Gas treatment apparatus

Abstract

To provide a gas treatment apparatus which efficiently separates and recovers recovered gas in treatment in a gas to be treated with less energy by a simple structure.SOLUTION: A gas treatment apparatus has: a treatment tower which stores a treatment liquid, and has a nozzle for blowing a gas to be treated into the treatment liquid provided on its lower part; a regeneration tower which has a heating device provided on its upper part, and a cooling device provided on its lower part; an upper communication pipe for communicating the upper part of the treatment tower and the upper part of the regeneration tower with each other; and a lower communication pipe for communicating the lower part of the treatment tower and the lower part of the regeneration tower with each other.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 "gas to be recovered") from a gas to be treated such as exhaust gas. [Background technology]

[0002] Carbon dioxide is a greenhouse gas that causes global warming, and therefore research is being conducted into techniques for separating and recovering carbon dioxide from combustion gases, etc. Patent Document 1 discloses a carbon dioxide gas recovery device that brings a gas to be treated into contact with a lean absorbing solution 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 absorbing solution to generate a rich absorbing solution, and heats the rich absorbing solution in a regeneration tower to separate and recover carbon dioxide as a gas.

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

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

[0005] [Patent Document 1] JP 2015-131735 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the technology described in the above Patent Document 1, since carbon dioxide is absorbed in the lean absorbing solution, it is necessary to send all of the rich absorbing solution that has absorbed carbon dioxide to a regenerator and heat it to separate the carbon dioxide, which causes problems such as the increase in size of the absorption tower and the regenerator, and the complexity of the equipment. There is also a problem that a lot of energy is consumed to move and heat the rich absorbing solution and the lean absorbing solution.

[0007] Furthermore, when carbon dioxide is separated as a solid precipitate, it is expected that the treatment device will be made 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 a gas to be recovered from a gas to be treated efficiently with little energy. [Means for solving the problem]

[0009] The gas treatment device of the present disclosure comprises a treatment tower which contains a treatment liquid and has a nozzle at its lower part for injecting a gas to be treated into the treatment liquid, a regeneration tower which has a heating device at its upper part and a cooling device at its lower part, an upper connecting pipe which connects the upper part of the treatment tower with the upper part of the regeneration tower, and a lower connecting pipe which connects the lower part of the treatment tower with the lower part of the regeneration tower. Effect of the Invention

[0010] According to the gas treatment device of the present disclosure, a treatment liquid containing a reactive component that reacts with the gas to be recovered in the gas to be treated and precipitates as a solid precipitate is placed in a treatment tower and a regeneration tower, and the gas to be treated is blown into the treatment liquid from a nozzle to bring the gas to be treated into contact with the treatment liquid, whereby the gas to be treated reacts with the reactive component in the treatment liquid and precipitates as a solid precipitate. A circulation flow is generated in the treatment liquid in the treatment tower and regeneration tower, which rises in the treatment tower due to the rise of bubbles of the gas to be treated blown from the nozzle, moves into the regeneration tower through the upper connecting pipe, descends in the regeneration tower, and returns to the bottom of the treatment tower through the lower connecting pipe. When the solid precipitate precipitated in the treatment liquid reaches the top of the regeneration tower on the flow of the treatment liquid, it is decomposed by heating of the heating device, and the gas to be recovered is separated and recovered. The remaining treatment liquid from which the gas to be recovered is separated is cooled in the bottom of the regeneration tower and returned to the bottom of the treatment tower, where it is contacted again with the gas to be treated. In this way, there is no need to provide a device for transferring the treatment liquid from the treatment tower to the regeneration tower, the treatment device can be made compact, and the gas to be recovered can be separated and recovered continuously with high energy efficiency. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a schematic diagram showing a gas treatment device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram showing an example of a gas treatment device 1 of the present disclosure. The gas treatment device 1 has a treatment tower 10, regenerators 20-1 and 20-2, upper communication pipes 22-1 and 22-2 that communicate the treatment tower 10 with the upper parts of the regenerators 20-1 and 20-2, and lower communication pipes 24-1 and 24-2 that communicate the treatment tower 10 with the lower parts of the regenerators 20-1 and 20-2.

[0013] A nozzle 12 is provided at the bottom of the treatment tower 10 for blowing the gas to be treated, such as exhaust gas, into the treatment tower 10. The nozzle 12 has an injection hole configured to inject the gas to be treated from a large number of small holes so that the gas to be treated is blown in as fine bubbles.

[0014] An exhaust hole 14 is formed at the top of the treatment tower 10 to discharge the treated gas, and recovery holes 26-1 and 26-2 are formed at the top of the regeneration towers 20-1 and 20-2 to discharge and recover the separated recovery gas.

