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Yeast suspension filtration: Flux enhancement using an upward gas/liquid slug flow—application to continuous alcoholic fermentation with cell recycle

✍ Scribed by Muriel Mercier; Claude Maranges; Christian Fonade; Christine Lafforgue-Delorme


Publisher
John Wiley and Sons
Year
1998
Tongue
English
Weight
178 KB
Volume
58
Category
Article
ISSN
0006-3592

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✦ Synopsis


This study deals with the use of an upward gas/liquid slug flow to reduce tubular mineral membrane fouling. The injection of air into the feedstream is designed to create hydrodynamic conditions that destabilize the cake layer over the membrane surface inside the filtration module complex. Experimental study was carried out by filtering a biological suspension (yeast) through different tubular mineral membranes. The effects of operating parameters, including the nature of the membrane, liquid and gas flowrates, and transmembrane pressure, were examined. When external fouling was the main limiting phenomenon, flux enhancements of a factor of three could be achieved with gas sparging compared with single liquid phase crossflow filtration. The economic benefits of this unsteady technique have also been examined. To investigate the possibility of long-term operation of the two-phase flow principle, dense cell perfusion cultures of Saccharomyces cerevisiae were carried out in a fermentor coupled with an ultrafiltration module. The air injection allowed a high and stable flux to be maintained over 100 h of fermentation, with a final cell concentration of 150 g dry weight/L. At equal biomass level, a twofold gain in flux could be attained compared with classical steady crossflow filtration at half the cost.