Bioprocess and Biosystems Engineering

, Volume 24, Issue 3, pp 187–193

Oxygen transfer characteristics of a centrifugal, packed-bed reactor during viscous xanthan fermentation

  •  Y. Lo
  •  C. Hsu
  •  S. Yang
  •  D. Min

DOI: 10.1007/s004490100250

Cite this article as:
Lo, Y., Hsu, C., Yang, S. et al. Bioprocess Biosyst Eng (2001) 24: 187. doi:10.1007/s004490100250

Abstract.

The oxygen transfer properties of a novel, centrifugal, packed-bed reactor (CPBR) during viscous xanthan fermentation were determined with respect to the effects of the arrangement of the centrifugal, packed bed (CPB) and the recirculation loop (RL). Characterized by the maximum volumetric transfer coefficient (kLa) in xanthan broth, the aeration efficiency of CPBR was compared to those in stirred-tank reactors (STR) equipped with disc turbines (DT) or marine propellers (MP), and to that in a water-in-oil emulsion (WIO). As expected, STR-WIO showed the highest kLa (0.038 s–1 at 2%) among all systems studied due to reduced broth viscosity; however, practical difficulties exist in product recovery. It was found that, at 3.5% xanthan the kLa in CPBR (0.018 s–1) was higher than that of STR (0.005 s–1) and close to that of STR-WIO (0.020 s–1), indicating improved oxygen transfer at such a xanthan concentration. The exterior baffles along the rotating fibrous matrix offer additional agitation in the viscous broth. A gas-continuous arrangement, in which the CPB was kept above the broth, was able to elevate kLa to 0.023 s–1, higher than that of STR-WIO. The external RL operated by a peristaltic pump was found to play an important role in CPBR aeration by providing better gas–liquid contact. With the improved oxygen transfer efficiency in CPBR at high xanthan concentrations, the CPBR system is practically the preferred system for xanthan fermentation. The characteristic roles of CPB arrangement and the RL should be considered primarily during scale-up operation.

Xanthan Oxygen transfer Viscosity Bioreactor Fermentation 

Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  •  Y. Lo
    • 1
  •  C. Hsu
    • 1
  •  S. Yang
    • 2
  •  D. Min
    • 3
  1. 1.Department of Animal and Food Sciences, University of Delaware, Newark, DE 19717, USA
  2. 2.Department of Chemical Engineering, The Ohio State University, Columbus, OH 43210, USA
  3. 3.Department of Food Science and Technology, The Ohio State University, Columbus, OH 43210, USA
  4. 4.Food Bioprocess Engineering and Food Safety Extension, Department of Nutrition and Food Science, 3304 Marie Mount Hall, University of Maryland, College Park, MD 20742-7521, USA, e-mail: YL89@umail.umd.edu, Tel.: +1-301-4054509, Fax: +1-301-3149327