CO₂

Annual CO₂ emissions for a specific fuel type

metric tons/year

Output

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)

 -

52-366

p

Measurement period index

 -

(Flare)_p

Volume of flare gas combusted during measurement period

standard cubic feet per period, scf/period

User input

44

Molecular weight of CO₂

kg/kg-mole

44

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

849.5

or

836.6

0.001

Unit conversion factor

metric tons per kilogram, mt/kg

0.001 

(%CO₂)_p

Mole percent CO₂ concentration in the flare gas stream during the measurement period

percent by volume

User input

y

Number of carbon-containing compounds other than CO₂ in the flare gas stream

- 

User input 

x

Index for carbon-containing compounds other than CO₂

- 

User input 

0.98

Assumed combustion efficiency of a flare

mole CO₂ per mole carbon

0.98 

(%C_X)_p

Mole percent concentration of compound “x” in the flare gas stream during the measurement period

percent by volume

User input 

CMN_X

Carbon mole number of compound “x” in the flare gas stream. E.g., CMN for ethane (C₂H₆) is 2; CMN for propane (C₃H₈) is 3

mole carbon atoms per mole compound

User input 

CO₂

Annual CO₂ emissions for a specific fuel type

metric tons/year

Output

0.98

Assumed combustion efficiency of a flare

mole CO₂ per mole carbon

0.98

0.001

Unit conversion factor

metric tons per kg

0.001

Flare_Norm    

Annual volume of flare gas combusted during normal operations from company records

MMscf/year

User input 

HHV

Higher heating value for fuel gas or flare gas from company records

Btu/scf (or MMBtu/MMscf)

User input 

EmF

Default CO₂ emission factor for flare gas (HHV basis)

kg CO₂/MMBtu

60

n

Number of start-up, shutdown, and malfunction events during the reporting year exceeding 500,000 scf/day

-

User input 

p

Start-up, shutdown, and malfunction event index

-

User input 

44

Molecular weight of CO₂

kg/kg-mole

44 

12

Atomic weight of C

kg/kg-mole

12 

(Flare_SSM)_p

Volume of flare gas combusted during indexed start-up, shutdown, or malfunction event from engineering calculation

scf/event

User input 

(MW)_p

Average molecular weight of the flare gas, from the analysis results or engineering calculations for the event

kg/kg-mole

User input 

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)

scf/kg-mole  

849.5

or

836.6 

(CC)_p

Average carbon content of the flare gas, from analysis results or engineering calculations for the event

kg C per kg flare gas

User input

CH₄

Annual methane emissions from flared gas

metric tons CH₄/year

Output 

CO₂

Emission rate of CO₂ from flared gas calculated in paragraph (b)(1) of this section

metric tons/year 

User input 

EmF_CH4

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

Table C-2

EmF

Default CO₂ emission factor for flare gas (HHV basis)

kg CO₂/MMBtu

60

0.02/0.98

Correction factor for flare combustion efficiency

-

0.02/0.98 

16/44

Correction factor ratio of the molecular weight of CH₄ to CO₂

-

16/44 

f_CH4

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

User Input

or

Default (0.4)

CO₂

Annual CO₂ mass emissions

metric tons/year

Output

Q_unit

Annual throughput of unit from company records

bbl/yr

User input 

CBF

Coke burn-off factor from engineering calculations

kg coke per barrel of feed

User input

or

Default (7.3 for catalytic cracking units; 11 for fluid coking units)

0.001

Conversion factor

metric ton/kg

0.001

CC

Carbon content of coke based on measurement or engineering estimate

kg C per kg coke

User input

or

Default (0.94)

44/12

Ratio of molecular weight of CO₂ to C

kg CO₂ per kg C

44/12

CH₄

Annual CH₄ emissions from catalytic cracking or fluid coking unit

metric tons CH₄/year

Output

AD

Annual activity (e.g., input or product rate)

activity/year (user specified)

User Input

EF_CH4

CH₄ emission factor

metric tons CH₄/AD (user specified)

User Input

N₂O

Annual N₂O emissions from catalytic cracking or fluid coking unit

metric tons N₂O/year

Output

AD

Annual activity (e.g., input or product rate)

activity/year (user specified)

User Input

EF_N2O

 N₂O emission factor

metric tons N₂O/AD (user specified)

