Black arsenic poisoning SCR denitration catalyst regeneration method

Abstract

The invention relates to a black arsenic poisoning SCR denitration catalyst regeneration method, in particular to a catalyst cleaning process for efficiently removing black arsenic by a cleaning solution with a neutral pH value. The invention aims to provide the black arsenic poisoning SCR denitration catalyst regeneration method. Under the condition that the pH value is neutral, the black arsenicon the surface of the SCR denitration catalyst is removed to the greatest extent, the original mechanical strength of the catalyst is not reduced, the loss of active components of the cleaned SCR denitration catalyst is reduced as much as possible, and certain anti-poisoning additives are implanted to enable the catalyst to have certain anti-black arsenic poisoning capability.

Description

technical field [0001] The invention relates to a method for regenerating an SCR denitrification catalyst poisoned by black arsenic, in particular to a catalyst cleaning process for efficiently removing black arsenic with a cleaning solution with a neutral pH. Background technique [0002] SCR denitrification technology has a remarkable effect on boiler flue gas NOx control, and the technology is mature. It has become one of the most widely used and most effective flue gas denitrification technologies in the world. In recent years, my country's SCR denitrification project has developed rapidly, and its application in coal-fired power plants has become more popular, and the market loading of denitrification catalysts has also increased year by year. However, since the chemical life of the catalyst is usually 16,000-24,000 hours, it brings a greater pressure on the disposal of the deactivated catalyst. At present, there has been a demand for the replacement of the deactivated ...

AI Technical Summary

Problems solved by technology

Black arsenic brought in by flue gas 2 o 3 The active site V that can be adsorbed on the surface of the catalyst 2 o 5 and TiO 2 , causing the hydroxyl groups on the surface of the catalyst to be blackened by black arsenic 2 o 3 Alternative, adsorbed black black arsenic 2 o 3 with O 2 and V 2 o 5 The reaction produces black black arsenic 2 o 5 , black black arsenic 2 o 5 Occupy and destroy the active site of the catalyst; at the same time, black black arsenic 2 o 3 Diffusion accumulates in the pores of the catalyst, restricting the diffusion of reactant gases in the catalyst

Since black arsenic poisoning of SCR denitrification catalyst is irreversible, it is easy to cause a decrease in catalyst activity. Therefore, it is necessary to invent a method to effectively remove black arsenic compounds on the surface of deactivated SCR denitrification catalyst to solve the regeneration problem of SCR denitrification catalyst poisoned by black arsenic. of

[0005] Treating the deactivated SCR denitration catalyst with strong acid and strong alkali will damage the mechanical strength of the regenerated catalyst and reduce the service life of the SCR denitration catalyst; New toxic components-sodium ions and calcium ions are added, resulting in a large amount of waste liquid in the subsequent cleaning work, which increases the cost of wastewater treatment; using H 2 o 2 When the solution cleans the black arsenic on the surface of the deactivated SCR denitration catalyst, it will cause the active component V on the catalyst surface 2 o 5 churn, increasing the cost of late-stage active implants for conventional regenerative techniques