Abstract:
Water hyacinth a fresh water aquatic plant is considered as a noxious weed in many parts of the world since it grows very fast and depletes nutrients and oxygen from water bodies adversely affecting the growth of both plants and animals. Thisexotic freshwater weed damageswetland resources over the Lake Tana basin, Ethiopia. Hence conversion of this problematic weed to value-added chemicals and fuels helps in self-sustainability,especially for developing countries.This study employs water hyacinth leaves (WHL) as a raw material for the production of Bioethanol. It was used dilute acid pretreatment, dilute acid hydrolysis, fermentation, and distillation processes. The experiment was designed by Central Composite Design (CCD) with three factors (acid concentration (0.5-2%) H2SO4, temperature(100-130oC), and time(30-90 min)of autoclaving. The different parameters of hydrolysis conditions were optimized. The effect of hydrolysis temperature, hydrolysis time, and acid concentration on total reducing sugar has been studied. The maximum yield of reducing sugar was achieved at 60 minutes of hydrolysis time, acid concentration of 1.25% and hydrolysis temperature of 130℃ with a maximum yield of 0.49 g/cm3reducing sugarunder optimized conditions.Based on central composite design ANOVA was carried out to determine the numerical significance of the quadratic response surface model, in which the p-value of the model was less than 0.0001, which shows the model was statistically valid. Consequently, based on this result, the designated model was adequate to fit the data of the response variable.Moreover, the produced total reducing sugar was fermented and a total ethanol yield of about 0.53% was obtained for the optimized sugar. Also the FTIR analysis shows that the appearance of a band peaks at 3450, 2856, 2790 and 1284 indicate the presence of the OH, CO, CH2, and CH3 functional groups respectively, confirming that ethanol solvent the presenceof ethanol in the product.