Pervaporation separation of methanol/methyl tert-butyl ether mixtures using polyarylethersulfone with cardo membranes

Membranes based on polyarylethersulfone with cardo (PES-C) were prepared for pervaporation (PV) separation of methanol (MeOH)/methyl tert-butyl ether (MTBE) mixtures. The membranes were characterized using wide angle X-ray diffraction (WAXRD), scanning electron microscopy (SEM) and contact angle metering. The swelling and mechanical properties of the membranes in MeOH/MTBE mixtures were studied. The degree of swelling (DS) was less than 7% originating from the good solvent proof and excellent mechanical properties of PES-C. N-methyl pyrrolidone (NMP) is found to be the optimum solvent for PES-C membrane preparation against N,N-dimethylformamide (DMF). The effect of annealing temperature and annealing time on the structure and PV performance of the PES-C membranes was thoroughly discussed. The results showed that increasing annealing temperature or annealing time would enhance MeOH permselectivity and reduce permeation flux. By varying feed MeOH content from 5 to 40 wt.%, permeation flux increased from 1.21 to 4.52 kg μm m−2 h−1, and MeOH content in the permeate was almost constant. The permeation flux increased and MeOH permselectivity decreased with increasing feed temperature.

► Polyarylethersulfone with cardo membranes were prepared for pervaporation. ► The degree of swelling of the membranes in MeOH/MTBE mixtures was less than 7%. ► The membranes have excellent solvent resistance and moderate mechanical strength. ► The product purity stayed higher than 98.5 wt.% with increasing feed MeOH content.