1 

Memorandum 

TO: David Jacobson, USEPA and Heidi Nelson-Ries, Stratus Consulting 

FROM: Dick Richards, Matthew Cleaver, and Nancy Holt, SAIC

DATE: June 15, 2012

SUBJECT: Review and Evaluation of 40 CFR Part 98 CO2 Emission Factors for EPW07072 TO 45 

On April 24, 2012, SAIC received technical direction from Stratus Consulting to conduct the following 

subtasks: 

• Review Tables C-1, MM-1, MM-2, NN-1, and NN-2 for consistency. 

• Review Table C-1 for other errors. 

• Identification of new sources (and new emission factors) for undocumented emission factors. 

• Reviewing JIRA tickets for updates to emission factors for any subpart. 

• Reviewing JIRA tickets for other equation or rule discrepancies. 

This memorandum summarizes SAIC’s findings for this effort. 

1. Review of CO2 Emission Factors and Other Characteristics of Fuels Identified in 40 CFR Part 

98 

SAIC reviewed the sources for emission factors and other characteristics for each fuel listed in the 

following tables in 40 CFR Part 98: 

• Table C-1 – Default CO2 Emission Factors and High Heat Values for Various Types of Fuel 

o Emission factor and heating value 

• Table MM-1 – Default Factors for Petroleum Products and Natural Gas Liquids 

o Density and carbon share (% Mass) 

• Table MM-2 – Default Factors for Biomass-Based Fuels and Biomass 

o Density and carbon share (% Mass) 

• Table NN-1 – Default Factors for Calculation Methodology 1 of This Subpart (NN) 

o Emission factor and heating value 

• Table NN-2 – Lookup Default Values for Calculation Methodology 2 of This Subpart (NN) 

o Emission factor 

If the source for an emission factor, or other characteristic, was undocumented, SAIC attempted to 

locate the source of the factor. If the current source could not be established, SAIC reviewed existing 

literature to either corroborate the factor or develop an alternate factor and source. In addition SAIC 

reviewed the characteristics for errors and other inconsistencies. 
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SAIC identified the following issues for the fuel characteristics listed in 40 CFR part 98: 

Table C-1 

• There was no source documented for either an emission factor or heating value for the 

following fuels in Table C-1: 

o Coke (from coal) – emission factor 

o Used Oil – heating value 

o Natural Gasoline – emission factor 

o Heavy Gas Oils – heating value 

o Municipal Solid Waste – heating value 

o Tires – heating value 

o Biogas (Captured methane) – heating value 

o Rendered Animal Fat – heating value 

o Vegetable Oil – heating value 

• The HHV for Solid Byproducts (25.83 MMBtu/short ton) was judged to be too high for a 

biomass material. 

Table MM-1

• No documentation for conditions associated with the density value for still gas. 

Table MM-2 

• No issues 

Table NN-1 and NN-2 

• The sources of factors for fuels in Table NN-1 and NN-2 are all assumed to be based directly 

from the corresponding fuels in Table C-1. 

Section 2 of this memorandum provides a detailed summary of our research efforts and findings for 

these fuels. Attachment A to this memorandum provides a summary of the values and sources for the 

HHV and emission factor listed for each fuel in the above tables. Attachment B summarizes the 

recommended updates to emission factors and heating values along with the corresponding source. 

2. Identification of New Sources and New Emission Factors for Undocumented CO2 Emission 

Factors 

The following sections summarize SAIC’s findings and recommendations regarding revisions to the fuel 

characteristic data presented in 40 CFR part 98. 

 
3 

2.1 Densities and HHVs for Liquid Petroleum Gases (LPG) 

Background: The primary value being assessed in this effort is the higher heating value (HHV), defined 

as the energy associated with the complete combustion of a substance, and inclusive of the energy 

associated with vaporization of the water in the reaction. The measurement involves heating the 

reactants from, and returning the products to, a temperature of 25°C. HHVs are generally measured in 

energy per unit of substance, such as Btu/lb, and can be calculated by multiplying the heat of 

combustion by the molecular weight of the compound, accounting for all necessary unit conversions. 

In 40 CFR Part 98 Table C-1, the HHV it is reported per unit of volume, i.e., MMBtu/gal, as opposed to

the more common per unit of mass approach. In order to express HHVs in a per unit of volume manner, 

a knowledge of the heat of combustion, the molecular weight and the liquid density of the compound 

under a desired set of temperature and pressure conditions is required. Since the LPGs presented in 40 

CFR Part 98 are gases under standard conditions (considered here to be 60°F and 1 atm), the selected 

densities must be associated with a different set of specified conditions to use units based on a liquid 

measure. This can be done by reporting the values at: (i) 60°F and their corresponding saturation 

pressures; (ii) 1 atm and their corresponding saturation temperature; or (iii) any set of temperature and 

pressure conditions under which the substance is a liquid. 

Findings: In order to assess the accuracy of the HHVs currently presented in 40 CFR Part 98, we 

compared them, where possible, with the values published by other well-established sources. A 

comparison of the LPG HHVs that were available on a per mass basis is presented in Table 1. 

Table 1: Comparison of LPG HHVs on a Per Unit Mass Basis and the Molecular Weight of Each Fuel 

Fuel 

HHV 

DOE* 

(Btu/lb) 

HHV 

NIST** 

(Btu/lb) 

HHV 

Guthrie*** 

(Btu/lb) 

Molecular Weight 

(g/mol) 

Butane 21,157 21,294 -- 58.1 

Isobutane 21,108 21,231 -- 58.1 

Isobutylene 20,739 20,689 20,618 56.1 

Propane 21,597 21,636 -- 44.1 

Propylene -- 21,016 20,934 42.1 

Ethane -- 22,293 -- 30.1 

Ethylene -- 21,592 -- 28.1 

Butylene**** -- 20,778 20,671 56.1 

 * Data from U.S. Department of Energy, Hydrogen Analysis Resource Center 

** Data obtained from NIST Webbook by using the most recent Heat of Combustion Value presented and converted to Btu/lb 

using the molecular weight 

*** Guthrie, Petroleum Products Handbook, 1960 

**** Average of 3 isomers: 1-Butene, trans-2-Butene, and cis-2-Butene 

A comparison of the density values reported from the sources in Table 1 is presented in Table 2a. 

 
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Table 2a: Comparison of Density Values at Saturation Pressure 

Fuel 

Density 

DOE 

(lb/gal) 

Density 

NIST 

(lb/gal) 

Density 

Guthrie 

(lb/gal) 

Temp not quoted* 60°F/15.5°C 68°F/20°C 77°F/25°C 60°F/15.5°C 

Butane 4.88 4.87 4.83 4.78 4.86 

Isobutane 4.67 4.69 4.65 4.60 4.69 

Isobutylene 4.97 -- -- -- 4.99 

Propane 4.23 4.23 4.17 4.11 4.22 

Propylene -- 4.34 4.28 4.21 4.34 

Ethane -- 2.97 2.83 2.63 3.11 

Ethylene** -- -- -- -- -- 

Butylene*** -- -- -- -- 5.10 

* By comparison, DOE temp appears to be 60°F/15.5°C. 

** Critical temperature for ethylene is 9.20°C, i.e., there is no liquid/gas phase boundary beyond this temperature. 

*** Average of 3 isomers: 1-Butene, trans-2-Butene, and cis-2-Butene

The difference in the density values obtained from NIST and Guthrie, both at 60°F and saturation 

pressure, are notable for ethane. In addition, only Guthrie provides a density value for butylene at 60°F 

and saturation pressure. 

A comparison of the LPG densities from Subpart MM with those from NIST is presented in Table 2b. 

Table 2b: Comparison of Subpart MM Densities with NIST Data at Various Conditions. 

Fuel 

Subpart MM Density* NIST 

(metric tons/bbl) (lbs/gal)** (lb/gal) 

Sat P, unless otherwise noted 1 atm -77°F 77°F 

[temp F] [temp °F] [Sat. T °F] [Sat P atm] [Sat P atm] 

Ethane 0.0866 [-128]*** 4.55 [-128) 4.54 [-128] 4.23 [3.66] 2.63 [41.35] 

Ethylene* 0.0903 [-155]*** 4.74 [-155] 4.74 [-155] 4.17 [7.29] -- 

Propane 0.0784 [77] 4.12 [77] 4.84 [-44] 5.02 [0.41] 4.11 [9.40] 

Propylene 0.0803 [77] 4.21 [77] 5.08 [-54] 5.21 [0.53] 4.21 [11.43] 

Butane 0.0911 [77] 4.78 [77] 5.02 [31] 5.52 [0.05] 4.78 [2.40] 

Butylene 0.0935 [77] 4.91 [77] -- -- -- 

Isobutane 0.0876 [77] 4.60 [77] 4.96 [11] 5.38 [0.09] 4.60 [3.46] 

Isobutylene 0.0936 [77] 4.91 [77] -- -- -- 

* By comparing the values from Subpart MM and NIST, the reported temperature conditions should be 77°F/25°C, as stated in 

this table, and not -77°F/-25°C, as stated in the Supplementary Information for Subpart MM as presented on the EPA 

Greenhouse Gas Reporting Program Resources website.

** Converted based on 1 bbl = 42 US gallons; considered to be a v/v conversion that applies to all LPGs. Conversion is defined 

in 40 CFR Part 98. 

*** 1 atm

A comparison of the Subpart MM density values with the available NIST values at 77°F and saturation 

pressure show that they are, for all intents and purposes, the same. The ethane and ethylene values at -

128°F and -155°F, respectively, and 1 atm also match, for all intents and purposes, what is found in the 

NIST Webbook. 
5 

A comparison of the HHVs per unit volume (Btu/gal) from the same sources as in Table 1 is presented in

Table 3. 

Table 3: Comparison of LPG HHVs on a Per Unit Volume Basis 

Fuel 

HHV Calculated 

NIST* 

(Btu/gal) 

HHV 

DOE* 

(Btu/gal) 

HHV 

Guthrie* 

(Btu/gal) 

Butane 103,701 103,220 103,047 

Isobutane 99,573 98,560 99,097 

Isobutylene -- 103,010 102,964 

Propane 91,520 91,420 91,044 

Propylene 91.209 -- 90,891 

Ethane 65,987 -- 69,433 

Ethylene** -- -- -- 

Butylene*** -- -- 105,334 

*Conditions for comparison are 60°F and saturation pressure (NIST was calculated at 60°F, DOE is presumed to be 60°F and 

saturation pressure based on comparison with NIST and Guthrie cites 60°F and saturation pressure). 

** Critical temperature for ethylene is 9.20°C, i.e., there is no liquid/gas phase boundary beyond this temperature. 

*** Average of 3 isomers: 1-Butene, trans-2-Butene, and cis-2-Butene 

Note: The California Air Resources Board (CARB) adopted 18.5x109 Joules/cubic meter at the HHV for ethane, which converts to 

66,375 Btu/gal. 

A comparison of the HHVs per unit volume (MMBtu/gal) from the same sources as in Table 1 with 

Subpart C is presented in Table 4. 

