDF generally raises the heating value of the waste because many of the noncombustible items are
removed.
A set of standards for classifying RDF types has been established by the American Society for
Testing and Materials. The type of RDF used is dependent on the boiler design. Boilers that are designed
to burn RDF as the primary fuel usually utilize spreader stokers and fire fluff RDF in a semi-suspension
2.1-10 EMISSION FACTORS 10/96
mode. This mode of feeding is accomplished by using an air swept distributor, which allows a portion of
the RDF to burn in suspension and the remainder to be burned out after falling on a horizontal traveling
grate. The number of RDF distributors in a single unit varies directly with unit capacity. The distributors
are normally adjustable so that the trajectory of the waste feed can be varied. Because the traveling grate
moves from the rear to the front of the furnace, distributor settings are adjusted so that most of the waste
lands on the rear two-thirds of the grate. This allows more time for combustion to be completed on the
grate. Bottom ash drops into a water-filled quench chamber. Some traveling grates operate at a single
speed, but most can be manually adjusted to accommodate variations in burning conditions. Underfire air
is normally preheated and introduced beneath the grate by a single plenum. Overfire air is injected through
rows of high-pressure nozzles, providing a zone for mixing and completion of the combustion process.
These combustors typically operate at 80 to 100 percent excess air.
Due to the basic design of the semi-suspension feeding systems, PM levels at the inlet to the
pollution control device are typically double those of mass burn systems and more than an order of
magnitude higher than MOD/SA combustors. The higher particulate loadings may contribute to the
catalytic formation of CDD/CDF. However, controlled Hg emissions from these plants are considerably
lower than from mass burn plants as a result of the higher levels of carbon present in the PM carryover, as
Hg adsorbs onto the carbon and can be subsequently captured by the PM control device.
Pulverized coal (PC)-fired boilers can co-fire fluff RDF or powdered RDF. In a PC-fired boiler
that co-fires fluff with pulverized coal, the RDF is introduced into the combustor by air transport injectors
that are located above or even with the coal nozzles. Due to its high moisture content and large particle
size, RDF requires a longer burnout time than coal. A significant portion of the larger, partially burned
particles disengage from the gas flow and fall onto stationary drop grates at the bottom of the furnace
where combustion is completed. Ash that accumulates on the grate is periodically dumped into the ash
hopper below the grate. Refuse-derived fuel can also be co-fired with coal in stoker-fired boilers.
2.1.2.5 Fluidized Bed Combustors -
In an FBC, fluff or pelletized RDF is combusted on a turbulent bed of noncombustible material
such as limestone, sand, or silica. In its simplest form, an FBC consists of a combustor vessel equipped
with a gas distribution plate and underfire air windbox at the bottom. The combustion bed overlies the gas
distribution plate. The combustion bed is suspended or "fluidized" through the introduction of underfire air
at a high flow rate. The RDF may be injected into or above the bed through ports in the combustor wall.
Other wastes and supplemental fuel may be blended with the RDF outside the combustor or added into the
combustor through separate openings. Overfire air is used to complete the combustion process.
There are 2 basic types of FBC systems: bubbling bed and circulating bed. With bubbling bed
combustors, most of the fluidized solids are maintained near the bottom of the combustor by using
relatively low air fluidization velocities. This helps reduce the entrainment of solids from the bed into the
flue gas, minimizing recirculation or reinjection of bed particles. In contrast, circulating bed combustors
operate at relatively high fluidization velocities to promote carryover of solids into the upper section of the
combustor. Combustion occurs in both the bed and upper section of the combustor. By design, a fraction
of the bed material is entrained in the combustion gas and enters a
10/96 Solid Waste Disposal 2.1-11
cyclone separator which recycles unburned waste and inert particles to the lower bed. Some of the ash is
removed from the cyclone with the solids from the bed.
Good mixing is inherent in the FBC design. Fluidized bed combustors have very uniform gas
temperatures and mass compositions in both the bed and in the upper region of the combustor. This allows
the FBCs to operate at lower excess air and temperature levels than conventional combustion systems.
Waste-fired FBCs typically operate at excess air levels between 30 and 100 percent and at bed
temperatures around 815EC (1,500EF). Low temperatures are necessary for waste-firing FBCs because
higher temperatures lead to bed agglomeration.
2.1.2.6 Modular Starved-air (Controlled-air) Combustors -
In terms of number of facilities, MOD/SA combustors represent a large segment of the existing
MWC population. However, because of their small sizes, they account for only a small percent of the total
capacity. The basic design of a MOD/SA combustor consists of 2 separate combustion chambers, referred
to as the "primary" and "secondary" chambers. Waste is batch-fed to the primary chamber by a
hydraulically activated ram. The charging bin is filled by a front end loader or other means. Waste is fed
automatically on a set frequency, with generally 6 to 10 minutes between charges.
Waste is moved through the primary combustion chamber by either hydraulic transfer rams or
reciprocating grates. Combustors using transfer rams have individual hearths upon which combustion
takes place. Grate systems generally include 2 separate grate sections. In either case, waste retention times
in the primary chamber are long, lasting up to 12 hours. Bottom ash is usually discharged to a wet quench
pit.
The quantity of air introduced into the primary chamber defines the rate at which waste burns.
Combustion air is introduced in the primary chamber at sub-stoichiometric levels, resulting in a flue gas
rich in unburned hydrocarbons. The combustion air flow rate to the primary chamber is controlled to
maintain an exhaust gas temperature set point, generally 650 to 980EC (1,200 to 1,800EF), which
corresponds to about 40 to 60 percent theoretical air.
As the hot, fuel-rich flue gases flow to the secondary chamber, they are mixed with additional air
to complete the burning process. Because the temperature of the exhaust gases from the primary chamber
is above the autoignition point, completing combustion is simply a matter of introducing air into the
fuel-rich gases. The amount of air added to the secondary chamber is controlled to maintain a desired flue
gas exit temperature, typically 980 to 1,200EC (1,800 to 2,200EF). Approximately 80 percent of the total
combustion air is introduced as secondary air. Typical excess air levels vary from 80 to 150 percent.
The walls of both combustion chambers are refractory lined. Early MOD/SA combustors did not
include energy recovery, but a waste heat boiler is common in newer installations, with 2 or more
combustion modules manifolded to a single boiler. Combustors with energy recovery capabilities also
maintain dump stacks for use in an emergency, or when the boiler and/or air pollution control equipment
are not in operation.
Most MOD/SA MWCs are equipped with auxiliary fuel burners located in both the primary and
secondary combustion chambers. Auxiliary fuel can be used during startup (many modular units do not
operate continuously) or when problems are experienced maintaining desired combustion temperatures. In
general, the combustion process is self-sustaining through control of air flow and feed rate, so that
continuous co-firing of auxiliary fuel is normally not necessary.
The high combustion temperatures and proper mixing of flue gas with air in the secondary
2.1-12 EMISSION FACTORS 10/96
combustion chamber provide good combustion, resulting in relatively low CO and trace organic emissions.
Because of the limited amount of combustion air introduced through the primary chamber, gas velocities in
the primary chamber and the amount of entrained PM are low. As a result, PM emissions of air pollutants
from MOD/SA MWCs are relatively low. Many existing modular systems do not have air pollution
controls. This is especially true of the smaller starved-air facilities. A few of the newer MOD/SA MWCs
have acid gas/PM controls.
2.1.2.7 Modular Excess Air Combustors -
There are fewer MOD/EA MWCs than MOD/SA MWCs. The design of MOD/EA units is
similar to that of MOD/SA units, including the presence of primary and secondary combustion chambers.
Waste is batch-fed to the primary chamber, which is refractory-lined. The waste is moved through the
primary chamber by hydraulic transfer rams, oscillating grates, or a revolving hearth. Bottom ash is
discharged to a wet quench pit. Additional flue gas residence time for fuel/carbon burnout is provided in
the secondary chamber, which is also refractory-lined. Energy is typically recovered in a waste heat boiler.
Facilities with multiple combustors may have a tertiary chamber where flue gases from each combustor are
mixed prior to entering the energy recovery boiler.
Unlike the MOD/SA combustors but similar to MB/REF units, a MOD/EA combustor typically
operates at about 100 percent excess air in the primary chamber, but may vary between 50 and 250 percent
excess air. The MOD/EA combustors also use recirculated flue gas for combustion air to maintain desired
temperatures in the primary and secondary chambers. Due to higher air velocities, PM emissions from
MOD/EA combustors are higher than those from MOD/SA combustors and are more similar in
concentration to PM emissions from mass burn units. However, NOx emissions from MOD/EA
combustors appear to be lower than from either MOD/SA or mass burn units.
2.1.3 Emissions4-7
Depending on the characteristics of the MSW and combustion conditions in the MWC, the
following pollutants can be emitted:
-PM,
-Metals (in solid form on PM, except for Hg),
-Acid gases (HCl, SO2),
-CO,
-NOx, and
-Toxic organics (most notably CDD/CDF).
A brief discussion on each of the pollutants is provided below, along with discussions on controls used to
reduce emissions of these pollutants to the atmosphere.
2.1.3.1 Particulate Matter -
The amount of PM exiting the furnace of an MWC depends on the waste characteristics, the
physical nature of the combustor design, and the combustor's operation. Under normal combustion
conditions, solid fly ash particulates formed from inorganic, noncombustible constituents in MSW are
released into the flue gas. Most of this particulate is captured by the facility's APCD and are not emitted to
10/96 Solid Waste Disposal 2.1-13
the atmosphere.
Particulate matter can vary greatly in size with diameters ranging from less than 1 micrometer to
hundreds of micrometers (µm). Fine particulates, having diameters less than 10µm (known as PM-10), are
of increased concern because a greater potential for inhalation and passage into the pulmonary region
exists. Further, acid gases, metals, and toxic organics may preferentially adsorb onto particulates in this
size range. The NSPS and EG for MWCs regulate total PM, while PM-10 is of interest for State
Implementation Plans and when dealing with ambient PM concentrations. In this chapter, "PM" refers to
total PM as measured by EPA Reference Method 5.
The level of PM emissions at the inlet of the APCD will vary according the combustor design, air
distribution, and waste characteristics. For example, facilities that operate with high underfire/overfire air
ratios or relatively high excess air levels may entrain greater quantities of PM and have high PM levels at
the APCD inlet. For combustors with multiple-pass boilers that change the direction of the flue gas flow,
part of the PM may be removed prior to the APCD. Lastly, the physical properties of the waste being fed
and the method of feeding influences PM levels in the flue gas. Typically, RDF units have higher PM
carryover from the furnace due to the suspension-feeding of the RDF. However, controlled PM emissions
from RDF plants do not vary substantially from other MWCs (i. e., MB/WW), because the PM is
efficiently collected in the APCD.
2.1.3.2 Metals -
Metals are present in a variety of MSW streams, including paper, newsprint, yard wastes, wood,
batteries, and metal cans. The metals present in MSW are emitted from MWCs in association with PM (e.
g., arsenic [As], Cd, chromium [Cr], and Pb) and as vapors, such as Hg. Due to the variability in MSW
composition, metal concentrations are highly variable and are essentially independent of combustor type. If
the vapor pressure of a metal is such that condensation onto particulates in the flue gas is possible, the
metal can be effectively removed by the PM control device. With the exception of Hg, most metals have
sufficiently low vapor pressures to result in almost all of the metals being condensed. Therefore, removal
in the PM control device for these metals is generally greater than 98 percent. Mercury, on the other hand,
has a high vapor pressure at typical APCD operating temperatures, and capture by the PM control device
is highly variable. The level of carbon in the fly ash appears to affect the level of Hg control. A high level
of carbon in the fly ash can enhance Hg adsorption onto particles removed by the PM control device.
2.1.3.3 Acid Gases -
The chief acid gases of concern from the combustion of MSW are HCl and SO2. Hydrogen
fluoride (HF), hydrogen bromide (HBr), and sulfur trioxide (SO3) are also generally present, but at much
lower concentrations. Concentrations of HCl and SO2 in MWC flue gases directly relate to the chlorine
and sulfur content in the waste. The chlorine and sulfur content vary considerably based on seasonal and
local waste variations. Emissions of SO2 and HCl from MWCs depend on the chemical form of sulfur and
chlorine in the waste, the availability of alkali materials in combustion-generated fly ash that act as
sorbents, and the type of emission control system used. Acid gas concentrations are considered to be
independent of combustion conditions. The major sources of chlorine in MSW are paper and plastics.
Sulfur is contained in many constituents of MSW, such as asphalt shingles, gypsum wallboard, and tires.
Because RDF processing does not generally impact the distribution of combustible materials in the waste
fuel, HCl and SO2 concentrations for mass burn and RDF units are similar.
2.1.3.4 Carbon Monoxide -
Carbon monoxide emissions result when all of the carbon in the waste is not oxidized to carbon
dioxide (CO2). High levels of CO indicate that the combustion gases were not held at a sufficiently high
2.1-14 EMISSION FACTORS 10/96
temperature in the presence of oxygen (O2) for a long enough time to convert CO to CO2. As waste burns
in a fuel bed, it releases CO, hydrogen (H2), and unburned hydrocarbons. Additional air then reacts with
the gases escaping from the fuel bed to convert CO and H2 to CO2 and H2O. Adding too much air to the
combustion zone will lower the local gas temperature and quench (retard) the oxidation reactions. If too
little air is added, the probability of incomplete mixing increases, allowing greater quantities of unburned
hydrocarbons to escape the furnace. Both of the conditions would result in increased emissions of CO.
Because O2 levels and air distributions vary among combustor types, CO levels also vary among
combustor types. For example, semi-suspension-fired RDF units generally have higher CO levels than
mass burn units, due to the effects of carryover of incompletely combusted materials into low temperature
portions of the combustor, and, in some cases, due to instabilities that result from fuel feed characteristics.
Carbon monoxide concentration is a good indicator of combustion efficiency, and is an important
criterion for indicating instabilities and nonuniformities in the combustion process. It is during unstable
combustion conditions that more carbonaceous material is available and higher CDD/CDF and organic
hazardous air pollutant levels occur. The relationship between emissions of CDD/CDF and CO indicates
that high levels of CO (several hundred parts per million by volume [ppmv]), corresponding to poor
combustion conditions, frequently correlate with high CDD/CDF emissions. When CO levels are low,
however, correlations between CO and CDDs/CDFs are not well defined (due to the fact that many
mechanisms may contribute to CDD/CDF formation), but CDD/CDF emissions are generally lower.
2.1.3.5 Nitrogen Oxides -
Nitrogen oxides are products of all fuel/air combustion processes. Nitric oxide (NO) is the
primary component of NOx; however, nitrogen dioxide (NO2) and nitrous oxide (N2O) are also formed in
smaller amounts. The combination of the compounds is referred to as NOx. Nitrogen oxides are formed
during combustion through (1) oxidation of nitrogen in the waste, and (2) fixation of atmospheric nitrogen.
Conversion of nitrogen in the waste occurs at relatively low temperatures (less than 1,090EC [2,000EF]),
while fixation of atmospheric nitrogen occurs at higher temperatures. Because of the relatively low
temperatures at which MWC furnaces operate, 70 to 80 percent of NOx formed in MWCs is associated
with nitrogen in the waste.
2.1.3.6 Organic Compounds -
A variety of organic compounds, including CDDs/CDFs, chlorobenzene (CB), polychlorinated
biphenyls (PCBs), chlorophenols (CPs), and polyaromatic hydrocarbons (PAHs), are present in MSW or
can be formed during the combustion and post-combination processes. Organics in the flue gas can exist in
the vapor phase or can be condensed or absorbed on fine particulates. Control of organics is accomplished
through proper design and operation of both the combustor and the APCDs.
Based on potential health effects, CDD/CDF has been a focus of many research and regulatory
activities. Due to toxicity levels, attention is most often placed on levels of CDDs/CDFs in the tetra-
through octa- homolog groups and specific isomers within those groups that have chlorine substituted in the
2, 3, 7, and 8 positions. As noted earlier, the NSPS and EG for MWCs regulate the total tetra- through
octa-CDDs/CDFs.
2.1.4 Controls8-10
A wide variety of control technologies are used to control emissions from MWCs. The control of
PM, along with metals that have adsorbed onto the PM, is most frequently accomplished through the use of
an ESP or fabric filter (FF). Although other PM control technologies (e. g., cyclones, electrified gravel
beds, and venturi scrubbers) are available, they are seldom used on existing systems, and it is anticipated
10/96 Solid Waste Disposal 2.1-15
that they will not be frequently used in future MWC systems. The control of acid gas emissions (i. e., SO2
and HCl) is most frequently accomplished through the application of acid gas control technologies such as
spray drying or dry sorbent injection, followed by a high-efficiency PM control device. Some facilities use
a wet scrubber to control acid gases. It is anticipated that dry systems (spray drying and dry sorbent
injection) will be more widely used than wet scrubbers on future U. S. MWC systems. Each of these
technologies is discussed in more detail below.
2.1.4.1 Electrostatic Precipitators -
Electrostatic precipitators consist of a series of high-voltage (20 to 100 kilojoules per coulomb [20
to 100 kilovolts]) discharge electrodes and grounded metal plates through which PM-laden flue gas flows.
Negatively charged ions formed by this high-voltage field (known as a "corona") attach to PM in the flue
gas, causing the charged particles to migrate toward, and be collected on, the grounded plates. The most
common types of ESPs used by MWCs are (1) plate wire units in which the discharge electrode is a bottom
weighted or rigid wire, and (2) flat plate units which use flat plates rather than wires as the discharge
electrode.
As a general rule, the greater the amount of collection plate area, the greater the ESP's PM
collection efficiency. Once the charged particles are collected on the grounded plates, the resulting dust
layer is removed from the plates by rapping, washing, or some other method and collected in a hopper.
When the dust layer is removed, some of the collected PM becomes re-entrained in the flue gas. To ensure
good PM collection efficiency during plate cleaning and electrical upsets, ESPs have several fields located
in series along the direction of flue gas flow that can be energized and cleaned independently. Particles re-
entrained when the dust layer is removed from one field can be recollected in a downstream field. Because
of this phenomena, increasing the number of fields generally improves PM removal efficiency.
Small particles generally have lower migration velocities than large particles and are therefore
more difficult to collect. This factor is especially important to MWCs because of the large amount of total
fly ash smaller than 1 µm. As compared to pulverized coal fired combustors, in which only 1 to 3 percent
of the fly ash is generally smaller than 1 µm, 20 to 70 percent of the fly ash at the inlet of the PM control
device for MWCs is reported to be smaller than 1 µm. As a result, effective collection of PM from MWCs
requires greater collection areas and lower flue gas velocities than many other combustion types.
As an approximate indicator of collection efficiency, the specific collection area (SCA) of an ESP
is frequently used. The SCA is calculated by dividing the collecting electrode plate area by the flue gas
flow rate and is expressed as square meters per 304.8 cubic meters per minute (square feet per 1000 cubic
feet per minute) of flue gas. In general, the higher the SCA, the higher the collection efficiency. Most
ESPs at newer MWCs have SCAs in the range of 400 to 600. When estimating emissions from
ESP-equipped MWCs, the SCA of the ESP should be taken into consideration. Not all ESPs are designed
equally and performance of different ESPs will vary.
2.1-16 EMISSION FACTORS 10/96
2.1.4.2 Fabric Filters -
Fabric filters are also used for PM and metals control, particularly in combination with acid gas
control and flue gas cooling. Fabric filters (also known as "baghouses") remove PM by passing flue gas
through a porous fabric that has been sewn into a cylindrical bag. Multiple individual filter bags are
mounted in an arranged compartment. A complete FF, in turn, consists of 4 to 16 individual compartments
that can be independently operated.
As the flue gas flows through the filter bags, particulate is collected on the filter surface, mainly
through inertial impaction. The collected particulate builds up on the bag, forming a filter cake. As the
thickness of the filter cake increases, the pressure drop across the bag also increases. Once pressure drop
across the bags in a given compartment becomes excessive, that compartment is generally taken off-line,
mechanically cleaned, and then placed back on-line.
Fabric filters are generally differentiated by cleaning mechanisms. Two main filter cleaning
mechanisms are used: reverse-air and pulse-jet. In a reverse-air FF, flue gas flows through unsupported
filter bags, leaving the particulate on the inside of the bags. The particulate builds up to form a particulate
filter cake. Once excessive pressure drop across the filter cake is reached, air is blown through the filter in
the opposite direction, the filter bag collapses, and the filter cake falls off and is collected. In a pulse-jet
FF, flue gas flows through supported filter bags leaving particulate on the outside of the bags. To remove
the particulate filter cake, compressed air is pulsed through the inside of the filter bag, the filter bag
expands and collapses to its pre-pulsed shape, and the filter cake falls off and is collected.
2.1.4.3 Spray Drying -
Spray dryers (SD) are the most frequently used acid gas control technology for MWCs in the
United States. When used in combination with an ESP or FF, the system can control CDD/CDF, PM (and
metals), SO2, and HCl emissions from MWCs. Spray dryer/fabric filter systems are more common than
SD/ESP systems and are used mostly on new, large MWCs. In the spray drying process, lime slurry is
injected into the SD through either a rotary atomizer or dual-fluid nozzles. The water in the slurry
evaporates to cool the flue gas, and the lime reacts with acid gases to form calcium salts that can be
removed by a PM control device. The SD is designed to provide sufficient contact and residence time to
produce a dry product before leaving the SD adsorber vessel. The residence time in the adsorber vessel is
typically 10 to 15 seconds. The particulate leaving the SD contains fly ash plus calcium salts, water, and
unreacted hydrated lime.
The key design and operating parameters that significantly affect SD performance are SD outlet
temperature and lime-to-acid gas stoichiometric ratio. The SD outlet approach to saturation temperature is
controlled by the amount of water in the slurry. More effective acid gas removal occurs at lower approach
to saturation temperatures, but the temperature must be high enough to ensure the slurry and reaction
products are adequately dried prior to collection in the PM control device. For MWC flue gas containing
significant chlorine, a minimum SD outlet temperature of around 115EC (240EF) is required to control
agglomeration of PM and sorbent by calcium chloride. Outlet gas temperature from the SD is usually
around 140EC (285EF).
The stoichiometric ratio is the molar ratio of calcium in the lime slurry fed to the SD divided by the
theoretical amount of calcium required to completely react with the inlet HCl and SO2 in the flue gas. At a
ratio of 1.0, the moles of calcium are equal to the moles of incoming HCl and SO2. However, because of
mass transfer limitations, incomplete mixing, and differing rates of reaction (SO2 reacts more slowly than
HCl), more than the theoretical amount of lime is generally fed to the SD. The stoichiometric ratio used in
SD systems varies depending on the level of acid gas reduction required, the temperature of the flue gas at
the SD exit, and the type of PM control device used. Lime is fed in quantities sufficient to react with the
10/96 Solid Waste Disposal 2.1-17
peak acid gas concentrations expected without severely decreasing performance. The lime content in the
slurry is generally about 10 percent by weight, but cannot exceed approximately 30 percent by weight
without clogging of the lime slurry feed system and spray nozzles.
2.1.4.4 Dry Sorbent Injection -
This type of technology has been developed primarily to control acid gas emissions. However,
when combined with flue gas cooling and either an ESP or FF, sorbent injection processes may also control
CDD/CDF and PM emissions from MWCs. Two primary subsets of dry sorbent injection technologies
exist. The more widely used of these approaches, referred to as duct sorbent injection (DSI), involves
injecting dry alkali sorbents into flue gas downstream of the combustor outlet and upstream of the PM
control device. The second approach, referred to as furnace sorbent injection (FSI), injects sorbent directly
into the combustor.
In DSI, powdered sorbent is pneumatically injected into either a separate reaction vessel or a
section of flue gas duct located downstream of the combustor economizer or quench tower. Alkali in the
sorbent (generally calcium or sodium) reacts with HCl, HF, and SO2 to form alkali salts
(e. g., calcium chloride [CaCl2], calcium fluoride [CaF2], and calcium sulfite [CaSO3]). By lowering the
acid content of the flue gas, downstream equipment can be operated at reduced temperatures while
minimizing the potential for acid corrosion of equipment. Solid reaction products, fly ash, and unreacted
sorbent are collected with either an ESP or FF.
Acid gas removal efficiency with DSI depends on the method of sorbent injection, flue gas
temperature, sorbent type and feed rate, and the extent of sorbent mixing with the flue gas. Not all DSI
systems are of the same design, and performance of the systems will vary. Flue gas temperature at the
point of sorbent injection can range from about 150 to 320EC (300 to 600EF) depending on the sorbent
being used and the design of the process. Sorbents that have been successfully tested include hydrated lime
(Ca[OH]2), soda ash (Na2CO3), and sodium bicarbonate (NaHCO3). Based on published data for hydrated
lime, some DSI systems can achieve removal efficiencies comparable to SD systems; however,
performance is generally lower.
By combining flue gas cooling with DSI, it may be possible to increase CDD/CDF removal
through a combination of vapor condensation and adsorption onto the sorbent surface. Cooling may also
benefit PM control by decreasing the effective flue gas flow rate (i. e., cubic meters per minute) and
reducing the resistivity of individual particles.
Furnace sorbent injection involves the injection of powdered alkali sorbent (either lime or
limestone) into the furnace section of a combustor. This can be accomplished by addition of sorbent to the
overfire air, injection through separate ports, or mixing with the waste prior to feeding to the combustor.
As with DSI, reaction products, fly ash, and unreacted sorbent are collected using an ESP or FF.
The basic chemistry of FSI is similar to DSI. Both use a reaction of sorbent with acid gases to
form alkali salts. However, several key differences exist in these 2 approaches. First, by injecting sorbent
directly into the furnace (at temperatures of 870 to 1,200EC [1,600 to 2,200EF]) limestone can be calcined
in the combustor to form more reactive lime, thereby allowing use of less expensive limestone as a sorbent.
Second, at these temperatures, SO2 and lime react in the combustor, thus providing a mechanism for
effective removal of SO2 at relatively low sorbent feed rates. Third, by injecting sorbent into the furnace
rather than into a downstream duct, additional time is available for mixing and reaction between the sorbent
and acid gases. Fourth, if a significant portion of the HCl is removed before the flue gas exits the
combustor, it may be possible to reduce the formation of CDD/CDF in latter sections of the flue gas
ducting. However, HCl and lime do not react with each other at temperatures above 760EC (1,400EF).
2.1-18 EMISSION FACTORS 10/96
This is the flue gas temperature that exists in the convective sections of the combustor. Therefore, HCl
removal may be lower than with DSI. Potential disadvantages of FSI include fouling and erosion of
convective heat transfer surfaces by the injected sorbent.
2.1.4.5 Wet Scrubbers -
Many types of wet scrubbers have been used for controlling acid gas emissions from MWCs.
These include spray towers, centrifugal scrubbers, and venturi scrubbers. Wet scrubbing technology has
primarily been used in Japan and Europe. Currently, it is not anticipated that many new MWCs being built
in the United States will use this type of acid gas control system. Wet scrubbing normally involves passing
the flue gas through an ESP to reduce PM, followed by a 1- or 2-stage absorber system. With single-stage
scrubbers, the flue gas reacts with an alkaline scrubber liquid to simultaneously remove HCl and SO2.
With two-stage scrubbers, a low-pH water scrubber for HCl removal is installed upstream of the alkaline
SO2 scrubber. The alkaline solution, typically containing calcium hydroxide (Ca[OH]2), reacts with the
acid gas to form salts, which are generally insoluble and may be removed by sequential clarifying,
thickening, and vacuum filtering. The dewatered salts or sludges are then disposed.
2.1.4.6 Nitrogen Oxides Control Techniques -
The control of NOx emissions can be accomplished through either combustion controls or add-on
controls. Combustion controls include staged combustion, low excess air (LEA), and flue gas recirculation
(FGR). Add-on controls which have been tested on MWCs include selective noncatalytic reduction
(SNCR), selective catalytic reduction (SCR), and natural gas reburning.
Combustion controls involve the control of temperature or O2 to reduce NOx formation. With
LEA, less air is supplied, which lowers the supply of O2 that is available to react with N2 in the combustion
air. In staged combustion, the amount of underfire air is reduced, which generates a starved-air region. In
FGR, cooled flue gas and ambient air are mixed to become the combustion air. This mixing reduces the O2
content of the combustion air supply and lowers combustion temperatures. Due to the lower combustion
temperatures present in MWCs, most NOx is produced from the oxidation of nitrogen present in the fuel.
As a result, combustion modifications at MWCs have generally shown small to moderate reductions in NOx
emissions as compared to higher temperature combustion devices (i. e., fossil fuel-fired boilers).
With SNCR, ammonia (NH3) or urea is injected into the furnace along with chemical additives to
reduce NOx to N2 without the use of catalysts. Based on analyses of data from U. S. MWCs equipped with
SNCR, NOx reductions of 45 percent are achievable.
With SCR, NH3 is injected into the flue gas downstream of the boiler where it mixes with NOx in
the flue gas and passes through a catalyst bed, where NOx is reduced to N2 by a reaction with NH3. This
technique has not been applied to U. S. MWCs, but has been used on MWCs in Japan and Germany.
Reductions of up to 80 percent have been observed, but problems with catalyst poisoning and deactivation
may reduce performance over time.
Natural gas reburning involves limiting combustion air to produce an LEA zone. Recirculated flue
gas and natural gas are then added to this LEA zone to produce a fuel-rich zone that inhibits NOx formation
and promotes reduction of NOx to N2. Natural gas reburning has been evaluated on both pilot- and
full-scale applications and achieved NOx reductions of 50 to 60 percent.
2.1.5 Mercury Controls11-14
10/96 Solid Waste Disposal 2.1-19
Unlike other metals, Hg exists in vapor form at typical APCD operating temperatures. As a result,
collection of Hg in the APCD is highly variable. Factors that affect Hg control are good PM control, low
temperatures in the APCD system, and a sufficient level of carbon in the fly ash. Higher levels of carbon
in the fly ash enhance Hg adsorption onto the PM, which is removed by the PM control device. To keep
the Hg from volatilizing, it is important to operate the control systems at low temperatures, generally less
than about 300 to 400EF.
Several mercury control technologies have been used on waste combustors in the United States,
Canada, Europe, and Japan. These control technologies include the injection of activated carbon or sodium
sulfide (Na2S) into the flue gas prior to the DSI- or SD-based acid gas control system, or the use of
activated carbon filters.
With activated carbon injection, Hg is adsorbed onto the carbon particle, which is then captured in
the PM control device. Test programs using activated carbon injection on MWCs in the United States have
shown Hg removal efficiencies of 50 to over 95 percent, depending on the carbon feed rate.
Sodium sulfide injection involves spraying Na2S solution into cooled flue gas prior to the acid gas
control device. Solid mercuric sulfide is precipitated from the reaction of Na2S and Hg and can be
collected in the PM control device. Results from tests on European and Canadian MWCs have shown
removal efficiencies of 50 to over 90 percent. Testings on a U. S. MWC, however, raised questions on the
effectiveness of this technology due to possible oversights in the analytical procedure used in Europe and
Canada.
Fixed bed activated carbon filters are another Hg control technology being used in Europe. With
this technology, the flue gas is passed through a fixed bed of granular activated carbon where the Hg is
adsorbed. Segments of the bed are periodically replaced as system pressure drop increases.
2.1.6 Emissions15-121
Tables 2.1-1, 2.1-2, 2.1-3, 2.1-4, 2.1-5, 2.1-6, 2.1-7, 2.1-8, and 2.1-9 present emission factors for
MWCs. The tables are for distinct combustor types (i. e., MB/WW, RDF), and include emission factors
for uncontrolled (prior to any pollution control device) levels and for controlled levels based on various
APCD types (i. e., ESP, SD/FF). There is a large amount of data available for this source category and, as
a result of this, many of the emission factors have high quality ratings. However, for some categories there
were only limited data, and the ratings are low. In these cases, one should refer to the EPA Background
Information Documents (BIDs) developed for the NSPS and EG, which more thoroughly analyze the data
than does AP-42, as well as discuss performance capabilities of the control technologies and expected
emission levels. Also, when using the MWC emission factors, it should be kept in mind that these are
average values, and emissions from MWCs are greatly affected by the composition of the waste and may
vary for different facilities due to seasonal and regional differences. The AP-42 background report for this
section includes data for individual facilities that represent the range for a combustor/control technology
category.
2.
1
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2
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Table 2.1-1 (Metric Units). PARTICULATE MATTER, METALS, AND ACID GAS EMISSION FACTORS FOR MASS BURN
AND MODULAR EXCESS AIR COMBUSTORSa,b
Uncontrolled ESPc DSI/ESPd SD/ESPe DSI/FFf SD/FFg
Pollutant kg/Mg
EMISSION
FACTOR
RATING kg/Mg
EMISSION
FACTOR
RATING kg/Mg
EMISSION
FACTOR
RATING kg/Mg
EMISSION
FACTOR
RATING kg/Mg
EMISSION
FACTOR
RATING kg/Mg
EMISSION
FACTOR
RATING
PMh 1.26 E+01 A 1.05 E-01 A 2.95 E-02 E 3.52 E-02 A 8.95 E-02 A 3.11 E-02 A
Asj 2.14 E-03 A 1.09 E-05 A NDk E 6.85 E-06 A 5.15 E-06 C 2.12 E-05 A
Cdj 5.45 E-03 A 3.23 E-04 B 4.44 E-05 E 3.76 E-06 A 1.17 E-05 C 1.36 E-05 A
Crj 4.49 E-03 A 5.65 E-05 B 1.55 E-05 E 1.30 E-04 A 1.00 E-04 C 1.50 E-05 A
Hgj 2.8 E-03 A 2.8 E-03 A 1.98 E-03 E 1.63 E-03 A 1.10 E-03 C 1.10 E-03 A
Nij 3.93 E-03 A 5.60 E-05 B 1.61 E-03 E 1.35 E-04 A 7.15 E-05 C 2.58 E-05 A
Pbj 1.07 E-01 A 1.50 E-03 A 1.45 E-03 E 4.58 E-04 A 1.49 E-04 C 1.31 E-04 A
SO2 1.73 E+00 A ND NA 4.76 E-01 C 3.27 E-01m A 7.15 E-01 C 2.77 E-01m A
HClj 3.20 E+00 A ND NA 1.39 E-01 C 7.90 E-02m A 3.19 E-01 C 1.06 E-01m A
a All factors in kg/Mg refuse combusted. Emission factors were calculated from concentrations using an F-factor of 0.26 dscm/joule (J) and a
heating value of 10,466 J/g. Other heating values can be substituted by multiplying the emission factor by the new heating value and dividing by
10,466 J/g. Source Classification Codes 5-01-001-04, 5-01-001-05, 5-01-001-06,
5-01-001-07, 5-03-001-11, 5-03-001-12, 5-03-001-13, 5-03-001-15. ND = no data. NA = not applicable.
b Emission factors should be used for estimating long-term, not short-term, emission levels. This particularly applies to pollutants
measured with a continuous emission monitoring system (e. g., SO2).
c ESP = Electrostatic Precipitator
d DSI/ESP = Duct Sorbent Injection/Electrostatic Precipitator
e SD/ESP = Spray Dryer/Electrostatic Precipitator
f DSI/FF = Duct Sorbent Injection/Fabric Filter
g SD/FF = Spray Dryer/Fabric Filter
h PM = Filterable particulate matter, as measured with EPA Reference Method 5.
j Hazardous air pollutants listed in the Clean Air Act.
k No data available at levels greater than detection limits.
m Acid gas emissions from SD/ESP- and SD/FF-equipped MWCs are essentially the same. Any differences are due to scatter in the
data.
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Table 2.1-2 (English Units). PARTICULATE MATTER, METALS, AND ACID GAS EMISSION FACTORS
FOR MASS BURN AND MODULAR EXCESS AIR COMBUSTORSa,b
Uncontrolled ESPc DSI/ESPd SD/ESPe DSI/FFf SD/FFg
Pollutant lb/ton
EMISSION
FACTOR
RATING lb/ton
EMISSION
FACTOR
RATING lb/ton
EMISSION
FACTOR
RATING lb/ton
EMISSION
FACTOR
RATING lb/ton
EMISSION
FACTOR
RATING lb/ton
EMISSION
FACTOR
RATING
PMh 2.51 E+01 A 2.10 E-01 A 5.90 E-02 E 7.03 E-02 A 1.79 E-01 A 6.20 E-02 A
Asj 4.37 E-03 A 2.17 E-05 A NDk E 1.37 E-05 A 1.03 E-05 C 4.23 E-06 A
Cdj 1.09 E-02 A 6.46 E-04 B 8.87 E-05 E 7.51 E-05 A 2.34 E-05 C 2.71 E-05 A
Crj 8.97 E-03 A 1.13 E-04 B 3.09 E-05 E 2.59 E-04 A 2.00 E-04 C 3.00 E-05 A
Hgj 5.6 E-03 A 5.6 E-03 A 3.96 E-03 E 3.26 E-03 A 2.20 E-03 C 2.20 E-03 A
Nij 7.85 E-03 A 1.12 E-04 B 3.22 E-05 E 2.70 E-04 A 1.43 E-04 C 5.16 E-05 A
Pbj 2.13 E-01 A 3.00 E-03 A 2.90 E-03 E 9.15 E-04 A 2.97 E-04 C 2.61 E-04 A
SO2 3.46 E+00 A ND NA 9.51 E-01 C 6.53 E-01m A 1.43 E-00 C 5.54 E-01m A
HClj 6.40 E+00 A ND NA 2.78 E-01 C 4.58 E-01m A 6.36 E-01 C 2.11 E-01m A
a All factors in lb/ton refuse combusted. Emission factors were calculated from concentrations using an F-factor of 9,570 dscf/MBtu and a
heating value of 4,500 Btu/lb. Other heating values can be substituted by multiplying the emission factor by the new heating value and dividing
by 4,500 Btu/lb. Source Classification Codes 5-01-001-04, 5-01-001-05, 5-01-001-06,
5-01-001-07, 5-03-001-11, 5-03-001-12, 5-03-001-13, 5-03-001-15. ND = no data. NA = not applicable.
b Emission factors should be used for estimating long-term, not short-term, emission levels. This particularly applies to pollutants measured with a
continuous emission monitoring system (e. g., SO2).
c ESP = Electrostatic Precipitator
d DSI/ESP = Duct Sorbent Injection/Electrostatic Precipitator
e SD/ESP = Spray Dryer/Electrostatic Precipitator
f DSI/FF = Duct Sorbent Injection/Fabric Filter
g SD/FF = Spray Dryer/Fabric Filter
h PM = Filterable particulate matter, as measured with EPA Reference Method 5.
j Hazardous air pollutants listed in the Clean Air Act.
k No data available at levels greater than detection limits.
m Acid gas emissions from SD/ESP- and SD/FF-equipped MWCs are essentially the same. Any differences are due to scatter in the
data.
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Table 2.1-3 (Metric Units). ORGANIC, NITROGEN OXIDES, CARBON MONOXIDE, AND CARBON DIOXIDE EMISSION
FACTORS FOR MASS BURN WATERWALL COMBUSTORSa,b
Uncontrolled ESPc SD/ESPd DSI/FFe SD/FFf
Pollutant kg/Mg
EMISSION
FACTOR
RATING kg/Mg
EMISSION
FACTOR
RATING kg/Mg
EMISSION
FACTOR
RATING kg/Mg
EMISSION
FACTOR
RATING kg/Mg
EMISSION
FACTOR
RATING
CDD/CDFg 8.35 E-07 A 5.85 E-07 A 3.11 E-07 A 8.0 E-08 C 3.31 E-08 A
NOxh 1.83 E+00 A ****
COh 2.32 E-01 A ****
CO2j 9.85 E+02 D ****
a All factors in kg/Mg refuse combusted. Emission factors were calculated from concentrations using an F-factor of 0.26 dscm/J and a heating
value of 10,466 J/g. Other heating values can be substituted by multiplying the emission factor by the new heating value and dividing by 10,466
J/g. Source Classification Codes 5-01-001-05, 5-03-001-12. * = Same as "uncontrolled" for these pollutants.
b Emission factors should be used for estimating long-term, not short-term, emission levels. This particularly applies to pollutants measured with a
continuous emission monitoring system (e. g., CO, NOx).
c ESP = Electrostatic Precipitator
d SD/ESP = Spray Dryer/Electrostatic Precipitator
e DSI/FF = Duct Sorbent Injection/Fabric Filter
f SD/FF = Spray Dryer/Fabric Filter
g CDD/CDF = total tetra- through octa- chlorinated dibenzo-p-dioxin/chlorinated dibenzofurans, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and
dibenzofurans are hazardous air pollutants listed in 1990 Clean Air Act.
h Control of NOx and CO is not tied to traditional acid gas/PM control devices.
j Calculated assuming a dry carbon content of 26.8% for feed refuse.126,135 CO2 emitted from this source may not increase total atmospheric CO2
because emissions may be offset by the uptake of CO2 by regrowing biomass.
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Table 2.1-4 (English Units). ORGANIC, NITROGEN OXIDES, CARBON MONOXIDE, AND CARBON DIOXIDE EMISSION
FACTORS FOR MASS BURN WATERWALL COMBUSTORSa,b
Uncontrolled ESPc SD/ESPd DSI/FFe SD/FFf
Pollutant lb/ton
EMISSION
FACTOR
RATING lb/ton
EMISSION
FACTOR
RATING lb/ton
EMISSION
FACTOR
RATING lb/ton
EMISSION
FACTOR
RATING lb/ton
EMISSION
FACTOR
RATING
CDD/CDFg 1.67 E-06 A 1.17 E-06 A 6.21 E-07 A 1.60 E-07 C 6.61 E-08 A
NOxh 3.56 E+00 A ****
COh 4.63 E-01 A ****
CO2
j 1.97 E+03 D ****
a All factors in lb/ton refuse combusted. Emission factors were calculated from concentrations using an F-factor of 9,570 dscf/MBtu and a
heating value of 4,500 Btu/lb. Other heating values can be substituted by multiplying the emission factor by the new heating value and dividing
by 4,500 Btu/lb. Source Classification Codes 5-01-001-05, 5-03-001-12. * = Same as "uncontrolled" for these pollutants.
b Emission factors should be used for estimating long-term, not short-term, emission levels. This particularly applies to pollutants measured with a
continuous emission monitoring system (e. g., CO, NOx).
c ESP = Electrostatic Precipitator
d SD/ESP = Spray Dryer/Electrostatic Precipitator
e DSI/FF = Duct Sorbent Injection/Fabric Filter
f SD/FF = Spray Dryer/Fabric Filter
g CDD/CDF = total tetra- through octa- chlorinated dibenzo-p-dioxin/chlorinated dibenzofurans, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and
dibenzofurans are hazardous air pollutants listed in the 1990 Clean Air Act.
h Control of NOx and CO is not tied to traditional acid gas/PM control devices.
j Calculated assuming a dry carbon content of 26.8% for feed refuse.126,135 CO2 emitted from this source may not increase total atmospheric CO2
because emissions may be offset by the uptake of CO2 by regrowing biomass.
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Table 2.1-5 (Metric And English Units). ORGANIC, NITROGEN OXIDES, CARBON MONOXIDE, AND CARBON DIOXIDE
EMISSION FACTORS FOR MASS BURN ROTARY WATERWALL COMBUSTORSa,b
Uncontrolled ESPc DSI/FFd SD/FFe
Pollutant kg/Mg lb/ton
EMISSION
FACTOR
RATING kg/Mg lb/ton
EMISSION
FACTOR
RATING kg/Mg lb/ton
EMISSION
FACTOR
RATING kg/Mg lb/ton
EMISSION
FACTOR
RATING
CDD/CDFf ND ND NA ND ND NA 4.58 E-08 9.16 E-08 D 2.66 E-08 5.31E-08 B
NOxg 1.13 E+00 2.25 E+00 E ******
COg 3.83 E-01 7.66 E-01 C ******
CO2
h 9.85 E+02 1.97 E+03 D ******
a Emission factors were calculated from concentrations using an F-factor of 0.26 dscm/J (9,570 dscf/MBtu) and a heating value of 10,466 J/g
(4,500 Btu/lb). Other heating values can be substituted by multiplying the emission factor by the new heating value and dividing by 10,466 J/g
(4,500 Btu/lb). Source Classification Codes 5-01-001-06, 5-03-001-13. ND = no data. NA = not applicable. * = Same as "uncontrolled" for
these pollutants.
b Emission factors should be used for estimating long-term, not short-term, emission levels. This particularly applies to pollutants measured with a
continuous emission monitoring system (e. g., CO, NOx).
c ESP = Electrostatic Precipitator
d DSI/FF = Duct Sorbent Injection/Fabric Filter
e SD/FF = Spray Dryer/Fabric Filter
f CDD/CDF = total tetra- through octa- chlorinated dibenzo-p-dioxin/chlorinated dibenzofurans, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and
dibenzofurans are hazardous air pollutants listed in the Clean Air Act.
g Control of NOx and CO is not tied to traditional acid gas/PM control devices.
h Calculated assuming a dry carbon content of 26.8% for feed refuse.126,135 CO2 emitted from this source may not increase total atmospheric CO2
because emissions may be offset by the uptake of CO2 by regrowing biomass.
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Table 2.1-6 (Metric And English Units). ORGANIC, NITROGEN OXIDES, CARBON MONOXIDE, AND CARBON DIOXIDE
EMISSION FACTORS FOR MASS BURN REFRACTORY WALL COMBUSTORSa,b
Uncontrolled ESPc DSI/ESPd
Pollutant kg/Mg lb/ton
EMISSION
FACTOR
RATING kg/Mg lb/ton
EMISSION
FACTOR
RATING kg/Mg lb/ton
EMISSION
FACTOR
RATING
CDD/CDFe 7.50 E-06 1.50 E-05 D 3.63 E-05 7.25 E-05 D 2.31 E-07 4.61 E-07 E
NOxf 1.23 E+00 2.46 E+00 A ****
COf 6.85 E-01 1.37 E+00 C ****
CO2
g 9.85 E+02 1.97 E+03 D ****
a Emission factors were calculated from concentrations using an F-factor of 0.26 dscm/J (9,570 dscf/MBtu) and a heating value of 10,466 J/g
(4,500 Btu/lb). Other heating values can be substituted by multiplying the emission factor by the new heating value and dividing by 10,466 J/g
(4,500 Btu/lb). Source Classification Codes 5-01-001-04, 5-03-001-11. * = Same as "uncontrolled" for these pollutants.
b Emission factors should be used for estimating long-term, not short-term, emission levels. This particularly applies to pollutants measured with a
continuous emission monitoring system (e. g., CO, NOx).
c ESP = Electrostatic Precipitator
d DSI/ESP = Duct Sorbent Injection/Electrostatic Precipitator
e CDD/CDF = total tetra- through octa- chlorinated dibenzo-p-dioxin/chlorinated dibenzofurans, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and
dibenzofurans are hazardous air pollutants listed in the Clean Air Act.
f Control of NOx and CO is not tied to traditional acid gas/PM control devices.
g Calculated assuming a dry carbon content of 26.8% for feed refuse.126,135 CO2 emitted from this source may not increase total atmospheric CO2
because emissions may be offset by the uptake of CO2 by regrowing biomass.
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Table 2.1-7 (Metric And English Units). ORGANIC, NITROGEN OXIDES, CARBON MONOXIDE, AND CARBON DIOXIDE
EMISSION FACTORS FOR MODULAR EXCESS AIR COMBUSTORSa,b
Uncontrolled ESPc DSI/FFd
Pollutant kg/Mg lb/ton
EMISSION
FACTOR
RATING kg/Mg lb/ton
EMISSION
FACTOR
RATING kg/Mg lb/ton
EMISSION
FACTOR
RATING
CDD/CDFe ND ND NA 1.11 E-06 2.22 E-06 C 3.12 E-08 6.23 E-08 E
NOxf 1.24 E+00 2.47 E+00 A ****
COf ND ND NA ****
CO2
g 9.85 E+02 1.97 E+03 D ****
a Emission factors were calculated from concentrations using an F-factor of 0.26 dscm/J (9,570 dscf/MBtu) and a heating value of 10,466 J/g
(4,500 Btu/lb). Other heating values can be substituted by multiplying the emission factor by the new heating value and dividing by 10,466 J/g
(4,500 Btu/lb). Source Classification Codes 5-01-001-07, 5-03-001-15. ND = no data. NA = not applicable. * = Same as "uncontrolled" for
these pollutants.
b Emission factors should be used for estimating long-term, not short-term, emission levels. This particularly applies to pollutants measured with a
continuous emission monitoring system (e. g., CO, NOx).
c ESP = Electrostatic Precipitator
d DSI/FF = Duct Sorbent Injection/Fabric Filter
e CDD/CDF = total tetra- through octa- chlorinated dibenzo-p-dioxin/chlorinated dibenzofurans, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and
dibenzofurans are hazardous air pollutants listed in the Clean Air Act.
f Control of NOx and CO is not tied to traditional acid gas/PM control devices.
g Calculated assuming a dry carbon content of 26.8% for feed refuse126,135 CO2 emitted from this source may not increase total atmospheric CO2
because emissions may be offset by the uptake of CO2 by regrowing biomass.
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Table 2.1-8 (Metric And English Units). EMISSION FACTORS FOR REFUSE-DERIVED FUEL-FIRED COMBUSTORSa,b
Uncontrolled ESPc SD/ESPd SD/FFe
Pollutant kg/Mg lb/ton
EMISSION
FACTOR
RATING kg/Mg lb/ton
EMISSION
FACTOR
RATING kg/Mg lb/ton
EMISSION
FACTOR
RATING kg/Mg lb/ton
EMISSION
FACTOR
RATING
PMf 3.48 E+01 6.96 E+01 A 5.17 E-01 1.04 E+00 A 4.82 E-02 9.65 E-02 B 6.64 E-02 1.33 E-01 B
Asg 2.97 E-03 5.94 E-03 B 6.70 E-05 1.34 E-04 D 5.41 E-06 1.08 E-05 D 2.59 E-06h 5.17 E-06h A
Cdg 4.37 E-03 8.75 E-03 C 1.10 E-04 2.20 E-04 C 4.18 E-05 8.37 E-05 D 1.66 E-05h 3.32 E-05h A
Crg 6.99 E-03 1.40 E-02 B 2.34 E-04 4.68 E-04 D 5.44 E-05 1.09 E-04 D 2.04 E-05 4.07 E-05 D
Hgg 2.8 E-03 5.5 E-03 D 2.8 E-03 5.5 E-03 D 2.10 E-04 4.20 E-04 B 1.46 E-04 2.92 E-04 D
Nig 2.18 E-03 4.36 E-03 C 9.05 E-03 1.81 E-02 D 9.64 E-05 1.93 E-04 D 3.15 E-05j 6.30 E-05j A
Pbg 1.00 E-01 2.01 E-01 C 1.84 E-03h 3.66 E-03h A 5.77 E-04 1.16 E-03 B 5.19 E-04 1.04 E-03 D
SO2 1.95 E+00 3.90 E+00 C ND ND NA 7.99 E-01 1.60E+00 D 2.21 E-01 4.41 E-01 D
HClg 3.49 E+00 6.97 E+00 E **ND ND NA 2.64 E-02 5.28 E-02 C
NOxk 2.51 E+00 5.02 E+00 A ******
COk 9.60 E-01 1.92 E+00 A ******
CO2
m 1.34 E+03 2.68 E+03 E ******
CDD/CDFn 4.73 E-06 9.47 E-06 D 8.46 E-06 1.69 E-05 B 5.31 E-08 1.06 E-07 D 1.22 E-08 2.44 E-08 E
a Emission factors were calculated from concentrations using an F-factor of 0.26 dscm/J (9,570 dscf/MBtu) and a heating value of 12,792 J/g (5,500 Btu/lb).
Other heating values can be substituted by multiplying the emission factor by the new heating value and dividing by 12,792 J/g (5,500 Btu/lb). Source
Classification Code 5-01-001-03. ND = no data. NA = not applicable. * = Same as uncontrolled for these pollutants.
b Emission factors should be used for estimating long-term, not short-term, emission levels. This particularly applies to pollutants measured with a
continuous emission monitoring system (SO2, NOx, CO).
c ESP = Electrostatic Precipitator
d SD/ESP = Spray Dryer/Electrostatic Precipitator
e SD/FF = Spray Dryer/Fabric Filter
f PM = total particulate matter, as measured with EPA Reference Method 5.
g Hazardous air pollutants listed in the Clean Air Act.
h Levels were measured at non-detect levels, where the detection limit was higher than levels measured at other similarly equipped MWCs. Emission factors
shown are based on emission levels from similarly equipped mass burn and MOD/EA combustors.
j No data available. Values shown are based on emission levels from SD/FF-equipped mass burn combustors.
k Control of NOx and CO is not tied to traditional acid gas/PM control devices.
m Based on source tests from a single facility.120 CO2 emitted from this source may not increase total atmospheric CO2 because emissions may be offset by the
uptake of CO2 by regrowing biomass.
n CDD/CDF = total tetra- through octa- chlorinated dibenzo-p-dioxin/chlorinated dibenzofurans, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and dibenzofurans are
hazardous air pollutants listed in the Clean Air Act.
2.1-28 EMISSION FACTORS 10/96
Table 2.1-9 (Metric And English Units). EMISSION FACTORS FOR MODULAR
STARVED-AIR COMBUSTORSa,b
Uncontrolled ESPc
Pollutant kg/Mg lb/ton
EMISSION
FACTOR
RATING kg/Mg lb/ton
EMISSION
FACTOR
RATING
PMd 1.72 E+00 3.43 E+00 B 1.74 E-01 3.48 E-01 B
Ase 3.34 E-04 6.69 E-04 C 5.25 E-05 1.05 E-04 D
Cde 1.20 E-03 2.41 E-03 D 2.30 E-04 4.59 E-04 D
Cre 1.65 E-03 3.31 E-03 C 3.08 E-04 6.16 E-04 D
Hge,f 2.8 E-03 5.6 E-03 A 2.8 E-03 5.6 E-03 A
Nie 2.76 E-03 5.52 E-03 D 5.04 E-04 1.01 E-03 E
Pbe ND ND NA 1.41 E-03 2.82 E-03 C
SO2 1.61 E+00 3.23 E+00 E **
HCle 1.08 E+00 2.15 E+00 D **
NOxg 1.58 E+00 3.16 E+00 B **
COg 1.50 E-01 2.99 E-01 B **
CO2h 9.85 E+02 1.97 E+03 D **
CDD/CDFj 1.47 E-06 2.94 E-06 D 1.88 E-06 3.76 E-06 C
a Emission factors were calculated from concentrations using an F-factor of 0.26 dscm/J (9,570 dscf/MBtu) and a heating
value of 10,466 J/g (4,500 Btu/lb). Other heating values can be substituted by multiplying the emission factor by the new
heating value and dividing by 10,466 J/g (4,500 Btu/lb). Source Classification Codes 5-01-001-01, 5-03-001-14. ND = no
data. NA = not applicable. * = Same as "uncontrolled" for these pollutants.
b Emission factors should be used for estimating long-term, not short-term, emission levels. This particularly applies to
pollutants measured with a continuous emission monitoring system (e. g., CO, NOx).
c ESP = Electrostatic Precipitator
d PM = total particulate matter, as measured with EPA Reference Method 5.
e Hazardous air pollutants listed in the Clean Air Act.
f Mercury levels based on emission levels measured at mass burn, MOD/EA, and MOD/SA combustors.
g Control of NOx and CO is not tied to traditional acid gas/PM control devices.
h Calculated assuming a dry carbon content of 26.8% for feed refuse.126,135 CO2 emitted from this source may not increase
total atmospheric CO2 because emissions may be offset by the uptake of CO2 by regrowing biomass.
j CDD/CDF = total tetra- through octa- chlorinated dibenzo-p-dioxin/chlorinated dibenzofurans, 2,3,7,8-tetrachlorodibenzo-p-
dioxin, and dibenzofurans are hazardous air pollutants listed in the Clean Air Act.
10/96 Solid Waste Disposal 2.1-29
Another point to keep in mind when using emission factors is that certain control technologies,
specifically ESPs and DSI systems, are not all designed with equal performance capabilities. The ESP and
DSI-based emission factors are based on data from a variety of facilities and represent average emission
levels for MWCs equipped with these control technologies. To estimate emissions for a specific ESP or
DSI system, refer to either the AP-42 background report for this section or the NSPS and EG BIDs to
obtain actual emissions data for these facilities. These documents should also be used when conducting
risk assessments, as well as for determining removal efficiencies. Since the AP-42 emission factors
represent averages from numerous facilities, the uncontrolled and controlled levels frequently do not
correspond to simultaneous testing and should not be used to calculate removal efficiencies.
Emission factors for MWCs were calculated from flue gas concentrations using an F-factor of 0.26
dry standard cubic meters per joule (dscm/J) (9,570 dry standard cubic feet per million British thermal
units [Btu]) and an assumed heating value of the waste of 10,466 J/g (4,500 Btu per pound [Btu/lb]) for all
combustors except RDF, for which a 12,792 J/g (5,500 Btu/lb) heating value was assumed. These are
average values for MWCs; however, a particular facility may have a different heating value for the waste.
In such a case, the emission factors shown in the tables can be adjusted by multiplying the emission factor
by the actual facility heating value and dividing by the assumed heating value (4,500 or 5,500 Btu/lb,
depending on the combustor type). Also, conversion factors to obtain concentrations, which can be used
for developing more specific emission factors or making comparisons to regulatory limits, are provided in
Tables 2.1-10 and 2.1-11 for all combustor types (except RDF) and RDF combustors, respectively.
Also note that the values shown in the tables for PM are for total PM, and the CDD/CDF data
represent total tetra- through octa-CDD/CDF. For SO2, NOx, and CO, the data presented in the tables
represent long-term averages, and should not be used to estimate short-term emissions. Refer to the EPA
BIDs which discuss achievable emission levels of SO2, NOx, and CO for different averaging times based on
analysis of continuous emission monitoring data. Lastly, for PM and metals, levels for MB/WW, MB/RC,
MB/REF, and MOD/EA were combined to determine the emission factors, since these emissions should be
the same for these types of combustors. For controlled levels, data were combined within each control
technology type (e. g., SD/FF data, ESP data). For Hg, MOD/SA data were also combined with the mass
burn and MOD/EA data.
2.1.7 Other Types Of Combustors122-134
2.1.7.1 Industrial/Commercial Combustors -
The capacities of these units cover a wide range, generally between 23 and 1,800 kilograms
(50 and 4,000 pounds) per hour. Of either single- or multiple-chamber design, these units are often
manually charged and intermittently operated. Some industrial combustors are similar to municipal
combustors in size and design. Emission control systems include gas-fired afterburners, scrubbers, or both.
Under Section 129 of the CAAA, these types of combustors will be required to meet emission limits for the
same list of pollutants as for MWCs. The EPA has not yet established these limits.
2.1.7.2 Trench Combustors -
Trench combustors, also called air curtain incinerators, forcefully project a curtain of air across a
pit in which open burning occurs. The air curtain is intended to increase combustion efficiency and reduce
smoke and PM emissions. Underfire air is also used to increase combustion efficiency.
2.1-30 EMISSION FACTORS 10/96
Table 2.1-10. CONVERSION FACTORS FOR ALL COMBUSTOR TYPES EXCEPT RDF
Divide By To Obtaina
For As, Cd, Cr, Hg, Ni, Pb, and CDD/CDF:
kg/Mg refuse
lb/ton refuse
4.03 x 10-6
8.06 x 10-6
µg/dscm
For PM:
kg/Mg refuse
lb/ton refuse
4.03 x 10-3
8.06 x 10-3
mg/dscm
For HCl:
kg/Mg refuse
lb/ton refuse
6.15 x 10-3
1.23 x 10-2
ppmv
For SO2:
kg/Mg refuse
lb/ton refuse
1.07 x 10-2
2.15 x 10-2
ppmv
For NOx:
kg/Mg refuse
lb/ton refuse
7.70 x 10-3
1.54 x 10-2
ppmv
For CO:
kg/Mg refuse
lb/ton refuse
4.69 x 10-3
9.4 x 10-3
ppmv
For CO2:
kg/Mg refuse
lb/ton refuse
7.35 x 10-3
1.47 x 10-2
ppmv
a At 7% O2.
10/96 Solid Waste Disposal 2.1-31
Table 2.1-11. CONVERSION FACTORS FOR REFUSE-DERIVED FUEL COMBUSTORS
Divide By To Obtaina
For As, Cd, Cr, Hg, Ni, Pb, and CDD/CDF:
kg/Mg refuse
lb/ton refuse
4.92 x 10-6
9.85 x 10-6
µg/dscm
For PM:
kg/Mg refuse
lb/ton refuse
4.92 x 10-3
9.85 x 10-3
mg/dscm
For HCl:
kg/Mg refuse
lb/ton refuse
7.5 x 10-3
1.5 x 10-2
ppmv
For SO2:
kg/Mg refuse
lb/ton refuse
1.31 x 10-2
2.62 x 10-2
ppmv
For NOx:
kg/Mg refuse
lb/ton refuse
9.45 x 10-3
1.89 x 10-2
ppmv
For CO:
kg/Mg refuse
lb/ton refuse
5.75 x 10-3
1.15 x 10-2
ppmv
For CO2:
kg/Mg refuse
lb/ton refuse
9.05 x 10-3
1.81 x 10-2
ppmv
a At 7% O2.
2.1-32 EMISSION FACTORS 10/96
Trench combustors can be built either above- or below-ground. They have refractory walls and
floors and are normally 8-feet wide and 10-feet deep. Length varies from 8 to 16 feet. Some units have
mesh screens to contain larger particles of fly ash, but other add-on pollution controls are normally not
used.
Trench combustors burning wood wastes, yard wastes, and clean lumber are exempt from
Section 129, provided they comply with opacity limitations established by the Administrator. The primary
use of air curtain incinerators is the disposal of these types of wastes; however, some of these combustors
are used to burn MSW or construction and demolition debris.
In some states, trench combustors are often viewed as a version of open burning and the use of
these types of units has been discontinued in some States.
2.1.7.3 Domestic Combustors -
This category includes combustors marketed for residential use. These types of units are typically
located at apartment complexes, residential buildings, or other multiple family dwellings, and are generally
found in urban areas. Fairly simple in design, they may have single or multiple refractory-lined chambers
and usually are equipped with an auxiliary burner to aid combustion. Due to their small size, these types of
units are not currently covered by the MWC regulations.
2.1.7.4 Flue-fed Combustors -
These units, commonly found in large apartment houses or other multiple family dwellings, are
characterized by the charging method of dropping refuse down the combustor flue and into the combustion
chamber. Modified flue-fed incinerators utilize afterburners and draft controls to improve combustion
efficiency and reduce emissions. Due to their small size, these types of units are not currently covered by
the MWC regulations.
Emission factors for industrial/commercial, trench, domestic, and flue-fed combustors are
presented in Table 2.1-12.
10
/
9
6
So
l
i
d

