循环灰对NH_3氧化反应影响的实验研究  

Experimental Study on the Effect of Circulating Ashes on Ammonia Oxidation

作　　者：侯祥松[1] 常东武[1] 张海[1] 岳光溪[1] 

机构地区：[1]清华大学热能工程系,北京市海淀区100084

出　　处：《中国电机工程学报》2008年第5期57-62,共6页Proceedings of the CSEE

基　　金：国家重点基础研究发展规划项目(2006CB200301)~~

摘　　要：循环灰对NH3氧化的催化作用对循环流化床锅炉的喷氨脱硝效果有重要影响。文中利用固定床反应器研究了石英砂、循环灰和循环灰主要成分对NH3氧化反应的影响。在实验中利用傅里叶红外光谱仪测量了NH3和O2通过反应器后产物气体中的NH3、NO和N2O的体积分数。与NH3气相反应氧化的结果对比,循环灰能够促进NH3的氧化,NH3的转化率显著提高,主要生成NO、N2O和N2。循环灰的主要成分中,铁氧化物Fe2O3和Fe3O4及CaO对NH3的氧化有较强的催化活性,并促进N2O的生成;而SiO2和Al2O3对NH3的氧化性能影响不大。NH3氧化生成产物的选择性与反应温度、循环灰的成分等因素有关。The de-NOx efficiency by ammonia injection in circulating fluidized bed （CFB） boiler is influenced by ammonia catalytic oxidation over circulating ash. In order to assess the mechanisms of thermal de-NOx in CFB boilers with ammonia （NH3） injection, the effect of circulating ashes on NH3 oxidation was experimentally studied. The experiments were conducted on a fixed bed reactor using quartz sand, circulating ash and its major component as bed materials. The concentrations of NH3, NO and N2O in exhaust gas from the reactor were measured with Fourier transform infrared（FTIR）. Compared with the quartz sand on which NH3 is nearly completely oxidized by homogeneous reactions, circulating ashes showed catalytic effect on NH3 oxidation, converting NH3 into NO, N2O and N2. The results also showed that for the major component of circulating ash, SiO2 and Al2O3 are nearly inert, while Fe2O3, Fe304 and CaO act as active catalysts. The formation of NO and N2O through NH3 oxidation is selectively catalyzed by circulating ashes, and influenced by ash composition, reaction temperature and O2 concentration.

关 键 词：氨气 循环流化床锅炉 循环灰 催化 N2O 

分 类 号：TK16[动力工程及工程热物理—热能工程]