Flaring Is (Not) Caring

I’ve written about natural gas flaring before – the spectacular case of Turkmenistan’s Door to Hell. Flaring is the process through which natural gas that cannot be captured is burned, converting it into carbon dioxide. On a practical level, the practice seems completely counterintuitive. Why would we burn 140 to 150 billion cubic meters of natural gas per year globally when demand clearly exists? Flaring worldwide emits 270 to 290 million tons of carbon dioxide per year – substantially more than just a drop in the bucket.

UntitledA satellite image of Texas at night. The large lights represent cities, with San Antonio at the top and Houston at the top right. The band of lights across the middle is all flaring from the Eagle Ford shale (image courtesy Dr. Michael Webber, University of Texas).

The underlying driver of flaring is economics. Natural gas is a cheap commodity with high up-front infrastructure costs. Over time, a large enough gas field will pay for the initial investment required to construct wells, pipelines, and turbines. Where smaller sources are concerned, the resource simply isn’t economically feasible to capture and transport. Sometimes, gas is produced in conjunction with oil; other times, exploration wells might form an outlet for a gas pocket. Unavoidably, gas will find its way from underground formations to the atmosphere.

There are two reasons why natural gas is burned rather than released as is. The first is human safety. While methane itself does not directly pose a health risk, it is both flammable and, in large enough quantities, an asphyxiant (the latter refers to the fact that methane displaces oxygen and thus can lead to suffocation). The second factor is its global warming potential. Methane is more than 20 times more effective than carbon dioxide as a greenhouse gas. The reason CO2 is so often cited as the ‘climate change culprit’ is because much more of it in the atmosphere; however, methane’s high warming potential means that emissions need to be managed effectively.

At the AAAS Science Conference in Chicago, I had a chance to talk to Dr. Michael Webber – an engineering professor at the University of Texas who studies the interactions between water resources and the energy sector. In particular, he has looked at ways to minimize both flaring and water quantity required for shale gas operations. As opposed to conventional gas, which can be easily produced just by drilling a well, shale gas is trapped in small pores that must be hydraulically fractured – cracked using explosive charges and water under high pressure. Hydraulic fracturing uses large volumes of water and produces large quantities of wastewater which must be treated. Dr. Webber suggests that uncaptured gas, which is highest in the initial stages of shale gas operations, can be adapted to produce energy for water treatment onsite. In this win-win scenario, CO2 emissions are minimized and otherwise wasted energy is used to increase water use efficiency. Particularly in states such as Texas, where shale gas is a rapidly growing industry and water resources are scarce, Dr. Webber’s research may play an important role in minimizing the environmental impacts of shale gas production.

Be warned: you may have just sustained a lethal dose of mostly harmless science If you enjoyed this article, please comment below and share with your friends! I’d love for you to follow me on WordPress or on Twitter @harmlessscience (just click Follow on the right sidebar). Thanks for reading!

Images from Wikimedia Commons

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2 responses to “Flaring Is (Not) Caring

  1. While releasing gads of methane into atmosphere is probably not a good thing, in the end, it does not matter which way “extra” natural gas is dispatched, since it converts naturally into carbon dioxide anyway, with a half life of about 13 years (I believe). So, it’s the carbon dioxide that will do us in. Indeed, the choice of natural gas as a fossil fuel over coal or oil is a bit of a red herring. While they may help a country meet short term emissions targets, in fact, as the blog post indicates, building natural gas infrastructure is an expensive business, and the investors in such are NOT going to want to shut it down shy of its depreciable lifetime. Yet, to make reasonable global emissions goals on a reasonable timeframe, that’s EXACTLY what’s going to be necessary. So, the answer is to retire old fossil fuel assets, and NOT invest in new ones. Few like that idea, however.

    It’s not everyone’s fault. The global framework is wrong, focused upon making incremental progress and “keeping temperature increase to two degrees Celsius” rather than embracing “get to zero emissions”. The latter is the proper target.

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