Scale-up effects on kinetic parameters and on predictions of a yeast recycle continuous ethanol fermentation model incorporating loss of cell viability

The scale-up effects on kinetic parameters and on predictions of a yeast re cycle continuous ethanol fermentation model incorporating loss of cell viab ility were evaluated. The average level of cell, viability estimated for la rge scale was similar to that estimated for small scale, although with a ma jor standard deviation. The values of specific rate of cell viability loss were equal for the two scales. These results were due to the utilization of the same aeration rate for both scales, one of the main factors for cell-v iability maintenance. The kinetic parameters were not significantly affecte d by the scale-up of the fermentation process. Major differences were obser ved for the maximum specific growth rate and for maximum ethanol concentrat ions for which, growth and ethanol production are totally inhibited. The sc ale-up did not result in lack of fit of the mathematical model to the exper imental data.