Mercury oxidation and adsorption characteristics of potassium permanganate modified lignite semi-coke
Mercury oxidation and adsorption characteristics of potassium permanganate modified lignite semi-coke
复制标题
高锰酸钾改性褐煤半焦的汞氧化及吸附特性
DOI：
10.1016/s1001-0742(11)61047-4
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发表时间：
2012-01-01
影响因子：
6.9
通讯作者：
Wang, Li
中科院分区：
文献类型：
--
作者：
Zhang, Huawei;Chen, Jitao;Wang, Li
研究了褐煤半焦和高锰酸钾改性褐煤半焦对气态Hg-0的吸附特性，旨在制备更有效、更廉价的吸附剂，用于控制单质汞的排放。采用BET比表面积（BET）、X射线粉末衍射（XRD）和X射线光电子能谱（XPS）等测试手段，分析了SC、Mn-SC和Mn-H-SC吸附汞前后的表面物理化学性质。结果表明，高锰酸钾改性对半焦的比表面积、孔结构和表面化学官能团等性能有显著影响。改性半焦对汞的吸附效率在低温下低于SC，但在高温下高于SC。Mn-SC和Mn-H-SC表面的非晶态Mn 7+、Mn 6+和Mn 4+是气态Hg-0的氧化和吸附活性中心，它们将单质汞氧化为Hg 2+并将其捕获，热处理使Mn-SC表面Mnx+的平均氧化度从3.80降低到3.46。但由于非晶态MnOx的形成，表面对气态Hg-0的氧化活性位增加，使得Mn-H-SC在高温下的汞吸附效率高于Mn-SC。
The adsorption characteristics of virgin and potassium permanganate modified lignite semi-coke (SC) for gaseous Hg-0 were investigated in an attempt to produce more effective and lower price adsorbents for the control of elemental mercury emission. Brunauer-Emmett-Teller (BET) measurements, X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to analyze the surface physical and chemical properties of SC, Mn-SC and Mn-H-SC before and after mercury adsorption. The results indicated that potassium permanganate modification had significant influence on the properties of semi-coke, such as the specific surface area, pore structure and surface chemical functional groups. The mercury adsorption efficiency of modified semi-coke was lower than that of SC at low temperature, but much higher at high temperature. Amorphous Mn7+, Mn6+ and Mn4+ on the surface of Mn-SC and Mn-H-SC were the active sites for oxidation and adsorption of gaseous Hg-0, which oxidized the elemental mercury into Hg2+ and captured it. Thermal treatment reduced the average oxidation degree of Mnx+ on the surface of Mn-SC from 3.80 to 3.46. However, due to the formation of amorphous MnOx, the surface oxidation active sites for gaseous Hg-0 increased, which gave Mn-H-SC higher mercury adsorption efficiency than that of Mn-SC at high temperature.