Optimizing bio-ethanol production from cabbage and onion peels waste using yeast (Saccharomyces cerevisiae) as fermenting agent

Abstract

Production of bio-ethanol from lingocellulosic materials is providing a long-term sustainable for fuel supply. Cabbage and onion peels waste is one of cheap source of lignocellosic materials to serve as feedstock for bio-ethanol production. With the objective of evaluating its potential for bio-ethanol production, different concentrations (50g, and 100g) of Cabbage and onion peels waste treated with 1% diluted sulfuric acid and untreated were subjected to batch fermentation for 12 days with 0.5% and 1% yeast inoculums. Percent of bio-ethanol production, cell density and reducing sugars were measured at an interval of 4 days starting from the beginning. Results of these study showed that ethanol production was observed starting from the 4th day of fermentation, but its amount peaked 26.51 from 100g substrate with 1% inoculum on the 8th day of fermentation, and declined on 12th days (21.06%) from the same substrate concentration. Pretreated substrate showed significantly higher ethanol production than untreated. In agreement with ethanol production, cell density and reduction in reducing sugar were observed in the same pattern. Compared ethanol production between untreated substrates yield of 20.96%, and treated substrates yielded of 26.51%. Overall, this study showed that acid pre-treatment, inoculum concentration, fermentation period and substrate concentration affect the amount of bio-ethanol production. Finally, it can be concluded that the production of bioethanol from Cabbage and onion peels waste is economically and environmentally viable. Extensive use of these Wastes for bioethanol production may have twofold advantages, viz. reduction of its negative impact on environmental hygiene and generation of bio-ethanol.