SCR催化剂低温协同脱除二噁英和NOx研究进展

摘要

The dioxincatalytic degradation mechanism and the NH3-SCR denitrification pathways was described.The research progress in synergistic removal of dioxin and NOxby conventional SCR catalysts (V2O5-WO3/Ti O2) was also focused on this study.It was concluded that the active temperature window of conventional SCR catalyst for denitrification is 300～400℃, and that for dioxin decomposition is 200～300℃.It was difficult to achieve the synergistic removal of dioxin and NOxat low temperature (＜200℃).In order to avoid the extra energy consumption and improve the synergistic removal efficiency of dioxin and NOxat low temperature, improve the catalyst activity at low temperature is one of the most effective methods.Therefore, catalyst internal components modification and external assistance were suggested to improve the catalyst activity at low temperature (＜200℃), including supporter selection and modification, elemental doping, ozone addition, UV irradiation and plasma assisstance.%分别阐述SCR催化剂降解二噁英机理和NH3-SCR脱硝机理;重点关注常规SCR催化剂(V2O5-WO3/Ti O2)协同脱除二噁英和NOx的研究进展.得出常规SCR催化剂脱硝活性温度区为300～400℃,催化降解二噁英的活性温度区为200～300℃,因此难以在低温区(＜200℃)实现两者协同脱除.为了避免烟气再热所需额外能耗,提高二噁英和NOx低温协同脱除效率,指出提高催化剂低温活性是解决上述问题的有效途径之一,并从催化剂成分改性和多途径耦合两方面提出了几种提升催化剂低温(＜200℃)活性的方法,详细阐述了载体选择和改性、元素掺杂、臭氧添加、紫外光照射、等离子体辅助等方法对催化剂低温活性的提升作用.