JP2020082017A - Carbon dioxide recovery system and operation method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carbon dioxide recovery system capable of reducing an absorption liquid component accompanying a gas to be treated from which carbon dioxide has been removed by an absorption tower. According to one embodiment, in a carbon dioxide recovery system, a gas to be treated containing carbon dioxide and an absorbing liquid are brought into contact with each other, and the absorbing liquid that has absorbed the carbon dioxide and the carbon dioxide are removed. It is provided with an absorption tower that discharges the absorption tower exhaust gas including the gas to be treated. Further, the system is a regeneration tower that dissipates the carbon dioxide from the absorption liquid discharged from the absorption tower, and discharges the absorption liquid that has released the carbon dioxide and the regeneration tower exhaust gas containing the carbon dioxide. To prepare for. Further, the system injects a cleaning liquid onto the absorption tower exhaust gas passing member having at least one hole through which the absorption tower exhaust gas passes and the absorption tower exhaust gas passing through the holes to absorb the absorption. It is provided with a cleaning unit including an injection unit for cleaning the tower exhaust gas with the cleaning liquid. [Selection diagram] Fig. 1

Description

Embodiments of the present invention relate to a carbon dioxide recovery system and a method for operating the same.

In recent years, carbon dioxide capture and storage (CCS) technology has been attracting attention as an effective countermeasure against global warming. For example, a carbon dioxide recovery system that recovers carbon dioxide in a process exhaust gas (gas to be treated) generated from an exhaust gas discharge facility such as a thermal power plant, a steel plant, a refuse incinerator, and a manufacturing facility by an absorption liquid is being considered. ..
In the carbon dioxide recovery system, the absorption liquid absorbs carbon dioxide in the gas to be treated in the absorption tower. However, when the gas to be treated from which carbon dioxide has been removed is discharged from the absorption tower, there is a problem that the gas to be treated accompanies the absorbing liquid component.

JP, 2008-1086, A

Therefore, it is an object of an embodiment of the present invention to provide a carbon dioxide recovery system and an operating method thereof capable of reducing the absorption liquid component accompanying the gas to be treated from which carbon dioxide has been removed by the absorption tower. ..

According to one embodiment, the carbon dioxide recovery system is a method in which a gas to be treated containing carbon dioxide and an absorbing liquid are brought into contact with each other, and the absorbing liquid absorbing the carbon dioxide and the treating target from which the carbon dioxide is removed An absorption tower for discharging the absorption tower exhaust gas containing gas is provided. Furthermore, the system is a regeneration tower that diffuses the carbon dioxide from the absorption liquid discharged from the absorption tower, and discharges the absorption liquid that has diffused the carbon dioxide and a regeneration tower exhaust gas containing the carbon dioxide. Equipped with. Further, the system comprises: an absorption tower exhaust gas passage member having at least one hole through which the absorption tower exhaust gas passes; and a cleaning liquid injected into the absorption tower exhaust gas passing through the inside of the holes to absorb the absorption liquid. And a spraying unit for cleaning the tower exhaust gas with the cleaning liquid.

It is a schematic diagram which shows the structure of the carbon dioxide recovery system of 1st Embodiment. 6 is a graph for explaining the operation of the cleaning unit of the first embodiment. It is sectional drawing which shows the structure of the washing|cleaning part of 1st Embodiment. It is a schematic diagram which shows the structure of the carbon dioxide recovery system of the modification of 1st Embodiment. It is sectional drawing which shows the structure of the washing|cleaning part of 2nd Embodiment. It is sectional drawing which shows the structure of the washing|cleaning part of 3rd Embodiment. It is sectional drawing which shows the structure of the washing|cleaning part of 4th Embodiment.

Embodiments of the present invention will be described below with reference to the drawings. 1 to 7, the same reference numerals are given to the same or similar configurations, and overlapping description will be omitted.

(First embodiment)
FIG. 1 is a schematic diagram showing the configuration of the carbon dioxide recovery system of the first embodiment.

