Gas treatment device and gas treatment method

Abstract

To inhibit a liquid composition from being biased in an absorber and a regenerator.SOLUTION: A gas treatment device 10 includes: an absorption side storage unit 26 for storing treatment liquid which is phase separated into a first phase part and a second phase part in an absorber 12; a first detector for detecting whether the liquid-liquid interface of the first phase part and the second phase part is within a prescribed range in the absorption side storage unit 26; a second detector for detecting whether the liquid level of the second phase part is within a prescribed range in the absorption side storage unit 26; a first flow rate adjusting mechanism 28 for adjusting the flow rate of the first phase part to be sent from the absorption side storage unit 26 to a regenerator 14 on the basis of the result of the detection by the first detector so that the liquid-liquid interface falls within the prescribed range; and a second flow rate adjusting mechanism 29 for adjusting the flow rate of the second phase part to be sent from the absorption side storage unit 26 to the regenerator 14 on the basis of the result of the detection by the second detector so that the liquid level of the second phase part falls within the prescribed range.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas processing apparatus and a gas processing method. [Background technology]

[0002] In recent years, carbon dioxide is thought to have a large impact on global warming. Carbon dioxide separation and capture technology has attracted attention as an effective measure against this global warming problem. There are various methods for separating and capturing CO2 from CO2 emission sources such as power plants and steelworks, but the chemical absorption method is suitable when the scale is large and the emitted CO2 is close to normal pressure. In this chemical absorption method, acidic CO2 is absorbed into an alkaline aqueous solution (treatment liquid) such as an amine aqueous solution, and the treatment liquid that has absorbed the CO2 is heated. This causes the CO2 in the treatment liquid to dissipate from the treatment liquid (called the regeneration process), and the separated CO2 is captured.

[0003] In this type of amine absorption method, a large amount of heat energy is required because heating is required to dissipate the CO2 from the CO2-absorbing treatment liquid. In addition, a temperature of 100°C or higher is required for heating. This is a factor that increases the cost required for CO2 separation and capture.

[0004] Therefore, the following Patent Documents 1 and 2 disclose gas treatment devices that use a treatment liquid that can be regenerated at low temperatures to save energy. Patent Document 1 discloses that a regeneration temperature of 100°C or less can be achieved by using a treatment liquid that is separated into two phases, a phase with a high CO2 content and a phase with a low CO2 content, by absorbing CO2. The treatment liquid is an alkaline liquid containing water, an amine compound, and an organic solvent. Patent Document 2 also discloses that the regeneration temperature can be further reduced by supplying a separation-promoting gas in the regeneration step that is a gas that is almost insoluble in the treatment liquid and is composed of any one of a hydrocarbon gas such as methane gas, hydrogen gas, and oxygen gas. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6906761 [Patent Document 2] Patent No. 6906766 [Patent Document 3] Patent No. 3364103 Summary of the Invention [Problem to be solved by the invention]

[0006] In the amine absorption method, regardless of the phase separation behavior of the treated liquid, there is a problem that the composition of the treated liquid varies due to the influence of moisture carried into the system, evaporation of the components of the treated liquid (mainly amines), loss of liquid components due to mist generation of the treated liquid, etc. Fluctuations in the composition of the treated liquid can make it difficult to maintain separation performance, so it is desirable to control it to a constant value as much as possible. In addition, when the amine-based treated liquid contains an organic solvent component such as ether, phase separation occurs depending on the amount of CO2 absorbed, so it is necessary to prevent the liquid composition from varying at each spot in the gas treatment device. More specifically, if the control of the discharge flow rate ratio of each phase that has separated into phases is not successful, the amine phase will accumulate in the absorber, resulting in a relatively high amine concentration, while the amine concentration will decrease in the regenerator, resulting in a high ether concentration. In this way, the liquid composition at each spot may become uneven.

[0007] Incidentally, the following Patent Document 3 discloses a control method for an amine absorption method using an amine-based treatment liquid that does not separate into two phases even when absorbing CO2. However, in a decarbonation system having an amine recovery section (water washing section) that recovers amines from exhaust gas and a water storage tank that extracts water containing amines from the amine recovery section, the liquid level of the treatment liquid is adjusted to be constant when the amine-containing water stored in the water storage tank is sent to the carbon dioxide absorption section, thereby maintaining the concentration of the treatment liquid constant.

[0008] In view of the above problems, an object of the present invention is to suppress the bias in the liquid composition in the absorber and the regenerator. [Means for solving the problem]

[0009] In order to achieve the above object, the gas treatment device of the present invention is a gas treatment device for releasing acidic compounds from a gas to be treated that contains acidic compounds that generate an acid when dissolved in water, by using a treatment liquid that is in a mixed state of a first component and a second component having a specific gravity smaller than that of the first component before absorbing the acidic compounds, and that undergoes phase separation into a first phase portion mainly containing the first component and a second phase portion mainly containing the second component upon absorption of the acidic compounds, the gas treatment device comprising: an absorber for bringing the gas to be treated and the treatment liquid into contact with each other to absorb the acidic compounds contained in the gas to be treated into the treatment liquid; a regenerator for heating the treatment liquid that has absorbed the acidic compounds to separate the acidic compounds from the treatment liquid; and a regenerator for separating the first phase portion and the first phase portion in the absorber. the absorption-side reservoir for storing the treatment liquid in a phase-separated state into the first phase portion and the second phase portion; a first detector for detecting whether a liquid-liquid interface between the first phase portion and the second phase portion in the absorption-side reservoir is within a predetermined range; a second detector for detecting whether a liquid level of the second phase portion in the absorption-side reservoir is within a predetermined range; a first flow rate adjustment mechanism for adjusting a flow rate of the first phase portion sent from the absorption-side reservoir to the regenerator based on a detection result by the first detector so that the liquid-liquid interface falls within the predetermined range; and a second flow rate adjustment mechanism for adjusting a flow rate of the second phase portion sent from the absorption-side reservoir to the regenerator based on a detection result by the second detector so that the liquid level of the second phase portion falls within the predetermined range.

[0010] In the present invention, when the treatment liquid absorbs the acidic compound in the absorber, the treatment liquid undergoes phase separation into a first phase portion mainly containing the first component and a second phase portion mainly containing the second component. This phase-separated treatment liquid is stored in the absorption-side reservoir. In the absorption-side reservoir, the second phase portion mainly containing the second component having a lower specific gravity accumulates above the first phase portion mainly containing the first component, generating a liquid-liquid interface between the first phase portion and the second phase portion. The first flow rate adjustment mechanism adjusts the flow rate of the first phase portion sent from the absorption-side reservoir to the regenerator so that this liquid-liquid interface falls within a predetermined range, and the second flow rate adjustment mechanism adjusts the flow rate of the second phase portion sent from the absorption-side reservoir to the regenerator so that the liquid level of the second phase portion falls within a predetermined range. Therefore, by utilizing the fact that the first phase portion and the second phase portion accumulate in layers in the absorption-side reservoir, the ratio of the first phase portion and the second phase portion accumulated in the absorption-side reservoir is adjusted within a predetermined range, and thus it is possible to suppress the occurrence of an imbalance between the first phase portion and the second phase portion between the absorber and the regenerator.

[0011] The first detector is not limited to a configuration that directly detects the position of the liquid-liquid interface between the first phase and the second phase. The first detector may be configured to detect whether the liquid-liquid interface is within a predetermined range by detecting that a predetermined amount of the first phase is stored using a pair of switches or sensors. The concept of the first flow rate adjustment mechanism and the second flow rate adjustment mechanism adjusting the flow rate so that the liquid-liquid interface or the liquid level is within a predetermined range also includes adjusting the flow rate so that the position of the liquid-liquid interface or the liquid level coincides with a target value.

[0012] The absorption-side reservoir may have a partition member that divides the space within the reservoir into a first space into which the treatment liquid is introduced from the absorber and which stores the treatment liquid in a state of phase separation into a first phase portion and a second phase portion, and a second space into which the second phase portion overflowing from the first space is introduced. In this case, the first detector may be used to detect whether a liquid-liquid interface between the first phase portion and the second phase portion in the first space is within a predetermined range, and the second detector may be used to detect whether an amount of the second phase portion stored in the second space is within a predetermined range.

[0013] In this embodiment, the absorption-side reservoir is divided by a partition member into a first space in which the phase-separated treatment liquid is stored and a second space in which only the second phase portion is stored. Therefore, the second flow rate control mechanism can prevent the first phase portion from being sent out, making it easy to adjust the flow rates by the first flow rate control mechanism and the second flow rate control mechanism.

[0014] The first flow rate adjustment mechanism may be configured to increase a flow rate of the first phase portion sent from the absorption-side reservoir to the regenerator when a detection result of the first detector indicates that the liquid-liquid interface between the first phase portion and the second phase portion is higher than the predetermined range, and to reduce a flow rate of the first phase portion sent from the absorption-side reservoir to the regenerator when a detection result of the first detector indicates that the liquid-liquid interface between the first phase portion and the second phase portion is lower than the predetermined range. The second flow rate adjustment mechanism may be configured to increase a flow rate of the second phase portion sent from the absorption-side reservoir to the regenerator when a detection result of the second detector indicates that the liquid level of the second phase portion is higher than the predetermined range, and to reduce a flow rate of the second phase portion sent from the absorption-side reservoir to the regenerator when a detection result of the second detector indicates that the liquid level of the second phase portion is lower than the predetermined range.

[0015] In this embodiment, when the amount of the first phase portion accumulated in the absorption-side reservoir is greater than a predetermined amount, the flow rate of the first phase portion sent from the absorption-side reservoir to the regenerator is increased, and when the amount is less than the predetermined amount, the flow rate of the first phase portion sent from the absorption-side reservoir to the regenerator is reduced. Also, when the amount of the second phase portion accumulated in the absorption-side reservoir is greater than a predetermined amount, the flow rate of the second phase portion sent from the absorption-side reservoir to the regenerator is increased, and when the amount is less than the predetermined amount, the flow rate of the second phase portion sent from the absorption-side reservoir to the regenerator is reduced. Therefore, it is possible to further suppress the occurrence of uneven distribution of the first phase portion and the second phase portion between the absorber and the regenerator.

[0016] The liquid-liquid interface between the first and second phases and the predetermined range of the liquid level of the second phase are controlled so that the ratio of the first and second phases contained in the treatment liquid when introduced into the gas treatment device is maintained in both the absorber and the regenerator. Therefore, when the liquid-liquid interface between the first and second phases in the absorption-side reservoir becomes higher than the predetermined range, the flow rate of the first phase sent from the absorption-side reservoir to the regenerator is increased, making it easier to maintain the ratio of the first and second phases at the initial ratio in both the absorber and the regenerator.

[0017] The gas treatment device may further include a regeneration side reservoir into which the treatment liquid heated in the regenerator is introduced, the regeneration side reservoir having an introduction liquid space in which the introduced treatment liquid is stored, and a regeneration liquid space that receives regenerated treatment liquid from the introduction liquid space even when the treatment liquid introduced into the introduction liquid space contains unregenerated treatment liquid, and an unregenerated liquid return mechanism that returns the unregenerated treatment liquid accumulated in the introduction liquid space to the regenerator when the treatment liquid contains the unregenerated treatment liquid.

