Abstract
This paper investigates the dynamic performance of bioethanol production process. The process is simulated by an experimentally validated model in the literature. The analysis of the open loop system revealed that the maximum productivity occurred at a moderate ethanol production and substrate consumption. Improvement of the process productivity beyond the maximum value is sought through periodic input forcing. Rectangular pulses were used to simulate the periodic input function because they are suitable for discrete control systems. The parameters of the rectangular pulse such as period, amplitude and central value were designed using numerical optimization. Forcing the optimized cycling input into the process revealed substantial increment of the ethanol production and substrate consumption. However, the obtained enhancement of productivity is considered marginal when compared to the existing maximum productivity. On the other hand, enrichment of productivity is considered reasonable when compared to that obtained when the process operates at steady state using the average value for the input periodic function.