CFNMHC = NMHC to CH4 conversion factor (CFNMHC 0.001 = conversion factor – kg to metric tonnes
(A) The operator shall calculate and report CH4 emissions from crude oil, naphtha, distillate oil, asphalt, and gas oil storage tanks using the U.S. EPA TANKS Model (Version 4.09D). VOC emission values generated by the model shall be converted to methane emissions using a default conversion factor of 0.6 (CH4 = 0.6 * VOC). Alternatively, operators may determine species specific conversion factors determined by storage tank headspace vapor analysis using ARB approved sampling and analysis methodology.
Equipment Fugitive Emissions
The operator shall calculate and report CH4 fugitive emissions for all gas service components as specified in CAPCOA (1999) Method 3: Correlation Equation Method in the following manner:
Components shall be identified as one of the following classification types: valve, pump seal, other, connector, flange, open-ended line. Operators shall use the Component Identification and Counting Methodology and screening methods found in CAPCOA (1999), which is incorporated by reference herein.
Screening values (SV) for each component comprising all natural gas, refinery fuel gas, and PSA off-gas systems shall be measured and recorded using instrumentation capable of detecting methane. Operators shall conduct screenings at the frequency interval required by their local air district.
Operators shall calculate VOC emissions in the following manner:
Zero Components – Use of Default Zero Factor. For zero components (components where the SV, corrected for background, equals 0.0 ppmv – i.e., the SV is indistinguishable from zero) for each screening period (e.g. month, quarter, year), operators shall calculate VOC emissions as follows:
6 = ∑ CCi * ZFi0 * t i=1 Where: EVOC-0 = zero component VOC emission (kg/screening period) EVOC-0