| dc.description.abstract | Introduction: The growing demand for renewable energy has led to increased interest in bioethanol production from non-food biomass. Sweet potato (Ipomoea batatas) peels, an agro-industrial waste, present a viable feedstock for bioethanol production using Saccharomyces cerevisiae. This study aimed to optimize fermentation conditions, specifically pH, temperature, fermentation time, and yeast-substrate ratio, to maximize bioethanol yield.
Methodology: Sweet potato peels were collected, dried, and then hydrolyzed using 0.5M, 1.0M, 1.5M and 2.0MHCl to release fermentable sugars. The fermentation process was carried out using Saccharomyces cerevisiae, with pH levels adjusted to 4.5, 5.0, 5.5, and 6.0. The effect of different fermentation conditions on bioethanol yield was assessed. ANOVA was used to determine the significance of independent factors and their interactions, and a regression model was developed to predict bioethanol yield.
Results: The optimized conditions for bioethanol production were temperature: 30°C, pH: 7.0, fermentation time: 72 minutes, and yeast amount: 0.35 g/50mL, yielding 0.0655 mol of bioethanol. ANOVA results indicated that pH and yeast amount significantly influenced bioethanol yield independently, while temperature and time were only significant in interaction with other factors. The quadratic effect of pH was strong, suggesting an optimal range for bioethanol production. The interaction of temperature with pH and temperature with yeast amount significantly influenced bioethanol yield. The regression model demonstrated high accuracy (R² = 99.42%) in predicting bioethanol production.
Conclusion and Recommendations: pH and yeast amount have a significant independent effect on bioethanol yield, while temperature and time are only significant when considered in interaction with other factors. Quadratic effects show that pH has a strong curvature, suggesting an optimal range for bioethanol production, while time has a borderline effect. Interaction analysis reveals that temperature combined with pH, as well as temperature combined with yeast amount, significantly influence bioethanol yield. The study recommends that the optimized parameters should be tested at a pilot scale before full-scale implementation so as to assess feasibility for bioethanol production from sweet potato peels. | en_US |
| dc.subject | Bioethanol, fermentation, optimization, pH, sweet potato peels, temperature, time, yeast-substrate ratio | en_US |
