Royal Institute of Technology (KTH), Department of Material Science and Engineering, Brinellvägen 23, 100 44 Stockholm, Sweden.
The City College of the City Universities of New York (CUNY), Department of Mechanical Engineering, New York, NY, USA.
Waste Manag. 2019 Jul 1;94:165-171. doi: 10.1016/j.wasman.2018.06.018. Epub 2018 Jun 18.
Consumption of electronics increases due to modern society's growing needs, which leads to increasing generation of waste electrical and electronic equipment (WEEE). Recycling of WEEE has been a global concern during the last few decades because of the toxic compounds that are produced during recycling. Different recycling techniques have been adapted on a commercial scale in order to overcome this issue, but the recycling of WEEE still lacks the technology to treat different kinds of feedstocks and to maximise the recycling rates. Pyrolysis is an alternative that has not been commercialised yet. One of the challenges for the implementation of this technology is the toxic brominated organic compounds that can be found in the pyrolysis oils. In this study, tetrabromobisphenol A (TBBPA), one of the major flame retardants, is reduced in three different WEEE fractions through solvent extraction as a treatment prior to pyrolysis. Two solvents have been experimentally investigated: isopropanol and toluene, the latter of which can be derived from pyrolysis oil. The results indicate that TBBPA was extracted during pre-treatment. Moreover, the total bromine content of WEEE material was reduced after the treatment with a maximum reduction of 36.5%. The pyrolysis experiments indicate that reduction of several brominated organic compounds was achieved in almost all the tested cases, and two brominated compounds (2,4,6-tribromophenol and 2,5-Dibromobenzo(b)thiophene) reached complete removal. Also, the thermal decomposition behaviour of the raw samples and the treated was investigated, showing that the reduction of TBBPA influences the decomposition by shifting the starting decomposition temperature.
由于现代社会不断增长的需求，电子产品的消耗量不断增加，这导致了电子废物（WEEE）的产生量不断增加。在过去几十年中，由于在回收过程中产生的有毒化合物，WEEE 的回收已成为全球关注的焦点。为了克服这个问题，已经在商业规模上采用了不同的回收技术，但 WEEE 的回收仍然缺乏处理不同原料和最大限度提高回收利用率的技术。热解是一种尚未商业化的替代方法。这项技术实施的挑战之一是在热解油中发现的有毒溴化有机化合物。在这项研究中，通过溶剂萃取作为热解前处理，从三种不同的 WEEE 中减少了四溴双酚 A（TBBPA），这是主要的阻燃剂之一。实验研究了两种溶剂：异丙醇和甲苯，后者可以从热解油中获得。结果表明 TBBPA 在预处理过程中被提取出来。此外，在用处理剂处理后，WEEE 材料的总溴含量减少，最大减少率为 36.5%。热解实验表明，在几乎所有测试案例中，都实现了几种溴化有机化合物的减少，两种溴化化合物（2,4,6-三溴苯酚和 2,5-二溴苯并[b]噻吩）达到了完全去除。此外，还研究了原始样品和处理样品的热分解行为，表明 TBBPA 的减少会通过改变起始分解温度来影响分解。
