Simulation: improving the performance in post-combustion CO₂ capture

This study was done to simulate by using Aspen HYSYS version 8.8 with Acid Gas Package for thermodynamic calculation for Post Combustion carbon dioxide capture (PCC). In order to tackle the main problems in PCC which are high operating cost and high energy consumption, this study was focused on the improvement that can be applied in this system where several parameters are varied in the simulation of PCC such as solvent used, number of absorber stages, stripper pressure and inlet stream flow rate. Cement flue gas was considered in this study since the carbon dioxide (CO₂) content of the cement flue gas is one of the highest emission than the other conventional power plants. The flue gas was coming from St. Mary’s cement plant in Canada where the CO₂ content is 23.1 wt% and using solvent namely monoethanolamine (MEA) and diglycolamine (DGA). A parametric study was also carried out in order to identify the specific operating conditions and parameters for this absorption-desorption system. This modification and solvent used have reduce the energy consumption and increase the CO₂ absorption efficiency. About 87% of energy savings and 97% CO2 capture were achieved by using 60 wt% of DGA and 40wt% of water (H₂O) with the modifications used which is 20 stages of absorber, 5000 kg mole/h of inlet flue gas flow rate, 100,000 kg mole/h of inlet solvent flow rate and 2.6 bar of stripper pressure. This study deals with the detailed study on maximizing CO₂ absorption and removal efficiency while maintaining the minimal energy consumption for the absorbent regeneration section. As perspectives, these simulation results will be compared to the ones obtained by Hassan (2005) in which using Aspen PLUS model.