JPS583642A - Catalyst using short fiber as carrier - Google Patents

Abstract

PURPOSE:To make a catalyst carrier suitable for a catalyst for treating the exhaust gas of an internal combustion engine, as the catalyst carrier, by adhering a fire resistant short fiber comprising silica or alumina or a fire resistant glass short fiber to a glass long fiber or a metal wire. CONSTITUTION:As a catalyst carrier, a fire resistant short fiber having a diameter of 3mu or less and based on silica, alumina or calcium oxide or a fire resistant glass short fiber F is adhered to a glass long fiber or a metal wire E. In the next stage, the surface of the obtained carrier is coated with a catalyst component to prepare a catalyst. This catalyst is suitable for treating the exhaust gas of an internal combustion engine such as a gasoline engine for an automobile.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalyst using short refractory fibers with a diameter of 3 microns or less as a carrier. The present invention also relates to the above catalyst, which is particularly suitable for treating exhaust gas from internal combustion engines.

Conventionally, granular pellets and honeycomb type refractories have been used as catalyst carriers, but these are not particularly satisfactory as carriers for exhaust gas treatment catalysts in internal combustion engines. Therefore, the present inventors first discovered that heat-resistant glass fiber (fiber diameter 6 to 9 microns) has a large surface area, good performance, and can be molded freely. announced a catalyst using heat-resistant glass fiber containing silica content of
No. 64) Furthermore, he announced a method for uniformly forming catalyst components on the surface of this glass fiber carrier (Japanese Patent Publication No. 51-216).
No. 29).

By the way, with today's glass fiber manufacturing technology, in the case of endless filaments, the diameter of the filament is generally limited to 6 microns (in the United States, there are some that are up to 3 microns, but the general limit is 6 microns). ), human skin is irritated and does not reach %5 microns or less.

However, in the case of short fibers with fiber lengths of 5 to 20 mm, due to different manufacturing methods, short fibers of 3 microns or less are manufactured, but these are single fibers (one filament). Because of its short length, it is impossible to form it into threads, cloth, textiles, etc.

On the other hand, the smaller the diameter of a single fiber, that is, one filament, the greater the surface area per unit weight, and -
The heat capacity per million units of surface area decreases. for example. When comparing 9 micron and 1 micron filaments, the latter has a larger surface area in both weight and volume ratios, and
When comparing the same surface area, the latter naturally has a smaller heat capacity. Looking at this fact from the performance perspective of the catalyst, the catalyst performance naturally increases in proportion to the surface area, and
The starting temperature decreases in inverse proportion to the heat capacity, making it possible to maintain the same level of catalyst performance at lower temperatures.

Therefore, when using fibers as a catalyst carrier, the smaller the diameter of the fibers, the better the catalytic performance.However, as mentioned above, the problem here is that when the fiber diameter is 3 microns or less, With current manufacturing technology, only short fibers of 5 to 20 mm can be produced, and because of these short fiber lengths, they cannot be formed into threads, cloth, textiles, etc. .

The present invention first establishes a method for forming these short fibers of 3 microns or less, and then forms a catalyst component in the form of a film on the surface of the short fibers to provide a high-performance catalyst. That is, the current refractory fibers of 3 microns or less include glass fiber, alumina, silica, titania, calcium,
Many types of products are produced with magnesium etc. as the main component, but all of these have fiber lengths of 5 to 2.
It is around o'υ. The conditions required for the catalyst carrier are that it should stably contact a gaseous body at a constant flow rate, for example, 1 to 5 meters per second, and should not cause pressure loss. The biggest problem, therefore, is how to form these fine short fibers with a diameter of 1 to 3 microns and a length of 5 to 20 mm into a stable shape so as to meet the requirements for the above-mentioned catalyst carrier.

The present invention solves this problem, and as a result, fine short fibers, which have not been put into practical use until now, can be used as a catalyst phase.
It is designed to be usable as a body.

That is, the present invention involves adhering refractory short fibers or refractory glass short fibers mainly composed of silica, alumina, calcium, magnesium, titania, etc. with a diameter of 6 microns or less to long glass fibers or metal wires, and The gist of this invention is a catalyst using short fibers as a carrier, the surface of which is coated with a known catalyst component. This catalyst is particularly suitable as a catalyst for treating exhaust gas from internal combustion engines such as gasoline engines for automobiles.

In the present invention, the reason why the fire-resistant staple fibers are limited to 3 microns or less in diameter is that, as mentioned above, the smaller the diameter of the fibers, the better the catalytic performance is, and that Refractory fibers with micro diameter are
This is because they are short fibers with a diameter of 5 microns or less and a length of 5 to 20 mm. In addition, in the present invention, various adhesives can be used to attach the fire-resistant short fibers to long glass fibers or metal wires (the diameter and length of these fibers or wires can be arbitrarily selected in the present invention). Although a heat-resistant adhesive can be used, it is particularly preferable to use a heat-resistant liquid/adhesive whose main component is alumina sol.
It is preferable to use a method of mixing fire-resistant short fibers with a heat-resistant adhesive and spraying the mixture onto the surface of long glass fibers or metal wires. Furthermore, in the present invention, as a means for uniformly coating the carrier made of refractory short fibers with the catalyst component, it is preferable to employ the method previously announced by the present inventors, as described above. In this method, a carrier is coated with an ester of a metal acid and an alcohol, which is to become a catalyst component, and this ester is gelled under heating and attached to the carrier surface.
Next, this is fired. (Tokuko 51-21
See Publication No. 629. ) The present invention will be explained in more detail below by giving specific examples of the present invention.

Example 1 Figure 1 shows an apparatus for adhering refractory short fibers to the surface of glass filaments, in which A is the glass melting part, B is the spinning part,
C indicates a part where a mixture of heat-resistant adhesive and fire-resistant staple fibers is sprayed, and D indicates a drying oven. [This figure 1 is the same as the conventional equipment for producing long glass fibers, but the only difference is that in the conventional equipment, the part C is the part where the sizing agent (surface treatment agent) is sprayed, and the main In the present invention, this part C is only changed so that the mixture of heat-resistant adhesive and fire-resistant staple fibers is sprayed onto the part C. ] Glass fibers having a diameter of 9 microns are spun using the apparatus shown in FIG. 1 in a self-evident manner. On the other hand, heat-resistant adhesives whose main component is alumina sol,
Fiber diameter 1 consisting of A/, 0.50 inch, 8i0250 inch
~3 micron refractory short fibers (ceramic fibers) are mixed, and this mixture is sprayed from part C and dried. The thus obtained long glass fibers (with a diameter of 9 microns) have a structure in which the refractory short fibers F are adhered to the surface of the glass filament E, as shown in FIG.

A glass fiber having the structure shown in FIG. 2 is used as a carrier, and a catalyst component is coated on the surface of the carrier. This was done by mixing 500 parts of a 20 molar chromic acid aqueous solution (weight ratio, the same hereinafter) with 500 parts of a 20 molar nickel lead acid aqueous solution, and further mixing 250 parts of propylene glycol, and carrying out an esterification reaction for 1 hour. 1250 parts of stable ester intermediate are obtained. 1,650 parts of a solution prepared by adding 100 parts of a 0.1 molar palladium chloride aqueous solution to 1,250 parts of this intermediate were applied by dip coating to 2,700 parts of the glass fibers to which the short fibers were adhered,
After drying at 200°C for 1 hour, ester decomposition is completed by baking at 600°C for 1 hour, and an active metal oxide catalyst is adhered and supported on the surface of the short fiber carrier in the form of a film with a thickness of 0.1 to 042 microns. , 6 in a reducing gas atmosphere containing hydrogen.
Activation treatment is performed at 00°C for 1 hour.

The catalyst obtained in this way was
111 cylinder (opening on both sides, metal wire attachment, 0.554), simulated automobile exhaust gas (-1.5 g of carbon oxide, 250 pI of hydrocarbons diluted with ml of air) was placed at a space velocity of 7.
Passing at a rate of 5,000 m/hr, carbon monoxide removal rate is 94%, hydrocarbon removal rate is 8% under the condition that the gas temperature is 150°C.
I got a result of 7chi.

Example 2 A heat-resistant adhesive whose main component is alumina sol and a 20380%
A mixture of refractory short fibers (high alumina mullite fibers) with a fiber diameter of 1 to 3 microns consisting of 0.8i0. The process has been completed.

This catalyst was delivered in a cylinder with a diameter of 10 (up to) and a length of 5aIk (openings on both sides, metal wire attachment, 0.!l9A), and applied to methanol exhaust gas treatment (methanol 1500ppm).
Containing air), a removal rate of 9.7% was obtained under the conditions of a space velocity of 40,000 per hour and an inlet gas temperature of 70°C.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 shows an apparatus for adhering refractory short fibers to the surface of long glass fibers, which is an embodiment of the present invention, and Fig. 2 shows an apparatus for adhering refractory short fibers to the glass long fibers. It is a figure which shows the state which is adhere|attached. Sub-Agent Akifuku Uchida Agent Ryoichi Hagiwara Figure 1 Figure 2 July J7, 1981 Commissioner of the Patent Office Haruki Shimada 1, Indication of the case 1982 Patent Application No. 101323 2, As a carrier of the name of the invention Catalyst 3 using short fibers, relationship with the amended case Patent applicant address: 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Representative: Kaede Yano 4, Fukuyo Osamu Address: Toranomon, Minato-ku, Tokyo Chome 24-11 χ Supplementary Specification ``Details of the Invention - * mvs'' Section 1 Supplement] Contents of E C1) 1 mm To correct line 52 of the contribution ``Calcium'' to ``NikikVum'' k . (2) - Issho IIs buy 2 lines r! To correct "Danesium" to "Ilnesia".

Claims (1)

[Claims] Refractory short fibers or refractory glass short fibers mainly composed of silica, alumina, calcium oxide, magnesia, titania, etc. with a diameter of 3 microns or less are bonded to long glass fibers or metal wires, and a known catalyst is applied to the surface of the refractory short fibers or short refractory glass fibers. A catalyst using short fibers as a carrier, characterized by being coated with components.