JPH06210122A - Gas-liquid contacting device - Google Patents

Abstract

PURPOSE:To obtain a gas-liquid contacting device where gas and liquid are effectively brought into contact with each other by installing dispersing plates for receiving liquid flowing down from above to disperse it and for causing it to flow downwards, between the plural stages of packings where tubular constitutional bodies are arranged. CONSTITUTION:Tubular constitutional body packings 2 whose tubular parts are in a straight line are arranged in plural stages in a CO2 absorber body. And between the packings 2 arranged in multistage in the vertical direction are interposed dispersing plates 10 consisting of perforated plates, etc. Consequently liq. absorbent flowing down from the lower end part of the packing 2 of the upper stage strikes against the dispersing plate 10 and is dispersed by the dispersing plate 10 again. Therefore the gas-liquid contact area on the absorbing surface of the packing 2 is kept wide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for removing CO ₂ contained in combustion exhaust gas by bringing it into contact with a CO ₂ absorbing liquid.
_{2 It} relates to a gas-liquid contact device capable of efficiently contacting a gas and a liquid, such as an absorption device.

[0002]

2. Description of the Related Art In recent years, the greenhouse effect of CO ₂ has been pointed out as one of the causes of the global warming phenomenon, and there is an urgent need to take countermeasures internationally in order to protect the global environment. CO ₂
Emissions of carbon dioxide are generated in all human activity fields that burn fossil fuels, and their emission regulations are likely to be tightened in the future. As one of the countermeasures, for a power generation facility of a thermal power plant that uses a large amount of fossil fuel, a method for removing / recovering CO _{2 in} the combustion exhaust gas of a boiler and releasing the recovered CO ₂ to the atmosphere The way to store without is actively researched.

By the way, regarding the CO ₂ absorbing device for removing CO ₂ contained in the combustion exhaust gas, the present inventors have previously described FIG.
A tubular structure having various cross-sections as shown in (also serving as a schematic view of the gas-liquid contactor of the present invention) is filled with a filling material in which the tubular portion of the structure has a linear shape, and the filling material is filled with a gas. We proposed a CO ₂ absorption device in which a large number of liquid contact surfaces are arranged so as to be parallel to the gas flow (see Japanese Patent Application No. 3-33089). That is, in FIG. 1, 1 is a CO ₂ absorber main body, 2 is a packing composed of a tubular structure in which the tubular portion has a linear shape, and arranged in a plurality of stages, 3 is a line for transporting the CO ₂ absorbing liquid, 4 liquid dispersion nozzle 5 is absorbing liquid reservoir that has absorbed CO _2, 6 is CO ₂ containing flue gas, 7 CO ₂
It is a clean exhaust gas from which Although the tubular structure may have various cross-sections as described above,
It may of course be a single shape or a combination of a plurality of shapes. In such a tubular packing, the flow of gas (hereinafter, also referred to as “gas”) is parallel to the absorption surface (gas-liquid contact surface), and the gas flow expands, contracts, or collides with the gas flow path. However, no eddy current is generated, and useless pressure loss due to this is hardly generated. The absorbing liquid is then retained on the absorbing surface of the tubular packing and, while continuing to flow down along the surface, comes into contact with the gas stream and CO ₂
Absorbs. It has been shown that such a mode can significantly reduce the pressure loss unlike the conventional packing such as Raschig ring.

[0004]

However, since the length of one unit of the tubular structure packing in the gas flow direction is limited due to manufacturing reasons, for example, 20 m in the gas flow direction.
To fill a certain degree of filling, it is necessary to stack the tubular structure fillings in about 20 stages. In this case, a gap is created between the tubular structures. Due to this gap, when the absorbing liquid flows from the upper tubular structure to the lower tubular structure,
The absorbing liquid flows in the form of threads and the dispersibility is impaired. Higher machining accuracy is required to reduce this gap, which leads to an increase in cost.

In view of the above-mentioned drawbacks of the proposed technique of the present invention, it is an object of the present invention to provide a gas-liquid contactor capable of improving the dispersibility when the absorbent flows from the upper stage to the lower stage of the tubular structure packing. .

[0006]

According to the present invention, a filling material is filled, a liquid is supplied from above the filling material, the supplied liquid is caused to flow down along the surface of the filling material, and a gas is supplied from the lower portion. In a gas-liquid contactor for supplying gas and liquid by contacting each other, the packings are arranged in a plurality of steps spaced apart from each other, and each step of the packings is a tubular structure having a cross-section of various shapes. The part has a linear shape, and a large number of gas-liquid contact surfaces are arranged so as to be parallel to the gas flow, and the liquid to be flowed down from above is dispersed between each of the packings in the plurality of stages. There is provided a gas-liquid contact device characterized by comprising a dispersion plate which is caused to flow downward.
Further, according to the present invention, there is provided the gas-liquid contactor, wherein the dispersion plate has a mesh-like portion having a mesh-like shape or a porous surface portion formed by a plurality of holes. Furthermore, according to the present invention, there is provided a gas-liquid contactor for absorbing CO _{2 in} the combustion exhaust gas having the above-mentioned aspect.

