Regenerated liquid capable of effectively recovering activity of sintered vanadium-based SCR catalyst

Abstract

The invention discloses a regenerated liquid capable of effectively recovering the activity of a sintered vanadium-based SCR catalyst. The regenerated liquid is characterized by being prepared from, by mass, 0.1-2 parts of organic dispersant, 1-8 parts of ammonium thiosulfate, 0.5-4 parts of ammonium fluoride, 0-40 parts of titanic oxide, 0-20 parts of binder, 0.1-10 parts of tungsten salt, 0.1-3 parts of vanadium salt and 100 parts of deionized water. Due to the fact that the regenerated liquid contains a redispersing agent composed of the organic dispersant, ammonium thiosulfate and ammonium fluoride, sintered and agglomerated vanadium and tungsten species in the sintered vanadium-based SCR catalyst can be well dispersed in a carrier material again through complexation, dispersion and readsorption, catalysis activity can be recovered, sulfur dioxide oxidation rate can be reduced, and service life can be prolonged; meanwhile, consumption of newly added active components can be reduced, and processing cost can be reduced.

Description

technical field [0001] The invention belongs to the technical field of SCR catalyst regeneration liquid, and in particular relates to a regeneration liquid capable of effectively restoring the activity of sintered vanadium-based SCR catalysts. Background technique [0002] By the end of 2015, the total number of selective reduction and denitration catalyst (SCR) implementation projects completed nationwide reached 670 million kw. In these projects, a large number of denitration catalysts were used, most of which were vanadium-based SCR catalysts. The service life of the vanadium-based SCR catalyst is relatively short, and generally deactivates in about 3 years, that is, it needs to be renewed. However, the treatment of the deactivated vanadium-based SCR catalyst becomes difficult because the vanadium in it has strong biological toxicity. "Technical Policy on Nitrogen Oxide Prevention and Control in Thermal Power Plants" Huanfa [2010] No. 10 clearly stated that deactivated c...

AI Technical Summary

Problems solved by technology

Although these two methods have good regeneration ability for catalysts with simple chemical poisoning and micropore blockage, the deactivation of SCR catalysts is often accompanied by severe sintering, that is, the vanadium and tungsten species in the catalyst are well dispersed from fresh to The state slowly aggregates into clusters and crystals, which not only leads to a significant decrease in catalytic activity, but also the aggregation of vanadium species will further lead to SO 2 The oxidation rate increases, which affects the durability of the regenerated catalyst. Therefore, adding new active components directly to the SCR catalyst after a long period of use will not only restore its good activation performance as imagined, but Sometimes the added active components will be aggregated into aggregates to further accelerate the deterioration of its performance - aggravate the agglomeration phenomenon and make SO 2 The oxidation rate is further increased, and the service life is further shortened

In addition, adding a large amount of active components such as expensive tungsten, vanadium, and molybdenum will also lead to an increase in regeneration costs

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