Rate based modeling of absorption and regeneration for CO2 capture by aqueous ammonia solution

A rate-based model, RateFrac, in Aspen Plus process simulator, is used to simulate the CO2 absorption and regeneration processes of a research scale pilot plant. The simulation results of the CO2 absorption and regeneration predicted by the rate-based model are in good agreement with the experimental data. The effects of lean solvent flow rate, NH3 concentration, CO2 loading, and temperature on the absorption process were analyzed. Optimization analysis for the CO2 regeneration process was carried out. The operation parameters include temperature of the rich solvent, temperature of the condenser, inner diameter and packed height of the stripper. Under the optimal operation conditions, the regeneration energy is 3.63 MJ/kgCO2, which is much lower than that reported for the research scale pilot plant (4–4.2 MJ/kgCO2).