What we're doing right
Carbon capture rocks
22nd November 2008
"Sequestration techniques are just one in a suite of solutions – there is no silver bullet for solving climate change”
Much research has gone into the idea of facilitating carbon sequestration – also called carbon capture and storage (CCS) – by taking carbon dioxide emitted by power plants and locking it away deep underground in porous rock or in emptied oil fields. Now, researchers at Columbia University say they have found that a rock called peridotite could do the job.
In a paper in the Proceedings of the National Academy of Sciences, they describe how the rock reacts with carbon dioxide to form solid carbonate crystals. By drilling several kilometres deep into peridotite deposits and injecting heated water with dissolved carbon dioxide, they say, the natural mineralization process could happen 100,000 times faster.
“This would be permanent and environmentally benign,” says Juerg Matter, a geochemist and co-author of the study, mainly because CCS methods that propose to trap the carbon dioxide as a gas inevitably pose a risk of leakage.
Using peridotite, Prof. Matter says, could potentially store up to four billion tonnes of carbon dioxide a year – out of 30 billion tonnes released worldwide – for up to 3,000 years. This would only work for carbon emissions near exposed peridotite deposits, which are currently found in oil-rich Oman, as well as on Pacific islands and the coast of Greece. Prof. Matter is also working on a CCS project in Iceland that uses volcanic basalt.
“But we really want to emphasize that sequestration techniques are just one in a suite of solutions – there is no silver bullet for solving climate change,” he says. “We have to start with the easier and cheap solutions, like fuel conservation, energy efficiency and, most of all, stopping deforestation.”
Published in The Green Report in The Globe and Mail