CN117813158A - Stainless steel sheet metal with catalyst coating film forming material formed thereon, stainless steel metal pipe, and urea SCR exhaust gas treatment device - Google Patents

Stainless steel sheet metal with catalyst coating film forming material formed thereon, stainless steel metal pipe, and urea SCR exhaust gas treatment device Download PDF

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Publication number
CN117813158A
CN117813158A CN202280055091.1A CN202280055091A CN117813158A CN 117813158 A CN117813158 A CN 117813158A CN 202280055091 A CN202280055091 A CN 202280055091A CN 117813158 A CN117813158 A CN 117813158A
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coating film
stainless steel
forming material
film forming
catalyst
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稻叶利晴
服部望
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Mitsui Yiaisi Co ltd
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Mitsui Yiaisi Co ltd
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/92Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J21/00Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
    • B01J21/06Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
    • B01J21/063Titanium; Oxides or hydroxides thereof
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J27/00Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/02Sulfur, selenium or tellurium; Compounds thereof
    • B01J27/04Sulfides
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/30Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/12Improving ICE efficiencies

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Combustion & Propulsion (AREA)
  • Health & Medical Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Biomedical Technology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Catalysts (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

The present invention aims to provide a stainless steel sheet metal, a stainless steel pipe, and a urea SCR exhaust gas treatment device each having a catalyst coating film forming material formed thereon, wherein anatase titania catalyst support particles having a cyanuric acid decomposition (isocyanic acid hydrolysis) catalytic function can be easily fixed to the stainless steel sheet metal, and the pencil hardness is H or higher in the scratch hardness test result, and the object is solved by: a stainless steel metal sheet having a catalyst coating film forming material (10), the catalyst coating film forming material (10) being formed by applying a coating film composition containing titanium oxide catalyst particles that promote urea hydrolysis and peroxytitanic acid to a stainless steel metal sheet (9) and firing the composition, the stainless steel metal sheet having the catalyst coating film forming material formed thereon being characterized in that: the coating film formed on the surface of the stainless steel sheet under the urea water spray nozzle in a dark environment has a scratch hardness (pencil method) specified in JIS K5600-5-4 of a hardness of H or more of pencil hardness.

Description

Stainless steel sheet metal with catalyst coating film forming material formed thereon, stainless steel metal pipe, and urea SCR exhaust gas treatment device
Technical Field
The present invention relates to a stainless steel sheet metal, a stainless steel pipe, and a urea SCR exhaust gas treatment device each having a catalyst coating film forming material formed thereon, and more particularly, to a stainless steel sheet metal, a stainless steel pipe, and a urea SCR exhaust gas treatment device each having a catalyst coating film forming material formed thereon that has excellent adhesion strength to the stainless steel sheet metal or the stainless steel pipe and contributes to catalytic activity.
Background
Conventionally, patent document 1 discloses a method of using peroxo titanic acid as a binder to facilitate adhesion of fine particles of titanium oxide to each other.
However, patent document 1 does not disclose the use of peroxytitanic acid as an adhesive for bonding with SUS metal.
In patent document 1, an electrode to be coated is formed with an electrode layer on a substrate, and a coating film is formed on the electrode layer.
The following are disclosed: as the substrate, a transparent electrode such as glass or PET is used, and a conductive substrate such as metallic titanium, metallic aluminum, metallic copper, or metallic nickel is used for the other substrate (paragraph 0069).
Moreover, the following is also disclosed: as the electrode layer, an electrode of tin oxide, antimony, iron or phosphorus doped tin oxide, tin and/or iron doped indium oxide, antimony oxide, zinc oxide, noble metals, or the like can be used (paragraph 0070).
In view of the above, the electrode layer is formed on the substrate, and the coating liquid is not directly applied to the metal to form the coating film. This is because patent document 1 is a technique of forming a semiconductor film for performing photoelectric conversion, and if there is no electrode layer, the technique is not originally established.
Therefore, in patent document 1, if the superiority of the adhesion between the substrate and the film using the peroxytitanic acid is not described at the same time, the peroxytitanic acid is merely an adhesive that converts to titanium oxide, and the conductive paths between the titanium dioxide particles that cause the solar cell to generate photoelectricity are maintained.
Prior art literature
Patent literature
Patent document 1: japanese patent No. 5354960
Disclosure of Invention
The present invention proposes a technique capable of easily fixing anatase titania catalyst support particles having a cyanuric acid decomposition (isocyanic acid hydrolysis) catalytic function to a stainless steel metal sheet, but has the following problems: if the aforementioned catalyst support particles are subjected to the catalytic action of hydrolysis for a long period of time without being firmly bonded to the stainless steel metal sheet, the film peeling is caused.
Accordingly, an object of the present invention is to provide a stainless steel sheet metal, a stainless steel pipe, and a urea SCR exhaust gas treatment device each having a catalyst coating film forming material capable of easily fixing anatase titania catalyst support particles having a cyanuric acid decomposition (isocyanic acid hydrolysis) catalytic function to the stainless steel sheet metal and having a pencil hardness of H or higher in the scratch hardness test result.
Other objects of the present invention will become apparent from the following description.
The above object is solved by the following inventions.
