where:
CO2 = Annual CO2 emissions for a specific fuel type (metric tons/year).
0.98 = Assumed combustion efficiency of a flare.
0.001 = Unit conversion factor (metric tons per kilogram, mt/kg).
n = Number of measurement periods. The minimum value for n is 52 (for weekly measurements); the maximum value for n is 366 (for daily measurements during a leap year).
p = Measurement period index.
44 = Molecular weight of CO2 (kg/kg-mole).
12 = Atomic weight of C (kg/kg-mole).
(Flare)p = Volume of flare gas combusted during measurement period (standard cubic feet per period, scf/period). If a mass flow meter is used, measure flare gas flow rate in kg/period and replace the term "(MW)p/MVC" with "1".
(MW)p = Average molecular weight of the flare gas combusted during measurement period (kg/kg-mole). If measurements are taken more frequently than daily, use the arithmetic average of measurement values within the day to calculate a daily average.
MVC = Molar volume conversion factor (849.5 scf/kg-mole at 68 °F and 14.7 pounds per square inch absolute (psia) or 836.6 scf/kg-mole at 60 °F and 14.7 psia).
(CC)p = Average carbon content of the flare gas combusted during measurement period (kg C per kg flare gas). If measurements are taken more frequently than daily, use the arithmetic average of measurement values within the day to calculate a daily average.
where:
CO2 = Annual CO2 emissions for a specific fuel type (metric tons/year).
n = Number of measurement periods. The minimum value for n is 52 (for weekly measurements); the maximum value for n is 366 (for daily measurements during a leap year).
p = Measurement period index.
(Flare)p = Volume of flare gas combusted during measurement period (standard cubic feet per period, scf/period). If a mass flow meter is used, you must determine the average molecular weight of the flare gas during the measurement period and convert the mass flow to a volumetric flow.
44 = Molecular weight of CO2 (kg/kg-mole).
MVC = Molar volume conversion factor (849.5 scf/kg-mole at 68 °F and 14.7 psia or 836.6 scf/kg-mole at 60 °F and 14.7 psia).
0.001 = Unit conversion factor (metric tons per kilogram, mt/kg).
(%CO2)p = Mole percent CO2 concentration in the flare gas stream during the measurement period (mole percent = percent by volume).
y = Number of carbon-containing compounds other than CO2 in the flare gas stream.
x = Index for carbon-containing compounds other than CO2.
0.98 = Assumed combustion efficiency of a flare (mole CO2 per mole carbon).
(%CX)p = Mole percent concentration of compound "x" in the flare gas stream during the measurement period (mole percent = percent by volume)
CMNX = Carbon mole number of compound "x" in the flare gas stream (mole carbon atoms per mole compound). E.g., CMN for ethane (C2H6) is 2; CMN for propane (C3H8) is 3.
Where:
CO2 = Annual CO2 emissions for a specific fuel type (metric tons/year).
0.98 = Assumed combustion efficiency of a flare.
0.001 = Unit conversion factor (metric tons per kilogram, mt/kg).
n = Number of measurement periods. The minimum value for n is 52 (for weekly measurements); the maximum value for n is 366 (for daily measurements during a leap year).
p = Measurement period index.
(Flare)p = Volume of flare gas combusted during measurement period (million (MM) scf/period). If a mass flow meter is used, you must also measure molecular weight and convert the mass flow to a volumetric flow as follows: Flare[MMscf] = 0.000001 * Flare[kg] * MVC/(MW)p, where MVC is the molar volume conversion factor [849.5 scf/kg-mole at 68 °F and 14.7 psia or 836.6 scf/kg-mole at 60 °F and 14.7 psia depending on the standard conditions used when determining (HHV)p] and (MW)p is the average molecular weight of the flare gas combusted during measurement period (kg/kg-mole).
(HHV)p = Higher heating value for the flare gas combusted during measurement period (British thermal units per scf, Btu/scf = MMBtu/MMscf). If measurements are taken more frequently than daily, use the arithmetic average of measurement values within the day to calculate a daily average.
