Transmission Best Management Transmission Best Management Practices and Opportunities Practices and Opportunities Lessons Learned Lessons Learned from Natural Gas STAR from Natural Gas STAR Transmission Technology Transfer Workshop Transmission Technology Transfer Workshop Duke Energy Gas Transmission, Duke Energy Gas Transmission, Interstate Natural Gas Association of America Interstate Natural Gas Association of America (INGAA) and (INGAA) and EPA’s Natural Gas STAR Program EPA’s Natural Gas STAR Program September 22, 2004 September 22, 2004
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Transmission Best Management Practices and Opportunities Lessons Learned from Natural Gas STAR Transmission Technology Transfer Workshop Duke Energy Gas.
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Transmission Best Management Transmission Best Management Practices and OpportunitiesPractices and Opportunities
Lessons LearnedLessons Learnedfrom Natural Gas STARfrom Natural Gas STAR
Transmission Technology Transfer WorkshopTransmission Technology Transfer Workshop
Duke Energy Gas Transmission,Duke Energy Gas Transmission,Interstate Natural Gas Association of America (INGAA) and Interstate Natural Gas Association of America (INGAA) and
EPA’s Natural Gas STAR ProgramEPA’s Natural Gas STAR Program
The transmission sector has several large The transmission sector has several large methane emission sources that can be methane emission sources that can be targeted for reductionstargeted for reductions
Transmission & Distribution Sector Transmission & Distribution Sector Best Management PracticesBest Management Practices
BMP 1: Directed inspection and maintenance at gates BMP 1: Directed inspection and maintenance at gates stations and surface facilities stations and surface facilities
BMP 2: Identify and rehabilitate leaky distribution pipe BMP 2: Identify and rehabilitate leaky distribution pipe
BMP 3: Directed inspection and maintenance at BMP 3: Directed inspection and maintenance at compressor stations compressor stations
BMP 4: Use of turbines at compressor stations BMP 4: Use of turbines at compressor stations
BMP 5: Identify and replace high-bleed pneumatic BMP 5: Identify and replace high-bleed pneumatic devices devices
Why Are Partner Reported Why Are Partner Reported Opportunities (PROs) Important?Opportunities (PROs) Important?
Partner Annual Reports document Program Partner Annual Reports document Program accomplishmentsaccomplishments BMPs: The consensus best practicesBMPs: The consensus best practices PROs: Partner Reported OpportunitiesPROs: Partner Reported Opportunities
Simple vehicles for sharing successes and Simple vehicles for sharing successes and continuing Program’s future continuing Program’s future PRO Fact SheetsPRO Fact Sheets Lessons Learned: Expansion on the most Lessons Learned: Expansion on the most
advantageous BMPs and PROsadvantageous BMPs and PROs Technology Transfer WorkshopsTechnology Transfer Workshops
Why Are Partner Reported Why Are Partner Reported Opportunities (PROs) Important?Opportunities (PROs) Important?
Many transmission facilities have identified practical, Many transmission facilities have identified practical, cost-effective methane emissions reduction cost-effective methane emissions reduction practicespractices
Transmission Partners report saving 134 Bcf since Transmission Partners report saving 134 Bcf since 1993, 60% from PROs1993, 60% from PROs
Replacing wet seal with dry seals account for 16% Replacing wet seal with dry seals account for 16% of PRO emissions reductionsof PRO emissions reductions Lessons Learned study availableLessons Learned study available
43 PROs apply to transmission Sector43 PROs apply to transmission Sector 19 focused on operating practices19 focused on operating practices 24 focused on technologies24 focused on technologies
PRO Fact Sheets are derived from Annual PRO Fact Sheets are derived from Annual Reports 1994 to 2002Reports 1994 to 2002 Total 57 posted PROsTotal 57 posted PROs epa.gov/gasstarepa.gov/gasstar
Gas STAR Lessons Learned StudiesGas STAR Lessons Learned Studies
9 Lessons Learned studies are applicable to 9 Lessons Learned studies are applicable to transmission sectortransmission sector 5 focused on operating practices5 focused on operating practices 4 focused on technologies4 focused on technologies
All 16 Lessons Learned studies are on Gas All 16 Lessons Learned studies are on Gas STAR web siteSTAR web site epa.gov/gasstarepa.gov/gasstar
Lessons Learned Studies for Lessons Learned Studies for Transmission SectorTransmission Sector
Using hot taps for in service pipeline connectionsUsing hot taps for in service pipeline connections
Convert gas pneumatic controls to instrument airConvert gas pneumatic controls to instrument air