[0018] In this embodiment, the treatment liquid introduced from the regenerator to the regeneration side reservoir may contain unregenerated treatment liquid (unregenerated liquid), and in that case, the unregenerated liquid return mechanism is operated to return the unregenerated liquid from the regeneration side reservoir to the regenerator. That is, the unregenerated liquid in the regeneration side reservoir can be returned to the regenerator without being returned to the absorber, while the regenerated treatment liquid can be returned to the absorber from the regenerated liquid space. Therefore, even if unregenerated treatment liquid is generated in the regenerator and accumulates in the regeneration side reservoir, this unregenerated treatment liquid is returned to the regenerator and heated again, so that the regeneration process of the unregenerated treatment liquid is promoted. Therefore, the treatment liquid having a composition ratio different from the composition ratio of the treatment liquid charged initially is suppressed from returning to the absorber, and therefore the ratio of the first phase portion and the second phase portion contained in the treatment liquid circulating between the regenerator and the absorber is suppressed from fluctuating. Therefore, it is possible to further suppress the occurrence of bias between the first phase portion and the second phase portion between the absorber and the regenerator. Furthermore, of the treatment liquid introduced into the introduction liquid space of the regeneration side reservoir, the regenerated treatment liquid flows into the regenerated liquid space, thereby preventing the regenerated treatment liquid from being returned from the introduction liquid space to the regenerator.

[0019] The gas treatment device according to the present invention is a gas treatment device for releasing acidic compounds from a gas to be treated that contains acidic compounds that generate an acid when dissolved in water, by using a treatment liquid that is in a mixed state of a first component and a second component having a specific gravity smaller than that of the first component before absorbing the acidic compounds, and that undergoes phase separation into a first phase portion mainly containing the first component and a second phase portion mainly containing the second component upon absorption of the acidic compounds, the gas treatment device comprising: an absorber for bringing the gas to be treated and the treatment liquid into contact with each other, and for absorbing the acidic compounds contained in the gas to be treated into the treatment liquid; The system comprises a regenerator that heats the treatment liquid that has absorbed the acidic compounds to separate the acidic compounds from the treatment liquid; a regeneration side reservoir into which the treatment liquid heated in the regenerator is introduced, the regeneration side reservoir having an introduction liquid space in which the introduced treatment liquid is stored, and a regenerated liquid space that receives regenerated treatment liquid from the introduction liquid space even when the treatment liquid introduced into the introduction liquid space contains unregenerated treatment liquid; and an unregenerated liquid return mechanism that returns the unregenerated treatment liquid accumulated in the introduction liquid space to the regenerator when the treatment liquid contains unregenerated treatment liquid.

[0020] In the present invention, when the treatment liquid is heated in the regenerator, the treatment liquid releases acidic compounds. Therefore, at least a part of the treatment liquid that has been phase-separated into a first phase portion and a second phase portion returns to a state where no phase separation occurs. The treatment liquid introduced from the regenerator to the regeneration side reservoir may contain unregenerated treatment liquid (unregenerated liquid). In this case, in the regeneration side reservoir, the regenerated treatment liquid flows from the introduction liquid space into the regenerated liquid space, while the unregenerated liquid is stored in the introduction liquid space. Then, an unregenerated liquid return mechanism is operated to return the unregenerated liquid to the regenerator. That is, the unregenerated liquid in the regeneration side reservoir can be returned to the regenerator without being returned to the absorber, while the regenerated treatment liquid can be returned from the regeneration liquid space to the absorber. Therefore, even if unregenerated treatment liquid is generated in the regenerator and accumulates in the regeneration side reservoir, this unregenerated treatment liquid is returned to the regenerator and heated again, so that the regeneration process of the unregenerated treatment liquid is promoted. This prevents the treated liquid with a composition ratio different from that of the initially charged treated liquid from returning to the absorber, thereby preventing fluctuations in the ratio of the first phase and the second phase contained in the treated liquid circulating between the regenerator and the absorber. This prevents bias in the first phase and the second phase between the absorber and the regenerator. Moreover, the regenerated treated liquid among the treated liquid introduced into the introduction liquid space of the regeneration side reservoir flows into the regenerated liquid space, preventing the regenerated treated liquid from returning from the introduction liquid space to the regenerator.

[0021] The unregenerated liquid return mechanism may include a first return mechanism for returning the first phase portion of the treatment liquid accumulating in the introduction liquid space to the regenerator so that the amount of the first phase portion is equal to or less than a predetermined amount, and a second return mechanism for returning the second phase portion of the treatment liquid in the introduction liquid space to the regenerator so that the liquid level of the treatment liquid accumulating in the introduction liquid space is equal to or less than a predetermined amount.

[0022] In this embodiment, when unregenerated treated liquid (unregenerated liquid) is generated, the unregenerated liquid accumulates in the liquid introduction space. The first phase portion of the unregenerated liquid accumulated in the liquid introduction space is returned to the regenerator by the first return mechanism, and the second phase portion is returned to the regenerator by the second return mechanism. At this time, the second return mechanism causes the second phase portion to flow out so that the liquid level of the treated liquid accumulated in the liquid introduction space becomes equal to or lower than a predetermined level, and the first return mechanism causes the first phase portion to flow out so that the amount of the first phase portion of the treated liquid accumulated in the liquid introduction space becomes equal to or lower than a predetermined level. Therefore, the regeneration process of the unregenerated liquid is promoted, and the ratio of the first phase portion and the second phase portion contained in the treated liquid circulating between the regenerator and the absorber is further suppressed from fluctuating.

[0023] The gas treatment device may include a first unregenerated liquid detector for detecting whether a first phase portion of the unregenerated treatment liquid has accumulated in a predetermined amount or more. In this case, the first return mechanism may return the first phase portion to the regenerator when the first unregenerated liquid detector detects that the first phase portion has accumulated in a predetermined amount or more.

[0024] In this embodiment, when it is detected that a predetermined amount or more of the first phase portion has accumulated in the introduction liquid space, the unregenerated first phase portion is returned to the regenerator, thereby preventing the unregenerated first phase portion from accumulating in the regeneration side reservoir.

[0025] The gas treatment device may include an absorption-side reservoir that stores the treatment liquid that has been phase-separated into the first phase portion and the second phase portion in the absorber, a first flow rate control mechanism that sends the first phase portion from the absorption-side reservoir to the regenerator, a second flow rate control mechanism that sends the second phase portion from the absorption-side reservoir to the regenerator, and a regenerated liquid flow rate control mechanism that sends the regenerated treatment liquid from the regeneration-side reservoir to the absorber so that a predetermined amount of the regenerated treatment liquid is accumulated in the regeneration-side reservoir.

[0026] In this embodiment, the regeneration-side reservoir is adjusted so that a predetermined amount of regenerated treated liquid is accumulated therein. In this case, the flow rates of the first and second phase portions sent from the absorption-side reservoir to the regenerator by the first and second flow rate control mechanisms are determined according to the flow rate of the regenerated liquid sent from the regeneration-side reservoir to the absorber by the regenerated liquid flow rate control mechanism. In other words, by adjusting the amount of regenerated treated liquid stored in the regeneration-side reservoir by the regenerated liquid flow rate control mechanism, it is possible to suppress the occurrence of an imbalance between the first and second phase portions between the absorber and the regenerator.

[0027] The regeneration-side reservoir may include a partition member that separates an introduction liquid space into which the treatment liquid is introduced from the regenerator and a regenerated liquid space into which the regenerated treatment liquid of the treatment liquid in the introduction liquid space flows in. In this case, the regenerated liquid flow rate adjustment mechanism may include a detector for detecting the liquid level of the regenerated treatment liquid in the regenerated liquid space, and a pump for sending the regenerated treatment liquid in the regenerated liquid space to the absorber so that the liquid level falls within a predetermined range based on a detection result by the detector.

[0028] In this embodiment, the pump sends the regenerated treated liquid toward the absorber so that the liquid level of the regenerated treated liquid stored in the regenerator space falls within a predetermined range. By controlling the liquid level in the regenerator-side reservoir in this manner, circulation of the treated liquid between the absorber and the regenerator is achieved in such a way that the first and second phases are less likely to become biased. In this case, the flow rate of the treated liquid sent from the absorber to the regenerator can be determined arbitrarily, so no special flow rate control is required on the absorber side.

[0029] The gas treatment device may include a first detector for detecting whether a liquid-liquid interface between the first phase portion and the second phase portion in the absorption-side reservoir is within a predetermined range. In this case, the first flow rate adjustment mechanism may be configured to adjust the flow rate of the first phase portion sent from the absorption-side reservoir to the regenerator based on a detection result by the first detector so that the liquid-liquid interface falls within the predetermined range.

[0030] In this embodiment, the liquid-liquid interface between the first phase and the second phase in the absorption-side reservoir is adjusted to fall within a predetermined range based on the detection result by the first detector. Therefore, in combination with the control of the amount of regenerated treated liquid stored in the regeneration-side reservoir, the bias between the first phase and the second phase between the absorber and the regenerator can be further suppressed.

[0031] A gas treatment method according to the present invention is a gas treatment method for releasing acidic compounds from a gas to be treated that contains acidic compounds that generate acid when dissolved in water, by using a treatment liquid that is in a mixed state of a first component and a second component having a specific gravity smaller than that of the first component before absorbing the acidic compounds, and that undergoes phase separation into a first phase portion mainly containing the first component and a second phase portion mainly containing the second component upon absorption of the acidic compounds, the method comprising: bringing the gas to be treated and the treatment liquid into contact with each other in an absorber to absorb the acidic compounds contained in the gas to be treated into the treatment liquid; storing the treatment liquid that has been phase-separated into the first phase portion and the second phase portion in the absorber in an absorption-side reservoir; the treatment liquid sent from the absorption side reservoir is heated in a regenerator to separate acidic compounds from the treatment liquid, a first detector is used to detect whether a liquid-liquid interface between the first phase portion and the second phase portion in the absorption side reservoir is within a predetermined range, a second detector is used to detect whether a liquid level of the second phase portion in the absorption side reservoir is within a predetermined range, and based on a detection result by the first detector, a flow rate of the first phase portion sent from the absorption side reservoir to the regenerator is adjusted so that the liquid-liquid interface falls within a predetermined range, and based on a detection result by the second detector, a flow rate of the second phase portion sent from the absorption side reservoir to the regenerator is adjusted so that the liquid level of the second phase portion falls within a predetermined range.

[0032] The space in the absorption-side reservoir may be partitioned into a first space into which the treatment liquid is introduced from the absorber and which stores the treatment liquid in a state of phase separation into a first phase portion and a second phase portion, and a second space into which the second phase portion overflowing from the first space is introduced. In this case, in the gas treatment method, the first detector may detect whether a liquid-liquid interface between the first phase portion and the second phase portion in the first space is within a predetermined range, and the second detector may detect whether an amount of the second phase portion stored in the second space is within a predetermined range.

