JPH0999242A - Plate-like catalyst and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a producing method of a plate-like catalyst excellent in formability and advantageous in cost effectiveness even in the case of a catalytic body having >=2 peak parts for turning laminar flow developed in a catalytic passage to turbulence flow. SOLUTION: In a producing method of the plate-like catalyst by forming the peak parts 2 and 3 in >=2 directions on a plate-like catalyst obtained by using a lath worked metallic base plate 7 as a base material and carrying a catalytic composition 9 on the lath surface and lath mesh of through holes, after the catalytic composition 9 is carried on the metallic base plate 7, the through holes 4 vertically running through the plate-like catalyst are formed in a prescribed interval at a position, where the peak part 2 is to be formed. And the peak part 2 in one direction along the array of the through holes is formed among the through holes and next, the peak part 3 in another direction crossing the peak part 2 in one direction at the through hole 4 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate catalyst and a method for producing the same, and more particularly to a plate catalyst for flue gas denitration in which a catalyst composition is supported on a metal lath which is a metal substrate, and a method for producing the same. .

[0002]

2. Description of the Related Art As a method for removing nitrogen oxides in exhaust gas, a method in which a catalyst is used to selectively reduce with ammonia is mainly used. As the denitration catalyst, titanium oxide (TiO ₂ ) is generally used. A catalyst composition made of an oxide such as molybdenum (Mo), vanadium (V), or tungsten (W) is formed into a granular shape, a plate shape, a honeycomb shape, or the like. Among them, the plate-like catalyst is a combination of plate-like unit catalysts using a metal base material or an inorganic fiber woven fabric as a substrate. Each unit catalyst is provided with a so-called mountain portion, and a gas is provided between the unit catalysts. A gas flow path parallel to the flow direction is formed. In particular, the plate-shaped catalyst using a metal base material is characterized in that the shape of the peak can be easily changed due to its deformability, the aperture ratio is high, and the pressure loss is smaller than that of the granular or honeycomb-shaped catalyst.

A gas flow path formed by such a combination of plate-like catalysts usually has a constant cross-sectional area from the inlet to the outlet and does not join with other flow paths on the way. In this case, the inflowing gas develops into a laminar flow from the inlet through the run-up section, like the fluid flowing in the parallel flat plate.Therefore, in the subsequent steady flow state, the gas component concentration distribution occurs in the cross section. In terms of the reactivity between the catalyst and the gas, an unfavorable phenomenon appears as a film resistance.

Therefore, instead of keeping the cross section of the flow passage constant from the inlet to the outlet, by appropriately providing a barrier or a protrusion in the middle of the flow passage, the developed laminar flow is converted into turbulent flow to separate the catalyst and gas. There is a way to increase the reactivity. As such a method, for example, in a method of combining unit catalysts, there is a method of changing the molding direction of the peaks from those adjacent to each other. For example, the catalysts having the peaks formed in the same direction are not parallel but have a certain angle. Then, a method of alternately combining them (Japanese Patent Laid-Open No. 55-152552) can be mentioned. in this case,
Since the cross section of the flow passage is repeatedly contracted and expanded due to the presence of peaks that are not parallel to the gas flow, the pressure loss is higher than when all are combined in parallel, but the steady flow region is small and there is a membrane resistance against the catalytic reaction. By reducing the part,
For example, it exhibits excellent denitration performance.

[0005]

The plate-shaped catalyst in the prior art described above combines the direction of the peaks formed in the unit catalyst with respect to the other adjacent catalysts at a certain angle. Since it is the same as manufacturing and combining two kinds of catalysts, the cost is increased.
Further, in order to combine the same unit catalyst in a certain direction and change the direction of the peak portion, it is necessary to form two or more peak portions of the unit catalyst. There was a problem that the intersection of the ridge and the mountain could not be formed properly.

The object of the present invention is to solve the above-mentioned problems of the prior art and to provide a catalyst body having two or more peaks for converting the laminar flow developed in the catalyst channel into a turbulent flow. An object of the present invention is to provide a plate-shaped catalyst which is excellent in moldability and is also economically advantageous, and a molding method thereof.

