The goal of this study is to compare batch and fed-batch reactors in a fermentation process. Two studies in which the concentration of the nutrient feed rate was varied. First, the fermentation reaction model was built and simulated for the batch reactor; however, due to a lack of manipulable variables, no optimization was performed on this reactor. Second, a fermentation reactor model was simulated for the fed-batch process; additionally, it was determined to build an optimization in the flow rate of the nutrients to maximize the ethanol production rate. After the simulations have been completed, the results are discussed and compared to evaluate the results obtained.