The carbon dioxide recovery system of FIG. 1 includes an exhaust gas discharge facility 1, an absorption tower 2, a cleaning unit 3, a rich liquid pump 4, a regenerative heat exchanger 5, a regenerating tower 6, a lean liquid pump 7, and a lean liquid pump. The liquid cooler 8 and the controller 9 are provided. The absorption tower 2 includes a packed bed 2a and a demister 2b. The cleaning unit 3 includes a cleaning liquid pump 3a, a cleaning liquid cooler 3b, one or more sprays 3c, and a partition plate 3d having one or more holes H. These sprays 3c are examples of an injection part, and this partition plate 3d is an example of an absorption tower exhaust gas passage member. The regeneration tower 6 includes a packed bed 6a.

FIG. 1 shows an X direction and a Y direction that are parallel to the installation surface of the absorption tower 2 or the regeneration tower 6 and are perpendicular to each other, and a Z direction that is perpendicular to the installation surface of the absorption tower 2 or the regeneration tower 6. In the present specification, for example, when explaining the configurations of the absorption tower 2 and the regeneration tower 6, the +Z direction is treated as an upward direction and the −Z direction is treated as a downward direction. The −Z direction may or may not match the gravity direction.

The exhaust gas discharge facility 1 is a facility for discharging process exhaust gas such as combustion exhaust gas. The process exhaust gas discharged from the exhaust gas discharge facility 1 is introduced into the absorption tower 2 through the process exhaust gas line. The exhaust gas discharge facility 1 is, for example, a power plant such as a thermal power plant, a factory such as a steel mill or a cleaning plant, or a combustion facility such as a refuse incinerator or a manufacturing facility. Process exhaust gas is discharged from, for example, a boiler in a thermal power plant. Process exhaust gas is an example of a gas to be treated that is treated by the carbon dioxide recovery system. Although the exhaust gas discharge facility 1 is provided inside the carbon dioxide recovery system in the present embodiment, it may be provided outside the carbon dioxide recovery system.

The absorption tower 2 is composed of, for example, a countercurrent gas-liquid contact device. The absorption tower 2 is provided with a gas inlet for introducing the process exhaust gas below the packed bed 2a, and an absorbent inlet for introducing the absorbent (lean liquid) above the packed bed 2a. The absorbing liquid introduced from the absorbing liquid introducing port falls into the packed bed 2a. On the other hand, the process exhaust gas introduced from the gas introduction port rises to the packed bed 2a.

The absorption tower 2 brings the process exhaust gas and the absorption liquid into gas-liquid contact in the packed bed 2a so that the absorption liquid absorbs carbon dioxide in the process exhaust gas. As a result, the absorbing liquid (rich liquid) that has absorbed carbon dioxide drops from the packed bed 2a and collects at the bottom of the absorption tower 2. This rich liquid is discharged to the outside from an absorption liquid discharge port provided at the bottom of the absorption tower 2. On the other hand, the absorption tower exhaust gas containing the process exhaust gas from which carbon dioxide has been removed rises from the packed bed 2a and heads toward the top of the absorption tower 2. However, this exhaust gas from the absorption tower is provided to the cleaning section 3 which will be described in detail later, which is provided inside the absorption tower 2 before being discharged (released) to the outside from the gas discharge port provided at the top of the absorption tower 2. Inflow.

The absorption tower 2 includes one packed bed 2a, but is not limited to this, and may include a plurality of packed beds or one or more other reaction parts (for example, trays). May be. Further, the carbon dioxide recovery system of the present embodiment may include a cooling tower that cools the absorption tower exhaust gas. Further, although the cleaning unit 3 is provided inside the absorption tower 2 in the present embodiment, it may be provided outside the absorption tower 2.

An example of an absorbing liquid is an amine-based aqueous solution containing one or more amines. Examples of amines are monoethanolamine and diethanolamine. The absorbing liquid may contain other amines.

The cleaning unit 3 is provided for cleaning the absorption tower exhaust gas with a cleaning liquid to remove the absorption liquid component that accompanies the absorption tower exhaust gas. The partition plate 3d partitions the space in the cleaning unit 3 into a lower region below the partition plate 3d and an upper region above the partition plate 3d. The lower region is an example of the first region and the upper region is an example of the second region. The partition plate 3d has one or more holes H through which the absorption tower exhaust gas and the cleaning liquid can pass.

