Experimental study on the CO2 mineralisation potential of German igneous rocks

Following the recent amendment to the Carbon Dioxide Storage Act, the way has been paved for future underground storage of CO<inf>2</inf> in Germany. However, the storage of gaseous CO<inf>2</inf> in the subsurface still faces opposition in society as it is often perceived as unsafe. This study evaluates the potential of an alternative storage method involving the in-situ mineralisation of CO<inf>2.</inf> Injecting dissolved CO<inf>2</inf> into geological formations, where it mineralises upon reacting with the surrounding rocks, may lead to greater public acceptance, since the CO<inf>2</inf> is stored in solid carbonate minerals. Here we present the first in a series of batch reactor experiments testing the chemical ability of different mafic and ultramafic volcanic and plutonic rocks from Germany to sequester CO<inf>2</inf> into carbonate minerals. The tested sample from the Vogelsberg volcanic complex was able to supply the necessary divalent metal cations to form carbonate minerals, which were successfully identified in the experimental products. Subsequent experiments will extend the study to a variety of different lithologies.