[font face=Serif][font size=5]Carbon-Dioxide Storage with Less Earthquake Risk[/font]
[font size=4]Underground rocks that react with carbon dioxide to form minerals could offer a safe way to keep the greenhouse gas from reaching the atmosphere.[/font]
By Mike Orcutt on April 1, 2013
[font size=3]There is increasing concern that storing carbon dioxide in underground rock formations could cause earthquakes that would allow it to escape, raising doubt that the strategy could play its expected role in slowing the harmful accumulation of the greenhouse gas in the atmosphere. But new research suggests that storing carbon in one particular type of underground rock could significantly reduce the risk.
A
study published this month in
Geophysical Research Letters suggests that storing carbon dioxide underground in a type of volcanic rock called reactive mafic rock could potentially present little seismic risk, because the surface of mafic rock reacts with carbon dioxide to form a solid mineral.
In the case of mineral sequestration, says
David Bercovici, a professor of geology and geophysics at Yale University and an author of the new paper, you are making rocks out of (the carbon dioxide). Its not sitting there as a high-pressure fluid, as would be the case with the storage rocks that are conventionally proposed. The newly formed minerals could help counter the conditions that lead to earthquakes.
Carbon capture and storage, or CCS, consists of techniques for capturing carbon dioxide emitted by fossil-fuel power plants and certain industrial facilities before it reaches the atmosphere, compressing it, and then burying it deep underground, where in theory it could be sequestered permanently in large geological formations. The International Energy Agency
has said that CCS will be needed to achieve over one-fifth of the emissions cuts required by 2050 to maintain a decent chance that the global average temperature wont rise more than 2 °C (see
The Carbon Capture Conundrum).
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