ISBN 9783843937528

978-3-8439-3752-8, Reihe Verfahrenstechnik

Matthias Wierschem
Enzymatic Reactive Distillation

243 Seiten, Dissertation Technische Universität Dortmund (2018), Softcover, A5

Zusammenfassung / Abstract

The production of enantiomerically pure components is increasingly important in the pharmaceutical and fine chemicals industry. Usually, batch reactors with chemical catalysts that are often not as selective as enzymes are the standard production technology in this sector. These processes often feature bad economic and ecological performance that is why process intensification and green chemistry approaches progressively gain attention in this sector. In this context, continuous Enzymatic Reactive Distillation (ERD) outweighs the disadvantages of standard processes by combining enantioselective enzyme catalysis and continuous in-situ product separation under mild conditions.

Since industrial examples of this technology are missing, this thesis follows the objective of a deeper investigation and evaluation of continuous ERD. The investigation was exemplarily carried out for the transesterification of ethyl butyrate and the enantiomerically pure production of (R)-1-phenylethyl acetate from racemic (R/S)-1-phenylethanol catalyzed by Candida antarctica lipase B. Kinetic and thermodynamic models were developed that successfully matched the experimental data and ultrasound (US) was shown to increase the reaction rate of enzymatic reactions by 50%. ERD experiments were carried out in pilot-scale and feasibility of ERD was confirmed for both chemical systems. A rate-based ERD model was validated that is able to predict operating points at various scales. Processes under various conditions were optimized with regard to costs on basis of the ERD model. An optimized US-assisted ERD process did not provide cost advantages compared to the ERD process. The combination of enzyme and chemical catalyzed racemization in a continuous Chemo-Enzymatic Reactive Distillation (CERD) column exhibited pure enantiomer production of (R)-1-phenylethyl acetate. Comparison of the CERD with a tube reactor and subsequent product separation revealed that CERD offers lower product and investment costs as well as lower energy consumption.