Modeling and optimization of bioethanol production yield from corn starch using response surface methodology

The demand for alternate fuels/biofuels is increasing rapidly to counter the adverse economic and environmental impacts created by conventional fossil fuels. The production of biofuels from various natural raw materials is gaining importance due to sustainability from renewable resources. Ethanol is widely used biofuel, manufactured from natural raw materials. In this work, bioethanol was produced from corn starch. Various factors that influence the production of bioethanol such as substrate loading, temperature, pH, reaction time, enzyme titer were studied. The maximum bioethanol yield (97.3%) was achieved at the substrate loading = 40% w/v, temperature = 55 °C, reaction time = 5 h, pH = 6, enzyme titer = 25 IU/mL. A central composite design (CCD) using response surface methodology (RSM) was employed to optimize the influencing factors for the bioethanol production yield. Optimization of these factors was able to achieve 98.3% of bioethanol yield at the process conditions of substrate loading = 30.4 w/v, temperature = 55.8 °C, reaction time = 5.2 h, pH = 5.2, and enzyme titer = 29.2 IU/mL. The experimental optimum values were in good agreement with predicted values from RSM.