Using the Novel Method of Nonthermal Plasma To Add Cl Active Sites on Activated Carbon for Removal of Mercury from Flue Gas.
Using the Novel Method of Nonthermal Plasma To Add Cl Active Sites on Activated Carbon for Removal of Mercury from Flue Gas.
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DOI：
10.1021/acs.est.6b01919
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发表时间：
2016-10
影响因子：
11.4
通讯作者：
Bi Zhang;Xiaobo Zeng;P. Xu;Juan Chen;Yang Xu;Guangqian Luo;Minghou Xu;H. Yao
中科院分区：
文献类型：
--
作者：
Bi Zhang;Xiaobo Zeng;P. Xu;Juan Chen;Yang Xu;Guangqian Luo;Minghou Xu;H. Yao
提出了一种利用低温等离子体在活性炭上添加Cl活性位以提高活性炭对烟气中汞的脱除效率的新方法。实验是通过一个实验室规模的介质阻挡放电低温等离子体系统和垂直吸附反应器进行的。结果表明，采用低温等离子体处理活性炭，在很短的处理时间内成功地增加了活性炭表面的Cl活性位，大大提高了活性炭的化学吸附除汞效率。AC处理中Cl 2浓度的增加促进了AC的效率。活性炭对汞的吸附量与活性炭中Cl 2的含量呈正相关，而Cl 2的含量取决于活性炭上Cl活性位的数量。处理后的活性炭在30-210 °C的温度范围内保持较高的除汞效率。烟气中的SO2和H2O对活性炭去除汞有抑制作用，而HCl对活性炭去除汞有促进作用。扫描电子显微镜和X射线光电子能谱分析表明，汞的化学吸附是由于在氯的非热等离子体处理过程中AC表面上产生的C-Cl基团。C-Cl基团作为活性中心对汞具有较强的吸附能，可将单质汞转化为HgCl 2。
A new method using nonthermal plasma to add Cl active sites on activated carbon was proposed to improve the efficiency of activated carbon (AC) for removal of mercury from flue gas. The experiments were conducted via a lab-scale dielectric barrier discharge nonthermal plasma system and a vertical adsorption reactor. The results showed that the nonthermal plasma treatment with a small amount of Cl2 successfully added Cl active sites on AC and greatly increased the mercury removal efficiency of AC by chemisorption in a very short treatment time. The increase in Cl2 concentration for AC treatment promoted the efficiency of AC. The capacity of mercury adsorption positively correlated with the content of Cl2 for AC treatment, which depends on the number of Cl active sites on activated carbon. The treated AC maintained a high mercury removal efficiency within a temperature range of 30-210 °C. SO2 and H2O in flue gas inhibited the removal of mercury by AC, while HCl had a promotional effect. Scanning electron microscopy and X-ray photoelectron spectroscopy analysis indicated the chemisorption of mercury was attributed to the C-Cl groups generated on AC surfaces during Cl2 nonthermal plasma treatment. The C-Cl groups as active sites had strong adsorption energy for mercury, which converted elemental mercury to HgCl2.