Degradation of brominated flame retardant in computer housing plastic by supercritical fluids.
Degradation of brominated flame retardant in computer housing plastic by supercritical fluids.
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DOI：
10.1016/j.jhazmat.2011.12.055
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发表时间：
2012-02
影响因子：
13.6
通讯作者：
Yanmin Wang;Fu-Shen Zhang
中科院分区：
文献类型：
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作者：
Yanmin Wang;Fu-Shen Zhang
研究了溴化阻燃剂（BFR）和含BFR的废旧电脑外壳塑料在不同超临界流体（水、甲醇、异丙醇和丙酮）中的降解过程。结果表明，溶剂类型对产物的脱溴和降解效率有较大影响。在四种溶剂中，异丙醇具有(1)脱溴效果好（脱溴效率95.7%）、(2)产油率高（60.0%）、(3)温度和压力要求温和的特点，是最适合从含bfr塑料中回收油的溶剂。然而，在这种情况下，去除的溴主要存在于油中。在sc-异丙醇中引入KOH可以捕获油中几乎所有的无机溴，从而获得无溴油。此外，KOH还能促进塑料的解聚。所得油主要由单环和双环芳香族化合物组成，其碳位在C9-C17之间，具有烷基取代基或脂肪桥，如丁基苯、（3-甲基丁基）苯、1,1′-（1,3-丙二基）双苯。酚类、烷基酚类和酯类是油中主要的含氧化合物。本研究为电子垃圾中含bfr塑料的脱溴同时回收有价化学物质提供了一种有效的方法。
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.