ABSTRACT

The phenomenon of the secondary reactions of volatiles prevails during the pyrolysis process of scrap tires, but less is known about the influence of volatiles’ residence time and temperature on the pyrolytic oil compositions. Experiments on the secondary reactions caused by residence time and temperature of volatiles were carried out on a lab-scale fixed bed reactor. The regularity of the secondary reactions was presented in detail according to the distribution of liquid and gaseous pyrolytic products. Considering the inadequacy of lab-to-industry research, experiments were further carried out on a pilot-scale auger reactor. The results of the pilot-scale system were corresponding well to the regularity obtained in lab-scale experiment, demonstrating the universality of the regularity in this work. At in situ pyrolysis condition without any secondary reactions, limonene content reached up to 46.24% while a high yield of BTEX (50.55%) was obtained at 700℃/60 s. A remarkable increase of methane and ethane was observed at 700℃/60 s, reaching 0.058 and 0.040 g·(g scrap tire)⁻¹, respectively. This paper provided a novel strategy to selectively produce target products in a simple and economical method. The results were of great significance for guiding the optimisation of pyrolysis parameters in industrial equipment to obtain desired valuable products.

摘要

废旧轮胎热解过程中普遍存在挥发物二次反应的现象，但对挥发物停留时间和温度对热解油组成的影响知之甚少。在实验室规模的固定床反应器上进行了挥发物停留时间和温度引起的二次反应实验。根据液态和气态热解产物的分布，详细介绍了二次反应的规律性。考虑到实验室到工业研究的不足，进一步在中试规模的螺旋钻反应器上进行了实验。中试系统的结果与小试获得的规律性较好地对应，证明了该规律性在本工作中的普适性。在没有任何二次反应的原位热解条件下，柠檬烯含量高达46.24%，而BTEX在700℃/60 s时的收率高达50.55%。700℃/60 s观察到甲烷和乙烷显着增加，分别达到0.058和0.040 g·（g废轮胎）^-1，分别。本文提供了一种以简单经济的方法选择性生产目标产品的新策略。研究结果对指导工业设备热解参数优化以获得所需有价值的产品具有重要意义。