EmF = Default CO2 emission factor of 60 kilograms CO2/MMBtu (HHV basis).
Where:
CO2 = Annual CO2 emissions for a specific fuel type (metric tons/year).
0.98 = Assumed combustion efficiency of a flare.
0.001 = Unit conversion factor (metric tons per kilogram, mt/kg).
FlareNorm = Annual volume of flare gas combusted during normal operations from company records, (million (MM) standard cubic feet per year, MMscf/year).
HHV = Higher heating value for fuel gas or flare gas from company records (British thermal units per scf, Btu/scf = MMBtu/MMscf).
EmF = Default CO2 emission factor for flare gas of 60 kilograms CO2/MMBtu (HHV basis).
n = Number of start-up, shutdown, and malfunction events during the reporting year exceeding 500,000 scf/day.
p = Start-up, shutdown, and malfunction event index.
44 = Molecular weight of CO2 (kg/kg-mole).
12 = Atomic weight of C (kg/kg-mole).
(FlareSSM)p = Volume of flare gas combusted during indexed start-up, shutdown, or malfunction event from engineering calculations, (scf/event).
(MW)p = Average molecular weight of the flare gas, from the analysis results or engineering calculations for the event (kg/kg-mole).
MVC = Molar volume conversion factor (849.5 scf/kg-mole at 68 °F and 14.7 psia or 836.6 scf/kg-mole at 60 °F and 14.7 psia).
(CC)p = Average carbon content of the flare gas, from analysis results or engineering calculations for the event (kg C per kg flare gas).
Where:
CH4 = Annual methane emissions from flared gas (metric tons CH4/year).
CO2 = Emission rate of CO2 from flared gas calculated in paragraph (b)(1) of this section (metric tons/year).
EmFCH4 = Default CH4 emission factor for "Fuel Gas" from Table C-2 of subpart C of this part (General Stationary Fuel Combustion Sources) (kg CH4/MMBtu).
EmF = Default CO2 emission factor for flare gas of 60 kg CO2/MMBtu (HHV basis).
0.02/0.98 = Correction factor for flare combustion efficiency.
16/44 = Correction factor ratio of the molecular weight of CH4 to CO2.
fCH4 = Weight fraction of carbon in the flare gas prior to combustion that is contributed by methane from measurement values or engineering calculations (kg C in methane in flare gas/kg C in flare gas); default is 0.4.
Where:
N2O = Annual nitrous oxide emissions from flared gas (metric tons N2O/year).
CO2 = Emission rate of CO2 from flared gas calculated in paragraph (b)(1) of this section (metric tons/year).
EmFN2O = Default N2O emission factor for "Fuel Gas" from Table C-2 of subpart C of this part (General Stationary Fuel Combustion Sources) (kg N2O/MMBtu).
EmF = Default CO2 emission factor for flare gas of 60 kg CO2/MMBtu (HHV basis).
Where:
CO2 = Annual CO2 mass emissions (metric tons/year).
Qr = Volumetric flow rate of exhaust gas from the fluid catalytic cracking unit regenerator or fluid coking unit burner prior to the combustion of other fossil fuels (dry standard cubic feet per hour, dscfh).
%CO2 = Hourly average percent CO2 concentration in the exhaust gas stream from the fluid catalytic cracking unit regenerator or fluid coking unit burner (percent by volume-dry basis).
%CO = Hourly average percent CO concentration in the exhaust gas stream from the fluid catalytic cracking unit regenerator or fluid coking unit burner (percent by volume-dry basis). When there is no post-combustion device, assume %CO to be zero.
44 = Molecular weight of CO2 (kg/kg-mole).
MVC = Molar volume conversion factor (849.5 scf/kg-mole at 68 °F and 14.7 psia or 836.6 scf/kg-mole at 60 °F and 14.7 psia).
0.001 = Conversion factor (metric ton/kg).
n = Number of hours in calendar year.
where:
Qr = Volumetric flow rate of exhaust gas from the fluid catalytic cracking unit regenerator or fluid coking unit burner prior to the combustion of other fossil fuels (dscfh).
