Preparation of OH/TiO2/PES composite membrane by a novel gas-phase hydrolysis method in gas-liquid membrane contactor to improve the separation efficiency of CO2 and CH4

Conventional gas separation methods are very limited for CO2 separation in terms of separation efficiency and cost. In this study, We obtained fluorinated TiO2/polyethersulfone (PES) composite membranes by gas-phase hydrolysis and compared the characterization results with the composite membranes prepared by the graft coating method. In the mixed gas separation experiment, we used diethanolamine (DEA) as the absorbent to test the separation performance of CO2/CH4 using the composite membranes prepared by gas phase hydrolysis in a gas-liquid membrane contactor (GLMC) system. DEA flow rate and concentration and feed gas flow were found to have a significant effect on separation performance. When the feed gas flow rate was kept constant at 30 ml/min and the DEA flow rate and concentration were 16 L/h and 1 mol/L, respectively, the collected CH4 concentration was 99.4 %. Meanwhile, the CO2 flux was 10.096 x 10-3 mol m- 2 s- 1, and the separation factor reached 110.444. Collectively, the application of TiO2/PES composite membranes in GLMC is an efficient method for CO2 capture and mixed gas separation.