Gas treatment apparatus

Abstract

To provide a gas treatment apparatus which has a simple structure and is capable of efficiently separating and collecting a component to be collected in a gas to be treated with less energy.SOLUTION: A gas treatment apparatus includes: an absorption tower with a nozzle provided in a bottom part for blowing a gas to be treated into a processing liquid inside the tower; a regeneration tower for collecting a component to be treated from the processing liquid inside the tower; a top communication pipe for making a top part of the absorption tower communicate with a top part of the regeneration tower; a bottom communication pipe for making a bottom part of the absorption tower communicate with a bottom part of the regeneration tower; and a supply pipe that is provided to be capable of exchanging heat with the processing liquid inside the regeneration tower and supplies the gas to be treated to the nozzle.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an apparatus for separating and recovering specific gas components such as carbon dioxide (hereinafter referred to as "recovered components") from a gas to be treated such as an exhaust gas. [Background technology]

[0002] Carbon dioxide is a greenhouse gas that causes global warming, and therefore research is being conducted into technologies for separating and capturing carbon dioxide from combustion gases, etc. Patent Document 1 discloses a carbon dioxide gas capture device that brings a gas to be treated into contact with a lean absorbent capable of absorbing carbon dioxide gas in an absorption tower, causes the carbon dioxide gas in the gas to be treated to be absorbed by the lean absorbent to produce a rich absorbent, and heats the rich absorbent in a regeneration tower to separate and capture the carbon dioxide as a gas.

[0003] In the above-mentioned device, an aqueous solution of isopropanol or the like is used as an absorbent, and when the gas to be treated is brought into contact with the absorbent in the absorption tower, carbon dioxide gas is selectively absorbed into the absorbent to form a rich absorbent. Next, when this rich absorbent is heated in the regeneration tower, the carbon dioxide in the rich absorbent is separated as a gas, and this separated carbon dioxide gas is recovered.

[0004] Furthermore, examples of treatment liquids that absorb carbon dioxide from the gas to be treated and separate it as a solid precipitate include isophoronediamine and calcium hydroxide aqueous solution. When using these treatment liquids, it is possible to separate the carbon dioxide as a solid precipitate, heat the solid precipitate in a batch process to decompose it, and recover the carbon dioxide gas. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-131735 Summary of the Invention [Problem to be solved by the invention]

[0006] In the technology described in Patent Document 1, carbon dioxide is absorbed in the lean absorbent, so all of the rich absorbent that has absorbed carbon dioxide must be sent to a regeneration tower and heated to separate the carbon dioxide, which results in problems such as the increase in size of the absorption tower and regeneration tower, making the equipment complex, and there is also the problem that a lot of energy is consumed to move and heat the rich absorbent and lean absorbent.

[0007] Furthermore, when carbon dioxide is separated as a solid precipitate, it is expected that the treatment equipment will be smaller, but since the decomposition of the solid precipitate is carried out in a batch process, there is a problem in improving the efficiency of the treatment.

[0008] An object of the present disclosure is to provide a gas treatment device that has a simple structure and that separates and recovers components to be recovered in a gas to be treated efficiently using little energy. [Means for solving the problem]

[0009] The gas treatment device of the present disclosure includes an absorption tower having a nozzle at the bottom for injecting a gas to be treated into the treatment liquid inside, a regeneration tower for recovering components to be recovered from the treatment liquid inside, an upper connecting pipe connecting the upper part of the absorption tower with the upper part of the regeneration tower, a lower connecting pipe connecting the lower part of the absorption tower with the lower part of the regeneration tower, and a supply pipe arranged to be able to exchange heat with the treatment liquid inside the regeneration tower and for supplying the gas to be treated to the nozzle. [Effects of the Invention]

