Eric Oelkers, UCL: Eric is one of the founders of the CarbFix carbon sequestration project. This is pumping CO2 into groundwater’s in Iceland and precipitating carbonate to lock-up CO2. Having now reached the point where we cannot achieve less than 1.5 degrees warming without artificially removing CO2 and storing it. We have been working on using different Isotope systems (Ca, Mg) to examine and quantify the amount of mineral precipitation that occurs in these aquifers.
Using stable Mg isotope signatures to assess the fate of magnesium during the in situ mineralisation of CO2 and H2S at the CarbFix site in SW-Iceland
The in-situ carbonation of basaltic rocks could provide a long-term carbon storage solution. To investigate the viability of this carbon storage solution, 175 tonnes of pure CO2 and 73 tonnes of a 75% CO2-24% H2S-1% H2-gas mixture were sequentially injected into basaltic rocks as a dissolved aqueous fluid at the CarbFix site at Hellisheidi, SW-Iceland. This paper reports the Mg stable isotope compositions of sub-surface fluids sampled prior to, during, and after the CO2 injections. These Mg isotopic compositions are used to trace the fate of this element during the subsurface carbonation of basalts.