This study aims to examine how the composition of pineapple peel and banana waste mixtures affects the quality of bioethanol production, particularly the calorific value and flash point, as a substitute for environmentally friendly fuel amid the significant dependence on fossil fuels that contribute to greenhouse gas emissions. The bioethanol production process was carried out using variations in raw material composition, namely 70% pineapple peel and 30% banana waste, 50% pineapple peel and 50% banana waste, and 30% pineapple peel and 70% banana waste. Saccharomyces cerevisiae yeast (15 grams) was used during the fermentation stage for 7 days, followed by double distillation and a dehydration process for one hour using silica sand. The flash point, calorific value, and alcohol content were tested to evaluate the fuel quality. The results showed that alcohol concentration gradually increased from the initial distillation stage (32–37%) to the dehydration stage (80–86%), with the 70% banana waste variation producing the highest concentration (86%). The highest net calorific value was also obtained from the same variation, reaching 22,973 J/g, indicating better combustion efficiency. As the percentage of banana waste increased, the flash point rose from 2°C to 6°C, indicating improved stability, although it remained below that of pure ethanol. These findings suggest that mixtures dominated by banana waste (70%) produce higher-quality bioethanol due to the higher content of simple sugars in banana waste. This study also highlights the potential utilization of fruit waste as a renewable raw material to reduce environmental impacts and support the development of sustainable alternative fuels. Further optimization of the purification process is recommended to meet industrial standards.
Keywords: bioethanol, pineapple peel, banana waste, calorific value, flash point.