CO2 absorbing rock

A rock found mostly in Oman can be harnessed to soak up the main greenhouse gas, carbon dioxide, at a rate that could help slow global warming, scientists say.
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 occuring process can be supercharged one million times to grow underground minerals that can permanently store 2 billion or more of the 30 million 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.
"To be near all that oil and gas infrastructure is not a bad thing," Matter said.
They also calculated the cost 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 prelimenary patent filing for the technique.
They say 4-5 billion tons of gas could be stored near Oman by using peridotite in parallel with another emerging technique developed by Columbia's Claus Lackner that used synthetic trees which suck CO2 out of the air.
Peridotite also occurs in the pacific island of Papua, New Guinea and Caledonia and along the coast of the Adriatic Sea and in small amounts in California.