Optimization of A Fed-Batch Fermenter Producing Baker’s Yeast Using Simulated Annealing Method

Modeling of fermentation processes is so complicated and uncertain; therefore it is necessary to provide a robust and appropriate dynamic optimization method. In order to obtain the maximum amount of yeast (Saccharomyces cerevisiae), the bioreactor must be operated under optimal conditions. To determine substrate feeding in a fed-batch bioreactor, a simulated annealing (SA) approach was examined. The optimal glucose feed rate profiles were computed by a stochastic and deterministic problems for various initial conditions to investigate their effects on optimal operation of the fed-batch bioreactor. Results declared a proper capability of SA method for determination of  optimal feeding policies in fermentation processes. The major advantage of the simulated annealing is its capability for handling the problems with model mismatches. Finally, an open loop sensitivity analysis of SA optimization method was tested by a mathematical model to note the effect of some key variables in the subsequent optimization study on the fermenter. Findings show slight difference between trends, thus the SA algorithm is an efficient, robust and satisfactory acceptable.