Utilization of bagasse to produce bioethanol

Abstract

The aim of the project was the production of low cost ethanol by using lignocellulosic materials basically the agro wastes like sugarcane bagasse using both physical and chemical processes such as mechanical size reduction, acid hydrolysis, fermentation and extractive distillation. The ethanol produced is mostly used as a source of fuel. The raw material used for the experiment is bagasse. First the bagasse is chipped and grinded. Then this is taken for acid hydrolysis. Dilute sulfuric acid of 0.15M, 0.25M and 0.45M concentration were used in this process. For the acid hydrolysis, 12.5 gm of bagasse was put in 100 ml of each of the concentrations and was allowed to soak for 1 day. Then it was auto-claved for half an hour and allowed to cool. The fermenting media was prepared, 5 gm of yeast was added to the above media and kept in incubator for 1 day.10 ml of this media was added to each of the samples in asceptical (laminar flow hood) manner and placed in orbital shaking incubator. The ph was adjusted to 5 and the fermenting temperature was kept at 350C.Fermentation may take up to 5 days. The sugar and ethanol was done both by qualitative and quantitative analysis. The sugar analysis involved the benedicts test, the Fehling test and DNS test. The benedicts and Fehling test gave orange, yellowish green, green and faint red precipitate respectively for 0.15M, 0.25M, and 0.45M acid respectively. The DNS test indicated that the less concentration of the acid used for hydrolysis the more glucose is obtained. The maximum glucose concentration was found to be 41.9474ppm and the lowest was 13.8632ppm. The iodoform test indicated yellow precipitated which illustrates the presence of ethanol. The quantitative analysis indicated the decreased ethanol concentration as the number days for fermentation increased. The maximum ethanol concentration was found to be 47.7368ppm and minimum was 36.000ppm