Table 4: Comparison of LPG HHVs on a Per Unit Volume Basis with Subpart C 

Fuel 

HHV Calculated 

NIST* 

(MMBtu/gal) 

HHV 

DOE* 

(MMBtu/gal) 

HHV 

Guthrie* 

(MMBtu/gal) 

HHV 

Subpart C 

(MMBtu/gal) 

Butane 0.104 0.103 0.103 0.101 

Isobutane 0.100 0.099 0.099 0.097 

Isobutylene -- 0.103 0.103 0.103 

Propane 0.092 0.091 0.091 0.091 

Propylene 0.091 -- 0.091 0.091 

Ethane 0.066 -- 0.069 0.069 

Ethylene** -- -- -- 0.100 

Butylene*** -- -- 0.105 0.103 

*Conditions for comparison are 60°F and saturation pressure (NIST was calculated at 60°F, DOE is presumed to be 60°F based 

on comparison with NIST and Guthrie cites 60°F and saturation pressure). 

** Critical temperature for ethylene is 9.20°C, i.e., there is no liquid/gas phase boundary beyond this temperature. 

*** Average of 3 isomers: 1-Butene, trans-2-Butene, and cis-2-Butene 

Note: The California Air Resources Board (CARB) adopted 18.5x10^9 Joules/cubic metre at the HHV for ethane, which converts 

to 0.066 MMBtu/gal. 

Recommendations: 

Density: With regard to the density, the most common approach is to report it at a standard 

temperature of 60 °F and the corresponding saturation pressure for the given compound. However, we 
6 

note that this is not possible for ethylene, since it cannot be liquefied above 48.6°F (9.2°C). As a result, 

we recommend selecting a value determined at slightly under the critical temperature, such as 41°F 

(5°C) and the corresponding saturation pressure, to report the density for ethylene (i.e., 2.58 lb/gal in 

the NIST Webbook). 

The recommended final density values to use for calculating per unit volume HHVs for Table C-1 are 

shown in Table 5. The values are the average of the existing values in Table 2a at 60°F and saturation 

pressure, with the exception of ethylene. A comparison with Subpart MM is not shown due to 

differences in temperature and pressure. 

Table 5: Proposed Subpart C LPG Density Values at 60°F and Saturation Pressure, Unless Otherwise 

Noted 

Fuel Density (lb/gal) 

Butane 4.87 

Isobutane 4.68 

Isobutylene 4.98 

Propane 4.23 

Propylene 4.34 

Ethane 3.04 

Ethylene* 2.58 

Butylene 5.10 

*Conditions: 41.0°F (5 °C) and saturation pressure 

HHV: Using the per unit mass HHV from NIST of 21,592 Btu/lb for ethylene in Table 1 and the density in 

Table 5, this give a per unit volume HHV of ethylene of 55,707 Btu/gal or 0.058 MMBtu/gal at 41.0°F (5

C) and saturation pressure. This varies substantially from the current value in Subpart C of 0.103, 

though it is unclear how this value was derived at 60°F, since ethylene cannot be liquefied at this 

temperature no matter what the pressure is applied. 

The recommended final per unit volume HHVs for Table C-1 of 40 CFR Part 98, subpart C are shown in 

Table 6, along with the most recent values. The values are the average of the existing values in Table 4 

and correspond to conditions of 60°F and saturation pressure, with the exception of ethylene. 

Table 6: Proposed Subpart C LPG HHVs at 60°F and Saturation Pressure, Unless Otherwise Noted, and 

the Most Recent Subpart C Values 

Fuel 

Proposed HHVs 

(MMBtu/gal) 

Subpart C HHVs 

(MMBtu/gal) 

Subpart NN HHVs* 

(MMBtu/gal) 

Butane 0.103 0.101 0.101 

Isobutane 0.099 0.097 0.097 

Isobutylene 0.103 0.103 -- 

Propane 0.091 0.091 0.091 

Propylene 0.091 0.091 -- 

Ethane 0.068 0.069 0.096 

Ethylene** 0.058 0.100 -- 

Butylene 0.105 0.103 -- 

* Converted from MMBtu/bbl from Table NN-1 using 1 bbl=42 gal 

** Conditions: 41°F (5°C) and saturation pressure 

Note: At minimum, the HHV for ethane should be updated in Subpart NN. 
7 

Table MM-1. §98.394(a)(1)(iii) states: “For products that are liquid at 60 degrees Fahrenheit and one 

standard atmosphere, all measurements of quantity shall be temperature-adjusted and pressure-adjusted 

to these conditions. For all other products, reporters shall use appropriate standard conditions specified in 

the standard method; if temperature and pressure conditions are not specified in the standard method or 

if a reporter uses an industry standard practice to determine quantity, the reporter shall use appropriate 

standard conditions according to established industry practices.” 

Since none of the LPG components included in Table MM-1 are liquids at 60°F and 1 atmosphere, 

reporters must use, in determining fuel quantities, appropriate standard conditions that are either 

specified in a standard method or consistent with established industry practice. To assist reporters in 

obtaining the most accurate results when using the defaults for LPG components in Table MM-1, SAIC 

recommends the addition of the following footnotes to the table that will allow these users to adjust their 

volumes to match the conditions of the default values: 

• For ethane and ethylene: “Conditions for density and emission factor are 1 atmosphere and 

saturation temperature.” 

• For all other LPGs: “Conditions for density and emission factor are 25°C (77°F) and saturation 

pressure.” 

2.2 Emission Factor for Coal Coke 

The existing emission factor for coal coke in Table C-1 is 102.04 kg CO2/MMBtu (27.85 Tg C/QBtu 

converted to CO2 using 3.664 as the conversion factor). This factor appears to have been sourced from 

the EPA GHG Inventory 1990-2005, Annex 2. However, SAIC believes that this is an incorrect emission 

factor for coal coke as this factor is identical to the factor for petroleum coke in the EPA GHG Inventory. 

Coke from coal has similar, but not identical, characteristics as petroleum coke. The following are 

definitions of petroleum coke and coal coke from the Energy Information Administration (EIA): 

Petroleum Coke: A residue high in carbon content and low in hydrogen that is the final product 

of thermal decomposition in the condensation process in cracking. This product is reported as 

marketable coke or catalyst coke. The conversion is 5 barrels (42 U.S. gallons each) per short 

ton. Coke (petroleum) has a heating value of 6.024 million Btu per barrel (0.143 

MMBtu/gallon).1 

Coal Coke: A solid carbonaceous residue derived from low-ash, low-sulfur bituminous coal from 

which the volatile constituents are driven off by baking in an oven at temperatures as high as 

2,000°F so that the fixed carbon and residual ash are fused together. Coke is used as a fuel and 

as a reducing agent in smelting iron ore in a blast furnace. Coal coke has a heating value of 24.8 

MMBtu/short ton.2

SAIC performed an Internet search to identify emission factors for coal coke as documented in existing

literature. Table shows the emission factors for coal coke from six different sources: 

 

1

 EIA Monthly Energy Review, 2012. http://205.254.135.7/totalenergy/data/monthly/pdf/sec13.pdf 

2

 EIA Monthly Energy Review, 2012. http://205.254.135.7/totalenergy/data/monthly/pdf/sec13.pdf 
8 

Table 7. Emission Factors for Coal Coke from Various Sources 

Emission Factor

(kg CO2/MMBtu) Source Notes 

113.67 EPA GHG Inventory 1990-2009, Annex 4, Table A-251. 

113.95 NRCAN. http://oee.nrcan.gc.ca/industrial/technicalinfo/benchmarking/canadian-steel-industry/6602 

112.96 IPCC 2006 Guidelines, Volume 2. http://www.ipccnggip.iges.or.jp/public/2006gl/vol2.html Listed as "Coke Oven 

Coke and Lignite 

Coke" 

114.12 TSU Internship Report, IPCC NGGIP / IGES, National GHG Emission 

Factors in Former Soviet Union Countries. http://www.ipccnggip.iges.or.jp/tsu/intern_report/TSU_InternshipReportOlga.pdf 

114.12 IEA, CO2 EMISSIONS FROM FUEL COMBUSTION. 2011. 

http://wds.iea.org/wds/pdf/documentation_co2_2011.pdf 

Listed as "Coke Oven 

Coke" 

113.45 F.H. Reed, H.W. Jackman, O.W. Rees, G.R. Hohe, and P.W. Henline, Use 

of Illinois Coal for Productions of Metallurgical Coke, Illinois State 

Geological Survey, Bulletin No. 71, 1947. 

Average of 182 sample 

runs 

Based on this search, SAIC believes that the emission factor for coal coke should be in the range of 113-

114 kg CO2/MMBtu, significantly higher than the current factor of 102.04 kg CO2/MMBtu. SAIC suggests 

an emission factor for coal coke of 113.67 kg CO2/MMBtu, based on the carbon coefficient for coke in

the EPA GHG Inventory 1990-2009, Annex 4, Table A-251. We are suggesting using the 1990-2009 

version of the Inventory instead of the latest 2010 version due to an apparent discrepancy in the 

emission factor for coal coke in the 2010 version. Annex 4, Table A-255 “2010 Potential CO2 Emissions,” 

lists a carbon coefficient for “Coke” of 25.61 Tg C/QBtu (93.90 kg CO2/MMBtu). However, the carbon 

coefficient for “Coke” in the same table for previous years (2005 - 2009) is listed as 31 Tg C/QBtu (113.67 

kg CO2/MMBtu). The current (2010) coefficient is identical to the coefficient for “Industrial Coking Coal” 

in Annex 2, Table A-35 “Key Assumptions for Estimating CO2 Emissions.” This coefficient was developed 

by SAIC based on coal samples from the USGS and represents the coefficient for coal used to make coke,

not the coke itself. However, it is our assumption that the fuel listed in Table A-255 as “Coke” is 

referring to the actual coke, not the coal used to make coke, and therefore should have a carbon 

coefficient of 31 Tg C/QBtu, as in previous years. In addition, Annex 2, Section 2.1 “Methodology for

Estimating Emissions of CO2 from Fossil Fuel Combustion,” page A-29, contains the following description 

of coking coal: “Coking coal, also called ‘coal coke,’ is used as a raw material (specifically as a reducing 

agent) in the blast furnace process to produce iron and steel, lead, and zinc ...” This is misleading as the 

terms “coking coal” and “coal coke” are typically used to describe two different materials. “Coking coal” 

is the raw material (usually low-ash, low-sulfur bituminous coal) used to make coke, and “coal coke” is 

the solid carbonaceous residue that remains after the coking coal is baked in an oven. 

 
9 

Table and Table show the carbon coefficients for coal by use and coal by rank in the GHG Inventory 

from 2005 to 2010. The adjustment of the carbon coefficient for Industrial Coking Coal in Annex 2 

appears to be correct, as this is a more appropriate factor for coal used to make coke. However, the 

change in coefficient for “Coke” in Annex 4 in 2010 appears to be an error. 