Qa = Volumetric flow rate of air to the fluid catalytic cracking unit regenerator or fluid coking unit burner, as determined from control room instrumentation (dscfh).
Qoxy = Volumetric flow rate of oxygen enriched air to the fluid catalytic cracking unit regenerator or fluid coking unit burner as determined from control room instrumentation (dscfh).
%O2 = Hourly average percent oxygen concentration in exhaust gas stream from the fluid catalytic cracking unit regenerator or fluid coking unit burner (percent by volume-dry basis).
%Ooxy = O2 concentration in oxygen enriched gas stream inlet to the fluid catalytic cracking unit regenerator or fluid coking unit burner based on oxygen purity specifications of the oxygen supply used for enrichment (percent by volume-dry basis).
%CO2 = Hourly average percent CO2 concentration in the exhaust gas stream from the fluid catalytic cracking unit regenerator or fluid coking unit burner (percent by volume-dry basis).
%CO = Hourly average percent CO concentration in the exhaust gas stream from the fluid catalytic cracking unit regenerator or fluid coking unit burner (percent by volume-dry basis). When no auxiliary fuel is burned and a continuous CO monitor is not required under 40 CFR part 63 subpart UUU, assume %CO to be zero.
where:
Qr = Volumetric flow rate of exhaust gas from the fluid catalytic cracking unit regenerator or fluid coking unit burner prior to the combustion of other fossil fuels (dscfh).
Qa = Volumetric flow rate of air to the fluid catalytic cracking unit regenerator or fluid coking unit burner, as determined from control room instrumentation (dscfh).
Qoxy = Volumetric flow rate of oxygen enriched air to the fluid catalytic cracking unit regenerator or fluid coking unit burner as determined from control room instrumentation (dscfh).
%N2,oxy = N2 concentration in oxygen enriched gas stream inlet to the fluid catalytic cracking unit regenerator or fluid coking unit burner based on measured value or maximum N2 impurity specifications of the oxygen supply used for enrichment (percent by volume-dry basis).
%N2,exhaust = Hourly average percent N2 concentration in the exhaust gas stream from the fluid catalytic cracking unit regenerator or fluid coking unit burner (percent by volume-dry basis).
Where:
CO2 = Annual CO2 mass emissions (metric tons/year).
Qunit = Annual throughput of unit from company records (barrels (bbls) per year, bbl/yr).
CBF = Coke burn-off factor from engineering calculations (kg coke per barrel of feed); default for catalytic cracking units = 7.3; default for fluid coking units = 11.
0.001 = Conversion factor (metric ton/kg).
CC = Carbon content of coke based on measurement or engineering estimate (kg C per kg coke); default = 0.94.
44/12 = Ratio of molecular weight of CO2 to C (kg CO2 per kg C).
Where:
CH4 = Annual methane emissions from coke burn-off (metric tons CH4/year).
CO2 = Emission rate of CO2 from coke burn-off calculated in paragraphs (c)(1), (c)(2), (e)(1), (e)(2), (g)(1), or (g)(2) of this section, as applicable (metric tons/year).
EmF1 = Default CO2 emission factor for petroleum coke from Table C-1 of subpart C of this part (General Stationary Fuel Combustion Sources) (kg CO2/MMBtu).
EmF2 = Default CH4 emission factor for "PetroleumProducts" from Table C-2 of subpart C of this part (General Stationary Fuel Combustion Sources) (kg CH4/MMBtu).
Where:
N2O = Annual nitrous oxide emissions from coke burn-off (mt N2O/year).
CO2 = Emission rate of CO2 from coke burn-off calculated in paragraphs (c)(1), (c)(2), (e)(1), (e)(2), (g)(1), or (g)(2) of this section, as applicable (metric tons/year).
EmF1 = Default CO2 emission factor for petroleum coke from Table C-1 of subpart C of this part (General Stationary Fuel Combustion Sources) (kg CO2/MMBtu).
EmF3 = Default N2O emission factor for "PetroleumProducts" from Table C-2 of subpart C of this part (kg N2O/MMBtu).
