Gas treatment system

Abstract

The present invention can remove water vapor with a simple structure. A gas treatment system according to one aspect of the present invention comprises: a separation device having a separation membrane having a function of separating carbon dioxide from a gas containing carbon dioxide; a negative pressure generation device for generating negative pressure in a flow path communicating with a downstream chamber of the separation membrane; and a water separation device that is provided on the flow path, separates moisture from the permeate gas containing carbon dioxide that has passed through the separation membrane by means of the negative pressure generated by the negative pressure generation device, and outputs the moisture separately from the permeate gas from which the moisture has been separated.

Description

Technical Field

[0001] This invention relates to a gas processing system. Background Technology

[0002] To suppress greenhouse gas emissions, carbon dioxide recovery systems exist. In recent years, membrane separation has been proposed as one method of carbon dioxide recovery. In membrane separation, water vapor contained in the exhaust gas passes through a separation membrane. Therefore, in a carbon dioxide recovery system employing membrane separation, by including a pressure differential generating device for creating a partial pressure difference between the upstream and downstream chambers of the separation membrane, and a dehumidification device in the gas path of the permeate gas flowing out of the downstream chamber of the separation membrane, carbon dioxide can be recovered after water vapor is removed (see, for example, Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2021-146318 Summary of the Invention

[0004] <Problem to be solved by this invention>

[0005] However, in prior art such as Patent Document 1, cooling water is circulated in order to dehumidify the device, which requires cooling mechanisms such as cooling water circulation pumps and radiators, so the dehumidification mechanism may be large.

[0006] One aspect of the present invention is to provide a gas treatment system capable of removing water vapor with a simple structure.

[0007] <Methods for solving problems>

[0008] According to one aspect of the invention, a gas processing system includes: a separation device having a separation membrane having the function of separating carbon dioxide from a gas containing carbon dioxide; a negative pressure generating device that generates a negative pressure in a flow path connected to a downstream chamber of the separation membrane; and a water separation device disposed in the flow path, which uses the negative pressure generated by the negative pressure generating device to separate water from the carbon dioxide-containing permeate gas that has passed through the separation membrane, and outputs the water separately from the permeate gas after the water has been separated.

[0009] <The Effects of the Invention>

[0010] According to one aspect of the invention, water vapor can be removed with a simple structure by using negative pressure generated by a negative pressure generating device to separate moisture from a carbon dioxide-containing gas flowing from the downstream chamber. Attached Figure Description

[0011] Figure 1 This is a schematic diagram showing the general structure of the carbon dioxide recovery system according to the first embodiment.

[0012] Figure 2 This is a schematic diagram showing the general structure of the carbon dioxide recovery system according to the second embodiment.

[0013] Figure 3 This is a schematic diagram showing the general structure of the carbon dioxide recovery system according to the third embodiment.

[0014] Figure 4 This is a graph showing the relationship between the exhaust velocity of the negative pressure generating device according to the third embodiment and the vacuum level reached in the space from the downstream chamber of the separation membrane to the suction flow path.

[0015] Figure 5 This is a graph showing the relationship between the temperature of the heat transfer section according to the third embodiment and the degree of vacuum reached.

[0016] Figure 6 This is a graph showing the relationship between saturated water vapor pressure, temperature of the heat transfer section according to this embodiment, and water vapor concentration.

[0017] Figure 7 This is a flowchart illustrating the processing steps of the control device according to the third embodiment.

[0018] Figure 8 This is a schematic diagram showing the general structure of the carbon dioxide recovery system according to the fourth embodiment.

[0019] Figure 9 This is a schematic diagram showing the general structure of the carbon dioxide recovery system according to the fifth embodiment.

[0020] Figure 10 This is a flowchart illustrating the processing steps performed by the control device according to the fifth embodiment.

[0021] Figure 11 This is a diagram showing the control procedures before the start of operation in the carbon dioxide recovery system according to the sixth embodiment.

[0022] Figure 12 This is a schematic diagram showing the general structure of the water separation device of the carbon dioxide recovery system according to the seventh embodiment.

[0023] Figure 13 This is a schematic diagram showing the general structure of the water separation device of a carbon dioxide recovery system according to a modified example of the seventh embodiment.

[0024] Figure 14 This is a diagram illustrating the control before and after operation in the control device according to the seventh embodiment.

[0025] Figure 15This is a schematic diagram showing the general structure of the water separation device in the carbon dioxide recovery system of the eighth embodiment.

[0026] Figure 16 This is a schematic diagram showing the general structure of the water separation device in the carbon dioxide recovery system of the eighth embodiment, variant 1.

[0027] Figure 17 This is a schematic diagram showing the general structure of the water separation device in the carbon dioxide recovery system of the eighth embodiment, variant 2.

[0028] Explanation of reference numerals in the attached figures

[0029] 1. Carbon dioxide recovery system

[0030] 140 Separation Device

[0031] 141 Separation Membrane

[0032] 142 Upstream Room

[0033] 143 Downstream Room

[0034] 144, 212 Exhaust Flow Path

[0035] 145, 401 through the gas flow path

[0036] 150, 610, 610A Water Separation Device

[0037] 151 Heat Transfer Section

[0038] 152 Liquid Recovery Pathway

[0039] 153 Carbon Dioxide Recovery Flow Path

[0040] 160 Negative Pressure Generator

[0041] 161 Inhalation Flow Path

[0042] 162 Discharge flow path

[0043] 170 Carbon Dioxide Recovery Unit

[0044] 210 Reheat Unit

[0045] 211 Not through the flow path

[0046] Pressure sensors 311, 312, 318, and 604

[0047] 313, 315, 316, 317 Dew Point Meters

[0048] 314 Temperature Sensor

[0049] 350, 550, 650 control devices

[0050] 411 Outlet

[0051] 412 Inlet

[0052] 413 Liquid discharge outlet

[0053] 414 Liquid recovery port

[0054] 501 Adjusting Valve

[0055] 511, 512 Bypass Flow Path

[0056] 601, 602 shut-off valves

[0057] 603 Vacuum Breaker Valve

[0058] 605, 702, 801 Gas Output Mechanism

[0059] 606, 606A, 701, 901 Liquid Discharge Mechanism

[0060] 611, 611A Vacuum Insulation Layer

[0061] 612, 612A piping

[0062] 613 Heat transfer components

[0063] 621 Vacuum suction flow path

[0064] 622 Exhaust Flow Path

[0065] 802 Fog Shield

[0066] 902 Siphon Circuit Breaker Detailed Implementation

[0067] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the embodiments described below are not intended to limit the present invention but are illustrative, and all features and combinations thereof described in the embodiments are not necessarily the essence of the present invention. It should be noted that in each drawing, the same or corresponding structures may sometimes be represented by the same or corresponding reference numerals, and their descriptions are omitted.

[0068] (First Implementation)

[0069] Figure 1This is a schematic diagram showing the general structure of a carbon dioxide recovery system (an example of a gas treatment system) according to the first embodiment. The carbon dioxide recovery system 1 of the first embodiment includes an exhaust gas emission source 110, a heat removal / dehumidification device 120, a dust removal device 130, a separation device 140, a water separation device 150, a negative pressure generating device 160, and a carbon dioxide recovery device 170.

