표제지
요약
목차
1. 연구배경과 목적 24
1.1. 연구배경 24
1.2. 연구 목표 27
2. 서론 31
2.1. 폐플라스틱 발생 현황 31
2.2. 폐플라스틱 처리 방법 34
2.2.1. 기계적 재활용 (Mechanical Recycling) 36
2.2.2. 화학적 재활용 (Chemical Recycling) 38
2.2.3. 에너지 회수 (Energy Recovery) 42
2.2.4. 매립 (Landfill) 43
2.2.5. 대한민국의 폐플라스틱 처리 현황 44
2.3. 플라스틱 열분해 메커니즘 46
2.3.1. 폴리에틸렌 (Polyethylene: PE) 48
2.3.2. 폴리프로필렌 (Polypropylene: PP) 51
2.3.3. 폴리스타이렌 (Polystyrene: PS) 52
2.3.4. 폴리염화비닐 (Polyvinylchloride: PVC) 54
2.3.5. 그 외의 플라스틱 57
2.3.6. 반응속도 연구 (Kinetic Study) 59
2.4. 열분해 공정 운전 변수 61
2.4.1. 열분해의 분류 61
2.4.2. 반응온도 (Reaction Temperature) 64
2.4.3. 증기 체류시간 (Vapor Residence Time) 65
2.4.4. 촉매 (Catalyst) 66
2.4.5. 열원 (Heat Source) 67
2.4.6. 반응기의 종류 68
2.5. 유해물질 77
2.5.1. 플라스틱 첨가제 77
2.5.2. 할로겐 화합물 (Halogenated Compounds) 79
2.6. 열분해 상업화 공정 82
2.6.1. Sapporo Plastic Recycling (SPR) 83
2.6.2. Cynar 85
2.6.3. Recycling Technologies 86
3. 플라스틱 열분해 실험 88
3.1. 플라스틱 시료의 종류 및 특성 분석 88
3.1.1. 공업 분석 (Proximate Analysis) 88
3.1.2. 원소 분석 (Ultimate Analysis) 89
3.1.3. 연소 크로마토그래피 (Combustion Ion Chromatography: CIC) 90
3.1.4. 열중량 분석 (Thermogravimetric Analysis: TGA) 90
3.2. 열분해 공정 91
3.2.1. Continuous Two-stage Pyrolysis 91
3.2.2. Discontinuous Two-step Pyrolysis 94
3.3. 생성물 분석 방법 97
3.3.1. 가스 분석 97
3.3.2. 오일 분석 98
3.3.3. 염소 함량 분석 99
3.4. 실험 계획 100
4. 플라스틱 열분해 실험 결과 102
4.1. TG-FTIR 분석 102
4.1.1. 실험 조건 103
4.1.2. 결과 및 고찰 106
4.1.3. 소결 119
4.2. 개별 플라스틱의 열분해 121
4.2.1. 실험 조건 121
4.2.2. 결과 및 고찰 124
4.2.3. 소결 155
4.3. PVC가 포함된 플라스틱 혼합물의 열분해 158
4.3.1. 실험 조건 158
4.3.2. 결과 및 고찰 165
4.3.3. 소결 194
4.4. 생활계 폐플라스틱의 열분해 196
4.4.1. 실험 조건 196
4.4.2. 결과 및 고찰 199
4.4.3. 소결 207
5. 결론 208
6. 참고문헌 215
7. 부록 234
7.1. 시료 분석 234
7.2. GC-TCD와 -FID를 이용한 가스 분석 237
7.2.1. 분석 조건 237
7.2.2. 보정 상수 238
7.2.3. 일부 가스의 크로마토그램 242
7.3. GC-MS와 -FID를 이용한 오일 분석 244
7.3.1. 분석 조건 244
7.3.2. 보정 상수 245
7.4. TG-FTIR 247
7.5. 반응속도 연구 (Kinetic Study) 249
7.6. 주요 플라스틱 열분해 생성물의 가격 251
7.7. 2단 열분해 공정에서 오거 반응기의 역할 252
7.7.1. 상 변화 및 열전달의 영향 252
7.7.2. 진동 준위 및 결합 길이의 영향 257
7.7.3. 플라스틱의 분자량 감소의 영향 259
Abstract 261
Table 2.1. Technologies for plastics separation 37
Table 2.2. The tolerance of tar in gas for applications 41
Table 2.3. Activation energy ranges of different types of plastics 59
Table 2.4. Activation energies and frequency factors of different types of plastics 60
Table 2.5. Classification of pyrolysis methods with operating parameters 62
Table 2.6. Additives used in plastics 78
Table 2.7. Industrial plastic pyrolysis plants in operating 83
Table 4.1. TG-FTIR conditions with constant purging with PE. 104
Table 4.2. Pyrolysis conditions of the two-stage pyrolysis of individual plastic. 122
Table 4.3. Mass balance of two-stage pyrolysis of LDPE 125
Table 4.4. Mass balance of two-stage pyrolysis of PP 137
Table 4.5. Mass balance of two-stage pyrolysis of PS 144
Table 4.6. System energy balance of PS 5. 146
Table 4.7. Fuel properties of pyrolysis oil from PS and commercial fuels. 154
Table 4.8. Pyrolysis conditions of the two-stage pyrolysis of mixture of LDPE and PVC. 160
Table 4.9. Pyrolysis conditions of mixture of LDPE, PP, PVC. 161
Table 4.10. Mass balance of the two-stage pyrolysis of LDPE and PVC mixture 166
Table 4.11. Mass balance of the pyrolysis of LDPE, PP, PVC mixture using the auger reactor 181
