废旧电路板真空热解

采用热重分析仪和固定床热解反应器对废旧电路板进行了低真空条件下的热分解实验.研究了混合废旧电路板在真空下的降解特性、热解动力学以及热解条件对热解产品产率的影响，并讨论了真空和氮气条件下电路板热解的差异.实验结果表明真空降低了电路板热解的表观活化能，提高了热解产物的挥发性，减少了二次裂解反应，因而真空有利于提高液体产品的产率，降低气体和固体产品的产率.废旧电路板的真空热解液体产品主要由酚、烷基酚、双酚A、水以及各种溴酚构成，液体中总溴高达13.47％，其中一半左右以有机溴的形式存在，因此液体产品适合用于分离提取化工原料而不宜用于作燃料.

Vacuum pyrolysis of waste printed circuit boards

Pyrolysis experiments of waste printed circuit boards(WPCBs) were carried out by means of thermogravimetric analysis(TG) and a bench-scale fixed-bed pyrolysis reactor under low vacuum.The present work investigated pyrolysis kinetics,thermal degradation characteristics and the effect of pyrolysis conditions on the products yield of WPCBs, and discussed the differences between pyrolysis under vacuum and pyrolysis in nitrogen.Experimental results showed that the apparent activation energy under vacuum became smaller than that in nitrogen, vacuum helped to increase the volatility of pyrolysis products,and weaken the secondary reaction,so the liquid yield under vacuum was increased at the expense of gas and solid yields.Liquid product mainly consisted of phenol, alkylphenol, biphenol A,water as well as various brominated phenols.The total bromine content in the liquid product was up to 13.47%, about one half of which existed as organic brominated compound, so the liquid product from vacuum pyrolysis could be separated into individual chemical compounds, but not suitable for use as fuel.