Method and product for increasing SO2 resistance of honeycombed SCR catalyst

Abstract

The invention discloses a method and product for increasing the SO2 resistance of a honeycombed SCR catalyst and belongs to the technical field of coal-fired flue gas denitration. The method specifically includes: preparing a micron-thickness circulating layer, used for the flowing of SCR reaction product N2, on the surface of the honeycombed SCR catalyst; coating the outer surface of the circulating layer with a molecular sieve membrane layer for preventing SO2 from contacting with the SCR catalyst; polishing one side, opposite to the inflow direction of flue gas, of a catalyst module to remove the molecular sieve membrane layer on the side so as to allow N2 to be able to flow out from the circulating layer on the side. The method has the advantages that the sieving effect of the molecular sieve membrane layer is utilized to prevent the SO2 from contacting with the honeycombed SCR catalyst, the denitration efficiency of the honeycombed SCR catalyst is unaffected, the SO2 poisoning problem of the honeycombed low-temperature SCR catalyst is solved, and the industrial application of the low-temperature SCR catalyst is promoted.

Description

technical field [0001] The invention belongs to the technical field of coal-fired flue gas denitrification, and more specifically relates to a method for improving the SO2 resistance of a honeycomb SCR catalyst. 2 performance methods and products. Background technique [0002] The promulgation of "Emission Standards of Air Pollutants for Thermal Power Plants (GB 13223-2011)" and "Action Plan for Energy Conservation and Emission Reduction Upgrading and Renovation of Coal Power Plants (2014-2020)" put forward new regulations on the emission limits of coal-fired power plants. demanding. NOx is one of the main pollutants emitted by coal-fired power plants. To meet the limit requirements of "ultra-clean emissions", efficient and stable flue gas denitrification must be achieved. At present, almost all large coal-fired power plants in my country have adopted selective catalytic reduction (SCR) technology as tail gas denitrification technology. Generally, the dosage of SCR cataly...

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Problems solved by technology

[0008] The method of directly applying the patent ZL 2016 1 0225266.5 cannot be used in actual industrial applications

If the idea in patent ZL 2016 1 0225266.5 is used, the molecular sieve is directly coated on the surface of the honeycomb catalyst to prevent SO 2 contact with the SCR catalyst, then due to the N 2 The molecular dynamics diameter is slightly larger than that of SO 2 , so the use of molecular sieve membranes to prevent SO 2 While in contact with the SCR catalyst, the product N of the SCR reaction 2 It also cannot diffuse well, causing the SCR reaction to fail to continue.

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