[0070] The exhaust emission source 110 can be a structure that releases exhaust gas containing carbon dioxide, or it can be a combustion mechanism that generates heat energy by burning fuel with air. The fuel can be any combustible medium, such as light oil, gasoline, or a combustible gas. The exhaust emission source 110 generates a gas (hereinafter also referred to as "exhaust gas") consisting of a mixture of carbon dioxide, moisture, nitrogen, and a specified compound through the combustion of fuel, and outputs this exhaust gas to the heat removal / dehumidification device 120.

[0071] The heat removal / dehumidification device 120 removes heat from the exhaust gas input from the exhaust gas emission source 110 and removes a portion of the moisture contained in the exhaust gas. For example, the heat removal / dehumidification device 120 removes heat from the exhaust gas. By cooling the exhaust gas to a predetermined temperature, the water vapor contained in the exhaust gas liquefies. The heat removal / dehumidification device 120 removes the liquefied moisture from the exhaust gas. The predetermined temperature can be any temperature, such as the room temperature of the room where the heat removal / dehumidification device 120 is installed. The heat removal / dehumidification device 120 outputs the partially dehydrated exhaust gas to the dust removal device 130.

[0072] The dust removal device 130 is a mechanism for removing dust (e.g., a specified compound) or other particles generated by the combustion of the exhaust gas source 110 from the exhaust gas, and is equipped with a dust filter, for example. The dust removal device 130 outputs the exhaust gas, after the dust and other particles have been removed by the mechanism, to the separation device 140.

[0073] The separation device 140 includes a separation membrane 141, an upstream chamber 142 and a downstream chamber 143 divided by the separation membrane 141. The exhaust gas output from the dust removal device 130 is discharged to the upstream chamber 142 side.

[0074] The separation membrane 141 has the function of separating carbon dioxide from the exhaust gas by passing carbon dioxide contained in the exhaust gas discharged into the upstream chamber 142. The separation membrane 141 can be any membrane capable of separating carbon dioxide, such as a transport membrane, an organic polymer membrane, an inorganic material membrane, or a liquid membrane.

[0075] Specifically, due to the pressure difference (partial pressure difference) between the upstream chamber 142 and the downstream chamber 143 generated by the negative pressure generating device 160 described later, the carbon dioxide contained in the exhaust gas flowing into the upstream chamber 142 permeates through the separation membrane 141, and the gas containing carbon dioxide flows into the downstream chamber 143.

[0076] The exhaust gas that does not pass through the separation membrane 141 (also called "non-permeable gas") flowing into the upstream chamber 142 is discharged through the exhaust flow path 144 connected to the upstream chamber 142.

[0077] The carbon dioxide-containing gas that has passed through the separation membrane 141 (hereinafter also referred to as "permeable gas") is discharged into the water separation device 150 via the permeable gas flow path 145.

[0078] In addition, when the separation membrane 141 allows carbon dioxide to pass through the waste gas, it also allows water vapor contained in the waste gas to pass through.

[0079] In other words, when carbon dioxide is separated and recovered using membrane separation methods, water vapor is also recovered simultaneously. When recovering carbon dioxide, it is preferable to remove as much water vapor as possible to increase the carbon dioxide concentration. On the other hand, as the structure for removing water vapor becomes larger, there is a problem of difficulty in securing an installation location.

[0080] In addition, when a dehumidification device is installed to remove water vapor, if the dehumidification device is a mechanism that cools the exhaust gas by circulating cooling water, then it requires power to operate the cooling mechanism such as the cooling water circulation pump and radiator.

[0081] Therefore, in the carbon dioxide recovery system 1 according to this embodiment, a water separation device 150 is provided that is less power-consuming and saves space compared to the conventional one.

[0082] The water separation device 150 is configured to remove moisture from the permeable gas flowing in from the self-separating device 140, and is connected to the negative pressure generating device 160 via the suction flow path 161 and the discharge flow path 162.

[0083] The negative pressure generating device 160 is a device that generates negative pressure in the flow path connected to the downstream chamber 143 of the separation membrane 141, for example, a pressure reducing pump. According to this embodiment, the negative pressure generating device 160 controls the pressure reduction of the permeate gas present in the downstream chamber 143 of the separation membrane 141, the permeate gas flow path 145, the heat transfer section 151 of the water separation device 150, and the suction flow path 161. This generates a pressure difference (partial pressure difference) between the upstream chamber 142 and the downstream chamber 143.

[0084] The permeate gas flowing into the downstream chamber 143 and present in the water separator 150 undergoes adiabatic expansion due to pressure reduction control by the negative pressure generator 160. Furthermore, the adiabatic expansion of the permeate gas present in the water separator 150 and the suction flow path 161 removes heat from the surroundings, thereby cooling the surroundings.

[0085] On the other hand, the negative pressure generating device 160 adiabatically compresses the permeate gas drawn in from the water separator 150 via the intake flow path 161, and discharges the adiabatically compressed permeate gas through the discharge flow path 162. Due to the adiabatic compression, the temperature of the permeate gas discharged from the discharge flow path 162 increases compared to the permeate gas present in the intake flow path 161. Furthermore, the degree of adiabatic compression can be determined according to the embodiment; for example, the pressure of the adiabatically compressed permeate gas can be equal to atmospheric pressure.

[0086] The water separation device 150 according to this embodiment includes a heat transfer section 151. The heat transfer section 151 is configured to perform heat exchange between the permeable gas that flows in from the permeable gas flow path 145 and has been adiabatically expanded by the negative pressure generating device 160, and the permeable gas that is adiabatically compressed and discharged from the negative pressure generating device 160. The structure of the heat transfer section 151 can be arbitrary as long as it enables heat exchange; examples of specific structures will be described in the embodiments described later.

[0087] The heat transfer section 151 generates moisture by cooling and condensing the water vapor contained in the permeable gas through heat exchange between the adiabatic expanded permeable gas and the adiabatic compressed permeable gas.

[0088] In this way, the water separation device 150 separates the water vapor contained in the permeate gas as moisture from the permeate gas. The moisture separated from the permeate gas is discharged from the liquid recovery passage 152.

[0089] On the other hand, the moisture separated from the permeate gas is recovered by the carbon dioxide recovery device 170 via the carbon dioxide recovery flow path 153.

[0090] As described above, the water separation device 150 according to this embodiment uses the negative pressure generated by the negative pressure generating device 160 to separate water from the permeable gas containing carbon dioxide flowing in from the downstream chamber 143, and outputs the water separately from the permeable gas (gas containing carbon dioxide) from which the water was separated. It should be noted that this embodiment is not limited to a structure that exchanges heat through the heat transfer section 151, as long as it is a structure that uses the power generated by the negative pressure generating device 160 to separate water from the permeable gas containing carbon dioxide.

[0091] Furthermore, the permeable gas flow path 145 according to this embodiment is configured to transfer heat from the heat transfer section 151. For example, the outer periphery of the permeable gas flow path 145 is formed of a predetermined metal that is easily heat-conducting, and the outer periphery of the permeable gas flow path 145 is connected to the heat transfer section 151. In this embodiment, the permeable gas, which has been warmed by adiabatic compression, is supplied with heat to the permeable gas flow path 145 via the heat transfer section 151. Because the permeable gas flow path 145 is warmed, condensation within the permeable gas flow path 145 can be suppressed.

