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A method for removing iron compounds on the surface of deactivated scr denitrification catalyst

A denitration catalyst, iron compound technology, applied in catalyst regeneration/reactivation, chemical instruments and methods, physical/chemical process catalysts, etc. , the mechanical strength of the denitration catalyst is reduced, and the effects of fly ash removal, surface active site recovery and high efficiency are achieved.

Inactive Publication Date: 2016-08-24
SOUTH CHINA UNIV OF TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Its described cleaning agent comprises organic acid (oxalic acid etc.) and mineral acid (sulfuric acid, hydrofluoric acid etc.), the disclosed method can effectively remove the iron compound accumulated on the catalyst surface, but because sulfuric acid and hydrofluoric acid are strong acids, It will corrode the catalyst steel substrate and the catalyst body, which will lead to a significant decrease in the mechanical strength of the denitration catalyst (especially the plate catalyst), and at the same time reduce the adhesion of the active components to the steel substrate, which seriously affects the regeneration quality and regeneration performance of the catalyst.

Method used

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  • A method for removing iron compounds on the surface of deactivated scr denitrification catalyst
  • A method for removing iron compounds on the surface of deactivated scr denitrification catalyst
  • A method for removing iron compounds on the surface of deactivated scr denitrification catalyst

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Embodiment 1

[0035] A method for removing iron compounds on the surface of an inactivated SCR denitration catalyst, comprising the steps of:

[0036] (1) prepare the tartaric acid solution of 3.0g / L, and adjust the pH value of the tartaric acid solution to 7 with ammonium carbonate, then add the lauric acid diethanolamide of 0.9g / L, obtain chemical cleaning agent;

[0037] (2) Purge the fly ash in the honeycomb deactivated SCR denitrification catalyst with a negative pressure dedusting device;

[0038] (3) Clean the honeycomb deactivated SCR denitrification catalyst with high-pressure deionized water;

[0039] (4) Put the honeycomb deactivated SCR denitrification catalyst after washing into the chemical cleaning agent obtained in step (1), clean it with 20Hz ultrasonic at 50°C for 10min, take it out, then rinse it, take it out and dry it in air at 80°C , and then roasted at 400° C. for 3 hours, and the cleaning process is completed, and a honeycomb SCR denitration catalyst with surface iron...

Embodiment 2

[0041] A method for removing iron compounds on the surface of an inactivated SCR denitration catalyst, comprising the steps of:

[0042] (1) prepare the tartaric acid solution of 2.26g / L, and adjust the pH value of the tartaric acid solution to 7 with ammonium carbonate, then add the lauric acid diethanolamide of 0.9g / L, obtain chemical cleaning agent;

[0043] (2) Purge the fly ash in the honeycomb deactivated SCR denitrification catalyst with a negative pressure dedusting device;

[0044] (3) Clean the honeycomb deactivated SCR denitrification catalyst with high-pressure deionized water;

[0045] (4) Put the honeycomb deactivated SCR denitrification catalyst after washing into the chemical cleaning agent obtained in step (1), and take it out after ultrasonic cleaning at 100 Hz for 5 minutes at 20°C, then rinse it, take it out and dry it in air at 100°C , and then roasted at 400° C. for 3 hours, and the cleaning process is completed, and a honeycomb SCR denitration catalyst ...

Embodiment 3

[0047] A method for removing iron compounds on the surface of an inactivated SCR denitration catalyst, comprising the steps of:

[0048] (1) prepare the tartaric acid solution of 5.0g / L, and adjust the pH value of the tartaric acid solution to 7 with ammonium carbonate, then add the fatty alcohol polyoxyethylene ether (JFC) of 0.9g / L, obtain chemical cleaning agent;

[0049] (2) Purge the fly ash in the honeycomb deactivated SCR denitrification catalyst with a negative pressure dedusting device;

[0050] (3) Clean the honeycomb deactivated SCR denitrification catalyst with high-pressure deionized water;

[0051] (4) Put the honeycomb deactivated SCR denitrification catalyst after washing into the chemical cleaning agent obtained in step (1), and take it out after ultrasonic cleaning at 50 Hz for 5 minutes at 30°C, then rinse it, take it out and dry it in air at 60°C , and then roasted at 400° C. for 3 hours, and the cleaning process is completed, and a honeycomb SCR denitrati...

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PUM

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Abstract

The invention discloses a method for removing iron compounds from the surface of a deactivated SCR (Selective Catalytic Reduction) denitration catalyst. The method comprises the following steps: (1) mechanically dedusting the deactivated SCR denitration catalyst; (2) performing bubbling washing on the deactivated SCR denitration catalyst by using high pressure deionized water; and (3) ultrasonically cleaning the washed deactivated SCR denitration catalyst in a chemical cleaning agent, and then performing bleaching, drying and roasting to obtain the SCR denitration catalyst without surface iron compounds, wherein the chemical cleaning agent is a neutral mixed solution containing tartaric acid derivatives and a surfactant. According to the method, the chemical cleaning agent is a neutral pH solution and has no acid corrosion to a denitration catalyst steel frame and a catalyst body, and therefore defects of existing cleaning agents are overcome; the chemical cleaning agent contains an efficient ferric complexing agent, has high iron removal scale-dissolving efficiency with the iron removal rate of 80% above, and can effectively remove harmful substances such as catalyst surface iron compounds and alkali metals, so that the porous structure of the catalyst is effectively restored.

Description

technical field [0001] The invention relates to a cleaning method for an inactivated SCR denitration catalyst, in particular to a method for removing iron compounds on the surface of an inactivated SCR denitration catalyst with a neutral cleaning solution. Background technique [0002] Among the many flue gas denitrification technologies, Selective Catalytic Reduction (SCR) denitrification technology is the most widely used, mature and effective flue gas denitrification technology in thermal power plants at home and abroad. The denitrification catalyst is the core of SCR denitrification technology, and most commercial SCR catalysts use V 2 o 5 、WO 3 or MoO 3 etc. as active components, titanium dioxide (TiO 2 ) as the carrier. [0003] However, due to the influence of ash, impurities and toxic and harmful chemical components in the flue gas, the catalytic activity of the SCR catalyst will continue to decrease until it completely loses its activity. Catalyst deactivation...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B01J38/00B01J38/52
Inventor 夏启斌刘建华张琛吴凡史伟伟
Owner SOUTH CHINA UNIV OF TECH