Enzymatic Reactive Distillation: Kinetic Resolution of rac-2-Pentanol with Biocatalytic Coatings on Structured Packings

Abstract

An enantioselective biocatalytic reaction was carried out for the first time in a fully integrated batch reactive distillation setup. The investigated reaction was the lipase catalyzed kinetic resolution of a racemic mixture of (R/S)-2-pentanol with ethyl butyrate. The reaction is strongly limited by the reaction equilibrium so that the reactive distillation helped to shift the equilibrium toward the product side. The enantioselectivity of the applied lipase was high with ee values >99% for 2-pentanol at conversions of 69 ± 3%. As established in our previous work, the biocatalyst was again immobilized within a hydrophobic silica coating for structured packings. The production of the biocatalytic coating was further developed as a spray-coating method to allow reproducible coatings which also can be applied on larger surfaces. The influence of the coating on separation efficiency and pressure drop was studied as well as the stability of the coating under the required process conditions. Overall, this work demonstrates the first kinetic resolution in a reactive distillation setup with structured packings and presents the catalytic coating as an alternative structure for (bio)catalytic columns internals.