W
a
s
t
e

D
i
s
p
o
s
a
l
2.
1
-
3
3
Table 2.1-12 (Metric And English Units). UNCONTROLLED EMISSION FACTORS FOR REFUSE COMBUSTORS OTHER THAN
MUNICIPAL WASTEa
EMISSION FACTOR RATING: D
PM SO2 CO
Total Organic
Compoundsb NOx
Combustor Type kg/Mg lb/ton kg/Mg lb/ton kg/Mg lb/ton kg/Mg lb/ton kg/Mg lb/ton
Industrial/commercial
Multiple chamber 3.50 E+00 7.00 E+00 1.25 E+00 2.50 E+00 5.00 E+00 1.00 E+01 1.50 E+00 3.00 E+00 1.50 E+00 3.00 E+00
Single chamber 7.50 E+00 1.50 E+01 1.25 E+00 2.50 E+00 1.00 E+01 2.00 E+01 7.50 E+01 1.50 E+01 1.00 E+00 2.00 E+00
Trench
Wood
(SCC 5-01-005-10,
5-03-001-06)
6.50 E+00 1.30 E+01 5.00 E-02 1.00 E-01 ND ND ND ND 2.00 E+00 4.00 E+00
Rubber tires
(SCC 5-01-005-11,
5-03-001-07)
6.90 E+01 1.38 E+02 ND ND ND ND ND ND ND ND
Municipal refuse
(SCC 5-01-005-12,
5-03-001-09)
1.85 E+01 3.70 E+01 1.25 E+00 2.50 E+00 ND ND ND ND ND ND
Flue-fed single chamber 1.50 E+01 3.00 E+01 2.50 E-01 5.00 E-01 1.00 E+01 2.00 E+01 7.50 E+00 1.50 E+01 1.50 E+00 3.00 E+00
Flue-fed (modified)3.00 E+00 6.00 E+00 2.50 E-01 5.00 E-01 5.00 E+00 1.00 E+01 1.50 E+00 3.00 E+00 5.00 E+00 1.00 E+01
Domestic single chamber
(no SCC)
Without primary burner 1.75 E+01 3.50 E+01 2.50 E-01 5.00 E-01 1.50 E+02 3.00 E+02 5.00 E+01 1.00 E+02 5.00 E-01 1.00 E+00
With primary burner 3.50 E+00 7.00 E+00 2.50 E-01 5.00 E-01 Neg Neg 1.00 E+00 2.00 E+00 1.00 E+00 2.00 E+00
a References 116-123. ND = no data. SCC = Source Classification Code. Neg = negligible.
b Expressed as methane.
2.1-34 EMISSION FACTORS 10/96
References For Section 2.1
1.Written communication from D. A. Fenn and K. L. Nebel, Radian Corporation, Research Triangle
Park, NC, to W. H. Stevenson, U. S. Environmental Protection Agency, Research Triangle Park,
NC. March 1992.
2.J. Kiser, "The Future Role Of Municipal Waste Combustion", Waste Age, November 1991.
3.September 6, 1991. Meeting Summary: Appendix 1 (Docket No. A-90-45, Item
Number II-E-12).
4.Municipal Waste Combustion Study: Combustion Control Of Organic Emissions,
EPA/530-SW-87-021c, U. S. Environmental Protection Agency, Washington, DC, June 1987.
5.M. Clark, "Minimizing Emissions From Resource Recovery", Presented at the International
Workshop on Municipal Waste Incineration, Quebec, Canada, October 1-2, 1987.
6.Municipal Waste Combustion Assessment: Combustion Control At Existing Facilities,
EPA 600/8-89-058, U. S. Environmental Protection Agency, Research Triangle Park, NC, August
1989.
7.Municipal Waste Combustors - Background Information For Proposed Standards: Control Of
NOx Emissions, EPA-450/3-89-27d, U. S. Environmental Protection Agency, Research Triangle
Park, NC, August 1989.
8.Municipal Waste Combustors - Background Information For Proposed Standards: Post
Combustion Technology Performance, U. S. Environmental Protection Agency, August 1989.
9.Municipal Waste Combustion Study - Flue Gas Cleaning Technology, EPA/530-SW-87-021c,
U. S. Environmental Protection Agency, Washington, DC, June 1987.
10.R. Bijetina, et al., "Field Evaluation of Methane de-NOx at Olmstead Waste-to-Energy Facility",
Presented at the 7th Annual Waste-to-Energy Symposium, Minneapolis, MN, January 28-30,
1992.
11.K. L. Nebel and D. M. White, A Summary Of Mercury Emissions And Applicable Control
Technologies For Municipal Waste Combustors, Research Triangle Park, NC, September, 1991.
12.Emission Test Report: OMSS Field Test On Carbon Injection For Mercury Control,
EPA-600/R-92-192, Office of Air Quality Planning and Standards, U. S. Environmental Protection
Agency, Research Triangle Park, NC, September 1992.
13.J. D. Kilgroe, et al., "Camden Country MWC Carbon Injection Test Results", Presented at the
International Conference on Waste Combustion, Williamsburg, VA, March 1993.
14.Meeting Summary: Preliminary Mercury Testing Results For The Stanislaus County Municipal
Waste Combustor, U. S. Environmental Protection Agency, Research Triangle Park, NC,
November 22, 1991.
10/96 Solid Waste Disposal 2.1-35
15.R. A. Zurlinden, et al., Environmental Test Report, Alexandria/Arlington Resources Recovery
Facility, Units 1, 2, And 3, Report No. 144B, Ogden Martin Systems of Alexandria/Arlington,
Inc., Alexandria, VA, March 9, 1988.
16.R. A. Zurlinden, et al., Environmental Test Report, Alexandria/Arlington Resource Recovery
Facility, Units 1, 2, And 3, Report No. 144A (Revised), Ogden Martin Systems of
Alexandria/Arlington, Inc., Alexandria, VA, January 8, 1988.
17.Environmental Test Report, Babylon Resource Recovery Test Facility, Units 1 And 2, Ogden
Martin Systems of Babylon, Inc., Ogden Projects, Inc., March 1989.
18.Ogden Projects, Inc. Environmental Test Report, Units 1 And 2, Babylon Resource Recovery
Facility, Ogden Martin Systems for Babylon, Inc., Babylon, NY, February 1990.
19.PEI Associates, Inc. Method Development And Testing For Chromium, No. Refuse-to-Energy
Incinerator, Baltimore RESCO, EMB Report 85-CHM8, EPA Contract No. 68-02-3849, U. S.
Environmental Protection Agency, Research Triangle Park, NC, August 1986.
20.Entropy Environmentalists, Inc. Particulate, Sulfur Dioxide, Nitrogen Oxides, Chlorides,
Fluorides, And Carbon Monoxide Compliance Testing, Units 1, 2, And 3, Baltimore RESCO
Company, L. P., Southwest Resource Recovery Facility, RUST International, Inc., January 1985.
21.Memorandum. J. Perez, AM/3, State of Wisconsin, to Files. "Review Of Stack Test Performed At
Barron County Incinerator," February 24, 1987.
22.D. S. Beachler, et al., "Bay County, Florida, Waste-To-Energy Facility Air Emission Tests.
Westinghouse Electric Corporation", Presented at Municipal Waste Incineration Workshop,
Montreal, Canada, October 1987.
23.Municipal Waste Combustion, Multi-Pollutant Study. Emission Test Report. Volume I,
Summary Of Results, EPA-600/8-89-064a, Maine Energy Recovery Company, Refuse-Derived
Fuel Facility, Biddeford, ME, July 1989.
24.S. Klamm, et al., Emission Testing At An RDF Municipal Waste Combustor, EPA Contract
No. 68-02-4453, U. S. Environmental Protection Agency, NC, May 6, 1988. (Biddeford)
25.Emission Source Test Report -- Preliminary Test Report On Cattaraugus County, New York
State Department of Environmental Conservation, August 5, 1986.
26.Permit No. 0560-0196 For Foster Wheeler Charleston Resource Recovery, Inc. Municipal Solid
Waste Incinerators A & B, Bureau of Air Quality Control, South Carolina Department of Health
and Environmental Control, Charleston, SC, October 1989.
27.Almega Corporation. Unit 1 And Unit 2, EPA Stack Emission Compliance Tests, May 26, 27,
And 29, 1987, At The Signal Environmental Systems, Claremont, NH, NH/VT Solid Waste
Facility, Prepared for Clark-Kenith, Inc. Atlanta, GA, July 1987.
2.1-36 EMISSION FACTORS 10/96
28.Entropy Environmentalists, Inc. Stationary Source Sampling Report, Signal Environmental
Systems, Inc., At The Claremont Facility, Claremont, New Hampshire, Dioxins/Furans Emissions
Compliance Testing, Units 1 And 2, Reference No. 5553-A, Signal Environmental Systems, Inc.,
Claremont, NH, October 2, 1987.
29.M. D. McDannel, et al., Air Emissions Tests At Commerce Refuse-To-Energy Facility May 26 -
June 5, 1987, County Sanitation Districts of Los Angeles County, Whittier, CA, July 1987.
30.M. D. McDannel and B. L. McDonald, Combustion Optimization Study At The Commerce
Refuse-To-Energy Facility. Volume I, ESA 20528-557, County Sanitation Districts of
Los Angeles County, Los Angeles, CA, June 1988.
31.M. D. McDannel et al., Results Of Air Emission Test During The Waste-to-Energy Facility,
County Sanitation Districts Of Los Angeles County, Whittier, CA, December 1988. (Commerce)
32.Radian Corporation. Preliminary Data From October - November 1988 Testing At The
Montgomery County South Plant, Dayton, Ohio.
33.Written communication from M. Hartman, Combustion Engineering, to D. White,
Radian Corporation, Detroit Compliance Tests, September 1990.
34.Interpoll Laboratories. Results Of The November 3-6, 1987 Performance Test On The No. 2 RDF
And Sludge Incinerator At The WLSSD Plant In Duluth, Minnesota, Interpoll Report No. 7-2443,
April 25, 1988.
35.D. S. Beachler, (Westinghouse Electric Corporation) and ETS, Inc, Dutchess County Resource
Recovery Facility Emission Compliance Test Report, Volumes 1-5, New York Department of
Environmental Conservation, June 1989.
36.ETS, Inc. Compliance Test Report For Dutchess County Resource Recovery Facility, May 1989.
37.Written communication and enclosures from W. Harold Snead, City of Galax, VA, to
Jack R. Farmer, U. S. Environmental Protection Agency, Research Triangle Park, NC,
July 14, 1988.
38.Cooper Engineers, Inc., Air Emissions Tests Of Solid Waste Combustion A Rotary
Combustion/Boiler System At Gallatin, Tennessee, West County Agency of Contra Costa County,
CA, July 1984.
39.B. L. McDonald, et al., Air Emissions Tests At The Hampton Refuse-Fired Stream Generating
Facility, April 18-24, 1988, Clark-Kenith, Incorporated, Bethesda, MD, June 1988.
40.Radian Corporation for American Ref-Fuel Company of Hempstead, Compliance Test Report For
The Hempstead Resource Recovery Facility, Westbury, NY, Volume I, December 1989.
41.J. Campbell, Chief, Air Engineering Section, Hillsborough County Environmental Protection
Commission, to E. L. Martinez, Source Analysis Section/AMTB, U. S. Environmental Protection
Agency, May 1, 1986.
42.Mitsubishi SCR System for Municipal Refuse Incinerator, Measuring Results At Tokyo-
10/96 Solid Waste Disposal 2.1-37
Hikarigaoka And Iwatsuki, Mitsubishi Heavy Industries, Ltd, July 1987.
43.Entropy Environmentalists, Inc. for Honolulu Resource Recovery Venture, Stationary Source
Sampling Final Report, Volume I, Oahu, HI, February 1990.
44.Ogden Projects, Inc., Environmental Test Report, Indianapolis Resource Recovery Facility,
Appendix A And Appendix B, Volume I, (Prepared for Ogden Martin Systems of Indianapolis,
Inc.), August 1989.
45.D. R. Knisley, et al. (Radian Corporation), Emissions Test Report, Dioxin/Furan Emission
Testing, Refuse Fuels Associates, Lawrence MA, (Prepared for Refuse Fuels Association),
Haverhill, MA, June 1987.
46.Entropy Environmentalists, Inc. Stationary Source Sampling Report, Ogden Martin Systems of
Haverhill, Inc., Lawrence, MA Thermal Conversion Facility. Particulate, Dioxins/Furans and
Nitrogen Oxides Emission Compliance Testing, September 1987.
47.D. D. Ethier, et al. (TRC Environmental Consultants), Air Emission Test Results At The
Southeast Resource Recovery Facility Unit 1, October - December, 1988, Prepared for Dravo
Corporation, Long Beach, CA, February 28, 1989.
48.Written communication from from H. G. Rigo, Rigo & Rigo Associates, Inc., to M. Johnston,
U. S. Environmental Protection Agency. March 13, 1989. 2 pp. Compliance Test Report Unit
No. 1 -- South East Resource Recovery Facility, Long Beach, CA.
49.M. A. Vancil and C. L. Anderson (Radian Corporation), Summary Report CDD/CDF, Metals,
HCl, SO2, NOx, CO And Particulate Testing, Marion County Solid Waste-To-Energy Facility,
Inc., Ogden Martin Systems Of Marion, Brooks, Oregon, U. S. Environmental Protection Agency,
Research Triangle Park, NC, EMB Report No. 86-MIN-03A, September 1988.
50.C. L. Anderson, et al. (Radian Corporation), Characterization Test Report, Marion County Solid
Waste-To-Energy Facility, Inc., Ogden Martin Systems Of Marion, Brooks, Oregon, U. S.
Environmental Protection Agency, Research Triangle Park, NC, EMB Report No. 86-MIN-04,
September 1988.
51.Letter Report from M. A. Vancil, Radian Corporation, to C. E. Riley, EMB Task Manager, U. S.
Environmental Protection Agency. Emission Test Results for the PCDD/PCDF Internal Standards
Recovery Study Field Test: Runs 1, 2, 3, 5, 13, 14. July 24, 1987. (Marion)
52.C. L. Anderson, et al., (Radian Corporation). Shutdown/Startup Test Program Emission Test
Report, Marion County Solid Waste-To-Energy Facility, Inc., Ogden Martin Systems Of Marion,
Brooks, Oregon, U. S. Environmental Protection Agency, Research Triangle Park, NC, EMB
Report No. 87-MIN-4A, September 1988.
53.Clean Air Engineering, Inc., Report On Compliance Testing For Waste Management, Inc. At The
McKay Bay Refuse-to-Energy Project Located In Tampa, Florida, October 1985.
2.1-38 EMISSION FACTORS 10/96
54.Alliance Technologies Corporation, Field Test Report - NITEP III. Mid-Connecticut Facility,
Hartford, Connecticut. Volume II Appendices, Prepared for Environment Canada. June 1989.
55.C. L. Anderson, (Radian Corporation), CDD/CDF, Metals, And Particulate Emissions Summary
Report, Mid-Connecticut Resource Recovery Facility, Hartford, Connecticut,
U. S. Environmental Protection Agency, Research Triangle Park, NC, EMB Report
No. 88-MIN-09A, January 1989.
56.Entropy Environmentalists, Inc., Municipal Waste Combustion Multi-Pollutant Study, Summary
Report, Wheelabrator Millbury, Inc., Millbury, MA, U. S. Environmental Protection Agency,
Research Triangle Park, NC, EMB Report No. 88-MIN-07A, February 1989.
57.Entropy Environmentalists, Inc., Emissions Testing Report, Wheelabrator Millbury, Inc.
Resource Recovery Facility, Millbury, Massachusetts, Unit Nos. 1 And 2, February 8 through 12,
1988, Prepared for Rust International Corporation. Reference No. 5605-B. August 5, 1988.
58.Entropy Environmentalists, Inc., Stationary Source Sampling Report, Wheelabrator Millbury,
Inc., Resource Recovery Facility, Millbury, Massachusetts, Mercury Emissions Compliance
Testing, Unit No. 1, May 10 And 11, 1988, Prepared for Rust International Corporation.
Reference No. 5892-A, May 18, 1988.
59.Entropy Environmentalists, Inc., Emission Test Report, Municipal Waste Combustion Continuous
Emission Monitoring Program, Wheelabrator Resource Recovery Facility, Millbury,
Massachusetts, U. S. Environmental Protection Agency, Research Triangle Park, NC, Emission
Test Report 88-MIN-07C, January 1989.
60.Entropy Environmentalists, Municipal Waste Combustion Multipollutant Study: Emission Test
Report - Wheelabrator Millbury, Inc. Millbury, Massachusetts, EMB Report No. 88-MIN-07,
July 1988.
61.Entropy Environmentalists, Emission Test Report, Municipal Waste Combustion, Continuous
Emission Monitoring Program, Wheelabrator Resource Recovery Facility, Millbury,
Massachusetts, Prepared for the U. S. Environmental Protection Agency, Research Triangle Park,
NC. EPA Contract No. 68-02-4336, October 1988.
62.Entropy Environmentalists, Emissions Testing At Wheelabrator Millbury, Inc. Resource
Recovery Facility, Millbury, Massachusetts, Prepared for Rust International Corporation.
February 8-12, 1988.
63.Radian Corporation, Site-Specific Test Plan And Quality Assurance Project Plan For The
Screening And Parametric Programs At The Montgomery County Solid Waste Management
Division South Incinerator - Unit #3, Prepared for U. S. EPA, OAQPS and ORD, Research
Triangle Park, NC, November 1988.
64.Written communication and enclosures from John W. Norton, County of Montgomery, OH, to Jack
R. Farmer, U. S. Environmental Protection Agency, Research Triangle Park, NC. May 31, 1988.
10/96 Solid Waste Disposal 2.1-39
65.J. L. Hahn, et al., (Cooper Engineers) and J. A. Finney, Jr., et al., (Belco Pollution Control Corp.),
"Air Emissions Tests Of A Deutsche Babcock Anlagen Dry Scrubber System At The Munich
North Refuse-Fired Power Plant", Presented at: 78th Annual Meeting of the Pollution Control
Association, Detroit, MI, June 1985.
66.Clean Air Engineering, Results Of Diagnostic And Compliance Testing At NSP French Island
Generating Facility Conducted May 17 - 19, 1989, July 1989.
67.Preliminary Report On Occidental Chemical Corporation EFW. New York State Department Of
Environmental Conservation, (Niagara Falls), Albany, NY, January 1986.
68.H. J. Hall, Associates, Summary Analysis On Precipitator Tests And Performance Factors,
May 13-15, 1986 At Incinerator Units 1, 2 - Occidental Chemical Company, Prepared for
Occidental Chemical Company EFW, Niagara Falls, NY, June 25, 1986.
69.C. L. Anderson, et al. (Radian Corporation), Summary Report, CDD/CDF, Metals and
Particulate, Uncontrolled And Controlled Emissions, Signal Environmental Systems, Inc., North
Andover RESCO, North Andover, MA, U. S. Environmental Protection Agency, Research Triangle
Park, NC, EMB Report No. 86-MINO2A, March 1988.
70.York Services Corporation, Final Report For A Test Program On The Municipal Incinerator
Located At Northern Aroostook Regional Airport, Frenchville, Maine, Prepared for Northern
Aroostook Regional Incinerator Frenchville, ME, January 26, 1987.
71.Radian Corporation, Results From The Analysis Of MSW Incinerator Testing At Oswego County,
New York, Prepared for New York State Energy Research and Development Authority, March
1988.
72.Radian Corporation, Data Analysis Results For Testing At A Two-Stage Modular MSW
Combustor: Oswego County ERF, Fulton, New York, Prepared for New York State's Energy
Research and Development Authority, Albany, NY, November 1988.
73.A. J. Fossa, et al., Phase I Resource Recovery Facility Emission Characterization Study,
Overview Report, (Oneida, Peekskill), New York State Department of Environmental
Conservation, Albany, NY, May 1987.
74.Radian Corporation, Results From The Analysis Of MSW Incinerator Testing At Peekskill,
New York, Prepared for New York State Energy Research and Development Authority,
DCN:88-233-012-21, August 1988.
75.Radian Corporation, Results from the Analysis of MSW Incinerator Testing at Peekskill, New
York (DRAFT), (Prepared for the New York State Energy Research and Development Authority),
Albany, NY, March 1988.
76.Ogden Martin Systems of Pennsauken, Inc., Pennsauken Resource Recovery Project, BACT
Assessment For Control Of NOx Emissions, Top-Down Technology Consideration, Fairfield, NJ,
pp. 11, 13, December 15, 1988.
77.Roy F. Weston, Incorporated, Penobscot Energy Recovery Company Facility, Orrington, Maine,
Source Emissions Compliance Test Report Incinerator Units A And B (Penobscot, Maine),
2.1-40 EMISSION FACTORS 10/96
Prepared for GE Company, September 1988.
78.S. Zaitlin, Air Emission License Finding Of Fact And Order, Penobscot Energy Recovery
Company, Orrington, ME, State of Maine, Department of Environmental Protection, Board of
Environmental Protection, February 26, 1986.
79.R. Neulicht, (Midwest Research Institute), Emissions Test Report: City Of Philadelphia
Northwest And East Central Municipal Incinerators, Prepared for the U. S. Environmental
Protection Agency, Philadelphia, PA, October 31, 1985.
80.Written communication with attachments from Philip Gehring, Plant Manager (Pigeon Point
Energy Generating Facility), to Jack R. Farmer, Director, ESD, OAQPS, U. S. Environmental
Protection Agency, June 30, 1988.
81.Entropy Environmentalists, Inc., Stationary Source Sampling Report, Signal RESCO, Pinellas
County Resource Recovery Facility, St. Petersburg, Florida, CARB/DER Emission Testing,
Unit 3 Precipitator Inlets and Stack, February and March 1987.
82.Midwest Research Institute, Results Of The Combustion And Emissions Research Project At The
Vicon Incinerator Facility In Pittsfield, Massachusetts, Prepared for New York State Energy
Research and Development Authority, June 1987.
83.Response to Clean Air Act Section 114 Information Questionnaire, Results of Non-Criteria
Pollutant Testing Performed at Pope-Douglas Waste to Energy Facility, July 1987, Provided to
EPA on May 9, 1988.
84.Engineering Science, Inc., A Report On Air Emission Compliance Testing At The Regional Waste
Systems, Inc. Greater Portland Resource Recovery Project, Prepared for Dravo Energy
Resources, Inc., Pittsburgh, PA, March 1989.
85.D. E. Woodman, Test Report Emission Tests, Regional Waste Systems, Portland, ME, February
1990.
86.Environment Canada, The National Incinerator Testing And Evaluation Program: Two State
Combustion, Report EPS 3/up/1, (Prince Edward Island), September 1985.
87.Statistical Analysis Of Emission Test Data From Fluidized Bed Combustion Boilers At Prince
Edward Island, Canada, U. S. Environmental Protection Agency, Publication No. EPA-450/3-
86-015, December 1986.
88.The National Incinerator Testing And Evaluation Program: Air Pollution Control Technology,
EPS 3/UP/2, (Quebec City), Environment Canada, Ottawa, September 1986.
89.Lavalin, Inc., National Incinerator Testing And Evaluation Program: The Combustion
Characterization Of Mass Burning Incinerator Technology; Quebec City (DRAFT), (Prepared for
Environmental Protection Service, Environmental Canada), Ottawa, Canada, September 1987.
90.Environment Canada, NITEP, Environmental Characterization Of Mass Burning Incinerator
Technology at Quebec City. Summary Report, EPS 3/UP/5, June 1988.
2.1-42 EMISSION FACTORS 10/96
91.Interpoll Laboratories, Results Of The March 21 - 26, 1988, Air Emission Compliance Test On
The No. 2 Boiler At The Red Wing Station, Test IV (High Load), Prepared for Northern States
Power Company, Minneapolis, MN, Report No. 8-2526, May 10, 1988.
92.Interpoll Laboratories, Results Of The May 24-27, 1988 High Load Compliance Test On Unit 1
And Low Load Compliance Test On Unit 2 At The NSP Red Wing Station, Prepared for Northern
States Power Company, Minneapolis, MN, Report No. 8-2559, July 21, 1988.
93.Cal Recovery Systems, Inc., Final Report, Evaluation Of Municipal Solid Waste Incineration.
(Red Wing, Minnesota facility) Submitted To Minnesota Pollution Control Agency, Report
No. 1130-87-1, January 1987.
94.Eastmount Engineering, Inc., Final Report, Waste-To-Energy Resource Recovery Facility,
Compliance Test Program, Volumes II-V, (Prepared for SEMASS Partnership.), March 1990.
95.D. McClanahan, (Fluor Daniel), A. Licata (Dravo), and J. Buschmann (Flakt, Inc.)., "Operating
Experience With Three APC Designs On Municipal Incinerators". Proceedings of the
International Conference on Municipal Waste Combustion, pp. 7C-19 to 7C-41, (Springfield),
April 11-14, 1988.
96.Interpoll Laboratories, Inc., Results Of The June 1988 Air Emission Performance Test On The
MSW Incinerators At The St. Croix Waste To Energy Facility In New Richmond, Wisconsin,
Prepared for American Resource Recovery, Waukesha, WI, Report No. 8-2560, September 12,
1988.
97.Interpoll Laboratories, Inc, Results Of The June 6, 1988, Scrubber Performance Test At The
St. Croix Waste To Energy Incineration Facility In New Richmond, Wisconsin, Prepared for
Interel Corporation, Englewood, CO, Report No. 8-2560I, September 20, 1988.
98.Interpoll Laboratories, Inc., Results Of The August 23, 1988, Scrubber Performance Test At The
St. Croix Waste To Energy Incineration Facility In New Richmond, Wisconsin, Prepared for
Interel Corporation, Englewood, CO, Report No. 8-2609, September 20, 1988.
99.Interpoll Laboratories, Inc., Results Of The October 1988 Particulate Emission Compliance Test
On The MSW Incinerator At The St. Croix Waste To Energy Facility In New Richmond,
Wisconsin, Prepared for American Resource Recovery, Waukesha, WI, Report No. 8-2547,
November 3, 1988.
100.Interpoll Laboratories, Inc., Results Of The October 21, 1988, Scrubber Performance Test At The
St. Croix Waste To Energy Facility In New Richmond, Wisconsin, Prepared for Interel
Corporation, Englewood, CO, Report No. 8-2648, December 2, 1988.
101.J. L. Hahn, (Ogden Projects, Inc.), Environmental Test Report, Prepared for Stanislaus Waste
Energy Company Crows Landing, CA, OPI Report No. 177R, April 7, 1989.
102.J. L. Hahn, and D. S. Sofaer, "Air Emissions Test Results From The Stanislaus County, California
Resource Recovery Facility", Presented at the International Conference on Municipal Waste
Combustion, Hollywood, FL, pp. 4A-1 to 4A-14, April 11-14, 1989.
10/96 Solid Waste Disposal 2.1-43
103.R. Seelinger, et al. (Ogden Products, Inc.), Environmental Test Report, Walter B. Hall Resource
Recovery Facility, Units 1 And 2, (Prepared for Ogden Martin Systems of Tulsa, Inc.), Tulsa, OK,
September 1986.
104.PEI Associates, Inc, Method Development And Testing for Chromium, Municipal Refuse
Incinerator, Tuscaloosa Energy Recovery, Tuscaloosa, Alabama, U. S. Environmental Protection
Agency, Research Triangle Park, NC, EMB Report 85-CHM-9, January 1986.
105.T. Guest and O. Knizek, "Mercury Control At Burnaby's Municipal Waste Incinerator",
Proceedings of the 84th Annual Meeting and Exhibition of the Air and Waste Management
Association, Vancouver, British Columbia, Canada, June 16-21, 1991.
106.Trip Report, Burnaby MWC, British Columbia, Canada. White, D., Radian Corporation, May
1990.
107.Entropy Environmentalists, Inc. for Babcock & Wilcox Co. North County Regional Resource
Recovery Facility, West Palm Beach, FL, October 1989.
108.P. M. Maly, et al., Results Of The July 1988 Wilmarth Boiler Characterization Tests, Gas
Research Institute Topical Report No. GRI-89/0109, June 1988-March 1989.
109.J. L. Hahn, (Cooper Engineers, Inc.), Air Emissions Testing At The Martin GmbH Waste-To-
Energy Facility In Wurzburg, West Germany, Prepared for Ogden Martin Systems, Inc., Paramus,
NJ, January 1986.
110.Entropy Environmentalists, Inc. for Westinghouse RESD, Metals Emission Testing Results,
Conducted At The York County Resource Recovery Facility, February 1991.
111.Entropy Environmentalists, Inc. for Westinghouse RESD, Emissions Testing For: Hexavalent
Chromium, Metals, Particulate. Conducted At The York County Resource Recovery Facility,
July 31 - August 4, 1990.
112.Interpoll Laboratories, Results of the July 1987 Emission Performance Tests Of The
Pope/Douglas Waste-To-Energy Facility MSW Incinerators In Alexandria, Minnesota, (Prepared
for HDR Techserv, Inc.), Minneapolis, MN, October 1987.
113.D. B. Sussman, Ogden Martin System, Inc., Submittal to Air Docket (LE-131), Docket
No. A-89-08, Category IV-M, Washington, DC, October 1990.
114.F. Ferraro, Wheelabrator Technologies, Inc., Data package to D. M. White, Radian Corporation,
February 1991.
115.D. R. Knisley, et al. (Radian Corporation), Emissions Test Report, Dioxin/Furan Emission
Testing, Refuse Fuels Associates, Lawrence, Massachusetts, (Prepared for Refuse Fuels
Association), Haverhill, MA, June 1987.
116.Entropy Environmentalists, Inc., Stationary Source Sampling Report, Ogden Martin Systems Of
Haverhill, Inc., Lawrence, Massachusetts Thermal Conversion Facility. Particulate,
Dioxins/Furans And Nitrogen Oxides Emission Compliance Testing, September 1987.
10/96 Solid Waste Disposal 2.1-45
117.A. J. Fossa, et al., Phase I Resource Recovery Facility Emission Characterization Study,
Overview Report, New York State Department of Environmental Conservation, Albany, NY, May
1987.
118.Telephone communciation between D. DeVan, Oneida ERF, and M. A. Vancil, Radian
Corporation. April 4, 1988. Specific collecting area of ESPs.
119.G. M. Higgins, An Evaluation Of Trace Organic Emissions From Refuse Thermal Processing
Facilities (North Little Rock, Arkansas; Mayport Naval Station, Florida; And Wright Patterson
Air Force Base, Ohio), Prepared for U. S. Environmental Protection Agency/Office of Solid Waste
by Systech Corporation, July 1982.
120.R. Kerr, et al., Emission Source Test Report--Sheridan Avenue RDF Plant, Answers (Albany,
New York), Division of Air Resources, New York State Department of Environmental
Conservation, August 1985.
121.U. S. Environmental Protection Agency, Emission Factor Documentation for AP-42 Section 2.1,
Refuse Combustion, Research Triangle Park, NC, May 1993.
122.Air Pollutant Emission Factors, APTD-0923, U. S. Environmental Protection Agency, Research
Triangle Park, NC, April 1970.
123.Control Techniques For Carbon Monoxide Emissions From Stationary Sources, AP-65,
U. S. Environmental Protection Agency, Research Triangle Park, NC, March 1970.
124.Air Pollution Engineering Manual, AP-40, U. S. Environmental Protection Agency, Research
Triangle Park, NC, 1967.
125.J. DeMarco, et al., Incinerator Guidelines 1969, SW. 13TS, U. S. Environmental Protection
Agency, Research Triangle Park, NC, 1969.
126.Municipal Waste Combustors - Background Information For Proposed Guidelines For Existing
Facilities, U. S. Environmental Protection Agency, Research Triangle Park, NC, EPA-450/3-89-
27e, August 1989.
127.Municipal Waste Combustors - Background Information for Proposed Standards: Control Of
NOx Emissions U. S. Environmental Protection Agency, Research Triangle Park, NC, EPA-450/3-
89-27d, August 1989.
127.J. O. Brukle, et al., "The Effects Of Operating Variables And Refuse Types On Emissions From A
Pilot-scale Trench Incinerator," Proceedings of the 1968 Incinerator Conference, American
Society of Mechanical Engineers, New York, NY, May 1968.
128.W. R. Nessen, Systems Study Of Air Pollution From Municipal Incineration, Arthur D. Little,
Inc., Cambridge, MA, March 1970.
130.C. R. Brunner, Handbook Of Incineration Systems, McGraw-Hill, Inc., pp. 10.3-10.4, 1991.
131.Telephone communication between K. Quincey, Radian Corporation, and E. Raulerson, Florida
Department of Environmental Regulations, February 16, 1993.
2.1-46 EMISSION FACTORS 10/96
132.Telephone communication between K. Nebel and K. Quincey, Radian Corporation, and
M. McDonnold, Simonds Manufacturing, February 16, 1993.
133.Telephone communication between K. Quincey, Radian Corporation, and R. Crochet, Crochet
Equipment Company, February 16 and 26, 1993.
134.Telephone communication between K. Quincey, Radian Corporation, and T. Allen, NC Division of
Environmental Management, February 16, 1993.
135.John Pacy, Methane Gas In Landfills: Liability Or Asset?, Proceedings of the Fourth National
Congress of the Waste Management Technology and Resource and Energy Recovery, Co-
sponsored by the National Solid Wastes Management Association and U. S. EPA, November 12-
14, 1975.
EPA Region 10 HAP and VOC Emission Factors for Lumber Drying, January 2021
WPP1 VOC1,2 Methanol2 Formaldehyde2 Acetaldehyde Propionaldehyde Acrolein
(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
Western True Firs3 0.00817x - 1.02133 0.00465x - 0.73360 0.00016x - 0.02764 0.0550 0.0003 0.0009
Western Hemlock 0.00369x - 0.39197 0.00249x - 0.39750 0.000046x - 0.007622 0.0677 0.0004 0.0012
Western Red Cedar 0.00817x - 1.02133 0.00465x - 0.73360 0.00016x - 0.02764 0.0677 0.0004 0.0012
Douglas Fir 0.01460x - 1.77130 0.00114x - 0.16090 0.000028x - 0.003800 0.0275 0.0003 0.0005
Engelmann Spruce 0.1769 0.00088x - 0.13526 0.000042x - 0.006529 0.0201 0.0002 0.0005
Larch 0.01460x - 1.77130 0.00114x - 0.16090 0.000028x - 0.003800 0.0275 0.0003 0.0005
Lodgepole Pine 1.1352 0.0550 0.0030 0.0104 0.0003 0.0008
Ponderosa Pine 0.02083x - 1.30029 0.00137x - 0.18979 0.000074x - 0.010457 0.0340 0.0010 0.0026
Western White Pine 0.02083x - 1.30029 0.00137x - 0.18979 0.000074x - 0.010457 0.0340 0.0010 0.0026
This spreadsheet calculates and compiles hazardous air pollutant (HAP) and volatile organic compound (VOC) emission factors (EF) in units of pounds of
pollutant per thousand board feet of lumber dried (lb/mbf) that are preferred by EPA Region 10 for estimating emissions from indirect steam-heated batch
lumber drying kilns. The EFs are based on actual lab-scale emission test data when available. When no suitable HAP or VOC test data is available for a
species of wood (e.g., western red cedar, engelmann spruce, larch and western white pine), EFs for similar species are substituted. When there are more
than one similar species, the highest of the EF for the similar species is substituted. When test data is available for some individual HAP but not others
(e.g., western true firs and lodgepole pine), data from the species and another similar to it are used to conservatively estimate HAP EF. The calculation of
VOC EF follows the methodology presented in EPA's OTM-26 (Interim VOC Measurement Protocol for the Wood Products Industry - July 2007,
commonly referred to as "WPP1 VOC"), except that adjustments to the RM25A measurement have been performed beyond formaldehyde and methanol
to include as many as five other compounds (acetaldehyde, propionaldehyde, acrolein, acetic acid and ethanol). With the VOC EF calculation factoring in
the contribution of individual compounds, no data substitution or estimation of the constituents is performed. To maintain the intergrity of the calculation,
only measured (not estimated) values for the constituents are used.
A summary of the EFs for each species of wood is included on this sheet. The sheets that follow present the original test data as well as the calculations
for creating each EF. There are two sheets per lumber species: one for HAPs and one for VOCs. The methanol, formaldehyde and VOC EF are
temperature dependent best-fit linear equations. The temperature variable reflects the maximum temperature of the heated air entering the lumber.
Because acetaldehyde, propionaldehyde and acrolein emissions across different species are not consistently dependent upon maximum drying
temperature, EF are calculated by averaging test results. Whereas HAP EF are derived in the HAP sheets, EF for individual VOC ethanol and acetic acid
are derived in the VOC sheets for douglas fir and ponderosa pine (only wood species undergoing testing for these two VOC compounds).
1 VOC emissions approximated consistent with OTM-26 underestimate emissions when the mass-to-carbon ratio of unidentified VOC exceeds that of
propane. Ethanol and acetic acid are examples of compounds that contribute to lumber drying VOC emissions (for some species more than others), and
both have mass-to-carbon ratios exceeding that of propane. Contribution of ethanol and acetic acid to VOC emissions has been quantified here when
emissions testing data is available.
3 Western true firs consist of the following seven species classified in the same Abies genus: bristlecone fir, California red fir, grand fir, noble fir, pacific
silver fir, subalpine fir and white fir.
Resinous Softwood Species (Pine Family)
Species
Non-Resinous Softwood Species
2 Because WPP1 VOC, methanol and formaldehyde emissions are dependent upon maximum drying temperature, a best-fit linear equation with
dependent variable maximum temperature of heated air entering the lumber has been generated to model emissions, with a couple of exceptions. For
engelmann spruce and lodgepole pine, a single VOC EF (based upon high-temperature drying) has been generated due to lack of sufficient test data to
build a best-fit linear equation.
Resinous Softwood Species (Non-Pine Family)
Page 1 of 49
Hazardous Air Pollutant Emission Factors for Drying Western True Fir Lumber
Step One: Compile Western True Fir HAP Emission Test Data by Drying Temperature1
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Lumber Moisture Content2 (%)Time to Final Moisture HAP Sample
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)Dimensions (Initial / Final)Content (hours)Collection Technique
180 0.096 0.0022 no data no data no data 2x6 122.0 / 15 42.6
180 0.148 0.0034 no data no data no data 2x6 133.2 / 15 46.9
225 no data no data 0.0550 no data no data 2x4 170 / 13 54 Dinitrophenylhydrazine
coated cartridges.7
240 0.42 0.0156 no data no data no data 2x6 126.3 / 15 24
240 0.419 0.0163 no data no data no data 2x6 119.0 / 15 24
1 Green highlight denotes data generated by testing conducted on the small-scale kiln at the University of Idaho. All other data was generated by testing conducted on the smaller of the two small-scale kilns at OSU.
2 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Two: Adjust Western True Fir HAP Emission Test Data to Account for Bias in Underlying Small-Scale Kiln to Represent Full-Scale Kiln Emissions1
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
180 0.0875 0.0016 no data no data no data
180 0.1348 0.0025 no data no data no data
225 no data no data 0.0550 no data no data
240 0.3827 0.0115 no data no data no data
240 0.3818 0.0120 no data no data no data
1 Green highlighted results from the test conducted at the University of Idaho have not been adjusted because the kiln was not calibrated to a full-scale kiln.
Adjusted OSU emission test data valuei = (OSU reported emission test data valuei) X (NCASI TB No. 845 study full-scale kiln valuei/NCASI TB No. 845 study OSU small-scale kiln valuei)
where:OSU reported emission test data valuei is the emission rate "lb/mbf" for compound "i" documented in Step One (not highlighted in green)
NCASI study full-scale kiln valuei is the average emission rate "lb/mbf" for compound "i" measured while drying southern yellow pine lumber in a full-scale indirect steam-heated batch lumber dry kiln
NCASI study OSU small-scale kiln valuei is the average emission rate "lb/mbf" for compound "i" measured while drying southern yellow pine lumber in OSU's small-scale indirect steam-heated batch lumber dry kiln
The lumber dried in the OSU kiln was (a) extracted from the pool of lumber dried in the full-scale kiln and (b) dried according the schedule employed by the full-scale kiln.
Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Full-Scale Kiln 0.205 0.0155 0.039 0.001 0.006
OSU Kiln 0.225 0.0210 0.065 0.003 0.009
Step Three: Calculate Western True Fir HAP Emission Factors
Methanol1 Formaldehyde1 Acetaldehyde2 Propionaldehyde3 Acrolein3
(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
0.00465x - 0.73360 0.00016x - 0.02764 0.0550 0.0003 0.0009
1 Because methanol and formaldehyde emissions are dependent upon drying temperature, best-fit linear equations model emissions with dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
2 The acetaldehyde EF reflects the results of a single test.
This sheet presents lab-scale HAP test data and calculations used to create HAP EF for drying western true fir lumber in an indirect steam-heated batch kiln. Western true fir consists of the following seven species classified in the same Abies genus:
bristlecone fir, California red fir, grand fir, noble fir, pacific silver fir, subalpine fir and white fir. The methanol and formaldehyde EF are temperature dependent best-fit linear equations. The temperature variable reflects the maximum temperature of the
heated air entering the lumber. The acetaldehyde EF reflects the results of a single test. No EF are presented for either propionaldehyde or acrolein as EPA Region 10 is not aware of any test data for those HAP.
Reference
NCASI Method
IM/CAN/WP-99.01
without cannisters.
NCASI chilled impinger
method.
3, 4, 5, 12, 14
5
Test data generated through the use of the smaller of the two small-scale kilns at Oregon State University (OSU) has been adjusted to account for bias documented in NCASI's May 2002 Technical Bulletin No. 845 entitled, "A Comparative Study of
VOC Emissions from Small-Scale and Full-Scale Lumber Kilns Drying Southern Pine." See last spreadsheet of this workbook for Stimson Lumber Company's October 18, 2019 letter to EPA Region 10 highlighting the bias.
NCASI TB No. 845 - Emission Rate (lb/mbf)
Page 2 of 49
propionaldehyde western true firs = (propionaldehyde western hemlock) * (acetaldehyde western true fir) / (acetaldehyde western hemlock)
acrolein western true firs = (acrolein western hemlock) * (acetaldehyde western true firs) / (acetaldehyde western hemlock)
Species Acetaldehyde Propionaldehyde Acrolein
Western True Firs 0.0550 0.0003 0.0009
Western Hemlock 0.0677 0.0004 0.0012
calculated values to estimate EF
See "Western True Fir Sub" sheet for more information.
3 Propionaldehyde and acrolein EF are not based upon western true fir test data for those compounds. The EF are estimated using western true fir acetaldehyde data and western hemlock acetaldehyde, propionaldehyde and acrolein test data as
follows:
Emission Factor (lb/mbf)
y = 0.00465x -0.73360
R² = 0.98422
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
170 190 210 230 250
Me
t
h
a
n
o
l

(
l
b
/
m
b
f
)
Dry Bulb Temperatures (°F)
y = 0.00016x -0.02764
R² = 0.99440
0.000
0.002
0.004
0.006
0.008
0.010
0.012
0.014
170 190 210 230 250
Fo
r
m
a
l
d
e
h
y
d
e

(
l
b
/
m
b
f
)
Dry Bulb Temperatures (°F)
Page 3 of 49
Volatile Organic Compound Emission Factors for Drying Western True Fir Lumber
Step One: Compile Western True Fir RM25A VOC Emission Test Data by Drying Temperature1
Maximum Dry Bulb Method 25A VOC Lumber Moisture Content2 (%)Time to Final Moisture Method 25A
Temperature (°F)as Carbon (lb/mbf)Dimensions (Initial/Final)Content (hours)Analyzer
180 0.26 2x6 106.3 / 15 36.6
180 0.27 2x6 113.6 / 15 43.2
180 0.22 2x6 122.0 / 15 42.6
180 0.25 2x6 133.2 / 15 46.9
190 0.63 2x4 138.1 / 15 70
190 0.50 2x4 138.1 / 15 75
200 0.53 2x4 96.1 / 15 47
225 0.39 2x4 170 / 13 54 JUM VE-7 7
240 0.62 2x6 126.3 / 15 25
240 0.6 2x6 119.0 / 15 25
1 Green highlight denotes data generated by testing conducted on the small-scale kiln at the University of Idaho. All other data was generated by testing conducted on the smaller of the two small-scale kilns at OSU.
2 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Two: Adjust Western True Fir VOC Emission Test Data to Account for Bias in Underlying Small-Scale Kiln to Represent Full-Scale Kiln Emissions1
Maximum Dry Bulb Method 25A VOC
Temperature (°F)as Carbon (lb/mbf)
180 0.22
180 0.22
180 0.18
180 0.21
190 0.52
190 0.42
200 0.44
225 0.39
240 0.52
240 0.50
1 Green highlighted results from the test conducted at the University of Idaho have not been adjusted because the kiln was not calibrated to a full-scale kiln.
Adjusted OSU emission test data value = (OSU reported emission test data value) X (NCASI TB No. 845 study full-scale kiln value/NCASI TB No. 845 study OSU small-scale kiln value)
where:OSU reported emission test data value is the RM25A VOC as carbon emission rate "lb/mbf" documented in Step One (not highlighted in green)
NCASI study full-scale kiln value is the average RM25A VOC as carbon emission rate "lb/mbf" measured while drying southern yellow pine lumber in a full-scale indirect steam-heated batch lumber dry kiln
NCASI study OSU small-scale kiln value is the average RM25A VOC as carbon emission rate "lb/mbf" measured while drying southern yellow pine lumber in OSU's small-scale indirect steam-heated batch lumber dry kiln
The lumber dried in the OSU kiln was (a) extracted from the pool of lumber dried in the full-scale kiln and (b) dried according the schedule employed by the full-scale kiln.
NCASI TB No. 845 - Emission Rate (lb/mbf)
RM25A VOC as carbon
Full-Scale Kiln 3.53333
OSU Kiln 4.25000
Step Three: Calculate/Compile Western True Fir Speciated HAP Emission Factors at Maximum Drying Temperatures Observed during RM25A VOC Testing1
Maximum Dry Bulb Methanol2 Formaldehyde3 Acetaldehyde Propionaldehyde Acrolein
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
180 0.1034 0.0012
190 0.1499 0.0028
200 0.1964 0.0044
225 0.3127 0.0084
240 0.3824 0.0108
1 See western true fir HAP sheet for lab-scale test data and calculations.
3, 4
Note that reporting the unspeciated VOC as propane (mass-to-carbon ratio of 1.22 and a response factor of 1) may underestimate the actual mass of VOC for certain wood species because VOC compounds like ethanol and acetic acid with higher mass-to-carbon ratios (1.92 and 2.5, respectively) and lower response factors
(0.66 and 0.575, respectively) can be a significant portion of the total VOC. Based upon the mass-to-carbon ratios and response factors noted above, 1 lb/mbf ethanol is reported as 0.4194 lb/mbf propane and 1 lb/mbf acetic acid is reported as 0.2806 lb/mbf propane through the use of EPA Reference Method 25A unless
compound-specific sampling and analysis is performed. The contribution of ethanol and acetic acid has been quantified through sampling and analysis for douglas fir and ponderosa pine. For douglas fir, ethanol's contribution over three tests was measured to be 0, 1.4 and 5.4 percent of WPP1 VOC, and acetic acid's
contribution over the same three tests was measured to be 37, 20 and 13 percent of WPP1 VOC. For ponderosa pine, ethanol's contribution over one test was measured to be 32 percent of WPP1 VOC, and acetic acid's contribution over the same test was measured to be 6.4 percent. Without western true fir lumber drying
test data for ethanol and acetic acid, EPA assumes propane adequately represents the mix of unspeciated VOC.
This sheet presents lab-scale EPA Reference Method 25A (RM25A) and speciated VOC test data and calculations used to create VOC EF for drying western true fir lumber in an indirect steam-heated batch kiln. Western true fir consists of the following seven species classified in the same Abies genus: bristlecone fir,
California red fir, grand fir, noble fir, pacific silver fir, subalpine fir and white fir. RM25A has some limitations in that it misses some pollutant compounds (or portions thereof) that are VOC and known to exist and reports the results “as carbon” which only accounts for the carbon portion of each compound measured. The
missed pollutant compounds (some HAP and some non-HAP) are accounted for through separate testing. RM25A test data is adjusted to fully account for three known pollutant compounds that are VOC using separate speciated test data and is reported “as propane” to better represent all of the unspeciated VOC compounds.
This technique is consistent with EPA’s Interim VOC Measurement Protocol for the Wood Products Industry - July 2007 (WPP1 VOC) except that the RM25A results are adjusted to account for not only methanol and formaldehyde but also for acetaldehyde in this case.
JUM 3-200
JUM 3-200
0.0550 no data no data
JUM VE-7
More specifically, ten separate drying-temperature-specific VOC emission rates (upon which a best-fit linear equation will be established) are calculated based upon underlying RM25A and speciated VOC test data as indicated above. Temperature-specific methanol and formaldehyde emission rates are calculated for each
temperature at which RM25A testing was performed using temperature-dependent best-fit linear equations. The temperature variable reflects the maximum temperature of the heated air entering the lumber. The temperature-independent acetaldehyde emission rate reflects the result of a single test. EPA Region 10 is not
aware of any further speciated VOC test data. That portion of the (speciated) VOC compounds that are measured by the RM25A test method (based on known flame ionization detector response factors) is subtracted from the RM25A measured emission rate. The remaining “unspeciated” RM25A emission rate is adjusted to
represent propane rather than carbon and then added to the speciated VOC emission rate to provide the “total” temperature-specific VOC emission rate. The resultant VOC EF is a 10-point best-fit linear equation with dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
JUM 3-200
Test data generated through the use of the smaller of the two small-scale kilns at Oregon State University (OSU) has been adjusted to account for bias documented in NCASI's May 2002 Technical Bulletin No. 845 entitled, "A Comparative Study of VOC Emissions from Small-Scale and Full-Scale Lumber Kilns Drying
Southern Pine." See last spreadsheet of this workbook for Stimson Lumber Company's October 18, 2019 letter to EPA Region 10 highlighting the bias.
3, 4, 5, 12
2
5
Reference
Page 4 of 49
2 Methanol EF = 0.00465x - 0.73360; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
3 Formaldehyde EF = 0.00016x - 0.02764; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
Step Four: Compile True Fir Speciated Non-HAP Emission Factors at Maximum Drying Temperatures Observed during RM25A VOC Testing
Maximum Dry Bulb Ethanol Acetic Acid
Temperature (°F)(lb/mbf)(lb/mbf)
180
190
200
225
240
Step Five: Convert Western True Fir Speciated HAP and Non-HAP Emission Factors to "as Carbon" and Total
Speciated Compound "X" expressed as carbon = (RFX) X (SCX) X [(MWC) / (MWX)] X [(#CX) / (#CC)]
where:RFX represents the flame ionization detector (FID) response factor (RF) for speciated compound "X"
SCX represents emissions of speciated compound "X" expressed as the entire mass of compound emitted
MWC equals "12.0110" representing the molecular weight (MW) for carbon as carbon is becoming the "basis" for expressing mass of speciated compound "X"
MWX represents the molecular weight for speciated compound "X"
#CX represents the number of carbon atoms in speciated compound "X"
#CC equals "1" as the single carbon atom is becoming the "basis" for expressing mass of speciated compound "X"
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Ethanol Acetic Acid Speciated Compounds
Temperature as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon
(°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
180 0.0279 0 0.0429
190 0.0405 0 0.0555
200 0.0530 0 0.0680
225 0.0844 0 SUM 0.0994
240 0.1032 0 0.1182
Element and Compound Information
Molecular Weight Number of Carbon Number of Hydrogen Number of Oxygen
(lb/lb-mol)Atoms Atoms Atoms
Methanol 0.72 32.042 CH40 1 4 1 1
Formaldehyde 0 30.0262 CH2O 1 2 1 16
Acetaldehyde 0.5 44.053 C2H4O 2 4 1 20
Propionaldehyde 0.66 58.0798 C3H6O 3 6 1 20
Acrolein 0.66 56.064 C3H4O 3 4 1 20
Ethanol 0.66 46.0688 C2H6O 2 6 1 1
Acetic Acid 0.575 60.0524 C2H4O2 2 4 2 1
Propane 1 44.0962 C3H8 3 8 0 16
Carbon -12.0110 C 1 ---
Hydrogen -1.0079 H -1 --
Oxygen -15.9994 O --1 -
Step Six: Subtract Speciated HAP and Non-HAP Compounds from Western True Fir RM25A VOC Emission Factors and Convert Result to "as Propane"
FROM STEP TWO FROM STEP FIVE Method 25A VOC Method 25A VOC
Method 25A VOC Speciated Compounds as Carbon without as Propane without
Maximum Dry Bulb as Carbon as Carbon Speciated Compounds Speciated Compounds
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
180 0.22 0.0429 0.1733 0.2120
180 0.22 0.0429 0.1816 0.2222
180 0.18 0.0429 0.1400 0.1713
180 0.21 0.0429 0.1649 0.2018
190 0.52 0.0555 0.4683 0.5731
190 0.42 0.0555 0.3602 0.4408
200 0.44 0.0680 0.3726 0.4560
225 0.39 0.0994 0.2906 0.3557
240 0.52 MINUS 0.1182 EQUALS 0.3972 0.4861
240 0.50 0.1182 0.3806 X 1.2238 =0.4658
Method 25A VOC as propane without speciated compounds = (VOCC) X (1/RFC3H8) X [(MWC3H8) / (MWC)] X [(#CC) / (#CC3H8)]
where:VOCC represents Method 25A VOC as carbon without speciated compounds
RFC3H8 equals "1" and represents the FID RF for propane. All alkanes, including propane, have a RF of 1.
MWC3H8 equals "44.0962" and represents the molecular weight for propane; the compound that is the "basis" for expressing mass of VOC per WPP1 VOC
MWC equals "12.0110" and represents the molecular weight for carbon
#CC equals "1" as the single carbon atom was the "basis" for which Method 25A VOC test results were determined as illustrated in Step One of this spreadsheet
no data no data
Element / Compound FormulaFID RF1
0.0150 no data no data no data
Reference
1 FID RF = volumetric concentration or "instrument display" / compound's actual known concentration. Numerator and denominator expressed on same basis (ie. carbon, propane, etc) and concentration in
units of "ppm."
no data
Propane
Mass
Conversion
Factor
Page 5 of 49
#CC3H8 equals "3" as three carbon atoms are present within propane; the compound that is the "basis" for expressing mass of VOC per WPP1 VOC
Note:The following portion from the equation immediately above, (1/RFC3H8) X [(MWC3H8) / (MWC)] X [(#CC) / (#CC3H8)], equals 1.2238 and can be referred to as the "propane mass conversion factor."
Step Seven: Calculate WPP1 VOC by Adding Speciated HAP and Non-HAP Compounds to Western True Fir RM25A VOC Emission Factors "as Propane"
WPP1 VOC = Method 25A VOC as propane without speciated compounds + ∑ speciated compounds expressed as the entire mass of compound
FROM STEP SIX
Method 25A VOC
as Propane without
Maximum Dry Bulb Speciated Compounds Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Ethanol Acetic Acid WPP1 VOC
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
180 0.2120 0.1034 0.0012 0.3716
180 0.2222 0.1034 0.0012 0.3818
180 0.1713 0.1034 0.0012 0.3309
180 0.2018 0.1034 0.0012 0.3614
190 0.5731 0.1499 0.0028 0.7808
190 0.4408 0.1499 0.0028 0.6485
200 0.4560 0.1964 0.0044 0.7118
225 0.3557 0.3127 0.0084 0.7317
240 0.4861 PLUS 0.3824 0.0108 PLUS EQUALS 0.9343
240 0.4658 0.3824 0.0108 0.9140
Step Eight: Generate Western True Fir Best-Fit Linear Equation with Dependent Variable Maximum Drying Temperature of Heated Air Entering the Lumber to Model WPP1 VOC Emissions
WPP1 VOC (lb/mbf):0.00817x - 1.02133 ; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber
no data no data
FROM STEP FOUR
no data no data
FROM STEP THREE
0.0550
y = 0.00817x -1.02133
R² = 0.74817
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
170 190 210 230 250
WP
P
1

V
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Dry Bulb Temperatures (°F)
Page 6 of 49
The Problem: Missing Data for Western True Firs Propionaldehyde and Acrolein EF
WPP1 VOC Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
lb/mbf (lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
Non-Resinous Softwood Species
Western
True Firs
0.00817x -
1.02133 0.00465x - 0.73360 0.00016x - 0.02764 0.0550 no data no data
Western
Hemlock
0.00369x -
0.39197 0.00249x - 0.39750 0.000046x - 0.007622 0.0677 0.0004 0.0012
WTF - Western True Firs WH - Western Hemlock
Compounds Whose Emission Factors are Known for WTF
Acetaldehyde: CH3CHO Methanol: CH3OH Formaldehyde: CH2O
Aldehyde Alcohol Aldehyde
MW: 44 g/g-mol MW: 32 g/g-mol MW: 30 g/g-mol
Boiling point: 70F @ 760 mmhg Boiler point: 149F @ 760 mmhg Boiler point: -6F @ 760 mmhg
Vapor pressure: 760 mmHg @ 68F Vapor pressure: 92 mmhg @ 68F Vapor pressure: 3,890 mmhg @ 77F
Compounds Whose Emission Factors are Unknown for WTF
Propionaldehyde: CH3CH2CHO Acrolein: C3H4O
Aldehyde Unsaturated aldehyde
MW: 58 g/g-mol MW: 56 g/g-mol
Boiling point: 120F @ 760mmhg Boiling Point: 126F @ 760 mmhg
Vapor pressure: 235 mmhg @ 68F Vapor pressure: 210 mmhg @ 68F
Propionaldehyde Fraction of Default Acrolein Fraction of Default
0.0004 N/A 0.0012 N/A
Option A: Use acetaldehyde as a basis 0.0003 0.81 0.0009 0.79
Option B: Use formaldehyde (200F) as a basis 0.0011 2.76 0.0033 2.76
Option C: Use formaldehyde (220F) as a basis 0.0012 3.03 0.0036 3.03
Option D: Use methanol (200F) as a basis 0.0008 1.95 0.0023 1.95
Option E: Use methanol (220F) as a basis 0.0008 1.93 0.0023 1.93
0.0007 1.77 0.0021 1.77
0.0007 1.85 0.0022 1.85
Option A: Use acetaldehyde as a basis
Propionaldehyde WTF = (Propionaldehyde WH) * (Acetaldehyde WTF) / (Acetaldehyde WH)
Acrolein WTF = (Acrolein WH) * (Acetaldehyde WTF) / (Acetaldehyde WH)
Acetaldehyde Propionaldehyde Acrolein
Western True Firs 0.0550 0.0003 0.0009
Western Hemlock 0.0677 0.0004 0.0012
Click on cell for calculation
Option B: Use formaldehyde (200F) as a basis
Propionaldehyde WTF = (Propionaldehyde WH) * (Formaldehyde 200F WTF) / (Formaldehyde 200F WH)
Acrolein WTF = (Acrolein WH) * (Formaldehyde 200F WTF) / (Formaldehyde 200F WH)
200 F
Formaldehyde
Western True Firs 0.00436 0.0011 0.0033
Western Hemlock 0.001578 0.0004 0.0012
Option C: Use formaldehyde (220F) as a basis
Propionaldehyde WTF = (Propionaldehyde WH) * (Formaldehyde 220F WTF) / (Formaldehyde 220F WH)
Acrolein WTF = (Acrolein WH) * (Formaldehyde 220F WTF) / (Formaldehyde 220F WH)
220 F
Formaldehyde
Western True Firs 0.00756 0.0012 0.0036
Western Hemlock 0.002498 0.0004 0.0012
Option D: Use methanol (200F) as a basis
Propionaldehyde WTF = (Propionaldehyde WH) * (Methanol 200F WTF) / (Methanol 200F WH)
Acrolein WTF = (Acrolein WH) * (Methanol 200F WTF) / (Methanol 200F WH)
200 F
Methanol
Western True Firs 0.1964 0.0008 0.0023
Western Hemlock 0.1005 0.0004 0.0012
Propionaldehyde Acrolein
Species
Option WESTERN TRUE FIRS SUBSTITUTE EMISSION FACTOR (lb/mbf)
Default option: WH EF become WTF EF
Option F: Use VOC (200F) as a basis
Option G: Use VOC (220F) as a basis
EMISSION FACTOR (lb/mbf)
EMISSION FACTOR (lb/mbf)
Propionaldehyde Acrolein
EMISSION FACTOR (lb/mbf)
EMISSION FACTOR (lb/mbf)
Propionaldehyde Acrolein
Option E: Use methanol (220F) as a basis
Propionaldehyde WTF = (Propionaldehyde WH) * (Methanol 220F WTF) / (Methanol 220F WH)
Acrolein WTF = (Acrolein WH) * (Methanol 220F WTF) / (Methanol 220F WH)
220 F
Methanol
Western True Firs 0.2894 0.0008 0.0023
Western Hemlock 0.1503 0.0004 0.0012
Option F: Use VOC (200F) as a basis
Propionaldehyde WTF = (Propionaldehyde WH) * (VOC 200F WTF) / (VOC 200F WH)
Acrolein WTF = (Acrolein WH) * (VOC 200F WTF) / (VOC 200F WH)
EMISSION FACTOR (lb/mbf)
200 F
VOC
Western True Firs 0.61267 0.0007 0.0021
Western Hemlock 0.34603 0.0004 0.0012
Option G: Use VOC (220F) as a basis
Propionaldehyde WTF = (Propionaldehyde WH) * (VOC 220F WTF) / (VOC 220F WH)
Acrolein WTF = (Acrolein WH) * (VOC 220F WTF) / (VOC 220F WH)
220 F
VOC
Western True Firs 0.77607 0.0007 0.0022
Western Hemlock 0.41983 0.0004 0.0012
EMISSION FACTOR (lb/mbf)
Propionaldehyde Acrolein
Propionaldehyde Acrolein
EMISSION FACTOR (lb/mbf)
Propionaldehyde Acrolein
Hazardous Air Pollutant Emission Factors for Drying Western Hemlock Lumber
Step One: Compile Western Hemlock HAP Emission Test Data by Drying Temperature1
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Lumber Moisture Content2 (%)Time to Final Moisture HAP Sample
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)Dimensions (Initial / Final)Content (hours)Collection Technique
180 0.083 0.0013 no data no data no data 2x4 102.3 / 14.7 49.5 NCASI Method 98.01 14, 15
180 0.075 0.0014 0.078 0.002 0.0012 2x4 102.3 / 14.7 49.5 NCASI Method 105 14, 15, 18
180 0.094 0.0015 0.141 0.0008 0.0012 2x4 or 2x6 93.5 / 17.5 no data NCASI Method 105 18
180 0.052 0.0007 no data no data no data 2x4 88.8 / 15 46.2 NCASI Method CI//WP-
98.01 13
180 0.0312 0.00082 no data no data no data 2x4 56.8 / 15 38.35
180 0.0304 0.00082 no data no data no data 2x4 51.1 / 15 35.75
200 0.098 0.0015 no data no data no data 2x6 81.0 / 15 45.2
200 0.175 0.0016 no data no data no data 2x6 73.7 / 15 36.5
200 0.154 0.0018 no data no data no data 2x6 100.1 / 15 47.4
200 0.044 0.0008 0.133 0.0008 0.0024 2x4 or 2x6 83.9 / 15.0 no data
200 0.077 0.0014 0.128 0.001 0.0011 2x4 or 2x6 98.6 / 15.0 no data
200 0.057 0.0014 no data no data no data 2x4 76.0 / 15 30.25 NCASI Method CI//WP-
98.01 9, 11, 14
215 0.138 0.0043 no data no data 0.0027 2x4 119.7 / 15 38 no data 6, 11, 14
225 0.189 0.0035 no data no data no data 2x6 82 / 15 31.3
225 0.167 0.0034 no data no data no data 2x6 77.4 / 15 28.6
225 0.24 0.004 no data no data no data 2x6 101.7 / 15 33.5
235 0.187 0.0045 0.084 0.0014 0.0019 2x4 or 2x6 76.2 / 15.0 no data NCASI Method 105 18
1 All data was generated by testing conducted on the smaller of the two small-scale kilns at OSU.
2 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Two: Adjust Western Hemlcock HAP Emission Test Data to Account for Bias in Underlying Small-Scale Kiln to Represent Full-Scale Kiln Emissions
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
180 0.0756 0.0010 no data no data no data
180 0.0683 0.0010 0.0468 0.0007 0.0008
180 0.0856 0.0011 0.0846 0.0003 0.0008
180 0.0474 0.0005 no data no data no data
180 0.0284 0.0006 no data no data no data
180 0.0277 0.0006 no data no data no data
200 0.0893 0.0011 no data no data no data
200 0.1594 0.0012 no data no data no data
200 0.1403 0.0013 no data no data no data
200 0.0401 0.0006 0.0798 0.0003 0.0016
200 0.0702 0.0010 0.0768 0.0003 0.0007
200 0.0519 0.0010 no data no data no data
215 0.1257 0.0032 no data no data 0.0018
225 0.1722 0.0026 no data no data no data
225 0.1522 0.0025 no data no data no data
11, 14NCASI Method CI//WP-
98.01
This sheet presents lab-scale test data and calculations used to create HAP EF for drying western hemlock lumber in an indirect steam-heated batch kiln. The methanol and formaldehyde EF are temperature dependent best-fit linear equations.
The temperature variable reflects the maximum temperature of the heated air entering the lumber. The acetaldehyde, propionaldehyde and acrolein EF are calculated by averaging test results.
NCASI Method CI//WP-
98.01
NCASI Method CI//WP-
98.01
NCASI Method 105
Reference
8, 11, 14
11, 14
14, 18
Test data generated through the use of the smaller of the two small-scale kilns at Oregon State University (OSU) has been adjusted to account for bias documented in NCASI's May 2002 Technical Bulletin No. 845 entitled, "A Comparative Study
of VOC Emissions from Small-Scale and Full-Scale Lumber Kilns Drying Southern Pine." See last spreadsheet of this workbook for Stimson Lumber Company's October 18, 2019 letter to EPA Region 10 highlighting the bias.
Page 9 of 49
225 0.2187 0.0030 no data no data no data
235 0.1704 0.0033 0.0504 0.0005 0.0013
Adjusted OSU emission test data valuei = (OSU reported emission test data valuei) X (NCASI TB No. 845 study full-scale kiln valuei/NCASI TB No. 845 study OSU small-scale kiln valuei)
where:OSU reported emission test data valuei is the emission rate "lb/mbf" for compound "i" documented in Step One (not highlighted in green)
NCASI study full-scale kiln valuei is the average emission rate "lb/mbf" for compound "i" measured while drying southern yellow pine lumber in a full-scale indirect steam-heated batch lumber dry kiln
NCASI study OSU small-scale kiln valuei is the average emission rate "lb/mbf" for compound "i" measured while drying southern yellow pine lumber in OSU's small-scale indirect steam-heated batch lumber dry kiln
The lumber dried in the OSU kiln was (a) extracted from the pool of lumber dried in the full-scale kiln and (b) dried according the schedule employed by the full-scale kiln.
Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Full-Scale Kiln 0.205 0.0155 0.039 0.001 0.006
OSU Kiln 0.225 0.0210 0.065 0.003 0.009
Step Three: Calculate Western Hemlock HAP Emission Factors
Methanol1 Formaldehyde1 Acetaldehyde2 Propionaldehyde2 Acrolein2
(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
0.00249x - 0.39750 0.000046x - 0.007622 0.0677 0.0004 0.0012
1 Because methanol and formaldehyde emissions are dependent upon maximum drying temperature, best-fit linear equations model emissions with dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber
2 Because acetaldehyde, propionaldehyde and acrolein emissions across different species are not consistently dependent upon maximum drying temperature, EF are calculated by averaging test results.
NCASI TB No. 845 - Emission Rate (lb/mbf)
y = 0.00249x -0.39750
R² = 0.65051
0.00
0.05
0.10
0.15
0.20
0.25
170 190 210 230 250
Me
t
h
a
n
o
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)
Dry Bulb Temperatures (°F)
y = 0.000046x -0.007622
R² = 0.782397
0.0000
0.0005
0.0010
0.0015
0.0020
0.0025
0.0030
0.0035
170 190 210 230 250
Fo
r
m
a
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Page 10 of 49
Volatile Organic Compound Emission Factors for Drying Western Hemlock Lumber
Step One: Compile Western Hemlock RM25A VOC Emission Test Data by Drying Temperature1,2
Maximum Dry Bulb Method 25A VOC Lumber Moisture Content3 (%)Time to Final Moisture Method 25A
Temperature (°F)as Carbon (lb/mbf)Dimensions (Initial/Final)Content (hours)Analyzer
180 0.73 2x6 126.6 / 15 66.5
180 0.66 2x6 139.3 / 15 67.9
180 0.6 2x6 127.8 / 15 65.7
180 0.67 2x6 132.7 / 15 67
180 0.17 2x4 114.8 / 15 45
180 0.07 2x4 103.1 / 15 40.7
180 0.12 2x4 98.0 / 15 37.5
180 0.4 2x4 115.7 / 15 52.9
180 0.236 2x4 or 2x6 93.5 / 17.5 no data JUM VE-7 18
180 0.142 2x4 102.3 / 14.7 49.5 JUM VE-7 15, 18
180 0.18 2x4 88.8 / 15 46.2 JUM VE-7 13
180 0.198 2x4 56.8 / 15 38.35
180 0.122 2x4 51.1 / 15 35.75
200 0.24 2x4 112.8 / 15 40 JUM VE-7 2
200 0.2 2x6 81.0 / 15 45.2
200 0.15 2x6 73.7 / 15 36.5
200 0.3 2x6 100.1 / 15 47.4
200 0.204 2x4 76.0 / 15 30.25 JUM 3-200 9, 11
200 0.214 2x4 or 2x6 83.9 / 15.0 no data
200 0.239 2x4 or 2x6 98.6 / 15.0 no data
215 0.34 2x4 112.9 / 15 32.7 no data 11
215 0.34 2x4 119.7 / 15 38 JUM 3-200 6, 11
225 0.28 2x6 82 / 15 31.3
225 0.27 2x6 77.4 / 15 28.6
225 0.31 2x6 101.7 / 15 33.5
235 0.247 2x4 or 2x6 81.6 / 15.0 no data
235 0.226 2x4 or 2x6 76.2 / 15.0 no data
3 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Two: Adjust Western Hemlock VOC Emission Test Data to Account for Bias in Underlying Small-Scale Kiln to Represent Full-Scale Kiln Emissions1
Maximum Dry Bulb Method 25A VOC
Temperature (°F)as Carbon (lb/mbf)
180 0.141
180 0.058
180 0.100
180 0.333
180 0.196
180 0.118
180 0.150
Test data generated through the use of the smaller of the two small-scale kilns at Oregon State University (OSU) has been adjusted to account for bias documented in NCASI's May 2002 Technical Bulletin No. 845 entitled, "A Comparative Study of VOC Emissions from Small-Scale and Full-Scale Lumber Kilns Drying
Southern Pine." See last spreadsheet of this workbook for Stimson Lumber Company's October 18, 2019 letter to EPA Region 10 highlighting the bias.
This sheet presents lab-scale EPA Reference Method 25A (RM25A) and speciated VOC test data and calculations used to create VOC EF for drying western hemlock lumber in an indirect steam-heated batch kiln. RM25A has some limitations in that it misses some pollutant compounds (or portions thereof) that are VOC and
known to exist and reports the results “as carbon” which only accounts for the carbon portion of each compound measured. The missed pollutant compounds (some HAP and some non-HAP) are accounted for through separate testing. RM25A test data is adjusted to fully account for five known pollutant compounds that are
VOC using separate speciated test data and is reported “as propane” to better represent all of the unspeciated VOC compounds. This technique is consistent with EPA’s Interim VOC Measurement Protocol for the Wood Products Industry - July 2007 (WPP1 VOC) except that the RM25A results are adjusted to account for not
only methanol and formaldehyde but also for acetaldehyde, propionaldehyde and acrolein in this case.
Note that reporting the unspeciated VOC as propane (mass-to-carbon ratio of 1.22 and a response factor of 1) may underestimate the actual mass of VOC for certain wood species because VOC compounds like ethanol and acetic acid with higher mass-to-carbon ratios (1.92 and 2.5, respectively) and lower response factors
(0.66 and 0.575, respectively) can be a significant portion of the total VOC. Based upon the mass-to-carbon ratios and response factors noted above, 1 lb/mbf ethanol is reported as 0.4194 lb/mbf propane and 1 lb/mbf acetic acid is reported as 0.2806 lb/mbf propane through the use of EPA Reference Method 25A unless
compound-specific sampling and analysis is performed. The contribution of ethanol and acetic acid has been quantified through sampling and analysis for douglas fir and ponderosa pine. For douglas fir, ethanol's contribution over three tests was measured to be 0, 1.4 and 5.4 percent of WPP1 VOC, and acetic acid's
contribution over the same three tests was measured to be 37, 20 and 13 percent of WPP1 VOC. For ponderosa pine, ethanol's contribution over one test was measured to be 32 percent of WPP1 VOC, and acetic acid's contribution over the same test was measured to be 6.4 percent. Without western hemlock lumber drying
test data for ethanol and acetic acid, EPA assumes propane adequately represents the mix of unspeciated VOC.
More specifically, twenty-three separate drying-temperature-specific VOC emission rates (upon which a best-fit linear equation will be established) are calculated based upon underlying RM25A and speciated VOC test data as indicated above. Temperature-specific methanol and formaldehyde emission rates are calculated for
each temperature at which RM25A testing was performed using temperature-dependent best-fit linear equations. The temperature variable reflects the maximum temperature of the heated air entering the lumber. The temperature-independent acetaldehyde, propionaldehyde and acrolein emission rates reflect the average of
all test results independent of the temperature of heated air entering the lumber. EPA Region 10 is not aware of any further speciated VOC test data. That portion of the (speciated) VOC compounds that are measured by the RM25A test method (based on known flame ionization detector response factors) is subtracted from
the RM25A measured emission rate. The remaining “unspeciated” RM25A emission rate is adjusted to represent propane rather than carbon and then added to the speciated VOC emission rate to provide the “total” temperature-specific VOC emission rate. The resultant VOC EF is a 23-point best-fit linear equation with
dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
no data 11
18
11
JUM VE-7
no data
18JUM VE-7
1 Blue highlight denotes data not considered by EPA Region 10 in 2012. The four test runs not considered here were obtained from a single "sample" and appeared to use a much
longer drying cycle than would be in common use in the Pacific Northwest. Therefore, these highlighted values were not used in the EF derivation.
2 Green highlight denotes data generated by testing conducted on the small-scale kiln at the University of Idaho. All other data was generated by testing conducted on the smaller of the
two small-scale kilns at OSU.
11
8, 11
no data
Reference
11
no data
JUM 3-200
Page 11 of 49
180 0.165
180 0.101
200 0.24
200 0.166
200 0.125
200 0.249
200 0.170
200 0.178
200 0.199
215 0.283
215 0.283
225 0.233
225 0.224
225 0.258
235 0.205
235 0.188
1 Green highlighted results from the test conducted at the University of Idaho have not been adjusted because the kiln was not calibrated to a full-scale kiln.
Adjusted OSU emission test data value = (OSU reported emission test data value) X (NCASI TB No. 845 study full-scale kiln value/NCASI TB No. 845 study OSU small-scale kiln value)
where:OSU reported emission test data value is the RM25A VOC as carbon emission rate "lb/mbf" documented in Step One (not highlighted in green)
NCASI study full-scale kiln value is the average RM25A VOC as carbon emission rate "lb/mbf" measured while drying southern yellow pine lumber in a full-scale indirect steam-heated batch lumber dry kiln
NCASI study OSU small-scale kiln value is the average RM25A VOC as carbon emission rate "lb/mbf" measured while drying southern yellow pine lumber in OSU's small-scale indirect steam-heated batch lumber dry kiln
The lumber dried in the OSU kiln was (a) extracted from the pool of lumber dried in the full-scale kiln and (b) dried according the schedule employed by the full-scale kiln.
NCASI TB No. 845 - Emission Rate (lb/mbf)
RM25A VOC as carbon
Full-Scale Kiln 3.53333
OSU Kiln 4.25000
Step Three: Calculate/Compile Western Hemlock Speciated HAP Emission Factors at Maximum Drying Temperatures Observed during RM25A VOC Testing11
Maximum Dry Bulb Methanol2 Formaldehyde3 Acetaldehyde Propionaldehyde Acrolein
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
180 0.0507 0.0007
200 0.1005 0.0016
215 0.1379 0.0023
225 0.1628 0.0027
235 0.1877 0.0032
1 See western hemlock HAP sheet for lab-scale test data and calculations.
2 Methanol EF = 0.00249x - 0.39750; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
3 Formaldehyde EF = 0.000046x - 0.007622; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
Step Four: Compile Western Hemlock Speciated Non-HAP Emission Factors at Maximum Drying Temperatures Observed during RM25A VOC Testing
Maximum Dry Bulb Ethanol Acetic Acid
Temperature (°F)(lb/mbf)(lb/mbf)
180
200
215
225
235
Step Five: Convert Western Hemlock Speciated HAP and Non-HAP Emission Factors to "as Carbon" and Total
Speciated Compound "X" expressed as carbon = (RFX) X (SCX) X [(MWC) / (MWX)] X [(#CX) / (#CC)]
where:RFX represents the flame ionization detector (FID) response factor (RF) for speciated compound "X"
SCX represents emissions of speciated compound "X" expressed as the entire mass of compound emitted
MWC equals "12.0110" representing the molecular weight (MW) for carbon as carbon is becoming the "basis" for expressing mass of speciated compound "X"
MWX represents the molecular weight for speciated compound "X"
#CX represents the number of carbon atoms in speciated compound "X"
#CC equals "1" as the single carbon atom is becoming the "basis" for expressing mass of speciated compound "X"
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Ethanol Acetic Acid Speciated Compounds
Temperature as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon
(°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
180 0.0137 0 0.0328
200 0.0271 0 0.0462
215 0.0372 0 0.05630.0002 0.0005 no data no data
0.0677 0.0004 0.0012
0.0185
no data no data
Page 12 of 49
225 0.0439 0 SUM 0.0630
235 0.0506 0 0.0698
Element and Compound Information
Molecular Weight Number of Carbon Number of Hydrogen Number of Oxygen
(lb/lb-mol)Atoms Atoms Atoms
Methanol 0.72 32.042 CH40 1 4 1 1
Formaldehyde 0 30.0262 CH2O 1 2 1 16
Acetaldehyde 0.5 44.053 C2H4O 2 4 1 20
Propionaldehyde 0.66 58.0798 C3H6O 3 6 1 20
Acrolein 0.66 56.064 C3H4O 3 4 1 20
Ethanol 0.66 46.0688 C2H6O 2 6 1 1
Acetic Acid 0.575 60.0524 C2H4O2 2 4 2 1
Propane 1 44.0962 C3H8 3 8 0 16
Carbon -12.0110 C 1 ---
Hydrogen -1.0079 H -1 --
Oxygen -15.9994 O --1 -
Step Six: Subtract Speciated HAP and Non-HAP Compounds from Western Hemlock RM25A VOC Emission Factors and Convert Result to "as Propane"
FROM STEP TWO FROM STEP FIVE Method 25A VOC Method 25A VOC
Maximum Dry Bulb Method 25A VOC Speciated Compounds as Carbon without as Propane without
Temperature as Carbon as Carbon Speciated Compounds Speciated Compounds
(°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
180 0.1413 0.0328 0.1085 0.1328
180 0.0582 0.0328 0.0254 0.0311
180 0.0998 0.0328 0.0670 0.0820
180 0.3325 0.0328 0.2998 0.3668
180 0.1962 0.0328 0.1634 0.2000
180 0.118 0.0328 0.0853 0.1043
180 0.150 0.0328 0.1169 0.1430
180 0.165 0.0328 0.1318 0.1613
180 0.101 0.0328 0.0686 0.0840
200 0.240 0.0462 0.1938 0.2371
200 0.166 0.0462 0.1200 0.1469
200 0.125 0.0462 0.0785 0.0960
200 0.249 0.0462 0.2032 0.2486
200 0.170 0.0462 0.1234 0.1510
200 0.178 0.0462 0.1317 0.1611
200 0.199 0.0462 0.1525 0.1866
215 0.283 0.0563 0.2264 0.2770
215 0.283 0.0563 0.2264 0.2770
225 0.233 0.0630 0.1697 0.2077
225 0.224 0.0630 0.1614 0.1976
225 0.258 0.0630 0.1947 0.2383
235 0.205 MINUS 0.0698 EQUALS 0.1356 0.1659
235 0.188 0.0698 0.1181 X 1.2238 =0.1446
Method 25A VOC as propane without speciated compounds = (VOCC) X (1/RFC3H8) X [(MWC3H8) / (MWC)] X [(#CC) / (#CC3H8)]
where:VOCC represents Method 25A VOC as carbon without speciated compounds
RFC3H8 equals "1" and represents the FID RF for propane. All alkanes, including propane, have a RF of 1.
MWC3H8 equals "44.0962" and represents the molecular weight for propane; the compound that is the "basis" for expressing mass of VOC per WPP1 VOC
MWC equals "12.0110" and represents the molecular weight for carbon
#CC equals "1" as the single carbon atom was the "basis" for which Method 25A VOC test results were determined as illustrated in Step One of this spreadsheet
#CC3H8 equals "3" as three carbon atoms are present within propane; the compound that is the "basis" for expressing mass of VOC per WPP1 VOC
Note:The following portion from the equation immediately above, (1/RFC3H8) X [(MWC3H8) / (MWC)] X [(#CC) / (#CC3H8)], equals 1.2238 and can be referred to as the "propane mass conversion factor."
1 FID RF = volumetric concentration or "instrument display" / compound's actual known concentration. Numerator and denominator expressed on same basis (ie. carbon, propane, etc) and concentration in units
of "ppm."
Reference

