热重-红外联用分析纸厂废弃塑料的热解特性

利用热重-红外联用技术(TG-FTIR)对纸厂废弃塑料的热解特性及气体释放特性进行了研究。研究表明,塑料的热解过程主要为2个阶段:第1阶段为氯的析出,第2阶段为碳链断裂。随着升温速率的增加,塑料热解的失重速率有所增加,且析出峰向高温方向移动。使用Doyle积分方法进行活化能计算,发现塑料热解所需要的活化能随着反应程度的增加而有所增大。塑料热解脱氯阶段符合三维扩散,球形对称Jander方程;碳链断裂阶段符合二维扩散,圆柱形对称方程。TG-FTIR结果表明,热解的第1阶段析出产物主要为HCl,第2阶段的热解产物主要为烃类化合物。

TG-FTIR Analysis on Pyrolysis Characteristics of Waste Plastics

Pyrolysis and emission characteristics of waste plastics of a paper mill were investigated at different heating rates by using thermogravimetric analysis coupled with Fourier transfer infrared spectrometer(TG-FTIR).Results showed that the process of pyrolysis was divided into two stages including dechlorination and fracture of carbon chain by forming smaller molecules hydrogen compounds.Mass loss and peak slightly increased with increasing heating rate.Doyle method was used to analyze activation energy of waste plastic pyrolysis and it turned out that the activation energy increased with the extent of pyrolysis reaction.Dechlorination followed the three-dimensional diffusion spherically symmetric model and Jander equation was the probable function,while the fracture of carbon chain followed two-dimensional cylindrical symmetric model. Emission gases in the process of pyrolysis were almost the same at different heating rates.Hydrogen chloride and most hydrocarbons were released at the first stage and the second stage of pyrolysis respectively.