The CarbFix Pilot Project–Storing carbon dioxide in basalt

Abstract

In situ mineral carbonation is facilitated by aqueous-phase chemical reactions with dissolved CO 2 . Evidence from the laboratory and the field shows that the limiting factors for in situ mineral carbonation are the dissolution rate of CO 2 into the aqueous phase and the release rate of divalent cations from basic silicate minerals. Up to now, pilot CO 2 storage projects and commercial operations have focused on the injection and storage of anthropogenic CO 2 as a supercritical phase in depleted oil and gas reservoirs or deep saline aquifers with limited potential for CO 2 mineralization. The CarbFix Pilot Project will test the feasibility of in situ mineral carbonation in basaltic rocks as a way to permanently and safely store CO 2 . The test includes the capture of CO 2 flue gas from the Hellisheidi geothermal power plant and the injection of 2200 tons of CO 2 per year, fully dissolved in water, at the CarbFix pilot injection site in SW Iceland. This paper describes the design of the CO 2 injection test and the novel approach for monitoring and verification of CO 2 mineralization in the subsurface by tagging the injected CO 2 with radiocarbon ( 14 C), and using SF 5 CF 3 and amidorhodamine G as conservative tracers to monitor the transport of the injected CO 2 charged water.