Gas treatment equipment

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 heating device; and a communication pipe which communicates the lower part of the treatment tower and the lower part of the regeneration tower with each other, and is inclined in such a way that it becomes lower from the treatment tower side toward the regeneration tower.SELECTED DRAWING: Figure 1

Description

Technical Field

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

[0002] Since carbon dioxide is a greenhouse gas that causes global warming, technologies for separating and recovering carbon dioxide from combustion gas and the like have been researched. Patent Document 1 discloses a carbon dioxide gas recovery apparatus in which a target processing gas is brought into contact with a lean absorption liquid capable of absorbing carbon dioxide gas in an absorption tower, the carbon dioxide gas in the target processing gas is absorbed into the lean absorption liquid to generate a rich absorption liquid, and the rich absorption liquid is heated in a regeneration tower to separate and recover carbon dioxide as a gas.

[0003] In the above apparatus, an aqueous solution such as isopropaminoethanol is used as the absorption liquid. When the target processing gas is brought into contact with the absorption liquid in the absorption tower, carbon dioxide gas is selectively absorbed by the absorption liquid to form a rich absorption liquid. Subsequently, when the rich absorption liquid is heated in the regeneration tower, carbon dioxide in the rich absorption liquid is separated as a gas, and the separated carbon dioxide gas is recovered.

[0004] Further, as processing liquids that absorb carbon dioxide from the target processing gas and separate it as solid precipitates, there are isophoronediamine and aqueous calcium hydroxide solution. When these processing liquids are used, it is conceivable to separate carbon dioxide as solid precipitates, heat and decompose the solid precipitates by batch processing, and recover carbon dioxide gas. Prior Art Documents Patent Documents

[0005] Patent Document 1 Japanese Unexamined Patent Publication No. 2015-131735 Summary of the Invention Problems to be Solved by the Invention

[0006] In the technology described in Patent Document 1 above, since carbon dioxide is absorbed into the lean absorbent, it is necessary to send all of the rich absorbent containing the absorbent carbon dioxide to a regeneration tower, heat it, and separate the carbon dioxide. This leads to problems such as the absorption tower and regeneration tower becoming large and the equipment becoming complex. There is also the problem that a lot of energy is consumed in moving and heating the rich and lean absorbent.

[0007] Furthermore, while miniaturization of processing equipment is expected when separating carbon dioxide as a solid precipitate, there are challenges in improving processing efficiency because the decomposition of the solid precipitate is done in batches.

[0008] The purpose of this disclosure is to provide a gas treatment apparatus that has a simple structure and efficiently separates and recovers the gas to be recovered from the gas to be treated with little energy. [Means for solving the problem]

[0009] The gas processing apparatus described herein is It contains reactive components that react with the gas to be recovered in the treated gas and precipitate as solid deposits. The apparatus comprises a processing tower having a processing liquid, a nozzle at the bottom for blowing the gas to be processed into the processing liquid, and a discharge port at the top for discharging the processed gas; a regeneration tower having a heating device and a recovery port at the top for recovering the recovered gas; and a connecting pipe connecting the lower part of the processing tower and the lower part of the regeneration tower, which is inclined to become lower from the processing tower side to the regeneration tower side. Furthermore, a flow straightening plate is provided on the inner surface of the regeneration tower, at a position that covers the connection portion between the communication pipe and the regeneration tower from above, and which protrudes into the regeneration tower. [Effects of the Invention]

[0010] According to the gas treatment apparatus of this 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 introduced into a treatment tower and a regeneration tower. When the gas to be treated is blown into the treatment liquid from a nozzle and brought into contact with the gas to be treated, the gas to be recovered reacts with the reactive component in the treatment liquid and precipitates as a solid precipitate. The solid precipitate settles in the treatment liquid and moves by gravity through a connecting pipe to the regeneration tower. When the solid precipitate that has moved to the regeneration tower is heated by a heating device, it decomposes and the gas to be recovered is separated and recovered as a gas. The concentration of the treatment liquid in the treatment tower and the concentration of the treatment liquid in the regeneration tower are maintained in equilibrium by convection, etc. Since the solid precipitate moves to the regeneration tower by gravity, there is no need to provide a device to send the treatment liquid from the treatment tower to the regeneration tower, the treatment apparatus can be made smaller, and the gas to be recovered can be separated and recovered continuously with energy efficiency. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of a gas treatment device. [Figure 2] This is a schematic diagram showing a modified gas treatment device. [Modes for carrying out the invention]

[0012] Embodiments of the present disclosure will be described below with reference to the drawings. Figure 1 is a schematic diagram showing an example of a gas treatment apparatus 1 of the present disclosure. The gas treatment apparatus 1 includes a treatment tower 10, a regeneration tower 20, and a connecting pipe 30 that connects the lower parts of the treatment tower 10 and the regeneration tower 20.

[0013] The processing tower 10 is a roughly cylindrical container capable of containing the processing liquid 18, and has an outlet 12 at its top for discharging the processed gas. The bottom wall 14 of the processing tower 10 slopes downward towards the area where the connecting pipe 30, described later, is connected.

[0014] A nozzle 16 is provided at the bottom of the processing tower 10 for injecting the gas to be processed, such as exhaust gas, into the processing tower 10. The nozzle 16 is configured to inject the gas to be processed from numerous small holes so that the gas to be processed is injected as fine bubbles.

[0015] The regeneration tower 20 is a roughly cylindrical container capable of containing the processing liquid 26 inside, and a recovery hole 22 is formed at the top for discharging and recovering the recovered gas separated from the processing liquid. The bottom wall 24 of the regeneration tower 20 is formed to be roughly flat so that solid precipitates moving through the connecting pipe 30, which will be described later, can accumulate there.

