published on 9 May 2019 in

CO2 turns into rock in Iceland

In Iceland, there are veritable “21st century alchemists” able to turn carbon dioxide in the atmosphere into rock. The alchemists are part of a research team within CarbFix, a project that has developed a safe, economically advantageous and environmentally friendly technology for permanently storing CO2 below ground. The storage process involves capturing carbon dioxide in the atmosphere, liquefying it and then injecting it into basaltic rocks at a depth of 1,000 metres. The solidification process then takes place inside the rock cavities into which the high pressure liquid is injected. At the CarbFix pilot site, located at 3 km south-west of the Hellisheidi power plant in Iceland, over 95% of the CO2 captured and injected has been turned into rock in the subsurface in less than two years. This challenges the widely-held belief that storage of minerals in the CCS projects takes hundreds or thousands of years.

Rock samples extracted from the injection site, in which carbonate minerals containing the injected CO2 are visible inside the host basaltic rock. Credits: CarbFix

At the end of 2018, 66,000 tons of sour gases had been captured and injected at Hellisheidi, 2/3 of which were carbon dioxide and 1/3 hydrogen sulphide (H2S), corresponding to a reduction of over 40% in emissions from the power plant.
The effectiveness of the CarbFix method has been recently verified and validated in a paper published in Nature Communications.
The only Achilles’ heel of the method is that it requires large volumes of desalinated water – 5 tons of water for every ton of injected CO2 – a resource of which Iceland has abundant supplies unlike many other areas of the Planet.

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