A team of scientists from Iceland has demonstrated an innovative new technique that enables carbon dioxide emissions from power plants to be pumped underground and converted to a mineral.
The CarbFix project aims to imitate the natural storage process of carbon dioxide already observed in basaltic rocks in Iceland’s geothermal fields and has implications for the commercial development of carbon capture and storage (CCS) technology.
The project partners recently reported in the journal Science that it is possible to permanently store carbon dioxide as minerals in basaltic rocks and that over 95 per cent of CO2 injected is mineralized within two years, instead of centuries or millennia as previously thought.
The project involved running experiments using carbon dioxide and hydrogen sulphide gases emitted by operations at the Hellisheidi geothermal power plant. Emissions were dissolved in water and reinjected into basalt formations 400-500 m below ground.
Tracer chemicals showed that 95 per cent of the carbon dioxide was turned to stone within two years. The hydrogen sulphide is also mineralized.
Some 3900 tons of carbon dioxide were channelled down into the bedrock in 2015, i.e. over 10 per cent of the carbon dioxide annually emitted by the Helisheidi plant.
CarbFix, whose partners include Reykjavik Energy, the University of Iceland, CNRS in Toulouse and Columbia University, has started scaling up the project but says that one challenge is the amount of water needed for the process.