User Input

CO₂

Annual CO₂ emissions

metric tons/year

Output 

CB_Q

Coke burn-off quantity per regeneration cycle or measurement period from engineering estimates

kg coke/cycle or kg coke/measurement period

User input 

n

Number of regeneration cycles or measurement periods in the calendar year

-

User input 

CC

Carbon content of coke based on measurement or engineering estimate

kg C per kg coke

User input

or

Default (0.94)

44/12

Ratio of molecular weight of CO₂ to C

kg CO₂ per kg C

44/12 

0.001

Conversion factor

metric ton/kg

0.001 

CO₂

Annual CO₂ emissions

metric tons/year

Output 

F_SG

Sour gas feed sent off-site for sulfur recovery

scf/year

User input 

44

Molecular weight of CO₂

kg/kg-mole

44 

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)

scf/kg-mole  

849.5

or

836.6

MF_C

Mole fraction of carbon in the sour gas sent off-site for sulfur recovery

kg-mole C/kg-mole gas

Default = 0.20

0.001

Conversion factor, kg to metric tons

metric ton/kg

0.001

CO₂

Annual CO₂ emissions

metric tons/year

Output 

F_SG

Volumetric flow rate of sour gas (including sour water stripper gas) fed to the sulfur recovery plant

scf/year

User input 

44

Molecular weight of CO₂

kg/kg-mole

44 

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)

scf/kg-mole  

849.5

or

836.6

MF_C

Mole fraction of carbon in the sour gas fed to the sulfur recovery plant

kg-mole C/kg-mole gas

Default = 0.20

0.001

Conversion factor, kg to metric tons

metric ton/kg

0.001

CO₂

Annual CO₂ emissions

metric tons/year

Output 

M_in

Annual mass of green coke fed to the coke calcining unit from facility records

metric tons/year

User input 

CC_GC

Average mass fraction carbon content of green coke from facility measurement data

metric ton carbon/metric ton green coke

User input 

M_out

Annual mass of marketable petroleum coke produced by the coke calcining unit from facility records

metric tons petroleum coke/year

User input 

M_dust

Annual mass of petroleum coke dust removed from the process through the dust collection system of the coke calcining unit from facility records. 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

metric ton petroleum coke dust/year

User input 

CC_MPC

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

User input 

44

Molecular weight of CO₂

kg/kg-mole

44 

12

Atomic weight of C

kg/kg-mole

12 

CO₂

Annual CO₂ emissions from uncontrolled asphalt blowing

metric tons CO₂/year

Output 

Q_AB

Quantity of asphalt blown

MMbbl/year

User input 

EF_AB,CO2

Emission factor for CO₂ from uncontrolled asphalt blowing from facility-specific test data

metric tons CO₂/MMbbl asphalt blown

default = 1,100

CH₄

Annual CH₄ emissions from uncontrolled asphalt blowing

metric tons CH₄/year

Output 

Q_AB

Quantity of asphalt blown

MMbbl/year

User input 

EF_AB,CH4

Emission factor for CH₄ from uncontrolled asphalt blowing from facility-specific test data

metric tons CH₄/MMbbl asphalt blown

default = 580

CO₂

 Annual CO₂ emissions from controlled asphalt blowing

metric tons CO₂/year

Output 

0.98

 Assumed combustion efficiency of thermal oxidizer or flare

-

0.98

Q_AB

 Quantity of asphalt blown

MMbbl/year

User input 

CEF_AB

 Carbon emission factor from asphalt blowing from facility-specific test data

metric tons C/MMbbl asphalt blown

User input

or

Default (2,750)

44

 Molecular weight of CO₂

kg/kg-mole

44 

12

 Atomic weight of C

kg/kg-mole

12 

CO₂

 Annual CO₂ emissions from controlled asphalt blowing

metric tons CO₂/year

 Output

Q_AB

 Quantity of asphalt blown

MMbbl/year

User input 

0.98

 Assumed combustion efficiency of thermal oxidizer or flare

-

0.98 

EF_AB,CO2

Emission factor for CO₂ from uncontrolled asphalt blowing from facility-specific test data

metric tons CO₂/MMbbl asphalt blown

User input

or

Default (1,100)

CEF_AB

 Carbon emission factor from asphalt blowing from facility-specific test data

metric tons C/MMbbl asphalt blown

User input

or

Default (2,750)