[0007]

[Means for Solving the Problems] The above object is to provide through-holes vertically penetrating the catalyst body at the intersections of two or more ridges of the plate-shaped catalyst so that the ridges do not directly overlap each other. ,
That is, a lath-processed metal substrate is loaded with a mixture or paste made of a catalyst composition and applied, and then through holes at predetermined intervals are formed in a portion where the mountain portion is formed. This can be achieved by making them intersect.

That is, the invention claimed in this application is as follows. (1) In a plate-shaped catalyst in which a lath-processed metal substrate is used as a base material, and a mountain portion is formed in a plate-shaped body having a catalyst composition supported on lath surfaces and through holes that are through holes, the mountain portion is bidirectional. A plate-shaped catalyst comprising the above-mentioned peaks, and through-holes vertically passing through the plate-shaped body are provided at the intersections of the peaks in one direction and the peaks in the other direction. (2) A method for producing a plate-shaped catalyst, comprising a lath-processed metal substrate as a base material, and forming ridges in two or more directions on a plate-shaped body carrying a catalyst composition on the lath surface and in the laths that are through holes. After supporting the catalyst composition on the metal substrate, through holes at predetermined intervals are formed vertically through the plate-like member at positions where peaks are to be formed, and the through holes are arranged along the arrangement thereof. A method for producing a plate-shaped catalyst, comprising providing a ridge portion in one direction, and then forming a ridge portion in the other direction intersecting at the through hole in the ridge portion in one direction.

Through holes are formed in advance at predetermined intervals at positions where the peaks of the plate-like catalyst are to be formed, and penetrate through the plate-like body vertically.
By providing a mountain portion in one direction along the arrangement between the through holes, and then forming a mountain portion in the other direction intersecting the through hole in the mountain portion in the one direction, the mountain portion in the other direction is formed. When forming, the peaks in the other direction do not directly overlap with the peaks in the one direction previously formed, so that the plate catalyst having the peaks in two or more directions can be easily obtained without losing the shape. Can be manufactured.

When a plurality of unidirectional peaks formed on a unit catalyst are combined at a certain angle with respect to adjacent catalysts, the relationship between the mutual angle of the peaks, the pressure loss and the catalyst performance (denitration performance) is shown. As shown in FIG. In the figure, the peaks in one direction are parallel to the gas flow, and when the crossing angle of the peaks in the other direction is changed,
That is, it can be seen that the pressure loss increases and the denitration performance also improves as the crossing angle increases from 0 °. As is clear from this, by combining the plate-like catalysts having two or more peaks in different directions proposed in the present invention, the catalytic performance, for example, denitration performance is improved. Also, by making a through hole at the intersection of different mountain parts,
The moldability of the ridges is improved, and the plate-shaped catalyst does not easily lose its shape.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to Examples. Example 1 FIG. 4 is an explanatory view showing an example of the method for producing a plate-shaped catalyst according to the present invention. In the figure, as the metal substrate, for example, a metal lath 7 obtained by lathing a thin plate having a thickness of 0.2 mm.
Is used as a catalyst composition, the catalyst composition 9 is prepared by adding water to a raw material such as titanium oxide and kneading in a paste form, and the metal lath 7 and the catalyst composition 9 are applied while sandwiched by the application sheet 8 from both upper and lower surfaces. The catalyst composition 9 is pressure-bonded and supported on the surfaces of the metal laths 7 and the laths, which are through holes, by supplying the rolls 10 to each other to form the plate-shaped catalyst 1. Next, the plate-shaped catalyst 1 is preliminarily placed on the obtained plate-shaped catalyst 1 at a position where a mountain portion is to be formed by a punching press machine 11.
Through holes 4 at predetermined intervals to pass through the
A mountain portion forming machine 12 forms a ridge portion a (2) in one direction along the arrangement of the through holes 4 between the through holes 4, and then a mountain portion forming machine 13 forms the formed one direction. 1 is formed by forming a mountain portion b (3) in the other direction that intersects at a right angle with the mountain portion a (2) and the through hole 4 and then cutting it into a predetermined size by a cutting machine 14. Such a plate-like catalyst was used.

