Gas treatment device

Abstract

To provide a gas treatment device capable of recovering a recovery target gas contained in a gas to be treated with less energy consumption.SOLUTION: A gas treatment device includes: an absorption container that accommodates a treatment liquid and in which a gas to be treated is supplied to the treatment liquid; a regeneration container to which a mixed liquid containing the treatment liquid and solid precipitates generated by a reaction between the treatment liquid and a recovery target gas contained in the gas to be treated is supplied from the absorption container, and in which the recovery target gas is separated from the solid precipitates; a connecting pipe which connects the absorption container and the regeneration container and through which the mixed liquid flows from the absorption container to the regeneration container; and a pump which sends the mixed liquid in the absorption container to the regeneration container through the connecting pipe. The regeneration container includes a solid-liquid separation mesh that separates the dropped mixed liquid into the solid precipitates and the treatment liquid, and a heating device that heats the solid-liquid separation mesh.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to gas treatment devices. [Background technology]

[0002] BACKGROUND ART Gas treatment devices that recover specific gas components (also referred to as recovered gas) contained in a gas to be treated are known (see, for example, Patent Document 1).

[0003] For example, a gas treatment device is known that includes an absorption tower, a regeneration tower, and a connecting pipe connecting them. In this gas treatment device, first, exhaust gas (an example of a gas to be treated) is brought into contact with a treatment liquid (also called an absorption liquid) in the absorption tower, and carbon dioxide (an example of a gas to be recovered) in the exhaust gas is absorbed by the treatment liquid. Next, a solid precipitate generated by the reaction between the treatment liquid and carbon dioxide and the treatment liquid are sent from the absorption tower to the regeneration tower, where they are heated. Then, carbon dioxide separated from the solid precipitate by heating is recovered. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-131735 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-described gas treatment device, since the solid precipitate and the treatment liquid are mixed in the regeneration tower, not only the solid precipitate but also the treatment liquid must be heated, which poses a problem of requiring more energy.

[0006] An object of one aspect of the present disclosure is to provide a gas treatment device that can recover a gas to be recovered from a gas to be treated using less energy. [Means for solving the problem]

[0007] A gas treatment device according to one aspect of the present disclosure includes an absorption vessel that contains a treatment liquid and into which a gas to be treated is supplied into the treatment liquid; a regeneration vessel that receives a mixed liquid containing the treatment liquid and a solid precipitate generated by a reaction between the treatment liquid and a gas to be recovered in the gas to be treated from the absorption vessel and separates the gas to be recovered from the solid precipitate; a connecting pipe that connects the absorption vessel and the regeneration vessel and through which the mixed liquid flows from the absorption vessel to the regeneration vessel; and a pump that sends the mixed liquid in the absorption vessel to the regeneration vessel via the connecting pipe. The regeneration vessel separates the mixed liquid dripped into the solid precipitate and the treatment liquid and deposits the solid precipitate while allowing the treatment liquid to fall. The regeneration vessel also includes a solid-liquid separation mesh that separates the mixed liquid dripped into the solid precipitate and the treatment liquid and deposits the solid precipitate while allowing the treatment liquid to fall, and a heating device that heats the solid-liquid separation mesh on which the solid precipitate has deposited. [Effects of the Invention]

[0008] According to the present disclosure, the gas to be recovered from the gas to be treated can be recovered with less energy. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram schematically illustrating a configuration of a gas treatment device according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a block diagram illustrating a configuration of a control device according to an embodiment of the present disclosure. [Figure 3] 1 is a flowchart illustrating the operation of a control device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0011] First, the configuration of a gas processing device 100 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram schematically showing the configuration of gas processing device 100. In Fig. 1, dotted arrows indicate the direction of gas flow, and solid arrows indicate the direction of liquid flow.

[0012] The gas treatment device 100 has, as its main components, an absorption vessel 1 and a regeneration vessel 2. In this embodiment, as shown in Fig. 1, the regeneration vessel 2 is provided above the absorption vessel 1, but the present invention is not limited to this.

