Optimum Conditions and Maximum Capacity of Amine-Based CO2 Capture Plant at Technology Centre Mongstad

Using amine-based solutions is a mature method for CO2 capture. This study simulates this process at Technology Centre Mongstad (TCM) using a rate-based model in Aspen Plus. The main purpose is to develop a rigorous model for TCM and find the operation limits, maximum utilization capacity, and maximum achievable CO2 removal efficiency at the plant. The model accuracy is verified by using different scenarios from the test campaign reports at TCM with three main configurations: Combined Heat and Power flue gas, Refinery Residue Fluid Catalytic Cracker flue gas, and cold rich-solvent bypass. The deviation between the experimental data and simulation results is compared. The model shows better accuracy with more detailed input data and accurate practical parameters. The verified model is used with all the TCM configurations to simulate the plant. Aspen Exchanger Design and Rating is also used to design real heat exchangers. To avoid flooding, the maximum gas flow to the absorber column is 52,000 Sm3/h. There is a maximum reboiler duty of 8.4 and 3.4 MW for the Residue Fluid Catalytic Cracker and the Combined Heat and Power flue gas strippers, respectively. The optimum operating condition to achieve a CO2 removal efficiency of 90% after amine lean loading adjustment, using maximum gas flow, both strippers, and 15% rich-solvent bypass, gives a total specific reboiler duty of 3.0 MJ/kgCO2. By using a maximum amine flow rate of 230 ton/h, a CO2 removal efficiency of 98% can be achieved. The optimum modification gives a bypass fraction of 19% and a specific reboiler duty of 3.63 MJ/kgCO2.