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 provided with a filter and a heating device for heating the filter; an upper communication pipe for communicating the upper part of the treatment tower and the upper part of the regeneration tower with each other; a lower communication pipe for communicating the lower part of the treatment tower and the lower part of the regeneration tower with each other; a flow adjustment device for controlling a flow of the treatment liquid in the regeneration tower; and a control device for controlling the heating device and the flow adjustment device.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 the bottom for injecting the gas to be treated into the treatment liquid, a regeneration tower which has a filter and a heating device for heating the filter, an upper connecting pipe which connects the upper part of the treatment tower to the upper part of the regeneration tower, a lower connecting pipe which connects the lower part of the treatment tower to the lower part of the regeneration tower, a flow adjustment device which controls the flow of the treatment liquid in the regeneration tower, and a control device which controls the heating device and the flow adjustment device. 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 recovered gas in the gas to be treated and precipitates as a solid precipitate is placed in the treatment tower and the 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, whereupon the recovered gas reacts with the reactive component in the treatment liquid and precipitates as a solid precipitate. The treatment liquid and solid precipitate in the treatment tower are sent to the regeneration tower through the upper connecting pipe, and the solid precipitate is captured by a filter. Then, when the filter is heated, the solid precipitate is decomposed and the recovered gas is recovered. The remaining treatment liquid from which the recovered gas has been separated is returned to the bottom of the treatment tower and contacted again with the gas to be treated. In this way, there is no need to provide a device for sending the treatment liquid from the treatment tower to the regeneration tower, and the treatment device can be made smaller, and the recovered gas 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] Filters 28-1 and 28-2 are provided at the top of the regenerators 20-1 and 20-2 to capture solid precipitates in the treatment liquid flowing through the regenerators 20-1 and 20-2. In addition, the regenerators 20-1 and 20-2 are provided with a heating device (not shown) for heating the filters 28-1 and 28-2. The heating device is for thermally decomposing the solid precipitates captured by the filters 28-1 and 28-2. The heating temperature depends on the type of gas to be treated and the treatment liquid, but when carbon dioxide is precipitated as a solid precipitate by an aqueous solution of isophoronediamine, it is preferable to heat the liquid to about 60 degrees.

[0016] The upper communicating pipes 22-1, 22-2 are provided with on-off valves 30-1, 30-2 for adjusting the flow of the treatment liquid in the upper communicating pipes 22-1, 22-2. The regenerators 20-1, 20-2 are provided with pumps 32-1, 32-2 for flowing the treatment liquid in the regenerators 20-1, 20-2. The on / off of the heating device, the opening / closing of the on-off valves 30-1, 30-2, and the on / off of the pumps 32-1, 32-2 are controlled by a control device (not shown).

[0017] 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, 34-1, 34-2 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, 34-1, 34-2 are appropriately selected and used depending on the type of gas to be absorbed.

[0018] 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, 34-1, and 34-2, 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.

[0019] Moreover, by driving the pumps 32-1 and 32-2 with the on-off valves 30-1 and 30-2 open, the treatment liquid in the gas treatment device 1 is circulated through the treatment tower 10, the upper connecting pipes 22-1 and 22-2, the regenerators 20-1 and 20-2, and the lower connecting pipes 24-1 and 24-2 in this order. As a result, solid precipitates precipitated in the treatment liquid 16 are captured by the filters 28-1 and 28-2.

[0020] Next, the on-off valve 30-2 of a part of the regenerators 20-2 is closed, and the treatment liquid 34-2 in the regenerators 20-2 is discharged by the pump 32-2. Then, the filter 28-2 is heated by the heating device provided in the regenerator 20-2. As a result, the solid precipitate captured by the filter 28-2 is decomposed, and the gas to be recovered is separated and recovered from the recovery hole 26-2. At this time, it is more efficient to heat the solid precipitate in a wet state rather than completely drying it, since less heat is required for decomposition. Meanwhile, the on-off valve 30-1 of the other regenerators 20-1 remains open, and the pump 32-1 continues to be driven. Then, the gas to be treated continues to be blown into the treatment liquid 16 from the nozzle 12.

[0021] When the filter 28-2 is sufficiently heated and the solid precipitate trapped in the filter 28-2 is decomposed, the on-off valve 30-2 is opened to resume circulation of the treatment liquid. Meanwhile, the on-off valve 22-1 is closed, and the treatment liquid 34-1 in the regenerator 20-1 is discharged by the pump 32-1. Then, the filter 28-1 is heated by the heating device provided in the regenerator 20-1. As a result, the solid precipitate trapped in the filter 28-1 is decomposed, and the gas to be recovered is separated and recovered through the recovery hole 26-1.

[0022] In this way, while continuing to blow the gas to be treated into the treatment liquid 16 from the nozzle 12, in some regeneration towers the circulation of the treatment liquid is stopped and the filter is heated to recover the recovered gas, while in other regeneration towers the capture of solid precipitates in the filter continues, thereby enabling the recovered gas to be recovered efficiently.

[0023] In the above embodiment, the regenerators 20-1, 20-2 are provided around the treatment tower 10, but the number of the regenerators 20-1, 20-2 is not limited in any way. It can be changed as appropriate depending on the size of the treatment device 1 and the type of gas to be treated. In addition, the positions at which the filters 28-1, 28-2, the on-off valves 30-1, 30-2, and the pumps 32-1, 32-2 are provided can be changed as appropriate.

[0024] 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]

[0025] 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]

[0026] 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 Filter 30-1, 30―2 On-off valve 32-1, 32-2 Pump 34-1, 34-2 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 provided with a filter and a heating device for heating the filter; 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 flow control device for controlling the flow of the treatment liquid in the regeneration tower; A control device for controlling the heating device and the flow adjustment device; A gas treatment device comprising:

2. The flow control device includes an on-off valve provided in the upper communicating pipe and a pump provided in the regeneration 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 for recovering the gas to be recovered is formed at the top of the regeneration tower. The gas treatment device of claim 1 .

4. The regeneration tower is provided in plurality, The control device controls the heating device and the flow adjustment device to stop the flow of the treatment liquid in some of the regeneration towers among the plurality of regeneration towers, heat the filter provided in the regeneration tower, and flow the treatment liquid in the other regeneration towers among the plurality of regeneration towers. The gas treatment device according to any one of claims 1 to 3.

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