1. A stainless steel metal sheet formed with a catalyst coating film forming material which is obtained by coating a stainless steel metal sheet with a coating film composition containing titanium oxide catalyst particles that promote urea hydrolysis and peroxytitanic acid and firing the coating film composition, and which has anatase titania, characterized in that:
a coating film of the catalyst coating film forming material formed on the surface of the stainless steel sheet metal under a urea water spray nozzle in a dark environment has a scratch hardness (pencil method) specified in JIS K5600-5-4 of a pencil hardness H or more,
the catalyst coating film forming material contains 0.05wt% or more of Na element and 0.05wt% or more of S element.
2. The stainless steel sheet metal with a catalyst coating film forming material formed thereon according to item 1, wherein:
the catalyst coating film forming material contains 0.05 to 0.35 weight percent of Na element and 0.05 to 0.50 weight percent of S element.
3. A stainless steel metal pipe having a catalyst coating film forming material formed by coating a coating film composition containing titanium oxide catalyst particles that promote urea hydrolysis and peroxytitanic acid on an inner surface of the stainless steel metal pipe and firing the coating film composition, the catalyst coating film forming material having anatase titanium dioxide, the stainless steel metal pipe having the catalyst coating film forming material formed thereon characterized in that:
a coating film of the catalyst coating film forming material formed on the inner surface of the stainless steel metal pipe under a urea water spray nozzle in a dark environment has a scratch hardness (pencil method) specified in JIS K5600-5-4 of a pencil hardness H or more,
the catalyst coating film forming material contains 0.05wt% or more of Na element and 0.05wt% or more of S element.
4. The stainless steel metal pipe with a catalyst coating film forming material formed thereon according to the above 3, wherein:
the catalyst coating film forming material contains 0.05 to 0.35 weight percent of Na element and 0.05 to 0.50 weight percent of S element.
5. A urea SCR exhaust treatment device, characterized in that:
a urea water supply pipe for supplying pressurized air and urea water is inserted into the pipe for supplying exhaust gas,
a urea water spray nozzle is connected near the top end of the urea water supply pipe,
a mixing section for mixing the exhaust gas flowing through the pipe with the sprayed urea water sprayed from the urea water spray nozzle,
the stainless steel sheet metal material for forming a catalyst coating film described in 1 or 2 is provided around the mixing section in a band shape in all or a part of the inner wall surface of the pipe.
6. A urea SCR exhaust treatment device, characterized in that:
a urea water supply pipe for supplying pressurized air and urea water is inserted into the pipe for supplying exhaust gas,
a urea water spray nozzle is connected near the top end of the urea water supply pipe,
a mixing section for mixing the exhaust gas flowing through the pipe with the sprayed urea water sprayed from the urea water spray nozzle,
the stainless steel metal pipe in which the catalyst coating film forming material described in 3 or 4 is formed is provided on all or part of the inner wall surface of the pipe around the mixing section.
Effects of the invention
According to the present invention, there can be provided a stainless steel metal sheet, a stainless steel metal pipe, and a urea SCR exhaust gas treatment device each having a catalyst coating film forming material formed thereon, in which anatase titania catalyst support particles having a cyanuric acid decomposition (isocyanic acid hydrolysis) catalytic function can be easily fixed to the stainless steel metal sheet, and the pencil hardness in the scratch hardness test result is H or higher.
Drawings
Fig. 1 is an explanatory diagram showing an example of a urea SCR exhaust gas treatment device according to the present invention.
Fig. 2 is a schematic cross-sectional view showing an example of a catalyst sheet according to the present invention.
Description of the reference numerals
1. Diesel engine
2. Exhaust pipe
3 hydrolysis device of urea solution (gasification device)
4. Piping for gasification
5. Exhaust gas inlet
6. Urea water supply pipe
7. Urea water spray nozzle
8. Mixing part
9. Metal sheet
10. Catalyst coating film forming material
11. Denitration device
12. Temperature adjusting part
Detailed Description
Hereinafter, preferred embodiments of the present invention will be described.
In fig. 1, 1 is a diesel engine, and 2 is an exhaust pipe that transmits exhaust gas discharged from the diesel engine 1.
Reference numeral 3 denotes a hydrolysis apparatus for urea water, which is also called a gasification apparatus. The hydrolysis device 3 is provided in the gasification pipe 4. An inlet 5 for exhaust gas is provided at an inlet of the gasification pipe 4, and the exhaust gas is introduced into the gasification pipe 4 from the inlet 5.
A urea water supply pipe 6 for supplying pressurized air (compressed air) and urea water is inserted into the gasification pipe 4, and a urea water spray nozzle 7 is provided near the tip of the urea water supply pipe 6. The urea water spray nozzle 7 is configured to be capable of supplying urea water spray into the gasification pipe 4.
Reference numeral 8 denotes a mixing section of the exhaust gas flowing through the gasification pipe 4 and the sprayed urea water discharged from the urea water spray nozzle.
A stainless steel metal sheet 9 is provided around the inner wall surface of the gasification pipe 4 around the mixing section 8 in a band shape, and a catalyst coating film forming material 10 that promotes urea hydrolysis is formed on the exhaust side surface of the stainless steel metal sheet 9.
