废弃印刷线路板热解油的分析

在固定床实验装置上进行 FR4型印刷线路板的热解,利用气相色谱-质谱、傅里叶变换红外光谱分析了热解油的组成,用氧弹式量热仪测定了热解油各馏分的热值,并初步探讨了溴化环氧树脂的热解机理。实验结果表明,FR4型印刷线路板热解产物中热解油的质量分数为18.23%。热解油由轻质馏分、重质馏分和石油蜡组成。轻质馏分中包括少量水和轻质油。轻质油的主要组分为苯酚、4-乙基苯酚、3-(1-甲基乙基)-苯酚、5-甲基-乙基苯,其他组分主要为烷基取代的苯和苯酚,还含有丙酮及少量其他含氧有机物(苯甲醚和苯并呋喃等),轻质油中溴含量较低。重质馏分和石油蜡所含官能团与轻质油基本相同。轻质油和重质馏分的低位热值分别为27 183 kJ/kg 和29 240 kJ/kg。溴化环氧树脂的热解反应存在 CH_2-O,C-C,CH-OH,C-Br 键的断裂。

Analysis of Pyrolysis Oil from Waste Printed Circuit Boards

FR4-type waste printed circuit boards were pyrolysed in a fixed bed reactor and the obtained pyrolysis oil was analysed by GC-MS and FTIR.Caloric values of fractions in pyrolysis oil were measured by oxygen bomb calorimeter.Pyrolysis mechanism of brominated epoxy resin was discussed together with analysis of pyrolysis products.18.23%(mass fraction)of pyrolysis oil was obtained from the pyrolysis of FR4-type waste printed circuit boards.It mainly consists of light fraction,heavy fraction and petroleum wax.Light fraction contains a small amount of water and balanced amount of light oil.Light oil mainly contains phenol,4-ethyl-phenol,3-(1-methylethyl)- phenol,ethylpentamethyl-benzene,other substituted benzenes and substituted phenols.Acetone, methoxybenzene and benzopyrans were detected in the light oil,as well as a small amount of bromide- contained compound.Functional groups of heavy fraction and petroleum wax are identical with those of light oil,i.e.,the main components are phenols and other aromatics.Low caloric values of light oil and heavy fraction are up to 27 183 kJ/kg and 29 240 kJ/kg,respectively.Cleavage of molecule bonds of CH_2—O,C—C,CH—OH,and C—Br occurs in the pyrolysis of brominated epoxy resin.