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; a supply pipe for supplying the gas to be treated to the nozzle; a recovery pipe for collecting the gas discharged from the regeneration tower; and a variable-valve type supercharger capable of adjusting the flow rate of the gas to be treated in the supply pipe, with its turbine provided in the supply pipe and its compressor provided in the recovery pipe.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 a treatment liquid therein, a regeneration tower for recovering components to be recovered from the treatment liquid therein, 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, a supply pipe for supplying the gas to be treated to the nozzle, a recovery pipe for recovering gas discharged from the regeneration tower, and a variable valve turbocharger having a turbine in the supply pipe and a compressor in the recovery pipe, and capable of adjusting the flow rate of the gas to be treated in the supply pipe. [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 that has absorbed the target components is sent to the regeneration tower. The treatment liquid sent to the regeneration tower decomposes and releases the target components. Furthermore, the opening area of ​​the variable valve turbocharger is adjusted according to the amount of the target components supplied and the amount of the target components recovered. In this way, 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 illustrates 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, each figure is a schematic diagram and is not necessarily a precise illustration.

[0013] 1 is a diagram showing a gas treatment device 30 according to the present disclosure. Absorption tower 1 is a vertically long container that contains treatment liquid 12 inside. A nozzle 9 is provided at the bottom of absorption tower 1 for supplying the gas to be treated and injecting it into treatment liquid 12. A discharge pipe 10 is provided at the top of absorption tower 1 for discharging the gas inside 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 supplies the gas to be treated from a supply source of the gas to be treated to the nozzle 9.

[0017] A variable valve supercharger (Variable Geometry Turbo Charger: VGT) 20 is provided on the supply pipe 5 and the recovery pipe 11. An exhaust turbine 21 of the variable valve supercharger 20 is provided on the supply pipe 5, and a compressor 22 is provided on the recovery pipe 11, and a variable valve (not shown) adjusts the flow rate of the gas to be treated passing through the exhaust turbine 21.

[0018] Sensors 24, 25 for detecting the concentration of the gas to be recovered and the flow rate of the gas to be treated are provided in the supply pipe 5 and the recovery pipe 11. A control unit 23 is provided in the variable valve turbocharger 20, and controls the opening degree of the variable valve based on the detection values ​​of the sensors 24, 25.

[0019] Next, we will explain the operation of recovering the components to be recovered from the gas to be treated using gas treatment device 30, using as an example a case where 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.

[0020] The insides of the absorption tower 1 and the regeneration tower 2 are filled with isophoronediamine as a treated liquid 12. The treated liquid 12 is filled to a position higher than the upper communicating pipe 3 and lower than the opening 13 of the recovery pipe 11.

[0021] When the gas to be treated is blown from nozzle 9 through supply pipe 5 into treatment liquid 12 in absorption tower 1, the gas to be treated rises as bubbles in treatment liquid 12 in absorption tower 1, and carbon dioxide as a component to be recovered reacts with treatment liquid 12, causing solid fine particles to precipitate. Components not absorbed in treatment liquid 12 continue to rise and are discharged from discharge pipe 10 located at the top of absorption tower 1.

[0022] 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.

[0023] The fine particles precipitated in the absorption tower 1 by the reaction between isophoronediamine and carbon dioxide move together with the circulating flow of the treated liquid to the regeneration tower 2. The fine particles that move to the regeneration tower 2 decompose and release carbon dioxide, which turns into gas and rises in the treated liquid 12 to be recovered from the recovery pipe 11.

[0024] When the amount of carbon dioxide in the gas to be treated supplied from supply pipe 5 exceeds the amount of carbon dioxide recovered from recovery pipe 11, the opening area of ​​the variable valve of variable valve turbocharger 20 is reduced and at the same time the carbon dioxide in recovery pipe 11 is pressurized by compressor 22 to promote recovery. This reduces the amount of carbon dioxide supplied to absorption tower 1 and lowers the partial pressure of carbon dioxide gas in regeneration tower 2, promoting the separation and release of carbon dioxide from treatment liquid 12 in regeneration tower 2. This makes it possible to balance the amount of carbon dioxide supplied to the gas treatment device and the amount of carbon dioxide recovered from the gas treatment device, enabling carbon dioxide to be effectively recovered from the gas to be treated.

[0025] When the amount of carbon dioxide in the gas to be treated supplied from the supply pipe 5 falls to the amount of carbon dioxide recovered from the recovery pipe 11, the opening area of ​​the variable valve is opened to the maximum to continue the treatment.

[0026] 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 the gas to be treated into the treatment liquid and the component to be recovered is released from the treatment liquid.

[0027] The regeneration tower 2 may also be provided with a heating device that heats the treatment liquid 12. This can promote the decomposition and release of the components to be recovered that have been absorbed in the treatment liquid 12. The regeneration tower 2 may also be configured with a heating device provided at its top and a cooling device provided at its bottom.

[0028] As described above, by injecting the target gas into the treatment liquid from the bottom of the absorption tower, the target components 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 that has absorbed the target components is sent to the regeneration tower. The treatment liquid that moves to the regeneration tower decomposes and releases the target components. Furthermore, by adjusting the opening area of ​​the variable valve turbocharger according to the amount of target components supplied and the amount of target components recovered, the amount of target components injected into the absorption tower is reduced, and the partial pressure of the target components in the regeneration tower is lowered, facilitating the decomposition and release of the target components from the treatment liquid. Therefore, the gas treatment device disclosed herein can efficiently separate and recover target components from the target gas without increasing the size or complexity of the gas treatment device. [Industrial Applicability]

[0029] 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]

[0030] 1. Absorption tower 2 Regeneration Tower 3 Upper communication pipe 4 Lower communication pipe 5 Supply pipe 9 nozzles 10 Discharge pipe 11 Recovery pipe 12 Processing liquid 20 Variable valve turbocharger 23 Control Unit 30 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 for supplying the target gas to the nozzle; a recovery pipe for recovering the gas discharged from the regeneration tower; a variable valve turbocharger having a turbine provided in the supply pipe and a compressor provided in the recovery pipe, the variable valve turbocharger being capable of adjusting the flow rate of the gas to be treated in the supply pipe; A gas treatment device comprising:

2. The supply pipe and the recovery pipe are provided with a concentration meter and a flow meter, respectively; The variable valve turbocharger has a control unit that adjusts the opening degree of the valve based on the detection values ​​of the concentration meter and the flow meter. The gas treatment device of claim 1 .

3. The control unit When the amount of carbon dioxide supplied through the supply pipe becomes higher than the amount of carbon dioxide recovered through the recovery pipe, the opening of the valve is reduced; When the amount of carbon dioxide supplied through the supply pipe becomes equal to or less than the amount of carbon dioxide recovered through the recovery pipe, the opening degree of the valve is maximized. The gas treatment device of claim 2 .

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