The absorption tower exhaust gas flowing into the cleaning unit 3 flows from the lower region of the cleaning unit 3 through these holes H to the upper region of the cleaning unit 3. The cleaning unit 3 includes at least one spray 3c, and for example, one spray 3c is provided above each hole H. These sprays 3c inject the cleaning liquid to the absorption tower exhaust gas passing through the holes H, and the injected cleaning liquid cleans the absorption tower exhaust gas. As a result, the absorbing liquid component that accompanies the absorption tower exhaust gas is removed.

The absorption tower exhaust gas that has passed through the holes H passes through the demister 2b and is then discharged (released) to the outside from the gas discharge port provided at the top of the absorption tower 2. The demister 2b captures the absorption liquid component that accompanies the absorption tower exhaust gas and further removes the absorption liquid component. On the other hand, the cleaning liquid sprayed from each spray 3c flows through the holes H to the lower region, is transferred by the cleaning liquid pump 3a, and is cooled by the cleaning liquid cooler 3b. The cooled cleaning liquid is supplied to the spray 3c and is sprayed again from the spray 3c to the absorption tower exhaust gas.

Note that further details of the cleaning unit 3 of this embodiment will be described later.

The absorption liquid discharged from the absorption liquid discharge port of the absorption tower 2 is transferred to the regeneration tower 6 via the regeneration heat exchanger 5 by the rich liquid pump 4. At this time, the absorbing liquid flowing from the absorption tower 2 to the regeneration tower 6 is heated by heat exchange in the regeneration heat exchanger 5.

The regeneration tower 6 is composed of, for example, a countercurrent gas-liquid contact device. The regeneration tower 6 is provided with an absorption liquid inlet for introducing the absorption liquid (rich liquid) discharged from the absorption tower 2 above the packed bed 6a.

The regeneration tower 6 heats the introduced absorption liquid to dissipate most of the carbon dioxide from the absorption liquid together with the vapor and separate the carbon dioxide from the absorption liquid. The regeneration tower 6 is equipped with a reboiler (not shown), and heats the absorbing liquid by exchanging heat between the high temperature steam and the absorbing liquid supplied to the reboiler. The absorption liquid introduced into the regeneration tower 6 passes through the packed bed 6 a and falls to the bottom of the regeneration tower 6.

As a result, the absorption liquid (lean liquid) from which carbon dioxide has been diffused is collected at the bottom of the regeneration tower 6 and is discharged to the outside from the absorption liquid discharge port provided at the bottom of the regeneration tower 6. On the other hand, the regeneration tower exhaust gas containing the released carbon dioxide and vapor is exhausted to the outside from a gas exhaust port provided at the top of the regeneration tower 6. The regeneration tower exhaust gas is then cooled by a gas cooler (not shown). As a result, the vapor in the exhaust gas from the regeneration tower is condensed and separated into carbon dioxide and condensed water. Since the condensed water contains the absorbing liquid component, it is returned to the regeneration tower 6. On the other hand, the separated carbon dioxide is transferred to a state such as a supercritical state or a liquid state according to the purpose by a compression pump, and stored or transported by a tank, a lorry, a pipeline or the like.

The regeneration tower 6 includes one packed bed 6a, but is not limited to this, and may include a plurality of packed beds or one or more other reaction parts (for example, trays). May be. Further, the regeneration tower 6 may be equipped with a flash drum (flash tank) that heats the absorbing liquid in the tank to diffuse carbon dioxide. Further, the carbon dioxide recovery system of the present embodiment includes a cleaning tower for cleaning the regeneration tower exhaust gas, a cooling tower for cooling the regeneration tower exhaust gas, a compression facility for compressing carbon dioxide obtained from the regeneration tower exhaust gas, and the like. May be.

The absorption liquid discharged from the regeneration tower 6 is returned to the absorption tower 2 by the lean liquid pump 7 via the regeneration heat exchanger 5 and the lean cooler 8. At this time, the absorption liquid flowing from the regeneration tower 6 to the absorption tower 2 is cooled by the heat exchange in the regeneration heat exchanger 5 and the cooling action in the lean cooler 8. The regeneration heat exchanger 5 performs heat exchange between the absorption liquid flowing from the absorption tower 2 to the regeneration tower 6 and the absorption liquid flowing from the regeneration tower 6 to the absorption tower 2.

