JPH0753208A - Zeolite composition for compacting, zeolite compact, zeolite sintered compact and their production and use - Google Patents

Abstract

PURPOSE:To obtain a zeolite composition for a catalyst carrier with the plastic formability improved by mixing a zeolite powder with beta-1,3-glucan and a porous metal compd. CONSTITUTION:One hundred pts.wt. of zeolite powder is mixed with 0.1-20 pts.wt. of beta-1,3-glucan and 65-250 pts.wt. of a porous metal compd. Curdlan, paramylon, etc., are preferably used as the beta-1,3-glucan. Metal oxides, metal hydroxides, metal phosphates or their mixture are used as the porous metal compd., and the metal oxides, metal hydroxides or their mixture are especially preferable. A metallic component is deposited on the compact of the composition or its sintered compact to form an NOx removing catalyst.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to molding and calcination of zeolite powder for catalyst carriers, and more specifically, to a composition for plastic molding of zeolite powder having no plastic moldability, which is obtained by using the composition. The present invention relates to a molded zeolite product, a molded zeolite calcined product, a method for producing the molded product and a calcined product, and use of the molded product and the calcined product as a catalyst.

[0002]

2. Description of the Related Art Zeolite powder, when used as a catalyst carrier or the like, is provided with an appropriate shape, for example, a spherical shape, a columnar shape, a granular shape, a honeycomb shape or the like. However, the zeolite powder itself has no plasticity at all, and even if it is kneaded with water, it is impossible to obtain a plastic material such as clay. Therefore, the zeolite itself cannot be plastically molded. Moreover, the zeolite powder is not sintered. Therefore, in order to impart plasticity and sinterability to the zeolite powder in order to plastically mold the conventional zeolite powder and fire it, generally, an inorganic binder such as natural clay or bentonite, kaolin, colloidal silica or the like is used. ,
A cellulosic organic binder is blended with zeolite powder, plastically molded and fired. For example, JP-A-48-39399 describes the use of crystalline cellulose as an organic binder. Further, in JP-A-59-26923 and JP-A-2-6846, an inorganic binder such as natural clay, bentonite, kaolin and colloidal silica, or an organic binder such as crystalline cellulose is added to zeolite powder. A method is described in which it is blended with water to obtain a water-based composition, which is molded, dried, and calcined to obtain a pellet-shaped molded and calcined product. However, according to such a conventional method, for example, when natural clay is used as a plasticizer, it is necessary to use a relatively large amount of natural clay. The properties of the zeolite per unit weight of the product, that is, the function as a catalyst carrier, is significantly reduced as compared with the zeolite powder itself.

In addition, regarding the molded and fired product of the zeolite having the honeycomb structure, in order to secure the mechanical strength that can be industrially practically used, the zeolite powder is mixed with the organic binder and the inorganic fibers as the reinforcing material. Then, the composition thus obtained is molded, dried, and fired to obtain a fired zeolite molded fired product having a honeycomb structure while preventing cracking during firing.
It is described in Japanese Patent No. 539. However, even in this method, the performance of the organic binder is not sufficient, and the plasticity and moldability of the composition used for molding are poor. Further, it is not possible to sufficiently prevent the occurrence of cracks. Therefore, depending on these techniques, while maintaining the function of zeolite as a catalyst carrier, mechanical strength that can be industrially practically secured, and a zeolite composition for a catalyst carrier having excellent moldability is specifically Not yet offered. Japanese Patent Laid-Open No. 4-1600
No. 14, gazette describes that zeolite powder having plastic moldability is β
Disclosed are a zeolite kneading composition for molding containing 1,3-glucan, a zeolite molded product obtained by molding the composition, and a molded sintered product obtained by sintering the molded product. It is described that a sintering agent may be added to the composition in order to maintain the strength after firing during the sintering of the product. Such clay minerals, kaolin, natural clay minerals such as halloysite, bentonite, acid clay, sepiolite, etc.,
Artificial clay minerals such as synthetic smectite and synthetic kaolin, and inorganic oxide or hydroxide powders such as aluminum hydroxide, titanium hydroxide, zinc hydroxide, silica and magnesia are mentioned. Then, these sinters are used alone or as a mixture of two or more kinds, usually about 10 to 60 parts by weight, preferably about 20 to 4 parts by weight with respect to 100 parts by weight of zeolite powder.
Although it is described to be used in the range of 5 parts by weight, it is desired to further improve the plastic moldability.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to a composition of zeolite for a catalyst carrier having improved plastic moldability, a zeolite molded product obtained by using the composition, a zeolite molded calcined product and the zeolite molded product, An object is to provide a method for producing a fired product.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that β-1,3-glucan 0.1 to 100 parts by weight of zeolite powder.
Unexpectedly, the function of zeolite as a catalyst carrier is lowered by adding 20 parts by weight and 65 to 250 parts by weight of a porous metal compound (particularly, a porous metal oxide, a porous metal hydroxide, etc.). By securing a mechanical strength that can be industrially practically used, and finding a molding composition having excellent moldability, and molding, drying and firing the composition, strength and dimensional accuracy can be obtained without cracking. It has been found that an excellent zeolite molded product for catalyst carrier and a calcined product can be easily obtained. This porous metal compound makes it possible to ensure mechanical strength, and can be industrially used while maintaining the activity as a catalyst carrier without deteriorating the function of the zeolite powder as a catalyst carrier. It is a thing. However, when the amount of the porous metal compound added to the zeolite powder increases, the activity when used as a catalyst tends to decrease slightly, but the mechanical strength (for example, bending strength) of the molded or fired product is improved. To do. On the other hand, when the amount of the porous metal compound added is reduced, the activity as a catalyst is improved, but the mechanical strength of the molded fired product tends to be reduced. Therefore, it is necessary to optimally adjust the addition amount of the porous metal compound in order to obtain a calcined product having excellent mechanical strength while maintaining the activity as a catalyst. That is, it is necessary to optimally adjust the addition amount of the porous metal compound so that the product (ξ) of the catalytic ability such as NO decomposition and the mechanical strength (for example, bending strength) becomes large.

