[표제지 등]

제출문

요약문

Summary

그림목차

표목차

칼라

목차

제1장 서론 24

제2장 이론 27

제1절 용융탄산염 연료전지의 원리 27

1. 원리 27

2. 용융탄산염 연료전지의 구성요소 29

1) 연료전극(anode) 29

2) 산소전극(cathode) 30

3) 전해질 지지체 30

4) 전지 몸체 31

제2절 Pack cementation 방법에 의한 전지 몸체의 피복 31

1. Pack cementation 방법의 개요. 32

2. Al 확산침투 피복과정 33

3. 피복 공정 35

4. 피복 반응 37

1) 단독확산반응 37

2) 교환반응 37

3) 열분해반응 37

제3절 Pack cementation에 의한 연료전극의 제조 39

제4절 MCFC 용 LiCoO₂ 산소전극의 제조. 40

제5절 PVB 바인더의 열분해 메카니즘. 42

제6절 MCFC 용 내부개질 촉매의 제조 및 특성에 관한 연구 46

1. 개질 반응 49

2. 평판형 내부개질 반응기의 물질수지식 및 반응기의 구조. 52

3. 속도식과 효율인자(effectiveness factor) 52

4. 금속 산화물 담지 니켈 촉매의 일반적 사항. 57

5. 내부개질 촉매의 연구내용과 범위. 58

1) MgO 담지 니켈 촉매의 제조와 특성에 관한 연구. 58

2) 판상형 LiAlO₂ 담지 니켈 촉매의 제조 및 촉매 반응기 해석에 관한 연구. 58

3) 내부 개질 용 상용 촉매의 개질 특성과 내부개질반응기의 기본 설계 변수의 결정. 58

제7절 Separator 재료의 내식성 평가 59

제8절 연료의 탈황 방법에 관한 연구 60

제3장 실험 62

제1절 Pack cementation 방법에 의한 전지 몸체의 피복. 62

1. 알루미늄 피복 62

2. 피막특성 측정 68

1) 피복양 및 표면거칠기 측정 68

2) X-선회절 분석 68

3) 미세조직 관찰 69

3. 부식실험 69

1) Out of cell 실험 69

2) 반쪽전지 실험 70

제2절 Pack cementation방법에 의한 연료전극(anode)의 제조 방법. 72

1. Pack cementation 공정. 72

2. Creep test 방법. 73

3. 분석 74

제4절 MCFC 용 LiCoO₂ 양극의 제조방법. 77

1. LiCoO₂의 제조 77

1) 고온 소성법에 의한 LiCoO₂ 제조 77

2) 구연산 졸-겔법(졸-겔법법)에 의한 LiCoO₂ 제조 77

2. 전기전도도 측정 81

3. 용해도 측정 실험 81

4. 반쪽 전지 실험 85

1) 반쪽 전지 실험 장치 85

2) 정상상태분극 실험방법 86

제5절 PVB 바인더의 열분해 메카니즘. 88

1. 시료의 준비 88

1) 순수 PVB 분말 88

2) 니켈 그린 시트 (nickel green sheet) 89

2. 실험 방법 및 사용 기기 90

1) TGA와 DSC 90

2) FTIR Spectroscopy(Specrtroscopy) 90

3) 기체 크로마토그래피(GC)와 질량 분석 90

제6절 MgO 담지 니켈 촉매의 제조 92

1. 공침법에 의한 제조 92

2. 함침법에 의한 촉매 제조 92

1) 알루미늄산 리튬에 담지된 니켈 촉매 92

2) 산화 마그네슘-산화 알루미늄 혼합 담체에 담지된 니켈 촉매 92

3) 산화 마그네슘에 담지된 니켈 촉매 93

3. 메탄의 수증기 개질 반응 실험 94

제7절 판상형 LiAlO₂ 담지 니켈 촉매의 제조 99

1. 촉매의 제조 99

2. 바인더(Binder)의 제조 99

3. 촉매의 환원 100

4. 촉매 특성의 측정 100

5. 장치및 실험 101

제8절 내부 개질 용 상용촉매의 성능 평가실험 108

1. 사용 촉매 108

2. 촉매 특성의 측정 108

3. 촉매의 환원 109

4. 장치 및 실험 109

1) 원료 가스의 유입 부분 109

2) 촉매충진 반응기 부분 109

3) 가스 분석 부분 110

제9절 Separator 재료의 내식성 평가 113

제10절 연료의 탈황 방법에 관한 연구 115

1. 탈황 실험장치 및 방법 115

