Petroleum and Natural Gas Systems Monitoring Checklist for Onshore Natural Gas Processing Final Rule: Mandatory Reporting of Greenhouse Gases (40 CFR Part 98)


United States
Environmental Protection
Agency

Petroleum and Natural Gas Systems	&EFA

Monitoring Checklist for Onshore Natural
Gas Processing

Final Rule: Mandatory Reporting of Greenhouse Gases (40 CFR Part 98)

What must be monitored?

If emissions are going to flares, need data elements under the source flare stacks.

Record these parameters on an annual basis, unless specified otherwise.

1. Reciprocating Compressor Rod Packing Venting

Record emissions at each reciprocating compressor in as-found mode. Each
mode must be monitored at least once in any three consecutive calendar years.

Reciprocating Compressor Emissions in Operating Mode:

~	Rod packing venting from	~ Blowdown vent emissions from
reciprocating compressor in	reciprocating compressor in operational
operational mode (standard cubic	mode (standard cubic feet per hour)
feet per hour)

~	Total time the compressor is in	~ Annual throughput (million standard
operating mode (hours)	cubic feet per day)

~	Mole fraction of GHG in the vent
gas

Reciprocating Compressors Emissions in Standby Pressurized Mode:

~	Blowdown vent emissions from ~ Total time the reciprocating compressor is
reciprocating compressor in standby	in standby, pressurized mode (hours)
pressurized mode (standard cubic

feet)

~	Mole fraction of GHG in the vent
gas

Petroleum and Natural Gas Monitoring Checklist
On-Shore Natural Gas Processing
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40 CFR 98, subpart W
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Reciprocating Compressors in Shutdown, Depressurized Mode:

~	Unit isolation valve emissions from ~ Total time the reciprocating compressor is
reciprocating compressor in	in shutdown, depressurized mode (hours)
shutdown depressurized mode

(standard cubic feet)

~	Mole fraction of GHG in the vent
gas

Record emission factors for recip

~	Total annual reciprocating	~
compressor emissions in operating
mode (cubic feet)

~	Total annual reciprocating	~
compressor emissions in shut down,
depressurized mode (cubic feet)

~	Total number of compressors	~
measured in standby, pressurized
mode

ing compressors in each mode.

Total annual reciprocating compressor
emissions in standby, pressurized mode
(cubic feet)

Total number of compressors measured in
operating mode

Total number of compressors measured in
shutdown, depressurized mode

~	Emission factor for rod packing ~
vent emission in operating mode
(cubic feet per hour)

~	Emission factor for blowdown vent ~
emissions in standby pressurized

mode (cubic feet per hour)

Emission factor for blowdown vent
emissions in operating mode (cubic feet
per hour)

Emission factor for isolation valve in
shutdown, depressurized mode (cubic feet
per hour)

Record emissions from each reciprocating compressor in all modes and total

annual emissions.

~	Concentration of CH4 in	~
produced/feed natural gas for
reciprocating compressor in onshore
natural gas processing facilities

~	Total time the reciprocating	~
compressor is in standby,
pressurized mode in reporting year

Concentration of C02 in produced/feed
natural gas for reciprocating compressor
in onshore natural gas processing facilities

Total time the reciprocating compressor is
in shutdown, depressurized mode in
reporting year (hours)

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On-Shore Natural Gas Processing
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40 CFR 98, subpart W
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(hours)

~ Total annual compressor emission ~ Total time the compressor is in operating
from all modes of operation	mode in reporting year (hours)

(standard cubic feet)

2. Centrifugal Compressor Venting

Record emissions at both wet and dry seal centrifugal compressors in as-
found mode. Each mode must be monitored at least once in any three

consecutive calendar years.