[0010] According to the gas treatment device disclosed herein, the target gas is injected into the treatment liquid from the bottom of the absorption tower, whereby the components to be recovered are absorbed into the treatment liquid. Furthermore, a circulating flow is generated in the treatment liquid, as it is drawn by the bubbles of the target gas rising through the treatment liquid, and the treatment liquid with the absorbed components is sent to the regeneration tower. Furthermore, heat exchange between the target gas and the treatment liquid warms the treatment liquid in the regeneration tower and cools the target gas, promoting the release of the target components through decomposition of the treatment liquid in the regeneration tower and promoting the absorption of the target gas into the treatment liquid in the absorption tower. Therefore, the target components can be efficiently separated and recovered from the target gas without increasing the size or complexity of the gas treatment device. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of a gas treatment device of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. Therefore, the components, the arrangement and connection of each component, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not recited in independent claims will be described as optional components. Furthermore, the drawings are schematic diagrams and are not necessarily precise illustrations.

[0013] 1 is a diagram showing a gas treatment device 20 according to the present disclosure. The absorption tower 1 is a vertically long container that contains a treatment liquid 12 inside. A nozzle 9 is provided at the bottom of the absorption tower 1 for supplying a gas to be treated and injecting it into the treatment liquid 12. A discharge pipe 10 is provided at the top of the absorption tower 1 for discharging the gas inside the absorption tower 1.

[0014] The regenerator 2 is a vertically long container similar to the absorption tower 1, and contains a treatment liquid 12 inside. A recovery pipe 11 for recovering gas inside the regenerator 2 is provided at the top of the regenerator 2.

[0015] The upper part of the absorption tower 1 and the upper part of the regeneration tower 2 are connected by an upper connecting pipe 3. The lower part of the absorption tower 1 and the lower part of the regeneration tower 2 are connected by a lower connecting pipe 4. The diameters of the upper connecting pipe 3 and the lower connecting pipe 4 are designed to allow the treated liquid to flow smoothly through their interiors.

[0016] A supply pipe 5 for supplying the gas to be treated is connected to the nozzle 9. The supply pipe 5 has a supply section 6 to which the gas to be treated is supplied from a supply source of the gas to be treated (not shown), a heat exchange section 7 for exchanging heat with the treatment liquid 12 in the regenerator 2, and a connection section 8 for supplying the gas to be treated after heat exchange to the nozzle 9. The heat exchange section 7 is provided in a spiral shape in close contact with the outer peripheral surface of the regenerator 2.

[0017] Next, we will explain the operation of recovering the components to be recovered from the gas to be treated using gas treatment device 20, using an example in which the gas to be treated is exhaust gas such as combustion gas, the component to be recovered is carbon dioxide, and the treatment liquid is isophoronediamine.

[0018] The absorber 1 and the regenerator 2 are filled with isophoronediamine as a treated liquid 12. The treated liquid 12 is filled up to the height between the upper communicating pipe 3 and the recovery pipe 11. The temperature of the treated liquid 12 in the absorber 1 is, for example, room temperature (20 to 25°C).

[0019] When high-temperature exhaust gas is supplied as the gas to be treated from supply unit 6, heat exchange takes place between heat exchange unit 7 and regeneration tower 2, cooling the gas to be treated and warming the treatment liquid 12 in regeneration tower 2. This heat exchange causes the temperature of treatment liquid 12 in the upper part of regeneration tower 2 to reach, for example, 60 to 70°C. The gas to be treated then passes through connecting unit 8 and is blown into treatment liquid 12 in absorption tower 1 from nozzle 9.

[0020] As the gas to be treated rises as bubbles in the treatment liquid 12 inside the absorption tower 1, carbon dioxide as a component to be recovered reacts with the treatment liquid 12, causing solid fine particles to precipitate. At this time, the gas to be treated is cooled by heat exchange, which promotes the reaction with the treatment liquid 12. Components that are not absorbed by the treatment liquid 12 continue to rise and are discharged from the discharge pipe 10 located at the top of the absorption tower 1.

