Kinetics and mathematical model of ethanol formation by immobilized yeast cells

Kinetics of the ethanol fermentation with the immobilized K yeast cells was studied both experimentally and theoretically. A kinetic model consisting of 6 equations was proposed. In this model the combined inhibition, i.e., glucose in uncompetitive inhibition and ethanol in noncompetitive inhibition with irreversible performance, was taken into consideration. Calculated values agreed approximately with the experimental results, and this model was found to be of practical use. The maximum average percent deviation of the model calculation was found to be 13.81% in simulation. The average percent deviation of the model prediction was shown to be 8.28% in the sweet potato hydrolysate. The concentration range of inhibition was determined to be 130-450 g/l for glucose and 3.07-16.45% (v/v) for ethanol.