Mathematical analysis of bioethanol production through continuous reactor with a settling unit

Bioethanol generated from biomass and bioenergy crops has been promulgated as one of the most feasible alternatives to fossil fuel, as it is considered to be clean, green and of course renewable. In this paper, we develop a nonlinear chemostat model for bioethanol production. The growth rate is given by a modified Andrew expression with inhibition by ethanol, which is often used to model the growth of biomass. Then the uniqueness, invariance and dissipation of solutions of the model are established. Steady state solutions of the model and their stability are also determined as a function of the residence time. We also investigate the effects of the model parameters on a physically valid region. Finally, we compare the performance of a reactor, using a recycling process, against that of without recycling process. With a substrate feed concentration of 100 g/L, there is a critical value of the residence time which identifies a turning point in the reactor performance for the removal of substrate. (c) 2018 Elsevier Ltd. All rights reserved.