The Significance of Methane:

Transcription

1 The Significance of Methane: Technical Perspective on Emissions 2013 INGAA Foundation Annual Meeting November 9, 2013 Jim McCarthy Innovative Environmental Solutions, Inc.

2 Methane from Natural Gas Transmission Natural gas contains 90 95% methane Methane is a greenhouse gas (GHG) 25 times more potent than CO 2» 2013 EPA rule will increase methane GWP from 21 to 25 (20% increase)» GWP is used to report GHG emissions on a CO 2 equivalent (CO 2 e) basis Greenhouse Gas GWP over 20 yrs GWP over 100 yrs Carbon Dioxide (CO 2 ) 1 1 Methane (CH 4 ) Natural gas transmission & storage (T&S) methane releases:» Blowdowns: releases for maintenance, during compressor startups or shutdowns and emergencies» Other venting: operational releases by design (e.g., pneumatic devices)» Fugitive emissions: unintended leaks (e.g., from connectors, valves) Includes compressor related leaks rod packing seals, isolation valve leakage, etc.

3 Perception: Transmission and storage methane emissions are not significant One view (based on EPA 2011 national GHG inventory) CO 2 dominates the U.S. GHG national inventory CO 2 is 83.7% of total 2011 U.S. GHGs (on CO 2 e basis)» Methane ranks 2 nd 8.8% of total CO 2 e emissions Natural Gas Systems are 25% of methane emissions Transmission & Storage is 30% of methane from NG systems Thus, methane emissions from leaks and vents in T&S sector are <0.7% of U.S. GHG inventory Everything Else, 99.35% T&S CH4, 0.65%

4 Perception: Transmission and storage methane emissions are important Another view (based on EPA 2011 national GHG inventory) Methane is an important GHG» Methane has higher GWP over shorter time horizon (e.g., 72 vs 25) Using 20-year GWP, methane is ~25% of national inventory Methane reductions provide more near-term bang for the buck» Natural gas systems are largest methane source (25% of total) T&S is 30% of natural gas system emissions Natural gas operations are the largest methane source and T&S is a significant contributor» T&S is 30% of methane inventory for NG systems T&S is 7.5% of national methane inventory T&S 30% Distribution 19% Production 37% Processing 14%

5 June 2013 Climate Action Plan Obama Administration released Climate Action Plan on 6/25/13 Supports natural gas as a bridge fuel» Partner with stakeholders to exchange lessons learned on natural gas resource development; share best practices» Promote coal to gas fuel-switching & heavy duty nat. gas vehicles Identifies methane reductions as a priority Curbing emissions of methane is critical to our overall effort to address global climate change.» Develop interagency strategy to assess data and identify gaps» Work with stakeholders to reduce emissions EPA understands there are data gaps What information is available on methane emissions from natural gas systems?

6 Sources of Information GRI / EPA study (1996 report of 1992 emissions) U.S. National Inventory (annual EPA GHG inventory)» Annual inventory reported to UNFCCC tracks GHGs since 1990 GHG Reporting Program (GHGRP)» EPA reporting rule started with 2010 combustion inventory» Subpart W added methane venting and leaks in 2011» Larger facilities with annual emissions >25K metric tons CO 2 e EPA Natural Gas Star (Voluntary program since late 1990 s)» Reductions (not total emissions) reported; data not verified EDF Industry study ( project)» Measurements at T&S compressor stations; report in Spring 2014 INGAA/PRCI: Compiling GHGRP data, including thousands of vent measurements; may provide new basis for emission factors/estimates

7 Sources of Information: Background and Gaps Source Blow downs Other Venting Leaks Total Methane Releases GRI/EPA Study EPA U.S. National Inventory GHG Reporting Program EPA Star Program EDF Industry INGAA PRCI Resulted in emission factors (EFs) based on 1992 data that are still used today Annual GHG inventory based on EFs; includes pipeline blowdowns and leaks; T&S EFs from GRI/EPA Study (20 years old) Compressor station only; not pipeline (1) Direct point in time leak/vent measurement (2) 20 year old EFs Voluntary reporting of reductions; data not verified; reductions were low hanging fruit Direct measurement at 40 to 50 stations (Six companies); extrapolate to national estimate Compile GHGRP data; supplement EPA data with equipment & operations data 1.4% gas loss from NG systems 25% of national inventory from NG systems and 30% of that is from T&S Capture 85 90% of U.S. GHGs; but, only ~25% of compressor stns Incomplete and not representative Incomplete (2014 report) Underway (2014 tech memos)

8 Industry Actions and Initiatives EPA regulation focus is reporting, not reduction Pipeline industry is addressing CH 4 releases (i.e., NG losses)» Improving facility efficiency» Monitoring compressor (e.g., rod packing) leakage and conducting maintenance as necessary» Reducing pneumatic emission or replacing NG with air systems» Conducting leak inspections & addressing sources as warranted» Using state of the art technologies e.g., infrared camera Ongoing efforts to improve emission factors, measurement technologies, and mitigation options» Project with EDF will provide new data and methods» INGAA PRCI data compilation & analysis will significantly supplement available data and provide new EFs & methods