FID RF1 FormulaElement / Compound
Propane
Mass Conversion
Factor
Page 13 of 49
Step Seven: Calculate WPP1 VOC by Adding Speciated HAP and Non-HAP Compounds to Western Hemlock RM25A VOC Emission Factors "as Propane"
WPP1 VOC = Method 25A VOC as propane without speciated compounds + ∑ speciated compounds expressed as the entire mass of compound
FROM STEP SIX
Method 25A VOC
as Propane without
Maximum Dry Bulb Speciated Compounds Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Ethanol Acetic Acid WPP1 VOC
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
180 0.1328 0.0507 0.0007 0.2534
180 0.0311 0.0507 0.0007 0.1505
180 0.0820 0.0507 0.0007 0.2014
180 0.3668 0.0507 0.0007 0.4863
180 0.2000 0.0507 0.0007 0.3194
180 0.1043 0.0507 0.0007 0.2238
180 0.1430 0.0507 0.0007 0.2624
180 0.1613 0.0507 0.0007 0.2808
180 0.0840 0.0507 0.0007 0.2034
200 0.2371 0.1005 0.0016 0.4064
200 0.1469 0.1005 0.0016 0.3161
200 0.0960 0.1005 0.0016 0.2653
200 0.2486 0.1005 0.0016 0.4179
200 0.1510 0.1005 0.0016 0.3202
200 0.1611 0.1005 0.0016 0.3304
200 0.1866 0.1005 0.0016 0.3558
215 0.2770 0.1379 0.0023 0.4836
215 0.2770 0.1379 0.0023 0.4836
225 0.2077 0.1628 0.0027 0.4392
225 0.1976 0.1628 0.0027 0.4290
225 0.2383 0.1628 0.0027 0.4697
235 0.1659 PLUS 0.1877 0.0032 PLUS EQUALS 0.4223
235 0.1446 0.1877 0.0032 0.4010
Step Seven: Generate Western Hemlock Best-Fit Linear Equation with Dependent Variable Maximum Drying Temperature of Heated Air Entering the Lumber to Model WPP1 VOC Emissions
WPP1 VOC (lb/mbf):0.00369x - 0.39197 ; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber
`
no data no data
FROM STEP FOUR
0.0677 0.0004 0.0012
FROM STEP THREE
y = 0.00369x -0.39197
R² = 0.49606
0.0
0.1
0.2
0.3
0.4
0.5
0.6
170 190 210 230 250
WP
P
1

V
O
C

(
l
b
/
m
b
f
)
Dry Bulb Temperatures (°F)
Page 14 of 49
Hazardous Air Pollutant Emission Factors for Drying Western Red Cedar Lumber
Western Red Cedar (Western True Firs and Western Hemlock Substitution) HAP Emission Factors
Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
0.00465x - 0.73360 0.00016x - 0.02764 0.0677 0.0004 0.0012
This sheet presents the HAP EF for drying western red cedar lumber. EPA Region 10 is not aware of any HAP emission
testing of western red cedar. When no test data is available for any HAP, data for a similar species is substituted as noted.
When there are more than one similar species, the highest of the EF for the similar species is substituted.
In the absence of western red cedar test data, western true fir test data has been substituted for methanol and
formaldehyde and western hemlock test data has been substituted for acetaldehyde, propionaldehyde and acrolein.
Western red cedar is similar to western true firs and western hemlock in that all species are non-resinous softwood species
in the scientific classification order Pinales. For methanol and formaldehyde, western true fir EF are greater. For
acetaldehyde, western hemlock EF is greater. EPA Region 10 is not aware of any western true fir test data for either
propionaldehye or acrolein. See the western true fir and western hemlock HAP sheets for lab-scale test data and
calculations.
Page 15 of 49
Volatile Organic Compound Emission Factors for Drying Western Red Cedar Lumber
Western Red Cedar (Western True Firs Substitution) WPP1 VOC Emission Factor
WPP1 VOC (lb/mbf):0.00817x - 1.02133 ; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumb
This sheet presents the VOC EF for drying western red cedar lumber. EPA Region 10 is aware of two tests being conducted while drying western red cedar
lumber, and both were conducted at 160°F. Because VOC emissions increase with maximum drying temperature, employing an EF based upon testing at
160°F would underreport emissions when drying at maximum drying temperatures greater than 160°F. A temperature of 160°F is not a particularly high
drying temperature. When little or no test data is available, data for a similar species is substituted as noted. When there are more than one similar species,
the highest of the EF for the similar species is substituted.
Given the limited western red cedar test data, western true fir test data has been substituted. Western red cedar is similar to western true firs and western
hemlock in that all species are non-resinous softwood species in the scientific classification order Pinales. Western true fir VOC emissions are greater than
western hemlock VOC emissions. See the western true fir and western hemlock VOC sheets for lab-scale test data and calculations.
Page 16 of 49
Hazardous Air Pollutant Emission Factors for Drying Douglas Fir Lumber
Step One: Compile Douglas Fir HAP Emission Test Data by Drying Temperature1
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Lumber Moisture Content2 (%)Time to Final Moisture HAP Sample
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)Dimensions (Initial / Final)Content (hours)Collection Technique
145 0.013 0.001 0.057 0.005 0.000 2x4 49.6 / 15 39.7 NCASI ISS/FP-A105.01
Link to June 8,
2012 Exterior
Wood Test Report
160 0.025 0.0008 no data no data no data 2x6 37.3 / 15 23.5
160 0.023 0.0008 no data no data no data 2x6 44.9 / 15 28.5
160 0.026 0.0017 no data no data no data 2x6 40.3 / 15 27.1
160 0.018 0.0011 no data no data no data 2x6 31.9 / 15 25.2
170 0.015 0.0005 no data no data no data 2x4 79.9 / 15 40.5 NCASI Method CI//WP-
98.01 13
170 0.026 0.0008 no data no data no data 2x4 56.9 / 15 27.5 NCASI Method 98.01 15
170 0.024 0.0008 0.03 0.0004 0.0005 2x4 56.9 / 15 27.5 NCASI Method 105 15, 18
175 0.019 0.001 0.006 0.0001 0.0004 2x4 32.5 / 15 17.8 NCASI ISS/FP-A105.01
Link to May 23,
2013 Sierra Pacific
Industries -
Centralia Test
Report
175 0.084 0.0016 0.042 0.0002 0.0008 4x5 39.5 / 15 150 NCASI ISS/FP-A105.01
Link to March 24,
2015 Columbia
Vista Test Report
180 0.050 0.0023 0.050 0.0005 0.0009 2x4 43.7 / 15 48 NCASI Method 105 18, 22
180 0.084 0.0019 0.061 0.0003 0.0007 4x4 44.7 / 15 111 NCASI Method 105 19
200 0.068 0.0018 0.043 0.0005 0.0009 2x4 64.3 / 15 60
200 0.069 0.0019 0.071 0.0006 0.0004 2x4 59.5 / 15 56
200 0.080 0.003 0.037 0.0006 0.0017 2x4 69.3 / 15 20.8 NCASI ISS/FP-A105.01
Link to February
10, 2012 Hampton
Lumber - Morton
Test Report
220 no data no data 0.030 no data no data 2x4 73 / 12 46
220 no data no data 0.022 no data no data 2x4 73 / 15 46
235 0.117 0.0043 0.067 0.0008 0.0012 2x4 or 2x6 47.7 / 15 19 NCASI Method 105 18, 21
1 Green highlight denotes data generated by testing conducted on the small-scale kiln at the University of Idaho. All other data was generated by testing conducted on the smaller of the two small-scale kilns at OSU.
2 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Two: Adjust Douglas Fir HAP Emission Test Data to Account for Bias in Underlying Small-Scale Kiln to Represent Full-Scale Kiln Emissions1
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
145 0.012 0.0007 0.034 0.0017 0.0000
160 0.023 0.0006 no data no data no data
160 0.021 0.0006 no data no data no data
160 0.024 0.0013 no data no data no data
7
NCASI Method 105
Dinitrophenylhydrazine
coated cartridges.
This sheet presents lab-scale test data and calculations used to create HAP EF for drying douglas fir lumber in an indirect steam-heated batch kiln. The methanol and formaldehyde EF are temperature dependent best-fit linear equations. The
temperature variable reflects the maximum temperature of the heated air entering the lumber. The acetaldehyde, propionaldehyde and acrolein EF are calculated by averaging test results.
Reference
NCASI Method
IM/CAN/WP-99.01
without cannisters.
3, 4, 12, 14
14, 18, 22
Test data generated through the use of the smaller of the two small-scale kilns at Oregon State University (OSU) has been adjusted to account for bias documented in NCASI's May 2002 Technical Bulletin No. 845 entitled, "A Comparative Study
of VOC Emissions from Small-Scale and Full-Scale Lumber Kilns Drying Southern Pine." See last spreadsheet of this workbook for Stimson Lumber Company's October 18, 2019 letter to EPA Region 10 highlighting the bias.
Page 17 of 49
160 0.016 0.0008 no data no data no data
170 0.014 0.0004 no data no data no data
170 0.024 0.0006 no data no data no data
170 0.022 0.0006 0.018 0.0001 0.0003
175 0.017 0.0007 0.004 0.0000 0.0003
175 0.077 0.0012 0.025 0.0001 0.0005
180 0.046 0.0017 0.030 0.0002 0.0006
180 0.077 0.0014 0.037 0.0001 0.0005
200 0.062 0.0013 0.026 0.0002 0.0006
200 0.063 0.0014 0.043 0.0002 0.0003
200 0.073 0.0022 0.022 0.0002 0.0011
220 no data no data 0.030 no data no data
220 no data no data 0.022 no data no data
235 0.107 0.0032 0.040 0.0003 0.0008
1 Green highlighted results from the test conducted at the University of Idaho have not been adjusted because the kiln was not calibrated to a full-scale kiln.
Adjusted OSU emission test data valuei = (OSU reported emission test data valuei) X (NCASI TB No. 845 study full-scale kiln valuei/NCASI TB No. 845 study OSU small-scale kiln valuei)
where:OSU reported emission test data valuei is the emission rate "lb/mbf" for compound "i" documented in Step One (not highlighted in green)
NCASI study full-scale kiln valuei is the average emission rate "lb/mbf" for compound "i" measured while drying southern yellow pine lumber in a full-scale indirect steam-heated batch lumber dry kiln
NCASI study OSU small-scale kiln valuei is the average emission rate "lb/mbf" for compound "i" measured while drying southern yellow pine lumber in OSU's small-scale indirect steam-heated batch lumber dry kiln
The lumber dried in the OSU kiln was (a) extracted from the pool of lumber dried in the full-scale kiln and (b) dried according the schedule employed by the full-scale kiln.
Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Full-Scale Kiln 0.205 0.0155 0.039 0.001 0.006
OSU Kiln 0.225 0.0210 0.065 0.003 0.009
Step Three: Calculate Douglas Fir HAP Emission Factors
Methanol1 Formaldehyde1 Acetaldehyde2 Propionaldehyde2 Acrolein2
(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
0.00114x - 0.16090 0.000028x - 0.003800 0.0275 0.0003 0.0005
1 Because methanol and formaldehyde emissions are dependent upon drying temperature, best-fit linear equations model emissions with dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
2 Because acetaldehyde, propionaldehyde and acrolein emissions across different species are not consistently dependent upon maximum drying temperature, EF are calculated by averaging test results.
NCASI TB No. 845 - Emission Rate (lb/mbf)
y = 0.00114x -0.16090
R² = 0.72273
0.00
0.02
0.04
0.06
0.08
0.10
0.12
140 160 180 200 220 240
Me
t
h
a
n
o
l

(
l
b
/
m
b
f
)
Dry Bulb Temperatures (°F)
y = 0.000028x -0.003800
R² = 0.713519
0.0000
0.0005
0.0010
0.0015
0.0020
0.0025
0.0030
0.0035
140 160 180 200 220 240
Fo
r
m
a
l
d
e
h
y
d
e

(
l
b
/
m
b
f
)
Dry Bulb Temperatures (°F)
Page 18 of 49
Volatile Organic Compound Emission Factors for Drying Douglas Fir Lumber
Step One: Compile Douglas Fir RM25A VOC Emission Test Data by Drying Temperature1
Maximum Dry Bulb Method 25A VOC Lumber Moisture Content2 (%)Time to Final Moisture Method 25A
Temperature (°F)as Carbon (lb/mbf)Dimensions (Initial/Final)Content (hours)Analyzer
145 0.24 2x4 49.6 / 15 39.7 JUM VE-7
Link to June 8, 2012
Exterior Wood Test
Report
160 0.51 2x6 37.3 / 15 23.5
160 0.55 2x6 44.9 / 15 28.5
160 0.45 2x6 40.3 / 15 27.1
160 0.46 2x6 31.9 / 15 25.2
170 0.65 2x4 79.9 / 15 40.5 JUM VE-7 13
170 0.24 2x4 56.9 / 15 27.5 JUM VE-7 15, 18
175 0.185 2x4 32.5 / 15 17.8 JUM VE-7
Link to May 23, 2013
Sierra Pacific Industries -
Centralia Test Report
175 0.86 4x5 39.5 / 15 150 JUM VE-7
Link to March 24, 2015
Columbia Vista Test
Report
180 0.942 2x4 38.9 / 15 63
180 0.669 2x4 44.9 / 15 42
180 0.21 2x4 56.3 / 15 27
180 0.575 2x4 or 2x6 43.7 / 15 no data JUM VE-7 18
180 0.39 4x4 29.8 / 19 67.5 JUM 3-200 10
180 0.845 4x4 44.7 / 15 111 JUM VE-7 19
200 0.707 2x4 or 2x6 64.3 / 15 no data
200 0.879 2x4 or 2x6 59.5 / 15 no data
200 0.66 2x4 69.3 / 15 20.8 JUM VE-7
Link to February 10,
2012 Hampton Lumber -
Morton Test Report
220 1.2 2x4 73 / 12 46
220 1.3 2x4 73 / 15 46
235 1.206 2x4 or 2x6 47.7 / 15 19 JUM VE-7 18, 21
2 Dry basis. Moisture content = (weight of water / weight wood) x 100.
Step Two: Adjust Douglas Fir VOC Emission Test Data to Account for Bias in Underlying Small-Scale Kiln to Represent Full-Scale Kiln Emissions1
Maximum Dry Bulb Method 25A VOC
Temperature (°F)as Carbon (lb/mbf)
145 0.200
160 0.424
160 0.457
160 0.374
160 0.382
170 0.540
170 0.200
175 0.154
175 0.715
180 0.942
180 0.669
180 0.21
180 0.478
180 0.324
180 0.703
200 0.588
This sheet presents lab-scale EPA Reference Method 25A (RM25A) and speciated VOC test data and calculations used to create VOC EF for drying douglas fir lumber in an indirect steam-heated batch kiln. RM25A has some limitations in that it misses some pollutant compounds (or portions thereof) that are VOC and
known to exist and reports the results “as carbon” which only accounts for the carbon portion of each compound measured. The missed pollutant compounds (some HAP and some non-HAP) are accounted for through separate testing. RM25A test data is adjusted to fully account for seven known pollutant compounds that
are VOC using separate speciated test data and is reported “as propane” to better represent all of the unspeciated VOC compounds. This technique is consistent with EPA’s Interim VOC Measurement Protocol for the Wood Products Industry - July 2007 (WPP1 VOC) except that the RM25A results are adjusted to account
for not only methanol and formaldehyde but also for acetaldehyde, propionaldehyde, acrolein, ethanol and acetic acid in this case.
More specifically, twenty-one separate drying-temperature-specific VOC emission rates (upon which a best-fit linear equation will be established) are calculated based upon underlying RM25A and speciated VOC test data as indicated above. Temperature-specific methanol, formaldehyde and ethanol emission rates are
calculated for each temperature at which RM25A testing was performed using temperature-dependent best-fit linear equations. The temperature variable reflects the maximum temperature of the heated air entering the lumber. The temperature-independent acetaldehyde, propionaldehyde, acrolein and acetic acid emission
rates reflect the average of all test results independent of the temperature of heated air entering the lumber. EPA Region 10 is not aware of any further speciated VOC test data. That portion of the (speciated) VOC compounds that are measured by the RM25A test method (based on known flame ionization detector
response factors) is subtracted from the RM25A measured emission rate. The remaining “unspeciated” RM25A emission rate is adjusted to represent propane rather than carbon and then added to the speciated VOC emission rate to provide the “total” temperature-specific VOC emission rate. The resultant VOC EF is a 21-
point best-fit linear equation with dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
JUM 3-200
JUM VE-7
JUM VE-7
JUM VE-7
3, 4, 12
2
18
7
Test data generated through the use of the smaller of the two small-scale kilns at Oregon State University (OSU) has been adjusted to account for bias documented in NCASI's May 2002 Technical Bulletin No. 845 entitled, "A Comparative Study of VOC Emissions from Small-Scale and Full-Scale Lumber Kilns Drying
Southern Pine." See last spreadsheet of this workbook for Stimson Lumber Company's October 18, 2019 letter to EPA Region 10 highlighting the bias.
Reference
1 Green highlight denotes data generated by testing conducted on the small-scale kiln at the University of Idaho. All other data was generated by testing conducted on the smaller of
the two small-scale kilns at OSU.
Page 19 of 49
200 0.731
200 0.549
220 1.2
220 1.3
235 1.003
1 Green highlighted results from the test conducted at the University of Idaho have not been adjusted because the kiln was not calibrated to a full-scale kiln.
Adjusted OSU emission test data value = (OSU reported emission test data value) X (NCASI TB No. 845 study full-scale kiln value/NCASI TB No. 845 study OSU small-scale kiln value)
where:OSU reported emission test data value is the RM25A VOC as carbon emission rate "lb/mbf" documented in Step One (not highlighted in green)
NCASI study full-scale kiln value is the average RM25A VOC as carbon emission rate "lb/mbf" measured while drying southern yellow pine lumber in a full-scale indirect steam-heated batch lumber dry kiln
NCASI study OSU small-scale kiln value is the average RM25A VOC as carbon emission rate "lb/mbf" measured while drying southern yellow pine lumber in OSU's small-scale indirect steam-heated batch lumber dry kiln
The lumber dried in the OSU kiln was (a) extracted from the pool of lumber dried in the full-scale kiln and (b) dried according the schedule employed by the full-scale kiln.
NCASI TB No. 845 - Emission Rate (lb/mbf)
RM25A VOC as carbon
Full-Scale Kiln 3.53333
OSU Kiln 4.25000
Step Three: Calculate/Compile Douglas Fir Speciated HAP Emission Factors at Maximum Drying Temperatures Observed during RM25A VOC Testing1
Maximum Dry Bulb Methanol2 Formaldehyde3 Acetaldehyde Propionaldehyde Acrolein
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
145 0.0044 0.0003
160 0.0215 0.0007
170 0.0329 0.0010
175 0.0386 0.0011
180 0.0443 0.0012
200 0.0671 0.0018
220 0.0899 0.0024
235 0.1070 0.0028
1 See douglas fir HAP sheet for lab-scale test data and calculations.
2 Methanol EF = 0.00114x - 0.16090; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
3 Formaldehyde EF = 0.000028x - 0.003800; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
Step Four: Compile Douglas Fir Speciated Non-HAP Emission Test Data by Drying Temperature
Maximum Dry Bulb Ethanol Acetic Acid Lumber Moisture Content1 (%)Time to Final Moisture VOC Sample
Temperature (°F)(lb/mbf)(lb/mbf)Dimensions (Initial / Final)Content (hours)Collection Technique
145 0.0000 0.166 2x4 49.6 / 15 39.7 NCASI ISS/FP-A105.01
Link to June 8, 2012
Exterior Wood Test
Report
175 0.0010 0.094 2x4 32.5 / 15 17.8 NCASI ISS/FP-A105.01
Link to May 23, 2013
Sierra Pacific Industries -
Centralia Test Report
175 0.0230 0.242 4x6 39.5 / 15 150 NCASI ISS/FP-A105.01
Link to March 24, 2015
Columbia Vista Test
Report
200 0.0610 0.142 2x4 69.3 / 15 20.8 NCASI ISS/FP-A105.01
Link to February 10,
2012 Hampton Lumber -
Morton Test Report
1 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Five: Calculate Douglas Fir Speciated Non-HAP Emission Factors
Ethanol1 Acetic Acid2
(lb/mbf)(lb/mbf)
0.00107x - 0.16537 0.1610
Reference
1 Because ethanol emissions are dependent upon drying temperature, a best-fit linear equation models emissions with dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
2 Because acetic acid emissions are independent of drying temperature, EF is calculated by averaging test results.
0.0003 0.00050.0275
Page 20 of 49
Step Six: Calculate/Compile Douglas Fir Speciated Non-HAP Emission Factors at Maximum Drying Temperatures Observed during RM25A VOC Testing
Maximum Dry Bulb Ethanol1 Acetic Acid
Temperature (°F)(lb/mbf)(lb/mbf)
145 0
160 0.00583
170 0.01653
175 0.02188
180 0.02723
200 0.04863
220 0.07003
235 0.08608
1 Ethanol EF = 0.00107x - 0.16537; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
Step Seven: Convert Douglas Fir Speciated HAP and Non-HAP Emission Factors to "as Carbon" and Total
Speciated Compound "X" expressed as carbon = (RFX) X (SCX) X [(MWC) / (MWX)] X [(#CX) / (#CC)]
where:RFX represents the flame ionization detector (FID) response factor (RF) for speciated compound "X"
SCX represents emissions of speciated compound "X" expressed as the entire mass of compound emitted
MWC equals "12.0110" representing the molecular weight (MW) for carbon as carbon is becoming the "basis" for expressing mass of speciated compound "X"
MWX represents the molecular weight for speciated compound "X"
#CX represents the number of carbon atoms in speciated compound "X"
#CC equals "1" as the single carbon atom is becoming the "basis" for expressing mass of speciated compound "X"
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Ethanol Acetic Acid Speciated Compounds
Temperature as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon
(°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
145 0.0012 0 0 0.0461
160 0.0058 0 0.0020 0.0527
170 0.0089 0 0.0057 0.0594
175 0.0104 0 0.0075 0.0628
180 0.0120 0 0.0094 0.0662
200 0.0181 0 0.0167 0.0797
220 0.0243 0 0.0241 SUM 0.0932
235 0.0289 0 0.0296 0.1034
Element and Compound Information
Molecular Weight Number of Carbon Number of Hydrogen Number of Oxygen
(lb/lb-mol)Atoms Atoms Atoms
Methanol 0.72 32.042 CH40 1 4 1 1
Formaldehyde 0 30.0262 CH2O 1 2 1 16
Acetaldehyde 0.5 44.053 C2H4O 2 4 1 20
Propionaldehyde 0.66 58.0798 C3H6O 3 6 1 20
Acrolein 0.66 56.064 C3H4O 3 4 1 20
Ethanol 0.66 46.0688 C2H6O 2 6 1 1
Acetic Acid 0.575 60.0524 C2H4O2 2 4 2 1
Propane 1 44.0962 C3H8 3 8 0 16
Carbon -12.0110 C 1 ---
Hydrogen -1.0079 H -1 --
Oxygen -15.9994 O --1 -
1 FID RF = volumetric concentration or "instrument display" / compound's actual known concentration. Numerator and denominator expressed on same basis (ie. carbon, propane, etc) and concentration in units of "ppm."
Element / Compound FID RF1 Formula Reference
0.0075 0.0001 0.0002 0.0370
0.1610
y = 0.00107x -0.16537
R² = 0.71667
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
140 160 180 200 220 240
Et
h
a
n
o
l

(
l
b
/
m
b
f
)
Dry Bulb Temperatures (°F)
Page 21 of 49
Step Eight: Subtract Speciated HAP and Non-HAP Compounds from Douglas Fir VOC Emission Factors and Convert Result to "as Propane"
FROM STEP TWO FROM STEP SIX Method 25A VOC Method 25A VOC
Maximum Dry Bulb Method 25A VOC Speciated Compounds as Carbon without as Propane without
Temperature as Carbon as Carbon Speciated Compounds Speciated Compounds
(°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
145 0.1995 0.0461 0.1535 0.1878
160 0.4240 0.0527 0.3713 0.4544
160 0.4573 0.0527 0.4046 0.4951
160 0.3741 0.0527 0.3214 0.3934
160 0.3824 0.0527 0.3298 0.4035
170 0.5404 0.0594 0.4810 0.5886
170 0.1995 0.0594 0.1401 0.1714
175 0.1538 0.0628 0.0910 0.1114
175 0.7150 0.0628 0.6522 0.7981
180 0.9420 0.0662 0.8758 1.0718
180 0.6690 0.0662 0.6028 0.7377
180 0.2100 0.0662 0.1438 0.1760
180 0.4780 0.0662 0.4118 0.5040
180 0.3242 0.0662 0.2580 0.3158
180 0.7025 0.0662 0.6363 0.7787
200 0.5878 0.0797 0.5081 0.6218
200 0.7308 0.0797 0.6511 0.7968
200 0.5487 0.0797 0.4690 0.5739
220 1.2000 0.0932 1.1068 1.3544
220 1.3000 MINUS 0.0932 EQUALS 1.2068 1.4768
235 1.0026 0.1034 0.8993 X 1.2238 =1.1005
Method 25A VOC as propane without speciated compounds = (VOCC) X (1/RFC3H8) X [(MWC3H8) / (MWC)] X [(#CC) / (#CC3H8)]
where:VOCC represents Method 25A VOC as carbon without speciated compounds
RFC3H8 equals "1" and represents the FID RF for propane. All alkanes, including propane, have a RF of 1.
MWC3H8 equals "44.0962" and represents the molecular weight for propane; the compound that is the "basis" for expressing mass of VOC per WPP1 VOC
MWC equals "12.0110" and represents the molecular weight for carbon
#CC equals "1" as the single carbon atom was the "basis" for which Method 25A VOC test results were determined as illustrated in Step One of this spreadsheet
#CC3H8 equals "3" as three carbon atoms are present within propane; the compound that is the "basis" for expressing mass of VOC per WPP1 VOC
Note:The following portion from the equation immediately above, (1/RFC3H8) X [(MWC3H8) / (MWC)] X [(#CC) / (#CC3H8)], equals 1.2238 and can be referred to as the "propane mass conversion factor."
Step Nine: Calculate WPP1 VOC by Adding Speciated HAP and Non-HAP Compounds to Douglas Fir VOC Emission Factors "as Propane"
WPP1 VOC = Method 25A VOC as propane without speciated compounds + ∑ speciated compounds expressed as the entire mass of compound
FROM STEP EIGHT
Method 25A VOC
as Propane without
Maximum Dry Bulb Speciated Compounds Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Ethanol Acetic Acid WPP1 VOC
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
145 0.1878 0.0044 0.0003 0 0.3818
160 0.4544 0.0215 0.0007 0.0058 0.6717
160 0.4951 0.0215 0.0007 0.0058 0.7124
160 0.3934 0.0215 0.0007 0.0058 0.6107
160 0.4035 0.0215 0.0007 0.0058 0.6209
170 0.5886 0.0329 0.0010 0.0165 0.8283
170 0.1714 0.0329 0.0010 0.0165 0.4111
175 0.1114 0.0386 0.0011 0.0219 0.3622
175 0.7981 0.0386 0.0011 0.0219 1.0490
180 1.0718 0.0443 0.0012 0.0272 1.3339
180 0.7377 0.0443 0.0012 0.0272 0.9998
180 0.1760 0.0443 0.0012 0.0272 0.4381
180 0.5040 0.0443 0.0012 0.0272 0.7661
180 0.3158 0.0443 0.0012 0.0272 0.5779
180 0.7787 0.0443 0.0012 0.0272 1.0408
200 0.6218 0.0671 0.0018 0.0486 0.9286
200 0.7968 0.0671 0.0018 0.0486 1.1036
200 0.5739 0.0671 0.0018 0.0486 0.8808
220 1.3544 0.0899 0.0024 0.0700 1.7060
220 1.4768 PLUS 0.0899 0.0024 PLUS 0.0700 EQUALS 1.8284
235 1.1005 0.1070 0.0028 0.0861 1.4857
FROM STEP SIX
0.1610
FROM STEP THREE
0.0275 0.0003 0.0005
Propane
Mass
Conversion
Factor
Page 22 of 49
Step Ten: Generate Douglas Fir Best-Fit Linear Equation with Dependent Variable Maximum Drying Temperature to Model WPP1 VOC Emissions
WPP1 VOC (lb/mbf):0.01460x - 1.77130 ; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber
y = 0.01460x -1.77130
R² = 0.62865
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
140 160 180 200 220 240
WP
P
1

V
O
C

(
l
b
/
m
b
f
)
Dry Bulb Temperatures (°F)
Page 23 of 49
Hazardous Air Pollutant Emission Factors for Drying Engelmann Spruce Lumber
Step One: Compile Engelmann Spruce (White Spruce Substitution) HAP Emission Test Data by Drying Temperature
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Lumber Moisture Content1 (%)Time to Final Moisture HAP Sample
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)Dimensions (Initial / Final)Content (hours)Collection Technique
180 0.025 0.0013 0.036 0.0003 0.0005 2x4 or 2x6 33.5 / 15 no data
235 0.078 0.0044 0.031 0.0007 0.001 2x4 or 2x6 32.7 / 15 no data
1 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Two: Adjust Engelmann Spruce (White Spruce Substitution) HAP Emission Test Data to Account for Bias in Underlying Small-Scale Kiln to Represent Full-Scale Kiln Emissions
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
180 0.023 0.0010 0.022 0.0001 0.0003
235 0.071 0.0032 0.019 0.0002 0.0007
Adjusted OSU emission test data valuei = (OSU reported emission test data valuei) X (NCASI TB No. 845 study full-scale kiln valuei/NCASI TB No. 845 study OSU small-scale kiln valuei)
where:OSU reported emission test data valuei is the emission rate "lb/mbf" for compound "i" documented in Step One (not highlighted in green)
NCASI study full-scale kiln valuei is the average emission rate "lb/mbf" for compound "i" measured while drying southern yellow pine lumber in a full-scale indirect steam-heated batch lumber dry kiln
NCASI study OSU small-scale kiln valuei is the average emission rate "lb/mbf" for compound "i" measured while drying southern yellow pine lumber in OSU's small-scale indirect steam-heated batch lumber dry kiln
The lumber dried in the OSU kiln was (a) extracted from the pool of lumber dried in the full-scale kiln and (b) dried according the schedule employed by the full-scale kiln.
Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Full-Scale Kiln 0.205 0.0155 0.039 0.001 0.006
OSU Kiln 0.225 0.0210 0.065 0.003 0.009
Step Three: Calculate Engelmann Spruce (White Spruce Substitution) HAP Emission Factors
Methanol1 Formaldehyde1 Acetaldehyde2 Propionaldehyde2 Acrolein2
(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
0.00088x - 0.13526 0.000042x - 0.006529 0.0201 0.0002 0.0005
1 Because methanol and formaldehyde emissions are dependent upon drying temperature, best-fit linear equations model emissions with dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
2 Because acetaldehyde, propionaldehyde and acrolein emissions across different species are not consistently dependent upon maximum drying temperature, EF are calculated by averaging test results.
This sheet presents lab-scale test data and calculations used to create HAP EF for engelmann spruce lumber in an indirect steam-heated batch kiln. EPA Region 10 is not aware of any HAP emission testing of englemann spruce. When actual
test data is not available, data for a similar species is substituted as noted. When there are more than one similar species, the highest of the EF for the similar species is substituted. In the absence of engelmann spruce test data, white spruce test
data has been substituted. The two wood species are similar in that both are resinous softwood species in the scientific classification genus Picea.
The methanol and formaldehyde EF are temperature dependent best-fit linear equations. The temperature variable reflects the maximum temperature of the heated air entering the lumber. The acetaldehyde, propionaldehyde and acrolein EF are
calculated by averaging test results.
Reference
NCASI Method 105 18
Test data generated through the use of the smaller of the two small-scale kilns at Oregon State University (OSU) has been adjusted to account for bias documented in NCASI's May 2002 Technical Bulletin No. 845 entitled, "A Comparative Study
of VOC Emissions from Small-Scale and Full-Scale Lumber Kilns Drying Southern Pine." See last spreadsheet of this workbook for Stimson Lumber Company's October 18, 2019 letter to EPA Region 10 highlighting the bias.
NCASI TB No. 845 - Emission Rate (lb/mbf)
Page 24 of 49
y = 0.00088x -0.13526R² = 1.00000
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
160 180 200 220 240
Me
t
h
a
n
o
l

(
l
b
/
m
b
f
)
Dry Bulb Temperatures (°F)
y = 0.000042x -0.006529
R² = 1.000000
0.0000
0.0005
0.0010
0.0015
0.0020
0.0025
0.0030
0.0035
160 180 200 220 240
Fo
r
m
a
l
d
e
h
y
d
e

(
l
b
/
m
b
f
)
Dry Bulb Temperatures (°F)
Page 25 of 49
Volatile Organic Compound Emission Factors for Drying Engelmann Spruce Lumber
Step One: Compile Engelmann Spruce (White Spruce Substitution) RM25A VOC Emission Test Data by Drying Temperature
Maximum Dry Bulb Method 25A VOC Lumber Moisture Content1 (%)Time to Final Moisture Method 25A
Temperature (°F)as Carbon (lb/mbf)Dimensions (Initial/Final)Content (hours)Analyzer
235 0.11 2x4 or 2x6 32.7 / 15 no data JUM VE-7 18
1 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Two: Adjust Engelmann Spruce (White Spruce Substitution) VOC Emission Test Data to Account for Bias in Underlying Small-Scale Kiln to Represent Full-Scale Kiln Emissions
Maximum Dry Bulb Method 25A VOC
Temperature (°F)as Carbon (lb/mbf)
235 0.09
Adjusted OSU emission test data value = (OSU reported emission test data value) X (NCASI TB No. 845 study full-scale kiln value/NCASI TB No. 845 study OSU small-scale kiln value)
where:OSU reported emission test data value is the RM25A VOC as carbon emission rate "lb/mbf" documented in Step One (not highlighted in green)
NCASI study full-scale kiln value is the average RM25A VOC as carbon emission rate "lb/mbf" measured while drying southern yellow pine lumber in a full-scale indirect steam-heated batch lumber dry kiln
NCASI study OSU small-scale kiln value is the average RM25A VOC as carbon emission rate "lb/mbf" measured while drying southern yellow pine lumber in OSU's small-scale indirect steam-heated batch lumber dry kiln
The lumber dried in the OSU kiln was (a) extracted from the pool of lumber dried in the full-scale kiln and (b) dried according the schedule employed by the full-scale kiln.
NCASI TB No. 845 - Emission Rate (lb/mbf)
RM25A VOC as carbon
Full-Scale Kiln 3.53333
OSU Kiln 4.25000
Step Three: Calculate/Compile Engelmann Spruce (White Spruce Substitution) Speciated HAP Emission Factors at Maximum Drying Temperatures Observed during RM25A VOC Testing1
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
235 0.0715 0.0033 0.0201 0.0002 0.0005
1 See engelmann spruce HAP sheet for lab-scale test data and calculations.
2 Methanol EF = 0.00088x - 0.13526; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
3 Formaldehyde EF = 0.000042x - 0.006529; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
Step Four: Compile Engelmann Spruce (White Spruce Substitution) Speciated Non-HAP Emission Factors at Maximum Drying Temperatures Observed during RM25A VOC Testing
Maximum Dry Bulb Ethanol Acetic Acid
Temperature (°F)(lb/mbf)(lb/mbf)
235 no data no data
Step Five: Convert Engelmann Spruce (White Spruce Substitution) Speciated HAP Emission Factors to "as Carbon" and Total
Speciated Compound "X" expressed as carbon = (RFX) X (SCX) X [(MWC) / (MWX)] X [(#CX) / (#CC)]
where:RFX represents the flame ionization detector (FID) response factor (RF) for speciated compound "X"
SCX represents emissions of speciated compound "X" expressed as the entire mass of compound emitted
MWC equals "12.0110" representing the molecular weight (MW) for carbon as carbon is becoming the "basis" for expressing mass of speciated compound "X"
MWX represents the molecular weight for speciated compound "X"
#CX represents the number of carbon atoms in speciated compound "X"
#CC equals "1" as the single carbon atom is becoming the "basis" for expressing mass of speciated compound "X"
This sheet presents lab-scale EPA Reference Method 25A (RM25A) and speciated VOC test data and calculations used to create VOC EF for drying white spruce lumber in an indirect steam-heated batch kiln. EPA Region 10 is not aware of any HAP or VOC emission testing of englemann spruce. When actual test
data is not available, data for a similar species is substituted as noted. When there are more than one similar species, the highest of the EF for the similar species is substituted. In the absence of engelmann spruce test data, white spruce test data has been substituted. The two wood species are similar in that both are
resinous softwood species in the scientific classification genus Picea. Although only one RM25A VOC test was performed while drying white spruce, it was performed while drying lumber at a relatively high maximum temperature of 235°F. Because emissions increase with maximum drying temperature, employing an
EF based upon testing at 235°F would overreport emissions when drying at maximum drying temperatures less than than 235°F.
RM25A has some limitations in that it misses some pollutant compounds (or portions thereof) that are VOC and known to exist and reports the results “as carbon” which only accounts for the carbon portion of each compound measured. The missed pollutant compounds (some HAP and some non-HAP) are accounted
for through separate testing. RM25A test data is adjusted to fully account for five known pollutant compounds that are VOC using separate speciated test data and is reported “as propane” to better represent all of the unspeciated VOC compounds. This technique is consistent with EPA’s Interim VOC Measurement
Protocol for the Wood Products Industry - July 2007 (WPP1 VOC) except that the RM25A results are adjusted to account for not only methanol and formaldehyde but also for acetaldehyde, propionaldehyde and acrolein in this case.
More specifically, one VOC emission rate is calculated based upon underlying RM25A and speciated VOC test data as indicated above. Temperature-specific methanol and formaldehyde emission rates are calculated for each temperature at which RM25A testing was performed using temperature-dependent best-fit
linear equations. The temperature variable reflects the maximum temperature of the heated air entering the lumber. The temperature-independent acetaldehyde, propionaldehyde and acrolein emission rates reflect the average of all test results independent of the temperature of heated air entering the lumber. EPA
Region 10 is not aware of any further speciated VOC test data. That portion of the (speciated) VOC compounds that are measured by the RM25A test method (based on known flame ionization detector response factors) is subtracted from the RM25A measured emission rate. The remaining “unspeciated” RM25A
emission rate is adjusted to represent propane rather than carbon and then added to the speciated VOC emission rate to provide the “total” temperature-specific VOC emission rate.
Note that reporting the unspeciated VOC as propane (mass-to-carbon ratio of 1.22 and a response factor of 1) may underestimate the actual mass of VOC for certain wood species because VOC compounds like ethanol and acetic acid with higher mass-to-carbon ratios (1.92 and 2.5, respectively) and lower response
factors (0.66 and 0.575, respectively) can be a significant portion of the total VOC. Based upon the mass-to-carbon ratios and response factors noted above, 1 lb/mbf ethanol is reported as 0.4194 lb/mbf propane and 1 lb/mbf acetic acid is reported as 0.2806 lb/mbf propane through the use of EPA Reference Method
25A unless compound-specific sampling and analysis is performed. The contribution of ethanol and acetic acid has been quantified through sampling and analysis for douglas fir and ponderosa pine. For douglas fir, ethanol's contribution over three tests was measured to be 0, 1.4 and 5.4 percent of WPP1 VOC, and
acetic acid's contribution over the same three tests was measured to be 37, 20 and 13 percent of WPP1 VOC. For ponderosa pine, ethanol's contribution over one test was measured to be 32 percent of WPP1 VOC, and acetic acid's contribution over the same test was measured to be 6.4 percent. Without white
spruce lumber drying test data for ethanol and acetic acid, EPA assumes propane adequately represents the mix of unspeciated VOC.
Reference
Test data generated through the use of the smaller of the two small-scale kilns at Oregon State University (OSU) has been adjusted to account for bias documented in NCASI's May 2002 Technical Bulletin No. 845 entitled, "A Comparative Study of VOC Emissions from Small-Scale and Full-Scale Lumber Kilns Drying
Southern Pine." See last spreadsheet of this workbook for Stimson Lumber Company's October 18, 2019 letter to EPA Region 10 highlighting the bias.
Page 26 of 49
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Ethanol Acetic Acid Speciated Compounds
Temperature as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon
(°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)SUM (lb/mbf)
235 0.0193 0 0.0055 0.0001 0.0002 no data no data 0.0251
Element and Compound Information
Molecular Weight Number of Carbon Number of Hydrogen Number of Oxygen
(lb/lb-mol)Atoms Atoms Atoms
Methanol 0.72 32.042 CH40 1 4 1 1
Formaldehyde 0 30.0262 CH2O 1 2 1 16
Acetaldehyde 0.5 44.053 C2H4O 2 4 1 20
Propionaldehyde 0.66 58.0798 C3H6O 3 6 1 20
Acrolein 0.66 56.064 C3H4O 3 4 1 20
Ethanol 0.66 46.0688 C2H6O 2 6 1 1
Acetic Acid 0.575 60.0524 C2H4O2 2 4 2 1
Propane 1 44.0962 C3H8 3 8 0 16
Carbon -12.0110 C 1 ---
Hydrogen -1.0079 H -1 --
Oxygen -15.9994 O --1 -
Step Six: Subtract Speciated HAP and Non-HAP Compounds from Engelmann Spruce (White Spruce Substitution) VOC Emission Factors and Convert Result to "as Propane"
FROM STEP TWO FROM STEP FIVE Method 25A VOC Method 25A VOC
Maximum Dry Bulb Method 25A VOC Speciated Compounds as Carbon without as Propane without
Temperature as Carbon as Carbon Speciated Compounds Speciated Compounds
(°F)(lb/mbf)MINUS (lb/mbf)EQUALS (lb/mbf)(lb/mbf)
235 0.0915 0.0251 0.0664 X 1.2238 =0.0812
Method 25A VOC as propane without speciated compounds = (VOCC) X (1/RFC3H8) X [(MWC3H8) / (MWC)] X [(#CC) / (#CC3H8)]
where:VOCC represents Method 25A VOC as carbon without speciated compounds
RFC3H8 equals "1" and represents the FID RF for propane. All alkanes, including propane, have a RF of 1.
MWC3H8 equals "44.0962" and represents the molecular weight for propane; the compound that is the "basis" for expressing mass of VOC per WPP1 VOC
MWC equals "12.0110" and represents the molecular weight for carbon
#CC equals "1" as the single carbon atom was the "basis" for which Method 25A VOC test results were determined as illustrated in Step One of this spreadsheet
#CC3H8 equals "3" as three carbon atoms are present within propane; the compound that is the "basis" for expressing mass of VOC per WPP1 VOC
Note:The following portion from the equation immediately above, (1/RFC3H8) X [(MWC3H8) / (MWC)] X [(#CC) / (#CC3H8)], equals 1.2238 and can be referred to as the "propane mass conversion factor."
Step Seven: Calculate WPP1 VOC by Adding Speciated HAP and Non-HAP Compounds to Engelmann Spruce (White Spruce Substitution) VOC Emission Factors "as Propane"
WPP1 VOC = Method 25A VOC as propane without speciated compounds + ∑ speciated compounds expressed as the entire mass of compound
FROM STEP SIX
Method 25A VOC
as Propane without
Maximum Dry Bulb Speciated Compounds Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Ethanol Acetic Acid WPP1 VOC
Temperature (°F)(lb/mbf)PLUS (lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)PLUS (lb/mbf)(lb/mbf)EQUALS (lb/mbf)
235 0.0812 0.0715 0.0033 0.0201 0.0002 0.0005 no data no data 0.1769
FROM STEP FOURFROM STEP THREE
Element / Compound FID RF1 Formula Reference
1 FID RF = volumetric concentration or "instrument display" / compound's actual known concentration. Numerator and denominator expressed on same basis (ie. carbon, propane, etc) and concentration in units
of "ppm."
Propane
Mass
Conversion
Page 27 of 49
Hazardous Air Pollutant Emission Factors for Drying Larch Lumber
Larch (Douglas Fir Substitution) HAP Emission Factors
Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
0.00114x - 0.16090 0.000028x - 0.003800 0.0275 0.0003 0.0005
This sheet presents the HAP EF for drying larch lumber. EPA Region 10 is not aware of any HAP emission testing of larch.
Consistent with other species, when actual test data is not available, data for a similar species is substituted as noted.
When there are more than one similar species, the highest of the EF for the similar species is substituted.
In the absence of larch test data, douglas fir test data has been substituted. Larch is similar to douglas fir, engelmann
spruce, white spruce, lodgepole pine, ponderosa pine and western white pine in that all seven species are resinous
softwood species in the scientific classification order Pinaceae, but larch does not share a common genus with any of these
species. It appears to be most similar to douglas fir, engelmann spruce and white spruce in that the four species have small,
sparse resin canals as opposed to the large numerous resin canals of the pines. See
http://www.faculty.sfasu.edu/mcbroommatth/lectures/wood_science/lab_2_resin_canal_species.pdf. While the white spruce
EF for formaldehyde is greater than that of douglas fir at high drying temperatures, the opposite is true at low drying
temperatures. The douglas fir EF equation for formaldehyde is based upon seven tests while the white spurce EF equation
is based upon two. All other HAP EF are greater for douglas fir at all drying temperatures. Under the circumstances, EPA
Region 10 has decided to substitue the douglas fir formaldehyde EF equation. See the white spruce (appearing under
engelmann spruce tab) and douglas fir HAP sheets for lab-scale test data and calculations.
Page 28 of 49
Volatile Organic Compound Emission Factors for Drying Larch Lumber
Larch (Douglas Fir Substitution) WPP1 VOC Emission Factor
VOC (lb/mbf):0.01460x - 1.77130 ; where x is maximum drying temperature in °F
This sheet presents the VOC EF for drying larch lumber. EPA Region 10 is not aware of any VOC emission testing of larch. When actual test data is not
available, data for a similar species is substituted as noted. When there are more than one similar species, the highest of the EF for the similar species is
substituted.
In the absence of larch test data, douglas fir test data has been substituted. Larch is similar to douglas fir, engelmann spruce, white spruce, lodgepole pine,
ponderosa pine and western white pine in that all seven species are resinous softwood species in the scientific classification order Pinaceae, but larch does
not share a common genus with any of these species. It appears to be most similar to douglas fir, engelmann spruce and white spruce in that the four
species have small, sparse resin canals as opposed to the large numerous resin canals of the pines. See
http://www.faculty.sfasu.edu/mcbroommatth/lectures/wood_science/lab_2_resin_canal_species.pdf. Because the douglas fir EF is greater than that of white
spruce (and EPA Region 10 is not aware of any VOC test data for engelmann spruce), the douglas fir EF has been substituted. See the douglas fir VOC
sheet for lab-scale test data and calculations.
Page 29 of 49
Hazardous Air Pollutant Emission Factors for Drying Lodgepole Pine Lumber
Step One: Compile Lodgepole Pine HAP Emission Test Data by Drying Temperature1
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Lumber Moisture Content2 (%)Time to Final Moisture HAP Sample
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)Dimensions (Initial / Final)Content (hours)Collection Technique
195 0.073 no data 0.012 no data no data no data no data no data no data
195 0.092 no data no data no data no data no data no data no data no data
195 0.064 no data no data no data no data no data no data no data no data
195 0.028 no data no data no data no data no data no data no data no data
195 0.02 no data no data no data no data no data no data no data no data
≤ 200°F
236 0.063 0.0041 no data no data no data 2x4 59.1 / 15 16
237 0.062 0.0041 no data no data no data 2x4 59.7 / 15 16.6
238 0.056 0.0039 no data no data no data 2x4 56.9 / 15 16
2 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Two: Adjust Lodgepole Pine VOC Emission Test Data to Account for Bias in Underlying Small-Scale Kiln to Represent Full-Scale Kiln Emissions1
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
236 0.057 0.0030 no data no data no data
237 0.056 0.0030 no data no data no data
238 0.051 0.0029 no data no data no data
Adjusted OSU emission test data valuei = (OSU reported emission test data valuei) X (NCASI TB No. 845 study full-scale kiln valuei/NCASI TB No. 845 study OSU small-scale kiln valuei)
where:OSU reported emission test data valuei is the emission rate "lb/mbf" for compound "i" documented in Step One (not highlighted in green)
NCASI study full-scale kiln valuei is the average emission rate "lb/mbf" for compound "i" measured while drying southern yellow pine lumber in a full-scale indirect steam-heated batch lumber dry kiln
NCASI study OSU small-scale kiln valuei is the average emission rate "lb/mbf" for compound "i" measured while drying southern yellow pine lumber in OSU's small-scale indirect steam-heated batch lumber dry kiln
The lumber dried in the OSU kiln was (a) extracted from the pool of lumber dried in the full-scale kiln and (b) dried according the schedule employed by the full-scale kiln.
Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Full-Scale Kiln 0.205 0.0155 0.039 0.001 0.006
OSU Kiln 0.225 0.0210 0.065 0.003 0.009
Step Three: Calculate Lodgepole Pine HAP Emission Factors
Methanol Formaldehyde Acetaldehyde1 Propionaldehyde1 Acrolein1
(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
0.0550 0.0030 0.0104 0.0003 0.0008
NCASI TB No. 845 - Emission Rate (lb/mbf)
This sheet presents lab-scale test data and calculations used to create HAP EF for drying lodgepole pine lumber in an indirect steam-heated batch kiln. The EF are calculated by averaging test results. Lodgepole pine testing was performed while
drying lumber at a relatively high maximum temperature of around 237°F. Because emissions increase with maximum drying temperature, employing an EF based upon testing at 237°F would overreport emissions when drying at maximum drying
temperatures less than than 237°F.
1 Blue highlight denotes data not considered by EPA Region 10 in 2012. Five test runs considered by EPA Region 10 in 2007 are not considered here due to lack of documentation. The omitted test values are presented in Oregon Department of
Environmental Quality memorandum May 8, 2007 entitled, "Title III Implications of Drying Kiln Source Test Results." The memorandum lists "Forintec #1, #2 and #5" along with "OSU QA # 1 and #2 " as the test data sources.
Reference
14
no data
NCASI Method
IM/CAN/WP-99.01
without cannisters.
3, 4, 12, 14
Test data generated through the use of the smaller of the two small-scale kilns at Oregon State University (OSU) has been adjusted to account for bias documented in NCASI's May 2002 Technical Bulletin No. 845 entitled, "A Comparative Study of
VOC Emissions from Small-Scale and Full-Scale Lumber Kilns Drying Southern Pine." See last spreadsheet of this workbook for Stimson Lumber Company's October 18, 2019 letter to EPA Region 10 highlighting the bias.
Page 30 of 49
acetaldehyde lodgepole pine = (acetaldehyde ponderosa pine) * (VOC lodgepole pine) / (VOC ponderosa pine)
propionaldehyde lodgepole pine = (propionaldehyde ponderosa pine) * (VOC lodgepole pine) / (VOC ponderosa pine)
acrolein lodgepole pine = (acrolein ponderosa pine) * (VOC lodgepole pine) / (VOC ponderosa pine)
240 F
VOC
Lodgepole Pine 1.1352 0.0104 0.0003 0.0008
Ponderosa Pine 3.69891 0.0340 0.0010 0.0026
calculated values to estimate EF
1 Acetaldehyde, propionaldehyde and acrolein EF are not based upon lodgepole pine test data for those compounds. The EF are estimated using lodgepole pine VOC data and ponderosa pine VOC, acetaldehyde, propionaldehyde and acrolein test
data as follows:
Emission Factor (lb/mbf)
Acetaldehyde Propionaldehyde AcroleinSpecies
Page 31 of 49
Volatile Organic Compound Emission Factors for Drying Lodgepole Pine Lumber
Step One: Compile Lodgepole Pine RM25A VOC Emission Test Data by Drying Temperature
Maximum Dry Bulb Method 25A VOC Lumber Moisture Content1 (%)Time to Final Moisture Method 25A
Temperature (°F)as Carbon (lb/mbf)Dimensions (Initial/Final)Content (hours)Analyzer
236 1.17 2x4 59.1 / 15 16.01
238 0.87 2x4 56.9 / 15 16.01
240 1.19 2x4 64.9 / 15 16.81
1 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Two: Calculate Lodgepole Pine VOC Emission Factor1
Maximum Dry Bulb Method 25A VOC
Temperature (°F)as Carbon (lb/mbf)
238 1.0767
Step Three: Adjust Ponderosa Pine VOC Emission Test Data to Account for Bias in Underlying Small-Scale Kiln to Represent Full-Scale Kiln Emissions1
Maximum Dry Bulb Method 25A VOC
Temperature (°F)as Carbon (lb/mbf)
238 0.8951
Adjusted OSU emission test data value = (OSU reported emission test data value) X (NCASI TB No. 845 study full-scale kiln value/NCASI TB No. 845 study OSU small-scale kiln value)
where:OSU reported emission test data value is the RM25A VOC as carbon emission rate "lb/mbf" documented in Step One (not highlighted in green)
NCASI study full-scale kiln value is the average RM25A VOC as carbon emission rate "lb/mbf" measured while drying southern yellow pine lumber in a full-scale indirect steam-heated batch lumber dry kiln
NCASI study OSU small-scale kiln value is the average RM25A VOC as carbon emission rate "lb/mbf" measured while drying southern yellow pine lumber in OSU's small-scale indirect steam-heated batch lumber dry kiln
The lumber dried in the OSU kiln was (a) extracted from the pool of lumber dried in the full-scale kiln and (b) dried according the schedule employed by the full-scale kiln.
NCASI TB No. 845 - Emission Rate (lb/mbf)
RM25A VOC as carbon
Full-Scale Kiln 3.53333
OSU Kiln 4.25000
Step Four: Compile Lodgepole Pine Speciated HAP Emission Factors at Maximum Drying Temperatures Observed during RM25A VOC Testing1
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
238 0.0550 0.0030 no data no data no data
1 See lodgepole pine HAP sheet for lab-scale test data and calculations.
Step Five: Compile Lodgepole Pine Speciated Non-HAP Emission Factors at Maximum Drying Temperatures Observed during RM25A VOC Testing
Maximum Dry Bulb Ethanol Acetic Acid
Temperature (°F)(lb/mbf)(lb/mbf)
238 no data no data
Step Six: Convert Lodgepole Pine Speciated HAP Emission Factors to "as Carbon" and Total
Speciated Compound "X" expressed as carbon = (RFX) X (SCX) X [(MWC) / (MWX)] X [(#CX) / (#CC)]
where:RFX represents the flame ionization detector (FID) response factor (RF) for speciated compound "X"
SCX represents emissions of speciated compound "X" expressed as the entire mass of compound emitted
MWC equals "12.0110" representing the molecular weight (MW) for carbon as carbon is becoming the "basis" for expressing mass of speciated compound "X"
MWX represents the molecular weight for speciated compound "X"
#CX represents the number of carbon atoms in speciated compound "X"
#CC equals "1" as the single carbon atom is becoming the "basis" for expressing mass of speciated compound "X"
Reference
This sheet presents lab-scale EPA Reference Method 25A (RM25A) and speciated VOC test data and calculations used to create VOC EF for drying lodgepole pine lumber in an indirect steam-heated batch kiln. Although three RM25A VOC tests were performed while drying lodgepole pine, they were performed while drying
lumber at a relatively high maximum temperature of around 238°F. Because emissions increase with maximum drying temperature, employing an EF based upon testing at 238°F would overreport emissions when drying at maximum drying temperatures less than than 238°F.
RM25A has some limitations in that it misses some pollutant compounds (or portions thereof) that are VOC and known to exist and reports the results “as carbon” which only accounts for the carbon portion of each compound measured. The missed pollutant compounds (some HAP and some non-HAP) are accounted for
through separate testing. RM25A test data is adjusted to fully account for two known pollutant compounds that are VOC using separate speciated test data and is reported “as propane” to better represent all of the unspeciated VOC compounds. This technique is consistent with EPA’s Interim VOC Measurement Protocol for the
Wood Products Industry - July 2007 (WPP1 VOC).
Note that reporting the unspeciated VOC as propane (mass-to-carbon ratio of 1.22 and a response factor of 1) may underestimate the actual mass of VOC for certain wood species because VOC compounds like ethanol and acetic acid with higher mass-to-carbon ratios (1.92 and 2.5, respectively) and lower response factors
(0.66 and 0.575, respectively) can be a significant portion of the total VOC. Based upon the mass-to-carbon ratios and response factors noted above, 1 lb/mbf ethanol is reported as 0.4194 lb/mbf propane and 1 lb/mbf acetic acid is reported as 0.2806 lb/mbf propane through the use of EPA Reference Method 25A unless
compound-specific sampling and analysis is performed. The contribution of ethanol and acetic acid has been quantified through sampling and analysis for douglas fir and ponderosa pine. For douglas fir, ethanol's contribution over three tests was measured to be 0, 1.4 and 5.4 percent of WPP1 VOC, and acetic acid's
contribution over the same three tests was measured to be 37, 20 and 13 percent of WPP1 VOC. For ponderosa pine, ethanol's contribution over one test was measured to be 32 percent of WPP1 VOC, and acetic acid's contribution over the same test was measured to be 6.4 percent. Without reliable lodgepole pine lumber
drying test data for ethanol and acetic acid, EPA assumes propane adequately represents the mix of unspeciated VOC.
More specifically, one VOC emission rate is calculated based upon underlying RM25A and speciated VOC test data as indicated above. Temperature-specific methanol and formaldehyde emission rates are calculated for each temperature at which RM25A testing was performed using temperature-dependent best-fit linear
equations. The temperature variable reflects the maximum temperature of the heated air entering the lumber. EPA Region 10 is not aware of any further speciated VOC test data. That portion of the (speciated) VOC compounds that are measured by the RM25A test method (based on known flame ionization detector response
factors) is subtracted from the RM25A measured emission rate. The remaining “unspeciated” RM25A emission rate is adjusted to represent propane rather than carbon and then added to the speciated VOC emission rate to provide the “total” temperature-specific VOC emission rate.
Test data generated through the use of the smaller of the two small-scale kilns at Oregon State University (OSU) has been adjusted to account for bias documented in NCASI's May 2002 Technical Bulletin No. 845 entitled, "A Comparative Study of VOC Emissions from Small-Scale and Full-Scale Lumber Kilns Drying Southern
Pine." See last spreadsheet of this workbook for Stimson Lumber Company's October 18, 2019 letter to EPA Region 10 highlighting the bias.
1 Three-run average.
JUM 3-200 3, 4, 12
Page 32 of 49
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Ethanol Acetic Acid Speciated Compounds
Temperature as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon
(°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)SUM (lb/mbf)
238 0.0148 0 no data no data no data no data no data 0.0148
Element and Compound Information
Molecular Weight Number of Carbon Number of Hydrogen
(lb/lb-mol)Atoms Atoms Atoms
Methanol 0.72 32.042 CH40 1 4 1 1
Formaldehyde 0 30.0262 CH2O 1 2 1 16
Acetaldehyde 0.5 44.053 C2H4O 2 4 1 20
Propionaldehyde 0.66 58.0798 C3H6O 3 6 1 20
Acrolein 0.66 56.064 C3H4O 3 4 1 20
Ethanol 0.66 46.0688 C2H6O 2 6 1 1
Acetic Acid 0.575 60.0524 C2H4O2 2 4 2 1
Propane 1 44.0962 C3H8 3 8 0 16
Carbon -12.0110 C 1 ---
Hydrogen -1.0079 H -1 --
Oxygen -15.9994 O --1 -
Step Seven: Subtract Speciated HAP and Non-HAP Compounds from Lodgepole Pine VOC Emission Factors and Convert Result to "as Propane"
FROM STEP THREE FROM STEP SIX Method 25A VOC Method 25A VOC
Maximum Dry Bulb Method 25A VOC Speciated Compounds as Carbon without as Propane without
Temperature as Carbon as Carbon Speciated Compounds Speciated Compounds
(°F)(lb/mbf)MINUS (lb/mbf)EQUALS (lb/mbf)X 1.2238 =(lb/mbf)
238 0.8951 0.0148 0.8803 1.0773
Method 25A VOC as propane without speciated compounds = (VOCC) X (1/RFC3H8) X [(MWC3H8) / (MWC)] X [(#CC) / (#CC3H8)]
where:VOCC represents Method 25A VOC as carbon without speciated compounds
RFC3H8 equals "1" and represents the FID RF for propane. All alkanes, including propane, have a RF of 1.
MWC3H8 equals "44.0962" and represents the molecular weight for propane; the compound that is the "basis" for expressing mass of VOC per WPP1 VOC
MWC equals "12.0110" and represents the molecular weight for carbon
#CC equals "1" as the single carbon atom was the "basis" for which Method 25A VOC test results were determined as illustrated in Step One of this spreadsheet
#CC3H8 equals "3" as three carbon atoms are present within propane; the compound that is the "basis" for expressing mass of VOC per WPP1 VOC
Note:The following portion from the equation immediately above, (1/RFC3H8) X [(MWC3H8) / (MWC)] X [(#CC) / (#CC3H8)], equals 1.2238 and can be referred to as the "propane mass conversion factor."
Step Eight: Calculate WPP1 VOC by Adding Speciated HAP and Non-HAP Compounds to Lodgepole Pine VOC Emission Factors "as Propane"
WPP1 VOC = Method 25A VOC as propane without speciated compounds + ∑ speciated compounds expressed as the entire mass of compound
FROM STEP SEVEN
Method 25A VOC
as Propane without
Maximum Dry Bulb Speciated Compounds Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Ethanol Acetic Acid WPP1 VOC
Temperature (°F)(lb/mbf)PLUS (lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)PLUS (lb/mbf)(lb/mbf)EQUALS (lb/mbf)
238 1.0773 0.0550 0.0030 no data no data no data no data no data 1.1352
FROM STEP FIVEFROM STEP FOUR
Element / Compound FID RF1 Formula Reference
1 FID RF = volumetric concentration or "instrument display" / compound's actual known concentration. Numerator and denominator expressed on same basis (ie. carbon, propane, etc) and concentration in
units of "ppm."
Propane
Mass
Conversion
Factor
Page 33 of 49
The Problem: Missing Data for Lodgepole Pine Acetaldehyde, Propionaldehyde and Acrolein EF
WPP1 VOC Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
lb/mbf (lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
Resinous Softwood Species (Pine Famiy)
Lodgepole
Pine 1.1352037 0.0550 0.0030 no data no data no data
Ponderosa
Pine
0.02083x -
1.30029 0.00137x - 0.18979 0.000074x - 0.010457 0.0340 0.0010 0.0026
LP - Lodgepole Pine PP - Ponderosa Pine
Compounds Whose Emission Factors are Known for WTF
Acetaldehyde: CH3CHO Methanol: CH3OH Formaldehyde: CH2O
Aldehyde Alcohol Aldehyde
MW: 44 g/g-mol MW: 32 g/g-mol MW: 30 g/g-mol
Boiling point: 70F @ 760 mmhg Boiler point: 149F @ 760 mmhg Boiler point: -6F @ 760 mmhg
Vapor pressure: 760 mmHg @ 68F Vapor pressure: 92 mmhg @ 68F Vapor pressure: 3,890 mmhg @ 77F
Compounds Whose Emission Factors are Unknown for WTF
Propionaldehyde: CH3CH2CHO Acrolein: C3H4O
Aldehyde Unsaturated aldehyde
MW: 58 g/g-mol MW: 56 g/g-mol
Boiling point: 120F @ 760mmhg Boiling Point: 126F @ 760 mmhg
Vapor pressure: 235 mmhg @ 68F Vapor pressure: 210 mmhg @ 68F
Acetaldehyde Fraction of Default Propionaldehyde Fraction of Default Acrolein Fraction of Default
0.034 N/A 0.001 N/A 0.0026 N/A
Option A: Use formaldehyde (240F) as a basis 0.0139 0.41 0.0004 0.39 0.0011 0.41
Option B: Use methanol (240F) as a basis 0.0134 0.40 0.0004 0.38 0.0010 0.40
Option C: Use VOC (240F) as a basis 0.0104 0.31 0.0003 0.29 0.0008 0.31
Option A: Use formaldehyde (240F) as a basis
Acetaldehyde LP = (Acetaldehyde PP) * (Formaldehyde 240F LP) / (Formaldehyde 240F PP)
Propionaldehyde LP = (Propionaldehyde PP) * (Formaldehyde 240F LP) / (Formaldehyde 240F PP)
Acrolein LP = (Acrolein PP) * (Formaldehyde 240F LP) / (Formaldehyde 240F PP)
240 F
Formaldehyde
Lodgepole Pine 0.0030 0.0139 0.0004 0.0011
Ponderosa Pine 0.007303 0.0340 0.0010 0.0026
Option B: Use methanol (240F) as a basis
Acetaldehyde LP = (Acetaldehyde PP) * (Methanol 240F LP) / (Methanol 240F PP)
Propionaldehyde LP = (Propionaldehyde PP) * (Methanol 240F LP) / (Methanol 240F PP)
Acrolein LP = (Acrolein PP) * (Methanol 240F LP) / (Methanol 240F PP)
240 F
Methanol
Lodgepole Pine 0.0550 0.0134 0.0004 0.0010
Ponderosa Pine 0.13901 0.0340 0.0010 0.0026
Option C: Use VOC (240F) as a basis
Acetaldehyde LP = (Acetaldehyde PP) * (VOC 240F LP) / (VOC 240F PP)
Propionaldehyde LP = (Propionaldehyde PP) * (VOC 240F LP) / (VOC 240F PP)
Acrolein LP = (Acrolein PP) * (VOC 240F LP) / (VOC 240F PP)
240 F
VOC
Lodgepole Pine 1.1352 0.0104 0.0003 0.0008
Ponderosa Pine 3.69891 0.0340 0.0010 0.0026
Click on cell for calculation
Acetaldehyde Propionaldehyde Acrolein
Species
Option LODGEPOLE PINE SUBSTITUTE EMISSION FACTOR (lb/mbf)
Default option: PP EF become LP EF
EMISSION FACTOR (lb/mbf)
Acetaldehyde Propionaldehyde Acrolein
EMISSION FACTOR (lb/mbf)
Acetaldehyde Propionaldehyde Acrolein
EMISSION FACTOR (lb/mbf)
Hazardous Air Pollutant Emission Factors for Drying Ponderosa Pine Lumber
Step One: Compile Ponderosa Pine HAP Emission Test Data by Drying Temperature
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Lumber Moisture Content1 (%)Time to Final Moisture HAP Sample
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)Dimensions (Initial / Final)Content (hours)Collection Technique
170 0.035 0.0027 0.042 0.0019 0.0017 2x4 82.6 / 15 42 NCASI Method 105 17, 18
176 0.05 0.0022 no data no data no data 2x10 & 2x12 107.1 / 12 55
176 0.08 0.0036 no data no data no data 2x10 & 2x12 124.1 / 12 57
180 0.058 0.005 0.100 0.0035 0.0055 2x4 103.9 / 15 39.4 NCASI Method 105
Link to March 7,
2013 Hampton
Affiliates - Randle
Test Report
235 0.144 0.0092 0.028 0.0032 0.0045 2x4 or 2x6 89.1 / 15 19 NCASI Method 105 18, 21
1 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Two: Adjust Ponderosa Pine HAP Emission Test Data to Account for Bias in Underlying Small-Scale Kiln to Represent Full-Scale Kiln Emissions
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
170 0.032 0.0020 0.025 0.0006 0.0011
176 0.046 0.0016 no data no data no data
176 0.073 0.0027 no data no data no data
180 0.053 0.0037 0.060 0.0012 0.0037
235 0.131 0.0068 0.017 0.0011 0.0030
Adjusted OSU emission test data valuei = (OSU reported emission test data valuei) X (NCASI TB No. 845 study full-scale kiln valuei/NCASI TB No. 845 study OSU small-scale kiln valuei)
where:OSU reported emission test data valuei is the emission rate "lb/mbf" for compound "i" documented in Step One (not highlighted in green)
NCASI study full-scale kiln valuei is the average emission rate "lb/mbf" for compound "i" measured while drying southern yellow pine lumber in a full-scale indirect steam-heated batch lumber dry kiln
NCASI study OSU small-scale kiln valuei is the average emission rate "lb/mbf" for compound "i" measured while drying southern yellow pine lumber in OSU's small-scale indirect steam-heated batch lumber dry kiln
The lumber dried in the OSU kiln was (a) extracted from the pool of lumber dried in the full-scale kiln and (b) dried according the schedule employed by the full-scale kiln.
Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
Full-Scale Kiln 0.205 0.0155 0.039 0.001 0.006
OSU Kiln 0.225 0.0210 0.065 0.003 0.009
Step Three: Calculate Ponderosa Pine HAP Emission Factors
Methanol1 Formaldehyde1 Acetaldehyde2 Propionaldehyde2 Acrolein2
(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
0.00137x - 0.18979 0.000074x - 0.010457 0.0340 0.0010 0.0026
1 Best-fit linear equations with dependent variable maximum drying temperature entering the lumber
This sheet presents lab-scale test data and calculations used to create HAP EF for drying ponderosa pine lumber in an indirect steam-heated batch kiln. The methanol and formaldehyde EF are temperature dependent best-fit linear equations.
The temperature variable reflects the maximum temperature of the heated air entering the lumber. The acetaldehyde, propionaldehyde and acrolein EF are calculated by averaging test results.
NCASI Method
IM/CAN/WP-99.01
without cannisters
Reference
3, 4, 12, 14
2 Because acetaldehyde, propionaldehyde and acrolein emissions across different species are not consistently dependent upon maximum drying temperature, EF are calculated by averaging test results.
Test data generated through the use of the smaller of the two small-scale kilns at Oregon State University (OSU) has been adjusted to account for bias documented in NCASI's May 2002 Technical Bulletin No. 845 entitled, "A Comparative Study
of VOC Emissions from Small-Scale and Full-Scale Lumber Kilns Drying Southern Pine." See last spreadsheet of this workbook for Stimson Lumber Company's October 18, 2019 letter to EPA Region 10 highlighting the bias.
NCASI TB No. 845 - Emission Rate (lb/mbf)
Page 35 of 49
y = 0.00137x -0.18979
R² = 0.89409
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
160 180 200 220 240
Me
t
h
a
n
o
l

(
l
b
/
m
b
f
)
Dry Bulb Temperatures (°F)
y = 0.000074x -0.010457R² = 0.907176
0.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
160 180 200 220 240
Fo
r
m
a
l
d
e
h
y
d
e