[0092] The carbon dioxide recovery system (an example of a gas treatment system) 1 according to this embodiment, by having the above-described structure, can cool and condense water vapor contained in the permeate gas without using an external cooling mechanism, thereby separating moisture. Therefore, the carbon dioxide recovery system 1 can efficiently remove water vapor contained in the exhaust gas.

[0093] In this embodiment, as a structure for removing water vapor, a heat removal / dehumidification device 120, which is a pre-process of the carbon dioxide separation device 140, and a water separation device 150, which is a post-process of the carbon dioxide separation device 140, are used to remove water vapor.

[0094] Furthermore, when water vapor is removed from the exhaust gas solely through a preceding process for separating carbon dioxide, a structure with high dehumidification efficiency is required, thus increasing the size of the dehumidification unit and the power required to operate it. On the other hand, if water vapor is not removed from the exhaust gas in the preceding process, condensation may occur during exhaust gas cooling.

[0095] Therefore, in this embodiment, the heat / dehumidification device 120 dehumidifies to a degree that prevents condensation of the gas (exhaust gas or permeate gas) in the flow path leading to the water separator 150. Then, the water separator 150 cools and removes the water vapor that has been highly concentrated after passing through the separation membrane 141 of the separation device 140. By removing water vapor in these two stages, condensation in the flow path can be suppressed and efficient water vapor removal can be achieved.

[0096] (Second Implementation)

[0097] The carbon dioxide recovery system according to the second embodiment is an embodiment in which a new structure is added to the carbon dioxide recovery system 1 according to the first embodiment.

[0098] Figure 2 This is a schematic diagram showing the general structure of a carbon dioxide recovery system (an example of a gas processing system) according to the second embodiment. The carbon dioxide recovery system 2 of the second embodiment is a structure in which a reheat device 210 is added to the carbon dioxide recovery system 1 of the first embodiment. In the structure of the carbon dioxide recovery system 2 of the second embodiment, the same reference numerals are assigned to the same structures as those in the carbon dioxide recovery system 1 of the first embodiment, and descriptions are omitted.

[0099] In the carbon dioxide recovery system 2 according to the second embodiment, a reheating device 210 is provided on the carbon dioxide recovery flow path 153 through which the permeate gas from the water separation device 150 to the carbon dioxide recovery device 170 through which water is separated is passed. The reheating device 210 is connected to the upstream chamber 142 of the separation device 140 via a non-permeable flow path 211.

[0100] The reheating device 210 has a heat exchange function that allows heat exchange between the permeate gas from which moisture has been separated (containing carbon dioxide) and the non-permeate gas that has not flowed in through the non-permeate flow path 211. By utilizing this heat exchange function, the reheating device 210 removes heat from the non-permeate gas that has not flowed in through the non-permeate flow path 211, thereby increasing the temperature of the permeate gas from which moisture has been separated (containing carbon dioxide) compared to before the heat exchange.

[0101] The reheating device 210 discharges the unexhausted gas after heat exchange through the exhaust flow path 212.

[0102] Therefore, the carbon dioxide recovery system 2 of the second embodiment, by having a reheating device 210, can reduce the relative humidity of the permeate gas from which moisture is separated, thereby preventing condensation in the carbon dioxide recovery flow path 153.

[0103] (Third Implementation)

[0104] The carbon dioxide recovery system according to the third embodiment is an embodiment in which a new structure is added to the carbon dioxide recovery system 2 according to the second embodiment.

[0105] Figure 3 This is a schematic diagram showing the general structure of a carbon dioxide recovery system (an example of a gas processing system) according to the third embodiment. The carbon dioxide recovery system 3 of the third embodiment newly includes pressure sensors 311, 312, 318, dew point meters 313, 315, 316, 317, a temperature sensor 314, and a control device 350, which are new additions to the carbon dioxide recovery system 2 of the second embodiment. In the structure of the carbon dioxide recovery system 3 of the third embodiment, the same reference numerals are assigned to structures identical to those in the carbon dioxide recovery system 2 of the second embodiment, and descriptions are omitted.

[0106] The control device 350 adjusts the negative pressure generated by the negative pressure generating device 160 based on the dew point temperature detected by dew point meters (an example of a detection unit) 313, 315, 316, 317 located between the downstream chamber 143 of the separation membrane 141 and the carbon dioxide recovery unit 170 (which recovers carbon dioxide-containing permeate gas output from the water separation unit 150) and the temperature of the heat transfer unit 151 detected by the temperature sensor 314.

[0107] For example, the control device 350 controls the negative pressure generating device 160 to make the water vapor concentration of the permeate gas from which water is separated in the water separation device 150 reaches a predetermined required value. The required value is determined based on the power of the negative pressure generating device 160 and the concentration of carbon dioxide that is desired to be recovered by the carbon dioxide recovery device 170.

[0108] Figure 4 This is a graph showing the correspondence between the exhaust velocity of the negative pressure generating device 160 according to this embodiment and the vacuum level reached in the space from the downstream chamber 143 of the separation membrane 141 to the suction flow path 161. Figure 4 The line 1401 shown indicates the exhaust speed required to reach the vacuum level.

[0109] That is, the control device 350 controls the rotation speed of the motor (not shown) inside the negative pressure generating device 160 according to the vacuum level reached from the change (reach) from atmospheric pressure P0, so that the exhaust speed reaches or exceeds the exhaust speed corresponding to the vacuum level, thereby realizing the reduction of pressure [Pa] represented by the vacuum level, in other words, the increase of vacuum level.

[0110] Figure 5 This is a graph showing the relationship between the temperature of the heat transfer section 151 according to this embodiment and the vacuum level [Pa]. As shown by line 1501, since the pressure expressed as the vacuum level decreases, in other words, the vacuum level increases, the gas absorbs more heat from the surroundings due to decompression and expansion, so the temperature of the heat transfer section 151 decreases.

[0111] Figure 6 This is a graph showing the relationship between saturated water vapor pressure, temperature of the heat transfer section 151 according to this embodiment, and water vapor concentration.

[0112] Line 1601 illustrates the relationship between the saturated water vapor pressure and the temperature of the heat transfer section 151. As shown by line 1601, the lower the temperature of the heat transfer section 151, the lower the saturated water vapor pressure. Therefore, as shown by line 1602, the lower the temperature of the heat transfer section 151, the lower the concentration of water vapor in the permeated gas. That is, the concentration of water vapor in the permeated gas can be adjusted by adjusting the temperature of the heat transfer section 151. Furthermore, to adjust the temperature of the heat transfer section 151, only the exhaust speed needs to be adjusted; in other words, only the rotational speed of the motor of the negative pressure generating device 160 needs to be adjusted.

[0113] The control device 350 calculates the water vapor concentration based on the dew point temperature detected by the dew point meters (an example of the detection unit) 313, 315, and 316, and the temperature of the heat transfer unit 151 detected by the temperature sensor 314. The method for calculating the water vapor concentration is not limited to the calculation method based on the dew point temperature and the temperature of the heat transfer unit 151; any method can be used.

