Polybenzimidazole (PBI) Membranes for Phenol Dehydration via Pervaporation

Phenol is an important commodity in chemical industries and dewatering is a critical process in its application. In this work, polybenzimidazole (PBI) membranes with various morphologies are employed for phenol dehydration via pervaporation, including flat-sheet dense membranes, single-layer and dual-layer hollow fiber membranes. Effects of cross-linking modification and post-thermal treatment on the performance of PBI flat-sheet dense membranes were investigated; effects of the operation temperature and feed composition are also studied, not only in terms of flux and separation factor, but also of the intrinsic permeance and selectivity of the membrane. In order to achieve a higher permeation flux, PBI single-layer hollow fiber membranes of thinner selective layers were developed and studied with the effect of different spinning parameters. The preliminary study of dual-layer PBI/PBI and PBI/poly(vinylidene fluoride) (PVDF) dual-layer hollow fiber membranes are also carried out to explore the potential of high-performance composite membranes for phenol dehydration. The promising separation performance of PBI membranes exhibited via benchmarking shows its great potential for phenol dehydration, and it may open new perspectives for the development of high-performance membranes for the pervaporation dehydration of phenol or other corrosive organics.