Synthesis and separation performance of SSZ-13 zeolite membranes on tubular supports

SSZ-13 zeolite membranes were synthesized on the inside surface of porous stainless steel tubes. In parallel with zeolite pores, the membranes had nonzeolite pores that were larger than the 0.38-nm zeolite pore diameter, but single-gas permeances of H-2, N-2, CH4, and n-C4H10 decreased with increasing kinetic diameter at 298 K. The CO2/CH4, H-2/CH4 and H2/n-C4H10 ideal selectivities were 11, 9.0, and 63, respectively, at 298 K, and the separation selectivities for the mixtures of the same gas pairs were 12, 8.2, and 5.7 at 298 K. The SSZ-13 membranes selectively removed H2O from HNO3/H2O liquid mixtures by pervaporation. to break the azeotrope at 69.5 wt % HNO3. The permeate concentration was 38.3% HNO3, and the total flux was 0.12 kg/m(2).h at 298 K.