Application of Dynamic Programming for Fermentative Ethanol Production by Zymomonas mobilis

Abstract

This paper discusses the application of dynamic Programming to the optimization of a batch fermentation for ethanol production. Using several experimental data sets available for Zymomonas mobilis culture at different environmental conditions, pH and temperature control policies are determined, which will maximize the yield of ethanol for batch culture. The influence of temperature was studied for the range from 30 to 40C and pH was varied from 5.0 to 7.5. A fermentation kinetics model was used in simulation studies to assess the positive effect of the time-varying profiles on the yield. The functionality with respect to temperature and pH was incorported in the specific growth rate constant. These results showed that it is possible to obtain an ethanol yield more than twice the value obtained when pH and temperature are kept constant throughout the experiment.