Amine based CO2 capture - CFD simulation of absorber performance

The paper deals with the numerical modeling of CO2 removal from flue gases by amine solvent in an absorber column, i.e. the first stage of a post-combustion capture installation. The complex flow system including multi-phase gas-liquid countercurrent streams with chemical reaction and heat transfer is considered to resolve the CO2 absorption. A Computational Fluid Dynamics (CFD) model simulates a small laboratory test rig which has provided the reference data for model validation. A 30% aqueous monoethanolamine (MEA) solution was employed as a chemical solvent. A 2-fluid Eulerian model has been employed to resolve the flow in a random packed bed. The calculations were carried out for varying lean loading (0.375-0.425 mol CO2/mol MEA), solvent to flue gases ratio (4.46-6.92 kg/kg) and CO2 content (8-16%), with the results showing reasonable absorber behavior and satisfactory consistency with experimental data. It was found that the removal efficiency is weakly dependent on CO2 content in exhaust gases as long as the amine solution loading is kept at a sufficiently high level.