According to the EPA, greenhouse gas emissions from burning natural gas are 50% less that those from coal for the same amount of energy. But some researchers argue that the leakage of methane, which is a more potent greenhouse gas than carbon dioxide, during hydraulic fracturing operations actually makes the total greenhouse gas emissions associated with natural gas from shale deposits comparable to or even greater than those from coal. According to Scientific American the Environmental Defense Fund recently released a study that found that methane leakage in hydraulic fracturing and transportation of natural gas has the potential to remove some or all of the benefits of being a low-carbon fuel, compared to coal, gasoline or diesel.
The U.S. Environmental Protection Agency (EPA) has released a new rule, Oil and Natural Gas Air Pollution Standards, under the Clean Air Act that requires new hydraulically fractured gas wells to use technology that will reduce the emissions of toxic substances, and it is hoped concomitantly methane. The rule requires that all new wells install technology that separates gas from liquid hydrocarbons from the flowback of wells to reduce toxic atmospheric emissions. It is estimated that the leakage of benzene and hexane will drop by 20,000 to 30,000 tons per year. Volatile organic compounds that mix with nitrogen oxides to create smog will be reduced by 190,000 to 290,000 tons per year, a nearly 95 percent reduction, according to the EPA.
The new standard does not mandate a reduction of methane emissions during hydraulic fracturing operations, but this would be a co-benefit of reducing toxic emissions.
I would say that this was a good move on EPA's part. If their estimations are correct, we may see a dip in benzene and hexane leakage... thereby preventing atmospheric contamination. Thanks for sharing this great post with us!
Posted by: Chad Davis | April 21, 2012 at 04:53 AM