[0114] The control device 350 controls the rotation speed of the motor inside the negative pressure generating device 160 so that the concentration of water vapor separated by the water separation device 150 is consistent with the required value of water vapor.

[0115] Next, the processing procedure in the control device 350 will be explained. Figure 7 This is a flowchart illustrating the processing procedure of the control device 350 according to this embodiment.

[0116] According to this embodiment, the carbon dioxide recovery system 3 begins to adjust the water vapor concentration of the permeate gas (S1701). The control device 350 calculates the water vapor concentration θaq1 of the permeate gas after the water is separated by the water separation device 150 based on the dew point temperature detected by the dew point meter (an example of the detection unit) 316 and the temperature of the heat transfer unit 151 detected by the temperature sensor 314 (S1702).

[0117] The control device 350 determines whether the condition "|water vapor concentration θaq1 - required water vapor concentration θaq_req|>0" is met (S1703). If the control device 350 determines that the condition "|water vapor concentration θaq1 - required water vapor concentration θaq_req|>0" is not met, in other words, if the detected water vapor concentration θaq1 is consistent with the required value θaq_req (S1703: No), the control device 350 considers the adjustment of water vapor concentration to be completed and ends the process.

[0118] On the other hand, when the control device 350 determines that the condition “|water vapor concentration θaq1―water vapor concentration requirement value θaq_req|>0” is met (S1703: Yes), it determines whether “water vapor concentration θaq1>water vapor concentration requirement value θaq_req” (S1704).

[0119] If the determination is that "water vapor concentration θaq1 > the required water vapor concentration value θaq_req" (S1704: Yes), the control device 350 performs control to increase the motor speed of the negative pressure generating device 160 compared to before the determination (S1705). The amount of increase in motor speed can be determined according to the implementation method.

[0120] On the other hand, if it is determined that "the water vapor concentration θaq1 is not greater than the required value of water vapor concentration θaq_req" (S1704: No), the control device 350 performs control to reduce the motor speed of the negative pressure generating device 160 compared to before the determination (S1706). The amount of reduction in motor speed can be determined according to the implementation method.

[0121] Then, the control device 350 calculates the water vapor concentration θaq2 (S1707) based on the dew point temperature detected by the dew point meter (an example of the detection unit) 313, 315 and the temperature of the heat transfer unit 151 detected by the temperature sensor 314.

[0122] The control device 350 determines whether the condition “|water vapor concentration θaq2―water vapor concentration requirement value θaq_req|=0” is met (S1708).

[0123] If the control device 350 determines that the condition “|water vapor concentration θaq2―water vapor concentration requirement value θaq_req|=0” is not met (S1708: No), it replaces the water vapor concentration θaq2 with the water vapor concentration θaq1 (S1709) and starts processing again from S1704.

[0124] On the other hand, if the control device 350 determines that the condition “|water vapor concentration θaq2―water vapor concentration required value θaq_req|=0” is met (S1708: Yes), the process ends.

[0125] According to this embodiment, the control device 350 can adjust the water vapor concentration by performing the above-described control.

[0126] Furthermore, according to this embodiment, the control device 350 can control the structure within the carbon dioxide recovery system 3 based on the detection results of various sensors. For example, the control device 350 can adjust the relative humidity of the permeate gas into the reheat unit 210, from which moisture has been separated, based on the detection results of the dew point meters 316 and 317. The method for adjusting the relative humidity can be any method, such as controlling the amount of non-permeable gas flowing into the non-permeable flow path 211.

[0127] In addition, the control device 350 can control the speed of the motor inside the negative pressure generating device 160 based on the pressure difference detected by the pressure sensors 311, 312, and 318.

[0128] The carbon dioxide recovery system 3 according to this embodiment, by having the above-described structure, can recover carbon dioxide at a desired concentration by adjusting the water vapor concentration. Therefore, it is possible to improve the accuracy of carbon dioxide recovery.

[0129] This embodiment shows an example of a sensor structure provided in the carbon dioxide recovery system 3, but is not limited to this sensor structure. The carbon dioxide recovery system 3 according to this embodiment only needs to be equipped with a sensor capable of detecting water vapor concentration and capable of performing [operations]. Figure 7 The processing order shown is sufficient.

[0130] (Fourth Implementation)

[0131] The carbon dioxide recovery system according to the fourth embodiment is an example of changing the permeable gas flow path connecting the separation device 140 and the water separation device 150 compared to the carbon dioxide recovery system 3 according to the third embodiment.

[0132] Figure 8 This is a schematic diagram showing the general structure of a carbon dioxide recovery system (an example of a gas processing system) according to the fourth embodiment. The carbon dioxide recovery system 4 according to the fourth embodiment has a permeable gas flow path 401 with a different shape compared to the carbon dioxide recovery system 3 according to the third embodiment. In the structure of the carbon dioxide recovery system 4 according to the fourth embodiment, the same reference numerals are assigned to structures identical to those in the carbon dioxide recovery system 3 according to the third embodiment, and descriptions are omitted.

[0133] Figure 8 The carbon dioxide recovery system 4 shown is positioned relative to the horizon GL, indicating the height of the inlets or outlets through which gas flows in or out. Figure 8 As shown, the heights of the liquid recovery port 414 (GL+A), liquid discharge port 413 (GL+B), inlet 412 (GL+C), and outlet 411 (GL+D) are as follows: D>C>B>A. The inlet 412 is configured to connect the permeable gas flow path 401 to the heat transfer section 151. Then, the permeable gas flowing in from the inlet 412 flows into the negative pressure generating device 160 via the heat transfer section 151.

[0134] like Figure 8 As shown, the outlet 411 on the downstream chamber 143 of the separator 140, which allows the permeable gas to flow out to the water separator 150, is positioned higher than the inlet 412 for allowing the permeable gas to flow into the water separator 150.

[0135] The permeable gas flow path 401, connecting the outlet 411 to the inlet 412, slopes downward from the separator 140 to the water separator 150. Therefore, the permeable gas can easily move from the separator 140 to the water separator 150. Furthermore, even if temporary condensation occurs within the permeable gas flow path 401, water droplets can be guided to the water separator 150.

[0136] Water and other substances separated by the water separation device 150 are discharged from the liquid outlet 413, which is lower than the inlet section 412.

[0137] In addition, the carbon dioxide recovery system 4 has a flow path 402 so that the water separated in the water separator 150 flows out from the liquid outlet 413 provided on the water separator 150 to the liquid outlet 414 provided below the liquid outlet 413.

[0138] Therefore, the carbon dioxide recovery system 4 according to this embodiment, by having the above-described structure, can suppress the backflow of water (droplets), thereby efficiently realizing the recovery of droplets (water).

[0139] (Fifth Implementation)

[0140] The carbon dioxide recovery system according to the fifth embodiment is an embodiment in which a new structure is added to the carbon dioxide recovery system 3 according to the third embodiment. It should be noted that the carbon dioxide recovery system according to the fifth embodiment may also have the structure shown in the carbon dioxide recovery system 4 according to the fourth embodiment.