1) 탈황 실험장치 115

2) 탈황방법 116

제11절 단위 전지 및 적층전지 실험 120

제4장 연구 결과 121

제1절 Pack cementation 방법에 의한 전지 몸체의 피복. 121

1. 피복 특성 121

1) 피복시간과 온도의 영향 121

2) 활성제의 영향 125

2. 피복층 및 확산층의 상분석 결과. 131

1) 피복시간의 영향 131

2) 피복 온도의 영향 132

3) 피막층의 미세조직 132

3. 부식실험 결과 142

1) Out of cell 실험 결과 142

2) 반쪽전지 실험 결과 148

제2절 Pack cementation에 의한 연료전극의 제조 결과. 153

1. Pack cementation 공정 후 전극의 상(phase)과 기공구조 153

2. Pack cementation 공정에서의 증착속도 162

3. Creep Test 결과. 168

제3절 MCFC용 LiCoO₂ 산소전극의 제조. 173

1. LiCoO₂ 분말제조 173

1) 고온소성법에 의한 분말제조 173

2) 구연산 졸-겔법에 의한 분말제조 173

3) 고온소성법과 구연산 졸-겔법의 비교 185

2. 전기전도 특성 185

3. 용해도 특성 189

4. 반쪽전지 실험결과 192

제4절 PVB 바인더의 열분해 메카니즘. 200

1. TGA 와 DSC 분석 결과 200

2. FTIR 분석 결과 200

3. 기체 크로마토그래피와 질량 분석 결과 211

제5절／제6절 MgO 담지 니켈 촉매의 제조와 특성에 관한 연구 225

1. 공침법으로 제조한 촉매의 활성 실험 225

2. 함침법으로 제조한 촉매의 활성 실험 231

1) 알루미늄산 리튬에 담지된 니켈 촉매 231

2) 산화 마그네슘-산화 알루미늄 혼합 담체에 담지된 니켈 촉매 234

3) 산화 마그네슘에 담지된 니켈 촉매 238

3. 기공 분포(pore distribution)및 SEM 분석 261

제6절／제7절 판상형 LiAlO₂ 담지 니켈 촉매의 제조 및 촉매 반응기 해석에 관한 연구. 274

제7절／제8절 내부 개질 용 상용 촉매의 개질 특성과 내부개질반응기의 기본 설계변수의 결정. 286

1. 생성물의 평균 조성 286

2. 메탄의 전화율 290

3. 단위 촉매량 당 생성시키는 수소의 양 290

제8절／제9절 Separator 재료의 내식성 평가 296

제9절／제10절 연료의 탈황에 관한 연구 304

1. 수첨탈황촉매의 예비유화(Presulfiding) 304

2. 탈황조업조건 306

1) 수첨탈황반응 306

2) 탈황 반응 조건 306

제10절／제11절 단위전지 및 적층전지 결과. 309

제5장 결론 313

1. 전지몸체의 부식 방지 연구 313

2. 연료전극의 creep 저하를 위한 연구 314

3. MCFC 용 LiCoO₂ 산소전극의 제조에 대한 연구. 315

4. PVB 바인더의 열부해 메카니즘에 관한 연구. 316

5. MgO 담지 니켈 촉매의 제조와 특성에 관한 연구. 316

6. 판상형 LiAlO₂ 담지 니켈촉매의 제조 및 촉매 반응기 해석에 관한 연구. 317

7. 내부 개질 용 상용 촉매의 개질 특성과 내부개질반응기의 기본설계 변수의 결정 318

8. Separator 재료의 내식성 평가 318

Table 2-1. Function of additives to ceramic batches 44

Table 2-2. Materials used for binders 45

Table 3-1. The composition of 316L stainless steel.［76］ 64

Table 3-2. Composition of aluminum pack powders tried in this work 66

Table 3-3. Composition of pack and operating temperature. 73

Table 3-4. Physical Properties of PVB 88

Table 3-5. The operation conditions of gas chromatography for product gas analysis 98

