Highly durable ZIF-8 tubular membranes via precursor-assisted processing for propylene/propane separation

Abstract

ZIF-8 membrane has been considered as a potential alternative to the traditional cryogenic distillation process for propylene/propane (C3H6/C3H8) separation. However, the scale-up preparation and stability of ZIF-8 membranes are limited by the weak binding strength between membrane and tubular support. Herein, we report a precursor-assisted processing method that featured strong binding strength at the interface of ZIF-8 membranes and tubular supports. ZIF-8 tubular membranes are then assembled into a membrane module with an effective membrane area of about 157 cm2 for efficient C3H6/C3H8 separation. Reliable binding strength is achieved and maintained over 10 min sonication which results in remarkable operation stability over 30 days. The C3H6 permeance and separation factor of this membrane module reached 1.08 × 10−8 mol m−2 s−1 Pa−1 and 55 at 60 °C and 0.7 MPa, with purity and productivity of 98.3% and 6.2 × 10−5 mol s−1, respectively. The good repeatability and durability of the ZIF-8 tubular membrane module demonstrate its potential for further scale-up towards practical application.