High-temperature thermal storage-based cement manufacturing for decarbonization
Xiaokang Liu, Xiaobo Li, Ronggui Yang
Abstract
Abstract Cost-effective CO 2 capture is essential for decarbonized cement production since it is one of the largest CO 2 emission sources, where 60% of direct emissions are from CaCO 3 decomposition and 40% are from fuel combustion. This work presents a low-carbon cement manufacturing process by integrating it with renewable energy for electric heating and thermal storage to replace the burning of fossil fuels in the conventional calciner. The low-carbon renewable energy reduces the indirect CO 2 emissions from electricity consumption. The high-temperature CO 2 is employed as the heat transfer fluid between the energy storage system and the calciner. In the proposed basic manufacturing process, the CO 2 from the CaCO 3 decomposition can be directly collected without energy-consuming separation since no impurities are introduced. Furthermore, the remaining CO 2 from fuel combustion in the kiln can be captured through monoethanolamine (MEA) absorption using waste heat. In the two situations, the overall CO 2 emissions can be reduced by 69.7% and 83.1%, respectively, including the indirect emissions of electricity consumption. The economic performance of different energy storage materials is investigated for materials selection. The proposed manufacturing process with a few high-temperature energy storage materials (BaCO 3 /BaO, SrCO 3 /SrO, Si, etc.) offers a higher CO 2 emission reduction and lower cost than alternative carbon capture routes, i.e., oxyfuel. The cost of CO 2 avoided as low as 39.27 $/t can be achieved by thermochemical energy storage with BaCO 3 /BaO at 1300 °C, which is superior to all alternative technologies evaluated in recent studies.