移动床吸附脱除火电厂烟气中汞的试验研究

Experimental study on removal of mercury emission from the flue-gases by using moved bed adsorption apparatus

为寻求火电厂吸附脱汞工艺条件,在有工业化前景的移动床吸附装置上,采用以火电厂飞灰为原料制备的2种吸附剂,模拟火电厂烟气汞浓度、温度开展试验研究。利用组合多功能X射线衍射仪、能量色散型X射线荧光光谱仪、全自动比表面积测定仪、扫描电子显微镜对样品的物理化学性质进行研究。结果表明:在60~100℃,主要为物理吸附脱汞,随着温度升高,脱汞率降低;随着吸附时间的延长,脱汞率呈下降趋势。移动床吸附装置的脱汞率高于固定床吸附装置。由于吸附剂A的比表面积、孔隙结构优于吸附剂B,含碳量高,因此脱汞率较高。

In order to find the optimum technology conditions for mercury adsorption removal in flue gases of thermal power plant, the experimental study of mercury removal was conducted on an industrial prospective switchable moved-bed apparatus with two adsorbents. A simulated flue gas was provided according to the mercury concentration and temperature in actual power plant, and two kinds of adsorbents were made by adding bentonite into fly ash in certain proportion. The physical and chemical properties of the samples were studied by combined multi-functional X ray diffraction meter, energy dispersive X ray fluorescence spectrometer, automatic surface area meter and scanning electron microscope. The results showed that the main mercury removal process was physical adsorption at 60-100 ℃, the mercury removal efficiency decreased when the adsorption temperature and adsorption time increased, and the mercury removal efficiency of adsorbent A was significantly higher than that of adsorbent B, because A has higher carbon content and better pore structure. On the whole, the mercury removal efficiency using moved-bed adsorption apparatus is higher than that of fixed-bed.