JP2000042399A - Catalyst packing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain the intermediate performance using existing catalysts by coexisting plural kinds of catalysts at a basket unit in one layer of a catalytic layer in a catalyst packing method of forming the catalyst layer by arranging many baskets, in which the catalyst is packed, in a reactor. SOLUTION: A catalyst packed device for removing NOx contained in a waste gas discharged from a boiler or the like is provided in the half-way of a duct 1 and an ammonia ejecting pipe 5 for ejecting ammonia (NH3) to an inlet side of a denitration device 2 having the catalyst layer 4 formed in a reactor 3 is provided. NOx in the waste gas is reduced and decreased with the catalyst forming the catalyst layer 4 in the denitration device 2 by ejecting ammonia in the duct of the inlet side of the denitration device 2 from the ammonia ejecting nozzle 6. In such a case, the inermediate property of that of plural kinds of the catalyst A and B is attained by coexisting plural kinds of the catalysts in one layer of the catalyst layer at the basket 7 unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for charging a denitration apparatus or the like with a catalyst.

[0002]

2. Description of the Related Art Generally, exhaust gas discharged from a boiler or the like contains nitrogen oxides (NOx), and such NOx is removed by a catalyst filling device such as a denitration device. I have.

FIG. 4 shows an example of a conventional denitration apparatus as a catalyst filling apparatus, wherein 1 is a duct through which exhaust gas discharged from a boiler or the like flows, 2 is provided in the middle of the duct 1 and a reactor 3 is provided. A denitration device having a catalyst layer 4 formed therein, 5 is an ammonia injection tube for injecting ammonia (NH ₃ ) into the inlet side of the denitration device 2, and 6 is an ammonia injection nozzle attached to the ammonia injection tube 5. By injecting ammonia from the ammonia injection nozzle 6 into the duct 1 on the inlet side of the denitration device 2 and reducing NOx contained in the exhaust gas by a catalyst forming the catalyst layer 4 in the denitration device 2, the boiler or the like The NOx contained in the discharged exhaust gas is reduced.

As shown in FIGS. 4 and 5, a large number of catalyst layers 4 formed inside the reactor 3 of the denitration apparatus 2 are arranged so that baskets 7 filled with catalyst are stacked vertically and horizontally. It has the structure which consists of.

[0005]

Conventionally, the catalyst used in the denitration apparatus 2 is usually one type. For example, as shown in FIG. 6, one of the catalysts A has a high denitration rate. In the case where the SO ₃ conversion is also high and the other catalyst B has a slightly low denitration rate but a low SO ₃ conversion, one of them is to be selected. In order to obtain a catalyst having intermediate characteristics between the catalysts A and B, it takes time and cost to develop the catalyst. Needless to say, the higher the denitration rate, the better the performance of the catalyst. However, if the conversion of SO ₃ is high, that is, if the rate at which SO ₂ is oxidized to SO ₃ is high, the SO ₃ and ammonia react with each other to generate a large amount of acidic ammonium sulfate and the like, which causes clogging and corrosion of an air preheater (not shown) and the like. Therefore, it is preferable that the SO ₃ conversion rate is low.

If both the catalysts A and B as described above are divided into two layers in the reactor 3 as shown in FIG. , 4 must be provided with an inspection space, and the reactor 3 becomes large, resulting in uneconomical specifications, which is one of the reasons for using one type of catalyst.

As described above, if only one type of catalyst is provided in the reactor 3, one type of catalyst may be disposed in the catalyst layer 4 in units of baskets 7, and the catalyst layer 4 may be formed in one layer. It can be avoided that the reactor 3 becomes large,
Although there was no problem, with the diversification of needs in recent years, when using two types of catalysts with different temperature characteristics, when using two types of catalysts, a denitration catalyst and a dioxin catalyst, In the case where two types of catalysts are used, there are many situations in which a plurality of catalyst layers 4 must be provided in the reactor 3, and the size of the reactor 3 has become unavoidable. That was the current situation.

The present invention has been made in view of the above circumstances, and it is possible to obtain an intermediate target performance between existing reactors without increasing the size of the reactor and without developing a new catalyst. It is intended to provide a possible catalyst filling method.

[0009]

According to the present invention, there is provided a reactor comprising:
A catalyst filling method for forming a catalyst layer by arranging a large number of baskets filled with a catalyst, wherein a plurality of types of catalysts are mixed in a basket unit in one catalyst layer. Such is the case.

In the above catalyst filling method, different types of catalysts can be provided for each row of the basket.

In the above-mentioned catalyst filling method, baskets filled with different kinds of catalysts can be arranged in a staggered manner.

According to the above means, the following effects can be obtained.

When a plurality of types of catalysts are mixed in a single catalyst layer in a basket unit, intermediate characteristics of the plurality of catalysts can be obtained, so that it is not necessary to develop a new catalyst, and the time and cost required for the development In addition, it is not necessary to divide a plurality of types of catalysts in the reactor one by one and arrange them as a plurality of catalyst layers, and it is not necessary to enlarge the reactor.

