COMPARISON OF VARIOUS CONTROL CONFIGURATIONS FOR CONTINUOUS BIOREACTORS

Five control configurations for continuous bioreactors are analyzed us ing a simple model. A controller-independent measure, the partial dist urbance gain, is used for evaluating their controllability with respec t to disturbance rejection. The computation of the partial disturbance gain is generalized to the case with several uncontrolled outputs. At substrate-limited growth conditions, the concentration turbidostat us ing the feed substrate concentration as the manipulated variable is th e best control configuration. The conventional turbidostat should be a voided. When the cell growth is not substrate limited, all these contr ol configurations are effective except the concentration nutristat whi ch is not feasible regardless if the growth is substrate limited or no t.