The control unit 9 controls various operations of the carbon dioxide recovery system. Examples of the control unit 9 are a processor, an electric circuit, a computer and the like. The control unit 9 controls, for example, the number of revolutions of the cleaning liquid pump 3a and the lean liquid pump 7, the cooling operation of the cleaning liquid cooler 3b and the lean liquid cooler 8, and the spraying operation of the spray 3c.

Hereinafter, further details of the cleaning unit 3 of the present embodiment will be described.

As described above, the cleaning unit 3 cleans the absorption tower exhaust gas with the cleaning liquid to remove the absorption liquid component that accompanies the absorption tower exhaust gas. Examples of the absorbing liquid component are a main component (for example, amine) of the absorbing liquid, an additive component of the absorbing liquid, and a secondary component generated due to deterioration of the absorbing liquid and the like. The cleaning unit 3 of the present embodiment removes these absorbing liquid components with a cleaning liquid.

The cleaning unit 3 of the present embodiment sprays the cleaning liquid from the spray 3c to the absorption tower exhaust gas passing through the holes H, that is, injects the cleaning liquid into the absorption tower exhaust gas in a mist form. This makes it possible to efficiently remove the absorbing liquid component that accompanies the absorption tower exhaust gas. Such cleaning with the spray 3c is effective, for example, in removing the absorbing liquid component from the absorption tower exhaust gas containing the absorbing liquid component scattered in the form of mist. The cleaning liquid is, for example, water or acidic water, but is not limited to these examples.

FIG. 2 is a graph for explaining the operation of the cleaning unit 3 of the first embodiment.

The horizontal axis of FIG. 2 represents the velocity (empty column velocity) of the absorption tower exhaust gas flowing in the cleaning unit 3 of the absorption tower 2. The vertical axis of FIG. 2 represents the removal rate of the absorbing liquid component removed from the exhaust gas from the absorption tower by the spray 3c. The absorption liquid component removal rate is a value obtained by dividing the concentration of the absorption liquid component in the absorption tower exhaust gas after cleaning by the concentration of the absorption liquid component in the absorption tower exhaust gas before cleaning.

As shown in FIG. 2, there is a correlation between the superficial velocity and the removal rate. Specifically, when the superficial velocity is smaller than the predetermined velocity X, the removal rate increases as the superficial velocity increases. However, when the superficial velocity is higher than the predetermined velocity X, the removal rate decreases as the superficial velocity increases. The symbol Y indicates the removal rate when the superficial velocity is the predetermined velocity X.

The reason why the phenomenon shown in FIG. 2 occurs is considered as follows. When the superficial velocity is smaller than X, the mist-like absorbing liquid component has a weak advancing force and does not collide with the droplets of the cleaning liquid from the spray 3c, and thus is difficult to be removed. On the other hand, when the superficial velocity is higher than X, even if the mist-like absorbing liquid component collides with the droplet of the cleaning liquid from the spray 3c, the absorbing liquid component penetrates the droplet and is not collected. , The removal rate will decrease. Further, the removal rate is reduced even when the mist of the absorbing liquid component is split into smaller mist by the impact of collision, and the droplets from the spray 3c are wound up by the rising exhaust gas of the absorption tower. ..

Generally, the inner diameter of the absorption tower 2 is set so that the absorption performance of carbon dioxide by the absorbing liquid is maximized, and the inner diameter of the cleaning unit 3 is also set to the same value as the inner diameter of the absorption tower 2. In this case, the superficial velocity in the cleaning unit 3 becomes smaller than X, and the removal rate becomes low.

Therefore, in the present embodiment, the partition plate 3d is provided in the cleaning unit 3 and the absorption tower exhaust gas is passed through the holes H provided in the partition plate 3d. As a result, the superficial velocity of the absorption tower exhaust gas becomes faster when passing through the inside of the hole H, so that the superficial velocity of the absorption tower exhaust gas passing through the inside of the hole H approaches X. It is possible to increase the removal rate of the exhaust gas from the absorption tower that is passing through H. This makes it possible to clean the absorption tower exhaust gas at an optimum superficial velocity (gas flow rate) for cleaning.

