Assessing CO2 Capture in Cement and Steel: A Comparison between Calcium Looping and Amine Scrubbing

Abstract The cement and steel industries account for around 14% of the global anthropogenic CO2 emissions. For these sectors, carbon capture and storage is one of the few solutions with the potential to achieve near-zero emissions. Regarding CO2 capture technologies, amine scrubbing recently reached the commercial stage, while calcium looping is a promising choice for large-scale industrial applications with interesting synergies with cement and steel production. This study assesses the potential reduction in CO2 emissions and the associated costs, comparing the integration of amine scrubbing and calcium looping in reference to cement and steel plants. Furthermore, both a gate-to-gate and a cradle-to-gate boundary are considered in the emission accounting. The findings show that calcium looping can achieve larger reductions in the equivalent CO2 emissions at competitive costs to amine scrubbing. Notably, costs per avoided CO2 are influenced by the boundaries considered in the environmental and economic assessment, ranging from 45 to 97 €/tCO2 considering a gate-to-gate boundary, to 109–162 €/tCO2 for a cradle-to-gate approach.