[0013] The absorption vessel 1 and the regeneration vessel 2 are containers whose interiors are sealed spaces. The absorption vessel 1 may be rectangular parallelepiped, cylindrical, or other shapes. The regeneration vessel 2 is a square prism with inverted trapezoidal sides, and the cross-sectional area of ​​the horizontal plane gradually decreases from the top to the bottom, but is not limited to this shape and may be other shapes (for example, rectangular parallelepiped, cylindrical, etc.).

[0014] The absorption vessel 1 contains a treatment liquid 3 for absorbing the gas to be recovered from the gas to be treated and separating it as a solid precipitate. Note that the symbol A in Fig. 1 indicates the liquid level of the treatment liquid 3 in the absorption vessel 1.

[0015] For example, when the gas to be treated is combustion gas (exhaust gas) and the gas to be recovered is carbon dioxide, an isophoronediamine aqueous solution or a calcium hydroxide aqueous solution can be used as the treatment liquid 3. The treatment liquid 3 may be appropriately selected depending on the type of gas to be absorbed and recovered.

[0016] The supply pipe 4 is a pipe that supplies the gas to be treated from the outside into the treatment liquid 3 in the absorption vessel 1. When the gas to be treated is discharged from the supply pipe 4 into the treatment liquid 3, the gas to be recovered in the gas to be treated reacts with and is absorbed by the treatment liquid 3, causing a solid precipitate to form.

[0017] Furthermore, when the gas to be treated is discharged from the supply pipe 4 into the treatment liquid 3, a large number of bubbles (circles in the figure) are generated and rise toward the liquid surface A. The rising of these bubbles generates a water current in the treatment liquid 3.

[0018] Normally, the water flow would cause the solid precipitate to be stirred in the absorption vessel 1, making it difficult for the solid precipitate to settle at the bottom of the absorption vessel 1. However, in this embodiment, to prevent such a situation, a plate-shaped partition member 5 extending upward from the bottom is provided near the center of the absorption vessel 1.

[0019] This partition member 5 divides the inside of the absorption vessel 1 into an area on the supply pipe 4 side (the area on the left side in the drawing) and an area on the connecting pipe 6 side (referred to as the area on the right side in the drawing). As a result, the influence of the water flow caused by rising bubbles is limited to the area on the supply pipe 4 side, and is less affected in the area on the connecting pipe 6 side. Therefore, in the area on the connecting pipe 6 side, agitation of the solid precipitate is less likely to occur, and the solid precipitate is more likely to deposit at the bottom of the area on the connecting pipe 6 side by natural settling.

[0020] The connecting pipe 6 is a pipe that connects the absorption vessel 1 and the regeneration vessel 2. One end of the connecting pipe 6 is disposed at the bottom of the absorption vessel 1 (specifically, the bottom of the region on the connecting pipe 6 side). The other end of the connecting pipe 6 is disposed above a solid-liquid separation mesh 11 (details of which will be described later) in the regeneration vessel 2.

[0021] The pump 7 pumps up the treated liquid 3 containing solid precipitates (hereinafter referred to as the mixed liquid) in the absorption vessel 1 and sends it to the regeneration vessel 2. As a result, the mixed liquid in the absorption vessel 1 flows through the connecting pipe 6 and is supplied into the regeneration vessel 2. The pump 7 is, for example, an electric pump.

[0022] The discharge pipe 8 is provided at the top of the absorption vessel 1 and is a pipe for discharging the treated gas inside the absorption vessel 1 to the outside. The treated gas is a gas obtained by removing a gas to be recovered (e.g., carbon dioxide) from a gas to be treated (e.g., combustion gas).

[0023] In the regeneration vessel 2, a heater 10 and a solid-liquid separation mesh 11 are provided.

[0024] The heating device 10 is, for example, a mesh-like planar heater. One end of the heating device 10 is fixed to the inner wall of the regeneration vessel 2 (for example, below the outlet of the connecting pipe 6), and the other end is suspended in the air. The heating device 10 is also inclined so that it becomes lower from one end to the other end.

