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《废弃塑料在超临界水中的资源化利用》共五章，首先阐述了废弃塑料的危害、传统处理方法的弊端、超临界水处理技术的原理、超临界水中废弃塑料资源化利用技术的研究进展。其次介绍了材料种类及表征、实验方法及流程、产物的分析方法。随后从超临界水气化、液化、固定二氧化碳、污染物共气化、制备疏水材料等多个层面出发，对多种热塑性和热固性塑料的资源化利用技术进行剖析。*后对国内外的塑料处理政策进行总结，说明了该技术未来的研究方向和挑战。

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精彩书评

希望引入新技术来解决现有废弃塑料处理问题，为相关领域的从业者和科研人员提供新的思路

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精彩书摘

CHAPTER 1
　　Background introduction
　　With the development of science and technology， the application of plastic has become increasingly widespread. Plastic is an organic polymer synthetic material widely used in agriculture， industry， construction， and other fields because of its easy processing， transportation， storage， and chemical stability [1]. Plastic was once considered to be one of the greatest inventions in the world. With the increasing demand for human life， traditional materials such as metak， wood， and paper are replaced by plastic in food packaging， bottled kettles， agricultural mulch， building materials， and other products [2]. With the wide application of plastic products， global annual plastic production is gradually increasing. Since the 1960s， plastic products have grown at an annual rate of about 8.7% [3]. Annual global plastic production from 1950 to 2018 is shown in Fig. 1.1. Global plastic increased from 1.5 million tons in 1950 to 359 million tons in 2018.
　　1.1 Current situation and hazards of plastic waste
　　While people enjoy the convenience brought by plastic products， the harm caused by plastic products has gradually become a problem plaguing humanity. In large-scale production， use， and disposal of plastics by humans， toxic substances added to plastic inevitably affect human health. Due to its easy aging， poor heat resistance， and flam-mability， plastic has a limited use time. Intense consumption and rapid scrapping of plastic products have led to significant waste plastic accumulation. The pollution caused by the accumulation of plastic waste poses an increasingly severe threat to the ecological environment.
　　It is clear from the study that the recycling rate and incineration rate of plastic waste have greatly improved compared to 1950 [4]. It can be seen that people’s awareness of the disposal and utilization of waste plastic has increased significantly. In addition， the researchers concerned provide statistics on the global production and final destiny of polymer resins， synthetic fibers， and additives in 2015 [4]. Of these plastics， 79% are discarded in landfills or the natural environment， 12% are incinerated， and only 9% are recycled [5]. If the current trend continues， it is predicted that by 2050， 26，000 Mt of primary plastic will be produced， while 9000 Mt of waste plastic will be recycled， 12，000 Mt of waste plastic will be incinerated， and 12，000 Mt of waste plastic will be discarded in landfills or the natural environment. The direct result of the huge consumption of plastic products is a dramatic increase in plastic waste that will seriously threaten the healthy development of the ecological environment and human society.
　　The complex decomposition of plastics and people’s unreasonable waste plastic treatment have brought great harm to human society and the natural environment.
　　1.1.1 Pollution to the natural environment
　　With the mass production and application of plastic， the amount of plastic entering the environment cannot be underestimated. By 2015，the amount of plastic detected in the global environment was believed to be 60—99 Mt. It is estimated that by 2060，the total amount of plastic in the environment will be quadruple that of 2015 [6].
　　The waste plastic in the environment is mainly microplastic. The particle size of microplastic ranges from a few microns to a few millimeters. It is a mixture of heterogeneous plastic particles with various shapes that is often difficult to distinguish with the naked eye. Microplastic contains organic pollutants， including polychlorinated biphenyls， polycyclic aromatic hydrocarbons (PAHs)， petroleum hydrocarbons， poly— brominated diphenyl ethers， alkylphenols， and bisphenol A [7]. Since ordinary plastic is not biodegradable， it will break into smaller plastic fragments or microplastic. Microplastic is dispersed along the terrestrial structure and washed into the deep sea via gravity flow [8]. Plastic is transferred in water and terrestrial environments in the manner shown in Fig. 1.2. This section will introduce the hazards of waste
　　1.1.1.1 The hazards of plastic on the water environment
　　Plastic waste harms the marine environment. The amount of plastic in the ocean is huge. More than 5 trillion plastic fragments are on the world’s sea surface， and more than 250，0001 are floating on the sea [9]. The plastic in the ocean is mainly microplastic. In Fig. 1.3， the formation process and impact of microplastic in the ocean are shown. Waste plastic on the sea surfece is exposed to the sea for a long time. Under die action of solar radiation and wave impact， the plastic degrades， embritdes， and fiag-ments， forming microplastic [10]. It can be seen that waste plastic on the ocean surface is mainly microplastic， that is， plastic particles with a diameter of less than 5 mm [11].
　　Waste plastic has a signicant impact on the marine ecosystem. Due to the chemical additives contained in plastic， plastic poses a huge threat t

