Title Page
ABSTRACT
국문 초록
PREFACE
Contents
CHAPTER 1. INTRODUCTION 20
1.1. Background 20
1.2. Reforming Process 25
1.2.1. Steam Reforming of Methane (SMR) 27
1.2.2. Dry Reforming of methane (DRM) 28
1.2.3. Partial Oxidation (POX) 29
1.2.4. Autothermal Reforming (ATR) 30
1.2.5. Tri-Reforming of methane (TRM) 31
1.1.6. Combined Steam CO₂ Reforming of methane (SCR) 32
1.3. Commercial process and catalyst 34
1.4. Catalytic deactivation 37
1.5. Strategies for the development of reforming catalyst 42
1.6. Research goal 47
CHAPTER 2. Experimental 48
2.1. Chemicals 48
2.2. Support and Catalyst Preparation 49
2.2.1. SiC-Al₂O₃ Support 50
2.2.2. MgO Support 50
2.2.3. SiC-Al₂O₃ -MgO supports 51
2.2.4. Ni-based 10Ni/SA and 10Ni/SAM catalysts 51
2.3. Catalyst Characterizations 52
2.3.1. N₂-physisorption 52
2.3.2. X-ray Fluorescence (XRF) 52
2.3.3. Powder X-ray diffraction (XRD) 54
2.3.4. Temperature programmed reduction (H₂-TPR) 54
2.3.5. CO₂-Temperature programmed desorption (CO₂-TPD) 54
2.3.6. Temperature programmed oxidation (TPO) 55
2.3.7. Temperature programmed hydrogenation (TPH) 55
2.3.8. Transmission electron microscope (TEM) 55
2.3.9. Thermogravimetric analysis (TGA) 56
2.3.10. Thermal conductivity analysis 56
2.4. Catalytic evaluation 57
CHAPTER 3. RESULT & DISCUSSION 62
3.1. The Steam CO₂ Reforming of Methane over Ni/SiC-Al₂O₃ Catalysts 62
3.1.1. Key Issues of Research 62
3.1.2. Characterization of support and catalysts 63
3.1.3. Catalytic performance 70
3.1.4. Conclusions 75
3.2. The Steam CO₂ Reforming of Methane over Ni/SiC-Al₂O₃-MgO Catalysts 76
3.2.1. Key Issues of Research 76
3.2.2. Catalyst Characterizations 77
3.2.3. Catalytic performance 84
3.2.4. Conclusions 89
3.3. The Steam CO₂ Reforming of Methane over Ni/SiC-Al₂O₃ and Ni/SiC-Al₂O₃-MgO Catalysts 90
3.3.1. Key Issues of Research 90
3.3.2. Catalyst Characterizations 91
3.3.3. long-term Stability Studies for Steam CO₂ Reforming of Methane 115
3.3.4. Conclusions 119
CHAPTER 4. Conclusions 120
REFERENCES 122
Table 1.1. Characteristics of reactions for syngas production 33
Table 1.2. Commercial SR catalysts and compositions 36
Table 1.3. catalyst deactivation occurs major reasons 38
Table 1.4. Types of carbon species 40
Table 1.5. Research trends on using MgO as a support in SCR 45
Table 1.6. Research trends on using SiC as a support in various reaction 46
Table 2.1. Catalysts Component 53
Table 2.2. Analytic conditions by online GC 61
Table 3.1. Physical properties of SA support and Ni/SA catalysts 64
Table 3.2. The catalytic activity of prepared catalysts in the SCR: CH₄, CO₂, and Carbon conversion, H₂ yield, H₂/CO ratio, carbon balance and Unreacted water. 72
Table 3.3. Physical properties of SAM support and Ni/SAM catalysts 78
Table 3.4. The catalytic activity of prepared catalysts in the SCR: CH₄, CO₂, and Carbon conversion, H₂ yield, H₂/CO ratio, carbon balance and Unreacted water. 86
Table 3.5. Physical properties of prepared catalysts and used catalysts 92
