Fermentation-based bio-ethanol production: A study on agro-waste utilisation with Saccharomyces cerevisiae

Abstract

This research discusses how agro-waste like sugarcane bagasse, orange peels and banana peels could be converted into bioethanol using the hydrolysis and fermentation process involving the Saccharomyces cerevisiae. Biomass ethanol also supplies 10–14 % of the world energy needs and this is a step in the right direction in relation to such problems like global warming and fossil fuel depletion. After washing and drying the recovered wastes, the lignocellulosic substrates were pre-treated using dilute acid hydrolysis, whereas the orange peels were pre-treated using a direct extraction process. The fermented samples of the samples that had been hydrolysed were inoculated with the yeast and allowed to ferment in a period of 20 days under conditioned laboratory tests. The determination of the concentration of ethanol in each of the samples was carried out using the potassium dichromate titration procedure. Sugarcane bagasse was determined to be the most yielding ethanol (1.11 %), followed by orange peels (0.38 %) and banana peels (0.23 %). These findings demonstrate that fermentable sugars in agro-waste can be a low cost and efficient source of ethanol. This approach has a two-fold benefit as it employs waste resources other than in the production of sustainable biofuels, which is significant in the potential of renewable energy-related applications and enhanced control of agricultural wastes. These results will support the development of biofuel and effective use of agricultural waste to generate renewable feedstock, as agro-waste will prove to be a viable feedstock source to produce ethanol.