【作者】 伍跃辉；

【导师】 孙德智；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2013， 博士

【摘要】 由于塑料的难降解性和使用量的逐年增大，废塑料对环境的潜在影响越来越严重。但是，废塑料作为一种资源可以加以资源化回收利用。近年来，国内外已开发出很多种废塑料资源化技术，为合理的发展废塑料的资源化产业，需要采用科学的方法从经济、社会和环境等方面对这些资源化技术进行评估，确定废塑料资源化技术的优先性，其中废塑料资源化过程中对环境的潜在影响需要进行生命周期分析。基于此，本文研究了废塑料资源化技术的评估方法，并对几种废塑料典型资源化技术进行了生命周期分析。本文综合分析了废塑料资源化技术对经济、社会和环境三个方面的影响，构建了三级评价指标，通过层次分析确定了各级指标的权重，采用德尔菲法赋值给每个指标。采用该评价体系分别对四种废塑料资源化技术进行了评估，结果表明，“直接再生”是废聚丙烯、废聚乙烯、废聚氯乙烯三种废塑料的“最优先”推荐的资源化技术，“共焦化”是废聚苯乙烯最优先推荐的资源化技术。评价结果表明，废塑料资源化过程中对环境的潜在影响不容忽视，需要引起足够的重视。本文较为系统地研究了废塑料资源化过程中对环境潜在影响的评价方法，确定了废塑料资源化生命周期评价模型的各项参数，包括：废塑料资源化的环境影响因子的特征化；废塑料资源化生命周期评价标准化基准值；环境负荷权重因子等。在此基础上，构建了可定量分析废塑料资源化过程中对环境的潜在影响的生命周期评价方法，并采用不确定性分析的方式对数据质量进行了检查，评价了四种废塑料资源化过程中对环境的潜在影响。研究结果表明，废塑料“直接再生”资源化技术中，“干燥阶段”对环境的潜在影响最大，是污染控制的重点环节，对环境潜在影响类型主要为“酸化”、“烟尘&粉尘”和“全球变暖”，三项占总环境潜在影响负荷的89.5%；废塑料的“催化裂解”资源化技术对环境的潜在影响类型主要是“臭氧耗竭”、“全球变暖”和“酸化”，产污的重点环节是“催化改质”阶段；废塑料“氢化裂解”资源化技术对环境的潜在影响类型主要为“全球变暖”、“烟尘&粉尘”，产污的重点环节是“氢化裂解”阶段；废塑料“共焦化”资源化技术的“入炉炼焦”阶段对环境的潜在影响最大，占总环境影响的93.5%，是污染控制的重点环节，该技术对环境的潜在影响类型主要是“酸化”、“烟尘&粉尘”和“全球变暖”影响。废塑料垃圾衍生燃料焚烧发电资源化技术的“锅炉焚烧”环节占总环境影响潜值99.6%，是污染控制的重点环节，该技术对环境的影响类型主要为“全球变暖”和“酸化”。废聚氯乙烯“高温焚烧”和“真空裂解”过程中，对环境的影响类型主要为固体废物，其环境影响负荷占总环境影响负荷分别为99.8%和99.6%，污染控制的重点环节分别是焚烧单元和裂解单元。本文从废塑料资源化技术产业化、废塑料资源化技术的环境管理、废塑料资源化技术的经济政策和废塑料资源化技术的中远期发展等方面提出了发展策略和建议。更多还原

【Abstract】 Because of the difficulty of degradable, the waste plastics become an increasinglyprominent environmental problem. On the other hand, the waste plastics is a kind ofrecycling resources. In recent years, the waste plastic recycling methods had developedrapidly in the world. It is necessary to use scientific methods to carry out assessment forthese waste plastic recycling methods. For considering the environmental potentialimpact of the plastic recycling process, life cycle assessment is a good choice forworking. This paper focus on evaluation method and life cycle assessment of wasteplastic recycling technology.In this paper, considering the effect of waste plastic recycling technology in threeaspects of economy, society and environment, we established the waste plastic recyclingtechnology three levels assessment method system based on the analytic hierarchyprocess and Delphi method. The first job is to establish an index system andcomprehensivly consider the weight of the third level indexes for waste plastic recyclingtechnology evaluation by the analytic hierarchy process. The next, gives the resourceoptimization scheme of the four main categories of waste plastics through the Delphimethod. Through the established evaluation method, found that “direct regeneration” isthe waste polypropylene, waste polyethylene, waste polyvinyl chloride of three kinds ofwaste plastics “top priority” recommended resource technology; for the wastepolystyrene, because of its special physical and chemical properties,"co-carbonization"will be the future priority resource technology. The evaluation results show that, theprocess of waste plastic recycling in the potential impact on the environment can not beignored, need to cause enough attention.The potential impacts of the plastics recycling process on the environment weresystematic researched in this paper. The parameters of the existing model wereimproved by confirming the environmental impact classification factors, the equivalentcoefficient and the weighting factor. On this basis, results uncertainty and potentialimpact of four kinds of waste plastics recycling technology of typical process on theenvironment were analyzed quantitatively.The evaluation results show that, in the “direct regeneration” approach, the mainenvironmental impacts (89.5%of the total environmental impacts) of the wastepolypropylene direct regeneration recycling technology were “acidification”,“dust” and“global warming”. The “dry stage” of the direct regeneration was the key link ofpollution control. In the “catalytic cracking” approach, the main environmental impactsof the catalytic cracking were “ozone depletion”,“global warming” and “acidification”.The “catalytic reforming stage” of the process was the key link of pollution control. Inthe “hydrocracking” process, the main environmental impacts of the hydrocracking were “global warming”,“dust”,“ozone depletion” and “acidification”. The“hydrocracking stage” of the process was the key link of pollution control. For“co-carbonization” process, the “coking stage” of the process was the key link ofpollution control and93.5%of the total environmental impacts of “co-carbonization”were “global warming”,“dust” and “acidification”. For “refuse derived fuel (RDF)”technology, the “combustion stage” of the process was the key link of pollution controland99.6%of the total environmental impacts of “RDF” technology were “globalwarming” and “acidification”. In the “incineration” and “vacuum pyrolysis” approachof the waste polyvinylchloride, the main environmental impacts were solid waste andconstitute99.8%and99.6%of the total environmental impacts respectively. The“combustion stage” of the “incineration” process was the key link of pollution control.For “vacuum pyrolysis” technology, the key link was “pyrolysis stage”.From technological development, economic development, environmentalmanagement and long term future development viewpoint, some policy suggestions areput forward for waste plastic recycling technology.更多还原