Synthesis of n-butyl acetate via reactive distillation column using Candida Antarctica lipase as catalyst.

Abstract

The reactive distillation process for the synthesis of n-butyl acetate via transesterification of ethyl acetate with n-butyl alcohol catalyzed by immobilized lipase was simulated and experimentally tested in this work. Based on the reaction kinetics, a reactive distillation process model was developed. The effects of theoretical stages number in the reaction section, the rectifying section and stripping section, reflux ratio, feed molar ratio and relative feed position on the transesterification distillation process were investigated. The transesterification of ethyl acetate with n-butyl alcohol was carried out in a small-scale reactive distillation column. The results showed that the optimal operating conditions are as follows: reaction section stages were 13, rectifying section stages were six, stripping section stages were five, reflux ratio was 1, mole ratio of ethyl acetate and n-butanol was 3:1, the feeding positions of n-butanol and ethyl acetate were at the top and bottom of the reaction section, respectively. Compared to the batch reaction with only 60% conversion of n-butanol, the reactive distillation column can improve the conversion of n-butanol (up to 93.6%).At the same time, the experiment verified that the conversion of n-butanol could still reach 72.5%, after the lipase-loaded packing storage in the reaction system at 70°C for 120days.