Preparation and characterization of OH/SiO2-TiO2/PES composite hollow fiber membrane using gas-liquid membrane contactor for CO2/CH4 separation

• PES composite hollow fiber membranes were fabricated by a high-temperature steam-induced hydrolysis method. • High temperature gas phase induced hydrolysis is a better method than graft coating. • The grafting rate of SiO 2 on the surface of PES membrane is higher than that of TiO 2 . • The PES modified membrane shows the optimum CH 4 /CO 2 selectivity of 554.89. In this study we used a high-temperature steam-induced hydrolysis method to obtain a fluorinated OH/SiO 2 -TiO 2 /polyethersulfone (PES) composite hollow fiber membrane for CO 2 capture. The purpose of grafting SiO 2 and TiO 2 on the surface of PES by hydrolyzing silicon precursors and titanium precursors at high temperature, is to improve the alkali corrosion resistance and hydrophobicity of the PES membrane. The OH/SiO 2 -TiO 2 /PES composite hollow fiber membranes prepared by the high-temperature steam-induced hydrolysis method and the graft coating method were measured by SEM, EDS, FTIR, WCA, AFM, XRD and XPS in order to characterize the morphology and structure of the prepared membranes. In the CO 2 /CH 4 separation performance test experiment, the OH/SiO 2 -TiO 2 /PES membrane prepared by the high-temperature steam hydrolysis method showed better separation performance than the original PES membrane. The effects of absorbent flow rate, absorbent concentration and feed gas flow rate on CO 2 flux and CO 2 /CH 4 were selectivity investigated. When the flow rate of the absorbent (DEA) reached 16 L/h, the flow rate of the feed gas (CO 2 /CH 4 = 40 : 60) was 30 ml/min, the concentration of the absorbent was 1 mol/L, The CH 4 concentration was 99.88 % and the optimal separation factor was as high as 554.89. In general, the results obtained in this work may provide promising insights into the use of fluorinated OH/SiO 2 -TiO 2 /PES composite membranes for carbon capture and CO 2 /CH 4 separation in GLMC application.