Where:
CO2 = Annual CO2 emissions (metric tons/year).
CBQ = Coke burn-off quantity per regeneration cycle or measurement period from engineering estimates (kg coke/cycle or kg coke/measurement period).
n = Number of regeneration cycles or measurement periods in the calendar year.
CC = Carbon content of coke based on measurement or engineering estimate (kg C per kg coke); default = 0.94.
44/12 = Ratio of molecular weight of CO2 to C (kg CO2 per kg C).
0.001 = Conversion factor (metric ton/kg).
Where:
CO2 = Annual CO2 emissions (metric tons/year).
FSG = Volumetric flow rate of sour gas (including sour water stripper gas) fed to the sulfur recovery plant or the sour gas feed sent off-site for sulfur recovery (scf/year).
44 = Molecular weight of CO2 (kg/kg-mole).
MVC = Molar volume conversion factor (849.5 scf/kg-mole at 68 °F and 14.7 psia or 836.6 scf/kg-mole at 60 °F and 14.7 psia).
MFC = Mole fraction of carbon in the sour gas fed to the sulfur recovery plant or the sour gas feed sent off-site for sulfur recovery (kg-mole C/kg-mole gas); default = 0.20.
0.001 = Conversion factor, kg to metric tons.
Where:
CO2 = Annual CO2 emissions (metric tons/year).
Min = Annual mass of green coke fed to the coke calcining unit from facility records (metric tons/year).
CCGC = Average mass fraction carbon content of green coke from facility measurement data (metric ton carbon/metric ton green coke).
Mout = Annual mass of marketable petroleum coke produced by the coke calcining unit from facility records (metric tons petroleum coke/year).
Mdust = Annual mass of petroleum coke dust removed from the process through the dust collection system of the coke calcining unit from facility records (metric ton petroleum coke dust/year). For coke calcining units that recycle the collected dust, the mass of coke dust removed from the process is the mass of coke dust collected less the mass of coke dust recycled to the process.
CCMPC = Average mass fraction carbon content of marketable petroleum coke produced by the coke calcining unit from facility measurement data (metric ton carbon/metric ton petroleum coke).
44 = Molecular weight of CO2 (kg/kg-mole).
12 = Atomic weight of C (kg/kg-mole).
Where:
CO2 = Annual CO2 emissions from uncontrolled asphalt blowing (metric tons CO2/year).
QAB = Quantity of asphalt blown (million barrels per year, MMbbl/year).
EFAB,CO2 = Emission factor for CO2 from uncontrolled asphalt blowing from facility-specific test data (metric tons CO2/MMbbl asphalt blown); default = 1,100.
Where:
CH4 = Annual methane emissions from uncontrolled asphalt blowing (metric tons CH4/year).
QAB = Quantity of asphalt blown (million barrels per year, MMbbl/year).
EFAB,CH4 = Emission factor for CH4 from uncontrolled asphalt blowing from facility-specific test data (metric tons CH4/MMbbl asphalt blown); default = 580.
where:
CO2 = Annual CO2 emissions from controlled asphalt blowing (metric tons CO2/year).
0.98 = Assumed combustion efficiency of the control device.
QAB = Quantity of asphalt blown (MMbbl/year).
CEFAB = Carbon emission factor from asphalt blowing from facility-specific test data (metric tons C/MMbbl asphalt blown); default = 2,750.
44 = Molecular weight of CO2 (kg/kg-mole).
12 = Atomic weight of C (kg/kg-mole).
where:
CO2 = Annual CO2 emissions from controlled asphalt blowing (metric tons CO2/year).
QAB = Quantity of asphalt blown (MMbbl/year).
0.98 = Assumed combustion efficiency of the control device.
EFAB,CO2 = Emission factor for CO2 from uncontrolled asphalt blowing from facility-specific test data (metric tons CO2/MMbbl asphalt blown); default = 1,100.
CEFAB = Carbon emission factor from asphalt blowing from facility-specific test data (metric tons C/MMbbl asphalt blown); default = 2,750.
