An optimal substrate feeding for an industrial scale fed-batch fermenter is
determined through iterative dynamic programming in order to maximize the
cell-mass production and to minimize the ethanol formation. An experimental
ly validated rigorous dynamic model comprises constraints in the optimizati
on problem. A new objective function is proposed to accommodate the competi
ng requirements of maximum yeast production and minimum ethanol formation.
The objective function is maximized with iterative dynamic programming with
respect to the sugar feed rate. Results prove the effectiveness of dynamic
programming for solving such high-dimensional and nonlinear optimization p
roblems, and the resulting optimal policy indicates that considerable incre
ase in yeast production in fed-batch fermenters can be achieved while minim
izing the undesired by-product, ethanol.