Browsing by Author "Mekonnen, Wondale"

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    Ethanol production from selected fruit peel waste (orange, mango and banana)
    (Addis Ababauniversity, 2012-11) Mekonnen, Wondale; Kaba, Tassisa(PhD)
    Waste disposal has become one of the major concerns for our city, Addis Ababa. Fruit peels are the major solid by-product. The dried fruit peels have a content of cellulose and hemicelluloses, which make it suitable as fermentation substrate when hydrolyzed. This thesis aims at utilizing fruit (Banana, Mango and Orange) peels for the production of bio-ethanol by using the yeast Saccharomyces cerevisiae, thus, producing a valuable product from the fruit peel wastes. The fruit peels were crushed in to 3-5 cm sizes for easy drying and grinding. Sample drying was carried out in oven (600C for 72hr) to obtain easily crushable material. After drying, each of the samples was milled separately. The maximum particle sizes of the ground mixed sample were 2 mm. Laboratory experiments of 16 run were conducted to produce bio-ethanol from those fruit peel wastes. The mill samples of 100gm (33.3gm from each sample) were taken and mixed, then passed through steam pretreatment, hydrolysis, fermentation and distillation process respectively to produce bio-ethanol. The ethanol concentrations of the samples collected every 3 hours intervals by rotary evaporator of fermented solution were measured by pycnometer (specific gravity bottle). The specific gravity of the produced alcohol was determined and alcohol concentration was got from the relationship between the specific gravity and the proportion of ethanol in alcohol solution at 20oC (Perry Chemical Engineering Handbook). The effects of acid concentration, temperature and time on dilute acid hydrolysis were investigated. The Design expert® 7 software were used and significance of the result was set from analysis of variance (ANOVA). Box-Behnken was applied to study the interaction effects, to see the contour and surface plot. The optimum results were obtained at 0.74%v/v acid concentration, 101.690 Investigation on the technical and economic feasibility of the work for ethanol production was performed. Results from the feasibility study indicated that the proposed work was feasible with rate of return (RR) 52.6% and the payback period of the project is estimated to be 2years