Bioethanol fuel production from rotten banana as an environmental waste management and sustainable energy

Abstract

Banana waste is discarded due to the imperfection during grading process. Banana biomass can be used as raw material to produce bioethanol. In this study, fermentation of banana waste was conducted using Saccharomyces cerevisiae, Type II under anaerobic condition. Production of bioethanol was determined and the effects of various operating conditions which included different temperatures, shaking period, rotten and fresh banana fruit and saccharification method were observed. Overall, the fermented banana fruit waste produced 4.1 to 7.1% bioethanol. The bioethanol yield from mixture of rotten banana fruit increased with increase fermentation period. It is also increased with yeast concentration, using 35% of water at 35°C. The optimum shaking hours for fermentation was 6 h at pH 5.8. Combination of enzyme (pectinase and cellulase) produced higher bioethanol than enzyme alone. Viscosity and acid value of the produced bioethanol followed the ASTM (American Standard for Testing Materials) and EN (European Norms) standards. Fermented banana treated with mixture of enzymes was the best method used for higher bioethanol production. The results showed that, utilization of mixture (skin and pulp) of rotten fruit was more suitable for bioethanol production as renewable energy which could reduce the cost of the initial process. In addition, it did not compete with the consumer food supply and could avoid the overloaded waste for compose, as well as could be used as fuel in the normal petrol engine. In addition to that, energy could be produced from waste banana fruit as environmental recycling process. Key words: Bioethanol, rotten banana, yeast, enzyme, temperature.