CO2 Capture from Cement Plants and Steel Mills Using Membranes

Carbon dioxide capture, utilization, and storage (CCUS) has been identified as an effective method of mitigating anthropogenic CO2 emissions. To date, most research and development has centered on capturing CO2 emitted from coal power plants, as they are the largest point source emitters globally. However, cement and steel plants also emit large amounts of CO2 and are potentially easier targets for a CO2 capture process because the CO2 in their flue gas tends to be more concentrated. In this paper, the feasibility of capturing CO2 from cement and steel plants is examined using currently available membrane technology. Coal power plant flue gas contains 13–15% CO2; cement and steel plant flue gas contains 20–30% CO2; this higher CO2 concentration is useful for all separation technologies, but especially for membranes where separation is strongly dependent on the partial pressure driving force. Membrane-based systems can capture 80% of the CO2 emitted from cement or steel production processes at costs of $40 to $50/tonne of CO2 captured. Lower costs are possible if lower capture rates are considered. This makes CO2 capture from these gas streams an attractive first application for commercial membranes recently developed for flue gas treatment.