ABSTRACT

Bioconversion of waste materials into useful products is very topical not only to protect natural resources, but also to limit environmental pollution. In this study, waste paper was enzymatically hydrolysed using crude enzyme from Trichoderma viridae for alcohol and biomass production. The T. viridae was maintained on sabouraud Dextrose Agar (SDA) slants. Spores from fully grown slants were dislodged into sterile saline containing 0.05% (v/v) Tween 80. The spores suspension was transferred into an enriched medium with carboxymethyl cellulose (CMC) as sole carbon source to induce cellulase synthesis. After seven days of fermentation, the filtrate of the medium was centrifuged and the obtained supernatant was used as the crude enzyme source. The waste paper was ground into powder and pretreated at 1210C for 15 minutes. The crude enzyme was transferred to the pretreated paper and the mixture was incubated at 370C for 72 hours for hydrolysis to take place. The sugar content and the specific gravity of hydrolysate were 6.94% and 1.033g/cm3 respectively. The hydrolysate sugar content was optimized with 67g of sugar (sucrose) and the sugar content rose to 21.54% while the specific gravity rose to 1.114g/cm3. After 7 days of fermentation of the hydrolysate with Baker’s yeast, the sugar content and specific gravity dropped to 2.59% and 1.005g/cm3 respectively while the pH reduced from 5.6 to 3.1. The temperature fluctuated between 290C and 300C with biomass production and alcohol yield of 1.99g/l and 89.0% respectively. Optimizing enzymatic hydrolysis parameters and proceeding to secondary distillation could give a better yield. 

TABLE OF CONTENTS

Pages

Title Page i

Certification ii

Dedication iii

Acknowledgements iv

Table of contents v

List of tables viii

List of figures ix

Abstract x

CHAPTER ONE: INTRODUCTION 1

1.1 Introduction 1

1.2 Aims and Objectives 3

CHAPTER TWO: LITERATURE REVIEW 4

2.1 Constituents of paper 4

2.1.1 Cellulose 4

2.1.2 Hemicellulose 4

2.1.3 Lignin 5

2.2 Alcohol production from cellulosic materials 5

2.3 Pretreatment 7

2.3.1 Physical pretreatment 7

2.3.1.1 High pressure steaming 7

2.3.1.2 Hydrothermal pretreatment 8

2.3.2 Chemical Pretreatment 8

2.3.2.1 Dilute acid pretreatment 8

2.3.2.2 Hydrogen peroxide pretreatment 8

2.3.2.3 Lime pretreatment 9

2.3.2.4 Ammonia fiber explosion (AFEX) 9

2.3.2.5 Organosolv pretreatment 9

2.4 Enzymatic hydrolysis and Microbial Cellulases 10

2.5 Ethanol fermentation 11

2.6 Biomass 11

CHAPTER THREE: MATERIALS AND METHODS 12

3.1 Materials 12

3.2 Methods 12

3.2.1 Processing of Waste paper 12

3.2.2 Pretreatment of waste paper 12

3.3 Media preparation and sterility test 12

3.4 Microorganism and inoculums preparation 13

3.5 Submerged fermentation for cellulase production 13

3.6 Enzymatic hydrolysis of pretreated waste paper 14

3.6.1 Sugar analysis 14

3.6.2 Measurement of soluble liquid 15

3.6.3 Optimization of sugar content 15

3.7 Alcohol fermentation 15

3.7.1 Determination of pH and temperature 16

3.7.2 Determination of Titratable Acidity 16

3.7.3 Determination of Biomass production 17

3.7.4 Alcohol content 17

3.8 Biomass separation 17

3.9 Distillation 18

CHAPTER FOUR: RESULTS 19

CHAPTER FIVE: DISCUSSION, CONCLUSION AND RECOMMENDATION 30

5.1 Discussion 30

5.2 Conclusion 31

5.3 Recommendation 31

REFERENCES 33