Upscaling SSZ-13 membranes for efficient separation of H₂/CH₄ mixtures

SSZ-13 membranes are highly desired for hydrogen separation from hydrocarbons. The H₂/CH₄ separation using tubular large-area SSZ-13 membranes with effective membrane area of 180 cm² were reported for the first time. The up-scaled SSZ-13 membranes consisted of a uniform zeolite layer with a thickness of 3.2 μm along the entire tube. The membrane exhibited H₂ permeance, H₂ flux, and H₂/CH₄ selectivity of 1.38 × 10^-7 mol m⁻² s⁻¹ Pa⁻¹ (410 GPU), 7.0 × 10^-3 mol m⁻² s⁻¹ and 67.2 for a 50–50 vol% H₂/CH₄ mixture, respectively, at pressure drop of 0.2 MPa. This separation performance was comparable to the reported ones of small-area zeolite membranes. The effects of conditions such as temperature, pressure, and feed flow rate on the separation performance of the large-area SSZ-13 membranes were investigated. Concentration polarization index was estimated to study and clarify the effect of concentration polarization on separation performance. Furthermore, the separation performance in a simulated refinery dry gas containing typical impurities was also evaluated. The large-area SSZ-13 membrane exhibited stable and good separation performance during the repeated separation tests and long-term storage. The results indicates that the membranes have great potential for H₂ separation from CH₄.