Table 4.12. Mass balance of the pyrolysis of plastic mixture and solid products from LPP 3 and 5 using the fixed bed reactor 185
Table 4.13. Mass balance of the continuous two-stage pyrolysis of LDPE, PP, PVC mixture 188
Table 4.14. Chlorine contents of oils obtained from discontinuous two-step pyrolysis and continuous two-stage pyrolysis 192
Table 4.15. Pyrolysis conditions of municipal plastic waste. 198
Table 4.16. Mass balance of the pyrolysis of municipal plastic waste using an auger reactor 199
Table 4.17. Mass balance of the pyrolysis of municipal plastic waste using a fixed bed reactor 201
Table 4.18. Chlorine contents of oils obtained from the pyrolysis of municipal plastic waste 204
Table 4.19. Possible heteroatoms-containing compounds in pyrolysis oils obtained from the pyrolysis of municipal plastic waste. 206
Table 7.1. Major characteristics of feed materials. 234
Table 7.2. Specification and analysis conditions of GC-TCD for product gas. 237
Table 7.3. Specification and analysis conditions of GC-FID for product gas. 238
Table 7.4. Relative response factor of gas compounds. 241
Table 7.5. Specification and analysis conditions of GC-MS for oil. 244
Table 7.6. Specification and analysis conditions of GC-FID for oil. 245
Table 7.7. Representative relative response factors of oil compounds. 246
Table 7.8. Relative response factor of oil compounds. 248
Table 7.9. Price of commercial petrochemicals possibly produced from plastic pyrolysis (accessed Sep 22, 2022). 251
Figure 2.1. Cumulative plastic waste generated, disposed, incinerated, and recycled 31
Figure 2.2. International and national initiatives targeting plastic waste 32
Figure 2.3. Plastic waste treatment methods in accordance with recycling routes 34
Figure 2.4. Material flow diagram of plastic packaging waste in South Korea 44
Figure 2.5. PE classification 48
Figure 2.6. Reaction pathway of LDPE pyrolysis 49
Figure 2.7. Cyclization pathway 50
Figure 2.8. Diels-Alder reaction and aromatization pathway 50
Figure 2.9. Reaction pathway of PP pyrolysis 51
Figure 2.10. Reaction pathway of PS pyrolysis 53
Figure 2.11. Initiation pathway of PVC pyrolysis, (a) HCl and (b) Cl- release[이미지참조] 55
Figure 2.12. Reaction pathway of PVC pyrolysis to form aromatic hydrocarbons 56
Figure 2.13. Reaction pathway of PET pyrolysis 57
Figure 2.14. Reaction pathway of PMMA pyrolysis 58
Figure 2.15. Comparison of heating direction of conventional and microwave-assisted pyrolysis 67
Figure 2.16. Comparison of reactor for plastic pyrolysis 70
Figure 2.17. Strength and attractiveness of pyrolysis technologies 74
Figure 2.18. Comparison of fluidized and spouted bed reactors 75
Figure 2.19. Formation of chlorinated hydrocarbons during pyrolysis of mixed plastic containing PVC 80
Figure 2.20. Schematic diagram of technical process of SPR 84
Figure 2.21. Schematic diagram of technical process of Cynar 85
Figure 2.22. Schematic diagram of technical process of Recycling Technologies 86
Figure 3.1. Diagram of two-stage pyrolysis process. 92
Figure 3.2. Diagram of the auger pretreatment process. 95
Figure 3.3. Diagram of the fixed bed pyrolysis process. 96
Figure 3.4. Research flow chart of the study 100
Figure 4.1. Diagram of TG-FTIR. 104