[0033] In the gas processing method, a flow rate of the first phase portion sent from the absorption side reservoir to the regenerator may be increased when the detection result of the first detector indicates that the liquid-liquid interface between the first phase portion and the second phase portion is higher than the predetermined range, a flow rate of the first phase portion sent from the absorption side reservoir to the regenerator may be reduced when the detection result of the first detector indicates that the liquid-liquid interface between the first phase portion and the second phase portion is lower than the predetermined range, a flow rate of the second phase portion sent from the absorption side reservoir to the regenerator may be increased when the detection result of the second detector indicates that the liquid level of the second phase portion is higher than the predetermined range, and a flow rate of the second phase portion sent from the absorption side reservoir to the regenerator may be reduced when the detection result of the second detector indicates that the liquid level of the second phase portion is lower than the predetermined range.

[0034] In the gas treatment method, the treatment liquid heated in the regenerator is introduced into a regeneration side reservoir, and the introduced treatment liquid is stored in an introduction liquid space in the regeneration side reservoir. Even if the treatment liquid introduced into the introduction liquid space contains unregenerated treatment liquid, the regenerated treatment liquid is caused to flow from the introduction liquid space into the regenerated liquid space. When the treatment liquid contains the unregenerated treatment liquid, the unregenerated treatment liquid accumulated in the introduction liquid space may be returned to the regenerator.

[0035] The gas treatment method according to the present invention is a gas treatment method for releasing acidic compounds from a gas to be treated that contains acidic compounds that generate an acid when dissolved in water, by using a treatment liquid that is in a mixed state of a first component and a second component having a specific gravity smaller than that of the first component before absorbing the acidic compounds, and that undergoes phase separation into a first phase portion mainly containing the first component and a second phase portion mainly containing the second component upon absorption of the acidic compounds, the method comprising the steps of: bringing the gas to be treated and the treatment liquid into contact with each other in an absorber, and releasing the acidic compounds contained in the gas to be treated from the gas to be treated; The treatment liquid is absorbed into the treatment liquid, and the treatment liquid sent from the absorber is heated in a regenerator to separate acidic compounds from the treatment liquid. The treatment liquid heated in the regenerator is introduced into a regeneration side reservoir, and the introduced treatment liquid is stored in an introduction liquid space in the regeneration side reservoir. Even if the treatment liquid introduced into the introduction liquid space contains unregenerated treatment liquid, the regenerated treatment liquid is allowed to flow from the introduction liquid space into the regenerated liquid space. If the treatment liquid contains unregenerated treatment liquid, the unregenerated treatment liquid accumulated in the introduction liquid space is returned to the regenerator.

[0036] In the gas treatment method, the first phase portion of the treatment liquid accumulating in the introduction liquid space may be returned to the regenerator so that the amount of the first phase portion accumulated in the introduction liquid space is equal to or less than a predetermined amount, and a second phase portion of the treatment liquid in the introduction liquid space may be returned to the regenerator so that the liquid level of the treatment liquid accumulating in the introduction liquid space is equal to or less than a predetermined amount.

[0037] In the gas treatment method, a first unregenerated liquid detector may detect whether a first phase portion of the unregenerated treatment liquid has accumulated in a predetermined amount or more, and when the first unregenerated liquid detector detects that a first phase portion of the unregenerated treatment liquid has accumulated in a predetermined amount or more, the first phase portion may be returned to the regenerator.

[0038] In the gas treatment method, the treated liquid that has been phase-separated into the first phase portion and the second phase portion in the absorber may be stored in an absorption-side reservoir, the first phase portion and the second phase portion may be sent from the absorption-side reservoir to the regenerator, and the regenerated treated liquid may be sent from the regeneration-side reservoir to the absorber so that a predetermined amount of the regenerated treated liquid is stored in the regeneration-side reservoir.

[0039] The space in the regeneration side reservoir may be partitioned into an introduction liquid space into which the treatment liquid is introduced from the regenerator, and a regenerated liquid space into which the regenerated treatment liquid from the treatment liquid in the introduction liquid space flows in. In this case, in the gas treatment method, a detector may be used to detect the liquid level of the regenerated treatment liquid in the regenerated liquid space, and based on the detection result by the detector, the regenerated treatment liquid in the regenerated liquid space may be sent to the absorber so that the liquid level falls within a predetermined range.

[0040] In the gas treatment method, a first detector may be used in the absorption-side reservoir to detect whether a liquid-liquid interface between the first phase portion and the second phase portion is within a predetermined range, and a flow rate of the first phase portion sent from the absorption-side reservoir to the regenerator may be adjusted based on a detection result by the first detector so that the liquid-liquid interface is within the predetermined range. Effect of the Invention

[0041] As described above, according to the present invention, it is possible to suppress the liquid composition from becoming biased in the absorber and the regenerator. [Brief description of the drawings]

[0042] [Figure 1] 1 is a diagram illustrating a gas treatment device according to a first embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a schematic configuration of an absorption-side reservoir provided in the gas treatment device. [Diagram 3] 5 is a view for explaining a method for adjusting the amount of treatment liquid stored in the inlet-side space of the absorption-side reservoir. FIG. [Figure 4]6 is a view for explaining a method for adjusting the amount of treatment liquid stored in a space adjacent to the absorption-side reservoir. FIG. [Diagram 5] FIG. 10 is a schematic view showing a modified example of the absorption side reservoir. [Figure 6] FIG. 10 is a schematic view showing a modified example of the absorption side reservoir. [Figure 7] FIG. 4 is a view partially illustrating a gas treatment device according to a modified example of the first embodiment. [Figure 8] FIG. 11 is a diagram illustrating an absorption tower provided in a gas treatment device according to a second embodiment. [Figure 9] FIG. 4 is a diagram illustrating a modification of the absorption tower. [Figure 10] FIG. 13 is a diagram illustrating a gas treatment device according to a third embodiment. [Figure 11] FIG. 2 is a diagram illustrating a schematic configuration of a regeneration side reservoir provided in the gas treatment device. [Figure 12] 5 is a diagram for explaining a method for adjusting the amount of treatment liquid stored in the inlet side space of the regeneration side reservoir. FIG. [Figure 13] 6 is a diagram for explaining a method for adjusting the amount of treatment liquid stored in the space adjacent to the regeneration-side reservoir. FIG. [Figure 14] FIG. 13 is a schematic diagram showing a modified example of the regeneration side reservoir. [Figure 15] FIG. 13 is a schematic diagram showing a modified example of the regeneration side reservoir. [Figure 16] FIG. 11 is a diagram illustrating a schematic diagram of a regenerator provided in a gas treatment device according to a fourth embodiment. [Figure 17] FIG. 13 is a diagram illustrating a gas treatment device according to a fifth embodiment. [Figure 18] FIG. 2 is a diagram illustrating a schematic configuration of a regeneration side reservoir provided in the gas treatment device. [Figure 19] 5 is a diagram for explaining a method for adjusting the amount of treatment liquid stored in the introduction liquid space of the regeneration side reservoir. FIG. [Figure 20] 5 is a diagram for explaining a method for adjusting the amount of treatment liquid stored in the regeneration liquid space of the regeneration side reservoir. FIG. [Figure 21] FIG. 2 is a diagram illustrating a schematic configuration of an absorption-side reservoir provided in the gas treatment device. [Figure 22] FIG. 13 is a schematic diagram showing a modified example of an absorption-side reservoir provided in the gas treatment device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0044] (First embodiment) As shown in FIG. 1, the gas treatment device 10 according to the first embodiment is a device that separates acidic compounds from a gas to be treated that contains the acidic compounds by using a treatment liquid having a property of reversibly absorbing and releasing the acidic compounds. In this embodiment, the target of separation is carbon dioxide (CO2), which is an acidic compound that generates an acid when dissolved in water, and is therefore effective as a measure against global warming. The acidic compound is not particularly limited as long as the aqueous solution is acidic, and may be, for example, hydrogen chloride, carbon dioxide, sulfur dioxide, carbon disulfide, etc. Examples of the gas to be treated that contains the acidic compounds include industrial exhaust gas, process gas generated during refining, and natural gas.

[0045] The treatment liquid is a treatment liquid in which the amine and the second component are mixed together before absorbing the acidic compound, and which undergoes phase separation into a first phase portion mainly containing the amine and a second phase portion mainly containing the second component upon absorption of the acidic compound. The treatment liquid is, for example, an alkaline absorbent containing water, an amine, and an organic solvent as the second component, and may contain 30 wt% amine, 60 wt% organic solvent, and 10 wt% water.

[0046] As an amine, for example, 2-aminoethanol (MEA: solubility parameter = 14.3 (cal / cm 3 ) 1 / 2 ), 2-(2-aminoethoxy)ethanol (AEE: solubility parameter = 12.7 (cal / cm 3 ) 1 / 2), secondary amines such as 2-(methylamino)ethanol (MAE), 2-(ethylamino)ethanol (EAE), and 2-(butylamino)ethanol (BAE), and tertiary amines such as triethanolamine (TEA), N-methyldiethanolamine (MDEA), tetramethylethylenediamine (TEMED), pentamethyldiethylenetriamine (PMDETA), hexamethyltriethylenetetramine, and bis(2-dimethylaminoethyl)ether.

[0047] As an organic solvent, for example, 1-butanol (solubility parameter = 11.3 (cal / cm 3 ) 1 / 2 ), 1-pentanol (solubility parameter = 11.0 (cal / cm 3 ) 1 / 2 ), octanol, diethylene glycol diethyl ether (DEGDEE), diethylene glycol dimethyl ether (DEGDME), etc., and a mixture of two or more kinds may be used.

[0048] When the solubility parameters of the amine and the organic solvent are within a predetermined range, the treatment liquid forms a single liquid phase when it does not absorb the acidic compound, but when it absorbs the acidic compound, it undergoes phase separation into a first phase portion that has a high content of the acidic compound and mainly contains the amine, and a second phase portion that has a low content of the acidic compound and mainly contains the second component. Here, the solubility parameter is expressed by the following formula (1).

[0049]

number

[0050] ΔH is the molar latent heat of vaporization, R is the gas constant, T is the absolute temperature, and V is the molar volume.

[0051] [Table 1]

[0052] As shown in Table 1, in an absorbent containing water, an amine, and an organic solvent, the solubility parameter of the amine minus the solubility parameter of the organic solvent is 1.1 (cal / cm 3 ) 1 / 2 More than 4.2(cal / cm 3 ) 1 / 2 When the combination of amine and organic solvent is selected as shown below, a treatment liquid is obtained that is separated into two phases by absorption of the acidic compound: a first phase portion having a high content of the acidic compound and mainly containing the amine, and a second phase portion having a low content of the acidic compound and mainly containing the second component. Even in this case, before absorption of the acidic compound, the amine and the second component are mixed together to form a single liquid phase.

[0053] When the value of the difference in solubility parameters is less than the lower limit, the treatment liquid may not separate into two phases even if it absorbs an acidic compound. On the other hand, when the value of the difference in solubility parameters exceeds the upper limit, the treatment liquid may separate into two phases before absorbing an acidic compound, and in the step of contacting the treatment liquid with a gas to be treated containing an acidic compound, the contact state between the treatment liquid and the gas to be treated may become uneven, and the absorption efficiency may decrease. Note that "good" in Table 1 means that the treatment liquid was in a single liquid phase before absorbing carbon dioxide, and separated into two liquid phases due to the absorption of carbon dioxide. Also, "not miscible" in Table 1 means that the treatment liquid was in a two-liquid phase state before absorbing carbon dioxide, and did not form a single liquid phase. Also, "not separated" in Table 1 means that the treatment liquid was in a single liquid phase even after absorbing carbon dioxide.

[0054] As shown in Fig. 1, the gas treatment device 10 includes an absorber 12, a regenerator 14, a feed flow path 16, and a return flow path 18. The absorber 12 is a device for bringing a gas to be treated, such as a process gas, into contact with a treatment liquid, so that the treatment liquid absorbs acidic compounds in the gas to be treated. In this embodiment, carbon dioxide is separated as the acidic compound.

[0055] The feed flow path 16 is a flow path that extracts the treated liquid (rich liquid) that has absorbed carbon dioxide from the absorber 12 and introduces it into the regenerator 14. The regenerator 14 is a device for releasing carbon dioxide from the rich liquid by heating the rich liquid. The return flow path 18 is a flow path that extracts the treated liquid (lean liquid) after releasing carbon dioxide from the regenerator 14 and returns it to the absorber 12.

[0056] The absorber 12 is connected to an inlet passage 22 for supplying the gas to be treated to the absorber 12, a discharge passage 24 for discharging the gas after treatment (treated gas), a feed passage 16 for sending the treated liquid to the regenerator 14, and a return passage 18 for returning the treated liquid from the regenerator 14 to the absorber 12. The inlet passage 22 is connected to the lower part of the absorber 12, and the discharge passage 24 is connected to the upper part of the absorber 12. The feed passage 16 is connected to the lower part of the absorber 12. That is, the feed passage 16 is connected to the absorber 12 at a position where the treated liquid accumulated in the absorber 12 can be extracted. The return passage 18 is connected to the upper part of the absorber 12. That is, the return passage 18 is connected to the absorber 12 at a position where the treated liquid can flow down inside the absorber 12.

[0057] In the absorber 12, the gas to be treated introduced through the inlet line 22 comes into contact with the treatment liquid returned through the return line 18, and carbon dioxide in the gas to be treated is absorbed by the treatment liquid. In addition, treated gas, which is the gas from which carbon dioxide has been removed, is discharged from the absorber 12 through the discharge line 24. The absorption of carbon dioxide in the absorber 12 is an exothermic reaction. This reaction heat generated in the absorber 12 increases the temperatures of the gas to be treated, the treated gas, and the treatment liquid.

[0058] The treated liquid (rich liquid) that has absorbed carbon dioxide in the absorber 12 is discharged from the absorber 12 through the feed flow path 16. The rich liquid is phase-separated into a first phase portion that mainly contains amine and a second phase portion that mainly contains a second component (organic solvent). The feed flow path 16 is provided with an absorption-side reservoir 26 that stores the phase-separated treated liquid (rich liquid) separately into a treated liquid mainly containing the first phase portion and a treated liquid mainly containing the second phase portion. The absorption-side reservoir 26 is configured to separate the first phase portion and the second phase portion using the specific gravity difference between them.

[0059] The feed flow path 16 includes an upstream section 16a connecting the absorber 12 and the absorption side reservoir 26, a first flow path section 16b connected to an inlet side space 26a in the absorption side reservoir 26, which will be described later, a second flow path section 16c connected to an adjacent space 26b in the absorption side reservoir 26, which will be described later, and a downstream section 16d where the first flow path section 16b and the second flow path section 16c join and are connected to the regenerator 14. The first flow path section 16b allows the treated liquid (first phase portion) to flow out from the inlet side space 26a. The second flow path section 16c allows the treated liquid (second phase portion) to flow out from the adjacent space 26b.

[0060] As shown in FIG. 2, the space in the absorption-side reservoir 26 is partitioned by a partition member 27 into an inlet-side space 26a, which is a first space, and an adjacent space 26b, which is a second space. The treatment liquid introduced into the absorption-side reservoir 26 through the feed flow path 16 is introduced into the inlet-side space 26a. The treatment liquid that has flowed into the inlet-side space 26a is in a phase-separated state. Therefore, the second phase portion of the treatment liquid, which has a low specific gravity, exceeds the upper end of the partition member 27 and is introduced into the adjacent space 26b. Therefore, the first phase portion is mainly stored in the inlet-side space 26a, and the second phase portion is mainly stored in the adjacent space 26b. In this way, in the absorption-side reservoir 26, the treatment liquid is separated into a treatment liquid mainly containing a first phase portion and a treatment liquid mainly containing a second phase portion.

[0061] The inlet space 26a is provided with a first detector 31 for detecting whether the liquid-liquid interface between the first phase portion and the second phase portion is within a predetermined range. The first detector 31 may be any type of sensor or switch that can be used to monitor the position of the liquid-liquid interface. For example, a sensor or switch such as an electrode type level switch, a float type level switch, a capacitance type level switch, an optical type level switch, or a guided pulse type level sensor may be adopted. The liquid-liquid interface may be directly detected by a sensor, or the upper and lower limits of the liquid-liquid interface may be detected by a pair of level switches. Note that FIG. 2 shows an example in which the liquid-liquid interface is monitored by a pair of level switches.

[0062] The first flow path section 16b is provided with a first flow rate adjustment mechanism 28 for adjusting the flow rate of the first phase portion sent from the absorption-side reservoir 26 to the regenerator 14. The first flow rate adjustment mechanism 28 is configured to be able to adjust the flow rate based on the detection result by the first detector 31. Therefore, by controlling the first flow rate adjustment mechanism 28, the height of the liquid-liquid interface between the first phase portion and the second phase portion falls within a predetermined range. As a result, the amount of the first phase portion stored in the absorption-side reservoir 26 is adjusted to a predetermined amount.

[0063] The first detector 31 constantly monitors the liquid-liquid interface, and the first flow rate adjustment mechanism 28 is configured to adjust the flow rate each time based on the detection result by the first detector 31. For this reason, the first flow rate adjustment mechanism 28 includes a pump and a controller, and the controller is configured to control the pump based on a signal from the first detector 31.

[0064] The adjacent space 26b is provided with a second detector 32 for detecting whether the liquid level of the second phase portion is within a predetermined range. The second detector 32 may be any type of sensor or switch that can be used to detect the position of the liquid level. For example, a sensor or switch such as an electrode type level switch, a float type level switch, a capacitance type level switch, an optical type level switch, or a guided pulse type level sensor may be used. The liquid level may be directly detected by a sensor, or the upper and lower limits of the liquid level may be detected by a pair of level switches.

[0065] The second flow path section 16c is provided with a second flow rate adjustment mechanism 29 that adjusts the flow rate of the second phase portion sent from the absorption-side reservoir 26 to the regenerator 14. The second flow rate adjustment mechanism 29 is configured to control the flow rate based on the detection result by the second detector 32. Therefore, by controlling the second flow rate adjustment mechanism 29, the liquid level of the second phase portion in the adjacent space 26b falls within a predetermined range. As a result, the amount of the second phase portion stored in the absorption-side reservoir 26 is adjusted to a predetermined amount.

[0066] The second detector 32 constantly monitors the liquid level, and the second flow rate adjustment mechanism 29 is configured to adjust the flow rate each time based on the detection result by the second detector 32. For this reason, the second flow rate adjustment mechanism 29 includes a pump and a controller, and the controller is configured to control the pump based on a signal from the second detector 32.

[0067] A heat exchanger 34 is provided at the downstream portion 16d of the feed flow path 16. The heat exchanger 34 is for exchanging heat between the treatment liquid (rich liquid) flowing through the feed flow path 16 and the treatment liquid (lean liquid) returned from the regenerator 14 to the absorber 12 through the return flow path 18. The heat exchanger 34 may be omitted.

[0068] The regenerator 14 is connected to a feed flow path 16 and a return flow path 18. The feed flow path 16 is connected to an upper part of the regenerator 14. The return flow path 18 is connected to a lower part of the regenerator 14. A pump 35 is provided in the return flow path 18.

[0069] The regenerator 14 stores the treatment liquid containing carbon dioxide introduced through the feed flow path 16. The regenerator 14 is provided with a heater 36 for heating the treatment liquid in the regenerator 14 to desorb carbon dioxide from the treatment liquid. When the treatment liquid is heated in the regenerator 14, not only is carbon dioxide desorbed, but water in the treatment liquid also evaporates. Note that desorption of carbon dioxide from the treatment liquid is an endothermic reaction.

[0070] A supply line 38 is connected to the regenerator 14 for supplying the gas containing carbon dioxide obtained in the regenerator 14 to a carbon dioxide consumer. In addition, a separation promoting gas for promoting separation of acidic compounds from the treatment liquid in the regenerator 14 may be supplied to the regenerator 14. The separation promoting gas is a hydrocarbon gas such as hydrogen gas, oxygen gas, or methane gas, water vapor, or the like.

[0071] Here, a description will be given of a gas processing method using the gas processing device 10 according to the first embodiment. The gas processing method includes an absorption step and a regeneration step.

[0072] The absorption step is a step in which the gas to be treated is brought into contact with the treatment liquid in the absorber 12. The gas to be treated, such as a process gas containing at least carbon dioxide, is supplied to the absorber 12 through an inlet 22. The treatment liquid is also introduced into the absorber 12 through a return path 18. The treatment liquid comes into contact with the carbon dioxide contained in the gas to be treated and absorbs the carbon dioxide. The treatment liquid (rich liquid) that has absorbed the carbon dioxide undergoes phase separation into a first phase portion having a high carbon dioxide content and a second phase portion having a low carbon dioxide content.

[0073] The treated liquid in the absorber 12 is introduced into the inlet space 26a of the absorption-side reservoir 26 through the upstream portion 16a of the feed flow path 16. Since the treated liquid introduced into the absorption-side reservoir 26 is in a phase-separated state, the treated liquid is stored in the inlet space 26a such that a second phase portion (mainly containing an organic solvent) having a smaller specific gravity than the first phase portion is located above a first phase portion (mainly containing amine). Then, a part of the second phase portion of the treated liquid passes over the upper end of the partition member 27 and is introduced into the adjacent space 26b.

[0074] In the inlet space 26a, a first detector 31 monitors whether the liquid-liquid interface between the first and second phases is within a predetermined range. In the adjacent space 26b, a first detector 31 monitors whether the liquid level of the second phase is within a predetermined range.

[0075] Here, a method for adjusting the amount of the treatment liquid stored in the inlet space 26a and the adjacent space 26b will be described with reference to Fig. 3 and Fig. 4. Fig. 3 shows a method in the case where the first detector 31 is configured with a pair of level switches (upper limit switch 31a and lower limit switch 31b).

