Where:
CH4V = Quarterly CH4 liberated from a ventilation monitoring point (metric tons CH4).
V = Volumetric flow rate for the quarter (acfm) based on sampling or a flow rate meter. If a flow rate meter is used and the meter automatically corrects to standard temperature and pressure, then use scfm and replace "520°R/T * P/1 atm" with "1".
MCF = Moisture correction factor for the measurement period, volumetric basis.
= 1 when V and C are measured on a dry basis or if both are measured on a wet basis.
= 1-(fH2O) when V is measured on a wet basis and C is measured on a dry basis.
= 1/[1-(fH2O)] when V is measured on a dry basis and C is measured on a wet basis.
(fH2O) = Moisture content of the CH4 emitted during the measurement period, volumetric basis (cubic feet water per cubic feet emitted gas).
C = CH4 concentration of ventilation gas for the quarter (%).
n = The number of days in the quarter where active ventilation of mining operations is taking place at the monitoring point. To obtain the number of days in the quarter, divide the total number of hours in the quarter where active ventilation is taking place by 24 hours per day.
0.0423 = Density of CH4 at 520 °R (60 °F) and 1 atm (lb/scf).
520 °R = 520 degrees Rankine.
T = Temperature at which flow is measured (°R) for the quarter.
P = Absolute pressure at which flow is measured (atm) for the quarter. The annual average barometric pressure from the nearest NOAA weather service station may be used as a default.
1,440 = Conversion factor (min/day).
0.454/1,000 = Conversion factor (metric ton/lb).
Where:
CH4VTotal = Total quarterly CH4 liberated from ventilation systems (metric tons CH4).
CH4V = Quarterly CH4 liberated from each ventilation monitoring point (metric tons CH4).
m = Number of ventilation monitoring points.
Where:
CH4D = Weekly CH4 liberated from the monitoring point (metric tons CH4).
Vi = Measured volumetric flow rate for the days in the week when the degasification system is in operation at that monitoring point, based on sampling or a flow rate meter (acfm). If a flow rate meter is used and the meter automatically corrects to standard temperature and pressure, then use scfm and replace "520°R/Ti * Pi/1 atm" with "1".
MCFi = Moisture correction factor for the measurement period, volumetric basis.
= 1 when Vi and Ci are measured on a dry basis or if both are measured on a wet basis.
= 1-(fH2O)I when Vi is measured on a wet basis and Ci is measured on a dry basis.
= 1/[1-(fH2O)i] when Vi is measured on a dry basis and Ci is measured on a wet basis.
(fH2O) = Moisture content of the CH4 emitted during the measurement period, volumetric basis (cubic feet water per cubic feet emitted gas).
Ci = CH4 concentration of gas for the days in the week when the degasification system is in operation at that monitoring point (%).
n = The number of days in the week that the system is operational at that measurement point. To obtain the number of days in the week, divide the total number of hours that the system is operational by 24 hours per day.
0.0423 = Density of CH4 at 520 °R (60 °F) and 1 atm (lb/scf).
520 °R = 520 degrees Rankine.
Ti = Temperature at which flow is measured (°R).
Pi = Absolute pressure at which flow is measured (atm).
1,440 = Conversion factor (minutes/day).
0.454/1,000 = Conversion factor (metric ton/lb).
Where:
CH4DTotal = Quarterly CH4 liberated from all degasification monitoring points (metric tons CH4).
(CH4D)i,j = Weekly CH4 liberated from a degasification monitoring point (metric tons CH4).
m = Number of monitoring points.
w = Number of weeks in the quarter during which the degasification system is operated.
Where:
CH4Destroyed = Quarterly CH4 destroyed (metric tons).
CH4 = Quarterly CH4 routed to the destruction device or offsite transfer point (metric tons).
DE = Destruction efficiency (lesser of manufacturer's specified destruction efficiency and 0.99). If the gas is transported off-site for destruction, use DE = 1.
Where:
CH4DestroyedTotal = Quarterly total CH4 destroyed at the mine (metric tons CH4).
CH4Destroyed = Quarterly CH4 destroyed from each destruction device or offsite transfer point.
d = Number of onsite destruction devices and points of offsite transport.
Where:
CH4 emitted (net)= Quarterly CH4 emissions from the mine (metric tons).
CH4VTotal = Quarterly sum of the CH4 liberated from all mine ventilation monitoring points (CH4V), calculated using Equation FF-2 of this section (metric tons).
CH4DTotal = Quarterly sum of the CH4 liberated from all mine degasification monitoring points (CH4D), calculated using Equation FF-4 of this section (metric tons).
CH4DestroyedTotal = Quarterly sum of the measured CH4 destroyed from all mine ventilation and degasification systems, calculated using Equation FF-6 of this section (metric tons).
Where:
CO2 = Total quarterly CO2 emissions from CH4 destruction (metric tons).
CH4Destroyedonsite = Quarterly sum of the CH4 destroyed, calculated as the sum of CH4 destroyed for each onsite, non-energy use, as calculated individually in Equation FF-5 of this section (metric tons).
44/16 = Ratio of molecular weights of CO2 to CH4.
40 C.F.R. §98.323