Process simulation of ammonia-based CO2 capture and regeneration in packed column

Post-combustion CO2 capture using aqueous ammonia offers advantages over the conventional amines solvent, including lack of corrosion, an enhanced CO2 loading capacity and low energy input requirement for solvent regeneration. In this paper, an aqueous ammonia-based CO2 absorption-desorption process integrated with washing column is modelled and simulated in Aspen Plus (R). The predicted results agreed with published experimental results. The effect of performance parameters such as the ammonia concentration in lean solution, CO2 fraction in the flue gas, inlet feed gas temperature, stripper operating temperature and pressure, lean solution temperature and flow rates of the flue gas, were investigated. The gas temperature showed trivial effect on CO2 absorption efficiency; therefore the absorber column can be fed with hot flue gases, eliminating the need for cooling. The results show that the washing columns coupled at top of the absorber and stripper columns enabled the system to maintain ammonia slip within permissible level.