ABSTRACT

This work critically analyses the saccharification of soursop peel for ethanol production. The increasing demand for ethanol production for various industrial purposes has necessitated increased production of this ethanol using lignocellulose biomass. Lignocellulose biomass is very rich and abundant source of energy and in the process of reducing the cost of ethanol production, lignocellulose biomass is now of interest due to its abundant availability. Aspergillus niger with its high enzymatic activity was used to hydrolyse the pretreated soursop peels. After hydrolysis, Saccharomyces cerevisiae were inoculated into the hydrolysates separately at room temperature to ferment for 11 days. During fermentation period, changes in the quality parameters of pH, temperature, titrateable acidity, total solid, specific gravity, sugar contents and alcohol yield were monitored. The temperature fluctuated between 290C and 300C with pH decreasing from 6.20 to 2.40. The sugar content reduced from 21.01% to 2.23% alcohol contents increased to a maximum of 9.86%. The work reveals that soursop peel is a good substrate for bioethanol production regarding to its 9.86% yield of ethanol after saccharification.     

TABLE OF CONTENTS

Certification i

Dedication ii

Acknowledgment iii

Table of Contents iv

List of tables viii

Abstract ix

CHAPTER ONE

1.0 INTRODUCTION 1

1.1 Saccharomyces cerevisiae 6

1.2 Aims 7

1.3 Objective 7

CHAPTER TWO

2.0 LITERATURE REVIEW 8

2.1 Soursop 8

2.2 Nutrient Composition of Soursop            12

2.2.1 Lignocellulosic Biomass 14

2.2.2 Second Generation Feedstock 14

2.2.4 Hydrolysis and Fermentation Of Lignocellulosic Biomass 15

2.3 Bioethanol 16

2.3.1 Production and Utilization of Ethanol in Nigeria 18

2.4 Microorganisms of Interest in this Research Work 20

2.4.1 Aspergillus niger 19

2.4.2 Saccharomyces cerevisiae                                                                                       20

CHAPTER THREE

MATERIALS AND METHODS

3.1 Study Area 21

3.2  Source of Materials 21

3.3 Micro-Organisms 21

3.3.1 Sample Preparation (pre-treatment) 21

3.3.2 Preparation of Fungi Inoculums Aspergillus niger. 23

3.4 Preparation of Yeast Inoculums (Palm wine Yeast) 22

3.5 Media Preparation 22

3.6 Deliquification of substrate 23

3.7 Optimization of Hydrolysate 23

3.8 Saccharification for bioconversion to produce ethanol 24

3.9 Method of Analysis 24

3..9.1 Determination of pH 24

3.9.2 Determination of Temperature 25

3.9.3 Determination of Specific Gravity. 25

3.9.4 Determination of Total Solids 26

3.9.5 Determination of Titratable Acidity (TTA) 26

3.9.6 Determination of Sugar Content. 27

3.9.7 Determination of Ethanol Content 28

3.9.8 Statistical Analysis 28

CHAPTER FOUR

4.1 RESULT 29

CHAPTER FIVE

DISCUSSION, CONCLUSION AND RECOMMENDATION

5.1 Discussion 31

5.2 Conclusion 32

5.3 Recommendation 32

Reference 33

Appendices  40