In the present embodiment, for example, a flat stainless steel sheet 9 is wound into a quasi-cylindrical sleeve in the sheet longitudinal direction, and the urea water supply pipe 6 is inserted into the top side, whereby the stainless steel sheet can be circumferentially provided in a band shape. The stainless steel sheet 9 is not limited to this, as long as it can be provided in a band shape.
The catalyst coating film forming material 10 is formed by applying a coating film composition containing titanium oxide catalyst particles that promote urea hydrolysis and peroxytitanic acid to the inner surface of the stainless steel metal sheet 9 and firing.
In the present embodiment, for example, the coating composition containing titanium oxide catalyst particles and peroxytitanic acid can be formed by horizontally and uniformly coating the coating composition on the surface of the flat stainless steel sheet 9 horizontally laid on the surface of the table surface on the side contacting the exhaust gas, drying the coating composition at room temperature, and firing the coating composition in an electric furnace.
The stainless steel used as the stainless steel sheet is an alloy steel containing 1.2% or less by mass of carbon, 10.5% or more by mass of chromium, and iron (Fe) as main components, which are specified in the international ISO standard. The steel may be any of martensitic stainless steel (e.g., SUS410, SUS 403) having high hardness, excellent strength and heat resistance, ferritic stainless steel (e.g., SUS 430) having high workability and heat resistance, and austenitic stainless steel (e.g., SUS304, SUS 316) having excellent workability and corrosion resistance, and among them, SUS304 and SUS316 are preferable.
In the mixing section 8, the following hydrolysis reaction occurs when the exhaust gas and the spray urea aqueous solution are mixed.
(NH 2 ) 2 CO+H 2 O→2NH 3 +CO 2
In the present invention, the catalyst coating film forming material may be formed by coating a coating film composition containing titanium oxide catalyst particles that promote urea hydrolysis and peroxytitanic acid on the inner surface of a stainless steel pipe, and firing the coating film composition.
For applying the coating composition, there are various methods such as brushing, dipping, spraying, thermal spraying, CVD, and the like.
In the present invention, the coating film formed on the inner surface of the stainless steel metal pipe under the urea water spray nozzle in a dark environment has a scratch hardness (pencil method) specified in JIS K5600-5-4 of pencil hardness H or more. The effect of the present invention can be exerted because the hardness is equal to or higher than the H hardness.
In the present invention, it is preferable that the film-forming material formed by firing the film composition contains 0.05wt% or more of Na element and 0.05wt% or more of S element. The Na element and the S element may each be contained in the coating composition together or independently.
Further, si element may be contained in an amount of 0.1wt% or more.
When Na element and S element are contained in the coating composition together, for example, a surfactant such as sodium alkylbenzenesulfonate can be contained in the coating composition.
The Si element may be contained in the coating composition so that the Si component such as a water-soluble silicone or a rinse component is contained in the aqueous coating composition as a surfactant or an aqueous emulsion dispersant or stabilizer of titanium dioxide.
The Na element and S element in the coating film forming material formed by firing the coating film composition more preferably contain 0.05 to 0.35wt% of Na element and 0.05 to 0.50wt% of S element.
As a result of containing Na element and S element in the coating composition, the coating composition not only contributes to an improvement in the catalytic effect on the film surface, but also contributes to an improvement in the coating strength. Since Na or SO4 contained in the coating composition is hydrophilic, it is estimated that this contributes to enhancement of the adsorption force of polar substances such as urea water or cyanic acid, which corresponds to the TiO2 catalyst.
The position where the stainless steel sheet metal 9 on which the catalyst coating film forming material 10 containing a hydrolysis catalyst is formed or the position where the inner wall of the pipe on which the catalyst coating film forming material 10 containing a hydrolysis catalyst is formed shown in fig. 2 is located is preferably in the vicinity of the position where the urea water spray nozzle 7 in the pipe shown in fig. 1 is located from the viewpoint of bringing urea water into contact with the catalyst.
In the case of an engine with a turbocharger, the urea water spray nozzle 7 is preferably disposed in the vicinity of the position of the urea water spray nozzle 7 even in the case of an engine with a turbocharger because the urea water spray nozzle 7 is disposed at the position of the exhaust pipe from the combustion chamber to the front of the turbocharger or at the position of the exhaust pipe from the combustion chamber to the rear of the turbocharger.
As shown in fig. 1, in the hydrolysis apparatus 3, NH is generated by a hydrolysis reaction of hydrolyzing urea 3 . In the denitration device 11, NO is contained by a denitration catalyst x And NH 3 Is reduced to N by the following reduction reaction 2 And is purified.
4NO+4NH 3 +O 2 →4N 2 +6H 2 O
6NO 2 +8NH 3 →7N 2 +12H 2 O
The denitration catalyst is not particularly limited, but may be used in TiO 2 Or SiO 2 -TiO 2 、WO 3 -TiO 2 、SiO 2 -TiO 2 、Al 2 O 3 -SiO 2 Equal binary composite oxides, or WO 3 -SiO 2 -TiO 2 、Mo 3 -SiO 2 -TiO 2 An active ingredient such as V, cr, mo, mn, fe, ni, cu, ag, au, pd, Y, ce, nd, W, in, ir, nb supported on a carrier such as an ternary composite oxide, having a honeycomb structure and having NH 3 (reducing agent) in the case of NO x The reduction and conversion into nitrogen gas for purification.
