Optimization of the post-combustion CO2 capture process applied to cement plant flue gases: parametric study with different solvents and configurations combined with intercooling

The present study is related to Aspen HysysTM simulations of the post-combustion CO2 capture process by absorption-regeneration. More precisely, the purpose of our works was to quantify the interest in terms of solvent regeneration energy of combining alternative process configurations ('Lean/Rich Vapor Compression' (L/RVC)) with an intercooled absorber (ICA). Water-wash sections were also added in the flow sheet for a more accurate simulation of the global process. The Norcem Brevik cement plant flue gas was taken as case study and three different solvents were considered, namely: monoethanolamine (MEA), piperazine (PZ) and piperazine-methyldiethanolamine (MDEA) blend. For each configuration and solvent, parametric studies were carried out in order to identify the operating conditions ((L/G)vol., intercooling temperature, stages and flow rate) minimizing the solvent regeneration energy. Total equivalent thermodynamic work and utilities costs were also analyzed. It could be highlighted that implementing ICA leads to supplementary energy savings. More precisely, the MDEA+PZ blend with RVC+ICA configuration leads to a regeneration energy of 2.19 GJ/tCO2 (35% energy savings in comparison with MEA 30% conventional configuration), the utilities costs being also lower (24.5% savings) in comparison with the same reference case.