Methane exhaust measurements at US gathering compressor stations

This study measured methane emissions from internal combustion engines used in natural gas compression at U.S. gathering and boosting stations. Researchers sampled 133 engines from 67 facilities across 11 states. Using a in-stack tracer gas method, they estimated combustion slip (methane that escapes during the combustion process) under normal conditions. The data was then used in a model to estimate total annual methane emissions from these engines. The results were compared with existing U.S. EPA emission inventories, and recommendations were made on how to improve the accuracy of methane estimates in the EPA’s Greenhouse Gas Inventory (GHGI)