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J4  2009, Vol. 43 Issue (5): 937-941    DOI: 10.3785/j.issn.1008-973X.2009.05.029
    
Conversion of bromine during the pyrolysis of waste printed circuit boards
MAO Yan-yan, MA Zeng-yi, YU Liang, YAN Jian-hua, CHEN Ling-hong, CEN Ke-fa
(State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China)
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Abstract  

The pyrolysis characteristics as well as HBr removal rate and bromine conversion rate during the pyrolysis of printed circuit boards (PCB) were investigated by using thermal gravimetric analysis (TGA) apparatus and quartz tube furnace for pyrolysis experiments under nitrogen atmosphere. Calcium hydroxide and calcium carbonate were used as additives with PCB powder in co-pyrolysis experiments. The effects of additives, Ca/Br molar ratio and co-pyrolysis temperature  were studied. The results indicated that when the additive is calcium hydroxide, the Ca/Br molar ratio is larger than 4∶1, and the pyrolysis temperature is 723 K, the pyrolysis has high  HBr removal rate and high conversion rate of organic bromine of PCB to inorganic bromine. When the Ca/Br molar ratio is 9∶1 and the pyrolysis temperature is 723 K, 96.33% of the bromine is converted to inorganic bromine, 99.88% of which is in solid. This result helps to the use of  pyrolysis products and the bromine recovery.



Published: 18 November 2009
CLC:  X705  
  TK16  
Cite this article:

MAO Yan-Yan, MA Ceng-Yi, TU Liang, et al. Conversion of bromine during the pyrolysis of waste printed circuit boards. J4, 2009, 43(5): 937-941.

URL:

http://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2009.05.029     OR     http://www.zjujournals.com/eng/Y2009/V43/I5/937


废弃印刷线路板热解过程中溴的转化

 利用热重分析仪和管式炉在氮气气氛下进行废弃印刷线路板热解实验,研究了热解特性以及在热解过程中HBr的脱除和溴的转化.分别选用Ca(OH)2和CaCO3作为添加剂与印刷线路板粉末进行混合热解实验,研究了不同添加剂、Ca/Br摩尔比、温度的影响.实验结果表明,当添加剂为Ca(OH)2,Ca/Br摩尔比大于4∶1, 723 K时,能够高效地脱除HBr并将印刷线路板中的有机溴转化为固体产物中的无机溴.当Ca/Br摩尔比为9∶1, 723 K时,96.33%的溴已经转化为无机溴,其中99.88%的无机溴存在于固体中,有利于热解产物的利用以及溴的回收.

[1] BARONTINI F, MARSANICH K, PETARCA L, et al. Thermal degradation and decomposition products of electronic boards containing BFRs [J]. Industrial and  Engineering Chemistry Research, 2005, 44(12): 41864199.
[2] HUANG Jian-jun, SHI Jia-biao, MENG Yue-dong, et al. DC arc plasma disposal of printed circuit board [J]. Plasma Science and Technology, 2004, 6(4): 24232426.
[3] LION Tzong-horng. Pyrolysis kinetics of electronic packaging material in a nitrogen atmosphere [J]. Journal of Hazardous Materials, 2003, 103(1/2): 107123.
[4] WEBB M, LAST P M, BREEN C. Synergic chemical analysis — the coupling of TG with FTIR, MS and GC-MS: 1. The determination of the gases released during the thermal oxidation of a printed circuit board [J]. Thermochimica Acta, 1999, 326(1/2): 151158.
[5] 甘舸,陈烈强,彭绍洪,等. 废旧电子电气设备回收处理的研究进展[J]. 四川环境, 2005, 24(3): 8993.
GAN Ge, CHE Lie-qiang, PENG Shao-hong, et al. Progress in recycle treatment of waste of electronic/ electric equipment [J]. Sichuan Environment, 2005, 24(3): 8993.
[6] 路洪洲,李佳,郭杰,等. 基于可资源化的废弃印刷线路板的破碎及破碎性能[J]. 上海交通大学学报, 2007, 41(4): 551556.
LU Hong-zhou, LI Jia, GUO Jie, et al. Pulverization characteristics and pulverizing of waste printed circuit boards (printed wiring boards) based on resource utilization [J]. Journal of Shanghai Jiaotong University, 2007, 41(4): 551556.
[7] 王博,冯素征,朱萍,等. 印刷线路板浸出液中铜的提取研究[J]. 中国资源综合利用, 2006, 24(9): 1114.
WANG Bo, FENG Su-zheng, ZHU Ping, et al. Research on copper extraction from printed circuit board leaching solution [J]. China Resources Comprehensive Utilization, 2006, 24(9): 1114.
[8] 李震,刘泽常,赵莹,等. 混合废塑料与煤共热解过程中氯的释放特性和机理[J]. 煤炭学报, 2007, 32(4): 420424.
LI Zheng, LIU Ze-chang, ZHAO Ying, et al. Emission characteristics of chlorine in the process of coal and WP co-pyrolysising and exploring on its mechanism [J]. Journal of China Coal Society, 2007, 32(4): 420424.
[9] 陆王琳,金余其,池涌,等. 废轮胎热解制油技术及油品应用前景[J]. 化工进展, 2007, 26(1): 1317.
LU Wang-lin, JIN Yu-qi, CHI Yong, et al. Waste tire pyrolysis and application prospect of pyrolysis oil [J]. Chemical Industry and Engineering Progress, 2007, 26(1): 1317.
[10] 曹青,刘岗,鲍卫仁,等.生物质与废轮胎共热解及催化对热解油的影响[J].化工学报, 2007, 58(5): 12831289.
CAO Qing, LIU Gang, BAO Wei-ren, et al. Influence of co-pyrolysis and catalysis of biomass with waste tire on pyrolytic oil properties [J]. Journal of Chemical Industry and Engineering (China), 2007, 58(5): 12831289.
[11] BARONTINI F, COZZANI V. Formation of hydrogen bromide and organobrominated compounds in the thermal degradation of electronic boards [J]. Journal of Analytical and Applied Pyrolysis, 2006, 77(1): 4155.
[12] CHIEN Yi-chi, WANG H P. Liquefaction of printed circuit board wastes with product oil recycling [J]. Journal of Environmental Science and Health. Part A—Toxic/Hazardous Substances & Environmental Engineering, 2000, 35(4): 635644.
[13] CHEN K S, CHEN H C, WU C H. Kinetics of thermal and oxidative decomposition of printed circuit boards [J]. Journal of Environmental Engineering, 1999, 125(3): 277283.
[14] 孙路石,陆继东,王世杰,等. 印刷线路板废弃物热解实验研究[J]. 化工学报, 2003, 54(3): 408412.
SUN Lu-shi, LU Ji-dong, WANG Shi-jie, et al. Experimental research on pyrolysis characteristics of printed circuit board wastes [J]. Journal of Chemical Industry and Engineering, 2003, 54(3): 408412.
[15] 李飞,赵增立,李海滨,等. 电子废物塑料熔融盐气化特性研究[J]. 燃烧科学与技术, 2005, 11(5): 470474.
LI Fei, ZHAO Zeng-li, LI Hai-bin, et al. Study on gasification characteristics of electronic waste plastic in molten salts [J]. Journal of Combustion Science and Technology, 2005, 11(5): 470474.
[16] IJI M, IKUTA Y. Pyrolysis-based material recovery from molding resin for electronic parts [J]. Journal of Environmental Engineering, 1998, 124(9): 821828.
[17] HORNUNG A, DONNER S, BALABANOVICH A, et al. Polypropylene as a reductive agent for dehalogenation of brominated organic compounds [J]. Journal of Cleaner Production, 2005, 13(5): 525530.
[18] 彭绍洪,陈烈强,蔡明招. 废旧电路板热解过程中溴化氢的生成及脱除[J]. 华南理工大学学报:自然科学版, 2006, 34(10): 1524.
PENG Shao-hong, CHEN Lie-qiang, CAI Ming-zhao. Forming and scavenging of hydrogen bromide during pyrolysis of waste printed circuit boards [J]. Journal of South China University of Technology: Natural Science Edition, 2006, 34(10): 1524.

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