A major feature of the present invention is that the optimum addition amount of the porous metal compound is set in order to solve such a problem. That is, the present inventors usually use 6 parts by weight of the porous metal compound in 100 parts by weight of the zeolite powder as the main component in the molding zeolite composition of the present invention.
5 to 250 parts by weight, preferably 70 to 250 parts by weight, more preferably about 10 to 250 parts by weight is added, whereby the mechanical strength which can be industrially practically used is not deteriorated without deteriorating the function of zeolite as a catalyst carrier. It was found that it can be ensured and that it has excellent moldability. Then, they have found that by further adding a clay mineral, inorganic fibers, a molding aid and the like, a more excellent effect can be exhibited. The present inventors have completed the present invention as a result of further research based on these findings. That is, the present invention provides (1) zeolite powder 100
(2) β-zeolite composition comprising 0.1 to 20 parts by weight of β-1,3-glucan and 65 to 250 parts by weight of a porous metal compound with respect to parts by weight,
The 1,3-glucan is curdlan, and the molding zeolite composition according to item (1), and (3) the porous metal compound is a porous metal oxide or / and a porous metal hydroxide. The molding zeolite composition according to item (1),
(4) The molding zeolite composition according to item (1), wherein the porous metal compound is aluminum oxide or / and aluminum hydroxide, and (5) the zeolite powder is 10
(1) The zeolite composition for molding according to the item (1), which has an average particle diameter of not more than μm, and (6) a clay mineral or / and an inorganic fiber. ), The zeolite composition for molding, (7) with respect to 100 parts by weight of the zeolite powder, β-
1,3-glucan 0.1-20 parts by weight, porous metal compound 65-250 parts by weight containing a zeolite molded article,

(8) The molded zeolite article according to item (7), characterized in that the molded article is a honeycomb structure.
(9) β-1, with respect to 100 parts by weight of zeolite powder
3-glucan 0.1 to 20 parts by weight, porous metal compound 6
5 to 250 parts by weight of a molded zeolite calcined product, (10) 0.1 to 20 parts by weight of β-1,3-glucan, and 100 parts by weight of zeolite powder, and a porous metal compound 65 To 250 parts by weight are mixed, The method for producing a zeolite composition according to item (1),
(11) β-
The molded zeolite article according to item (7), which is obtained by molding a molding zeolite composition containing 0.1 to 20 parts by weight of 1,3-glucan and 65 to 250 parts by weight of a porous metal compound. (12) Zeolite powder 10
Β-1,3-glucan 0.1 to 20 parts by weight relative to 0 parts by weight
(1) A method for producing a fired zeolite molded article according to item (9), characterized in that a zeolite molded article containing 65 parts by weight of a porous metal compound and 65 to 250 parts by weight of the porous metal compound is sintered.
3) Zeolite molded product according to item (7), which is a nitrogen oxide removal catalyst, (14) Zeolite molded calcined product according to item (9), which is a nitrogen oxide removal catalyst, and (15) zeolite molded product. , VA, VIA, VIIA, VIII of the periodic table
(13) Zeolite molding, characterized in that it carries one or more metal components selected from the group consisting of Group I, Group IB, Group IIB and Group IIIB. For burned material, VA group, VIA group, VIIA of the periodic table
A sintered shaped zeolite product according to item (14), characterized in that it carries one or more metal components selected from the group consisting of group VIII, group VIII, group IB, group IIB and group IIIB. Is.

The molding zeolite composition of the present invention comprises 0.1 to 20 parts by weight of β-1,3-glucan and 100 to 100 parts by weight of zeolite powder, and a porous metal compound 65 to 250.
It is characterized by containing parts by weight. The zeolite powder used in the composition of the present invention may be either a natural zeolite powder or a synthetic zeolite powder, and two or more kinds may be mixed and used. The natural zeolite may be any of chabazite type, natural mordenite type, clinoptilolite type, erionite type and the like. Examples of the synthetic zeolite include A type (Shilton B (registered trademark) manufactured by Mizusawa Chemical Industry Co., Ltd., Mizuka Sieves 4A (registered trademark))
Etc.), X type (Mizuka Sieves X manufactured by Mizusawa Chemical Industry Co., Ltd.)
(Registered trademark), Y type (Mizuka Sieves Y (registered trademark) manufactured by Mizusawa Chemical Industry Co., Ltd.), synthetic mordenite type, high silica type (MFI type, etc.), Si / A
Any one having a different atomic ratio or structure, or a zeolite composed of other elements may be used. The type of these zeolites is appropriately selected depending on the purpose of use, but for example, a high silica type (MFI type) is preferably used for a nitrogen oxide decomposition catalyst. It is desirable that these zeolite powders have a relatively small particle size and have an appropriate distribution. In particular, the average particle size is 1
It is preferable to have a particle size of 0 μm or less. The most preferable particle size is an average particle size of 5 μm or less. The β-1,3-glucan used in the composition of the present invention mainly acts as a plasticizer for zeolite powder.
In this β-1,3-glucan, glucose is mainly β-
It is a glucan linked by 1,3-bond, and specifically, curdlan, laminaran, baramiron, callose, pakiman and the like are used. These β-
Among 1,3-glucans, β-1,3 of microbial origin
-Glucan is preferred, and therefore curdlan, paramylon and the like are preferably used, and curdlan is most preferably used. All of these give a high plasticity to the zeolite powder when used in a small amount.

