Comparison of various configurations of the absorption-regeneration process using different solvents for the post-combustion CO2 capture applied to cement plant flue gases

Abstract

Carbon Capture Utilization or Storage (CCUS) has gained widespread attention as an option for reducing CO2 emissions from power plants but specific developments are still needed for the application to cement plants. More precisely, the post-combustion CO2 capture process by absorption-regeneration is the more mature technology but its cost reduction is still necessary. The present study is focusing on Aspen Hysys™ simulations of different CO2 capture process configurations (namely “Rich Solvent Recycle” (RSR), “Solvent Split Flow” (SSF), “Lean/Rich Vapor Compression” (L/RVC)) applied to the flue gas coming from the Norcem Brevik cement plant (taken as case study) and using three different solvents, namely: monoethanolamine (MEA), piperazine (PZ) and piperazine-methyldiethanolamine (MDEA) blend. For each configuration and solvent, different parametric studies were carried out in order to identify the operating conditions ((L/G)vol., split fraction, flash pressure variation, etc.) minimizing the solvent regeneration energy. Total equivalent thermodynamic works and utilities costs were also analyzed. It was shown that the configurations studied allow regeneration energy savings in the range 4–18%, LVC and RVC leading to the higher ones. As perspectives, other configurations and combination of configurations will be considered in order to further reduce the energy consumption of the process.