Whole-Process Integration and Economic Analysis of Postcombustion CO2 Capture with PZ-MDEA: From Experimental Validation to Industrial Application

Studying different absorbents and process configurations is crucial for the process performance of postcombustion CO2 capture, which can reduce the regeneration energy consumption of the stripper and improve the economics of the process. In this study, postcombustion CO2 capture processes using 30 wt % MEA and 20 wt % PZ+20 wt % MDEA as absorbents were established and investigated. Then, 30 wt % MEA and a mixed solution of 20 wt % PZ + 20 wt % MDEA were used as absorbents. Three process configurations were simulated, including the standard configuration, the AIC-SSF configuration combining interstage cooling (AIC) and split rich solvent flow (SSF), and the AIC-SSF-MVR configuration integrated with mechanical vapor recompression (MVR). The results indicate that, under standard operating conditions, the 20 wt % PZ + 20 wt % MDEA mixed amine exhibits a reboiler heat duty of 2.73 GJ/t CO2, which is 24.6% lower than that of the standard MEA baseline condition (3.62 GJ/t CO2). When adopting the AIC-SSF-MVR process configuration, the minimum regeneration energy consumption is further lowered to 2.14 GJ/t CO2, which is 40.9% less than that of the standard MEA operating condition. Economic analysis via APEA shows that the AIC-SSF-MVR process configuration using a 40 wt % PZ-MDEA solution delivers the lowest CO2 capture cost of 53.83 $/t CO2. This value is approximately 27.9% lower relative to the standard MEA operating conditions (74.69 $/t CO2).