烟气成分对燃煤飞灰汞吸附的影响

在小型固定床试验台上开展了烟气成分对燃煤飞灰汞吸附影响的试验研究。结果表明：在CO2-O2-N2的体系中，单独加入SO2，飞灰的汞吸附能力表现出与SO2的浓度有密切的关系；单独加入0~100′10-6 HCl，随着HCl浓度的增加，飞灰的汞吸附能力逐渐增加，在50′10-6左右达到最佳吸附效果，而后飞灰的汞吸附能力有所降低，但影响不大；单独加入NO，大大促进了飞灰对汞的吸附。HCl和SO2共同作用时，飞灰对汞的吸附效果要好于SO2单独存在时，但比HCl单独存在时要差一些；再加入NO后飞灰的汞吸附效率与吸附量都得到很大的提高。飞灰对Hg0的吸附是物理吸附与化学吸附双重作用的结果。

Effect of Flue Gas Components on Mercury Adsorption by Coal-fired Fly Ash

An experiment was conducted to study the effects of flue gas components on the mercury adsorption by coal-fired fly ash by using a bench-scale fixed bed. The results show that in the CO2-O2-N2-SO2 system, the mercury adsorption capacity of fly ash has close relation with the concentration of SO2. In the CO2-O2-N2-HCl system, the range of HCl concentration is 0~100′10-6, and the mercury adsorption capacity of fly ash gradually improves as the HCl concentration increases, and the optimum effect of mercury adsorption is possibly realized at the HCl concentration of 50′10-6, then the mercury adsorption capacity becomes lower but little effect. In the CO2-O2-N2-NO system, NO largely enhances the mercury adsorption. The effect of mercury adsorption by fly ash for the joint action of SO2 and HCl is better than that of SO2 alone, but worse than that of HCl alone. In the CO2-O2-N2-HCl-SO2-NO system, the adsorption efficiency and the capacity of mercury are greatly increased. The mercury adsorption by fly ash is a combination of the chemical adsorption and physical adsorption.