ABSTRACT

Electronic waste is the fastest growing waste stream and one of the most significant constituents is electronic plastics. In this study, the combustion kinetic of typical electronic plastic waste—television set (TV) plastic shell—was investigated using two basic kinetic methods. The reaction mechanism and kinetic compensation effect were probed as well. The thermogravimetric analysis (TGA) revealed that its degradation process can be divided into four stages, namely, reaction initiation stage (20–300 °C), major reaction stage (300–450 °C), minor reaction stage (450–600 °C), and reaction cessation stage (600–1,000 °C). The activation energy (E) were calculated and indicated that, the kinetic parameters from six model-free methods gradually decreased with α increasing from 0.1 to 0.35, and then slightly increased. The Flynn--Wall--Ozawa (FWO) method was more reliable and E values decreased from 155.0 to 147.51 kJ/mol with α range of 0.1–0.35, then gradually increased to 165.21 kJ/mol. Within the Coats--Redfern method, the first-order (F1) model had higher coefficient of determination (R²) and comparable E values with that from FWO method. The result of kinetic compensation effect confirmed that the compensation effect existed between E and A during the plastic waste combustion. A linear relationship lnA = 0.183E-3.11 (R² = 0.991) was obtained. The pre-exponential factors (A) were also determined as 7.67 × 10¹⁰ min⁻¹ based on the F1 reaction model and FWO method.

Implications: Municipal solid waste (MSW) is a complex mixture of different components and the plastic takes up a significant portion in total MSW. Understanding the combustion process of typical electronic plastic waste and further probing its combustion kinetic are significant. Through this study, it will be significant for the reactor designing and optimizing in practice.

摘要

电子垃圾是增长最快的垃圾流，其中最重要的成分之一是电子塑料。在这项研究中，使用两种基本动力学方法研究了典型电子塑料废物——电视机 (TV) 塑料外壳的燃烧动力学。并探讨了反应机理和动力学补偿效应。热重分析（TGA）表明其降解过程可分为四个阶段，即反应起始阶段（20-300°C），主要反应阶段（300-450°C），次要反应阶段（450-600°C） C) 和反应停止阶段 (600–1,000 °C)。计算活化能 ( E ) 并表明，六种无模型方法的动力学参数随着α从 0.1 增加到 0.35，然后略有增加。Flynn--Wall--Ozawa (FWO) 方法更可靠，E值从 155.0 下降到 147.51 kJ/mol，α范围为 0.1-0.35，然后逐渐增加到 165.21 kJ/mol。在 Coats--Redfern 方法中，一阶 ( F1 ) 模型具有更高的决定系数 (R ² ) 和与FWO 方法相当的E值。动力学补偿效应的结果证实，在塑料垃圾燃烧过程中，E和A之间存在补偿效应。线性关系 ln A = 0.183 E -3.11 (R ² = 0.991) 获得。基于F1反应模型和 FWO 方法，指数前因子 ( A ) 也被确定为 7.67 × 10 ¹⁰ min ^-1。

影响：城市固体废物 (MSW) 是不同成分的复杂混合物，塑料在 MSW 总量中占很大比例。了解典型电子塑料垃圾的燃烧过程，进一步探索其燃烧动力学具有重要意义。通过本研究，对于实际中反应器的设计和优化具有重要意义。