44

 Molecular weight of CO₂

kg/kg-mole

44 

12

 Atomic weight of C

kg/kg-mole

12 

CH₄

 Annual methane from controlled asphalt blowing

metric tons CH₄/year

Output

0.02

 Fraction of methane uncombusted in thermal oxidizer or flare based on assumed 98% combustion efficiency

-

0.02 

Q_AB

 Quantity of asphalt blown

 MMbbl/year

User input 

EF_AB,CH4

Emission factor for CH₄ from uncontrolled asphalt blowing from facility-specific test data

metric tons CH₄/MMbbl asphalt blown

User input 

or

Default (580)

CH₄

Annual methane emissions from the delayed coking unit vessel opening

metric ton/year

Output 

N

Cumulative number of vessel openings for all delayed coking unit vessels of the same dimensions during the year

-

User input 

H

 Height of coking unit vessel

feet

User input 

P_CV

Gauge pressure of the coking vessel when opened to the atmosphere prior to coke cutting or, if the alternative method provided in paragraph (i)(2) of this section is used, gauge pressure of the coking vessel when depressurization gases are first routed to the atmosphere

pounds per square inch gauge, psig

User input 

14.7

Assumed atmospheric pressure

pounds per square inch, psi

14.7

f_void

Volumetric void fraction of coking vessel prior to steaming

cf gas/cf of vessel

Default (0.6)

D

Diameter of coking unit vessel

feet

User input 

16

Molecular weight of CH₄

kg/kg-mole

16 

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)

scf/kg-mole  

849.5

or

836.6 

Default (0.01) 

E_X

Annual emissions of each GHG from process vent

metric ton/yr

Output 

N

Number of venting events per year

-

User Input 

P

Index of venting events

-

User Input 

(VR)_p

Average volumetric flow rate of process gas during the event from measurement data, process knowledge, or engineering estimates

scf per hour

User Input 

(MF_X)_p

Mole fraction of GHG_X in process vent during the event from measurement data, process knowledge, or engineering estimates

kg-mol of GHG x/kg-mol vent gas

User Input 

MW_X

Molecular weight of GHG_X

kg/kg-mole

44 for CO₂

44 for N₂O

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)

scf/kg-mole  

849.5

or

836.6 

(VT)_p

Venting time for the event

hours

User Input 

0.001

Conversion factor

metric ton/kg

0.001 

CH₄

Methane emission rate from blowdown systems

mt CH₄/year

Output 

Q_Ref

Quantity of crude oil plus the quantity of intermediate products received from off site that are processed at the facility

MMbbl/year

User input 

EF_BD

Methane emission factor for uncontrolled blown systems

scf CH₄/MMbbl

Default (137,000)

16

Molecular weight of CH₄

kg/kg-mole

16 

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)

scf/kg-mole  

849.5

or

836.6 

0.001

Conversion factor

metric ton/kg

0.001

CH₄

Annual methane emissions from storage tanks

metric tons/year

Output

0.1

Default emission factor for storage tanks

metric ton CH₄/MMbbl

0.1 

Q_{Re f}

Quantity of crude oil plus the quantity of intermediate products received from off site that are processed at the facility

MMbbl/year

User input 

CH₄

Annual methane emissions from storage tanks

metric tons/year

Output 

Q_un

Quantity of unstabilized crude oil received at the facility

MMbbl/year

User input 

ΔP

Pressure differential from the previous storage pressure to atmospheric pressure

pounds per square inch, psi

User input 

MF_CH4

Average mole fraction of CH₄ in vent gas from the unstabilized crude oil storage tanks from facility measurements (measurement data or default value)

kg-mole CH₄/kg-mole gas

User input

or

Default (0.27)

995,000

Correlation Equation factor

scf gas per MMbbl per psi

995,000 

16

Molecular weight of CH₄

kg/kg-mole

16 

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)

 scf/kg-mole

849.5

or

836.6 

0.001

Conversion factor

metric ton/kg

0.001 

CH₄

Annual CH₄ emissions from storage tanks  

metric tons/year 

Output 

GGR

Annual gas generation rate for all unstabilized crude oil storage tanks

scf/year

User input 

MF_CH4

Average mole fraction of CH₄ in vent gas from the unstabilized crude oil storage tanks from facility measurements

kg-mole CH₄/kg-mole gas

User input

or

Default (0.27)

16

Molecular weight of CH₄

kg/kg-mole

16 

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)

scf/kg-mole 

849.5

or

836.6 

0.001

Conversion factor

metric ton/kg

0.001