[0021] When the gas to be treated turns into bubbles and rises in the treatment liquid 12, an upward flow is generated in the treatment liquid 12 in the absorption tower 1, as if being pulled by the flow of the bubbles. This flow generates a circulation flow in the treatment liquid 12, which rises in the absorption tower 1, moves to the top of the regeneration tower 2 through the upper communicating pipe 3, descends in the regeneration tower 2, and moves to the bottom of the absorption tower 1 through the lower communicating pipe 4.

[0022] The fine particles precipitated in the absorption tower 1 by the reaction between isophoronediamine and carbon dioxide move to the regeneration tower 2 together with the circulating flow of the treated liquid. The treated liquid that moves to the regeneration tower 2 is heated by the heat exchanger 7, and when the treated liquid 12 is heated, the fine particles contained therein are also heated. This heating causes the fine particles to decompose and release carbon dioxide, which turns into gas and rises in the treated liquid 12 to be recovered from the recovery pipe 11.

[0023] Next, a modified example of the gas treatment device of the present disclosure will be described. In the above example, the heat exchanger 7 of the supply pipe 5 is spirally provided on the outer circumferential surface of the regenerator 2. However, the supply pipe 5 may be configured so that a portion thereof passes through the interior of the regenerator 2, and the heat exchanger 7 may be provided inside the regenerator 2. With this structure, the treatment liquid 12 comes into direct contact with the outer surface of the heat exchanger 7, thereby efficiently transferring heat from the gas to be treated to the treatment liquid 12.

[0024] In the above example, the gas to be treated is an exhaust gas such as a combustion gas, the component to be recovered is carbon dioxide, and the treatment liquid is isophoronediamine, but the types of the gas to be treated, the component to be recovered, and the treatment liquid are not limited to these. In other words, the present invention can be applied to various cases as long as the component to be recovered is separated from a high-temperature gas to be treated into a treatment liquid and the component to be recovered is released by heating the treatment liquid.

[0025] As described above, by injecting the target gas into the treatment liquid from the bottom of the absorption tower, the components to be recovered are absorbed into the treatment liquid. Furthermore, a circulating flow is generated in the treatment liquid, as it is drawn by the bubbles of the target gas rising through the treatment liquid. The treatment liquid with the absorbed components is then sent to the regeneration tower. Furthermore, heat exchange between the target gas and the treatment liquid warms the treatment liquid in the regeneration tower and cools the target gas, promoting the release of the target components through decomposition of the treatment liquid in the regeneration tower and facilitating the absorption of the target gas into the treatment liquid in the absorption tower. Therefore, the target components can be efficiently separated and recovered from the target gas without increasing the size or complexity of the gas treatment equipment. [Industrial Applicability]

[0026] The present invention can be suitably applied to applications in which a predetermined component is separated and recovered from a gas to be treated. [Explanation of symbols]

[0027] 1. Absorption tower 2 Regeneration Tower 3 Upper communication pipe 4 Lower communication pipe 5 Supply pipe 6 Supply section 7 Heat exchange section 8 Connecting part 9 nozzles 10 Discharge pipe 11 Recovery pipe 12 Processing liquid 20 Gas treatment equipment

Claims

1. an absorption tower having a nozzle at the bottom for blowing the gas to be treated into the treatment liquid inside; a regeneration tower that recovers components to be recovered from the treated liquid therein; an upper communication pipe communicating an upper portion of the absorption tower with an upper portion of the regeneration tower; a lower communication pipe that communicates a lower portion of the absorption tower with a lower portion of the regeneration tower; a supply pipe that is provided to be capable of heat exchange with the treatment liquid in the regeneration tower and that supplies the gas to be treated to the nozzle; A gas treatment device comprising:

2. The supply pipe is provided on the outer peripheral surface of the regeneration tower. The gas treatment device of claim 1 .

3. The supply pipe is spirally provided on the outer circumferential surface of the regeneration tower. The gas treatment device of claim 1 .

4. The supply pipe is provided so as to pass through the inside of the regeneration tower. The gas treatment device of claim 1 .

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