Table 3.6. The catalytic activity of prepared catalysts in the SCR: CH₄, CO₂, and Carbon conversion, H₂ yield, H₂/CO ratio TGA, and Unreacted water 98
Table 3.7. The catalytic activity of prepared catalysts in the SCR: CH₄, CO₂, and Carbon conversion, H₂ yield, H₂/CO ratio, carbon balance and TGA 117
Figure 1.1. 2020 Global Temperature Rise Graph Compared to 1850 22
Figure 1.2. The comparison of the current and planned large-scale capacity of CO₂ capture projects with the requirements of the Net Zero Scenario between 2020-2030 22
Figure 1.3. Reference of derivatives form syngas 24
Figure 1.4. six methods for syngas production through reforming processes 26
Figure 1.5. Model of the reactions and the carbonaceous deposition 41
Figure 2.1. Preparation method of supports and Ni-based catalysts 49
Figure 2.2. SCR reaction system 59
Figure 2.3. Schematic flow chart of the experimental setup for the activity test of Ni-based catalysts for SCR system 60
Figure 3.1. Nitrogen adsorption/desorption isotherms of the (a) support and (b) Calcined catalyst samples 65
Figure 3.2. X-ray diffraction patterns of (a) the support and (b) reduced catalysts.(◈ 2H-SiC ■ 6H-SiC ◇ γ-Al₂O₃ ○ Ni ♧ NiAl₂O₄) 67
Figure 3.3. H₂-TPR profiles of Ni/SA catalyst 69
Figure 3.4. CO₂-TPD profile of Ni/SA catalysts 69
Figure 3.5. The catalytic activity of Ni/SA catalysts during the SCR reaction : (a) CH₄ conversion, (b) CO₂ conversion, and (c) H₂/CO ratio. (Reaction condition: Temp.=... 74
Figure 3.6. Nitrogen adsorption/desorption isotherms of the (a)support and (b)Calcined catalyst samples 79
Figure 3.7. X-ray diffraction patterns of (a) the support and (b) reduced catalysts(◈ 2H-SiC ■ 6H-SiC ◇ Al₂O₃ ○ Ni ♧ NiAl₂O₄ ◎ MgO ☆ MgAl₂O₄ ★MgAl) 81
Figure 3.8. H₂-TPR profiles of Ni/SAM catalysts 83
Figure 3.9. CO₂-TPD profile of Ni/SAM catalysts. 83
Figure 3.10. The catalytic activity of Ni/SAM catalysts during the SCR reaction : (a) CH₄ conversion, (b) CO₂ conversion, and (c) H₂/CO ratio. (Reaction condition: Temp.=... 88
Figure 3.11. Nitrogen adsorption/desorption isotherms of the (a) support and (b) Calcined catalyst samples 93
Figure 3.12. H₂-TPR profile of the catalyst samples 96
Figure 3.13. CO₂-TPD profile of the catalyst samples 96
Figure 3.14. The catalytic activity of Ni/SA and Ni/SAM catalysts during the SCR reaction : (a) CH₄ Conversion, (b) CO₂ Conversion, and (c) H₂/CO ratio. (Reaction... 100
Figure 3.15. X-ray diffraction patterns of the (a) reduced catalysts and (b) spent catalysts (after 850 ℃ reaction)... 102
Figure 3.16. TGA result of the used catalysts after SCR reaction at 850 ℃ 104
Figure 3.17. TPO results of the spent catalysts after SCR reaction at 850 ℃ 106
Figure 3.18. TPH results of the spent catalysts after SCR reaction at 850 ℃ 108
Figure 3.19. TEM image of the spent catalysts 112
Figure 3.20. TEM-EDS image of spent Catalysts 114
Figure 3.21. The catalytic activity of Ni/SA, Ni/SAM and Ni/Al₂O₃ catalysts during the SCR reaction : (a) CH₄ Conversion and (b) CO₂ Conversion (Reaction condition: Temp.=... 116
Figure 3.22. TGA result of the used catalysts after SCR reaction for 100 h 118