Table 3-6. Properties of catalysts. 103

Table 3-7. Properties of catalysts 108

Table 3-8. Sulfur 화합물의 열분해 가능온도 118

Table 3-9. 탈황반응촉매의 물성 119

Table 4-1. Self diffusivity of Al and element of 316L S.S (㎠／sec) 131

Table 4-2. Weight in mg of non-coated and Al-coated 316L stainless steel specimen before and after corrosion for various times 143

Table 4-3. ICP data of each anodes by fabricated pack cementation 154

Table 4-4. The rate constant of pack cementation process 162

Table 4-5. The activation energy of Al and Cr deposition with pack cementation. 164

Table 4-6. The creep strain of Al-Ni and (Al+Cr)-Ni anode under the 650℃, 200psi, 100hr. 169

Table 4-7. The creep strain of various codeposited anodes under the 650℃ , 100psi, 100hr creep test condition. 172

Table 4-8. LiCoO₂ property with increase of calcination temperature 174

Table 4-9. Reaction mechanisms at the cathode 194

Table 4-10. Experiment results of Methane Steam Reforming Reaction using Ni／MgO catalyst manufactured by coprecipitation method. 226

Table 4-11. Surface area data of Ni／MgO catalyst manufactured by coprecipitation method 227

Table 4-12. Catalyst manufaction condition using impregnation method 232

Table 4-13. Surface area data of Ni／MgO catalysts manufactured by impregnation method (precursor : nickel nitrate, solvent : ethanol) 260

Table 4-14. The experimental data and the results calculated by integral method 280

Table 4-15. Reaction rate constants based on unit mass and unit surface area of catalysts. 285

Table 4-16-1. Composition of product gas as a function of temperature. 286

Table 4-16-2. Composition of product gas as a function of space velocity. 288

Table 4-16-3. Composition of product gas as a function of S／C ratio. 290

Table 4-17. 탈황 반응 조건 (촉매 1g당) 307

Table 4-18. 반응조건에 따른 잔류 황성분 농도 308

Table 4-19. The performance of unit cells and Stacks. 309

Fig. 2-1. Schematic(Shematic) representation of typical fuel cell Showing the reactant／product gases and ion conduction flow path for(foo) SOFC, PAFC, PEFC and MCFC. 28

Fig. 2-2. Idealized depleted zone formation during pack aluminizing time(t₂ > t₁) 34

Fig. 2-3. Schematic diagram of NiAl coating on Ni-Based superalloy by a) one step process and b) two step process［9］. 36

Fig. 2-4. Schematic diagram of gas diffusions during aluminum deposition. 38

Fig. 2-5. Types of Reforming for MCFC 47

Fig. 3-1. Flowchart of aluminizing 316L stainless steel by pack cementation. 65

Fig. 3-2. The schematic diagram of the furnace used for pack cementation 67

Fig. 3-3. The schematic diagram of half cell corrosion test apparatus. 71

Fig. 3-4. Schematic(Shematic) diagram of pack cementation for anode 75

Fig. 3-5. Schematic diagram of creep test apparatus 76

Fig. 3-6. The flow diagram(daigram) of LiCoO₂ preparation(preperation) process(High temp. calcination process) 79

Fig. 3-7. The flow diagram(daigram) of LiCoO₂ preparation(preperation) process(Citrate sol-gel process) 80

Fig. 3-8. The apparatus of conductivity measurement 83

Fig. 3-9. The schematic diagram of solubility(silubility) test apparatus 84

Fig. 3-10. The schematic diagram of half cell apparatus 87

Fig. 3-11. Structure and reaction of PVB 88

Fig. 3-12. Process of nickel green sheet fabrication. 89

Fig. 3-13. Schematic diagram of the apparatus(appratus) for gas trap. 91

Fig. 3-14. Apparatus of methane steam reforming reaction 96

Fig. 3-15. Schematic diagram of reactor for methane steam reforming reaction. 97

Fig. 3-16. Catalyst fabrication process. 104

Fig. 3-17. SEM image of the CAT-1 and CAT-2. 105

Fig. 3-18. SEM image of the CAT-3 and CAT-4. 105

Fig. 3-19. Diagram of experimental apparatus. 106

Fig. 3-20. Diagram of catalytic reactor. 107

Fig. 3-21. The Schematic diagram of catalytic reforming 111

Fig. 3-22. Diagram of catalytic reactor 112

Fig. 3-23. The schematic diagram of electrochemical corrosion test apparatus 114

Fig. 3-24. The schematic diagram of desulfurization reactor. 117

Fig. 4-1. Weight gain vs. time for 316L stainless steel specimen aluminium-pack-cemented at 900℃ with a pack composition of 30wt.%Al-5wt.%NH₄Cl-65wt.%Al₂O₃. 122

