Kinetic resolution of racemic glycidyl butyrate using a multiphase membrane enzyme reactor: experiments and model...

A laboratory-scale multiphase hollow fiber membrane reactor was employed to investigate the lipase-catalyzed enzymatic resolution of racemic glycidyl butyrate. A mathematical formulation was developed to simulate the performance of this system. Model parameters were determined independently (except the effective rate constant, k(s)) and incorporated in the model simulations. In this study, two modes of operation are considered: subtractive resolution, in which the unreacted substrate is recovered in the organic stream; and product recovery, where the optically pure product of the enzymatic reaction is recovered in the aqueous stream. Good agreement was obtained between theoretical predictions and experimental results under a variety of conditions. The effect of mass transport limitations on the performance of this system was investigated. An increase in enzyme loading resulted in a higher Thiele modulus due to an elevated rate constant as well as a concomitant decrease in the effective diffusivity. Optical purity decreased in both subtractive resolution and product recovery at higher Thiele modulus with the effect being more pronounced in the product recovery mode. Finally, normalized plots were established to describe the effect of enzyme immobilization on both the effective enzymes activity and effective diffusivity.