Skepticism, Medicine and Science News

Peridotite may help soak up CO2

CO2 in the atmosphere is the main contributor to human-forced global warming, and finding novel ways to remove/reduce CO2 emissions is therefore an important area of research. A recent study found that the rock peridotite may help reduce CO2 in the atmosphere by solidifying it. When CO2 in its gaseous state comes in contact with peridotite, it is converted into solid minerals such as calcite. This is a naturally occurring process, but the scientist say it can be sped up about 1 million times. 

Peridotite is the most common rock found in the earth’s mantle, but it is mostly below the upper crust. Oman, in particular, have a reasonable amount of exposed peridotite, and would therefore be well suited for this kind of CO2 storage. The process of artificially accelerating the carbonation rate is not thoroughly described in the referenced article, but I will try to explain it based on what I understood from the original paper. First they propose drilling and hydrofracture the rock at depth, and then inject a hot liquid at about 185 degrees Celsius. Pure CO2 is the injected at 25 degrees, and this would overall achieve a 1 million times increase in the carbonation rate. Estimates show that this would enable Oman alone to permanently store 2 billion of the 30 billion tons of CO2 annually released by burning of fossil fuels. By using this technique together with another technique developed at Columbia University that uses synthetic “trees” which suck carbon dioxide out of the air, the researchers even estimate that as much as 4-5 billion tons of CO2 could potentially be stored annually in and near Oman. 

The research was done by Peter Kelemen and Juerg Matter at Columbia University’s Lamont-Doherty Earth Observatory in New York. 

A peridotite rock


November 10, 2008 Posted by | Chemistry, Geology | , , , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment