JPH10365A - Catalyst carrier and method for producing the same - Google Patents

Abstract

(57) [Problem] To provide an inexpensive metal catalyst carrier having excellent thermal conductivity and thermal shock resistance. SOLUTION: There is provided a columnar winding body formed by winding a metal foil body having a plurality of convex portions on the surface so that flat portions of the metal foil body do not adhere to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As a catalyst member, a honeycomb-shaped catalyst carrier having a catalyst such as a noble metal supported thereon is used. Honeycomb-shaped catalyst carriers for supporting a catalyst are roughly classified into ceramic and metal. Examples of the ceramic catalyst carrier include cordierite, silica-alumina, and SiC. Among them, cordierite is most frequently used. Cordierite has excellent heat resistance,
Since it can be continuously molded into any shape having various numbers of cells, it can be manufactured at low cost, and is widely used as a catalyst carrier for a catalyst member for purifying exhaust gas from automobiles. . However, there is a problem that the thermal conductivity is inferior to that of a metal honeycomb catalyst carrier, and cracks are easily generated by thermal shock. On the other hand, honeycomb catalyst carriers made of metal have advantages such as excellent thermal conductivity, thermal shock resistance, and mechanical strength, but have not been widely used because of their high price.

[0003]

The reason why the metallic honeycomb-shaped catalyst carrier is expensive is that it is manufactured by a process in which corrugated and plate-shaped metal foils are alternately arranged and partially welded. , Because the production is very complicated. An object of the present invention is to provide a honeycomb catalyst carrier made of metal at a low cost by continuously manufacturing the same from a single metal foil body.

[0004]

According to the present invention, there is provided a metal honeycomb catalyst carrier comprising a plurality of convex portions provided on a surface thereof, the plurality of convex portions being provided so that the flat portions do not adhere to each other. Are wound in a dispersed arrangement, and the outer periphery thereof is bonded by spot welding or the like to form a desired shape. According to the present invention, continuous molding is possible. Further, the pressure loss of the catalyst carrier can be easily adjusted by the number and shape of the projections to be formed.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A catalyst support of the present invention is a cylindrical rolled body obtained by winding a metal foil having a plurality of convex portions on its surface so that flat portions of the metal foil do not adhere to each other. It is provided with. The convex portion may be formed as a hemisphere, a pyramid-shaped projection, or the like on the surface of the metal foil body by embossing or the like, or may be formed by processing the metal foil body itself into a rectangular shape, a wavy shape, or the like. Good. As a specific means for preventing the flat portions of the metal foil body from adhering to each other, it is effective that the arrangement of the convex portions does not have regularity. Thus, even if one place is in close contact, a gap can be formed in another place. In the case where regularity is provided, it is necessary to provide a convex portion at a position where flat portions do not adhere to each other during winding.

[0006] It is preferable that a cylindrical metal member is provided so as to be inscribed on the outer peripheral side surface of the wound body. By inserting the above-mentioned cylindrical wound body into the inside of the cylindrical metal member, the outer peripheral end of the cylindrical wound body is bonded to the surface facing the inner surface, and the shape of the wound body is reduced. There is no need to fix. Further, by providing the sliding members with claws or the like at the openings at both ends of the metal member, it is possible to prevent the wound body from moving during operation and coming off. Further, the shape of the cylindrical metal member is not limited to a cylinder, but may be a polygonal column.

[0007] Further, it is preferable that the convex portion has a partially broken hole. In this case, the gas flowing into the catalyst carrier becomes turbulent due to the cracks, so that the chance of contact between the gas and the catalyst increases. Further, the purifying ability is improved by increasing the surface area of the catalyst carrier.

It is preferable that the metal foil is made of stainless steel containing Al. It is necessary that the metal material used as the catalyst carrier has corrosion resistance.
In particular, stainless steel containing Al is excellent in heat resistance, and furthermore, the Al in the component becomes fibrous A by heat treatment.
It forms l ₂ O ₃ , which is preferred because it is effective for supporting the catalyst.

In the method for producing a catalyst carrier according to the present invention, the end of a metal foil having a plurality of projections on its surface is bonded to a rod-shaped or cylindrical metal member, and then the core material is used as a center axis. The metal foil body is wound in a cylindrical shape so that the flat portions do not adhere to each other. By bonding one end of the metal foil body to a rod-shaped or cylindrical core material using a spot welding machine or the like, and then winding the foil body, accurate winding can be achieved.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Example 1 Length 200 mm, width 20 mm
Stainless steel (70 wt% Fe-
As shown in FIG. 1, a plurality of substantially hemispherical projections 3 are formed on a metal foil body 1 made of 25 wt% Cr-5 wt% Al) by pressing.
Was formed in a certain direction. The projections 3 had an average diameter of the sphere of 3 mm and an average height of the ridge of 2.5 mm, and were formed on the surface of the metal foil body 1 in 92 pieces. However, no protrusion is provided at the end in the length direction of the metal foil body 1. This metal foil 1
As shown in FIG. 2, after being wound in the length direction, the end on the outer peripheral side is bonded to the flat portion 2 of the metal foil body 1 inscribed by spot welding, and has a diameter of 50 mm and a height of 50 mm. A cylindrical wound body of 20 mm was obtained. This wound body was heat-treated at 1000 ° C. for 3 hours to form an oxide film on the surface. Further, this wound body is immersed in a slurry in which aluminum hydroxide and barium oxide are dispersed in water, and then subjected to a heat treatment at 500 ° C. for 1 hour to form a corrosion-resistant layer on the surface of the wound body and form a catalyst carrier. I got

