Izr. prof. dr. Jožef Ritonja, univ. dipl. inž., dr. Jernej Černelič, univ. dipl. inž., both Univerza v Mariboru, Fakulteta za elektrotehniko, računalništvo in informatiko;
prof. dr. Andreja Goršek, univ. dipl. inž., izr. prof. dr. Darja Pečar, univ. dipl. inž., both Univerza v Mariboru, Fakulteta za kemijo in kemijsko tehnologijo

Povzetek:
Mathematical models of fermentation processes are indispensable for designing bioreactors, simulation of their operation, optimization of fermentation processes, and design and synthesis of control systems for their control. The paper focuses on the determination of a dynamic mathematical model of the milk fermentation process taking place in a batch bioreactor. Models known in the literature do not allow the analysis of the influence of temperature changes on metabolism during fermentation. The paper presents the findings of an extensive multidisciplinary study. We developed a new mathematical model that considers the impact of temperature on the dynamics of CO2 release during fermentation in a batch bioreactor. Based on laboratory tests and theoretical analysis, the appropriate structure of the derived extended model was first determined. This was followed by the identification of the model parameters of the fermentation process in the laboratory bioreactor by particle swarm optimization. In the end, we compared the measurements of laboratory tests with simulations with a derived model. The derived augmented model proved to be very suitable for simulations, and above all, it enables the design and synthesis of a control system for batch bioreactors.

Keywords:
biotechnology; bioprocess engineering; fermentation process; batch bioreactors; modeling of the fermentation process; identification of parameters; particle swarm optimization