Optimal Linear Feedback Control Applied to the Temperature Control of a Bioreactor

This paper presents the dynamic behavior of a nonlinear bioreactor model designed for fermentation processes, subject to temperature variations throughout the day. Ethanol production is presented by analyzing the fermenter’s temperature, which is controlled by the flow of the cooling fluid (water) that passes through the fermenter jacket. To optimize ethanol production during a period, a control design considering the optimal linear feedback control (OLFC) designed for nonlinear systems is introduced to control the flow of the cooling fluid of the bioreactor. Numerical and computational simulations demonstrated that the proposed control is efficient in maintaining the temperature at the desired levels and is resistant to parametric variations. With the results obtained from the optimal control (OLFC) and state-dependent Riccati equation (SDRE) control, a neuro-fuzzy control system is obtained, thus enabling the application of the proposed control in other bioreactor systems with similar dynamics.