Laboratory and pilot-scale study on dehydration of benzene by pervaporation

Three different kinds of PVA/PAN composite pervaporation (PV) membranes, which were treated or crosslinked with formaldehyde, glutaraldehyde and maleic acid, respectively, were used and compared on dehydration of benzene on a laboratory scale. In terms of water flux, the best membrane for the dehydration of benzene was chosen. Effects of feed velocity and the water content in feed on water flux were investigated. Two regression equations were obtained to calculate flux of water and flux of benzene. Based on these laboratory experimental results, a pilot-plant with plate–frame membrane modules was constructed. The pilot experiment was carried out successfully and the results showed that the water content could be reduced from 600 to 30 ppm at temperature about 70 °C and downstream pressure about 2000 Pa. The preliminary economical evaluation of this process was compared with that of conventional distillation process for the dehydration of benzene, which showed that the PV process had economical superiority over the conventional distillation. These pilot experimental results provided basic dada for industrial process design on the dehydration of benzene by PV.