 
10 

Table 8. Carbon Coefficients (Tg C/QBtu) for Coal By Use in EPA GHG Inventory 2005 through 2010 

(Annex 2) 

Fuel Type 2005 2006 2007 2008 2009 2010 

Residential Coal 26.00 26.00 26.00 25.71 25.71 25.71 

Commercial Coal 26.00 26.00 26.00 25.71 25.71 25.71

Industrial Coking Coal 31.00 31.00 31.00 25.61 25.61 25.61 

Industrial Other Coal 25.63 25.63 25.63 25.82 25.82 25.82 

Electric Power Coal 25.76 25.76 25.76 26.05 26.05 26.05 

Table 9. Carbon Coefficients (Tg C/QBtu) for Coal by Rank in EPA GHG Inventory 2005 through 2010 

(Annex 4) 

Fuel Type 2005 2006 2007 2008 2009 2010 

Anthracite Coal 28.26 28.26 28.26 28.28 28.28 28.28 

Bituminous Coal 25.49 25.49 25.49 25.44 25.44 25.44 

Sub-bituminous Coal 26.48 26.48 26.48 26.50 26.50 26.50 

Lignite 26.30 26.30 26.30 26.65 26.65 26.65 

Coke 31.00 31.00 31.00 31.00 31.00 25.61 

Unspecified 25.34 25.34 25.34 25.34 25.34 25.34 

Recommendation: SAIC recommends updating the emission factor for coal coke in Table C-1 from 

102.04 kg CO2/MMBtu to 113.67 kg CO2/MMBtu, based on the carbon coefficient for coke (31 Tg 

C/QBtu) in the EPA GHG Inventory 1990-2009, Annex 4, Table A-251. 

2.3 HHV for Used Oil 

Used oil means petroleum-derived or synthetically-derived oil whose physical properties have changed 

as a result of handling or use, such that the oil cannot be used for its original purpose. Used oil consists 

primarily of automotive oils (e.g., used motor oil, transmission oil, hydraulic fluids, brake fluid, etc.) and 

industrial oils (e.g., industrial engine oils, metalworking oils, process oils, industrial grease, etc).3

The current heating value for used oil in Table C-1 is 0.135 MMBtu/gallon, however, the source of this

heating value is not known. In order to verify this heating value SAIC performed an Internet search to 

identify emission factors for used oil as documented in existing literature. 

 

 

3

 EPA GHGRP, § 98.6 Definitions. 
11 

Table shows the heating values for used oil from five different sources. The mean heating value of all 

identified sources is 0.140 MMBtu/gallon, which is slightly higher than the current value of 0.135 

MMBtu/gallon. 
12 

Table 10. Heating Value for Used Oil from Various Sources 

Heating Value 

Btu/gallon 

Heating Value 

MMBtu/gallon Source 

140,000 0.140 American Recycler. 2010. 

http://www.americanrecycler.com/0110/used002.shtml 

140,000 0.140 EPA, Managing Used Oil: Advice for Small Businesses.1996. 

http://www.epa.gov/osw/conserve/materials/usedoil/usedoil.htm 

138,000 0.138 California Environmental Protection Agency. 2004. 

http://oehha.ca.gov/risk/pdf/UsedOilInBunkerFuel.pdf 

138,000 0.138 Graziano, D.J. and E.J. Daniels. 1995. Assessment of Opportunities to Increase 

the Recovery and Recycling Rates of Waste Oils. U.S. DOE, Argonne National 

Laboratory, Center for Industrial Technology. 

http://infohouse.p2ric.org/ref/34/33500.pdf 

141,600 0.142 TECHNICAL REVIEW DOCUMENT for OPERATING PERMIT 95OPEP007. 

http://www.cdphe.state.co.us/ap/downop/ep007trd.pdf

Based on this research, SAIC believes the heating value for used oil should be slightly higher than the 

value currently listed in Table C-1. SAIC suggests using the value from the U.S. DOE Argonne National

Laboratory because it provides the most documentation to substantiate the heating value for used oil. 

The heating value in this document was derived from the analysis of the physical properties of 231 

samples of used oil. 

Recommendation: SAIC recommends updating the heating value for used oil in Table C-1 from 0.135 

MMBtu/gallon to 0.138 MMBtu/gallon. The updated source is “Graziano, D.J. and E.J. Daniels, 

Assessment of Opportunities to Increase the Recovery and Recycling Rates of Waste Oils, U.S. DOE, 

Argonne National Laboratory, Center for Industrial Technology, 1995. 

http://infohouse.p2ric.org/ref/34/33500.pdf.” 

2.4 Density for Still Gas 

Still gas, or refinery gas, is any form or mixture of gases produced in refineries by distillation, cracking, 

reforming, and other processes. The principal constituents are methane, ethane, ethylene, normal 

butane, butylene, propane, and propylene.4

The current density for still gas in Table MM-1 is 0.1405 metric tons/bbl. This density was developed

using the heat content of still gas as estimated by EIA, 6 million Btu per fuel oil equivalent barrel, and 

the relationship of heat content to density from U.S. Department of Commerce, Bureau of Standards, 

Thermal Properties of Petroleum Products, Miscellaneous Publication No.97, November 9, 1929. This 

document uses specific gravity at 60 degrees F. Because still gas is essentially a mixture of C1 – C4

alkanes, with densities of approximately 0.09 metric tons/bbl, SAIC believes the listed density value for 

still gas of 0.1405 metric tons/bbl is too high, and should be closer to the density of its components. 

Because the components of still gas are liquids at different conditions, and none are liquid at 60°F and 

one atmosphere, a potential solution is to determine the density based on the average composition of 

 

4

 EPA GHGRP, TSD - Petroleum Products and Natural Gas Liquids. 
13 

the components. SAIC reviewed existing literature but was not able to locate a published density for still 

gas. 

2.5 HHV for Heavy Gas Oils 

Heavy Gas Oils are petroleum distillates with an approximate boiling range from 651°F to 1,000°F.5 The 

current heating value for heavy gas oils in Table C-1 is 0.148 MMBtu/gallon. SAIC has confirmed that the 

heating value was derived using the carbon coefficient denominated in Tg C/QBtu from the EPA GHG 

Inventory, 1990-2009, Table A-33 (coefficient for crude oil) and density and carbon share from subpart

MM, which were sourced from a the Shell Oil Company Mars Blend Crude assay page, January 28, 2009. 

Recommendation: No change to heating value. Heating value was derived using the carbon coefficient 

denominated in Tg C/QBtu from the EPA GHG Inventory, 1990-2009, Table A-33 (coefficient for crude 

oil) and density and carbon share from subpart MM. 

2.6 Emission Factor for Natural Gasoline 

Natural Gasoline is a term used in the gas processing industry to refer to a mixture of liquid 

hydrocarbons (mostly pentanes and heavier hydrocarbons) extracted from natural gas. Natural Gasoline 

contributes to the gasoline/naphtha "octane pool," and is used primarily to make motor gasoline. The 

current emission factor natural gasoline in Table C-1 is 66.83 kg CO2/MMBtu. This factor is most likely 

based on the carbon coefficient for Natural Gasoline in the EPA GHG Inventory, 1990 - 2005, Annex 2, 

Table A-36. However, the Inventory shows a carbon coefficient of 18.24 Tg C/QBtu, which converts to 

66.88 kg CO2/MMBtu. 

It should be noted that the carbon coefficient for natural gasoline was updated in the EPA GHG 

Inventory to 14.47 Tg C/QBtu (53.06 kg CO2/MMBtu) starting in 2007. However, this is the same 

coefficient as natural gas. SAIC believes this is an error and suggests listing the source for the coefficient 

as EPA GHG Inventory, 1990 - 2005, Annex 2, Table A-36. 

Recommendation: SAIC recommends updating the emission factor for natural gasoline from 66.83 kg 

CO2/MMBtu to 66.88 kg CO2/MMBtu. The source is EPA GHG Inventory, 1990 - 2005, Annex 2, Table A36. 

2.7 HHV for Rendered Animal Fat 

Rendered animal fats, including tallow, yellow grease, and lard are fats extracted from animals which 

can be used as fuel or as a feedstock in making biodiesel. The current heating value for animal fat in 

Table C-1 is 0.125 MMBtu/gallon, however, the source of this heating value is not known. SAIC 

performed an Internet search for relevant documents that discuss the use of animal fats for fuel. This 

review resulted in the identification of 16 heating values for various types of animal fats from six 

different sources. The heating values range from 0.124 to 0.127 MMBtu/gallon. The mean heating 

 

5

 EPA GHGRP. http://ecfr.gpoaccess.gov/cgi/t/text/textidx?c=ecfr&sid=9529156b734ae1cb3d017cf1d32f99e3&rgn=div5&view=text&node=40:21.0.1.1.3&idno=40#40:21.

0.1.1.3.3.1.7 
14 

value for all samples is 0.125 MMBtu/gallon, which is exactly the same as the current value listed in 

Table C-1. Table 11 shows the heating values identified for several types of animal fats. 

Table 11. Heating Value for Animal Fats from Various Sources6

Fuel 

Heating 

Value 

Source 

Unit 

Converted to 

MMBtu/gal Source 

Chicken Fat 16,873 Btu/lb 0.124 Adams, Thomas T. A Demonstration of Fat and 

Grease as an Industrial Boiler Fuel. 2002. 

http://www.biorefinery.uga.edu/ 

docs/biofuel_oil_report.pdf 

Yellow Grease 16,899 Btu/lb 0.124

Choice White Grease 16,893 Btu/lb 0.124

Tallow 16,920 Btu/lb 0.124

Semi-Finished Lard 16,941 Btu/lb 0.124 Pearl, Gary. Animal Fats and Recycled Cooking Oils

Alternatives as Burner Fuels. March 2001. 

http://fatforfuel.us /images/GaryPearl.pdf 

Finished Lard 16,990 Btu/lb 0.125

Choice White Grease 16,977 Btu/lb 0.125

Chicken Fat 17,000 Btu/lb 0.125 University of Auburn. BROILER PROCESSING 

TIMELY INFORMATION – JUNE 2008. 

http://www.ag.auburn.edu /poul /pdf/wogsjun08.pdf 

Lard 17,165 Btu/lb 0.126 Kinast, J.A., Production of Biodiesels from Multiple 

Feedstocks andProperties of Biodiesels 

andBiodiesel/Diesel Blends. NREL, 2003. 

http://www.biofuels.coop/ 

archive/biodiesel_report.pdf 

Edible Tallow 17,144 Btu/lb 0.126

Inedible Tallow 17,061 Btu/lb 0.125

LFFA Yellow Grease 17,215 Btu/lb 0.126

HFFA Yellow Grease 17,154 Btu/lb 0.126

Tallow 18,000 Btu/lb 0.126 NOAA, CAMEO Chemicals, Data Sheet for Tallow. 

http://cameochemicals.noaa.gov/ chris/TLO.pdf 

Methyl Tallowate 126,684 Btu/gal 0.127 Nelson, Richard. ENERGETIC AND ECONOMIC 

FEASIBILITY ASSOCIATED WITH THE 

PRODUCTION, PROCESSING, AND 

CONVERSION OF BEEF TALLOW TO A 

SUBSTITUTE DIESEL FUEL. 2006. http://aegbiofuels.com/Pubs /2006_Energetic_BD_Prod.pdf 

Recommendation: No change to heating value for rendered animal fat. SAIC recommends using the 

average of the six sources listed in Table 6 above as the updated source for this heating value. 

2.8 HHV for Vegetable Oil 

Vegetable Oil is oil extracted from vegetation that is generally used as a feedstock in making biodiesel. 

The current heating value for animal fat in Table C-1 is 0.120 MMBtu/gallon, however, the source of this 

heating value is not known. SAIC performed an Internet search for relevant documents that discuss the

use of vegetable oil for fuel. This review resulted in the identification of five heating values for various 

types of vegetable oils from four different sources. The heating values range from 0.120 to 0.121 

MMBtu/gallon. The mean heating value for all samples is 0.120 MMBtu/gallon, which is the same as the 

current value listed in Table C-1. 

