JPH03127608A - Method and device for absorbing gas - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

Industrial Application Field The present invention relates to a gas absorption device and a gas absorption method, and is used in the field of sorting and removing harmful components or unrecoverable gas components from gases such as factory gas and exhaust gas, such as steel pickling lines. HCl is removed from factory gas, and S from flue gas is removed.
The present invention relates to a gas absorption device and a gas absorption method that can be used to remove H and S from gases used in the cellophane manufacturing process. From conventional technology factories, gases generated in large quantities such as exhaust gas. Methods for removing specific gas components generally include a direct combustion method, a catalytic method, and a chemical absorption method. Particularly in the chemical liquid absorption method, how the chemical liquid and the generated gas are brought into contact is important from the standpoint of device design. Currently, the methods used are: ■ Injecting gas into the chemical solution, ■ Spraying the chemical solution and counterflowing the generated gas, ■ Reacting the chemical droplets with the gas, and ■ Charging the reaction tower with packing. However, there is a method of spraying a chemical solution and allowing the chemical solution attached to the surface of the filling material to contact and absorb the generated gas, but these methods are not sufficient to bring the chemical solution into contact with the generated gas, and the gas absorption device becomes large. do. The problem that the invention tries to solve is 1! II provides an efficient device and method for increasing the contact between gas and chemical liquid, and by using a sinterable metal porous body structured in a three-dimensional network, the contact area can be increased simply by increasing the contact area. Instead, it is possible to increase the chance of a contact reaction between the gas and the liquid film on the porous skeleton by utilizing the visual vortex generated near the skeleton when the gas passes through the pores of the porous body. Also, the extremely thin liquid film formed in the pores increases gas/liquid absorption without increasing the pressure drop of the passing gas by as much as 11 J. In addition, since the metal porous body can be easily energized or heated by induction, there is an advantage that the reaction efficiency can be increased by controlling the temperature of the liquid film of the skeleton to the optimum reaction temperature. Means and Effects for Solving the Problems The present invention provides: (1) three-dimensional connected pores with a porosity of 70% by volume or more, a pore diameter of 0.5-10 mm, and a specific surface area of 300-300 mm;
A gas absorption device comprising a three-dimensional network-shaped sintered metal porous body having a bulk specific gravity of 2,000 g/d and a bulk specific gravity of 0.3 to 2.0, with a coating of an absorbing chemical liquid formed on at least the surface of the metal skeleton, (2) Claim (1) A gas absorption method characterized by passing a gas or a gas and an absorption chemical solution through the device described above to absorb and remove a specific gas component in the one-pass gas into the absorption gas chemical solution; (3) Average Iron-based powder with a particle size of 50 l or less is applied to the skeleton of the three-dimensional network organic polymer material, dried, and heat treated to remove the skeleton of the three-dimensional network organic polymer material. Manufactured by sintering iron-based powder and forming three-dimensional connected pores with a porosity of 70% by volume or more and a pore diameter of 0.5 to 10 m.
g, a gas formed by forming a coating of an absorbing chemical liquid on at least the metal skeleton surface of a three-dimensional network-shaped sintered metal porous body having a specific surface a of 300 to 2000 m''/m'' and a bulk specific gravity of 0.3 to 2.0; Absorption device. (4) A slurry containing iron-based powder with an average particle size of 50← or less is poured into the gaps between the spheres of a large number of organic polymer spheres closely arranged in a mold, dried, and heat-treated. The organic polymer spheres are removed, and the iron-based powder is sintered to form three-dimensional connected pores.The porosity is 70% by volume or more, and the pore diameter is 0.5.
~10m5. Specific surface area 300~2000rn'/r
n', bulk ratio fi 0.3 to 2.017) A gas absorption device comprising a three-dimensional mesh-like sintered metal porous body and a coating of an absorbing chemical liquid formed on at least the surface of the metal skeleton. (5) The method according to claim (2), wherein the porous combustion metal body is heated by electricity or induction to control the skeleton portion to a reaction temperature. It is. This will be explained in detail below. The gas absorption device of the present invention has a coating of an absorbing chemical liquid formed on the surface of a metal skeleton of a so-called three-dimensional network-like sintered metal porous body in which three-dimensional interconnected pores are formed. These metal porous bodies can be suitably manufactured, for example, by the following manufacturing method. ■Patent Application 1983-185884 ■ // 83-185885 ■ // 83-1137853 ■ /l 83-210642 ■Patent Application 1997-97822 The gas absorption of the present invention refers to the case where a gas simply dissolves in a liquid ( This includes both cases (physical absorption) and cases where dissolved gas causes a chemical reaction with the liquid (chemical absorption). The metal constituting the porous metal body is selected in consideration of corrosion resistance depending on the type of chemical solution or gas used. In the present invention, the contact area between the gas and the absorbed chemical liquid is defined as the contact area. In order to increase the reaction chance and not significantly increase the gas pressure drop, the sintered metal porous body has a porosity of 70% by volume or more, a pore diameter of 0.5 to 10 mm, and a specific surface of 1a3 (10 to 2000r).
n'/m'', and the bulk specific gravity is set to 0.3 to 2.0. A typical manufacturing method of such a three-dimensional network-like sintered metal porous body will be explained below. First, claim (3) Describing an example of the method for manufacturing the porous body of the present invention When manufacturing the porous body of the present invention: For example, iron powder having an average particle size of 50 mm or less and containing 2.1 to 4.5% of C is used. Generally, powder alloys are fired in acid form using a high-pressure press, but in claim (3), iron powder in the form of a slurry is applied to the skeleton of a three-dimensional network organic polymer material without using a high-pressure press. In the method of the present invention, which does not use a high-pressure press, if the average particle size is 50 or more, it will be difficult to coat the skeleton of the three-dimensional network organic polymer material, and the bonding force between the particles will be insufficient. Therefore, in the present invention, iron powder with an average particle size of 501L or less is used.Also, in the present invention, liquid phase sintering is promoted in order to increase the bonding force between particles.Containing 2.1% or more of C. Because the rapidly cooled granulated pig iron is easy to crush, fine iron powder can be easily produced using a ball mill, etc., and during sintering, it is easy to undergo liquid phase sintering because it contains a large amount of low-melting point leadebrite eutectic, and the solid particles between particles are easily produced. Bonding is easily obtained, but iron powder containing 4.5% or more of C is likely to cause thermal strain cracking due to thermal stress during sintering. Adjust to. [0] = 4/3 ([C] - 2) to 4/3 ([C] +
7)...(1)

[Ol: Oxygen content of surface-oxidized iron powder (C1: Carbon content of surface-oxidized iron powder) By adjusting this oxygen content, iron powder contains appropriate amounts of carbon and oxygen, but during sintering, carbon When the amount of 01 is less than 4/3 ([01-2), decarburization is insufficient during sintering, resulting in poor toughness. It is difficult to produce an excellent porous body, and when the amount of [0] is more than 4/3 ([C] + 7), there are many unreduced oxides in the skeleton of the iron-based sintered body, and the porous body is easily broken and has low strength. According to the findings of the inventors,

By keeping 0 to the first equation, the production of porous iron bodies with excellent toughness is stabilized. Adjustment of the oxygen content of iron powder can be achieved by oxidizing the surface of iron powder. This surface oxidation of iron powder can be achieved by wet grinding, or it can be obtained by boiling pig iron powder with no surface oxidation, for example, with water, or by heating it at a low temperature in the atmosphere ( This surface oxidized iron powder is kneaded with a binder and applied to the skeleton of the three-dimensional network organic polymer material. As the binder, an organic or inorganic binder can be used. As the organic binder, for example, CMC, polyacrylic acid, etc. can be used, and as the inorganic binder, water glass etc. can be used. The three-dimensional network organic polymer material is a porous polymer material having three-dimensional communicating pores, such as urethane foam, synthetic m
#I three-dimensional fabric etc. can be used. Application can be performed, for example, by a spray method or a dipping method. In the present invention, the above-mentioned coating product is heated to produce iron powder [0
1 and [01 are reacted together and a sintering reaction is caused. Therefore, a vacuum furnace or a reduction furnace for manufacturing general powder alloys may be used, but a non-oxidizing atmosphere such as Ar or gas is sufficient for the heating furnace.For example, the skeleton of urethane foam is
It is removed by heating at 80-350°C for about 30 minutes. Further, the coated material is self-reductively sintered by heating at 600 to 1200°C to obtain an iron-based porous body in which three-dimensionally connected pores are formed in an iron-based skeleton. With this method, for example, by selecting the pore size of the urethane foam, an iron-based porous body with the desired pore size can be obtained, and the thickness of the slurry-like iron powder applied to the urethane foam skeleton can be controlled. For example, if 7A is adjusted by dipping multiple times, the porosity will be 70% by volume.