Centrifugal Compressor Emissions in Operating Mode, Wet and Dry Seal Compressors:

~	Wet seal oil degassing vents	~
emissions from centrifugal
compressor in operational mode
(standard cubic feet per hour)

~	Total time the centrifugal	~
compressor is in operating mode
(hours)

~	Type of meters used for making ~
measurements

~	Mole fraction of GHG in the vent ~
gas

Blowdown vent emissions centrifugal
compressor in operational mode (standard
cubic feet per hour)

Number of wet seals connected to the
degassing vent

Fraction of operating time vent gas is sent
to vapor recovery or fuel gas

Annual throughput (million standard
cubic feet per day)

Centrifugal Compressors in Not-operating, Depressurized Mode, Wet and Dry Seal
Compressors:

~	Unit isolation valve emissions from ~ Total time the centrifugal compressor is in
centrifugal compressor in shutdown	shutdown, depressurized mode (hours)
depressurized mode (standard cubic

feet)

~	Mole fraction of GHG in the vent
gas

Record emission factors for centrifugal compressors in each mode.

~ Total annual emissions from all ~ Total annual emissions from all

centrifugal compressor in operating	centrifugal compressor in shut down,

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40 CFR 98, subpart W
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mode (cubic feet)

depressurized mode (cubic feet)

~	Total number of centrifugal	~
compressors measured in operating
mode

~	Emission factor for wet seal	~
degassing vent in operating mode
(cubic feet per hour)

~	Emission factor for isolation valve
in shutdown, depressurized mode
(cubic feet per hour)

Total number of centrifugal compressors
measured in shutdown, depressurized
mode

Emission factor for blowdown vent
emissions in operating mode (cubic feet
per hour)

Record emissions from each centrifugal compressor in all modes and total

annual emissions.

Concentration of CH4 in
produced/feed natural gas for
centrifugal compressor in onshore
natural gas processing facilities
Total time the centrifugal
compressor is in shutdown,
depressurized mode in reporting
year (hours)

Total time the centrifugal
compressor is in operating mode in
reporting year (hours)

Concentration of C02 in produced/feed
natural gas for centrifugal compressor in
onshore natural gas processing facilities

Total annual centrifugal compressor
emission from all modes of operation
(standard cubic feet)

3. Blowdown Vents

~	Number of repetitive blowdowns ~
for each equipment type of a

unique volume

~	Actual temperature in the	~
blowdown equipment chamber

(°F)

~	Emissions per equipment type
(cubic feet)

Total volume of blowdown equipment
chambers (including pipelines,
compressors and vessels) between isolation
valves (cubic feet)

Actual pressure in the blowdown
equipment chamber (psia)

4. Dehydrator Vents

Petroleum and Natural Gas Monitoring Checklist

On-Shore Natural Gas Processing	40 CFR 98, subpart W

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For glycol dehydrator with a throughput greater than or equal to 0.4 million cubic feet per
day:

~
~
~

Feed natural gas flow rate	~ Feed natural gas water content

(million standard cubic feet per

day)

Outlet natural gas water content ~ Absorbent circulation pump type (natural

Absorbent circulation rate

gas pneumatic/air pneumatic/ electric)
~ Absorbent type (TEG/DEG/EG)

~	Use of stripping natural gas (Y/N) ~ Use of flash tank separator (Y/N)

~	Total time of operation (hours) ~ Wet natural gas temperature (°F)

~ Wet natural gas composition

~ Wet natural gas pressure (psig)

~	Concentration of CH4 in natural ~ Concentration of CO2 in natural gas

gas

~	Vent gas controls used

For glycol dehydrator with a throughput less than to 0.4 million standard cubic feet per
year:

~ Count of glycol dehydrators

~ Vent gas controls used

For absorbent desiccant dehydrators:

~ Count of desiccant dehydrators

~ Vent gas controls used

~ Time between refilling (days)

~ Pressure of the gas (psia)

~	Height of the dehydrator vessel

(ft)

~	Percent of packed vessel volume
that is gas

~ Inside diameter of the vessel (ft)

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On-Shore Natural Gas Processing
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5. Acid Gas Removal (AGR) Vent Stacks