(
l
b
/
m
b
f
)
Dry Bulb Temperatures (°F)
Page 36 of 49
Volatile Organic Compound Emission Factors for Drying Ponderosa Pine Lumber
Step One: Compile Ponderosa Pine RM25A VOC Emission Test Data by Drying Temperature1
Maximum Dry Bulb Method 25A VOC Lumber Moisture Content2 (%)Time to Final Moisture Method 25A
Temperature (°F)as Carbon (lb/mbf)Dimensions (Initial/Final)Content (hours)Analyzer
170 1.59 2x4 82.6 / 15 42 JUM VE-7 17, 18
170 1.795 1x4 112.8 / 15 29
170 1.925 1x4 88.7 / 15 28
176 1.29 2x10 & 2x12 107.1 / 12 55
176 1.54 2x10 & 2x12 124.1 / 12 57
176 1.40 2x10 & 2x12 114.8 / 12 58.5
176 1.30 2x10 & 2x12 93.0 / 12 57.1
180 1.48 2x4 103.9 / 15 39.4
180 1.72 2x4 122.0 / 15 43.6
235 3.00 2x4 or 2x6 89.1 / 15 19 JUM VE-7 18, 21
2 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Two: Adjust Ponderosa Pine VOC Emission Test Data to Account for Bias in Underlying Small-Scale Kiln to Represent Full-Scale Kiln Emissions
Maximum Dry Bulb Method 25A VOC
Temperature (°F)as Carbon (lb/mbf)
170 1.32
170 1.795
170 1.925
176 1.07
176 1.28
176 1.16
176 1.08
180 1.23
180 1.43
235 2.49
1 Green highlighted results from the test conducted at the University of Idaho have not been adjusted because the kiln was not calibrated to a full-scale kiln.
Adjusted OSU emission test data value = (OSU reported emission test data value) X (NCASI TB No. 845 study full-scale kiln value/NCASI TB No. 845 study OSU small-scale kiln value)
where:OSU reported emission test data value is the RM25A VOC as carbon emission rate "lb/mbf" documented in Step One (not highlighted in green)
NCASI study full-scale kiln value is the average RM25A VOC as carbon emission rate "lb/mbf" measured while drying southern yellow pine lumber in a full-scale indirect steam-heated batch lumber dry kiln
NCASI study OSU small-scale kiln value is the average RM25A VOC as carbon emission rate "lb/mbf" measured while drying southern yellow pine lumber in OSU's small-scale indirect steam-heated batch lumber dry kiln
The lumber dried in the OSU kiln was (a) extracted from the pool of lumber dried in the full-scale kiln and (b) dried according the schedule employed by the full-scale kiln.
NCASI TB No. 845 - Emission Rate (lb/mbf)
RM25A VOC as carbon
Full-Scale Kiln 3.53333
OSU Kiln 4.25000
Step Three: Calculate/Compile Ponderosa Pine Speciated HAP Emission Factors at Maximum Drying Temperatures Observed during RM25A VOC Testing1
Maximum Dry Bulb Methanol2 Formaldehyde3 Acetaldehyde Propionaldehyde Acrolein
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
170 0.0431 0.0021
176 0.0513 0.0026
180 0.0568 0.0029
235 0.1322 0.0069
1 See ponderosa pine HAP sheet for lab-scale test data and calculations.
JUM VE-7
Link to March 7, 2013
Hampton Affiliates -
Randle Test Report
0.0340
This sheet presents lab-scale EPA Reference Method 25A (RM25A) and speciated VOC test data and calculations used to create VOC EF for drying ponderosa pine lumber in an indirect steam-heated batch kiln. RM25A has some limitations in that it misses some pollutant compounds (or portions thereof) that are
VOC and known to exist and reports the results “as carbon” which only accounts for the carbon portion of each compound measured. The missed pollutant compounds (some HAP and some non-HAP) are accounted for through separate testing. RM25A test data is adjusted to fully account for seven known
pollutant compounds that are VOC using separate speciated test data and is reported “as propane” to better represent all of the unspeciated VOC compounds. This technique is consistent with EPA’s Interim VOC Measurement Protocol for the Wood Products Industry - July 2007 (WPP1 VOC) except that the
RM25A results are adjusted to account for not only methanol and formaldehyde but also for acetaldehyde, propionaldehyde, acrolein, ethanol and acetic acid in this case.
More specifically, ten separate drying-temperature-specific VOC emission rates (upon which a best-fit linear equation will be established) are calculated based upon underlying RM25A and speciated VOC test data as indicated above. Temperature-specific methanol and formaldehyde emission rates are calculated
for each temperature at which RM25A testing was performed using temperature-dependent best-fit linear equations. The temperature variable reflects the maximum temperature of the heated air entering the lumber. The temperature-independent acetaldehyde, propionaldehyde and acrolein emission rates reflect
the average of all test results independent of the temperature of heated air entering the lumber. The ethanol and acetic acid emission rates reflect the results of a single test. EPA Region 10 is not aware of any further speciated VOC test data. That portion of the (speciated) VOC compounds that are measured by
the RM25A test method (based on known flame ionization detector response factors) is subtracted from the RM25A measured emission rate. The remaining “unspeciated” RM25A emission rate is adjusted to represent propane rather than carbon and then added to the speciated VOC emission rate to provide the
“total” temperature-specific VOC emission rate. The resultant VOC EF is a 10-point best-fit linear equation with dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
0.0010 0.0026
JUM 3-200
JUM 3-200
Reference
2
3, 4, 12
3, 4
JUM VE-7
Test data generated through the use of the smaller of the two small-scale kilns at Oregon State University (OSU) has been adjusted to account for bias documented in NCASI's May 2002 Technical Bulletin No. 845 entitled, "A Comparative Study of VOC Emissions from Small-Scale and Full-Scale Lumber Kilns
Drying Southern Pine." See last spreadsheet of this workbook for Stimson Lumber Company's October 18, 2019 letter to EPA Region 10 highlighting the bias.
1 Green highlight denotes data generated by testing conducted on the small-scale kiln at the University of Idaho. All other data was generated by testing conducted on the smaller of the
two small-scale kilns at OSU.
Page 37 of 49
2 Methanol EF = 0.00137x - 0.18979; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
3 Formaldehyde EF = 0.000074x - 0.010457; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber.
Step Four: Compile Ponderosa Pine Speciated Non-HAP Emission Test Data by Drying Temperature
Maximum Dry Bulb Ethanol Acetic Acid Lumber Moisture Content1 (%)Time to Final Moisture VOC Sample
Temperature (°F)(lb/mbf)(lb/mbf)Dimensions (Initial / Final)Content (hours)Collection Technique
180 0.826 0.162 2x4 103.9 / 15 39.4 NCASI Method 105
Link to March 7, 2013
Hampton Affiliates -
Randle Test Report
1 Dry basis. Moisture content = (weight of water / weight wood) x 100
Step Five: Calculate Ponderosa Pine Speciated Non-HAP Emission Factors
Ethanol Acetic Acid
(lb/mbf)(lb/mbf)
0.826 0.162
Step Six: Calculate/Compile Ponderosa Pine Speciated Non-HAP Emission Factors at Maximum Drying Temperatures Observed during RM25A Testing
Maximum Dry Bulb Ethanol Acetic Acid
Temperature (°F)(lb/mbf)(lb/mbf)
170
176
180
235
Step Seven: Convert Ponderosa Pine Speciated HAP and Non-HAP Emission Factors to "as Carbon" and Total
Speciated Compound "X" expressed as carbon = (RFX) X (SCX) X [(MWC) / (MWX)] X [(#CX) / (#CC)]
where:RFX represents the flame ionization detector (FID) response factor (RF) for speciated compound "X"
SCX represents emissions of speciated compound "X" expressed as the entire mass of compound emitted
MWC equals "12.0110" representing the molecular weight (MW) for carbon as carbon is becoming the "basis" for expressing mass of speciated compound "X"
MWX represents the molecular weight for speciated compound "X"
#CX represents the number of carbon atoms in speciated compound "X"
#CC equals "1" as the single carbon atom is becoming the "basis" for expressing mass of speciated compound "X"
Maximum Dry Bulb Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Ethanol Acetic Acid Speciated Compounds
Temperature as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon as Carbon
(°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
170 0.0116 0 0.3461
176 0.0139 0 0.3487
180 0.0153 0 SUM 0.3505
235 0.0357 0 0.3749
Element and Compound Information
Molecular Weight Number of Carbon Number of Hydrogen Number of Oxygen
(lb/lb-mol)Atoms Atoms Atoms
Methanol 0.72 32.042 CH40 1 4 1 1
Formaldehyde 0 30.0262 CH2O 1 2 1 16
Acetaldehyde 0.5 44.053 C2H4O 2 4 1 20
Propionaldehyde 0.66 58.0798 C3H6O 3 6 1 20
Acrolein 0.66 56.064 C3H4O 3 4 1 20
Ethanol 0.66 46.0688 C2H6O 2 6 1 1
Acetic Acid 0.575 60.0524 C2H4O2 2 4 2 1
Propane 1 44.0962 C3H8 3 8 0 16
Carbon -12.0110 C 1 ---
Hydrogen -1.0079 H -1 --
Oxygen -15.9994 O --1 -

Step Eight: Subtract Speciated HAP and Non-HAP Compounds from Ponderosa Pine VOC Emission Factors and Convert Result to "as Propane"
FROM STEP TWO FROM STEP SEVEN Method 25A VOC Method 25A VOC
Maximum Dry Bulb Method 25A VOC Speciated Compounds as Carbon without as Propane without
Temperature as Carbon as Carbon Speciated Compounds Speciated Compounds
(°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
170 1.3219 0.3461 0.9758 1.1942
170 1.7950 0.3461 1.4489 1.7732
0.1620.826
0.0093 0.0004
1 FID RF = volumetric concentration or "instrument display" / compound's actual known concentration. Numerator and denominator expressed on same basis (ie. carbon, propane, etc) and concentration in units
of "ppm."
Element / Compound FID RF1 Formula Reference
Reference
0.2843 0.03730.0011
Page 38 of 49
170 1.9250 0.3461 1.5789 1.9323
176 1.0725 0.3487 0.7238 0.8857
176 1.2803 0.3487 0.9316 1.1401
176 1.1639 0.3487 0.8152 0.9976
176 1.0808 0.3487 0.7321 0.8959
180 1.2304 0.3505 0.8799 1.0769
180 1.4300 MINUS 0.3505 EQUALS 1.0795 1.3210
235 2.4941 0.3749 2.1192 X 1.2238 =2.5934
Method 25A VOC as propane without speciated compounds = (VOCC) X (1/RFC3H8) X [(MWC3H8) / (MWC)] X [(#CC) / (#CC3H8)]
where:VOCC represents Method 25A VOC as carbon without speciated compounds
RFC3H8 equals "1" and represents the FID RF for propane. All alkanes, including propane, have a RF of 1.
MWC3H8 equals "44.0962" and represents the molecular weight for propane; the compound that is the "basis" for expressing mass of VOC per WPP1 VOC
MWC equals "12.0110" and represents the molecular weight for carbon
#CC equals "1" as the single carbon atom was the "basis" for which Method 25A VOC test results were determined as illustrated in Step One of this spreadsheet
#CC3H8 equals "3" as three carbon atoms are present within propane; the compound that is the "basis" for expressing mass of VOC per WPP1 VOC
Note:The following portion from the equation immediately above, (1/RFC3H8) X [(MWC3H8) / (MWC)] X [(#CC) / (#CC3H8)], equals 1.2238 and can be referred to as the "propane mass conversion factor."
Step Nine: Calculate WPP1 VOC by Adding Speciated HAP and Non-HAP Compounds to Ponderosa Pine VOC Emission Factors "as Propane"
WPP1 VOC = Method 25A VOC as propane without speciated compounds + ∑ speciated compounds expressed as the entire mass of compound
FROM STEP EIGHT
Method 25A VOC
as Propane without
Maximum Dry Bulb Speciated Compounds Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein Ethanol Acetic Acid WPP1 VOC
Temperature (°F)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
170 1.1942 0.0431 0.0021 2.2650
170 1.7732 0.0431 0.0021 2.8440
170 1.9323 0.0431 0.0021 3.0031
176 0.8857 0.0513 0.0026 1.9652
176 1.1401 0.0513 0.0026 2.2195
176 0.9976 0.0513 0.0026 2.0771
176 0.8959 0.0513 0.0026 1.9753
180 1.0769 0.0568 0.0029 2.1621
180 1.3210 PLUS 0.0568 0.0029 PLUS EQUALS 2.4063
235 2.5934 0.1322 0.0069 3.7581
Step Ten: Generate Ponderosa Pine Best-Fit Linear Equation with Dependent Variable Maximum Drying Temperature to Model WPP1 VOC Emissions
WPP1 VOC (lb/mbf):0.02083x - 1.30029 ; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumber
0.826 0.1620.00100.0340 0.0026
FROM STEP SIXFROM STEP THREE
Propane
Mass
Conversion
Factor
y = 0.02083x -1.30029
R² = 0.49876
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
160 180 200 220 240
WP
P
1

V
O
C

(
l
b
/
m
b
f
)
Dry Bulb Temperatures (°F)
Page 39 of 49
Hazardous Air Pollutant Emission Factors for Drying Western White Pine Lumber
Western White Pine (Ponderosa Pine Substitution) HAP Emission Factors
Methanol Formaldehyde Acetaldehyde Propionaldehyde Acrolein
(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)(lb/mbf)
0.00137x - 0.18979 0.000074x - 0.010457 0.0340 0.0010 0.0026
This sheet presents the HAP EF for drying western white pine lumber. EPA Region 10 is not aware of any HAP emission testing of western white pine. When
actual test data is not available, data for a similar species is substituted as noted. When there are more than one similar species, the highest of the EF for the
similar species is substituted.
Given the limited western white pine test data, ponderosa pine test data has been substituted. Western white pine is similar to ponderosa pine and lodgepole
pine in that all three species are resinous softwood species in the scientific classification genus Pinus. EPA Region 10 is aware of three Lodgepole Pine test runs
for methanol and formaldehyde and none for acetaldehyde, propionaldehyde and acrolein. Five ponderosa pine test runs were conducted for methanol and
formaldehyde and three for acetaldehyde, propionaldehyde and acrolein. While the lodgepole pine runs were conducted at about the same maximum drying
temperature, the ponderosa pine runs were distributed across a wide maximum drying temperature range. Based upon the available test data, ponderosa pine is
higher-emitting than lodgepole pine for methanol and formaldehyde. See the ponderosa pine and lodgepole pine HAP sheets for lab-scale test data and
calculations.
Page 40 of 49
Volatile Organic Compound Emission Factors for Drying Western White Pine Lumber
Western White Pine (Ponderosa Pine Substitution) VOC Emission Factor
WPP1 VOC (lb/mbf):0.02083x - 1.30029 ; where dependent variable "x" equal to the maximum drying temperature of heated air entering the lumb
This sheet presents the VOC EF for drying western white pine lumber. EPA Region 10 is aware of one test being conducted while drying western white
pine lumber, and it was conducted at 170°F. Because VOC emissions increase with maximum drying temperature, employing an EF based upon testing at
170°F would underreport emissions when drying at maximum drying temperatures greater than 170°F. A temperature of 170°F is not a particularly high
drying temperature. When little or no actual test data is available, data for a similar species is substituted as noted. When there are more than one similar
species, the highest of the EF for the similar species is substituted.
Given the limited western white pine test data, ponderosa pine test data has been substituted. Western white pine is similar to ponderosa pine and
lodgepole pine in that all three species are resinous softwood species in the scientific classification genus Pinus. EPA Region 10 is aware of three
lodgepole pine test runs and eight ponderosa pine test runs. While the lodgepole pine runs were conducted at about the same maximum drying
temperature, the ponderosa pine runs were distributed across a wide maximum drying temperature range. Based upon the available test data, ponderosa
pine is higher-emitting than lodgepole pine. See the ponderosa pine and lodgepole pine HAP and VOC sheets for lab-scale test data and calculations.
Page 41 of 49
Index to References Appearing in
EPA Region 10 HAP and VOC Emission Factors for Lumber Drying, June 2018
Reference No.1
(Undated) J.U.M. Flame Ionization Detector Response Factor Technical Information presented at http://www.jum-aerosol.com/images/E-Fakt-02.pdf
Notes
Methanol response factor (RF) of 0.72 equals average of three response factors 0.69, 0.68 and 0.79 for J.U.M. models 3-200 and VE-7. These two
models were exclusively employed to determine Method 25A VOC in the testing EPA Region 10 is relying upon to support VOC emission factor
derivation.
An alternative RF of 0.65 from Appendix 3 to EPA’s Interim VOC Measurement Protocol for the Wood Products Industry -July 2007 at
http://www.epa.gov/ttn/emc/prelim/otm26.pdf could have been employed instead.
Employing RF of 0.72 (as opposed to 0.65) generates lower VOC emission factors (EF). A higher RF means that the EPA Method 25A flame ionization
detector (FID) measures more of the compound. With the methanol EF having already been determined through speciated sampling and analysis,
assuming the FID measures a greater portion of the methanol leaves less of the Method 25A measurement to be accounted for as unspeciated VOC.
Reference No. 2
National Council of the Paper Industry for Air and Stream Improvement, Inc. Technical Bulletin No. 718. July 1, 1996. A Small-Scale Kiln Study on Method
25A Measurements of Volatile Organic Compound Emissions from Lumber Drying.
Notes
To convert Method 25A VOC from “lb C/ODT” to “lb C/mbf,” the following calculations were performed:
White Fir –Runs 15 and 16.
(0.85 lb/ODT) X (0.57 lb/mbf) / (0.77 lb/ODT) = 0.63 lb/mbf
(0.68 lb/ODT) X (0.57 lb/mbf) / (0.77 lb/ODT) = 0.50 lb/mbf
See pages 14 and 15 of the reference document.
Western Red Cedar –Runs 10 and 11.
(0.12 lb/ODT) X (0.12 lb/mbf) / (0.15 lb/ODT) = 0.096 lb/mbf
(0.17 lb/ODT) X (0.12 lb/mbf) / (0.15 lb/ODT) = 0.136 lb/mbf
See pages 14 and 15 of the reference document.
Douglas fir –Runs 1 and 3.
(1.00 lb/ODT) X (0.81 lb/mbf) / (0.86 lb/ODT) = 0.942
(0.71 lb/ODT) X (0.81 lb/mbf) / (0.86 lb/ODT) = 0.669
See pages 12 and 15 of the reference document.
Ponderosa Pine –Runs 5 and 6.
(1.92 lb/ODT) X (1.86 lb/mbf) / ( 1.99 lb/ODT) = 1.795 lb/mbf
(2.06 lb/ODT) X (1.86 lb/mbf) / (1.99 lb/ODT) = 1.925 lb/mbf
See pages 14 and 15 of the reference document.
Page 42 of 49
The moisture content of wood was originally reported on a wet basis. It has been corrected to be on a dry basis using the following equation:
(moisture content on dry basis) = (moisture content on wet basis) / [1 –(moisture content on wet basis)]
Reference No. 3
Small-scale Kiln Study Utilizing Ponderosa Pine, Lodgepole Pine, White Fir, and Douglas-fir. Report by Michael R. Milota to Intermountain Forest
Association. September 29, 2000.
Reference No. 4
Milota, Michael. VOC and HAP Emissions from Western Species. Western Dry Kiln Association: May 2001, p. 62-68.
Reference No. 5
Milota, M.R. 2003. HAP and VOC Emissions from White Fir Lumber Dried at High and Conventional Temperatures. Forest Prod. J. 53(3):60-64.
Reference No. 6
VOC and HAP Emissions from the High Temperature Drying of Hemlock Lumber. Report by Michael R. Milota to Hampton Affiliates. June 21, 2004.
Reference No. 7
Fritz, Brad. 2004. Pilot-and Full-Scale Measurements of VOC Emissions from Lumber Drying of Inland Northwest Species. Forest Prod. J. 54(7/8):50-56.
Notes
To convert acetaldehyde from "µg/min-bf" to “lb/mbf,” the following calculations were performed:
White fir.
0.0550 lb/mbf = (7.7 µg/min-bf) X (60 min/hr) X (54 hr) X (kg/1x109g) X (2.205 lb/kg) X (1,000 bf/mbf).
See page 54 of the reference document.
Douglas fir.
0.030 lb/mbf = (4.9 µg/min-bf) X (60 min/hr) X (46 hr) X (kg/1x109g) X (2.205 lb/kg) X (1,000 bf/mbf).
0.022 lb/mbf = (3.6 µg/min-bf) X (60 min/hr) X (46 hr) X (kg/1x109g) X (2.205 lb/kg) X (1,000 bf/mbf).
See page 53 of the reference document.
Reference No. 8
VOC and Methanol Emissions from the Drying of Hemlock Lumber. Report by Michael R. Milota to Hampton Affiliates. August 24, 2004.
Reference No. 9
VOC, Methanol, and Formaldehyde Emissions from the Drying of Hemlock Lumber. Report by Michael R. Milota to Hampton Affiliates. October 15, 2004.
Reference No. 10
VOC Emissions from the Drying of Douglas-fir Lumber. Report by Michael R. Milota to Columbia Vista Corporation. June 14, 2005.
Reference No. 11
Milota, M.R. and P. Mosher. 2006. Emissions from Western Hemlock Lumber During Drying. Forest Prod. J. 56(5):66-70.
Reference No. 12
Milota, M.R. 2006. Hazardous Air Pollutant Emissions from Lumber Drying. Forest Prod. J. 56(7/8):79-84.
Page 43 of 49

Reference No.13
VOC, Methanol, and Formaldehyde Emissions from the Drying of Hemlock, ESLP, and Douglas Fir Lumber. Report by Michael R. Milota to Hampton
Affiliates. March 23, 2007.
Reference No. 14
Oregon Department of Environmental Quality memorandum May 8, 2007 entitled, "Title III Implications of Drying Kiln Source Test Results."
Notes
The reference document presents a compilation of EF.
Reference No. 15
HAP Emissions from the Drying of Hemlock and Douglas-fir Lumber by NCASI 98.01 and 105. Report by Michael R. Milota to Hampton Affiliates. May 22,
2007 report.
Reference No. 16
EPA Interim VOC Measurement Protocol for the Wood Products Industry -July 2007 presented at http://www.epa.gov/ttn/emc/prelim/otm26.pdf
Notes
VOC determined through use of this document is referred to as WPP1 VOC. The document is alternatively known as EPA Other Test Method 26 or
“OTM26.”
Default formaldehyde RF of 0 and propane (an alkane) RF of 1 appear in Appendix 3 –Procedure for Response Factor Determination for the Interim VOC
Measurement Protocol for the Wood Products Industry.
Reference No.17
HAP Emissions by NCASI 98.01 and 105 from Drying of Ponderosa Pine and White Wood Lumber. Report by Michael R. Milota to Hampton Affiliates.
July 25, 2007.
Reference No.18
Milota, M.R. and P. Mosher. 2008. Emission of Hazardous Air Pollutants from Lumber Drying. Forest Prod. J. 58(7/8):50-55.
Reference No. 19
VOC Emissions From the Drying of Douglas-fir Lumber. Report by Michael R. Milota to Columbia Vista Corp. November 12, 2010.
Reference No.20
NCASI Technical Bulletin No. 991. September 2011. Characterization, Measurement, and Reporting of Volatile Organic Compounds Emitted from
Southern Pine Wood Products Sources.
Notes
Acetaldehyde and propionaldehyde RF appear in Table C-1 of Appendix C. The values are estimates based upon dividing the compound’s effective
carbon numbers (ECN) by the number of carbon atoms in the compound. See Attachment 2 to Appendix C.
Acrolein RF is also an estimate based upon dividing the compound’s ECN by the number of carbon atoms in the compound. In this case, the RF estimate
does not appear in Table C-1 of Appendix C. The value is calculated as described above pursuant to Attachment 2 to Appendix C.
RF = (ECN) / (number of carbon atoms in compound)
Page 44 of 49
where ECN = 2 given the aliphatic carbon contribution of CH2CHCHO (see Table 2.1 to Appendix C) and the number of carbon atoms in acrolein = 3.
RF = 2/3 or 0.66
Reference No. 21
Email of 03/26/12 email from Oregon State University's Michael Milota to EPA Region 10's Dan Meyer.
Page 45 of 49
NCASI Technical Bulletin No. 845
Full Scale Kiln Oregon State
Universtity Kiln
VOC as carbon 3.533333 4.25 6 1 – 3 & 5 – 7 Table 8.2
Formaldehyde 0.0155 0.021 2 1 & 3 Table 9.5**
Methanol 0.205 0.225 2 1 & 3 Table 9.6**
Acetaldehyde 0.039 0.065 1 3
Acrolein 0.006 0.009 1 3
Propionaldehyde 0.001 0.003 1 3
* Value reflects arithmetic mean in those instances when more than one run was performed
** Run 3 data also in Appendix BB1
Appendix BB1
Emission Rate (lb/mbf)*
Pollutant # of Runs Run ID Location of Data
within Technical
Bulletin
C. A. Miller and P. Lemieux, 2007, Emissions from the Burning of Vegetative Debris in
Air Curtain Destructors, J. AWMA, 57, 959-967

1
Emissions from the Burning of Vegetative Debris in Air Curtain
Destructors
1
2
3
4
5
1C. Andrew Miller
2Paul M. Lemieux
U.S. Environmental Protection Agency
Office of Research and Development
1National Risk Management Research Laboratory
2National Homeland Security Research Center
Research Triangle Park, NC 27711
6
7
8
9
10
11
12
13
14

ABSTRACT
Although air curtain destructors (ACDs) have been used for quite some time to dispose of
vegetative debris, relatively little in-depth testing has been conducted to quantify
emissions of pollutants other than carbon monoxide and particulate matter. As part of an
effort to prepare for possible use of ACDs to dispose of the enormous volumes of debris
generated by Hurricanes Katrina and Rita, the literature on ACD emissions was reviewed
to identify potential environmental issues associated with ACD disposal of construction
and demolition (C&D) debris. Although no data have been published on emissions from
C&D debris combustion in an ACD, a few studies provided information on emissions
from the combustion of vegetative debris. These studies are reviewed, and the results
compared to studies of open burning of biomass. Combustion of vegetative debris in
ACD units results in significantly lower emissions of particulate matter and carbon
monoxide per unit mass of debris compared to open pile burning. The available data are
not sufficient to make general estimates regarding emissions of organic or metal
compounds. The highly transient nature of the ACD combustion process, a minimal
degree of operational control, and significant variability in debris properties make
prediction of ACD emissions impossible in general. Results of scoping tests conducted
in preparation for possible in-depth emissions tests demonstrate the challenges associated
with sampling ACD emissions, and highlight the transient nature of the process. The
environmental impacts of widespread use of ACDs for disposal of vegetative debris and
their potential use to reduce the volume of C&D debris in future disaster response
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scenarios remain a considerable gap in understanding the risks associated with debris 
disposal options. 
INTRODUCTION AND BACKGROUND 
On August 29, 2005, Hurricane Katrina came ashore along the Gulf Coast, with the eye 
initially passing over Plaquemines Parish with 140 mph 1 wind speeds, then continuing 
north and hitting the Louisiana/Mississippi border with wind speeds still over 125 mph. 
Less than a month later, Hurricane Rita made landfall near the Texas/Louisiana border as 
a major hurricane with 120 mph wind speeds.  Both of these storms produced major 
storm surges, which combined with the high winds to create enormous amounts of debris 
from destroyed structures, downed trees, and other vegetative debris.  Hurricane Wilma 
struck the southern Gulf Coast of Florida a month later as a major hurricane, again 
leaving behind a trail of damage and substantial debris.  It is clear that 2005 was a 
landmark year for hurricanes and tropical storms, but 2004 was also notable for the 
damage caused by four hurricanes to hit Florida.  Although the 2006 hurricane season 
was relatively quiet for the U.S., it has been predicted that the number of hurricanes and 
tropical storms will continue to be above the long­term average for at least the next 
decade, and that the intensity of storms may also be increasing. 2­4 These predictions, in 
addition to the increases in building and population in coastal areas prone to hurricane 
damage, 5 emphasize the need to understand the implications of options for disposal of 
hurricane debris. 
The debris left by each of these storms presented and continues to present tremendous 
challenges for disaster recovery efforts, first in the efforts to restore transportation, 
power, and communications, but ultimately in the need to dispose of massive volumes of 
solid waste material.  Hurricanes often create debris measured in millions of cubic yards, 
and can overwhelm local waste management capabilities. 6 The volume of debris from 
Hurricane Katrina has been estimated to be on the order of 100 million cubic yards, or 
approximately 50 million tons, including vegetative and construction and demolition 
(C&D) debris, household hazardous wastes, white goods (including large appliances), 
and waste containers (including propane and fuel tanks). 7 This compares to an estimated 
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245 million tons per year of municipal solid waste generated in the U.S. in 2005, which 
translates to approximately 3.7 million tons per year in Louisiana, based on per capita 
waste generation estimates. 8 Clearly, the debris generated by Hurricanes Katrina and 
Rita represented a major and very sudden increase in the level of solid waste that required 
disposal. 
One of the methods used to reduce this enormous volume of debris is to burn combustible 
material, either in large open piles or using air curtain incinerators, also called air curtain 
destructors (ACDs).  More controlled combustion processes, such as found in municipal 
solid waste combustion systems, may not be suitable due to distance from the disaster site 
or because of design or regulatory limits on the properties of the waste feed.  Even so, 
any combustion process, and particularly uncontrolled combustion without flue gas 
cleaning systems, generates potentially significant levels of pollutants that could be 
emitted into the air.  The use of ACDs to reduce the volume of hurricane debris is 
therefore an approach that carries with it the potential for additional and possibly lasting 
environmental damage.  To develop a comprehensive and protective plan for responding 
to future disasters, it is important to understand the capabilities and potential risks 
associated with debris burning and its alternatives, including landfilling, grinding, 
material reuse, and use as or conversion to alternative fuels. 
The purpose of this paper is to discuss the results of pilot­ and full­scale tests that have 
been previously reported, and to compare those results with results from open pile 
burning of debris and limited testing of emissions from an ACD conducted during the 
U.S. Environmental Protection Agency’s (EPA) response to Hurricane Katrina. 
AIR CURTAIN DESTRUCTOR 
Air curtain destructors are generally used to dispose of vegetative debris, such as from 
large land clearing or forest management operations.  These units operate by burning the 
combustible material in an enclosed space with an open top, over which a high velocity 
“curtain” of air is directed to reduce the escape of large particles and to improve air 
circulation into the burning debris.  Figure 1 illustrates the general operation of an ACD. 
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In this schematic diagram, the air flow inside the firebox is depicted as flowing in a 
generally circular pattern, counterclockwise.  The circulation in an actual unit is much 
more complex (as will be discussed below) but in general provides circulation of air into 
the combustion zone, and recirculates at least a portion of combustion byproducts back 
into the high temperature combustion region surrounding the debris.  This combination of 
high air flow into the combustion zone and recirculation of the combustion products is 
designed to reduce visible particulate matter (PM) emissions and provide increased gas­ 
phase residence times compared to open pile burning. 
There are several types of ACD designs.  The firebox can be a pit dug into the ground 
with a transportable blower and curtain air plenum positioned to blow the curtain air over 
and down into the pit. 9 These designs are common in applications such as destruction of 
forest clearing debris because they are relatively light and can be towed into remote areas 
with poor roads.  A second type of ACD uses a refractory­lined firebox that is entirely 
above ground. 10 These are approximately the size of a large waste dumpster and 
incorporate the air curtain fan on the same skid as the firebox.  A third design extends the 
side and back walls of the firebox to minimize the impact of wind and may also 
incorporate provisions for introducing combustion air (underfire air) into the firebox, 
underneath the debris to improve the airflow through the combustion zone.  This type of 
unit cannot be transported as an integral unit and can require a week or more to set up and 
begin operations.  In some cases, such as shown in Figure 2, these larger units have a 
more complex loading arrangement.  Other variants on the design include misters or even 
secondary combustion chambers. 
For all these designs, the operation when burning vegetative debris is fundamentally the 
same.  The initial charge of debris is loaded into the unit and ignited, usually with diesel 
fuel or kerosene.  Once the debris has ignited, the blower is started and additional debris 
is loaded into the unit as needed to maintain combustion.  The ignition process can 
generate a temporary puff of black smoke as the diesel fuel ignites, and smoke typically 
increases for a brief period as subsequent loads of debris are loaded.  Generally, no 
auxiliary fuel is used to maintain good combustion within the unit. 
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PREVIOUS WORK 
Published data on emissions from ACD units are scarce.  There have been a number of 
studies of open burning over the past decade that provide some basis for comparison.  For 
ACDs, however, the data are less available and tend to be less detailed.  A brief 
description of ACD operation and emissions published by the U.S. Forest Service 11 is an 
example of the available documents that describe ACD operations and describe 
emissions, although only qualitatively. 
CO and PM 
There are a few studies that have been done over the past 40 years on ACD emissions. 
Data from three full­scale tests have been found, and two papers that evaluated pilot­scale 
ACD systems are also in the literature.  The earliest of the full­scale studies was 
published in 1972 by Lambert, who described emissions from a pit­type ACD unit used 
to burn forest­clearing debris. 12 The pit in which the debris was burned was 41 feet long, 
8 feet wide, and 15 feet deep (12.5 m x 2.4 m x 4.6 m).  Lambert reported emissions of 
carbon monoxide (CO) and carbon dioxide (CO2), Ringlemann smoke number, and 
temperatures.  CO and CO2 were measured using a continuous emission monitor (CEMs), 
PM measurements were taken using a high volume (“hi­vol”) ambient sampler, and 
opacity was measured using the Ringelmann visual method (although no longer in 
official use in the U.S., the Ringelmann method has been used since the 1880s, as 
described in Ref. 13; a brief but more technical discussion of the method can be found in 
Ref. 14).  Temperatures were measured with thermocouples in the debris bed and with an 
optical pyrometer.  The average CO measured was 140 ppm, with CO2 at 0.75%.  PM 
levels were reported as “too low to measure,” although opacities were reported to be at ½ 
Ringlemann smoke number (5%) for 95% of the operating time.  During unit startup, the 
opacity was reported to be 40% (Ringlemann 2), and when diesel fuel was introduced to 
ignite the bed, Ringlemann numbers as high as 8 were noted. 12 
Temperatures were consistently found to be at least 1600 °F (920 °C), and increased with 
time.  Peak temperatures of over 2200 °F (1250 °C) were measured after 11 hours of 
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operation in one test, and as high as 2500 °F (1420 °C) in a separate test. Average steady 
state temperatures were measured at 1950 °F (1120 °C), dropping to 1450 °F (840 °C) 
within an hour after the blower was turned off.  Lambert reported that overloading of the 
unit by piling logs 3 feet above the air curtain did not visibly change opacity, and also 
noted the presence of a blue flame along the length of the air plenum that was visible 
during night operations.  He attributed this flame to the combustion of volatile products 
that were forced up the air plenum side wall into an area with adequate oxygen to allow 
combustion to be completed.  Lambert also described burning railroad ties in the unit, 
which produced heavy black smoke below the air curtain, with the pit surface “uniformly 
covered with a sheet of bright orange flames all along the air curtain.” 
A more recent report describing emissions from ACDs was prepared by Fountainhead 
Engineering in 2000. 15 This study reports emissions from an above­ground ACD unit 
(Air Burners Model S­127), and provides data on CO, CO2, and PM emissions and 
opacity sampled at the top of the ACD unit.  Over four test runs, the average CO 
concentration was measured at 54 ppm at CO2 levels of 0.2%, suggesting a greater level 
of dilution than in the Lambert study.  PM concentrations were measured at 6600 μg/m3  , 
and emission rates were reported at 2.14 lb/hr (0.97 kg/hr).  At this concentration, opacity 
levels measured using EPA Method 9 16 were found to range between 4% and 7.5%, with 
an average of 5.4%. 
The final full scale measurements were reported by Trespalacios describing operation of 
an ACD burning vegetative hurricane debris in Toa Baja, Puerto Rico. 17 This study 
measured pollutants on the perimeter of the ACD operation site rather than taking 
samples from the outlet of the unit.  The unit used in this operation was similar to that 
used in the Fountainhead tests.  Concentrations of CO and PM were measured at points 
50 (15 m) and 100 feet (30 m) upwind and downwind from the ACD.  More detailed data 
on organic and metal emissions were also collected. 
Average CO concentrations 50 ft (15 m) downwind from the ACD were 9.3 ppm, and 
average PM concentrations at the same location were 570 μg/m3  .  The average values are 
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for three measurements taken over 10 s intervals shortly after loading “dirty debris,” a 
wet mixture of soil and vegetative debris.  It is very possible that the steady state 
averages would be lower than those reported, but additional measurements were not 
reported. 
Assuming a factor of 10 dilution at 50 ft (93 ppm CO at the ACD face), the 
corresponding PM concentrations would be 5700 μg/m 3 , which is consistent with the 
Fountainhead data.  It is unclear what the actual dilution factor is, but the relationship 
between CO and PM in the Trespalacios study appears to be of the same order of 
magnitude as the Fountainhead data.  A factor of 6 dilution would result in CO of 56 ppm 
(vs. 54 ppm for the Fountainhead measurements) and PM of 3400 μg/m 3 , yielding a 
PM:CO ratio roughly half that of the Fountainhead unit. 
There are three pilot­scale studies reported in the literature that are also relevant.  The 
first of these was published in 1968, and is very consistent with the later full scale results 
noted above.  Burckle et al. burned cordwood, municipal solid waste (MSW), and tires in 
a pilot­scale ACD. 18 The unit was 3 ft wide x 3 ft long x 4 ft deep (0.9 m x 0.9 m x 1.2 
m) in size.  When burning a 318 lb (144 kg) charge of wood with the air curtain fan 
operating at 420 scfm (11.9 sm 3 /min), CO was measured at 100­1000 ppm over the 
course of the test.  The tests were conducted for a single fuel charge, and measurements 
were initiated after combustion had stabilized and continued until the fuel charge burned 
out.  CO2 concentrations while burning wood at these conditions ranged from 0.1% to 
1.75%.  These values are consistent with the range of concentrations from full scale units. 
PM was measured at 0.53 grains/dscf (1.2 g/m 3 ), corrected to 12% CO2, and an emission 
factor of 12.7 lb/ton of fuel was calculated for this test.  This concentration value seems 
quite high, but if the values are corrected to 0.2% CO2 (the CO2 concentrations reported 
in the Fountainhead study), the concentrations are much closer to the results reported for 
the full scale units.  The correction to 12% CO2 reflects a comparison with enclosed 
combustion systems such as boilers or incinerators, and may not be as appropriate a 
comparison as a lower CO2 concentration likely to be measured in an open burning 
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situation.  At 0.2% CO2, PM concentrations would be approximately 20,000 μg/m , 
which is roughly three times the value reported in the Fountainhead report.  Although this 
is considerably higher than the 6600 μg/m3  value from the Fountainhead report, it is 
reasonably close considering the difference in scale.  Differences in fuel and scale make 
it difficult to conclude whether the two results are in fact comparable or if the similarity 
is simply coincidental.   In either case, the Burckle paper provides valuable information 
on the transient nature of the process. 
An interesting aspect of the Burckle paper is the finding that PM emissions from wood 
were relatively insensitive to air flow rate.  For municipal solid waste (MSW) and tires, 
the PM emissions increased linearly (as measured by lb/ton of fuel burned) with 
increasing air flow.  Burckle et al. attributed this to the higher ash content of both MSW 
and tires compared to wood.  They do not explain why the PM emissions increase with 
air flow, but do suggest that other fuels such as sawdust may exhibit higher PM emissions 
as smaller particles could be entrained in the air/gas flows and carried out of the unit. 
This may have significant implications for burning of C&D debris, which will have 
significantly higher levels of incombustibles and will also likely have higher levels of 
dust and debris fragments that can be stirred up by handling and loading activities and the 
air curtain and possible underfire air flows. 
The second pilot­scale study is less directly applicable, but does provide some additional 
insight into the ACD combustion process.  Linak et al. burned 1 lb (454 gm) charges of 
black polyethylene agricultural sheet plastic in a 1 ft x 1 ft x 1 ft (0.3 m x 0.3 m x 0.3 m) 
pilot­scale unit and made detailed measurements of the organic compounds emitted from 
the process. 19 They also measured CO and PM and compared the results with and 
without the use of a simulated air curtain.  The peak CO dropped slightly from 42 ppm 
without the air curtain to 37 ppm with the air curtain on when burning new sheet plastic. 
With the same fuel, average as­measured CO concentrations dropped from 29 ppm with 
the air curtain off to 23 ppm when the air curtain was on.  It is unclear whether this 
reduction was due to improved performance or to dilution of the CO by the curtain air. 
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Interestingly, PM concentrations increased when using the simulated air curtain.  For the 
new sheet plastic, PM concentrations were measured at 4730 μg/m 3 when the air curtain 
was on and at 3560 μg/m 3 when it was off.  CO2 levels during these tests were reported to 
“vary minimally” in the range of 0.3­0.6%.  Although the fuel used in these tests was 
significantly different, the reported PM concentrations were very similar to those reported 
in the full scale tests.  It is unclear whether this is due to similarities in the combustion 
process or coincidental. 
The third pilot­scale study was reported by Lutes and Kariher, and focused on the open 
burning of land clearing debris. 20 Samples of woody debris from Tennessee and Florida 
were burned in a 36 in (91 cm) long x 18 in (46 cm) wide x 16 in (41 cm) deep pilot­scale 
ACD.  The unit was tested with curtain air on and off.  Results for CO and PM2.5 showed 
only minor changes in concentration, but significant reductions in mass of emissions per 
unit mass of fuel burned.  Average CO concentrations were reported at 34 ppm without 
the blower and 37 ppm with the blower (as measured conditions), and average PM2.5 
concentrations were measured at 24,600 μg/m3  without the blower and 40,400 μg/m3  with 
the blower.  On the basis of emissions per unit mass of fuel, CO fell from 20 g/kg without 
the blower to 12 g/kg with the blower.  Similarly, PM2.5 emissions fell from 12 g/kg 
without the blower to 10 g/kg with the blower.  The higher concentrations of CO and PM 
but lower emissions per unit mass of fuel are a consequence of the more rapid 
consumption of fuel when the blower was used.  For comparable fuel charges, the rate of 
fuel consumption when the blower was used was as much as two times faster than when 
the blower was not used. 20 This leads to higher average pollutant concentrations, but 
over a shorter period of time.  For full­scale units, the dilution of the exhaust gases by 
ambient air entrained into the exhaust plume may also lead to significant differences in 
reported exhaust concentrations.  The dilution will depend upon where the sample is 
collected – both the location across the opening of the ACD and how high above the 
ACD exit the sample is collected. 
Organics, Metals, and Other Emissions 
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The Lambert study did not measure emissions other than CO2, CO, and PM. 12 The 
Fountainhead study did take SO2 and NO2 measurements, but concentrations were 
sporadic.  SO2 was found on only one of four runs (at 1 ppm) and NO2 measured 
inconsistently at 1­4 ppm. 15 
More extensive measurements of trace compounds were taken during the Toa Baja study. 
Several metals and organics were measured upwind and downwind of the ACD in an 
effort to quantify emissions from the combustion process.  Six metals were detected in 
the samples: aluminum (Al), cadmium (Cd), chromium (Cr), iron (Fe), lead (Pb), and 
potassium (K).  Al and Fe were detected more consistently, but were also detected at 
higher levels upwind than downwind, on average.  Of the remaining metals, only Pb was 
detected in more than one of the 8 samples collected, and then in only two. 17 It is 
probable that the higher Al and Fe concentrations are the consequence of the use of “dirty 
fuel” (wet vegetation combined with soil).  The high upwind values further suggest these 
metals are the result of soil­borne elements, and also make it questionable whether the 
downwind samples were emitted from the ACD as opposed to being from fugitive dust. 
Because emissions of metals are very strongly dependent upon the composition of the 
fuel, the applicability of these results to other units is limited to a recognition that ACD 
combustion conditions appear to be adequate to result in the formation of metal­ 
containing particles. 
Of the volatile organic compounds detected, benzene, toluene, chloromethane, and 
formaldehyde were detected in each downwind sample at concentrations higher than the 
upwind sample.  Besides these compounds, only p­xylene and propionaldehyde were 
detected in more than two (of eight) samples.  The downwind propionaldehyde 
concentrations were each lower than the upwind concentration, suggesting that the source 
was not the combustion process.  p­xylene was detected at levels above the upwind 
concentration in at least one sample during each test, indicating that the source was the 
ACD. 
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Concentrations of polychorinated dibenzo­d­dioxins (PCDDs) and polychorinated 
dibenzofurans (PCDFs) were also measured upwind and downwind of the ACD unit. 
Toxic equivalent (TEQ) concentrations of PCDDs and PCDFs were not detected in the 
upwind samples, but were detected in four of six downwind samples, indicating the 
formation of PCDDs/Fs in the combustion process.  No other semivolatile organics were 
detected in the Toa Baja samples. 17 
The pilot­scale study by Burckle et al. measured total hydrocarbons, carbonyls (reported 
as formaldehyde), and carboxyls (reported as acetic acid).  A continuous hydrocarbon 
(HC) monitor showed a large initial spike in HC concentrations, which then decreased to 
a minimum and gradually increased again as the fuel charge burned out.  The spike 
occurred within 10 min of loading, and the second peak was reported at about 60 min 
after loading.  The reported data suggest that increasing curtain air flow can, in at least 
some cases, result in increased HC concentrations for wood, tires, and MSW (see Figure 
3).  In general, HC emissions (on the basis of mass of emissions per mass of fuel) from 
wood were lower than HC emissions from tires, which were in turn lower than the HC 
emissions from MSW. 18 
The pilot scale work reported by Linak et al. noted that, “The use of forced air slightly 
reduced the time necessary to burn each charge, but it did not affect the types or 
concentrations of PICs [products of incomplete combustion] emitted.” 19 The study 
identified 37 volatile and semivolatile organic compounds in the collected samples, as 
well as 18 polycyclic aromatic hydrocarbons (PAHs).  Linak et al. noted that emissions of 
benzene, toluene, ethyl benzene, and 1­hexane increased slightly when the forced air was 
operating and suggested that this may be due to quenching of the flame by the cooler 
forced air.  With the exception of this difference, there was little reported change in the 
measured emissions of organic compounds due to changes in fuel type or operating 
condition. 
Comparison of ACD and Open Burning Emissions 
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For PM, the general range of open biomass burning emissions tends to be on the order of 
10 g/kg of fuel.  Gerstle and Kemnitz reported total PM emissions of 6­12 g/kg for 
landscape refuse and 7­9 g/kg for municipal refuse. 21 For different types of biomass, 
Andreae and Merlet reported PM2.5 emissions between 4 and 13 g/kg and total PM 
emissions up to 18 g/kg, 22 Lemieux et al. reported values for total PM emissions ranging 
between 10 and 19 g/kg, 23 and Dennis et al. used emissions of 8­19 g/kg of total PM in 
their estimates of total emissions from open burning. 24 These values are significantly 
higher than the emissions per unit mass of fuel calculated in the Fountainhead test, which 
were at 0.05 g/kg.  It is very likely that even poorly operated systems will exhibit 
significantly lower PM emission levels when they are able to increase the high­ 
temperature residence time of the pyrolyzed organics that form most of the fine PM.  For 
instance, an early dedicated vegetative debris burner was reported to have experienced 
“excessive smoke” due to overcharging the unit during a test.  Even at this overload 
condition, the reported PM emissions were 1.1 g/kg, roughly an order of magnitude lower 
than uncontrolled open burning. 25 There are likely to be some differences in emissions 
due to the different biomass types and burning conditions, which ranged from prescribed 
burning of savanna to burning of residential vegetative debris in small piles.  Even so, the 
PM emission factors for open burning are relatively consistent given the wide variety of 
materials and conditions. 
Interestingly, the pilot­scale results were similar to the reported uncontrolled open 
burning emission rates.  It is unclear why the pilot­scale ACD studies were unable to 
similarly duplicate the reduced PM concentrations indicated by the full­scale ACD tests, 
but the complexities involved in achieving simultaneous similarity in combustion, heat 
transfer, and air flow may be a significant barrier to effective pilot­scale evaluations of 
ACD emissions, at least without using a computational fluid dynamics (CFD) approach 
to the design of the experimental apparatus.  The hypothesis noted above that a higher 
residence time may play a significant role in reducing emissions of organics and 
unburned fuel could well be one of the reasons why pilot­scale units have not been able 
to effectively simulate the emission rates measured during tests of full­scale units. 
Scaling an ACD system to simulate physical conditions may well result in combustion 
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product residence times that are below characteristic reaction times needed to achieve 
higher burnout levels. 
Reported emissions of CO from open biomass burning varied significantly.  Andreae and 
Merlet reported values of 65­110 g/kg of CO, Lemieux et al. reported a range of 16­110 
g/kg, and Gerstle and Kemnitz reported 25­40 g/kg of CO emissions. 21­23 Hays et al. 
reported CO concentrations of 4­2000 ppm for the several types of biomass tested, with 
similar ranges over 2­3 orders of magnitude noted for each type. 26 These values compare 
to approximately 0.5 g/kg of CO from an ACD burning woody debris as reported in the 
Fountainhead study. 27 (The full report notes a CO emission rate of approximately 20 
lb/hr, compared to a PM emission rate of 2.1 lb/hr for the same runs.  The calculated PM 
mass emission factor of 0.054 g/kg of fuel is provided in a separate letter to the Georgia 
Department of Natural Resources.  The 0.054 g/kg PM emission factor would result in a 
CO mass emission factor of approximately 0.5 g/kg of fuel, given the same fuel feed rate 
during the test runs.)  The reduction in CO is not as substantial as that shown for PM, but 
is still significant.  It is difficult to directly compare the Lambert and Toa Baja results 
because of a lack of fuel feed data, but they seem to be of the same order of magnitude as 
the Fountainhead study (assuming an order of 10 dilution in the Toa Baja results). 
There are a number of studies that report trace organic emissions from different types of 
open burning.  In many of these studies, the lists of organic compounds are quite 
extensive.  Rather than evaluate each compound, we will simply note that: (a) existing 
data on trace organic emissions from full­scale ACDs are almost nonexistent; (b) studies 
of open burning have consistently found considerable trace organic compound emissions; 
and (c) even well­controlled industrial combustion sources exhibit some level of trace 
organic emissions.  Thus, one would expect to measure some trace organics in ACD 
emissions. 
Similarly, the presence of PCDDs and PCDFs indicated in the Toa Baja study should be 
expected, as these compounds have also been found in studies of uncontrolled open 
burning. Gullett et al. showed that PCDDs and PCDFs from the simulated open burning 
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of forest biomass were not solely from the volatilization of condensed material, but were 
also formed in the combustion process. 28 This pilot­scale work verified earlier 
measurements of actual forest and biomass fires that showed these events emit PCDDs 
and PCDFs. 29, 30 
CONTEMPORARY SCOPING MEASUREMENTS OF ACD OPERATION 
In the aftermath of Hurricanes Katrina and Rita, there was interest in using ACDs to 
dispose of a portion of the enormous volume of debris left in the storms’ wakes.  Given 
the age of many homes in the affected areas, it was expected that a considerable number 
of homes would likely contain asbestos in one or more products and forms.  The majority 
of asbestos was expected to be in chrysotile form, which can be thermally transformed 
into a non­hazardous forsterite form at temperatures above 800° C (1470° F). 31, 32 With 
the highly transient nature of ACD operation and the need to maintain temperatures 
above 800° C, the question was raised regarding the potential for ACDs to be used as a 
means to achieve the thermal conversion of chrysotile to forsterite under actual operating 
conditions.  In late October 2005, researchers from EPA’s Office of Research and 
Development (ORD) conducted a limited number of simple scoping tests on a full­scale 
ACD that was being used to demonstrate its ability to burn vegetative debris in the New 
Orleans area.  The purpose of these scoping tests was to provide preliminary information 
on possible disposal options, evaluate ACD operating characteristics, and determine the 
most effective approaches to sampling for pollutant emissions during more in­depth 
testing. 
Operation and Measurements 
The ACD used was an Air Burners, LLC model S327, burning only dry vegetative debris. 
Loading of the unit occurred from the air plenum side. The unit was situated so that the 
air curtain was blowing in the same direction as the prevailing wind, which was reported 
at 10­15 mph with gusts of 25 mph. 
Gas temperature and velocity and concentrations of several gases were measured 
approximately 6­15 in above the top of the ACD wall.  A rough traverse of the area over 
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the top of the ACD was made to identify any variations in gas concentrations, 
temperatures, or velocities.  Portable continuous emission monitors were used to measure 
concentrations of CO2, CO, oxygen (O2), oxides of nitrogen (NOx), and sulfur dioxide 
(SO2).  Temperature measurements were taken using thermocouples and with a Series 
OS523­2 Omegascope infrared thermometer.  Five type K thermocouples were installed 
in the ACD prior to loading with debris to measure wall and combustion bed 
temperatures at approximately the midpoint of the unit’s length, at 7, 32, and 71 in (18, 
81, and 180 cm, respectively) from the ACD bottom on the blower side and 32 and 61 in 
(81 and 150 cm, respectively) on the side opposite the blower.  A K­type thermocouple 
was also used at the tip of the sampling probe to measure gas temperatures. 
Thermocouple signals were recorded using a hand­held thermocouple readout and 
entered onto manual data sheets.  The optical pyrometer was used to take temperatures 
across the surface of the burning debris bed, and the results were recorded manually. 
Observations and Results 
During “steady state” operation, the opacity of the plume was near zero, and the location 
of the plume had to be determined using an infrared video detector.  When additional 
debris was loaded into the unit after it had reached steady state operation, the opacity 
increased to a readily visible level, which lasted for less than a minute following the 
introduction of the debris charge.  The formation of a visible plume did not occur 
consistently after each charge of debris.  Transient plumes were observed in similar 
operations of an ACD with extended back and side walls operating in a different location, 
but also burning dry vegetative debris. 
The averages of five gas concentration measurements for CO, CO2, NO, NO2, and SO2 
are shown in Table 2.  The measurements were taken over the span of 46 minutes in 
different locations, with each measurement lasting less than a minute.  The gas 
concentrations generally showed relatively high variability, which is not surprising for 
the low number of measurements taken.  Concentrations of CO and CO2 were higher than 
those reported previously, but the low number of measurements and possible differences 
in measurement methods make it difficult to draw meaningful conclusions in comparison 
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to previous work.  Concentrations of NO, NO2, and SO2 showed similarly high 
variability, with the low number of measurements again being of concern.  Unfortunately, 
mass feed rates for the fuel were not measured during these scoping tests, so it is not 
possible to estimate the emission factors for these pollutants. 
There was considerable variation in temperatures across the unit, measured from the 
blower side to the loading side.  The unit is typically loaded from the side opposite the 
blower.  However, for the Phase 1 tests, the unit was loaded from the blower side to allow 
greater access for gas and temperature measurements.  For this discussion, we will refer 
to the blower side and the loading side (the side opposite the blower) as this terminology 
more accurately reflects typical operating practice. The higher temperatures were noted 
along the blower side.  Blower side wall temperatures ranged from 670° to 1030° C, with 
the highest temperatures nearest the combustion bed.  Wall temperatures were at a 
minimum near the midpoint of the 8 ft (2.4 m) wall height, with temperatures increasing 
again to 930° C approximately 3 ft (0.9 m) from the top.  On the blower side, the wall 
temperatures were 750° C at a point about 3 ft (0.9 m) above the combustion bed and 
600° C at a point about 4 ft (1.2 m) from the top.  Combustion bed temperatures 
measured with the optical pyrometer ranged from 1020° C near the blower side to 740° C 
near the loading side.  The average temperature (average of all locations and all times) 
was 920° C. 
Unlike the simple circular pattern suggested in Figure 2, the flow of exhaust gases is 
quite complex in the unit.  Velocity measurements suggest that the vast majority of 
exhaust flow is occurring in a relatively narrow area along the length of the unit on the 
side opposite the blower (see Figure 5).  Measurements of 15 fps in this narrow area were 
close to the estimated temperature­adjusted flow velocity based on the ACD fan output. 
This distribution pattern is not thought to significantly impact the level or composition of 
emissions from the ACD.  However, this finding is important relative to designing 
approaches to sampling emissions from ACDs.  Sampling procedures should take into 
account the significant variability in gas velocities across the top of the ACD to ensure 
that the gas sampling locations selected include the area(s) of highest emissions outflow. 
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Following the completion of these tests, plans were completed for more detailed testing 
of emissions from the combustion of C&D and vegetative debris from ACDs.  However, 
as the recovery effort progressed, several factors led to the potential for using ACDs to be 
significantly reduced.  The concerns over emissions raised by previous work (noted 
above) and by an external review of debris disposal using ACDs; 33 more available 
landfill space than expected in the immediate aftermath of the storm; and a significantly 
longer lead time for making decisions regarding the demolition of severely damaged 
buildings all resulted in a decision not to use ACDs as a disposal option at that time. 
Therefore, there was a reduced need to conduct the more detailed tests during the initial 
period of storm recovery.  However, there is still considerable interest in conducting 
more detailed studies of air emissions from ACDs 34 and it is possible that such tests will 
be conducted in the future. 
DISCUSSION AND CONCLUSIONS 
When properly operated, both anecdotal evidence and comparison with measurements 
from simple open burning indicate that ACDs burn vegetative debris in such a way that 
emissions of PM are reduced, probably significantly, compared to open burning. 
Concentrations of PM as indicated by opacity measurements are lower for ACDs, which 
produce plumes with very low opacity for the majority of operating time, and generate 
visible plumes only during start up and immediately after loading.  These transient 
“puffs” of emissions are likely to be accompanied by increased emissions of organic 
compounds as well as PM, based on experience with transient events in rotary kiln 
incinerators and with biomass combustion. 35­37 
The lower PM and CO emissions are consistent with the improved combustion conditions 
that are present with ACDs as compared to open burning – better air flow, containment of 
heat around the combustion zone, and more controlled introduction of debris.  These 
improved conditions would suggest that emissions of organic compounds are also lower 
for ACDs than for open burning, but adequate data are not yet available to draw such a 
conclusion.  The existing data do show a significant potential for emissions of toxic 
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organic compounds.  The indications of PCDD/PCDF emissions during the Toa Baja 
tests, for instance, suggest that ACD combustion of chlorine­containing material could 
lead to the formation and emission of chlorinated organics. 
The questions about emissions from C&D debris remain open. Under normal conditions, 
C&D debris can be maintained separately from vegetative debris.  However, these types 
of debris are intermingled during disasters and separating them during recovery would 
require time and resources that are more effectively used for other response needs. 
Therefore we are left with a need to understand how emissions may differ when burning 
C&D as opposed to vegetative debris, or (more likely in a practical situation) a mixture of 
the two.  Differences in composition and heat content make a direct extrapolation from 
existing data from vegetative debris combustion unrealistic.  Higher concentrations of 
relatively inert inorganic compounds, particularly metals, would be expected in C&D 
debris; whether those compounds are emitted into the ambient atmosphere or are retained 
in the bottom ash remains unknown.  The likely presence of chlorine and other halogens 
in C&D debris may also have a significant impact on the types of compounds that are 
formed in the combustion process and possibly emitted into the air.  Higher 
concentrations of sulfur are also likely in C&D debris than in vegetative material, which 
can also significantly impact the high­temperature chemistry within the ACD firebox. 
Our current understanding of the behavior of these compounds in combustion 
environments is largely shaped by studies of either open burning or enclosed and 
controlled combustion of municipal solid waste, neither of which can be directly applied 
to the current problem. In short, the combustion of C&D debris in ACDs is a new 
problem that has not been addressed by previous research. 
REFERENCES 
1.  Knabb, R.D.; Rhome, J.R.; Brown, D.P.Tropical Cyclone Report: Hurricane 
Katrina, 23­30 August 2005; TCR­AL122005; National Weather Service, National 
Hurricane Center: Miami, FL, 2005. 
2.  Elsner, J.B.; Kara, A.B.; Owens, M.A. Fluctuations in North Atlantic Hurricane Frequency; Journal of Climate 1999, 12, 427­437. 
530 
531 
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535 
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537 
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541 
542 
543 
544 
545 
546 
547 
548 
549 
550 
551 
552 
553 
554 
555 
556 
557 
558 
559 
560
19 
3.  Goldenberg, S.B.; Landsea, C.W.; Mestas­Nunez, A.M.; Gray, W.M. The Recent 
Increase in Atlantic Hurricane Activity: Causes and Implications; Science 2001, 293, 
474­479. 
4.  Webster, P.J.; Holland, G.J.; Curry, J.A.; Chang, H.R. Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming Environment; Science 2005, 309, 
1844­1846. 
5.  Crossett, K.M.; Culliton, T.J.; Wiley, P.C.; Goodspeed, T.R. Population Trends 
Along the Coastal United States: 1980­2008; National Oceanic and Atmospheric 
Administration: Washington, DC, 2004. 6.  U.S. Environmental Protection Agency. Planning for Disaster Debris; EPA 530­K­ 
95­010; Office of Solid Waste: Washington, DC, 1995. 
7.  Luther, L. Disaster Debris Removal After Hurricane Katrina: Status and Associated 
Issues; RL33477; Congressional Research Service: Washington, DC, 2006. 
8.  U.S. Environmental Protection Agency. Municipal Solid Waste in the United States: 2005 Facts and Figures; 530­R­06­011; Office of Solid Waste: Washington, DC, 
2006. 
9.  Gilbert, K.W., Air Curtain Incinerator, U.S. Patent Office No. 4,756,258, July 12, 
1988. 
10. O'Connor, B.M., Air Curtain Incinerator, U.S. Patent Office No. 7,063,027, Jun 20, 2006. 
11. Shapiro, A.R.The Use of Air Curtain Destructors for Fuel Reduction; 0251 1317 
SDTDC; USDA, Forest Service: San Dimas, CA, 2002. 
12. Lambert, M.B. Efficiency and economy of an air curtain destructor used for slash 
disposal in the Northwest. Presented at American Society of Agricultural Engineers Winter Meeting, Chicago, IL, December 11­15, 1972. 
13. Uekoetter, F. The strange career of the Ringelmann Smoke Chart; Environmental 
Monitoring and Assessment 2005, 106, 11­26. 
14. Hesketh, H.E. Fine particles in gaseous media; Lewis Publishers: Chelsea, MI, 1986. 
15. Fountainhead Engineering. Final Report Describing Particulate and Carbon Monoxide Emissions from the Whitton S­127 Air Curtain Destructor 00­21; 
Fountainhead Engineering: Chicago, IL, 2000. 
16. U.S. Environmental Protection Agency. Method 9 ­ Visual Determination of the 
Opacity of Emissions from Stationary Sources; Code of Federal Regulations 1990, Title 40 Part 60. 17. Trespalacios, M.J. Ambient Air Monitoring and Sampling at the Toa Baja Landfill 
Site, Toa Baja, Puerto Rico; Lockheed Martin Technology Services WA 0­112 Trip 
Report; U.S. Environmental Protection Agency, Region 2: Edison, NJ, 2005. 
18. Burckle, J.O.; Dorsey, J.A.; Riley, B.T. The effects of the operating variables and 
refuse types on the emissions from a pilot­scale trench incinerator. Presented at National Incinerator Conference, 1968. 
19. Linak, W.P.; Ryan, J.V.; Perry, E.; Williams, R.W.; DeMarini, D.M. Chemical and 
biological characterization of products of incomplete combustion from the simulated 
field burning of agricultural plastic; Journal of the Air Pollution Control Association 1989, 29, 836­846. 20. Lutes, C.C.; Kariher, P.H.Evaluation of the Emissions from the Open Burning of 
Land­Clearing Debris; EPA­600/R­96­128; National Risk Management Research 
561 
562 
563 
564 565 566 
567 
568 
569 570 
571 
572 
573 
574 575 576 
577 
578 
579 580 
581 
582 
583 
584 585 586 
587 
588 
589 590 
591 
592 
593 
594 595 
596 
597 
598 
599 600 
601 
602 
603 
604 605 
606
20 
Laboratory, U.S. Environmental Protection Agency: Research Triangle Park, NC, 
1996. 
21. Gerstle, R.W.; Kemnitz, D.A. Atmospheric emissions from open burning; Journal of the Air Pollution Control Association 1967,17, 324­327. 22. Andreae, M.O.; Merlet, P. Emissions of trace gases and aerosols from biomass 
burning; Global Biogeochemical Cycles 2001, 15, 955­966. 
23. Lemieux, P.M.; Lutes, C.C.; Santoianni, D.A. Emissions of organic air toxics from 
open burning: A comprehensive review; Prog. Energ. Combust. Sci.2004,30, 1­32. 
24. Dennis, A.; Fraser, M.; Anderson, S.; Allen, D. Air pollutant emissions associated with forest, grassland, and agricultural burning in Texas; Atmos. Environ. 2002, 36, 
3779­3792. 
25. Sterling, M. Brush and trunk burning plant in the City of Detroit; Journal of the Air 
Pollution Control Association 1965,15, 580­582. 
26. Hays, M.D.; Geron, C.; Linna, K.J.; Smith, N.D.; Schauer, J.J. Speciation of gas­ phase and fine particle emissions from burning of foliar fuels; Environ. Sci. Technol. 
2002, 36, 2281­2295. 
27. Bawkon, B., Fountainhead Engineering. Particulate Emission Test Data: Whitton 
Technologies S­127 Air Curtain Destructor; personal communication to T. Cutrer; 
Georgia Department of Natural Resources; Atlanta, GA; December 7, 2000. 28. Gullett, B.K.; Touati, A. PCDD/F emissions from forest fire simulations; Atmos. 
Environ. 2003,37, 803­813. 
29. Clement, R.; Tashiro, C. Forest fires as a source of PCDD and PCDF. Presented at 
11th International Symposium on Chlorinated Dioxins and Related Compounds, 
Research Triangle Park, NC, September 23­27, 1991. 30. Walsh, P.; Brimblecombe, P.; Creaser, C.; Olphert, R. Biomass burning and 
polychlorinated dibenzo­p­dioxins and furans in the soil; Organohalogen Compounds 
1994, 20, 283­287. 
31. MacKenzie, K.J.D.; Meinhold, R.H. Thermal reactions of chrysotile revisited: A 29Si 
25Mg MAS NMR study; American Minerologist 1994, 79, 43­50. 32. Crummett, C.D.; Candela, P.A.; Wylie, A.G.; Earnest, D.J. Examination of the 
Thermal Transformation of Chrysotile by Using Dispersion Staining and 
Conventional X­ray Diffraction Techniques. Presented at American Geophysical 
Union, Fall 2004 Meeting, 2004. 
33. U.S. EPA Science Advisory Board. Synthesis of Written and Oral Comments on Demolition and Disposal of Hurricane Debris; U.S. Environmental Protection 
Agency: Washington, DC, 2005. 
34. U.S. Senate Committee on Environment & Public Works, Written Testimony of Dr. 
Mike D. McDaniel, Secretary, Louisiana Department of Environmental Quality, New 
Orleans, LA, February 26, 2007. 35. Linak, W.P.; Kilgroe, J.D.; McSorley, J.A.; Wendt, J.O.L.; Dunn, J.E. On the 
Occurrence of Transient Puffs in a Rotary Kiln Incinerator Simulator I. Prototype 
Solid Plastic Wastes; Journal of the Air Pollution Control Association 1987, 37, 54. 
36. Linak, W.P.; McSorley, J.A.; Wendt, J.O.L.; Dunn, J.E. On the Occurrence of Transient Puffs in a Rotary Kiln Incinerator Simulator II. Contained Liquid Wastes on Sorbent; Journal of the Air Pollution Control Association 1987, 37, 934. 
607 
608 
609 
610 611 612 
613 
614 
615 616 
617 
618 
619 
620 621 622 
623 
624 
625 626 
627 
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629 
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633 
634 
635 636 
637 
638 
639 
640 641 
642 
643 
644 
645 646 
647 
648 
649 
650 651
21 
37. Lemieux, P.M.; Linak, W.P.; McSorley, J.A.; Wendt, J.O.L.; Dunn, J.E. 
Minimization of Transient Emissions from Rotary Kiln Incinerators; Combustion 
Science and Technology 1990,74, 311­325. 
652 
653 
654 
655 656 657
22 
FIGURE CAPTIONS 
Figure 1.  Schematic of air curtain destructor operation. 
Figure 2.  Photographs of different air curtain destructor designs. 
Figure 3. Emission factors vs. curtain air flows for carbonyls (top), carboxyls (center), 
and total hydrocarbons (bottom) reported by Burckle et al. 18 
Figure 4.  Air curtain bed temperatures as measured by optical pyrometry. 
Figure 5.  Velocity profile across top of air curtain destructor.  The velocity peaks near 
the side wall opposite the air curtain plenum. 
658 
659 
660 
661 
662 
663 
664 
665 
666 
667 
668
23 
Tables 669 
670 
Table 1.  Summary of CO and PM concentrations reported in the literature. 
Report 12 (a) Lambert 
Full scale 
15 Fountainhead 17 Toa Baja (b) 
Burckle 18 et al. 
Pilot scale Linak et 19 al. 
Lutes and 20 Kariher 
Fuel Wood Wood Wood/Soil Cord Polyethylene Woody (wet) wood plastic Debris 
CO (ppm) 140 54  9.3 100­1000 23  37 
PM 
opacity 
5% opacity (~ 0.5 g/kg) 3 6600 μg/m 
5.4% opacity 
3 568 μg/m 20000 3(c) μg/m 
3 4730 μg/m 3 40000 μg/m 
and concen­ 
tration PM (d) NA 0.054 g/kg NA 5.0 g/kg NA 10 g/kg emission factor CO2 0.75% 0.2% NA 0.1­1.75% 0.3­0.6% 0.05% 
a. Pit­type unit b. Ambient measurements taken 50 feet downwind of the ACD unit 
c. Corrected to 0.2% CO2.  Reported values were 0.53 grains/dscm (1.2 3 )g/m   at 12% CO2. d. Not available 
671 
672 673 674 675 676 
677 
Table 2.  Concentrations of gases measured at top of air curtain destructor. 
Average Range 
O2 (%) 18.0  16.2 – 19.5 
CO (ppm) 237 319 ­ 183 
CO2 (%) 2.5 1.2 – 4.1 
NO (ppm) 75.0  11 – 100 
NO2 (ppm) 4.0 0 – 10 
SO2 (ppm) 4.6 2 – 8 
678 679 
680
24 
Figures 681 
682 
Blower 
Air Curtain 
Debris 
Flame 
Circulating 
Air Flow 
Firebox 
Blower 
Air Curtain 
Debris 
Flame 
Circulating 
Air Flow 
Firebox 
Figure 1.  Schematic diagram of air curtain destructor operation. 
683 684 
685 
686 
Figure 2.  Photographs of different air curtain destructor designs. 
687 688 689 690
25 
Carboxyls 
Em
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2 
4 
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8 
10 
12 
14 
Carbonyls 
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1 
2 
3 
4 
5 
6 
7 
Cordwood 
Tires 
Municipal Solid Waste 
Linear Regression 
Total Hydrocarbons 
Curtain Air Flow, scfm 
100  200  300  400  500  600  700 
Em
i
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a
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5 
10 
15 
20 
25 
Figure 3. Emission factors vs. curtain air flows for carbonyls (top), carboxyls (center), 
and total hydrocarbons (bottom) reported by Burckle et al. 18 
691 692 693 
694 
695 
696
26 
Average Bed Temperature 
(as measured by optical pyrometer, deg F) 
Distance from Fan End (in) 
60  80  100  120  140  160 
Di
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)

