Effective and green tire recycling through microwave pyrolysis

Abstract

Waste tire rubber has become a severe environmental issue, which calls for a green method to recycle this rubber. Microwave thermolysis serves as an ideal recycling process for used tires. By surveying the dielectric characteristics from 25 to 700 °C under microwave frequencies of 915 and 2466 MHz, the microwave absorption ability of waste tire rubbers was studied. At temperatures below 350 °C, the dielectric characteristics were relatively steady. Both the loss factor and relative dielectric constant (DC) increased sharply with the rise in temperature. The reason for this is the release of volatile substances, which increases the electrical conductivity. The performance of microwave absorption of tire rubber during thermolysis, and thus the efficiency of microwave tire rubber thermolysis, can be largely impacted by the specimen dimension. The calculation of the reflection loss (RL) of the tire rubber specimens suggests that when the waste tire rubber is 5 mm thick, the highest microwave absorption can be achieved at 915 MHz and 592.1 °C, with RL of −17.30 dB. The product after microwave pyrolysis of waste tire rubber comprises 35% carbon black, 40% oil, and 25% gas. Based on this investigation of the optimal condition of microwave absorption, a proper microwave pyrolysis recycling system was designed for waste tire. This system is efficient at recycling the waste tire rubber into valuable carbon black, oil, and gas products.

摘要

目的

废旧轮胎正成为一个日益严峻的环境问题。本文旨在研究发掘一个高效绿色的处理废旧轮胎的方法。本文探讨微波热解废旧轮胎的可能性,同时研究不同环境温度、微波频率以及样本大小对 微波热解废旧轮胎效率的影响。

方法

1. 通过实验分析,验证影响微波热解废旧轮胎的关键因素,同时找出微波热解废旧轮胎的最佳条件。2. 理论设计多个与分解效率相关的变量,推导其计算公式,从而证明提高热解效率的关键因 素。3. 分析热解后产物,证明该方法是高效绿色 的。

结论

1. 微波热解废旧轮胎的最佳条件是:轮胎样品厚度为5 mm、微波频率为915 MHz 以及环境温度为592.1 °C。2. 分解产物中包含35%的炭黑、40%的原油以及25%的可燃性气体;这证明微波热解 法是有效的。3. 所有产物皆可重复利用,证明该方法是高效绿色的。