Production and Destruction of Toxic Chemicals in Plastics Combustion

用TG-DSC热重仪研究了聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、6-尼龙和烷基苯磺酸等几种树脂在有氧和无氧气氛中的热分解行为。它们在吸热或放热反应、分解速度和自燃特性方面表现出各自的特性。用GC/MS检测器对500℃、650℃和800℃下产生的产物进行分析。聚乙烯在500℃和650℃时产生大量碳氢化合物，在800℃时产生大量芳香烃。分析了聚氯乙烯分解产物中的氯苯和氯苯酚。一氯苯和一氯苯酚的产量比其他同系物多得多，因此氯苯和氯酚的产生被认为是通过加氯的过程来产生的。氧的存在促进了氯化反应。分解产物中含有大量的2-一氯苯酚、2，4-二氯苯酚、2，6-二氯苯酚和2，4，6-三氯苯酚。2，4，6-位很容易被氯交换。对城市垃圾焚烧厂的烟气和飞灰进行了分析，研究了氯代苯、氯代酚和二恶英的浓度之间的回归关系。

Thermal decomposition of several kinds of resins, polyethylene, polypropylene, polystyrene, polyvinyl chloride, 6-nylon and alkyl-benzene sulphoic acid were investigated by using TG-DSC thermogravimeter in the atmosphere with and without oxygen. They show individual properties in endothermic or exothermic reaction, decomposition speed and auto-ignition characteristics. The product generated at 500, 650 and 800 deg.c were analyzed by GC/MS detector. Polyethylene produces much hydrocarbons at 500 and 650 deg.c, and much aromatic hydrocarbons at 800 deg.c. Chlorobenzenes and chrorophenols were analyzed for the decomposition products from polyvinyl chloride. The production of mono-chlorobenzenes and mono-chlorophenols are much more than the other congeners, so that chloro-benzenes and chloro-phenols are thought to be produced through the process of chlorine addition. The chlorination are promoted by the existence of oxygen. There were much amount of 2-mono-chlorophenol, 2,4-di- chlorophenol, 2,6-di-chlorophenol and 2,4,6-tri-chlorophenols in the decomposition products. The 2,4,6-positions are easily exchanged by chlorine. The flue gas and flyash from municipal refuse incineration plant were analyzed and the regression between the concentrations of chloro-benzenes and chloro-phenols and dioxins were investigated.