Using pipeline pump-down techniques to lower gas line pressure Using pipeline pump-down techniques to lower gas line pressure before maintenancebefore maintenance
DI&M at compressor stationsDI&M at compressor stations
Reducing emissions when taking compressors off-lineReducing emissions when taking compressors off-line
Reducing emissions from compressor rod packing systemsReducing emissions from compressor rod packing systems
Replacing wet seals with dry seals in centrifugal compressorReplacing wet seals with dry seals in centrifugal compressor
Options for reducing methane emissions from pneumatic devices in Options for reducing methane emissions from pneumatic devices in the natural gas industrythe natural gas industry
Composite wrap for non-leaking pipeline defectsComposite wrap for non-leaking pipeline defects
Close Main and Unit Valves Prior to Close Main and Unit Valves Prior to BlowdownBlowdown
What is the problem?What is the problem? Main valves are closed for Main valves are closed for
maintenance practices and the gas is maintenance practices and the gas is vented to the atmospherevented to the atmosphere
Partner solutionPartner solution Close main AND unit valves AND blow Close main AND unit valves AND blow
down isolated sections of equipmentdown isolated sections of equipment Methane savingsMethane savings
Based on venting of high pressure Based on venting of high pressure equipment, large volume vessels or equipment, large volume vessels or pipeline segments to the atmosphere pipeline segments to the atmosphere during routine maintenanceduring routine maintenance
ApplicabilityApplicability All compressor stationsAll compressor stations
Pipe Glycol Dehydrator to Vapor Pipe Glycol Dehydrator to Vapor Recovery UnitRecovery Unit
What is the problem?What is the problem? Methane gas from glycol dehydrator Methane gas from glycol dehydrator
is vented to the atmosphereis vented to the atmosphere Partner solutionPartner solution
Reroute vented gas to Vapor Reroute vented gas to Vapor Recovery Unit (VRU)Recovery Unit (VRU)
Methane savingsMethane savings Based on an electric or energy Based on an electric or energy
exchange circulation pump, can exchange circulation pump, can recover 3 to 9 Mcf of methane per recover 3 to 9 Mcf of methane per MMscf of gas processedMMscf of gas processed
ApplicabilityApplicability No limitations when the VRU No limitations when the VRU
discharges to fuel gas or main discharges to fuel gas or main compressor stationcompressor station
Perform Leak Repair During Pipeline Perform Leak Repair During Pipeline ReplacementReplacement
What is the problem?What is the problem? Corrosion and debris in pipelines Corrosion and debris in pipelines
accumulate in valve seats, preventing accumulate in valve seats, preventing tight closures and causing emissions tight closures and causing emissions during isolation of pipelinesduring isolation of pipelines
Partner solutionPartner solution Inspect and repair pipeline valves in Inspect and repair pipeline valves in
vicinity of ongoing pipeline repair/ vicinity of ongoing pipeline repair/ replacement projectsreplacement projects
Methane savingsMethane savings Based on leak rates through gate valves Based on leak rates through gate valves
Inspect & Repair Compressor Station Inspect & Repair Compressor Station Blowdown ValvesBlowdown Valves
What is the problem?What is the problem? Pressure, thermal and mechanical Pressure, thermal and mechanical
stresses wear blowdown valves making stresses wear blowdown valves making them significant emission sources them significant emission sources through inaccessible vent stacksthrough inaccessible vent stacks
Partner solutionPartner solution Annually inspect and repair leaking Annually inspect and repair leaking
blowdown valves at compressor stationsblowdown valves at compressor stations
Methane savingsMethane savings Based on EPAs emission factor for Based on EPAs emission factor for
transmission compressor station transmission compressor station blowdown valvesblowdown valves
ApplicabilityApplicability Applicable to all sitesApplicable to all sites
Install Pressurized Storage of Install Pressurized Storage of CondensateCondensate
What is the problem?What is the problem? Condensate from compressor scrubbers, Condensate from compressor scrubbers,
when transferred to atmospheric tanks, when transferred to atmospheric tanks, flash methane to the atmosphereflash methane to the atmosphere
Partner solutionPartner solution Pressurized storage and transport of Pressurized storage and transport of
condensate recovers methane and NGLscondensate recovers methane and NGLs
Methane savingsMethane savings Based on estimate of condensate Based on estimate of condensate
production of 0.01 barrel per Mscf of gas production of 0.01 barrel per Mscf of gas and methane emissions of 0.25 Mcf/ and methane emissions of 0.25 Mcf/ barrelbarrel
