Comparative investigation of fine bubble and macrobubbleaeration on gas utility and biotransformation productivity

The sufficient provision of oxygen is mandatory for enzymatic oxidations in aqueous solution, however, in process optimization this still is a bottleneck that cannot be overcome with the established methods of macrobubble aeration. Providing higher mass transfer performance through microbubble aerators, inefficient aeration can be overcome or improved. Investigating the mass transport performance in a model protein solution, the microbubble aeration results in higher kLa values related to the applied airstream in comparison with macrobubble aeration. Comparing the aerators at identical kLa of 160 and 60 1/h, the microbubble aeration is resulting in 25 and 44 times enhanced gas utility compared with aeration with macrobubbles. To prove the feasibility of microbubbles in biocatalysis, the productivity of a glucose oxidase catalyzed biotransformation is compared with macrobubble aeration as well as the gas-saving potential. In contrast to the expectation that the same productivities are achieved at identically applied kLa, microbubble aeration increased the gluconic acid productivity by 32% and resulted in 41.6 times higher oxygen utilization. The observed advantages of microbubble aeration are based on the large volume-specific interfacial area combined with a prolonged residence time, which results in a high mass transfer performance, less enzyme deactivation by foam formation, and reduced gas consumption. This makes microbubble aerators favorable for application in biocatalysis.

Subjects

aeration technology

gas utilization

glucose oxidase

microbubbles

multiphase reaction

DDC Class

600: Technik

Funding(s)

Projekt DEAL

More Funding Information

We are grateful for the financial support provided by the Deutsche Forschungsgemeinschaft (DFG) within the combined project LI 899/10-1 and SCHL 617/14-1.

Publication version

publishedVersion

Lizenz

https://creativecommons.org/licenses/by/4.0/

Name

bit.27556-ohne-werbung.pdf

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1.59 MB

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Adobe PDF

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Comparative investigation of fine bubble and macrobubbleaeration on gas utility and biotransformation productivity