Preliminary analysis of combining amine absorption and calcium-looping CO2 capture in cement plant

The cement industry is responsible for a significant amount of global carbon dioxide (CO2) emissions, accounting for approximately 8%. Furthermore, the share of CO2 emissions will increase in the next decade as the higher share of power generation is achieved from renewable sources, which will make its contribution highly noticeable. Accelerating the low-carbon transition for the cement industry is not that simple. To address this challenge, several strategies have been proposed to reduce CO2 emissions: (i) reducing the clinker-to-cement ratio and improving energy efficiency, which can be achieved through the use of alternative fuels and raw materials, and (ii) deployment of innovative technologies. The latter can be accomplished by the development and implementation of carbon capture and storage technologies (CCS), which involve capturing the CO2 from the cement production process and subsequently its underground storage in geological formations. Within this study, two main capture methods are considered in terms of cement production: amine absorption and calcium looping. The former approach is an already mature, commercial and well-established technology. Calcium looping is marked by potential high-grade heat recovery from the process, which may provide the amine capture heat needs. Therefore, the objective of this work is to assess the potential of combining both technologies in one reference cement plant and to provide the preliminary analysis in terms of energy and economic performance. Obtained results indicate that specific primary energy consumption for CO2 avoided can be more than twice lower when combining both technologies, 2.3 MJ/kgCO2 compared to 5.6 MJ/kgCO2 for case where only amine absorption units are implemented. However, CO2 capture will increase the overall cost of clinker from 67 EUR/t to approximately 150 EUR/t. Nevertheless, for cement industry, all the decarbonization strategies will be necessary to achieve substantial reductions in CO2, along with meeting the growing demand for sustainable construction materials.