低温等离子体耦合氯化钙模拟烟气脱汞实验研究
Experimental Study on Mercury Removal by Non-thermal Plasma Coupled With CaCl2
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摘要: 采用介质阻挡放电低温等离子体（dielectric barrier discharge non-thermal plasma,DBD-NTP）结合氯化钙（Ca Cl2）吸附剂进行了模拟烟气脱汞实验研究。实验结果表明,Ca Cl2能够有效的吸附经DBD-NTP氧化的汞化合物,而DBD-NTP中间耦合Ca Cl2氧化脱汞方式效果更佳,在输入能量为120J/L条件下,汞脱除效率在数分钟内就可达到98%以上;通过对Ca Cl2吸附的汞化合物采取程序升温脱附法（temperature programmed desorption,TPD）以及能谱分析（energy dispersive spectroscope,EDS）,推断汞化合物产物形态为HgC l2、Hg2O、HgO 3和HgO的混合物;在DBD-NTP中间耦合Ca Cl2氧化脱汞过程中,除了发生汞的气相氧化反应外,NTP还能够激发Cl元素参与到Hg0的氧化过程,并且形成的汞氧化物能够提供一定的活性位,通过表面诱导反应进一步促进对Hg0的氧化作用。Abstract: The oxidation of elemental mercury was investigated using dielectric barrier discharge non-thermal plasma（DBD-NTP） technology combined with calcium chloride adsorbent（Ca Cl2） in the simulated flue gas. The results indicate that most of Hg~0 was oxidized by DBD-NTP, and the oxidized mercury was effectively adsorbed by Ca Cl2. While better mercury removal result is obtained by DBD-NTP coupled with Ca Cl2, when the specific energy density is about 120J/L, approximately 98% mercury removal efficiency is observed within a few minutes. The mercury species adsorbed on the Ca Cl2 was analyzed by temperature programmed desorption（TPD） and energy dispersive spectroscopy（EDS）. It is concluded that the mercury species are Hg Cl2, Hg2 O, Hg O3 and Hg O. In addition to the gas-phase oxidation of Hg~0 within DBD-NTP coupled with Ca Cl2, it was proposed that Cl was stimulated and involved in the Hg~0 oxidation process, and the oxidized mercury species can act as an active site to enhance the Hg~0 removal through surface-reactions.
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