Fig. 4-2. Weight gain plotted as a function of temperature for 316L stainless steel specimen pack-cemented for 2hours with a pack composition of 30wt.%Al-5wt.% NH₄Cl-65wt.% Al₂O₃. 123

Fig. 4-3. Arrhenius plot 124

Fig. 4-4. Weight gain plotted as a function of activator (NH₄Cl) amount for 316L stainless steel specimen aluminium-pack-cemented at various temperatures for 2hours. 127

Fig. 4-5. (a) Thickness and (b) weight gain plotted as a function of aluminium amount for 316L stainless steel specimen aluminium-pack-cemented at 900℃ for 2 hours with different amount of activator. 128

Fig. 4-6. Thickness and weight gain plotted as a function of aluminium amount for 316L stainless steel specimen aluminium-pack-cemented at 900℃ for 2hours with a different activator(NH₄Cl) amount of (a) 5wt.%, (b) 7wt.% and (c) 10wt.%. 129

Fig. 4-7. Surface roughness test for 316L stainless steel specimen aluminium-pack-cemented with a different activator (NH₄Cl) amount of (a) 5wt.%, (b) 7wt.% and (c) 10wt.%. 130

Fig. 4-8. X-ray diffraction patterns of 316L stainless steel specimen aluminium-pack-cemented at 900℃ for various times with a pack composition of 30wt.%Al-5wt.%NH₄Cl-65wt.%Al₂O₃. 134

Fig. 4-9. X-ray diffraction patterns of 316L stainless steel specimen aluminium-pack-cemented at various temperatures for 2hours with a pack composition of 30wt.%Al-5wt.%NH₄Cl-65wt.% Al₂O₃. 135

Fig. 4-10. SEM micrograph for the cross section of 316L stainless steel specimen aluminium-pack-cemented at 9000C for 2hours with a pack composition of 30wt.%Al-5wt.% NH₄Cl-65wt.%Al₂O₃. 136

Fig. 4-11. Optical micrographs(×400) for the cross section of aluminized 316L stainless steel specimen polished from the surface at a rate of approximately 1㎛／sec for (a) 0, (b) 10, (c) 20, (d) 30 and (e) 40 seconds. 137

Fig. 4-12. X-ray diffraction patterns of the aluminized 316L stainless steel specimen polished from the surface at a rate of approximately 1㎛／sec for (a) 0, (b) 10, (c) 20, (d) 30 and (e) 40 seconds. 138

Fig. 4-13. EPMA result for 316L stainless steel specimen aluminium-pack-cemented at 9000C for 2hours with a pack composition of 30wt.%Al-5wt.% NH₄Cl-65wt.%Al₂O₃. 139

Fig. 4-14. Two-step : (a) SEM micrograph and (b) EPMA result for the rectangular part in (a) of 316L stainless steel specimen aluminium-pack-cemented at 900℃ for 2hours with a pack composition of 30wt.%Al-5wt.% NH₄Cl-65wt.%Al₂O₃ and... 140

Fig. 4-15. One-step : (a) SEM micrograph and (b) EPMA result for the rectangular part in (a) of 316L stainless steel specimen aluminium-pack-cemented at 1100℃ for 2hours with a pack composition of 30wt.%Al-5wt.%NH₄Cl-65wt.%Al₂O₃. 141

Fig. 4-16. SEM micrographs (×400) for the cross section of 316L stainless steel specimen, which has been aluminium-pack-cemented at 900℃ for 2hours, corroded in 62 mol.%Li₂CO₃-38mol% K₂CO₃ at 650℃ for (a) 10 hours, (b) 60 hours... 144