FIG. 3 is a cross-sectional view showing the configuration of the cleaning unit 3 of the first embodiment.

FIG. 3A is a sectional view showing a vertical section of the spray 3c and the partition plate 3d. FIG. 3B is a top view showing the shape of the partition plate 3d. FIG. 3A is a sectional view taken along the line A-A′ shown in FIG. The cleaning unit 3 of this embodiment includes a plurality of sprays 3c, and one spray 3c is provided above each hole H (FIG. 3(a)). These sprays 3c wash the absorption tower exhaust gas with the cleaning liquid by spraying the cleaning liquid on the absorption tower exhaust gas passing through these holes H.

The inner diameter of the hole H of the present embodiment is set so that the superficial velocity of the absorption tower exhaust gas in the hole H becomes a value close to X. As a result, the superficial velocity optimum for cleaning can be realized and the cleaning effect can be maximized. Moreover, since the inner diameter of the hole H can be adjusted without changing the structure of the absorption tower 2, the performance of the existing cleaning unit 3 and the new cleaning unit 3 can be easily improved. Further, since the structure of the cleaning unit 3 can be configured in the same manner as the conventional structure except for the spray 3c and the partition plate 3d, it is possible to reduce the manufacturing cost of the absorption tower 2 and the cleaning unit 3 and the manufacturing period.

FIG. 4 is a schematic diagram showing a configuration of a carbon dioxide recovery system of a modified example of the first embodiment.

The carbon dioxide recovery system of FIG. 4 includes a second cleaning unit 10 and a second demister 2c in the absorption tower 2 in addition to the components shown in FIG. The second cleaning unit 10 is located above the demister 2b, and the second demister 2c is located above the second cleaning unit 10. The second cleaning unit 10 includes a cleaning liquid pump 10a, a cleaning liquid cooler 10b, and a packed bed 10c.

The absorption tower exhaust gas that has passed through the demister 2b flows into the second cleaning unit 10. The second cleaning unit 10 makes the absorption tower exhaust gas rising in the packed bed 10c and the cleaning liquid falling in the packed bed 10c come into gas-liquid contact, and cleans the absorption tower exhaust gas with the cleaning liquid. As a result, the absorbing liquid component that accompanies the absorption tower exhaust gas is removed. The cleaning liquid is, for example, water or acidic water, but is not limited to these examples.

The absorption tower exhaust gas that has passed through the packed bed 10c passes through the second demister 2c, and then is discharged (released) to the outside from the gas discharge port provided at the top of the absorption tower 2. The second demister 2c captures the absorbing liquid component that accompanies the absorption tower exhaust gas and further removes the absorbing liquid component. On the other hand, the cleaning liquid that has passed through the packed bed 10c is transferred by the cleaning liquid pump 10a and cooled by the cleaning liquid cooler 10b. The cooled cleaning liquid is supplied to the packed bed 10c again.

As described above, the absorption tower 2 of the present embodiment may include the second cleaning unit 10 including the packed bed 10c in addition to the cleaning unit (first cleaning unit) 3 including the spray 3c. In this case, it is possible to realize a configuration in which the mist-like absorbing liquid component is mainly removed by the first cleaning unit 3 and the gaseous absorbing liquid component is mainly removed by the second cleaning unit 10. The second cleaning unit 10 is provided inside the absorption tower 2 in the present embodiment, but may be provided outside the absorption tower 2.

As described above, the cleaning unit 3 of the present embodiment sprays the cleaning liquid on the partition plate 3d having the holes H through which the absorption tower exhaust gas passes and the absorption tower exhaust gas passing through the holes H. , A spray 3c for cleaning the gas discharged from the absorption tower with a cleaning liquid. Therefore, according to the present embodiment, by setting the velocity of the absorption tower exhaust gas passing through the holes H to an appropriate value, the absorption tower exhaust gas is discharged when the absorption tower exhaust gas is released from the absorption tower 2. It is possible to reduce the absorption liquid component that accompanies the gas.