ApplicabilityApplicability Compressor stations receiving field Compressor stations receiving field
Use Ultrasound to Identify LeaksUse Ultrasound to Identify Leaks
What is the problem?What is the problem? Leakage through blowdown, vents Leakage through blowdown, vents
and PRVs cannot be easily detected and PRVs cannot be easily detected when discharged through roof ventswhen discharged through roof vents
Partner solutionPartner solution Use Ultrasonic leak detectors which Use Ultrasonic leak detectors which
can detect leaks inside a valvecan detect leaks inside a valve Methane savingsMethane savings
Assumption that 100 leaks can be Assumption that 100 leaks can be found through the operation’s with found through the operation’s with an emission rate of 20 Mcf/yr/valvean emission rate of 20 Mcf/yr/valve
ApplicabilityApplicability All in-service shut-off valves with All in-service shut-off valves with
Use YALEUse YALE®® Closures for ESD Testing Closures for ESD Testing
What is the problem?What is the problem? Gas from dump valves during ESD Gas from dump valves during ESD
testing is vented to the atmospheretesting is vented to the atmosphere Partner solutionPartner solution
Use YALEUse YALE®® closures to block dump closures to block dump valves for testing individual valve valves for testing individual valve with minimal gas ventingwith minimal gas venting
Methane savingsMethane savings Based on retrofitting ten 8 inch ESD Based on retrofitting ten 8 inch ESD
valves with a 3 foot stack and relief valves with a 3 foot stack and relief rate of 400 Mcf/minute on a 500 psig rate of 400 Mcf/minute on a 500 psig systemsystem
ApplicabilityApplicability All ESD valvesAll ESD valves
Directed Inspection and Maintenance Directed Inspection and Maintenance at Compressor Stationsat Compressor Stations
What is the problem?What is the problem? Gas leaks are Gas leaks are invisibleinvisible, , unregulatedunregulated and and go unnoticedgo unnoticed
STAR Partners find that valves, connectors, STAR Partners find that valves, connectors, compressor seals and open-ended lines (OELs) are compressor seals and open-ended lines (OELs) are major sourcesmajor sources 27 Bcf methane emitted per year by reciprocating 27 Bcf methane emitted per year by reciprocating
compressors seals and OELscompressors seals and OELs Open ended lines contribute half these emissionsOpen ended lines contribute half these emissions
Facility fugitive methane emissions depend on Facility fugitive methane emissions depend on operating practices, equipment age and maintenanceoperating practices, equipment age and maintenance
Methane Emissions from Leaking Components at Gas Plants
Clearstone Engineering, 2002, Identification and Evaluation of Opportunities to Reduce Methane Losses at Four Gas Processing Plants. Report of results from field study of 4 gas processing plants in WY and TX to evaluate opportunities to economically reduce methane emissions.
VoluntaryVoluntary program to identify and fix leaks program to identify and fix leaks that are cost-effective to repairthat are cost-effective to repair
Outside of mandatory LDAR Outside of mandatory LDAR
Survey cost will pay out in the first yearSurvey cost will pay out in the first year
Provides valuable data on leakersProvides valuable data on leakers
How Much Gas Can Be Saved?How Much Gas Can Be Saved?
Natural Gas STAR Lessons Learned study for DI&M Natural Gas STAR Lessons Learned study for DI&M at compressor stations estimatesat compressor stations estimates Potential Average Gas Savings ~ 29,000 Potential Average Gas Savings ~ 29,000
Mcf/yr/compressor stationMcf/yr/compressor station
Value of gas saved ~ $87,000 / compressor stationValue of gas saved ~ $87,000 / compressor station
Average initial implementation cost ~ $26,000 / Average initial implementation cost ~ $26,000 / compressor stationcompressor station
Real-time visual image of gas leaksReal-time visual image of gas leaks Quicker identification & repair of leaksQuicker identification & repair of leaks Screen hundreds of components an hourScreen hundreds of components an hour Screen inaccessible areas simply by viewing themScreen inaccessible areas simply by viewing them
To what extent are you implementing these To what extent are you implementing these opportunities?opportunities?
Can you suggest other opportunities?Can you suggest other opportunities?
How could these opportunities be improved upon or How could these opportunities be improved upon or altered for use in your operation?altered for use in your operation?
What are the barriers (technological, economic, lack What are the barriers (technological, economic, lack of information, regulatory, focus, manpower, etc.) of information, regulatory, focus, manpower, etc.) that are preventing you from implementing these that are preventing you from implementing these practices?practices?