CO2 = CO2-A
Where: CO2 = total CO2 emissions from the combustion of fuel gas (metric tonnes/yr) CO2A,B,C = CO2 emissions from the combustion sources in fuel gas system A,B,C, etc. (metric tonnes/yr)
= CO2 emissions from the combustion of fuel gas system X,
where X is the total number of fuel gas systems (metric tonnes/yr)
(f) Method for Calculating CO2 Emissions from Fuel Combustion for Fuel Mixtures. (Petroleum Refineries and Crude Oil and Natural Gas Processing Facilities)
Where individual fuels are mixed prior to combustion, the operator shall choose one of the methods below to calculate and report CO2 emissions.
Determine fuel flow rate and appropriate fuel specific parameters (carbon content, HHV) of each fuel stream prior to mixing, calculate CO2 emissions for each fuel in the mixture using the appropriate methodology (specified in section 95125(c) for natural gas and associated gas, 95125(f)(1)(B)-(D) for refinery fuel gas and flexigas, and 95113(d)(3) for low Btu gas) and sum individual fuel emissions to calculate emissions resulting from combustion of the mixture.
Determine CO2 emissions using a Continuous Emissions Monitor System (CEMS) as specified in section 95125(g).
Operators of petroleum refineries where refinery fuel gas is mixed with natural gas and/or low Btu gas shall use the methods specified in sections 95125(d)(3)(A) or 95125(e),
Operators of oil and gas production facilities and natural gas production and processing facilities where associated gas or low Btu gas is mixed with natural gas prior to combustion shall use methods specified in section 95125(c).
Method for Calculating CO2 Emissions Using Continuous Emissions Monitoring Systems.
The operator of a facility that combusts fossil fuels or biomass and operates continuous emissions monitoring systems (CEMS) in response to federal, state, or air pollution control district/air quality management district (AQMD/APCD) regulations, including 40 CFR Part 60 or 40 CFR Part 75, may use CO2 or O2 concentrations and flue gas flow measurements to determine hourly CO2 mass emissions using methodologies provided in 40 CFR Part 75, Appendix F. The operator shall report CO2 emissions for the report year in metric tonnes based on the sum of hourly CO2 mass emissions over the year, converted to metric tonnes.