[0007]

The liquid flowing down from the upper tubular structure is dispersed by the dispersion plate and supplied to the lower tubular structure. Therefore, the gas-liquid contact area in the tubular structure can be significantly increased, and the gas-liquid contact efficiency can be significantly improved.

[0008]

EXAMPLES Next, the present invention is applied to CO contained in combustion exhaust gas.
₂ as examples CO ₂ absorber to remove in contact with CO ₂ absorbing liquid will be described with reference to the drawings. In FIG. 1, in the CO ₂ absorber main body 1, a plurality of stages of tubular structure packings 2 having tubular tubular portions are arranged. The apparatus body 1 is connected to a CO ₂ absorbent transport line 3 that connects the upper liquid dispersion nozzle 4 and the lower absorbent reservoir 5 to each other. The liquid dispersion nozzle 4 is provided so as to disperse the CO ₂ absorbing liquid sent through the transportation line 3 into the filling 2 as evenly as possible. At the bottom of the device body 1, there is a filler 2
The absorption liquid reservoir 5 is provided for accumulating the CO ₂ absorption liquid that has absorbed CO ₂ while flowing downward through the absorption liquid. CO ₂ -containing combustion exhaust gas 6 is provided on the lower side of the device body 1
An opening is provided for introduction therein. An opening is provided above the apparatus body 1 for discharging the clean exhaust gas 7 from which CO ₂ has been removed by the absorbing liquid while flowing upward through the filling 2.

A partially enlarged view of the filling 2 is shown in FIG. The packing 2 is formed in a tubular structure having a horizontal cross-sectional lattice shape, and allows the combustion exhaust gas flowing from the lower part to the upper part in the apparatus main body 1 to pass through the tubular part, while absorbing the liquid supplied from the liquid dispersion nozzle 4. It is designed to flow downward through the tubular portion. The inner wall surface of the tubular portion is an absorption surface (gas-liquid contact surface) on which the combustion exhaust gas and the CO ₂ absorption liquid react.
Are configured. The filling 2 is a porcelain tubular structure 2'having a length De on one side of the lattice of, for example, 15 mm, and is denoted by reference numeral 2 in FIG.
₁ , 2 ₂ , 2 ₃ , 2 _4, ... Are arranged in the lateral direction. The dimensions of the packing 2 thus configured are, for example, an area of 300 mm ² and a length of 500 mm. The filling 2 is arranged in the apparatus main body 1 in the vertical direction, for example, in 20 stages.

In the tubular packing 2 as described above, the gas flow is parallel to the absorption surface as described above, and the expansion, contraction, collision, and vortex of the gas flow in the gas flow path are small,
The pressure loss resulting from this is very small.

The shape of the tubular structure 2'is not limited to the lattice shape shown in FIG. 2, and may be any shape such as hexagonal, rectangular, triangular or U-shaped as long as it forms a gas parallel flow. The material may be porcelain, metal, ceramic fiber such as silica fiber, or plastics such as polyethylene, as long as they are not affected by corrosion or swelling by the absorbing liquid. Regarding the manufacturing method, the one shown in Fig. 2 is generally an extrusion molding method, but other combinations of flat plate and molding plate, corrugated machine molding method, etc. are applied, and an economical manufacturing method is selected depending on the shape and material. it can.

A feature of the present invention is that, as shown in the sectional view of FIG. 3, a dispersion plate 10 is interposed between each of the packings 2 arranged in multiple stages in the vertical direction. The dispersion plate 10 is composed of, for example, a perforated plate. The porosity of the perforated plate (the ratio of the area of the holes to the total area including the area of the holes) is preferably 80% or more in order to prevent an increase in pressure loss when the gas passes. The shape of the holes of the perforated plate is not limited to a circular shape, but may be a deformed hole such as a star shape.

FIG. 4 shows the flow of the absorbing liquid when the dispersion plate is not provided between the packings 2. Absorbing liquid is packing 2
When it flows down from the lower end of the, it flows in the form of threads and the dispersibility is impaired. In particular, if the gap between the respective fillers 2 is 5 mm or more, the absorbing liquid becomes a filament and the dispersibility is likely to be impaired.