20 
30 
40 
50 
60 
70 
80 
1300 
1400 
1500 
1600 
1700 
1800 
1900 
Figure 4.  Air curtain bed temperatures as measured by optical pyrometry.  Temperatures are lower near the curtain air plenum. 
697 698 699 
700
27 
701 Gas velocity at ACD exit 
Distance from side wall, ft (blower at 8.3 ft) 
0  2  4  6  8  10 
Ve
l
o
c
i
t
y
,

f
p
s

0 
10 
20 
30 
40 
Direction of gas flow 
Figure 5.  Velocity profile across top of air curtain destructor.  The velocity peaks near 
the side wall opposite the air curtain plenum. 
702 703 
704 705 706 
707
Air Curtain Incinerator
1
Air Curtain Incinerator Emissions Factors Determination From: Brian Clerico, AQE II and Errol Villegas, Permit Services Manager To: Arnaud Marjollet, Director of Permit Services
Date: April 04, 2017
Re: Recommendation for Air Curtain Incinerator Emission Factor Determination for Woody Biomass from Agricultural Sources and Forest Vegetation The purpose of this memo is to examine available test data and recommend emission factors appropriate for an air curtain incinerator (ACI) burning woody biomass derived from agricultural sources and forest vegetation. 1. BACKGROUND The San Joaquin Valley is a large agricultural region that annually generates hundreds of thousands of tons of woody biomass debris primarily from the pruning and removal of orchards and vineyards. The main historical disposal option for this material has been open burning, but open burning of ag waste has been curtailed by 80% since 2003, largely made possible by the availability of the option of chipping the material and sending it to a nearby biomass power plant. In recent years, as the biomass power industry has lost its financial and societal support and decreased in numbers from 15 facilities to five today (with none of the five buring much ag waste), the San Joaquin Valley has accumulated a glut of wood material in need of disposal. This excess has been exacerbated by California’s recent extreme drought and the bark beetle infestation which has resulted in over 100 million dead trees in the State, mostly in the southern Sierra Nevada, which is in the Valley Air District. For areas where the buildup of wood material has become an acute hazard, air curtain incinerators (ACIs) have become an important disposal option. Within the San Joaquin Valley, CalFire is currently using ACIs for wildfire hazard reduction in forested areas, and an almond huller has received an Authority to Construct to install an ACI to dispose of an accumulation of wood sticks from their almond processing operation. To quantify emissions from ACIs for purposes of permitting and emissions inventory, the most representative emission factors should be used. This memo is intended to identify and recommend the most representative emission factors for ACIs burning woody biomass from agricultural sources and forests. A number of emission tests have been conducted on ACIs. A table of the emission factors derived from those tests is provided in Table 1 below along with the emission factors for open burning of almond orchard residues and biomass power plants for comparison in Table 2.
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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In selecting the most representative emission factors, the District was guided by the following considerations: (1) A limited number of emissions tests have been published to date; (2) The source test results published show a wide variance; (3) Air curtain incineration may be regarded as a controlled form of open burning; (4) The PM10, CO, and VOC emission factors for open burning show a high degree of dependence on the material burned; (5) The ARB open burn emission factors for agricultural orchard and vine residues provide an upper bound for PM10, CO, and VOC because the visual evidence indicates the ACI is performing significantly better at reducing smoke and visible particulates (and, by extension, other products of incomplete combustion such as PM10, CO and VOC) than open burning of woody biomass derived from agricultural or forest vegetation. The open burn emission factors for almond orchards will be used in Table 2 to represent a type of woody agricultural residue common in the San Joaquin Valley; (6) The emission factors for biomass power plants controlled by a fabric filter provide a lower bound for PM10 (0.089 lb-PM10/ton)1; (7) SOx emissions are entirely material dependent; thus, the open burn SOx emission factors for agricultural orchard and vine crops, or for forests, are also likely the most representative for ACIs. The emission factors from Table 1 (page 3) were evaluated using the criteria listed above. A. AP-42, 2.1-12, J.O. Burckle Test from Table 1 (NOx and PM10) The current AP-42 emission factors for the incineration of wood (cord wood) are based on a pilot scale study from 1968. The unit tested was not a functional ACI but a pilot scale version constructed for the purpose of emissions testing. The maximum temperature reached by the pilot scale firebox was 1,300 ⁰F, which is approximately 300 to 900 ⁰F less than an ACI in the field. The PM10 emission factor resulting from this study is higher than the ARB and AP-42 PM10 emission factors in Table 2 for the open burning of almond orchard wood, which is a representative type of orchard wood waste for the San Joaquin Valley. The NOx emission factor obtained was 4 lb-NOx/ton, which is much higher than any of the tests on actual ACIs and similar to open burn emission factors for NOx from Table 2. 1 The seven most recent source tests for the biomass power plants Merced Power and Ampersand Chowchilla showed an average PM10 emission rate of 0.089 lb-PM10/ton. This average source test value is a more representative estimate of the PM10 emissions from biomass plants than the permitted value (0.61 lb-PM10/ton). As a comparison, a boiler fired on dry wood with a heating value of 7,610 Btu/lb has an uncontrolled emission rate of 5.5 lb-PM10/ton (Table, 1.6-1), which is approximately the same emission factor for open burning of orchard agricultural residues.
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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The emission factors from this study were not considered representative for an ACI burning woody biomass derived from agricultural sources or forests for the following reasons: (1) The unit tested was not an actual ACI; (2) The maximum combustion temperatures were lower than a typical ACI; (3) The AP-42 ACI PM10 emissions factor is higher than the open burn PM10 emission factors for most agricultural sources (Table 2); and (4) The NOx emission factor is significantly higher than any of the air curtain tests (note that lower combustion temperatures would be expected to lead to lower NOx emissions, adding an additional degree of caution regarding the results of this test).
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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2. ASSESSMENT OF SOURCE TESTS RESULTS Table 1 below summarizes the emission factors derived from source tests conducted on ACIs. For comparison, Table 2 summarizes the generally accepted emission factors for open burning and for biomass power plants. Table 1 - Emissions Test Results of Air Curtain Incinerators
Test Material Year NOx (lb/ton) SOx (lb/ton) PM10 (lb/ton) CO (lb/ton) VOC (lb/ton) Notes AP-42, 2.1-12, J.O. Burckle Wood and cord wood 1968 4 - 13 - - Pilot Scale Box Trench Burner, Max temp 1,300 F. Fountainhead Engineering, Michigan Wood 2000 Not reported* Not reported 0.12 1.1 Not reported Modified EPA Methods. USDA, Baker Oregon, (Air Curtain S-217) Forest vegetation 2002 Not measured Not measured 1.1 (PM2.5) 2.6 1.1 Missoula Fire Science Lab
USDA, San Bernardino (McPherson M30) Forest vegetation 2003 Not measured Not measured 1.4 (PM2.5) 30 0.6 Missoula Fire Science Lab BC Hydro, Jordan River British Columbia Wood 2003 0.04 0.0031 0.13 0.61 0.11 Modified EPA Methods and Canadian Methods Victoria, Australia Wood 2016 0.27 0.23 0.0064 4.2 0.096 (US)EPA Methods US EPA – Hurricane Katrina Vegetative material 2016 1.6 0.49 7.7 6.9 0.41 See Attachment A, Table 5-1 for NOx, SOx, CO, and VOC; Table 5-4 for PM10 * The Victoria, Australia test indicated the Fountainhead test showed 0.05 lb-NOx/ton, but this was not confirmed by the Valley Air District. Table 2 – Emission Factors for Biomass Open Burn and Biomass Power Plant
Source Material Year NOx (lb/ton) SOx (lb/ton) PM10 (lb/ton) CO (lb/ton) VOC (lb/ton) Notes/ Documentation Open Burn – ARB Almond 1992 5.9 0.1 7.0 52 5.2 ARB Memo Open Burn – ARB Forest Not indicated 3.5 0.1 19 - 30 154 - 312 8 - 21 ARB Memo Open Burn – AP-42 Almond 1974 - - 6 (PM) 46 6 AP-42, Table 2.5-5 Open Burn – AP-42 Forest 1995 4 (est.) - 17 140 19 AP-42, Table 2.5-5 Merced Power (N-4607-8) & Ampersand Chowchilla (C-6923-3) Biomass - 1.2 (1.1) 0.61 (0.033) 0.61 (0.089) 0.87 (0.25) 0.076 Permitted EFs (top) and average of seven source tests (indicated in parentheses) of two active biomass power plants
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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B. Fountainhead, Table 1 (PM10, CO) The Fountainhead study was conducted in October, 2000 in Clarkston, Michigan using a Whitton Model S-127 ACI having a 15-18 ton per hour capacity, burning wood debris. The nature of the wood debris is not described, but the location of the test is in a forested region of Michigan. The test will therefore be considered in this analysis to establish representative emission factors for agricultural sources and forest vegetation. The PM10 emission factor (0.13 lb-PM10/ton) from the Fountainhead test is only slightly greater than the average PM10 emission factor (0.089 lb-PM10/ton) measured from the seven most recent source tests of the biomass power plants Merced Power (N-4607-8) and Ampersand Chowchilla (C-6923-3), which have a fabric filter for PM10 control. The fabric filter has been established as the highest level of PM10 control for biomass combustion through extensive emissions testing with District oversight. In general, fabric filters are expected to achieve at least 99% control for PM10. For open burning of almond orchard wood, the accepted PM10 emission factor is 7.0 lb-PM10/ton. When compared to the 0.13 lb-PM10/ton emission factor from the Fountainhead test, the ACI would appear to have achieved over 98% control efficiency, which is comparable to the fabric filter control efficiency rate used to control biomass combustion emissions. The District at this point does not believe that sufficient information is available to overrule the District’s doubt that an ACI can achieve a nearly equal level of PM10 emission control as a high efficiency fabric filter. For instance, ACIs are known to have visible emissions during the approximately 10 - 30 minute start-up period before the air curtain is engaged, when the combustion process is presumably roughly equivalent to an open burn. Also, when new material is added to the firebox, the flow of the air curtain is broken, and the ACI emits a puff of smoke. The fabric filter does not have such gaps associated with its effectiveness as a PM10 control device. Moreover, it is uncertain whether the emission factor adequately accounts for the periodic puffs of smoke from loading because the sampling probe is positioned for the maximum firebox exit velocity during steady-state operation of the air curtain, which is usually at the edge of the firebox opposite the air manifold, whereas the puff of smoke occurs above the material drop point, typically more toward the middle of the firebox. These considerations lead one to believe that the ACI emission factor for PM10 should be higher than the biomass power plant emission factor for PM10. C. BC Hydro, Table 1 (NOx, SOx, PM10, CO, and VOC) The BC Hydro study was conducted in March, 2003 in Jordon River, British Columbia using an Air Burners Inc. Model S-116 ACI loaded between 4 – 8 metric tonnes per hour, burning wood debris. Although the nature of the wood debris is not described, the location of the test is in a forested region of British Columbia. The test will therefore be considered in this analysis to establish representative emission factors for agricultural sources and forest vegetation.
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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Similar to the Fountainhead results, the PM10 emission factor from BC Hydro (0.12 lb-PM10/ton was roughly equivalent to the average PM10 emission factor from biomass power plants. As discussed above, the District believes that the ACI emission factor for PM10 is likely higher than the fabric filter controlled biomass power plant emission factor for PM10. The BC Hydro test also reported a NOx emission factor (0.04 lb-NOx/ton) that is significantly lower than the average emission factor (1.1 lb-NOx/ton) from seven recent source tests conducted on the biomass power plants using selective non-catalytic reduction (SNCR) with ammonia injection as a NOx control. NOx reduction levels from SNCR range from 30 to 50% according to EPA’s Fact Sheet (EPA-452/F-03-031). It follows then that the BC Hydro NOx emission test would appear to represent a 99% reduction in NOx compared to open burn and a 96% reduction compared to the biomass boiler already controlled by SNCR.
Two possible explanations for the lower NOx emission factors from the ACI tests are that the biomass power plants burn plant material that is higher in nitrogen (i.e. fuel NOx) or that the boiler operates at a higher combustion temperature (i.e. thermal NOx). An analysis of the nitrogen content of the plant material burned in the biomass boiler versus the nitrogen content of the plant material burned in the ACI would need to be performed to establish that the fuel is the source of the difference in NOx emissions.2 A comparison of peak operating temperatures does not suggest that the air curtain would produce less thermal NOx. Biomass boilers may reach temperatures of 1,850 ⁰F; whereas an ACI can reach temperatures over 2,000 ⁰F. Factors other than temperature, such as residence time in the combustion hot zones, may account for differences in thermal NOx emissions, but the District is not aware that this speculative explanation has been demonstrated. These considerations lead the District to believe that the NOx emission factor for an ACI should be significantly higher than recorded in this test. D. Victoria, Australia, Table 1 (NOx, SOx, PM10, CO, and VOC) The Victoria study was conducted in February, 2016 at a recycling plant. The material burned was “clean” wood, i.e. vegetative material and uncoated wood pallets, at a rate of 4.2 metric tonnes per hour. Therefore, this source test will be considered in this analysis to establish emission factors for agricultural sources and forest vegetation. The PM10 emission factor from the Victoria test (0.0064 lb-PM10/ton) was significantly lower than the average PM10 emission factor (0.089 lb-PM10/ton) measured from biomass power plants. For the reasons discussed above, this PM10 emission rate cannot be used at this time.
2 Extensive Operating Experiments on the Conversion of Fuel-Bound Nitrogen into Nitrogen Oxides in the Combustion of Wood Fuel, Forests 2017, 8, 1. For timber wood having nitrogen content between 0.04 and 1.2%, the conversion of nitrogen to NOx ranged from approximately 66% to 15%, respectively, i.e. the rate of nitrogen to NOx conversion decreased exponentially with increasing nitrogen content.
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The Victoria test also reported a NOx emission factor (0.27 lb-NOx/ton) that is significantly lower than recent source tests conducted on the biomass power plants using selective non-catalytic ammonia injection as a NOx control. Similar to the BC Hydro test results, the District believe that the NOx emission factor for an ACI should be significantly higher than recorded in this test. E. USDA, Baker, Oregon from Table 1 (PM10, CO, and VOC) USDA performed an ACI emission study in October, 2002 in Baker, Oregon, using an Air Curtain Inc. Model S-217 ACI, having a capacity of 6 tons per hour. The material burned was Ponderosa Pine trees. The test will therefore be considered in this analysis to establish representative emission factors for agricultural sources and forest vegetation. The PM10 emission factor obtained from the USDA Baker, Oregon test is 1.15 lb-PM10/ton, which is the third highest PM10 emission factor of all the source tests conducted on actual ACIs. The USDA source tests measured PM2.5. This was converted into a PM10 emission factor by using the ratio of PM10 to PM2.5 from ARB open burn emission factors for almond agricultural residues. For almond agricultural residues, the ratio of PM10 to PM2.5 is 7.0 lb-PM10/ton to 6.7 lb-PM2.5/ton. Therefore 1.1 lb-PM2.5/ton × (7.0 lb-PM10/ton ÷ 6.7 lb-PM2.5/ton) = 1.15 lb-PM10/ton This emission factor is an order of magnitude larger than the PM10 emissions measured for the biomass power plants (0.089 lb-PM10/ton), which are controlled by a fabric filter, and yet lower than the emission factor for open burning of almond wood (7.0 lb-PM10/ton), which is an uncontrolled source. As the ACI is a controlled form of open burning, it is reasonable that the PM10 emission factor for an ACI would be lower than the PM10 emission factor for open burning. Thus, the USDA emission factor for PM10 falls between the expected upper bound (uncontrolled open burning) and lower bound (biomass power plant with a fabric filter). As PM10, CO and VOC are the products of incomplete combustion, acceptance of the PM10 emission factor implies an acceptance of the CO and VOC emission factors as well. The USDA study did not include NOx or SOx emission factors. F. USDA, San Bernardino from Table 1 (PM10, CO, and VOC) USDA performed a second ACI emission study in June, 2003 in San Bernardino (Lake Arrowhead), California, using a McPherson Model M30 ACI burning forest vegetation. The burn rate (tons per hour) of the unit was not identified. The test will therefore be considered in this analysis to establish representative emission factors for agricultural sources and forest vegetation.
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The PM emission factor obtained from the San Bernardino study is 1.46 lb-PM10/ton, similar to the Baker, Oregon study above. The USDA source tests measured PM2.5. This was converted into a PM10 emission factor by using the ratio of PM10 to PM2.5 from ARB open burn emission factors for almond agricultural residues. For almond agricultural residues, the ratio of PM10 to PM2.5 is 7.0 lb-PM10/ton to 6.7 lb-PM2.5/ton. Therefore 1.4 lb-PM2.5/ton × (7.0 lb-PM10/ton ÷ 6.7 lb-PM2.5/ton) = 1.46 lb-PM10/ton For CO, the reported emission factor was 30 lb-CO/ton, which is an order of magnitude higher than the CO emission factor reported for the Baker, Oregon study and more than four times larger than the next highest reported CO emission factor in Table 1. The San Bernardino report includes tables comparing the Baker, Oregon results to the San Bernardino results. Those tables also show the CO emission factor for the Baker, Oregon study to be ten times larger, i.e. 26 lb-CO/ton than originally reported. It should be noted that the Baker, Oregon study and the San Bernardino study have different lead authors, and no mention is made in the report of USDA making a correction to the originally reported CO emission factor from the Baker, Oregon study. USDA has not responded to requests for clarification of this matter. Norbert Fuhrmann, Vice President of Air Burners, Inc. disputed the 26 lb-CO/ton emission factor in the San Bernardino report, stating that the originally reported value from Baker, Oregon of 2.6 lb-CO/ton was correct and that an error in the placement of the decimal had likely been made in the San Bernardino report. If Mr. Fuhrmann’s contention is correct, the CO emission factors from the USDA studies would agree better with the other ACI CO emission factors reported in Table 1. Nevertheless, since USDA has not issued a correction for the San Bernardino CO emission factor, the District will regard the reported value of 30 lb-CO/ton as the official value from this study. As noted at the beginning of this analysis, the District is primarily concerned with choosing the most representative emission factors for an ACI incinerating woody biomass derived from agricultural sources and forests. The CO emission factor reported in the San Bernardino study (30 lb-CO/ton) is roughly the same order of magnitude as the open burn emission factors in Table 2 for almond wood (e.g. 46 lb-CO/ton and 52 lb-CO/ton). Since the available data suggests that the ACI should perform an order of magnitude better than open burning for the products of incomplete combustion (i.e. PM10, CO and VOC), the CO emission factor from this study will not be considered representative for an ACI burning woody biomass derived from agricultural sources or forests. In ATC project N-1162806, for an ACI burning almond sticks at an almond huller, the concern about the representativeness of the CO emission factor in the San Bernardino study extended to the other pollutants measured in that study (PM2.5 and VOC). One of the criteria for selecting emission factors in the ATC project was to accept or reject emission factor sets for PM10, CO and VOC because of the assumption that the emission factors of these pollutants are related as the products of incomplete combustion. Therefore, none of the reported emission factors from San Bernardino were used in the ATC project. However, since other emission factor sets of PM, CO and VOC have been evaluated based on the reported PM emission factor, and PM
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emission factor from the San Bernardino study is comparable to the Baker, Oregon study, the District has now reconsidered the use of the PM and VOC emission factors from the San Bernardino study. Therefore, in this memo, the District will include the PM and VOC emission factors from the San Bernardino study with the Baker, Oregon study as representative for the burning of woody biomass derived from both agricultural sources and forests. The USDA study did not include NOx or SOx emission factors. G. Assessment of EPA “Katrina” Study (NOx, SOx, PM10, CO, and VOC) The District received a draft copy of EPA’s Managing Debris after a Natural Disaster: Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: Source Emissions Measurement Results, November 17, 2016 (see Attachment A). The study measured emissions and estimated emission factors for an ACI burning vegetative and construction and demolition debris in 2008 as part of the cleanup from Hurricane Katrina. Three test runs of the emissions from vegetative debris and three test runs for construction and demolition debris were measured separately. Based on the District’s analysis of EPA’s document (Attachment B), the District concluded that the emission factors from EPA’s study are likely overstated and cannot be found to be representative of the emissions from incineration of the agricultural or forest wood biomass in California. Therefore, the results of this test are not recommended to be used in future permitting actions for air curtain incinerators in the District and will not be discussed any further. 3. EMISSION FACTOR DETERMINATION Based on the following reasons, a single set of ACI emission factors will be recommended for use for both agricultural wood (such as orchard pruning, almond sticks, orchard removals, etc) and forest vegetation (such as large parts of tree trunk, branches and other woody materials): (1) There are no published ACI emission studies specific to agricultural wood; all the available ACI studies are based on forest vegetation or a mix of forest vegetation and generic wood (e.g. wood pallets). (2) The USDA studies that are the basis of the PM10, CO, and VOC emission factors recommended in Table 3 below burned forest vegetation, with can be large sections of trunks and small wood. Among the ACI tests considered as potentially representative, the USDA studies produced the highest PM10 and VOC emission factors. (3) The ARB (August 17, 2000 Memorandum) open burn emission factors for the products of incomplete combustion (i.e. PM10, CO, and VOC) are generally higher
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for forest vegetation than for agricultural materials. Since ACI may be considered a controlled form of open burning, the same pattern present in the open burn emission factors may be expected in the ACI emission factors so use of emissions factors for forest debris is likely to conservatively overstate emissions from agricultural waste. (4) The SOx emission factor is entirely material dependent, and the SOx emission factor for open burning orchard and vineyard residues is the same as for forest vegetation. (5) The open burn emission factors for NOx for orchard and vineyard wood residues are higher than the NOx open burn emission factor for forest wood. When taken with point (1) above, this means that a single NOx emission factor based on a forest vegetation test may be too low if it is also used to represent woody agricultural residues. However, the District’s estimated NOx emission factor includes a compliance margin that more than compensates for the potential greater NOx emissions from woody agricultural residues. Based on the analysis presented in Section 2 above, the District has determined the following emission factors to be appropriately conservative and representative for the burning of woody biomass derived from agricultural sources and forest vegetation in an ACI. NOx Only the BC Hydro and Victoria ACI emissions tests reported a NOx emission factor. However, for the reasons discussed in Sections 2D and 2E above, the emission factors derived from those tests appear to be insufficiently conservative when compared to the NOx emission factor for a biomass boiler. Therefore, the District estimated a more conservative NOx emission factor of 1.0 lb-NOx/ton by multiplying the emission factors reported by BC Hydro and Victoria by a ratio of concentrations. The numerator in this ratio was based on NOx concentration measurements from a 2007 EPA study, Emissions from the Burning of Vegetative Debris in Air Curtain Destructors, J. AWMA, 57, 959-967. This 2007 EPA study did not include measurements of exhaust flow rate or tons of vegetative debris burned; therefore, no emission factors could be derived from the study by itself. Although the open burn emission factors for NOx for orchard and vineyard residues is higher than the NOx open burn emission factor for forest vegetation by a factor of 1.5 to 1, the District’s estimated NOx emission factor is almost 4 times higher than the highest NOx emission factor measured among the potentially representative ACI emissions tests. Therefore, the recommended NOx emission factor provides a sufficient compliance margin to allow for the potential that smaller sized wood pieces from agricultural sources would burn hotter in an ACI, and potentially producing more thermal NOx, than large wood pieces from forest vegetation. See Attachment C for the derivation of the 1.0 lb-NOx/ton emission factor.
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SOx Since SOx emissions are entirely dependent on the sulfur content of the material burned, the most representative SOx emission factor for an ACI burning woody biomass derived from agricultural sources and forests will be the same as for open burning of those materials, i.e. 0.1 lb-SOx/ton (ARB Memo, “Agricultural Burning Emission Factors,” 2000). PM10 Our current engineering judgement is that PM10 emissions from the combustion of woody biomass in ACIs should be higher than PM10 emissions from a biomass power plant controlled by a fabric filter baghouse. Although there is a growing body of evidence that ACIs are capable of achieving complete combustion with minimal PM10 emissions, to remain conservative when establishing a PM10 emission factor for ACI, the District is recommending the use of the higher PM10 emissions factors derived from the USDA studies in Baker, Oregon and San Bernardino. The emission factors from the USDA Baker, Oregon (1.15 lb-PM10/ton) and USDA San Bernardino (1.46 lb-PM10/ton) studies are the second and third highest PM emission factors among the full scale ACIs tested, and the only PM emission factors that are lower than the PM10 emission factors for uncontrolled open burning of woody agricultural and forest biomass and higher than the PM10 emission factor for a biomass power plant with fabric filter for PM10 control. The average PM10 emission factor for the USDA tests is (1.15 lb-PM10/ton + 1.46 lb-PM10/ton)/2 = 1.3 lb-PM10/ton. Therefore, the 1.3 lb-PM10/ton emission factor derived from the two USDA studies will be accepted as the most representative and conservative PM emission factor for the burning of woody biomass from agricultural sources and forests in an ACI. CO As PM10, CO and VOC are all the products of incomplete combustion, acceptance of the PM10 emission factor from the USDA Baker, Oregon study implies an acceptance of the CO emission factor (2.6 lb-CO/ton) as well. The CO emission factor from the San Bernardino study was not included for reasons discussed in Section 2F of this memo. Among the full scale ACIs tested, the Baker, Oregon study produced the median value for a CO emission factor. VOC As PM10, CO and VOC are all the products of incomplete combustion, acceptance of the PM10 emission factors from the USDA studies implies acceptance of the VOC emission factors, as well (1.1 lb-VOC/ton and 0.6 lb-VOC/ton, with an average of 0.9 lb-VOC/ton). Among the full scale ACIs tested, the USDA studies produced the highest two emission factors for VOC.
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CONCLUSION Table 3 below summarizes the emission factors selected from the determination above for an ACI burning woody biomass derived from agricultural sources and forest vegetation. Table 3: Emission Factors for Air Curtain Incinerator Burning Woody Biomass (Agricultural Sources and Forest Vegetation)
Pollutant Emission Factor (lb/ton) Source
NOx 1.0 SJV Estimation Using/Averaging Data from Multiple Studies, Attachment B
SOx 0.1 ARB Open Burn for Orchard and Vine Crops and Forest Biomass, Table 2
PM10 1.3 Average of USDA Baker, Oregon and USDA San Bernardino Air Curtain Tests, Table 1
CO 2.6 USDA, Baker, Oregon Air Curtain Test, Table 1
VOC 0.9 Average of USDA Baker, Oregon and USDA San Bernardino Air Curtain Tests, Table 1 Please note, as discussed in Section 2F above, the USDA San Bernardino ACI study was not included in the emission factor determination for Authority to Construct (ATC) project N-1162806, for an ACI burning almond sticks at an almond huller. The PM10 and VOC emission factors in that project were 1.1 lb-PM10/ton and 1.1 lb-VOC/ton (based on USDA Baker, Oregon). Table 4 below includes a wood ash handling emission factor, which is for the combined activities of unloading from a dump truck and spreading coal fly ash at a landfill. Table 4: Emission Factor for Wood Ash Handling
Pollutant Emission Factor (lb/ton) Source
PM10 0.233 Fugitive particulate emission factors for dry fly ash disposal, Journal of the Air & Waste Management Association, 63(&): 806-818, 2013 Attachment A: Managing Debris after a Natural Disaster, EPA’s Evaluation of Air Curtain Incinerator Emission Source Test Results Attachment B: Managing Debris after a Natural Disaster, SJVAPCD’s Analysis of EPA’s Air Curtain Incinerator Study Attachment C: Derivation of NOx Emission Factor for Air Curtain Incineration of Woody Biomass 3 The emission factor was reported as 18 g/Mg for PM2.5 and 96 g/Mg for PM10 – PM2.5. Thus, the total PM10 emission factor is 18 g/Mg + 96 g/Mg = 114 g/Mg. 114 g/Mg = 114 lb/106 lb × 2,000 lb/1 ton = 0.228 lb-PM10/ton or 0.23 lb-PM10/ton.
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Attachment A Managing Debris after a Natural Disaster: EPA’s Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: Source Emissions Measurement Results (November 17, 2016)
Managing Debris after a Natural Disaster, EPA Air Curtain Emissions Study (11-17-2016).pdf
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Attachment B Managing Debris after a Natural Disaster: Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: SJVAPCD Analysis of EPA’s Air Curtain Incinerator Study
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Analysis of EPA’s Air Curtain Incinerator Study From: Brian Clerico, AQE II To: Arnaud Marjollet, Director of Permit Services Reviewed by: Errol Villegas, Permit Services Manager
Date: March 10, 2017 Re: Evaluation of EPA’s Air Curtain Incinerator Study: Managing Debris after a Natural Disaster: Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: Source Emissions Measurement Results, November 17, 2016 Background The District received a draft copy of EPA’s Managing Debris after a Natural Disaster: Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: Source Emissions Measurement Results, November 17, 2016 (see Attachment A). The study measured emissions and estimated emission factors for an air curtain incinerator (ACI) burning vegetative and construction and demolition debris in 2008 as part of the cleanup from Hurricane Katrina. Three test runs of the emissions from vegetative debris and three test runs for construction and demolition debris were measured separately. The District’s interest in evaluation of this test is in its potential applicability to assessing emissions from Air Curtain Burners that may be employed in and around the San Joaquin Valley to burn vegetative material, such as may be necessary to process over 100 million trees that have died in surrounding forests due to California’s recent extreme drought. Therefore, in evaluating the source test results from this EPA study, the District focused solely on the test runs pertaining to vegetative debris.
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EPA Air Curtain Incinerator Draft Emission Factors Table 1 summarizes the emission factors obtained from this study. Table 1: EPA Emission Factors for Air Curtain Incinerator (Vegetative Debris)
Pollutant Emission Factor (lb/ton) Source
NOx 1.6 Managing Debris after a Natural Disaster: Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: Source Emissions Measurement Result, Table 5-1 for NOx, SOx, CO, and VOC; Table 5-4 for PM10. See Attachment A
SOx 0.49 PM10 7.7 CO 6.9 VOC 0.41 Analysis The District has identified the following concerns with EPA’s draft emission factors for vegetative debris: (1) The vegetative debris in the study is not representative of the types of agricultural or forest wood material in California that would be disposed of in an ACI. The vegetative debris incinerated consisted of material that had been submerged in brackish water for an unknown amount of time before it was recovered and brought to the test site. Section 3.2.1 Feed Debris from the report describes the vegetative material incinerated as follows: It must be noted that the vegetative debris used for fuel was recovered as part of the Hurricane Katrina response and had sat in brackish water for an unknown period of time prior to being recovered and brought to the test site. The debris used in the tests therefore was likely representative of much of the vegetative debris recovered during hurricane response activities, where the debris was exposed to salt water for extended periods of time. This uncontrollable variable may have influenced emissions of chlorinated organic compounds including chlorinated benzenes and phenols as well as polychlorinated dibenzo-p-dioxins and polychlorinated furans. Given the known dependence of PM10, VOC, CO, and SOx emission factors on the material burned, emission factors derived from vegetative debris soaked in salt water cannot be treated as universally applicable to all biomass materials. (2) The pollutant mass emission rates are a function of the measured pollutant concentrations multiplied by total flow rate from the air curtain firebox. EPA’s calculated flow rates used to derive the pollutant mass emission rates may be overstated by a factor of 3 - 6.
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That EPA’s calculated flow rates may be overstated can be seen by a comparison of the calculated “slot” (or linear) velocity derived from the calculated flow rates being 3 to 6 times higher than the measured slot velocity for the same make and model ACI operated by EPA burning the same material in a 2007 study EPA published a 2007 study of limited testing of the Air Burners Model S-327 ACI burning hurricane Katrina vegetative debris in Emissions from the Burning of Vegetative Debris in Air Curtain Destructors, J. AWMA, 57, 959-967. In that study, EPA noted the following: Velocity measurements suggest that the exhaust flow is occurring in a relatively narrow area along the length of the unit on the side opposite the blower (see Figure 5). Measurements of 15 fps [i.e. 15 ft/s] in this narrow area were close to the estimated temperature adjusted flow velocity based on the ACD fan output. The “narrow area” referred to above is an 18 inch-wide slot running the length of the ACI. The measured velocity beyond this slot is 0 f/s, meaning all the exhaust exits the firebox along this slot opposite the blower. This is a finding corroborated by other ACI studies. The 15 ft/s appears to be an average slot velocity measurement, uncorrected for temperature, although the exact temperature corresponding to this velocity is unclear. EPA did not perform velocity measurements in the draft ACI emission factor study; however, EPA did make use of the findings from the 2007 study to design their sample collection scoop for the ACI emission factor study: The entry face of the extraction scoop was 18 inches by 5 inches, with the longer dimension spanning the final 18 inches of the ACB firebox width on the side opposite the blower plenum as shown in Figure 2-2. This 18-inch span along the length of the ACB represents the area where, from earlier flow determinations on an identical burner, essentially all the combustion product gases exit the firebox. With this experience in mind, and the earlier measurement of 15 ft/sec bulk velocity in that 18-inch span, estimated extraction scoop isokinetic variation during the sampling runs was calculated. During the test program, isokinetic variation was between 47.8% and 90.9%, with an average of 65.9%.[Section 3.2.3] Using the calculated flow rates from the emission factor study, an average slot velocity can be calculated. EPA’s calculated flow rates from the firebox are based on a mass balance calculation of carbon (Section 3.4 of the EPA report in Attachment A). Taking the average calculated flow rates from Table 3-2 of the report (104,147 dscfm) and dividing by the area of the slot (27 feet by 1.5 feet), yields and average slot velocity of 43 ft/s at 68 ⁰F, or 94 ft/s at 700 ⁰F (average scoop temperature along the slot). Since the slot velocity is directly proportional to the average volumetric flow rate, if the volumetric flow is overstated by a factor of 3 (43 ft/s ÷ 15 ft/s) to 6 (94 ft/s ÷ 15 ft/s), then so too will be the emission factors, which are based on the calculated flow rates.
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One possible objection to this comparison of the calculated versus the measured slot velocities would be that we do not know the feed rate to the ACI when the velocity measurements were made in the EPA 2007 study. If the feed rates during the slot velocity measurements in the 2007 study were low in comparison to the feed rates during the emission measurements in the emission factor study, then the claim above is not valid. We do know, however, that during the emission factor study, the feed rates to the ACI were reported as 4.8 ton/hr, 4.8 ton/hr and 6.8 ton/hr. Air Burners Model S-327 ACI has a capacity of 6-10 tons/hr. Thus, the feed rates to the ACI during the emission factor study were either below the rated capacity of the unit or on the low side. It seems unlikely during the 2007 study, EPA would have operated the ACI at a feed rate 3 to 6 times lower, i.e. 1 – 2 ton/hr, to account for the observed difference in the measured to the calculated velocities. (3) The high SOx emission factor suggests a possible overstatement of all the emission factors by a factor of 4 - 5. The draft SOx emission factor (0.49 lb/ton) is more than twice the next highest reported emission factor for an ACI and almost five times the open burn value for almonds or forest material. Since SOx emissions are purely a function of the sulfur content of the material burned, the high SOx emission factor could be another indicator that the emission factors are high across the board by a factor of four to five because of EPA’s flow rate calculation estimation procedure above. An alternative explanation for the high sulfur is that the wood burned could have a considerable amount of sulfur contamination from being submerged in brackish water for an unknown amount of time; however, this could raise concerns of the representativeness of the emission factors for material not subjected to the same conditions. On the other hand, when coupled with concern number 2, above, the weight of evidence starts to lead to a conclusion that the emissions factors are significantly overestimated. The following concerns relate specifically to EPA’s particulate matter (PM10) emission factor. (4) EPA’s proposed PM10 emission factor is greater than the currently accepted emission factor for open burning of almond wood as well as many other agricultural materials. The emission factors for open burning of almond wood (6 lb-PM/ton, AP-42, Table 2.5-5; or 7.0 lb-PM10/ton, ARB Memo, “Agricultural Burning Emission Factors,” August 17, 2000) are lower than EPA’s proposed air curtain emission factor (7.7 lb-PM10/ton). For the same material burned, we believe all parties should agree that the PM10 emission factor for the ACI should be significantly lower than the emission factor for open burning. At a minimum, this suggests that EPA’s proposed emission factor cannot be universally applied to all wood materials.
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When considered in conjunction with concerns 2 and 3 above, and the expectation of actual control of PM10 emissions when comparing ACI to open burning (prior tests demonstrated a control efficiency of 54% to 99+%), the weight of evidence continues to grow that emissions estimates from this study are likely and significantly overstated. (5) The hurricane occurred in August 2005, whereas the vegetative debris was retrieved and tested in June 2008. Thus vegetative debris/wood may have been submerged in brackish water for up to three years prior to being sent to the air curtain for incineration. The salt water likely left a residue of salts (i.e. inorganic species) precipitated on and in the wood, which would increase the measured PM concentrations. Possible effect on PM10 EF: 30% too high. The PM fraction contained a relatively high amount of inorganic condensable PM (EPA report, Table 5 – 4: 38% weighted average; 51% in Run 1 and 26% in Run 2, Run 3 not reported). The report noted a variety of chlorinated organics found in the air toxics analysis. The predominant anionic species in salt water is chloride ion, which could be the source of the elemental chlorine in the chlorinated organics observed. Wood is porous, so salts containing chloride ion could infiltrate and precipitate on the wood over time. The presence of salts in combustion processes are known to produce condensable PM, which can be seen in detached white plumes. This phenomenon would be consistent with the opacities recorded in this study, which were higher than in other air curtain tests: e.g. Run 3 failed opacity (using NSPS Subpart EEEE standard). One potential cause for higher opacity could be associated with overloading the air curtain firebox; however, the higher opacities cannot be due to overloading because according to Air Burners Inc., the model air curtain has a capacity of 6-10 tons/hour, but in the Katrina study, it was fed at an average rate of 4.8 tons/hr. Additionally, for open burning, wet wood is known to produce more smoke than dry wood. According to the moisture analysis EPA performed on the vegetative debris burned, the water content was not more than 30%, which is similar to “green” wood. In conversation with District staff, Air Burners, Inc. has claimed that the ACI should be able to burn green wood and maintain compliance with NSPS visible emission limits of 10% opacity or less. As a reference, District Rule 4901, Wood Burning Fireplaces and Wood Burning Heaters, which is a PM rule, prohibits the sale of wood having greater than 20% moisture. For comparison, the average moisture content of almond tree derived biomass = 18% according to the ARB agricultural burning emission factors memo. (6) The average isokinetic variation (ratio of Velocitysample/Velocity“stack”) was 65.9%. Estimated effect on PM10 EF: 10%+ too high. A low isokinetic % means the measured PM value is higher than the actual PM value (https://www.arb.ca.gov/testmeth/vol1/vol1suppl.doc). 90 – 110% (or under some conditions 80 – 120%) is the normal acceptable quality control range. The magnitude of error depends on a number of variables, especially particle size distribution. EPA characterizes the overestimation error from anisokinetic sampling
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conditions in the Katrina study as “slight” perhaps because the PM emission factor appears to be predominantly composed of PM2.5. However, in ARB’s Supplement to Stationary Source Test Methods, Volume 1, Chaper IX, pg. 6), an example is given of a study where an isokinetic variation of 50% represented an 80% over-estimate of the PM12 emissions. On the Fountainhead test, a similar sized unit to the unit used in the EPA study, the reported average isokinetic variation was 112%, which would lead one to believe that the reported Fountainhead emission factor was on the low side, but also that isokinetic sampling is achievable with such as source. From page 90 (pg 106 .pdf) of EPA’s report, ”If isokinetic rate calculations are based upon the estimated total flow rates presented in Table 5-14, variation was between 6.1% and 46.5% isokinetic.” Meaning if EPA’s calculated flow is 100% correct, then the isokinetic variation (#1) is dramatically worse than the 65.9%. The bias to a higher PM rate grows exponentially higher at lower isokinetic percentages. Conclusion Based on the analysis presented above, the District concludes that the weight of evidence suggests that emission factors from EPA’s study Managing Debris after a Natural Disaster: Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: Source Emissions Measurement Results (November 17, 2016) are likely overstated and cannot be found to be representative of the emissions from incineration of vegetative materials. Therefore, the results of this test are not recommended to be used in future permitting actions for air curtain incinerators in the District.
4 This may be a typographical error as volumetric flow rates are presented in Table 3-2, whereas Table 5-1 present mass emission rates.
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Attachment C Derivation of NOx Emission Factor for Air Curtain Incineration of Woody Biomass
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NOx Emission Factor Estimation
There are two published source tests on ACIs where NOx emission factors were derived: BC Hydro (0.040 lb-NOx/ton) and Victoria, Australia (0.274 lb-NOx/ton). These values are significantly lower than the biomass power plant NOx emissions, which is equipped with NOx control selective non-catalytic reduction system). EPA published NO and NO2 concentration measurements (ppmv) from an ACI burning vegetative debris in a 2007 study, Emissions from the Burning of Vegetative Debris in Air Curtain Destructors, J. AWMA, 57, 959-967; however, no emission factor (lb-NOx/ton material burned) was published or derived from the data because no flow rates or material throughputs corresponding to the measured concentrations were measured or published. This 2007 EPA study measured an average NOx (NO + NO2) concentration of 79 ppmv from the air curtain, which is higher than the NOx concentration measurements from the BC Hydro (3.4 ppmv) and Victoria, Australia (19.5 ppmv) tests. Assuming the NOx emission factor that could be derived from the 2007 EPA test data will be proportional to its NOx concentration, following ratio will be used: ൬݈ܾ −ܱܰݔݐ݋݊൰ா௉஺ (ଶ଴଴଻) = ൬݈ܾ −ܱܰݔݐ݋݊൰ ௌ௢௨௥௖௘ ்௘௦௧ ௑ × (݌݌݉ݒ ܱܰݔ)ா௉஺ (ଶ଴଴଻)(݌݌݉ݒ ܱܰݔ)ௌ௢௨௥௖௘ ்௘௦௧ ௑

Source Test X = BC Hydro The NOx emission factor from the BC Hydro test was 0.040 lb-NOx/ton.5 The average NOx concentration measured during the BC Hydro test was 6.5 mg/m3 (at 20 ⁰C). The molar volume of an ideal gas at 20⁰C is 24.1 × 10-3 m3/g-mol.
6.5 ݉݃ ܱܰ௫݉ଷ(ܽݐ 20଴ܥ) × 1 ݃ ݉݋݈ ܱܰଶ46 ݃ ܱܰଶ × 1 ݃1,000 ݉݃ × 24.1 × 10
ିଷ ݉ଷ (ܽݐ 20଴ܥ)1 ݃ ݉݋݈ = 3.4 ݌݌݉ݒ ܱܰ௫ ൬݈ܾ −ܱܰݔݐ݋݊൰ா௉஺ (ଶ଴଴଻)= ൬0.040 ݈ܾ −ܱܰݔݐ݋݊൰஻஼ ு௬ௗ௥௢ × (79 ݌݌݉ݒ ܱܰݔ)ா௉஺ (ଶ଴଴଻)(3.4 ݌݌݉ݒ ܱܰݔ)஻஼ ு௬ௗ௥௢ ൬݈ܾ −ܱܰݔݐ݋݊൰௄ா௉஺ (ଶ଴଴଻)= 0.93 ݈ܾ −ܱܰݔݐ݋݊
5 Based on an emission rate of 0.12 kg-NO2/hr and 6 metric tonnes feed/hr EF = 0.12 kg/hr x 2.2 lb/kg x 1 hr/6 tonne x 1 tonne/1.1 tons = 0.040 lb-NOx/ton
Air Curtain Incinerator Emission Factor Determination March 10, 2017
22
Source Test X = Victoria, Australia The NOx emission factor from the Victoria test was 0.247 lb-NOx/ton. The average NOx concentration measured during the Victoria test was 40.0 mg/Nm3 (i.e. at 0 ⁰C). The molar volume of an ideal gas at 0⁰C is 22.4 × 10-3 m3/g-mol. 40.0 ݉݃ ܱܰଶܰ݉ଷ × 1 ݃ ݉݋݈ ܱܰଶ46 ݃ ܱܰଶ × 1 ݃1,000 ݉݃ × 22.4 × 10
ିଷ ܰ݉ଷ1 ݃ ݉݋݈ = 19.5 ݌݌݉ݒ ܱܰ௫ ൬݈ܾ −ܱܰݔݐ݋݊൰ܧܲܣ (2007)= ൬0.274 ݈ܾ −ܱܰݔݐ݋݊൰஺௨௦௧௥௔௟௜௔ × (79 ݌݌݉ݒ ܱܰݔ)ܧܲܣ (2007)(19.5 ݌݌݉ݒ ܱܰݔ)஺௨௦௧௥௔௟௜௔ ൬݈ܾ −ܱܰݔݐ݋݊൰ܧܲܣ (2007)= 1.1 ݈ܾ −ܱܰݔݐ݋݊ Average NOx Emission Factor Average NOx emission factor (lb/ton) = (0.93 lb-NOx/ton + 1.1 lb-NOx/ton) ÷ 2 Average NOx emission factor (lb/ton) = 1.0 lb-NOx/ton
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION 10

1200 Sixth Avenue, Suite 900
Seattle, WA 98101-3140
OFFICE OF

AIR, WASTE, AND TOXICS

MAY 08 2014
MEMORANDUM
SUBJECT: Particulate Matter Potential to Emit Emission Factors for Activities at Sawmills,
Excluding Boilers, Located in Pacific Northwest Indian Country
FROM: Dan Meyer, Environmental Engineer"~\• A
Air Permits & Diesel Unit c.::..LJ ....... '-.._
THRU: Donald A. Dossett, P.E., Manager Q:;.J
Air Permits & Diesel Unit
TO: Permit File
EPA Region 10 has compiled the attached list ofpmticulate matter (PM-CAA § Ill pollutant,
PMw and PM2.s-criteria pollutants) emission factors ("EFs") for use in determining the
potential emissions, more commonly referred to as potential to emit ("PTE"), for activities at
sawmills, excluding boilers, located in Pacific Northwest Indian Country. 1 The EFs are presented
. in units appropriate for the particular activity. PTE generally represents the maximum capacity of
a source to emit a pollutant under its physical and operational design taking into consideration
restrictions that are federally enforceable. While PM, PMto and PM2.s PTE are all used to
determine applicability of the Compliance Assurance Monitoring program and Prevention of
Significant Deterioration construction permit program, only PMw and PM2.s are employed to
determine applicability of the Title V operating permit progrmn.2
The Federal Air Rules for Reservations ("F ARR") limit particulate matter emissions from
applicable activities at sawmills. The rules and the rationale for not employing them to determine
PTE are as follows: (a) 20 percent opacity limit (40 CFR § 49.124) -lack of a correlation
between opacity and particulate matter emissions, (b) requirements for limiting fugitive
emissions ( 40 CFR § 49 .126) -lack of a correlation between compliance with requirements and
particulate matter emissions, (c) non-combustion stack 0.1 grain per dry standard cubic foot PM
emission limit (40 CFR § 49.125)-resultant PTE would be unrealistically high as we assume
that an unreasonable amount of wood residue is exhausted to atmosphere rather than recovered
for sale or combustion in on-site boiler.
There are no other federal regulations beyond the F ARR that limit particulate matter emissions
from activities addressed by this memorandum. Under the circumstances, it is appropriate to
employ the EFs presented in the attachment to estimate PTE, unless a more representative (e.g.
site-specific) EF is available.
1 Activities include log bucking and debarking, sawing, lumber drying, mechanical and pneumatic conveyance of

wood residue, wind erosion of wood residue piles and traffic along paved and unpaved roads.

2 October 16, 1995 EPA memorandum entitled, "Definition of Regulated Pollutant for Particulate Matter for

Purposes ofTitle V"

EPA Region 10 Particulate Matter Potential to Emit Emission Factors for Activities at Sawmills, Excluding Boilers, Located in Pacific Northwest
Indian Country, May 2014
EF
Reference
No.
Emissions Generating Activity1 PM2
EF
PM10
% of PM
PM10
EF
PM2.5
% of PM
PM2.5
EF Units
1, 2, 3, 4 Log Bucking3 0.035 50 0.0175 25 0.00875 lb/ton log
1, 2, 3, 5 Log Debarking3 0.024 50 0.012 25 0.006 lb/ton log
1, 2, 3, 6 Sawing3 0.350 50 0.175 25 0.0875 lb/ton log
1, 3, 7 Lumber Drying - Resinous Softwood Species4 0.02 100 0.02 100 0.02 lb/mbf
1, 3, 7 Lumber Drying - Non-Resinous Softwood Species5 0.05 100 0.05 100 0.05 lb/mbf
1, 2, 3, 8
"Drop" of "wet" material5 from one surface to another including, but not limited to, (a) each mechanical
conveyance drop between point of generation and storage
bin (but not including bin unless open to atmosphere) (b) loadout from storage bin into a truck bed or railcar and (c)
drop onto a pile. Apply EF to each "drop."
0.00075 N/A 0.00035 N/A 0.00005 lb/bdt
material
1, 2, 3, 8
"Drop" of "dry" material5 from one surface to another
including, but not limited to, (a) each mechanical conveyance drop between point of generation and storage
bin (but not including bin unless open to atmosphere) (b)
loadout from storage bin into a truck bed or railcar and (c) drop onto a pile. Apply EF to each "drop."
0.0015 N/A 0.0007 N/A 0.0001 lb/bdt material
1, 3, 9 Pneumatically convey material6 through medium
efficiency cyclone to bin 0.5 85 0.425 50 0.25 lb/bdt material
1, 3, 9 Pneumatically convey material6 through high efficiency
cyclone to bin 0.2 95 0.19 80 0.16 lb/bdt material
1, 3, 9 Pneumatically convey material6 through cyclone to bin. Exhaust routed through baghouse. 0.001 99.5 0.000995 99 0.00099 lb/bdt material
1, 3, 9 Pneumatically convey material6 into target box 0.1 85 0.085 50 0.05 lb/bdt
material
1, 2, 10 Wind Erosion of Pile 0.38 50 0.19 25 0.095 ton/acre-yr
1, 2, 11 Paved Roads Emission factors based upon site-specific parameters. lb/VMT
1, 2, 12 Unpaved Roads Emission factors based upon site-specific parameters. lb/VMT
Acronyms
bdt: bone dry ton
mbf: 1000 board foot lumber
VMT: vehicle mile traveled
1 If any activity occurs within a building, reduce the PM, PM10 and PM2.5 emission factor ("EF") by 100 percent (engineering judgement) as
emissions struggle to escape through doorways and other openings. If an activity's by-products are evacuated pneumatically to a target box, cyclone or bag filter system, then only the associated downstream conveyance emissions are counted.
2 PM refers to the CAA § 111 pollutant generally measured using EPA Reference Method 5 to determine the filterable fraction of particulate
matter. "Particulate matter” is a term used to define an air pollutant that consists of a mixture of
solid particles and liquid droplets found in the ambient air. PM does not include a condensable fraction.
3 EF for log bucking, debarking and sawing are expressed in units of "lb/ton log" in the table above. The EF can be expressed in units of
"lb/mbf" lumber as follows:
lb/mbf = (lb PM/ton log) X (ton/2000 lb) X (LD lb/ft3) X (LRF bf lumber/ft3 log) X (1000 bf/mbf)
where "LD" stands for log density and "LRF" stands for log recovery factor
• LD values are species-specific and are provided by The Engineering ToolBox and are listed at http://www.engineeringtoolbox.com/weigt-wood-d_821.html
• LRF value of 6.33 bf/ft3 log is specific to softwood species of the Pacific Coast East. See Section 2 of Appendix D to Forest Products Measurements and Conversion Factors with Special Emphasis on the U.S. Pacific Northwest. College of Forest Resources, University of
Washington. 1994. See http://www.ruraltech.org/projects/conversions/briggs_conversions/briggs_append2/appendix02_combined.pdf
4 Douglas Fir, Engelmann Spruce, Larch, Lodgepole Pine, Ponderosa Pine and Western White Pine
5 White Fir, Western Hemlock and Western Red Cedar
6 The "material" in this entry refers to bark, hogged fuel, green chips, dry chips, green sawdust, dry sawdust, shavings and any other woody by-
product of lumber production.
Page 1 of 3

No.
1
2
3
Although this activity may be subject to the FARR visible emissions limit of 20% opacity (40 CFR § 124(d)), the limit was not further
considered in deriving an emission factor due to the lack of a correlation between opacity and particulate matter emissions.
Although this activity may be subject to the FARR stack PM emission limit of 0.1 gr/dscf (40 CFR § 125(d)(3)), that limit was not further
considered in deriving an emission factor because the resultant PTE would be unrealistically high.
EF Reference
Although this activity may be subject to the FARR requirements for limiting fugitive particulate matter emissions (40 CFR §126), those requirements were not further considered in deriving an emission factor due to lack of a correlation between compliance with requirements
and particulate matter emissions.
4
For PM, PM10, and PM2.5 EF, apply engineering judgement to estimate that log bucking emissions are one-tenth sawing emissions. EPA has
stated that log bucking is normally a negligible source of fugitive PM emissions. See page 2-125 of Assessment of Fugitive Particulate
Emission Factor for Industrial Processes, EPA-450/3-78-107, September 1978. The document can be downloaded from internet at http://nepis.epa.gov/Simple.html by entering EPA publication number. For sawing emissions details, see Reference No. 3 below.
5
• For PM EF, see Table 2-47 of Assessment of Fugitive Particulate Emission Factor for Industrial Processes, EPA-450/3-78-107, September
1978. See also Table 2-59 of Technical Guidance for Controls of Industrial Process Fugitive Particulate Emissions, EPA-450/3-77-010,
March 1977. Both documents can be downloaded from internet at http://nepis.epa.gov/Simple.html by entering EPA publication number. EPA revoked the PM EF from WebFIRE on January 1, 2002. See detailed search results for SCC 3-07-008-01 (include revoked factors) at
http://cfpub.epa.gov/webfire/index.cfm?action=fire.detailedSearch
• For PM10 and PM2.5 EF, apply engineering judgement to estimate that (a) PM10 emissions are one-half PM emissions and (b) PM2.5 emissions are one-half PM10 emissions.
• Sawing consists of the following cummulative activities: breaking the log into cants and flitches with a smooth edge, breaking cant further
down into multiple flitches and/or boards, taking the flitch and trim off all irregular edges to leave four-sided lumber and trimming to square
the ends.
7
6
• For PM10 and PM2.5 EF, apply engineering judgement to estimate that all PM emitted is organic aerosols and fully PM10 and PM2.5
emissions.
• For PM EF, see ODEQ ACDP Application Guidance AQ-EF02 (4/25/00). Douglas fir is a resinous softwood species and western hemlock
is a non-resinous softwood species.
• For PM EF, see Table 2-47 of Assessment of Fugitive Particulate Emission Factor for Industrial Processes, EPA-450/3-78-107, September
1978. See also Table 2-59 of Technical Guidance for Controls of Industrial Process Fugitive Particulate Emissions, EPA-450/3-77-010,
March 1977. Both documents can be downloaded from internet at http://nepis.epa.gov/Simple.html by entering EPA publication number. EPA revoked the PM EF from WebFIRE on January 1, 2002. See detailed search results for SCC 3-07-008-01 (include revoked factors) at
http://cfpub.epa.gov/webfire/index.cfm?action=fire.detailedSearch
• For PM10 and PM2.5 EF, apply engineering judgement to estimate that (a) PM10 emissions are one-half PM emissions and (b) PM2.5 emissions are one-half PM10 emissions.
• See Section 13.2.4 of EPA's AP-42, November 2006 at http://www.epa.gov/ttn/chief/ap42/ch13/final/c13s0204.pdf. Apply Equation 1 on
page 13.2.4-4 to estimate emissions resulting from material drops as follows: E [lb PM/ton] = (k) X (0.0032) X (U/5)1.3 / (M/2)1.4
Wet Material Drop
PM
PM10
PM2.5
The following conservative assumptions were made in
applying Equation 1:
Mean wind speed (U) =
(U/5)1.3 =
Material moisture content (M) =
(M/2)1.4 =
Particulate
0.74
0.35
0.053
15
6.66930
34
21.05520
k
miles per hour
percent. Value based upon observations
(M/2)1.4 0.0032 (U/5)1.3
0.0032 6.6693 21.0552
lb PM
ton
0.00075
0.00035
0.00005
Note: • Mean wind speed of 15 mph is a reasonable upper bounder estimate.
MCD = MCW / (1-MCW); where
MCD: moisture content dry basis
MCW: moisture content wet basis
• Moisture content of 34 percent for "wet" material is based upon observation that
average moisture content (dry basis) of green douglas fir lumber (common to the Pacific Northwest) is 51 percent as recorded prior to lab scale kiln VOC
emissions testing conducting by Oregon State University's Mike Milota and organized in Microsoft Excel workbook entitled, "EPA Region 10 HAP and VOC
Emission Factors for Lumber Drying, December 2012." 51 percent moisture
content (dry basis) is equivalent to 34 percent moisture content (wet basis) as illustrated below:
8
0.51 = MCW / (1 - MCW)
0.51 - (0.51)(MCW) = MCW
(1.51)(MCW) = 0.51
MCW = 0.34, or 34 percent
Page 2 of 3
8

Dry Material Drop
lb PM
ton
PM 0.74 0.0015
PM10 0.35 0.0007
PM2.5 0.053 0.0001
The following conservative assumptions were made in applying Equation 1:
Mean wind speed (U) = 15 miles per hour
(U/5)1.3 = 6.6693
Material moisture content (M) = 13 percent
(M/2)1.4 = 10.5552
Note: • Mean wind speed of 15 mph is a reasonable upper bounder estimate.
MCD = MCW / (1-MCW); where
MCD: moisture content dry basis
MCW: moisture content wet basis
0.15 = MCW / (1 - MCW)
0.15 - (0.15)(MCW) = MCW
(1.15)(MCW) = 0.15
MCW = 0.13, or 13 percent
11
12
Particulate k 0.0032 (U/5)1.3 (M/2)1.4
See Equation 1 on page 13.2.1-4 of Chapter 13.2.1 of AP-42, January 2011 at http://www.epa.gov/ttn/chief/ap42/ch13/final/c13s0201.pdf
See Equation 1a on page 13.2.2-4 of Chapter 13.2.2 of AP-42, November 2006 at http://www.epa.gov/ttn/chief/ap42/ch13/final/c13s0204.pdf
• Moisture content of 13 percent for "dry" material is based upon observation that
typical moisture content (dry basis) of kiln-dried lumber is 15 percent as recorded
during lab scale kiln emissions testing conducting by Oregon State University's Mike Milota and organized in Microsoft Excel workbook entitled, "EPA Region 10
HAP and VOC Emission Factors for Lumber Drying, December 2012." 15 percent
moisture content (dry basis) is equivalent to 13 percent moisture content (wet basis) as illustrated below:
9
• For PM EF, see Oregon Department of Environmental Quality (ODEQ) Wood Products Emission Factors, AQ-EF02 Revised 08/01/11. http://www.deq.state.or.us/aq/permit/acdp/docs/AQ-EF02.pdf
• For PM10 and PM2.5 EF, see ODEQ Wood Products Emission Factors - PM10/PM2.5 Fractions, AQ-EF03 Revised 08/01/11.
http://www.deq.state.or.us/aq/permit/acdp/docs/AQ-EF03.pdf
10
• For PM EF, see last row of Table 11.9-4 on page 11.9-11 of Section 11.9 of EPA's AP-42, July 1998 at
http://www.epa.gov/ttn/chief/ap42/ch11/final/c11s09.pdf.
• For PM10 and PM2.5 EF, apply engineering judgement to estimate that (a) PM10 emissions are one-half PM emissions and (b) PM2.5 emissions are one-half PM10 emissions.
0.0032 6.6693 10.5552
Page 3 of 3

Directions: Enter and select information in the boxes in the column on the right:
FIELDS SELECTIONSCOMPANY NAME:FACILITY ID NUMBER:
PERMIT NUMBER
FACILITY CITY:
FACILITY COUNTY:
SPREADSHEET PREPARED BY:
EMISSION SOURCE ID NO.:
MAXIMUM HEAT INPUT (MILLION BTU PER HOUR):MMBTU/HR
TYPE OF BOILER:
TYPE OF FUEL:
FUEL HEATING VALUE
FUEL HEATING VALUE (BTU/LB):BTU/LB 16.00 MM BTU/TON
DEFAULT IS AS FOLLOWS (not used for Greenhouse Gas calcs --See below for GHG d
8000 BTU/LB DRY WOOD
4500 BTU/LB WET WOOD (TYPE OVER NUMBER AT ABOVE RIGHT IF YOU HAVE SITE SPECIFIC DATA)
OTHER SOURCE-SPECIFIC DATA
ACTUAL YEARLY FUEL USAGE (TONS PER YEAR):TPYCALCULATED POTENTIAL YEARLY USAGE (TONS PER YEAR)TPYREQUESTED ANNUAL LIMITATION (TONS PER YEAR)TPY(TYPEOVER IF NECESSARY - DEFAULT IS POTENTIAL)
TYPE OF PARTICULATE CONTROL:
NOX CONTROL IF PRESENT (DEFAULT IS ZERO)%
SITE SPECIFIC STACK TEST DATA FOR PARTICULATE:LB/MMBTU
(IF AVAILABLE: OUTLET FILTERABLE PARTICULATE ONLY)
(LEAVE AS ZERO IF NO DATA AVAILABLE)
NOTE: EF is "Emission Factor"
(decimal fraction)