The spray 3c may be replaced with another device that sprays the cleaning liquid. The partition plate 3d may be replaced with another member having the holes H, for example, a member having a shape other than the plate shape.

(Second embodiment)
FIG. 5 is a sectional view showing the configuration of the cleaning unit 3 of the second embodiment. FIG. 5A shows a first example of the cleaning unit 3 of the second embodiment. FIG. 5B shows a second example of the cleaning unit 3 of the second embodiment.

The cleaning unit 3 in FIG. 5(a) is provided with two sprays 3c on top of each hole H. Since these sprays 3c are arranged so as to face downward, the spraying liquid is sprayed so that the direction in which the cleaning liquid is sprayed and the direction in which the absorption tower exhaust gas flows are opposed to each other. According to this example, by spraying the cleaning liquid from the two sprays 3c into one hole H, the cleaning effect is improved as compared with the case where the cleaning liquid is sprayed from one spray 3c into one hole H. You can

FIG. 5C is a schematic diagram for explaining the details of the example of FIG. 5A. The arrow L indicates the direction in which the cleaning liquid is ejected from one spray 3c, the arrow G indicates the direction in which the absorption tower exhaust gas flows, and the symbol K indicates a straight line parallel to the arrows L and G. As shown in FIG. 5( a ), each spray 3 c sprays the cleaning liquid in a conical shape. The “direction in which the cleaning liquid is sprayed” in FIG. 5( c) indicates the average spraying direction of the cleaning liquid. ing. The average injection direction of the cleaning liquid is, for example, the direction along the central axis of the conical shape. In this example, the arrow L points in the -Z direction and the arrow G points in the +Z direction, and the direction in which the cleaning liquid is jetted and the direction in which the absorption tower exhaust gas flows are opposite to each other. The straight line K extends parallel to the Z direction. The directions of the arrow L and the arrow G may be deviated from parallel as long as the direction in which the cleaning liquid is injected and the direction in which the absorption tower exhaust gas flows are opposed to each other.

The cleaning unit 3 in FIG. 5B also has two sprays 3c on the upper part of each hole H, but these sprays 3c are arranged so as to face obliquely downward. Therefore, the cleaning liquid is jetted obliquely downward from these sprays 3c and easily collides with the wall surface of the hole H. When the droplets of the cleaning liquid collide with the wall surface of the holes H, it is possible to prevent the droplets from being taken up by the exhaust gas from the absorption tower. This facilitates removal of the absorbing liquid component near the wall surface of the hole H by the cleaning liquid. The inclination of the spray direction of the cleaning liquid is preferably set to 10 degrees or more and 80 degrees or less when the state of FIG. 5A is set to 0 degrees, and more specifically, it is set to about 45 degrees. ..

FIG. 5D is a schematic diagram for explaining the details of the example of FIG. 5B. The arrow L indicates the direction in which the cleaning liquid is sprayed from one spray 3c, and the arrow G indicates the direction in which the absorption tower exhaust gas flows. Further, the symbol K indicates a straight line parallel to the arrow G, the symbol K′ indicates a straight line parallel to the arrow L, and the symbol θ indicates the angle between the straight line K and the straight line K′ (0 Degree ≤ θ ≤ 90 degrees). This angle θ corresponds to the above-mentioned “inclination of the cleaning liquid ejection direction”. The straight line K'is an example of the first straight line, and the straight line K is an example of the second straight line. The method of determining the direction in which the cleaning liquid is sprayed from each spray 3c (the average spraying direction of the cleaning liquid) is the same as in the case of FIG. In this example, the arrow L points in a direction inclined by an angle θ from the −Z direction, the arrow G points in the +Z direction, and the angle between the straight line K and the straight line K′ is θ. As described above, this angle θ is preferably set to 10 degrees or more and 80 degrees or less, and more specifically, set to about 45 degrees.

According to the present embodiment, by spraying the cleaning liquid into each hole H from the plurality of sprays 3c, the cleaning effect can be improved as compared with the case where the cleaning liquid is sprayed from one spray 3c into one hole H. You can The number of sprays 3c for each hole H is two in the above-mentioned first and second examples, but may be three or more.