[0025] The heating device 10 heats the solid-liquid separation mesh 11 placed thereon. As will be described in detail later, the start and stop of heating by the heating device 10 is controlled by a control device 15 (see FIG. 2).

[0026] The solid-liquid separation mesh 11 is a member that separates the dropped mixed liquid into a solid precipitate and the treatment liquid 3, depositing the solid precipitate while allowing the treatment liquid 3 to fall.

[0027] For example, the solid-liquid separation mesh 11 is a planar member having a fine mesh or a rough surface. The solid-liquid separation mesh 11 can be made of a chemical-resistant and heat-resistant substance (such as stainless steel or ceramic).

[0028] As described above, the solid-liquid separation mesh 11 is placed on the heating device 10 which is inclined so as to decrease in height from one end to the other, and therefore the solid-liquid separation mesh 11 is also provided with an inclination so as to decrease in height from one end to the other, similar to the heating device 10. In addition, one end of the solid-liquid separation mesh 11 is placed below the outlet of the connecting pipe 6.

[0029] The mixed liquid discharged from the connecting pipe 6 drips onto one end of the solid-liquid separation mesh 11 and flows from one end to the other. As a result, the mixed liquid is separated into a solid precipitate and the treated liquid 3, and the solid precipitate is deposited on the solid-liquid separation mesh 11, while the treated liquid 3 falls downward into the regeneration vessel 2.

[0030] The arrangement of the solid-liquid separation mesh 11 is not limited to the arrangement on the heating device 10. For example, the solid-liquid separation mesh 11 may be suspended from the upper part of the regeneration vessel 2, supported from the lower part of the regeneration vessel 2, or fixed to the side of the regeneration vessel 2. In this case, the heating device 10 may also be of a shape and arrangement position suitable for the arrangement of the solid-liquid separation mesh 11.

[0031] Outside the regeneration vessel 2, an S-trap 12 and a tank 14 are provided.

[0032] The S-trap 12 is an S-shaped pipe. The upstream end of the S-trap 12 is connected to the bottom of the regeneration vessel 2. The downstream end of the S-trap 12 is connected to the top of the absorption vessel 1.

[0033] The treated liquid 3 that has fallen through the solid-liquid separation mesh 11 flows from the bottom of the regeneration vessel 2 into the S-trap 12 and is stored upstream of the S-trap 12 and at the bottom of the regeneration vessel 2 (not shown). When the liquid level of the treated liquid 3 stored at the bottom of the regeneration vessel 2 reaches the same height as the top of the S-trap 12 (height a in Figure 1), a siphon effect occurs and the treated liquid 3 stored in the S-trap and regeneration vessel 2 is discharged into the absorption vessel 1.

[0034] The tank 14 is a container connected to the top of the regeneration vessel 2 and has an enclosed space inside. The tank 14 contains the gas to be recovered (e.g., carbon dioxide) separated from the solid precipitate deposited on the solid-liquid separation mesh 11 when the solid-liquid separation mesh 11 is heated.

[0035] As described above, the horizontal cross section of the regeneration vessel 2 decreases from top to bottom, which reduces the liquid surface area of ​​the treatment liquid 3 stored at the bottom of the regeneration vessel 2. This reduces contact between the gas to be recovered, which is generated from the solid precipitate by heating, and the treatment liquid 3 stored at the bottom of the regeneration vessel 2.

[0036] The components of the gas treatment device 100 shown in FIG. 1 have been described above, but the gas treatment device 100 may further include a control device 15 and a deposition amount sensor 16 shown in FIG.

[0037] The configuration of the control device 15 will be described below with reference to Fig. 2. Fig. 2 is a block diagram showing the configuration of the control device 15.

[0038] Although not shown in the drawings, the control device 15 has, as hardware, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores computer programs, a RAM (Random Access Memory) that is a working memory, etc. Each unit described below is realized by the CPU reading out a computer program from the ROM and executing it in the RAM.

