Extended simulation model for a brewery fermentation process

The paper presents an extended simulation model of a brewery fermentation process in order to facilitate the development/investigation of novel process control strategies. The simulation model builds on an existing laboratory scale theoretical model by incorporating effects observed in practical industrial pilot and full scale fermentations. The model has been modified/extended to incorporate the following: yeast growth, being a function of the initial dissolved oxygen concentration and cell sterol content; the effects of yeast vitality and dissolved oxygen on overall fermentation rate; and the inclusion of ester formation. The paper highlights these recent extensions and shows typical responses under varying fermentation conditions. The purpose of the developed simulation model, which has been implemented in the Matlab/SIMULINK environment, is to evaluate discrete-time bilinear model structures for the purpose of nonlinear model-based prediction and control. The main objectives of the control strategies is to deal with the problem of fermentation end-time variability.