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摘要: 将程序升温热解反应系统和元素Hg在线检测系统耦合，在200℃～1200℃，研究了晋城煤在N2、CO2和H2气氛下热解过程中Hg的释放特性，特别是元素Hg在释放总Hg中的分布。在N2、CO2、H2气氛下，Hg的释放均起始于200℃左右，至1200℃时释放率达95%以上，且Hg的释放率均大于挥发分产率。释放汞的主要形式是元素汞，可说明炭在汞释放中起还原作用；N2气氛下Hg释放总量中元素Hg占97%，CO2和H2气氛下Hg释放总量中元素Hg占73%，说明H2和CO2可将部分元素汞转化为其他价态的汞。Abstract: Release behaviors of Hg during pyrolysis of Jincheng (JC) coal, a Chinese anthracite, were studied under N2, CO2 and H2 atmospheres in a temperature-programmed unit coupled with an on-line atomic fluorescence spectroscopy. In all the atmospheres, Hg release starts at about 200℃ and increases with the increase of temperature. The release ratio (RR) of Hg is more than 95% at 1200℃, which is higher than the corresponding volatile yield. Carbon in coal may be a reducing agent during the Hg emission. Under N2 atmosphere, 97% of Hg is released as elemental form. Under CO2 and H2 atmosphere, however, only 73% of Hg is released as elemental form due to the restriction of the chemical equilibrium. H2 can promote the release of volatiles and increase the release rate of Hg, which decreases the contact probability of mercury compound with C and results in the reduction of elemental form Hg.
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Key words:
- coal /
- pyrolysis /
- atmosphere /
- mercury
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