升温速率对废塑料热解过程的影响

摘要

In this paper, pyrolysis experiments of plastic wastes, i.e. polyethylene ( PE), polypropylene (PP), polyvinylchloride(PVC) and their mixtures, were made at temperature rise rates of lO℃/min,20℃/min and 30℃/min in nitrogen atmosphere in which the temperature was from 20℃ to 700℃.Effects of pyrolysis process of waste plastics at different temperature rise rate were analyzed, and kinetics investigations were carried out by Coast - Redfern integration method. Pyrolysis characteristics and kinetic parameters of these three kinds of plastic wastes and their mixtures were obtained. The results show that temperature rise rate has an influence on pyrolysis rate, pyrolysis temperature range, activation energy and pre -exponential factor. The greater temperature rise rate, the faster pyrolysis reacts, the greater activation energy required, the more energy consumption on pyrolysis process. Therefore, in the pyrolysis process of waste plastics, temperature rise rate, pyrolysis materials, pyrolysis temperature and other conditions should be considered integrally. This research can provide theoretical and experimental data for the design of pyrolysis technology of plastic wastes.%选取废旧塑料聚乙烯(polyethylene,PE)、聚丙烯(polypropylene,PP)、聚氯乙烯(polyvi-nyl chloride,PVC)及其混合物,在氮气气氛下进行热解实验,实验温度从室温到700℃,升温速率分别为10℃/min、20℃/min和30℃/min.讨论了不同升温速率对废塑料热解过程的影响,并采用Coast-Redfem法进行了热解动力学分析,得到了三种废塑料及其混合物的热解特性及反应动力学、参数.研究结果表明,升温速率对热解速率,热解温度段,活化能,频率因子都有影响.升温速率越快,热解反应越快,所需的活化能也越大,热解过程对能量的消耗越多.因此,在废塑料热解过程中,要综合考虑升温速率,热解原料,热解温度等条件.本文可为废塑料热解工艺的研究提供理论依据和参考数据.