An iron-based porous body containing ~90% by volume is obtained. using this method,
S:, Mn, Xi, Cr, Mo. When manufacturing a steel bar body with a composition equivalent to ordinary alloy steel containing 1 or more of Cu, AQ, etc., pig iron containing these alloy components is manufactured in advance, and this is 50 L or less. It may be ground into powder and used as the above-mentioned iron powder, or it may be used as a distant relative by mixing powder of these alloys or ferroalloy powder of 50p or less and mixing it into a slurry. Next, in claim (4), an iron-based porous body is manufactured by the following method. FIGS. 2 and 3 are diagrams showing an example of the manufacturing method. A mold 7 is prepared in which a large number of organic polymer spheres 6 are tightly packed. During the subsequent heat treatment, the organic polymer spheres 6 thermally decompose and disappear to form pores. Therefore, when organic polymer spheres disappear, it is desirable that they generate a small amount of gas and are easily thermally decomposed and disappear.If organic polymer spheres that have a high specific gravity are used, a large amount of gas will be generated during degreasing. 1. For example, if the iron-based sintered skeleton is thin, the pressure of this gas will cause the iron-based sintered skeleton to crack, deform, or fall off. For example, styrene 1 expansion foam (manufactured by Sekisui Chemical Co., Ltd.) and Expancel plastic micro hollow spheres (Japan Ferrite!! By heat treatment with water etc.), the apparent specific gravity is 0.30.
The result is an organic polymer sphere that is hollow or has many fine bubbles. When organic polymer spheres 6 with an apparent specific gravity of 0.30 or less are used after such foaming treatment, the amount of gas generated during heat treatment is small, so the iron-based sintered skeleton is free from cracks. No deformation or falling off will occur. As shown in FIG. 2, for example, when a large number of organic polymer spheres 6 are placed in a mold 7 and pressurized, the organic polymer spheres 6 come into close contact with each other. Further, as shown in FIG. 3, for example, when the mutual contact points of the organic polymer spheres 6 are bonded with an adhesive 8, the polymer spheres 6 come into close contact with each other. A slurry-like mixing liquid made by kneading iron-based powder and a binding liquid is poured into the molds 7 arranged in close contact with each other, and the mixing liquid is placed in the gaps between the organic polymer spheres 6. The mixing liquid at this time is manufactured by the method described in claim (3). The mold into which the kneading solution is poured is dried and heat treated. During the heat treatment, the organic polymer spheres 6 are removed by heating at 180-350°C for about 30 minutes, and the crosstalk liquid is heated at 800-150°C.
By self-reductive sintering by heating at 200° C., an iron-based porous body with a porosity of 70% by volume or more, in which three-dimensional connected pores are formed in an iron-based skeleton, is obtained. A schematic diagram of the cross section of the porous body thus obtained is shown in FIG.
are micropores created between metal powders after sintering. The surface of the steel frame has large particles, making it easy for chemical solutions to adhere to it (1) increasing reaction activity. F! because there are small branches near the skeleton. 4 flow is likely to occur, which also increases the reaction activity. In addition, since it is network-like and has micropores, it has a large specific surface area and increases reaction activity. In addition, the organic polymer skeleton inside the skeleton was burned away and
There are communicating cavities (micropores) with a diameter of 100 to 300 l, and the chemical solution communicates with the cavities by capillary action, diffuses to the entire skeleton, and spreads to each skeleton throughout the porous body and its surface. As it is evenly distributed, it is easy for the absorbed chemical solution to uniformly diffuse on the surface of the metal porous body skeleton. In addition, the pore diameter was set to 0.5 m/m to 10 m/m because
When the thickness is less than 0.5 layer, the liquid film generated inside the pores may combine and form droplets inside the pores.
In this case, the pressure drop increases significantly, which is undesirable in terms of equipment.If the pressure drop exceeds 10, a liquid film will naturally exist on the surface of the skeleton, but due to the surface tension, it will be difficult to form a liquid film inside the pores, making the reaction inefficient. This is not preferable because it shows a decrease in In addition, the porosity is 70% or more, and the specific surface area is 300 to 2000 m.
? /m2/m3, and the bulk specific gravity was 9.3 to 2.0.