 

6

 Heating values were converted from Btu/lb to MMBtu/gallon using the density of animal fat as listed in Table 

MM-2. Heating Values from Adams, Pearl, Auburn, and Kinast were converted from “as fired”, or Lower Heating 

Value, to Higher Heating Value by multiplying by the PCC default conversion factor of 1.05. 
15 

Table 12 shows the heating values identified in the search. 

 
16 

Table 12. Heating Value for Vegetable Oils from Various Sources7

Fuel 

Heating 

Value 

Source 

Unit 

Converted to 

MMBtu/gal Source 

Soy Methyl Ester 17,153 Btu/lb 0.120 Kinast, J.A., Production of Biodiesels from Multiple Feedstocks 

andProperties of Biodiesels andBiodiesel/Diesel Blends. 

NREL, 2003. 

http://www.biofuels.coop/archive/biodiesel_report.pdf 

Canola Methyl 

Ester 

17,241 Btu/lb 0.121

Waste Vegetable 

Oil 

120,000 Btu/gal 0.120 Bartok, John W. University of Connecticut. Approximate 

Heating Value of Common Fuels, 2004. 

http://www.hrt.msu.edu/energy/pdf/heating%20value%20of%2

0common%20fuels.pdf 

Used Vegetable Oil 120,000 Btu/gal 0.120 Reeb, J. Home Heating Fuels. 2009. 

http://extension.oregonstate.edu/catalog/pdf/ec/ec1628-e.pdf 

Soybean Oil 38.37 kJ/g 0.121 Argeros, Anastasios. Heat of Combustion of Oils, April 30, 

1998. 

http://www.infolizer.com/s5e1asa1up5enna15ed4u/Heat-ofcombustion-of-oils.html 

Recommendation: No change to heating value for vegetable oil. SAIC recommends using the average 

of the four sources listed in Table 7 above as the updated source for this heating value. 

2.9 HHV for Tires 

Tires can be used as fuel either in shredded form - known as tire-derived fuel (TDF) — or whole, 

depending on the type of combustion device. Scrap tires are typically used as a supplement to 

traditional fuels such as coal or wood. Generally, tires need to be reduced in size to fit in most 

combustion units. Besides size reduction, use of TDF may require additional physical processing, such as 

de-wiring.8 

The current heating value for tires in Table C-1 is 26.87 MMBtu/short ton. This heating value is most

likely sourced from the Energy Information Administration, Renewable Energy Annual 2005, Table 10 - 

Average Heat Content of Selected Biomass Fuels. However, this publication is no longer available and 

SAIC performed an Internet search to identify heating values for tires as documented in existing 

literature. The results of this research showed a consistently higher heat content then that currently 

listed in Table C-1. Table 13 shows the heat content for tires as reported by four different sources. 

Table 13. Heating Value for Tires from Various Sources 

Higher Heating Value

(MMBtu/short ton) Source 

28 - 31 Gray, Terry. T.A.G Resource Recovery. TIRE DERIVED FUEL: ENVIRONMENTAL 

CHARACTERISTICS AND PERFORMANCE. 2004. 

https://www.rma.org/getfile.cfm?ID=934&type=publication 

 

7

 Heating values were converted from Btu/lb to MMBtu/gallon, where necessary, using the density of vegetable oil 

as listed in Table MM-2. Heating Values from Argeros were converted from Lower Heating Value to Higher Heating 

Value by multiplying by the PCC default conversion factor of 1.05. 

8

 EPA, http://www.epa.gov/osw/conserve/materials/tires/tdf.htm 
17 

Higher Heating Value

(MMBtu/short ton) Source 

31.0 Jones, 1990. R.M. Jones, J.M. Kennedy, Jr., and N.L. Heberer, "Supplementary Firing of 

Tire-Derived Fuel (TDF) in a Combination Fuel Boiler," TAPPI Journal, May 1990. 

http://tappi.micronexx.com/JOURNALS/PDF/90MAY107.6771.pdf 

31.0 TMTS Associates. Alternate Fuels and Heat Recovery to Cut Fuel Costs. 2009. 

http://www.tmtsassociates.com/literature/altfuel.html 

30.0 Connecticut Dept. of Energy and Environmental Protection. 2011. 

http://www.ct.gov/dep/cwp/view.asp?A=2714&Q=324902 

24 - 32 California Integrated Waste Management Board. 1992. Tires as a fuel supplement: 

Feasibility study: Report to Legislature. Sacramento. 

http://www.calrecycle.ca.gov/publications/Tires/40193001.pdf 

27.78 EPA, Waste Reduction Model (WARM). 2010. Introduction to WARM and Tires. 

http://www.epa.gov/climatechange/wycd/waste/downloads/tires-chapter10-28-10.pdf 

28.00 U.S. EPA. 1991. Market for Scrap Tires. 

http://www.epa.gov/wastes/conserve/materials/tires/tires.pdf 

The review of existing literature found heating values for tires ranging from 12,000 to 16,000 Btu/lb (24 

to 32 MMBtu/short ton), depending on the composition of the rubber and whether or not the steel has 

been removed (de-wired). Whole tires have a lower heating value than tires that have been de-wired 

and processed into TDF. It is assumed that the fuel listed in Table C-1 as “Tires” is intended to represent 

all tires used as fuel and includes both whole tires and TDF. Therefore, SAIC believes that a heating

value of 28 MMBtu/short ton is an acceptable heating value for tires. The single source to use for this 

heating value is a 1991 document from EPA titled “Markets for Scrap Tires” which states that “Tires have 

a fuel value of 12,000 to 16,000 Btu per pound, slightly higher than that of coal.”9 This converts to a 

heating value of 24 to 32 MMBtu/short ton. The average of these values is 28 MMBtu/short ton. 

Recommendation: SAIC recommends updating the heating value for tires in Table C-1 from 26.87 

MMBtu/short ton to 28.00 MMBtu/short ton. The updated source is “U.S. EPA. 1991. Market for Scrap 

Tires. http://www.epa.gov/wastes/conserve/materials/tires/tires.pdf.“

2.10 Municipal Solid Waste (MSW) 

The nominal source for the MSW emission factor in Table C-1 is the California Air Resources Board’s 

(CEC) Compendium of Emission Factors; however, CEC cites the factor in the instructions to the Energy 

Information Administration’s Form EIA-1605 (Voluntary Reporting of Greenhouse Gases) that was 

developed in the mid-1990s. Because the composition of MSW has changed significantly since then due 

to increased use of plastic packaging and increased materials recycling, among other factors, EPA should 

update the emission factor and HHV for this fuel. 

Because of its extreme variability of MSW, studies of its characteristics tend to be based on data from an 

EPA model that uses a materials flow methodology that relies on a mass balance approach to estimate 

tons of materials and products generated, recycled, or discarded at the national level.10 The resulting 

data are used by EPA to estimate GHG emissions for the annual U.S. greenhouse gas emissions 

 

9

 U.S. EPA. 1991. Market for Scrap Tires. http://www.epa.gov/wastes/conserve/materials/tires/tires.pdf 

10 U.S. EPA, Municipal Solid Waste in the United States: 2009 Facts and Figures, EPA530-R-10-012, December 2010. 
18 

inventory. The Energy Information Administration (EIA) also used these data to estimate the biogenic 

and non-biogenic shares of total MSW consumed for energy.11 

In previous work for EIA, SAIC developed several estimates of CO2 emissions from MSW based on EPA 

MSW composition data. SAIC adapted EIA’s approach to estimate the biogenic and non-biogenic share 

of CO2 emissions from MSW combustion (Method 1). In Method 2, we adapted EIA’s method further by 

using alternative characteristic data (HHV, moisture content, carbon content) for MSW components. For 

Method 3, SAIC applied the estimates of biogenic and non-biogenic CO2 emissions generated in Methods 

1 and 2 and the average HHV for MSW from EIA survey data to the estimate of non-biogenic CO2

emissions per ton of MSW derived from EPA’s greenhouse gas inventory. These methods are 

summarized in Table 14 and the emission factors and HHVs they produced are shown, and compared 

with the existing Table C-1 values, in Table 15. (These calculations were executed with 2009 data, the

most recent year for which all necessary data were available.) 

Table 14. Summary of Methods Used to Calculate CO2 Emission Factors and HHVs of MSW 

Method Description

Method 1 CO2 emissions (kg CO2/ton) were calculated for each component of MSW from EPA estimates of 

the quantity combusted, carbon content (dry basis), and moisture content. 

Method 1a CO2 emissions (kg CO2/MMBtu) were determined using HHVs for each MSW component from EIA 

(2007) that were assumed to be wet basis. 

Method 1b CO2 emissions (kg CO2/MMBtu) were determined using HHVs for each MSW component from EIA 

(2007) that were assumed to be dry basis. 

Method 2 CO2 emissions calculated from EPA estimates, for each component of MSW, of the quantity 

combusted, carbon content (dry basis), and moisture content. Different data for MSW component 

characteristics were used, including HHVs that were known to be dry basis. 

Method 3 CO2 emissions (kg CO2/ton) were calculated from total U.S. non-biogenic emissions and total 

MSW combusted estimated for U.S. GHG emissions inventory. CO2 emissions (kg CO2/MMBtu) 

calculated using average HHV for MSW reported to EIA (9.94 MMBtu/ton). 

Method 3a Used non-biogenic fraction of MSW estimated in Method 1

Method 3b Used non-biogenic fraction of MSW estimated in Method 2

Table 15. Summary of Calculated CO2 Emission Factors and HHVs

Method 

HHV Emission Factor 

MMBtu/ton Btu/lb kg CO2/ton kg CO2/MMBtu 

Method 1a 11.42 5,711 1,179.87 103.29

Method 1b 9.73 4,864 1,179.87 121.29

Method 2 12.18 6,088 1,085.71 89.17

Method 3a 9.94 4,968 900.53 90.63

Method 3b 9.94 4,968 896.25 90.20

Table C-1 9.95 4,975 902.47 90.70

SAIC also calculated the share of total CO2 emissions resulting from MSW combustion provided by 

biogenic and non-biogenic components of MSW (see Table 16). The biogenic/non-biogenic shares 

resulting from Method 1 and Method 2 emissions calculations were remarkably similar throughout the 

time series, showing a 55/45 split between biogenic and non-biogenic sources in 2009. 

 

11 U.S. Energy Information Administration, Methodology for Allocating Municipal Solid Waste to Biogenic and NonBiogenic Energy, May 2007. 
19 

Table 16. Biogenic and Non-Biogenic Shares of CO2 Emitted from MSW Combustion 

Method Source 

Share of CO2 Emitted from MSW Combustion (percent) 

1990 1995 2000 2005 2006 2007 2008 2009 

1 Biogenic 71.2 67.2 63.1 59.2 58.8 57.4 57.4 55.2

Non-Biogenic 28.8 32.8 36.9 40.8 41.2 42.6 42.6 44.8

2 Biogenic 69.4 65.8 62.0 58.3 57.6 56.6 56.5 55.0

Non-Biogenic 30.6 34.2 38.0 41.7 42.4 43.4 43.5 45.0

Recommendation: Method 3 is perhaps the most reliable approach to determining a CO2 emission 

factor and HHV for MSW combustion because it is based on accepted values for total U.S. CO2 emissions 

from this source, the total MSW combusted from EPA’s GHG inventory, and measured HHVs for fuel 

consumed by MSW combustors collected by EIA surveys. The values produced by Method 3 are very 

close to the existing values in Table C-1, it may not be necessary to revise the latter values. 