Figure 4.2. (a) Thermogravimetry curves and (b) FT-IR absorbance spectra at degradation temperatures of PE with constant purging. 108
Figure 4.3. FT-IR spectra of PE at reaction temperatures without purge gas until the reaction temperature in the wavenumber range of (a) 4000-650 and (b) 1100-650cm-1[이미지참조] 110
Figure 4.4. FT-IR spectra of PP at reaction temperatures without purge gas until the reaction temperature in the wavenumber range of (a) 4000-650 and (b) 1100-650cm-1[이미지참조] 112
Figure 4.5. FT-IR spectra of PS at reaction temperatures without purge gas until the reaction temperature in the wavenumber range of (a) 4000-650 and (b) 1100-650cm-1[이미지참조] 114
Figure 4.6. FT-IR spectra of PET at reaction temperatures without purge gas until the reaction temperature. 116
Figure 4.7. FT-IR spectra of waste vinyl at reaction temperatures without purge gas until the reaction temperature in the wavenumber range of (a) 4000-650 and (b) 1100-650 cm-1.[이미지참조] 118
Figure 4.8. Comparison of chain dissociation of PE in (a) conventional fluidized bed reactor and (b) two-stage pyrolysis reactor. 127
Figure 4.9. Formation of styrene from 1,3-butadiene. 130
Figure 4.10. Temperature programs of auger reactor-off and -on mode in two-stage pyrolysis process. 132
Figure 4.11. Plots of ln (dx/dt) vs. 1000/T of (a) auger reactor-on and (b) -off modes. 134
Figure 4.12. Plots of logβ vs. 1000/T of (a) auger reactor-on and (b) -off modes. 136
Figure 4.13. Comparison of oils from the two-stage pyrolysis of PP. 140
Figure 4.14. Oil compositions according to the reactors' temperatures. 148
Figure 4.15. Comparison of BTEX and styrene yield with catalytic pyrolysis of PS. 150
Figure 4.16. Yield of styrene dimer, its derivatives and trimer according to the fluidized bed reactor temperature. 152
Figure 4.17. Formation mechanisms of major styrene dimer derivatives. 152
Figure 4.18. Images of waste LDPE, PP, PVC and recovered sample from LPP 1-5. 163
Figure 4.19. GC-MS total ion chromatograph of oil from the auger reactor (LP 5). 169
Figure 4.20. Content of major gas compounds obtained from the fluidized bed reactor. 171
Figure 4.21. Chlorine contents in oils from the auger and fluidized bed reactors. 173
Figure 4.22. (a) TG and (b) DTG curves of plastic mixtures based on PVC content. 176
Figure 4.23. Absorbance spectra of waste plastic mixtures in TG-FTIR at (a) 300 ℃ and (b) 500 ℃. 178
Figure 4.24. Chlorine contents of feed materials and solid product obtained from the auger reactor. 183
Figure 4.25. Oil compositions derived from the fixed bed and two-stage pyrolysis. 190
Figure 7.1. TG and DTG curves of (a) LDPE, (b) PP, (c) PS, and (d) PVC. 235
Figure 7.2. GC-TCD chromatogram of product gas of PP 7. 242
Figure 7.3. GC-FID chromatogram of product gas of PP 7. 242
Figure 7.4. GC-TCD chromatogram of product gas of PS 6. 243
Figure 7.5. GC-FID chromatogram of product gas of PS 6. 243
Figure 7.6. FT-IR peak of (a) toluene and (b) benzene in vapor phase. 247
Figure 7.7. Plastic particle size of (a) auger reactor-off and (b) auger reactor-on modes entering the fluidized bed reactor. 253
Figure 7.8. Temperature dependence of Raman frequencies of peak presents at 182 cm-1[이미지참조] 257
Figure 7.9. Thermal expansion of C-C bond length 258
Figure 7.10. Molecular weight of virgin and preheated PS. 260