Recently, the State Environmental Protection Bureau delegation went to Jiangsu, Shanghai investigagion selective catalytic reduction denitration catalyst recycling and subsequent disposal. The study is mainly to promote the selective catalytic reduction denitration resource utilization and safe disposal of the catalyst after elimination, rational planning its whereabouts, thus to reduce the running cost of environmental protection, resolve the environmental issues.

 

Denitration system has already become an important part of coal-fired power plant, wherein the tungsten trioxide denitration catalyst is the core part of SCR system which takes the higher proportion of total investment. Currently, the denitration catalyst commonly used in the market are based on titanium dioxide as the carrier, vanadium pentoxide as the main active ingredient, tungsten trioxide (and / or molybdenum trioxide) as the anti-oxidant, anti-sulfide, anti-toxic auxiliary component. Theoretically, as the catalyst, it doesn’t as a reactant and cannot be consumed, so its effect is supposed to be permanent. However, in China, the catalyst market is now really staying in a relatively chaotic situation; usually, the catalyst will be deactivation after about three years. The main reasons which cause catalyst deactivation are sintering, poisoning, intoxication, calcium, alkali metal poisoning, and poisoning of sulfur trioxide, and the voids plug fouling of catalyst, ect..

 

The regeneration or replacement of denitration catalyst will directly affect the running costs of the SCR system, therefore, the research on SCR catalyst deactivation and regeneration has an important practical significance. In practical applications, the regeneration techniques of failure tungsten trioxide denitration catalyst are generally the two kinds of live regeneration and plant regeneration. Since the site regeneration will pollute the around environment and water quality of the plant, also the quality and performance of catalyst which regenerated in the site are poor, and therefore, plant regeneration is the development direction. SCR catalyst is impregnated plant regeneration during a series of cleaning, ash removal, ultrasonic treatment, the active ingredient (vanadium, tungsten, molybdenum, etc.), and finally achieve the goal of restoring catalyst activity.