[0016] A heating device (not shown) is provided above the regeneration tower 20. The heating device is for thermally decomposing the precipitated solid material. The heating temperature depends on the type of gas and liquid being treated, but when carbon dioxide is precipitated as a solid material by an aqueous solution of isophorone diamine, it is preferable to heat to approximately 60 degrees Celsius.

[0017] A connecting pipe 30 is connected to the lower part of the processing tower 10 and the regeneration tower 20, connecting the inside of the processing tower 10 and the inside of the regeneration tower 20. The connecting pipe 30 is inclined so that the regeneration tower 20 side is lower, so that solid precipitates that fall onto the bottom wall 14 of the processing tower 10 enter the connecting pipe 30 due to the slope of the bottom wall 14 and then move onto the bottom wall 24 of the regeneration tower 20 due to gravity. In addition, if there is a difference in concentration between the processing liquid 18 in the processing tower 10 and the processing liquid 26 in the regeneration tower 20, the connecting pipe 30 is formed to a predetermined diameter so that the processing liquid flows between the processing tower 10 and the regeneration tower 20 by convection or other means, and the concentration becomes uniform.

[0018] The processing tower 10, the regeneration tower 20, and the connecting pipe 30 are filled with processing liquids 18 and 26 for absorbing the gas to be recovered from the gas to be processed and separating it as a solid precipitate. When the gas to be processed is combustion gas and the gas to be recovered is carbon dioxide, isophorone diamine or an aqueous solution of calcium hydroxide can be used as the processing liquid. The processing liquids 18 and 26 are appropriately selected and used depending on the type of gas to be recovered to be absorbed.

[0019] Next, the operation of the gas treatment device 1 will be described. With the treatment tower 10, the regeneration tower 20 and the communication pipe 30 filled with the treatment liquid, the gas to be treated is blown into the treatment liquid 18 from the nozzle 16. Among the blown-in gas to be treated, the gas to be recovered reacts with the treatment liquid, is absorbed, and precipitates as a solid precipitate.

[0020] The solid precipitate precipitates in the treatment tower 10, is guided into the communication pipe 30 along the slope of the bottom wall 14 by gravity, enters the communication pipe 30, and moves onto the bottom wall 24 of the regeneration tower 20. The movement of the solid precipitate is carried out by its own weight without external action such as by a pump.

[0021] In the regeneration tower 20, the solid precipitate precipitated at the bottom is heated by a heating device not shown in the figure. When the heating device heats the upper part of the treatment liquid 26 in the regeneration tower 20, the treatment liquid 26 flows, and the heated treatment liquid 26 rolls up the solid precipitate on the bottom wall 24 of the regeneration tower 20 while heating it. The heated solid precipitate decomposes, and the gas to be recovered is collected as gas above the regeneration tower 20 and recovered from the recovery hole 22.

[0022] As the treatment proceeds, the concentration of the treatment liquid 18 in the treatment tower 10 decreases, and the concentration of the treatment liquid 26 in the regeneration tower 20 increases. However, the treatment liquid 18 in the treatment tower 10 flows due to the blowing of the gas to be treated, and the treatment liquid 26 in the regeneration tower 20 flows due to heating respectively, so the overall concentration is maintained substantially uniform. Therefore, the gas to be treated can be blown continuously, and the gas to be recovered can be recovered continuously.

[0023] Figure 2 shows a modified example of the gas treatment device 1'. The same members are denoted by the same reference numerals, and detailed description thereof is omitted. In this example, a flow straightening plate 28 protruding into the regeneration tower 20 is formed at the upper part of the connection portion with the communication pipe 30 on the inner surface of the regeneration tower 20. Since the solid precipitate precipitated in the treatment tower 10 is very fine particles, the solid precipitate in the communication pipe 30 may be stirred and pushed back by the flow of the treatment liquid 26 in the regeneration tower 20. However, providing the flow straightening plate 28 can prevent the solid precipitate from being stirred.

[0024] The gas treatment apparatus of this disclosure is not limited in any way to the gas to be treated or the gas to be recovered, as long as it can separate the gas to be recovered as a solid precipitate using a treatment liquid, in addition to separating carbon dioxide from exhaust gas. [Industrial applicability]

[0025] This method is particularly suitable for separating and recovering the gas to be recovered from the gas to be treated. [Explanation of symbols]

[0026] 10 Processing Towers 12 Discharge hole 14 Bottom wall 16 nozzles 18 Treatment solution 20 Regeneration Tower 22 Recovery holes 24 Bottom wall 26 Processing solution 28 Rectifier plate 30 Communication pipe

Claims

1. A treatment tower comprising a treatment liquid containing a reaction component that reacts with the gas to be recovered in the gas to be treated and precipitates as a solid precipitate, a nozzle for blowing the gas to be treated into the treatment liquid provided at the bottom, and a discharge hole formed at the top for discharging the treated gas, A regeneration tower is provided with a heating device and has a recovery port formed at the top for recovering the gas to be recovered, A connecting pipe is provided that connects the lower part of the processing tower and the lower part of the regeneration tower, and is inclined to become lower from the processing tower side to the regeneration tower side. It has, A flow straightening plate is provided on the inner surface of the regeneration tower, at a position that covers the connection portion between the communication pipe and the regeneration tower from above, and which protrudes into the regeneration tower. Gas treatment device.

2. The bottom wall of the processing tower is sloped downwards toward the connection point with the connecting pipe. The gas treatment apparatus according to claim 1.

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