Review of CO2 Storage in Basalts
IEAGHG published a report in 2011 as an initial high level overview of the status of basalts as an option for the geological storage of CO2 (IEAGHG, 2011). This 2016 technical review aims to provide an update to the 2011 report as injection has now started at two high profile pilot projects (Big Sky’s Wallula project, US and CarbFix, Iceland). Recent data from both projects gives an insight into the reactions that are taking place and the timescales required for mineral formation. Field data and modelling has enabled the amount of CO2 reacting with mafic elements to create stable carbonate minerals to be estimated.
Although sedimentary formations are considered to have the largest potential for CO2, basalts are present both on and offshore in large deposits in regions where suitable sedimentary formations do not exist. This study also reports on the new injection technologies used including the implications for the large volumes of water required in comparison to injection in conventional reservoirs. This review also includes a short section on the potential of ultramafic minerals to fix CO2 by carbonation reactions