If using Calculation Methodology 1:

~	Total throughput into the AGR
unit and/or total throughput out of
the AGR unit (cubic feet per year)

~	Emissions recovered and
transferred outside the facility
(cubic feet)

If using Calculation Methodology 2:

~	Total throughput flowing out of
the AGR unit at actual conditions
(cubic feet)

~	Emissions recovered and
transferred outside the facility
(cubic feet)

If using Calculation Methodology 3:

Volume fraction of CO2 content in the
vent from the AGR unit

Volume fraction of CO2 content in vent
gas from the AGR unit

~	Total throughput through the
AGR unit at actual conditions
(cubic feet)

~	Volume fraction of C02 content
in natural gas out of the AGR unit

~	Actual Temperature (°F )

If using Calculation Methodology 4:

~	Natural gas feed temperature

~	Natural gas flow rate

~	Unit operating hours, excluding
downtime for maintenance or
standby

~	Solvent pressure

~	Solvent circulation rate

~	Volume fraction of C02 content in natural
gas into the AGR unit

~	Actual pressure (psia)

~	Emissions recovered and transferred
outside the facility (cubic feet)

~	Natural gas feed pressure

~	Acid gas content of feed natural gas

~	Acid gas content of outlet natural gas

~	Exit temperature of natural gas

~	Solvent temperature

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40 CFR 98, subpart W
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Solvent weight

6. Flare Stack Emissions

~	Continuous flow monitor on flare ~ Continuous gas analyzer on the gas to the
(Y/N)	flare (Y/N)

~	Volume of gas sent to flare annually ~ Percent of gas sent to un-lit flare
(cubic feet)

~	Flare combustion efficiency (98% if ~ Mole fraction of CO2 in gas to the flare
manufacturer data not available)

~	Mole fraction of gas hydrocarbon ~ Actual Process Temperature (°F)
constituents (such as methane, ethane,

propane, butane, and pentanes-plus)

~	Actual Process Pressure (psia)

7.	Valve Equipment Leaks Using Leak Detection

~	Concentration of CH4 in feed	~	Concentration of C02 in feed natural gas
natural gas

~	Report C02 emissions from all ~	Report CH4 emissions from all valves
valves (standard cubic feet)	(standard cubic feet)

~	Operating time of leaking	~	Total number of components found leaking
component (hours)

8.	Connector Equipment Leaks Using Leak Detection

~	Concentration of CH4 in feed	~	Concentration of CO2 in feed natural gas
natural gas

~	Report CO2 emissions from all ~	Report CH4 emissions from all connectors
connectors (standard cubic feet)	(standard cubic feet)

~	Operating time of leaking	~	Total number of components found leaking
component (hours)

9.	Open Ended Line Equipment Leaks Using Leak Detection

~	Concentration of CH4 in feed	~	Concentration of CO2 in feed natural gas
natural gas

~	Report CO2 emissions from all ~	Report CH4 emissions from all open ended

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40 CFR 98, subpart W
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open ended lines (standard cubic



lines (standard cubic feet)



feet)





~

Operating time of leaking

~

Total number of components found leaking



component (hours)





10.

Pressure Relief Valve Equipment Leaks Using Leak Detection

~

Concentration of CH4 in feed

~

Concentration of CO2 in feed natural gas



natural gas





~

Report CO2 emissions from all

~

Report CH4 emissions from all pressure



pressure relief valves (standard



relief valves (standard cubic feet)



cubic feet)





~

Operating time of leaking

~

Total number of components found leaking



component (hours)





11.

Meter Equipment Leaks Using Leak Detection

~

Concentration of CH4 in feed

~

Concentration of CO2 in feed natural gas



natural gas





~

Report CO2 emissions from all

~

Report CH4 emissions from all meters



meters (standard cubic feet)



(standard cubic feet)

~

Operating time of leaking

~

Total number of components found leaking

component (hours)

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On-Shore Natural Gas Processing
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