Synthesis of ZIF-8 Membrane by Secondary Growth Method for Propylene/ Propane Separation

Propylene/ propane separation is one of the most importance but challenging task in the petrochemical industry. In this study, a continuous well-intergrown ZIF-8 membrane on porous α-alumina substrate was successfully prepared by a novel secondary growth method displayed high propylene/ propane molecular sieve separation performance. It is displayed that, the resulted ZIF-8 membrane was defect-free and compact, with a thickness of about 3 μm. The resulted membrane presented high propylene molecular sieve separation performance. The propylene permeance reached 120 × 10-10 mol m-2 s-1 Pa-1, and the separation factors for propylene/ propane were calculated to be 62 at ambient condition. The experimental data also revealed that, the membranes had excellent reproducibility and long-term stability