Evolutionary process scheduling approach for energy cost minimization in a yeast production factory: design, simulation, and factory implementation

Energy efficiency is today the main issue for any yeast production company. Portuguese yeast companies are not an exception. Purely replacing some equipment with more energy efficient ones surely contributes to decrease the overall energy consumption, but it is not enough. A yeast production process needs to be characterized and analyzed as a distributed and resource-constrained system. To achieve that in a Portuguese yeast factory, a suitable solution to obtain a dynamic resource-constrained process scheduling was pursued. A genetic algorithm (GA) based scheduling system was used to scheduling optimization of factory’s fermentation units to minimize their specific cost at yeast production. Numerical simulations were first effectuated for calibration and validation of the yeast production model developed. A 2.29% reduction in the electricity cost per ton and per week of yeast production was achieved, which means about 7500 euros/year if the level of optimization is maintained.