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A Falling‐Film Microreactor for Enzymatic Oxidation of Glucose
Author(s) -
Illner Sabine,
Hofmann Christian,
Löb Patrick,
Kragl Udo
Publication year - 2014
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201400028
Subject(s) - microreactor , gluconic acid , glucose oxidase , chemistry , catalysis , chemical engineering , mass transfer , batch reactor , oxygen , enzyme catalysis , chromatography , organic chemistry , enzyme , engineering
Many oxidation processes require the presence of molecular oxygen in the reaction media. Reactors are needed that provide favorable conditions for the mass transfer between the gas and the liquid phase. In this study, two recent key technologies, microreactor technology and biotechnology, were combined to present an interesting alternative to conventional methods and open up excellent possibilities to intensify chemical processes in the field of fine chemicals. An enzyme‐catalyzed gas/liquid phase reaction in a falling‐film microreactor (FFMR) was examined for the first time. The test reaction was the oxidation of β‐ D ‐glucose to gluconic acid catalyzed by glucose oxidase (GOx). Various factors influencing the biotransformation, such as oxygen supply, temperature, enzyme concentration, and reaction time were investigated and compared to those in conventional batch systems. The most critical factor, the volumetric mass‐transfer coefficient for the efficient use of oxygen‐dependent enzymes, was determined by using the integrated online detection of dissolved oxygen in all systems. The extremely large surface‐to‐volume ratio of the FFMR facilitated the contact between the enzyme solution and the gaseous substrate. Hence, in a continuous bubble‐free FFMR system with a residence time of 25 seconds, a final conversion of up to 50 % in enzymatic oxidation was reached, whereas conversion in a conventional bubble column resulted in only 27 %. Finally, an option for scale‐up was shown through an enlarged version of the FFMR.