初温和终温对废轮胎热解产物分布影响

以热重分析和固定床热解实验为基础,研究初温和终温对废轮胎热解产率及气相产物特性影响。实验结果表明:废轮胎的热解过程存在两个主要失重过程,第一失重温度区间为200～500℃,第二失重温度区间为650～800℃;升温速率仅改变了热解的最大失重速率,并未改变废轮胎最终热解失重率。固定床实验表明:初始温度低于100℃时,废轮胎在800℃时热解已基本结束;当终温为800℃,初始温度在100～550℃范围内时,随着初始温度的提高,固、气两相产物产率均提高,而液相产物产率降低;其中气相中H2、CO、CH4的含量高于初始温度小于100℃时的含量;分析认为:可通过调节热解的初始温度调节废轮胎热解在不同热解阶段的时间分配,适当提高热解初始温度有利于提高整个热解过程中的时间利用效率、改变废轮胎热解产物的分布;废轮胎热解气化的最佳温度区间为500～800℃。

INFLUENCE OF THE INITIAL AND THE FINIAL TEMPERATURE ON THE PYROLYTIC PRODUCT DISTRIBUTION OF SCRAP TIRES

Based on thermo-gravimetric analysis(TGA) and the fixed reactor experiments,the relations between initial temperature and the pyrolysis of scrap tire are studied.The TGA shows that initial temperature has great influences on scrap tire pyrolysis.From TG analysis,it's found that there are two major weight loss stages.The first stage is between 200~500 ℃,and the second one lies in 650~800 ℃.With the rise of heating rate,the maximum weight loss rate is increased,but the final weight loss does not change.The fixed reactor test shows that when the initial temperature is less than 100 ℃,the pyrolysis of scrap tire ends at 800 ℃.At 800 ℃,both the yield of char and gas production and the contend of H2,CO and CH4 increase with increasing the initial temperature from 100 ℃ to 550 ℃.After analysis,it is concluded that the distribution of the products produced by the process can be changed by operating a selective initial temperature.A rational arrangement of initial temperature is also contributed to improve the efficiency,the best temperature range for pyrolysis and gasification of scrap tire is 500~800 ℃.