Title Page
Contents
List of Abbreviations 9
Abstract 10
1. Introduction 12
2. Materials and methods 15
2.1. Raw materials 15
2.2. Thermal acid hydrolysis 15
2.3. Sonication of Kariba weed 16
2.4. Optimization of Enzymatic Saccharification 17
2.5. Selection of yeast for fermentation 18
2.5.1. Seed Culture 18
2.6. Ethanol Fermentation 18
2.7. Analytical Methods and Statistical analyses 19
3. Results and Discussion 21
3.1. Composition of Kariba weed 21
3.2. Optimization of pretreatment methods of Kariba weed 22
3.2.1. Thermal acid hydrolysis of Kariba weed 22
3.2.2. Sonication of Kariba weed 25
3.3. Enzymatic Saccharification 27
3.4. Fermentation 30
3.4.1. Fermentation using S. cerevisiae 30
3.4.2. Fermentation using K. marxianus 32
3.4.3. Fermentation using P. stipitis 32
4. Process Simulation for the production of bioethanol using Kariba weed biomass 36
5. Conclusion 39
References 41
Table 1. Composition analysis of Kariba weed 21
Fig. 1. Effect of pretreatment conditions 24
Fig. 2. Effect of pretreatment time of Kariba weed slurry 26
Fig. 3. Effect of enzymatic saccharification with 29
Fig. 4. Bioethanol production from Kariba weed hydrolysate using S. cerevisiae 31
Fig. 5. Bioethanol production from Kariba weed hydrolysate using K. marxianus 33
Fig. 6. Bioethanol production from Kariba weed hydrolysate using P. stipitis 35
Fig. 7. Process Simulation for the production of bioethanol from Kariba weed. 38