(Third Embodiment)
FIG. 6 is a cross-sectional view showing the configuration of the cleaning unit 3 of the third embodiment. FIG. 6A shows a first example of the cleaning unit 3 of the third embodiment. FIG.6(b) has shown the 2nd example of the washing|cleaning part 3 of 3rd Embodiment.

The cleaning unit 3 in FIG. 6A has a plurality of sprays 3c in each hole H. Since the plurality of sprays 3c shown in FIG. 6A are arranged so as to face the direction of the central axis of the hole H, the cleaning liquid is sprayed in the direction away from the wall surface S of the hole H. These sprays 3c are fixed to the wall surface S of the hole H and face right side.

When these sprays 3c spray the cleaning liquid, the droplets of the cleaning liquid collide with the wall surface S on the opposite side of each spray 3c. As a result, as in the case of FIG. 5B, it is possible to prevent the droplets from being taken up by the absorption tower exhaust gas. This also applies to the cleaning unit 3 in FIG. 6(b).

The cleaning unit 3 in FIG. 6B also has a plurality of sprays 3c in each hole H. However, these sprays 3c are directed obliquely downward. When the state of FIG. 5(a) is 0 degree and the state of FIG. 6(a) is 90 degrees, the inclination of the cleaning liquid spraying direction is preferably set to 10 degrees or more and 80 degrees or less.

The cleaning unit 3 of FIG. 6A has two rows of sprays 3c in each hole H, but may have three or more rows of sprays 3c in each hole H. This also applies to the cleaning unit 3 in FIG. 6(b).

As described above, the cleaning unit 3 of this embodiment has the spray 3c in the hole H. As a result, as in the first and second embodiments, it is possible to reduce the absorption liquid component that accompanies the absorption tower exhaust gas.

(Fourth Embodiment)
FIG. 7 is a sectional view showing the configuration of the cleaning unit 3 of the fourth embodiment. FIG. 7A shows a first example of the cleaning unit 3 of the fourth embodiment. FIG.7(b) has shown the 2nd example of the washing|cleaning part 3 of 4th Embodiment.

The cleaning unit 3 of FIG. 7A has a plurality of sprays 3c in each hole H. Since the plurality of sprays 3c shown in FIG. 7A are arranged so as to face the wall surface S of the hole H, the cleaning liquid is sprayed in the direction toward the wall surface S of the hole H. These sprays 3c are fixed in the vicinity of the central axis of the hole H, and face right side.

When these sprays 3c spray the cleaning liquid, the droplets of the cleaning liquid collide with the wall surface S opposite to each spray 3c. As a result, as in the case of FIG. 5B, it is possible to prevent the droplets from being taken up by the absorption tower exhaust gas. This also applies to the cleaning unit 3 in FIG. 7(b).

The cleaning unit 3 in FIG. 7B also has a plurality of sprays 3c in each hole H. However, these sprays 3c are directed obliquely downward. When the state of FIG. 5(a) is 0 degree and the state of FIG. 7(a) is 90 degrees, it is desirable to set the inclination of the cleaning liquid jet direction to 10 degrees or more and 80 degrees or less.

The cleaning unit 3 of FIG. 7A has two rows of sprays 3c in each hole H, but may have three or more rows of sprays 3c in each hole H. Desirably, four or more rows of sprays 3c may be provided in each hole H so that the cleaning liquid can be sprayed on the entire wall surface S. This also applies to the cleaning unit 3 in FIG. 7(b).

As described above, the cleaning unit 3 of this embodiment has the spray 3c in the hole H. As a result, as in the first to third embodiments, it is possible to reduce the absorption liquid component that accompanies the absorption tower exhaust gas.

Although some embodiments have been described above, these embodiments are presented only as examples and are not intended to limit the scope of the invention. The novel systems and methods described herein can be implemented in various other forms. Further, various omissions, substitutions, and changes can be made to the modes of the system and method described in this specification without departing from the scope of the invention. The appended claims and their equivalents are intended to cover such forms and modifications as fall within the scope and spirit of the invention.