[0014]

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

FIGS. 1 and 2 show an example of an embodiment of the present invention. In the drawings, portions denoted by the same reference numerals as those in FIGS. 4 and FIG. 5, but the feature of the illustrated example is that different types (for example, A, B) differ for each row of baskets 7 as shown in FIG. 1 and FIG. This is characterized in that a plurality of types of catalysts are mixed in a unit of basket 7 in one catalyst layer 4.

Next, the operation of the illustrated example will be described.

When a plurality of types of catalysts are mixed in one basket 7 in one catalyst layer 4, intermediate characteristics of a plurality of catalysts A and B can be obtained, and a new catalyst need not be developed.
The time and cost required for its development are eliminated.

Further, the plurality of types of catalysts A and B need not be divided into one layer in the reactor 3 and disposed as two catalyst layers 4 and 4, so that the reactor 3 does not need to be enlarged.

Furthermore, with the diversification of needs in recent years, when two types of catalysts having different temperature characteristics are used, when two types of catalysts, a denitration catalyst and a dioxin catalyst, are used, two types of catalysts, a denitration catalyst and a CO catalyst, are used. In the case where different kinds of catalysts are used, it is possible to cope without disposing the plurality of catalyst layers 4 in the reactor 3, and the size of the reactor 3 can be avoided.

In this way, it is possible to obtain an intermediate target performance between the existing catalysts without increasing the size of the reactor 3 and without developing a new catalyst.

FIG. 3 shows another example of the embodiment of the present invention. In the drawing, the portions denoted by the same reference numerals as those in FIGS. 1 and 2 represent the same components, and are filled with different types of catalysts. The arranged baskets 7 are arranged in a staggered manner, and a plurality of types of catalysts are mixed in a unit of the basket 7 in one catalyst layer 4.

As shown in FIG. 3, even if baskets 7 filled with different types of catalysts are arranged in a staggered manner,
Intermediate characteristics of the plurality of catalysts A and B can be obtained, so that a new catalyst does not have to be developed, and the time and cost required for the development are not required.
There is no need to divide the layers into layers and dispose them as two catalyst layers 4 and 4, eliminating the need to make the reactor 3 large, and furthermore, two types having different temperature characteristics due to diversification of needs in recent years. When a catalyst is used, when two types of catalysts, a denitration catalyst and a dioxin catalyst, are used, and when two types of catalysts, a denitration catalyst and a CO catalyst, are used, a plurality of catalyst layers 4 Can be installed without disposing the reactor 3
It is possible to avoid an increase in the size of the device.

Thus, in the case of the example shown in FIG.
As in the case of the example shown in FIG. 2, it is possible to obtain an intermediate target performance between existing reactors without increasing the size of the reactor 3 and developing new catalysts. it can.

It should be noted that the catalyst filling method of the present invention is not limited to the above-described illustrated example, and the number of types of catalysts to be mixed is not limited to two but may be more than two. The ratio can be appropriately selected in consideration of not only the performance but also the ease of filling and replacement into the reactor, etc., and the gas flow direction is not limited to horizontal, but may be applied to other types of catalyst packing devices such as vertical flow. It goes without saying that various changes can be made without departing from the gist of the present invention, such as the fact that the present invention may be applied.

[0025]

As described above, the first aspect of the present invention is as described above.
According to the catalyst filling methods described in (1) to (3), it is possible to obtain an intermediate target performance between existing catalysts without increasing the size of the reactor and without developing a new catalyst. Excellent effects can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic side sectional view of an example of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a front sectional view of another example of the embodiment of the present invention, and is a sectional view corresponding to the section taken along line II-II of FIG.

FIG. 4 is a schematic side sectional view of an example of the related art having a single catalyst layer.

FIG. 5 is a perspective view showing a catalyst layer.

FIG. 6 is a graph showing the denitration ratio and the SO ₃ conversion ratio with respect to the temperature of catalysts A and B.

FIG. 7 is a schematic side sectional view of an example of a conventional example having two catalyst layers.

[Explanation of symbols]

 2 DeNOx device (catalyst filling device) 3 Reactor 4 Catalyst layer 7 Basket

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiro Ozawa 3-2-1 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries, Ltd. Toyosu General Office F-term (reference) 4G070 AA01 AB05 BA08 BB06 CA01 CA06 CB19 DA11 DA21

Claims (3)

[Claims] 1. A catalyst filling method for forming a catalyst layer by arranging a large number of baskets filled with a catalyst in a reactor, wherein a plurality of types of catalysts are mixed in a unit of a basket in one catalyst layer. A method for charging a catalyst, comprising: 2. The catalyst filling method according to claim 1, wherein different types of catalysts are provided for each row of the basket. 3. The catalyst filling method according to claim 1, wherein baskets filled with different types of catalysts are arranged in a staggered manner.