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Contents
List of figures ix
List of tables xix
Foreword xxi
Acknowledgement xxiii
Abbreviations xxv
1.Background introduction 1
1.1 Current situation and hazards of plastic waste 1
1.1.1 Pollution to the natural environment 2
1.1.2 A threat to human health 4
1.1.3 Cause a waste of resources 5
1.2 Traditional treatment methods6
1.2.1 Landfill treatment 7
1.2.2 Mechanical recovery 7
1.2.3 Incineration method 8
1.2.4 Thermal decomposition 8
1.3 Supercritical water technology 9
1.3.1 Supercritical water characteristics 9
1.3.2 Resource utilization of waste plastics in supercritical water 10
References 20
2.Analysis of types of plastics 29
2.1 Introduction to raw materials 29
2.1.1 Polycarbonate plastic 29
2.1.2 Polypropylene plastic 29
2.1.3 Acrylonitrile butadiene styrene plastic 29
2.1.4 Polyethylene terephthalate plastic 31
2.1.5 High-impaa polystyrene plastic 31
2.1.6 Polystyrene plastic 31
2.1.7 Polyethylene plastic 32
2.1.8 Urea—formaldehyde plastic 32
2.1.9 Circuit board 32
2.1.10 Lignite 33
2.1.11 Soda lignin 33
2.1.12 Artificial seawater 33
2.1.13 Formic add and hydrochloric acid solvent 33
2.2 Material characterization 34
2.2.1 Elemental and proximate analysis 34
2.2.2 Thermogravimetric analysis 34
2.3 Experimental bench 40
2.3.1 Quartz tube reactor 40
2.3.2 Batch kettle reactor 41
2.4 Product analysis 42
2.4.1 Gas phase products 42
2.4.2 Liquid phase products 43
2.4.3 Solid phase products 45
References 46
3.Resource utilization of thermoplastics in supercritical water 47
3.1 Gasification 47
3.1.1 Experimental investigation on gasification characteristics of polycarbonate microplastics in supercritical water 47
3.1.2 Experimental study on gasification performance of polypropylene plastics in supercritical water 58
3.1.3 Experimental investigation on in-situ hydrogenation induced gasification characteristics of acrylonitrile butadiene styrene

microplastics in supercritical water 74
3.1.4 Experimental investigation on gasification characteristics of polyethylene terephthalate microplastics in supercritical water 85
3.1.5 Experimental investigation on gasification characteristics of high impact polystyrene plastics in supercritical water 99
3.2 Liquefaction 110
3.2.1 Hydrothermal liquefaction of polycarbonate plastics in sub-/supercritical water and an exploration of reaction pathways 110
3.3 Liquefaction reaction pathways exploration 123
3.3.1 Liquefaction kinetics of polycarbonate 126
3.4 Carbon dioxide fixation 141
3.4.1 In the supercritical water/C02 environment 141
3.4.2 In C02 environment 147
3.5 Coordinated treatment of pollutants 157
3.5.1 Hydrogen/methane production from supercritical water gasification of lignite coal with plastic waste blends 157
3.5.2 Cogasification of plastic wastes and soda lignin in supercritical water 169
3.6 Preparation of hydrophobic materials 182
3.6.1 Hydrophobic behavior 183
3.6.2 Microstructure 186
3.6.3 Functional groups 191
References 193
4.Resource utilization of thermosetting plastics in supercritical water 201
4.1 Hydrogen-rich syngas production by gasification of urea—formaldehyde
plastics in supercritical water 201
4.1.1 Effect of reaction temperature 201
4.1.2 Effect of reaction time 202
4.1.3 Effect of feedstock mass fraction 203
4.1.4 Effect of reaction pressure 204
4.1.5 Compared with the polystyrene plastics 205
4.1.6 Reaction analysis 207
4.1.7 Kinetic study 207
4.1.8 Conclusions 209
4.2 Resource utilization of circuit boards 210
4.2.1 Effect of reaction temperature 210
4.2.2 Effect of the reaction time 215
4.2.3 Effect of feedstock concentration 219
4.2.4 Effect of additive 220
4.2.5 Conclusion 222
References 223
5.Development prospects for resource utilization of waste plastics 227
5.1 Necessity of recycling waste plastics 227
5.1.1 Biodiversity conservation 228
5.1.2 Maintaining soil fertility 229
5.1.3 Saving resources 231
5.2 Comprehensive treatment countermeasures of waste plastics 232
5.2.1 Policy 232
5.2.2 General situation of domestic and foreign waste plastic treatment 237
5.2.3 Existing shortcomings 239
5.2.4 Improvement measures 240
5.3 Prospect of waste plastics treatment with supercritical water 242
5.3.1 Existing problems 243
5.3.2 Future development direction 244
References 245
Index 249
List of figures
Figure 1.1 Global annual production of plastic.1
Figure 1.2 The transfer of microplastic in different environments.3
Figure 1.3 The formation and influence of microplastic in the ocean.3
Figure 1.4 Main treatment methods for waste plastic.6
Figure 2.1 Chemical structure of(A)BPA;(B)DPC;(C)PC.BPA，bisphenol A;30 DPC，diphenyl carbonate;PC，polycarbonate.
Figure 2.2 Molecular structure of ABS plastic here.ABS，acrylonitrile butadiene styrene.30
Figure 2.3 Chemical structure of polyethylene terephthalate(PET).31
Figure 2.4 Molecular structure of HIPS plastic.HIPS，high-impact polystyrene.31
Figure 2.5 Molecular structure of PS plastic.PS，polymer synthesized.32
Figure 2.6 Chemical structures of(A)hydroxymethylurea;(B)1，3-32 bishydroxym

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