Non-Linear Control of Baker's Yeas Bioreactor Based on a Kinetic and Mass Transfer Model

A structured unsegregated cybernetic model able to describe a diauxic growth phenomena of cells colony in aerobic condition. In this paper, the model has been proven in the simulation of the behavior of a batch and fed-batch bioreactors achieving satisfactory results. For simulating fed batch system, at first, the optimal substrate feeding in to bioreactor has been obtained by solving optimal control problem. Applying this profile to process model shows that ethanol concentration is much less in comparison with a constant feed rate. Also, because in many fermentationprocesses, oxygen transfer is the rate limiting step, so for preventing from oxygen starvation that causes ethanol production, oxygen mass transfer coefficient is simulated on the function of impeller speed and air flow rate and then, control of oxygen concentration by PI and GLC controller have been considered. Results show that two controllers have a same performance, but because of simpler structure in PI controllers, PI controller is better than GLC for this process. Also cell concentration without using controller have been brought and shown that productivity is smaller in comparison with using controllers.

کلیدواژه ها:

cybernetic model ، fed-batch bioreactor ، optimal control ، Saccharomyces cerevisiae