Hydrolysis Process Optimization and Characterization of Bioethanol from Food Waste (Case Study on JIT Students’ Cafeteria Food Waste)

Abstract

Food waste from Jimma institute of Technology students’ cafeteria was used as a raw material for bioethanol production. The major components of Food waste from JIT students’ cafeteria collected on Tuesday were found to be injera, bread, rice, and potato. Obviously, these components are carbohydrate-rich biomass which can be converted to ethanol. The conversion of this biomass into ethanol involved upstream processing which includes hydrolysis and the downstream process which includes fermentation and distillation stages. This study mainly focused on investigating optimal conditions for the hydrolysis stage. The effects of three important parameters, (namely temperature, acid concentration and hydrolyzing time) on the yield of bioethanol during hydrolysis of the food waste were investigated. The optimum condition for the hydrolysis process was determined based on the maximum bioethanol yield obtained during processing at various interactions of operating parameters. From the results obtained the yield of ethanol has a positive relationship with temperature and hydrolyzing time. The yield of ethanol had a negative relationship with acid concentration. The relationship between ethanol yield and three parameters (namely temperature, acid concentration and hydrolyzing time) was obtained from experimental results which were interrelated with a model equation. The maximum ethanol produced was 30.6mL from 60g of food waste sample this was obtained at a temperature of 120oC, hydrolyzing time of 1hour and acid concentration of 1%. The minimum ethanol was produced at a temperature of 120oC, acid concentration of 5.00% and hydrolyzing time of 60 minutes was 16.41 mL from 60g of food waste sample. The ethanol produced after distillation had a density of 0.802g/cm3, viscosity of 1.2 cP, having an alcohol content of 70%, the pH value of 6.67, Flammability 15 oC and boiling point 79oC. Ethanol produced in this experiment was used as solvents for different chemicals, to wash laboratory equipment’s to prevent contamination and it’s used for blended with fuel if it further purified.