[0039] As shown in FIG. 2, the control device 15 is electrically connected to each of the deposition amount sensor 16 and the heating device 10.

[0040] The deposition amount sensor 16 detects the amount of deposition deposited on the solid-liquid separation mesh 11 at all times and outputs the detection result to the control device 15. Note that the deposition amount sensor 16 may be a known sensor that detects the deposition amount based on, for example, color or thickness.

[0041] As shown in FIG. 2, the control device 15 includes a determination unit 17 and a control unit 18.

[0042] The determination unit 17 determines whether or not a sufficient amount of solid precipitate has accumulated on the solid-liquid separation mesh 11. Specifically, when the amount of accumulation detected by the accumulation amount sensor 16 reaches a predetermined amount, the determination unit 17 determines that a sufficient amount of solid precipitate has accumulated on the solid-liquid separation mesh 11. The predetermined amount is set based on the results of a previously conducted experiment or simulation and is an amount suitable for separating the solid precipitate into the gas to be recovered.

[0043] The determination unit 17 may determine that the solid precipitate has been sufficiently deposited when a certain time has elapsed since the previous stopping of heating of the solid-liquid separation mesh 11. The certain time here is the time required for the solid precipitate to be sufficiently deposited, which is set based on the results of a previously conducted experiment or simulation.

[0044] The control unit 18 controls the heating device 10 to start heating when the determining unit 17 determines that a sufficient amount of solid precipitate has accumulated on the solid-liquid separation mesh 11. As a result, the solid-liquid separation mesh 11 arranged on the heating device 10 is heated, and the gas to be recovered is separated from the solid precipitate accumulated on the solid-liquid separation mesh 11. The heating temperature at this time is set based on the results of experiments or simulations carried out in advance.

[0045] The control unit 18 controls the heating device 10 to stop heating after a certain time has elapsed since the start of heating. The certain time here is set based on the results of a previously conducted experiment or simulation, and is the time required for the target gas to be separated from a sufficiently accumulated solid deposit.

[0046] Note that, when the heating starts, the control unit 18 may operate a recovery pump (not shown) capable of sending the gas to be recovered separated from the solid precipitate to the tank 14, and after a certain time has passed, stop the recovery pump together with stopping the heating. By controlling the recovery pump in this way, the separated gas to be recovered can be efficiently recovered into the tank 14.

[0047] The configuration of the control device 15 has been described above.

[0048] Next, the operation of the control device 15 will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the operation of the control device 15.

[0049] 3 starts, for example, when the supply of the gas to be treated begins into the absorption vessel 1. When the flow in FIG. 3 starts, the deposition amount sensor 16 starts outputting the detection result.

[0050] First, the determining unit 17 determines whether or not a sufficient amount of solid precipitate has accumulated on the solid-liquid separation mesh 11 based on the detection result of the accumulation amount sensor 16 (step S1).

[0051] If the solid deposits have not accumulated sufficiently (step S1 / NO), the flow returns to step S1. In this case, the determination unit 17 determines again whether the solid deposits have accumulated sufficiently based on the newly received detection result of the deposition amount sensor 16.

[0052] If a sufficient amount of solid precipitate has accumulated (step S1 / YES), the control unit 18 causes the heating device 10 to start heating (step S2).

[0053] If the certain time has not elapsed since the start of heating (step S3 / NO), heating continues.

[0054] If a certain time has elapsed since the start of heating (step S3 / YES), the control unit 18 causes the heating device 10 to stop heating (step S4).

[0055] This is the end of the flow. Note that the above flow is repeated.

[0056] The operation of the control device 15 has been described above.

