Fossil fuels like coal are relatively cheap and abundant, which is a huge motivation for finding a way to burn those fuels without releasing carbon dioxide into the atmosphere. The most obvious approach is sequestration – capturing the CO2 during combustion and storing it away. While simple in concept, carbon sequestration is a huge challenge to accomplish on a large scale, and at an acceptable cost.
There have been many laboratory and pilot studies, but virtually no large-scale demonstrations of carbon sequestration. This situation is now changing.
Researchers based at the Pacific Northwest National Laboratory in Richland, Washington are conducting a test of injecting 1,000 tons of CO2 into basalt formations half a mile underground in southeastern Washington. The geochemical nature of basalt allows it to react with carbon dioxide and form carbonate minerals such as limestone. CO2in liquid form is being injected into the deep porous basalt layers, which are buried beneath thick and impermeable rock layers that will prevent it from escaping upward.
The injection well will be monitored closely for the next 14 months and samples removed at the end of that time to evaluate the results. According to DOE estimates, there is enough storage capacity in geologic formations in the US and Canada to sequester 900 years of CO2 emissions. So if the technology is proven to work and can be implemented at an acceptable cost, our fossil fuel resources might end up being useful assets that aren’t also major liabilities. Some day, there might really be clean coal.
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Web Links
Field test could lead to reducing CO2 emissions worldwide
http://www.pnnl.gov/news/release.aspx?id=997
Photo, taken on August 24, 2010, courtesy of the Idaho National Laboratory via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY.