【作者】 吴正胜；

【导师】 张于峰；

【作者基本信息】 天津大学 ， 热能工程， 2012， 博士

【摘要】 本论文是在天津市科委“科技创新专项基金”的资助下完成的，目的是研发出一种绿色环保的废旧电线电缆及电机绕组回收利用新技术和装备。由于废旧电缆中含有易于造成二次污染的PVC分子，传统的焚烧处理法尾气污染严重，处理成本高。热解技术作为一种可替代焚烧技术的新型热化学处理技术，具有降低尾气污染物排放，固化有害物质，并有效回收原料中的金属组分等优势。因此，我们应用有机分子高温热解的原理，研发出适用于处理废旧机电产品的清洁工艺与绿色装备。具体的研究内容为：（1）废旧线缆热解的基础性实验应用热失重分析方法（TGA），针对两种主要线缆绝缘材料—PVC绝缘材料和PE绝缘材料，分析测量了它们热分解过程中主要的特征温度，并计算得到了PVC绝缘材料和PE绝缘材料的热解反应动力学参数，建立了两者热解反应的动力学模型。实验结果表明，PVC绝缘材料和PE绝缘材料的活化能分别为152kJ/mol和160kJ/mol。这部分属于基础性的实验研究。（2）设计研发了废旧线缆和电机绕组的热解回收中试装置以基础性实验的实验参数为依据，结合废旧线缆和电机绕组的特点，综合考虑了便捷的操作性能、高效的传热性能、良好的保温性能、低成本的尾气处理成本等因素，设计并制造了新型的废旧线缆和电机绕组热解回收装置。本台热解装置的主要创新工艺是热解气在高温状态下的二次燃烧。传统的废弃物热解装置将热解产物分为气、液、固三部分分别回收。我们认为高温热解气的冷凝不仅增加了装置的复杂性，而且冷凝会带来大量的物理热损失。从以往的运行经验看出，冷凝得到的焦油必须通过深加工才可能成为燃料补充热解所需能量。因此，本台装置设计了高温热解气的二次燃烧系统，实现了热解气在高温状态下的二次燃烧。不仅简化了工艺，热解气的热值可达到50.94MJ/m3。（3）废旧线缆热解的中试试验重点考察了高温热解气的成分和热值随温度变化的规律；热解产物分布的特点；热解残炭的成分和热值。结果表明，废旧线缆热解分为两个阶段，第一阶段为脱出HCl反应，第二阶段产生可燃热解气。可燃热解气的热值50.94MJ/Nm3。热解残炭中固定碳含量为23%，其热值为1776kJ/kg。应用静态经济分析和动态经济分析指标，对废旧线缆热解回收方案进行了经济性评价。方案的内部收益率达到40%，具备进一步工业化的基础。更多还原

【Abstract】 This paper aims to develop a green technology and equipment for recycling scrapcables and motors, funded by Tianjin Science and Technology Innovation fund.Because of the existing of PVC molecules in scrap cables, traditional incinerationmethods pollution will exhaust lots of pollutant gas, so the cost of the exhaust gastreatment processing is very high. Pyrolysis technology as a new thermochemicalmethod, has advantages in reducing the harmful substances in exhaust emissions, andthe effective recovery of raw materials and the metal component, which is consideredas a potential alternative of incineration. Therefore, appling organic molecularpyrolysis principle, we developed a suitable cleaning technology for recycling usefulmaterials and metals in waste machinery and electronic products. The specificresearch contents:(1) TGA analysis of scrap cable insulationsApplication of thermogravimetric analysis (TGA), we analyzed the characteristicsof the two main insulation materials—PVC and PE; measured the characteristictemperature; calculated the kinetic parameters, and established the dynamics model ofthe pyrolysis reaction of the two materials. Results show that, the activation energy ofPVC and PE insulation materials were152kJ/mol and160kJ/mol. This part is thebasis experimental study.(2) Design of a new type semi-pilot scale device for recycling scrap cables andmotorsConsidered of the basis parameters of insulation materials, combined with thecharacteristics of scrap cables and motors, we designed and manufactured a new typesemi-device for recycling scrap cables and motors, which has advantages ofconvenient loading, efficient heat transfer and good insulation performance, low costand low cost of flue gas treatment.The main innovation of this process is that the sythesis gas produced by pyrolysisof insulations combusted under high temperature, with no condensation process. Webelieve that condensation process of high temperature sythesis gas will not onlyincrease the complexity of the device, and cause a lot of heat loss. From previousexperience, we see that the obtained tar must pass through a deeper processing tobecome a supplemental fuel. Therefore, the device is designed with a high temperature sythesis gas combustion system. The calorific value of sythesis gas canreach50.94MJ/m3.(3) Semi-pilot scale experimentThe vatiation discipline of the composition and calorific value of sythesis gaswith pyrolysis temperature was tested. Product distribution characteristics weremeasured, and the composition and calorific value of residue char were tested. Resultsindicate that, pyrolysis process of scrap cables is divided into two stages, the firststage for the emergence of HCl, the second stage for producing a combustible sythesisgas. The calorific value of combustible sythesis gas is50.94MJ/Nm3. The content offixed carbon in residue char is23%, and the calorific value of the char is1776kJ/kg.Application of static economic analysis and dynamic economic analysis index,pyrolysis scheme for scrap cables and motors is evaluated. The program’s internalincome rate reached40%, which indicates a great potential of further industrialization.更多还原