Application of fuzzy control to fed-batch yeast fermentation

Abstract

A new fuzzy controller has been designed and compared with the one developed previously for the control of fed-batch yeast fermentation. The respiratory quotient (RQ) was used as controller input and flow rate of glucose solution was controlled to maximize conversion of glucose to biomass. The new controller was found to be stable throughout the production period, keeping the glucose flow rate at the desired value, whereas the old controller was unstable towards the end of the fermentation and was unable to control and minimize the ethanol concentration in the fermentation broth. © Springer-Verlag Berlin Heidelberg 1997.