1: exhaust gas discharge facility, 2: absorption tower, 2a: packed bed,
2b: demister, 2c: second demister, 3: cleaning unit,
3a: cleaning liquid pump, 3b: cleaning liquid cooler, 3c: spray, 3d: partition plate,
4: Rich liquid pump, 5: Regeneration heat exchanger, 6: Regeneration tower, 6a: Packed bed,
7: lean liquid pump, 8: lean liquid cooler, 9: control unit, 10: second cleaning unit,
10a: cleaning liquid pump, 10b: cleaning liquid cooler, 10c: packed bed

Claims (12)

An absorption tower in which a treatment target gas containing carbon dioxide is brought into contact with an absorption liquid, and the absorption liquid absorbing the carbon dioxide, and an absorption tower exhaust gas containing the treatment target gas from which the carbon dioxide has been removed, and an absorption tower. ,
The carbon dioxide is diffused from the absorption liquid discharged from the absorption tower, the absorption liquid that has diffused the carbon dioxide, and a regeneration tower that discharges a regeneration tower exhaust gas containing the carbon dioxide,
An absorption tower exhaust gas passage member having at least one hole through which the absorption tower exhaust gas passes, and a cleaning liquid is injected into the absorption tower exhaust gas passing through the inside of the holes, and the absorption tower exhaust gas is washed with the cleaning liquid. A cleaning unit including an injection unit that is cleaned by
Carbon dioxide recovery system equipped with. The absorption tower exhaust gas passage member partitions the space in the cleaning section into a first region and a second region,
The absorption tower exhaust gas flows from the first region to the second region through the holes,
The cleaning liquid flows from the injection unit to the first region through the holes.
The carbon dioxide recovery system according to claim 1. The carbon dioxide recovery system according to claim 2, wherein the cleaning unit re-injects the cleaning liquid, which has flowed into the first region, into the absorption tower exhaust gas passing through the inside of the hole from the injection unit. The carbon dioxide according to any one of claims 1 to 3, wherein the injection unit includes one or more sprays that inject the cleaning liquid in a mist form into the absorption tower exhaust gas passing through the holes. Recovery system. The carbon dioxide recovery system according to claim 4, wherein the injection unit includes two or more sprays for one hole of the absorption tower exhaust gas passage member. The carbon dioxide according to any one of claims 1 to 5, wherein the injection unit injects the cleaning liquid such that a direction in which the cleaning liquid is injected and a direction in which the absorption tower exhaust gas flows are opposite to each other. Recovery system. The direction in which the cleaning liquid is sprayed from the spraying unit is parallel to the first straight line,
The flow direction of the absorption tower exhaust gas in the holes is parallel to the second straight line,
The carbon dioxide recovery system according to claim 1, wherein an angle between the first straight line and the second straight line is 10 degrees or more. The carbon dioxide recovery system according to claim 7, wherein an angle between the first straight line and the second straight line is 80 degrees or less. The carbon dioxide recovery system according to any one of claims 1 to 8, wherein the injection unit is provided in the hole and injects the cleaning liquid in a direction away from a wall surface of the hole. The carbon dioxide recovery system according to claim 1, wherein the injection unit is provided in the hole and injects the cleaning liquid in a direction toward a wall surface of the hole. 11. The method according to claim 1, further comprising a packed bed through which the absorption tower exhaust gas and the cleaning liquid pass, and further comprising a second cleaning unit that cleans the absorption tower exhaust gas in the packed bed with the cleaning liquid. The carbon dioxide capture system described. The gas to be treated containing carbon dioxide and the absorbing liquid are contacted in the absorption tower, the absorbing liquid absorbing the carbon dioxide, and the absorption tower exhaust gas containing the gas to be treated from which the carbon dioxide has been removed, Discharged from the absorption tower,
The carbon dioxide is diffused from the absorption liquid discharged from the absorption tower in the regeneration tower, and the absorption liquid containing the carbon dioxide is discharged from the regeneration tower exhaust gas containing the carbon dioxide. ,
In a cleaning section including an absorption tower exhaust gas passage member having at least one hole through which the absorption tower exhaust gas passes, a cleaning liquid is injected from an injection section to the absorption tower exhaust gas passing through the inside of the hole, Cleaning the absorption tower exhaust gas with the cleaning liquid,
A method of operating a carbon dioxide recovery system, including: