JP3288073B2 - Method for manufacturing catalyst member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a catalyst member used for combustion, exhaust gas purification, and the like.

[0002]

2. Description of the Related Art Heretofore, a catalyst layer has been coated on a hamcam-like ceramic such as cordierite or a corrugated ceramic for combustion, purification of exhaust gas, and the like.
Further, after processing paper or felt-like inorganic fiber into a predetermined shape according to the application, the catalyst slurry is coated and carried before use.

[0003]

In the case of the above-mentioned honeycomb-like ceramics and corrugated-like ceramics, the external shape is extremely restricted, and they are generally formed in a circular or square shape. Further, even when paper or felt-like inorganic fiber is processed into a predetermined shape and then loaded with a catalyst, the shape is easily deformed and deformed in the process of processing the shape, resulting in poor production yield.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a manufacturing method capable of processing a catalyst member having a predetermined shape with good mass productivity.

[0005]

In order to solve this problem, the present invention provides a process for kneading inorganic ceramic fibers and an organic binder, extruding and drying to obtain a primary molded body.
If, impregnated with the primary molded body to the catalyst slurry, dried, it is an gist a method for manufacturing a catalyst member comprising a firing. Further, the present invention is a step of kneading an inorganic ceramic fiber and an organic binder and carbon fiber or carbon powder, extrusion molding, and drying to obtain a primary molded body,
Impregnating the primary molded body to the catalyst slurry, dried, it is an gist a method for manufacturing a catalyst member comprising a firing.

[0006]

According to the present invention having the above structure, a molded body can be manufactured with good mass productivity by kneading inorganic ceramic fibers and an organic binder to an appropriate viscosity and extruding the mixture into a predetermined shape with a die. When the obtained molded body is cut to a desired length and dried, at this point, the molded body is kept in an organic binder. After that, when the compact is impregnated with the catalyst slurry, dried and fired, the organic binder is burned off, but the shape of the compact is maintained by the cohesive force (coupling force) of the catalyst powder contained in the catalyst slurry. Therefore, the mechanical strength of the obtained catalyst member is determined by the amount of the catalyst powder attached to the molded body, the particle size of the catalyst powder, the inorganic binder contained in the catalyst slurry, and the like.

The present invention is a method for mass-producing a highly porous (small heat capacity) catalyst member using inorganic ceramic fibers. The porosity of the extruded product can be changed to some extent by controlling the amount of the organic binder added and the molding conditions (pressure, water, etc.). It is effective to add and extrude carbon fiber or carbon powder (particularly pitch-based).

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a catalyst member according to an embodiment of the present invention will be described with reference to the drawings. Example 1 Alumina-silica fiber (fiber length 5 mm, fiber diameter about 3 μm) 80
A small amount of fats and oils and water were added to 20 parts by weight and 20 parts of methylcellulose (molecular weight: 4000), kneaded, and then extruded to produce a molded article 1 as shown in FIG. 1 and dried at 40 ° C. Then, as shown in FIG. 2, 100 g of Al ₂ O ₃ .CeO ₂ powder (specific surface area: 120 m ² / g), 4 g of aluminum nitrate, 500 g of water, 50 g of isopropyl alcohol, and an aqueous solution of dinitrodiammine platinum were used as shown in FIG. After impregnating in a catalyst slurry liquid 2 (average particle diameter 1 μm) obtained by adding 3 g in terms of Pt, FIG.
As shown in the figure, the compact 1 was fixed to an aluminum structure 3, dried at 80 ° C. for 20 minutes, and heat-treated at 400 ° C. to obtain a catalyst member 4 having Pt supported on the compact 1 and to attach the catalyst member 4 to an aluminum structure 3. It was adhered to body 3.

In this embodiment, methylcellulose (molecular weight 4000) was used as an organic binder. This is because a cellulosic organic binder is most suitable as a molding aid. However, pulp can be used to reduce the cost.

Next, two catalyst members 4 bonded to the aluminum structure 3 are combined as shown in FIG.
The combustion device as shown in was assembled. In FIG. 5, reference numeral 5 denotes an isobutane gas cylinder. A valve 7 is provided between the isobutane gas cylinder 5 and the nozzle 6, and controls the flow rate of the fuel gas supplied from the cylinder 5. The fuel gas ejected from the nozzle 6 sucks the surrounding air by the attraction of the gas flow, and is uniformly mixed in the mixing chamber 8.
It is supplied to the combustion chamber 9. The combustion chamber 9 is configured by combining two catalyst members 4 closely attached to the wall of the aluminum structure 3, and the outer wall of the aluminum structure 3 is
Becomes

Next, the operation of the above configuration will be described. First, when the heater 11 is heated and a part of the adjacent catalyst member 4 becomes high in temperature and reaches a sufficient activation temperature, the valve 7 is opened, and the fuel gas is supplied from the nozzle 6 to the mixing chamber 8, Is also supplied by the attraction. The fuel gas and air are introduced into the combustion chamber 9 through the mixing chamber 8 and start catalytic combustion from the activated catalyst member 4 near the heater 11, and the reaction gradually spreads to the entire catalyst member 4 in the combustion chamber 9. Then, the combustion gas is discharged from the exhaust port 12. The heat of reaction is provided to the outside via the aluminum structure 3 where the combustion exhaust gas and the catalyst member 4 are in contact.

Using isobutane as fuel, the excess air ratio (air / fuel) was set at 1.02, 500 Kcal / h, and the combustion rate was determined from the exhaust gas characteristics (HC, CO). As a result, in the example according to the present invention, a combustion characteristic of 95% or more was obtained.

Example 2 Alumina-silica fiber (fiber length 5 mm, fiber diameter about 3 μm) 80
Part and pitch-based carbon fiber (fiber length 3mm, fiber diameter about 1μm)
A small amount of fats and oils and water were added to 10 parts and 7 parts of methylcellulose (molecular weight 4000), kneaded, and extruded to produce a molded article 1 as shown in FIG. Thereafter, the molded body 1 was dried at 40 ° C. Then, 100 g of Al ₂ O ₃ .CeO ₂ powder (specific surface area: 120 m ² / g), aluminum nitrate 4
g, 500 g of water, 50 g of isopropyl alcohol and 3 g of an aqueous solution of dinitrodiammine platinum in impregnated with a catalyst slurry (average particle size: 1 μm) obtained by adding 3 g in terms of Pt. After drying for a minute
A heat treatment was performed at 400 ° C. to obtain a catalyst member carrying Pt on the compact 1 and the catalyst member was bonded to the aluminum structure.

Next, using two catalyst members bonded to the aluminum structure, the combustion rate was determined from the combustion exhaust gas characteristics (HC, CO) of isobutane in the same manner as in Example 1. As a result, in Example 2, combustion characteristics of a combustion rate of 95% or more were obtained.

In this embodiment, pitch-based carbon fibers are used.
Can be reduced to 1/3. Also, when extrusion molding is performed with pitch-based carbon powder, the amount of the organic binder (methyl cellulose) used is about 1/2.
As a result, substantially the same molded body could be obtained. When a catalyst material is used as the final product, the organic components are burned off by heat treatment.Therefore, it is important to select an inexpensive material and process it to an equivalent material for the molding aid used for the molding means called extrusion molding. It is. Generally, the organic binder (cellulose) used for the molding aid is more expensive than the pitch-based carbon fiber or carbon powder, and the pitch-based carbon fiber or carbon powder is effectively used to maintain the porosity of the molded article. It is preferred to use. However, extrusion molding using only inorganic ceramic fibers and pitch-based carbon fibers or carbon powder is difficult because of poor moldability. Therefore, it is indispensable to add an organic binder to some extent and to mold.

In this embodiment, an example in which the obtained catalyst member is used for combustion is shown. However, the catalyst member obtained in the present invention can be processed into various shapes and can be used for various other purposes.

[0017]

As described above, according to the present invention, at least an inorganic ceramic fiber and an organic binder are kneaded, extruded and dried, then impregnated into a catalyst slurry, dried,
By firing, excellent porosity with the desired shape,
It is possible to produce a catalyst member having a small heat capacity with good mass productivity. In addition, the use of expensive organic binders can be reduced by using carbon fibers or carbon powder.

[Brief description of the drawings]

FIG. 1 is a perspective view of a molded body used for a catalyst member according to one embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which the compact is impregnated with a catalyst slurry liquid.

FIG. 3 is a perspective view showing a state where a catalyst member obtained by supporting Pt on the molded body is bonded to an aluminum structure.

FIG. 4 is a side sectional view of a combustion device formed by combining two catalyst members bonded to the aluminum structure.

FIG. 5 is a front sectional view of the combustion device.

[Explanation of symbols]

 Reference Signs List 1 molded body 2 catalyst slurry liquid 3 aluminum structure 4 catalyst member

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B01J 21/00-38/74 C04B 38/00-38/10

Claims (2)

(57) [Claims] 1. A process for kneading an inorganic ceramic fiber and an organic binder, extruding and drying to obtain a primary molded body.
And extent, impregnated with the primary molded body to the catalyst slurry, dried,
Method for producing a catalyst member comprising a firing. 2. A step of kneading an inorganic ceramic fiber, an organic binder, and a carbon fiber or a carbon powder, extruding and drying to obtain a primary molded body;
I from the impregnation the catalyst slurry, dried, and firing
Method for producing that catalyst member.