The method in 98.33(e)(3)(iv) for calculating biogenic CO2 emissions from MSW combustion requires the 

use of a default factor of 0.6 for the biogenic share of CO2, which appears to be consistent with MSW 

combusted 8-10 years ago. SAIC recommends that (1) the factor be updated to 0.55 to reflect trends in 

waste composition and (2) the factor be updated at least every 5 years going forward. 

2.11 HHV for Wood 

The HHV for wood and wood residuals in Table C-1 is a wet basis value that assumes moisture content of

12 percent. GHGRP reporters have indicated that they use wood fuel with significantly different 

moisture content, which results calculation of inaccurate CO2 emissions from burning this fuel. These 

users have requested that EPA provide HHVs for a range of moisture contents for wood fuel. 

Recommendation: SAIC recommends that EPA revise Table C-1 to indicate the basis for the existing 

default HHV, provide a dry basis default HHV (17.48 MMBtu/short ton), and include a footnote 

instructing users how to convert the dry basis value to wet basis using measured moisture content. The

footnote should read as follows: 

Use the following formula to calculate a wet basis HHV for use in Equation C-1 using the following 

formula: HHVw = ((100 – M)/100) * HHVd, where HHVw = wet basis HHV, M = moisture content 

(percent), and HHVd = dry basis HHV from Table C-1. 

2.12 HHV for Solid Byproducts 

Subpart A defines Solid Byproducts as “plant matter such as vegetable waste, animal materials/wastes, 

and other solid biomass, except for wood, wood waste, and sulphite lyes (black liquor).” The HHV 

included in Table C-1 is 25.83 MMBtu/short ton. This HHV is comparable to the value bituminous coal 

and seems very high for material that probably contains a significant amount of moisture. (SAIC 

confirmed with the survey manager at EIA that the HHV data collected are meant to be “as-received” or 

wet basis values.) The original source of this HHV, and possibly the definition of the fuel category, is the 

EIA-860B survey (Annual Electric Generator--Nonutility). The value is a weighted average for the Solid

Byproducts consumed by three facilities reporting in the 1999 survey. 
20 

The EIA-860B has been discontinued and HHV data on fuels used at power plants are collected on Form 

EIA-923. The EIA-923 survey does not use the Solid Byproducts fuel category, replacing it with Other 

Biomass Solids. In the 2010 EIA-923 survey, 31 facilities reported the consumption of Other Biomass 

Solids and the weighted average HHV of this fuel was 10.39 MMBtu/short ton, which appears to be 

more consistent with other biomass fuels. 

Recommendation: SAIC recommends that the HHV for Solid Byproducts be changed to the weighted 

average for Other Biomass Solids reported in the EIA-923 survey (10.39 MMBtu/short ton). As the 

Agricultural Byproducts and Solid Byproducts categories for solid biomass fuels in Table C-1 have caused 

confusion among GHGRP reporters, EPA should consider redefining the solid biomass fuel categories in 

the future to create more recognizable categories such as crop residues, food processing wastes, 

wastewater treatment sludge, and animal manure. 

2.13 HHV for Biogas 

EIA collects HHV data for fuels burned at power plants on Form EIA-923, including landfill gas (LFG) and 

other biomass gases (OBS), which is probably all digester gas. SAIC calculated the following weighted 

average HHVs for these fuels reported in 2010: 

• Landfill Gas: 0.485 MMBtu/Mcf 

• Other Biomass Gases: 0.655 MMBtu/Mcf 

The higher HHV for other biomass gases compared to landfill gas is consistent with the typical methane

content of these gases (50 percent for methane and 65 percent for digester gas). 

Recommendation: SAIC recommends that separate HHVs be provided for landfill gas and digester using 

the above values calculated from the 2010 EIA-923 data. The methane concentration in landfill gas is 

typically lower The CO2 emission factor emission factor will be the same for these gases because all the 

CO2 from fuel combustion is derived exclusively from the methane in each gas. 

3. Review of JIRA Tickets for Necessary Updates to Emission Factors, Equations, and Other 

SAIC conducted a review of historical JIRA tickets to identify those that addressed errors in emission

factors, equations, or other aspects of the mandatory reporting of greenhouse gases rule. (This review

did not address emission factors for subparts I, L, or W.) The results of this review are shown in Table 17. 

Many of these issues are addressed in Section 2 above. The following section presents analysis and 

recommendations for the biogas pass-through CO2 issue identified by this review. 

Table 17. Errors in Emission Factors, Equations, and Other Aspects of the Rule Identified in JIRA Tickets 

JIRA # Subpart Description

Emission Factor Issues

22317 C Separate emission factors (presumably for N2O) for low NOx boilers

21056 C Basis (wet or dry) for MSW emission factor in Table C-1

18337 C Alternative moisture content for biomass emission factors in Table C-1

17590 C Table C-1 factor for wood assumes low moisture content

15266 C Emission factor for biogas does not include pass-through CO2 resulting in overestimation of non14345 biogenic emissions when biogas and fossil fuels are co-fired 

11589

13986 C Separate emission factors for pipeline quality and field natural gas
21 

JIRA # Subpart Description

Equation Errors

21490 C Equation C-1: Table C-1 factor for biogas (pass through CO2)

21061 K Equation K-5: Output is in kg instead of metric tons

20979

20674 K Equation K-3: Error in output units (kg instead of metric tons)

14997 NN Equations NN-1, NN-4, and NN-6: Differences in default values in Tables NN-1 and NN-2 used 

in Equations NN-1 and NN-4 result in negative net deliveries of natural gas to customers in 

Equation NN-6 

14135

Other Rule or GHGRP Issues

19151 P Include ASTM method D2163 specifically in §98.164(b)(5)

18617 Z Specify that "tons" in subpart Z is meant to be short tons

16351 EE Provide guidance in §98.316(b)(11) for calculating weighted avg. C content if more than one waste 

type is used in a single process line 

15226 AA In Table AA-2, it is not clear that CH4 emission factor (0.0027 kg/MMBtu) applies to all fuels.

14982 HH Errors in subpart HH calculation spreadsheet for Equations HH-6, HH-7, and HH-8

14320 C In Eq. C-10 calculation spreadsheet, it is unclear whether CH4 & N2O should be entered as native 

gas or CO2e 

11263 C Parenthetical statement in applicability tool re: using Tier 1 method is incorrect

3.1 Pass-Through CO2 in Biogas 

The anaerobic digestion of organic matter yields a gas containing methane (CH4) and CO2. Landfill gas is 

typically has 50 percent CH4 and 50 percent CO2. Digesters that use sewage or animal manure usually 

have a higher ratio of CH4 to CO2, about 60:40 or higher. When biogas is burned, the CO2 included in fuel 

passes through the combustion device is emitted to the atmosphere along with the CO2 resulting from 

the combustion of CH4. Table 18 illustrates how pass through CO2 is not treated consistently in 40 CFR 

part 98. The subpart C Tier 1 and Tier 2 calculation methods that use a default emission factor 

denominated in kg CO2/MMBtu excludes pass-through because the energy content of the biogas is 

derived solely from the CH4 in the fuel. The remaining subpart C methods (Tiers 3 and 4) and the subpart 

D method include the pass-through CO2 in the total emissions. 

Table 18. Treatment of Pass-Through CO2 in Biogas in Calculating Total CO2 Emissions 

Subpart Method Description Pass-Through CO2 Included? 

C Tier 1 Eq. C-1 (CO2 = Fuel volume * Default HHV * Default EF) No 

Tier 2 Eq. C-2a (CO2 = Fuel volume * Measured HHV * Default EF) No 

Tier 3 Eq. C-5 (CO2 = 44/12 * Fuel volume * CC * MW/MVC) Yes 

Tier 4 CEMS Yes 

D §75.13(a) CEMS Yes 

§75.13(b) Appendix G, Eq. G-4 Yes 

Note: EF= emission factor; MW = molecular weight; MVC = molar volume conversion factor; CEMS = continuous emissions 

monitoring system 

The calculation of biogenic CO2 emissions using the applicable methods in §98.33(e) excludes passthrough CO2 (see Table 19). This presents a particular problem for subpart D facilities because they are 

required by 98.43(b) to calculate total non-biogenic CO2 emissions as the difference between total CO2 

emissions and biogenic CO2 emissions, which results in the pass-through CO2 being included with the 

non-biogenic emissions. 
22 

Table 19. Treatment of Pass-Through CO2 in Biogas in Calculating Biogenic CO2 Emissions 

Method Description Pass-Through CO2 Included? 

§98.33(e)(1) Eq. C-1 (CO2 = Fuel volume * Default HHV * Default EF) No 

§98.33(e)(2) Eq. C-12, C-13, & C-14 (CO2 = CO2 Measured by CEMS * % Biogenic) n/a* 

§98.33(e)(3) % biogenic determined using ASTM methods specified in §98.34(d) or (e). 

For MSW and tires only. 

n/a 

§98.33(e)(4) Eq. C-15. (For wood, wood waste, or other solid biomass-derived fuel.) n/a 

§98.33(e)(5) Eq. C-15a. (CO2 = Fuel MMBtu * Default EF; for units subject to subpart D.) No 

*Not applicable to biogas because “CO2 emissions must consist solely of combustion products.”

Note: EF= emission factor; CEMS = continuous emissions monitoring system 

Recommendation: The problem with pass-through CO2 for biogas can be overcome by permitting 

facilities to calculate biogenic CO2 emissions using Equation G-4 in Appendix G of 40 CFR part 75, which 

would yield a value that includes the pass-through CO2. 
23 

Attachment A 

Sources for Emission Factors and Other Characteristics of Fuels Listed in 40 CFR Part 98
Table A-1. Characteristics and Data Sources for Fuels Listed in Table C-1 

Fuel type Default HHV HHV Unit HHV Source 

Emission 

Factor EF Unit 

Anthracite 25.09 MMBtu/short 

ton 

EPA Climate Leaders, Stationary Combustion Guidance (2004), Table B-1 

103.54 kg CO2/MMBtu EPA GHG Invento

Bituminous 24.93 MMBtu/short

ton 

EPA Climate Leaders, Stationary Combustion Guidance (2004), Table B-1 

93.40 kg CO2/MMBtu EPA GHG Invento

Subbituminous 17.25 MMBtu/short 

ton 

EPA Climate Leaders, Stationary Combustion Guidance (2004), Table B-1 

97.02 kg CO2/MMBtu EPA GHG Invento

Lignite 14.21 MMBtu/short 

ton 

EPA Climate Leaders, Stationary Combustion Guidance (2004), Table B-1 

96.36 kg CO2/MMBtu EPA GHG Invento

Coke 24.8 MMBtu/short 

ton 

EIA AER 2008, Table A5 102.04 kg CO2/MMBtu EPA GHG Invento

(Factor is for petro

Mixed (Commercial sector) 21.39 MMBtu/short 

ton 

EIA AER 2008, Table A5 95.26 kg CO2/MMBtu EPA GHG Invento

Mixed (Industrial coking) 26.28 MMBtu/short 

ton 

EIA AER 2008, Table A5 93.65 kg CO2/MMBtu EPA GHG Invento

Mixed (Industrial sector) 22.35 MMBtu/short 

ton 

EIA AER 2008, Table A5 93.91 kg CO2/MMBtu EPA GHG Invento

Mixed (Electric Power sector) 

