If CCS, carbon capture and storage/sequestration, is to work for fossil fuels, we need to be able to safely lock away the captured carbon somewhere, in a fashion that keeps it from leaking back out. Now, a test of injection into a basalt formation appears to be successful, turning CO2 into carbonate rock even faster than expected. Volcanic rocks help turn carbon emissions to stone — and fast | Science News "A new technique turns climate-warming carbon emissions to stone. In a test program in Iceland, more than 95 percent of the carbon dioxide injected into basaltic lava rocks mineralized into solid rock within two years. This surprisingly fast transformation quarantined the CO2 from the atmosphere and could ultimately help offset society’s greenhouse gas emissions, scientists report in the June 10 Science. “It’s working, it’s feasible and it’s fast enough to be a permanent solution for storing CO2 emissions,” says study coauthor Juerg Matter, a geochemist at the University of Southampton in England." Scientists Turn Carbon Dioxide Emissions into Stone [Video] - Scientific American For the first time, carbon dioxide emissions from an electric power plant have been captured, pumped underground and solidified—the first step toward safe carbon capture and storage, according to a paper published Thursday in the journal Science. “This opens another door for getting rid of carbon dioxide or storing carbon dioxide in the subsurface that really wasn’t seen as a serious alternative in the past,” said study co-author Martin Stute, a hydrologist at the Lamont-Doherty Earth Observatory at Columbia University in New York."
When volcanoes discharge basalt (or similar minerals), or such minerals become otherwise exposed to the atmosphere, this is exactly what happens. At the surface it is said to be 0.1 petagrams carbon trapped per year from CO2. The folks in Iceland were surprised by high rates of carbonation, suggesting we do not have a good handle on reaction rates at the encountered temperatures and pressures. Or surface areas perhaps? Basalt loves CO2 well enough, but it usually comes in big chunks which means not much surface area (per gram, etc.).
Still not ready for prime time, but at least another step forward for CCS today: The world’s biggest plant to capture CO2 from the air just opened in Iceland This is project is aiming for 4,000 metric tons per year, at a cost of about $600 to $800 per metric ton. Volumes would need to rise, and costs fall, considerably before it becomes a viable path.