Next, this catalyst carrier was immersed in an aqueous solution of dinitrodiamine platinum, dried, and then heat-treated at 500 ° C. for 3 hours to obtain a catalyst having Pt supported on the surface. This catalyst was placed in a quartz tube, and isobutane 1000 p
The air containing pm was flowed at a space velocity of 10,000 [h ^-1 ]. At this time, the isobutane concentrations before and after the catalyst body were measured using gas chromatography, and the conversion rate of isobutane of the catalyst body was determined from this. As a result, the environmental temperature 20
70% at 0 ° C and 100% at 250 ° C.

<< Embodiment 2 >> Length 250 mm, width 20 mm
Stainless steel (70 wt% Fe-
A metal foil body 11 made of 25 wt% Cr-5 wt% Al)
As shown in FIG. 3, a rectangular shape having a plurality of peaks 13 each having a height of 2.0 mm and a width of 2.0 mm connected in the width direction is formed. A cylindrical catalyst body having a height of 20 mm was produced. With respect to the obtained catalyst, the conversion of isobutane was determined in the same manner as in Example 1. As a result, 68% at an ambient temperature of 200 ° C. and 98% at an ambient temperature of 250 ° C.
Met.

<< Example 3 >> A stainless steel metal foil body similar to that of Example 1 was used, as shown in FIG. 4, with a peak height of 2.3 mm on average and a diameter of 3 mm on average. A certain convex portion 23 was formed in a certain direction by pressing. This convex part 2
74 are formed on the surface of the metal foil body 21, and among them, the top of the plurality of projections has a crack 26. Using this, a cylindrical catalyst body having a diameter of 50 mm and a height of 20 mm was produced in the same manner as in Example 1. With respect to the obtained catalyst, the conversion of isobutane was determined in the same manner as in Example 1. As a result, 75% at 200 ° C. and 100% at 250 ° C.
%Met.

Example 4 A metal foil body 31 similar to that used in Example 2 was wound around a stainless steel metal rod 35 having a diameter of 5 mm and a length of 20 mm as shown in FIG. , 50 mm in diameter and 20 mm in length around these
A metal cylinder 36 made of stainless steel was arranged. With respect to the obtained catalyst, the conversion of isobutane was determined in the same manner as in Example 1. As a result, 76% at 200 ° C. and 9% at 250 ° C.
9%.

Comparative Example A catalyst body was prepared in the same manner as in Example 1 using a commercially available metal honeycomb body as a catalyst carrier. The metal honeycomb body has a diameter of 50 mm and a thickness of 2 mm.
A corrugated one having a cylindrical shape of 0 mm and a through hole of 200 cells / square inch in the thickness direction was used. With respect to the obtained catalyst, the conversion of isobutane was determined in the same manner as in Example 1. As a result, 71% at an ambient temperature of 200 ° C. and 250 ° C.
Was 100%.

From the above, it can be seen that the catalyst using the metal catalyst carrier of the present example exhibits almost the same characteristics as the catalyst using the metal catalyst carrier of the comparative example.

[0018]

According to the present invention, it is possible to easily produce a metal catalyst carrier having the same characteristics as those obtained when a commercially available corrugated honeycomb body is used. This makes it possible to provide a metal catalyst carrier excellent in thermal conductivity, thermal shock resistance, mechanical strength, and the like at low cost.

[Brief description of the drawings]

FIG. 1 is a perspective view of a metal foil used for a catalyst carrier according to Example 1 of the present invention.

FIG. 2 is a vertical cross-sectional view of the catalyst carrier of the embodiment, taken along a central axis.

FIG. 3 is a perspective view of a metal foil used for a catalyst carrier according to Example 2 of the present invention.

FIG. 4 is a longitudinal sectional view of a metal foil used for a catalyst carrier of Example 3;

FIG. 5 is a vertical sectional view with respect to a center axis of a catalyst carrier of Example 4.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal foil body 2 Flat part 3 Convex part 11 Metal foil body 13 Mountain 21 Metal foil body 23 Convex part 26 Rupture 31 Metal foil body 35 Metal rod 36 Metal cylinder

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yoshitaka Kawasaki 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Masato Hosaka 1006 Odaka Kadoma Kadoma City Osaka Pref.

Claims (5)

[Claims] 1. A catalyst carrier comprising a columnar wound body formed by winding a metal foil body having a plurality of projections on its surface such that flat portions of the metal foil body do not adhere to each other. 2. The catalyst carrier according to claim 1, further comprising a cylindrical metal member inscribed on an outer peripheral side surface of the wound body. 3. The catalyst carrier according to claim 1, wherein the projection has a partially broken hole. 4. The catalyst carrier according to claim 1, wherein said metal foil body is made of stainless steel containing Al. 5. An end portion of a metal foil body having a plurality of convex portions on its surface is bonded to a rod-shaped or cylindrical core material, and the metal foil body is flattened with the core material as a central axis. A method for producing a catalyst carrier, wherein the catalyst carriers are wound in a columnar shape so that they do not adhere to each other.