Toward a Functional Definition of Methane Super-Emitters: Application to Natural Gas Production Sites

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• 作者：Daniel Zavala-Araiza ; David Lyon ; Ram贸n A. Alvarez ; Virginia Palacios ; Robert Harriss ; Xin Lan ; Robert Talbot ; Steven P. Hamburg
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：July 7, 2015
• 年：2015
• 卷：49
• 期：13
• 页码：8167-8174
• 全文大小：373K
• ISSN：1520-5851

文摘

Emissions from natural gas production sites are characterized by skewed distributions, where a small percentage of sites鈥攃ommonly labeled super-emitters鈥攁ccount for a majority of emissions. A better characterization of super-emitters is needed to operationalize ways to identify them and reduce emissions. We designed a conceptual framework that functionally defines superemitting sites as those with the highest proportional loss rates (methane emitted relative to methane produced). Using this concept, we estimated total methane emissions from natural gas production sites in the Barnett Shale; functionally superemitting sites accounted for roughly three-fourths of total emissions. We discuss the potential to reduce emissions from these sites, under the assumption that sites with high proportional loss rates have excess emissions resulting from abnormal or otherwise avoidable operating conditions, such as malfunctioning equipment. Because the population of functionally superemitting sites is not expected to be static over time, continuous monitoring will likely be necessary to identify them and improve their operation. This work suggests that achieving and maintaining uniformly low emissions across the entire population of production sites will require mitigation steps at a large fraction of sites.