[0141] Figure 9 This is a schematic diagram showing the general structure of a carbon dioxide recovery system (an example of a gas processing system) according to the fifth embodiment. The carbon dioxide recovery system 5 according to the fifth embodiment newly includes bypass flow paths 511 and 512, an adjusting valve 501, and a control device 550 compared to the carbon dioxide recovery system 3 according to the third embodiment. Furthermore, a pressure sensor 319 is newly provided to detect the pressure of the permeated gas discharged from the negative pressure generating device 160. In the structure of the carbon dioxide recovery system 5 of the fifth embodiment, the same reference numerals are used for structures identical to those in the carbon dioxide recovery system 3 of the third embodiment, and descriptions are omitted.

[0142] Furthermore, conventional negative pressure generating devices often lack the ability to precisely adjust the negative pressure based on factors such as motor speed. When such a negative pressure generating device is installed in a carbon dioxide recovery system, it becomes difficult to control the device to ensure that the water vapor concentration matches the required value. Therefore, it will be explained how, in the carbon dioxide recovery system 5 according to this embodiment, the discharge flow rate of the permeable gas is controlled by performing spillback control using bypass flow paths 511 and 512 and adjusting valve 501.

[0143] Figure 9 The carbon dioxide recovery system 5 shown is provided with bypass flow paths 511 and 512, which are connected between the suction flow path (an example of the first flow path) 161, which allows carbon dioxide-containing gas to flow from the water separator 150 into the negative pressure generator 160, and the discharge flow path (an example of the second flow path) 162, which allows carbon dioxide-containing gas to flow from the negative pressure generator 160 out of the water separator 150.

[0144] In addition, the carbon dioxide recovery system 5 is equipped with an adjustment valve 501, which is provided on the bypass flow paths 511 and 512 and its opening is adjustable, so that the permeable gas in the discharge flow path 162 returns to the suction flow path 161.

[0145] According to this embodiment, the control device 550 adjusts the opening degree of the adjusting valve 501. By adjusting the opening degree of the adjusting valve 501, the exhaust speed based on the reduced pressure of the negative pressure generating device 160 is adjusted. For example, when the opening degree of the adjusting valve 501 increases, the permeable gas present in the suction flow path 161 increases, thus the exhaust speed decreases. When the opening degree of the adjusting valve 501 decreases, the permeable gas present in the suction flow path 161 decreases, thus the exhaust speed increases. Figure 4 As shown, there is a corresponding relationship between the exhaust velocity and the vacuum level reached. Therefore, the control device 550 can control the vacuum level reached by adjusting the opening of the adjusting valve 501. In this way, similar to the third embodiment, the control device 550 adjusts the concentration of water vapor separated by the water separator 150 by adjusting the opening of the adjusting valve 501.

[0146] Specifically, the control device 550 calculates the water vapor concentration based on the dew point temperature detected by the dew point meters (an example of the detection unit) 313, 315, and 316, and the temperature of the heat transfer unit 151 detected by the temperature sensor 314. Then, the control device 550 adjusts the opening of the adjusting valve 501 so that the water vapor concentration after separation by the water separator 150 is consistent with the required water vapor value.

[0147] In addition, besides adjusting the opening degree according to the water vapor concentration, the control device 550 can also adjust the opening degree of the regulating valve 501 according to the detection result of the pressure sensor 319 so that the amount of permeable gas discharged from the discharge path 162 to the water separator 150 meets the specified standard.

[0148] Next, the processing steps in the control device 550 will be explained. Figure 10 This is a flowchart illustrating the processing steps of the control device 550 according to this embodiment.

[0149] According to this embodiment, the carbon dioxide recovery system 5 begins to adjust the water vapor concentration of the permeate gas (S2001). The control device 550 calculates the water vapor concentration θaq1 of the permeate gas after the water is separated by the water separation device 150 based on the dew point temperature detected by the dew point meter (an example of the detection unit) 316 and the temperature of the heat transfer unit 151 detected by the temperature sensor 314 (S2002).

[0150] The control device 550 determines whether the condition "|water vapor concentration θaq1 - required water vapor concentration θaq_req|>0" is met (S2003). If the control device 550 determines that the condition "|water vapor concentration θaq1 - required water vapor concentration θaq_req|>0" is not met, in other words, if the detected water vapor concentration θaq1 is determined to be consistent with the required value θaq_req (S2003: No), the control device 550 considers the adjustment of water vapor concentration to be completed and ends the process.

[0151] On the other hand, when the control device 550 determines that the condition “|water vapor concentration θaq1―water vapor concentration requirement value θaq_req|>0” is met (S2003: Yes), it determines whether “water vapor concentration θaq1>water vapor concentration requirement value θaq_req” (S2004).

[0152] When the control device 550 determines that "the water vapor concentration θaq1 > the required value of water vapor concentration θaq_req" (S2004: Yes), it performs control to reduce the opening degree of the regulating valve 501 compared with that before the determination (S2006).

[0153] On the other hand, if the control device 550 determines that "the water vapor concentration θaq1 is not greater than the required value of water vapor concentration θaq_req" (S2004: No), it performs control to increase the opening degree of the regulating valve 501 compared with that before the determination (S2005).

[0154] Then, the control device 550 calculates the water vapor concentration θaq2 based on the dew point temperature detected by the dew point meter (an example of the detection unit) 313, 315 and the temperature of the heat transfer unit 151 detected by the temperature sensor 314 (S2007).

[0155] Control device 550 determines whether the condition “|water vapor concentration θaq2―water vapor concentration requirement value θaq_req|=0” is met (S2008).

[0156] If the control device 550 determines that the condition “|water vapor concentration θaq2―water vapor concentration requirement value θaq_req|=0” is not met (S2008: No), it replaces the water vapor concentration θaq2 with the water vapor concentration θaq1 (S2009) and starts processing again from S2004.

[0157] On the other hand, if the control device 550 determines that the condition “|water vapor concentration θaq2―water vapor concentration required value θaq_req|=0” is met (S2008: Yes), the process ends.

[0158] The control device 550 according to this embodiment can adjust the water vapor concentration by performing the above-described control. The carbon dioxide recovery system 5 can recover a desired concentration of carbon dioxide by adjusting the water vapor concentration. Therefore, the accuracy of carbon dioxide recovery can be improved.

[0159] (Sixth Implementation Method)

[0160] In the above embodiment, the control of carbon dioxide recovery operation in the carbon dioxide recovery system will be described. Furthermore, when the carbon dioxide recovery operation of the carbon dioxide recovery system stops, the water vapor content in the pipe through which the permeate gas passes tends to increase compared to when it is running. Therefore, condensate may accumulate when operation stops.

[0161] Therefore, in this embodiment, control is performed to evaporate the condensate before operation begins. This embodiment uses the structure of the carbon dioxide recovery system 3 shown in the third embodiment as an example, but other structures can also be used.

[0162] Figure 11 This is a diagram showing the control before the start of operation in the carbon dioxide recovery system 3 according to this embodiment.

[0163] Line 2101 indicates whether the carbon dioxide recovery system 3 is operating or not. As shown by line 2101, carbon dioxide recovery by the carbon dioxide recovery system 3 begins when it becomes operational at time t2. Time t2 is, for example, the start-up time. Before time t1, since it is before the start of operation, the system is not operating.

