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제1장 서론 21

제1절 연구 개발 배경 및 필요성 21

제2절 수소의 공급과 수요 전망 22

제2장 수소 PSA공정과 흡착공정의 이론적 해석 25

제1절 수소 PSA 공정 25

제2절 COG 처리용 수소 PSA 공정 34

제3절 수학적 모델링(Modeling)과 다층흡착탑의 거동특성 38

1. 물질수지 38

2. 에너지 수지식(Energy Balances) 43

3. 운동량수지식(Momentum Balance) 47

4. 흡착속도(Adsorption Rate) 48

5. 경계조건(Boundary Conditions) 49

6. 다층흡착탑의 수치해석법 50

제3장 PSA 공정 실험 53

제1절 Bench 및 Pilot PSA System 실험장치 53

1. Bench Scale PSA System. 53

2. Pilot Scale PSA System 57

제2절 공정 운전 63

1. Lab Scale 공정 63

2. Pilot Plant 공정 70

3. 공정설계를 위한 기초자료 72

제4장 Bench Scale PSA공정 해석 77

제1절 파과 실험 77

제2절 동적 평형 상태에서 COG PSA 공정의 거동 89

제3절 6-step과 7-step공정의 비교 97

제4절 공정변수(Operating Variable)의 영향 99

1. 흡착압력과 충전비의 영향 99

2. 공급유량과 충전비의 영향 101

3. 정화량과 충전비의 영향 103

제5절 다층흡착탑의 흡착특성 및 고찰 115

제5장 Pilot Plant PSA공정 해석 124

제1절 단층 흡착탑 공정 127

1. 정화유량의 영향 134

2. 공급유량의 영향 134

3. 흡착단계 시간의 영향 135

4. Backfill Step의 영향 136

제2절 활성탄과 제올라이트를 이용하는 Double Layer 흡착탑 공정 137

1. 흡착시간의 영향 139

2. 공급 유량의 영향 139

3. Backfill Step의 영향 140

제3절 분자체 탄소와 제올라이트를 이용한 Double Layer공정 실험 140

1. 공급유량의 영향 143

2. 흡착시간의 영향 143

3. 정화량의 영향 143

4. Backfill Step의 영향 144

제4절 Triple Layered Bed(CMS:5A:13X＝40:50:40) 실험결과 145

제6장 ADSIM에 의한 Pilot Plant 모사 결과 146

제1절 Two-bed PSA공정 146

제2절 Four-bed PSA 공정 159

제7장 결론 171

참고문헌 176

[부록] 181

Table 1. 국내 고순도 수소의 수요추이 24

Table 2. Bench PSA System의 흡착탑 및 흡착제 사양 54

Table 3. Pilot Plant의 흡착탑 및 흡착제 사양 59

Table 4. Bench실험 Feed기체의 조성 65

Table 5. PSA공정의 전처리 과정을 거치기 전의 COG 조성 71

Table 6. 그 밖의 불순물의 조성 71

Table 7. 공정의 각 스텝별 시간(Step Duration, 단위: 초) 72

Table 8. Stoichiometric breakthrough times, ts(이미지참조). 89

Table 9. P／F ratios of experimental runs 115

Table 10. 전처리 후의 COG조성 125

Table 11. 단층(Zeolite 5A) 흡착탑 two-bed PSA 공정 실험 결과 132

Table 12. 대표적인 수소 PSA의 공정성능 비교 132

Table 13. Double Layered Bed(AC:5A＝50:80) 실험결과 138

Table 14. Double Layered Bed(CMS:5A＝40:90) 실험결과 142

Table 15. Two-bed 공정의 Performance 비교 148

Table 16. Four-bed Pilot Process의 모사결과 160

Figure 1. Union-Carbide four-bed PSA system. 29

Figure 2. Union-Carbide Polybed PSA system for hydrogen purification. 30

Figure 3. Air Product & Chemicals PSA system for simultaneous(simulataneous) production of H₂ and CO₂ from reformer gases. 31

Figure 4. COG 기체의 전처리 과정 36

Figure 5. PSA 공정의 수소생성물 후처리 과정 37

Figure 6. Simulated (a) concentration profiles at t₁and (b) characteristic diagram for the activated carbon bed. 44

Figure 7. Simulated (a) concentration profiles at ta(이미지참조) and (b) characteristic diagram for the double layered bed. 45

Figure 8. Simulation scheme of a layered bed as a bed made of two single adsorbent beds 52

