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

To evaluate the removing effect of different forms of NO_x 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 NH_3/NO on NO,NO_2 and N_2O 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 NH_3.High temperature could promote the removal of NO and oxidation of NH_3 to N_2O.And increasing space velocity,the NO removal would trend from rise to decline; as well,high mole ratio of NH_3/NO could accelerate the NO removal and NH_3 releasing.However,the removal of NO_2,N_2O is hard to achieve completely react with NH_3.Thus,for ultra-low NO_x emission,the coal combustion parameters should be optimized properly to avoid the formation of N2 O.