Within a preferable range in terms of reaction activity, products within this range can be easily produced by the methods of claims (3) to (4). In addition to having excellent strength, the porous body of the present invention is easy to cut, process, and weld, and can be processed into a desired shape. If it is sealed, a gas absorption device can be manufactured easily. Examples of various gas absorptions are shown in Table 1, and the present invention is applicable to these. (Left below) Table 2 shows a comparison of the packing used in conventional gas absorption towers and one example of the metal porous body of the present invention. Table 2 Examples Examples Pig oxide powder with an average particle size of 10 g (C: 3.0%, Mn:
0.3%, Si: 0.1%, P: 0.02%, s:
0.01%. Oxygen: 6%) was added with 18% and 8% by weight of Cr and Ni powders with an average particle size of 5 μm, respectively, and applied to a mesh urethane foam using Poval as a binder, and heat treated to obtain a pore size of 7 m/m. A stainless steel sintered porous body with a porosity of 95% and a pressure drop of 50 mm H20/m was prepared in a reaction tower (1 liter cube) shown in Fig. 4, and S02 was heated to 50 mm.
2+g/s of power plant combustion exhaust gas 11 containing OOPP Liao
P) 17 from the top of the porous body 15 by passing at a flow rate of ec.
．． When the desulfurization rate of the treated gas 12 was measured by dropping the Mg(OHh solution 13 of No.5) from the chemical spray nozzle !4 at a rate of 50 degrees/min, it showed a desulfurization rate of 88.0%.
more excreted. On the other hand, the desulfurization efficiency was 40.0% when a commercially available reaction column filler (Toyo Tire & Rubber Industries ■, Virex-200) was filled. Effect of the invention Gas absorption of the present invention? Since the reaction efficiency is high when using a chemical, it is possible to downsize the device, reduce the number of chemical solutions, and reduce costs.

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view of a three-dimensional network metal porous body, Figure 2
3 to 3 are diagrams for explaining the method for producing a metal porous body according to claim 4, and FIG. 4 is an explanatory diagram (longitudinal sectional view) of the example. 1... Steel bridge wire, 2◆... Hole, 3... Communication cavity, 4...◆Micro hole, 6... Organic polymer sphere, 7--- Cavity, 10--・Processing gas, nozzle, 15・ψ・・Formwork, 8・Adhesive, 9・・・close contact, 11・・Exhaust gas, 12・13・・chemical solution, 14・・・・chemical solution spray/porous body , 16...Medical solution drain port.

Claims (5)

[Claims] (1) Three-dimensional connected pores are formed, the porosity is 70% by volume or more, the pore diameter is 0.5-10mm, and the specific surface area is 300-300mm.
A gas absorption device comprising a three-dimensional mesh-like sintered metal porous body having a density of 2000 m^2/m^3 and a bulk specific gravity of 0.3 to 2.0, and a coating of an absorbing chemical liquid formed on at least the surface of the metal skeleton. (2) A gas absorption method characterized by passing a gas or a gas and an absorbing chemical solution through the device according to claim (1), and absorbing and removing a specific gas component in the passing gas into the absorbing gas chemical solution. . (3) Apply iron-based powder with an average particle size of 50μ or less to the skeleton of the three-dimensional network organic polymer material, dry it, heat treat it to remove the skeleton of the three-dimensional network organic polymer material, and remove the iron powder. Three-dimensional interconnected pores produced by sintering the system powder have a porosity of 70% by volume or more, a pore diameter of 0.5 to 10 mm, and a specific surface area of 5.
00~2000m^2/m^3, bulk specific gravity 0.3~2.
A gas absorption device comprising a three-dimensional mesh-like sintered metal porous body having a coating of an absorbing chemical solution formed on at least the surface of the metal skeleton. (4) A slurry containing iron-based powder with an average particle size of 50μ or less is poured into the gaps between the spheres of a large number of organic polymer spheres closely arranged in a mold, dried, and heat-treated. Three-dimensional connected pores produced by removing organic polymer spheres and sintering iron-based powder have a porosity of 70% by volume or more, a pore diameter of 0.5 to 10 mm, and a specific surface area of 300 to 2000 m ^2
/m^3 and a bulk specific gravity of 0.3 to 2.0, a three-dimensional network-like sintered metal porous body has a coating of an absorbing chemical solution formed on at least the surface of the metal skeleton. (5) The method according to claim (2), wherein the porous combustion metal body is heated by electricity or induction to control the skeleton portion to a reaction temperature.