In the present embodiment, the temperature adjusting portion 12 is preferably provided on the outer peripheral side of the vaporizing piping 4 so as to cover the vaporizing piping 4. For example, a pipe jacket heater (mantle heater) is preferable as the temperature adjusting unit 12.
Here, in the present invention, the effect of suppressing the formation of cyanuric acid is reliably exhibited at a temperature exceeding the heating system temperature range (less than 30 to 130 ℃, preferably less than 100 ℃) in which cyanuric acid is not formed by thermal decomposition of urea, from the viewpoint of preventing crystallization. The sprayed urea water sprayed from the urea water spray nozzle is brought into contact with the catalyst coating film forming material 10 at 135 to 350 ℃, more preferably at 150 to 250 ℃, and hydrolysis is promoted by the by-products other than ammonia generated by thermal decomposition of urea, that is, isocyanate (hn=c=o), cyanic acid (HOCN) and moisture in the atmosphere to be converted into hydration reaction of ammonia and carbon dioxide, whereby isocyanate or cyanuric acid for the reaction of polymerization into cyanuric acid is reduced, as a result of which the amount of cyanuric acid generated by urea is reduced, whereby clogging of piping due to a high-melting point substance can be suppressed.
As a method of adjusting the heating temperature of urea to a temperature at which cyanuric acid is not generated, as shown in fig. 1, the temperature of the gasification pipe 4 can be adjusted by a temperature adjusting unit 12 provided on the outer peripheral side of the exhaust pipe. This can adjust the temperature of the exhaust gas introduced into the gasification pipe 4. By providing the temperature adjustment unit 12, the temperature can be adjusted when the exhaust gas temperature needs to be adjusted. As a result, the amount of cyanuric acid produced is reduced, and clogging of piping due to the high-melting point material can be suppressed.
In the present embodiment, an air pipe (double pipe structure) not shown is preferably provided on the outer periphery of the gasification pipe 4, and compressed air is preferably caused to flow through the air pipe. The air amount may be adjusted in conjunction with a temperature sensor of the exhaust gas. In this case, the temperature adjusting portion 12 may be provided on the outer periphery of the air pipe provided on the outer periphery of the gasification pipe.
In the present invention, in the thermal decomposition of urea by the heat of the exhaust gas, the amount of isocyanic acid or cyanuric acid used for the cyanuric acid polymerization reaction is reduced, and as a result, the amount of cyanuric acid produced by urea is reduced, whereby the ammonia supply amount can be increased.
Therefore, the denitration efficiency is not caused by the retention of the reducing agent hydrogen source in the pipingReduced supply loss of the reducing agent hydrogen source, or downstream NO x The reduction performance is reduced by the surface coverage of the denitration catalyst or clogging of the mesh of the honeycomb catalyst.
Further, since the amount of cyanuric acid produced is reduced, clogging of the pipe by a high-melting point substance in the upstream portion of the catalyst reaction tube can be suppressed, and a decrease in engine output due to an increase in exhaust pipe back pressure and even a worst case failure in engine stop can be suppressed.
Hereinafter, a method of fixing the catalyst support particles containing titanium dioxide particles to the surface of a stainless steel metal sheet or a stainless steel metal piping in the present invention will be described.
The preparation of the dispersion of the titanium dioxide particles immobilized with the binder (peroxo titanic acid) is performed as follows.
An aqueous solution containing titanium such as an aqueous solution of titanium chloride is reacted with an alkaline substance such as aqueous ammonia to form a suspension of titanium hydroxide fine particles.
Subsequently, a commercially available 1wt% aqueous solution of peroxo titanic acid (titanium peroxide), for example, which is prepared by reacting the suspension with an oxidizing agent such as hydrogen peroxide, can be used.
For example, 5g of anatase type titanium dioxide reagent powder having a particle diameter of 1nm to 100nm is added to 10g of an aqueous solution containing 1wt% of peroxytitanic acid, and stirred to prepare a white paint type titanium dioxide dispersion coating liquid A.
Next, in order to prevent the repulsion of the coating liquid a against the stainless steel sheet metal, a uniform thin liquid coating was applied, and 3wt% of a higher alcohol-based liquid dishwashing detergent was added to the coating liquid a as a surfactant to prepare a uniformly mixed coating liquid B so as not to foam.
Examples of the surfactant include anionic surfactants containing Na and S, such as linear alkylbenzene surfactants and higher alcohol surfactants.
Examples of the linear alkylbenzene system include linear alkylbenzene sulfonates, specifically, sodium linear alkylbenzene sulfonate.
Examples of the higher alcohols include alkyl sulfate salts and alkyl ether sulfate salts. Amphoteric surfactants such as sodium alkyl sulfobetaines, e.g., sodium alkyl hydroxysulfobetaines, may also be used.
Next, the application of the titanium dioxide dispersion to a stainless steel sheet metal will be described.
The coating liquid B was uniformly applied to the surface of the stainless steel metal sheet in the form of a white aqueous paint with bristles until the metal surface was not seen. The moisture was allowed to dry at room temperature for about 16 hours to form a dried titanium dioxide layer on the stainless steel sheet metal.
Then, the peroxytitanic acid is subjected to an adhesive heat treatment.
In order to dry the moisture of the stainless steel metal sheet coated with titanium oxide and peroxytitanic acid, the following heat treatment was performed: the temperature was raised from room temperature to 80℃with a thermostatic dryer at a heating rate of 50℃per hour on average, and maintained at a temperature of 80℃for 1 hour.
Then, in order to perform a heat treatment at 250 ℃ for converting the peroxytitanic acid into titanium dioxide and a binder, the following heat treatment was performed: the temperature was raised from room temperature to 400℃with an electric furnace at a temperature rising rate of 50℃per hour on average, and maintained at 400℃for 1 to 18 hours.
Thus, the peroxytitanic acid can chemically bond (adhere) the stainless steel metal surface and the titania surface of the catalyst carrier.
The organic surfactant contained in the layer as an impurity is oxidized in an air atmosphere at 400 ℃ to become an organic low-molecular-weight substance, and disappears from the coating layer as a gas.
In this embodiment, there is also a case where Na element or S element remains. In this case, na element or S element is used as Na salt, SO 4 The sulfuric acid group remains in the catalyst layer, has hydrophilicity or has the ability to absorb water molecules or polar substances. The Si component is oxidized to form SiO 2 ,SiO 2 Can also function slightly as cyanuric acid decomposition catalyst alone.
Since the peroxytitanic acid itself is converted into titanium dioxide having a catalytic effect, an anatase type titanium dioxide film obtained by converting the peroxytitanic acid remains on the surface of the support particles, even if the support particles are peeled from the surface of the stainless steel, and the surface of the film also functions as a catalyst.
Thus, a coating layer of titanium dioxide having a heat resistance of 400 ℃ is formed on the metal surface, and it is possible to fix titanium dioxide catalyst support particles to stainless steel metal with a practical strength, which is a technical problem. As a result, the titania catalyst support particles can be firmly fixed to the stainless steel metal, and therefore the titania catalyst support particles are less likely to peel off from the stainless steel metal sheet, and the titania catalyst remains, whereby the hydrolysis efficiency can be maintained for a longer period of time. Since the hydrolysis efficiency can be maintained for a longer period of time, the replacement frequency is reduced, and the durability period can be prolonged.
The results of measuring the film strength of the coated catalyst by pencil hardness method are verified in examples.
As a comparative example, a stainless steel sheet was coated with a coating liquid B prepared by mixing titanium oxide particles without peroxo titanic acid, and the coating film was fired at 400 ℃.
As an example, firing was performed using a coating liquid B using peroxo titanic acid, and the strength of the coating film was 3H which was strong.
The Na element and S element contained in the organic surfactant contribute not only to the improvement of the catalytic effect on the film surface but also to the improvement of the film strength.
The film formed by coating the metal surface with a brush and drying in the room has no photocatalytic function because the peroxytitanic acid is in the form of amorphous (amorphous) titanium oxide.
Thus, by firing the film dried at normal temperature at 250 ℃ or higher, an anatase crystal film having a photocatalytic function and a cyanuric acid decomposition (isocyanic acid hydrolysis) catalytic function with high adhesion is obtained.
That is, by baking at a temperature of 250 ℃ or higher, anatase titania catalyst particles as a catalyst carrier become a crystalline film of anatase titania formed on the surface of the stainless steel metal sheet, exert cyanuric acid decomposition catalytic function, and peroxo titanic acid itself is also converted into anatase titania crystals, which themselves also have slightly cyanuric acid decomposition catalytic function.
In the present embodiment, if baking is performed at a firing temperature of, for example, 800 ℃ or higher, anatase titania is phase-converted into rutile titania. Even in the rutile type titanium dioxide, some effects can be obtained, and from the viewpoint of exerting a larger effect, it is preferable to perform baking at a temperature at which phase inversion does not occur, for example, at a temperature of 250 to 500 ℃, and further, it is preferable to perform baking at a temperature of 400 to 500 ℃. The firing time is preferably 1 to 4 hours, more preferably 2 to 3 hours, at the firing temperature described above.
Anatase titanium dioxide crystals converted from peroxytitanic acid do not have a specific surface area of about 50m unlike the catalyst carrier used 2 The catalyst support anatase titania powder per gram is porous and therefore has a lower catalytic activity than the catalyst support anatase titania powder.
Therefore, it can be said that the peroxo-titanic acid used in the present invention mainly functions as a binder.
Examples
Hereinafter, examples of the present invention will be described, but the present invention is not limited to these examples.
Example 1
1. Production of stainless steel sheet metal with catalyst coating film forming material
(1) Preparing a dispersion coating solution (coating solution A)
The aqueous solution of titanium chloride and aqueous ammonia are reacted to form a suspension of titanium hydroxide particles.
Next, a commercially available 1wt% aqueous solution of titanium peroxo titanate (titanium peroxo) prepared by reacting the suspension with a hydrogen peroxide oxidizing agent was obtained.
To 10g of the aqueous solution containing 1wt% of peroxytitanic acid was added 5g of anatase type titanium dioxide reagent powder (titanium dioxide powder) having a particle diameter of 1nm to 100nm, and the mixture was stirred to prepare a white coating type titanium dioxide dispersion (coating liquid A).
