Study On The Preparation Technology And Denitrification Performance Of Cordierite-based Vanadium SCR Catalysts

China has lots of coal, coal accounted for the vast majority of China's energy structure. With the development of China's industrialization, more and more nitrogen oxides discharged into air, which come from coal combustion in the Coal-fired power plant and has become a major component of air pollution. There are many denitration technology in the world, selective catalytic reduction (SCR) NOx is the most important technology of flue gas denitrification, both at home and abroad dedicated to high-performance catalyst for a wide range of research and development, studies conducted in western countries more mature, has successfully achieved a commercial , while there is no independent research and development of China's commercial SCR catalyst. Furthermore, most of the commercial SCR catalyst preparation are kneading method: all the ingredients were mixed together with help squeeze agent and binder, kneaded and baked to the finished. In this method, the weight of TiO2 accounted for 80% of the total catalyst weight, there are high costs and insufficient use of highly active component.In this paper, Al2O3 and TiO2 sol were prepared by the sol-gel method, the TiO2 /CC carrier and TiO2-Al2O3/CC were prepared with ultrasonic impregnation and static impregnation, respectively, and through the impregnation load active components WO3 and V2O5, three kinds catalysts of V2O5-WO3/TiO2, V2O5-WO3/TiO2/Al2O3 (ultrasonic impregnation), V2O5-WO3/TiO2/Al2O3(static impregantion) were prepared. Discussed the preparation process of catalyst pretreatment, carrier, other active components and additives load method. The preparation of the carrier introducted ultrasound innovativly. Combined the results of SEM, BET and XRD, the influenced factors of the catalyst preparation were analysed. The results showed that: (1) Pre-treatment with 15% H2O2 significantly increased surface area compared with HNO3; (2) In the supports load process: room temperature impregnation and ultrasonic assisted impregnation process were better than water bath heating impregnation process; ultrasound technology greatly reduced the load processing time; the activity with TiO2/Al2O3 double oxide carrier catalysts were better than catalyst of TiO2 single oxides catalysts; (3) In the active components and additives loading process, a total impregnation or step impregnation were found little effect on the catalytic activity.Catalyst activity in complete set of device evaluation activity assay was carried out to study the effect of its activity under various substances(V2O5, WO3, TiO2) and catalytic reaction conditions (temperature, O2 concentration, ammonia nitrogen ratio and space velocity). The results showed that: (1) the best loading content of TiO2 ranged within16% to 28%, optimal loading of WO3 ranged within 4% to 13%, the best loading of V2O5 ranged within 1% to 3%; (2) NO denitrification rate increases with the increase value of imports and the decrease of space velocity, denitrification rates in the conditions with ammonia ratio of 1.0-1.2 and O2 concentration of 2.0-2.5% (NO = 500ppm) were relatively higher. At 10000h-1 space velocity, catalyst denitration rate up to 76% of 350℃- 450℃.