Biotechnological Studies on Biofuel Production From Agricultural Wastes

Abstract

Fruits peels, an agricultural waste discarded in huge amounts, were effectively fractionated into its oligosaccharides composition to dedicate their added values utilization. Four fruits peels (Banana, Watermelon, Orange and Mango) were studied. The starch, pectin, hemicellulose, celluloses, lignin and proteins fractions were determined in terms of dry weights percentages for these peels. Mango peels showed the highest oligosaccharides levels, even lignin content was highest by 17.25%. Also, banana peels showed high oligosaccharides levels with the lowest level of lignin by 4.82%. Lab-scale bioreactor was carried out for enzymes production and saccharifaction, the banana and mango peels were released the greatest saccharified pentose and hexose sugars, the total fermentable sugars were 27.77 and 21.13 g.l -1 , respectively. Cofermentation were conducted by selected yeast strain belong to Kluyveromyces marxianus to contribute previously sexual regenerative Saccharomyces cerevisiae for bioethanol co-production. As expected, co-fermentation increased the productivity by more than 18%, the substantial bioethanol yield were observed by saccharifed banana peels with 10.74 g.l -1 , the adding of CaO lead finally to 97.5 wt % of pure bioethanol by duplicate the distillation process. The reaction molar ratio of cocked oil to ethyl acetate were established by 0.1, 0.125, 0.2, 0.25, 0.5 and 1.0 mol.mol -1 respectively. The highest reaction conversion was attained at temperature reaction of 60 °C, molar ratio of oil to ethyl acetate at 1 : 6 ratio (0.17 mol.mol -1 ) within 6 hours of reaction time, and catalyst concentration of 0.5 wt %.