Pervaporation removal of methanol from methanol/organic azeotropes using organosilica membranes: Experimental and modeling

Membrane-based separation of organic/organic mixtures is of great importance in the chemical and petro-chemical industries, but remains very challenging owing to the harsh working conditions. Herein, ultrathin and chemically stable Bis(triethoxysilyl)acetylene (BTESA)-derived organosilica membranes were reproducibly pre-pared, and for the first time they were utilized in the pervaporation separation of methanol/organic azeotropes. The as-prepared BTESA membranes exhibited exceptional pervaporation performance in a 10 wt%/90 wt% methanol/dimethyl carbonate (DMC) mixture, and showed a high separation factor of approximately 120 with a permeation flux of 2-4 kg m(-2) h(-1) at 50 degrees C. This impressive performance was primarily the result of the pref-erential sorption of methanol and the efficient size sieving of DMC. In addition, the effects of feed concentration and temperature on methanol/DMC pervaporation performance were thoroughly investigated. Importantly, a generalized solution-diffusion model successfully described the pervaporation performance of BTESA mem-branes, and the usefulness of this model was further confirmed via the pervaporation of methanol/methyl acetate and methanol/methyl tert-butyl ether (MTBE) mixtures. This work demonstrates the great potential of orga-nosilica membranes for high-performance organic/organic pervaporation.