40 CFR Appendix B to Part 72, Methodology for Conversion of Emissions Limits

Appendix B to Part 72 - Methodology for Conversion of Emissions Limits

For the purposes of the Acid Rain Program, all emissions limits must be expressed in pounds of SO2 per million British Thermal Unit of heat input (lb/mmBtu).

The factor for converting pounds of sulfur to pounds of SO2 is based on the molecular weights of sulfur (32) and SO2 (64). Limits expressed as percentage of sulfur or parts per million (ppm) depend on the energy content of the fuel and thus may vary, depending on several factors such as fuel heat content and atmospheric conditions. Generic conversions for these limits are based on the assumed average energy contents listed in table A-2. In addition, limits in ppm vary with boiler operation (e.g., load and excess air); generic conversions for these limits assume, conservatively, very low excess air. The remaining factors are based on site-specific heat rates and capacities to develop conversions for Btu per hour. Standard conversion factors for residual oil are 42 gal/bbl and 7.88 lbs/gal.

Table B-1 - Conversion Factors

[Emission limits converted to lbs SO2/MMBtu by multiplying as below]

Unit measurement Plant fuel type
Bituminous coal Subbituminous coal Lignite coal Oil
Lbs sulfur/ MMBtu 2.0 2.0 2.0 2.0
% sulfur in fuel 1.66 2.22 2.86 1.07
Ppm SO2 0.00287 0.00384 0.00167
Ppm sulfur in fuel 0.00334
Tons SO2/hour 2,000,000/(HEATRATE*SUMNDCAP*capacity factor) 1
Lbs SO2/hour 1,000/(HEATRATE*SUMNDCAP*capacity factor) 1

1 In these cases, if the limit was specified as the “site” limit, the summer net dependable capability for the entire plant is used; otherwise, the summer net dependable capability for the unit is used. For units listed in the NADB, “HEATRATE” shall be that listed in the NADB under that field and “SUMNDCAP” shall be that listed in the NADB under that field. For units not listed in the NADB, “HEATRATE” is the generator net full load heat rate reported on Form EIA-860 and “SUMNDCAP” is the summer net dependable capability of the generator (in MWe) as reported on Form EIA-860.

Table B-2 - Assumed Average Energy Contents

Fuel type Average heat content
Bituminous Coal 24 MMBtu/ton.
Subbituminous Coal 18 MMBtu/ton.
Lignite Coal 14 MMBtu/ton.
Residual Oil 6.2 MMBtu/bbl.

This is a list of United States Code sections, Statutes at Large, Public Laws, and Presidential Documents, which provide rulemaking authority for this CFR Part.

This list is taken from the Parallel Table of Authorities and Rules provided by GPO [Government Printing Office].

It is not guaranteed to be accurate or up-to-date, though we do refresh the database weekly. More limitations on accuracy are described at the GPO site.


United States Code
U.S. Code: Title 42 - THE PUBLIC HEALTH AND WELFARE

§ 7401 - Congressional findings and declaration of purpose

§ 7403 - Research, investigation, training, and other activities

§ 7410 - State implementation plans for national primary and secondary ambient air quality standards

§ 7411 - Standards of performance for new stationary sources

§ 7426 - Interstate pollution abatement

§ 7601 - Administration

§ 7602 - Definitions

§ 7603 - Emergency powers

§ 7604 - Citizen suits

§ 7605 - Representation in litigation

§ 7606 - Federal procurement

§ 7607 - Administrative proceedings and judicial review

§ 7608 - Mandatory licensing

§ 7609 - Policy review

§ 7610 - Other authority

§ 7611 - Records and audit

§ 7612 - Economic impact analyses

§ 7613 - Repealed. Pub. L. 101–549, title VIII, § 803, Nov. 15, 1990, 104 Stat. 2689

§ 7614 - Labor standards

§ 7615 - Separability

§ 7616 - Sewage treatment grants

§ 7617 - Economic impact assessment

§ 7618 - Repealed. Pub. L. 101–549, title I, § 108(q), Nov. 15, 1990, 104 Stat. 2469

§ 7619 - Air quality monitoring

§ 7620 - Standardized air quality modeling

§ 7621 - Employment effects

§ 7622 - Employee protection

§ 7623 - Repealed. Pub. L. 96–300, § 1(c), July 2, 1980, 94 Stat. 831

§ 7624 - Cost of vapor recovery equipment

§ 7625 - Vapor recovery for small business marketers of petroleum products

§ 7625-1

§ 7625a - Statutory construction

§ 7626 - Authorization of appropriations

§ 7627 - Air pollution from Outer Continental Shelf activities

§ 7628 - Demonstration grant program for local governments