Regulations last checked for updates: May 18, 2024

Title 40 - Protection of Environment last revised: May 16, 2024
Appendix - Table NN-1 to Subpart NN of Part 98—Default Factors for Calculation Methodology 1 of This Subpart
Fuel Default higher heating value 1 Default CO2
emission
factor
(kg CO2/MMBtu)
Natural Gas1.026 MMBtu/Mscf53.06
Propane3.84 MMBtu/bbl62.87
Normal butane4.34 MMBtu/bbl64.77
Ethane2.85 MMBtu/bbl59.60
Isobutane4.16 MMBtu/bbl64.94
Pentanes plus4.62 MMBtu/bbl70.02

1 Conditions for higher heating values presented in MMBtu/bbl are 60 °F and saturation pressure.

[78 FR 71977, Nov. 29, 2013]
source: 74 FR 56374, Oct. 30, 2009, unless otherwise noted.