Synthesis and characterization of alumina supported sub-nanoporous SiO2–10 wt%TiO2 membrane for nitrogen separation

Membrane of SiO2–10TiO2 was produced by dip coating on mesoporous-titania-coated macroporous alumina support. The amorphous SiO2–10TiO2 top layer with thickness of 0.9 μm was obtained as a homogenous and defect free surface. Gas permeation tests show a decrease in permeation in order of CH4 > N2 for the support, and N2 > CH4 for the multilayer membrane. The membrane delivering promised single gas separation factor for N2/CH4 (1.75). It was also observed that the membrane separation factor in binary gas mixture was 12–15% of the single gas separation factor, while the permeation revealed a decrease in gas mixture.