ABSTRACT

The disposal of groundnut shells as waste has become a major concern that constitute an environmental hazard for many countries because it is a major solid by-product. Dried groundnut shells have a high content of pectin, cellulose and hemicellulose, which make it suitable as fermentation substrate when hydrolyzed. The present work aims at utilizing groundnut shells for the production of ethanol and biomass using baker's yeast. It is also one of the measures of converting waste into useful products. The groundnut shells were ground to fIne powder and hydrolyzed by boiling with 2M H2SO4until almost all the cellulose are digested to glucose. The hydrolysate was neutralized with 0.1% KOH and filtered. Determination of reducing sugar by Fehling's reagent confirmed presence of glucose in the medium. 17°Brix sugar (1.0698 S.G) produced from the hydrolysis was optimized to 25°Bnx (1.1057 SG) with 101g of sucrose and fermented to ethanol, using baker's yeasts by batch fermentation at room temperature. The pH range of 4.91 to 6.8 at temperature of 28°C and 29.5°C, producing biomass of 1.02-1.84 with an increase in treatable acidity from 0.27-2.20 and fall in the sugar content from 1.82 to 0.00 after 7 days of fermentation. 68.3% ethanol was obtained after distillation. Further distillation of the sample under controlled fermentation could produce a higher percentage of ethanol. The result of the experiment conducted shows that Cellulosic agricultural wastes particularly groundnuts shell is a potential substrate which can be exploited in industries for bioethanol production on a commercial scale as they are cheap and more importantly renewable.