Production of ethanol from bagasse

Abstract

PURPOSE OF THE PROJECT
Bio-fuel has been a source of energy that human beings have used since ancient times. Increasing the use of bio-fuels or energy generation purposes is of particular interest nowadays because they allow mitigation of greenhouse gases, provide means of energy independence and may even offer new employment possibilities. Bio-fuels are being investigated as potential substitutes for current high pollutant fuels obtained from conventional sources. The aim of the project is the production of low cost ethanol by using lignocellulosic materials basically the agro wastes like sugarcane bagasse, rice husk, wheat straw, corn fiber, crop residues, grasses and other materials like saw dust, wood chips, solid animal wastes etc.
BREIF DESCRIPTION OF THE EXPERIMENT
The raw material used for the experiment is bagasse. First the bagasse is chipped and grinded (may be upto powder form). Then this is taken for acid hydrolysis. Dilute sulphuric acid of 0.2M, 0.3M and 0.5M concentration were used in this process. For the acid hydrolysis, 5 gms 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 gms 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 35 0 C.Fermentation may take upto 10 days.
ANALYSIS OF ETHANOL AND SUGAR
Sugar is analyised by DNS method. For ethanol analysis, after each interval of 24 hrs, 5 ml of the sample is taken and filtered. The filtrate is to be analyzed under UVspectrophotometer. Quantification of ethanol was done by using standard ethanol.
RESULTS AND DISCUSSION
The ethanol concentration increased as the number of days increased. The following graphs show the plot between the ethanol conc.in ml/lt vs number of days for 0.2M, 0.3M and 0.5M.
The ethanol concentration decreased as the molarity of acid used (sulphuric acid) increased. The maximum concentration of ethanol obtained was 389.22 ml/lt of acid hydrolysed bagasse used.