热重分析法对废旧电路板热解过程动力学和热力学分析  

Kinetics and thermodynamics during pyrolysis of scrap printed circuit board by TGA

作　　者：阳宇 夏勇[1] 王君 欧阳少波 熊道陵[1] 李立清[1] YANG Yu;XIA Yong;WANG Jun;OUYANG Shaobo;XIONG Daoling;LI Liqing(Faculty of Materials Metallurgy and Chemistry,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China;Shanxi Key Laboratory of Comprehensive Utilization of Tailings Resources,College of Chemical Engineering and Modern Materials,Shangluo University,Shangluo 726000,Shanxi,China)

机构地区：[1]江西理工大学材料冶金化学学部,江西赣州341000 [2]商洛学院化学工程与现代材料学院,陕西省尾矿资源综合利用重点实验室,陕西商洛726000

出　　处：《有色金属科学与工程》2024年第1期43-50,共8页Nonferrous Metals Science and Engineering

基　　金：江西省自然科学基金资助项目(2020BAB214021);江西省教育厅科学技术研究资助项目(GJJ200809);陕西省自然科学基金资助项目(2021JQ-840);江西理工大学大学生创新创业训练资助项目(DC2022-004)。

摘　　要：废旧电路板(SPCB)是一种典型的有机废弃物,可通过热解技术实现其资源化利用。采用热重分析技术(TGA)对其热解特性进行研究,揭示热解过程反应动力学和热力学。实验在氮气气氛下,考察了不同升温速率(5、10、15℃/min)对SPCB热失重特性的影响,结果表明热解过程主要发生在250~400℃温度区间,随着升温速率增大,SPCB热失重(TG)曲线逐渐向高温方向偏移,在对应的热失重速率(DTG)曲线中,存在一个明显的失重峰,且峰值温度不断增加,热滞后现象显著。采用Flynn-Wall-Ozawa(FWO)模型、Kissinger-Akahira-Sunose(KAS)模型和Friedman(FM)模型进行动力学分析,拟合得到平均表观活化能(Ea)分别为168.46、167.31、234.84 kJ/mol,活化能均随转化率增加而相应增大。利用FWO模型对热力学参数进行计算,在相同升温速率下,随着转化率的增大,吉布斯自由能变(ΔG)逐渐降低,对应的焓变(ΔH)和熵变(ΔS)不断增加;在相同转化率时,ΔH和ΔS随升温速率增加稍有降低,而ΔG逐渐增加。Scrap printed circuit board(SPCB)is a typical organic waste,which could be utilized as a resource by pyrolysis technology.The pyrolysis characteristics of SPCB were studied by thermogravimetric analysis(TGA)to reveal the reaction kinetics and thermodynamics during the pyrolysis process.Under N2 atmosphere,the effects of different heating rates,e.g.5℃/min,10℃/min and 15℃/min,on the thermal decomposition behavior of SPCB were investigated in detail.The results observed showed that the pyrolysis process was mainly occurred in the temperature range of about 250℃to 400℃.With the increase of heating rates,the thermogravimetry(TG)curves of SPCB was gradually deviated to the high temperature direction.For the derivative thermogravimetry(DTG)curves,there was an obvious mass loss peak,and the corresponding peak temperature kept increasing,indicating that there was a significant thermal hysteresis phenomenon.The Flynn-Wall-Ozawa(FWO)model,Kissinger Akahira-Sunose(KAS)model and Friedman(FM)model were used to analyze the thermogravimetric data.The average apparent activation energies(Ea)were 168.46 kJ/mol,167.31 kJ/mol and 234.84 kJ/mol,respectively,which increased with the increase of conversion rate.The thermodynamic parameters were calculated using FWO model.Under the same heating rate,the Gibbs free energy change(ΔG)was gradually decreased with the increase of conversion rate,while the corresponding enthalpy change(ΔH)and entropy change(ΔS)were all increased.Meanwhile,at the same conversion,both ofΔH andΔS decreased slightly with the increase of heating rate,whileΔG was increased gradually.

关 键 词：废旧电路板 热解特性 动力学 热力学 

分 类 号：TQ524[化学工程—煤化学工程] X784[环境科学与工程—环境工程]