哥玩 Abstract: The effects of gas compositions舊睡 on NOx reduction and NH哥懂3 slip by selective non-catalytic r習線eduction (SNCR) with NH3 were investigated in a simu科船lated cement precalciner at小制mosphere. The result我動s show that the presence員聽 of H2O improves NOx reduction and wid科得ens the reduction temperature window 森村significantly. O2 is indispensable for reducing NOx. The 算如optimum reduction tempera山笑ture decreases and the tempera男坐ture window widens to a lower te從村mperature with the inc就子rease of O2 content. In addition, the increase of O國子2 content also results in a 綠志decrease of the maximum NOx redu見習ction efficiency. The effect 歌事of SO2 on NOx reduction is n有金egligible in the simulated preca吧唱lciner atmosphere. To increase C對湖O concentration makes NO re務南duction take place at relat計爸ively low temperatures. However, NH3 will tend to be oxidized into NO 影錢instead of reducing NO 懂市after entering the stream contai關時ning O2 at high temperatures if it is initially章黃 blended with a high concentratio哥船n of CO in an oxygen-free environmen鐘吧t. The increase of H2O, O2, SO2 or CO concentration is helpful員這 to reduce NH3 slip in the temperature region be西東low 900 °C. These effe舞少cts are resulted from the fact that 舞好the generation and c動開onsumption of O and OH rad村電icals which are crucial to NO re匠了duction and formation can be infl請東uenced by the four gas compositions. In作笑 industrial operation of SNCR算又 for cement precalciner,輛房 these effects should be taken化技 into account to increase NOx red知和uction efficiency and av藍人oid NH3 slip.
