Theoretical and experimental investigation of CO₂ separation from CH₄ and N₂ through supported ionic liquid membranes

Alarming concentration of CO2 in atmosphere has risen global concern for its mitigation to avoid global warming. Supported ionic liquid membranes (SILMs) have dual benefits as they combine striping process of liquids with high solubility of CO2 in room temperature ionic liquids (RTIL) in membranes. In this study, we have investigated the performance of a recently synthesized RTIL in SILM, experimentally and theoretically. Benzimidazolium-1-acetate was used to prepare SILM over a polyimide support. The prepared SILM was tested for different gas mixtures (CO2/CH4 and CO2/N-2). In order to evaluate the commercial potential of these membranes, there were also tested under different operating conditions. Density functional theory (DFT) calculations were also performed to predict the interactions of CO2 with the RTIL. SILM showed high selectivity of 37.92 and 40.29 for CO2/CH4 and CO2/N-2 respectively. These results also strengthen DFT calculation results indicating promising applications for gas separation.