燃气电厂蜂窝式SCR脱硝催化剂性能检测与评估

Performance Assessment and Analysis of Honeycomb SCR Denitration Catalyst in Gas Power Plant

选择性催化还原(SCR)烟气脱硝催化剂的性能优劣直接关系到SCR脱硝设备的脱硝效率及运行效果。以某9F级燃气电厂在运SCR蜂窝式脱硝催化剂为研究对象,对其在约60000 h运行状态下的几何外观、理化特性和工艺特性进行了检测与分析。采用X射线荧光光谱(XRF)、电感耦合等离子体发射光谱(ICP)、X射线衍射(XRD)、扫描电镜(SEM)和氮气吸脱附等表征方法对催化剂结构形貌以及理化特性进行分析,并模拟催化剂出厂检测工况进行活性测试。结果表明,催化剂整体性能保持良好,但催化剂样品微量元素钠、铁含量偏高,存在碱金属中毒现象,且孔径分布图显示微孔结构中大孔段消失,上述检测结果表明催化剂的脱硝效率下降,并引起脱硝系统喷氨量增大。考虑该电厂目前NO x排放仍达所在地方标准要求,建议电厂在运行中关注喷氨量变化趋势,定期跟踪检测催化剂性能,以便及时发现催化剂可能出现的快速失活现象,并对催化剂进行再生或更换处理。

The performance of the denitration catalyst could affect the efficiency and operation behavior of SCR system directly.In this paper,the exterior appearance as well as the physicochemical and operational characteristics of the in transit Honeycomb SCR Denitration catalyst are tested and analyzed after 60000 h operation in a 9F Gas Power Plant.XRF,ICP,XRD,SEM and N 2 adsorption and desorption were used to characterize the structure,morphology and physicochemical properties of the catalyst.Activity test of simulated catalyst under factory test conditions.The results show that the overall performance of the catalyst is well maintained,but the contents of sodium and iron are high in the catalyst sample,the catalyst sample is alkali metal poisoning.In the pore size distribution diagram we can see the large pore segment of the microporous structure disappears.So this results show that the denitration efficiency of catalyst decreased and the ammonia injection of SCR system increased.Considering the local standard and the NO x concentration we suggested that the power plant should pay attention to the variation trend of ammonia injection amount during operation,track and detect the catalyst performance regularly,so as to find out the possible rapid deactivation phenomenon of the catalyst in time,and carry out regeneration or replacement treatment of the catalyst.