Fig. 4-17. X-ray diffraction patterns of 316L stainless steel specimen, which has been aluminium-pack-cemented at 900℃ for 2 hours, corroded in 62 mol% Li₂CO₃-38 mol%K₂CO₃ at 650℃ for various times. 145

Fig. 4-18. SEM micrographs (×40O) for the cross section of 316L stainless steel specimen, which has been aluminium-pack-cemented at 900℃ for 2hours, corroded in 62 mol%Li₂CO₃-38 mol%K₂CO₃ at 650℃ for (a) 10hours, (b) 60hours and... 146

Fig. 4-19. X-ray diffraction patterns of 316L stainless steel specimen, which has been aluminium-pack-cemented at 9000C for 2hours, corroded in 62 mol% Li₂CO₃-38 mol%K₂CO₃ at 650℃ for various times. 147

Fig. 4-20. Half cell test results performed in 62mol% Li₂CO₃-38 mol%K₂CO₃ at 650℃ for 316L stainless steel specimen non-coated or aluminium-coated under different conditions. 150

Fig. 4-21. X-ray diffraction patterns after half cell test performed on 316L stainless steel specimen non-coated or aiuminium-coated under different conditions. 151

Fig. 4-22. SEM micrographs (×400) taken after corrosion test for the cross section of 316L stainless steel specimen (a) non-coated, (b) Al-coated at 900℃ and (c) 1100℃ and Al-coated at 900℃ and subsequently annealed at 1100℃. 152

Fig. 4-23. SEM images of various anodes fabricated with Pack process 157

Fig. 4-24. Identification of intermetallic Al-Ni compound in aluminized Ni anode. 158

Fig. 4-25. The variation of porosity with deposited metal content in Al-Ni and Cr-Ni anode 159

Fig. 4-26. Pore distribution of Al-Ni anode as a function of Al content 160

Fig. 4-27. Pore distribution of Cr-Ni anode as a function of Cr content 161

Fig. 4-28. Deposited metal content in Al-Ni anode and Cr-Ni anode vs time. 165

Fig. 4-29. Comparison of predicted and experimental Al weight gain 166

Fig. 4-30. Arrhenius plot for Al, Cr vapour deposition. 167

Fig. 4-31. Creep strain vs. time of pure Ni anode and Al-Ni anode 170

Fig. 4-32. Creep strain vs. deposited metal content in anode 171

Fig. 4-33. XRD analysis of LiCoO₂ synthesized by high temperature calcination methode. 175

Fig. 4-34. The effect of temperature on the mean pore diameter by porosimeter analysis 176

Fig. 4-35. Particle size with increase of calcination temperature 177

Fig. 4-36. The SEM image of LiCoO₂ precursor. 178

Fig. 4-37. Thermal gravimetry analysis of LiCoO₂ precursor(precusor) 180

Fig. 4-38. IR analysis of LiCoO₂ material at various calcination temperature 181

Fig. 4-39. XRD analysis of LiCoO₂ material synthesized by citrate sol-gel process (pH 1, pH 1.97) 182

Fig. 4-40. XRD analysis of LiCoO₂ material synthesized by citrate sol-gel process (pH 3, pH 5) 183

Fig. 4-41. XRD analysis of LiCoO₂ material synthesized by citrate sol-gel process (pH7,R＝1) 184

Fig. 4-42. SEM image of LiCoO₂ synthesized by a) high temperature calcination method and b) citrate sil-gel process (pH.1) 186

Fig. 4-43. Particle size distribution of LiCoO₂ synthesized by high temperature calcination method(a,b,c,d) and citrate sol-gel process(e) 187

Fig. 4-44. The conductivity vs. temperature. 188

Fig. 4-45. The solubility in molten salt ((Li／K)₂CO₃ ＝ 62／38m／o, at 650℃) 191

Fig. 4-46. The effect of bubbling on the steady state polarization curve 195

Fig. 4-47. The steady state polarization curves 196

Fig. 4-48. The steady state polarization curves 197

Fig. 4-49. The effect of temperature on the steady state polarization curve 198

Fig. 4-50. The steady state polarization(polarzation) curves of LiCoO₂-and NiO-cathode 199

