活性焦汞吸附性能实验研究

Experimental Study on Mercury Absorption Performance of Activated Coke

由于SO_2/Hg协同脱除具有较高经济性,采用实验室固定床反应器研究了120℃时AC(活性焦)在模拟烟气条件下协同脱除SO_2/Hg的性能。通过系统地研究温度及O_2,H_2O,SO_2和Hg浓度对AC吸附Hg效率的影响,发现AC对Hg的吸附能力较低。AC吸附Hg的关键步骤是对HgO的氧化,AC表面吸附态的氧是Hg^0的吸附活性位,表明SO_2/Hg的吸附过程既包括物理吸附也包括化学吸附。AC表面存在着SO_2和Hg的竞争吸附,高浓度的SO_2将会降低Hg的吸附效率。增加烟气中的H_2O将增强汞的吸附效率。

The collaborative SO2/Hg removal technology is of high economic efficiency. By using fixed bed reactor in laboratory, the paper investigates the collaborative SO2/Hg removal performance of activated coke（AC） at the temperature of 120 ℃ in a simulated gas condition. Through a systematic research on the impact of temperature, O2, H2 O, SO2 and Hg on mercury absorption of AC, it is found that AC is inferior in mercury absorption. The key step of mercury absorption is the oxidation of Hg^0, and the adsorbed O2 on AC surface is the active site for Hg^0 oxidation, which indicates that adsorption process of SO2/Hg is a combination of physisorption and chemisorption. There is competitive adsorption between SO2 and mercury on the surface of AC, and the high concentration of SO2 causes low mercury removal efficiency. Increase of H2 O in flue gas can raise mercury absorption efficiency.