(2) Preparing a surfactant-containing solution (coating solution B)
Next, in order to prevent the repulsion of the coating liquid a against the stainless steel metal sheet (SUS 304), a uniform thin liquid coating was applied, and 3wt% of a liquid dishwashing detergent containing Na and S such as sodium alkylbenzenesulfonate was added to the coating liquid a as a surfactant, and mixed uniformly so as not to foam, to prepare a surfactant-containing solution (coating liquid B).
(3) Coating a surfactant-containing solution (coating liquid B)
The coating liquid B was uniformly applied to the surface of the stainless steel metal sheet in the form of a white aqueous paint with bristles until the metal surface was not seen. The moisture was allowed to dry at room temperature for approximately 16 hours.
(4) Catalyst coating film Forming Material (titanium oxide catalyst layer)
The following heat treatment was performed in order to dry the moisture of the stainless steel metal sheet coated with the coating liquid B: the temperature was raised from room temperature to 80℃with a thermostatic dryer at a heating rate of 50℃per hour on average, and maintained at a temperature of 80℃for 1 hour.
Then, in order to perform a heat treatment at 250 ℃ for converting the peroxytitanic acid into titanium dioxide and a binder, the following heat treatment was performed: the temperature was raised from room temperature to 400℃with an electric furnace at a temperature rising rate of 50℃per hour on average, and was kept at a temperature of 400℃for 3 hours (firing treatment).
Thus, a stainless steel sheet metal with a catalyst coating film forming material formed thereon was obtained.
2. Test
(1) Test 1: cyanuric acid production inhibition test
The obtained stainless steel sheet was set at the lower part of the urea nozzle of the SCR bench foundation test apparatus shown in fig. 1, the sheath heater was set at 250 ℃, and under such conditions that urea water was allowed to drip and cyanuric acid was generated,actual exhaust of diesel engine (containing NO at concentration of 1000 ppm) x ) Flowing through the hydrolysis apparatus 3 of FIG. 1 at 250deg.C under SV90,000/h treatment conditions, and blowing NO as urea water x /NH 3 The urea-water SCR was operated for 4 hours with an equivalence ratio of 1.
(2) Test 2: pencil scratch hardness test
Based on JIS K5600-5-4: 1999, scratch hardness test apparatus, scratch hardness test was performed on stainless steel metal sheet on which a catalyst coating film forming material (titania catalyst layer) was formed. The results are shown in Table 1.
Example 2
In example 1, the same procedure as in example 1 was repeated except that SUS430 was used instead of SUS304 for the stainless steel metal sheet, the heating temperature was changed from 400 ℃ to 500 ℃ and the heating time was changed from 3 hours to 2 hours, and test 1 and test 2 were performed under the same conditions.
The results of test 2 are shown in table 1.
Example 3
Test 1 and test 2 were performed under the same conditions as in example 1 except that the heating time was changed from 3 hours to 4 hours in example 1.
The results of test 2 are shown in table 1.
Example 4
In example 1, test 1 and test 2 were performed under the same conditions, except that SUS304 was used instead of SUS316 in the stainless steel metal sheet, which was produced in the same manner as in example 1.
The results of test 2 are shown in table 1.
Comparative example 1
The same procedure as in example 1 was repeated except that the commercially available 1wt% peroxytitanic acid of example 1 was not used, and test 1 and test 2 were carried out under the same conditions.
The results of test 2 are shown in table 1.
(Table 1)
(3) Evaluation
Evaluation of test 1
As a result of test 1, in comparative example 1, precipitation of foreign matter such as cyanuric acid was not observed from the stainless steel metal sheet, but catalyst peeling was visually observed at the urea water contact portion, and the metal surface of the stainless steel metal sheet was exposed.
In contrast, in examples 1 to 3, no precipitation of foreign matter such as cyanuric acid was observed on the stainless steel metal sheet, and it was visually confirmed that the catalyst remained on the sheet without being peeled off from the sheet.
That is, as in examples 1 to 3, by mixing and firing peroxo-titanic acid as a binder with the coating film, even if a stainless steel metal sheet on which a catalyst coating film forming material is formed is provided around a liquid dropping portion under a urea water SCR nozzle, precipitation of foreign matters such as cyanuric acid is not observed on the stainless steel metal sheet, and the catalyst is not peeled off from the sheet but remains on the sheet, so that it is possible to confirm that the durability of the catalyst coating layer of cyanuric acid is increased.
b evaluation of test 2
In test 1, it was confirmed that the catalyst was hard to be peeled off from the stainless steel sheet metal of examples 1 to 3, and thus test 2 was performed as an objective strength index. As a comparison, test 2 was also performed on the stainless steel sheet metal of comparative example 1.
As in comparative example 1, when a titanium dioxide powder coating film (cyanuric acid decomposition catalyst) produced without using peroxytitanic acid was coated on a stainless steel metal sheet, the scratch hardness test resulted in a coating film having a brittle strength and a pencil hardness of 6B or less.
In contrast, in example 1, the adhesion between the titanium oxide powder coating film and the SUS sheet was enhanced after mixing the titanium oxide powder coating film with the peroxytitanic acid as a binder and firing the mixture at 400 ℃ for 3 hours after drying, and the adhesion strength of the titanium oxide powder coating film was pencil hardness 3H.