Fig. 4-51. TG curves of PVB and nickel green sheet. a) PVB in air, b) PVB in nitrogen, c) nickel green sheet in air, d) nickel green sheet in nitrogen. 202

Fig. 4-52. DSC curves of PVB and green sheet 203

Fig. 4-53. FTIR spectra of PVB residues in air. a) 25℃, b) 200℃, c) 300℃, d) 350℃, e) 400℃, f) 450℃... 204

Fig. 4-54. FTIR spectra of PVB residues in nitrogen. a) 200℃, b) 300℃, c) 350℃, d) 400℃, e) 450℃, f) 550℃, g) 650℃... 205

Fig. 4-55. FTIR spectra of gases evolved from PVB in air at a) 200℃, b) 300℃, c) 350℃, d) 400℃, e) 450℃, f) 550℃, g) 650℃... 207

Fig. 4-56. FTIR spectra of nickel green sheet residues in air a) 300℃, b) 350℃, c) 370℃, d) 410℃, e) 450℃, f) 500℃.... 208

Fig. 4-57. FTIR spectra of gases evolved from nickel green sheet in air at a) 300℃, b) 350℃, c) 370℃, d) 410℃, e) 450℃, f) 500℃. 1. stretching bends by butanal, 2. stretching bend by CO₂, 3. C-H stretching bend by butanal. 209

Fig. 4-58. FTIR spectra of gases evolved from nickel green sheet at A) 330℃ B)380℃ C)420℃ D)480℃ E)500℃ F)560℃ in nitrogen 1. stretching bend of butanal, 2. C-H stretching bends of butanal, 3. C-O stretching bend, 4. Aromatic... 210

Fig. 4-59. Gas chromatograms of PVB in air. A)200℃ B)300℃ C)350℃ D)400℃ E)450℃ F)550℃ G)650℃ 213

Fig. 4-60. Gas chromatograms of PVB in nitrogen. A)200℃ B)300℃ C)350℃ D)400℃ E)450℃ F)550℃ G)650℃ 214

Fig. 4-61. Gas Chromatograms of nickel green sheet in air A)200℃ B)300℃ C)350℃ D)400℃ E)450℃ F)550℃ G)650℃ 215

Fig. 4-62. Gas Chromatograms of nickel green sheet in nitrogen. A)200℃ B)300℃ C)350℃ D)400℃ E)450℃ F)550℃ G)650℃ 216

Fig. 4-63. Mass spectrum of gases evolved from PVB at 400℃ in air 1. Unknown gases, 2. Propenes, 3. Propane, 4. Acetaldehyde, 5. 2-Methyl propene, 6. n-Butane, 7. Propenal 8. Propanol, 9. Butanol, 10. Butenal, 11. Benzene, 12. Toluene 217

Fig. 4-64. Unknown gases peak area changes depended on pyrolysis temperature in various conditions. A) PVB in air, B) PVB in nitrogen, C) Nickel green sheet in air, D) Nickel green sheet in nitrogen. 218

Fig. 4-65. Butanal gas peak area changes depended on pyrolysis temperature in various conditions. A) PVB in air, B) PVB in nitrogen, C) Nickel green sheet in air, D) Nickel green sheet in nitrogen. 219

Fig. 4-66. Benzene and toluene gases peak area changes depended on pyrolysis temperature in various conditions. A) PVB in air, B) PVB in nitrogen, C) Nickel green sheet in air, D) Nickel green sheet in nitrogen. 220

Fig. 4-67. Gas chromatograms of condensed liquid in air. A)200℃ b)300℃ C)350℃ D)400℃ E)450℃ F)550℃ G)650℃ 222

Fig. 4-68. Mass spectrum of liquid condensed gases evolved from PVB at 400℃ in air.... 223

Fig. 4-69. Various gas peak area changes depended on pyrolysis temperature in condensed liquid. A)Acetic acid, B)Butanal, C)Butanoic acid, D)Phenol, E)Acetophenone, F)2-methyl phenol and 4-methyl phenol. 224

Fig. 4-70. X-ray diffraction analysis of Ni／MgO catalyst manufactured by coprecipitation method(methode)(calcined at 400℃ for 10 hr) 228