Figure 9. Schematic diagram of a two-bed PSA system. 55

Figure 10. Photo of Bench scale PSA system. 56

Figure 11. Photo of pilot scale PSA system (포항제철 현장) 60

Figure 12. Pilot PSA system 흡착탑의 상세구조 61

Figure 13. Pilot plant 의 분석 및 제어장치 62

Figure 14. Intouch 에 의해서 구현된 PSA 공정 제어 프로그램 66

Figure 15. Schematic diagram of a four-bed pilot PSA system 67

Figure 16. Flow diagram and cycle sequence of a six-step PSA process. Values in the parenthesis are step times. 68

Figure 17. Flow diagram and cycle sequence of a seven-step PSA process Values in the parenthesis are step times. 69

Figure 18. Adsorption isotherms of CH₄, CO, N₂, CO₂, and H₂ on activated carbon at 293.15 K. 75

Figure 19. Adsorption isotherms for CH₄, CO, N₂, CO₂, and H₂ on zeolite 5A at 293.15 K. 76

Figure 20. Breakthrough curves of a zeolite 5A bed under 10 atm adsorption pressure and 8.6 L／min feed rate (Adsorption bed was initially saturated with H₂ at 299.15 K and 10 atm). 80

Figure 21. Breakthrough curves of an activated carbon bed under 10 atm adsorption pressure and 8.6 L／min feed rate (Adsorption bed was initially saturated with H₂ at 300.15 K and 10 atm). 81

Figure 22. Breakthrough curves of a layered bed (c.r.＝0.65) under 10 atm adsorption pressure and 8.6 L／min feed rate (Adsorption bed was initially saturated with H₂ at 299.15 K and 10 atm). 82

Figure 23. Breakthrough curves of a layered bed (c.r.＝0.32) under 10 atm adsorption pressure and 8.6 L／min feed rate (Adsorption bed was initially saturated with H₂ at 299.15 K and 10 atm). 83

Figure 24. Profiles of concentration and temperature at (a) 180 s and (b) 300 s from the beginning of breakthrough experiment for an activated carbon bed. 84

Figure 25. Profiles of concentration and temperature at (a) 180 s and (b) 300 s from the beginning of breakthrough experiment for a zeolite 5A bed 85

Figure 26. Profiles of concentration and temperature at (a) 180 s and (b) 300 s from the beginning of breakthrough experiment for a layered bed (c.r.＝0.32). 86

Figure 27. Profiles of concentration and temperature at (a) 180 s and (b) 300s from the beginning of breakthrough experiment for a layered bed (c.r.＝0.65). 87

Figure 28. Effect of carbon ratio on stoichiometric breakthrough time, ts(이미지참조). 88

Figure 29. DySAP 모사기의 초기화면 92

Figure 30. DySAP 모사기의 데이터 입력화면 93

Figure 31. DySAP 모사기에 의한 결과출력의 한 예 94

Figure 32. Cyclic approach to a dynamic steady state of gas composition of effluent stream for a layered bed process with 0.65 carbon ratio under 10 atm adsorption pressure, 8 L／min feed rate, and 0.7 L／min purge rate. 95

Figure 33. Transient variation of temperature at (a) z＝10cm, (b) z＝30cm, (c) z＝50 cm, and (d) z＝75 cm for a layered bed process with 0.65 carbon ratio under 10 atm adsorption pressure, 8 L／min feed rate, and 0.7 L／min purge rate. 96

Figure 34. Effects of feed rate on H₂ purity and recovery for six- and seven-step processes using double layered bed (c.r.＝0.35) under 11 atm adsorption pressure and 0.7 L／min purge rate. 98

Figure 35. Effects of adsorption pressure on (a) H₂ purity and (b) H₂ recovery for activated carbon bed process, zeolite 5A bed process, and double layered bed (c.r.＝0.5) process under 7 L／min feed rate and 0.7 L／min purge rate. 105

Figure 36. Effects of carbon ratio on (a) H₂ purity and (b) H₂ recovery at three adsorption pressures, 7 L／min feed rate, and 0.7 L／min purge rate. 106

Figure 37. Average composition variation of products with carbon ratio under 5 atm adsorption pressure, 7 L／min feed rate, 0.7 L／min purge rate. 107

Figure 38. Effects of carbon ratio and adsorption pressure on (a) H₂ purity and (b) H₂ recovery under 7 L／min feed rate and 0.7 L／min purge rate. 108

