Dynamics of Batch Fermentation

It is common in industrial fermentations to operate at an experimentally determined optimal grow th temperature for the yeast being used. Depending upon how the fermentation progresses, the temperature can be 

In this section, we develop a simplistic model of beer fermentation. This model is based upon the work of Engasser (1981) and Gee and Ramirez (1987). The fermentation medium is assumed to contain three major sugars. These are glucose, maltose, and maltotriose and are the limiting nutrients. The fermentation is carried out in a batch reactor which can be considered to be ideally mixed. The material balance relations for each sugar are 

The parameters n, are the specific reaction rates for the uptake of sugar i. These reactions are first-order in the biomass concentration. The specific rates must refiect the catalyzed enzymatic reactions that occur within yeast cells that convert sugar into alcohol. These rates are given by the Monod expression for glucose, 

The rates of biomass and ethanol are related to the consumption of the individual sugars by constant yield coefficients 

U = overall heat-transfer coefficient, J/hr m °C A = heat-transfer area, m  

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