Yuanchen Technology: Precautions in the use of denitrification catalyst (2/2)

Jun 22, 2022
If you want to achieve the reaction by denitrification catalyst, you need to consider other reaction requirements when operating, especially the very critical temperature, PH value, etc., and also the choice of oxides and reductants. Therefore, it is important to pay attention to different details in this regard, especially some precautions. The denitrification reaction in the industrial field is very important, and it has more types, for example, in the production of insulation pipe, its production process in this regard also includes this reaction, and for the galvanization reaction, there is also such a process, and for the water cycle reaction, there is also such a reaction, for this reason, we should pay attention to different concerns when using.

Effect of water vapor

For most flue gas SCR denitrification units in operation, condensation of water vapor should be avoided. Water condensation on the denitration catalyst can transfer toxic substances (alkali metals, calcium, magnesium) from the fly ash to the denitration catalyst, which can lead to deactivation of the denitration catalyst. In addition, it can harden the fly ash and clog the denitration catalyst, causing the performance of the soot blowing unit to deteriorate. The risk of poisoning in oil-fired boilers is higher, mainly due to the high content of water-soluble alkali metals. Poisoning can become severe if the boiler is burning biomass fuels, due to the high water-soluble K content in these fuels.

Effect of fly ash

Fly ash is a major cause of denitrification catalyst blockage. Small particles of fly ash are deposited in the pores of the denitrification catalyst, preventing NOx, and reaching the surface of the denitrification catalyst, thus causing the denitrification catalyst to deactivate. The fly ash also causes wear and tear of the denitration catalyst. The measures to reduce the clogging and wear of denitration catalyst are mainly.

1) Optimize the flow field design by using CFD computer numerical simulation and physical model test to adjust the airflow distribution in the SCR reactor to avoid low velocity areas or dead ends of flue gas flow.

2) Install soot blowers above each layer of denitrification catalysts to perform regular blowing of denitrification catalysts.

(3) Select the appropriate flue gas velocity inside the denitration catalyst to ensure low flue gas resistance and low abrasion, but also to effectively use the flow of flue gas to avoid ash plugging.

4) Adopt top hardening technology for denitrification catalyst to improve the wear of denitrification catalyst.

Industrial SCR Honeycomb Catalysts

Effect of Sulfur and Ammonium Sulfate

Sulfur and sulfur ammonium salts are another major cause of denitrification catalyst blockage. It is the main active component of SCR denitrification catalyst, but also promotes oxidation into. The system ejected below 250°C can easily form sulfur ammonium salts, which will not only block the denitrification catalyst pores and micropores, but also cause sticky fouling of downstream heat exchange equipment.

Sintering phenomenon

When the temperature rises to 450°C, sintering of the denitrification catalyst occurs, resulting in deactivation of the denitrification catalyst. Therefore, we design the SCR reaction in a reasonable temperature range, and the best temperature for the reaction is usually 360°C.


(1) The most used SCR denitrification catalysts in engineering are mainly composed of oxides.

(2) In the process of SCR application, passivation of denitrification catalysts can be caused by alkali metal influence, alkaline earth metal influence, arsenic poisoning, sulfur and ammonium sulfide influence, sintering and other factors, which need to be prevented by taking corresponding measures.

(3) The research direction of denitrification catalysts should meet the domestic engineering needs, focusing on the design and preparation of high activity denitrification catalysts, improving the composition of denitrification catalysts, increasing the activity, reducing the cost and improving the life of denitrification catalysts.

(4) In practical engineering application, denitrification catalysts should be protected by reasonable flow field design to prevent deposition of fly ash and regular blowing of denitrification catalysts; temperature control to prevent sintering of denitrification catalysts; denitrification catalysts should be protected when they are out of use.

Anhui Yuanchen Environmental Protection Technology Co., Ltd ("Yuanchen Technology") is a high-tech enterprise integrating R&D, production and sales of dust bag and denitrification catalyst. The dust bags (mainly PPS, PTFE, P84 and composite series filter materials) and SCR denitrification catalysts have been widely used in cement, steel, glass kilns, waste incineration power generation, biomass power generation, non-ferrous metal smelting and other industries. In the future, Yuanchen Technology will be guided by "becoming the guardian of global ecological environment", always rooted in environmental protection, and insist on the great cause of guarding the blue sky and white clouds. Leveraging on the national ecological civilization construction pattern, we will continue to deepen technology, optimize management, strengthen brand, refine industry, solidify advantages, and create synergistic value for industry through comprehensive and integrated governance and services.


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