Thermal decomposition of waste epoxy PCBs was performed in different atmospheres （nitrogen, argon, air and vacuum） at a heating rate of 10 ℃/rain by DSC-TGA, and the pyrolysis characteristic was analyzed. The gases...Thermal decomposition of waste epoxy PCBs was performed in different atmospheres （nitrogen, argon, air and vacuum） at a heating rate of 10 ℃/rain by DSC-TGA, and the pyrolysis characteristic was analyzed. The gases volatilized from the experiment were qualitatively analyzed by TG-FTIR. Kinetics study shows that pyrolysis reaction takes place between 300 and 400℃, and the activation energies are 256, 212 and 186.2 kJ/mol in nitrogen, argon and vacuum, respectively. There are two mass-loss processes in the decomposition under air atmosphere. In the first mass-loss process, the decomposition is the main reaction, and in the second process, the oxidation is the main reaction. The activation energy of the second mass-loss process is 99.6 kJ/mol by isothermal heat-treatments. TG-FTIR analysis shows carbon dioxide, carbon monoxide, hydrogen bromide, phenol and substituent phenol are given off during the pyrolysis of waste epoxy PCBs.展开更多
Pyrolysis experiments of a typical printed circuit boards has been carried out under various conditions in a laboratory installation Liquid yield of 15%～21%, gas yield of 15%～20% and solid yield of about 60% were ob...Pyrolysis experiments of a typical printed circuit boards has been carried out under various conditions in a laboratory installation Liquid yield of 15%～21%, gas yield of 15%～20% and solid yield of about 60% were obtained The liquid products had high gross calorific values that might be recycled as fuel oils after simple treatment CO, CO 2 and N 2 were the main constitutes of the gas products Using combustion method, organic carbon of 7% in the solid products could be removed Then the solid products, which contained high purity fiberglass and CaCO 3, could be reused as filling materials in the process of SMC production In addition, the effects of final pyrolysis temperature (FPT) and particle size on pyrolysis products had been investigated The yield of gas products will be increased under high temperature and with powder展开更多
Pyrolysis kinetics of a kind of printed circuit board waste was investigated under various conditions with thermogravimetry (TG) in the present work. The dynamic thermogravimetric analysis curve and its derivative wer...Pyrolysis kinetics of a kind of printed circuit board waste was investigated under various conditions with thermogravimetry (TG) in the present work. The dynamic thermogravimetric analysis curve and its derivative were analyzed to obtain information on the kinetic parameters. The data from experiments were processed to determine the pyrolysis mechanism of printed circuit board and the kinetic parameters such as activation energy E(kJ/mol) and pre-exponential factor A(1/min). A tube-type apparatus was used to pyrolyze printed circuit board waste under different conditions,and the products were analysised by using FTIR and EPMA.展开更多
基金Project(2006AA06Z375) supported by the National High-tech Research and Development Program of China
文摘Thermal decomposition of waste epoxy PCBs was performed in different atmospheres （nitrogen, argon, air and vacuum） at a heating rate of 10 ℃/rain by DSC-TGA, and the pyrolysis characteristic was analyzed. The gases volatilized from the experiment were qualitatively analyzed by TG-FTIR. Kinetics study shows that pyrolysis reaction takes place between 300 and 400℃, and the activation energies are 256, 212 and 186.2 kJ/mol in nitrogen, argon and vacuum, respectively. There are two mass-loss processes in the decomposition under air atmosphere. In the first mass-loss process, the decomposition is the main reaction, and in the second process, the oxidation is the main reaction. The activation energy of the second mass-loss process is 99.6 kJ/mol by isothermal heat-treatments. TG-FTIR analysis shows carbon dioxide, carbon monoxide, hydrogen bromide, phenol and substituent phenol are given off during the pyrolysis of waste epoxy PCBs.
文摘Pyrolysis experiments of a typical printed circuit boards has been carried out under various conditions in a laboratory installation Liquid yield of 15%～21%, gas yield of 15%～20% and solid yield of about 60% were obtained The liquid products had high gross calorific values that might be recycled as fuel oils after simple treatment CO, CO 2 and N 2 were the main constitutes of the gas products Using combustion method, organic carbon of 7% in the solid products could be removed Then the solid products, which contained high purity fiberglass and CaCO 3, could be reused as filling materials in the process of SMC production In addition, the effects of final pyrolysis temperature (FPT) and particle size on pyrolysis products had been investigated The yield of gas products will be increased under high temperature and with powder
文摘Pyrolysis kinetics of a kind of printed circuit board waste was investigated under various conditions with thermogravimetry (TG) in the present work. The dynamic thermogravimetric analysis curve and its derivative were analyzed to obtain information on the kinetic parameters. The data from experiments were processed to determine the pyrolysis mechanism of printed circuit board and the kinetic parameters such as activation energy E(kJ/mol) and pre-exponential factor A(1/min). A tube-type apparatus was used to pyrolyze printed circuit board waste under different conditions,and the products were analysised by using FTIR and EPMA.
文摘针对电子废弃物FR1酚醛树脂纸基印刷线路板,利用热重（TG）试验探讨了其粉末在N2气氛中不同升温速率（10 K/min、20 K/min、30 K/min）下的热解特性,通过Kissinger和FWO热解动力学模型对其平均表观活化能和指前因子等热解动力学参数进行求解,分析其热解难易程度。结果表明,整体热解过程可分为室温~180℃和180~580℃两个阶段,高于580℃时热解残余率基本不变;当升温速率为20 K/min时试样最大热失重率为71.51%,残余固体较少,热解较充分。热解动力学分析表明,机理模型假设为f（α）=（1-α）n1级反应时,Kissinger法求得试验样品表观活化能E为170.83 k J/mol,指前因子A为7.41×1014min-1;FWO法求得转化率α=0.3~0.5即样品处于最大热失重峰区域时平均表观活化能E为169.71 k J/mol,相关系数r可达0.99以上;两种方法计算结果吻合,模型假设合理。热解动力学参数对比表明,FR1酚醛树脂纸基印刷线路板表观活化能和指前因子分别为FR4环氧树脂线路板和聚四氟乙烯线路板的1.03倍、224倍及0.76倍、48倍,更易进行热解反应,对其进行热解焚烧连续处置具有可行性。