HIGH HEAT VALUE (HHV) FOR GHGs
FOR TIER 1 and TIER 3, the FUEL HEATING VALUE entered above is overriden with the EPA DEFAULT:15.38 MMBTU/TON
This default HHV is from EPA's MRR, Table C-1, "Wood and Wood Residuals"
FOR TIER 2, the FUEL HEATING VALUE entered above is used. The value entered must be the annual average HHV of the fuel
determined using procedures in the EPA MRR (see 98.33(a)(2) )
NOTE: Using Tier 1, therefore the EPA default HHV will be used for all GHG calculations (CO2, CH4 and N2O)
SINCE TIER 3 IS NOT BEING USED
DO NOT ENTER FUEL CARBON CONTENT
9999R02
ANYTOWN
ANYCOUNTY
ES-1
25.00
0
0
0.500
ENTER CALCULATION TIER
from EPA Mandatory Reporting Rule (MRR) Subpart C -
www.epa.gov/climatechange/emissions/ghgrulemaking.html
8000
3,000.0013,687.5013,687.50
ADDITIONAL INFORMATION FOR GREENHOUSE GAS (GHG) EMISSIONS
WOODWASTE COMBUSTION EMISSIONS CALCULATOR REVISION L 09/03/2019 - INPUT SCREEN
Instructions: Enter emission source / facility data on the "INPUT" tab/screen. The air emission results and summary of
input data are viewed / printed on the "OUTPUT" tab/screen. The different tabs are on the bottom of this screen.
This spreadsheet is for your use only and should be used with caution. DENR does not guarantee the accuracy of the
information contained. This spreadsheet is subject to continual revision and updating. It is your responsibility to be aware
of the most current information available. DENR is not responsible for errors or omissions that may be contained herein.
Facility Name, Inc.01/12/00999
Your Name
FACILITY ID NO.:
PERMIT NUMBER:EMISSION SOURCE DESCRIPTION:FACILITY CITY:EMISSION SOURCE ID NO.:FACILITY COUNTY:
PARTICULATE CONTROL DEVICE:
SPREADSHEET PREPARED BY:FUEL HEAT VALUE:8000 BTU/LB
ACTUAL FUEL THROUGHPUT:3000 TON/YR 15.38POTENTIAL FUEL THROUGHPUT:13688 TON/YR BOILER TYPE:STOKERREQUESTED MAX. FUEL THRPT:13688 TON/YR NO STACK TEST DATA USEDMETHOD USED TO COMPUTE ACTUAL GHG EMISSIONS: TIER 1: DEFAULT HIGH HEAT VALUE AND DEFAULT EFCARBON CONTENT USED FOR GHGS (AS A FRACTION):CARBON CONTENT NOT USED FOR CALCULATION TIER CHOSEN
AIR POLLUTANT EMITTED lb/hr tons/yr lb/hr tons/yr lb/hr tons/yr uncontrolled controlled
PARTICULATE MATTER (PM)7.93 7.61 10.43 45.66 7.93 34.71 0.417 0.317
PARTICULATE MATTER<10 MICRONS (PM10)7.18 6.89 9.43 41.28 7.18 31.43 0.377 0.287
PARTICULATE MATTER<2.5 MICRONS (PM2.5)4.43 4.25 8.18 35.81 4.43 19.38 0.327 0.177
SULFUR DIOXIDE (SO2)0.63 0.60 0.63 2.74 0.63 2.74 0.025 0.025
NITROGEN OXIDES (NOx)12.25 11.76 12.25 53.66 12.25 53.66 0.490 0.490CARBON MONOXIDE (CO)15.00 14.40 15.00 65.70 15.00 65.70 0.600 0.600
VOLATILE ORGANIC COMPOUNDS (VOC)0.43 0.41 0.43 1.86 0.43 1.86 0.017 0.0171.2E-03 1.2E-03 1.2E-03 5.3E-03 1.2E-03 5.3E-03 4.8E-05 4.8E-05
CAS
TOXIC / HAZARDOUS AIR POLLUTANT NUMBER lb/hr lb/yr lb/hr lb/yr lb/hr lb/yr
Acetaldehyde (TH)75070 2.08E-02 39.840 2.08E-02 181.770 2.08E-02 181.770 8.30E-04 8.30E-04
Acetophenone (H)98862 8.00E-08 1.54E-04 8.00E-08 7.01E-04 8.00E-08 7.01E-04 3.20E-09 3.20E-09
Acrolein (TH)107028 1.00E-01 192.000 1.00E-01 876.000 1.00E-01 876.000 4.00E-03 4.00E-03
Antimony Unlisted Compounds (component of SBC) (H)SBC-other 1.98E-04 0.379 1.98E-04 1.730 1.98E-04 1.730 7.90E-06 7.90E-06
Arsenic Unlisted Compounds (component of ASC) (TH)ASC-other 5.50E-04 1.056 5.50E-04 4.818 5.50E-04 4.818 2.20E-05 2.20E-05
Benzene (TH)71432 1.05E-01 201.600 1.05E-01 919.800 1.05E-01 919.800 4.20E-03 4.20E-03
Benzo(a)pyrene (T)50328 6.50E-05 0.125 6.50E-05 0.569 6.50E-05 0.569 2.60E-06 2.60E-06
Beryllium Metal (unreacted) (component of BEC) (T/H)7440417 2.75E-05 0.053 2.75E-05 0.241 2.75E-05 0.241 1.10E-06 1.10E-06
Cadmium Metal (unreacted) (component of CDC) (T/H)7440439 1.03E-04 0.197 1.03E-04 0.898 1.03E-04 0.898 4.10E-06 4.10E-06
Carbon tetrachloride (TH)56235 1.13E-03 2.160 1.13E-03 9.855 1.13E-03 9.855 4.50E-05 4.50E-05
Chlorine (TH)7782505 1.98E-02 37.920 1.98E-02 173.010 1.98E-02 173.010 7.90E-04 7.90E-04
Chlorobenzene (TH)108907 8.25E-04 1.584 8.25E-04 7.227 8.25E-04 7.227 3.30E-05 3.30E-05
Chloroform (TH)67663 7.00E-04 1.344 7.00E-04 6.132 7.00E-04 6.132 2.80E-05 2.80E-05
Chromium Unlisted Cmpds(H)(add w/chrom acid to get CRC)CRC-other 4.38E-04 0.840 4.38E-04 3.833 4.38E-04 3.833 1.75E-05 1.75E-05
Chromic acid (VI) (component of solCR6 and CRC)(T/H)7738945 8.75E-05 0.168 8.75E-05 0.767 8.75E-05 0.767 3.50E-06 3.50E-06
Cobalt Unlisted Compounds (component of COC) (H)COC-other 1.63E-04 0.312 1.63E-04 1.424 1.63E-04 1.424 6.50E-06 6.50E-06
Dinitrophenol, 2,4- (H)51285 4.50E-06 8.64E-03 4.50E-06 0.039 4.50E-06 0.039 1.80E-07 1.80E-07
Di(2-ethylhexyl)phthalate (DEHP) (TH)117817 1.18E-06 2.26E-03 1.18E-06 1.03E-02 1.18E-06 1.03E-02 4.70E-08 4.70E-08
Ethyl benzene (H)100414 7.75E-04 1.488 7.75E-04 6.789 7.75E-04 6.789 3.10E-05 3.10E-05
Ethylene dichloride (1,2-dichloroethane) (TH)107062 7.25E-04 1.392 7.25E-04 6.351 7.25E-04 6.351 2.90E-05 2.90E-05
Formaldehyde (TH)50000 1.10E-01 211.200 1.10E-01 963.600 1.10E-01 963.600 4.40E-03 4.40E-03
Hexachlorodibenzo-p-dioxin 1,2,3,6,7,8 (TH)57653857 4.48E-10 8.59E-07 4.48E-10 3.92E-06 4.48E-10 3.92E-06 1.79E-11 1.79E-11
Hydrogen chloride (hydrochloric acid) (TH)7647010 4.75E-01 912.000 4.75E-01 4161.000 4.75E-01 4161.000 1.90E-02 1.90E-02
Lead Unlisted Compounds (component of PBC) (H)PBC-other 1.20E-03 2.304 1.20E-03 10.512 1.20E-03 10.512 4.80E-05 4.80E-05
Manganese Unlisted Compounds (component of MNC) (TH)MNC-other 4.00E-02 76.800 4.00E-02 350.400 4.00E-02 350.400 1.60E-03 1.60E-03
Mercury, vapor (component of HGC)(T/H)7439976 8.75E-05 0.168 8.75E-05 0.767 8.75E-05 0.767 3.50E-06 3.50E-06
Methyl bromide (H) (bromomethane)74839 3.75E-04 0.720 3.75E-04 3.285 3.75E-04 3.285 1.50E-05 1.50E-05
Methyl chloride (H) (chloromethane)74873 5.75E-04 1.104 5.75E-04 5.037 5.75E-04 5.037 2.30E-05 2.30E-05
Methyl chloroform (TH) (1,1,1 trichloroethane)71556 7.75E-04 1.488 7.75E-04 6.789 7.75E-04 6.789 3.10E-05 3.10E-05
Methyl ethyl ketone (T)78933 1.35E-04 0.259 1.35E-04 1.183 1.35E-04 1.183 5.40E-06 5.40E-06
Methylene chloride (TH) (dichloromethane)75092 7.25E-03 13.920 7.25E-03 63.510 7.25E-03 63.510 2.90E-04 2.90E-04
Naphthalene (H)91203 2.43E-03 4.656 2.43E-03 21.243 2.43E-03 21.243 9.70E-05 9.70E-05
Nickel metal (Component of 373024/NIC) (T/H)7440020 8.25E-04 1.584 8.25E-04 7.227 8.25E-04 7.227 3.30E-05 3.30E-05
Nitrophenol, 4- (H)100027 2.75E-06 5.28E-03 2.75E-06 2.41E-02 2.75E-06 2.41E-02 1.10E-07 1.10E-07
Pentachlorophenol (TH)87865 1.28E-06 2.45E-03 1.28E-06 1.12E-02 1.28E-06 1.12E-02 5.10E-08 5.10E-08
Perchloroethylene (tetrachloroethylene) (TH)127184 9.50E-04 1.824 9.50E-04 8.322 9.50E-04 8.322 3.80E-05 3.80E-05
Phenol (TH)108952 1.28E-03 2.448 1.28E-03 11.169 1.28E-03 11.169 5.10E-05 5.10E-05
Phosphorus Metal, Yellow or White (H)7723140 6.75E-04 1.296 6.75E-04 5.913 6.75E-04 5.913 2.70E-05 2.70E-05
Polychlorinated biphenyls (TH)1336363 2.04E-07 3.91E-04 2.04E-07 1.78E-03 2.04E-07 1.78E-03 8.15E-09 8.15E-09
Polycyclic Organic Matter (H)POMTV 3.13E-03 6.000 3.13E-03 27.375 3.13E-03 27.375 1.25E-04 1.25E-04
Propionaldehyde (H)123386 1.53E-03 2.928 1.53E-03 13.359 1.53E-03 13.359 6.10E-05 6.10E-05
Propylene dichloride (H) (1,2 dichloropropane)78875 8.25E-04 1.584 8.25E-04 7.227 8.25E-04 7.227 3.30E-05 3.30E-05
Selenium compounds (H)SEC 7.00E-05 0.134 7.00E-05 0.613 7.00E-05 0.613 2.80E-06 2.80E-06
Styrene (TH)100425 4.75E-02 91.200 4.75E-02 416.100 4.75E-02 416.100 1.90E-03 1.90E-03
Tetrachlorodibenzo-p-dioxin, 2,3,7,8- (TH)1746016 2.15E-10 4.13E-07 2.15E-10 1.88E-06 2.15E-10 1.88E-06 8.60E-12 8.60E-12
Toluene (TH)108883 2.30E-02 44.160 2.30E-02 201.480 2.30E-02 201.480 9.20E-04 9.20E-04
Trichloroethylene (TH)79016 7.50E-04 1.440 7.50E-04 6.570 7.50E-04 6.570 3.00E-05 3.00E-05
Trichlorophenol, 2,4,6- (H)88062 5.50E-07 1.06E-03 5.50E-07 4.82E-03 5.50E-07 4.82E-03 2.20E-08 2.20E-08
Vinyl chloride (TH)75014 4.50E-04 0.864 4.50E-04 3.942 4.50E-04 3.942 1.80E-05 1.80E-05
Xylene (TH)1330207 6.25E-04 1.200 6.25E-04 5.475 6.25E-04 5.475 2.50E-05 2.50E-05
* Highest HAP (Hydrogen chloride (hydrochloric acid) (TH))7647010 4.75E-01 912.000 4.75E-01 4161.0 4.75E-01 4161.0 1.90E-02 1.90E-02
* Total HAPs NA 9.71E-01 1.86E+03 9.71E-01 8.50E+03 9.71E-01 8.50E+03 3.88E-02 3.88E-02
ANYCOUNTY
CONTROL EFF.
PM10PM2.5
(AFTER CONTROLS / LIMITS)
EMISSION FACTOR
uncontrolled / controlled
POTENTIAL EMSSIONS
POTENTIAL EMSSIONS
(AFTER CONTROLS / LIMITS)
CRITERIA AIR POLLUTANT EMISSIONS INFORMATION
TOXIC / HAZARDOUS AIR POLLUTANT EMISSIONS INFORMATION
LEAD
ACTUAL EMISSIONS
(AFTER CONTROLS / LIMITS)
EMISSION FACTOR
lb/mmBtu
lb/mmBtu
CALC'D AS 45.9%
ACTUAL EMISSIONS
WOODWASTE COMBUSTION EMISSIONS CALCULATOR REVISION L 09/03/2019 - OUTPUT SCREEN
Instructions: Enter emission source / facility data on the "INPUT" tab/screen. The air emission results and summary of input data are viewed / printed on the "OUTPUT" tab/screen. The different tabs are on the bottom of this screen.
This spreadsheet is for your use only and should be used with caution. DENR does not guarantee the accuracy of the
information contained. This spreadsheet is subject to continual revision and updating. It is your responsibility to be aware
of the most current information available. DENR is not responsible for errors or omissions that may be contained herein.
0
CALC'D AS 24%CALC'D AS 23.9%
NOX
SOURCE / FACILITY / USER INPUT SUMMARY (FROM INPUT SCREEN)
Facility Name, Inc.
25 MMBTU/HR DRY WOOD (<= 19 % MOISTURE) FIRED BOILER 9999R02ANYTOWN
COMPANY:01/12/00999
POLLUTANT
ES-1
PM
MECHANICAL COLLECTOR (NO REINJECTION)
HHV Used for GHGs (MMBTU/TON):
Your Name
(AFTER CONTROLS / LIMITS) (BEFORE CONTROLS / LIMITS)
(BEFORE CONTROLS / LIMITS)
TOXIC AIR POLLUTANT CAS Num.uncontrolled controlled
Acetaldehyde (TH)75070 8.30E-04 8.30E-04
Acrolein (TH)107028 4.00E-03 4.00E-03
Arsenic Unlisted Compounds (component of ASC) (TH)ASC-other 2.20E-05 2.20E-05
Benzene (TH)71432 4.20E-03 4.20E-03
Benzo(a)pyrene (T)50328 2.60E-06 2.60E-06
Beryllium Metal (unreacted) (component of BEC) (T/H)7440417 1.10E-06 1.10E-06
Cadmium Metal (unreacted) (component of CDC) (T/H)7440439 4.10E-06 4.10E-06
Carbon tetrachloride (TH)56235 4.50E-05 4.50E-05
Chlorine (TH)7782505 7.90E-04 7.90E-04
Chlorobenzene (TH)108907 3.30E-05 3.30E-05
Chloroform (TH)67663 2.80E-05 2.80E-05
Di(2-ethylhexyl)phthalate (DEHP) (TH)117817 4.70E-08 4.70E-08
Ethylene dichloride (1,2-dichloroethane) (TH)107062 2.90E-05 2.90E-05
Soluble Chromate Cmpds, as Chrome (VI) (TH)SOLCR6 3.50E-06 3.50E-06
Formaldehyde (TH)50000 4.40E-03 4.40E-03
Hexachlorodibenzo-p-dioxin 1,2,3,6,7,8 (TH)57653857 1.79E-11 1.79E-11
Hydrogen chloride (hydrochloric acid) (TH)7647010 1.90E-02 1.90E-02
Manganese Unlisted Compounds (component of MNC) (TH)MNC-other 1.60E-03 1.60E-03
Mercury, vapor (component of HGC)(T/H)7439976 3.50E-06 3.50E-06
Methyl chloroform (TH) (1,1,1 trichloroethane)71556 3.10E-05 3.10E-05
Methyl ethyl ketone (T)78933 5.40E-06 5.40E-06
Methylene chloride (TH) (dichloromethane)75092 2.90E-04 2.90E-04
Nickel metal (Component of 373024/NIC) (T/H)7440020 3.30E-05 3.30E-05
Pentachlorophenol (TH)87865 5.10E-08 5.10E-08
Perchloroethylene (tetrachloroethylene) (TH)127184 3.80E-05 3.80E-05
Phenol (TH)108952 5.10E-05 5.10E-05
Polychlorinated biphenyls (TH)1336363 8.15E-09 8.15E-09
Styrene (TH)100425 1.90E-03 1.90E-03
Tetrachlorodibenzo-p-dioxin, 2,3,7,8- (TH)1746016 8.60E-12 8.60E-12
Toluene (TH)108883 9.20E-04 9.20E-04
Trichloroethylene (TH)79016 3.00E-05 3.00E-05
Vinyl chloride (TH)75014 1.80E-05 1.80E-05
Xylene (TH)1330207 2.50E-05 2.50E-05
* BIOGENIC CO2 has 0 CO2eNOTE: CO2e means CO2 equivalent
Note: Do not use greenhouse gas emission estimates from this spreadsheet for PSD (Prevention of Significant Deterioration) purposes.
GREENHOUSE GAS EMISSIONS - POTENTIAL TO EMITNOT BASED ON EPA MRR METHOD
NOTE: The DAQ Air Emissions Reporting Online (AERO) system requires short tons The EPA MRR requires metric tons
1.66E-01 8.69E-01
TOTAL TOTAL TOTAL
22,643.87
1.74E+008.31E+00
zero *
short tons/yr, CO2e
4,770.72zero *
4.95E+01 1.83E-01
4.75E-02 1.14E+00 416.100
2.15E-10 5.16E-09 1.88E-06
7.50E-04
9.50E-04 2.28E-02 8.322
6.25E-04 1.50E-02 5.475
2.30E-02 5.52E-01 201.480
4.50E-04 1.08E-02 3.9421.80E-02 6.570
2.04E-07 4.89E-06 1.78E-03
1.28E-03 3.06E-02 11.169
1.35E-04 3.24E-03 1.183
1.28E-06 3.06E-05 0.011
8.75E-05 2.10E-03 0.767
7.75E-04 1.86E-02 6.789
8.25E-04 1.98E-02 7.2277.25E-03 1.74E-01 63.510
7.227
7.00E-04 1.68E-02 6.132
4.00E-02 9.60E-01 350.400
4.48E-10 1.07E-08 0.0004.75E-01 1.14E+01 4161.000
1.10E-01 2.64E+00 963.6008.75E-05 2.10E-03 0.767
EMISSION FACTOREXPECTED ACTUAL EMISSIONS AFTER CONTROLS / LIMITATIONS (FOR PERMITTING PURPOSES)lb/mmBtu
TOXIC AIR POLLUTANT EMISSIONS INFORMATION (FOR PERMITTING PURPOSES)
lb/hr
GREENHOUSE GAS
1.13E-03 2.70E-021.03E-04 2.46E-03
1.56E-03
5.50E-04
6.50E-05
1.00E-01
2.08E-02 4.98E-01
4.74E-01
short tons/yrmetric tons/yr
metric tons/yr,
CO2e short tons/yr
2.82E-05 1.03E-02
8.25E-04 1.98E-02
1.05E-01
2.75E-05 6.60E-04
7.25E-04 1.74E-021.18E-06
2.52E+00
POTENTIAL EMISSIONS With Requested Emission Limitation -
utilize requested fuel limit and EPA
MRR Emission Factors
GREENHOUSE GAS EMISSIONS INFORMATION (FOR EMISSIONS INVENTORY PURPOSES) - CONSISTENT WITH EPA MANDATORY REPORTING RULE (MRR) METHOD
1.98E-02
lb/yrlb/day
ACTUAL EMISSIONS
EPA MRR CALCULATION METHOD: TIER 1
1.32E-022.40E+00
0.898
919.800
876.000
181.770
4.818
173.0109.855
0.5690.241
6.351
CARBON DIOXIDE (CO2) - (BIOGENIC
EMISSIONS*)
302.43302.4357.80
short tons/yr,
CO2e
zero *22,643.87
4.35E+01 1.74E+00
8.69E-01
POTENTIAL EMISSIONS - utilize max heat input capacity and EPA MRR Emission
Factors
METHANE (CH4)3.66E-01
NITROUS OXIDE (N2O)
4,327.93
3.32E-01
2.59E+02
short tons/yr
4.35E+01
2.59E+02
POLLUTANT UNCON (NO INJ)UNCONTR CONTR.UNCON (NO INJ)UNCONTR CONTR.UNCON (NO INJ)UNCONTR CONTR.UNCON (NO INJ)UNCONTR CONTR.OR W/INJ MECH ELEGB WETSCR FABFILT ESP RATIO1 RATIO2 TESTUNC TESTCONSELECTEDSELECTED OR W/INJ MECH ELEGB WETSCR FABFILT ESP RATIO1 RATIO2 TESTUNC TESTCON SELECTEDSELECTED OR W/INJ MECH ELEGB WETSCR FABFILT ESP RATIO1 RATIO2 TESTUNC TESTCON SELECTEDSELECTED OR W/INJ MECH ELEGB WETSCR FABFILT ESP RATIO1 RATIO2 TESTUNC TESTCONSELECTEDSELECTEDCPM0 017 0 017 0 017 0 017 0 017 0 017 NA NA 0 017 0 017 0 017 0 017 0 017 0 017 0.017 0.017 NA NA 0.017 0.017 0.017 0.017 0.017 0.017 0.017 0.017 NA NA 0.017 0.017 0.017 0.017 0.017 0.017 0.017 0.017 NA NA 0.017 0.017FPM0 400 0 300 0 100 0 066 0 100 0 054 1 333 0 000 0 000 0.330 0.220 0.100 0.066 0.100 0.054 1.500 0.000 0.000 0.560 0.350 0.100 0.066 0.100 0.054 1.600 0.000 0.000 0.560 0.540 0.100 0.066 0.100 0.054 1.037 0.000 0.000FPM100.360 0.270 0.074 0.065 0 074 0 040 1 333 0 900 0 000 0 000 0 290 0 200 0 074 0 065 0 074 0 040 1 450 0 909 0 000 0 000 0 500 0 320 0 074 0 065 0 074 0 040 1 563 0 914 0 000 0 000 0 500 0 490 0 074 0 065 0 074 0 040 1 020 0 907 0 000 0 000FPM2 5 0 310 0 160 0 065 0 065 0 065 0 035 1 938 0 533 0 000 0 000 0 250 0 120 0 065 0 065 0 065 0 035 2 083 0 545 0 000 0 000 0 430 0 190 0 065 0 065 0 065 0 035 2 263 0 543 0 000 0 000 0 430 0 290 0 065 0 065 0 065 0 035 1 483 0 537 0 000 0 000TPM0 417 0 317 0 117 0 083 0 117 0 071 0 017 0 017 0 417 0 317 0 347 0 237 0 117 0 083 0 117 0 071 0 017 0 017 0 347 0 237 0 577 0 367 0 117 0 083 0 117 0 071 0 017 0 017 0 577 0 367 0 577 0 557 0 117 0 083 0 117 0 071 0 017 0 017 0 577 0 557TPM100.377 0.287 0.091 0.082 0.091 0.057 0.017 0.017 0.377 0.287 0.307 0.217 0.091 0.082 0.091 0.057 0.017 0.017 0.307 0.217 0.517 0.337 0.091 0.082 0.091 0.057 0.017 0.017 0.517 0.337 0.517 0.507 0.091 0.082 0.091 0.057 0.017 0.017 0.517 0.507TPM2.5 0.327 0.177 0.082 0.082 0.082 0.052 0.017 0.017 0.327 0.177 0.267 0.137 0.082 0.082 0.082 0.052 0.017 0.017 0.267 0.137 0.447 0.207 0.082 0.082 0.082 0.052 0.017 0.017 0.447 0.207 0.447 0.307 0.082 0.082 0.082 0.052 0.017 0.017 0.447 0.307FALSETRUEFALSEFALSEFALSEFALSEFALSEFALSEFALSETRUEFALSEFALSEFALSEFALSEFALSEFALSEFALSETRUEFALSEFALSEFALSEFALSEFALSEFALSEFALSETRUEFALSEFALSEFALSEFALSEFALSEFALSE(THE ABOVE T/F SHOWS WHAT TYPE OF CONTROL WAS PICKED)(ABOVE T/F INDICATES IF TEST IS USED)(THE ABOVE T/F SHOWS WHAT TYPE OF CONTROL WAS PICKED)(ABOVE T/F INDICATES IF TEST IS USED)(THE ABOVE T/F SHOWS WHAT TYPE OF CONTROL WAS PICKED)(ABOVE T/F INDICATES IF TEST IS USED)(THE ABOVE T/F SHOWS WHAT TYPE OF CONTROL WAS PICKED)(ABOVE T/F INDICATES IF TEST IS USED)
RATIO 2 IS THE RATIO OF FPM10 OR FPM 2.5 TO FPM FOR THE SELECTED CONTROL. THIS NUMBER MULTIPLIED RATIO 2 IS THE RATIO OF FPM10 OR FPM 2.5 TO FPM FOR THE SELECTED CONTROL. THIS NUMBER MULTIPLIED RATIO 2 IS THE RATIO OF FPM10 OR FPM 2.5 TO FPM FOR THE SELECTED CONTROL. THIS NUMBER MULTIPLIED RATIO 2 IS THE RATIO OF FPM10 OR FPM 2.5 TO FPM FOR THE SELECTED CONTROL. THIS NUMBER MULTIPLIEDBY THE TEST DATA FOR FPM GIVES FPM10 AND FPM2.5 RATIOED FROM TEST DATA BY THE TEST DATA FOR FPM GIVES FPM10 AND FPM2.5 RATIOED FROM TEST DATA BY THE TEST DATA FOR FPM GIVES FPM10 AND FPM2.5 RATIOED FROM TEST DATA BY THE TEST DATA FOR FPM GIVES FPM10 AND FPM2.5 RATIOED FROM TEST DATA
RATIO1 IS THE RATIO OF UNCONTROLLED TO CONTROLLED FOR SELECTED CONTROL AND POLLUTANT RATIO1 IS THE RATIO OF UNCONTROLLED TO CONTROLLED FOR SELECTED CONTROL AND POLLUTANT RATIO1 IS THE RATIO OF UNCONTROLLED TO CONTROLLED FOR SELECTED CONTROL AND POLLUTANT RATIO1 IS THE RATIO OF UNCONTROLLED TO CONTROLLED FOR SELECTED CONTROL AND POLLUTANTAND THEN (TESTUNC = TESTCON*RATIO1 FOR FPM,FPM10, FPM2.5)AND THEN (TESTUNC = TESTCON*RATIO1 FOR FPM,FPM10, FPM2.5)AND THEN (TESTUNC = TESTCON*RATIO1 FOR FPM,FPM10, FPM2.5)AND THEN (TESTUNC = TESTCON*RATIO1 FOR FPM,FPM10, FPM2.5)ARE WE USING TRUE TRUE ARE WE USING FALSE FALSE ARE WE USING FALSE FALSE ARE WE USING FALSE FALSEDRY WOOD ?:WET WOOD ?:BARK AND WET WOOD ?BARK ?:
DRY WOOD ALL OTHERFUEL USED INDICATOR:TRUE FALSESO20 025 0 025NOx0.49 0.22CO0606 (CO FACTOR CHANGES FOR FLUIDIZED BED - SEE CELL FORMULA)VOC 0 017 0 017LEAD 4.80E-05 4.80E-05CO2195195
All CRITERIA/TAP/HAP emission factors are from AP-42 Section 1.6
Per Jim Boyer, NCDAQ Toxics (ref E-mail and phone conversation 4/28/03):1 Phosphorous should be listed as the HAP2 PCB summary from AP-42 (can add all PCB's to get total PCB's):decachlorobiphenyl2.70E-10dichlorobiphenyl 7 40E-10pentachlorobiphenyl1 20E-09hexachlorobiphenyl5.50E-10monochlorobiphenyl2 20E-10 tetrachlorbiphenyl 2 50E-09trichlorobiphenyl2.60E-09heptachlorobiphenyl6 60E-11sum = 8.15E-093 Fluorides include only inorganic fluorides therefore no fluorides in AP-42 for wood combustion should be included4. Represent o-xylene as xylene, indicated it is really o-xylene
The metals As, Be, Mn, Hg, Cr, Cd, and Ni are represented in the output tab as discussed with Lori Cherry NCTOXICS on 11/18/02. I E berylium is berylium metal not just berylium and compounds etc
POM summary: (POMS WERE ADDED FROM ALL POMS IDENTIFIED ON JIM SOUTHERLANDS (DAQ)MASTER POLLUTANT LIST)acenaphthene 9 10E-07acenaphthylene5.00E-06anthracene3 00E-06benzo(a)anthracene 6.50E-08benzo(a)pyrene 2.60E-06benzo(b)fluoranthene 1 00E-07include per Jim Boyerbenzo(e)pyrene 2 60E-09include per Jim Boyerbenzo(g,h,I)perylene 9.30E-08include per Jim Boyerbenzo(j k)fluoranthene 1 60E-07benzo(k)fluoranthene 3.60E-08dibenzo(a,h)anthracene 9.10E-09fluoranthene1 60E-06fluorene3 40E-06indeno(1,2,3,c,d) pyrene 8.70E-08include per Jim Boyernaphthalene9 70E-054-nitrophenol 1.10E-07perylene5.20E-10include per Jim Boyerphenanthrene7 00E-06pyrene3 70E-062,3,7,8-Tetrachlorodibenzo-p-dioxins 8.60E-12SUM=1.25E-04
6/2008 - Hexachlorodibenzo-p-dioxin 1 2 3 6 7 8 factor revised from 1 6e-6 per memo from Keith Overcash / TPBThe new 1 2 3 6 7 8-HxCDD EF for wood boilers is 1 79 E-11 lb/MMBtu for dry wood (8 000 Btu/lb) and 3 18 E-11 lb/MMBtu for wet wood (4 500 Btu/lb)
2/1/2010: Greenhouse Gas Factors Based on EPA Mandatory Reporting Rule Approach (40CFR Part 98) - http://www.epa.gov/climatechange/emissions/ghgrulemaking.htmlA CO2 from Table C-1: 93 8 kg CO2/mm BtuB CH4 from Table C-2:0 0072 kg CH4/MMBtuC. N2O from Table C-2:0.0036 kg N2O/MMBtu

3/8/2017 CH4 and N20 changed to reflect wood and wood residuals instead of biomass
ALL HAP/TAP FACTORS ARE FOR BOTH UNCONTROLLED AND CONTROLLED (SAME FACTOR) FROM AP-42. FLUORIDES WERE ADDED UP FROM FLUORIDE CONTAINING COMPOUNDS IN AP-42. PCB'S WERE ADDED UP FROM CHLOROBIPHENYL COMPOUNDS IN AP-42. POMS WERE ADDED FROM ALL POMS IDENTIFIED ON JIM SOUTHERLANDS (DAQ)MASTER POLLUTANT LIST. THE FOLLOWING COMPOUNDS DO NOT APPEAR IN AP-42, BUT WERE ON THE 2000E WOODWORKING SPREADSHEET (NOT INCLUDED ON THIS SPREADSHEET): DICHLOROBENZENE (106467), 1,2 DICHLOROPROPANE (78875), 1,2 DICHLOROETHANE (107062), 4,6 DINITRO-2-METHYL PHENOL (534521), 2,4 DINITROTOLUENE (121142), HEXACHLOROBENZENE (118741), TRICHLOROBENZENE (120821), 1,1,1 TRICHLOROETHANE (71556). POUNDS/DAY FOR TOXICS BASED ON 24 HOUR MAXIMUM DAY. LB/YR FOR TOXICS BASED ON REQUESTED ANNUAL LIMITATION (WHICH DEFAULTS AS MAXIMUM PRODUCTION IF NO LIMITATION IS REQUESTED)
BARK AND WET WOODSTACK TEST DATA CALCS BARK STACK TEST DATA CALCSSTACK TEST DATA CALCSDRY WOOD WET WOOD STACK TEST DATA CALCS
Version Date Author RevisionsWWC2000AReduced number of decimal places on control efficiency included with PMs and PM T/HAPs in Input sheet.Added comment to PM control device selector explaining what is meant by mechanical collector.Removed references to questionable AP-42 control efficiencies for mechanical collectors.Added flags indicating when user input PM control efficiencies were being used.Added CAS numbers to Emission Factor sheet and referenced on Input sheet.WWC2000B Revised emission factor formula for T/HAPs on Input sheet.WWC2000C Changed designation and corrected emission factor for hexachlorodibenzo-p-dioxin.WWC2000D Corrected emission factor units header on Input sheet.
WWC2000E Corrected formulae referencing PM control efficiency that should have been referencing PM-10 or PM-2.5 control efficiencies.
WWC2000F 7/31/2002 Brendan Davey Put into new format. Revised for new AP-42 7/2001
WWC2006G 6/1/2006 Brendan Davey Added missing HAPs/TAPs currently in AP-42: methyl chloroform, propylene dichloride, perchloroethylene, ethylene dichloride
Removed trichloroethane (1,1,2) since not on AP-42 factor list (added previously in error)
Corrected spelling of naphthalene and corrected typo in the header units for the PTE HAP/TAP columns.
Fluorides removed per Jim Boyer NCDAQ/TPB (no inorganic fluorides in AP-42), and o-xylene represented as only xylene (not o-xylene, but with note)
Description of metal pollutant emissions were changed to match NC DAQ/TPB recommendations
VOC factor changed from 0.013 to 0.017 per 9/03 AP-42 revisionMEK designation changed to TAP onlyCarbon Dioxide added for informational purposesWWC2006H10/13/2008 Brendan Davey Greenhouse gases reviewed and added (CO2, N2O, CH4)Hexachlorodibenzo-p-dioxin 1,2,3,6,7,8 (T) factor revised (significantly lower) per DAQ memo dated April 28, 2008WWC2010I2/1/2010 Sushma Masemore Greenhouse gases calculations changed to be consistent with EPA Mandatory Reporting Rule published in October 2009WWC2011J7/15/2011 Brendan Davey Added note on output sheet to not use GHG emissions for PSD purposesWWC2017K3/8/2017 Chris Scott Minor changes to metal toxics description and CAS# in output tabGreenhouse gas factors (CH4 and N2O) changed from “biomass fuels” to “wood and wood residuals”, which is believed to be more appropriate (ref. of 40 CFR Part 98, Subpart C, Table C-2)Calculations updated to reflect revised Global Warming Potentials (GWP) for methane and nitrous oxide; updates effective January 1, 2014 (ref. 40 CFR 98, Subpart A, Table A-1)WWC2019L 9/3/2019 Patrick Ballard Removed 75694 Trichlorofluoromethane from the spreadsheet because it should no longer be listed as a TAP in the Wood Waste Combustion Spreadsheet. 57653-85-7 Hexachlorodibenzo-p-dioxin marked as a HAP and a TAP. Refference - May 28, 2015 SAB report titled "Recommendations for Twenty North Carolina Toxic Air Pollutnats".
WOODWASTE COMBUSTION EMISSIONS CALCULATOR REVISION L 09/03/2019 - REVISION SCREEN
Instructions: Enter emission source / facility data on the "INPUT" tab/screen. The air emission results and summary of input data are viewed / printed on the "OUTPUT" tab/screen. The different tabs are on the bottom of this screen.
This spreadsheet is for your use only and should be used with caution. DENR does not guarantee the accuracy of the information contained. This spreadsheet is subject to continual revision and updating. It is your responsibility to be aware of
the most current information available. DENR is not responsible for errors or omissions that may be contained herein.
Response Summary:
To be eligible businesses shall not do any of the follow:

1) Emit more than 5 tons per year of each of the following pollutants: Sulfur Dioxide (SO2), Carbon Monoxide (CO),
Nitrogen Oxides (NOx), Particulate Matter (PM10), Ozone (O3), or Volatile Organic Compounds (VOCs).
2) Emit more than 500 lbs/yr of any single Hazardous Air Pollutant (HAP), and emit more than 2000 lbs/yr of any
combination of HAPs
3) Emit more than 500 lbs/yr of any combination of air contaminants not listed in 1 or 2

A copy of this registration notice and worksheets are required on site to verify permit exemption status.

Please be aware a the Small Source Exemption ONLY exempts the site from the air permitting requirements of R307-
401-5 thru R307-401-8 of the Utah Administrative Code, all other air quality regulations still apply.

Q4.
Please fill out the following contact information:
Site Contact Site Owner
Name Jess Bonsall 48forty Solutions - Salt
Lake City Plant (Site 269)
48forty Solutions,
LLC
Mailing Address 11740 Katy Freeway 1820 West G Avenue 11740 Katy Freeway
Mailing Address 2 Suite 1200 Bldg 641 Suite 1200
City Houston Tooele Houston
State TX UT TX
Zip Code 77079 84074 77079
Phone [phone]-8577
Fax 0 0 0
Email [e-mail] [e-mail] kbagwell@montrose-
env.com

Q5. County the Site is located in:
Tooele County

Q6. Briefly describe the process including the end products, raw materials, and process equipment used.
48forty Site 269 is a wood pallet repair and recycling facility. The facility operates a propane-fired kiln to heat-treat the
pallets and an Air Curtain Incinerator (ACI) to handle scrap wood generated from the wood working process.

Q7. List emission units
HEATER - Propane-fired heater for Kiln
KILN - wood heating kiln powered by HEATER
SAWS - Table saws for wood working
ENG1 - Diesel-fired engine for ACI
ACI - Air Curtain Incinerator for clean wood

Q8. List any pollution control equipment
Forced draft air curtain on the ACI provides particulate control

Q9. Please include Annual Emission Rates calculation spreadsheet.
[Click here]

Q11. Contact Information: (person filling out form - signature will be required)
Name Katrina Bagwell
Title Principal Engineer
Phone [phone] ([e-mail])
Date September 24, 2024

Q10. By signing below, I hereby certify that the information and data submitted in this notice fully describes
this site and ONLY this site. The information provide is true, accurate, and complete to the best of my
knowledge. I understand that I am responsible for determining whether the site remain eligible for this
exemption before making operational or process changes in the future, and agree to notify the Division of
Air Quality when this site is not longer eligible for this exemption. (Signature of Owner/Manager)
[Click here]

Embedded Data:
N/A

400 Northridge Road, Suite 400, Sandy Springs, Georgia 30350
September 3, 2024

Jess Bonsall
ESG Director
48forty Solutions, LLC
11740 Katy Fwy, Suite 1200
Houston, TX 77079
[e-mail]

RE: Small Source Exemption Registration
48forty – Salt Lake City Plant (Site 269)
1820 West G Avenue, Building 64, Tooele, UT 84074

Montrose Environmental Solutions, Inc. (Montrose) has performed an air permit applicability determination for
the operations at 48forty Solutions, LLC’s (48forty) wood pallet repair and recycling facility located near Salt Lake
City in Utah. Based on the data and information provided to Montrose, 48forty’s facility-wide emissions are
estimated to be below state air permitting thresholds, exempting 48forty from the requirement to obtain an
approval order per Utah Code, UTAC R307-401.9. A summary of facility-wide emissions with the outlined
calculation methods and assumptions are included in Attachment 1. Note, this Small Source Registration only
exempts 48forty from the air permitting requirements contained at UTAC R307-401-5 thru R307-401-8; all other
air quality regulations still apply (see regulatory discussion below).
This memorandum serves to document 48forty’s small source exemption registration notice to Utah Department
of Environmental Quality (UDEQ) and to provide a record of the air permit exemption status to be maintained as
part of the onsite environmental records. Attachment 2 contains a copy of the Small Source Exemption
Registration form submitted to UDEQ along with the submittal confirmation and any associated records.
If in any year after this small source exemption determination has been issued, actual emissions for any pollutant
exceed the small source exemption threshold limits contained in Table 1 of this memorandum, a Notice of Intent
(NOI) Application must be submitted within 180 days after the end of the calendar year in which the source
exceeded the emission threshold (UTAC R307-401-9(2)).
FACILITY OPERATIONS
Pallets are received at the facility in the unloading dock and sorted for repair or tear-down using table saws. A kiln
with a 0.85 MMBtu/hr propane-fueled heater is used to heat-treat the pallets. Clean wood waste generated from
the woodworking operations is currently being transported to the nearby landfill for disposal or ground into mulch
by a third party. Due to rising waste disposal fees and irregular demand for mulch products, 48forty is planning to
install an air curtain incinerator (ACI) to handle the clean scrap wood and reduce the amount of waste disposal
sent to the local landfill. The ACI utilizes a 74-hp diesel engine as a pilot fuel source for igniting the fire that
Small Source Exemption Registration 48forty SLC (Site 269) September 2024

2 Montrose Environmental Solutions, Inc.
combusts the wood waste. The air curtain of the ACI controls emissions by capturing smoke particles below the
air curtain, allowing for secondary combustion and creating a more complete combustion process. Biochar, or ash,
is produced as a byproduct of wood combustion and can be beneficially used in many products and industries.
EMISSIONS SUMMARY
Facility emissions are comprised of propane combustion emissions (from the gas heater supplying heat to the
kiln), diesel combustion emissions (from the internal combustion engine serving as a pilot ignition in the ACI), and
wood waste combustion emissions from the ACI. Fugitive particulate matter emissions result from the facility’s
wood sawing operations and biochar ash handling. A very small amount of VOC emissions result from the heat
treatment of wood in the kiln.
Facility emission calculations and detailed calculation methodology are included in Attachment 1. Emissions are
based on the maximum expected operating hours or maximum expected operating capacity of each emission
source or operation (see details of operating assumption data outlined in Attachment 1). As seen in the facility-
wide emissions summary of Attachment 1 and Table 1 below, all estimated annual facility emissions are below
the small source exemption thresholds.

Table 1: Facility-Wide Emissions Compared to Small Source Exemption Thresholds
Equipment
Description
CO
(tpy)
NOx
(tpy)
PM
(tpy)
PM10
(tpy)
PM2.5 (tpy)
SO2
(tpy)
VOC
(tpy)
Total HAP
(tpy)
Max
Individual
HAP
(tpy)
Kiln Heater -
Propane-fired 6.52E-02 1.13E-01 6.09E-03 6.09E-03 6.09E-03 1.57E-04 8.70E-03 1.47E-03 1.40E-03
Kiln - Wood
Offgas -- -- -- -- -- -- 1.09E-02 -- --
Table Saws for
Wood Cutting -- -- 0.20 0.10 0.05 -- -- -- --
ACI Auxiliary
Diesel Engine 0.46 2.15 0.15 0.15 0.15 0.14 0.17 1.94E-03 5.72E-04
Air Curtain
Incinerator 3.77 1.45 3.77 1.89 1.60 0.15 1.31 0.51 0.25
Biochar Ash
Handling -- -- -- 0.02 0.02 0.01 -- -- --
FACILITY TOTAL (tpy): 4.30 3.71 4.13 2.17 1.83 0.29 1.50 0.51 0.248
SMALL SOURCE
EXEMPTION
THRESHOLDS
(tpy):
5 5 5 5 5 5 5 1 0.25

Small Source Exemption Registration 48forty SLC (Site 269) September 2024

3 Montrose Environmental Solutions, Inc.
REGULATORY REVIEW
Standards of Performance for Commercial and Industrial Solid Waste Incineration Units
[NSPS 40 CFR Part 60, Subpart CCCC]
The ACI will be subject to 40 CFR Part 60, Subpart CCCC – Standards of Performance for Commercial and Industrial
Solid Waste Incineration Units. Per 40 CFR 60.2245, since the ACI will only burn 100 percent wood waste and clean
lumber (the materials listed in 40 CFR 60.2245(b)), the ACI is only subject to the requirements listed at 40 CFR
60.2242 and 40 CFR 60.2245 through 60.2260.
Opacity Limitations [40 CFR 60.2250]
The ACI will demonstrate compliance by complying with applicable requirements under § 60.2250, which limits
visible emissions from the source to 10% opacity (6-minute average), except 35% opacity (6-minute average)
during the startup period that is within the first 30 minutes of operation.
Testing [40 CFR 60.2255]
Within 60 days after the ACI reaches the charge rate at which it will operate, but no later than 180 days after its
initial startup, the facility must conduct an initial test for opacity as specified in 40 CFR 60.8 using EPA Method 9
to determine compliance with the opacity limitation. After the initial test for opacity, the facility should conduct
annual tests no more than 12 calendar months following the date of the previous test.
Recordkeeping & Reporting [40 CFR 60.2260]
The following records have to be maintained upon ACI installation:
a. Prior to commencing construction of the ACI, submit these three items:
i. Notification of intent to construct the air curtain incinerator
ii. Planned initial startup date
iii. Types of materials that will be burned in the ACI.
b. Keep records of results of all initial and annual opacity tests onsite for at least 5 years.
c. Make all records available for submittal or for an inspector’s onsite review.
d. Submit the results (as determined by the average of three 1-hour blocks consisting of ten 6-minute average
opacity values) of the initial opacity tests no later than 60 days following the initial test. Submit annual
opacity test results within 12 months following the previous report.
e. Submit initial and annual opacity test reports as electronic or paper copy on or before the applicable
submittal date.
f. Keep a copy of the initial and annual reports onsite for a period of 5 years.
Small Source Exemption Registration 48forty SLC (Site 269) September 2024

4 Montrose Environmental Solutions, Inc.
Standards of Performance for Stationary Compression Ignition Internal Combustion
Engines [NSPS 40 CFR Part 60, Subpart IIII]
The diesel engine that will power the ACI will be subject to the New Source Performance Standard (NSPS) 40 CFR
60 Subpart IIII, Standards of Performance for Stationary Compression Ignition Internal Combustion Engines (NSPS
IIII). This standard applies to owners and operators of stationary compression-ignition (CI) internal combustion
engines (ICE) that commence construction after July 11, 2005, where the engine is manufactured on or after April
1, 2006, and are not fire pump engines. The proposed diesel engine meets this criteria.
Pursuant to 40 CFR 60.4204(b), owners or operators of 2007 model year and later non-emergency stationary CI
ICE with a displacement of less than 30 liters per cylinder must comply with the emission standards for new CI
engines in §60.4201.
The diesel engine is a USEPA Tier 4 certified engine and therefore, meets the requirements under §60.4201. The
facility will comply with all applicable requirements under this regulation.
Stationary Reciprocating Internal Combustion Engine [NESHAP 40 CFR Part 63, Subpart
ZZZZ]
The diesel engine is subject to the Stationary Reciprocating Internal Combustion Engine (RICE) NESHAP (40 CFR 63
Subpart ZZZZ) as a new engine, because construction of the engine will commence on or after June 12, 2006.
Pursuant to 40 CFR 63.6590(c), new stationary RICE located at an area source must meet the requirements of the
NESHAP by complying with the requirements of NSPS IIII. No further requirements of the NESHAP apply to this
engine.
CLOSURE
For any questions or new information pertaining to this small source exemption determination, please contact
Mrs. Katrina Bagwell, P.E. of Montrose Environmental (678-336-8561, [e-mail]).
Attachments
Attachment 1 – Facility-Wide Emission Calculations
Attachment 2 – Small Source Exemption Registration
Attachment 3 – Manufacturer’s Specifications (ACI)

cc: Jeremy Roberts, 48forty Solutions, LLC

Attachment 1
Facility-Wide Emission Calculations

Jeremy Roberts
Unit ID Equipment Description
CO
(tpy)
NOx
(tpy)
PM
(tpy)
PM10
(tpy)
PM2.5
(tpy)
SO2
(tpy)
VOC
(tpy)
Total HAP
(tpy)
Max Individual
HAP
(tpy)
HEATER Heater - Propane-fired 6.52E-02 1.13E-01 6.09E-03 6.09E-03 6.09E-03 1.57E-04 8.70E-03 1.47E-03 1.40E-03
KILN Kiln - Wood heating ------------1.09E-02 ----
SAWS Table Saws for Wood Cutting ----0.20 0.10 0.05 --------
ENG1 ACI Auxillary Diesel Engine 0.46 2.15 0.15 0.15 0.15 0.14 0.17 1.94E-03 5.72E-04
ACI Air Curtain Incinerator 3.77 1.45 3.77 1.89 1.60 0.15 1.31 0.51 0.25
BA Biochar Ash Handling ------0.02 0.02 0.01 ------
4.30 3.71 4.13 2.17 1.83 0.29 1.50 0.51 0.248
5 5 5 5 5 5 5 1 0.25
Y Y Y Y Y Y Y Y Y
Limits for Small Source Exemption (tpy)
Within small source exemption thresholds?
Facility-Wide Potential Emissions Summary
48forty - Salt Lake City Plant (Site 269)
September 2024
Facility -Wide Total (tpy):
Propane Heater for Kiln - Potential Emission Calculations
48forty - Salt Lake City Plant (Site 269)

Equipment Details
Rating 0.85 MMBtu/hour
Operational Hours 1,872 hours/year
Sulfur Content 0.18 gr/100 ft3
Fuel Propane
Criteria Pollutant
Concentration
(ppm)
Emission
Factor
(lb/10^3 gal)
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)Reference
NOX 13 0.12 0.11
CO 7.5 0.07 0.07
PM10 0.7 0.01 0.01
PM2.5 0.7 0.01 0.01
SO2 0.018 0.00 0.00
VOC 1.0 0.01 0.01
HAP 0.00 0.00 See Below
Green House Gas Pollutant
Global
Warming
Potential
Emission
Factor
(lb/10^3 gal)
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)Reference
CO2 (mass basis)1 12,500 116 109
Methane (mass basis)25 0.2 0.00 0.00
N2O (mass basis)298 0.9 0.01 0.01
CO2e 111
Hazardous Air Pollutant
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)Reference
2-Methylnaphthalene 2.40E-05 2.00E-08 1.87E-08
3-Methylchloranthrene 1.80E-06 1.50E-09 1.40E-09
7,12-Dimethylbenz(a)anthracene 1.60E-05 1.33E-08 1.25E-08
Acenaphthene 1.80E-06 1.50E-09 1.40E-09
Acenaphthylene 1.80E-06 1.50E-09 1.40E-09
Anthracene 2.40E-06 2.00E-09 1.87E-09
Benz(a)anthracene 1.80E-06 1.50E-09 1.40E-09
Benzene 2.10E-03 1.75E-06 1.64E-06
Benzo(a)pyrene 1.20E-06 1.00E-09 9.36E-10
Benzo(b)fluoranthene 1.80E-06 1.50E-09 1.40E-09
Benzo(g,h,i)perylene 1.20E-06 1.00E-09 9.36E-10
Benzo(k)fluoranthene 1.80E-06 1.50E-09 1.40E-09
Chrysene 1.80E-06 1.50E-09 1.40E-09
Dibenzo(a,h)anthracene 1.20E-06 1.00E-09 9.36E-10
Dichlorobenzene 1.20E-03 1.00E-06 9.36E-07
Fluoranthene 3.00E-06 2.50E-09 2.34E-09
Fluorene 2.80E-06 2.33E-09 2.18E-09
Formaldehyde 7.50E-02 6.25E-05 5.85E-05
Hexane 1.80E+00 1.50E-03 1.40E-03
Indeno(1,2,3-cd)pyrene 1.80E-06 1.50E-09 1.40E-09
Naphthalene 6.10E-04 5.08E-07 4.76E-07
Phenanathrene 1.70E-05 1.42E-08 1.33E-08
Pyrene 5.00E-06 4.17E-09 3.90E-09
Toluene 3.40E-03 2.83E-06 2.65E-06
Arsenic 2.00E-04 1.67E-07 1.56E-07
Beryllium 1.20E-05 1.00E-08 9.36E-09
Cadmium 1.10E-03 9.17E-07 8.58E-07
Chromium 1.40E-03 1.17E-06 1.09E-06
Cobalt 8.40E-05 7.00E-08 6.55E-08
Manganese 3.80E-04 3.17E-07 2.96E-07
Mercury 2.60E-04 2.17E-07 2.03E-07
Nickel 2.10E-03 1.75E-06 1.64E-06
Selenium 2.40E-05 2.00E-08 1.87E-08
LPG-Fired Boilers & Heaters
Manufacturer Data
or AP-42 Table 1.5-1
AP-42 Table 1.5-1
&
Table A-1 to
Subpart A of Part 98
Emission Factor
(lb/10^6 scf)
No HAP data in
AP-42 Chapter 1.5.
AP-42 Table 1.4-3
and
Table 1.4-4
used to generate
HAP data in this
section.
Page 2 of 7
Version 1.0
November 29, 2018
Pallet Usage Days Hours Per Day Annualb Hourlyc
Unit (Pallets/Day)(Days/Yr)(Hrs/Day)Pollutant Units (tpy)(lb/hr)
Kiln - Wood Heating 3,744 312 6 VOC 0.000004 lb/Pallet 1.09E-02 0.002
Notes/References
c An example calculation for annual VOC emissions follows.
VOC (tpy) = (Hourly Emissions, lb/hr)*(8,760 hrs/yr)/(2000 lb/ton)
VOC (tpy) = (0.00 lb/hr)*(8,760 hrs/yr)/(2,000 lb/ton)
= 0.0109 tpy VOC
e An example calculation for hourly VOC emissions follows.
VOC (lb/hr) = (Pallet Usage, Pallets/Day)*(Emission Factor, lb/Pallet)/(Hrs/Day)
VOC (lb/hr) = (3744 Pallets/Day)*(0.00 lb/Pallet)/(6 Hrs/Day)
= 0.002 lb/hr VOC
a Per EPA document number EPA-600/R-96-119a, Wood Products in the Waste Stream - Characterization and Combustion Emissions, Vol. 1 , October, 1996, p.7-
25, Table 7-9; typical VOC (as phenols) in plywood/pallets is 0.00000004 lbs VOC / lb WOOD. The typical pallet weighs 60 lbs, but assuming a 100 lb pallet, the
total VOC per pallet would be 0.000004 lbs.
Kiln - Wood Heating - Potential Emission Calculations
September 2024
Emission Rates
Emission
factor a
48forty - Salt Lake City Plant (Site 269)
Annual Board
Cuta
Hourly Board
Cutb
Control
Efficiencyc
Emission
Factord Annuale Hourlyf
Unit (tons/yr) (tons/hr)(%)Pollutant (Lb/ton)(T/Yr)(Lb/Hr)
Wood Sawing 23,418 3 95%PM 0.35 0.20 0.05
PM10 0.175 0.10 0.02
PM2.5 0.088 0.05 0.01
a
b
c
d
e
PM (tons/yr) = ((Annual Board Cut, tons/Yr)*(Emission Factor, Lb/ton)*(1-Control Efficiency))/2000, Lbs/Ton
PM (tons/yr) = ((23,418 tons/Hr)*(0.35000 Lb/ton)*(1-0.95)*(2000 Lbs/Ton)
= 0.20 T/Yr PM
f An example calculation for hourly PM emissions follows:
PM (lb/hr) = (Hourly Board Cut, ton/Hr)*(Emission Factor, Lb/ton)*(1-Control Efficiency)
PM (lb/hr) = (3 tons/Hr)*(0.35000 Lb/ton)*(1-0.95)
= 0.05 lb/hr PM
Enclosed Building 95% Control Efficiency
Based on USEPA Memorandum dated May 08, 2014 re: Particulate Matter Potential to Emit at Sawmills, Excluding Boilers, Located in
Pacific Northwest Indian Country
An example calculation for annual PM emissions follows:
Wood Sawing - Potential Emission Calculations
48forty - Salt Lake City Plant (Site 269)
September 2024
Emission Rates
Conservative assumption that every potential pallet to the site goes to the Saw Room to be trimmed.
Based on 8,760 hours of potential operation.
Particulate Matter (PM)
Equipment Specifications -Air Curtain Incinerator (ACI)
Annual Throughput 2900 tons/yr
Unit Max Rated Capacity 7.0 tons/hr, wood waste
Criteria Emissions Calculations
Pollutant Emission factor a
(lb/ton)
Annual Emissions
(tons/yr)
Hourly Emissions
(lb/hr)
CO 2.6 3.77 18.20
NOx 1.0 1.45 7.00
PM b 2.6 3.77 18.20
PM10 1.3 1.89 9.10
PM2.5 1.1 1.60 7.70
SO2 0.1 0.15 0.70
VOC 0.9 1.31 6.30
HAP/TAP Emissions Calculations
Pollutant CAS No.Emission factors c
(lb/MMBtu)
Annual Emissions d
(tons/yr)
Hourly Emissions
(lb/hr)
Acetaldehyde (TH)75-07-0 8.30E-04 1.08E-02 5.23E-02
Acetophenone (H)98-86-2 3.20E-09 4.18E-08 2.02E-07
Acrolein (TH)107-02-8 4.00E-03 5.22E-02 2.52E-01
Antimony Compounds (H)SBC 7.90E-06 1.03E-04 4.98E-04
Arsenic Compounds (TH)ASC-Other 2.20E-05 2.87E-04 1.39E-03
Benzene (TH)71-43-2 4.20E-03 5.48E-02 2.65E-01
Benzo(a)pyrene (T)50-32-8 2.60E-06 3.39E-05 1.64E-04
Beryllium Metal (T/H)7440-41-7 1.10E-06 1.44E-05 6.93E-05
Cadmium Metal (T/H)7440-43-9 4.10E-06 5.35E-05 2.58E-04
Carbon tetrachloride (TH)56-23-5 4.50E-05 5.87E-04 2.84E-03
Chlorine (TH)7782-50-5 7.90E-04 1.03E-02 4.98E-02
Chlorobenzene (TH)108-90-7 3.30E-05 4.31E-04 2.08E-03
Chloroform (TH)67-66-3 2.80E-05 3.65E-04 1.76E-03
Chromic acid (VI) (T/H)7738-94-5 3.50E-06 4.57E-05 2.21E-04
Chromium Compounds (H)CRC-other 1.75E-05 2.28E-04 1.10E-03
Cobalt Compounds (H)COC-other 6.50E-06 8.48E-05 4.10E-04
Dinitrophenol, 2,4- (H)51-28-5 1.80E-07 2.35E-06 1.13E-05
Di(2-ethylhexyl)phthalate (DEHP) (TH)117-81-7 4.70E-08 6.13E-07 2.96E-06
Ethyl benzene (H)100-41-4 3.10E-05 4.05E-04 1.95E-03
Ethylene dichloride (1,2-dichloroethane) (TH)107-06-2 2.90E-05 3.78E-04 1.83E-03
Formaldehyde (TH)50-00-0 4.40E-03 5.74E-02 2.77E-01
Hexachlorodibenzo-p-dioxin 1,2,3,6,7,8 (TH)57653-85-7 1.60E-06 2.09E-05 1.01E-04
Hydrogen chloride (hydrochloric acid) (TH)7647-01-0 1.90E-02 2.48E-01 1.20E+00
Lead PBC 4.80E-05 6.26E-04 3.02E-03
Manganese Compounds (TH)MNC 1.60E-03 2.09E-02 1.01E-01
Mercury, vapor (T/H)7439-97-6 3.50E-06 4.57E-05 2.21E-04
Methyl bromide (H) (bromomethane)74-83-9 1.50E-05 1.96E-04 9.45E-04
Methyl chloride (H) (chloromethane)74-87-3 2.30E-05 3.00E-04 1.45E-03
Methyl chloroform (TH) (1,1,1 trichloroethane)71-55-6 3.10E-05 4.05E-04 1.95E-03
Methyl ethyl ketone (T)78-93-3 5.40E-06 7.05E-05 3.40E-04
Methylene chloride (TH) (dichloromethane)75-09-2 2.90E-04 3.78E-03 1.83E-02
Naphthalene (H)91-20-3 9.70E-05 1.27E-03 6.11E-03
Nickel (T/H)7440-02-0 3.30E-05 4.31E-04 2.08E-03
Nitrophenol, 4- (H)100-02-7 1.10E-07 1.44E-06 6.93E-06
Pentachlorophenol (TH)87-86-5 5.10E-08 6.66E-07 3.21E-06
Perchloroethylene (tetrachloroethylene) (TH)127-18-4 3.80E-05 4.96E-04 2.39E-03
Phenol (TH)108-95-2 5.10E-05 6.66E-04 3.21E-03
Phosphorus Metal (H)7723-14-0 2.70E-05 3.52E-04 1.70E-03
Polychlorinated biphenyls (TH)1336-36-3 8.15E-09 1.06E-07 5.13E-07
Polycyclic Organic Matter (H)56553/7PAH 1.25E-04 1.63E-03 7.88E-03
Propionaldehyde (H)123-38-6 6.10E-05 7.96E-04 3.84E-03
Propylene dichloride (H) (1,2 dichloropropane)78-87-5 3.30E-05 4.31E-04 2.08E-03
Selenium compounds (H)SEC 2.80E-06 3.65E-05 1.76E-04
Styrene (TH)100-42-5 1.90E-03 2.48E-02 1.20E-01
Tetrachlorodibenzo-p-dioxin, 2,3,7,8- (TH)1746-01-6 8.60E-12 1.12E-10 5.42E-10
Toluene (TH)108-88-3 9.20E-04 1.20E-02 5.80E-02
Trichloroethylene (TH)79-01-6 3.00E-05 3.92E-04 1.89E-03
Trichlorophenol, 2,4,6- (H)88-06-2 2.20E-08 2.87E-07 1.39E-06
Vinyl chloride (TH)75-01-4 1.80E-05 2.35E-04 1.13E-03
Xylene (TH)1330-20-7 2.50E-05 3.26E-04 1.58E-03
0.51 2.45
0.25 1.20
Greenhouse Gas Emissions Calculations
Pollutant Emission factor e
(kg/MMBtu)
Emission factor
(lb/MMBtu)
Annual Emissions
(tons/yr)
Hourly Emissions
(lb/hr)
CO2e f
(metric
tons/yr)
CO2 93.80 206.79 2698.66 13028.00 2409.51
CH4 7.20E-03 1.59E-02 0.21 1.00 4.62
N2O 3.60E-03 7.94E-03 0.10 0.50 27.56
Notes/References
b Total PM factor is not available so total PM was conservatively estimated to be twice PM10.
c Emission factors obtained from NCDEQ's emission estimation spreadsheet for wood waste combustion, rev. L (revised September 3, 2019).
d Throughput in tons converted to MMBtu using the following factor:
9.00 MMbtu/ton (converted from 4,500 Btu/lb wood waste, from USEPA AP-42 Section 1.6)
e Emission factors from Tables C-1 and C-2 to Subpart C of Part 98 - Default CO2 Emission Factors and High Heat Values for Certain Types of Fuel.
f Global Warming Potential from 40 CFR Part 98, Subpart A, Table A-1.
a Emission factors are from Table 3 - "Air Curtain Incinerator Emissions Factor Determination," from Air Burners, Inc. Operating Manual, version 3-27-2020, with the exception of PM2.5, which
is from Table 1 of the same document.
Air Curtain Incinerator (ACI) - Potential Emission Calculations
48forty - Salt Lake City Plant (Site 269)
September 2024
TOTAL HAPs
Max Individual HAP (Hydrogen chloride)
Annual Operating
Hours Throughputa
Emission
Factorb Annual Hourly
Unit (hrs/yr)(tons/hr)Pollutant (lb/ton)(tpy)(lb/hr)
Biochar Ash 1,872 0.21 PM 0.11 0.02 0.02
PM10 0.11 0.02 0.02
PM2.5 0.04 0.01 0.01
3%
PM10 (g/Mg):53
PM2.5 (g/Mg):19
b Emission factors converted from the below emission factors for PM10 and PM2.5 (g/Mg of
ash), from Table 1 of "Fugitive Emissions from a Dry Coal Fly ash Storage Pile (2012)"
Available at: https://www3.epa.gov/ttnchie1/conference/ei20/session5/smueller.pdf.
Assuming PM = PM10.
Biochar Ash Handling - Potential Emission Calculations
48forty - Salt Lake City Plant (Site 269)
September 2024
Particulate Matter
(PM)
a Biochar ash throughput (tons/hr) = wood waste throughput [ACI Max Operating Capacity,
tons/hr] x ash percentage of wood combusted [%]
Ash percentage of wood combusted1:
1) Ash percentage of 3% conservatively assumed from maximum ash content present in
Table 2 of "Emissions from Wood-Fired Combustion Equipment" report prepared by
Envirochem Services Inc. for the Ministry of Environment dated June 30, 2008.
Available at: https://www2.gov.bc.ca/assets/gov/environment/waste-
management/industrial-waste/industrial-waste/pulp-paper-
wood/emissions_report_08.pdf
Equipment Specifications -Diesel Engine (ENG1)
Annual Operating Hours 1872 hrs/yr
Unit Max Rated Capacity 74 hp
Criteria Emissions Calculations
Pollutant Emission factor a
(lb/hp-hr)
Annual Emissions b
(tons/yr)
Hourly Emissions c
(lb/hr)
CO 6.68E-03 0.46 0.49
NOx 3.10E-02 2.15 2.29
PM/PM10/PM2.5 2.20E-03 0.15 0.16
SOx 2.05E-03 0.14 0.15
VOC 2.47E-03 0.17 0.18
HAP/TAP Emissions Calculations
Pollutant CAS No.Emission factors d
(lb/MMBtu)
Emission factors
(lb/hp-hr)
Annual
Emissions
(tons/yr)
Hourly
Emissions e
(lb/hr)
Acetaldehyde (H,T)75070 7.67E-04 5.37E-06 3.72E-04 3.97E-04
Acrolein (H,T)107028 9.25E-05 6.48E-07 4.48E-05 4.79E-05
Arsenic unlisted compounds (H,T)ASC-Other 4.00E-06 2.80E-08 1.94E-06 2.07E-06
Benzene (H,T)71432 9.33E-04 6.53E-06 4.52E-04 4.83E-04
Benzo(a)pyrene (H,T)50328 1.88E-07 1.32E-09 9.12E-08 9.74E-08
Beryllium metal (unreacted) (H,T)7440417 3.00E-06 2.10E-08 1.45E-06 1.55E-06
1,3-Butadiene (H,T)106990 3.91E-05 2.74E-07 1.90E-05 2.03E-05
Cadmium metal (elemental unreacted) (H,T)7440439 3.00E-06 2.10E-08 1.45E-06 1.55E-06
Chromic Acid (VI) (H,T)7738945 3.00E-06 2.10E-08 1.45E-06 1.55E-06
Formaldehyde (H,T)50000 1.18E-03 8.26E-06 5.72E-04 6.11E-04
Lead unlisted compounds (H)PBC-Other 9.00E-06 6.30E-08 4.36E-06 4.66E-06
Manganese unlisted compounds (H,T)MNC-Other 6.00E-06 4.20E-08 2.91E-06 3.11E-06
Mercury vapor (H,T)7439976 3.00E-06 2.10E-08 1.45E-06 1.55E-06
Napthalene (H)91203 8.48E-05 5.94E-07 4.11E-05 4.39E-05
Nickel metal (H,T)7440020 3.00E-06 2.10E-08 1.45E-06 1.55E-06
Selenium compounds (H)SEC 1.50E-05 1.05E-07 7.27E-06 7.77E-06
Total PAH (H)PAH 1.68E-04 1.18E-06 8.15E-05 8.70E-05
Toluene (H,T)108883 4.09E-04 2.86E-06 1.98E-04 2.12E-04
Xylene (H,T)1330207 2.85E-04 2.00E-06 1.38E-04 1.48E-04
1.94E-03 2.08E-03
5.72E-04 6.11E-04
Greenhouse Gas Emissions Calculations
Pollutant Emission factor e
(kg/MMBtu)
Emission factor
(lb/MMBtu)
Emission factors
(lb/hp-hr)
Annual
Emissions
(tons/yr)
Hourly
Emissions e
(lb/hr)
CO2e f
(metric
tons/yr)
CO2 73.96 163.05 1.14 79.06 84.46 70.59
CH4 1.10E-03 2.43E-03 1.70E-05 1.18E-03 1.26E-03 0.03
N2O 1.10E-04 2.43E-04 1.70E-06 1.18E-04 1.26E-04 0.03
Notes/References
b Example calculation for hourly CO emission rate for ENG1 is as follows:
CO (lb/hr) =(Horsepower Rating, hp) * (Emission Factor, lb/hp-hour)
(74 hp) * (0.006680 lb/hp-hr) = 0.49 lb/hr CO
c Example calculation for annual CO emission rate for ENG1 is as follows:
CO (tpy) =(CO, lb/hr) x (Annual Operating Hours, hr/yr) / (2,000 lb/T)
(0.49 lb/hr) x (1872 hr/yr) / (2,000 lb/ton) = 0.46 tpy CO
d Emission factors are from AP-42, Chapter 3.3 (revised 10/96) and Chapter 1.3 (revised 5/10) for metal HAP.
e Maximum hourly PTE calculated from the pollutant emission factor, average brake-specific fuel consumption (BSFC), and the maximum engine rating
Avg BSFC =7,000 Btu/hp-hr
f Global Warming Potential from 40 CFR Part 98, Subpart A, Table A-1.
Total HAP
Max Individual HAP (Formaldehyde)
Diesel Engine (pilot fuel for ACI) - Potential Emission Calculations
48forty - Salt Lake City Plant (Site 269)
September 2024
a Emission factors are as specified in AP-42 Tables 3.3-1 (dated 10/96). PM and PM2.5 emissions are assumed to be equal to PM10 emissions.

Attachment 2
Small Source Exemption Registration

Utah Division of Air Quality Revised: 6/21/06
SMALL SOURCE EXEMPTION REGISTRATION

Businesses eligible for this exemption shall not: 1) emit more than 5 tons per year of each of the
following pollutants: sulfur dioxide (SO2), carbon monoxide (CO), nitrogen oxides (NOx), particulate
matter (PM10), ozone (O3), or volatile organic compounds (VOCs) or 2) emit more than 500 pounds
per year of any single hazardous air pollutant (HAP), and emit more than 2000 pounds per year
for any combination of HAPs, or 3) emit less than 500 pounds per year of any air contaminant not
listed in (1)( or (2) above and less than 2000 pounds per year of any combination of air contaminants
not listed in (1) or (2) above.

Please keep copies of the registration notice and worksheets on site at your business to verify your
permit exemption status. Please be aware that the small source exemption only exempts your
business from the permitting requirements of R307-401-5 through 8 of the Utah Administrative Code,
not other applicable air quality regulations.

1. Business Name and Mailing Address:
____________________________
____________________________
____________________________
____________________________
Phone # ( ____ ) ____-__________
Fax # ( ____ ) ____-__________
2. Business Contact for Air Quality Issues:
______________________________
______________________________
______________________________
______________________________
Phone # ( ____ ) ____-___________
Fax # ( ____ ) ____-___________
3. Owners Name and Mailing Address:
_______________________________
_______________________________
_______________________________
_______________________________
Phone # ( ____ ) ____-__________
Fax # ( ____ ) ____-__________
4. Business Location (street address if
different from above and directions to site):
_________________________________
_________________________________
_________________________________
_________________________________
5. County where business is located:
______________________________
6. Start-up Date of Business:
Month: _____________ Year: _______
7. Briefly describe your process by describing end products, raw materials, and process
equipment used at your business. Attach additional sheets if necessary.

48forty Solutions, LLC
11740 Katy Freeway, Suite 1200
Houston, TX 77079
48forty Solutions, LLC
11740 Katy Freeway, Suite 1200
Houston, TX 77079
877 779 8577
877 779 8577
713 458 4523
48forty Solutions - Salt Lake City Plant (Site 269)
1820 West G Avenue, Bldg 641
Tooele, UT 84074
Tooele County
48forty Site 269 is a wood pallet repair and recycling facility. The facility operates a propane-fired
kiln to heat-treat the pallets and a planned Air Curtain Incinerator (ACI) to handle scrap wood generated
from the wood working process.
Jess Bonsall
ESG Director - 48forty Solutions
[e-mail]
[e-mail]
(453)-843-4280
8. List any pollution control equipment:

9. Typical operating Schedule:
10. Annual Emission Rates:
Provide an estimate of the actual annual emissions of the following air contaminants from your
business. Emission calculation worksheets are available for some common processes.
Please attach all worksheets and calculations.
Sulfur Dioxide (SO2)….. ______ lbs / year Particulate Matter (PM10) ….……... ______ lbs / year
Carbon Monoxide (CO) ______ lbs / year Ozone (O3) ……………………..…. ______ lbs / year
Nitrogen Oxides (Nox) ______ lbs / year Volatile Organic Compounds (VOC)______ lbs / year
Other Air Contaminants ______ lbs / year Describe__________________________________
HAZARDOUS AIR POLLUTANTS:
Complete Attachment C before selecting one of the following emission estimate ranges.
For an individual hazardous air pollutant:
0 - 250 lbs/year: ________ 250-350 lbs/year: __________ 350-500 lbs/year: _________
For a combination of hazardous air pollutants:
0-1000 lbs/year: ________ 1000-1500 lbs/year: __________ 1500-2000 lbs/year: _________

11. □ By checking this box, I hereby certify that the information and data submitted in this notice
fully describes this site and only this site and is true, accurate, and complete, based on
reasonable inquiry and to the best of my knowledge. I recognize that falsification of the
information and data submitted in this notice is a violation of R19-2-115, Utah
Administrative Code.

□ By checking this box, I understand that I am responsible for determining whether I remain
eligible for this exemption before making operational or process changes in the future and
agree to notify the Division of Air Quality when this business is no longer eligible for this
exemption.

Signature of Owner/Manager: __________________________________Title: __________________

Print Name: ____________________________ Phone # : (_____)___________ Date: ___________

Division Reviewer: _____________________________________________Date: ____________________
Small Source Applicable Yes___ No___ ____________________________________________________

The forced draft air curtain on the ACI acts as a
particulate control
10 hrs/day - 6 days/wk - 52 wks/yr
*For the kiln propane heater & the 74hp diesel engine, max expected operating sched is 6hrs/day
Jeremy Roberts
Plant Manager
435 843-4280
X
X
589
8,596
7,420
4,334
2,991
Jeremy Roberts (Sep 9, 2024 07:23 MDT)
Jeremy Roberts
Sep 9, 2024

Attachment 3
Manufacturer’s Specifications (ACI)

(Vers. 03.27.2020)
Factory and Main Office
Air Burners, Inc.
4390 SW Cargo Way
Palm City, FL 34990
Phone: [phone] or 888-566-3900
FAX: [phone]
E-mail: [e-mail]
© 1998-2020 Air Burners, Inc.
The words Air Burners and the Air Burners Logo are Registered Trademarks of Air Burners, Inc.
All Rights Reserved. Subject to change without notice. Dimensions & metric conversions rounded.
Visit Our Website at:
www.AirBurners.com
Operating Manual
S-Series Air Curtain Burner
Equipped With
Electric Motor and VFD Speed Control
S116E S119E S220E S223E, S327 S330E
Above Ground Self Contained
Refractory Walled Air Curtain Burner
"Better Economically - Better Environmentally"

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
Page i
S-327
S-327

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
INDEX

PRINCIPLE OF AIR CURTAIN BURNING ........................................ Page 1

GENERAL DESCRIPTION OF S-SERIES ....................................... Page 2

SAFETY CONSIDERATIONS .......................................................... Page 5

HOW TO SET UP THE MACHINE ................................................... Page 8

SITE PREPARATION ....................................................................... Page 10

LOADING AND STARTING A FIRE ................................................. Page 13

HOW TO FEED A FIRE ................................................................... Page 17

SHUTDOWN .................................................................................... Page 18

ASH REMOVAL ............................................................................... Page 19

TROUBLESHOOTING ..................................................................... Page 20

MAINTENANCE AND CARE OF THE UNIT .................................... Page 21

VFD SERVICING SPECIFICATIONS & MOTOR/VFD WIRING ....... Page 22

VFD/MOTOR WIRING (Continued) ................................................... Page 23

LIFTING POINTS ............................................................................. Page 25

CHECKING COUPLING ALIGNMENT ............................................. Appendix 1

Page ii

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
S-111E
S-111 E
S-220E Electric Series FireBox

NOTICE:
All electrical connections and installations must be made
by a licensed local electrician according to respective
codes and regulations by the local competent authorities.
Page iii
(Vers. 03.27.2020) Page 1 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
PRINCIPLE OF AIR CURTAIN INCINERATION

OPERATION
Air curtain incinerators are designed primarily as a pollution control device. Using a
Diesel engine or electric motor driven fan, these machines generate a curtain of air
with a very particular mass flow and velocity. This curtain of air acts as a trap over the
top of an earthen trench or thermo-ceramic lined FireBox. The wood debris is dumped
into the trench or FireBox and then ignited (usually with a propane torch or with a small
amount of Diesel fuel) just as you would light any other pile of wood you intended to
burn. Once the fire has gained strength the air curtain is turned on. The air curtain
traps most of the smoke particles and causes them to re-burn under the air curtain
where the temperatures may exceed 1,800º F (950º C). These machines do not inject
any fuels into the fire, the fire is sustained only by adding more wood debris. The air
from the air curtain is not heated.
(Vers. 03.27.2020) Page 2 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
GENERAL DESCRIPTION S-SERIES

The self-contained refractory walled air curtain system is manufactured as an over-the-
road transportable combustion system designed to reduce clean wood waste and veg-
etative growth to ash in a safe, controlled burning process without excessive particu-
late emissions. The FireBox is open to the ground, except for the Roll-off versions; they
have a floor to accommodate the roll-off rail system.

The standard S-Series machines are offered in several sizes. The smallest is the
S116 (16 ft. firebox) and the largest is the S330 (30 ft. firebox). The table below shows
the approximate dimensions.
Diesel Engine Version: S330 & S327: HATZ 4H50TIC (Tier 4 Final) or equivalent engine. S223, S220, S-119 & S-116: HATZ 3H50TIC (Tier 4 Final) or equivalent engine.
Drive System: PTO & mechanical direct coupling drive.
Electric Motor Version: Motor: 3-Phase, heavy-duty, with enclosed pre-programmed variable frequency speed controller (VFD); Power in: Three Phase 480V, 50Hz or 60Hz, or selected other voltages;
Drive System: Direct drive.
Options: Ash clean-out rake - price will be quoted for plain faceplate (S300) or universal quick disconnect(S200 & S100); Steel floor: Ember screen (S200 & S100 only); Rough-terrain removable dolly.
Fuel Consumption: Indicated fuel consumption rates approximated.
Through-Put: Through-put depends on many factors, such as nature and type of wood waste, its moisture content, prescribed opacity limits, operator skills, elevation of location, etc. The figures stated here are guidelines only. If more specific information is required, please contact the Factory.
NOTES: All weights and dimension are approximate. Dimensional drawings can be provided on request.
Subject to change without notice.

Above-Ground Air Curtain Burner Dimensions
Model Overall Size L x W x H FireBox L x W x H Weight lbs. Fuel gal/hr.
Average Thru-put tons/hr.
S330 40' 4" x 11' 10" x 9' 6" 30' 2" x 8' 5" x 8' 1" 59,000 3.0 11-13
S327 37' 4" x 11' 10" x 9' 6" 27' 2" x 8' 5" x 8' 1" 54,600 3.0 9-11
S223 33' 3" x 8' 6" x 8' 6" 22’ 11” x 6’ 2” x 7’ 1" 40,250 2.0 7-9
S220 30' 1" x 8' 6" x 8' 6" 19’ 8” x 6’ 2” x 7’ 1" 36,650 2.0 5-7
S119 27' 3” x 7' 2" x 7' 4" 19 x 5’ x 6' 30,100 1.9 3-5
S119R* 27' 6” x 7' 2" x 8' 3" 19 x 5’ x 6' 39,900 1.9 3-5
S116 24 7”' x 7' 2" x 7' 4" 16' x 5’ x 6' 27,500 1.9 2-4
S116R* 24' 11” x 7' 2" x 8' 3" 16' x 5’ x 6' 36,300 1.9 2-4
T24 19' 8" × 7' 8" × 5' 8" 12' × 4' × 4' 9,983 0.35 ½-1
* Cable-hoist version; Hook-lift version is 5” shorter
(Vers. 03.27.2020) Page 3 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
GENERAL DESCRIPTION S-SERIES (E-VERSION)

When delivered to a job site, the S-Series machine is ready for use as soon as it is off-
loaded and properly connected to a power source. The entire system is built on a skid
type base frame which is designed for easy movement over the ground. The forward
equipment deck supports an Electric Motor and a Variable Frequency Speed Controller
(VFD). The motor is directly coupled with the fan. When viewed from the front of the
unit, the patented air disbursement manifold is mounted on the left top side of the com-
bustion chamber. The back of the FireBox is fitted with refractory lined doors that allow
ash removal and access to the burn chamber.

The electric motor that turns the fan is controlled by the VFD unit housed securely be-
hind the front deck enclosure in a NEMA IV housing. The high velocity air is sent down
the manifold through the vanes and directed to the outlet nozzles. A balanced and dis-
tributed air flow is directed across the top of the box and then reflected down into the
combustion zone.

The curtain of air acts as a top over the FireBox, trapping a large percentage of the es-
caping particulate matter (smoke) and causing it to burn down even further under the
curtain before finally escaping through the curtain as a hot gas. The air from the noz-
zles travels across the FireBox creating the air curtain effect; then it reflects off the far
side thermo-ceramic wall adding oxygen to the combustion zone helping to generate a
hotter more complete fire. This additional agitation helps prevent the fire from starving
for oxygen as the ash builds up during burning operations.
All of this is carefully engineered to provide the correct amount of air at the correct
velocity. It is sometimes thought that more air flow will actually increase the burn
rate. This is INCORRECT. Modifying the air flow will actually have the opposite
effect and reduce the machine’s through-put. Additionally, it will reduce the ma-
chine’s ability to meet air quality minimum standards. There is a maximum rate at
which wood can burn. Trying to exceed that rate by adding more air to an air cur-
tain burner causes two major problems:

1) It will cool the fire reducing combustion efficiency creating more smoke (carbon
dioxide and nitrogen enriched). This will begin a circular effect of further reduc-
ing the oxygen and further reducing combustion efficiency. The result is your
through-put drops and smoke increases.
2) Increasing the air flow beyond design standards will over-pressurize the Fire-
Box causing larger sized particles to be ejected from the FireBox. Besides vio-
lating the EPA limits for PM (particulate matter) the larger hotter embers eject-
ed will pose a much greater fire hazard.
(Vers. 03.27.2020) Page 4 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL

IMPORTANT:
Notice, how dirt is placed all around the inside bottom to close any openings under the
skids that may be caused by uneven terrain. This will prevent smoke from escaping.
FireBox in Operation:
Smoked trapped by Air Curtain and re-burned
S-327 Rear Doors Open
(Vers. 03.27.2020) Page 5 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
SAFETY CONSIDERATIONS

READ ALL SECTIONS OF THIS MANUAL BEFORE YOU BEGIN BURNING OPERATIONS

The S-Series machine operator is dealing with fire on a daily basis; it is very important
that each and every individual involved with the machine be alert and practice very rig-
id safety precautions.

When you are running the S-Series unit, you are responsible for assuring that it is op-
erated in the safest possible manner at all times. If you notice something wrong, cor-
rect it immediately, and if you cannot correct it, find someone who can and/or shut
down the machine.

Basic Safety Points:

1) The unit should be placed on cleared, earthen dirt.
The unit should be placed on level ground to facilitate loading, dumping and
moving of the unit. The rear doors weigh approximately 2,000 lbs. each and
should not be opened, if the unit is inclined on any axis more than 5 degrees.

2) The unit should be placed such that no combustible material is stored
within a minimum 100 foot clearance in any direction.
The S-Series units do not have a bottom and should not be located over com-
bustibles such as dry grass or peat moss. In addition hot embers will escape
from the unit and, depending on the wind, will land on the ground around the
unit. The unit should not be located within 100 feet of any stored combustible
materials. The waste material to be burned during the day’s operation can be
staged within the 100 foot perimeter to facilitate loading. The operator must
monitor the loading pile to insure embers do not ignite the loading pile. The
combustible materials to be stored for burning at a later date must be stored
outside the 100 foot perimeter or in accordance with the chart on page 6 of this
manual which suggests adjustments for wind speed.

3) The unit should not be operated when the wind speeds reach 20 MPH, as
the potential to carry hot embers is significantly increased.
As an operator you should always be aware of wind speed and direction. In-
creased wind speed will affect the integrity of the “air curtain” and will cause hot
embers to travel farther. See the wind speed chart regarding suggested set-
back on page 6.
DANGER:
Watch for the danger notices throughout this manual.
(Vers. 03.27.2020) Page 6 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
4) NEVER use highly combustible materials to light the unit.
Highly combustible materials such as gasoline, refined spirits, etc. ignite at an
explosive rate which may cause serious injury or death. The safest method to
start the fire in the FireBox is to use materials such as paper and kindling wood.
In the absence of these materials or when starting materials with a high mois-
ture content use Diesel fuel as an acceptable option.

5) NEVER climb on the unit to view or light the fire.
Use the ladder built into the unit and never go beyond the top step, or use a
step ladder or similar platform located at a safe distance from the unit. Do not
stand along the rails or on top of the S-Series unit under any circumstance.

6) Shut the unit down in an emergency.
Stop loading the unit, stop the air flow by pressing the STOP Button on the con-
trol panel or by disengaging the master switch on the external power supply line.
Dump dirt or sand on to the fire. Water should only be used as a last resort, as it
will likely damage the refractory panels.
WIND SPEED VS. SAFE DISTANCE
Approximate Safe Distance for:
Wind Speed
(MPH)
Structures
(Houses, etc.)
Woods/Trees Stored Brush Piles
10 300' 150' 100' 12 300' 150' 100' 14 300' 200' 150' 16 400' 250' 150' 18 400' 250' 200' 20 500' 250' 200'
DANGER: The above distances serve as a GUIDELINE ONLY! You
MUST ALWAYS observe the down range area regardless of the wind
speed. You must always observe local fire ordinances and directives
from the local fire department or other authorities.
DANGER: Falling into the FireBox will cause serious injury or death.
(Vers. 03.27.2020) Page 7 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
7) Personal Safety
Operators need to be aware of the following potential hazards:

A) Flying hot embers being released from the fire. Operators or anyone within
the 100 foot radius of the fire should wear appropriate fire resistant clothing. The
ideal outwear for an operator would include a “Nomex” jacket, leather gloves,
eye protection, hard hat, cotton work jeans and steel-toe boots. Operators
should never wear synthetic material (i.e. polyester) around the fire, as this type
of material can melt and cause injury. Additionally, some synthetic materials will
support combustion and could be very dangerous around fire. One hundred per-
cent cotton materials would be the minimum, cotton treated with a fire
retardant would be better and fire proof materials like “Nomex” would be best.

B) Noise ear protection is recommended around the machines. It is a
good practice to wear approved ear protection when working in close proximity
to the fan and engine.

C) Hot Panels. The backs of the thermo-ceramic panels and parts of the
steel structure can reach temperatures as high as 500 degrees Fahrenheit .
Caution should be taken to insure operator and visitors do not come in contact
with these hot areas.

