Energy consumption and economic analysis of CO2 capture from flue gas by membrane separation coupled with hydrate method

Hydrate-based CO2 capture (HBCC), as a new gas separation technique, has been widely studied. CO2 hydrate formation requires a higher pressure and lower temperature. In this study, a novel integrated process using membrane separation coupled with hydrate method was proposed to improve the efficiency of CO2 capture. The CO2 separation process from flue gas was simulated and optimized using Aspen Plus, revealing that the CO2 concentration was increased from 15 % to 42.32 % after membrane separation, and further rose to 87.35 % following Hydrate-based gas separation. The energy consumption for CO2 capture was calculated to be 2.81 GJ/tCO2, with an exergy loss during the hydrate-based separation stage reaching up to 33.26 %. The total cost of CO2 capture, including equipment investment, was determined to be 82.35 $/t, with an estimated payback period of approximately 6 years. Thus, the process using membrane separation coupled with hydrate method was reasonable and feasible through the energy, exergy and economic analysis. This research introduces a promising large-scale industrial CO2 capture process for the advancement of Hydrate-based CO2 capture technology.