Modeling of pre-combustion carbon capture with CO2-selective polymer membranes

CO₂-selective polymer membranes were recently applied to pilot-scale and bench-scale pre-combustion capture and the obtained CO₂ capture ratios were reported to be less than 90%, which limits their application in industrial processes such as IGCC plants. This work is aimed to explore the possibility of achieving a CO₂ capture ratio >95% and CO₂ purity >95% in a gas-separation unit equipped with currently-available CO₂-selective polymer membranes. A mathematical model for single-stage membrane gas separation was developed, and the effect of membrane characteristics (permeance and selectivity), as well as the operating parameters such as feed and permeate pressure, and feed flow rate on the performance of CO₂ capture was investigated. The simulation results reveal the optimal conditions that are necessary for a high-performance CO₂ capture process using the real industrial syngas and highlight the potential of facilitated transport membranes for CO₂ removal in both the oxygen-blown and air-blown IGCC processes.