19.73 MMBtu/short 

ton 

EIA AER 2008, Table A5 94.38 kg CO2/MMBtu EPA GHG Invento

Natural Gas 0.001028 MMBtu/scf EIA AER 2008, Table A4 53.02 kg CO2/MMBtu California Air Reso

Emission Factors, 

Distillate Fuel Oil No. 1 0.139 MMBtu/gallon Derived using the carbon coefficient denominated 

in Tg C/QBtu from the EPA GHG Inventory, 1990-2009, Table A-33 and density and carbon share from subpart MM 

73.25 kg CO2/MMBtu Factor derived from 

sources in table M

Distillate Fuel Oil No. 2 0.138 MMBtu/gallon Derived using the carbon coefficient denominated 

in Tg C/QBtu from the EPA GHG Inventory, 1990-2009, Table A-33 and density and carbon share from subpart MM 

73.96 kg CO2/MMBtu Factor derived from 

sources in table M

Distillate Fuel Oil No. 4 0.146 MMBtu/gallon Derived using the carbon coefficient denominated 

in Tg C/QBtu from the EPA GHG Inventory, 1990-2009, Table A-33 and density and carbon share from subpart MM 

75.04 kg CO2/MMBtu Factor derived from 

sources in table M

Residual Fuel Oil No. 5 0.14 MMBtu/gallon Derived using the carbon coefficient denominated 

in Tg C/QBtu from the EPA GHG Inventory, 1990-2009, Table A-33 and density and carbon share from subpart MM 

72.93 kg CO2/MMBtu Factor derived from 

sources in table M

Residual Fuel Oil No. 6 0.15 MMBtu/gallon Derived using the carbon coefficient denominated 

in Tg C/QBtu from the EPA GHG Inventory, 1990-2009, Table A-33 and density and carbon share from subpart MM 

75.10 kg CO2/MMBtu Factor derived from 

sources in table M

Used Oil 0.135 MMBtu/gallon NOT IDENTIFIED 74.00 kg CO2/MMBtu WBCSD/WRI, The 

Accounting and Re

Industry Calculatiohttp://www.wbcsd.

Kerosene 0.135 MMBtu/gallon EIA AER 2005, Table A1 75.20 kg CO2/MMBtu Factor derived from 

sources in table M
Fuel type Default HHV HHV Unit HHV Source 

Emission 

Factor EF Unit 

Liquefied petroleum gases (LPG) 

0.092 MMBtu/gallon CARB Compendium of Emission Factors, Table 4, 

2007 

62.98 kg CO2/MMBtu EPA GHG Invento

Using 3.664 to con

Propane 0.091 MMBtu/gallon EIA AER 2005, Table A1 61.46 kg CO2/MMBtu Factor derived from 

sources in table M

Propylene 0.091 MMBtu/gallon Bureau of Standards, Miscellaneous Publication 

No. 97, 1929. Thermal Properties of Petroleum Products. 

65.95 kg CO2/MMBtu Factor derived from 

sources in table M

Ethane 0.069 MMBtu/gallon Bureau of Standards, Miscellaneous Publication 

No. 97, 1929. Thermal Properties of Petroleum Products. 

62.64 kg CO2/MMBtu Factor derived from 

sources in table M

Ethanol 0.084 MMBtu/gallon Bureau of Standards, Miscellaneous Publication 

No. 97, 1929. Thermal Properties of Petroleum Products. 

68.44 kg CO2/MMBtu Factor derived from 

sources in table M

Ethylene 0.1 MMBtu/gallon Bureau of Standards, Miscellaneous Publication 

No. 97, 1929. Thermal Properties of Petroleum Products. 

67.43 kg CO2/MMBtu Factor derived from 

sources in table M

Isobutane 0.097 MMBtu/gallon Bureau of Standards, Miscellaneous Publication 

No. 97, 1929. Thermal Properties of Petroleum Products. 

64.91 kg CO2/MMBtu Factor derived from 

sources in table M

Isobutylene 0.103 MMBtu/gallon Bureau of Standards, Miscellaneous Publication 

No. 97, 1929. Thermal Properties of Petroleum Products. 

67.74 kg CO2/MMBtu Factor derived from 

sources in table M

Butane 0.101 MMBtu/gallon Bureau of Standards, Miscellaneous Publication 

No. 97, 1929. Thermal Properties of Petroleum Products. 

65.15 kg CO2/MMBtu Factor derived from 

sources in table M

Butylene 0.103 MMBtu/gallon Bureau of Standards, Miscellaneous Publication 

No. 97, 1929. Thermal Properties of Petroleum Products. 

67.73 kg CO2/MMBtu Factor derived from 

sources in table M

Naphtha (<401 deg F) 0.125 MMBtu/gallon EIA AER 2005, Table A1 68.02 kg CO2/MMBtu Factor derived from 

sources in table M

Natural Gasoline 0.11 MMBtu/gallon EIA AER 2005, Table A1 66.83 kg CO2/MMBtu NOT IDENTIFIED 

1990 - 2005, Anne

Other Oil (>401 deg F) 0.139 MMBtu/gallon EIA AER 2005, Table A1 76.22 kg CO2/MMBtu Factor derived from 

sources in table M

Pentanes Plus 0.11 MMBtu/gallon EIA AER 2005, Table A1 70.02 kg CO2/MMBtu Factor derived from 

sources in table M

Petrochemical Feedstocks 0.129 MMBtu/gallon EIA AER 2005, Table A-36. The underlying value 

in this source is 5.248 MMBtu/bbl which appears to be incorrectly transcribed in the EPA GHG Inventory as 5.428. The corrected heat content in MMBtu/gallon should be 0.125 

70.97 kg CO2/MMBtu California Air Reso

Emission Factors, 

Petroleum Coke 0.143 MMBtu/gallon EIA AER 2005, Table A1 102.41 kg CO2/MMBtu Factor derived from 

sources in table M

Special Naphtha 0.125 MMBtu/gallon EIA AER 2005, Table A1 72.34 kg CO2/MMBtu Factor derived from 

sources in table M
Fuel type Default HHV HHV Unit HHV Source 

Emission 

Factor EF Unit 

Unfinished Oils 0.139 MMBtu/gallon EPA GHG Inventory 1990 - 2005, Annex 2, Table 

A-36 

74.49 kg CO2/MMBtu California Air Reso

Emission Factors, 

Heavy Gas Oils 0.148 MMBtu/gallon NOT IDENTIFIED 74.92 kg CO2/MMBtu Factor derived from 

sources in table M

Lubricants 0.144 MMBtu/gallon EIA AER 2005, Table A1 74.27 kg CO2/MMBtu Factor derived from 

sources in table M

Motor Gasoline 0.125 MMBtu/gallon EIA AER 2008, Appendix A, Table A1 (for 

conventional motor gasoline) 

70.22 kg CO2/MMBtu Current source is E

C/QBtu = 70.83 kg factor of 3.664). Tvalue of 70.22 kg Cof Subpart MM fuefrom the AER. 

Aviation Gasoline 0.12 MMBtu/gallon EIA AER 2005, Table A1 69.25 kg CO2/MMBtu Factor derived from 

sources in table M

Kerosene-Type Jet Fuel 0.135 MMBtu/gallon EIA AER 2005, Table A1 72.22 kg CO2/MMBtu Factor derived from 

sources in table M

Asphalt and Road Oil 0.158 MMBtu/gallon EIA AER 2005, Table A1 75.36 kg CO2/MMBtu Factor derived from 

sources in table M

Crude Oil 0.138 MMBtu/gallon EPA GHG Inventory 1990 - 2005, Annex 2, Table 

A-36 

74.49 kg CO2/MMBtu California Air Reso

Emission Factors, 

Municipal Solid Waste 9.95 MMBtu/short 

ton 

NOT IDENTIFIED 90.70 kg CO2/MMBtu California Air Reso

Emission Factors, 

Tires 26.87 MMBtu/short 

ton 

NOT IDENTIFIED 85.97 kg CO2/MMBtu EIA 1605b

Plastics 38 MMBtu/short 

ton 

SRA Document, Sources for Data Contained In Tables C-1 and C-2, October 6, 2010 states that the plastics HHV from "revisions package". 

75.00 kg CO2/MMBtu SRA Document, S

C-1 and C-2, Octoemission factor fro

Petroleum Coke 30 MMBtu/short 

ton 

EIA AER 2005, Table A1 102.41 kg CO2/MMBtu Factor derived from 

sources in table M

Blast Furnace Gas 0.000092 MMBtu/scf Gannon, H.E. (editor), The Making, Shaping, and 

Treating of Steel, Tenth Edition (1985). Page 131 

274.32 kg CO2/MMBtu 2006 IPCC Guidel

Inventories, Table 

Coke Oven Gas 0.000599 MMBtu/scf Gannon, H.E. (editor), The Making, Shaping, and 

Treating of Steel, Tenth Edition (1985). Page 131 

46.85 kg CO2/MMBtu 2006 IPCC Guidel

Inventories, Table 

Propane Gas 0.002516 MMBtu/scf SRA Document, Sources for Data Contained In 

Tables C-1 and C-2, October 6, 2010 states that the propane gas HHV conversion to gas volume from "revisions package". 

61.46 kg CO2/MMBtu SRA Document of 

propane gas emissMausami July 200

Fuel Gas 0.001388 MMBtu/scf SRA Document, Sources for Data Contained In 

Tables C-1 and C-2, October 6, 2010 states that the fuel gas HHV from "revisions package". 

59.00 kg CO2/MMBtu SRA Document, S

C-1 and C-2, Octoemission factor fro

Wood and Wood Residuals 

15.38 MMBtu/short 

ton 

EPA Climate Leaders, Stationary Combustion Guidance (2004), Table B-2 

93.80 kg CO2/MMBtu California Air Reso

Emission Factors, 

Agricultural Byproducts 8.25 MMBtu/short 

ton 

EIA, Renewable Energy Annual 2009, January 2012, Table 1.10 

118.17 kg CO2/MMBtu 2006 IPCC Guidel
Fuel type Default HHV HHV Unit HHV Source 

Emission 

Factor EF Unit 

Peat 8.00 MMBtu/short 

ton 

EIA, Renewable Energy Annual 2009, January 2012, Table 1.10

111.84 kg CO2/MMBtu 2006 IPCC Guidel

Solid Byproducts 25.83 MMBtu/short 

ton 

EIA, Renewable Energy Annual 2009, January 2012, Table 1.10

105.51 kg CO2/MMBtu 2006 IPCC Guidel

Biogas (Captured methane) 

0.000841 MMBtu/scf NOT IDENTIFIED. EPA Climate Leaders, 

Stationary Combustion Guidance (2004), Table B2, lists landfill and wastewater biogas. Landfill gas is listed at 502.50 Btu/scf, wastewater gas as "varies". The source of the current factor (0.841x10-3 MMBtu/scf) is not known at this time.

