Researchers at Purdue University and the Environmental Defense Fund haveย concluded in a recentย study that natural gas power plants releaseย 21โ120 times more methane thanย earlierย estimates.ย
Published in the journal Environmental Science and Technology, the study also found that for oil refineries, emission ratesย were 11โ90 times more than initial estimates. Natural gas, long touted as aย cleaner and more climate-friendly alternative to burning coal, is obtained in the U.S. mostly via the controversial horizontal drilling method known as hydraulic fracturing (โfrackingโ).
The scientistsย measured air emissions at three natural gas-fired power plants and threeย refineries in Utah, Indiana, and Illinoisย using Purdue’s flying chemistry lab, theย Airborne Laboratory for Atmospheric Research (ALAR). Theyย compared their results to dataย fromย the U.S. Environmental Protection Agencyโs (EPA) Greenhouse Gas Reporting Program.
โPower plants currently use more than one third of natural gas consumed in the U.S. and the volume used is expected to increase as market forces drive the replacement of coal with cheaper natural gas,โ the Environmental Defense Fund (EDF) said in a press release. The nonprofitย commissioned and funded the study with a grant from the Afred P. Sloanย Foundation.
โBut if natural gas is going to deliver on its promise, methane emissions due to leaks, venting, and flaring need to be kept to aย minimum.โ
Methane Leaks Major Source ofย Emissions
Methane is a more potent greenhouse gasย than carbon dioxide but hangs around the atmosphere for a shorter time,ย with a global warming effectย 84โ87 times that of CO2 overย a 20-year period, according to the EPA.
โ[Methane is] a better fuel all around as long as you don’t spill it,โ Paul Shepson, an atmospheric chemistry professor at Purdue, saidย in a press release. โBut it doesn’t take much methane leakage to ruin your whole day if you care about climateย change.โ
The researchers were careful to differentiate between emissions related to natural gas combustion versus leakage, with the latter found to be the primaryย source of methane emissions in this small, preliminaryย study. Previous estimates of methane emissions were reported to the EPA from the facilities themselves and were restricted to what came out of the smokestack, which means they excludedย leaksย from equipment such as steam turbines andย compressors.
The study was done as part of EDF‘s ongoing series of studies measuring methane emissions and leakage throughout the U.S. natural gas supply chain. EDF said in its press release that the Purdue scientistsย plan to follow up with research at additional oil refineries and power plants.ย Purdue stated in a press release that support for the research also came from the National Science Foundation (NSF).ย
Natural gas recently eclipsed coal as a power source feeding the U.S. electricย grid, according to dataย published by the U.S. Energy Information Administration (EIA).ย
โFor decades, coal has been the dominant energy source for generating electricity in the United States. EIA‘s Short-Term Energy Outlook (STEO) is now forecasting that 2016 will be the first year that natural gas-fired generation exceeds coal generation in the United States on an annual basis,โ explained the EIA inย March 2016. โNatural gas generation first surpassed coal generation on a monthly basis in April 2015, and the generation shares for coal and natural gas were nearly identical in 2015, each providing about one-third of all electricityย generation.โ
Trump Admininstrationย Dismantling Methaneย Regulations
The Purdue-EDF research results were published the same week President Donald Trump proposed massive cuts to the EPA, which would include a 23 percent cut to the enforcement division tasked with overseeing emissions atย gas-fired power plants and oil refineries. The Trump administration has also announced its intentions to halt former President Barack Obama’s proposed methane emissions rule for gas situated on U.S. public lands and has alreadyย reversedย the Obama EPA‘s information request for methane emissions data from U.S. domestic oil and gasย producers.
As DeSmog previously reported, Carl Icahn, the business tycoon who interviewed and vetted current EPA Administrator Scott Pruitt,ย owns petrochemical refineries with a documented history of exceeding allowable emissions rates set by the EPA. In addition to being a major donor toย Trump’s campaign, Icahn also serves as anย adviser on regulatory issuesย to the Trump White House, a position set to benefit his extensive business holdings andย raising concerns about conflicts of interest.
Icahn, however, has dismissed these concerns, telling Bloomberg Businessweek, โIt may sound corny to you, but I think doing certain things helps the country a lot. And yeah, it helps me. Iโm not apologizing forย that.โ
Main image: Natural gas power plantย Credit: Wikimediaย Commons
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