石灰石脱硫反应对喷氨脱硝反应影响的实验研究

An Experimental Study of the Effect of Limestone Desulfurization Reaction on Ammonia-injected Denitrification Reaction

在循环流化床锅炉炉膛尾部或旋风分离器入口喷入氨气可以降低烟气中的NOx含量。在循环流化床锅炉中,为脱硫而加入的石灰石会影响喷氨脱硝反应。通过实验研究了石灰石热解产物和脱硫产物对喷氨脱硝反应的影响,发现石灰石的热解产物在脱硫前,比表面积较大,CaO对喷氨脱硝反应显示出一定的催化活性,能够促进喷氨脱硝反应;石灰石的脱硫产物,对喷氨脱硝反应影响较小,但在T>1 200 K以上时,能够促进NH3的氧化,降低NH3的逸出,对喷氨脱硝反应有利。

To inject ammonia into a CFB(circulating fluidized bed) boiler at its furnace tail portion or at the inlet of a cyclone separator can reduce the NOx content in flue gases.In a CFB boiler,the injection of limestone for the purpose of desulfuration may influence the ammonia-injected denitrification reaction.An experimental study was conducted of the impact of pyrolytic and desulfuration products of the limestone on ammonia-injected denitrification reaction.It has been found that the pyrolytic reaction products of limestone prior to desulfuration have a relatively big specific surface area and CaO exhibits a definite catalytic activity,which can promote the ammonia-injected denitrification reaction.The desulfuration products of the limestone exercise a relatively small influence on the ammonia-injected denitrification reaction.When the temperature is above 1 200 K,however,the products in question can promote the oxidation of NH3 and reduce the escape of NH3,both aspects being considered as favorable to the ammoniainjected denitrification reaction.