Low-Carbon Cement Researchers:Thermal Solar Process that eliminates CO2 ­from lime production. via@techreview

Researchers at George Washington University have invented a solar-powered process that makes lime from limestone without emitting any carbon dioxide and demonstrated it in a proof-of-concept device. The researchers estimate that the process could cost less than the conventional one and eliminate a major global source of carbon dioxide emissions. Rather than simply heating up limestone until it releases carbon dioxide, as in the conventional method, the process uses a combination of heat and electrolysis, which produces lime, oxygen, and either carbon or carbon monoxide, based on the temperatures used. The researchers built a device that includes three Fresnel lenses for concentrating sunlight. High temperatures reduce the amount of electricity needed and cause the lime to precipitate out of the mixture, making it easy to separate.

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 http://www.technologyreview.com/fromthelabs/428147/low-carbon-cement/

Source: David Schaller www.sustainablepractices.info