Simulations of various Configurations of the Post-combustion CO2 Capture Process Applied to a Cement Plant Flue Gas: Parametric Study with Different Solvents

Abstract

In order to reduce the operating costs of post-combustion CO2 capture process by absorption-regeneration using amine based solvents for its application in the cement industry, the present study was focused on the Aspen HysysTM simulation of different CO2 capture process configurations (namely conventional configuration, “Rich Solvent Recycle” (RSR), “Solvent Split Flow” (SSF) and “Lean/Rich Vapor Compression” (L/RVC)) applied to the flue gas coming from the Norcem Brevik cement plant in Norway and using three different solvents, namely: monoethanolamine (MEA), piperazine (PZ) and piperazine-methyldiethanolamine (MDEA) blend. For each configuration and solvent, a parametric study was carried out in order to identify the specific operating conditions (flow rates ratio (L/G), split fraction, injection stage in the columns, flash pressure, etc.) minimizing the solvent regeneration energy and highlighting the energetical interest of such configurations. Energy savings of almost 30% were estimated with the RVC configuration and MDEA+PZ blend. A decrease of the condenser cooling energy was also noted. As perspectives, other configurations (such as InterCooled Absorber (ICA)) and combination of configurations will be considered in order to further reduce the energy consumption of the process. In addition to OPEX calculations, the consequence in terms of CAPEX of implementing each process configuration will have to be estimated for evaluating more precisely the global economic interest of using alternative process configurations for the application to cement plant flue gases.