Petroleum Refineries
Monitoring Checklist

Subpart Y, Greenhouse Gas Reporting Program

SERA

United 5
Environmental Protection
Agency

For flares, measure these parameters

Carbon Dioxide Emissions

If you monitor carbon content at least weekly

~

Volume of flare gas combusted during
measurement period (daily or weekly)
(standard cubic feet (scf)/period)

~

Average carbon content of flare gas
combusted during measurement period
(daily or weekly) (kg C/kg flare gas)

~

Average molecular weight of flare gas
combusted during measurement period
(daily or weekly) (kilogram
(kg)/kilogram-mole)





Or:
~

Volume of flare gas combusted during
measurement period (daily or weekly)
(scf/period)

~

Mole percent concentration of compound
""x" in the flare gas stream during the
measurement period (mole percent =
percent by volume)

~

Mole percent CO2 concentration in the
flare gas stream during the
measurement period (mole percent =
percent by volume)





If you monitor heat content at least weekly:





Volume of flare gas combusted during
~ measurement period (daily or weekly)
(million (MM) scf/period)

~

Higher heating value (HHV) for flare
gas during measurement period (daily
or weekly) (British thermal units
(Btu/scf = mmBtu/MMscf)

If you do not measure the higher heating value or carbon content of the flare gas at least weekly:

Annual volume of flare gas combusted

~	during normal operations from company
records (MMscf/year)

HHV for fuel gas or flare gas from

~	company records (Btu/scf =
mmBtu/MMscf)

Number of start-up, shutdown, and

~	malfunction events during the year
exceeding 500,000 scf/day

~

~

~

Volume of flare gas combusted during
indexed start-up, shutdown, or
malfunction event (scf/event)

Average molecular weight of the flare
gas during indexed start-up, shutdown,
or malfunction event (kg/kg-mole)

Average carbon content of flare gas
combusted during indexed start-up,
shutdown, or malfunction event (kg C/kg
flare gas)

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Greenhouse Gas Reporting Program

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40 CFR 98, subpart Y
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Methane emissions (optional)	

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) (If not
monitored, must use default of 0.4)

Note: The reporting of methane and
nitrous oxide emissions from flares is
required. The alternative calculation
methods involve the use of default
emission factors and fuel volumes and
do not require monitoring beyond what
is included on the checklist.

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Greenhouse Gas Reporting Program

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40 CFR 98, subpart Y
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For catalytic cracking units and traditional fluid coking units with rated
capacities greater than 10,000 barrels per stream day, measure these

parameters...

Carbon Dioxide Emissions

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)

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

You must also determine the hourly average exhaust gas flow rate from the fluid catalytic cracking
unit regenerator or fluid coking unit burner prior to the combustion of other fossil fuels by
monitoring:	

Volumetric flow rate of exhaust gas from
¦—I the fluid catalytic cracking unit regenerator
or fluid coking unit burner prior to the
combustion of other fossil fuels (dry scfh)

Or if using equation Y-7a:

Volumetric flow rate of air to the fluid
catalytic cracking unit regenerator or
~ fluid coking unit burner, as determined
from control room instrumentation
(dscfh)

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)

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)

Oxygen 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)

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)

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 CFRpart 63 subpart UUU,
assume % CO to be zero

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40 CFR 98, subpart Y
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Or if using equation Y-7b:

Volumetric flow rate of air to the fluid
catalytic cracking unit regenerator or
~ fluid coking unit burner, as determined
from control room instrumentation
(dscfh)

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)

Nitrogen (N2) concentration in oxygen
enriched gas stream inlet to the fluid
catalytic cracking unit regenerator or
|—1 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)

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)

Methane and nitrous oxide emissions	

Calculate emissions using either unit specific measurement data, a unit specific emission
factor based on a source test of the unit, or default values provided in the rule.

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Greenhouse Gas Reporting Program

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40 CFR 98, subpart Y
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If you operate and maintain a CEMS for catalytic cracking units or fluid
coking units, in addition to the Tier 4 Calculation Methodology and associated
requirements specified in 40 CFR 98, subpart C (General Stationary Fuel
Combustion Sources), monitor these parameters if applicable...

