聚烯烃热解/催化热解过程的原位实时在线诊断与反应机理研究

Waste plastics are known as the “second mineral resources”. The recycling of waste plastics not only reduces the environmental pollution but also make great economic benefits. Pyrolysis, as a kind of important chemical recycle method(for fuels and chemical stocks) , is drawing great attention of researchers in relevant field all over the world. But the researches on pyrolysis of polymers mainly forces on the detection and analysis of stable products, and the measure of properties of matter. The active intermediates have rarely been reported. But the intermediates are usually the key components for understanding of pyrolysis mechanisms. The lack of clear understandings of mechanisms is not favor for optimizing the reaction conditions of pyrolysis, and for adjusting the composition of products. .The polyolefin, part of the general purpose plastics, are selected as research objects in this project, for their wide usage. Three platform of experimental setups are take into use, which are TG-PI-TOFMS( thermogravimetric analyzer photon ionization time of flight mass spectrometer), the PY-PI-TOFMS(pyrolysis-photon ionization time of flight mass spectrometer), and the ultrahigh-resolution mass spectrometer. The setups are employed to study the dynamic processes of pyrolysis, detect the unstable intermediates, and identify the complex products. The thermal analysis kinetics and reaction pathway analysis will be done based on the experimental data. An accurate mechanism for pyrolysis and catalytic pyrolysis of polyolefin will be built up, with the help of experimental data and the theoretical arithmetic data. The mechanism will server for optimizing the catalyst and pyrolysis conditions in order to get high quality products, and promoting the development of practical facilities.

废弃塑料被称为人类的“第二矿藏”，对其回收再利用，可以极大减少对环境的破坏并带来相当可观的经济效益。热解作为化学回收(再生为油和化学原料)的重要方式，越来越受到国际相关领域研究人员的重视。而目前对聚合物热解的研究往往停留在稳定产物的探测，以及宏观物理性质的测定方面，对热解过程中起关键作用的活性中间体关注较少，这不利于理解塑料热解的机理以及改善反应条件，优化产物构成。.本项目拟采用热重质谱联用技术、分子束取样结合质谱技术、超高分辨质谱等实验手段，针对用量巨大的聚烯烃类通用塑料的热解/催化热解中的微观化学反应过程、产物的精确鉴定等开展实验研究。通过热分析动力学、反应路径分析等实验分析方法与理论计算结果相结合，最终建立聚烯烃热解/催化热解的反应机理。以机理为指导，调整催化剂与反应条件，优化产物构成，为塑料废弃物热解回收装置的发展提供理论支持。

废弃塑料被称为人类的“第二矿藏”，对其回收再利用，可以极大减少对环境的破坏并带来相当可观的经济效益。热解是化学回收(再生为油和化学原料)的重要方式。针对当前国内外对聚合物热解中起关键作用的活性中间体探测和机理发展方面的不足，本项目发展了热重飞行时间质谱联用方法，并结合分子束取样质谱技术和超高分辨质谱等实验手段，对用量巨大的聚烯烃类通用塑料的热解/催化热解中的微观化学反应过程、产物的精确鉴定等开展实验研究；通过热分析动力学、反应路径分析等分析方法揭示了断键和产物生成的机制及催化剂添加对热解产物定向转化的影响；针对聚烯烃与生物质的共热解/催化共热解行为开展实验研究，明确了共热解过程中出现的协同效应和催化剂对共热解产物的重整作用，为塑料废弃物热解回收装置的发展提供理论支持。