The purpose is to pump CO2 into a basalt rock, where it would be captured by forming limestone. The technique involves forming so-called seltzer water which reacts with calcium in porous basalt and forces the dissolved CO2 into harmless calcium carbonate, more commonly known as limestone. It means there would be no risk of CO2 leakage. As basalt is a very common rock in the Earth’s crust, the technique could be carried out on a massive scale if proved effective.
The first stage of the CarbFix experiment (an American-Icelandic joint venture) will last six months to one year.