商用蜂窝式SCR催化剂脱除NO_x试验研究

为了评价燃煤电厂广泛采用的选择性催化还原工艺对不同形态NO_x的脱除效果,以某商用蜂窝式SCR催化剂为例,在SCR脱硝试验装置上研究了氧量、温度、空速、氨氮摩尔比等反应条件对NO、N_2O和NO_2脱除过程的影响。结果表明,氧量可以促进NO氧化以及NO与氨的催化还原反应;高温可以促进NO的脱除和氨气氧化为N_2O;空速升高会导致NO脱除率先升高后降低;氨氮摩尔比提高在促进NO脱除的同时会增加氨逃逸;与NO_2可以完全脱除相反,N_2O与氨气不发生反应。因此,为真正实现NO_x的超净排放,应适当控制锅炉运行参数避免N_2O的生成。

Experimental research on NOx removal by using a commercial honeycomb type SCR catalysts

To evaluate the removing effect of different forms of NOx by SCR (selective catalytic reduction) technology widely used in coal -fired power plants,this study takes the commercial honeycomb type SCR catalysts as an example to investigate the influence of oxygen concentration,temperature,space velocity and mole ratio of NH3/NO on NO,NO2 and N2 O removing process in a SCR denitration test rig.The results showed that oxygen could improve the oxidation of NO and catalytic reducing reaction between NO and NH3.High temperature could promote the removal of NO and oxidation of NH3 to N2O.And increasing space velocity,the NO removal would trend from rise to decline;as well,high mole ratio of NH3/NO could accelerate the NO removal and NH3 releasing.However,the removal of NO2,N2O is hard to achieve completely react with NH3.Thus,for ultra-low NOx emission,the coal combustion parameters should be optimized properly to avoid the formation of N2O.