Description
ABSTRACT
The production of bio-ethanol from Elephant grass (Pennisetunpurpureum) stem was carried out using elephant grass stem as a feedstock andSaccharomyces cerevisiae (brewer’s yeast) at 0.5% (w/v), 1%(w/v), 1.5%(w/v), 2%(w/v) and 2.5%(w/v) concentrations as cells by simultaneous saccharification and fermentation (SSF). The study determined the most suitable pre-treatment method from the following pretreatment methods; 1M H2SO4, 0.1M H2SO4, 1M NaOH, 0.2M NaOH, Boiling, and 3M NH4OH. IM NaOH pre-treatment gave the highest cellulose and lowest lignin content. The effects of temperature at 25oC, 30oC, 35oC, 40oC and 45oC; pH values of
3.5, 4.0, 4.5, 5.0, 5.5, 6.0 and 6.5; substrate concentration values of 1%(w/v), 2%(w/v),
3%(w/v), 4%(w/v) and 5%(w/v); particle size range of 53-106µm, 106-150µm, 150250µm, 250-300µm and 300-425µm; and cell loading of Saccharomyces cerevisiae (brewer’s yeast) at 0.5% (w/v), 1%(w/v), 1.5%(w/v), 2%(w/v), 2.5%(w/v) on the hydrolysis and fermentation process were investigated to obtain optimum conditions of fermentation. The optimum conditions of fermentation were obtained at temperature of 350C, pH value of 5.5, substrate concentration of 30g/l, particle size range of 250-300µm after 72 hours of fermentation time. Also substrate concentration of 30g/l, gave highest ethanol concentration of 23.4g/l and a yield of 78%. From the research, the kinetic Parameters which are reaction constant k and order of reaction n were evaluated to be 8.172×10-8l/g.s and 2 respectively.
TABLE OF CONTENTS
i Title page
ii Certification
iii Dedication
iv Acknowledgment
v Abstract
vi Table of Contents
ix List of Tables
x List of Figures
CHAPTER ONE
INTRODUCTION
1.1 Background Information
1.2 Problem Statement
1.3 Justification of Study
1.4 Objectives of Study
1.5 Scope of Study
CHAPTER TWO
LITERATURE REVIEW
2.1 Cellulose
2.2 Cellulose Chemistry
2.3. Cellulases
2.4. Cellulose Conversion
2.5 Pre-Treatment of Lignocellulosic Material
2.5.1 Physical pre-treatment.
2.5.2 Physicochemical pre-treatment
2.5.3 Chemical pre-treatment:
2.6 Factors Affecting Enzymatic Hydrolysis of Cellulose
2.6.1 Enzyme-related factors affecting hydrolysis
2.6.2 Effects of substrate concentration
2.6.3 Effects of substrate particle size
2.6.4 Effects of pH
2.6.5 Effects of temperature
2.7 Ethanol
2.7.1 Uses of ethanol
2.7.2 Ethanol as disinfectants
2.7.3 Ethanol as domestic lighting agent
2.7.4 Ethanol as transportation fuel
2.7.5 Bio-ethanol production process
2.7.6 Process description of simultaneous saccharification and fermentation (SSF)
2.7.7 Fermentation
2.7.8 Distillation
2.7.9 Dehydration
CHAPTER THREE
MATERIALS AND METHOD
3.1 List of Materials and Equipment
3.1 Culturing of the yeast (Saccharomyces cerevisiae)
3.2 Sample Collection/Preparation
3.3 Pre-Treatment of Substrate
3.4 Substrate Analysis
3.5 Simultaneous Saccharification and Fermentation (SSF) of Elephant Grass
3.5.1 Effect of substrate concentration
3.5.2 Effect of substrate particle size
3.5.3 Effect of yeast concentration
3.5.4 Effect of temperature
3.5.5 Effect of pH
CHAPTER FOUR
RESULT AND DISCUSSION
4.1 Introduction
4.2 Determination of suitable Pre-treatment Method
4.3 Simultaneous Sacharification and Fermentation of Elephant Grass Stem
4.3.1 Fourier Transform Infrared Analysis (FTIR)
4.3.2 Effect of substrate concentration on ethanol yield
4.3.4 Effect of substrate concentration on residual sugar
4.3.5 Effect of particle size on ethanol yield
4.3.6 Effect of temperature on ethanol yield
4.3.7 Effect of pH on ethanol yield
4.3.8 Effect of pH on residual sugar
CHAPTER FIVE
CONCLUSIONS AND RECOMMENDATIONS
5.1 Conclusions
5.2 Recommendations
References
Appendices