According to the present embodiment, the punching press 11 preliminarily forms the through holes 4 at the positions where the peaks of the plate-shaped catalyst 1 are to be formed, and the through holes 4 are provided between the through holes 4.
After forming the ridges a (2) in one direction along the arrangement of the through holes 4, the ridges a (2) in one direction and the ridges b (3) in the other direction intersecting at the through holes 4. By forming the ridges, as shown in FIG. 3 which is an enlarged view of the main portion of FIG. 1, the ridges a and the ridges b do not directly overlap with each other. There is nothing to do. Therefore, the plate-shaped catalyst 1 having the peaks a and the peaks b in two directions can be manufactured accurately and easily.

In this embodiment, by changing the shape of the mountain portion forming machine, the mountain portion a and the mountain portion b can be simultaneously molded. Further, the angle between the mountain portion a and the mountain portion b can be set to 45 degrees or other angles as shown in FIG. 2, for example.

[0014]

According to the invention described in claim 1 of the present application, by providing a through hole vertically passing through the plate-shaped catalyst at the intersection of the ridge portion in one direction and the ridge portion in the other direction, It is possible to obtain a plate-like catalyst which has excellent moldability and is less likely to lose its shape such as distortion, and which has peaks in two or more directions. Further, although the obtained plate-shaped catalyst has a slightly high pressure loss, it has high denitration performance and is advantageous in terms of cost. According to the invention of claim 2 of the present application, after the catalyst composition is supported on the metal substrate, through holes with predetermined intervals are provided at the positions where the peaks are to be formed, and the through holes are arranged in an array. A ridge portion in one direction is provided along the ridge portion in the other direction, and then a ridge portion in the other direction intersecting with the through hole is formed in the ridge portion in the one direction. Since the portion does not directly overlap the previously shaped ridge portion in one direction, a plate-shaped catalyst having ridge portions in two or more directions can be accurately and easily manufactured.

[Brief description of drawings]

FIG. 1 is a view showing a plate-like catalyst which is an embodiment of the present invention.

FIG. 2 is a view showing a plate-like catalyst which is another embodiment of the present invention.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is an explanatory view showing a method for producing a plate-shaped catalyst of the present invention.

FIG. 5 is a diagram showing the relationship between the crossing angle of the peaks of the unit catalysts of the plate-shaped catalyst laminate, the pressure loss, and the denitration performance.

[Explanation of symbols]

1 ... Plate catalyst (unit catalyst), 2 ... Mountain portion a, 3 ... Mountain portion b,
4 ... Through hole, 7 ... Metal lath, 8 ... Coating sheet, 9 ... Catalyst composition (paste), 10 ... Coating roll, 11 ... Punching press machine, 12 ... Mountain part a molding machine, 13 ... Mountain part b molding machine, 14 ... Cutting machine.

Claims (2)

[Claims] 1. A plate-shaped catalyst comprising a lath-processed metal substrate as a base material, and a plate-shaped body having a catalyst composition supported on the lath surface and through-holes, wherein the mountain portion is formed. A plate-shaped catalyst, characterized in that it has two-direction peaks, and through holes that vertically penetrate the plate-like body are provided at the intersections of the one-direction peaks and the other-direction peaks. 2. A method for producing a plate-shaped catalyst comprising a lath-processed metal substrate as a base material, and a plate-shaped body having a catalyst composition carried on the lath surface and through-holes as laths, having peaks in two or more directions. In the method, after supporting the catalyst composition on the metal substrate, through holes at predetermined intervals are formed vertically through the plate-like member at positions where peaks are to be formed, and the through holes are arranged in an array thereof. A method for producing a plate-shaped catalyst, characterized in that a ridge portion in one direction is provided along the ridge portion, and then a ridge portion in the other direction intersecting with the through hole is formed in the ridge portion in one direction.