title: Assessing the Methane Emissions from Natural Gas-Fired Power Plants and Oil Refineries.
abstract: Presently, there is high uncertainty in estimates of methane (CH4) emissions from natural gas-fired power plants (NGPP) and oil refineries, two major end users of natural gas. Therefore, we measured CH4and CO2emissions at three NGPPs and three refineries using an aircraft-based mass balance technique. Average CH4emission rates (NGPPs: 140 ± 70 kg/h; refineries: 580 ± 220 kg/h, 95% CL) were larger than facility-reported estimates by factors of 21-120 (NGPPs) and 11-90 (refineries). At NGPPs, the percentage of unburned CH4emitted from stacks (0.01-0.08%) was much lower than respective facility-scale losses (0.09-0.34%), and CH4emissions from both NGPPs and refineries were more strongly correlated with enhanced H2O concentrations (R2avg= 0.65) than with CO2(R2avg= 0.21), suggesting noncombustion-related equipment as potential CH4sources. Additionally, calculated throughput-based emission factors (EF) derived from the NGPP measurements made in this study were, on average, a factor of 4.4 (stacks) and 37 (facility-scale) larger than industry-used EFs. Subsequently, throughput-based EFs for both the NGPPs and refineries were used to estimate total U.S. emissions from these facility-types. Results indicate that NGPPs and oil refineries may be large sources of CH4emissions and could contribute significantly (0.61 ± 0.18 Tg CH4/yr, 95% CL) to U.S. emissions.
authors.affiliation: Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Tegan N
authors.identifier: 0000-0002-5402-2016
authors.initials: TN
authors.lastname: Lavoie
authors.affiliation: Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States.|Department of Earth, Atmospheric and Planetary Science and Purdue Climate Change Research Center, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Paul B
authors.initials: PB
authors.lastname: Shepson
authors.affiliation: Department of Earth, Atmospheric and Planetary Science and Purdue Climate Change Research Center, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Chloe A
authors.initials: CA
authors.lastname: Gore
authors.affiliation: School of Aviation and Transportation Technology, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Brian H
authors.initials: BH
authors.lastname: Stirm
authors.affiliation: Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Robert
authors.initials: R
authors.lastname: Kaeser
authors.affiliation: School of Aviation and Transportation Technology, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Bernard
authors.initials: B
authors.lastname: Wulle
authors.affiliation: Environmental Defense Fund, Austin, Texas 78701, United States.
authors.forename: David
authors.initials: D
authors.lastname: Lyon
authors.affiliation: Environmental Defense Fund, Austin, Texas 78701, United States.
authors.forename: Joseph
authors.initials: J
authors.lastname: Rudek
mesh_terms: D000393:Air Pollutants; D000401:Aircraft; D008697:Methane; D059206:Natural Gas; D011210:Power Plants
chemical_list: D000393:Air Pollutants; D059206:Natural Gas; D008697:Methane