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ORIGINAL RESEARCH article

Front. Chem. Eng.
Sec. Biochemical Engineering
Volume 6 - 2024 | doi: 10.3389/fceng.2024.1470991

Novel Sparging Strategies to Enhance Dissolved Carbon Dioxide Stripping in Industrial Scale Stirred Tank Reactors

Provisionally accepted
Nicolas Nickel Nicolas Nickel 1*Jürgen Fitschen Jürgen Fitschen 2Ingrid Haase Ingrid Haase 1Maike Kuschel Maike Kuschel 2Torsten Schulz Torsten Schulz 2Thomas Wucherpfennig Thomas Wucherpfennig 2Michael Schlüter Michael Schlüter 1*
  • 1 Hamburg University of Technology, Hamburg, Germany
  • 2 Boehringer Ingelheim, Ingelheim, Germany

The final, formatted version of the article will be published soon.

    Aerated stirred tank reactors are widely used in bio-process engineering and pharmaceutical industries. To supply the organisms with oxygen and control the pH value, oxygen is transferred from air bubbles into the liquid phase and at the same time carbon dioxide is stripped from the liquid phase with the same gas bubbles. The volumetric mass transfer coefficients for oxygen and carbon dioxide are therefore of crucial importance for the design and scale-up of aerated stirred tank reactors. In this experimental work, the volumetric mass transfer coefficients for oxygen and carbon dioxide are investigated simultaneously to study their mutual influence. The mass transfer performance for oxygen and carbon dioxide is conducted in stirred tank reactors on 3 L laboratory scale, 30 L pilot scale and 15 000 L production scale. First, the influence of dissolved carbon dioxide on the oxygen mass transfer performance is investigated in a 30 L pilot scale stirred tank reactor. The results show that the volumetric mass transfer coefficient of oxygen is not affected by the concentration of dissolved carbon dioxide, but the total mass flux of oxygen decreases with increasing carbon dioxide concentration due to the decreasing partial pressure difference.With rising gassing rate and volumetric power input, both mass transfer coefficients for oxygen and carbon dioxide show the same increasing trend. While this trend can also be observed when scaling down to the 3 L laboratory scale reactor, a significantly different effect must be considered for the scale up to the 15 000 L industrial scale reactor. The limited absorption capacity for carbon dioxide of the gas bubbles during the long residence time in the industrial scale reactor is noticeable here, which is why the specific interfacial area is of negligible importance. This effect is used to develop a method for independent control of oxygen and carbon dioxide mass transfer performance on industrial scale and to increase the mass transfer performance for carbon dioxide by up to 25 %.

    Keywords: Mass transfer performance, volumetric mass transfer coefficient of oxygen and carbon dioxide, Carbon dioxide stripping, Stirred tank reactor, Experimental results

    Received: 26 Jul 2024; Accepted: 17 Oct 2024.

    Copyright: © 2024 Nickel, Fitschen, Haase, Kuschel, Schulz, Wucherpfennig and Schlüter. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Nicolas Nickel, Hamburg University of Technology, Hamburg, Germany
    Michael Schlüter, Hamburg University of Technology, Hamburg, Germany

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.