Solvent Selection for Post-Combustion CO2 Capture

Abstract

This paper discusses using computational molecular modeling and process optimization to select solvents for post-combustion CO2 capture from fossil fuel fired power plants. Post-combustion CO2 capture processes require considerable energy thus reducing the output of the power plant. For solvent-based capture, the bulk of this required energy is the heat used to regenerate the solvent, and the balance is the electricity required for liquid pumping, the flue gas fan and the final compression of the CO2 product. The approach is based on computer aided molecular design to generate novel solvents. Key properties for absorption and stripping are obtained for 50 candidate solvents. These solvents are then evaluated in detail with the integrated approach using equilibrium models and compared with the performance of monoethanolamine (MEA) with equilibrium models. We find that many of these new solvents reduce the equivalent energy required for capturing 90% of CO2 emissions.