The swing adsorption reactor cluster for post-combustion CO2 capture from cement plants

The swing adsorption reactor cluster is a promising new method for post-combustion CO2 capture using a synergistic combination of temperature and pressure swings. The pressure swing is carried out by a vacuum pump and allows for 90% CO2 capture using only a small temperature swing, which is carried out by a heat pump. The small temperature swing allows the heat pump to transfer heat from carbonation to regeneration at a very high efficiency, minimizing the energy penalty. When applied to a cement plant, the energy penalty reduces further relative to a coal power plant that has a lower CO2 content in the flue gas. Higher CO2 concentrations allow a given CO2 capture ratio to be achieved with a smaller temperature swing, thus further improving the heat pump efficiency. As a result of the high heat pump efficiency and of the limited amount of waste heat available, heat integration with the cement plant yielded negligible efficiency gains. A swing adsorption reactor cluster post-combustion CO2 capture facility can therefore be constructed independently from the cement plant, making it attractive for retrofits. The specific energy consumption for CO2 avoidance of the process was determined as 2.04 MJ(LHV)/kg(CO2) when using electricity from the average European power mix, which is lower than all competing technologies recently assessed in the literature aside from oxyfuel CO2 capture. Primary energy consumption will continue to decline as the electricity sector decarbonizes, increasing the attractiveness of the swing adsorption reactor cluster over coming decades. (C) 2019 Elsevier Ltd. All rights reserved