44 = Molecular weight of CO2 (kg/kg-mole).
12 = Atomic weight of C (kg/kg-mole).
where:
CH4 = Annual methane emissions from controlled asphalt blowing (metric tons CH4/year).
0.02 = Fraction of methane uncombusted in the controlled stream based on assumed 98% combustion efficiency.
QAB = Quantity of asphalt blown (million barrels per year, MMbbl/year).
EFAB,CH4 = Emission factor for CH4 from uncontrolled asphalt blowing from facility-specific test data (metric tons CH4/MMbbl asphalt blown); default = 580.
Where:
Mcoke = Typical dry mass of coke in the delayed coking unit vessel at the end of the coking cycle (metric tons/cycle).
[RHO]bulk = Bulk coke bed density (metric tons per cubic feet; mt/ft3). Use the default value of 0.0191 mt/ft3.
Hdrum = Internal height of delayed coking unit vessel (feet).
Houtage = Typical distance from the top of the delayed coking unit vessel to the top of the coke bed (i.e., coke drum outage) at the end of the coking cycle (feet) from company records or engineering estimates.
D = Diameter of delayed coking unit vessel (feet).
Where:
Mwater = Mass of water in the delayed coking unit vessel at the end of the cooling cycle just prior to atmospheric venting (metric tons/cycle).
[RHO]water = Density of water at average temperature of the delayed coking unit vessel at the end of the cooling cycle just prior to atmospheric venting (metric tons per cubic feet; mt/ft3). Use the default value of 0.0270 mt/ft3.
Hwater = Typical distance from the bottom of the coking unit vessel to the top of the water level at the end of the cooling cycle just prior to atmospheric venting (feet) from company records or engineering estimates.
Mcoke = Typical dry mass of coke in the delayed coking unit vessel at the end of the coking cycle (metric tons/cycle) as determined in paragraph (i)(1) of this section.
[RHO]particle = Particle density of coke (metric tons per cubic feet; mt/ft3). Use the default value of 0.0382 mt/ft3.
D = Diameter of delayed coking unit vessel (feet).
Where:
Tinitial = Average temperature of the delayed coking unit vessel when the drum is first vented to the atmosphere ( °F).
Toverhead = Temperature of the delayed coking unit vessel overhead line measured as near the coking unit vessel as practical just prior to venting to the atmosphere. If the temperature of the delayed coking unit vessel overhead line is less than 216 °F, use Toverhead = 216 °F.
Tbottom = Temperature of the delayed coking unit vessel near the bottom of the coke bed. If the temperature at the bottom of the coke bed is less than 212 °F, use Tbottom = 212 °F.
Where:
Tinitial = Average temperature of the delayed coking unit vessel when the drum is first vented to the atmosphere ( °F).
Poverhead = Pressure of the delayed coking unit vessel just prior to opening the atmospheric vent (pounds per square inch gauge, psig).
Where:
Msteam = Mass of steam generated and released per decoking cycle (metric tons/cycle).
fConvLoss = fraction of total heat loss that is due to convective heat loss from the sides of the coke vessel (unitless). Use the default value of 0.10.
Mwater = Mass of water in the delayed coking unit vessel at the end of the cooling cycle just prior to atmospheric venting (metric tons/cycle).
Cp,water = Heat capacity of water (British thermal units per metric ton per degree Fahrenheit; Btu/mt- °F). Use the default value of 2,205 Btu/mt- °F.
Mcoke = Typical dry mass of coke in the delayed coking unit vessel at the end of the coking cycle (metric tons/cycle) as determined in paragraph (i)(1) of this section.
Cp,coke = Heat capacity of petroleum coke (Btu/mt- °F). Use the default value of 584 Btu/mt- °F.
Tinitial = Average temperature of the delayed coking unit vessel when the drum is first vented to the atmosphere ( °F) as determined in paragraph (i)(3) of this section.
Tfinal = Temperature of the delayed coking unit vessel when steam generation stops ( °F). Use the default value of 212 °F.
