JP4204692B2 - Nitrogen oxide removal catalyst, method for producing the same, and method for removing nitrogen oxides using the catalyst - Google Patents

Description

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【表２】

【００６４】
【表３】

[0001]
[Industrial application fields]
The present invention relates to a method for removing nitrogen oxide from an exhaust gas containing nitrogen oxide (hereinafter sometimes abbreviated as “denitration”). Specifically, in addition to gas engines, gas turbines, boilers, diesel engines, etc., nitrogen oxides (hereinafter sometimes referred to as NOx) contained in high-temperature exhaust gas discharged from various industrial processes are used as reducing agents, such as ammonia or urea, and melamine. The present invention relates to a denitration catalyst suitable for catalytic reduction using a solid reducing agent such as cyanuric acid, ammonium carbonate, or ammonium hydrogencarbonate, a production method thereof, and a denitration method using the catalyst.
[0002]
The “denitration catalyst” of the present invention means a catalyst for catalytically reducing NOx in exhaust gas using the above reducing agent and converting it into harmless nitrogen and water.
[0003]
[Prior art]
Currently, as a method of removing NOx in exhaust gas, NOx can be selectively removed even in exhaust gas containing high concentration of oxygen, and since a small amount of reducing agent is used and economical, ammonia is used as the reducing agent. The selective catalytic reduction method used is the mainstream.
[0004]
As a catalyst used in this catalytic reduction method, many catalysts that combine alumina, silica, zeolite, titanium oxide and the like and oxides such as vanadium, copper, tungsten, molybdenum, and iron have been proposed so far. Among these, the catalyst mainly composed of titanium oxide is not widely affected by sulfur oxides (SOx) in exhaust gas, and is currently widely used because of its low oxidation ability from SO2 to SO3 in exhaust gas. ing. The reaction temperature is usually about 250 to 400 ° C.
[0005]
Some exhaust gas temperatures exceed 400 ° C, such as gas turbine exhaust gas and diesel engine exhaust gas. To remove NOx in such high temperature exhaust gas, a denitration catalyst that exhibits excellent activity in a relatively wide temperature range is used. is necessary.
[0006]
As a catalyst for removing NOx in exhaust gas whose exhaust gas temperature exceeds 400 ° C., a precipitate obtained by neutralizing an aqueous solution containing a soluble titanium compound, a soluble tungsten compound and a soluble cerium compound with a basic substance is calcined. JP-A-8-257402 discloses a catalyst that obtains high activity by using a catalyst component obtained in this manner. This catalyst is generally integrally formed into a pipe shape or honeycomb shape, but since the surface area per unit of the catalyst is small and the aperture ratio is low, a large amount of exhaust gas from heavy oil fired boilers and coal fired boilers is used. When exhaust gas containing dust is treated, dust adheres to the catalyst or accumulates between the catalysts, thereby causing a problem that the catalyst performance is lowered and the pressure loss of the catalyst layer is increased, thereby preventing smooth operation.
[0007]
In order to solve these disadvantages, the catalyst obtained by supporting the catalyst substance on the honeycomb-shaped substrate has sufficient strength to withstand use even if the thickness of the honeycomb-shaped substrate is reduced. It is often used because it can increase the surface area per unit and the denitration device is compact.
[0008]
However, since the thermal expansion coefficient differs between the catalytic material and the honeycomb-shaped substrate, the catalytic material may crack due to thermal strain, or the catalytic material layer may peel off due to vibration or impact. Accordingly, various production methods and catalysts have been proposed for the purpose of improving the adhesion between the honeycomb-shaped substrate and the catalyst substance. In particular, when a metal base material having a large surface area per unit of catalyst is used, a coating layer having a large surface roughness is formed on the surface of the metal base material by composite plating, and then a catalyst material is supported (Japanese Patent Laid-Open No. 57). -19040) and a method of forming a porous coating layer made of a metal oxide on the surface of a metal substrate and then supporting a catalyst substance (Japanese Patent Laid-Open No. 61-181537) and the like.
