Abstract The non-metallic fraction of waste printed circuit boards (PCBs) has received extensive attention for material recycling, due to the potential risk of brominated flame retardants and heavy metals in PCBs. Here, the catalytic pyrolysis of PCBs was performed at 400–600 °C in a two-stage fixed bed reactor. Low-cost Fe and Ni metals were investigated for their catalytic effect on the product yields and bromine removal from the pyrolysis products. In the absence of additives, the maximum oil yield of 50.1 wt% was obtained at 500 °C from the PCBs pyrolysis. The addition of Ni particles decreased the oil yield to 29.1 wt%, and increased the gas yield to 9.6 wt% at 600 °C. The Fe/Ni mixture had a synergistic effect on the product yields, which depended on different pyrolysis temperatures. The composition of the oils from the PCBs pyrolysis was dominated by phenol derivatives. The presence of Fe or Ni particles promoted the formation of phenol and other aromatic compounds, such as benzene and toluene. Moreover, the transformation of bromine species was exhaustively investigated. The higher temperature promoted the conversion of brominated compounds into HBr. Fe particles exhibited excellent debromination performance, which not only reduced the formation of organobromine compounds, but also captured some of the evolved bromine.

中文翻译：

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印刷电路板的两阶段催化热解和脱溴：零价铁和镍金属的影响

摘要 废印刷电路板（PCBs）中的非金属部分由于含有溴化阻燃剂和重金属的潜在风险，在材料回收方面受到了广泛关注。在这里，多氯联苯的催化热解是在两级固定床反应器中在 400-600°C 下进行的。研究了低成本的 Fe 和 Ni 金属对产物产率和从热解产物中去除溴的催化作用。在没有添加剂的情况下，在 500 °C 下，PCBs 热解的最大产油率为 50.1 wt%。Ni 颗粒的加入将油产率降低至 29.1 wt%，并将气体产率提高至 600 °C 时的 9.6 wt%。Fe/Ni 混合物对产物产率有协同作用，这取决于不同的热解温度。多氯联苯热解油的成分主要是苯酚衍生物。Fe 或 Ni 颗粒的存在促进了苯酚和其他芳香族化合物（如苯和甲苯）的形成。此外，对溴物质的转化进行了详尽的研究。较高的温度促进了溴化化合物向 HBr 的转化。Fe颗粒表现出优异的脱溴性能，不仅减少了有机溴化合物的形成，而且还捕获了一些放出的溴。较高的温度促进了溴化化合物向 HBr 的转化。Fe颗粒表现出优异的脱溴性能，不仅减少了有机溴化合物的形成，而且还捕获了一些放出的溴。较高的温度促进了溴化化合物向 HBr 的转化。Fe颗粒表现出优异的脱溴性能，不仅减少了有机溴化合物的形成，而且还捕获了一些放出的溴。