JP2002035606A - Method of producing catalyst for purifying gas containing organic chlorinated compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a catalyst for purifying an waste gas containing organic chlorinated compounds, by which a catalytic component can be uniformly dispersed on the surface of each titanium oxide particle as a catalyst carrier. SOLUTION: In the method of producing the catalyst for purifying the gas containing organic chlorinated compounds, in which a catalytically active component is deposited on titanium oxide particle, the catalytically active component is deposited in the presence of an amino alcohol.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method for purifying exhaust gas containing organic chlorinated compounds, and more particularly to a method for purifying exhaust gas suitable for removing harmful organic chlorinated compounds such as dioxin from exhaust gas.

2. Description of the Related Art Conventionally, in the case of a catalyst in which a catalyst component is supported on a carrier mainly composed of titanium oxide, the surface of titanium oxide particles as a carrier is subjected to a coprecipitation method or an impregnation method using oxalic acid chelate. The catalyst component was supported.

However, in these methods, the dispersion of the catalyst component on the particle surface is poor, and in order to exhibit high catalytic performance, it is necessary to disperse the catalyst component in fine particles uniformly on the surface of the catalyst carrier. There is. In addition, the size of the area (specific surface area) in contact with the outside air is also a large factor that determines the catalytic performance. However, the conventional titanium oxide particles have a specific surface area of about 60 to 80 m ² / g in the raw material powder for the catalyst carrier, There is a limit to increasing the specific surface area using titanium oxide particles. An object of the present invention is to highly disperse a catalyst component on the surface of a titanium oxide particle as a carrier,
An object of the present invention is to provide a method for producing an exhaust gas purifying catalyst containing an organic chlorinated compound.

Means for Solving the Problems To achieve the above object, the invention claimed in the present application is as follows. (1) A method for producing a catalyst for purifying a gas containing an organic chlorinated compound, in which a catalytically active component is supported on titanium oxide particles, wherein an amino alcohol is coexistent when the catalytically active component is supported. A method for producing a catalyst for purifying a compound-containing gas. (2) The method according to (1), wherein a titanium ion is allowed to coexist in addition to the amino alcohol. (3) The method according to (1) or (2), wherein one or more particles selected from alumina, silica, and a composite oxide thereof are used in addition to the titanium oxide particles. (4) The peak of the pore size distribution of the obtained catalyst is at least 3
(1) to (3), wherein the first peak is in the range of 300 nm to 450 nm, the second peak is in the range of 50 nm to 100 nm, and the third peak is in the range of 30 nm or less. The method according to any of the above. (5) Titania particles having a particle diameter of 5 nm to 600 nm are prepared as a titania raw material, and a thermally decomposable substance having a particle diameter equal to or larger than a target pore diameter of the catalyst is kneaded as a porosifying agent,
Baking to form a first peak of the pore size distribution, pores of other pore sizes are formed as gaps between the titania particles, and in any stage during the preparation of the catalyst, in the presence of amino alcohol. A method for producing a gas purification catalyst containing an organic chlorine compound, comprising adding a catalytically active component. In the present invention, the amino alcohol added when the catalyst component is supported is an alcohol having an amino group, and is a lower amino alcohol such as aminoethanol, aminobutanol and aminopropanol, for example, 2- (2-aminoethyl Amino) ethanol and 2-amino alcohols such as 2-amino-2-methyl-1-propanol.

