Method for solving problem of SO2 poisoning of low-temperature SCR denitration catalyst

Abstract

The invention discloses a method for solving problem of SO2 poisoning of a low-temperature SCR denitration catalyst. Basic gas reacts with metal sulfates deposited onto the surface of the catalyst; metal oxides are replaced out; the catalyst activity is recovered; the NO2 or NO and O2 are used for decomposing ammonium salt deposited onto the surface of the catalyst; the catalyst is prevented frombeing covered. The method has the advantages that the poisoned catalyst can be regenerated off line; the catalyst surface metal sulfates and ammonium salt generation and decomposition can reach dynamic balance on line; the catalyst active ingredients are not lost and are not covered by ammonium salt; the goal of resisting SO2 poisoning of the low-temperature SCR denitration catalyst is reached. The method can also be used for the regeneration of other SO2 poisoning catalysts, such as the generation of the SO2 poisoning methane catalytic oxidation catalysts. In addition, in the online use process, the method can also be used for converting some metal oxide dust in the smoke gas into effective active ingredients of the catalyst. The method has the advantages that the service life of the catalyst is effectively prolonged; the operation cost of the SCR system is reduced.

Description

technical field [0001] The invention belongs to the field of energy and environmental materials, and in particular relates to a low-temperature SCR denitrification catalyst SO 2 poisoning method. Background technique [0002] At present, my country's air pollution problem is very serious, mainly due to the excessive discharge of polluting gases such as sulfur dioxide, nitrogen oxides, and dust particles. Among them, nitrogen oxides can directly stimulate the human lungs and cause respiratory diseases, and are also an important reason for the formation of photochemical smog and acid rain. Therefore, controlling and reducing nitrogen oxide emissions is an important measure to protect the atmospheric environment. For this reason, my country has introduced strict nitrogen oxide emission standards, among which Beijing requires the city's new boilers to implement 30mg / m 3 The emission limit value of this standard is close to the most stringent boiler emission standard in the wo...

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Problems solved by technology

[0006] However, the reality is that the catalytic performance of most low-temperature active catalysts is sufficient to catalyze SO 2 Oxidation to SO 3 , therefore, it is difficult to suppress the formation of sulfate on the surface of the catalyst, so that the catalyst's low-temperature SO 2 The problem of poisoning has not been solved in essence

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