Pervaporative recovery of n-butanol from aqueous solutions with MCM-41 filled PEBA mixed matrix membrane

• GCMC simulation shows that butanol has stronger interaction with MCM-41 than water.
• The diffusion coefficient of n-butanol is higher than that of water in MCM-41.
• The fractional free volume of MCM-41 is much higher than that of PEBA.
• The DS values of MCM-41–PEBA in n-butanol solutions are higher than in water.
• MCM-41–PEBA membrane has high pervaporation separation index (PSI) value.

MCM-41 filled poly(ether-block-amide) (PEBA) mixed matrix membranes were prepared and investigated in this work. The properties of MCM-41 for n-butanol aqueous solutions separation were analyzed with molecular simulation. The sorption simulation indicates that n-butanol has a stronger interaction with MCM-41 than water, so that the sorption to n-butanol is preferential. The diffusion simulation shows that the diffusion coefficient of n-butanol is higher than that of water in MCM-41. n-Butanol and water diffuse faster in MCM-41 than in PEBA as MCM-41 has higher fractional free volume than PEBA. With a series of MCM-41–PEBA mixed matrix membranes prepared, swelling study and pervaporation experiments verify preferential sorption of n-butanol and good permeation property of the mixed matrix membranes. Compared with the plain PEBA membrane, MCM-41 filled mixed matrix membranes display significantly improved permeation flux and almost equivalent n-butanol/water separation factor, agreeing well with the simulation results. According to the calculated values of pervaporation separation index, MCM-41–PEBA membrane shows better pervaporation performance than many membranes reported in the literature.