On the other hand, FIG. 5 shows a case where the dispersion plate 10 is provided between the respective packings 2. The absorbing liquid that flows down from the lower end of the upper packing 2 hits the dispersion plate 10 and the dispersion plate 1
It is dispersed again by 0. Therefore, it is possible to secure a large gas-liquid contact area on the absorption surface of the packing 2, and to reduce CO ₂
The absorption efficiency can be significantly improved. When the holes of the perforated plate have a star shape, it is possible to prevent the absorption liquid from passing through the holes 11 and thereby preventing the gas from passing through the holes 11.

In another embodiment of the present invention, the dispersion plate 10
May be composed of a wire mesh. This embodiment has the same effect as the above embodiment. In this case, the absorption liquid passes through the mesh, so that the gas passage through the mesh is less likely to be hindered. Note that a mesh made of plastic or other material may be used instead of the wire mesh.

Although the effectiveness of the present invention is apparent from the above description, a 30% monoethanolamine aqueous solution is used as the CO ₂ absorbing solution, and a porcelain tubular material having an area of 300 mm ² , a length of 500 mm and a De of 15 mm shown in FIG. Using a wire mesh as the structure and the dispersion plate, the dispersibility of the absorbing liquid flowing from above was observed at room temperature and atmospheric pressure. As a result, it was confirmed that the two tubular structures were vertically assembled with the wire mesh interposed therebetween, and the absorption liquid supplied to the upper tubular structure was almost evenly dispersed and flowed down at the outlet of the lower tubular structure. It was From this, it was confirmed that the present invention can significantly improve the CO ₂ absorption efficiency.

[0017]

As described above, according to the present invention,
By providing the dispersion plate between the tubular structures, the liquid flowing down from the upper tubular structure can be dispersed and supplied to the lower tubular structure. Therefore, the gas-liquid contact area of the tubular structure can be increased, and the gas-liquid contact efficiency can be significantly improved. Further, since high precision is not required for processing each tubular structure, it is possible to reduce the manufacturing cost.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a CO ₂ absorber used in an embodiment of the present invention and a conventional CO ₂ absorber.

FIG. 2 is a configuration diagram showing a tubular structure provided in a CO ₂ absorption device.

FIG. 3 is a configuration diagram showing a state where a dispersion plate is provided between the tubular structures according to the present invention.

FIG. 4 is an explanatory diagram of a flow of an absorbing liquid when a conventional dispersion plate is not provided.

FIG. 5 is an explanatory diagram of a flow of an absorbing liquid when a dispersion plate according to the present invention is provided.

Front Page Continuation (72) Inventor Zenji Hotta 3-3-22 Nakanoshima, Kita-ku, Osaka City, Osaka Prefecture Kansai Electric Power Co., Inc. (72) Koichi Kitamura 3-22-3 Nakanoshima, Kita-ku, Osaka City, Osaka Prefecture Kansai Electric Power Co., Inc. (72) Inventor Masaki Kawasaki 3-3-22 Nakanoshima, Kita-ku, Osaka City, Osaka Prefecture Kansai Electric Power Co., Inc. (72) Kunihiko Yoshida 3-322 Nakanoshima, Kita-ku, Osaka City, Osaka Prefecture Kansai Electric Power Co., Inc. (72) Shigeru Shimojo, Inventor Shigeru Shimojo, 3-3-22 Nakanoshima, Kita-ku, Osaka, Osaka Prefecture Kansai Electric Power Co., Inc. Heavy Industry Co., Ltd. (72) Inventor Masaki Iijima 2-5-1, Marunouchi, Chiyoda-ku, Tokyo Sanryo Heavy Industry Co., Ltd. (72) Kaoru Mitsuoka 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima Prefecture Mitsubishi Heavy Industry Co., Ltd. Hiroshima Laboratory

Claims (4)

[Claims] 1. A filling material is filled, a liquid is supplied from above the filling material, the supplied liquid is caused to flow down along the surface of the filling material, and a gas is supplied from a lower portion to bring the gas and the liquid into contact with each other. In the gas-liquid contacting device, the packing is arranged in a plurality of steps spaced apart from each other, and each step of the packing is a tubular structure having various shapes in cross section, and the tubular portion shows a linear shape,
A large number of the gas-liquid contact surfaces are arranged so as to be parallel to the flow of gas, and the liquid to be flowed down from above is received between each of the packings in the plurality of stages, and the liquid is dispersed to flow down. A gas-liquid contact device comprising a plate. 2. The gas-liquid contact device according to claim 1,
A gas-liquid contact device, wherein the dispersion plate has a mesh portion having a mesh shape. 3. The gas-liquid contact device according to claim 1,
A gas-liquid contact device having a porous surface portion formed by piercing a plurality of dispersion plates. 4. The gas is combustion exhaust gas and the liquid is CO ₂
The gas-liquid contact device according to claim 1, wherein the gas-liquid contact device is an absorbing liquid.