52.07 kg CO2/MMBtu EPA Climate Lead

Guidance (2004), T

Ethanol 0.084 MMBtu/gallon EIA AER 2009, Table A3 68.44 kg CO2/MMBtu Factor derived from 

sources in table M

Biodiesel 0.128 MMBtu/gallon EIA AER 2009, Table A3 73.84 kg CO2/MMBtu Factor derived from 

sources in table M

Rendered Animal Fat 0.125 MMBtu/gallon NOT IDENTIFIED 71.06 kg CO2/MMBtu Factor derived from 

sources in table M

Vegetable Oil 0.12 MMBtu/gallon NOT IDENTIFIED 81.55 kg CO2/MMBtu Factor derived from 

sources in table M

Table A-2. Characteristics and Data Sources for Fuels Listed in Table MM-1 

Product Density 

Density 

Unit 

Density 

Temp 

Density 

Phase Density Source 

Carbon 

Share 

Carbon 

Share Unit Carbon Share Source 

Distillate No. 1 0.1346 metric 

tons/bbl 

60F Liquid Alliance of Automobile 

Manufacturers, Diesel Survey - Winter 2008 

86.40 % of mass Perry’s Chemical Engineer’s 

Handbook, 1997 ed., pg. 27-10, Table 27-6 

Distillate No. 2 0.1342 metric 

tons/bbl 

60F Liquid Alliance of Automobile 

Manufacturers, Diesel Survey - Winter 2008 

87.30 % of mass Perry’s Chemical Engineer’s 

Handbook, 8th ed., 2008, Table 24-6, pg. 24-9 

Distillate Fuel Oil No. 4 

0.1452 metric 

tons/bbl 

60F Liquid Perry’s Chemical Engineer’s 

Handbook, 8th ed., 2008, pg. 24-9, Table 24-6 

86.47 % of mass Perry’s Chemical Engineer’s 

Handbook, 8th ed., 2008, pg. 24-9, Table 24-6 

Residual Fuel Oil No. 5 (Navy Special) 

0.1365 metric 

tons/bbl 

60F Liquid Wauquier, J.-P., ed. Petroleum 

Refining, Crude Oil, Petroleum Products and Process Flowsheets (Editions Technip - Paris, 1995) pg. 225, Table 5.16 

85.67 % of mass US EIA, Carbon Emissions 

Coefficients for U.S. Fuels, October 31, 1994 

Residual Fuel Oil No. 6 (a.k.a. Bunker C) 

0.1528 metric 

tons/bbl 

60F Liquid Perry's Chemical Engineer's 

Handbook, 8th ed., 2008, Table 24-6, pg. 24-9 

84.67 % of mass Perry's Chemical Engineer's 

Handbook, 8th ed., 2008, Table 24-6, pg. 24-9 
Product Density 

Density 

Unit 

Density 

Temp 

Density 

Phase Density Source 

Carbon 

Share 

Carbon 

Share Unit Carbon Share Source 

Kerosene- Type Jet Fuel 0.1294 metric tons/bbl 60F Liquid O.J. Hadaller and A.M. Momenthy, The Characteristics 

of Future Fuels, Part 1, “Conventional Heat Fuels” (Seattle, WA: Boeing Corp., September 1990), pp. 46-50 

86.30 % of mass O.J. Hadaller and A.M. Momenthy, 

The Characteristics of Future Fuels, Part 1, “Conventional Heat Fuels” (Seattle, WA: Boeing Corp., September 1990), pp. 46-50 

Kerosene 0.1346 metric 

tons/bbl 

60F Liquid subpart MM assumes density 

for kerosene and Distillate No. 1 are the same because the physical characteristics of the products are very similar 

86.40 % of mass subpart MM assumes carbon 

share for kerosene as Distillate No. 1 are the same because the physical characteristics of the products are very similar 

Diesel—Other 0.1452 metric 

tons/bbl 

60F Liquid Perry’s Chemical Engineer’s 

Handbook, 8th ed., 2008, pg. 24-9, Table 24-6 

86.47 % of mass Perry’s Chemical Engineer’s 

Handbook, 8th ed., 2008, pg. 24-9, Table 24-6 

Naphthas (< 401°F) 

0.1158 metric 

tons/bbl 

60F Liquid Meyers, Handbook of 

Petroleum Refining Processes, 3rd ed., (New York, NY: McGraw Hill, 2004), p. 2.10 

84.11 % of mass G.H. Unzelman, “A Sticky Point for 

Refiners: FCC Gasoline and the Complex Model,” Fuel Reformulation (July/August 1992), p. 29. The data sources are the same as those in EIA's Documentation for Emissions of Greenhouse Gases in the United States 

Other Oils (> 401°F) 

0.1390 metric 

tons/bbl 

60F Liquid Maximum density requirement 

for Fuel Oil No.2 in ASTM Standard D396-09 

87.30 % of mass Perry’s Chemical Engineer’s 

Handbook, 8th ed., 2008 Table 24-6, pg. 24-9 

Heavy Gas Oils 

0.1476 metric 

tons/bbl 

60F Liquid Shell Oil Company Mars Blend 

Crude assay page, January 28, 2009 

85.80 % of mass Shell Oil Company Mars Blend 

Crude assay page, January 28, 2009 

Residuum 0.1622 metric 

tons/bbl 

60F Liquid Shell Oil Company Mars Blend 

Crude assay page, www.marscrude.com/mars_assays/july99/assay99.xls, January 28, 2009 

85.70 % of mass EIA's Documentation for 

Emissions of Greenhouse Gases in the United States, October 2008, Pg. 191: "If one knows nothing about the composition of a particular petroleum product, assuming that it is 85.7 percent carbon by mass is not an unreasonable first approximation." 

Aviation 

Gasoline 

0.1120 metric 

tons/bbl 

60F Liquid Thermal Properties of 

Petroleum Products, Bureau of Standards No.97 (1929) 

85.00 % of mass U.S. EPA, Inventory of U.S. 

Greenhouse Gas Emissions and Sinks: 1990 -2007, Annex 2, Page A-62 

Special Naphthas 

0.1222 metric 

tons/bbl 

60F Liquid Based on an analysis of five 

types of special napthas in EIA's Documentation for Emissions of Greenhouse Gases in the United States, 2006 

84.76 % of mass Based on an analysis of five types 

of special napthas in EIA's Documentation for Emissions of Greenhouse Gases in the United States, 2006 
Product Density 

Density 

Unit 

Density 

Temp 

Density 

Phase Density Source 

Carbon 

Share 

Carbon 

Share Unit Carbon Share Source 

Lubricants 0.1428 metric 

tons/bbl 

60F Liquid ASTM and Other Specifications

for Petroleum Products and Lubricants, Philadelphia, PA, 1985 

85.80 % of mass EIA's Documentation for 

Emissions of Greenhouse Gases in the United States, 2006 

Waxes 0.1285 metric 

tons/bbl 

60F Liquid American Society for Testing

and Materials, ASTM and Other Specifications for Petroleum Products and Lubricants (Philadelphia, PA, 1985), updated to four significant digits 

85.30 % of mass EIA's Documentation for 

Emissions of Greenhouse Gases in the United States 

Petroleum Coke 

0.1818 metric 

tons/bbl 

60F Solid ASTM and Other Specifications 

for Petroleum Products and Lubricants, Philadelphia, PA, 1985 

92.28 % of mass S. W. Martin, “Petroleum Coke,” in 

Virgil Guthrie (ed.), Petroleum Processing Handbook (New York, NY: McGraw-Hill, 1960), pp. 14-15 

Asphalt and 

Road Oil 

0.1634 metric 

tons/bbl 

60F Liquid ASTM and Other Specifications 

for Petroleum Products and Lubricants, Philadelphia, PA, 1985 

83.47 % of mass EIA's Documentation for 

Emissions of Greenhouse Gases in the United States, October 2008, Chapter 6, pg. 201 

Still Gas 0.1405 metric 

tons/bbl 

NOT 

IDENTIFIED 

NOT 

IDENTIFIED 

Density is based on the heat content of still gas as estimated by EIA, 6.0 million Btu per barrel, and the relationship of heat content to density from U.S. Department of Commerce, Bureau of Standards, Thermal Properties of Petroleum Products, Miscellaneous Publication No.97 November 9, 1929. 

77.70 % of mass Carbon content is based on data 

from the 2006 Intergovernmental Panel on Climate Change Guidelines, Volume 2; Energy Tables 1.2 and 1.3. 

Ethane 0.0866 metric 

tons/bbl -128F Liquid Handbook of Chemistry and Physics, Section 3 79.89 % of mass Based on atomic weights of the elements in the compound from 

the periodic table 

Ethylene 0.0903 metric 

tons/bbl -155F Liquid Handbook of Chemistry and Physics, Section 3 85.63 % of mass Based on atomic weights of the elements in the compound from 

the periodic table 

Propane 0.0784 metric 

tons/bbl -77F Liquid Handbook of Chemistry and Physics, Section 3 81.71 % of mass Based on atomic weights of the elements in the compound from 

the periodic table 

Propylene 0.0803 metric 

tons/bbl -77F Liquid Handbook of Chemistry and Physics, Section 3 85.63 % of mass Based on atomic weights of the elements in the compound from 

the periodic table 

Butane 0.0911 metric 

tons/bbl -77F Liquid Handbook of Chemistry and Physics, Section 3 82.66 % of mass Based on atomic weights of the elements in the compound from 

the periodic table 

Butylene 0.0935 metric 

tons/bbl -77F Liquid Handbook of Chemistry and Physics, Section 3 85.63 % of mass Based on atomic weights of the elements in the compound from 

the periodic table 
Product Density 

Density 

Unit 

Density 

Temp 

Density 

Phase Density Source 

Carbon 

Share 

Carbon 

Share Unit Carbon Share Source 

Isobutane 0.0876 metric 

tons/bbl -77F Liquid Handbook of Chemistry and Physics, Section 3 82.66 % of mass Based on atomic weights of the elements in the compound from 

the periodic table 

Isobutylene 0.0936 metric 

tons/bbl -77F Liquid Handbook of Chemistry and Physics, Section 3 85.63 % of mass Based on atomic weights of the elements in the compound from 

the periodic table 

Pentanes Plus 0.1055 metric 

tons/bbl 

60F Liquid Handbook of Chemistry and 

Physics, Section 15 

83.63 % of mass Based on values for atomic 

weights of the elements in the compound from the periodic table 

Miscellaneous Products 

0.1380 metric 

tons/bbl 

60F Liquid U.S. National Research 

Council, International Critical Tables of Numerical Data, Physics, Chemistry, and Technology (New York, NY: McGraw-Hill, 1927). 

85.49 % of mass U.S. National Research Council, 

International Critical Tables of Numerical Data, Physics, Chemistry, and Technology (New York, NY: McGraw-Hill, 1927). 

Table A-3. Characteristics and Data Sources for Fuels Listed in Table MM-2 

Product Density 

Density 

Unit Density Source 

Density 

Temp 

Density 

Phase 

Carbon 

Share 

Carbon 

Share Unit Carbon Share Source 

Em

Fa

Ethanol (100%) 

0.1267 metric 

tons/bbl 

Handbook of Chemistry and Physics, Section 15 

60F Liquid 52.14 % of mass Based on values for atomic 

weights of the elements in the compound from the periodic table 

0.2

Biodiesel(100%, methyl ester) 

0.1396 metric 

tons/bbl 

A Comprehensive Analysis of 

Biodiesel Impacts on Exhaust Emissions, October 2002 

60F Liquid 77.30 % of mass A Comprehensive Analysis of 

Biodiesel Impacts on Exhaust Emissions, October 2002 

0.

Rendered 

Animal Fat 

0.1333 metric 

tons/bbl 

Griffin Industries, Material Safety Data Sheet, Identity: Chicken Fat, March 19, 2007 

60F Liquid 76.19 % of mass Cyberlipid Center, Lipids of Land 

Animals, accessed September 9, 

2008 

0.

