Comparative study of bioethanol yield from yam, potato, watermelon, and pineapple peels using different concentrations of hydrochloric acid

This study was aimed at determining the optimum yield of bioethanol (as biofuel and industrial chemical) from yam, potato, watermelon, and pineapple peels using different concentrations of hydrochloric acid (HCl). Results obtained from acid hydrolysis, fermentation and distillation revealed that yam peel gave the highest quantity of glucose (38.7±0.90%) and ethanol (18.40±0.18%) at an acid concentration of 1.5 M, watermelon peel equally recorded the highest yield of glucose (18.3±0.50%) and ethanol (8.35±0.14%) at 1.5 M. For potato peel, the highest quantity of glucose (33.8±1.10%), and ethanol (18.23±0.04%) was at 2.0 M; this concentration (2.0 M) was equally the optimum for pineapple peel, the highest glucose concentration and ethanol yield of which was 24.5±0.62% and 11.44±0.29%, respectively. Utilizing these agro-wastes for the production of bioethanol provides a means of recycling these biological wastes which are normally prone to rapid microbial spoilage.