[0009]
Each of the above-mentioned inventions has a drawback that the catalyst cost is increased because the catalyst material is supported after the coating layer is formed on the metal substrate in advance, and the catalyst cost increases.
[0010]
[Problems to be solved by the invention]
The object of the present invention is to overcome the drawbacks of conventional catalysts in view of the above points, is inexpensive, has good adhesion of the catalyst material to the honeycomb substrate, and can efficiently remove nitrogen oxides in exhaust gas Furthermore, the present invention provides a catalyst for removing nitrogen oxides having excellent durability, a method for producing the same, and a method for removing nitrogen oxides using the catalyst.
[0011]
[Means for Solving the Problems]
The present inventors have found a method for firmly supporting a catalyst material obtained by a predetermined preparation method on a honeycomb base material having a large surface area per unit of catalyst, and have completed the present invention. That is, the present invention is specified as follows.
[0012]
(1) a catalyst material was slurried and supported on the honeycomb-shaped substrate, dried and calcined, a nitrogen oxide removing catalyst obtained by carrying a catalyst material on the honeycomb-shaped substrate, those wherein catalyst material The supported catalyst layer has a thickness of 50 to 94.5% by weight of titanium oxide, 5 to 30% by weight of tungsten oxide, 0.5 to 10% by weight of cerium oxide and 0 to 10% by weight of zirconium oxide. There are 0.03～0.2Mm, in the manufacturing method of the aperture ratio from 65 to 90% of the range near Ru nitrogen oxide removing catalyst, catalytic material titanium oxide sol and / or zirconium oxide sol as a slurry stabilizer A method for producing a catalyst for removing nitrogen oxides, wherein 1 to 10% by weight in terms of oxide is used.
[0013]
(2) Nitrogen oxidation according to (1), obtained by calcining a precipitate obtained by precipitating an aqueous liquid containing a soluble titanium compound, a soluble tungsten compound and a soluble cerium compound in an aqueous medium. A method for producing an object removal catalyst.
[0014]
(3) The nitrogen oxide according to (1), wherein the precipitate is obtained by neutralizing an aqueous liquid in which a soluble titanium compound, a soluble tungsten compound and a soluble cerium compound are dissolved in an aqueous medium with a basic substance. A method for producing a catalyst for removal.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[0018]
The catalyst of the present invention is characterized in that it contains titanium oxide as a constituent component. Regarding the type of titanium source used in preparing the catalyst, it is calcined in addition to titanium oxide and titanium oxide sol. The titanium oxide is not particularly limited as long as it produces a titanium oxide, but a soluble titanium compound that is soluble in an aqueous medium is preferably used. For example, inorganic titanium compounds such as titanium tetrachloride and titanium sulfate, and organic titanium compounds such as titanium oxalate and tetraisopropyl titanate can be used.
[0019]
The raw materials for tungsten oxide and cerium oxide are not particularly limited as long as these oxides and oxide sols are produced after firing, but are preferably soluble in an aqueous medium. A compound is used. Examples of the soluble tungsten compound include ammonium metatungstate, ammonium paratungstate, and the like. Examples of the soluble cerium include, for example, cerous nitrate, cerium nitrate, cerium carbonate, cerous sulfate, and cerium sulfate. Can be given.
[0020]
In addition to zirconium oxide and zirconium oxide sol, the raw material for zirconium oxide may be any of hydroxide, ammonium salt, oxalate, halide, sulfate, nitrate, and the like.
[0021]
After these catalyst materials are dried and calcined, titanium oxide is 50 to 94.5% by weight, preferably 58 to 90.5% by weight, tungsten oxide is 5 to 30% by weight, preferably 9 to 25% by weight. And cerium oxide in the range of 0.5 to 15% by weight, preferably 0.5 to 10% by weight, and zirconium oxide in the range of 0 to 10% by weight, preferably 0 to 7% by weight. Since the activity of the denitration catalyst to be obtained becomes high, it is preferable.
[0022]
In addition, basic compounds used for neutralizing and precipitating an aqueous solution in which a soluble titanium compound, a soluble tungsten compound and a soluble cerium compound are dissolved in an aqueous medium include ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, Examples include potassium carbonate. Of these, ammonia or an aqueous solution thereof (ammonia water) is preferably used from the viewpoint of detergency and handleability of the coprecipitate slurry.
[0023]
Therefore, a method for preparing titanium oxide supporting tungsten oxide and cerium oxide will be specifically described below as an example using water as an aqueous medium and ammonia water as a basic compound.
[0024]
First, soluble titanium compounds such as titanium tetrachloride and soluble tungsten compounds such as ammonium metatungstate and soluble cerium compounds such as cerium nitrate are dissolved in water to form an acidic titanium-tungsten-cerium-containing aqueous solution. Next, while maintaining the temperature of this aqueous solution at 60 ° C. or lower, preferably 50 to 0 ° C., ammonia water is added so that the final pH is 5 to 8, preferably 5 or more and less than 7 And precipitate. In addition, when the aqueous solution of a tungsten compound and a cerium compound is basic, an aqueous solution containing these is added to the titanium-containing aqueous solution simultaneously with the ammonia water and precipitated.
[0025]
The “final pH” in the present invention means the pH of the precipitate slurry or gel when the precipitation operation is completed.
[0026]
When the temperature in the precipitation operation exceeds 60 ° C., the activity of the resulting catalyst is lowered, which is not preferable. When the final pH is lower than 5, the activity of the resulting catalyst is lowered, and when it exceeds 8, the activity is lowered, and further, re-dissolution of tungsten occurs, which is not preferable.
[0027]
The titanium-tungsten-cerium precipitate obtained by the precipitation operation is separated from the precipitate slurry, washed well, dried, and then fired to obtain titanium-tungsten-cerium oxide. The separation, washing, drying and calcination can be carried out under the conditions generally used for the preparation of this kind of oxide, but 5-30 wt% of tungsten oxide and 0% of cerium oxide. When the material containing 5 to 15% by weight is heated and fired in the range of 400 to 700 ° C., particularly 450 to 750 ° C., a catalyst material excellent in durability is obtained, which is preferable.
[0028]
As a result of intensive studies on the shape of the honeycomb-shaped catalyst, it was found that the opening ratio of the catalyst is preferably 65% to 90%, and more preferably 65% to 86%. When the opening ratio is less than 65%, the pressure loss is remarkably increased, and at the same time, the geometric surface area of the catalyst is relatively decreased. On the other hand, when the opening ratio of the catalyst exceeds 90%, the thickness of the catalyst material is relatively decreased, which causes a decrease in the denitration rate.
[0029]
Further, it has been found that the geometric surface area of the catalyst is preferably in the range of 2000 to 5000 m2 / m3, and more preferably in the range of 2000 to 4000 m2 / m3. When the geometric surface area of the catalyst is less than 2000 m2 / m3, the denitration rate is low, and when it exceeds 5000 m2 / m3, the pressure loss increases remarkably.
[0030]
The exhaust gas temperature of the NOx generation source varies depending on the operating conditions. For example, when switching from a low load to a high load, the exhaust gas temperature at the outlet rapidly rises from about 300 ° C. to about 600 ° C. in a few minutes. In this case, NH3 adsorbed in the catalyst is desorbed as the exhaust gas temperature rises, so that NH3 is released into the exhaust gas, causing secondary pollution, which is not preferable.
[0031]
When removing NOx in the exhaust gas in the presence of NH3, when the exhaust gas temperature rises rapidly, how to reduce the desorption amount of NH3 adsorbed in the catalyst is a very big problem.
[0032]
According to a study by the present inventors, the amount of NH3 desorbed from the catalyst due to a sharp rise in exhaust gas temperature decreases as the amount of catalyst substance supported on the honeycomb substrate decreases, that is, as the supported catalyst layer thickness decreases. I understood. That is, the supported catalyst layer thickness is preferably 0.03 mm to 0.2 mm, and more preferably 0.03 mm to 0.15 mm. When the supported catalyst layer thickness is less than 0.03 mm, the denitration activity itself decreases, and a sufficient denitration effect cannot be achieved. On the other hand, if the supported catalyst layer thickness exceeds 0.2 mm, the amount of NH3 desorbed when the exhaust gas temperature rises is undesirably increased, and in addition, the responsiveness of the denitration catalyst to a sudden change in temperature is lowered. In addition, the wall thickness of the honeycomb-shaped substrate is reduced, and the mechanical strength is reduced.
[0033]
In addition, it is required that NOx be efficiently removed by sufficiently following changes in the load of the NOx generation source, that is, changes in exhaust gas temperature, gas amount, NOx concentration, and the like. According to a study by the present inventors, it has been found that favorable results can be obtained when NH3 is in a state where a certain amount of NH3 is adsorbed and held. Therefore, when paying attention to the specific surface area of the supported catalyst material, the NH3 adsorption performance is improved when a catalyst material having a specific surface area of 20 m2 / g or more, preferably 30 m2 / g or more is supported, resulting in improved load response and denitration activity. Found a significant improvement.
[0034]
As the honeycomb-shaped substrate supporting the catalyst material of the present invention, a honeycomb structure carrier mainly composed of a ceramic material such as alumina, silica, silica alumina, titania, zirconia, magnesium silicate, mullite, cordierite, and inorganic fibers is used. Can do. Among these, when using a honeycomb-shaped substrate made of cordierite, or a honeycomb-shaped substrate made of a heat-resistant metal such as stainless steel, ferritic stainless steel, or Fe—Cr—Al alloy, the aperture ratio is large, and the unit of the catalyst The per surface area is also large, which is particularly preferable. Other honeycomb structure carriers can also be used.
[0035]
The method for supporting the catalyst substance on the honeycomb substrate will be specifically described below.
[0036]
When adding a suitable amount of water or the like to the catalyst material to form a slurry, add 1 to 10% by weight of titanium oxide sol and / or zirconium oxide sol as a slurry stabilizer in terms of oxide, and then carry it on a honeycomb substrate for drying and firing. As a result, the catalyst material can be firmly supported by the honeycomb substrate.
[0037]
That is, when an appropriate amount of water or the like is added to a catalyst material composed of titanium oxide, tungsten oxide, cerium oxide and / or zirconium oxide and supported on a honeycomb-shaped material, the titanium oxide sol and / or zirconium oxide sol is oxidized as a slurry stabilizer. 1 to 10% by weight is added to the catalyst substance in terms of product. Commercially available products can be used as the titanium oxide sol and zirconium oxide sol to be used. When it is desired to increase the thickness of the catalyst layer, a predetermined thickness can be obtained by supporting the catalyst material slurry of the present invention several times. When the added amount of titanium oxide sol and / or zirconium oxide sol is less than 1% by weight, it is not preferable because the peel strength of the supported catalyst substance is weak. When the added amount is 10% by weight or more, titanium oxide in the slurry stabilizer is not preferable. Further, since there is too much zirconium oxide, it adversely affects the denitration performance and causes a decrease in activity, which is not preferable. Accordingly, the amount of the slurry stabilizer to be added is preferably in the range of 1 to 10% by weight, more preferably in the range of 3 to 7% by weight in terms of oxide with respect to the catalyst component. The catalyst carrying the catalyst component is dried to remove water and calcined to obtain a finished catalyst.
[0038]
The catalyst for removing nitrogen oxides according to the present invention can be used in combination with composite oxides such as alumina, silica, titania-silica, and zeolite with a specific ratio of silica / alumina.
[0039]
The catalyst for removing nitrogen oxides of the present invention is suitably used in a method for removing ammonia by decomposing nitrogen oxides in exhaust gas into nitrogen and water using ammonia as a reducing agent.
[0040]
There is no restriction | limiting in particular about the composition of the waste gas processed using the catalyst for nitrogen oxide removal of this invention, This invention can be used for the process of the various exhaust gas containing NOx. For example, sulfur oxide 0 to 10,000 ppm, oxygen 1 to 20 vol%, carbon dioxide 1 to 15 vol%, water vapor 5 to 80 vol%, dust 0.001 to 30 g / Nm3 and NOx (mainly NO) 10 to 10,000 ppm Used for treatment of contained exhaust gas. Furthermore, the denitration catalyst of the present invention can also be used for the treatment of special exhaust gases such as NOx containing exhaust gas not containing sulfur oxides and NOx containing exhaust gas containing halogen compounds.
[0041]
The exhaust gas treatment conditions using the catalyst for removing nitrogen oxides of the present invention cannot be specified unconditionally because it differs depending on the type, properties, required denitration rate, etc. of the exhaust gas. May be determined as appropriate.
[0042]
As the reducing agent, ammonia, urea, melamine, cyanuric acid, ammonium carbonate, ammonium hydrogen carbonate, or the like that generates ammonia by decomposition is used. In view of the dispersibility and handling of the reducing agent, it is preferable to inject ammonia gas, liquid ammonia, ammonia water, urea aqueous solution, ammonium carbonate aqueous solution, ammonium hydrogen carbonate aqueous solution or the like or in liquid form. When a reducing agent that decomposes to produce ammonia is used, the amount of reducing agent added is determined by the amount of ammonia produced from the reducing agent. For example, urea is 1/2 mol of ammonia water, and melamine is 1/3 mol. It becomes the injection amount.
[0043]
The amount of ammonia used as the reducing agent is within the range of the ammonia / NOx (NO conversion) molar ratio of 0.3 / 1 to 3/1, preferably 0.3 / It can be suitably selected from 1 to 1.5 / 1. In particular, in the case of the catalyst for removing nitrogen oxides of the present invention, a high NOx removal rate can be obtained even when the ammonia / NOx (NO conversion) molar ratio is 1.5 / 1 or less, and NOx can be efficiently decomposed and removed. . For example, in the case of boiler exhaust gas treatment, most of the NOx contained in the exhaust gas is NO, so the ammonia / NOx (NO conversion) molar ratio is particularly preferably near 1, but the required denitration rate, leakage In consideration of the amount of ammonia and the like, it is appropriately selected within a range of about 2/1 or less.
[0044]
The reaction temperature is 400 to 700 ° C, but 450 to 650 ° C is particularly preferable. The space velocity should be in the range of 1000 to 100,000 Hr-1, preferably 3000 to 80,000 Hr-1. This is because if it is less than 1000 Hr-1, the treatment apparatus becomes too large and inefficient, and if it exceeds 100,000 Hr-1, it is because if it is too high, the denitration rate decreases.
[0045]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.
[0046]
Example 1
First, titanium-tungsten-cerium oxide powder was prepared by the method described below. 11.4 kg of titanium tetrachloride (TiCl4) is gradually added dropwise to 80 liters of water (hereinafter referred to as L) under ice cooling and stirring, and dissolved in this aqueous solution with an aqueous solution of ammonium metatungstate (50 wt. %) And an aqueous solution prepared by dissolving 0.5 kg of ceric nitrate 0.5 kg in 1 L of water was added. While keeping this aqueous solution at a temperature of about 30 ° C., with stirring well, aqueous ammonia was added until the pH reached 6, and the mixture was further left for aging for 2 hours. The titanium-tungsten-cerium precipitate slurry thus obtained is filtered, the obtained titanium-tungsten-cerium precipitate slurry is washed with water, dried at 150 ° C. for 10 hours, and then calcined at 600 ° C. for 5 hours. Titanium oxide: tungsten oxide: cerium oxide = 76.8: 20: 3.2 (weight ratio), and a specific surface area of 110 m 2 / m 3 according to the BET method was obtained.
[0047]
Next, 50 g of zirconium oxide sol containing 30% by weight of zirconium oxide and 1 kg of water are added to 500 g of the obtained titanium-tungsten-cerium oxide powder, and the mixture is stirred with a homodisper to obtain a uniform slurry solution. A 200-inch / inch2 metal honeycomb carrier having a cell-shaped cell thickness of 0.05 mm is dipped, then dried with hot air at 80 ° C., and then fired at 600 ° C. for 5 hours in an air atmosphere. A catalyst (A) having a thickness of 0.05 mm was obtained. The composition ratio of the catalyst (A) thus obtained was TiO 2: WO 3: CeO 2: ZrO 2 = 74.6: 19.4: 3.1: 2.9 (weight ratio), and the geometric surface area was 2450 m 2 / m3 and the aperture ratio were 85%. The specific surface area of the supported catalyst material was 95 m2 / m3.
[0048]
(Example 2)
In Example 1, a catalytic material having a specific surface area of 105 m @ 2 / m @ 3 was obtained in the same manner as in Example 1 except that 75 g of titanium oxide sol containing 20% by weight of titanium oxide as the titanium oxide was added to the powder. Thus, a catalyst (B) having a composition ratio of TiO 2: WO 3: CeO 2 = 77.5: 19.4: 3.1 (weight ratio) was obtained. The specific surface area of the obtained supported catalyst material was 88 m @ 2 / m @ 3.
[0049]
(Example 3)
Catalysts (C) to (G) were obtained in the same manner as in Examples 1 and 2, except that the composition ratio, the number of cells of the metal honeycomb carrier, and the thickness of the catalyst component were changed in Examples 1 and 2. Table 1 shows a list of prepared catalysts.
[0050]
(Comparative Example 1)
In Example 1, a comparative catalyst (a) having a catalyst component thickness of 0.02 mm, a geometric surface area of 2500 m 2 / m 3, an aperture ratio of 92%, and the same composition as the catalyst (A) was obtained. It was.
[0051]
(Comparative Example 2)
In Example 1, a catalyst component (b) having a catalyst component thickness of 0.3 mm, a geometric surface area of 1900 m 2 / m 3, an aperture ratio of 54%, and the same composition as the catalyst (A) was obtained. .
[0052]
(Comparative Example 3)
A catalyst material having a specific surface area of 90 m 2 / m 3 was obtained in the same manner as in Example 1 except that 50 g of a silica sol containing 30% by weight of silicon oxide as a silicon oxide was added to the powder, and the composition ratio was TiO 2: A catalyst (c) in which WO3: CeO2: SiO2 = 74.6: 19.4: 3.1: 2.9 (weight ratio) was obtained. The specific surface area of the obtained supported catalyst material was 72 m @ 2 / m @ 3.
[0053]
(Comparative Example 4)
Using 4.8 kg of commercially available anatase-type titanium oxide powder as a titanium source, 0.54 kg of monoethanolamine and 2.7 L of water are mixed with this, and an aqueous solution in which 1.4 kg of ammonium paratungstate is added and dissolved is added. Mix well with a kneader, dry at 150 ° C. for 10 hours, fire at 600 ° C. for 5 hours, and have a specific surface area of titanium oxide: tungsten oxide: cerium oxide = 76.8: 20: 3.2 (weight ratio). A titanium-tungsten-cerium oxide of 76 m2 / m3 was obtained. Thereafter, a comparative catalyst (d) was obtained in the same manner as in Example 1. The specific surface area of the obtained supported catalyst material was 58 m2 / m3.
[0054]
(Comparative Example 5)
In Comparative Example 4, a catalyst material having a specific surface area of 17 m 2 / m 3 was obtained in the same manner as in Comparative Example 4 except that calcination was carried out at 800 ° C. for 5 hours, and a catalyst was prepared to obtain catalyst (e). The specific surface area of the obtained supported catalyst material was 14 m @ 2 / m @ 3.
[0055]
(Test Example 1)
A denitration activity test was performed using the catalysts (A) to (G) prepared in Examples 1 to 3 and the comparative catalysts (a) to (e) prepared in Comparative Examples 1 to 5. The activity test was performed under the following conditions, and the denitration rate was determined by the following equation (1). Further, the pressure loss of each catalyst was measured under the condition of a denitration activity test of 500 ° C. The results are shown in Table 2.
[0056]
(Activity test conditions)
NOx: 70 ppm NH3: 70 ppm O2: 15% H2O: 10% N2: Balance Gas temperature: 400-700 ° C Space velocity: 15000 Hr-1
Denitration rate (%) = [(reactor inlet NOx concentration) − (reactor outlet NOx concentration)] / (reactor inlet NOx concentration) × 100 (1)
(Test Example 2)
A peel strength test was performed using the catalysts (A) to (G) prepared in Examples 1 to 3 and the catalysts (a) to (e) prepared in Comparative Examples 1 to 5. The peel strength test was performed by the following method, and the peel degree was determined by the following equation (2). The results are shown in Table 3.
[0057]
1) The weight of the catalyst component (the weight of the catalyst component before peeling) is measured in advance, and the catalyst is heated at 550 ° C. in an electric furnace.
[0058]
2) A catalyst is put into water from an electric furnace.
[0059]
3) The catalyst is taken out and dried at 150 ° C., and the weight of the catalyst component from which the support layer is peeled off (weight after peeling) is measured.
[0060]
Degree of peeling (%) = [(weight of catalyst component before peeling) − (weight of catalyst component after peeling)] / (weight of catalyst component before peeling) × 100 (2)
[0061]
【The invention's effect】
The catalyst prepared by the method described in the present invention exhibits high denitration activity in a wide temperature range, particularly at a high temperature range of 400 ° C. or higher, and has excellent durability. For this reason, by using the catalyst of this invention, the nitrogen oxide in the high temperature waste gas discharged | emitted from a boiler, a gas turbine, a gas engine, a diesel engine, a heating furnace, and various industrial processes can be removed efficiently.
[0062]
[Table 1]

[0063]
[Table 2]

[0064]
[Table 3]

Claims (3)

The catalyst material was slurried and supported on the honeycomb-shaped substrate, dried and calcined, a nitrogen oxide removing catalyst obtained by carrying a catalyst material on the honeycomb-shaped substrate, a titanium oxide as those the catalyst material 50 to 94.5% by weight of the product, 5 to 30% by weight of tungsten oxide, 0.5 to 10% by weight of cerium oxide and 0 to 10% by weight of zirconium oxide. a 03～0.2Mm, the aperture ratio in the manufacturing process 65 to 90% of the range near Ru nitrogen oxide removing catalyst, the titanium oxide sol and / or zirconium oxide sol as a slurry stabilizer to the catalyst material A method for producing a catalyst for removing nitrogen oxide, wherein 1 to 10% by weight in terms of oxide is used. 2. The nitrogen oxide removing material according to claim 1, wherein the catalyst material is obtained by calcining a precipitate obtained by precipitating an aqueous liquid containing a soluble titanium compound, a soluble tungsten compound and a soluble cerium compound in an aqueous medium. A method for producing a catalyst. The catalyst for removing nitrogen oxides according to claim 2, wherein the precipitate is obtained by neutralizing an aqueous liquid obtained by dissolving a soluble titanium compound, a soluble tungsten compound and a soluble cerium compound in an aqueous medium with a basic substance. Manufacturing method.