[0057] As described above, the gas treatment device 100 of this embodiment comprises an absorption vessel 1 that contains a treatment liquid 3 and into which the gas to be treated is supplied into the treatment liquid 3; a regeneration vessel 2 that receives a mixed liquid containing the treatment liquid 3 and a solid precipitate generated by a reaction between the treatment liquid 3 and the gas to be recovered in the gas to be treated from the absorption vessel 1, and separates the gas to be recovered from the solid precipitate; a connecting pipe 6 that connects the absorption vessel 1 and the regeneration vessel 2 and through which the mixed liquid flows from the absorption vessel 1 to the regeneration vessel 2; and a pump 7 that sends the mixed liquid in the absorption vessel 1 to the regeneration vessel 2 via the connecting pipe 6. The regeneration vessel 2 is characterized by comprising a solid-liquid separation mesh 11 that separates the mixed liquid dripped into the solid precipitate and the treatment liquid 3 and deposits the solid precipitate while allowing the treatment liquid 3 to fall, and a heating device 10 that heats the solid-liquid separation mesh 11 on which the solid precipitate has deposited.

[0058] This feature allows the solid precipitate to be heated intensively, so that the gas to be recovered from the gas to be treated can be recovered with less energy than when the mixed liquid is heated.

[0059] The present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure. [Industrial Applicability]

[0060] The gas treatment device of the present disclosure is useful in a technique for recovering a specific gas component contained in a gas to be treated. [Explanation of symbols]

[0061] 1 Absorption container 2 Recycled container 3 Processing liquid 4 Supply pipe 5 Partition member 6 Connecting pipe 7. Pump 8 Discharge pipe 10 Heating device 11 Solid-liquid separation mesh 12 S-trap 14 Tank 15 Control device 16 Accumulation sensor 17 Judgment section 18 Control Unit 100 Gas treatment device

Claims

1. an absorption vessel containing a treatment liquid and into which the gas to be treated is supplied; a regeneration vessel to which a mixed liquid containing the treatment liquid and a solid precipitate generated by a reaction between the treatment liquid and the gas to be recovered in the gas to be treated is supplied from the absorption vessel, and which separates the gas to be recovered from the solid precipitate; a connecting pipe connecting the absorption vessel and the regeneration vessel, through which the mixed liquid flows from the absorption vessel to the regeneration vessel; a pump that sends the mixed liquid in the absorption vessel to the regeneration vessel through the connecting pipe, The regeneration container is a solid-liquid separation mesh that separates the dropped mixed liquid into the solid precipitate and the treatment liquid, and deposits the solid precipitate while allowing the treatment liquid to fall; a heating device that heats the solid-liquid separation mesh on which the solid precipitate has accumulated, Gas treatment equipment.

2. The regeneration vessel is disposed above the absorption vessel, One end of the connecting pipe is disposed at the bottom of the absorption vessel, the other end of the connecting pipe is disposed above the solid-liquid separation mesh in the regeneration vessel, an S-trap having an upstream end connected to the bottom of the regeneration vessel and a downstream end connected to the top of the absorption vessel; a tank connected to an upper portion of the regeneration vessel and configured to accommodate the recovered gas separated from the solid precipitate; The gas treatment device of claim 1 .

3. The treatment liquid that has fallen through the solid-liquid separation mesh is stored on the upstream side of the S-trap and at the bottom of the regeneration container, When the liquid level of the treatment liquid stored at the bottom of the regeneration container reaches the same height as the top of the S-trap, a siphon phenomenon occurs, and the treatment liquid stored in each of the S-trap and the regeneration container is discharged into the absorption container. The gas treatment device of claim 2 .

4. Further, a control device for controlling the heating device is provided. The control device when the amount of the solid precipitate deposited on the solid-liquid separation mesh reaches a predetermined amount, the heating device starts heating the solid-liquid separation mesh; The gas treatment device of claim 1 .

5. The solid-liquid separation mesh is provided with an inclination that decreases from one end, where the mixed liquid is dropped, to the other end. The gas treatment device of claim 1 .

6. The regeneration container has a horizontal cross-sectional area that gradually decreases from the top to the bottom. The gas treatment device of claim 1 .

7. The treatment liquid is an aqueous solution of isophoronediamine. The gas treatment device of claim 1 .

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