Propylene - propane separation using Zeolitic-Imidazolate Framework (ZIF-8) membranes: Process techno-commercial evaluation

Several recent studies investigated the use of the novel Zeolitic-Imidazolate Framework (ZIF-8) membranes for olefin-paraffin separation. In this manuscript, a techno-commercial model is developed to examine the use of these membranes for separating propylene from propane. Single-stage and two-stage membrane processes were assessed for their performance compared to distillation. The assessment was conducted considering 70 wt% propylene feed, typically produced from the upstream depropanizer. The single-stage process was found technically capable and commercially competent to produce the chemical grade propylene (93 wt%), but not the polymer grade (99.5 wt%). Alternatively, the two-stage process was capable of producing both propylene grades at promising recovery and cost figures. The published propylene/propane selectivity of 35 appears adequate in meeting the separation demands, subject to the adoption of proper unit design. Future research should grant more attention towards aspects such as ZIF-8 membranes’ manufacturability, cost, and performance in real environments.