Analysis of a double calcium loop process configuration for CO2 capture in cement plants

The results of the energy and mass balances performed on the proposed schemes reveal that as much as 94% of the total amount of CO2 generated can be captured (equivalent to 92% CO2 avoided) with an increase in the overall process heat demand of just 1.1 GJth/tcement. Moreover, this value could be as low as 0.3 GJth/tcement if a second configuration is used to capture only the CO2 derived from the calcination of the CaCO3 in the raw meal of the cement plant, resulting in a CO2 capture efficiency of 58%. A preliminary economic analysis of both configurations indicates that the cost of cement increases from 74 $/tcement typical of a reference cement plant to 106 and 85 $/tcement, respectively, while the calculated avoided costs are of the order of 42 and 27 $/tCO2 avoided, respectively. The results obtained show that the configurations proposed could be feasible and competitive within certain operating windows that are discussed in this work.