Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085, China.
J Hazard Mater. 2012 Feb 29;205-206:156-63. doi: 10.1016/j.jhazmat.2011.12.055. Epub 2011 Dec 27.
The degradation process of brominated flame retardant (BFR) and BFR-containing waste computer housing plastic in various supercritical fluids (water, methanol, isopropanol and acetone) was investigated. The results showed that the debromination and degradation efficiencies, final products were greatly affected by the solvent type. Among the four tested solvents, isopropanol was the most suitable solvent for the recovery of oil from BFR-containing plastic for its (1) excellent debromination effectiveness (debromination efficiency 95.7%), (2) high oil production (60.0%) and (3) mild temperature and pressure requirements. However, in this case, the removed bromine mostly existed in the oil. Introduction of KOH into the sc-isopropanol could capture almost all the inorganic bromine from the oil thus bromine-free oil could be obtained. Furthermore, KOH could enhance the depolymerization of the plastic. The obtained oil mainly consisted of single- and duplicate-ringed aromatic compounds in a carbon range of C9-C17, which had alkyl substituents or aliphatic bridges, such as butyl-benzene, (3-methylbutyl)-benzene, 1,1'-(1,3-propanediyl)bis benzene. Phenol, alkyl phenols and esters were the major oxygen-containing compounds in the oil. This study provides an efficient approach for debromination and simultaneous recovering valuable chemicals from BFR-containing plastic in e-waste.
研究了溴系阻燃剂（BFR）和含 BFR 的废旧电脑机箱塑料在各种超临界流体（水、甲醇、异丙醇和丙酮）中的降解过程。结果表明，溶剂类型对脱溴和降解效率、最终产物有很大影响。在四种测试溶剂中，异丙醇是从含 BFR 塑料中回收油的最适宜溶剂，因为它具有以下优点：（1）脱溴效果优异（脱溴效率 95.7%）；（2）产油量高（60.0%）；（3）温度和压力要求温和。然而，在这种情况下，去除的溴大多存在于油中。在 sc-异丙醇中引入 KOH 可以捕获油中的几乎所有无机溴，从而得到无溴油。此外，KOH 可以增强塑料的解聚。得到的油主要由 C9-C17 碳范围内的单环和双环芳烃组成，这些芳烃带有烷基取代基或脂肪族桥，如丁基苯、（3-甲基丁基）-苯、1,1'-(1,3-丙二基)双苯。酚、烷基酚和酯是油中主要的含氧化合物。本研究为从电子废物中的含 BFR 塑料中进行脱溴和同时回收有价值的化学品提供了一种有效的方法。
