Mineral Trapping of CO2 in Operated Geothermal Reservoirs - Numerical Simulations on Various Scales

We present a novel approach for storing CO2 not only by hydrodynamic trapping within a reservoir but for converting it into the geochemically more stable form of calcite. The combination of CO2 storage and geothermal energy production is generally feasible because candidate sites are available, anhydrite is transformable into calcite and alkalinity can be provided by fly ashes or even in-situ. However, under the current circumstances the technology is not economical because the storable amount at depth is significantly less than one million tons over the life time of a geothermal heating plant.