[0164] Line 2102 represents the calculated concentration of water vapor present in the permeate gas of the carbon dioxide recovery system 3 (within the pipe). For example, the control device 350 calculates the water vapor concentration in the flow path (within the pipe) based on dew point meters 313 and 315 and temperature sensor 314. It should be noted that this embodiment is not limited to the example of using dew point meters 313 and 315 for calculating water vapor concentration; other dew point meters 316 and 317 present in the carbon dioxide recovery system 3 may also be used.

[0165] As shown in line 2102, the water vapor concentration before operation is, for example, c%. The water vapor concentration used as a reference during operation is x% (an example of a specified concentration). Therefore, the control device 350 controls the operation so that the water vapor concentration is below x% before operation begins. It should be noted that x% is a water vapor concentration preset according to the specific implementation. Figure 11 In the example shown, let c% > x%.

[0166] Therefore, the control device 350 begins controlling the reduction of water vapor concentration from time t1, y seconds before the start of operation. In this embodiment, an evaporation purging timer is provided within the control device 350. As shown in line 2103, the evaporation purging timer is activated at time t1, y seconds earlier than the start of operation t2. It should be noted that y seconds is a number of seconds defined according to the embodiment.

[0167] Then, the control device 350, triggered by the activation of the evaporation and purging timer, outputs a command to the negative pressure generating device 160 indicating the motor speed R2. The value of the motor speed R2 is higher than the operating motor speed R1.

[0168] Therefore, as shown in line 2102, the water vapor concentration gradually decreases from c%. Then, when the control device 350 determines that the water vapor concentration is below x%, it outputs a command to the negative pressure generating device 160 indicating the motor speed R1. After that, the negative pressure generating device 160 operates at the motor speed R1.

[0169] According to this embodiment, the carbon dioxide recovery system 3 can adjust the water vapor concentration to x at the moment t2 when the carbon dioxide recovery system 3 starts operating.

[0170] Thus, according to this embodiment, the control device 350 activates the negative pressure generating device 160 y seconds before the start of gas treatment in the carbon dioxide recovery system 3, so that the concentration of water vapor contained in the permeate gas in the carbon dioxide recovery system 3 is reduced to a predetermined concentration of x% or less. Therefore, in the carbon dioxide recovery system 3 according to this embodiment, the retention of condensate can be suppressed.

[0171] (Seventh Implementation)

[0172] This describes the situation where the water separation device in the carbon dioxide recovery system according to the seventh embodiment has a heat insulation structure that reduces external heat dissipation.

[0173] Figure 12 This is a schematic diagram showing the general structure of the water separation device of the carbon dioxide recovery system according to this embodiment. In the carbon dioxide recovery system 6 according to the seventh embodiment, in addition to the structure of the carbon dioxide recovery system 3 according to the third embodiment, a vacuum insulation layer 611 is provided on the outer periphery of the water separation device 610, and a new structure for adjusting the pressure of the vacuum insulation layer 611 is provided. Furthermore, the carbon dioxide recovery system 6 is equipped with a control device 650 different from the processing and control device 350. In the structure of the carbon dioxide recovery system 6 according to the seventh embodiment, the same reference numerals are assigned to structures identical to those in the carbon dioxide recovery system 3 according to the third embodiment, and descriptions are omitted.

[0174] The water separation device 610 may have the same structure as the embodiment described above, except that a vacuum insulation layer 611 is provided on its outer periphery. In this embodiment, as an example of the heat transfer unit 151, it includes: multiple pipes 612 for allowing permeable gas to flow from the separation device 140 to the negative pressure generating device 160; and a heat transfer member 613 for applying the heat transferred from the multiple pipes 612 to the permeable gas discharged from the outlet 162A and guiding the permeable gas downwards. With this structure, the heat transfer unit 151 can exchange heat between the adiabatic expanded permeable gas in the negative pressure generating device 160 and the adiabatic compressed permeable gas discharged from the outlet 162A. Furthermore, the heat from the adiabatic compressed permeable gas discharged from the outlet 162A can heat the permeable gas flow path 145 connected via the multiple pipes 612.

[0175] In the carbon dioxide recovery system 6, a vacuum suction flow path 621 is provided between the vacuum insulation layer 611 connected to the outer periphery of the water separation device 610 and the negative pressure generating device 160.

[0176] Furthermore, a shut-off valve 602 is provided on the vacuum suction flow path 621 to allow the negative pressure generating device 160 and the vacuum insulation layer 611 to be opened and closed.

[0177] Furthermore, a shut-off valve 601 is provided on the suction flow path 161 connecting the water separation device 610 and the negative pressure generating device 160, allowing the water separation device 610 and the negative pressure generating device 160 to be opened and closed. After the suction flow path 161 merges with the vacuum suction flow path 621, the flow enters the negative pressure generating device 160.

[0178] An exhaust flow path 622 for discharging gas to the outside is provided at the branch of the flow path after the confluence of the suction flow path 161 and the vacuum suction flow path 621. In addition, a vacuum breaker valve 603 is provided to enable the exhaust flow path 622 to be opened and closed.

[0179] According to this embodiment, the shut-off valve 601, shut-off valve 602, and vacuum breaker valve 603 are electrically operated and can be opened and closed according to the input signal.

[0180] The control device 650 adjusts the negative pressure generated by the negative pressure generator 160 based on the detection results of various sensors (e.g., pressure sensors 312, 604) installed in the carbon dioxide recovery system 6. Furthermore, the control device 650 controls the opening and closing of the shut-off valves 601, 602, and 603.

[0181] For example, when the carbon dioxide recovery system 6 stops operating, the control device 650 controls the shut-off valves 601 and 602 to remain open. When the carbon dioxide recovery system 6 stops operating, the control device 650 can control the vacuum breaker valve 603 to remain closed, or it can control the vacuum breaker valve to remain open.

[0182] Then, before the carbon dioxide recovery system 6 starts carbon dioxide recovery operation (gas processing), in order to improve the insulation performance of the vacuum insulation layer 611, the control device 650 controls the closing of the shut-off valve 601 and the vacuum breaking valve 603, and controls the opening of the shut-off valve 602. After that, the negative pressure generating device 160 is activated to reduce the pressure in the vacuum insulation layer 611 and increase the vacuum degree in the vacuum insulation layer 611.

[0183] Then, when the pressure sensor 604 detects that the specified pressure has been reached, the control device 650 controls the shut-off valve 602 to close and the shut-off valve 601 to open. It should be noted that the vacuum insulation layer 611 remains closed. Afterwards, the same control procedures as described in the above embodiment are followed.

[0184] Furthermore, the carbon dioxide recovery system 6 is equipped with a gas output mechanism 605 for recovering the permeate gas after moisture separation and a liquid output mechanism 606 for recovering the separated moisture. For example... Figure 12 As shown, the liquid output mechanism 606 can be equipped with a siphon circuit breaker to automatically inject external gas so that the liquid can be easily discharged. By installing a siphon circuit breaker, backflow caused by reverse siphon effect can be prevented.

[0185] Furthermore, the carbon dioxide recovery system 6 according to this embodiment does not constitute a limitation on the structure of the water separation device 610. Therefore, a modified example of the water separation device will be described.

