Monday, March 15, 2010

Carbon Capture on Peridotite - A Geo-engineering project that might actually work.

Peridotite is the name for a class of rock that contains silica, magnesium and iron. It can be used to absorb carbon dioxide efficiently, according to Peter Kelemen and Juerg Matter at Columbia University. Absorption into basalt was discussed in my previous post.

There are large deposits of peridotite in Oman as well as Papua New Guinea and Caledonia. It is the most common rock in the earth's mantle, but it is located below the earth's crust, for the most part.

Kelemen has ambitious plans. He says that the Oman deposits could absorb 12% of world wide carbon dioxide emissions every year. However, the gas would need to be transported to Oman, which is not that practical.

On the other hand, injection of ocean water into deep peridotite deposts would allow the peridotite to strip out dissolved CO2, and later the ocean water could be returned to the sea to absorb additional CO2.

This sounds like a geoengineering project that might actually work.