Fig. 4-71. X-ray diffraction analysis of Ni／MgO catalyst manufactured by coprecipitation method(methode)(calcined at 400℃ for 10 hr and reduced at 350℃, 10hr) 229

Fig. 4-72. X-ray diffraction analysis of Ni／MgO catalystd manufactured by coprecipitation method(methode)(calcined at 400℃ for 10 hr, reduced at 350℃ for 10hr and reacted at 650℃) 230

Fig. 4-73. Effect of reaction temp. in methane steam reforming reaction at each steam／carbon ratio 233

Fig. 4-74. Effect of MgO／Al₂O₃ ratio in methane steam reforming reaction (calcined at 700℃ for 1 hr and reduced at 250℃ for 3 hr) 235

Fig. 4-75. Effect of MgO／Al2O3 ratio in methane steam reforming reaction (calcined at 700℃ for 1hr and reduced at 350℃ for 3 hr) 236

Fig. 4-76. Effect of MgO／Al₂O₃ ratio in methane steam reforming reaction(calcined at 700℃ for 1 hr and reduced at 450℃ for 3 hr) 237

Fig. 4-77. Effect of calcination temp. on Ni／MgO catalyst in methane steam reforming reaction (precursor: nickel acetylacetonate, calcined for 6 hr and reduced at 450 ℃ for 5 hr) 240

Fig. 4-78. Effect of calcination temp. on Ni／MgO catalyst in methane steam reforming reaction (precursor: nickel acetylacetonate, calcined for 16 hr and reduced at 450 ℃ for 5hr) 241

Fig. 4-79. Effect of calcination time on Ni／MgO catalyst in methane steam reforming reaction (precursor: nickel acetylacetonate, calcined at 600℃ and reduced at 450℃ for 5hr) 242

Fig. 4-80. Effect of calcination time on Ni／MgO catalyst in ethane steam reforming reaction (precursor: nickel acetylacetonate, calcined at 1,000℃ and reduced at 450℃ for 5hr) 243

Fig. 4-81. Effect of calcination temp.on Ni／MgO catalyst in methane steam reforming reaction (calcined for 6 hr and reduced at 550 ℃ for 5 hr) 244

Fig. 4-82. Effect of calcination temp.on Ni／MgO catalyst in methane steam reforming reaction (calcined for 16 hr and reduced at 550 ℃ for 5 hr) 245

Fig. 4-83. Effect of calcination temp.on Ni／MgO catalyst in methane steam reforming reaction (calcined for 6 hr and reduced at 650 ℃ for 5 hr) 246

Fig. 4-84. Effect of calcination temp.on Ni／MgO catalyst in methane steam reforming reaction (calcined for 16 hr and reduced at 650 ℃ for 5 hr) 247

Fig. 4-85. Effect of calcination time on Ni／MgO catalyst in methane steam reforming reaction (calcined at 600 ℃ and reduced at 550 ℃ for 5 hr) 248

Fig. 4-86. Effect of calcination time on Ni／MgO catalyst in methane steam reforming reaction (calcined at 800 ℃ and reduced at 550 ℃ for 5 hr) 249

Fig. 4-87. Effect of calcination time on Ni／MgO catalyst in methane steam reforming reaction (calcined at 1,000 ℃ and reduced at 550 ℃ for 5 hr) 250

Fig. 4-88. Effect of calcination time on Ni／MgO catalyst in methane steam reforming reaction (calcined at 600 ℃ and reduced at 650 ℃ for 5hr) 251

Fig. 4-89. Effect of calcination time on Ni／MgO catalyst in methane steam reforming reaction (calcined at 800 ℃ and reduced at 650 ℃ for 5 hr) 252

Fig. 4-90. Effect of calcination time on Ni／MgO catalyst in methane steam reforming reaction (calcined at 1,000 ℃ and reduced at 650 ℃ for 5 hr) 253

Fig. 4-91. Effect of reduction temp. on Ni／MgO catalyst in methane steam reforming reaction (calcined at 600℃ for 6 hr) 254

Fig. 4-92. Effect of reduction temp. on Ni／MgO catalyst in methane steam reforming reaction (calcined at 800 ℃ for 6 hr) 255

Fig. 4-93. Effect of reduction temp. on Ni／MgO catalyst in methane steam reforming reaction (calcined at 1,000 ℃ for 6 hr) 256