[0186] Figure 13 This is a schematic diagram showing the general structure of the water separation device of a modified carbon dioxide recovery system according to the seventh embodiment. Except for the water separation device 610A, the structure of this modified carbon dioxide recovery system 6A is the same as that of the carbon dioxide recovery system 6 according to the seventh embodiment. In the structure of the modified carbon dioxide recovery system 6A, the same reference numerals are assigned to structures identical to those in the carbon dioxide recovery system 6 according to the seventh embodiment, and descriptions are omitted.

[0187] The water separation device 610A has a vacuum insulation layer 611A on its outer periphery. Furthermore, in the water separation device 610A, the gas flow path 145 and the suction flow path 161 are connected to the same side (in...). Figure 13 The water separation device 610A shown is the right side (the side shown).

[0188] Compared to the above embodiment, since the positions of the permeable gas flow path 145 and the suction flow path 161 are different, the heat transfer section 151A of the water separation device 610A has a different shape than the heat transfer section 151. Specifically, the heat transfer section 151A is formed as a single pipe 612A that reciprocates in the horizontal direction. According to this shape, similar to the seventh embodiment, heat exchange can occur between the permeable gas that has been adiabatically expanded by the negative pressure generating device 160 and the permeable gas that has been adiabatically compressed and discharged from the outlet 162A.

[0189] By performing the same control as in the seventh embodiment, the control device 650 can start the carbon dioxide recovery operation of the carbon dioxide recovery system 6A with the insulation performance of the vacuum insulation layer 611A improved.

[0190] Furthermore, the carbon dioxide recovery system 6A is provided with a gas output mechanism 605A for recovering the permeate gas after water separation and a liquid output mechanism 606A for recovering the separated water. As described above, the liquid output mechanism 606A may have a different shape than the liquid output mechanism 606 shown in the seventh embodiment.

[0191] Next, the control of the control device 650 according to the seventh embodiment will be described. It should be noted that the control device 650 related to the variant of the seventh embodiment also performs the same control, so its description is omitted.

[0192] Figure 14 This diagram illustrates the control of the control device 650 according to this embodiment before operation begins and after operation ends.

[0193] Line 2401 indicates whether the carbon dioxide recovery system 6A is operating or stopped. As shown by line 2401, when it is operating at time t14, the carbon dioxide recovery system 6A begins to recover carbon dioxide. Time t14 is, for example, the start-up time. Before time t11, since it is before starting work, operation is stopped. The period between time t11 and time t14 is the preparation period for operation. Time t15 is, for example, the end-of-operation time. After time t15, operation stops.

[0194] Time t11 to time t12 is the preparation period for the construction of vacuum insulation layer 611, and time t13 to time t14 is the period for evaporating retained water.

[0195] Line 2403 indicates the open / closed state of the shut-off valve 602 installed on the vacuum suction flow path 621, line 2404 indicates the open / closed state of the shut-off valve 601 installed on the suction flow path 161, and line 2407 indicates the open / closed state of the vacuum breaker valve 603.

[0196] Between time t11 and time t12, as shown by line 2403, the shut-off valve 602 on the vacuum suction flow path 621 is opened; as shown by line 2404, the shut-off valve 601 on the suction flow path 161 is closed; and as shown by line 2407, the vacuum breaking valve 603 is closed. Then, the control device 650 outputs a command indicating the motor speed R3 to the negative pressure generating device 160. The motor speed R3 is set to a value higher than the aforementioned motor speeds R2 and R1.

[0197] Therefore, as shown in line 2405, the pressure of the vacuum insulation layer 611A decreases from atmospheric pressure to z[Pa]. It should be noted that z[Pa] is a preset pressure to maximize the insulation performance of the vacuum insulation layer 611A. After the pressure of the vacuum insulation layer 611A reaches z[Pa] at time t12, the control device 650 controls the closing of the shut-off valve 602 on the vacuum suction flow path 621 and opens the shut-off valve 601 on the suction flow path 161. It should be noted that the vacuum breaker valve 603 remains closed. Then, the control device 650 outputs a command to the negative pressure generating device 160 to decrease the motor speed from R3 to R2. Then, at time t13, the motor speed of the negative pressure generating device 160 reaches the motor speed R2.

[0198] Then, the control device 650 controls the evaporation of condensate between time t13 and time t14. The control between time t13 and time t14 is consistent with that according to the sixth embodiment... Figure 11 The processing order shown is the same, so the explanation is omitted.

[0199] Subsequently, at time t15, the carbon dioxide recovery operation of the carbon dioxide recovery system 6A stops. As shown in line 2402, the control device 650 outputs a command to the negative pressure generating device 160 to reduce the motor speed to 0.

[0200] Furthermore, as shown in line 2407, the control device 650 controls the vacuum breaker valve 603 to open. Also, the control device 650 controls the shut-off valve 602 on the vacuum suction flow path 621 to open. Therefore, as shown in line 2405, the pressure in the vacuum insulation layer 611 rises to atmospheric pressure. Furthermore, as shown in line 2406, the water vapor concentration gradually increases from x% to c%.

[0201] In the carbon dioxide recovery system 6A according to this embodiment, carbon dioxide recovery operation can begin under a pressure z [Pa] in the vacuum insulation layer 611A. Since the insulation performance is high under a pressure z [Pa] in the vacuum insulation layer 611A, high-efficiency heat exchange can be achieved within the water separation device 610. Therefore, in the carbon dioxide recovery system 6A according to this embodiment, the energy efficiency during water separation can be improved.

[0202] (Eighth Implementation Method)

[0203] In the carbon dioxide recovery system of the eighth embodiment, the gas output mechanism and the liquid output mechanism installed in the water separation device 150 will be described.

[0204] Figure 15 This is a schematic diagram showing the general structure of the water separation device in the carbon dioxide recovery system of the eighth embodiment. As an example of a gas-liquid separation structure, the water separation device 150 according to this embodiment is provided with a gas output mechanism 702 and a liquid output mechanism 701. In the structure of the water separation device 150, the same reference numerals are assigned to structures that are the same as those in the above embodiment, and the description is omitted.

[0205] like Figure 15 As shown, the water separation device 150 is maintained in a state where water is present on its bottom surface. The liquid inlet 701A of the liquid output mechanism 701 is located below the surface of the accumulated water. The liquid output mechanism 701 according to this embodiment has a liquid seal structure to prevent the ingress of permeable gas.

[0206] In addition, a siphon circuit breaker is provided in the liquid output mechanism 701 to automatically inject external gas to facilitate liquid discharge.

[0207] Furthermore, in the water separation device 150, the permeable gas is discharged from the discharge path 162. The discharged permeable gas moves downward through the heat transfer section 151. The heat transfer section 151 separates water from the permeable gas. The separated water falls downward.

[0208] A shielding plate 702A extending horizontally is provided in the upward direction of the gas output mechanism 702. By providing the shielding plate 702A in the upward direction of the gas output mechanism 702, moisture falling from the heat transfer section 151 is prevented from flowing from the gas output mechanism 702 into the carbon dioxide recovery flow path 153.

[0209] Furthermore, the carbon dioxide recovery system according to this embodiment does not constitute a limitation on the structure of the gas output mechanism 702 and the liquid output mechanism 701 of the water separation device 150. Therefore, a modified example of the water separation device will be described.

