ABSTRACT
Cassava emerges as a promising renewable feedstock for bioethanol due to its high starch content, rapid growth rate, and adaptability to diverse climates. However, challenges like low lignin content and potential competition with food production exist. Sustainable practices including dedicated cultivation areas, improved cassava varieties, and integrated biorefineries are crucial for mitigating these concerns. The production of bioethanol through the optimization of alkaline hydrolysis is affected by several factors such as temperature, time, substrate concentration and alkaline concentration. In this study, a box-behnken design was used to evaluate the influence of pretreatment time, temperature, NaOH concentration, and solid-to-liquid ratio on sugar yield. Statistical analysis confirmed the model's significance (p-value < 0.0001), indicating a strong correlation between these factors and sugar yield. Notably, pretreatment time, temperature, and solid-to-liquid ratio, along with their interactions, were identified as significant factors (p-value < 0.05). The optimal condition for maximizing sugar yield was identified as a 60-minute pretreatment at 60°C with a 0.6 M NaOH solution and a solid-to-liquid ratio of 30. Response surface plots provided valuable insights into the combined effects of different factors on sugar yield.Beyond optimizing pretreatment, the experiment also determined the cassava bagasse's composition. The high cellulose content (25% dry weight) is promising for bioethanol production. Moisture content (28.6%) was measured, which is crucial for storage and processing considerations. XRF analysis revealed the presence of essential elements for microbial growth during fermentation, suggesting minimal supplementation might be needed. In carrying out this research, further research areas were identified. These include exploring the potential benefits of combining this method with enzymatic hydrolysis and identifying cost-effective alternatives for the NaOH solution. Ultimately, integrating the optimized pretreatment step with bioethanol fermentation using robust yeast strains remains a key goal. By addressing these aspects and prioritizing sustainable practices, cassava bioethanol production has the potential to become a viable and environmentally friendly alternative to fossil fuels.