The strength of the coating film was increased from 6B to 3H, by 9 grades, as evaluated in accordance with JIS pencil strength.
In addition, regarding the material of the SUS sheet, the effect was confirmed by the sheet of austenitic SUS304 which is used as a piping material and is generally used, and it was confirmed that the same coating film strength was obtained even with the same material of austenitic SUS316 (example 4) and ferritic SUS430 (example 2), and different stainless steel metal sheets.
In addition, 2 kinds of commercial monolithic ceramic denitration catalysts were prepared as threshold indicators of the catalyst layer strength required for exhaust gas treatment SCR catalysts, and abrasion of the surface of each catalyst was measured under the same test (test 2) conditions, and pencil hardness of the denitration catalyst was HB and H.
Therefore, it was found that if the pencil hardness is H or more, the catalyst layer strength of the general denitration catalyst is higher than the abrasion resistance strength, and it was confirmed that a catalyst coating layer having the catalyst layer strength required for the commercial exhaust gas treatment SCR catalyst can be formed on the stainless steel metal sheet.
3. Analysis of film surface
(1) Analysis results
The composition of the catalyst coated film surfaces formed on the stainless steel metal sheets manufactured in examples 1 to 4 and comparative example 1 was analyzed. The results are shown in Table 2. The analysis result is a result when the elemental composition of only the catalyst layer after the composition (Fe, cr, ni, mn, mo) of the stainless steel metal sheet was removed is 100%.
As the analysis device, a scanning electron microscope/energy dispersive X-ray analysis device (generally, the device is abbreviated as SEM/EDX) can be used.
As the SEM/EDX device, SEM "S-3400N" manufactured by Hitachi high technology with EDX detector "EMAX" manufactured by horiba, ltd. Further, as a cheaper and simple analysis device, a desk-top X-ray fluorescence elemental analyzer or a hand-held portable X-ray fluorescence elemental analyzer can be used.
In this example, analysis was performed using a scanning electron microscope/energy dispersive X-ray analysis device (SEM/EDX), and "S-3400N/EMAX" manufactured by Hitachi high technology Co., ltd.
(Table 2)
Example 1 Example 2 Example 3 Example 4 Comparative example 1
Element(s) Composition wt% Composition wt% Composition wt% Composition wt% Composition wt%
C 6.78 27.54 24.25 33.24 3.07
N 0.00 0.40 0.00 3.06
O 45.95 39.45 41.97 37.27 44.62
Na 0.08 0.23 0.13 0.35 0.15
Si 0.31 0.30 0.61 0.45 0.22
P 0.38 0.66
S 0.18 0.40 0.22 0.50 0.33
Ti 46.70 31.31 32.81 24.46 51.61
Sum total 100 100 100 100 100
(2) Evaluation
As a result of analysis of the compositions of examples 1 to 4 and comparative example 1, it was found that both Na element and S element were contained.
However, as shown in examples 1 to 4, it was confirmed that the use of peroxo-titanic acid as the binder contained 0.05wt% or more of Na element and 0.05wt% or more of S element, and this contributes to not only improving the catalytic effect on the film surface but also further improving the film strength.
In this example, as shown in table 1, it was confirmed that the coating film strength was improved in examples 1 to 4.
Further, according to examples 1 to 4, it was confirmed that the effect of improving the catalytic effect was more remarkably exhibited by containing 0.05 to 0.35wt% of Na element and 0.05 to 0.50wt% of S element.

Claims (6)

1. A stainless steel metal sheet formed with a catalyst coating film forming material which is obtained by coating a stainless steel metal sheet with a coating film composition containing titanium oxide catalyst particles that promote urea hydrolysis and peroxytitanic acid and firing the coating film composition, and which has anatase titania, characterized in that:
a coating film of the catalyst coating film forming material formed on the surface of the stainless steel sheet metal under a urea water spray nozzle in a dark environment has a scratch hardness (pencil method) specified in JIS K5600-5-4 of a pencil hardness H or more,
the catalyst coating film forming material contains 0.05wt% or more of Na element and 0.05wt% or more of S element.
2. The stainless steel sheet metal formed with a catalyst coating film forming material according to claim 1, characterized in that:
the catalyst coating film forming material contains 0.05 to 0.35 weight percent of Na element and 0.05 to 0.50 weight percent of S element.
3. A stainless steel metal pipe having a catalyst coating film forming material formed by coating a coating film composition containing titanium oxide catalyst particles that promote urea hydrolysis and peroxytitanic acid on an inner surface of the stainless steel metal pipe and firing the coating film composition, the catalyst coating film forming material having anatase titanium dioxide, the stainless steel metal pipe having the catalyst coating film forming material formed thereon characterized in that:
a coating film of the catalyst coating film forming material formed on the inner surface of the stainless steel metal pipe under a urea water spray nozzle in a dark environment has a scratch hardness (pencil method) specified in JIS K5600-5-4 of a pencil hardness H or more,
the catalyst coating film forming material contains 0.05wt% or more of Na element and 0.05wt% or more of S element.
4. The stainless steel metal pipe having a catalyst coating film forming material formed thereon according to claim 3, wherein:
the catalyst coating film forming material contains 0.05 to 0.35 weight percent of Na element and 0.05 to 0.50 weight percent of S element.
5. A urea SCR exhaust treatment device, characterized in that:
a urea water supply pipe for supplying pressurized air and urea water is inserted into the pipe for supplying exhaust gas,
a urea water spray nozzle is connected near the top end of the urea water supply pipe,
a mixing section for mixing the exhaust gas flowing through the pipe with the sprayed urea water sprayed from the urea water spray nozzle,
a stainless steel sheet metal material having a catalyst coating film forming material according to claim 1 or 2 formed around the mixing section in a band shape is provided on the entire or partial inner wall surface of the pipe.
6. A urea SCR exhaust treatment device, characterized in that:
a urea water supply pipe for supplying pressurized air and urea water is inserted into the pipe for supplying exhaust gas,
a urea water spray nozzle is connected near the top end of the urea water supply pipe,
a mixing section for mixing the exhaust gas flowing through the pipe with the sprayed urea water sprayed from the urea water spray nozzle,
a stainless steel metal pipe in which the catalyst coating film forming material according to claim 3 or 4 is formed is provided on all or part of the inner wall surface of the pipe around the mixing section.
CN202280055091.1A 2021-08-18 2022-03-14 Stainless steel sheet metal with catalyst coating film forming material formed thereon, stainless steel metal pipe, and urea SCR exhaust gas treatment device Pending CN117813158A (en)

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PCT/JP2022/011357 WO2023021761A1 (en) 2021-08-18 2022-03-14 Stainless steel metal sheet on which catalyst-coating-film-forming material is formed, stainless steel metal pipe, and urea scr exhaust gas treatment device

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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0894523A1 (en) * 1997-07-28 1999-02-03 Siemens Aktiengesellschaft Static mixer and exhaust duct for a combustion system
JP2000202300A (en) * 1999-01-19 2000-07-25 Hitachi Metals Ltd Photocatalytic member and its production
CN1441856A (en) * 2000-07-25 2003-09-10 关西涂料株式会社 Coating material for forming titanium oxide film, method for forming titanium oxide film and use of said coating material
EP2172266A1 (en) * 2008-09-12 2010-04-07 Süd-Chemie Ag Urea hydrolysis catalyst
CN102361680A (en) * 2009-02-02 2012-02-22 康明斯过滤Ip公司 Increased reductant decomposition reactor robustness through the use of a hydrolytic catalyst coating
CN103562135A (en) * 2011-05-24 2014-02-05 信越化学工业株式会社 Method for manufacturing microparticulate anatase or rutile titanium oxide dispersion and component having photocatalytic thin film on surface
CN103582526A (en) * 2011-06-07 2014-02-12 株式会社大赛璐 Photocatalytic coating film and method for producing same
US20160051931A1 (en) * 2014-08-25 2016-02-25 N.E. Chemcat Corporation Urea hydrolysis catalyst, selective reduction catalyst containing urea hydrolysis material, and exhaust gas cleaning apparatus
CN109477337A (en) * 2016-07-14 2019-03-15 信越化学工业株式会社 Have built-in material and its manufacturing method with the active superficial layer of visible light responsive photocatalytic

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3869314B2 (en) 2002-03-29 2007-01-17 バブコック日立株式会社 Exhaust gas denitration apparatus and urea vaporizer used therefor
JP5241277B2 (en) 2008-03-11 2013-07-17 日揮触媒化成株式会社 Exhaust gas treatment equipment
JP5174488B2 (en) 2008-02-25 2013-04-03 日揮触媒化成株式会社 Exhaust gas treatment equipment
JP5354960B2 (en) 2008-05-30 2013-11-27 日揮触媒化成株式会社 Paint for forming porous metal oxide semiconductor film for photoelectric cell and photoelectric cell

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0894523A1 (en) * 1997-07-28 1999-02-03 Siemens Aktiengesellschaft Static mixer and exhaust duct for a combustion system
JP2000202300A (en) * 1999-01-19 2000-07-25 Hitachi Metals Ltd Photocatalytic member and its production
CN1441856A (en) * 2000-07-25 2003-09-10 关西涂料株式会社 Coating material for forming titanium oxide film, method for forming titanium oxide film and use of said coating material
EP2172266A1 (en) * 2008-09-12 2010-04-07 Süd-Chemie Ag Urea hydrolysis catalyst
CN102361680A (en) * 2009-02-02 2012-02-22 康明斯过滤Ip公司 Increased reductant decomposition reactor robustness through the use of a hydrolytic catalyst coating
CN103562135A (en) * 2011-05-24 2014-02-05 信越化学工业株式会社 Method for manufacturing microparticulate anatase or rutile titanium oxide dispersion and component having photocatalytic thin film on surface
CN103582526A (en) * 2011-06-07 2014-02-12 株式会社大赛璐 Photocatalytic coating film and method for producing same
US20160051931A1 (en) * 2014-08-25 2016-02-25 N.E. Chemcat Corporation Urea hydrolysis catalyst, selective reduction catalyst containing urea hydrolysis material, and exhaust gas cleaning apparatus
CN109477337A (en) * 2016-07-14 2019-03-15 信越化学工业株式会社 Have built-in material and its manufacturing method with the active superficial layer of visible light responsive photocatalytic

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