[0210] Figure 16This is a schematic diagram showing the general structure of the water separation device in a carbon dioxide recovery system according to Modification 1 of the eighth embodiment. The water separation device 150 of this modification includes a mist baffle 802, a gas output mechanism 801, and a liquid output mechanism 701. In the structure of the water separation device 150, the same reference numerals are assigned to structures identical to those in the eighth embodiment, and descriptions are omitted.

[0211] The fog-blocking plate 802 is disposed between the heat transfer section 151 and the gas output mechanism 801. In other words, it removes fine mist (droplets) in the permeable gas flow discharged from the negative pressure generator 160 upstream of the gas output mechanism 801.

[0212] The gas output mechanism 801 has an opening 801A, into which gas moving in an upward direction (different from the direction of gas flow, which is downward) can flow. It should be noted that this embodiment does not limit the orientation of the opening surface of the opening 801A to the downward direction. In other words, it is not limited to allowing gas moving in an upward direction to flow in; it can also be configured to allow gas moving in a left-right direction to flow in.

[0213] Figure 17 This is a schematic diagram showing the general structure of the water separation device in the carbon dioxide recovery system according to Modification 2 of the eighth embodiment. The water separation device 150 of this modification is provided with a gas output mechanism 801 and a liquid output mechanism 901. In the structure of the water separation device 150, the same reference numerals are assigned to structures identical to those in the eighth embodiment and Modification 1 of the eighth embodiment, and descriptions are omitted.

[0214] In the liquid output mechanism 901, a liquid inlet 901A is provided on the bottom surface of the water separation device 150. Furthermore, the liquid output mechanism 901 discharges the liquid flowing in from the inlet 901A via a liquid recovery passage 152. Additionally, a siphon circuit breaker 902 is provided on the liquid recovery passage 152. By providing the siphon circuit breaker 902, external gas can be automatically injected to facilitate liquid discharge, and backflow caused by reverse siphon effect can be prevented.

[0215] <Function>

[0216] In the carbon dioxide recovery system according to the above embodiment, moisture can be separated by heat exchange between the permeate gas, which has been adiabatically expanded by the negative pressure generator 160, and the permeate gas, which has been adiabatically compressed and discharged from the negative pressure generator 160. In the above embodiment, moisture can be separated using the power of the negative pressure generator for carbon dioxide recovery, without the need for cooling mechanisms such as cooling water circulation pumps or radiators, thus allowing for the removal of water vapor with a simple structure. Furthermore, since no power is required for cooling mechanisms such as cooling water circulation pumps or radiators, energy savings are achieved.

[0217] The preferred embodiments and variations of the present invention have been described above. However, the present invention is not limited to the embodiments described above. Various modifications, substitutions, etc., of the above embodiments can be applied without departing from the scope of the present invention. Furthermore, each of the features described with reference to the above embodiments can be appropriately combined as long as there is no technical contradiction.

Claims

1. A gas processing system, comprising: A separation device having a separation membrane that has the function of separating carbon dioxide from a gas containing carbon dioxide; A negative pressure generating device that generates negative pressure in the flow path connected to the downstream chamber of the separation membrane; as well as A water separation device is installed in the flow path. It uses the negative pressure generated by the negative pressure generator to separate water from the carbon dioxide-containing permeate gas that has passed through the separation membrane, and outputs the water separately from the permeate gas after the water has been separated.

2. The gas handling system according to claim 1, wherein, The negative pressure generating device draws in the permeable gas from the downstream chamber via the water separator, which has undergone adiabatic expansion due to negative pressure, and then adiabatically compresses it before discharging it into the water separator. The water separation device has a heat exchanger structure that allows heat exchange between the permeating gas flowing from the downstream chamber, which has expanded adiabatically due to the negative pressure of the negative pressure generating device, and the permeating gas discharged from the negative pressure generating device, which has been compressed adiabatically, thereby condensing the water vapor contained in the permeating gas discharged from the negative pressure generating device.

3. The gas handling system according to claim 2, wherein, The flow path of the permeable gas from the downstream chamber to the water separation device is configured to allow heat transfer from the adiabatic compressed permeable gas discharged from the negative pressure generating device via the heat exchanger structure.

4. The gas handling system according to claim 1 or 2, wherein, The gas processing system further includes a reheating device, which raises the temperature of the permeate gas after the water has been separated from the water separator to that of the non-permeate gas that has not passed through the separation membrane by exchanging heat between the permeate gas after the water has been separated from the water separator and the non-permeate gas that has not passed through the separation membrane.

5. The gas handling system according to claim 1 or 2, wherein, The gas processing system further includes a control device that adjusts the negative pressure generated by the negative pressure generator based on the water vapor concentration of the permeable gas after the water has been separated by the water separation device, obtained from the detection results of the detection unit.

6. The gas handling system according to claim 1 or 2, wherein, The outlet of the downstream chamber of the separation device, which allows the permeable gas to flow out to the water separation device, is positioned higher than the inlet of the water separation device, which allows the permeable gas from the downstream chamber to flow in. The gas processing system further includes a flow path that allows the water separated in the water separator to flow from a discharge port on the water separator to a liquid recovery port located below the discharge port.

7. The gas handling system according to claim 1 or 2, wherein, The gas processing system also includes: A bypass flow path is connected between the first flow path and the second flow path. The first flow path allows the permeable gas to flow from the water separator into the negative pressure generating device, and the second flow path allows the permeable gas to be discharged from the negative pressure generating device back to the water separator. A regulating valve, disposed in the bypass flow path and having an adjustable opening, is used to return the permeable gas from the second flow path to the first flow path; and The control device adjusts the opening of the regulating valve based on the water vapor concentration of the permeable gas after the water has been separated by the water separation device, obtained from the detection results of the detection unit.

8. The gas handling system according to claim 1 or 2, wherein, Before the gas processing begins, the negative pressure generating device is activated in a manner that brings the concentration of water vapor in the gas present in the gas processing system to below a specified concentration.

9. The gas handling system according to claim 1 or 2, wherein, The gas processing system also includes: A suction flow path connects the vacuum insulation layer located on the outer periphery of the water separation device to the negative pressure generating device. A shut-off valve, disposed in the suction flow path, allows the negative pressure generating device and the vacuum insulation layer to be opened and closed; and The control device, before the gas processing performed by the gas processing system begins, controls the closing of the shut-off valve after controlling the opening of the shut-off valve and the activation of the negative pressure generating device to increase the vacuum level of the vacuum insulation layer.

10. The gas handling system according to claim 1 or 2, wherein, The water separation device includes: a liquid output mechanism that outputs the water; and a gas output mechanism that outputs the permeated gas after the water has been separated. The liquid output mechanism has a liquid seal structure that inhibits gas mixing.

11. The gas handling system according to claim 1 or 2, wherein, The water separation device has the following features: A liquid output mechanism that outputs the water; and A gas output mechanism outputs the permeated gas after the moisture has been separated. And it is provided with at least one of the following components: A fog deflector is provided to remove droplets in the permeable gas stream discharged from the negative pressure generator upstream of the gas output mechanism. The opening of the gas output mechanism is configured to allow permeable gas flowing in in a direction different from the direction of the permeable gas discharged from the negative pressure generating device; and A shielding component that prevents droplets from flowing into the opening of the gas output mechanism.

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