Please use this identifier to cite or link to this item:
|Title:||Increase of ethanol productivity in an airlift reactor with a modified draught tube|
|Author(s):||Vicente, A. A.|
Teixeira, J. A.
|Journal:||Canadian Journal of Chemical Engineering|
|Citation:||"Canadian Journal of Chemical Engineering". ISSN 0008-4034. 77 (1999) 497-502.|
|Abstract(s):||Static mixers were introduced in the draught tube of a three-phase, concentric tube type airlift bioreactor, resulting in a 30% increase in ethanol productivity during glucose fermentation with a highly flocculent strain of Saccharomyces cerevisiae. Increased productivity was obtained as a consequence of the floc size reduction provoked by the new design of the draught tube and of the smaller applied aeration rates, allowing a higher dilution rate to be used. Steady state data at different dilution rates were measured for both systems and the results were compared in terms of specific consumption / production rates and ethanol productivity. An approach based on heterogeneous catalysis principles was used in order to consider the presence of porous yeast flocs. Total glucose conversion was achieved at a dilution rate of 0.34 hˉ¹. The smaller floc size contributed to the higher observed reaction rates by reducing diffusional limitations inside the flocs. The respiratory quotient had a constant value (around 23) at all dilution rates, meaning that the metabolic state of the cells in the flocs remained constant, having a strong fermentative metabolism.|
|Appears in Collections:||CEB - Publicações em Revistas/Séries Internacionais / Publications in International Journals/Series|