A Procedure for Estimation of Fermentation Kinetic Parameters in Fed-Batch Bioethanol Production Process with Cell Recycle

The configuration of industrial fermentation in ethanol plants in Brazil is predominantly of the type fed-batch culture with cell recycle. In this operation mode, yeast is exposed through a long period to inhibitors, high cell concentration and fluctuations in the quality of the raw material, with impact on process kinetic and operating performance. In this context, for the implementation of suitable operational strategies, it is necessary to have kinetic models able to describe the process as realistically as possible. Bearing this in mind, in this work the kinetic of the alcoholic fermentation of sugarcane juice was studied in fed-batch fermentation with cell recycle. The accuracy of prediction of a mechanistic kinetic model is evaluated, not only by their precision in describing experimental observations, but essentially by the challenges involved in the estimation of their parameters. The model used to describe the fermentation provided a good prediction of concentration of cell, substrate and ethanol.