[0076] First, it is determined whether the lower limit switch 31b detects the gas phase, the first phase portion, or the second phase portion (step ST11).

[0077] If it is determined that the lower limit switch 31b detects the first phase portion, the process proceeds to step ST12, where it is determined whether the upper limit switch 31a detects the gas phase, the first phase portion, or the second phase portion. If it is determined that the upper limit switch 31a detects the first phase portion, the amount of the first phase portion stored is too large, so the first flow rate adjustment mechanism 28 is adjusted so that the flow rate of the first flow rate adjustment mechanism 28 is increased by a predetermined amount (step ST13). If it is determined that the upper limit switch 31a detects the second phase portion, the amount of the first phase portion stored is within the appropriate range, so the flow rate of the first flow rate adjustment mechanism 28 is not changed (step ST14). If it is determined that the upper limit switch 31a detects the gas phase, the amount of the first phase portion and the second phase portion stored is too small, so the first flow rate adjustment mechanism 28 is adjusted so that the flow rate of the first flow rate adjustment mechanism 28 is decreased by a predetermined amount (step ST15).

[0078] On the other hand, if it is determined in step ST11 that the lower limit switch 31b has detected the second phase portion, the amount of stored first phase portion is too small, so the first flow rate control mechanism 28 is adjusted so that the flow rate of the first flow rate control mechanism 28 is reduced by a predetermined amount (step ST21).

[0079] Furthermore, in step ST11, if it is determined that the lower limit switch 31b has detected the gas phase, the amount of the first phase and second phase portions stored is too small, so the first flow rate control mechanism 28 is adjusted so that the flow rate of the first flow rate control mechanism 28 is reduced by a predetermined amount (step ST22).

[0080] The first phase portion at the flow rate adjusted in this manner is sent from the inlet side space 26a to the first flow path portion 16b.

[0081] 4, the second flow rate adjustment mechanism 29 adjusts the flow rate so that the liquid level of the second phase portion detected by the second detector 32 falls within a predetermined range (preferably so that it is constant) (step ST31). That is, when the liquid level of the second phase portion is higher than the predetermined range, the flow rate by the second flow rate adjustment mechanism 29 is increased, and when the liquid level is lower than the predetermined range, the flow rate by the second flow rate adjustment mechanism 29 is reduced.

[0082] The second phase portion at the flow rate adjusted in this manner is sent from the adjacent space 26b to the second flow path section 16c. That is, the first phase portion mainly containing amine is discharged through the first flow path section 16b, and the second phase portion mainly containing the second component (organic solvent) is discharged through the second flow path section 16c. At this time, the first flow rate adjustment mechanism 28 and the second flow rate adjustment mechanism 29 adjust the ratio of the first phase portion to the second phase portion in the absorption side reservoir 26 to fall within a predetermined range, so that the bias of the liquid composition in the absorber 12 and the regenerator 14 is suppressed.

[0083] The first phase portion and the second phase portion join together in the downstream portion 16d and are heated in the heat exchanger 34 by heat exchange with the treatment liquid (lean liquid) flowing through the return path 18. The treatment liquid that has passed through the heat exchanger 34 is introduced into the regenerator 14.

[0084] The treatment liquid introduced into the regenerator 14 is heated by the heater 36, whereby carbon dioxide is separated from the treatment liquid (regeneration step). The carbon dioxide separated from the treatment liquid is sent to a demand destination through a supply line 38.

[0085] The treated liquid (lean liquid) stored in the regenerator 14 flows through the return path 18 and returns to the absorber 12. The treated liquid in the return path 18 heats the treated liquid flowing through the feed path 16 in the heat exchanger 34.

[0086] As described above, in this embodiment, when the treatment liquid absorbs the acidic compound in the absorber 12, the treatment liquid undergoes phase separation into a first phase portion mainly containing the first component and a second phase portion mainly containing the second component. This phase-separated treatment liquid is stored in the absorption-side reservoir 26. In the absorption-side reservoir 26, the second phase portion mainly containing the second component having a lower specific gravity accumulates above the first phase portion mainly containing the first component, and a liquid-liquid interface is generated between the first phase portion and the second phase portion. Then, the first flow rate adjustment mechanism 28 adjusts the flow rate of the first phase portion sent from the absorption-side reservoir 26 to the regenerator 14 so that this liquid-liquid interface falls within a predetermined range, and the second flow rate adjustment mechanism 29 adjusts the flow rate of the second phase portion sent from the absorption-side reservoir 26 to the regenerator 14 so that the liquid level of the second phase portion falls within a predetermined range. Therefore, by utilizing the fact that the first phase portion and the second phase portion accumulate in layers in the absorption-side reservoir 26, the ratio of the first phase portion and the second phase portion accumulated in the absorption-side reservoir 26 is adjusted to be within a predetermined range. For this reason, for example, when the ratio of the first phase portion is high in the absorber 12 and the ratio of the second phase portion is high in the regenerator 14, a larger amount of the first phase portion is introduced into the absorption-side reservoir 26. At this time, the first flow rate control mechanism 28 is adjusted so as to send out a larger amount of the first phase portion from the absorption-side reservoir 26. Therefore, it is possible to suppress the occurrence of an imbalance between the first phase portion and the second phase portion between the absorber 12 and the regenerator 14.

[0087] In this embodiment, the space in the absorption-side reservoir 26 is divided by the partition member 27 into an inlet-side space 26a, which is a first space in which the phase-separated treatment liquid is stored, and an adjacent space 26b, which is a second space in which only the second phase portion is stored. Therefore, the second flow rate control mechanism 29 can prevent the first phase portion from being sent out, and therefore the flow rate control by the first flow rate control mechanism 28 and the second flow rate control mechanism 29 can be easily performed.

[0088] In this embodiment, the first detector 31 is configured by a pair of level switches, but as shown in Fig. 5, the first detector 31 may be configured by a level sensor that can directly detect the liquid-liquid interface. In this case, when the liquid-liquid interface is not detected by the first detector 31, that is, when the amount of the first phase portion stored is too small, the first flow rate adjustment mechanism 28 is adjusted to reduce the flow rate sent out from the inlet side space 26a. On the other hand, when the liquid-liquid interface is detected by the first detector 31, if the liquid-liquid interface is lower than a predetermined position, the first flow rate adjustment mechanism 28 is adjusted to reduce the flow rate sent out from the inlet side space 26a, and if the liquid-liquid interface is higher than the predetermined position, the first flow rate adjustment mechanism 28 is adjusted to increase the flow rate sent out.

[0089] In the above embodiment, the space in the absorption-side reservoir 26 is divided into the inlet-side space 26a and the adjacent space 26b, but the present invention is not limited to this configuration. For example, as shown in FIG. 6, the space in the absorption-side reservoir 26 may be formed as one space, and the treatment liquid may be stored in this space. In this case, a conduit 40 is inserted into the absorption-side reservoir 26, and the second flow path section 16c is connected to this conduit 40. The upper end of the conduit 40 is set at a position where the second phase portion can flow in. The first detector 31 is composed of a level sensor that detects the liquid-liquid interface, and the second detector 32 is composed of a level sensor that detects the liquid level of the second phase portion.

[0090] In this case, the first flow rate control mechanism 28 adjusts the flow rate sent out from the absorption-side reservoir 26 so that the liquid-liquid interface remains at a constant level. The second flow rate control mechanism 29 adjusts the flow rate sent out from the absorption-side reservoir 26 so that the liquid level of the second phase portion remains at a constant level. Since the upper end of the conduit 40 is located at a height equivalent to the second phase portion, the conduit 40 can discharge only the second phase portion.

[0091] In addition, when the space inside the absorption-side reservoir 26 is not partitioned into the inlet-side space 26a and the adjacent space 26b, the first flow path portion 16b may be connected to the bottom of the absorption-side reservoir 26, and the second flow path portion 16c may be connected to the upper part of the absorption-side reservoir 26. In this case, the conduit 40 can be omitted.

[0092] 7, the reflux path 18 may be provided with a component measuring device 42 and a refill container 43. The component measuring device 42 is configured to be capable of measuring the composition ratios of the amine, the second component (organic solvent), and water in the treatment liquid (lean liquid). When it is confirmed that the treatment liquid has been sufficiently regenerated, the refill container 43 can replenish the missing components based on the composition ratios measured by the component measuring device 42. A flow rate controller 44 may be provided in the reflux path 18.

[0093] Second embodiment 8 shows the second embodiment. Note that the same components as those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0094] In the second embodiment, the absorption-side reservoir 26 is integrally formed with the absorber 12. That is, an absorption tower 46 is formed including the absorber 12 and the absorption-side reservoir 26 provided below the absorber 12. In the absorption tower 46, the space within the absorber 12 and the space within the absorption-side reservoir 26 are formed as one continuous space.

[0095] The upper plate 47 of the absorption-side reservoir 26 is configured to guide the treated liquid (the treated liquid that has absorbed acidic compounds) in the absorber 12 so as not to flow into the adjacent space 26b of the absorption-side reservoir 26. The treated liquid in the absorber 12 is introduced into the inlet-side space 26a of the absorption-side reservoir 26 through a gap between the upper plate 47 and the side wall of the absorption-side reservoir 26. A first flow path section 16b is connected to the inlet-side space 26a, and a second flow path section 16c is connected to the adjacent space 26b. The feed flow path 16 does not have an upstream section 16a.

[0096] The partition member 27 separating the inlet space 26a from the adjacent space 26b may be omitted. In this case, as shown in Fig. 9, a conduit 40 is inserted into the absorption-side reservoir 26, and the second flow path section 16c is connected to the conduit 40. The upper end of the conduit 40 is set at a position where the second phase portion can flow in. As a result, only the second phase portion flows into the second flow path section 16c through the conduit 40. On the other hand, the first flow path section 16b is connected to the bottom of the absorption-side reservoir 26. Therefore, the first phase portion in the absorption-side reservoir 26 flows out of the absorption-side reservoir 26 through the first flow path section 16b.

[0097] It should be noted that the description of the other configurations, operations, and effects will not be repeated, but the description of the first embodiment can be applied to the second embodiment.

[0098] Third embodiment 10 and 11, in the third embodiment, a regeneration side reservoir 50 is added. Note that the same components as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0099] The regeneration side reservoir 50 is provided in the return flow path 18, and the treated liquid heated in the regenerator 14 is introduced therein. The space in the regeneration side reservoir 50 is divided into an introduction liquid space 50a and a regenerated liquid space 50b by a partition member 51. The introduction liquid space 50a is further divided into an inlet side space 50a1 and an adjacent space 50a2 by an auxiliary partition 52. The inlet side space 50a1 (introducing liquid space 50a) is introduced with the treated liquid drawn out from the regenerator 14. This treated liquid includes the treated liquid (regenerated liquid) that has been regenerated in the regenerator 14, but the regeneration of the treated liquid in the regenerator 14 may not keep up, and a treated liquid (unregenerated liquid) containing acidic compounds may be generated without being regenerated. In that case, the unregenerated liquid is included in the treated liquid introduced into the regeneration side reservoir 50. Since the unregenerated liquid includes acidic compounds, it is phase-separated into a first phase portion and a second phase portion. On the other hand, the regenerated liquid is not phase-separated. The first phase portion, which mainly contains amine, is separated from the regenerated liquid, while the second phase portion, which mainly contains the second component (organic solvent), is mixed with the regenerated liquid. Therefore, when unregenerated liquid is generated, the first phase portion of the unregenerated liquid accumulates below the regenerated liquid mixed with the second phase portion in the inlet side space 50a1. In addition, in the regenerated liquid mixed with the second phase portion, the proportion of the regenerated liquid is higher at the lower side, and the proportion of the second component is higher at the upper side.

[0100] The partition member 51 has a communication hole 51a that communicates the inlet side space 50a1 and the regenerated liquid space 50b. The communication hole 51a is provided at a position where the ratio of the regenerated liquid (regenerated phase) or the regenerated liquid is high in the inlet side space 50a1. Therefore, the regenerated processing liquid (regenerated liquid) among the processing liquids accumulated in the inlet side space 50a1 flows into the regenerated liquid space 50b. Therefore, the regenerated liquid is accumulated in the regenerated liquid space 50b. Note that only the regenerated liquid does not always flow into the regenerated liquid space 50b, and when the ratio of the second phase portion that mixes with the regenerated liquid is high, the second phase portion of the unregenerated liquid may also flow into the regenerated liquid space 50b.

[0101] When unregenerated liquid is generated, the treated liquid (mainly the second phase portion) that exceeds the upper end of the auxiliary partition 52 among the treated liquid accumulated in the inlet side space 50a1 is introduced into the adjacent space 50a2. Therefore, the second phase portion of the unregenerated liquid is mainly accumulated in the adjacent space 50a2.

[0102] The inlet space 50a1 (introducing liquid space 50a) is provided with a first unregenerated liquid detector 55 for detecting whether the first phase portion of the unregenerated liquid is accumulated in a predetermined amount or more. The first unregenerated liquid detector 55 may be any type of sensor or switch that can be used to monitor the position of the liquid-liquid interface between the first phase portion and the regenerated liquid. For example, a sensor or switch such as an electrode type level switch, a float type level switch, a capacitance type level switch, an optical type level switch, or a guided pulse type level sensor can be adopted. The liquid-liquid interface may be directly detected by a sensor, or the upper and lower limits of the liquid-liquid interface may be detected by a pair of level switches. Since it is preferable that the unregenerated first phase portion does not accumulate in the introducing liquid space 50a as much as possible, the first unregenerated liquid detector 55 is preferably set so as to be able to detect the liquid-liquid interface between the first phase portion and the regenerated liquid even when the interface is at a low position.

[0103] A first return path 56 that connects the inlet side space 50a1 and the regenerator 14 is connected to the regenerator 50. The first return path 56 is provided with a first return mechanism 57 for returning the first phase portion in the inlet side space 50a1 to the regenerator 14. The first return path 56 may be provided with a heat exchanger for heating the first phase portion.

[0104] The adjacent space 50a2 is provided with a second unregenerated liquid detector 58 for detecting whether the liquid level of the second phase portion of the unregenerated liquid is within a predetermined range. The second unregenerated liquid detector 58 may be any type of sensor or switch that can be used to detect the liquid level of the second phase portion. For example, a sensor or switch such as an electrode type level switch, a float type level switch, a capacitance type level switch, an optical type level switch, or a guided pulse type level sensor can be used. The liquid level may be directly detected by a sensor, or the upper and lower limits of the liquid level may be detected by a pair of level switches. Note that the flow rate of the second return mechanism 60 described later can be set arbitrarily, so the second unregenerated liquid detector 58 can be omitted.

[0105] A second return path 59 that connects the adjacent space 50a2 and the regenerator 14 is connected to the regenerator 50. The second return path 59 is provided with a second return mechanism 60 for returning the second phase portion in the adjacent space 50a2 to the regenerator 14. The second return path 59 may be provided with a heat exchanger for heating the second phase portion.

[0106] The first return mechanism 57 and the second return mechanism 60 constitute an unregenerated liquid return mechanism that returns the unregenerated treatment liquid accumulated in the introduction liquid space 50a from the regeneration side reservoir 50 to the regenerator 14.

[0107] Here, a method for adjusting the amount of the treatment liquid stored in the inlet-side space 50a1 and the adjacent space 50a2 in the regeneration-side reservoir 50 will be described with reference to FIGS.

[0108] In the inlet space 50a1, the first unregenerated liquid detector 55 monitors whether the liquid-liquid interface between the first phase portion and the regenerated liquid is within a predetermined range (step ST41). When the first unregenerated liquid detector 55 detects the first phase portion, the first return mechanism 57 is operated (step ST42). That is, since it is determined that the amount of the first phase portion of the unregenerated liquid stored in the regenerator 50 is excessive, the first return mechanism 57 is operated to return the first phase portion of the unregenerated liquid from the inlet space 50a1 to the regenerator 14. As a result, the amount of the first phase portion of the unregenerated liquid stored in the regenerator 50 is adjusted to a predetermined amount. The unregenerated liquid returned to the regenerator 14 is reheated in the regenerator 14. Since it is desirable that the first phase portion is hardly stored in the regenerator 50, the "predetermined amount" is preferably an amount close to zero.

[0109] In the adjacent space 50a2, the second unregenerated liquid detector 58 monitors whether the liquid level of the processing liquid (mainly the second phase portion in the adjacent space 50a2) is below a predetermined level (step ST51). When the second unregenerated liquid detector 58 determines that the liquid level is higher than the predetermined range, the flow rate by the second return mechanism 60 is increased (step ST52). As a result, the unregenerated second phase portion is returned to the regenerator 14 and reheated. Also, the liquid level of the processing liquid in the adjacent space 50a2 becomes below a certain level. When the second unregenerated liquid detector 58 is omitted, the flow rate of the second return mechanism 60 is set arbitrarily.

[0110] The flow rate of the pump 35 can be set arbitrarily by the user.

[0111] In this embodiment, the first return mechanism 57 and the second return mechanism 60 are operated to return the unregenerated treated liquid from the regeneration side reservoir 50 to the regenerator 14. By the operation of the return mechanisms 57 and 60, at least a part of the unregenerated treated liquid is returned to the regenerator 14. Therefore, even if unregenerated treated liquid is generated in the regenerator 14 and accumulates in the regeneration side reservoir 50, this unregenerated treated liquid is returned to the regenerator 14 and heated again, so that the regeneration process of the unregenerated treated liquid is promoted. Therefore, the treated liquid having a composition ratio different from the composition ratio of the treated liquid charged initially is prevented from returning to the absorber 12, so that the ratio of the first phase part and the second phase part contained in the treated liquid circulating between the regenerator 14 and the absorber 12 is prevented from fluctuating. Therefore, it is possible to further prevent the occurrence of a bias between the first phase part and the second phase part between the absorber 12 and the regenerator 14.

[0112] In this embodiment, the introduction liquid space 50a is divided into an inlet side space 50a1 and an adjacent space 50a2, and the second unregenerated liquid detector 58 is provided in the adjacent space 50a2. The second return mechanism 60 is controlled based on the detection result of the second unregenerated liquid detector 58. However, this configuration is not limited to this, and for example, as shown in FIG. 14, the introduction liquid space 50a may be configured as one space without the auxiliary partition 52. A conduit 62 is inserted into the introduction liquid space 50a, and an inlet (upper end) 62a of the conduit 62 is set at a position where the second phase portion in the introduction liquid space 50a accumulates. The second return path 59 is connected to the introduction liquid space 50a via the conduit 62. In this case, the flow rate by the second return mechanism 60 may be set to an arbitrary value. The second return mechanism 60 draws in the second phase portion, so that the liquid level of the second phase portion is adjusted to be equal to or lower than the height of the inlet 62a of the conduit 62. The first return mechanism 57 adjusts the flow rate according to the detection result by the first unregenerated liquid detector 55.

[0113] The conduit 62 may have a bent shape as shown in Fig. 15. Even in this case, the position of the inlet 62a is set to a position suitable for allowing the second phase portion to flow in.

[0114] Although a description of the other configurations, operations, and effects will be omitted, the descriptions of the first and second embodiments can be applied to the third embodiment.

[0115] (Fourth embodiment) 16 shows the fourth embodiment. Note that the same components as those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0116] In the fourth embodiment, the regenerator-side reservoir 50 is integrally formed with the regenerator 14. That is, a regenerator tower 64 is formed including the regenerator 14 and the regenerator-side reservoir 50 provided below the regenerator 14. In the regenerator tower 64, the space within the regenerator 14 and the space within the regenerator-side reservoir 50 are formed as one continuous space.

[0117] The upper plate 65 of the regeneration-side reservoir 50 is configured to guide the treatment liquid so that the treatment liquid in the regenerator 14 does not flow into the adjacent space 50a2 in the regeneration-side reservoir 50. Through an opening 65a formed in the upper plate 65, the treatment liquid in the regenerator 14 is introduced into the introduction liquid space 50a of the regeneration-side reservoir 50. The introduction liquid space 50a may be partitioned into an inlet side space 50a1 and an adjacent space 50a2, or may be configured as a single space as in FIG. 14 .

[0118] It should be noted that the explanations of the other configurations, operations and effects will be omitted, but the explanations of the first to third embodiments can be applied to the fourth embodiment.

[0119] Fifth embodiment The control in the regeneration-side reservoir 50 described in Fig. 12 and Fig. 13 is based on the assumption that the liquid level control (control shown in Fig. 3) is performed in the absorption-side reservoir 26. In contrast, as shown in Fig. 17, the gas treatment device 10 of the fifth embodiment does not include the absorption-side reservoir 26, but includes the regeneration-side reservoir 50. The feed flow path 16 is not branched into the first flow path portion 16b and the second flow path portion 16c at the middle portion, but is configured as a single flow path. The feed flow path 16 is provided with a pump 69 for sending the treatment liquid to the regenerator 14. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0120] As the regeneration-side reservoir 50 in the fifth embodiment, the configurations shown in Fig. 11 and Fig. 14 to Fig. 16 can be adopted. However, in the fifth embodiment, since the liquid level control is not performed in the absorption-side reservoir 26, the liquid level control is performed in the regeneration-side reservoir 50.

[0121] As shown in Fig. 18, the regeneration side reservoir 50 is provided with a first unregenerated liquid detector 55 and a liquid level detector 68. In Fig. 18, the auxiliary partition 52 is not provided, the liquid introduction space 50a is configured as a single space, and the conduit 62 is inserted therein, so that the second unregenerated liquid detector 58 is not provided, but the auxiliary partition 52 and the second unregenerated liquid detector 58 may be provided in the same configuration as in Fig. 11.

