ARE MONOD MODELS ENOUGH FOR BIOREACTOR CONTROL? PART II – SOME SIMULATION RESULTS

In this contribution a cybernetic model and a simple Monod based model were used to simulate the control of glucose and ethanol in Saccharomyces cerevisiae fed-batch cultivation. The main objectives were to investigate the type of modeling, the choice of the control variable (glucose or ethanol) and the kind of control action which is more suitable to control the studied system. It was found that the cybernetic model produces better qualitative and quantitative results and also that ethanol control shows a smooth behavior when compared to glucose control. According to the results obtained, an on-off control strategy based on ethanol measurements was suggested as an easier way to control the system without using effectively a controller.