Title Page
Contents
ABSTRACT 18
Chapter 1. Overall Introduction 21
1.1. Current status and future prospects of biorefinery 21
1.2. Recovery of bioactive compounds by extraction 25
1.3. Production of fermentable sugars by saccharification 27
1.4. Production of value-added substances by fermentation 29
1.5. Recycling of process residue by pyrolysis 31
1.6. Objectives 32
Chapter 2. Development of Extraction Processes to Recover Bioactive Compounds from Biomass 34
2.1. Introduction 34
2.2. Materials and Methods 37
2.2.1. Materials 37
2.2.2. Lutein recovery from Tetraselmis suecica 38
2.2.3. Lutein recovery from Dunaliella tertiolecta 41
2.2.4. Hesperidin and narirutin recovery from mandarin peel 43
2.2.5. Analytical methods 45
2.3. Results and Discussion 50
2.3.1. Lutein recovery from Tetraselmis suecica 50
2.3.2. Lutein recovery from Dunaliella tertiolecta 71
2.3.3. Hesperidin and narirutin recovery from mandarin peel 90
2.4. Conclusions 106
Chapter 3. Development of Saccharification Process to Produce Fermentable Sugar from Biomass 107
3.1. Introduction 107
3.2. Materials and Methods 109
3.2.1. Materials 109
3.2.2. Saccharification process of orange peel 110
3.2.3. Saccharification process of spent coffee ground 113
3.2.4. Saccharification process of chestnut shell 117
3.2.5. Analytical methods 121
3.3. Results and Discussion 122
3.3.1. Saccharification process of orange peel 122
3.3.2. Saccharification process of spent coffee ground 137
3.3.3. Saccharification process of chestnut shell 153
3.4. Conclusions 164
Chapter 4. Development of Fermentation Processes to Produce Value-Added Substances using Biomass Hydrolysates 165
4.1. Introduction 165
4.2. Materials and Methods 167
4.2.1. Materials 167
4.2.2. Lactic acid production from spent coffee ground hydrolysates 168
4.2.3. Ethanol production from chestnut shell hydrolysates 169
4.2.4. Bacterial cellulose production from chestnut shell hydrolysates 170
4.2.5. Analytical methods 172
4.3. Results and Discussion 173
4.3.1. Lactic acid fermentation using spent coffee ground hydrolysates 173
4.3.2. Ethanol fermentation using chestnut shell hydrolysates 178
4.3.3. Bacterial cellulose production and structural characterization 182
4.4. Conclusions 190
Chapter 5. Development of Zero-Waste Process through Pyrolysis and its Application to Supercapacitor 191
5.1. Introduction 191
5.2. Materials and Methods 193
5.2.1. Materials 193
5.2.2. Carbonization of T. suecica residues and fabrication of electrodes 194
5.2.3. Characterization of carbon material 195
5.2.4. Electrochemical Analysis of electrodes 196
5.3. Results and Discussion 197
5.3.1. Material analysis 197
5.3.2. Electrochemical performance 207
5.4. Conclusions 216
Chapter 6. Overall Conclusions 217
Reference 218
국문요약 241
Table 1. Factors and their levels in the response surface methodology for lutein recovery from Tetraselmis suecica 40
Table 2. Factors and their levels in the response surface methodology for lutein recovery from Dunaliella tertiolecta 42
Table 3. Detailed fabricating conditions of bioelastomers 44
Table 4. Experimental designs and their responses for five-level, three-factor response surface analysis 55
Table 5. ANOVA for response surface quadratic model of the lutein contents 58
Table 6. ANOVA for response surface quadratic model of ABTS radical scavenging activity 59
Table 7. Numerical optimization of lutein extraction based on multiple regression models 64
Table 8. Antioxidant activity of the lutein standard and lutein extract 66
Table 9. Summary of lutein extraction from microalgae 70
Table 10. Experimental design for response surface analysis and their experimental response 75
Table 11. ANOVA of statistical predictive model for lutein recovery 78
Table 12. Numerical optimization of extraction conditions for lutein recovery from Dunaliella tertiolecta 82
Table 13. Comparison of antioxidant activity between lutein standard and Dunaliella tertiolecta extracts 84
Table 14. Summary of extraction conditions for lutein recovery from various microalgae 89
Table 15. Radical scavenging activity of the fabricated bioelastomer 96
Table 16. Physical properties of Bioelastomer-MPE 0% (control, PMDS) and Bioelastomer-MPE 15% 105
Table 17. Variables and their levels in the central composite design for experimental conditions of pretreatment 111
Table 18. Factors and their levels in the response surface methodology (RSM) 116
Table 19. Variables and their levels in the central composite design 120
Table 20. CCD, experimental and estimated data for five-level-three-factor response surface analysis 123
Table 21. ANOVA for response surface quadratic model on the glucan content 129
Table 22. ANOVA for response surface quadratic model on the enzymatic digestibility 130
Table 23. Numerical optimization and validation of pretreatment based on the regression models 132
Table 24. Summary of the increase in glucose yield based on pretreatments and enzymatic hydrolysis 136
Table 25. The central composite design and their responses for five-level, three-factor response surface analysis 138
Table 26. Analysis of variance for the response surface quadratic model of the glucan content 141
Table 27. Analysis of variance for the response surface quadratic model of the mannan content. 142
Table 28. Analysis of variance for the response surface quadratic model of the enzymatic digestibility 143
Table 29. Numerical optimization for KOH pretreatment of spent coffee grounds (SCGs) based on multiple regression model analysis 149
Table 30. CCD with three variables at five levels and experimental response 157
Table 31. ANOVA for predicted response surface model 161
Table 32. Numerical optimization of NaOH pretreatment conditions for CNS and predicted and experimental responses 163