Fig. 4-94. Effect of reduction temp. on Ni／MgO catalyst in methane steam reforming reaction (calcined at 600 ℃ for 16 hr) 257

Fig. 4-95. Effect of reduction temp. on Ni／MgO catalyst in methane steam reforming reaction (calcined at 800 ℃ for 16 hr) 258

Fig. 4-96. Effect of reduction temp. on Ni／MgO catalyst in methane steam reforming reaction (calcined at 1,000 ℃ for 16 hr) 259

Fig. 4-97. Cumulative volume vs. pore diameter of the catalyst calcined at each temp. for 6 hour. 263

Fig. 4-98. Cumulative volume vs pore diameter of the catalysts calcined at each temp. for 16 hr. 264

Fig. 4-99. Cumulative volume vs pore diameter of the catalysts calcined at 600℃ for 6 hr, reduced at 550℃ for 5 hr and reacted at 650 ℃. 265

Fig. 4-100. Cumulative volume vs pore diameter of the catalysts calcined at 800 ℃ for 6 hr, reduced at 550 ℃ for 5 hr and reacted at 650 ℃. 266

Fig. 4-101. Cumulative volume vs pore diameter of the catalysts calcined at 1,000℃ for 6 hr, reduced at 550℃ for 5 hr and reacted at 650 ℃ 267

Fig. 4-102. SEM photography of the catalyst calcined at 600℃ for 6 hr calcined catalyst 268

Fig. 4-103. SEM photography of the catalyst calcined at 600℃ for 6 hr, reduced at 550 ℃ for 5 hr and reacted at 650℃ 269

Fig. 4-104. SEM photography of the catalyst calcined at 800℃ for 6 hr 270

Fig. 4-105. SEM photography of the catalyst calcined at 800℃ for 6 hr, reduced at 550 ℃ for 5 hr and reacted at 650 ℃ 271

Fig. 4-106. SEM photography of the catalyst calcined at 1,000℃ for 6 hr 272

Fig. 4-107. SEM photography of the catalyst calcined at 1,000℃ for 6 hr, reduced at 550 ℃ for 5 hr and reacted at 650℃ 273

Fig. 4-108. Dependence of methane conversion on the catalyst length using CAT-1. 276

Fig. 4-109. Dependence of methane conversion on the catalyst length using CAT-2. 277

Fig. 4-110. Dependence of methane conversion on the catalyst length using CAT-3. 278

Fig. 4-111. Dependence of methane conversion on the catalyst length using CAT-4. 279

Fig. 4-112. Graphical procedure for finding reaction rate constant using CAT-1. 281

Fig. 4-113. Graphical procedure for finding reaction rate constant using CAT-2. 282

Fig. 4-114. Graphical procedure for finding reaction rate constant using CAT-3. 283

Fig. 4-115. Graphical procedure for finding reaction rate constant using CAT-4. 284

Fig. 4-116. Selectivity, Conversion vs. Temperature at F／W＝3720ml／hr.g-cat., S／C＝2／1 287

Fig. 4-117. Selectivity, Conversion vs. Space Velocity at Temp＝650℃, 289

Fig. 4-118. Selectivity, Conversion vs. S／C Ratio at T＝650℃, F／W＝3720ml／hr.g-cat. 292

Fig. 4-119. Fe／Cr 합금의 정상분극 특성(CO₂ gas) 293

Fig. 4-120. Fe／Cr 합금의 정상분극 특성(CO₂ + H ₂O) 294

Fig. 4-121. Cr 함유량에 따른 icorr(이미지참조) 변화 295

Fig. 4-122. Fe／Cr 합금계의 EIS spectra (CO₂ gas) 298

Fig. 4-123. Fe／Cr 합금계의 EIS spectra (CO₂+H₂O) 299

Fig. 4-124. Fe／Cr／Al 합금의 정상분극 특성 (CO₂ gas) 300

Fig. 4-125. Al 함유량에 따른 icorr(이미지참조) 변화 301

Fig. 4-126. Fe／Cr／Al 합금계의 EIS spectra (CO₂ gas) 302

Fig. 4-127. Al 함유량에 따른 Rcorr(이미지참조) 변화 303