~ Fuel use in the CO boiler or other post-unit combustion device

If you do not operate a CEMS for catalytic cracking units and traditional
fluid coking units with rated capacities of 10,000 barrels per stream day or
less (if you do not continuously or no less frequently than daily monitor the
02, C02, and, if necessary, CO concentrations in the exhaust stack), measure

these parameters...

Carbon dioxide emissions	

[Optional] Carbon content of coke

. . .	based on measurement or engineering

n Annual throughput of unit from company n estimate (kg c/kg coke) (|fnot baged

recor s ( arre s yr)	on measuremen^ or engineering

estimate, must use default of 0.94)

[Optional] Coke burn-off factor from
engineering calculations (kg coke/barrel
~ of feed) (If not monitored, must use

default of 7.3 for catalytic cracking units
or default of 11 for fluid coking units)

Methane and nitrous oxide emissions	

Calculate emissions using either unit specific measurement data, a unit specific emission
factor based on a source test of the unit, or default values provided in the rule.

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Greenhouse Gas Reporting Program

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40 CFR 98, subpart Y
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If you do not operate a CEMS for fluid coking units that use flexicoking
design, measure these parameters...

Use methods described in 40 CFR 98, subpart C (General Stationary Combustion Sources) or
monitor same parameters for traditional fluid coking units.

If you do not operate a CEMS for catalytic reforming units, but you
continuously or no less frequently than daily monitor the O2, CO2, and (if

necessary) CO concentrations in the exhaust stack from the catalytic
reforming unit catalyst regenerator prior to the combustion of other fossil
fuels, calculate emissions following the requirements of catalytic cracking
units with rated capacities greater than 10,000 barrels per stream day;
otherwise, measure these parameters...

Carbon dioxide emissions	

Coke burn-off quantity per regeneration

~	cycle from engineering estimates (kg	~ Number of regeneration cycles in year
coke/cycle)

[Optional] Carbon content of coke based
on measurement or engineering estimate

~	(kg C/kg coke); If not based on
measurement or engineering estimate,
must use default of 0.94

Methane and nitrous oxide emissions	

Calculate emissions using either unit specific measurement data, a unit specific emission
factor based on a source test of the unit, or default values provided in the rule.

Petroleum Refineries Monitoring Checklist	40 CFR 98, subpart Y

Greenhouse Gas Reporting Program	February 2018

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If you operate and maintain a CEMS for sulfur recovery plants, in addition to
the Tier 4 Calculation Methodology and associated requirements specified in
40 CFR 98, subpart C (General Stationary Fuel Combustion Sources),

monitor this parameter...

j—I Fuel use in the Claus burner, tail gas incinerator, or other combustion sources that discharge via
the final exhaust stack from the sulfur recovery plant

If you do not operate a CEMS for onsite sulfur recovery plants and for sour
gas sent off site for sulfur recovery, measure these parameters...

Carbon Dioxide Emissions

Volumetric flow rate of sour gas feed
(including sour water stripper gas) to

[Optional] Mole fraction of carbon in
the sour gas to the sulfur recovery

|—| the sulfur recovery plant, from

plant, from measurement if available

measurement if available, engineering
calculations, or company records

~ or engineering calculations (kg-mole
C/kg-mole gas); If not based on

(scf/year)

measurement or engineering

calculations, must use default of 0.20

Non-Claus sulfur recovery units may alternatively elect to monitor:

~ Number of venting events per year	~ Venting time for the event (hours)

q gas during the event (scf/hour) [or this
may be determined from process
knowledge or engineering estimates]

Average volumetric flow rate of process

Mole fraction of CO2 in process vent
during the event (kg-mol GHG/kg-mol

~ vent gas) [or this may be determined
from process knowledge or
engineering estimates]

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Greenhouse Gas Reporting Program

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40 CFR 98, subpart Y
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If you operate and maintain a CEMS for coke calcining units, in addition to
the Tier 4 Calculation Methodology and associated requirements specified in
40 CFR 98, subpart C (General Stationary Fuel Combustion Sources),

monitor this parameter...

¦—I Fuel use in the coke calcining unit that discharges via the final exhaust stack from the coke
calcining unit

If you do not operate a CEMS for coke calcining units, measure these

parameters...

