StacksVerified U.S. regulatory reference

40 CFR Part 98, Table AA-2

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov
FuelFossil fuel-based emissions factors (kg/mmBtu HHV)
Kraft rotary lime kilnsKraft calciners a
CH4N2 O | CH4 | N2 O
Residual Oil (any type)0.0027 | 0 | 0.0027 | 0.0003
Distillate Oil (any type)0.0027 | 0 | 0.0027 | 0.0004
Natural Gas0.0027 | 0 | 0.0027 | 0.0001
Biogas0.0027 | 0 | 0.0027 | 0.0001
Petroleum coke0.0027 | 0 | b NA | b NA
Other FuelsSee Table C-2 | 0 | See Table C-2 | See Table C-2

a Includes, for example, fluidized bed calciners at kraft mills.

b Emission factors for kraft calciners are not available.

[78 FR 71965, Nov. 29, 2013, as amended at 81 FR 89264, Dec. 9, 2016]