Emission Source with Example EF Units
- Stationary Combustion
- Kg CO2/tonne
- Kg CO2/Btu or MJ
- Kg CO2/scf or m3
- Kg CO2/gallon or L
- Mobile Combustion
- Kg CO2/scf or m3
- Kg CO2/gallon or L
- Fugitive CH4 (gas transmission and storage)
- CH4/million m3 of marketable gas
Considerations
- Considerations for both Stationary and Mobile Combustion: EFs are generally estimated based on sample measurements of the average carbon content of the fuel and then applied to activity data collected in energy units (e.g., MJ or Btu) rather than units of mass or volume.* Some standard fuels may have EFs expressed in mass or volume, but only when there is high consistency in the fuel. Fuel type and characteristics combusted must match the EF selected and appropriate units of mass.
- Considerations for Fugitive CH4 (gas transmission and storage): These EFs typically set a default rate for fugitive CH4 emissions assuming typical steady-state leak rates and typical frequency of intermittent leak rates across a range of equipment (e.g., valves, compressors), maintenance activities, and equipment malfunctions.