[0015] Heating devices 28-1 and 28-2 are provided at the connection parts of the upper connecting pipes 22-1 and 22-2 at the top of the regeneration towers 20-1 and 20-2, and cooling devices 30-1 and 30-2 are provided at the bottom of the regeneration towers 20-1 and 20-2. The heating devices 28-1 and 28-2 are for thermally decomposing the precipitated solid matter. The heating temperature depends on the type of gas to be treated and the type of treatment liquid, but when carbon dioxide is precipitated as a solid matter by an aqueous solution of isophoronediamine, it is preferable to heat to about 60 degrees.

[0016] The treatment tower 10, the regeneration towers 20-1, 20-2, the upper connecting pipes 22-1, 22-2, and the lower connecting pipes 24-1, 24-2 are filled with treatment liquids 16, 32-1, 32-2 for absorbing the gas to be recovered from the gas to be treated and separating it as a solid precipitate. When the gas to be treated is a combustion gas and the gas to be recovered is carbon dioxide, isophoronediamine or an aqueous calcium hydroxide solution can be used as the treatment liquid. The treatment liquids 16, 32-1, 32-2 are appropriately selected and used depending on the type of gas to be absorbed.

[0017] Next, the operation of the gas treatment device 1 will be described. With the treatment tower 10, the regenerators 20-1 and 20-2, the upper communicating pipes 22-1 and 22-2, and the lower communicating pipes 24-1 and 24-2 filled with the treatment liquids 16, 32-1, and 32-2, the gas to be treated is blown into the treatment liquid 16 from the nozzle 12. Of the gas to be treated that has been blown in, the gas to be recovered reacts with the treatment liquid and precipitates as a solid precipitate.

[0018] When the gas to be treated is blown into the treatment liquid 16, bubbles of the gas to be treated rise in the treatment liquid 16, causing a circulation flow to be generated in the treatment liquids 16, 32-1, and 32-2, which rises in the treatment tower 10, passes through the upper connecting pipes 22-1 and 22-2 from the top of the treatment tower 10 to the top of the regenerators 20-1 and 20-2, and then descends through the regenerators 20-1 and 20-2 to the bottom of the treatment tower 10 through the lower connecting pipes 24-1 and 24-2. The solid precipitates precipitated in the treatment liquid 16 ride on the circulation flow of the treatment liquids 16, 32-1, and 32-2 to the top of the regenerators 20-1 and 20-2, and are heated by the heating devices 28-1 and 28-2. The heated solid precipitates are decomposed, and the gas to be recovered is separated and recovered from the recovery holes 26-1 and 26-2.

[0019] The treated liquids 32-1, 32-2 from which the recovered gas has been separated descend within the regeneration towers 20-1, 20-2, are cooled by cooling devices 30-1, 30-2, pass through the lower connecting pipes 24-1, 24-2 to reach the bottom of the treatment tower 10, and are again brought into contact with the gas to be treated, thereby continuously recovering the recovered gas.

[0020] In the above embodiment, the regenerators 20-1 and 20-2 are provided around the treatment tower 10, but the number of the regenerators 20-1 and 20-2 is not limited in any way. It can be changed appropriately depending on the size of the treatment device 1, the type of gas to be treated, etc.

[0021] The gas treatment device of the present disclosure is not limited in any way to the gas to be treated or the recovered gas to be separated, so long as it can separate the recovered gas as a solid precipitate using a treatment liquid, in addition to separating carbon dioxide from exhaust gas. [Industrial Applicability]

[0022] This is suitably applicable to cases where a gas to be recovered is separated from a gas to be treated and recovered. [Explanation of symbols]

[0023] 10 Processing Tower 12 Nozzles 14 Discharge hole 16 Processing fluid 20-1, 20-2 Regeneration Tower 22-1, 22-2 Upper communication pipe 24-1, 24-2 Lower communication pipe 26-1, 26-2 Recovery holes 28-1, 28-2 Heating device 30-1, 30-2 Cooling device 32-1, 32-2 Processing solution

Claims

1. a treatment tower containing a treatment liquid and having a nozzle at its lower part for blowing the gas to be treated into the treatment liquid; a regeneration tower having a heating device at its upper portion and a cooling device at its lower portion; an upper communicating pipe communicating an upper portion of the treatment tower with an upper portion of the regeneration tower; a lower connecting pipe connecting a lower part of the treatment tower and a lower part of the regeneration tower; A gas treatment device comprising:

2. The regeneration tower is provided in plurality around the treatment tower. The gas treatment device of claim 1 .

3. a discharge hole for discharging the treated gas is formed at the top of the treatment tower; A recovery hole is formed at the top of the regeneration tower to recover the gas to be recovered separated from the gas to be treated. The gas treatment device according to claim 1 or 2.

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