(673d) Enabling Molecular Sieving Behaviors of Mixed Matrix Membranes for Efficient C3H6/C3H8 Separations

Propylene/propane (C₃H₆/C₃H₈)separation has been implemented by utilizing highly energy-intensive cryogenic distillation due to similar physical properties between them (i.e., T_b of C₃H₆ and C₃H₈ is -47.6 and -42.1 °C, respectively). Membrane-based separation is an attractive alternative due to its small footprint as well as good energy efficiency. Conventional polymeric membranes, however, have been suffering from poor separation performance as well as plasticization-induced selectivity loss. Mixed matrix membranes (MMMs), essentially hybrid membranes consisting of dispersed molecular sieves for exceptional separation performance and continuous polymeric membranes for good processability have been suggested to address the technical issues mentioned above. Especially, zeolitic imidazolate framework-8, ZIF-8 crystallites are considered the appropriate molecular sieve for C₃H₆/C₃H₈ separation. More recently, we demonstrated Co-substituted ZIF-8, ZIF-67 containing MMMs exhibit further enhanced C₃H₆/C₃H₈ separation efficiency compared to ZIF-8 containing counterparts due to excellent molecular sieving behavior of ZIF-67. In this talk, we will present the current progress in developing MMMs for C₃H₆/C₃H₈ separations.