Ex-situ mineral carbonation – A parameter study on carbon mineralisation in an autoclave as part of a large-scale utilisation process

The exothermic carbonation reaction includes the degradation of alkaline earth metal (mainly Mg-, Ca-) oxides, hydroxides or silicates under participation of carbon dioxide under aqueous conditions and the formation of stable carbonates with long-term storage of carbon dioxide. The extent of reaction depends on different influencing factors, which significantly affect the economic and ecological feasibility of this technology. With special regard to the possibilities of upscaling and balancing in the context of life cycle analyses for the carbon capture and usage approach, various material-specific and process-related parameters and also combinations of these have been tested experimentally and evaluated. Hereby, significant differences in the carbonation extent were identified with achieved carbonation degrees from below 5 up to 60%, corresponding to 305 kgCO2/tfeed. This study is a comprehensive investigation of those material-specific and process-related parameters and their combination and aims to ensure the economic viability of enhanced weathering by increasing the degree of carbonation.