Main content area

Fabrication of bilayer catalytic composite membrane PVA-SA/SPVA and application for ethyl acetate synthesis

Bo, Shutong, Zhang, Li, Han, Shang, Li, Yuewen, Li, Weixing, Xing, Weihong
Journal of membrane science 2018 v.563 pp. 10-21
Fourier transform infrared spectroscopy, acetic acid, alginates, asymmetric membranes, catalysts, coatings, crosslinking, esterification, ethanol, ethyl acetate, pervaporation, polyvinyl alcohol, scanning electron microscopy, thermogravimetry
In this study, a dual-function catalytic composite membrane (CCM) was developed by coating a sulfonated-polyvinyl alcohol (SPVA) casting solution onto a polyvinyl alcohol (PVA)-sodium alginate (SA) membrane. SPVA was synthesized via sulfoisophthalic acid (SIPA) cross-linked PVA. The membranes were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG), scanning electron microscopy (SEM), pervaporation and pervaporation coupled esterification experiments, etc. The dehydration of ethanol via pervaporation was studied over the concentration range of 3.5–11 wt% water in ethanol. The conversions of acetic acid in a batch reactor (BR) with CCM, pervaporation catalytic membrane reactor (PVCMR) with CCM and BR with free SIPA were compared. The experimental results showed that the conversion reached 96% in 12 h at 75 °C with 20% molar fraction of catalyst, an initial molar ratio (alcohol/acid) of 2:1 and an S/m ratio of 1.13 cm2 g-1 in PVCMR. With these conditions, the conversion was enhanced significantly by approximately 24% compared to BR. After five successive runs, the membrane still maintained outstanding stability.