Scientists Say A Rock can Soak Up Carbon Dioxide

When carbon dioxide comes in contact with the rock, peridotite, the gas is converted into solid minerals such as calcite.

Geologist Peter Kelemen and geochemist Juerg Matter said the naturally occurring process can be supercharged 1 million times to grow underground minerals that can permanently store 2 billion or more of the 30 billion tons of carbon dioxide emitted by human activity every year.

Peridotite is the most common rock found in the Earth's mantle, or the layer directly below the crust. It also appears on the surface, particularly in Oman, which is conveniently close to a region that produces substantial amounts of carbon dioxide in the production of fossil fuels.

They also calculated the costs of mining the rock and bringing it directly to greenhouse gas emitting power plants, but determined it was too expensive.

The scientists, who are both at Columbia University's Lamont-Doherty Earth Observatory in New York, say they have kick-started peridotite's carbon storage process by boring down and injecting it with heated water containing pressurized carbon dioxide. They have a preliminary patent filing for the technique.

They say 4 billion to 5 billion tons a year of the gas could be stored near Oman by using peridotite in parallel with another emerging technique developed by Columbia's Klaus Lackner that uses synthetic "trees" which suck carbon dioxide out of the air.

Peridotite also occurs in the Pacific islands of Papua New Guinea and Caledonia, and along the coast of the Adriatic Sea and in smaller amounts in California.

I wonder how much this would cost per ton of CO2?

via Reuters and Green Car Congress