Carbon Dioxide Emissions

Annual mass of green coke fed to the
~ coke calcining unit from facility records
(metric tons/year)

~

~

Average mass fraction carbon content of
green coke from facility measurement
data (metric ton C/metric ton green coke)

Annual mass of marketable petroleum
coke produced by coke calcining unit
from facility records (metric tons
petroleum coke/year)

Annual mass of petroleum coke dust
collected in the dust collection system

~	of the coke calcining unit from facility
records (metric ton petroleum coke
dust/year)

Average mass fraction carbon content
of marketable petroleum coke

~	produced by the coke calcining unit
from facility measurement data (metric
ton C/metric ton petroleum coke)

Methane and nitrous oxide emissions	

Calculate emissions using either unit specific measurement data, a unit specific emission
factor based on a source test of the unit, or default values provided in the rule.

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Greenhouse Gas Reporting Program

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40 CFR 98, subpart Y
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For uncontrolled asphalt blowing operations or asphalt blowing operations
controlled by vapor scrubbing, measure these parameters...

The same methods (and thus same parameters measured) to estimate emissions as "Other process vents"
can be used. Alternatively, the following parameters can be measured to calculate emissions in
conjunction with other emission/conversion factors:

Carbon dioxide emissions		

[Optional] Emission factor for CO2
from uncontrolled asphalt blowing
from facility-specific test data (metric
tons C02/MMbbl asphalt blown); If
not based on facility-specific test data
must use default of 1,100.

Methane emissions		

[Optional] Emission factor for CH4
from uncontrolled asphalt blowing
from facility-specific test data (metric
tons CHVMMbbl asphalt blown); If
not based on facility-specific test data
must use default of 580

|—1 Annual quantity of asphalt blown	1—1

U (MMbbl/year)'	U

|—1 Annual quantity of asphalt blown	1—1

U (MMbbl/year)'	U

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Greenhouse Gas Reporting Program

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40 CFR 98, subpart Y
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For controlled asphalt blowing operations, measure these parameters...

The same methods (and thus same parameters measured) to estimate emissions as "Other process vents"
can be used. Alternatively, the following parameters can be measured to calculate emissions in
conjunction with other emission/conversion factors:

Carbon Dioxide Emissions		

[Optional] Carbon emission factor
from asphalt blowing from facility-
specific test data (metric tons
C/MMbbl asphalt blown); If not based
on facility-specific test data must use a
default of= 2,750

[Optional] Emission factor for CO2 from
uncontrolled asphalt blowing from
|—1 facility-specific test data (metric tons

C02/MMbbl asphalt blown); If not based
on facility-specific test data must use a
default of 1,100

|—1 Annual quantity of asphalt blown	1—1

U (MMbbl/year)'	U

Methane Emissions

|—1 Annual quantity of asphalt blown
U (MMbbl/year)'

[Optional] Emission factor for CH4
from uncontrolled asphalt blowing
from facility-specific test data (metric
tons CH4/MMbbl asphalt blown); If not
based on facility-specific test data must
use a default of 580

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Greenhouse Gas Reporting Program

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For delayed coking units, measure these parameters...

Methane Emissions	

On December 9, 2016 (81 FR 89261), the EPA finalized amendments to the DCU emissions
calculation methodology. The new method estimates emissions from DCU using a steam generation
model. Key inputs to this heat balance include the mass of water and coke in the coke drum vessel and
the average temperature of the coke drum contents when venting first occurs. As an alternative to
monitoring the average temperature of the coke drum, the calculation method provides a temperature-
pressure correlation. Finally, if a reporter has DCU vent gas measurements, these measurements can be
used to develop a unit-specific methane emissions factor for the DCU. These amendments are effective
January 1, 2019 for the RY 2018 report (which must be submitted by March 31, 2019). Reporters must
begin to collect the data necessary to calculate emissions in accordance with the amended method
beginning January 1, 2018.

Mass Coke in the Coke Drum Vessel:	

Typical dry mass of coke in the delayed
q coking unit vessel at the end of the
coking cycle from company records
(metric tons/cycle)

Or:

~ Height of coking unit vessel (feet)	~ Diameter of coking unit vessel (feet)

Typical distance from the top of the
delayed coking unit vessel to the top of
rj the coke bed (i.e., coke drum outage) at
the end of the coking cycle (feet) from
company records or engineering
estimates.