[DELTA]Hvap = Heat of vaporization of water (British thermal units per metric ton; Btu/mt). Use the default value of 2,116,000 Btu/mt.
Where:
CH4 = Annual methane emissions from the delayed coking unit decoking operations (metric ton/year).
Msteam = Mass of steam generated and released per decoking cycle (metric tons/cycle) as determined in paragraph (i)(3) of this section.
EmFDCU = Methane emission factor for delayed coking unit (kilograms CH4 per metric ton of steam; kg CH4/mt steam) from unit-specific measurement data. If you do not have unit-specific measurement data, use the default value of 7.9 kg CH4/metric ton steam.
N = Cumulative number of decoking cycles (or coke-cutting cycles) for all delayed coking unit vessels associated with the delayed coking unit during the year.
0.001 = Conversion factor (metric ton/kg).
Where:
EX = Annual emissions of each GHG from process vent (metric ton/yr).
N = Number of venting events per year.
P = Index of venting events.
(VR)p = Average volumetric flow rate of process gas during the event (scf per hour) from measurement data, process knowledge, or engineering estimates.
(MFX)p = Mole fraction of GHG x in process vent during the event (kg-mol of GHG x/kg-mol vent gas) from measurement data, process knowledge, or engineering estimates.
MWX = Molecular weight of GHG x (kg/kg-mole); use 44 for CO2 or N2O and 16 for CH4.
MVC = Molar volume conversion factor (849.5 scf/kg-mole at 68 °F and 14.7 psia or 836.6 scf/kg-mole at 60 °F and 14.7 psia).
(VT)p = Venting time for the event, (hours).
0.001 = Conversion factor (metric ton/kg).
Where:
CH4 = Methane emission rate from blowdown systems (mt CH4/year).
QRef = Quantity of crude oil plus the quantity of intermediate products received from off site that are processed at the facility (MMbbl/year).
EFBD = Methane emission factor for uncontrolled blown systems (scf CH4/MMbbl); default is 137,000.
16 = Molecular weight of CH4 (kg/kg-mole).
MVC = Molar volume conversion factor (849.5 scf/kg-mole at 68 °F and 14.7 psia or 836.6 scf/kg-mole at 60 °F and 14.7 psia).
0.001 = Conversion factor (metric ton/kg).
Where:
CH4 = Annual methane emissions from equipment leaks (metric tons/year).
NCD = Number of atmospheric crude oil distillation columns at the facility.
NPU1 = Cumulative number of catalytic cracking units, coking units (delayed or fluid), hydrocracking, and full-range distillation columns (including depropanizer and debutanizer distillation columns) at the facility.
NPU2 = Cumulative number of hydrotreating/hydrorefining units, catalytic reforming units, and visbreaking units at the facility.
NH2 = Total number of hydrogen plants at the facility.
NFGS = Total number of fuel gas systems at the facility.
Where:
CH4 = Annual methane emissions from storage tanks (metric tons/year).
0.1 = Default emission factor for storage tanks (metric ton CH4/MMbbl).
QRef = Quantity of crude oil plus the quantity of intermediate products received from off site that are processed at the facility (MMbbl/year).
Where:
CH4 = Annual methane emissions from storage tanks (metric tons/year).
Qun = Quantity of unstabilized crude oil received at the facility (MMbbl/year).
[DELTA]P = Pressure differential from the previous storage pressure to atmospheric pressure (pounds per square inch, psi).
MFCH4 = Average mole fraction of CH4 in vent gas from the unstabilized crude oil storage tanks from facility measurements (kg-mole CH4/kg-mole gas); use 0.27 as a default if measurement data are not available.
995,000 = Correlation Equation factor (scf gas per MMbbl per psi).
16 = Molecular weight of CH4 (kg/kg-mole).
MVC = Molar volume conversion factor (849.5 scf/kg-mole at 68 °F and 14.7 psia or 836.6 scf/kg-mole at 60 °F and 14.7 psia).
0.001 = Conversion factor (metric ton/kg).
40 C.F.R. §98.253