Separation of light gas mixtures using zeolite SSZ-13 membranes

High-quality SSZ-13 membranes with enhanced permeances were synthesized on the symmetric mullite supports by modifying the synthesis recipes, and shown to be useful for light gas separations. The best SSZ-13 membrane displayed doubled CO2 permeance and comparative CO2/CH4 selectivities compared to our previous mullite supported SSZ-13 membranes. Single-gas permeance of CO2, H2, N2, CH4, C2H6 and C3H8 decreased at 298 K with increasing kinetic diameter, except for CO2. The CO2/CH4, CO2/N2, H2/CH4 and N2/CH4 ideal selectivities were 360, 20, 62 and 16, respectively, at room temperature. The mixture selectivities for the same equimolar gas pairs at 298 K were 406, 32, 43 and 16, and the faster-gas permeances of 4.4, 3.2, 1.8 and 0.22 mol/(m2 s Pa), respectively. Calcination times, long-time operation and long-term storage had few effects on membrane performance.