Mass of Water in the Coke Drum Vessel:

~ Diameter of coking unit vessel (feet)

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.

Average Temperature of the Coke Drum Vessel:

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 a value of 216 °F.

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 a
value of 212 °F.

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Greenhouse Gas Reporting Program

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Or:

Pressure of the delayed coking unit vessel
~ just prior to opening the atmospheric vent
(pounds per square inch gauge, psig).

Methane Emissions Calculation:	

[Optional] 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/mctric ton steam.

Cumulative number of decoking cycles
(or coke-cutting cycles) for all delayed
coking unit vessels associated with the
delayed coking unit during the year.

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Greenhouse Gas Reporting Program

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40 CFR 98, subpart Y
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For other process vents that exceed the volume percent thresholds provided in

the rule, measure these parameters...

For Each Greenhouse Gas	

~ Number of venting events per year

[Optional] Average volumetric flow rate
rj of process gas during the event (scf/hour)
[or this may be determined from process
knowledge or engineering estimates].

~	Venting time for the event (hours)

[Optional] Mole fraction of each GHG
in process vent during the event

~	(kg -mol GHG/kg-mol vent gas) [or this
may be determined from process
knowledge or engineering estimates]

For uncontrolled blowdown systems, measure these parameters...

The same methods (and thus same parameters measured) to estimate emissions as "Other process vents"
can be used. Alternatively, the following parameters can be measured to calculate emissions in
conjunction with other emission/conversion factors:

[Optional] Methane emission factor for

Annual quantity of crude oil plus the	uncontrolled blown systems (scf

n quantity of intermediate products received n CH4/MMbbl); If emission factor is not

from off site that are processed at the	, ^ , ,, u ,,

,,	'	monitored, must use default of

facility (MMbbl/year)

137,000

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Greenhouse Gas Reporting Program	February 2018

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For equipment leaks, measure these parameters..

~ Process-specific CH4 composition (from measurement data or process knowledge)

Or:

~

~

~

Number of atmospheric crude oil
distillation columns at the facility

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

Cumulative number of
hydrotreating/hydrorefining units,
catalytic reforming units, and visbreaking
units at the facility

~

~

Number of hydrogen plants at the
facility

Number of fuel gas systems at the
facility

For storage tanks (other than those processing unstabilized crude oil) that
have a vapor-phase methane concentration of 0.5 volume percent or more,

measure these parameters...

~ Tank-specific [liquid-phase] CH4 composition (from measurement data or product knowledge).

Or:

~

Annual quantity of crude oil plus the quantity of intermediate products received from offsite
that are processed at the facility (MMbbl/year)

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40 CFR 98, subpart Y
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For storage tanks that process unstabilized crude oil, measure these

parameters...

Tank-specific [vapor-phase] CH4
~ composition (from measurement data or
product knowledge)

~ Gas generation rate

Or:

|—| Annual quantity of unstabilized crude oil
received at the facility (MMbbl/year)

~

[Optional] Mole fraction of CH4 in
vent gas from the unstabilized crude
oil storage tank from facility
measurements (kg-mole CH4/kg-mole
gas); default = 0.27 if measurement
data are not available

Pressure differential from the previous
~ storage pressure to atmospheric pressure
(psi)

For crude oil, intermediate, or product loading operations for which the
equilibrium vapor-phase concentration of CH4 is 0.5 volume percent or more,

measure these parameters...

~ Product-specific, vapor-phase CH4 composition (from measurement data or process knowledge)

See also the information sheet for Petroleum Refineries at:
https://www.epa.gov/ghgreporting/subpart-v-information-sheet

This document is provided solely for informational purposes. It does not provide legal advice, have
legally binding effect, or expressly or implicitly create, expand, or limit any legal rights, obligations,
responsibilities, expectations, or bene fits in regard to any person. This information is intended to assist
reporting facilities/owners in understanding key provisions of the Greenhouse Gas Reporting Program.

Petroleum Refineries Monitoring Checklist	40 CFR 98, subpart Y

Greenhouse Gas Reporting Program	February 2018

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