[0122] The first unregenerated liquid detector 55 is a detector for detecting whether or not a predetermined amount or more of the first phase portion of the unregenerated liquid has accumulated, and is disposed in the introducing liquid space 50a (or the inlet side space 50a1).

[0123] The liquid level detector 68 is a detector for detecting whether the liquid level in the regenerated liquid space 50b is within a predetermined range, and is disposed in the regenerated liquid space 50b. Since the regenerated liquid space 50b and the introduction liquid space 50a are in communication with each other through the communication hole 51a, the liquid level detector 68 may be disposed in the introduction liquid space 50a.

[0124] The first return mechanism 57 is activated when the first unregenerated liquid detector 55 detects a first phase portion of a predetermined amount or more. That is, when a liquid-liquid interface between the first phase portion and the regenerated liquid is detected, it is determined that a first phase portion of a predetermined amount or more has been accumulated, and the first return mechanism 57 is activated. When the first return mechanism 57 is activated, the first phase portion in the introduction liquid space 50a is returned to the regenerator 14. Since it is preferable that the first phase portion does not accumulate in the introduction liquid space 50a as much as possible, it is preferable that the first unregenerated liquid detector 55 is set so that it can detect the liquid-liquid interface between the first phase portion and the regenerated liquid even when the interface is at a low position.

[0125] 18, when the conduit 62 is used, if the liquid level of the processing liquid (mainly the second phase portion near the liquid level) is higher than the upper end (inlet 62a) of the conduit 62, the second return mechanism 60 draws in the corresponding amount of processing liquid (mainly the second phase portion). This makes it possible to adjust the liquid level of the processing liquid to a predetermined value or lower.

[0126] The pump 35 adjusts the outflow flow rate of the regenerated liquid so that the liquid level in the regenerated liquid space 50b falls within a predetermined range based on the detection result by the liquid level detector 68. That is, the pump 35 and the liquid level detector 68 function as a regenerated liquid flow rate adjustment mechanism 70 that sends the regenerated treated liquid from the regeneration-side reservoir 50 to the absorber 12 so that a predetermined amount of the regenerated treated liquid is accumulated in the regeneration-side reservoir 50. Note that, when the first unregenerated liquid detector 55 detects the gas phase, the pump 35 is configured to reduce the flow rate.

[0127] Here, a method for adjusting the amount of treatment liquid stored in the regeneration-side reservoir 50 will be described with reference to FIGS.

[0128] In FIG. 19, in the introduction liquid space 50a (or the inlet side space 50a1), the first unregenerated liquid detector 55 monitors the position of the liquid-liquid interface between the first phase portion of the unregenerated liquid and the regenerated liquid (mixed with the unregenerated second phase portion) (step ST61). That is, the first unregenerated liquid detector 55 monitors whether the gas phase, the unregenerated first phase portion, the regenerated liquid (mixed with the unregenerated second phase portion), or the gas phase is detected. In this step ST61, if the regenerated phase (mixed with the unregenerated second phase portion) is detected (if it is determined that the liquid-liquid interface is within a predetermined range), it is determined that the flow rate is appropriate, so the temperature in the regenerator 14 is checked (step ST62). If it is within the predetermined temperature range, the flow rate of the first return mechanism 57 is maintained as it is, and the heat input by the heater 36 is also maintained (step ST63). On the other hand, if the temperature inside the regenerator 14 exceeds the predetermined range, the flow rate of the first return mechanism 57 is reduced, and the amount of heat input by the heater 36 is reduced (step ST64).

[0129] In step ST61, if the first unregenerated liquid detector 55 detects a gas phase, the flow rate of the pump 35 is reduced (step ST65). That is, since the first unregenerated liquid detector 55 is for monitoring whether or not the first phase portion is detected, the detection of a gas phase by the first unregenerated liquid detector 55 is considered to indicate the occurrence of some kind of malfunction.

[0130] Furthermore, when it is determined that the first phase portion is detected by the first unregenerated liquid detector 55 (when it is determined that the liquid-liquid interface is higher than the predetermined range), the first return mechanism 57 is operated (step ST66). As a result, the first phase portion in the introduced liquid space 50a is returned to the regenerator 14. At this time, the amount of heat input by the heater 36 of the regenerator 14 is increased (step ST67).

[0131] Meanwhile, as shown in FIG. 20, the liquid level detector 68 monitors whether the liquid level in the regenerated liquid space 50b is within a predetermined range (step ST71). Then, when the liquid level is out of the predetermined range, the pump 35 adjusts the pumping flow rate from the regenerator 14 (step ST72). That is, when the liquid level of the regenerated processing liquid becomes higher than the predetermined range, the pump 35 increases the rotation speed. On the other hand, when the liquid level of the regenerated processing liquid becomes lower than the predetermined range, the pump 35 decreases the rotation speed. This adjusts the amount of regenerated liquid stored in the regenerated liquid space 50b to a predetermined amount.

[0132] In this manner, the first return mechanism 57 adjusts the amount of the first phase portion stored in the regeneration-side reservoir 50 to a predetermined amount or less, and the second return mechanism 60 adjusts the amount of the second phase portion stored in the regeneration-side reservoir 50 to a predetermined amount or less. This allows the regeneration of the treatment liquid by the regenerator 14 to be completed.

[0133] In this embodiment, the treatment liquid introduced from the regenerator 14 to the regeneration side reservoir 50 may contain regenerated treatment liquid and unregenerated treatment liquid (unregenerated liquid). In this case, in the regeneration side reservoir 50, the regenerated treatment liquid flows into the regenerated liquid space 50b, while the unregenerated liquid is stored in the introduction liquid space 50a. Then, the return mechanisms 57, 60 are operated to return the unregenerated liquid to the regenerator 14. By the operation of the return mechanisms 57, 60, at least a part of the unregenerated liquid is returned to the regenerator 14. Therefore, even if unregenerated treatment liquid is generated in the regenerator 14 and accumulates in the regeneration side reservoir 50, this unregenerated treatment liquid is returned to the regenerator 14 and heated again, so that the regeneration process of the unregenerated treatment liquid is promoted. Therefore, the treatment liquid having a composition ratio different from the composition ratio of the treatment liquid charged initially is suppressed from returning to the absorber 12, and therefore the ratio of the first phase part and the second phase part contained in the treatment liquid circulating between the regenerator 14 and the absorber 12 is suppressed from fluctuating. Therefore, the occurrence of an imbalance between the first phase portion and the second phase portion between the absorber 12 and the regenerator 14 can be suppressed.

[0134] In this embodiment, the pump 35 sends the regenerated treated liquid toward the absorber 12 so that the liquid level of the regenerated treated liquid accumulated in the regenerated liquid space 50b falls within a predetermined range. By controlling the liquid level in the regeneration side reservoir 50 in this manner, it is possible to obtain circulation of the treated liquid between the absorber 12 and the regenerator 14 in such a way that the first and second phases are unlikely to become unevenly distributed, even without controlling the flow rate of the treated liquid sent from the absorber 12 to the regenerator 14.

[0135] Even when the liquid level control is performed in the regeneration-side reservoir 50, the absorption-side reservoir 26 may be provided. In this case, however, simplified control can be performed in the absorption-side reservoir 26.

[0136] Specifically, in the absorption side reservoir 26, as shown in Fig. 21 or 22, a first detector 31 for detecting whether the liquid-liquid interface between the first phase and the second phase is within a predetermined range is provided in the inlet side space 26a. The first flow rate control mechanism 28 is controlled based on the detection result of the first detector 31 so that the liquid-liquid interface between the first phase and the second phase is within a predetermined range. Note that Fig. 21 shows a case where the first detector 31 is composed of a pair of level switches, and Fig. 22 shows a case where the first detector 31 is composed of a level sensor.

[0137] On the other hand, the second detector 32 for monitoring the liquid level of the second phase portion is omitted in the adjacent space 26b. Therefore, the flow rate by the second flow rate control mechanism 29 for sending out the second phase portion from the absorption-side reservoir 26 can be arbitrarily set by the user.

[0138] Although a description of the other configurations, operations, and effects will be omitted, the descriptions of the first to fourth embodiments can be applied to the fifth embodiment.

[0139] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The present invention is not limited to the above-described embodiments, and various modifications and improvements can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0140] 10: Gas treatment equipment 12: Absorber 14:Regenerator 26: Absorption side reservoir 27: Partition material 28: 1st flow rate adjustment mechanism 29:Second flow rate adjustment mechanism 31: First detector 32: Second detector 35: Pump 50:Regeneration side reservoir 50a: Liquid introduction space 50b: Regeneration liquid space 51: Partition material 55: First unregenerated liquid detector 57: First return mechanism (unregenerated liquid return mechanism) 58: Second unregenerated liquid detector 60: Second return mechanism (unregenerated liquid return mechanism) 68: Liquid level detector 70: Regenerated liquid flow regulator

Claims

1. A gas treatment device for releasing acidic compounds from a gas to be treated, the acidic compounds generating an acid when dissolved in water, using a treatment liquid that is in a mixed state of a first component and a second component having a specific gravity smaller than that of the first component before absorbing the acidic compounds, and that undergoes phase separation into a first phase portion mainly containing the first component and a second phase portion mainly containing the second component upon absorption of the acidic compounds, the gas treatment device comprising: an absorber for bringing the gas to be treated and the treatment liquid into contact with each other to absorb the acidic compounds contained in the gas to be treated into the treatment liquid; a regenerator for heating the treatment liquid having absorbed the acidic compounds to separate the acidic compounds from the treatment liquid; an absorption-side reservoir for storing the treated liquid that has been phase-separated into the first phase portion and the second phase portion in the absorber; a first detector for detecting whether a liquid-liquid interface between the first phase portion and the second phase portion is within a predetermined range in the absorption side reservoir; a second detector for detecting whether the liquid level of the second phase portion is within a predetermined range in the absorption side reservoir; a first flow rate adjustment mechanism that adjusts a flow rate of a first phase portion sent from the absorption-side reservoir to the regenerator based on a detection result by the first detector so that the liquid-liquid interface falls within a predetermined range; a second flow rate control mechanism that adjusts a flow rate of the second phase portion sent from the absorption-side reservoir to the regenerator based on a detection result by the second detector so that the liquid level of the second phase portion falls within a predetermined range; A gas treatment device comprising:

2. the absorption-side reservoir has a partition member that divides a space within the reservoir into a first space into which the treatment liquid is introduced from the absorber and into which the treatment liquid in a phase-separated state into a first phase portion and a second phase portion is stored, and a second space into which the second phase portion overflowing from the first space is introduced; the first detector is used to detect whether a liquid-liquid interface between the first phase portion and the second phase portion in the first space is within a predetermined range; The gas treatment device according to claim 1 , wherein the second detector is used to detect whether an amount of the second phase portion stored in the second space is within a predetermined range.

