Comparative Analysis of the Oxyfuel and Calcium Looping Processes for Low-Carbon Cement Production

In this work, the performance of a cement plant with the integrated calcium-looping (CaL) system being developed in the H2020 CLEANKER project are simulated and benchmarked against alternative CO2 capture options, namely: (i) Tail-end CaL configuration (an end-of-pipe CaL option, with circulating fluidized bed reactors) (ii) Full Oxyfuel configuration (where both the pre-calciner and the rotary kiln are operated in oxy-combustion mode), and (iii) Partial Oxyfuel configuration (where only the pre-calciner is converted to oxy-combustion). Both CaL and oxyfuel options are integrated with a CO2 purification unit (CPU). The analysis performed shows that CaL systems provide greater CO2 reductions (both direct and indirect) than oxyfuel systems, but are subject to greater fuel consumption. The integrated CaL system shows better energy performance than the tail end CaL system (which is the most fuel consuming system) thanks to the presence of a single calciner. The full oxyfuel system shows the lowest SPECCA value among the systems studied but is penalized by the high electric energy demand. Finally, the partial oxyfuel system has lower electricity consumption than the full oxyfuel system, but it is the system with the highest CO2 emissions.