Abstract:
Using the hollow fiber ultrafiltration membrane of polyacrylonitrile (PAN) as the support layer and the tartaric acid (Tac) as the cross-linking agent, the polyvinyl alcohol-perfluorosulfonic acid/polyacrylonitrile (PVA-PFSA/PAN) composite pervaporation membrane was prepared for dehydration of ethyl acetate (EAc)-H2O and EAc-ethanol (EtOH)-H2O solutions. Effects of feed temperature and water content on the pervaporation performance were investigated for dehydration of EAc-H2O solutions. Total permeation flux and separation factor of PVA-PFSA/PAN composite membrane for the feed water concentration of 2% (mass fraction) at 40 ℃ were 81.1 g/(m2·h) and 1890, respectively. In addition, when EAc-EtOH-H2O (mass ratio is 90∶2∶8) ternary solutions were dehydrated, effect of feed temperature and dehydration performance were studied. Total permeation flux of PVA-PFSA/PAN composite membrane was 251.0 g/(m2·h) at 40 ℃, and the mass fraction of feed water was decreased from 8% to 4.66% after 12 h. The PVA-PFSA/PAN composite membrane had good dehydration performance, and could be applied in the new enhanced esterification process of EAc production. Commercial software Aspen Plus 11.1 was used to simulate the process. The simulation results showed that the onepass yield of EAc and the conversion of raw materials in the process were enhanced at the same operating conditions compared with the conventional reactive distillation, and the process of EAc production simplified.