This process could led to the creation of a permanent storage solution for some of the tons of CO2 pumped into the atmosphere each year.
As part of the process, CO2 and water is injected into the ground and the mixture reacts with surrounding rock to form stone. The mineralization of the gas took about two years, which according to researchers is a much shorter time period than their expectation.
So far, the injection of CO2 into underground reservoirs has failed to provide feasible storage for one big reason: leaks. Gas seeps out and escapes when seismic activity creates cracks in impermeable rock. In order to address this issue, the researchers decided to blend CO2 with hydrogen sulfide and water and then injected it into porous basalt with a hope that the mixture would react with the basalt and solidify into stone over about 10 years.
The mixture was then checked after less than two years and the researchers were surprised to find about 95% of their injection had already formed carbonate rock. The findings of the study were described in details in a report in the journal Science.
The process was tried by the researchers at a hydrothermal power plant in Iceland because it allowed them to capture the gas directly from the turbines. According to researchers, the process holds potential for other power plants, but it can be done by separating out oxygen and nitrogen from the CO2.