Vegetable Oil 0.1460 metric 

tons/bbl 

Weast, R.C., et al. CRC Handbook of Chemistry and Physics, Boca Raton: CRC Press, 1988-1989 

60F Liquid 76.77 % of mass Cyberlipid Center, Positional 

distribution of major fatty acids in triglycerides of some plant oils, accessed August 13, 2009 

0.4

Table A-4. Data Sources for HHVs and Emission Factors for Fuels Listed in Table NN-1

Fuel HHV HHV Unit HHV Source 

Emission 

Factor EF Unit 

Natural Gas 1.028 MMBtu/Mscf Assume same as Table C-1 53.02 kg CO2/MMBtu Assume same as TabPropane 3.822 MMBtu/bbl Assume same as Table C-1 61.46 kg CO2/MMBtu Assume same as TabNormal butane 4.242 MMBtu/bbl Assume same as Table C-1 65.15 kg CO2/MMBtu Assume same as TabEthane 4.032 MMBtu/bbl NOTE: Table NN-1 uses 0.096 as HHV for Ethane 62.64 kg CO2/MMBtu Assume same as TabIsobutane 4.074 MMBtu/bbl Assume same as Table C-1 64.91 kg CO2/MMBtu Assume same as TabPentanes plus 4.620 MMBtu/bbl Assume same as Table C-1 70.02 kg CO2/MMBtu Assume same as Tab
Table A-5. Emission Factors and Data Sources for Fuels Listed in Table NN-2

Fuel Emission Factor EF Unit EF Source

Natural Gas 0.055 MT CO2/Mscf Assume same as Table NN-1Propane 0.235 MT CO2/bbl Assume same as Table NN-1Normal butane 0.276 MT CO2/bbl Assume same as Table NN-1Ethane 0.253 MT CO2/bbl Assume same as Table NN-1Isobutane 0.266 MT CO2/bbl Assume same as Table NN-1Pentanes plus 0.324 MT CO2/bbl Assume same as Table NN-1
32 

Attachment B 

Recommended Updates to Heating Values and Emission Factors for Fuels Listed in 40 CFR Part 98 
Table B-1. Recommended Updates to Higher Heating Values for Fuels in Table C-1 

Current HHV Recommended HHV 

 Fuel type HHV HHV Unit Source HHV HHV Unit 

Natural Gas 0.001028 MMBtu/scf EIA AER 2008, Table A4 0.001026 MMBtu/scf EIA AER 2009, Table A4Used Oil 0.135 MMBtu/gallon NOT IDENTIFIED 0.138 MMBtu/gallon Graziano, D.J. and E.J. Danie

Increase the Recovery and RDOE, Argonne National LaboTechnology, 1995. http://infoh

Propane 0.091 MMBtu/gallon EIA AER 2005, Table A1 0.091 MMBtu/gallon Heating value determined ba

from DOE, NIST and Guthrie 

Propylene 0.091 MMBtu/gallon Bureau of Standards, Miscellaneous 

Publication No. 97, 1929. Thermal Properties of Petroleum Products. 

0.091 MMBtu/gallon Heating value determined ba

from DOE, NIST and Guthrie 

Ethane 0.069 MMBtu/gallon Bureau of Standards, Miscellaneous 

Publication No. 97, 1929. Thermal Properties of Petroleum Products. 

0.068 MMBtu/gallon Heating value determined ba

from DOE, NIST and Guthrie 

Ethylene 0.100 MMBtu/gallon Bureau of Standards, Miscellaneous 

Publication No. 97, 1929. Thermal Properties of Petroleum Products. 

0.058 MMBtu/gallon Heating value determined ba

from DOE, NIST and Guthrie 

Isobutane 0.097 MMBtu/gallon Bureau of Standards, Miscellaneous 

Publication No. 97, 1929. Thermal Properties of Petroleum Products. 

0.099 MMBtu/gallon Heating value determined ba

from DOE, NIST and Guthrie 

Isobutylene 0.103 MMBtu/gallon Bureau of Standards, Miscellaneous 

Publication No. 97, 1929. Thermal Properties of Petroleum Products. 

0.103 MMBtu/gallon Heating value determined ba

from DOE, NIST and Guthrie 

Butane 0.101 MMBtu/gallon Bureau of Standards, Miscellaneous 

Publication No. 97, 1929. Thermal Properties of Petroleum Products. 

0.103 MMBtu/gallon Heating value determined ba

from DOE, NIST and Guthrie 

Butylene 0.103 MMBtu/gallon Bureau of Standards, Miscellaneous 

Publication No. 97, 1929. Thermal Properties of Petroleum Products. 

0.105 MMBtu/gallon Heating value determined ba

from DOE, NIST and Guthrie 

Petrochemical Feedstocks 0.129 MMBtu/gallon EIA AER 2005, Table A-36. The underlying 

value in this source is 5.248 MMBtu/bbl which appears to be incorrectly transcribed in the EPA GHG Inventory as 5.428. The corrected heat content in MMBtu/gallon should be 0.125 

0.125 MMBtu/gallon EIA AER 2005, Table A-36. T

5.248 MMBtu/bbl which appethe EPA GHG Inventory as 5.MMBtu/gallon should be 0.12

Heavy Gas Oils 0.148 MMBtu/gallon NOT IDENTIFIED 0.148 MMBtu/gallon Heating value derived using t

Tg C/QBtu from the EPA GHG (coefficient for crude oil) and subpart MM 

Tires 26.87 MMBtu/short 

ton 

NOT IDENTIFIED 28.00 MMBtu/short ton U.S. EPA. 1991. Market for 

http://www.epa.gov/wastes/co

Solid Byproducts 25.83 MMBtu/short 

ton 

EIA, Renewable Energy Annual 2009, January 2012, Table 1.10. (Based on weighted average HHV of fuel reported to the Energy Information Administration on Form 

10.39 MMBtu/short ton Weighted average HHV for O

Energy Information Administr
Current HHV Recommended HHV 

 Fuel type HHV HHV Unit Source HHV HHV Unit 

EIA-860B for 1999.)

Biogas (Captured methane) 0.841 X 10-3 MMBtu/scf NOT IDENTIFIED. EPA Climate Leaders, 

Stationary Combustion Guidance (2004), Table B-2, lists landfill and wastewater biogas. Landfill gas is listed at 502.50 Btu/scf, wastewater gas as "varies". The source of the current factor 0.841x10-3 is not known at this time. ̶ MMBtu/scf ̶ Landfill Gas -̶ ̶ ̶ 0.485 X 10-3 MMBtu/scf Energy Information Administr

average HHV for landfill gas r

Digester Gas ̶ ̶ ̶ 0.655 X 10-3 MMBtu/scf Energy Information Administr

average HHV for other bioma

Rendered Animal Fat 0.125 MMBtu/gallon NOT IDENTIFIED 0.125 MMBtu/gallon HHV derived using the averag

of animal fats as listed in the - Adams, Thomas T. A DemoIndustrial Boiler Fuel. 2002. docs/biofuel_oil_report.pdf - Pearl, Gary. Animal Fats an

Alternatives as Burner Fuels. 

/images/GaryPearl.pdf - University of Auburn. BROIINFORMATION – JUNE 2008/pdf/wogsjun08.pdf - Kinast, J.A., Production of BandProperties of Biodiesels a2003. http://www.biofuels.coo- NOAA, CAMEO Chemicals, http://cameochemicals.noaa.g- Nelson, Richard. ENERGET

ASSOCIATED WITH THE PR

CONVERSION OF BEEF TAFUEL. 2006. http://aeg-biofu/2006_Energetic_BD_Prod.pd

Vegetable Oil 0.120 MMBtu/gallon NOT IDENTIFIED 0.120 MMBtu/gallon HHV derived using the averag

of vegetable oils as listed in th- Kinast, J.A., Production of BandProperties of Biodiesels a2003. http://www.biofuels.cooBartok, John W. University oValue of Common Fuels, 200http://www.hrt.msu.edu/energmmon%20fuels.pdf - Reeb, J. Home Heating Fuehttp://extension.oregonstate.e- Argeros, Anastasios. Heat ohttp://www.infolizer.com/s5e1
Current HHV Recommended HHV 

 Fuel type HHV HHV Unit Source HHV HHV Unit 

combustion-of-oils.html

Table B-2. Recommended Updates to Emission Factors in Table C-1 

Fuel Type 

Current Emission Factor 

(kg CO2/MMBtu) 

Recommended Emiss

(kg CO2/MMB

EF Source EF 

Anthracite 103.54 EPA GHG Inventory 1990 - 2005, Annex 2, Table A-32 103.69 EPA GHG Inventory, 1990-2

Bituminous 93.40 EPA GHG Inventory 1990 - 2005, Annex 2, Table A-32 93.28 EPA GHG Inventory, 1990-2Subbituminous 97.02 EPA GHG Inventory 1990 - 2005, Annex 2, Table A-32 97.17 EPA GHG Inventory, 1990-2Lignite 96.36 EPA GHG Inventory 1990 - 2005, Annex 2, Table A-32 97.72 EPA GHG Inventory, 1990-2Coke 102.04 EPA GHG Inventory 1990 - 2005, Annex 2, Table A-28 (Factor is 

for petroleum coke)

113.67 EPA GHG Inventory 1990-20

Mixed (Commercial sector) 95.26 EPA GHG Inventory 1990 - 2005, Annex 2, Table A-32 94.27 EPA GHG Inventory, 1990-2Mixed (Industrial coking) 93.65 EPA GHG Inventory 1990 - 2005, Annex 2, Table A-32 93.90 EPA GHG Inventory, 1990-2Mixed (Industrial sector) 93.91 EPA GHG Inventory 1990 - 2005, Annex 2, Table A-32 94.67 EPA GHG Inventory, 1990-2Mixed (Electric Power sector) 94.38 EPA GHG Inventory 1990 - 2005, Annex 2, Table A-32 95.52 EPA GHG Inventory, 1990-2Natural Gas 53.02 California Air Resources Board, Compendium of Emission 

Factors, 2007, Table 4 

53.06 Updated emission factor use

convert from carbon to CO2 

Liquefied petroleum gases (LPG) 62.98 EPA GHG Inventory 1990 - 2005, Annex 2, Table A-29. Using 

3.664 to convert carbon to CO2 

61.71 EPA GHG Inventory 1990 - 2

C/QBtu). Converted to CO2 factor of 61.71 kg CO2/MMB

Natural Gasoline 66.83 NOT IDENTIFIED (May be from EPA GHG Inventory 1990 - 2005, Annex 2, Table A-36) 66.88 EPA GHG Inventory, 1990 - Petrochemical Feedstocks 70.97 California Air Resources Board, Compendium of Emission 

Factors, 2007 

71.02 Updated emission factor use

convert from carbon to CO2 

Unfinished Oils 74.49 California Air Resources Board, Compendium of Emission 

Factors, 2007, Table 4. 

74.54 Updated emission factor use

convert from carbon to CO2 
Fuel Type 

Current Emission Factor 

(kg CO2/MMBtu) 

Recommended Emiss

(kg CO2/MMB

EF Source EF 

Crude Oil 74.49 California Air Resources Board, Compendium of Emission 

Factors, 2007 

74.54 Updated emission factor use

convert from carbon to CO2