Waste-free process for continuous flow enzymatic esterification using a double pervaporation system

The enzyme catalytic esterification reaction of acetic acid and ethanol in [bmim]PF(6) ionic liquid was studied to manufacture natural ethyl acetate by a continuous waste-free process. The optimal parameters of the reaction were determined in batch experiments, and then a continuous set-up was constructed. Ethyl acetate and water formed in the bioreactor were removed by a double pervaporation system using hydrophobic and hydrophilic membranes, respectively. Acetic acid and ethanol were added as they were consumed, thus steady state concentrations in the reactor were maintained and continuous operation for 72 hours long was ensured without any activity loss of the enzyme.