Table 33. FT-IR wavenumber range and functional groups present in the TR and TRB 201
Figure 1. Comparison of conventional biorefinery concept (a) and integrated biorefinery concept (b). 24
Figure 2. A schematic diagram of this study's objectives. 33
Figure 3. The effect of various solvents on lutein recovery from Tetraselmis suecica. 52
Figure 4. The effect of various concentrations of solvent on lutein recovery from Tetraselmis suecica. 53
Figure 5. The three-dimensional response surface plots representing the effects of each factor on the lutein contents. Effects of temperature and time (a), temperature and S/L ratio (b) and time and S/L ratio (c). 61
Figure 6. The three-dimensional response surface plots representing the effects of each factor on ABTS radical scavenging activity. Effects of temperature and time (a), temperature and S/L ratio (b) and time and S/L ratio (c). 62
Figure 7. Material balance of microalgae to lutein based on 1000 g Tetraselmis suecica. 68
Figure 8. The effect of extraction solvents on lutein recovery from Dunaliella tertiolecta. 73
Figure 9. Three-dimensional graph of the interaction between variables affecting the lutein recovery from Dunaliella tertiolecta. The effects of (a) temperature and reaction time; (b) temperature and solid loading; (c) reaction time and solid loading. 80
Figure 10. Mass balance of the overall lutein production process from Dunaliella tertiolecta. 86
Figure 11. Effects of the mixing ratio of MeOH:DMSO solution on flavanone (hesperidin and narirutin) recovery from mandarin peels. 91
Figure 12. Effect of microwave power and irradiation time on the hesperidin (a) and narirutin (b) recovery from MPs. 94
Figure 13. Antibacterial activity of Bioelastomer-MPE 15% against gram-positive (S. aureus), Gram-negative (E. coli), and antibiotic-resistant... 99
Figure 14. Fourier transform infrared (FT-IR) spectra of the Bioelastomer-MPE 0% (control, PMDS, black) and the Bioelastomer-MPE... 101
Figure 15. SEM images of B-MPE 0% (a) and B-MPE 15% (b) (inset: film-type product). 103
Figure 16. 3D response surfaces indicating the effects of thermal-alkaline pretreatment variables. The effects of X₁ and X₂ on GC (A); the effects of X₁ and X₃ on GC (B); the effects of X₂ and X₃ on GC (C). (X 1 : time, X₂ : KOH conc.... 125
Figure 17. 3D response surfaces indicating the effects of thermal-alkaline pretreatment variables. The effects of X₁ and X₂ on ED (A); the effects of X₁ and X₃ on ED (B); the effects of X₂ and X₃ on ED (C). (X₁: time, X₂: KOH conc.... 126
Figure 18. Enzymatic hydrolysis of orange peel. Filled symbols represent pretreated group and not filled symbols represent control group... 134
Figure 19. The three-dimensional response surface plot for the effect of the experimental factors on glucan content. Effects of temperature and KOH concentration (a), temperature and time (b) and KOH concentration and time (c). 145
Figure 20. The three-dimensional response surface plot for the effect of the experimental factors on mannan content. Effects of temperature and KOH concentration (a), temperature and time (b) and KOH concentration and time (c). 146
Figure 21. The three-dimensional response surface plot for the effect of the experimental factors on enzymatic digestibility. Effects of temperature and KOH concentration (a), temperature and time (b) and KOH concentration and time (c). 147
Figure 22. Enzymatic hydrolysis profiling of SCGs by various enzyme loadings (control group=filled symbol, and experimental group=hollow symbol). 152
Figure 23. Effect of NaOH concentration on the biomass to glucose conversion of chestnut shell. 155
Figure 24. Response surface plot representing the effect of interactions between variables on BtG of CNS: (a) the effect of temperature and reaction time; (b) the effect of temperature and NaOH concentration; (c) the effect of reaction... 159
Figure 25. Lactic acid production by fermentation of L. brevis ATCC 8287 (a) and L. parabuchneri ATCC 49374 (b) using SCG hydrolysates... 175
Figure 26. Mass balance of lactic acid production based on 1000 g SCG. 177
Figure 27. Profiles of bioethanol fermentation by S. cerevisiae K35 using glucose (filled symbols) and CNS hydrolysates (hollow symbols) as carbon sources. 179
Figure 28. Schematic illustration of mass balance for the overall process of converting CNS to bioethanol. 181
Figure 29. Profiles of BC concentration during fermentation by Gluconacetobacter xylinus ATCC 53524. 183
Figure 30. Mass balance of bacterial cellulose production based on 1000 g chestnut shell. 185
Figure 31. SEM images of bacterial cellulose produced from commercial refined glucose (a) and chestnut hydrolysates (b) after 96 h fermentation. 187
Figure 32. FT-IR spectra of bacterial cellulose produced from commercial refined glucose (black) and CNS hydrolysates (red). 189
Figure 33. The dataset of the physical properties of the algae, showing the morphological change, atomic vibration modes, decomposition process and specific surface area, with carotenoid extraction and carbonization. SEM image of... 200
Figure 34. Structure and quantitative analysis of the elementary compositions for TRB. (a) The Raman spectra, (b) XRD pattern, (c) EDS... 204
Figure 35. XPS spectrum of the TRB. (a) Survey scan and narrow scan for the curve fit of the (b) C 1s, (c) O 1s and (d) N 1s. 206
Figure 36. Electrochemical performance evaluation by constructing a three-electrode system (half-cell) including NDB-E in 1 M H₂SO₄ electrolyte.... 212
Figure 37. Electrochemical performance of the symmetric supercapacitor (full-cell) at 1 M H₂SO₄ . (a) The CV curve of symmetric devices for... 215