[Function] The catalyst component is adsorbed on the titanium oxide particles via the hydroxyl group of the amino alcohol, while ions of the catalyst component are trapped in the amino group of the amino alcohol. The catalyst component can be supported in the state. In addition, when titanium ions coexist with amino alcohol, there is an effect of increasing the specific surface area. In addition, by supporting titania and a catalyst component on a carrier having a large specific surface area such as alumina and silica, a catalyst having the same or higher activity as that of a conventional catalyst and having a larger specific surface area can be obtained. The catalyst may be produced by a known method except that an amino alcohol coexists when the catalytically active component is supported. The amount of the amino alcohol to be added during the production of the catalyst is preferably from 10 to 40% by weight, particularly preferably from 25 to 32% by weight, based on the catalyst raw material composition. The particle size of the titanium oxide particles used in the present invention is 5 nm to 6 nm.
Those having a range of 00 nm are preferred. The catalyst produced according to the present invention reduces the diffusion resistance in the pores of molecules having a size of about dioxins and improves the catalyst performance,
The pore size distribution of the catalyst has at least three peaks,
Of 300 nm to 450 nm, preferably 350 nm
nm to 450 nm (more preferably 380 nm to 42 nm).
0 nm), the second peak is 50 nm to 100 n
m, preferably in the range of 75 nm to 100 nm (more preferably in the range of 90 nm to 100 nm), and the third peak has a range of 30 nm or less, preferably 20 nm or less. The pore size distribution of the catalyst in the present invention is a value measured by a mercury porosimetry and read from a differential pore volume distribution diagram. The catalyst pore size distribution of the first peak has an effect of reducing the diffusion resistance of dioxins inside the catalyst, and the catalyst pore size distribution of the second peak coexists with the first peak. Has a function of inducing dioxins approached through the pore diameter of the third peak to the pore diameter distribution of the third peak, and the pore diameter distribution of the third peak is represented by the first and second pore diameters.
In addition to the presence of the dioxins, the dioxins which are not captured in the pore size distributions of the first and second peaks are finally captured. In the catalyst of the present invention, the carrier is titanium oxide, and the catalytically active component is vanadium oxide and / or vanadium oxide.
Alternatively, the active ingredient is desirably tungsten oxide, and vanadium oxide among the active ingredients is 0.01% to 30% by weight, preferably 1% to 5% by weight of the total weight of the catalyst.
It is desirable that the content of tungsten oxide be 0.01% to 30% by weight, preferably 10% to 20% by weight of the total weight of the catalyst. If it exceeds this range, sufficient catalytic performance cannot be obtained. Further, the specific surface area of the catalyst is preferably 50 m ² / g or more, preferably 75 m ² / g or more, more preferably 100 m ² / g or more. When the specific surface area is less than this range, the catalytic performance per unit volume is not sufficient and is not practical. As a method for producing the catalyst having the above specific pore size distribution, the following method is preferably used. That is, one or two or more kinds of titania particles having a particle size of 5 nm to 600 nm as the titania raw material (in this case, the titania particles are primary particles composed of a single crystal or a dense polycrystalline particle, or substantially Secondary particles composed of primary particles), a catalytically active component (vanadium oxide or / and tungsten oxide), and a porogen (for example, having a particle size of 50 nm to 1000 nm).
Kneading together with an amino alcohol and molding, followed by baking, and titania particles having a particle size of 5 to 600 nm in the same manner as described above. Primary particles composed of single crystal or dense polycrystalline particles, or secondary particles composed substantially of primary particles)
Is used as a carrier material, and a porosifying agent (for example, a particle size of 50 nm
A method of kneading, molding and firing together with a 1000 nm easily heat-decomposable compound) and an amino alcohol, and then supporting and firing the catalytically active component by an impregnation method. The active ingredient may be supported by a coprecipitation method or the like at the time of producing the titania particles. The particle size of the raw material titania particles is 5n
m to 600 nm, preferably 50 nm to 400 nm.
nm, more preferably 100 nm to 200 nm. Outside this range, it is difficult to form pores corresponding to the second peak or pores corresponding to the third peak.

BEST MODE FOR CARRYING OUT THE INVENTION In the process for producing a catalyst according to the present invention, the porogen is a calcination temperature or lower (about 400 ° C. to 80
(0 ° C.), for example, a material which is easily thermally decomposed, such as methacrylic resin, acrylic resin, acetal resin, and phenol resin. The particle size of the porous agent is larger than the pore size to be produced. For example, 40
In the case of opening pores of 0 nm, a porogen having a particle diameter of 400 nm or more is used. The rough guide is about 1.2 to 1.5 times the pore diameter to be produced, but this value is determined in consideration of the physical properties (depending on the type of the above-mentioned resin) of the porogen. The second and third peaks have a particle size of 5 nm to 60 nm.
As a gap of 0 nm titania particles (in this case, the titania particles are primary particles composed of a single crystal or dense polycrystalline grains, or secondary particles substantially composed of primary particles). It can be formed by controlling the packing density. In addition, in order to obtain a second peak of 50 nm to 100 nm, for example, as the raw material titania, a particle size of 5 nm to 60 nm is used.
It can also be obtained by using secondary particles of 0 nm, kneading and firing. The size of the secondary particles can be controlled by the temperature, pH, and use of a surfactant during the preparation. Further, it can also be controlled by performing a high dispersion treatment with a sand mill. Further, a third peak of 30 nm or less can be formed as a gap between the primary particles of titania. The gap between the primary particles can be formed by appropriately selecting the particle size of the primary particles themselves and the production condition of the secondary particles so as to obtain a target pore size. Since the pores of the catalyst are formed during the production of the titania support, any of the kneading method, the impregnation method and the coprecipitation method may be used for supporting the catalytically active component.
In the case of the kneading method or the like, the active component is supported at the same time as the carrier preparation (pore formation), and in the case of the impregnation method or the like, the active component is supported after the carrier preparation (after pore preparation). . In the case of the coprecipitation method, the active ingredient is supported on the titania raw material before the preparation of the carrier (before the preparation of the pores). In the kneading method, a mixture of vanadium oxide or tungsten oxide (and / or, hereinafter, the same applies hereinafter) is mixed with a raw material that changes into an oxide during firing, for example, hydroxides, halides, and ammoniums of these metals. Salts, sulfates, etc. may be mixed. In the case of the impregnation method, the titanium oxide carrier (powder
(Vanadium oxide or tungsten oxide is supported on granules, plates, rods, honeycombs, etc.) When the titanium oxide is a powder or a slurry, it is mixed with a solution of a vanadium salt or a tungsten salt to impregnate the active metal component. When the titanium oxide is a molded body, the titanium oxide is directly poured into a solution of a vanadium salt or a tungsten salt to impregnate the active ingredient. The order of impregnation, when using vanadium oxide and tungsten oxide, after supporting the tungsten oxide on the titanium oxide, finally supporting the vanadium oxide,
There is a method of supporting vanadium oxide on titanium oxide and then supporting tungsten oxide at the end, or a method of simultaneously impregnating titanium oxide with vanadium oxide and tungsten oxide. As a starting material for vanadium, for example, an aqueous solution of oxalic acid of ammonium metavanadate or an aqueous solution of vanadyl sulfate is used. For example, an aqueous solution of ammonium tungstate is used as a starting material for tungsten.
In the case of the co-precipitation method, an aqueous solution of a water-soluble titanium compound (for example, tetrachlorotitanium) and a water-soluble vanadium compound (for example, vanadyl sulfate) or a water-soluble tungsten compound (for example, ammonium tungstate) is prepared, and the pH is adjusted to neutral. A precipitate is obtained while preparing an appropriate solution so as to be in the vicinity and taking care not to generate excessive heat. The precipitate is filtered, washed (washed with water), dried and calcined to obtain a catalyst. It is also possible to carry either V or W in this way, and later carry the other active metal in another way.

The present invention will be described below in more detail with reference to examples. Example 1 28 g of 2- (2-aminoethylamino) ethanol as aminoethanol was dissolved in 200 ml of distilled water to form a solution, and 88 g of titanium oxide particles having an average particle size of 90 nm were added thereto.
After stirring at room temperature for 3 hours, an aqueous vanadium sulfate solution (28.6 g / 100 ml distilled water) was added to the mixture,
After stirring for 1 hour, water was evaporated at 80 ° C. Thereafter, a predetermined molding aid shown in Table 1 is added, and after kneading, extrusion molding is performed to obtain a honeycomb or cylindrical catalyst molded body. 300-600 ° C in air (or oxygen-added air)
The catalyst was obtained by firing at (preferably 400 ° C.). Table 2 shows the physical properties of the produced catalyst. Table 9 shows the composition of the catalyst used in the comparative example. The evaluation of the obtained catalyst was performed as follows. The catalyst is packed in a fixed-bed microreactor device, the reaction temperature is 200 ° C., and the W / F is 0.0.
17 (g / min / ml), the test gas was 300 ppm of the indicator organic halogen compound, the oxygen concentration was 10%, and the evaluation test of the catalyst with respect to the decomposition of the organic halogen compound was performed as a nitrogen balance. As the indicator organic halogen compound, o-chlorophenol which is an alternative indicator substance for dioxins was used. The specific surface area of the catalyst is multi-point BET by nitrogen adsorption.
It was measured by the method. Table 3 shows the results. Where K / Ko
Is an index of the catalyst activity as compared with the case of the comparative example. Table 3
As is clear from the above, it was confirmed that the catalyst of the present invention had higher performance than the catalyst of the comparative example. Example 2 In Example 1, 30 g of 2- (2-aminoethylamino) ethanol and an aqueous solution of vanadium sulfate (19.1 g /
100 ml of distilled water) and an aqueous solution of titanyl sulfate (15.
A catalyst of the present invention was prepared in the same manner as in Example 1 except that 6 g / 100 ml of distilled water was used. The physical properties and evaluation results of the obtained catalyst are shown in Tables 4 and 5, respectively. Example 3 In Example 2, 60 g of aminoethanol was added to distilled water 2
A solution dissolved in 50 ml, vanadium sulfate (38.5 g /
100 ml of distilled water) and an aqueous solution of titanyl sulfate (32.2)
g / 100 ml of distilled water) with a specific surface area of 100 m
A catalyst of the present invention was prepared in the same manner as above except that 76 g of ² / g silica particles were added, and those listed in Table 6 were used as molding aids. The physical properties and evaluation results of the obtained catalyst are shown in Tables 7 and 8, respectively. As a result of the evaluation, it was confirmed that the catalyst had higher performance as shown in Table 7 than the catalyst of the comparative example. Comparative Examples 1-3 Ammonium vanadate is added to the oxalic acid solution. Ammonium metavanadate is added according to the amount supported in each example. The amounts are shown in Table 9. To this, a raw titanium oxide powder is added, a predetermined molding aid is added, and after kneading and extrusion molding, a honeycomb or cylindrical catalyst molded body is obtained. This was calcined at 500 ° C. to obtain a catalyst. The obtained catalyst was evaluated in the same manner as in the example, and the results were shown in Table 3,
5 and 8 respectively.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

[Table 8]

[Table 9] Example 4 and Comparative Example 4 Preparation of Catalyst (Kneading Method) Using 90 g of titania powder supporting vanadium by the method shown in Example 1, a silane coupling agent for adjusting viscosity in order to improve moldability (Shin-Etsu) Surface treatment was performed with KBM603 manufactured by Silicone Co., Ltd.). The molding and baking procedures are as follows. First, a silane coupling agent is put into an aqueous solution adjusted to a predetermined pH with acetic acid and ammonia water, stirred, and then allowed to stand at room temperature for 24 hours. The standing liquid and the titania powder having the particle size blended are mixed with a homogenizer, and dried at 80 ° C. until the mixed liquid is free of moisture. Then, after pulverization and classification, a binder and a porosifying agent are used. It is mixed with various additives such as distilled water, plasticizer and lubricant, kneaded and allowed to stand. After standing for a certain period of time, the mixture is kneaded again and molded. Molding was performed in a noodle shape (pencil shape) using an extrusion jig. After the molding, it was dried again, and then calcined in an air atmosphere at 400 ° C. for 3 hours to obtain a titania carrier. As shown in Table 10, two kinds of carrier samples were prepared by changing the particle diameters of the raw material titania and the porogen. The catalyst performance obtained as described above was evaluated as follows. Reaction temperature 200 ° C, W / P 0.017 using a fixed-bed microreactor device
(G · min / ml), indicator substance o-chlorophenol, reaction gas: indicator substance concentration 300 ppm, oxygen concentration 1
A performance evaluation test of the catalyst was performed with a nitrogen balance of 0%. The specific surface area of the catalyst was measured by a multipoint BET method using nitrogen adsorption. The pore distribution was measured with a mercury intrusion porometer and read from a differential pore volume distribution diagram. Table 1 shows the results
1 is shown. From Table 11, it can be seen that the catalyst of Example 4 (the present invention) having three peaks in the pore structure has a factory with a higher decomposition rate per unit specific surface area than the case of the two peaks (Comparative Example 4).

[Table 10]

[Table 11]

According to the present invention, when the catalytically active component is loaded on the titanium oxide particles, the catalyst component can be loaded with high dispersibility by coexisting with the amino alcohol, and as a result, a higher loading than the conventional one can be obtained. Catalyst performance can be obtained. In addition, by supporting and coexisting titanium ions as a carrier component simultaneously with the catalyst component, the catalyst component to oxide particles having a high specific surface area other than titanium oxide,
By supporting a carrier component, it is possible to dramatically improve catalyst performance.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) B01J 37/08 B01D 53/36 G (72) Inventor Masao Namba 3-1-1 Tamama, Tamano-shi, Okayama Prefecture Mitsui Engineering & Shipbuilding Co., Ltd. Tamano Works Co., Ltd. BA02A BA02B BA04A BA04B BA21C BB04A BB04B BC54B CA04 CA10 CA19 DA06 EA01Y EA06 EA19 EB18X EB18Y EC03Y EC10X EC10Y FA02 FB04 FB06 FB34 FB67 FC04

Claims (5)

[Claims] 1. A method for producing a catalyst for purifying an organic chlorinated compound-containing gas, wherein a catalytically active component is supported on titanium oxide particles, wherein an amino alcohol is coexistent when the catalytically active component is supported. A method for producing a catalyst for purifying a chlorinated compound-containing gas. 2. The method according to claim 1, wherein a titanium ion is present in addition to the amino alcohol. 3. In addition to the titanium oxide particles, alumina
3. The method according to claim 1, wherein one or more particles selected from silica and a composite oxide thereof are used. 4. The obtained catalyst has at least three peaks in the pore size distribution, and the first peak has a peak of 300 nm to 450 nm.
4. The method according to claim 1, wherein the range of m, the second peak is in the range of 50 nm to 100 nm, and the third peak is in the range of 30 nm or less. 5. A material having a particle size of 5 nm to 60 as a titania raw material.
A titania particle of 0 nm is prepared, and a thermally decomposable substance having a particle size equal to or larger than a target pore size of the catalyst is kneaded as a porosifying agent, followed by firing to form a first peak of the pore size distribution. A pore having a pore diameter of not less than an organic chlorinated compound, which is formed as a gap between the titania particles and is characterized by adding a catalytically active component in the presence of an amino alcohol at any stage during the preparation of the catalyst. A method for producing a gas purification catalyst.