Investigating natural analogues for CO2 sequestration in ultramafic rocks: a reactive transport modelling approach

Serpentinites of Ligurian ophiolites are studied as natural analogues for CO2 mineral sequestration in Italy. Mineralogical and geochemical observations indicate that silicification and carbonation are typical alteration processes induced by the interaction of CO2 charged fluids with pristine ultramafic rocks. Multicomponent reactive transport models have been applied to reproduce natural patterns and investigate carbon sequestration efficiency under high PCO2 conditions. Temporal changes in porosity and permeability are predicted to affect the spatial and temporal occurrence of secondary minerals. The feedback between mineralogical transformations and transport properties of the geological media emerges as a key factor controlling the mineral carbonation potential of the investigated ultramafic rocks.