reports for Greenwire. "For oil refineries, emissions may be 11 to 90 times higher than EPA estimates." Researchers "used Purdue's flying atmospheric chemistry lab—a Beechcraft Duchess light twin-engine airplane equipped with an airflow measurement probe—to collect daily samples at three natural gas power plants and three refineries from July 30 to Oct. 1, 2015."
Paul Shepson, director of Purdue's Climate Change Research Center, said "EPA's greenhouse gas reporting program focuses on how much escapes from belching power stacks, without considering that methane could be leaking from compressors, valves and industrial hardware," Hess writes. He told Hess, "The good news from our study is that while emissions are greater than anticipated, natural gas-burning power plants are still cleaner, relative to burning coal."
Shepson said "The amount of methane escaping from the plants in the pilot study, combined with previous estimates of methane leakage in the supply chain, is still below the 'breaking point at which it would cancel out the positive climate impacts of switching from coal to natural gas," Hess writes.