D) Ash and dust can be released during the operation and during cleaning.
Operators should wear appropriate breathing masks to protect themselves from
inhaling the dust and ash.
DANGER: You must insure debris does not build up on the equipment
front deck. It must be keep clean at all times during operation to prevent a
fire that would damage or destroy the motor and accessories.
(Vers. 03.27.2020) Page 8 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
HOW TO SET UP THE MACHINE

A) POSITIONING THE UNIT

The S-Series units are totally self-contained and ready to use upon delivery to the job
site. The electrically powered S-Series units are built on a skid base that is designed to
facilitate dragging the unit into position near the on-site external electric power connec-
tion and grounding rod. The weights of the various units are given in the General De-
scription section. Ensure lifting or tow cables are certified for these weights.

With respect to the prevailing wind direction, the unit should be positioned such that
the wind comes over the back of the manifold. This is the preferred position. It is also
acceptable to have the wind blow into the manifold. It is discouraged, however, to have
the wind come from either end of the machine, as this will tend to disrupt the air cur-
tain.

B) PRE-OPERATION CHECKS:

1. Check Ground Wire connection from grounding lug to grounding rod
and power pole (on left side of FireBox below the air fan) and repair
if needed.
2. Check intake air filter for cooling fan on VFD (lower left side) for
cleanliness (open small access door, setup may vary).
3. Make sure Fan Speed Switch is set to OFF Position before turning
main power switch to ON.
DANGER: When you tow (drag) the S-Series units, especial-
ly in soft soil, watch that the dirt does not build up under the
panels and lift the panels off the rails. Never walk inside the
box when it is being towed. Typically, the softer soils will re-
quire a longer cable. If the rear of the unit sinks in soft soil
while it is being towed, use another vehicle to follow and carry
some of the load. If you are still having trouble dragging the
unit, try a different length of tow cable. Always stay clear of the
tow cable while the dragging operation is underway.
(Vers. 03.27.2020) Page 9 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
HOW TO SET UP THE MACHINE

C) STARTING/SHUT-DOWN
Electric Motor and VFD
Starting: Ensure that an appropriate ground
wire is properly connected to the grounding
lug (See Page 23) and the grounding rod.
Ensure that the power on the main external
breaker or switch is turned on.
Insure that the FAN SPEED SWITCH is
placed in Position OFF.
Insure the red POWER BUTTON is OFF
(pushed in).
Set the MAIN POWER SWITCH to the ON
position; this will connect power to the unit.
Wait 15 seconds for the VFD to boot up be-
fore going to the next step.
Pull out the red POWER BUTTON
(ON Position).
Load FireBox and start fire per Operating
Manual Page 13.
Set AIR CURTAIN FAN SPEED CONTROL-
LER to Position NORMAL 2. Once the ma-
chine is fully operational, you may select Po-
sition NORMAL 1 for energy conservation, as
long as this does not result in excessive par-
ticulate (smoke) release.
Shut-down: Turn AIR CURTAIN FAN SPEED
CONTROLLER to OFF. Wait 15 seconds for
the VFD to boot down before going to the next
step.
Push in the red POWER BUTTON to turn off
power to Motor.
Set MAIN POWER SWITCH to OFF.
Control Panel
Control Switches, Indicator Lights & Hour Meter
(Vers. 03.27.2020) Page 10 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
SITE PREPARATION

THE GOALS TO GOOD SITE PREPARATION ARE:

To place the wood piles for easy access.
To sort the waste wood pile.
To organize the inflow of new wood waste.

When locating the FireBox;

Consider access for your truck and trailer to load and unload the FireBox. Ensure
there is enough room to maneuver your truck and trailer.

Consider where the waste piles will be located. We generally recommend two waste
piles (explained in next section).

Consider the predominate wind direction. Hot embers will be escaping from the Fire-
Box during all burning operations.

Consider the available 480V three-phase power pole connection and underground
feed to the FireBox from there. Power to be supplied pursuant to Local Code and the
FireBox must also be properly grounded by a grounding rod pursuant to local code.

DANGER: This machine DOES NOT prevent hot embers from es-
caping. This machine is designed primarily as a pollution control de-
vice to reduce the smoke (particulate matter) generated from burning
clean wood waste.
(Vers. 03.27.2020) Page 11 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
SITE PREPARATION

Faster operation through staging the wood piles

Air Burners FireBoxes were designed primarily as a pollution control device, but oper-
ated correctly they will burn clean wood two or three times faster than open burning. To
achieve the best throughput the fire must remain at the highest temperature possible.
You achieve this by remembering three rules;

1) Don’t smother the fire with a huge load or a load of very dense material.
2) Load “less more often” smaller bucket loads more often.
3) Sort out a pile of your best burnable wood, use it to create a hot fire.

The basic principle of operation is not too different from a campfire. You use your best
wood to get it started and, If the fire dies down you add some more good wood to bring
it back up. The big difference is that on your campfire you are probably not adding root
balls and leaves and pine needles. These are the high moisture content and dense
materials that bring the fire temperature down.

The temperature drops (smoke in-
creases) and your burn rate slows
down, if you overload the machine
with materials that have high mois-
ture content such as tree branches
with leaves and needles, or green
branches such as palm fronds.
While these are certainly ok to burn
in the FireBox, you want to add
them to a hot fire so they dry out
and ignite quickly. To keep the tem-
perature up and to maintain the
highest throughput of waste you
should mix the very burnable wood with the less burnable materials throughout the
course of the burning operation. The most common way to accomplish this is to stage
a pile of the most burnable materials or what we call the “two pile system.”
“If it’s burning clean, it’s burning hot. If there is smoke, you’re losing money.”
(Vers. 03.27.2020) Page 12 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
SITE PREPARATION

The “Two Pile System”

For an efficient operation you would have two piles:

The first pile or “main debris” pile, is the material being generated from the landfill or
transfer station operation and is located away from the ember path, but with good ac-
cess to your loading machinery.

The second pile or “good wood” pile is your best and most burnable wood. When you
first setup the site the operator should spend some time sorting through the main de-
bris pile pulling out what appears to be your best and most burnable materials. This is
the material you will start the fire with, this is the material that will give you a good hot
burning base fire. You will also draw from the good wood pile throughout the day, if
you should need to stoke up the fire (more on this in the following sections).

As the FireBox operator is drawing from the main debris pile throughout the day he
should continue to replenish the “good wood” pile as necessary. The good wood pile
only needs to be enough material to stoke-up the fire if needed and enough material to
get you started the next day.
DANGER: You must insure debris does not build up on the equipment
front deck. It must be keep clean at all times during operation to prevent a
fire that would damage or destroy the motor and accessories.
IMPORTANT WARNING ABOUT BURNING OF PALLETS
Wooden Pallets, especially spent pallets burn extremely hot. DO NOT load
the FireBox above approximately 3/4 of the height of the burn chamber. Heat
damage to the manifold and other structure may occur which would not be
covered under your Limited Factory Warranty.
(Vers. 03.27.2020) Page 13 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
LOADING AND STARTING THE FIREBOX

THE GOALS IN STARTING AN S-SERIES UNIT ARE: To achieve an even fire across the length of the box.
To start the fire from the bottom of the initial pile.
To build a hot base fire.

There are two methods for lighting the unit; a cold start and a hot start. A cold start
means the FireBox is clean and has no hot coals left from a previous burn. A hot start
uses heat from the coals of the previous days burn.

COLD START
Unit should be on level ground, the air fan should be off, but the main power switch
should be on with the speed control set to zero.

To prevent smoke from escaping under the box, shovel dirt along the inside bottom
edges of the panels. It will only need a couple inches to prevent the smoke from es-
caping underneath the unit. This is generally only a concern on hard ground and it usu-
ally only lasts for the first hour of burning. As burning continues the ash will build up
and seal off the bottom of the unit as well.

Load your most burnable material (materials from the “Good Wood” pile as discussed
in the previous section) which is the smaller, drier and cleaner wood, into the FireBox
to a level of about half way up. Ensure the entire bottom area of the FireBox is cov-
ered. If you are using Diesel fuel to assist in the lighting, spray it (approximately 10
gallons) across the top of this first load of wood. Be sure to get some Diesel on the
wood near the lighting holes in the FireBox side and on the wood towards the back.
This will help make it easier to light.
DANGER: If you are using an accelerant, first insure there are NO HOT
COALS remaining in the FireBox.
DANGER: DO NOT use highly volatile accelerants, such as gasoline or
kerosene, to light the fire. These fluids ignite almost explosively and may
cause injury or death.
(Vers. 03.27.2020) Page 14 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
LOADING AND STARTING THE FIREBOX

Once you have this smaller material loaded and your accelerant added (if used) load
some larger, heavier material on top, such as logs or big branches. Load these heavier
materials, also from your “good wood” pile, to a height just below the manifold nozzles.
This heavier material will help compress the smaller material which will give you a bet-
ter light-off. If there are large air spaces between the materials in the FireBox the heat
will not build up as quickly and the fire may be more difficult to light.

This material once burning will become your hot base fire to support continued burn-
ing. Use your best and driest materials (good wood) for startup as this will form a
strong base for continued burning plus it will start quicker and burn hotter. If you will be
burning stumps, then it is best to load them after the first hour of burning when the fire
is up to full temperature.

The level of material in the FireBox for light-off should be kept just below the manifold
nozzles.

If you are using Diesel fuel as an igniter it is sometimes helpful to add a second coat to
the top load again, ENSURE THERE ARE NO HOT COALS REMAINING IN THE
UNIT before adding the accelerant.

Your goal is to develop a good hot base fire and to maintain a good hot fire throughout
your burning operation. This will give you the cleanest burn and the most throughput.

There is always smoke on start-up as all of the material in the box contains moisture,
compared to later in the burn operation when only the new material you are loading
contains moisture. Plus, the air curtain cannot be fully engaged until the fire has
strengthened or you run the risk of blowing out the fire.
DANGER: NEVER stand on the machine, as you may
fall in causing serious injury or death.
(Vers. 03.27.2020) Page 15 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
LOADING AND STARTING THE FIREBOX
To minimize start-up smoke you can:
Use your driest materials.
Ensure your materials do not retain dirt or sand.
Use Diesel fuel to accelerate the light up.

COLD START LIGHTING

The air should be off. The main power switch
should be ON with the Speed Controller set to
OFF and Red Push Button OFF (pushed in).

2. For best results and quickest light up, start the fire
from the bottom because fire will spread up much
better than it will spread down.

3. Use a propane torch (like a weed burner) or oil
soaked rags on poles to light the fire.

4. The fire must be started from the access doors in
the panels on the manifold side of the unit. Access Door for Lighting

If you are using Diesel fuel as a starter, let the fire burn until you begin to see wisps of
white smoke replacing the wisps of black smoke from the Diesel fuel, or if you are us-
ing propane torches wait until the fire has strengthened and flames are reaching the
top of the FireBox. Then engage the air setting the speed controller to Position Normal
1. As the fire burns stronger increase the air by switching to Position Normal 2.

Don’t increase the air too quickly as you can “blow” the fire out. If you add air and the
smoke gets heavy then reduce the fan speed and let the fire “catch-up.” Once it clears
up you can increase the air again.

Sometimes it is helpful to “fan” the fire during the start-up phase. You accomplish this
by increasing the air fan RPM’s for 3 to 8 minutes, then decreasing them (i.e. Position
Normal 1 up to Position Normal 2 and back down to Position Normal 1). This some-
times helps to spread the fire throughout the material. How much air to add and when
to add it during startup will vary with the type of materials being burned.
(Vers. 03.27.2020) Page 16 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
LOADING AND STARTING THE FIREBOX

HOT START
A hot start uses the coals from the previous day’s burning operation. Depending on
how much ash is in the unit a hot start can be done once or twice before the unit will
need to be emptied. The more ash in the FireBox that you start with the LESS room
you have for burning new materials.

First, insure there are enough coals remaining to generate enough heat to get the new
waste materials burning. You CANNOT add an accelerant, if the waste materials do
not light, as that would be too dangerous. You can use propane torches in the lighting
holes, if you have trouble with a hot start. If the material does not light, the FireBox
must be emptied before trying a cold start with the use of an accelerant.

.

HOT START LIGHTING
Similarly to a cold start you begin with your best and most burnable materials.

1) Load the FireBox to about one third or half way with the “Good Wood”. The
wood should begin burning as soon as you start loading.

2) Set the fan speed at Position Normal 2. This should help fan the flames and
spread the fire. If you experience heavy smoke then reduce the RPM’s by
switching to Position Normal 1 or disengage the air fan altogether by switching
to Position OFF. Be cautious not to “blow out” the fire.

3) As the fire begins to heat up, increase the RPM’s to the maximum Position
Normal 2.
DANGER: Do not use an accelerant for a Hot Start, as it may ignite
unexpectedly and cause injury or death.
(Vers. 03.27.2020) Page 17 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
HOW TO FEED A FIRE
It will generally take 30 to 60 minutes for the fire to build to a point where the tempera-
tures are sufficient for the unit to be operating with minimal smoke.

1. Add material from your “Good Wood” pile slowly for the first hour. It takes about
an hour for the fire to reach minimum temperature. Your goal is to achieve an
even and hot fire across the unit.

2. If you get excessive smoke and ash when you load the wood waste while drop-
ping the load through the air curtain, then you may need to turn the RPM’s
down temporarily. This may especially be required earlier in the burn operation.

3. Take caution when loading the unit that the material to be burned is not
“dumped” in the box too quickly causing hot embers to be thrown from the unit.

4. If you have an area in the box that is smoking, this indicates the temperature is
low in that area. Add material from the Good Wood pile to increase the fire tem-
perature. Once that area is burning add some of the heavier material.

5. The rate at which you load the unit varies depending on moisture content of the
materials and the temperature of the fire. If you overload the box you will notice
an increase in white smoke. White smoke is an indication that the temperature
is dropping. If the smoke increases stop loading until the fire has caught-up.
You can also bring the temperature up by adding materials from the “Good
Wood” pile.

6. For the highest throughput load “LESS MORE OFTEN.” Smaller bucket loads
more often will give the materials a better chance to burn and will result in your
highest throughput of material. Oversized bucket loads may smother the fire
for a short period before it ignites this will slow the burning down and reduce
your daily throughput.

7. The load in the box should not go higher than one (1) foot below the manifold. If
the material is piled higher it will begin to break the air curtain and more
smoke will escape.

The fire should be loaded continuously throughout the day in order to maintain operat-
ing temperatures. If the fire is not loaded continuously, the temperature will drop, the
through-put will go down and more smoke will escape.
“If it’s burning clean, it’s burning hot, If there is smoke, you’re losing money.”
(Vers. 03.27.2020) Page 18 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
SHUTDOWN

HOW TO BURN FIRE DOWN FOR SHUT DOWN

All loading should stop one or two hours before you intend to put the fire out.

As the fire burns down, maintain the air speed until the box begins to smoke. As the
smoke increases reduce the air speed in increments to Positions Normal 1 and the
Cool Down Position. This will help to reduce the smoke.

The air in the manifold needs air flow, both to accelerate the burn down and to protect
the manifold from warping due to excessive heat. DO NOT shut off the air flow (turn
off the motor) while there are still flames within 24 inches of the manifold. Doing
so may cause elevated temperatures to warp the manifold, nozzle assembly, etc. Your
warranty does NOT cover damage due to excessive heat.

Once the fire has burned down to about one or two feet and flames are not visible near
the manifold, it will be safe to turn the SPEED SWITCH to the COOL-DOWN mode.
After appropriate burn-down time, turn the SPEED SWITCH to OFF and push the RED
POWER BUTTON to OFF. Finally, turn the Main FireBox Fan Switch counterclockwise
to the horizontal OFF position.

Make sure the fire is contained as necessary to comply with your local regulations. Do
not spray the refractory walls with water, as this will damage them.

Some local authorities allow the FireBox to be secured and the embers to smolder all
night. There is generally no smoke from this smoldering. Insure the work site is se-
cured or has a constant security guard to prevent any people or animals from getting
near the FireBox. The inside temperatures of the FireBox will remain very high most of
the night.

If you are not allowed to smolder through the night, then verify that the fire inside is
completely out. If it is still burning or smoldering you can either water down the embers
or you can use sand or dirt to cover the remaining hot spots. Ensure the fire is out and
the job site secure before you leave.
DANGER: Falling into the FireBox will cause serious injury or death.
(Vers. 03.27.2020) Page 19 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
ASH REMOVAL

HOW TO EMPTY THE S-SERIES UNITS

The FireBox will operate with up to 3 feet of ash inside, but as the ash gets deeper the
efficiency of the unit goes down. Three feet of ash would represent approximately 20
hours of burning. The FireBox should not be run with over 3 feet of ash inside.

We recommend removing the ash every morning before burning operations begin.
This will give you maximum capacity in the FireBox and the ash will be easier to han-
dle.

There is only one way to empty the ash out of the electrically powered FireBox, name-
ly, by excavating it out.

EXCAVATING

The ash can be remove by reaching in with an excavator or by driving into the box with
a small skip loader type vehicle and scooping the ash out. Remember to use the ap-
propriate breathing apparatus, especially if you drive in the FireBox and be cau-
tious of any remaining hot embers.
DANGER: When removing ashes from the FireBox, make
sure that no hot ashes, embers, burning or hot materials are
carried by the wind to places where they could start a fire!
DANGER: When removing ash from the FireBox be aware of
the wind direction and insure all operators wear appropriate
face masks to prevent inhaling the ash.
(Vers. 03.27.2020) Page 20 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
TROUBLESHOOTING

1. Fire will not start.

Material in FireBox has too much air space. To correct, load heavy material such as
stumps to make the lower material pack down. Use torches and light from the bottom
so the fire burns up.

2. Fire burning at one end.

Load heavy materials directly on top of the burning area. This causes the flames to fan
out in an effort to reach the top of the pile. As the fire begins to spread, keep material
piled on top of the flames until the entire FireBox is burning.

3. Fire smoking too much.

The most common reason for a smoking fire is too much dirt or dense materials going
into the FireBox and reducing the heat. You must make sure the wood waste material
is free from large amounts of dirt. Load from your “Good Wood” pile to bring the tem-
perature back up.

You may have overloaded the FireBox or loaded the box too fast. Example; if you only
have 1 ton of material burning you can not load in 3 tons of material. The new material
will smother the fire. Stop loading and let the fire catch up. The material you are load-
ing may have a very high moisture content. You can either load at a slower rate or mix
the wetter material with dryer material.

If you are letting the fire burn down or the load in the box is less than 3 feet deep, you
may need to turn the air down by reducing the motor speed.

4. Smoke from one area of the box

The area is probably not burning well. Add smaller material from your “Good Wood”
pile to this area to help build the fire. As the smoke clears add heavier material.

5. Smoke from under the base rails or bottom of panels.

Loose dirt was not properly shoveled around inside of box to seal between panel bot-
toms and the ground. To fix, shovel dirt around the outside where the smoke is escap-
ing. Once the ash inside builds up this will stop.
(Vers. 03.27.2020) Page 21 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
ALWAYS INSURE THAT THE FIREBOX UNIT IS PROPERLY GROUNDED. CHECK
GROUND CONNECTION AT GROUNDING LUG AND GROUNDING ROD.
CHECK GROUND WIRE AND GROUD WIRE GAUGE (AWG).
FOLLOW LOCAL CODES.
MAINTENANCE AND CARE

A. Daily Check List:
1. Ensure that the ground wire is properly connected
to the FireBox grounding lug and the grounding
rod and that the wire gauge meets AWG of local
code.
2. Ensure that the VFD cooling fan intake air filter is
clean (lower left; to remove filter reach under rain
hood and loosen two (2) thumbscrews holding fil-
ter access door. (Position and type may vary).
3. Insure that the external power grid from the power
company is providing proper power to the pole
(480V balanced three-phase). Brown-outs
(voltage deficiency or under voltage) or excessive
voltage spikes can cause default shut-downs by
the VFD protective circuitry. Such default shut
down requires the powering off of the VFD to initi-
ate an automatic reset of the unit. As the air fan
would not be supplying air to the manifold for the
reset period of time, such shut down should be absolutely avoided, once there is
a fire in the FireBox to prevent warping of the manifold. Do not operate the Fire-
Box S-Series (Electric), if weather conditions may indicate a possible interruption
of power during the work day.
4. Do not wash down the NEMA IV enclosure with a water hose, as water may en-
ter through the cooling fan vents.

B. Periodic Maintenance
1. Grease the electric motor bearings (very sparingly, consult electric motor book-
let/manual).
2. Grease both (inside and outside) air fan bearings every 2-4 months on models
with fan-to-motor coupling where the air fan is not coupled directly to the motor
(Do NOT over-grease)
3. For FireBox models equipped with a coupling connecting the air fan to the mo-
tor, inspect the adjustment of the coupler hubs and realign them by re-adjusting
the motor mounts as needed.*)

*) For instructions see Appendix A

Cooling Fan Rain Hood
(Position, type or cover may vary)
(Vers. 03.27.2020) Page 22 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
VFD SERVICING SPECIFICATIONS

Other than as indicated under Periodic Maintenance, there are no user-serviceable
parts. Should the VFD require attention or re-programming, a qualified technician
should be engaged to perform this work.

There are no supply voltage (480V) circuit breakers or fuses inside the NEMA enclo-
sure, only three internal control circuit fuses. Call the factory for programming sup-
port, id needed.
MOTOR / VFD WIRING

Power:
480V balanced three-phase into control box from power pole (grid) and min. 460V
three-phase out from control box to electric motor. The motor is rated at 460V to allow
for a voltage drop of up to approximately 20V by the VFD. The unit can be set to han-
dle either 50Hz or 60Hz power.

The S-330E/S-327E is fitted with a 75 HP (56 kW) and the S-220E and S-100E Series
are fitted with a 30 HP (22.4 kW) premium three-phase motor.

Air Fan Rotation:
Fan Rotation is clockwise as viewed from the motor end or counter-clockwise as seen
from the outside of the FireBox. The motor rotation is set at the factory and the VFD is
programmed also at the factory for the proper speed settings (Positions are 0-1-2-3).
NOTICE: All electrical connections and installations must
be made by a licensed local electrician according to respec-
tive codes and regulations by the competent authorities.
(Vers. 03.27.2020) Page 23 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
Default Shut-down of VFD and Motor / VFD Wiring (Continued)

The external power lead of proper
gauge (AWG) must be connected to
the power distribution block in the up-
per left corner (see right photo; (VFD
model and connection block may
vary).

The unit may be shipped without a
NEMA housing cutout for the external
power lead feedthrough. It may have
to be positioned and provided by the
local licensed electrician.

A main breaker or fuse switch (not
supplied) must be installed externally
per local code.

Ensure proper grounding of the unit
per local code and connect a ground-
ing rod to the grounding lug on the
I-beam located on the left side below
the main air curtain fan. Use proper
wire gauge.
Grounding Lug
View inside the NEMA IV box (door open)
Components shown may vary.
NOTICE: All electrical connections and installations must
be made by a licensed local electrician according to respec-
tive codes and regulations by the competent authorities.
NOTE: The VFD is set to “Coast-to-
Stop”. That means the power to the
motor is not turned off when setting
the Fan Speed Control Switch to OFF,
but the speed is reduced to 0 by the
frequency settings. The fan may con-
tinue to rotate slowly. Always push in
the red STOP BUTTON to completely
shut off the power to the motor/fan,
then turn off the MAIN POWER
SWITCH. See also the Start/Stop in-
structions on Page 9.
(Vers. 03.27.2020) Page 24 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
THERMO-CERAMIC PATCHING COMPOUND
For minor repair of S-Series refractory panels and doors.

Air Burners Part # 6900-1003
Thermo-Ceramic Wet Pre-Mix

NOTE: This is an air cured product, reseal unused portion immediately.
Once opened the shelf life is one (1) year.

Directions:
1) Cracking of the panels is normal as they flex in the heat. Filling the cracks
every 6 months or as needed will extend the life of your Thermo-Ceramic
Panels.

2) Air Burners patching compound is pre-mixed and ready to use (may require
some stirring).

3) Storage: Compound should be stored indoors in a frost free location.

4) Preparation: The area in and around the damaged area to be patched must
be cleaned and brushed to provide the best surface for the compound to ad-
here. Remove all loose refractory and debris from the area to be patched.

5) Wet the cleaned surface with a light spray or damp cloth.

6) Installation: Using a trowel or similar tool, pack the refractory compound ma-
terial into cracks and into areas where the refractory is missing. To achieve
proper thickness, trim off the excess material using a sharp flat blade or the
side of the trowel.

7) Allow the material to harden overnight before placing the FireBox back into
service. After the compound has hardened operate the FireBox under nor-
mal conditions.
Contact Air Burners, Inc., should you require assistance with
this maintenance tasks. Send Email to [e-mail],
call 772-220-7303 or 888-566-3900
(Customer Support)
(Vers. 03.27.2020) Page 25 of 25

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
LIFTING POINTS
There are four designated lifting pad eyes for lifting all FireBox Series units by suitable
crane. Only lift by attaching cables or straps to these four pad eyes. Their locations are
marked with yellow lifting point labels with up-arrows.

There are two lifting points in the front and two in the rear of all FireBoxes.

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
CHECKING COUPLING ALIGNMENT
This Technical Memorandum covers FireBox Models equipped with Dodge Raptor Couplings.
The S-327 and S-330 use Size E30 (Air Burners Replacement Part Number 5000-2120) and
all other FireBox models use Size E20 (Air Burners Replacement Part Number 5000-5123).
Certain FireBoxes equipped with electric motors are also fitted with Dodge Raptor couplings.
The general coupling information in this Technical Memorandum applies to them also.
WEAR PROTECTIVE GEAR
SHAFT HUB ELEMENT HUB PTO
The coupling shown above is an E20 with
the protective guard removed.
TOOLS REQUIRED
Coupling hubs should be aligned using straight
edges or calipers. Laser alignment tools, or
other precision alignment equipment can be
used but are not required. Tools 1. Two open-end wrenches, 3/4”
2. Torque wrench
3. Sockets/wrenches, 9/16” & 7/16”
4. Straight Edge Ruler or Calipers

Step 1 Preparation
1. Lock out engine/motor to prevent accidental start which could cause injury.
2. Remove the protective metal guard (Not shown in image above) from fan.
3. Take off the element by removing the Grade A bolts holding the two halves together. Bolts
should be used only one time. All bolts use thread locking patches.
4. If any coupling adjustments are required, be prepared to realign the engine by adjusting
the four engine isolators until the measurements of Steps 2, 3 and 4 are achieved.
Step 2 Verify Gap Between Hubs
1. Measure the distance “A” between the hubs with
calipers or other appropriate tool
2. If needed, set distance “A” as follows:

GAP MEASUREMENT “A”
E20 2.46” 62mm
E30 2.55” 65mm
A
Appendix A - Page 1

Series (E) Refractory Walled Air Curtain Burner (Electric Motor & VFD)
OPERATING MANUAL
CHECKING COUPLING ALIGNMENT
Step 5 Element Installation
1. Place first element half on hubs and hand-tighten the flange head bolts. When tightening
the bolts, start at the center bolt hole and then install the bolts on the neighboring holes.
2. Place the second half of the element on the hubs and follow the same procedure. Hand-
tighten the flange head bolts.
3. Use a torque wrench to tighten all fasten-
ers for the E20 and E30 to these torque
values (same for both):
B1
B2
Step 3 Verify Angular Alignment of Hubs
1. Measure the distance “B” between the hubs with calipers
or other appropriate tool at four places on the outer diam-
eter of the hub 90° apart.
2. Use the “B2” and “B1 ” measurements to calculate “C”
by subtracting the smaller measurement from the larger
number, and do this for each of the 90° apart planes .
3. Adjust the engine isolators until the “C” measurements of
both planes do not exceed these Angular Values:
ANGULAR VALUE “C”
E20 0.235” 6mm
E30 0.284” 7.2mm C=B2-B1
Step 4 Verify Parallel Alignment of Hubs
1. Check parallel misalignment by placing a
straight edge across the outside diameter of the
hubs and measuring the gap between the
straight edge and the hub at four locations 90°
apart.
2. Adjust the engine isolators until the “D” meas-
urements do not exceed these Parallel Values.
PARALLEL VALUE “D”
E20 0.188” 4.8mm
E30 0.188” 4.8mm
D
D is the distance between
straight edge and lower
outer hub edge
ELEMENT BOLT TORQUE VALUES
Bolt Size In-lbs ft-lbs Nm
E20 & E30 3/8 502 42 57
Appendix A - Page 2
S220E
FIREBOX SPECIFICATIONS
AIR BURNERS, INC.
4390 SW Cargo Way ● Palm City, FL 34990 Phone [phone] ● FAX [phone]
E-mail: [e-mail] ● www.AirBurners.com
Rev. 03.17.2020
Note: Achievable through-put depends on several variables, especially the nature of the waste material, the burn chamber temperature and the loading rate.
All weights and dimensions are approximate and metric conversions are rounded. Specifications are subject to change without notice.

1 Power 30 HP Premium Electric Motor, 3-Phase 460V, 60Hz or 50 Hz; Full enclosure; Security
locks; NEMA IV Enclosure for VFD Speed Control.
2 Burn Container
(FireBox)
4" (102 mm) thick refractory wall panels filled with proprietary thermal ceramic material;
Two full height refractory rear doors; Two ignition holes; FireBox open to the ground
3 Safety Systems
Brown-outs (voltage deficiency or under voltage) or excessive voltage spikes will cause
default shut-downs by the VFD protective circuitry to prevent overload conditions on the
motor side. Grounding lug provided
4 Control Panel NEMA IV enclosure with external power switch preprogrammed air fan speed setting
switch, and emergency shut-off switch; Hour meter
5 Air Supply Custom heavy duty fan coupled directly to motor
6 Power-in Max 480V balanced 3-Phase power, 60Hz or 50Hz
7 Transportation
& Set-up
Shipped completely assembled; Ready for immediate use; Lifting pads provided for crane
lifting; Electrical hook-up to power grid to be performed by licensed electrician pursuant to
applicable local codes
8 Options Ash clean-out rake with standard universal quick disconnect for Skidsteer or Bobcat;
Ember screen
9 Average Through-put 5-7 Tons per Hour (Average – See Note)
10 Power Consumption Approximately 22 kW
11 Weight 36,650 lbs. (16,620kg)
12 Dimensions
Overall Size
L × W × H
Fire Box
L × W × H
30' 1" × 8' 6" × 8' 6"
(9.2m × 2.6m × 2.6m)
19' 8" × 6’ 2” × 7' 1"
(6m × 1.9m × 2.2m)
General: A self-contained, completely assembled above ground Air
Curtain Burner (air curtain incinerator or FireBox) with a refractory
lined burn-container for permanent (stationary) applications. De-
signed for the high temperature burning of forest slash, land clearing debris, green waste, storm debris, and other waste streams in compli-
ance with the requirements of US EPA 40CFR60.
Shipped from the factory completely assembled ready for immediate
use upon connection to a power grid and does not require disassem-
bly for relocation. The firebox is also used for disaster recovery and
Homeland Security contingencies.
Air Curtain Incinerator
1
Air Curtain Incinerator Emissions Factors Determination From: Brian Clerico, AQE II and Errol Villegas, Permit Services Manager To: Arnaud Marjollet, Director of Permit Services
Date: April 04, 2017
Re: Recommendation for Air Curtain Incinerator Emission Factor Determination for Woody Biomass from Agricultural Sources and Forest Vegetation The purpose of this memo is to examine available test data and recommend emission factors appropriate for an air curtain incinerator (ACI) burning woody biomass derived from agricultural sources and forest vegetation. 1. BACKGROUND The San Joaquin Valley is a large agricultural region that annually generates hundreds of thousands of tons of woody biomass debris primarily from the pruning and removal of orchards and vineyards. The main historical disposal option for this material has been open burning, but open burning of ag waste has been curtailed by 80% since 2003, largely made possible by the availability of the option of chipping the material and sending it to a nearby biomass power plant. In recent years, as the biomass power industry has lost its financial and societal support and decreased in numbers from 15 facilities to five today (with none of the five buring much ag waste), the San Joaquin Valley has accumulated a glut of wood material in need of disposal. This excess has been exacerbated by California’s recent extreme drought and the bark beetle infestation which has resulted in over 100 million dead trees in the State, mostly in the southern Sierra Nevada, which is in the Valley Air District. For areas where the buildup of wood material has become an acute hazard, air curtain incinerators (ACIs) have become an important disposal option. Within the San Joaquin Valley, CalFire is currently using ACIs for wildfire hazard reduction in forested areas, and an almond huller has received an Authority to Construct to install an ACI to dispose of an accumulation of wood sticks from their almond processing operation. To quantify emissions from ACIs for purposes of permitting and emissions inventory, the most representative emission factors should be used. This memo is intended to identify and recommend the most representative emission factors for ACIs burning woody biomass from agricultural sources and forests. A number of emission tests have been conducted on ACIs. A table of the emission factors derived from those tests is provided in Table 1 below along with the emission factors for open burning of almond orchard residues and biomass power plants for comparison in Table 2.
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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In selecting the most representative emission factors, the District was guided by the following considerations: (1) A limited number of emissions tests have been published to date; (2) The source test results published show a wide variance; (3) Air curtain incineration may be regarded as a controlled form of open burning; (4) The PM10, CO, and VOC emission factors for open burning show a high degree of dependence on the material burned; (5) The ARB open burn emission factors for agricultural orchard and vine residues provide an upper bound for PM10, CO, and VOC because the visual evidence indicates the ACI is performing significantly better at reducing smoke and visible particulates (and, by extension, other products of incomplete combustion such as PM10, CO and VOC) than open burning of woody biomass derived from agricultural or forest vegetation. The open burn emission factors for almond orchards will be used in Table 2 to represent a type of woody agricultural residue common in the San Joaquin Valley; (6) The emission factors for biomass power plants controlled by a fabric filter provide a lower bound for PM10 (0.089 lb-PM10/ton)1; (7) SOx emissions are entirely material dependent; thus, the open burn SOx emission factors for agricultural orchard and vine crops, or for forests, are also likely the most representative for ACIs. The emission factors from Table 1 (page 3) were evaluated using the criteria listed above. A. AP-42, 2.1-12, J.O. Burckle Test from Table 1 (NOx and PM10) The current AP-42 emission factors for the incineration of wood (cord wood) are based on a pilot scale study from 1968. The unit tested was not a functional ACI but a pilot scale version constructed for the purpose of emissions testing. The maximum temperature reached by the pilot scale firebox was 1,300 ⁰F, which is approximately 300 to 900 ⁰F less than an ACI in the field. The PM10 emission factor resulting from this study is higher than the ARB and AP-42 PM10 emission factors in Table 2 for the open burning of almond orchard wood, which is a representative type of orchard wood waste for the San Joaquin Valley. The NOx emission factor obtained was 4 lb-NOx/ton, which is much higher than any of the tests on actual ACIs and similar to open burn emission factors for NOx from Table 2. 1 The seven most recent source tests for the biomass power plants Merced Power and Ampersand Chowchilla showed an average PM10 emission rate of 0.089 lb-PM10/ton. This average source test value is a more representative estimate of the PM10 emissions from biomass plants than the permitted value (0.61 lb-PM10/ton). As a comparison, a boiler fired on dry wood with a heating value of 7,610 Btu/lb has an uncontrolled emission rate of 5.5 lb-PM10/ton (Table, 1.6-1), which is approximately the same emission factor for open burning of orchard agricultural residues.
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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The emission factors from this study were not considered representative for an ACI burning woody biomass derived from agricultural sources or forests for the following reasons: (1) The unit tested was not an actual ACI; (2) The maximum combustion temperatures were lower than a typical ACI; (3) The AP-42 ACI PM10 emissions factor is higher than the open burn PM10 emission factors for most agricultural sources (Table 2); and (4) The NOx emission factor is significantly higher than any of the air curtain tests (note that lower combustion temperatures would be expected to lead to lower NOx emissions, adding an additional degree of caution regarding the results of this test).
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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2. ASSESSMENT OF SOURCE TESTS RESULTS Table 1 below summarizes the emission factors derived from source tests conducted on ACIs. For comparison, Table 2 summarizes the generally accepted emission factors for open burning and for biomass power plants. Table 1 - Emissions Test Results of Air Curtain Incinerators
Test Material Year NOx (lb/ton) SOx (lb/ton) PM10 (lb/ton) CO (lb/ton) VOC (lb/ton) Notes AP-42, 2.1-12, J.O. Burckle Wood and cord wood 1968 4 - 13 - - Pilot Scale Box Trench Burner, Max temp 1,300 F. Fountainhead Engineering, Michigan Wood 2000 Not reported* Not reported 0.12 1.1 Not reported Modified EPA Methods. USDA, Baker Oregon, (Air Curtain S-217) Forest vegetation 2002 Not measured Not measured 1.1 (PM2.5) 2.6 1.1 Missoula Fire Science Lab
USDA, San Bernardino (McPherson M30) Forest vegetation 2003 Not measured Not measured 1.4 (PM2.5) 30 0.6 Missoula Fire Science Lab BC Hydro, Jordan River British Columbia Wood 2003 0.04 0.0031 0.13 0.61 0.11 Modified EPA Methods and Canadian Methods Victoria, Australia Wood 2016 0.27 0.23 0.0064 4.2 0.096 (US)EPA Methods US EPA – Hurricane Katrina Vegetative material 2016 1.6 0.49 7.7 6.9 0.41 See Attachment A, Table 5-1 for NOx, SOx, CO, and VOC; Table 5-4 for PM10 * The Victoria, Australia test indicated the Fountainhead test showed 0.05 lb-NOx/ton, but this was not confirmed by the Valley Air District. Table 2 – Emission Factors for Biomass Open Burn and Biomass Power Plant
Source Material Year NOx (lb/ton) SOx (lb/ton) PM10 (lb/ton) CO (lb/ton) VOC (lb/ton) Notes/ Documentation Open Burn – ARB Almond 1992 5.9 0.1 7.0 52 5.2 ARB Memo Open Burn – ARB Forest Not indicated 3.5 0.1 19 - 30 154 - 312 8 - 21 ARB Memo Open Burn – AP-42 Almond 1974 - - 6 (PM) 46 6 AP-42, Table 2.5-5 Open Burn – AP-42 Forest 1995 4 (est.) - 17 140 19 AP-42, Table 2.5-5 Merced Power (N-4607-8) & Ampersand Chowchilla (C-6923-3) Biomass - 1.2 (1.1) 0.61 (0.033) 0.61 (0.089) 0.87 (0.25) 0.076 Permitted EFs (top) and average of seven source tests (indicated in parentheses) of two active biomass power plants
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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B. Fountainhead, Table 1 (PM10, CO) The Fountainhead study was conducted in October, 2000 in Clarkston, Michigan using a Whitton Model S-127 ACI having a 15-18 ton per hour capacity, burning wood debris. The nature of the wood debris is not described, but the location of the test is in a forested region of Michigan. The test will therefore be considered in this analysis to establish representative emission factors for agricultural sources and forest vegetation. The PM10 emission factor (0.13 lb-PM10/ton) from the Fountainhead test is only slightly greater than the average PM10 emission factor (0.089 lb-PM10/ton) measured from the seven most recent source tests of the biomass power plants Merced Power (N-4607-8) and Ampersand Chowchilla (C-6923-3), which have a fabric filter for PM10 control. The fabric filter has been established as the highest level of PM10 control for biomass combustion through extensive emissions testing with District oversight. In general, fabric filters are expected to achieve at least 99% control for PM10. For open burning of almond orchard wood, the accepted PM10 emission factor is 7.0 lb-PM10/ton. When compared to the 0.13 lb-PM10/ton emission factor from the Fountainhead test, the ACI would appear to have achieved over 98% control efficiency, which is comparable to the fabric filter control efficiency rate used to control biomass combustion emissions. The District at this point does not believe that sufficient information is available to overrule the District’s doubt that an ACI can achieve a nearly equal level of PM10 emission control as a high efficiency fabric filter. For instance, ACIs are known to have visible emissions during the approximately 10 - 30 minute start-up period before the air curtain is engaged, when the combustion process is presumably roughly equivalent to an open burn. Also, when new material is added to the firebox, the flow of the air curtain is broken, and the ACI emits a puff of smoke. The fabric filter does not have such gaps associated with its effectiveness as a PM10 control device. Moreover, it is uncertain whether the emission factor adequately accounts for the periodic puffs of smoke from loading because the sampling probe is positioned for the maximum firebox exit velocity during steady-state operation of the air curtain, which is usually at the edge of the firebox opposite the air manifold, whereas the puff of smoke occurs above the material drop point, typically more toward the middle of the firebox. These considerations lead one to believe that the ACI emission factor for PM10 should be higher than the biomass power plant emission factor for PM10. C. BC Hydro, Table 1 (NOx, SOx, PM10, CO, and VOC) The BC Hydro study was conducted in March, 2003 in Jordon River, British Columbia using an Air Burners Inc. Model S-116 ACI loaded between 4 – 8 metric tonnes per hour, burning wood debris. Although the nature of the wood debris is not described, the location of the test is in a forested region of British Columbia. The test will therefore be considered in this analysis to establish representative emission factors for agricultural sources and forest vegetation.
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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Similar to the Fountainhead results, the PM10 emission factor from BC Hydro (0.12 lb-PM10/ton was roughly equivalent to the average PM10 emission factor from biomass power plants. As discussed above, the District believes that the ACI emission factor for PM10 is likely higher than the fabric filter controlled biomass power plant emission factor for PM10. The BC Hydro test also reported a NOx emission factor (0.04 lb-NOx/ton) that is significantly lower than the average emission factor (1.1 lb-NOx/ton) from seven recent source tests conducted on the biomass power plants using selective non-catalytic reduction (SNCR) with ammonia injection as a NOx control. NOx reduction levels from SNCR range from 30 to 50% according to EPA’s Fact Sheet (EPA-452/F-03-031). It follows then that the BC Hydro NOx emission test would appear to represent a 99% reduction in NOx compared to open burn and a 96% reduction compared to the biomass boiler already controlled by SNCR.
Two possible explanations for the lower NOx emission factors from the ACI tests are that the biomass power plants burn plant material that is higher in nitrogen (i.e. fuel NOx) or that the boiler operates at a higher combustion temperature (i.e. thermal NOx). An analysis of the nitrogen content of the plant material burned in the biomass boiler versus the nitrogen content of the plant material burned in the ACI would need to be performed to establish that the fuel is the source of the difference in NOx emissions.2 A comparison of peak operating temperatures does not suggest that the air curtain would produce less thermal NOx. Biomass boilers may reach temperatures of 1,850 ⁰F; whereas an ACI can reach temperatures over 2,000 ⁰F. Factors other than temperature, such as residence time in the combustion hot zones, may account for differences in thermal NOx emissions, but the District is not aware that this speculative explanation has been demonstrated. These considerations lead the District to believe that the NOx emission factor for an ACI should be significantly higher than recorded in this test. D. Victoria, Australia, Table 1 (NOx, SOx, PM10, CO, and VOC) The Victoria study was conducted in February, 2016 at a recycling plant. The material burned was “clean” wood, i.e. vegetative material and uncoated wood pallets, at a rate of 4.2 metric tonnes per hour. Therefore, this source test will be considered in this analysis to establish emission factors for agricultural sources and forest vegetation. The PM10 emission factor from the Victoria test (0.0064 lb-PM10/ton) was significantly lower than the average PM10 emission factor (0.089 lb-PM10/ton) measured from biomass power plants. For the reasons discussed above, this PM10 emission rate cannot be used at this time.
2 Extensive Operating Experiments on the Conversion of Fuel-Bound Nitrogen into Nitrogen Oxides in the Combustion of Wood Fuel, Forests 2017, 8, 1. For timber wood having nitrogen content between 0.04 and 1.2%, the conversion of nitrogen to NOx ranged from approximately 66% to 15%, respectively, i.e. the rate of nitrogen to NOx conversion decreased exponentially with increasing nitrogen content.
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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The Victoria test also reported a NOx emission factor (0.27 lb-NOx/ton) that is significantly lower than recent source tests conducted on the biomass power plants using selective non-catalytic ammonia injection as a NOx control. Similar to the BC Hydro test results, the District believe that the NOx emission factor for an ACI should be significantly higher than recorded in this test. E. USDA, Baker, Oregon from Table 1 (PM10, CO, and VOC) USDA performed an ACI emission study in October, 2002 in Baker, Oregon, using an Air Curtain Inc. Model S-217 ACI, having a capacity of 6 tons per hour. The material burned was Ponderosa Pine trees. The test will therefore be considered in this analysis to establish representative emission factors for agricultural sources and forest vegetation. The PM10 emission factor obtained from the USDA Baker, Oregon test is 1.15 lb-PM10/ton, which is the third highest PM10 emission factor of all the source tests conducted on actual ACIs. The USDA source tests measured PM2.5. This was converted into a PM10 emission factor by using the ratio of PM10 to PM2.5 from ARB open burn emission factors for almond agricultural residues. For almond agricultural residues, the ratio of PM10 to PM2.5 is 7.0 lb-PM10/ton to 6.7 lb-PM2.5/ton. Therefore 1.1 lb-PM2.5/ton × (7.0 lb-PM10/ton ÷ 6.7 lb-PM2.5/ton) = 1.15 lb-PM10/ton This emission factor is an order of magnitude larger than the PM10 emissions measured for the biomass power plants (0.089 lb-PM10/ton), which are controlled by a fabric filter, and yet lower than the emission factor for open burning of almond wood (7.0 lb-PM10/ton), which is an uncontrolled source. As the ACI is a controlled form of open burning, it is reasonable that the PM10 emission factor for an ACI would be lower than the PM10 emission factor for open burning. Thus, the USDA emission factor for PM10 falls between the expected upper bound (uncontrolled open burning) and lower bound (biomass power plant with a fabric filter). As PM10, CO and VOC are the products of incomplete combustion, acceptance of the PM10 emission factor implies an acceptance of the CO and VOC emission factors as well. The USDA study did not include NOx or SOx emission factors. F. USDA, San Bernardino from Table 1 (PM10, CO, and VOC) USDA performed a second ACI emission study in June, 2003 in San Bernardino (Lake Arrowhead), California, using a McPherson Model M30 ACI burning forest vegetation. The burn rate (tons per hour) of the unit was not identified. The test will therefore be considered in this analysis to establish representative emission factors for agricultural sources and forest vegetation.
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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The PM emission factor obtained from the San Bernardino study is 1.46 lb-PM10/ton, similar to the Baker, Oregon study above. The USDA source tests measured PM2.5. This was converted into a PM10 emission factor by using the ratio of PM10 to PM2.5 from ARB open burn emission factors for almond agricultural residues. For almond agricultural residues, the ratio of PM10 to PM2.5 is 7.0 lb-PM10/ton to 6.7 lb-PM2.5/ton. Therefore 1.4 lb-PM2.5/ton × (7.0 lb-PM10/ton ÷ 6.7 lb-PM2.5/ton) = 1.46 lb-PM10/ton For CO, the reported emission factor was 30 lb-CO/ton, which is an order of magnitude higher than the CO emission factor reported for the Baker, Oregon study and more than four times larger than the next highest reported CO emission factor in Table 1. The San Bernardino report includes tables comparing the Baker, Oregon results to the San Bernardino results. Those tables also show the CO emission factor for the Baker, Oregon study to be ten times larger, i.e. 26 lb-CO/ton than originally reported. It should be noted that the Baker, Oregon study and the San Bernardino study have different lead authors, and no mention is made in the report of USDA making a correction to the originally reported CO emission factor from the Baker, Oregon study. USDA has not responded to requests for clarification of this matter. Norbert Fuhrmann, Vice President of Air Burners, Inc. disputed the 26 lb-CO/ton emission factor in the San Bernardino report, stating that the originally reported value from Baker, Oregon of 2.6 lb-CO/ton was correct and that an error in the placement of the decimal had likely been made in the San Bernardino report. If Mr. Fuhrmann’s contention is correct, the CO emission factors from the USDA studies would agree better with the other ACI CO emission factors reported in Table 1. Nevertheless, since USDA has not issued a correction for the San Bernardino CO emission factor, the District will regard the reported value of 30 lb-CO/ton as the official value from this study. As noted at the beginning of this analysis, the District is primarily concerned with choosing the most representative emission factors for an ACI incinerating woody biomass derived from agricultural sources and forests. The CO emission factor reported in the San Bernardino study (30 lb-CO/ton) is roughly the same order of magnitude as the open burn emission factors in Table 2 for almond wood (e.g. 46 lb-CO/ton and 52 lb-CO/ton). Since the available data suggests that the ACI should perform an order of magnitude better than open burning for the products of incomplete combustion (i.e. PM10, CO and VOC), the CO emission factor from this study will not be considered representative for an ACI burning woody biomass derived from agricultural sources or forests. In ATC project N-1162806, for an ACI burning almond sticks at an almond huller, the concern about the representativeness of the CO emission factor in the San Bernardino study extended to the other pollutants measured in that study (PM2.5 and VOC). One of the criteria for selecting emission factors in the ATC project was to accept or reject emission factor sets for PM10, CO and VOC because of the assumption that the emission factors of these pollutants are related as the products of incomplete combustion. Therefore, none of the reported emission factors from San Bernardino were used in the ATC project. However, since other emission factor sets of PM, CO and VOC have been evaluated based on the reported PM emission factor, and PM
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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emission factor from the San Bernardino study is comparable to the Baker, Oregon study, the District has now reconsidered the use of the PM and VOC emission factors from the San Bernardino study. Therefore, in this memo, the District will include the PM and VOC emission factors from the San Bernardino study with the Baker, Oregon study as representative for the burning of woody biomass derived from both agricultural sources and forests. The USDA study did not include NOx or SOx emission factors. G. Assessment of EPA “Katrina” Study (NOx, SOx, PM10, CO, and VOC) The District received a draft copy of EPA’s Managing Debris after a Natural Disaster: Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: Source Emissions Measurement Results, November 17, 2016 (see Attachment A). The study measured emissions and estimated emission factors for an ACI burning vegetative and construction and demolition debris in 2008 as part of the cleanup from Hurricane Katrina. Three test runs of the emissions from vegetative debris and three test runs for construction and demolition debris were measured separately. Based on the District’s analysis of EPA’s document (Attachment B), the District concluded that the emission factors from EPA’s study are likely overstated and cannot be found to be representative of the emissions from incineration of the agricultural or forest wood biomass in California. Therefore, the results of this test are not recommended to be used in future permitting actions for air curtain incinerators in the District and will not be discussed any further. 3. EMISSION FACTOR DETERMINATION Based on the following reasons, a single set of ACI emission factors will be recommended for use for both agricultural wood (such as orchard pruning, almond sticks, orchard removals, etc) and forest vegetation (such as large parts of tree trunk, branches and other woody materials): (1) There are no published ACI emission studies specific to agricultural wood; all the available ACI studies are based on forest vegetation or a mix of forest vegetation and generic wood (e.g. wood pallets). (2) The USDA studies that are the basis of the PM10, CO, and VOC emission factors recommended in Table 3 below burned forest vegetation, with can be large sections of trunks and small wood. Among the ACI tests considered as potentially representative, the USDA studies produced the highest PM10 and VOC emission factors. (3) The ARB (August 17, 2000 Memorandum) open burn emission factors for the products of incomplete combustion (i.e. PM10, CO, and VOC) are generally higher
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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for forest vegetation than for agricultural materials. Since ACI may be considered a controlled form of open burning, the same pattern present in the open burn emission factors may be expected in the ACI emission factors so use of emissions factors for forest debris is likely to conservatively overstate emissions from agricultural waste. (4) The SOx emission factor is entirely material dependent, and the SOx emission factor for open burning orchard and vineyard residues is the same as for forest vegetation. (5) The open burn emission factors for NOx for orchard and vineyard wood residues are higher than the NOx open burn emission factor for forest wood. When taken with point (1) above, this means that a single NOx emission factor based on a forest vegetation test may be too low if it is also used to represent woody agricultural residues. However, the District’s estimated NOx emission factor includes a compliance margin that more than compensates for the potential greater NOx emissions from woody agricultural residues. Based on the analysis presented in Section 2 above, the District has determined the following emission factors to be appropriately conservative and representative for the burning of woody biomass derived from agricultural sources and forest vegetation in an ACI. NOx Only the BC Hydro and Victoria ACI emissions tests reported a NOx emission factor. However, for the reasons discussed in Sections 2D and 2E above, the emission factors derived from those tests appear to be insufficiently conservative when compared to the NOx emission factor for a biomass boiler. Therefore, the District estimated a more conservative NOx emission factor of 1.0 lb-NOx/ton by multiplying the emission factors reported by BC Hydro and Victoria by a ratio of concentrations. The numerator in this ratio was based on NOx concentration measurements from a 2007 EPA study, Emissions from the Burning of Vegetative Debris in Air Curtain Destructors, J. AWMA, 57, 959-967. This 2007 EPA study did not include measurements of exhaust flow rate or tons of vegetative debris burned; therefore, no emission factors could be derived from the study by itself. Although the open burn emission factors for NOx for orchard and vineyard residues is higher than the NOx open burn emission factor for forest vegetation by a factor of 1.5 to 1, the District’s estimated NOx emission factor is almost 4 times higher than the highest NOx emission factor measured among the potentially representative ACI emissions tests. Therefore, the recommended NOx emission factor provides a sufficient compliance margin to allow for the potential that smaller sized wood pieces from agricultural sources would burn hotter in an ACI, and potentially producing more thermal NOx, than large wood pieces from forest vegetation. See Attachment C for the derivation of the 1.0 lb-NOx/ton emission factor.
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SOx Since SOx emissions are entirely dependent on the sulfur content of the material burned, the most representative SOx emission factor for an ACI burning woody biomass derived from agricultural sources and forests will be the same as for open burning of those materials, i.e. 0.1 lb-SOx/ton (ARB Memo, “Agricultural Burning Emission Factors,” 2000). PM10 Our current engineering judgement is that PM10 emissions from the combustion of woody biomass in ACIs should be higher than PM10 emissions from a biomass power plant controlled by a fabric filter baghouse. Although there is a growing body of evidence that ACIs are capable of achieving complete combustion with minimal PM10 emissions, to remain conservative when establishing a PM10 emission factor for ACI, the District is recommending the use of the higher PM10 emissions factors derived from the USDA studies in Baker, Oregon and San Bernardino. The emission factors from the USDA Baker, Oregon (1.15 lb-PM10/ton) and USDA San Bernardino (1.46 lb-PM10/ton) studies are the second and third highest PM emission factors among the full scale ACIs tested, and the only PM emission factors that are lower than the PM10 emission factors for uncontrolled open burning of woody agricultural and forest biomass and higher than the PM10 emission factor for a biomass power plant with fabric filter for PM10 control. The average PM10 emission factor for the USDA tests is (1.15 lb-PM10/ton + 1.46 lb-PM10/ton)/2 = 1.3 lb-PM10/ton. Therefore, the 1.3 lb-PM10/ton emission factor derived from the two USDA studies will be accepted as the most representative and conservative PM emission factor for the burning of woody biomass from agricultural sources and forests in an ACI. CO As PM10, CO and VOC are all the products of incomplete combustion, acceptance of the PM10 emission factor from the USDA Baker, Oregon study implies an acceptance of the CO emission factor (2.6 lb-CO/ton) as well. The CO emission factor from the San Bernardino study was not included for reasons discussed in Section 2F of this memo. Among the full scale ACIs tested, the Baker, Oregon study produced the median value for a CO emission factor. VOC As PM10, CO and VOC are all the products of incomplete combustion, acceptance of the PM10 emission factors from the USDA studies implies acceptance of the VOC emission factors, as well (1.1 lb-VOC/ton and 0.6 lb-VOC/ton, with an average of 0.9 lb-VOC/ton). Among the full scale ACIs tested, the USDA studies produced the highest two emission factors for VOC.
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CONCLUSION Table 3 below summarizes the emission factors selected from the determination above for an ACI burning woody biomass derived from agricultural sources and forest vegetation. Table 3: Emission Factors for Air Curtain Incinerator Burning Woody Biomass (Agricultural Sources and Forest Vegetation)
Pollutant Emission Factor (lb/ton) Source
NOx 1.0 SJV Estimation Using/Averaging Data from Multiple Studies, Attachment B
SOx 0.1 ARB Open Burn for Orchard and Vine Crops and Forest Biomass, Table 2
PM10 1.3 Average of USDA Baker, Oregon and USDA San Bernardino Air Curtain Tests, Table 1
CO 2.6 USDA, Baker, Oregon Air Curtain Test, Table 1
VOC 0.9 Average of USDA Baker, Oregon and USDA San Bernardino Air Curtain Tests, Table 1 Please note, as discussed in Section 2F above, the USDA San Bernardino ACI study was not included in the emission factor determination for Authority to Construct (ATC) project N-1162806, for an ACI burning almond sticks at an almond huller. The PM10 and VOC emission factors in that project were 1.1 lb-PM10/ton and 1.1 lb-VOC/ton (based on USDA Baker, Oregon). Table 4 below includes a wood ash handling emission factor, which is for the combined activities of unloading from a dump truck and spreading coal fly ash at a landfill. Table 4: Emission Factor for Wood Ash Handling
Pollutant Emission Factor (lb/ton) Source
PM10 0.233 Fugitive particulate emission factors for dry fly ash disposal, Journal of the Air & Waste Management Association, 63(&): 806-818, 2013 Attachment A: Managing Debris after a Natural Disaster, EPA’s Evaluation of Air Curtain Incinerator Emission Source Test Results Attachment B: Managing Debris after a Natural Disaster, SJVAPCD’s Analysis of EPA’s Air Curtain Incinerator Study Attachment C: Derivation of NOx Emission Factor for Air Curtain Incineration of Woody Biomass 3 The emission factor was reported as 18 g/Mg for PM2.5 and 96 g/Mg for PM10 – PM2.5. Thus, the total PM10 emission factor is 18 g/Mg + 96 g/Mg = 114 g/Mg. 114 g/Mg = 114 lb/106 lb × 2,000 lb/1 ton = 0.228 lb-PM10/ton or 0.23 lb-PM10/ton.
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Attachment A Managing Debris after a Natural Disaster: EPA’s Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: Source Emissions Measurement Results (November 17, 2016)
Managing Debris after a Natural Disaster, EPA Air Curtain Emissions Study (11-17-2016).pdf
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Attachment B Managing Debris after a Natural Disaster: Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: SJVAPCD Analysis of EPA’s Air Curtain Incinerator Study
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Analysis of EPA’s Air Curtain Incinerator Study From: Brian Clerico, AQE II To: Arnaud Marjollet, Director of Permit Services Reviewed by: Errol Villegas, Permit Services Manager
Date: March 10, 2017 Re: Evaluation of EPA’s Air Curtain Incinerator Study: Managing Debris after a Natural Disaster: Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: Source Emissions Measurement Results, November 17, 2016 Background The District received a draft copy of EPA’s Managing Debris after a Natural Disaster: Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: Source Emissions Measurement Results, November 17, 2016 (see Attachment A). The study measured emissions and estimated emission factors for an air curtain incinerator (ACI) burning vegetative and construction and demolition debris in 2008 as part of the cleanup from Hurricane Katrina. Three test runs of the emissions from vegetative debris and three test runs for construction and demolition debris were measured separately. The District’s interest in evaluation of this test is in its potential applicability to assessing emissions from Air Curtain Burners that may be employed in and around the San Joaquin Valley to burn vegetative material, such as may be necessary to process over 100 million trees that have died in surrounding forests due to California’s recent extreme drought. Therefore, in evaluating the source test results from this EPA study, the District focused solely on the test runs pertaining to vegetative debris.
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EPA Air Curtain Incinerator Draft Emission Factors Table 1 summarizes the emission factors obtained from this study. Table 1: EPA Emission Factors for Air Curtain Incinerator (Vegetative Debris)
Pollutant Emission Factor (lb/ton) Source
NOx 1.6 Managing Debris after a Natural Disaster: Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: Source Emissions Measurement Result, Table 5-1 for NOx, SOx, CO, and VOC; Table 5-4 for PM10. See Attachment A
SOx 0.49 PM10 7.7 CO 6.9 VOC 0.41 Analysis The District has identified the following concerns with EPA’s draft emission factors for vegetative debris: (1) The vegetative debris in the study is not representative of the types of agricultural or forest wood material in California that would be disposed of in an ACI. The vegetative debris incinerated consisted of material that had been submerged in brackish water for an unknown amount of time before it was recovered and brought to the test site. Section 3.2.1 Feed Debris from the report describes the vegetative material incinerated as follows: It must be noted that the vegetative debris used for fuel was recovered as part of the Hurricane Katrina response and had sat in brackish water for an unknown period of time prior to being recovered and brought to the test site. The debris used in the tests therefore was likely representative of much of the vegetative debris recovered during hurricane response activities, where the debris was exposed to salt water for extended periods of time. This uncontrollable variable may have influenced emissions of chlorinated organic compounds including chlorinated benzenes and phenols as well as polychlorinated dibenzo-p-dioxins and polychlorinated furans. Given the known dependence of PM10, VOC, CO, and SOx emission factors on the material burned, emission factors derived from vegetative debris soaked in salt water cannot be treated as universally applicable to all biomass materials. (2) The pollutant mass emission rates are a function of the measured pollutant concentrations multiplied by total flow rate from the air curtain firebox. EPA’s calculated flow rates used to derive the pollutant mass emission rates may be overstated by a factor of 3 - 6.
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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That EPA’s calculated flow rates may be overstated can be seen by a comparison of the calculated “slot” (or linear) velocity derived from the calculated flow rates being 3 to 6 times higher than the measured slot velocity for the same make and model ACI operated by EPA burning the same material in a 2007 study EPA published a 2007 study of limited testing of the Air Burners Model S-327 ACI burning hurricane Katrina vegetative debris in Emissions from the Burning of Vegetative Debris in Air Curtain Destructors, J. AWMA, 57, 959-967. In that study, EPA noted the following: Velocity measurements suggest that the exhaust flow is occurring in a relatively narrow area along the length of the unit on the side opposite the blower (see Figure 5). Measurements of 15 fps [i.e. 15 ft/s] in this narrow area were close to the estimated temperature adjusted flow velocity based on the ACD fan output. The “narrow area” referred to above is an 18 inch-wide slot running the length of the ACI. The measured velocity beyond this slot is 0 f/s, meaning all the exhaust exits the firebox along this slot opposite the blower. This is a finding corroborated by other ACI studies. The 15 ft/s appears to be an average slot velocity measurement, uncorrected for temperature, although the exact temperature corresponding to this velocity is unclear. EPA did not perform velocity measurements in the draft ACI emission factor study; however, EPA did make use of the findings from the 2007 study to design their sample collection scoop for the ACI emission factor study: The entry face of the extraction scoop was 18 inches by 5 inches, with the longer dimension spanning the final 18 inches of the ACB firebox width on the side opposite the blower plenum as shown in Figure 2-2. This 18-inch span along the length of the ACB represents the area where, from earlier flow determinations on an identical burner, essentially all the combustion product gases exit the firebox. With this experience in mind, and the earlier measurement of 15 ft/sec bulk velocity in that 18-inch span, estimated extraction scoop isokinetic variation during the sampling runs was calculated. During the test program, isokinetic variation was between 47.8% and 90.9%, with an average of 65.9%.[Section 3.2.3] Using the calculated flow rates from the emission factor study, an average slot velocity can be calculated. EPA’s calculated flow rates from the firebox are based on a mass balance calculation of carbon (Section 3.4 of the EPA report in Attachment A). Taking the average calculated flow rates from Table 3-2 of the report (104,147 dscfm) and dividing by the area of the slot (27 feet by 1.5 feet), yields and average slot velocity of 43 ft/s at 68 ⁰F, or 94 ft/s at 700 ⁰F (average scoop temperature along the slot). Since the slot velocity is directly proportional to the average volumetric flow rate, if the volumetric flow is overstated by a factor of 3 (43 ft/s ÷ 15 ft/s) to 6 (94 ft/s ÷ 15 ft/s), then so too will be the emission factors, which are based on the calculated flow rates.
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One possible objection to this comparison of the calculated versus the measured slot velocities would be that we do not know the feed rate to the ACI when the velocity measurements were made in the EPA 2007 study. If the feed rates during the slot velocity measurements in the 2007 study were low in comparison to the feed rates during the emission measurements in the emission factor study, then the claim above is not valid. We do know, however, that during the emission factor study, the feed rates to the ACI were reported as 4.8 ton/hr, 4.8 ton/hr and 6.8 ton/hr. Air Burners Model S-327 ACI has a capacity of 6-10 tons/hr. Thus, the feed rates to the ACI during the emission factor study were either below the rated capacity of the unit or on the low side. It seems unlikely during the 2007 study, EPA would have operated the ACI at a feed rate 3 to 6 times lower, i.e. 1 – 2 ton/hr, to account for the observed difference in the measured to the calculated velocities. (3) The high SOx emission factor suggests a possible overstatement of all the emission factors by a factor of 4 - 5. The draft SOx emission factor (0.49 lb/ton) is more than twice the next highest reported emission factor for an ACI and almost five times the open burn value for almonds or forest material. Since SOx emissions are purely a function of the sulfur content of the material burned, the high SOx emission factor could be another indicator that the emission factors are high across the board by a factor of four to five because of EPA’s flow rate calculation estimation procedure above. An alternative explanation for the high sulfur is that the wood burned could have a considerable amount of sulfur contamination from being submerged in brackish water for an unknown amount of time; however, this could raise concerns of the representativeness of the emission factors for material not subjected to the same conditions. On the other hand, when coupled with concern number 2, above, the weight of evidence starts to lead to a conclusion that the emissions factors are significantly overestimated. The following concerns relate specifically to EPA’s particulate matter (PM10) emission factor. (4) EPA’s proposed PM10 emission factor is greater than the currently accepted emission factor for open burning of almond wood as well as many other agricultural materials. The emission factors for open burning of almond wood (6 lb-PM/ton, AP-42, Table 2.5-5; or 7.0 lb-PM10/ton, ARB Memo, “Agricultural Burning Emission Factors,” August 17, 2000) are lower than EPA’s proposed air curtain emission factor (7.7 lb-PM10/ton). For the same material burned, we believe all parties should agree that the PM10 emission factor for the ACI should be significantly lower than the emission factor for open burning. At a minimum, this suggests that EPA’s proposed emission factor cannot be universally applied to all wood materials.
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When considered in conjunction with concerns 2 and 3 above, and the expectation of actual control of PM10 emissions when comparing ACI to open burning (prior tests demonstrated a control efficiency of 54% to 99+%), the weight of evidence continues to grow that emissions estimates from this study are likely and significantly overstated. (5) The hurricane occurred in August 2005, whereas the vegetative debris was retrieved and tested in June 2008. Thus vegetative debris/wood may have been submerged in brackish water for up to three years prior to being sent to the air curtain for incineration. The salt water likely left a residue of salts (i.e. inorganic species) precipitated on and in the wood, which would increase the measured PM concentrations. Possible effect on PM10 EF: 30% too high. The PM fraction contained a relatively high amount of inorganic condensable PM (EPA report, Table 5 – 4: 38% weighted average; 51% in Run 1 and 26% in Run 2, Run 3 not reported). The report noted a variety of chlorinated organics found in the air toxics analysis. The predominant anionic species in salt water is chloride ion, which could be the source of the elemental chlorine in the chlorinated organics observed. Wood is porous, so salts containing chloride ion could infiltrate and precipitate on the wood over time. The presence of salts in combustion processes are known to produce condensable PM, which can be seen in detached white plumes. This phenomenon would be consistent with the opacities recorded in this study, which were higher than in other air curtain tests: e.g. Run 3 failed opacity (using NSPS Subpart EEEE standard). One potential cause for higher opacity could be associated with overloading the air curtain firebox; however, the higher opacities cannot be due to overloading because according to Air Burners Inc., the model air curtain has a capacity of 6-10 tons/hour, but in the Katrina study, it was fed at an average rate of 4.8 tons/hr. Additionally, for open burning, wet wood is known to produce more smoke than dry wood. According to the moisture analysis EPA performed on the vegetative debris burned, the water content was not more than 30%, which is similar to “green” wood. In conversation with District staff, Air Burners, Inc. has claimed that the ACI should be able to burn green wood and maintain compliance with NSPS visible emission limits of 10% opacity or less. As a reference, District Rule 4901, Wood Burning Fireplaces and Wood Burning Heaters, which is a PM rule, prohibits the sale of wood having greater than 20% moisture. For comparison, the average moisture content of almond tree derived biomass = 18% according to the ARB agricultural burning emission factors memo. (6) The average isokinetic variation (ratio of Velocitysample/Velocity“stack”) was 65.9%. Estimated effect on PM10 EF: 10%+ too high. A low isokinetic % means the measured PM value is higher than the actual PM value (https://www.arb.ca.gov/testmeth/vol1/vol1suppl.doc). 90 – 110% (or under some conditions 80 – 120%) is the normal acceptable quality control range. The magnitude of error depends on a number of variables, especially particle size distribution. EPA characterizes the overestimation error from anisokinetic sampling
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conditions in the Katrina study as “slight” perhaps because the PM emission factor appears to be predominantly composed of PM2.5. However, in ARB’s Supplement to Stationary Source Test Methods, Volume 1, Chaper IX, pg. 6), an example is given of a study where an isokinetic variation of 50% represented an 80% over-estimate of the PM12 emissions. On the Fountainhead test, a similar sized unit to the unit used in the EPA study, the reported average isokinetic variation was 112%, which would lead one to believe that the reported Fountainhead emission factor was on the low side, but also that isokinetic sampling is achievable with such as source. From page 90 (pg 106 .pdf) of EPA’s report, ”If isokinetic rate calculations are based upon the estimated total flow rates presented in Table 5-14, variation was between 6.1% and 46.5% isokinetic.” Meaning if EPA’s calculated flow is 100% correct, then the isokinetic variation (#1) is dramatically worse than the 65.9%. The bias to a higher PM rate grows exponentially higher at lower isokinetic percentages. Conclusion Based on the analysis presented above, the District concludes that the weight of evidence suggests that emission factors from EPA’s study Managing Debris after a Natural Disaster: Evaluation of the Combustion of Storm-Generated Vegetative and C&D Debris in an Air Curtain Burner: Source Emissions Measurement Results (November 17, 2016) are likely overstated and cannot be found to be representative of the emissions from incineration of vegetative materials. Therefore, the results of this test are not recommended to be used in future permitting actions for air curtain incinerators in the District.
4 This may be a typographical error as volumetric flow rates are presented in Table 3-2, whereas Table 5-1 present mass emission rates.
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Attachment C Derivation of NOx Emission Factor for Air Curtain Incineration of Woody Biomass
Air Curtain Incinerator Emission Factor Determination March 10, 2017
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NOx Emission Factor Estimation
There are two published source tests on ACIs where NOx emission factors were derived: BC Hydro (0.040 lb-NOx/ton) and Victoria, Australia (0.274 lb-NOx/ton). These values are significantly lower than the biomass power plant NOx emissions, which is equipped with NOx control selective non-catalytic reduction system). EPA published NO and NO2 concentration measurements (ppmv) from an ACI burning vegetative debris in a 2007 study, Emissions from the Burning of Vegetative Debris in Air Curtain Destructors, J. AWMA, 57, 959-967; however, no emission factor (lb-NOx/ton material burned) was published or derived from the data because no flow rates or material throughputs corresponding to the measured concentrations were measured or published. This 2007 EPA study measured an average NOx (NO + NO2) concentration of 79 ppmv from the air curtain, which is higher than the NOx concentration measurements from the BC Hydro (3.4 ppmv) and Victoria, Australia (19.5 ppmv) tests. Assuming the NOx emission factor that could be derived from the 2007 EPA test data will be proportional to its NOx concentration, following ratio will be used: ൬݈ܾ −ܱܰݔݐ݋݊൰ா௉஺ (ଶ଴଴଻) = ൬݈ܾ −ܱܰݔݐ݋݊൰ ௌ௢௨௥௖௘ ்௘௦௧ ௑ × (݌݌݉ݒ ܱܰݔ)ா௉஺ (ଶ଴଴଻)(݌݌݉ݒ ܱܰݔ)ௌ௢௨௥௖௘ ்௘௦௧ ௑

Source Test X = BC Hydro The NOx emission factor from the BC Hydro test was 0.040 lb-NOx/ton.5 The average NOx concentration measured during the BC Hydro test was 6.5 mg/m3 (at 20 ⁰C). The molar volume of an ideal gas at 20⁰C is 24.1 × 10-3 m3/g-mol.
6.5 ݉݃ ܱܰ௫݉ଷ(ܽݐ 20଴ܥ) × 1 ݃ ݉݋݈ ܱܰଶ46 ݃ ܱܰଶ × 1 ݃1,000 ݉݃ × 24.1 × 10
ିଷ ݉ଷ (ܽݐ 20଴ܥ)1 ݃ ݉݋݈ = 3.4 ݌݌݉ݒ ܱܰ௫ ൬݈ܾ −ܱܰݔݐ݋݊൰ா௉஺ (ଶ଴଴଻)= ൬0.040 ݈ܾ −ܱܰݔݐ݋݊൰஻஼ ு௬ௗ௥௢ × (79 ݌݌݉ݒ ܱܰݔ)ா௉஺ (ଶ଴଴଻)(3.4 ݌݌݉ݒ ܱܰݔ)஻஼ ு௬ௗ௥௢ ൬݈ܾ −ܱܰݔݐ݋݊൰௄ா௉஺ (ଶ଴଴଻)= 0.93 ݈ܾ −ܱܰݔݐ݋݊
5 Based on an emission rate of 0.12 kg-NO2/hr and 6 metric tonnes feed/hr EF = 0.12 kg/hr x 2.2 lb/kg x 1 hr/6 tonne x 1 tonne/1.1 tons = 0.040 lb-NOx/ton
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Source Test X = Victoria, Australia The NOx emission factor from the Victoria test was 0.247 lb-NOx/ton. The average NOx concentration measured during the Victoria test was 40.0 mg/Nm3 (i.e. at 0 ⁰C). The molar volume of an ideal gas at 0⁰C is 22.4 × 10-3 m3/g-mol. 40.0 ݉݃ ܱܰଶܰ݉ଷ × 1 ݃ ݉݋݈ ܱܰଶ46 ݃ ܱܰଶ × 1 ݃1,000 ݉݃ × 22.4 × 10
ିଷ ܰ݉ଷ1 ݃ ݉݋݈ = 19.5 ݌݌݉ݒ ܱܰ௫ ൬݈ܾ −ܱܰݔݐ݋݊൰ܧܲܣ (2007)= ൬0.274 ݈ܾ −ܱܰݔݐ݋݊൰஺௨௦௧௥௔௟௜௔ × (79 ݌݌݉ݒ ܱܰݔ)ܧܲܣ (2007)(19.5 ݌݌݉ݒ ܱܰݔ)஺௨௦௧௥௔௟௜௔ ൬݈ܾ −ܱܰݔݐ݋݊൰ܧܲܣ (2007)= 1.1 ݈ܾ −ܱܰݔݐ݋݊ Average NOx Emission Factor Average NOx emission factor (lb/ton) = (0.93 lb-NOx/ton + 1.1 lb-NOx/ton) ÷ 2 Average NOx emission factor (lb/ton) = 1.0 lb-NOx/ton
THE PRINCIPLE OF AIR CURTAIN BURNING
AIR BURNERS, INC. 4390 SW Cargo Way ● Palm City, FL 34990 USA Phone [phone] ● FAX [phone] E-mail: [e-mail] ● www.AirBurners.com © 2017 Air Burners, Inc. Rev. 11.26.2017
Technical Memorandum
Page 1 of 3
Overview Air Curtain Burners, also called FireBoxes, were designed principally as a pollution control device. The prima-ry objective of an air curtain machine is to reduce the particulate matter (PM), smoke or “black carbon”, which results from burning clean wood waste. It is sometimes hard to visualize without seeing a machine in opera-tion, but the machines do not burn anything, rather they control the results of something burning.
You could look at it as a pollution control device for open burning. Clean wood waste is loaded into the FireBox, and an accelerant such as Diesel fuel is poured onto the wood and the pile is ignited. This is very similar to starting a campfire. The air curtain is not engaged until the fire has grown in strength or the air curtain may blow the fire out. Once the fire has reached suitable strength, usually in 15 to 20 minutes, the air curtain is engaged. The air curtain then runs at steady state throughout the burning operation and the waste wood is loaded at a rate consistent with the rate of burn. Our smallest machine will burn at a rate of 2 to 4 ton per hour, our largest machine can burn in excess of 12 tons per hour.
The Principle The purpose of the air curtain is to stall or slow down the smoke particles on their way out of the FireBox. In doing this the particles are subjected to the highest temperatures in the FireBox. Stalling the smoke particles in this region just under the air curtain causes them to re-burn, further re-ducing their size to an acceptable limit. The result is a very clean burn with opacities well under 10% per EPA Method 9 Testing (as compared to open burning which typically can run at 80% to 100% opacity).
Operation The picture to the right shows an Air Burners FireBox S-327 completely full and burning while in the background a pile of wood is open burned.
The wood pile that is open burning continued to burn for two weeks. That entire pile could have been elimi-nated with the FireBox in less than 20 hours.