Figure 39. Effects of feed rate on (a) H₂ purity and (b) H₂ recovery for activated carbon bed process, zeolite 5A bed process and double layered bed (c.r.＝0.5) process under 11 atm adsorption pressure and 0.7 L／min purge rate. 109

Figure 40. Effects of carbon ratio on (a) H₂ purity and (b) H₂ recovery at three feed rates, 11 atm adsorption pressure, and 0.7 L／min purge rate. 110

Figure 41. Effects of carbon ratio and feed rate on (a) H₂ purity and (b) H₂ recovery under 10 atm adsorption pressure and 0.7 L／min purge rate. 111

Figure 42. Effects of purge rate on (a) H₂ purity and (b) H₂ recovery for activated carbon bed process, zeolite 5A bed process, and double layered bed (c.r.＝0.5) process under 11 atm adsorption pressure and 7 L／min feed rate. 112

Figure 43. Effects of carbon ratio on (a) H₂ purity and (b) H₂ recovery at three purge rates, 11 atm adsorption pressure, and 7 L／min feed rate. 113

Figure 44. Effects of carbon ratio and purge rate on (a) H₂ purity and (b) H₂ recovery under 10 atm adsorption pressure and 7 L／min feed rate. 114

Figure 45. Concentration profiles of gas phase at the end of adsorption step for (a)activated carbon bed,... 120

Figure 46. Concentration profiles of (a) activated carbon bed process and (b) zeolite 5A bed process at the end of adsorption step at cyclic steady state under 7 atm adsorption pressure, 7 L／min feed rate, and 0.7 L／min purge rate. 121

Figure 47. Concentration profiles of double layered bed processes with (a) 0.5 carbon ratio and (b) 0.7 carbon ratio at the end of adsorption step at cyclic steady state under 7 atm adsorption pressure, 7 L／min feed rate, and 0.7 L／min purge rate. 122

Figure 48. Temperature variations with time at cyclic steady state for a layered bed (c.r.＝0.65) PSA process under 8 atm adsorption pressure, 7 L／min feed rate, and 0.7 L／min purge rate. 123

Figure 49. ADSIM 의 full flowsheet sheet 128

Figure 50. ADSIM의 Cycle Definition File 129

Figure 51. ADSIM 의 cycle report file 130

Figure 52. 두개의 탑을 사용하는 pilot PSA 공정의 개념적 flow diagram과 pressure history 133

Figure 53. Predicted pressure history for a pilot plant at a cyclic steady state for a 6-step process using two zeolite beds. 149

Figure 54. Experimental pressure history at a cyclic steady state of a 6-step pilot process using two zeolite beds. 150

Figure 55. Concentration profiles at the end of the adsorption step for a 6-step pilot process using two zeolite beds. 151

Figure 56. Temperature variations with time at cyclic steady state for a zeolite bed PSA process under 10 atm adsorption pressure, 7.1 N㎥／h feed rate, and 0.8 N㎥／h purge rate. 152

Figure 57. H₂ concentration profile at the end of each step at cyclic steady state 153

Figure 58. Temperature history of a 6-step pilot process using two zeolite beds at cyclic steady state. 154

Figure 59. H₂ concentration profiles at the end of each step at cyclic steady state for a 6-step pilot process using two AC／5A double layered beds 155

Figure 60. Concentration profiles at the end of adsorption step for a 6-step pilot process using two AC／5A double layered beds. 156

Figure 61. Temperature histories at cyclic steady state for a 6-step pilot process of Run27 using two AC／5A double layered beds. 157

Figure 62. Temperature histories at cyclic steady state for a 6-step pilot process using two AC／5A double layered beds under 10 atm adsorption pressure, 7.1 N㎥／h feed rate, and 0.8 N㎥／h purge rate 158

Figure 63. Predicted pressure history at cyclic steady state for a 9-step pilot process using four AC／5A double layered beds. 164

Figure 64. Concentration profiles in the gas phase at the end of adsorption step for a 9-step pilot process using two AC／5A double layered beds 165

Figure 65. H₂ concentration profiles at the end of each step at cyclic steady state for a 9-step pilot process using four AC／5A double layered beds 166

Figure 66. Schematic of the process cycle for a four-bed nine-step process 167

Figure 67. Predicted pressure history at cyclic steady state for a 8-step pilot process using four AC／5A double layered beds. 168

Figure 68. Concentration profiles in the gas phase at the end of adsorption step for a 8-step pilot process using two AC／5A double layered beds 169

Figure 69. H₂ concentration profiles at the end of each step at cyclic steady state for a 8-step pilot process using four AC／5A double layered beds. 170