SCR催化剂对汞的催化氧化研究进展

Research Progress in Catalytic Oxidation of Mercury by SCR Catalysts

文章综述了目前国内外选择性催化还原(SCR)催化剂催化氧化燃煤烟气中汞的研究现状。介绍了钒基、铜基、铁基、锰基、铈基以及贵金属SCR催化剂对汞的催化氧化性能;分别分析了烟气温度、烟气组分(Cl2、HCl、SO2、NH3等)、空速等因素对各催化剂汞氧化性能的影响;最后运用文献对比方法综合概括了燃煤烟气条件对汞氧化的影响,并结合我国燃煤电厂现状,对SCR催化脱汞技术的发展方向提出建议:利用SCR催化剂实现燃煤烟气中汞的氧化,结合现有污染物控制设备实现汞的脱除,是一种经济、高效的燃煤烟气脱汞技术;当前应深入研究SCR催化剂对汞的催化氧化机理,开发能够实现NOx与汞协同控制的,稳定、高效、普适性强的低温SCR催化剂。

This paper reviews the recent status in the researches of using selective catalytic reduction （SCR） catalysts for oxidizing mercury emitted from coal combustion flue gas. Characteristics of mercury catalytic oxidation by catalysts such as vanadium-based, copper-based, iron-based, manganese-based, cerium-based and noble metal based were summarized. The influence of temperature, flue gas components, e.g. C12, HC1, SO2 and NH3 and space velocity on mercury oxidation performance of the catalysts was briefly discussed respectively. Finally, the performances of SCR catalysts reported in literatures were analyzed, the major research tendency was explored and the relevant proposal made when taking into consideration the situation of coal-fired power plants in the country. Summarily, using of SCR catalysts combined with existing air pollution control devices can facilitate mercury removal from coal combustion flue gas in an economical and efficient way. The follow-up studies suggested in this paper include to deepen the probes into the mechanism involved in mercury oxidation by SCR catalysts, and to develop stable, effective low-temperature SCR catalysts that are capable of controlling emissions of NOx and mercury simultaneously.