This project corresponds to Task 9 of the Research Program on the CO2 Geological Storage, a partnership between IPGP, Total, Schlumberger and ADEME
It aims to determine the thermodynamic constants , kinetics of carbonation of geological minerals and reaction mechanisms of carbonatation.
This project relies on the idea that the mineral storage of carbon, which includes the transformation of CO2 into solid carbonate is the only long-term storage. From a thermodynamic point of view , these reactions are very favorable when CO2 reacts with minerals rich in Fe , Mg , Ca , such as olivine and pyroxene . If the carbonation of calcium silicates (such as wollastonite) is fast, that of magnesium minerals such as olivine is much slower . A layer of silica formed during the reaction , is porous and permeable in the first case but is not at all in the case of the olivine . It then forms a passivating barrier that significantly slows the carbonation reaction . We have also put in evidence that other cations (Fe, Al ), very present in the natural environment could reduce this effect passivation .
Such reactions occur also naturally in ophiolite massifs or in the alteration of oceanic lithosphere . We are working to better understand these reactions and to identify the parameters that control by performing experiments HP (100-200 bar) and HT (50-200 ° C).