3. The first flow rate adjustment mechanism is increasing a flow rate of the first phase portion sent from the absorption side reservoir to the regenerator when a detection result of the first detector indicates that the liquid-liquid interface between the first phase portion and the second phase portion is higher than the predetermined range; a flow rate of the first phase portion sent from the absorption side reservoir to the regenerator is reduced when a detection result of the first detector indicates that the liquid-liquid interface between the first phase portion and the second phase portion is lower than the predetermined range, The second flow rate adjustment mechanism is increasing a flow rate of the second phase portion sent from the absorption side reservoir to the regenerator when a detection result of the second detector indicates that the liquid level of the second phase portion is higher than the predetermined range; 3. The gas treatment device according to claim 1, further comprising: a second detector configured to reduce a flow rate of the second phase portion sent from the absorption side reservoir to the regenerator when the detection result of the second detector indicates that the liquid level of the second phase portion is lower than the predetermined range.

4. a regeneration-side reservoir into which the treatment liquid heated in the regenerator is introduced, the regeneration-side reservoir having an introduction liquid space in which the introduced treatment liquid is stored, and a regeneration liquid space for receiving regenerated treatment liquid from the introduction liquid space even when the treatment liquid introduced into the introduction liquid space contains unregenerated treatment liquid; an unregenerated liquid returning mechanism that returns the unregenerated processing liquid accumulated in the liquid introduction space to the regenerator when the unregenerated processing liquid is included in the processing liquid; The gas treatment device of claim 1 or 2, further comprising:

5. A gas treatment device for releasing acidic compounds from a gas to be treated, the acidic compounds generating an acid when dissolved in water, using a treatment liquid that is in a mixed state of a first component and a second component having a specific gravity smaller than that of the first component before absorbing the acidic compounds, and that undergoes phase separation into a first phase portion mainly containing the first component and a second phase portion mainly containing the second component upon absorption of the acidic compounds, the gas treatment device comprising: an absorber for bringing the gas to be treated and the treatment liquid into contact with each other to absorb the acidic compounds contained in the gas to be treated into the treatment liquid; a regenerator for heating the treatment liquid having absorbed the acidic compounds to separate the acidic compounds from the treatment liquid; a regeneration-side reservoir into which the treatment liquid heated in the regenerator is introduced, the regeneration-side reservoir having an introduction liquid space in which the introduced treatment liquid is stored, and a regeneration liquid space for receiving regenerated treatment liquid from the introduction liquid space even when the treatment liquid introduced into the introduction liquid space contains unregenerated treatment liquid; and an unregenerated liquid returning mechanism that returns the unregenerated treatment liquid accumulated in the liquid introduction space to the regenerator when the unregenerated treatment liquid is contained in the treatment liquid.

6. 6. The gas treatment device according to claim 5, wherein the unregenerated liquid return mechanism includes a first return mechanism for returning the first phase portion of the treatment liquid accumulating in the introduction liquid space to the regenerator so that the amount of the first phase portion is equal to or less than a predetermined amount, and a second return mechanism for returning the second phase portion of the treatment liquid in the introduction liquid space to the regenerator so that the liquid level of the treatment liquid accumulating in the introduction liquid space is equal to or less than a predetermined amount.

7. a first unregenerated liquid detector for detecting whether a first phase portion of the unregenerated treatment liquid has accumulated in a predetermined amount or more; The gas treatment device according to claim 6 , wherein the first return mechanism returns the first phase portion to the regenerator when the first unregenerated liquid detector detects that a predetermined amount or more of the first phase portion has accumulated.

8. an absorption-side reservoir for storing the treated liquid that has been phase-separated into the first phase portion and the second phase portion in the absorber; a first flow control mechanism for directing a first phase portion from the absorption side reservoir to the regenerator; a second flow control mechanism for sending a second phase portion from the absorption side reservoir to the regenerator; a regenerated liquid flow rate control mechanism that sends the regenerated treated liquid from the regenerating-side reservoir to the absorber so that a predetermined amount of the regenerated treated liquid is accumulated in the regenerating-side reservoir; The gas treatment device of claim 5 comprising:

9. the regeneration-side reservoir includes a partition member separating an introduction liquid space into which the treatment liquid is introduced from the regenerator and a regeneration liquid space into which the regenerated treatment liquid from the treatment liquid in the introduction liquid space flows; The gas treatment device described in claim 8, wherein the regenerated liquid flow rate adjustment mechanism includes a detector for detecting the liquid level of the regenerated treatment liquid in the regenerated liquid space, and a pump for sending the regenerated treatment liquid in the regenerated liquid space to the absorber so that the liquid level falls within a predetermined range based on the detection result by the detector.

10. a first detector for detecting whether a liquid-liquid interface between the first phase portion and the second phase portion is within a predetermined range in the absorption side reservoir; 10. The gas treatment device according to claim 8, wherein the first flow rate adjustment mechanism is configured to adjust a flow rate of the first phase portion sent from the absorption side reservoir to the regenerator based on a detection result by the first detector so that the liquid-liquid interface falls within a predetermined range.

11. A gas treatment method for releasing acidic compounds from a gas to be treated, the acidic compounds generating an acid when dissolved in water, using a treatment liquid in which a first component and a second component having a smaller specific gravity than the first component are mixed together before absorbing the acidic compounds, and which undergoes phase separation into a first phase portion mainly containing the first component and a second phase portion mainly containing the second component upon absorption of the acidic compounds, the method comprising: In an absorber, the gas to be treated and the treatment liquid are brought into contact with each other to absorb the acidic compounds contained in the gas to be treated into the treatment liquid; The treated liquid, which has been phase-separated into the first phase portion and the second phase portion in the absorber, is stored in an absorption-side reservoir; The treated liquid sent from the absorption side reservoir is heated in a regenerator to separate acidic compounds from the treated liquid; using a first detector, detecting whether a liquid-liquid interface between the first phase portion and the second phase portion in the absorption side reservoir is within a predetermined range; using a second detector to detect whether the liquid level of the second phase portion is within a predetermined range in the absorption-side reservoir; adjusting a flow rate of the first phase portion sent from the absorption-side reservoir to the regenerator based on a detection result by the first detector so that the liquid-liquid interface falls within a predetermined range; a flow rate of the second phase portion sent from the absorption-side reservoir to the regenerator is adjusted based on a detection result by the second detector so that the liquid level of the second phase portion falls within a predetermined range.

12. a space within the absorption-side reservoir is partitioned into a first space into which the treatment liquid from the absorber is introduced and in which the treatment liquid in a phase-separated state into a first phase portion and a second phase portion is stored, and a second space into which the second phase portion overflowing from the first space is introduced, the first detector detects whether a liquid-liquid interface between the first phase portion and the second phase portion in the first space is within a predetermined range; The gas processing method according to claim 11 , wherein the second detector detects whether an amount of the second phase portion stored in the second space is within a predetermined range.

13. increasing a flow rate of the first phase portion sent from the absorption side reservoir to the regenerator when a detection result of the first detector indicates that the liquid-liquid interface between the first phase portion and the second phase portion is higher than the predetermined range; reducing a flow rate of the first phase portion sent from the absorption side reservoir to the regenerator when a detection result of the first detector indicates that the liquid-liquid interface between the first phase portion and the second phase portion is lower than the predetermined range; increasing a flow rate of the second phase portion sent from the absorption side reservoir to the regenerator when a detection result of the second detector indicates that the liquid level of the second phase portion is higher than the predetermined range; 13. The gas processing method according to claim 11, further comprising: reducing a flow rate of the second phase portion sent from the absorption side reservoir to the regenerator when the detection result of the second detector indicates that the liquid level of the second phase portion is lower than the predetermined range.

14. The treated liquid heated in the regenerator is introduced into a regeneration-side reservoir; In the regeneration side reservoir, the introduced treatment liquid is stored in an introduction liquid space, and even if the treatment liquid introduced into the introduction liquid space contains unregenerated treatment liquid, the regenerated treatment liquid is allowed to flow from the introduction liquid space into the regeneration liquid space; The gas processing method according to claim 11 or 12, wherein when the processing liquid contains the unregenerated processing liquid, the unregenerated processing liquid accumulated in the liquid introduction space is returned to the regenerator.

15. A gas treatment method for releasing acidic compounds from a gas to be treated, the acidic compounds generating an acid when dissolved in water, using a treatment liquid in which a first component and a second component having a smaller specific gravity than the first component are mixed together before absorbing the acidic compounds, and which undergoes phase separation into a first phase portion mainly containing the first component and a second phase portion mainly containing the second component upon absorption of the acidic compounds, the method comprising: In an absorber, the gas to be treated and the treatment liquid are brought into contact with each other to absorb the acidic compounds contained in the gas to be treated into the treatment liquid; The treated liquid sent from the absorber is heated in a regenerator to separate acidic compounds from the treated liquid; The treated liquid heated in the regenerator is introduced into a regeneration-side reservoir; In the regeneration side reservoir, the introduced treatment liquid is stored in an introduction liquid space, and even if the treatment liquid introduced into the introduction liquid space contains unregenerated treatment liquid, the regenerated treatment liquid is allowed to flow from the introduction liquid space into the regeneration liquid space; When the treatment liquid contains an unregenerated treatment liquid, the unregenerated treatment liquid accumulated in the liquid introduction space is returned to the regenerator.

16. returning the first phase portion of the treatment liquid accumulated in the liquid introduction space to the regenerator so that the amount of the first phase portion accumulated in the liquid introduction space is equal to or less than a predetermined amount; The gas processing method according to claim 15 , wherein a second phase portion of the processing liquid in the liquid introduction space is returned to the regenerator so that a liquid level of the processing liquid accumulated in the liquid introduction space becomes equal to or lower than a predetermined level.

17. a first unregenerated liquid detector detects whether a first phase portion of the unregenerated treatment liquid is accumulated in a predetermined amount or more; The gas processing method according to claim 16 , wherein the first phase portion is returned to the regenerator when the first unregenerated liquid detector detects that a predetermined amount or more of the first phase portion has accumulated.

18. The treated liquid, which has been phase-separated into the first phase portion and the second phase portion in the absorber, is stored in an absorption-side reservoir; directing a first phase portion and a second phase portion from the absorption reservoir to the regenerator; The gas processing method according to claim 15, wherein the regenerated treated liquid is sent from the regeneration-side reservoir to the absorber so that a predetermined amount of the regenerated treated liquid is accumulated in the regeneration-side reservoir.

19. a space in the regeneration-side reservoir is partitioned into an introduction liquid space into which the treatment liquid is introduced from the regenerator, and a regeneration liquid space into which the regenerated treatment liquid from the treatment liquid in the introduction liquid space flows; A detector detects the liquid level of the regenerated treatment liquid in the regenerated liquid space; 19. The gas processing method according to claim 18, further comprising the step of: feeding the regenerated treatment liquid in the regenerated liquid space to the absorber so that the liquid level falls within a predetermined range based on a detection result by the detector.

20. 20. The gas processing method according to claim 18 or 19, further comprising the steps of: detecting, using a first detector in the absorption-side reservoir, whether a liquid-liquid interface between the first phase portion and the second phase portion is within a predetermined range; and adjusting a flow rate of the first phase portion sent from the absorption-side reservoir to the regenerator based on a detection result by the first detector so that the liquid-liquid interface is within the predetermined range.

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