Curdlan, as described in New Food Industry, Vol. 20, No. 10, pp. 49-57 (1978), is mainly composed of .beta.-1,3-glucoside bonds and usually heated. It is a polysaccharide having coagulability, that is, β-1,3-glucan having the property of coagulating (forming a gel) when heated in the presence of water. Such curdlan is produced by a microorganism of the genus Alcaligenes or Agrobacterium. Specific examples of such microorganisms include, for example, Alcaligenes fuecalis var Myxogenes strain 10C3K (Agricultural Biological Chemistry).
ural Biological Chemistry), Vol. 30, p. 196 (1966)), or a variant NT of Alcaligenes faecalis barr Myxogenes strain 10C3K.
Ku (IFO 13140) (Japanese Patent Publication No. 48-3267)
3), Agrobacterium radiobactor (IFO)
13127) and its variant U-19 (IFO 12
126) (Japanese Patent Publication No. 48-32674) and the like can be used. Curdlan is a kind of β-1,3-glucan produced by microorganisms as described above,
In the present invention, this may be used as it is, or may be highly purified before use, if necessary. Paramylon is a microorganism called Euglen.
a) is a type of β-1,3-glucan that accumulates in cells. Paramylon is commercially available, for example, from Carbohydrate Research,
25 , 231-242 (1979) and Japanese Patent Application Laid-Open No. 1-3.
It is already known from Japanese Patent No. 7297. In addition, paramylon may be alkali-treated, if necessary, in order to have heat-coagulability. In the present invention, paramylon may be used as it is in an unpurified form, or may be highly purified before use, if necessary. Similarly, other β-1,3-glucans may be used in an unpurified state, or may be highly purified before use, if necessary. Particularly, in the present invention, β
Among the -1,3-glucans, curdlan having heat-coagulability and paramylon treated with alkali are most preferably used. Β- having such heat coagulability
By using 1,3-glucan as a plasticizer, a kneaded solid composition having sufficient moldability and a molded product having sufficient strength can be obtained in the process of molding, drying and firing zeolite. As mentioned above,
According to the present invention, the β-1,3-glucan as described above is necessary for imparting molding plasticity to the zeolite powder which originally has no molding plasticity.

In the composition of the present invention, β-1,3-
Glucan, alone or as a mixture of two or more, is usually 0.1 to 20 per 100 parts by weight of zeolite powder.
It is used in parts by weight, preferably 0.5 to 10 parts by weight. The porous metal compound used in the composition of the present invention has, for example, a surface area of usually 5 to 500 m ² /
For example, a porous metal compound having g, preferably 10 to 500 m ² / g is used. As the metal compound, for example, a metal oxide, a metal hydroxide, a metal phosphate or a mixture thereof is used, and a metal oxide, a metal hydroxide or a mixture thereof is particularly preferable. Examples of the metal of the metal compound include Mg, Al, Ca, Ti and M
n, Fe, Co, Ni, Cu, Zn, Zr, Ag, P
Examples thereof include t and Au. Of these, Al, Ti, Zr and the like are preferable, and Al is particularly preferable. As the porous metal compound, specifically, aluminum oxide (for example,
β, γ, δ, η, θ, χ, κ-Al ₂ O _3, etc.), aluminum hydroxide (for example, dodide, gibbsite, bayerite, nordstrandite, boehmite, diaspore, alumina gel, etc.), titanium oxide ( For example,
Anatase, rutile, etc.), titanium hydroxide (eg, titania gel), zirconium oxide, zirconium hydroxide, aluminum phosphate, titanium phosphate,
Zirconium phosphate or a mixture thereof is used, among which the above-mentioned aluminum oxide, aluminum hydroxide, titanium oxide or a mixture thereof are preferable, and particularly aluminum oxide (especially γ, δ, η-Al ₂
O _{3 and the} like), aluminum hydroxide (in particular, boehmite and the like) or a mixture thereof is preferable.

This porous metal compound is capable of ensuring the mechanical strength, and is capable of industrially maintaining the activity as a catalyst carrier without deteriorating the function of the zeolite powder as a catalyst carrier. It is practical. When the amount of the porous metal compound added to the zeolite powder increases, the activity when used as a catalyst tends to slightly decrease, but the mechanical strength (for example, bending strength) of the molded or fired product is improved. Further, when the amount of the porous metal compound added is reduced, the activity as a catalyst is improved, but the mechanical strength of the molded and baked product tends to be reduced. Hence,
It is necessary to adjust the addition amount of the porous metal compound in order to obtain a calcined product having excellent mechanical strength while maintaining the activity as a catalyst. That is, it is necessary to adjust the addition amount of the porous metal compound so that the product (ξ) of the catalytic ability such as NO decomposition and the mechanical strength (for example, bending strength) becomes large. A major feature of the present invention is that the optimum addition amount of this porous metal compound is set. That is, in the composition of the present invention, the main component, zeolite powder 100, is used.
The amount of the porous metal compound is usually 65 to 250 with respect to parts by weight.
Parts by weight, preferably 70 to 250 parts by weight, more preferably 100 to 250 parts by weight. In the composition of the present invention, a clay mineral may be used in order to improve the moldability and further maintain the strength of the fired product after firing. As the clay mineral, 1: 1 layer type clay mineral and 2: 1 layer type clay mineral are used. As the 1: 1 layer type clay mineral, for example, kaolinite group mineral is used. Specifically, kaolinite, halloysite, datesite, lizardite, amethite, and natural clay (Kibushi clay, frog eye clay, etc.)
Etc. can be mentioned. These may be used alone or in combination of two or more. Of these, kaolinite, halloysite, kibushi clay and the like are preferably used.

On the other hand, examples of the 2: 1 layer type clay mineral include, for example, pyrophyllite group minerals (pyrophyllite, etc.), smectite group minerals (montmorillonite, bentonite,
Synthetic smectite, hectorite, etc.) and vermiculite group minerals (vermiculite, etc.) are used. These may be used alone or in combination of two or more. Preferably, a smectite group mineral is used. Among them, bentonite and synthetic smectite are particularly preferable. In the composition of the present invention, the above-mentioned 1: 1 layer type clay mineral and 2: 1 layer type clay mineral are used in a weight ratio of 10/90 to 95/5. Preferably, 30/7
It is used in a weight ratio of 0 to 90/10, more preferably 55/45 to 85/15. The 1: 1 layer type clay mineral is a sintering agent that has the effect of increasing the mechanical strength of the fired zeolite product, but the mineral molecules are oriented in layers during extrusion molding, and interlayer slippage is likely to occur. Therefore,
When a 1: 1 layer type clay mineral is used alone or when its weight ratio is high, cracks are generated in the layer direction in which the molecules are oriented,
It tends to crack. As a result, the mechanical strength of the calcined zeolite is not satisfactory. On the other hand, since the 2: 1 layer type clay mineral is finely crystalline, it is difficult to orient in a layered form. Therefore, if the 1: 1 layer type clay mineral is mixed with an appropriate amount of the 2: 1 layer type clay mineral, the above 1: 1 layer type clay mineral is used. The drawbacks possessed by can be compensated. Further, when the 2: 1 layer type clay mineral is used alone or when the weight ratio thereof is large, the moldability of the kneaded solid composition for zeolite molding is poor and it becomes difficult to apply it to extrusion molding. A molded product obtained by extrusion-molding such a composition does not have a smooth molded surface and is inferior in strength. In the composition of the present invention, the total content of these clay minerals (1: 1 layer type clay mineral and 2: 1 layer type clay mineral) as a sintering agent is usually 5 to 100 parts by weight of zeolite. It is in the range of 50 parts by weight, preferably 10 to 45 parts by weight.

Further, in the composition of the present invention, an inorganic fiber can be blended as a reinforcing material. Examples of the inorganic fiber include glass fiber, carbon fiber, alumina fiber, silica fiber, alumina silicate fiber, rock wool, zirconia fiber, silicon carbide fiber, titanium fiber, boron fiber, magnesia fiber, slag wool, asbestos, Examples thereof include sepiolite. Among these,
Glass fiber and sepiolite are preferably used. In the composition of the present invention, the inorganic fiber is zeolite 100.
With respect to parts by weight, 0.1 to 20 parts by weight, preferably 0.2
˜15 parts by weight, most preferably 0.5 to 10 parts by weight. In the composition of the present invention, by further using an auxiliary agent, it is possible to impart a higher plastic moldability to the zeolite powder, which is molded, dried, and, if necessary, calcined. As a result, a molded product having even higher strength can be obtained. Such an auxiliary agent is used according to the zeolite powder to be used and various properties of the required zeolite molded product, and an ordinary auxiliary agent for molding zeolite powder is used. Therefore, for example, a cellulosic compound, a polyhydric hydroxy compound, or a polyvinyl polymer is preferably used as the auxiliary agent. As the cellulose compound,
Methyl cellulose, ethyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose,
Examples thereof include hydroxyethyl methyl cellulose and the like. As such a cellulosic compound, any commercially available one can be used regardless of its molecular weight and the like, and is appropriately selected according to the application. As the polyhydric hydroxy compound, glycerin, ethylene glycol, propylene glycol, triethylene glycol, 1,3-
Examples thereof include alkylene glycols such as butylene glycol, and polyoxyalkylene glycols such as polyethylene glycol and polypropylene glycol. Also for these polyvalent hydroxy compounds, regardless of their molecular weights, all commercially available products can be used,
It is appropriately selected depending on the application.

Examples of polyvinyl polymers include polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid resins, polyacrylic acid salts such as ammonium polyacrylate, acrylic acid-maleic acid copolymers and ammonium salts thereof. . The polyacrylic acid resin may be crosslinked. Such cross-linked polyacrylic acid resin is already known and can be obtained as a commercial product. These polyvinyl polymers, regardless of their molecular weight and the like, can use all commercially available products,
It is appropriately selected depending on the application. Other than the above, various organic substances can be used as the auxiliary agent, and for example, carboxymethyl starch, sodium alginate, ammonium alginate, etc. can be preferably used as the auxiliary agent. These auxiliaries may be used alone or as a mixture of two or more kinds. The auxiliary is usually about 0.1 to 30 parts by weight (when a mixture of two or more kinds is used), preferably about 0.2 to 100 parts by weight of the zeolite powder.
Used in the range of 15 parts by weight. As described above, in the present invention, various kinds of auxiliary agents are used,
Among them, methyl cellulose-based molding aids, for example, methyl cellulose, hydroxypropyl methyl cellulose,
Hydroxyethylmethyl cellulose and the like are preferably used. In particular, the viscosity of these 2% aqueous solutions at 20 ° C. is 20 to 100,000 centipoise, especially 400
Those in the range of up to 100,000 centipoise are preferably used. In particular, according to the present invention, when the β-1,3-glucan having heat coagulability, particularly curdlan or alkali-treated paramylon, is used in combination with the methylcellulose-based molding auxiliary as an auxiliary, the moldability is improved. It is possible to obtain a zeolite molding composition excellent in, and as described later, after molding the composition, after heat-coagulating these heat-coagulable β-1,3-glucan in the molded product, By drying, it is possible to obtain a high-strength molded product without cracking.

Further, as the polyhydric hydroxy compound, polyethylene glycol, preferably having a molecular weight of about 6000, is used, and the above-mentioned porous metal compound, further, an inorganic sintering agent, an inorganic fiber, a methylcellulose type molding aid and the like are used. When used in combination, a zeolite molded product having excellent strength, particularly a zeolite honeycomb, can be obtained. Further, in the present invention, if necessary, an alkyl ether of polyethylene glycol, a surfactant known as a wetting agent, a lubricant such as zinc stearate, aluminum stearate, magnesium stearate, etc. are appropriately used for forming a zeolite. It may be contained in the composition or the zeolite molded product. In the present invention, a fired product having a significantly high strength can be obtained by molding the composition as described above, drying and firing. In particular, by firing a composition containing inorganic fibers, it is possible to obtain a fired product having extremely high mechanical strength. The composition according to the present invention is usually used as a wet solid composition (hereinafter referred to as a kneaded solid composition) by adding a solvent such as water for extrusion molding. However, the composition according to the invention may be in the form of a slurry or other forms. The method for preparing the kneaded solid composition for zeolite molding of the present invention is not particularly limited. For example, β-1,3-glucan and, if necessary, the above-mentioned porous metal compound, clay mineral, auxiliary agent, etc. are added to the zeolite powder in a powder form, or β-1,3-glucan and, if necessary, And previously dissolve the auxiliary agent in water or a small amount of a water-soluble organic solvent such as methanol or ethanol,
This is added to a mixture of zeolite powder, a porous metal compound, and a clay mineral, and thereafter, β-1,3-glucan, an auxiliary agent, a clay mineral, and the like are sufficiently mixed so that they are not unevenly distributed to form a uniform mixture. Then, an appropriate amount of water or an aqueous solution is added to the obtained mixture, and the mixture is sufficiently kneaded to obtain a kneading fixing composition suitable for plastic molding. The β-1,3-glucan, the porous metal compound, the clay mineral, and the auxiliary may be separately mixed with the zeolite powder. Here, the aqueous solution is preferably a mixture of water and a water-soluble organic solvent such as methanol or ethanol. The amount of these organic solvents in the aqueous solution may be any suitable amount. However, in the present invention, it is preferable to use water.

The kneaded solid composition for zeolite molding prepared as described above is molded into a desired shape by an extrusion molding method, dried at room temperature to 110 ° C., and further, if necessary, calcined to give a final product. It is possible to obtain a shaped or calcined zeolite according to the invention. Firing is usually 5
It is carried out at a temperature in the range of 00 to 800 ° C, preferably 550 to 700 ° C. The zeolite shaped product and the calcined product according to the present invention may have any shape, for example, granules,
Examples thereof include spherical materials, round bars, square bars, hollow tubes, thin plates, sheets, films and honeycombs. In particular, according to the kneading solid composition for zeolite molding of the present invention, a molded product having a complicated shape such as a honeycomb structure or a fired product can be easily obtained. In the present invention, after molding the zeolite-containing kneading solid composition containing water obtained by kneading, when drying the molded product, the molded product is heated in the presence of water, the heat coagulability β-1,3-
It is preferred that the glucan be thermally coagulated and then dried. Generally, while suppressing free evaporation of water contained in the molded product, if necessary, by heating the molded product in the presence of additional water, the thermosetting β-1,3
-The glucan can be solidified. More specifically, heating by microwaves, heating in a saturated steam atmosphere, heating in a closed container, or the like can be performed.
As described above, the temperature at which β-1,3-glucan is heated and coagulated depends on the β-1,3-glucan used, but is usually in the range of 70 to 150 ° C. Heating time is usually 0.5
It is about 12 hours. In the case of heating by microwave, it is usually about 10 seconds to 10 minutes. The molded product of the present invention can impart strength to the molded product by solidifying the heat-coagulable β-1,3-glucan contained in the molded product, and thus, when the molded product is subsequently dried, The molded product does not crack. Heat coagulability β-
Drying of the molded product after the 1,3-glucan is heated and coagulated may be carried out by an ordinary drying method, for example, standing at a high temperature, hot air drying, or drying at a low temperature.

Further, the alkali metal ions in the molded zeolite product and the calcined product of the present invention can be easily ion-exchanged with various metal ions. That is, the alkali metal ions in the zeolite in the zeolite molded product and the calcined product of the present invention, such as hydroxide ions in the porous metal compound, VA group of the periodic table, VIA group, VIIA group, VIII group, I
It can be ion-exchanged with one or more metal components selected from Group B, IIB and IIIB, or can be supported on a clay mineral which is a component other than the above. Examples of such metal components include V, Cr, Mo, W, Mn, Fe,
Co, Ni, Ru, Rh, Pd, Pt, Cu, Ag, A
u, Zn, or the like is used. Such ions can be exchanged with the alkali metal ions in the zeolite molded product and the calcined product alone or as a mixture of two or more kinds. Thus, in order to exchange the alkali metal ions in the zeolite molded product and the calcined product with metal ions of other species, nitrates, sulfates, chlorides of such metal ions,
Aqueous solution such as acetate (saturated aqueous solution or 0.001 to 10
M, preferably 0.001 to 5 M aqueous solution). The contact is usually performed at room temperature for 2 to 72 hours, preferably 5 to 48 hours, more preferably 10 to 30 hours. The amount of the metal component supported is usually 0.1 to 20% by weight, preferably 0.5 to 10% by weight. The zeolite honeycomb formed product and the fired product of the present invention have a strength that does not crack even by such an operation, and as described above, the alkali metal ions in the zeolite formed product and the fired product are exchanged with other metal ions. The obtained molded product is useful as a catalyst in various applications. For example, according to the present invention, a high silica type zeolite having sodium ions as alkali metal ions is used as a calcined product, and the sodium ions are converted into Cu, Co, Ag, Pt, Ni, Fe.
Those ion-exchanged with one kind or two or more kinds of metal ions such as can be used as a catalyst for decomposing nitrogen oxide (NO). In particular, a honeycomb molded body was molded from the zeolite composition of the present invention by an extrusion molding method, dried at 115 ° C, and then fired at 700 to 800 ° C. This zeolite honeycomb fired product, in which the above metal ions, particularly copper ions, are ion-exchanged with sodium ions (ion exchange amount of 50% or more) is a particularly excellent catalyst for removing nitrogen oxides.

Conventionally, V ₂ O ₅ -Tio ₂ -W (Mo) O ₃ has been used for removing NO from a fixed NO generation source (cord energy etc.).
A NO selective reduction process on a system catalyst has been put to practical use. However, in this method, ammonia, which is dangerous and expensive, must be used. When the zeolite calcined product of the present invention, particularly the substituted honeycomb-shaped calcined product, is used, ammonia is not required for removing NO. It is very effective as it itself has degrading activity. Furthermore, this catalyst can also be used in the process of decomposing nitrogen oxides from combustion exhaust gas containing nitrogen oxides, oxygen, and steam in the coexistence of carbonaceous hydrogen. Examples of such a process include exhaust gas treatment from a diesel engine, exhaust gas treatment from a lean-burn type gasoline engine, and boiler exhaust gas treatment.
Further, a Y-type zeolite having sodium ions as alkali metal ions is used to obtain a calcined product according to the present invention, and the sodium ions are ion-exchanged with at least one selected from iron, nickel and copper ions to give hydrogen sulfide. It has a catalytic action to oxidatively decompose sulfur compounds such as mercaptan and mercaptan. Such an ion-exchanged zeolite molded product and a calcined product can be obtained by, in addition to the above-described method, forming a composition of a previously ion-exchanged zeolite powder according to the present invention, and molding and calcining the composition. Further, in particular, the honeycomb fired product preferably has a large aperture ratio in order to be useful as an adsorbent or a catalyst. This is because when liquid or gas comes into contact with the zeolite and flows, it can pass without receiving resistance (that is, low pressure loss). The aperture ratio is usually 50 to 90%, preferably 50 to 80%, and more preferably 55 to 80%.

As described above, the zeolite composition for molding and the zeolite molded product for the catalyst carrier provided by the present invention are not limited to zeolite powder, β-1,3-glucan, and a porous metal compound, and may be appropriately used. It may contain other additives. For example, a composition or molded product containing clay minerals,
Examples thereof include compositions and molded products containing inorganic fibers, compositions and molded products containing auxiliaries, and compositions and molded products containing inorganic fibers and auxiliaries. Similarly to the zeolite powder, β-1,3-glucan, and porous metal compound, the calcined zeolite may also appropriately contain other additives. For example, a fired product containing clay minerals, a fired product containing inorganic fibers,
Examples include fired products in which the metal ions in the fired product are exchanged with other metal ions. As described above, the molding zeolite composition of the present invention has excellent plastic moldability, and can be molded into a desired shape by, for example, extrusion molding, which is dried and, if necessary, calcined. By doing so, it is possible to obtain a zeolite molded product or a fired product that is excellent in strength and dimensional accuracy. In particular, according to the present invention, by using β-1,3-glucan having heat-coagulability and a porous metal compound, a molded zeolite product having sufficient strength in the process of molding, drying, and calcination of zeolite, A fired product can be obtained.
Further, by using the molding zeolite composition of the present invention, it is possible to easily obtain a molded product having a complicated shape such as a honeycomb structure, which has been difficult in the past, by an extrusion molding method. By firing, a honeycomb structure fired product of zeolite can be obtained. Further, the molded product and the calcined product of the present invention can be suitably used as a carrier for various catalysts based on zeolite. In particular, the honeycomb structure according to the present invention is
It can be used as a catalyst for decomposing nitrogen oxides discharged from ships, aircraft, cogeneration plants, boilers and the like.

[0020]

The present invention will be described below with reference to examples, but the present invention is not limited to these examples. [Reference Example 1] According to the method described in JP-B-48-32573, the fermented solution was treated with alkali, centrifuged, and then neutralized with an acid to obtain a curdlan solution.
The curdlan solution was desalted and concentrated, dried with a spray dryer and concentrated to obtain curdlan. [Example 1] MFI-type zeolite powder having a silica / alumina molar ratio of 31 (MIZUKASIEVES E manufactured by Mizusawa Chemical Industry Co., Ltd.)
X-122, specific surface area 322 m ² / g, average particle size 4.
6 μm) 350 g (solid content) aluminum hydroxide (manufactured by Mizusawa Chemical Industry Co., Ltd., finely divided alumina; boehmite, specific surface area 220 m ² / g, average particle diameter 4.0 μm) 350 g
(Solid content) was further added, and as a sintering agent, bentonite powder (Belleclay manufactured by Mizusawa Chemical Industry Co., Ltd.) 50 g (solid content) and Kibushi clay 200 g (solid content), and glass fiber (Nippon Sheet Glass Co., Ltd.) , Micrograss chopped strand (RESO15) 50g, and further curdlan (Takeda Pharmaceutical Co., Ltd., Piopoly (trade name)-
P) 20.0 g and methyl cellulose (Shin-Etsu Chemical Co., Ltd. (Metroses, SM 3000) 40.0 g, polyethylene glycol (Sanyo Chemical Co., Ltd., Macrogol 6000) 10.0 g were added and the mixture was placed on a tabletop. Dry mixing was performed for about 1 hour using a shaft kneader. Next, distilled water was added to this mixture so that the total amount of water was 620 g, and the mixture was kneaded under reduced pressure (about 100 to 700 mmHg) for about 1 hour.
In this kneading, cold water at 10 ° C. was circulated in the jacket of the kneader to cool the kneaded product. The kneaded material thus obtained was placed in a polyethylene bag and aged at room temperature (about 23 ° C.) for 3 days. Next, this was loaded into an extrusion molding machine (DE-35 type manufactured by Honda Iron Works Co., Ltd.) and kneaded under reduced pressure to obtain a kneaded solid composition for forming zeolite alumina. next,
A honeycomb forming mold is attached to the above-mentioned extrusion molding machine, and using this, the above-mentioned kneading solid composition for forming zeolite is placed on one side 3
A 0 mm square was formed into a honeycomb formed article having 300 cells / square inch. This was cut into a length of 5 cm, heated in a microwave oven for 30 seconds, and then dried in a dryer at 115 ° C. for about 2 hours. Then, the obtained dried molded product was placed in an electric furnace and fired at 700 ° C. for 2 hours to obtain a zeolite-alumina honeycomb fired product having an opening ratio of 63%.

Example 2 A glass beaker having a volume of 3 liters was charged with 2000 ml of an 8 mM aqueous copper nitrate solution. The honeycomb (30 mm mouth x 50 mm) fired product obtained in Example 1 was suspended in an aqueous solution of copper nitrate, and the solution was contacted for 24 hours at room temperature while stirring with a magnetic stirrer for ion exchange. After the ion exchange, the honeycomb was collected, washed with water, and dried at 110 ° C. for 3 hours. After drying in air, 5
Calcined at 00 ° C for 3 hours, supported on copper, MFI type zeolite-
An alumina honeycomb catalyst was obtained. A certain amount (500 mg) of this honeycomb catalyst was dissolved in 5 ml of 46% hydrofluoric acid,
Then, this solution was diluted to 50 ml with distilled water, and then the copper content was measured by an atomic absorption spectrophotometry. As a result, 1.256% by weight of copper was supported on this honeycomb catalyst.

Example 3 Supporting copper prepared in Example 2,
20mmφ MFI zeolite-alumina honeycomb catalyst
It was cut to a size of 29 mmH (volume: 9.1 ml) and filled in a stainless reaction tube having an inner diameter of about 21 mmφ. Next, a model gas having the gas composition shown below was used with a space velocity of 44,000H.
After passing through the catalyst layer at r ⁻¹ and a reaction temperature of 350 ° C., the gas concentrations before and after the reaction were measured by glass chromatography and a chemiluminescence type NOX meter, and the nitrogen oxide removal rate was calculated. The results of the removal rate of nitrogen oxides are shown in [Table 1]. Gas composition NO; 1000 ppm CO; 1000 ppm O ₂ ; Vol 10% H ₂ O; Vol 10% (steam) C ₃ H ₈ ; 1000 ppm N ₂ ; Remaining amount Also, the kneading composition (polyethylene) prepared in Example 1 Aged in a bag). Next, using a flow tester (manufactured by Shimadzu Corporation), the above-mentioned zeolite-
Alumina molding kneading composition with a diameter of 5.0mmφ × 100mm
L was extruded. This molded product is referred to as Example 1 below.
It was dried and calcined in the same manner as above to obtain a zeolite-alumina round bar calcined product. Then, in the same manner as in Example 2, copper was supported on this round bar fired product. Next, 10 pieces of the above-mentioned round bar fired product cut into a length of 50 mm were prepared. For this sample, strength tester (Shimadzu Autograph AG-
1000A type), the three-point bending strength was measured at a bending span of 30 mm and a crosshead speed of 0.5 mm / min.
The average value of the 10 measured values is shown in [Table 1]. This strength measurement value is relatively representative of the strength of the honeycomb body formed from the same kneading composition.

[Example 4] MFI zeolite powder 200
g, aluminum hydroxide powder 500 g, added distilled water amount 6
A zeolite-alumina honeycomb fired product was obtained in the same manner as in Example 1 except that 80 g was added. After loading copper on this honeycomb in the same manner as in Example 2 (0.927% by weight of copper was loaded on this honeycomb catalyst), the same procedure as in Example 3 was performed to remove nitrogen oxides. The removal rate was measured. Further, with respect to the kneaded composition of this example, a 5 mmφ round bar baked product was obtained in the same manner as in Example 3, and copper was supported on this round bar baked product in the same manner as in Example 2. The three-point bending strength of this round bar fired product was measured in the same manner as in Example 3. The results are shown in [Table 1].

Comparative Example 1 A zeolite-honeycomb molded body was prepared in the same manner as in Example 1 except that 700 g of MFI zeolite was used without adding aluminum hydroxide. After preparing a copper-supported catalyst in the order of 2 and 3, the catalyst activity was evaluated and the three-point bending strength test was measured. The measurement results are shown in [Table 1]. [Comparative Example 2] An alumina honeycomb molded body was prepared in the same manner as in Example 1 except that 700 g of aluminum hydroxide was used without using MFI type zeolite in Example 1.
After preparing a copper-supported catalyst according to the following Examples 2 and 3,
The three-point bending strength test was measured while the catalytic activity was evaluated. The measurement results are shown in [Table 1].

[Table 1]

[0025]

The zeolite composition for molding according to the present invention has excellent plastic moldability and can be molded into a desired shape by, for example, extrusion molding, which is dried and, if necessary, calcined. By doing so, it is possible to obtain a zeolite molded product or a fired product that is excellent in strength and dimensional accuracy. The molded product and calcined product of the present invention can be suitably used as a carrier for various catalysts based on zeolite. In particular, the honeycomb structure according to the present invention can be used as a catalyst for decomposing nitrogen oxides discharged from automobiles, ships, aircraft, cogeneration plants, boilers and the like.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location B01J 29/70 9343-4G 29/76 9343-4G 35/04 301 P 8017-4G

Claims (16)

[Claims] 1. β to 100 parts by weight of zeolite powder
-1,3-Glucan 0.1 to 20 parts by weight and porous metal compound 65 to 250 parts by weight are contained in the zeolite composition for molding. 2. The molding zeolite composition according to claim 1, wherein the β-1,3-glucan is curdlan. 3. The molding zeolite composition according to claim 1, wherein the porous metal compound is a porous metal oxide or / and a porous metal hydroxide. 4. The molding zeolite composition according to claim 1, wherein the porous metal compound is aluminum oxide or / and aluminum hydroxide. 5. The zeolite composition for molding according to claim 1, wherein the zeolite powder has an average particle diameter of 10 μm or less. 6. The zeolite composition for molding according to claim 1, which further contains a clay mineral or / and an inorganic fiber. 7. β to 100 parts by weight of zeolite powder
-1,3-Glucan 0.1 to 20 parts by weight and porous metal compound 65 to 250 parts by weight, a zeolite molded article characterized by the above. 8. The molded zeolite product according to claim 7, wherein the molded product is a honeycomb structure. 9. β to 100 parts by weight of zeolite powder
-1,3-Glucan 0.1 to 20 parts by weight and porous metal compound 65 to 250 parts by weight, a molded zeolite fired product. 10. A quantity of 100 parts by weight of zeolite powder,
The method for producing a zeolite composition according to claim 1, wherein 0.1 to 20 parts by weight of β-1,3-glucan and 65 to 250 parts by weight of the porous metal compound are mixed. 11. With respect to 100 parts by weight of zeolite powder,
The molded zeolite composition according to claim 7, wherein the molded zeolite composition comprises 0.1 to 20 parts by weight of β-1,3-glucan and 65 to 250 parts by weight of a porous metal compound. Manufacturing method. 12. With respect to 100 parts by weight of zeolite powder,
The method for producing a fired zeolite molded product according to claim 9, wherein a zeolite molded product containing 0.1 to 20 parts by weight of β-1,3-glucan and 65 to 250 parts by weight of a porous metal compound is sintered. . 13. The molded zeolite product according to claim 7, which is a catalyst for removing nitrogen oxides. 14. The molded zeolite fired product according to claim 9, which is a catalyst for removing nitrogen oxides. 15. A zeolite molded article, comprising a VA group of the periodic table,
The zeolite shaped product according to claim 13, which carries one or more metal components selected from the group consisting of VIA group, VIIA group, VIII group, IB group, IIB group and IIIB group. 16. A VA of the periodic table is added to the fired zeolite molding.
15. The zeolite-molded calcination according to claim 14, wherein one or more metal components selected from the group consisting of Group VIA group VIIA group VIII group IB group IIB group IIIB are supported. object.