Coupled Pervaporation-Reaction Distillation Process for the Production of n-Bromopropane

The reaction of n-C3H7OH+HBr=n-C3H7Br+H2O was used to experimentally study a coupled pervaporation (PV)-reaction distillation (RD) process. The results show that polyvinyl alcohol (PVA) is a suitable membrane material for water removal. The typical separation properties of PVA polyacrylonitrile (PAN) composite membranes are a highest flux of 780 g/(m2*h) and a separation factor of 840 for the C3H7OH concentration in the original feed of 95% at 90℃ and below 3300 Pa(abs). Reaction distillation produced the n-bromopropane from the distillation column as a ternary azeotropic liquid mixture of C3H7OH, H2O and C3H7Br, with a product concentration of about 92%. The coupled PV-RD membrane reactor experiment shows that the BrPr yield can reach 92%, much higher than that for reaction-distillation without pervaporation.