AIR BURNERS, INC. 4390 SW Cargo Way ● Palm City, FL 34990 USA Phone [phone] ● FAX [phone] E-mail: [e-mail] ● www.AirBurners.com © 2017 Air Burners, Inc. Rev. 11.26.2017
Page 2 of 3
For proper operation, the air curtain machine has to be designed to provide a curtain of air over the fire that has a mass flow and velocity that are in balance with the potential mass flow and ve-locity of the burning wood waste. If the air curtain velocity is too high, the FireBox or Trench can become over pressurized and over agitated. The higher pressure will lift the curtain and cause it to become ineffective. The over-agitation will cause embers and ash to be blown out of the box or pit past the ineffective air curtain at a significantly higher rate than normal. If the mass flow of the curtain is too low then the unburned particles (smoke) will penetrate the curtain on the high velocity of the hot gasses being generated from the burning wood.

Air Curtain Burners do not
burn anything.

They control the results of
something burning.
"The Wood Waste is the Fuel"
1. Air curtain machine manifold and nozzles directing high velocity air flow over and into refractory lined fire box or earthen trench.
2. Refractory lined wall as on the S-Series machines, or earthen wall as used with the T-Series trench burners.
3. Wood waste material to be burned .
4. Initial airflow forms a high velocity “air curtain” over fire.
5. Continued air flow over-oxygenates the fire keeping temperatures high. Higher temperatures provide near 100% combustion efficiency and that results in a cleaner and more complete burn.
See 70 sec. Streaming Video Clip of an operating FireBox here

AIR BURNERS, INC. 4390 SW Cargo Way ● Palm City, FL 34990 USA Phone [phone] ● FAX [phone] E-mail: [e-mail] ● www.AirBurners.com © 2017 Air Burners, Inc. Rev. 11.26.2017
Page 3 of 3

RECYCLING The ash from typical wood waste is a very useful soil additive and as such offers a commodity that can be marketed to plant nurseries, farms, etc. as a potting soil additive. A certain amount of Biochar will also be included in the residual ashes. Recycling our resources is not only socially and politically imperative, but it often reaps the additional benefit of tax incentives or tax cred-its. Solid waste landfills are diminishing rapidly, and permits are difficult to secure for new sites. The Air Burners System pro-vides an affordable and environmentally sound alternative to grinding and the indiscriminate depositing of woody debris into landfills.

Related Reports
Disposal of Woody Debris by Fire with perfect combustion efficiency releases no Black Carbon and virtually only Bio-
genic CO2, making this process carbon neutral.
CLICK HERE
Air Curtain Burner vs. Wood Grinder - Disposal of Wood Waste
A Comparison of Critical Emissions and Basic Economic Parameters from Two Disposal Methods.
CLICK HERE
Disposal of Trees Affected by the Pine Beetle - The Dilemma and why Air Curtain Burners Should Be Used.
CLICK HERE
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https://www.tandfonline.com/action/journalInformation?journalCode=uawm20
Journal of the Air & Waste Management Association
ISSN: 1096-2247 (Print) 2162-2906 (Online) Journal homepage: www.tandfonline.com/journals/uawm20
Fugitive particulate emission factors for dry fly ash
disposal
Stephen F. Mueller, Jonathan W. Mallard, Qi Mao & Stephanie L. Shaw
To cite this article: Stephen F. Mueller, Jonathan W. Mallard, Qi Mao & Stephanie L. Shaw
(2013) Fugitive particulate emission factors for dry fly ash disposal, Journal of the Air & Waste
Management Association, 63:7, 806-818, DOI: 10.1080/10962247.2013.795201
To link to this article: https://doi.org/10.1080/10962247.2013.795201
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Published online: 19 Jun 2013.
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TECHNICAL PAPER
Fugitive particulate emission factors for dry fly ash disposal
Stephen F. Mueller,
1,⁄Jonathan W. Mallard,
1 Qi Mao,
1 and Stephanie L. Shaw
2
1Tennessee Valley Authority, Muscle Shoals, Alabama, USA
2Electric Power Research Institute, Palo Alto, California, USA⁄Please address correspondence to: Stephen F. Mueller, TVA, P.O. Box 1010, Muscle Shoals, AL 35662-1010, USA; e-mail: [e-mail]
Dry fly ash disposal involves droppingash from a truck and the movement of a heavy graderor similar vehicle across the ash surface.
These operations are known to produce fugitive particulate emissions that are not readily quantifiable using standard emission
measurement techniques. However, there are numerous situations–such as applying for a source air permit–that require these
emissions be quantified. Engineers traditionally use emission factors (EFs) derived from measurements of related processes to estimate
flyashdisposalemissions.Thisstudynearadryflyashdisposalsiteusingstate-of-the-artparticulatemonitoringequipmentexaminesfor
the first time fugitive emissions specific to fly ash handling at an active disposal site. The study measured hourly airborne mass
concentrations for particles smaller than 2.5 µm (PM2.5) and 10 µm (PM10) along with meteorological conditions and atmospheric
turbidityathightemporalresolutiontocharacterizeandquantifyfugitiveflyashemissions. Fugitiveflyashtransportanddispersionwere
computedusingtheon-sitemeteorologicaldataandaregulatoryairpollutantdispersionmodel(AERMOD).Modeloutputscoupledwith
ambientmeasurementsyieldedfugitiveflyashEFsthataveraged96gMg 1 (ofashprocessed)forthePMc fraction(=PM10 -PM2.5) and
18gMg 1 for PM2.5. Median EFs were much lowerdue to the strongly skewed shape of the derived EF distributions. Fugitive EFs from
nearby unpaved roads were also characterized. Our primary finding is that EFs for dry fly ash disposal are considerably less than EFs
derived using US Environmental Protection Agency AP-42 Emissions Handbook formulations for generic aggregate materials. This
appearstobeduetoalargedifference(afactorof10+)betweenfugitivevehicularEFsestimatedusingtheAP-42formulationforvehicles
driving on industrial roads (in this case, heavy slow-moving grading equipment) and EFs derived by the current study.
Implications:Fugitive fly ash emission factors (EFs) derived by this study contribute to the small existing knowledge base for a
type of pollutant that will become increasingly important as ambient particulate standards become tighter. In areas that are not in
attainment with standards, realistic EFs can be used for compliance modeling and can help identify which classes of sources are best
targeted to achieve desired air quality levels. In addition, understanding the natural variability in fugitive fly ash emissions can
suggest methods that are most likely to be successful in controlling fugitive emissions related to dry fly ash storage.
Supplemental Materials:Supplemental materials are available for this paper.Go to the publisher’s online edition of the Journal of
the Air & Waste Management Association.
Introduction
The U.S. Environmental Protection Agency (EPA) defines
fugitive emissions in Title V (parts 70 and 71) of the Clean Air
Act as emissions that cannot “reasonably pass through a stack,
chimney, vent, or other functionally-equivalent opening”(see
Code of Federal Regulations, CFR, CFR title 40, part 70.2,
2011). This definition includes gases, liquid droplets, and solid
particulate matter. Emissions streams that pass through a vent,
stack, or chimney are confined, making them relatively easy to
sample. By contrast, fugitiveemissions are not confined and that
makes quantifying them a challenge.
Despite the difficulties measuring them, fugitive emissions
can often comprise a large portion of the total emissions asso-
ciated with a source that is required to obtain an air permit.
Fugitive particulate matter emissions (hereafter,“fugitive emis-
sions”) can also be difficult to control. They must be considered
when determining whether a source adversely impacts attain-
ment of ambient air quality standards. In addition, fugitive
emissions must be addressed for New Source Review and
Prevention of Significant Deterioration impact analyses for elec-
tric generating units larger than 250 million BTU per hour heat
input (CFR title 40, part 51, §166, 2008). Fugitive emissions
modeling is generally required if annual emissions of a pollutant
exceed certain thresholds. These thresholds are 10 English tons
per year (tpy) for fine particle (PM2.5) mass and 15 tpy for
particles <10 µm in size (PM10). Accurate emissions estimates
may, in many situations, determine whether annual emission
estimates fall above or below the threshold for modeling.
Quantifying fugitive emissions is especially important to source
operators that handle granular materials (e.g., coal, fly ash, lime-
stone) or that operate vehicles on unpaved surfaces.
Quantifying fugitive emissions for air permitting purposes
generally relies on published emission factors. These factors
relate the amount of particulate material emitted into the air
from a specific process to some more easily quantifiable aspect
of the process. For example, a formula exists (U.S. EPA, 1995,
and subsequent updates) that estimates the amount of fugitive
806
Journal of the Air & Waste Management Association,63(7):806–818, 2013. Copyright © 2013 A&WMA. ISSN: 1096-2247 print
DOI: 10.1080/10962247.2013.795201
emissionsassociatedwiththedumpingofaloadofmaterialfrom
a dumptruck or similar material conveyor.Thevalue determined
in this manner—expressed as mass of particulate matter emitted
per mass of material deposited—is an emission factor (EF).
This paper describes a study designed to quantify fugitive EFs
forparticlessmallerthan10and2.5micrometers(PM10 andPM2.5,
respectively) associated with dry fly ash disposal at a coal-fired
power plant. Theintent of this work was to developEFs specific to
fly ash storageactivitiesand compare themwith EFs derivedusing
standard formulations in theU.S. EPA AP-42 emissions handbook
(U.S.EPA,1995,andsubsequentupdates).TheAP-42handbookis
the widely accepted authoritative source in the United States for
estimating EFs for all types of sources and pollutants.
Previous Work
The dry disposal of fly ash requires that ash be dropped or
dumped onto the ground from a haul truck and leveled by a
grader. Dropping and grading operations produce fugitive dust,
and the emissions caused by these types of actions have been
parameterizedtoalimitedextentbypreviousstudies.Inpractice,
parametric formulas are used to approximate emissions from a
variety of activities even though not all such activities (such as
grading fly ash) have been explicitly studied. Hence, there is a
need to investigate the applicability of published fugitive emis-
sions formulations. Our review of previous work focuses on
fugitive emissions from the dropping of aggregate materials
and from the movement of vehicles over surfaces composed of
loose, granular materials.
Fewemissionsdatacanbefoundfordroppingoperations,and
only those from Cowherd et al. (1974) are readily accessible.
Cowherd et al. sampled dust from aggregate storage operations
with high-volume filter samplers in the immediate downwind
vicinityof the operations.The aggregatestorage operationswere
associated with a sand and gravel pit. Sources of fugitive emis-
sions were a combination of wind erosion from aggregate piles,
aggregate dumping (both sand and gravel), and vehicles moving
on the unpaved surfaces between piles and dump trucks. High-
volume samplers were operated to measure airborne dust con-
centrations and an Anderson high-volume cascade impactor was
used to determine particle size distributions. Five monitors were
placed immediately downwind of five aggregate piles (one per
pile). None of the monitors consistently recorded the highest
concentrations, indicating that the location of the fugitive emis-
sion source was not stationary. This analysis was hampered by
operations logs that contained only daily summary information
and 24-hr particulate concentrations that included periods when
no aggregate handling occurred. Data were available to evaluate
fugitive emissions as a function of precipitation, wind speed,
aggregate size, and activity levels.
Cowherd et al. concluded that wind speed was not a major
factor (i.e., wind erosion of dust from storage piles was not
important). This is not surprising because (1) the study occurred
in Ohio during the summer when winds are generally not very
strong and (2) the sand and gravel piles contained mostly larger
particles not easily eroded by wind. Also, aggregate size was not
found to be a predictor of fugitive emissions. Only wetness
(“wet”days were defined as those receiving rainfall on the day
before or the day of sampled operations) and activity level at the
site were significant predictors of fugitive emissions. Estimated
EFs across all particle sizes averaged 0.42 lb per ton of material
handled (“ton”denotes the unit equal to 2000 pounds). Separate
measurements were made by Cowherd et al. (1974) near a con-
trived aggregate offloading operation using a pile of crushed
limestone and a front loader. Analysis produced an estimated
EF of 0.11 lb/ton of limestone processed, and the airborne dust
had a mass mean diameter of 1.4 µm.
As reported in the U.S. EPA AP-42 emissions handbook
(U.S. EPA, 1995), material dropping operations were quantified
by a U.S. EPA-sponsored study in the 1980s. The AP-42 hand-
book assigns the EF formulation (factor Edrop)an“A”rating for
the highest level of certainty. Factor Edrop is represented by
Edrop ¼0:0016 kdrop
U=2:2
1:3
M=2
1:4 ð1Þ
where kdrop isadimensionlessparticlesizefractionmultiplier,U is
wind speed (m sec
1), and M is the material moisture content (in
percent).Unitsof Edroparekilogramsofairborneparticlesemitted
per megagram of material dropped, and AP-42 defines kdrop as
0.74forparticles <30µm,0.35for particles<10µm,and0.053for
particles <2.5 µm. Equation 1 is most applicable when dropping
conditions fallwithinthe range of conditions that occurred during
the studyonwhichitisbased,asfollows:materialsiltcontent S of
between 0.44 and 19%, 0.25 M 4.8%, and 0.6 U 6.7 m
sec 1.Siltcontent isdefinedasthefractionofparticles <75µmin
size. Note that fly ash as handled at power plants is typically
conditioned with moisture to suppress dust so that M >10%. In
addition,S inflyashisnear100%,wellabovetherangeofthedata
behind eq 1. Thus, if eq 1 is applied to fly ash dropping it is used
outside the recommended range of applicability.
One of the earliest (if not the first) comprehensive compila-
tions of particulate fugitive EFs for unpaved roads was made by
Cowherd et al. (1974). Most references in Cowherd et al. are
obscure reports no longer available, and Cowherd et al. (1974)
must be relied upon as the source of information on these
studies. One exception is the work of Hoover (1973), who
reported measurements of dust deposition near a gravel road.
All approaches to quantifying fugitive emissions have used
measurements of airborne particles, or particle deposition plus
dispersionand deposition estimates, to link measured downwind
concentrations or deposition back to emission rates. Some
focused on suspended particles across a large size range (3–
100 µm diameter), whereas others collected data exclusively on
smaller particles (in the 1–10 µm range). The largest particles—
especially those >30 µm—tended to deposit quickly and could
be captured by simple “dustfall”collectors. Smaller particles
were collected on filters from sampling air streams. Cowherd
et al. (1974) mostly focused on fugitive emissions from paved
andunpaved(dirtand gravel)roads. Theyreportedunpavedroad
fugitive emissions of between 0.5 and 13.9 lb per vehicle mile
traveled (lb/VMT) for total particle concentrations, between 0.4
and 5.2 lb/VMT for particles smaller than 10 µm, and between
0.11 and 0.43 lb/VMT for particles smaller than 2 µm.
Mueller et al. / Journal of the Air & Waste Management Association 63 (2013) 806–818 807
Section13.2inAP-42listsEFsforvariousfugitivedustsources,
including vehicles traveling on unpaved surfaces. Fugitive emis-
sionsassociatedwithwinderosionemissionsarenotconsideredby
this study because measured wind speed never met the erosion
thresholdcriteriainAP-42.TheupdatedversionoftheEPAAP-42
handbook contains numerous referencesto studiesofunpavedand
pavedroadfugitiveemissions.Theonlysuchreferencefromapeer-
reviewed (and thus readily accessible) source is Dyck and Stuckel
(1976), whose experimental results for unpavedindustrialsurfaces
are described here and are incorporated into the handbook along
with data from Cowherd et al. (1974) and others.
Dyck and Stuckel (1976) deployed a 4.5-ton flatbed truck
carrying different weight loads driven along a dry unpaved dirt
road while high-volume particulate samplers were operated at
varying locations upwind (for background samples) and down-
wind (4 between 15 and 76 m). Truck speeds—held steady
during each experiment—were varied between 4.5 and 11.2 m
sec 1 (16–40 km hr
1). Truck weight was varied at 3900, 5700,
and 7500 kg and three road types were tested. Experiments each
lasted 1 hr and included multiple truck passes.Results computed
from each of four downwind air samplers were averaged toyield
one EF per experiment. Multivariate regressions were done to
determine relationships between EF, truck weight, truck speed,
road silt content, road surface moisture content, and wind speed.
Dyck and Stuckel (1976) computed the fugitive emission rate
using a dispersion equation for an infinite line source, measured
1-hr particleconcentrations,thenumberoftruckpassesperhour,
and meteorological data collected nearby.
Variations in road moisture content had no effect on com-
puted EFs, but this is probably because the tests were only
conducted during dry conditions. The results suggested a linear
relationship between the fugitive EF for dust and the predictors
of vehicle weight, speed, silt content, and road type, as follows:
ED&S ¼5:286 3:599 R þ 0:00271 VWS ð2Þ
where R is road type (¼0 or 1),V is vehicle speed (miles per
hour),W is vehicle weight (tons), and S is road surface silt
content (percent). At a speed of about 12 m sec
1, with road
silt of 5–20% and for the vehicle weights used in the Dyck and
Stuckel experiments, eq 2 yields EFs of between 5 and 30 lb/
VMT, similar to those reported by Cowherd et al. (1974).
Two AP-42 road dust EF formulations are given, one for
traffic on public roads and one for vehicles driving at industrial
sites. The latter is the EF formula typically used for estimating
dust emitted from heavy machinery such as graders/bulldozers
operating at a power plant (its application to grading fly ash is
described later). Traffic on public roads is assumed to be pri-
marily from automobiles and small trucks whose speeds vary
over a larger range than that for heavy trucks at industrial sites.
Thus, the public road formulation allows for vehicle speed but
neglects vehicle weight. The opposite is true for the industrial
site formulation. Both unpaved road formulations are assigned a
quality rating of “B”(one level below the rating for the dropping
formulation), but the designation degrades if conditions fall
outside those used to derive the formulations.
For industrial unpaved roads or surfaces the AP-42 EF Eir is
given as
Eir ¼0:282kir
S
12
a W
3
0:45
ð3Þ
with kir being a dimensionless particle size fraction parameter
(different from kdrop in eq 1),W is vehicle weight (in tons), and
exponent a ¼0.9 for particles smaller than 10 µm. Values for kir
are 1.5 for the PM10 mass fraction and 0.15 for the PM2.5
fraction. Units of Eir are kilograms of airborne particles emitted
pervehiclekilometer traveled.Likewise,TheAP-42formulation
for Epr (public unpaved roads) is
Epr ¼0:282 kpr
S=12 V=30
d
M=0:5
c Cnf
2
64
3
75 ð4Þ
with kpr ¼1.8 for the PM10 mass fraction and 0.18 for the PM2.5
fraction. Exponents cand d aregivenas0.2and0.5,respectively,
for all particles <10 µm. Vehicle speed (V) is in units of miles per
hour but the conversion factor has been included in eq 4 to
produce Epr in metric units. Parameter Cnf is included to remove
the contributions of vehicle fleet exhaust and brake and tirewear
that were combined with road dust in the field experiments
performed to derive eq 4. AP-42 gives Cnf as 0.00047 and
0.00036 lb/VMT for PM10 and PM2.5, respectively.
The primary applicability of eq 3 is for 2 S 25%, 2 W
290 tons,V <70 km hr
1,andM 13%. Likewise, the applic-
ability of eq 4 is primarily for 2 S 35%, 1.5 W 3tons,16
V 88 km hr
1,andM 13%. Thus, eq 3 is applicable over a
muchgreatervehicleweightrangethaneq4,whereaseq4is
applicable over a greater vehicle speed range than eq 3. These
limitations must be remembered when interpreting later compar-
isons between EFs. The sensitivities of eqs 1, 3, and 4 to various
physical parameters (e.g.,M and S) are illustrated in Supplemental
Information.Notethatjustbecause W doesnotappearineq4and V
does not appear ineq 3does not mean that fugitive emissions under
those conditions do not respond to Wand V. Data scatter tends to be
large with these kinds of relationships and it is likely that para-
meters exhibiting relatively small variations do not become signifi-
cantpredictorswhen multivariate statisticalanalyses are performed.
An alternate EF for fugitive dust from nonagricultural
unpaved roads was developed by researchers at the University
of California–Davis and the Desert Research Institute and
adapted by the California Air Resources Board and the
Western Regional Air Partnership (WRAP, 2006). This EF is a
constant value of 2.27 lb/VMT for PM10 and is scaled down to
0.227 lb/VMT for PM2.5. These values are slightly lower than
those produced for California roads using the AP-42 methodol-
ogy. More recently, Gillies et al. (2005) estimated fugitive road
dust emitted by various sized vehicles traveling on unpaved
roads at speeds as high as 80 km hr
1. Their estimates used
light scattering and wind measurements at various heights to
calculate total horizontal particle (PM10 mass) fluxes for each
vehicle pass at three downwind distances. These experiments
confirmed the sensitivity of particulate EFs to vehicle size
Mueller et al. / Journal of the Air & Waste Management Association 63 (2013) 806–818808
(including four to eight wheels per vehicle) and speed. Gillies
et al. suggested that unpaved road EFs were even greater than
those estimated by AP-42 for high vehicle speeds. No data were
collected for vehicles with treads (i.e., bulldozers) or for speeds
<16 km hr
1.
Despite several studies of emissions from vehicles traversing
unpaved surfaces, none duplicated the conditions relevant to fly
ashhandling,thatis,thehighmoisturecontentofdroppedloads,S
100%, and vehicles moving at extremely slow speeds on either
treads or specially designed tires for use on loose surfaces.
Vehicles with treads or special tires are used because they provide
better traction on surfaces composed of loose materials. It is
possible that the reduced surface slippage of thesevehicles results
inlessdustemissionsthanfromroadtires.Therefore,aneedexists
to explicitly examine fly ash handling fugitive emissions.
Experimental Method
Approach
The method used to quantify fly ash disposal EFs was—like
previous studies—inferential and based on ash handling infor-
mation, meteorological data, and a transport/diffusion model to
link source activity with measured downwind concentrations.
An illustration of the monitoring approach is provided in
Figure 1. Air sampling downwind of the fly ash storage area
collected data that included impacts from both fly ash and
unpaved road dust. Light scattering (so-called “bscat”) data
detected the presence of particle plumes and airborne particle
samplers provided information on particle mass concentrations
for two particle size ranges. Digital photographs and statistical
methods were used to remove the influence of road and con-
struction dust, allowing quantification of the fly ash influence.
Records and other observations of ash handling enabled a cou-
plingofsimulated(usingtheatmosphericdispersionmodel)dust
emission estimates with on-site ash handling activity.
The field measurement campaign was conducted at the
1200-MW Colbert coal-fired electric generating plant operated
by the Tennessee Valley Authority in northwest Alabama.
ColbertdoesnotoperateSO2 removal technology andcurrently
burns about 7000 tons of low-sulfur bituminous coal daily. Fly
ash is conveyed pneumatically to hoppers that hold it for trans-
port to the disposal area (the so-called “dry stack”). Fly ash is
conditioned (moistened prior to transport) to around 15%
moisture and is then transferred to 30-ton haul trucks that
transport it about 1.5 km to the disposal site. At the dry stack
(latitude: 34.731 N/longitude: 87.834 W) the ash is dumped
onto the top of the stack and spread into a pile of uniform
height. During the study the stack top was about 30 m above
the surrounding ground level and the active disposal area cov-
ered roughly 1–2 ha. The terraced sides of the dry stack are
covered with short grass.Occasionally, as the ash level rises the
exposed outer edge of the ash is covered in clay, an activity that
isveryinfrequentanddidnotoccurduringperiodsanalyzedfor
fugitive emission rates.
Activity logs provide data on the daily amount of fly ash
moved to the dry stack, the number of truck loads hauled, and
whether other materials were handled at the site. The fly ash
disposal foreman reported that each load of ash dumped is
leveled by a grader (bulldozer) to a depth of 18–24 inches
(0.46–0.61 m). Given the typical volume of ash per truck load,
this is equivalent to a circular pile about 3.5 m in radius. Each
load requires an average of 8 min for pile leveling work. The
average speed of the grader is 5 miles per hour (2.2 m sec
1).
This speed constrains the distance traveled by the grader while
processing a load to about 1000 m. The processing time allows a
Figure 1.Schematic of sampling scheme designed to capture fugitive fly ash particles downwind of a fly ash disposal area. Unpaved roads between the disposal site
and monitoring equipment were a major source of confounding emissions.
Mueller et al. / Journal of the Air & Waste Management Association 63 (2013) 806–818 809
maximum of about 7–8 ash loads deposited per hour. However,
in some cases up to 12 loads were deposited per hour. We
assumed that the grading activity was slightly more efficient
during the peak periods (i.e., less than 8 min was needed to
level a pile) but that some grading work continued into the next
hour. The foreman also reports that piles are typically dumped in
contiguous areas which allows for the most efficient means of
leveling multiple piles and constrains the ash dumping/proces-
sing activities to only a small portion of the dry stack top on any
given day. This information was used to model fugitive fly ash
dispersion from the storage area and to compute EFs using AP-
42 formulations.
Measurements
Detailed meteorological data were collected to characterize
site weather (e.g., precipitation amount), airflow variations by
direction, atmospheric turbulence, and turbidity. The latter data
were critical in detecting particle plumes from nearby fugitive
dust sources. Except for the nephelometer (for light scattering
measurements) the meteorological instruments were deployed
on or near a 10-m tower (Figure 2) in a grassy field located
north of the fly ash dry stack. The field had a slight (4%)
positive elevation gradient from southeast to northwest. This put
the base of the tower (located about 60 m northwest of monitor-
ing Site 2) at an elevation about 2–3 m above Site 2.
Temperature, relative humidity, and three-dimensional airflow
(using sonic anemometers) were measured at 2.3 and 9.6 m
above the ground. A net radiometer was mounted at the lower
tower level and a tipping bucket rain gauge was located nearby.
Particle concentration data were needed to calculate the con-
tributions of fugitive sources to total concentrations of PM10
(CPM10)orPM2.5 (CPM2.5). These measurements were made
hourly using Met One beta attenuation monitors (BAMs), a
Federal Equivalence Method instrument, located at three sites
(a list of measurements and instrumentation is provided in
Figure 2.Aerial photograph of the area around the fly ash disposal site showing locations for various physical features and monitoring equipment. The photograph
predates the study by a few years (all sides and most of the top of the fly ash dry stack were covered by vegetation during the study) and was taken when the grass was
dormant. Monitoring sites 2 and 3 (triangles) are labeled. The meteorological tower is represented by a square. A cartoon camera illustrates the location of the video
surveillance system. Four circles denote locations of potential ash disposal sites used in the dispersion modeling. The background monitoring site, not in this field of
view, was about 1500 m northwest of the dry stack.
Mueller et al. / Journal of the Air & Waste Management Association 63 (2013) 806–818810
Supplemental Information). Measurements at Site 1 (not shown
in Figure 2) approximated background conditions, and Sites 2
and 3 were downwind of the fly ash disposal area when winds
had a southerly component. Similar instrumentation has been
used in other studies to measure fugitive dust impacts
(e.g., Watson et al., 2011). Particle mass was also collected
using BGI PQ200 Federal Reference Method high-volume filter
samplers. Tandem samplers with PM10 inlets were used at both
Site 1 and Site 2, with one collecting mass on a Teflon filter and
the other collecting mass on a quartz filter. This enabled subse-
quent analysis for organic material (quartz) and silicates (Teflon)
along with other elements. The filter sampling was done for 12
hr starting a 7:30 a.m. local time to characterize airborne parti-
culate composition during the daytime when fugitive dust
impacts were most likely to occur.
Sites 2 and 3 were located 227 m and 283 m at a compass
direction of 17 from the center of a circle roughly encompass-
ing the active fly ash disposal area. Site 2 was 23 m from the
industrialunpaved(clay)road—calledthe “berm”road—thatwas
the source of most of the road dust impacts recorded during the
study. The base of the berm road was about 3.7 m above the
elevation of Site 2, but the BAMs sampling inlets were 2.4 m
above ground, placing the particulate measurements at just over 1
m from the vertical center height of road dust plumes. A seldom-
used gravel “access”road was between the berm road and Site 2.
The access road was 3.5 m from Site 2 and at the same elevation.
The digital camera used was a Mobotix M24M surveillance
system. The primary benefit of this video system is its relatively
high resolution (3 megapixels per image) and motion detection
capability. The camerawas configured to operate Monday through
Friday,from7:30a.m.through5:00p.m.localtime,andcoincided
with the schedule of the ash handling crews. The camera viewing
angle covered the northwest part of the ash pile, while the image
foreground included the access road, the berm road, and a perpen-
dicular road that connects the berm and main roads. Six video
motion windows (VMW) were defined to closely monitor activ-
ities occurring inside the camera field of view. When one or more
VMWs detected movement the camera automatically stored
images at a predetermined minimum time interval (to conserve
camera memory we used 10 sec and, later, 5 sec). The images
provided a vehicle census during the study, a record of vehicular
activities (i.e., grading work), and a means of quantifying vehicle
speed. The types of vehicles involved in fly ash hauling and
dumping were heavy-duty haul trucks, water trucks, and excava-
tors.Vehiclesinvolvedinroadanddrainageconstructionsincluded
front loaders, graders, bulldozers, a watering truck, a school bus
(for personnel transport), pickup trucks, and small utility vehicles
of various types. The surveillance system helped determine the
likely cause of light scattering spikes observed at Site 2.
Fly ash plume modeling
The U.S. EPA AERMOD atmospheric dispersion model
(U.S. EPA, 2004) is the tool that is recommended by the
U.S.EPAforcomputing thedispersion ofatmosphericpollutants
within a few tens of kilometers from a regulated source.
AERMOD is capable of simulating pollutants emitted from a
nonbuoyant area source such as a fly ash disposal site.
AERMOD is a Gaussian plume model with the highest simu-
latedpollutantconcentrationsatplumecenterlineanddecreasing
concentrations—following a Gaussian distribution—toward a
plume’s lateral (cross-wind) boundaries. AERMOD is a spatially
uniform steady-state model in that it only considers one set of
meteorological conditions for representing the entire period of
pollutant transport from source to downwind receptor. The
model calculates a pollutant concentration C based on a user-
supplied emission rate Q. If AERMOD is run with Q ¼1 then
each simulated concentration is mathematicallyequivalent to the
rate-normalized concentration C/Q because in the model C is
directly proportional to Q.
The Gaussian plume assumption represents an analytical
challenge because it is a statistical approach to dispersion mod-
eling that is most relevant when simulating a large number of
plumes under similar conditions. In truth, no plume is “infi-
nitely”wide as the Gaussian assumption implies. When used in
the current analysis, an extremely wide plume can yield nonzero
estimates of C/Q at downwind monitoring sites. These results
would produce very high emission rates but with a correspond-
ing very low probability of being real. To avoid this problem, all
AERMOD model results were based on a 4sy finite-width
plume, rather than allowing AERMOD to assume a Gaussian
plume of infinite width. Thus, the value of C/Q was set to zero
for periods when a receptor (i.e., air monitoring station) was
more than 2sy from the plume centerline.
AERMOD is normally run using hourly meteorological data.
This approach neglects sub-hourly meteorological variability
that could be important in determining 1-hr average concentra-
tions. Wind direction variations are especially problematic in
summer when wind speeds are often light and direction varia-
bility is large. This problem was minimized by processing six
individual 10-min meteorological averaging periods each hour
and using them to model 10-min average concentrations that
were subsequently combined to yield hourly averages.
The method used here was to provide AERMOD all
meteorological parameters that were measured at the study
site and allow the model to select the parameters using its
built-in data preferences. Thus, AERMOD was given wind
speed, direction (u), air temperature, relative humidity, the
standard deviation of the vertical wind component (sw) and
the standard deviation of the horizontal wind direction (su)at
both tower levels along with solar radiation, net radiation,
precipitation amount, and surface roughness (z0). Surface
roughness, computed by wind direction sector for the study
site using data for 10-min periods under neutral atmospheric
stability, averaged 0.03 m for the important southerly sectors.
This low value indicates a relatively smooth surface. Wind
speed, wind direction,sw, and su are the parameters most
likely to be used by AERMOD when calculating C/Q.
AERMOD also reads and uses other derived parameters
(e.g., surface heat flux, Monin Obukhov length). These were
computed following procedures outlined in AERMOD docu-
mentation (U.S. EPA, 2004) but were unlikely to be used. The
height of the mixing layer (zm) was not measured on site. A
constant 800 m was used as the convective zm for all events
and a constant 200 m was input for the mechanically mixed
zm. Tests conducted on sensitivity to zm in AERMOD found
Mueller et al. / Journal of the Air & Waste Management Association 63 (2013) 806–818 811
that the value did not affect C/Q over the short distances
between the source (fly ash disposal site) and the monitoring
sites. Thus, the parameters that controlled simulated C/Q in
this study were measured U,,s , and sw.
AERMOD was applied in two ways to simulate dispersion
from an area source with a diameter of 7 m and a release height
ofzero.Thisapproachassumesthatairflowstreamlinesfollowthe
contour of the fly ash dry stack. An elevated release could only
occur with strong winds that force streamline separation in the lee
of the dry stack. With nearly all 10-min wind speeds of 1 to 3 m
sec 1, the likelihood of streamline separation was very low
because the pressure perturbation that can create streamline
separationinthe lee ofair flowingovera hillisa positive function
of wind speed (Jackson and Hunt, 1975). An “elevated”plume
would produce a negative association between concentration (at
the monitoring sites) and speed because streamline separation
increaseswithspeed.Faster transportallowslesstimefor particles
to disperse from aloft to the surface, thereby reducing the down-
wind concentration of particles at ground level beneath an ele-
vatedplume (theU
1 dilutioneffectwouldfurthercompoundthis
negative association; see, for example, plume dispersion formula-
tions for a Gaussian plume in Hanna et al., 1982). However, a
comparison of plume concentration versus wind speed for hours
with wind directions most closely aligned (15 ) with the mon-
itoring sites—implying that plumes were sampled near center-
line—indicated that wind speed variance accounted for about
one-third of the total variance in concentrations and the associa-
tion was positive. This is the kind of association that would occur
for a ground-level plume in which reduced transport time from
higher winds means less dispersion and higher concentrations
near the plume centerline (in this case the effect of reduced
transport and diffusion time of the surface plume clearly over-
comes and is a stronger effect than the opposing U
1 effect).
Inoneapproach,AERMODsimulationswerebasedonactual
sub-hourly meteorological data and results combined to produce
one hour average C/Q for four alternate source locations on the
dry stack. These locations were at the downwind, upwind, wes-
ternmost and easternmost edges of the circle defining the active
ashstoragearea(seeFigure2).Thisapproachprovidedestimates
of the uncertainty due to not knowing the exact location of ash
depositsforeacheventhour.AsecondapproachappliedaMonte
Carlo sampling procedure to estimate alternate sub-hourly
meteorology based on measured variations in input parameters.
This approach provided estimates of the uncertainty due to
meteorological variability between the monitoring and ash dis-
posal sites. In both approaches, the area emission rate for the ith
particle size fraction was determined from
QaðiÞ¼CxsðiÞ
C=Q
ð5Þ
with units of emitted particle mass per unit area per unit time.
Thevalue Cxs(i)representsthe “excess”concentrationassociated
with the fly ash fugitive dust plume and derived from observa-
tions as described later. During each hour the mass of fly ash
processed at the sourcewas known (Mash) in units of mass of ash
per unit area per unit time. The equivalent particulate emission
factor Eash(i)—with units of emitted particle mass per mass of
processed ash—was computed as
EashðiÞ¼QaðiÞ
Mash
ð6Þ
Separating road dust and fly ash from background
particulate levels
Individually quantifying road and fly ash disposal contribu-
tions to measured hourly CPM2.5 and CPMc (¼CPM10 –CPM2.5)
was difficult because there is no direct means of knowing the
degree to which airborne particles were derived from soil or fly
ash (soil and ash chemical signatures are too similar). We used an
indirect phenomenological approach based on camera informa-
tion, measured bscat, and derived statistical relationships between
various measured parameters. This method was not perfect but it
captured the majority of local sources and enabled us to isolate
those eventsthatwere most likelyassociatedonlywithfugitive fly
ash emissions. If anything, the approach may have enabled some
contributionsfromunknownsources toimpact the flyashcalcula-
tions, thereby slightly overestimating fly ash fugitive emissions.
Particle concentrations for the two mass fractions at Sites 2
and 3 were impacted by background sources (i.e., upwind of the
plant site), fly ash disposal activity and local sources (those
between the fly ash site and the monitoring sites). Measured
background levels of PM10 and PM2.5 when airflow was from
thesoutherlydirectionswereprovidedbySite1data.Subtracting
background values from Site 2 and 3 values provided concentra-
tions due to the combined effects from fly ash disposal and local
sources. Fly ash contributions at Sites 2 and 3 were computed
using measured bscat at Site 2 to remove local source impacts.
The procedure was developed after analyzing 447 hr of data
when wind directions were from the south-southeast through
south-southwest sectors. Relationships were examined between
bscat,CPM2.5,CPMc, and associated meteorological parameters.
From scaling arguments it can be shown that, unless the
number of particles in the PMc size fraction is a lot more
abundant than those <2.5 µm, the measurement of bscat will be
more sensitive to CPM2.5 than CPMc. Note that CPM2.5 is signifi-
cantly correlated (>99% level of confidence) with CPMc but the
associated variance (r2) is small,10%, implying that only a
small portion of the PM2.5 and PMc at Site 2 comes from the
same source(s). Multivariate analysis for conditions when air-
flow was from the south-southeast through west southwest sec-
tors also yielded the following:
bscat is significantly correlated with Site 2 CPM2.5 and CPMc
but the association with CPMc is weak (i.e., they share little
varianceincommon).Thecorrelationof bscat withCPMc isdue
to the association between CPM2.5 and CPMc.
Seventy-six percent of the variance in CPM2.5 at Site 2 is
associatedwithvariancein bscat andasmalladditionalamount
of variance is associated with relative humidity at 2.3 m (f2)
and the standard deviation of bscat (sbscat). Predictor variable
confidence exceeds 99% for all predictors.
The multivariate regression between CPM2.5 and its predictors
bscat,sbscat and f2 (r2 ¼0.81) is given by
Mueller et al. / Journal of the Air & Waste Management Association 63 (2013) 806–818812
CPM2:5 ¼cbscatbscat þ cf2f2 þ cssbscat þ cint ð7Þ
In eq 7,cbscat ¼0.201 Mm µg m
3,cf2 ¼0.054 µg m
3
percent 1,cs ¼0.052 Mm µg m
3, and cint ¼6.56 µg m
3.
This equation provides a means for directly estimating CPM2.5
from other measured parameters. The association between
CPM2.5 and sbscat was not nearly as strong as the association
between CPMc and sbscat.
The larger particles in the coarse size fraction are not well
represented by visual wavelength bscat primarily because of the
lower light scattering efficiency and smaller number concentra-
tion of particles larger than a micrometer in diameter
(Friedlander, 2000). However, it is clear from examining bscat
and CPMc time-series plots that fugitive sources produce coarse
particles. One way to model CPMc is to find a surrogate for the
various physical processes (vehicle passages, ash dumps, etc.)
that generate fugitive emissions. We found the best surrogate to
be the standard deviation of 1-min bscat. Peaks in bscat are an
indication ofphysical activity that generates fugitivedust. As the
activity increases and produces more PMc, 1-min bscat exhibits
more peaks and these translate into larger variance in bscat.
A multivariate analysis of CPMc and various parameters
yielded the following:
Hourly CPMc is highly correlated (r2 ¼0.67) with sbscat.
CPMc issignificantlycorrelatedwithwindspeedat2.3m(U2).
CPM2.5 provides some additional correlation with CPMc
beyond what is captured by sbscat and U2.
Jointly,sbscat,U2 and CPM2.5 are associated with 71% of the
variancein CPMc.Althoughsomewhatlowerthanthemodelof
CPM2.5,thisisstillaveryhighcorrelation.Theresultantmodel
is expressed as
CPMc ¼csbbscat þ cU2U2 þ cPM25CPM2:5 þ cint ð8Þ
In eq 8,cs ¼3.87 Mm µg m
3,cU2 ¼7.85 µg s m
-4,cPM25 ¼
1.57, and cint ¼29.4 µg m
3. All predictors in eq 8 are
significant at greater than 99% confidence. Comparing eqs 7
and 8 in terms of regression parameters reveals that CPMc is >10
times more sensitive to sbscat than CPM2.5 is to bscat.
Given these relationships, it is possible to estimate CPM2.5
and CPMc from parameters that are continuously measured
onsite. The procedure to determine fugitive dust plume hourly
“excess”concentrations for the ith particle size fraction at
Site 2 was to first compute an adjusted concentration that
removed the influence of local sources from the measured
value,Cobs(i):
CadjðiÞ¼CobsðiÞ ClocalðiÞð9Þ
In eq 9,
ClocalðiÞ¼cbscatðiÞðbobs
scat badj
scatÞþcsðiÞðsobs
bscat sadj
bscatÞ
þ cPM25ðiÞðCobs
PM25 Cadj
PM2:5Þð10Þ
where “obs”and “adj”superscripts refer to the hourly values
measured, respectively, across all minutes and those minutes for
which no local disturbances were identified. Minutes when bscat
was impacted by a local source were those when bscat increased
>20% above the baseline value. Note that cbscat ¼0 for the PMc
size fraction and cPM2.5 ¼0 for the PM2.5 size fraction. In
addition,CPM2.5 must be computed before CPMc because the
former is needed to compute the latter.
Cxs(i) is computed from Cadj(i)as
CxsðiÞ¼CadjðiÞ CbckðiÞð11Þ
with Cbck(i) representing the background concentration of parti-
cle size fraction i. Site 1 PM2.5 concentrations were strongly
correlated with those at Site 2, and PM2.5 background at Sites
2 and 3 was determined from the linear regression between Sites
1and2.However,therewaslittleassociationbetweenPMc levels
atSites 1and2. For the >90% of hourswhensufficient datawere
available, daily average background PMc concentrations at Sites
2 and 3 were computed using daytime PMc levels measured at
Sites2and3duringhourswhennoflyashhandlingoccurredand
when the contribution of local fugitive sources to PMc were
insignificant (i.e.,<1% of the hourly particulate loading based
on bscat data). The PMc level observed at Site 1 was used as a
background estimate of last resort for only a few (<10%) of all
hours analyzed.
Site 3 measurements were immediately downwind of Site 2
whenwindswerefavorableforfugitiveflyashimpacts.Adjusted
Site 3 concentrations were computed assuming equal propor-
tionality between Site 3 and Site 2 such that the ratio Cadj/Cobs
was equal at the two sites.
Results
Fly ash emission factors
Hours were analyzed for fugitive fly ash emissions as long as
they met a list of criteria that included wind directions between
south-southeast and south-southwest (to ensure optimal align-
ment between the source area and downwind monitors), the
availability of valid data, no precipitation, the absence of other
dust source interferences whose influence could not be removed
(including screening of events based on PM10 chemical signa-
tures to remove periods clearly affected by biomass burning),
and a reliable indication that fly ash disposal was actively occur-
ring. A description of how fly ash disposal activity was deter-
mined is provided in the Supplemental Information.
After removing background and local source interferences,
measured particulate concentrations were, in 10% of all cases,
not significantly different from zero for PMc. The occurrence
was more frequent for PM2.5 because of the relatively low frac-
tion of particulate emissions in the smaller size fraction and the
relatively large uncertainty in the measurement. Measurement
sensitivity was determined prior to the start of ambient measure-
ments following manufacturer guidelines that all instruments be
initially operated for 3 days with special inlet filters that remove
particlessmaller than10µminsize.Asubsequentcomparisonof
the “zero”concentration data provides information on measure-
ment sensitivity. Our zero-air comparisons yielded a mean sen-
sitivity for the BAMs data of 3.6 µg m
3 for both PM10 and
Mueller et al. / Journal of the Air & Waste Management Association 63 (2013) 806–818 813
PM2.5 measurements. Figure 3 illustrates the frequency distribu-
tions of Cobs at each measurement site during the periods when
ash was typically processed. Fine particle concentrations rarely
exceeded 30 µg m
3 but PM10 values exceeded 60 µg m
3 a
significant fraction of the time. Mean measured values C ;
listed in each plot, do not varymuch by site for PM2.5 but exhibit
a lot of differentiation for PM10. This shows that fugitive dust
emissions are primarily in the coarse particle size fraction.
Figure 4 illustrates the distributions of PM2.5 and PMc Cxs for
the cases analyzed to determine EFs. About 60% of the PM2.5
Cxs and 47% of the PMc Cxs was below 3.6 µg m
3, making the
signal-to-noise ratio especially low for PM2.5 emissions.
Although Cxs values were not always >3.6 µg m
3, they were
usually >1µgm 3 (BAMprecisionlevel).However,whenCxs was
<1µgm 3 it was usually <<1µgm 3 (and even <0). For cases
when4µgm 3<Cxs <0.5µgm 3,Cxs wasarbitrarilysetto3.6µg
m 3 to calculate an EF upper limit during extremely low and
highly uncertain plume levels (cases were not analyzed if Cxs <
-4 µg m
3). These were typically events when ash handling rates
were very low at the disposal site. Table 1 summarizes the EFs
computed from field data and compares them with values derived
usingaggregateAP-42EFformulationsforashhandlingprocesses
(i.e., eqs. 2 and 3). These results include only those hourly events
when the derived number of ash truck loads was at least one and
when EFs were computable using both the field study and AP-42
methods.
Emission factors based on field study data exhibited a much
larger range than factors derived from AP-42 formulations. This
is probably because natural variability in atmospheric conditions
coupled with large variations in ash handling conditions
Figure 3.Frequency distributions of measured PM2.5 and PM10 concentrations
at the three monitoring sites for Monday–Friday, 07:00 a.m. through 3:00 p.m.
local standard time, when fly ash was typically moved to the storage area. Mean
values (µg m
3) are denoted C. All meteorological conditions are represented.
Figure 4.Distributions of “excess”fugitive fly ash plume concentrations (Cxs)
determined for fly ash plume events captured by the particulate monitors.
Mueller et al. / Journal of the Air & Waste Management Association 63 (2013) 806–818814
conspired to produce large variations in downwind concentra-
tions used to compute fugitive fly ash EFs. Factors derived using
AP-42 formulations were based on a small range in input para-
meters and the EFs themselves do not rely on downwind mea-
surements for verification. In addition to differences in range/
variability, field study EFs were smaller in magnitude and more
strongly skewed toward low values than AP-42 values (and this
was despite the fact that EFs based on field study data included
values representing an upper limit whenever extremely low con-
centrationsweremeasured). Coarsemass EFs averaged63%less
for field study data compared to AP-42 values and PM2.5 EFs
averaged 38% less. Median values showed an even greater dis-
parity. This is especially noteworthy because of the conservative
approach used to estimate EFs when Cxs was very low.
Fly ash emission factor uncertainties
Simulated emission rate uncertainty (which translates directly
intoEFuncertainty)wasexaminedbycomputingthevariabilityin
AERMOD-derived Qa due to uncertainty in the exact location of
fugitive emissions on the fly ash dry stack and uncertainty in the
meteorological data input to AERMOD. The Qa uncertainty due
to source location (“location”uncertainty) derives from the fact
thattheexactdistanceanddirectionfromwhereashwasdeposited
relative to the downwind monitors were not known during any
given hour. Source–receptor distances varied from 176 to 278 m
for Site 2 and from 232 m to 334 for Site 3. Likewise, source–
receptor directions varied 12 relative to direct alignment
between the assumed fly ash emission centroid at Sites 2 and 3.
Meteorological uncertainty may exist (although we have no evi-
dence that suggests it is important), because meteorological mea-
surements critical to AERMOD dispersion calculations were co-
located with the downwind monitors and not with the source. In a
convectiveboundarylayer,turbulenceanditsimpactonwindscan
vary considerably over the few hundred meters separating the
source and measurement locations, especially when using 10-
min averaging periods for dispersion calculations.
Location uncertainty was determined by simulating downwind
impacts for four separate locations representing extremes in
source–receptor distance and direction (see locations in
Figure 2). The resulting emission rates are denoted Qloc.
Meteorological uncertainty was examined using a Monte Carlo
resamplingof sub-hourly meteorologicalparameters for eachfugi-
tive fly ash event. Rates generated from this exercise are denoted
Qmet. The source position was set to the ash disposal centroid
location (source–receptor distances of 227 and 283 m for Sites 2
and 3) for Qmet simulations. A thousand independent replications
of 10-min meteorological parameters provided alternate realities
of conditions driving transport and diffusion. Meteorological
variances were taken directly from the observed variability of
10-min parameters during each event hour. Each replicated set of
meteorology was modeled by AERMOD. The means and uncer-
tainties associated with Qmet represent an independent calculation
of the sensitivity of simulated emission rates to meteorological
variability between the measurement location (tower) and the fly
ash disposal area. The Monte Carlo replication methodology is
described further in the Supplemental Information. The most vari-
able input parameter was wind direction which is typical of weak
airflow summertime conditions in Alabama. Wind direction varia-
bilitycanresultineitherdirectplumehitsonareceptor,a “glancing
blow”byaplume,oratotalmiss.Impactsfromplumesthatpassed
a receptor at a distance >2sy were assumed to make no contribu-
tion to measured particle concentrations. However, plumes that
impacted a receptor “on edge”(near the 2sy limit) can result in
high emission rate estimates and contributed to the large upper tail
of the Qmet (and Eash) frequency distributions.
Simulated 90% confidence intervals for Qloc and Qmet are
summarized in Table 2. Meteorological uncertainty effects were
Table 1.Fly ash dry disposal fugitive emission factors derived from field data and using AP-42 formulations for dropping and grading operations
Particle size range Source Number of events Range Mean Median Standard deviation
PMc Field data 74 0–965 96 24 178
PMc AP-42 74 173–322 260 232 40
PM2.5 Field data 76 0–197 18 6 32
PM2.5 AP-42 76 19–36 29 26 5
Note: Range, mean, median, and standard deviation given as grams of particles emitted/Mg ash.
Table 2.Average simulated fugitive fly ash emission rates (g ha
1 sec 1) for all event hours on days when the site material processing log indicated nonzero fly ash
disposal activity
a
Particle size fraction Mean Qloc
Qloc uncertaintyb
(90% confidence) Mean Qmet
Qmet uncertaintyc
(90% confidence)
Coarse 716
d 86% to þ149% 962
e 61% to þ1374%
Fine 84
d (Same as above) 159
e 60% to þ1577%
Notes:aResultsarebasedontheassumptionofafinite-widthplumeequalto 2sy.Aminimumparticle concentrationof0.5µgm
3wasassumed.bDuetouncertainty
using four different source locations.
cDue to meteorological uncertainty.
dThesevalues are 53% greater than the means derived using the center of the ash storage
area as the source region.
eExcludes values outside the 90% confidence interval. This method of calculation also reduces to only 18% the difference created by
moving the source to the center of the dry stack. Thus,Qmet >Qloc by 59 and 123% for PMc and PM2.5, respectively.
Mueller et al. / Journal of the Air & Waste Management Association 63 (2013) 806–818 815
larger than location uncertainty effects. Source location uncer-
tainty is more likely to produce emission rate estimates that are
less than the average rate based on all four potential source
locations. Meteorological uncertainty is more likely to produce
overestimates compared to the average of Qa based on all
meteorological realizations. The upper distribution tail is so
extreme that mean Qmet values in Table 2 are based only on the
results that fall within the 90% confidence interval to avoid an
otherwise absurdly large summary statistic. The mean for coarse
mass Qmet was34%higher thanthemeanfor Qloc (denoted Qloc),
but the fine mass mean Qmet was nearly double Qloc.
These results should not be interpreted as indicating that the
Qmet results are somehow more realistic than Qloc, because the
former only represent hypothetical multiparameter variations in
meteorology.Qmet results indicate the worst-case level of uncer-
tainty that would exist if the observed meteorological data did
notrepresentconditionsovertheashdisposal area.The drystack
top is 20–30 m above the elevation at Site 2 and 17–27 m above
the top measurement level on the meteorological tower. There is
a possibility that the elevation difference and source-receptor
distance might conspire to introduce meteorological dissimila-
rities betweenthetowerandthedrystack.Thus,theMonteCarlo
test for meteorological uncertainty is an acknowledgment of its
potential impact on emission rate estimates while recognizing
that these test results likely overstate the influence of any differ-
ences on simulated dispersion results.
The PMc Eash values based on this study are so much lower
than the AP-42 based values that the potential meteorological
uncertainty does not alter the conclusion that the former are
significantly lower than the latter. The difference between the
meanstudy-derivedandAP-42PM2.5 Eash valuesislessthanthat
for PMc Eash and the two sets of PM2.5 results may not be as
different as implied, based on the potential for meteorological
uncertainty. However, the median PM2.5 Eash values still exhibit
a large difference that remains significant even if meteorological
uncertainty was important.
Factors affecting differences between field-derived
and AP-42 EFs
Differences between AP-42 and our estimates of Eash are due
entirely to the AP-42 estimates of fugitive dust from graders
driving over ash (eq 3). This is because the average contribution
to total fugitive fly ash emissions of grading operations—using
the AP-42 formulation for vehicles on unpaved industrial sur-
faces—is >99% of the total of estimated dumping (eq 1) and
grading emissions. Uncertainty in applying AP-42 eqs 1 and 3
was computed based on expected uncertainty in ash moisture
content(M) of10-20%,silt content (S)offlyash(10%), grader
operating times (20% error), and wind speed (based on two
tower level options). The mean of the AP-42 PMc Eash values
that included parameter uncertainty was nearly identical to that
listed in Table1, but the range expandedto 156–443 gMg
1,the
median increased to 242 g Mg
1, and the standard deviation
increased to 62 g Mg
1. These results illustrate that uncertainty
inherent in the AP-42 approach is capable of producing greater
variability in Eash than is implied by using singlevalues for input
parameters, but the AP-42 method is unlikely to produce sig-
nificantly lower values more in line with those computed using
our field study approach.
The apparent overestimate of fugitive emissions from slow
vehicles on unpaved industrial surfaces motivated us to inves-
tigate the relative merits of the two AP-42 EFs for unpaved
surfaces (eqs 3 and 4) at an alternate location at the plant.
The two unpaved roads near Site 2 offered that opportunity.
Dust emission factors (Eroad) for the two unpaved roads were
determined based on data (particle concentration and nephel-
ometer) from Site 2, meteorological measurements, line
source dispersion calculations (conditions summarized in
Table 3), and various assumptions described in Supplemental
Information. Also summarized there are the influences of
these assumptions, the road characteristics and the behavior
of the road dust plumes. Results of the Eroad analysis based
on observations are summarized in Table 4. Coarse mass
Eroad—denoted EobroadðPMcÞ—was found to average 90 g per
vehicle kilometer traveled (VKT
1) for both roads but with
emissions from the seldom-traveled gravel/dirt access road
averaging nearly 4 times greater than the more frequently
used clay-surfaced berm road. Individual event values ranged
from near zero to more than 600 g VKT
1. However, the
distribution of Eob
roadðPMcÞ is skewed toward small values with
a median emission factor of 44 g VKT
1. Values of
Eob
roadðPM2:5Þ are much smaller, averaging 4 g VKT
1 with
a median of around 2 g VKT
1.
Emission factors computed using AP-42 formulations (eqs 3
and4yieldingEir and Epr)aresummarizedinTable4for thesame
events. Less traffic at industrial sites is expected to contribute to
higherlevels ofsurface silt. Also, industrialsitetrafficisexpected
to move more slowly, such that vehicle speed is unlikely to be
important. Intermittent precipitation can be expected to condition
public road surfaces in ways not expected for industrial roads
(unless the latter are watered as is now standard practice at many
sites, including the berm road). This requires using surface moist-
ure content when estimating Epr with eq 4. Averages of road
surface parameters and estimated EFs are listed in Table 4 for
the 42 road emission events analyzed. Field data indicated that the
access road EFs were higher than those for the berm road, con-
sistent with the public road formula (eq 4) but not the industrial
road formula (eq 3). All methodologies agree that PM2.5 EFs are
much lower than PMc EFs. Also,Eob
road was less than Eir and Epr
for both roads. Even though the berm and access roads were not
composed of fly ash, the large differences between Eob
road and Eir
Table 3.Average parameters used to compute dispersion of fugitive road dust at
Site 2
Parameter Mean
U, m sec
1 2.0
x,m 29
sw, m sec
1 0.31
Kz,m2 sec 1 0.9
Plume depth
a,m 6
Note:aEquals 2sz.
Mueller et al. / Journal of the Air & Waste Management Association 63 (2013) 806–818816
suggest an explanation for why field-derived values of Eash were
so much lower than their AP-42 counterparts using the industrial
road formulation.
Conclusion
Five months of measurements at the TVAColbert fossil plant
captured a number of hours when meteorological conditions
coincided with activities that produced fugitive particulate emis-
sions. A methodology for removing local source effects on
measured particle concentrations enabled an estimate of fly ash
fugitive particulate emission rates and emission factors. A sepa-
rate set of brief (1–3 min) periods was analyzed to indepen-
dently estimate fugitive road dust emission factors. Results from
both source types were compared with EFs derived using for-
mulations in the EPA AP-42 emissions handbook.
The flyash disposal process at Colbert requires that “dry”ash
(although the ash is not totally free of water this process is
distinctly different from the “wet”process in which ash is
pumped in a water slurry to a wet ash disposal pond) be dumped
from the bed of a haul truck and then immediately spread into a
layer of uniform thickness before the next load arrives. Multiple
ash loads are usually deposited during peak work hours.
Downwind measurements of hourly particle concentrations
appear to respond as expected to this activity. However, atmo-
spheric variability drives plume dynamics in a way that makes it
difficult to measure fugitive plumes on a consistent basis. Also,
duringthefieldstudysomeeventsproducedsuchlowdownwind
concentrations that fugitive fly ash plumes could not be detected
withhighconfidence abovethebackgroundlevels.Thisisduein
part to atmospheric variability and in part to the measurement
sensitivity of the monitoring equipment. Previous studies of this
type relied on even coarser measurement methods (dustfall col-
lectors and high-volume particle samples operated for extended
periods of time very near the source). It is difficult to conduct
close-proximity measurements in an operational setting such as
the one at Colbert. To our knowledge this study represents the
first attempt toconduct a fugitivedust measurement campaign at
an operating fly ash disposal area. The study data integrate
emissions over the multiple operations involved in fly ash
disposal, rather than relying on parameterizations of individual
processes (i.e., dumping and grading). In addition, this study
measured both coarse and fine particles at 1 hr time resolution,
thereby minimizing the uncertainties introduced when longer
averaging times are involved and even more atmospheric varia-
bility comes into play. Data from this study represent a fresh
examination of the fugitive emissions formulations that have
been used for several decades without being reevaluated.
The picture that emerges is that AP-42 formulations produce
EFssignificantlyhigherthanthosederivedfromthecurrentstudy.
When applied to ash disposal the AP-42 formulations result in a
narrowrangeofEFs,evenwhenthe uncertaintyoffactors likeash
moisture content and the representativeness of the formulations
for high silt content materials (such as fly ash) are considered. By
contrast, the natural variability of the atmosphere produces EFs
thatcoveramuchwiderrangeofvalues,withmostclusteredinthe
lowerrangeofvaluesbutafewspreadouttoformalonguppertail
to the distribution. The selection of a “best”metric is perhaps
debatable under these circumstances, but given that EFs are typi-
cally applied to produce long-term (especially annual) estimates
of total emission it seems that use of a mean or median value is
appropriate. The mean is more conservative than the median due
to the distribution skewness, but even so the EFs derived here
remain quite low when compared to equivalent AP-42 EFs.
It is important to remember that EFs for fly ash disposal are
strongly influenced by the AP-42 formulation (eq 3) for fugitive
emissions from vehicles moving over unpaved surfaces. This
formulation is distinctly different from the one recommended for
use on unpaved public roads (eq 4) in which vehicle speed and
surface moisture content are treated explicitly. Thus, the compar-
isonoffugitive road EFs fromboth AP-42 and field data supports
our belief that the AP-42 industrial unpaved road EF formulation
is biased high for a surface composed mostly of silt-sized parti-
cles. Results from this study suggest that coarse particle EFs for
unpavedsurfacesaremuchlessthanthosederivedusingeitherthe
industrial or public road formulation. Fine particle (PM2.5)EFs
determined by the present study are also somewhat lower than
those produced using either AP-42 formulation.
Reasons why EFs derived from AP-42 formulations are
greater than those derived by this study are not obvious, but a
Table 4.Data, road conditions, and mean fugitive road dust emission factors
a
Method Road
Sample
size
Average vehicle speed
(m sec
1)
Average vehicle
weight (Mg)
Sb
(%)
Mc
(%)
PMc EFd
(g VKT
1)
PM2.5 EFd
(g VKT
1)
Observed Berm 36 N/A N/A N/A N/A 64 (69) 3 (3)
Access 6 N/A N/A N/A N/A 245 (132) 12 (6)
AP-42:
industrial
Berm 36 N/A 22 13 N/A 974 108
Access 6 N/A 2 15 N/A 388 43
AP-42:
public
Berm 36 4.5 N/A 13 12 163 18
Access 6 7.5 N/A 15 1 363 40
Notes:a“N/A”(notapplicable)isshowntoindicatethataparameterwasnotusedintheemissionfactorcalculation.bEstimatedsiltcontentbasedoninformationinAP-
42for roadtypeandknowledgeofthebermroadconstructionschedule.
cEstimatedmoisturebasedoninformationinAP-42for roadtypeandbasedonwateringof
berm road.
dValues in parentheses represent emission factors based on a correction for vehicle wake effects.
Mueller et al. / Journal of the Air & Waste Management Association 63 (2013) 806–818 817
number of reasons can be contemplated. The EF formulation for
dropping operations is based on materials that were far drier than
the moisture content of the fly ash. The EF for vehicles driving
on unpaved surfaces at industrial sites was based on data for
surfaces with silt content far below what is appropriate for fly
ash, and most data were for vehicles traveling at speeds well
abovethose involved ingradingflyash. Contemporarymeasure-
ment technology is capable of providing hourly particle concen-
trations,whereasolder measurements utilizedhigh-volumefilter
measurements that required sampling periods longer than 1 hr
and were incapable of detecting short-term emission rate varia-
tions. Long sampling periods necessarily include variable
meteorology, and that implies the possibility of a highly variable
relationship between emissions source and downwind measure-
ment locations while measurements are made. It is not clear how
this might affect derived emission factors, but it is not surprising
that AP-42 formulations provide emission estimates that do not
match closely with those measured using modern techniques.
It is interesting to compare the relationship between PM2.5
and PM10 for the different sources and emission factor deriva-
tions. The ratio of PM2.5 to PM10 in fugitive fly ash plumes was
observed to be 9%, which compares very well with the ratio of
10% that is inherent in the AP-42 formulations. However, the
fraction of PM10 that is PM2.5 in fugitive road dust was
observed to be only 4%, which is considerably lower than the
10% ratio in the AP-42 results. The ratio of PM2.5/PM10 of 0.1
in the AP-42 EFs is consistent with the ratio reported by a
fugitive dust study of western sources (WRAP, 2005). That
same report also mentioned that there was some evidence the
ratio might be closer to 0.05 and that would be very similar to
the 0.04 ratio reported here.
Finally, fly ash is the particulate matter collected by electro-
static precipitators (ESPs) similar in design to controls used on
most large combustion sources. The small size of the particles
(all being smaller than “silt”or 75 µm in diameter) is character-
istic of ESPs. The AP-42 emissions handbook (U.S. EPA, 1995,
Tables 1.1-6 through 1.1-8) differentiates the emitted size dis-
tributions of particles from coal-fired boilers based on boiler
type and particulate control technology. Colbert has dry bottom
pulverized coal boilers with ESP controls, and these are the
primary determinants for fly ash size based on U.S. EPA gui-
dance. Therefore, dry fly ash fugitive disposal EFs estimated
from this study should be representative of conditions at other
plantswith drybottom pulverized boilers and ESPs.Other boiler
types (especially cyclone boilers) and plants with baghouse
controls likely produce fly ash with somewhat different charac-
teristics (and with potentially different fly ash EFs), but plants of
this type are less common in the United States.
Acknowledgment
The authors are grateful for the support provided by Colbert
plant personnel in conducting the field measurements for this
study. Funding for this work was provided by the Electric Power
Research Institute and the Tennessee Valley Authority.
References
Cimorelli,A.J.,S.G.Perry,A.Venkatram,J.C.Weil,R.J.Paine,R.B.Wilson,R.F.
Lee, W.D. Peters, R.W. Brode, and J.O. Paumier. 2004. AERMOD:
Description of Model Formulation. EPA-454/R-03-004. Research Triangle
Park, NC: U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards.
Code of Federal Regulations, 2011. Title 40, Sections 70.2. Washington, DC:
Office of the Federal Register, Government Printing Office.
Code of Federal Regulations, 2008. Title 51, Section 166. Washington, DC:
Office of the Federal Register, Government Printing Office.
Cowherd, C., Jr., K. Axetell, Jr., C.M. Guenther, and G.A. Jutze. 1974.
Development of Emission Factors for Fugitive Dust Sources. Midwest
Research Institute report to the EPA. EPA-450/3-74-037. http://www.epa.
gov/nscep/index.html
Dyck,R.J.,andJ.J. Stukel.1976.Fugitive dustemissionsfromtruckson unpaved
roads.Environ. Sci. Technol. 10: 1046–48. doi:10.1021/es60121a015
U.S. Environmental Protection Agency. 1995 [with subsequent updates].
Compilation of Air Pollutant Emission Factors—Volume I: Stationary Point
and Area Sources, AP-42, Fifth Edition. Research Triangle Park, NC: Office
of Air Quality Planning and Standards. http://www.epa.gov/ttn/chief/ap42
(accessed 12 March 2013).
U.S. Environmental Protection Agency. 2004.User’s Guide for the AMS/EPA
Regulatory Model—AERMOD, EPA-454/B-03-001. Research Triangle Park,
NC: Office of Air Quality Planning and Standards.
Friedlander, S.K. 2000.Smoke, Dust, and Haze, 130–139. New York, NY:
Oxford University Press.
Gillies,J.A.,V.Etyemezian,H.Kuhns,D.Nikolic,andD.A.Gillette.2005.Effect
of vehicle characteristics on unpaved road dust emissions.Atmos. Environ.
39:2341–47. doi:10.1016/j.atmosenv.2004.05.064
Hanna, S.R., G.A. Briggs, and R.P. Hosker, Jr. 1982.Handbook of Atmospheric
Diffusion. Washington, DC: U.S. Department of Energy. DOE/TIC-11223,
25–34.
Hoover, J.M. 1973.Surface Improvement and Dust Palliation of Unpaved
Secondary Roads and Streets. Report on ERI Project 856-S. Ames:
Engineering Research Institute, Iowa State University.
Jackson, P.S, and J.C.R. Hunt. 1975. Turbulent wind flow over a hill,
Q. J. R. Meteorol. Soc. 101:929–55. doi:10.1002/qj.49710143015
Watson, J.G., J.C. Chow, L. Chen, X. Wang, T.M. Merrifield, P.M. Fine, asnd K.
Barker. 2011. Measurement system evaluation for upwind/downwind sam-
pling of fugitive dust emissions.Aerosol Air Qual. Res. 11. doi:10.4209/
aaqr.2011.03.0028
Western Regional Air Partnership. 2005. Analysis of the Fine Fraction of
Particulate Matter in Fugitive Dust—Final Report. Midwest Research
Institute report for the Western Governors’Association Western Regional
Air Partnership. http://www.epa.gov/ttnchie1/ap42/ch13/related/mri_final_
fine_fraction_dust_report.pdf
Western Regional Air Partnership. 2006.WRAP Fugitive Dust Handbook, chap.
6. Western Governors’Association, WGA contract 30204-111. http://www.
wrapair.org/forums/dejf/fdh/content/fdhandbook_rev_06.pdf
About the Authors
Stephen Mueller,Jonathan Mallard, and Qi Mao perform environmental
studies for the Tennessee Valley Authority.Stephanie Shaw (Electric Power
Research Institute) is a senior project manager for air quality studies.
Mueller et al. / Journal of the Air & Waste Management Association 63 (2013) 806–818818
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