Gas treatment system

Abstract

To improve the recovery rate of a desired component in a gas treatment system for separating and recovering the desired component contained in a raw material gas.SOLUTION: The gas treatment system (1) includes a separation membrane module (11) in which a separation membrane (12) for separating a desired component contained in a raw material gas is disposed, a detection means (220) for detecting a temperature of an upstream end of the separation membrane, a detection means (221) for detecting a temperature of a downstream end thereof, a heating medium flow path (3) through which a heating medium for exchanging heat with the separation membrane module flows, and a control unit (800) for controlling a flow rate of the heating medium. The heat medium flow path includes a heat exchange unit (303) that exchanges heat with the separation membrane module by circulating the heat medium from the downstream end side to the upstream end side of the separation membrane module, a detection means (320) that detects the temperature of the heat medium at the upstream end of the heat exchange unit, a detection means (321) that detects the temperature of the heat medium at the downstream end of the heat exchange unit, and a control valve (310) that adjusts the flow rate of the heat medium on the upstream side of the heat exchange unit. The control part controls the opening of the control valve based on the temperature detected by each detection means.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to gas processing systems. [Background technology]

[0002] There are known gas treatment systems that separate and recover desired components such as CO2 contained in gas emitted from emission sources such as combustors and power generators. Some gas treatment systems of this type selectively separate the desired components such as CO2 using a separation membrane module in which a separation membrane is arranged inside a container through which the gas to be treated flows (for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 255055 [Patent Document 2] Japanese Patent Publication No. 2022-106322 Summary of the Invention [Problem to be solved by the invention]

[0004] In the gas processing system described above, a temperature gradient occurs in the separation membrane in the separation membrane module along the gas flow direction, and the permeability of the desired components, such as CO2, to be recovered by the separation membrane decreases downstream, resulting in a decrease in the recovery rate of the desired components.

[0005] The present invention has been made in consideration of these points, and one of its objects is to improve the recovery rate of desired components in a gas treatment system that separates and recovers desired components contained in gas discharged from an emission source. [Means for solving the problem]

[0006] A gas processing system according to one embodiment of the present invention comprises a separation membrane module having a separation membrane for separating a desired component contained in a source gas containing the desired component, a first temperature detector for detecting the temperature of the upstream end of the separation membrane in the direction of gas flow along the separation membrane, a second temperature detector for detecting the temperature of the downstream end of the separation membrane in the direction of gas flow, a heat medium flow path for circulating a heat medium that exchanges heat with the separation membrane module, and a controller for controlling the flow rate of the heat medium in the heat medium flow path. The heat medium flow path comprises a heat exchanger that circulates the heat medium from the downstream end to the upstream end in the direction of gas flow within the separation membrane module and exchanges heat with the gas flowing within the separation membrane module, a third temperature detector for detecting the temperature of the heat medium at the upstream end of the heat exchanger, a fourth temperature detector for detecting the temperature of the heat medium at the downstream end of the heat exchanger, and a control valve located upstream of the heat exchanger for adjusting the flow rate of the heat medium supplied to the heat exchanger. The control unit controls the opening of the control valve based on the temperatures detected by the temperature detection means. [Effects of the Invention]

[0007] According to the present invention, it is possible to improve the recovery rate of desired components in a gas treatment system that separates and recovers desired components contained in gas discharged from an emission source. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of a gas processing system according to a first embodiment. [Figure 2] FIG. 2 is a block diagram illustrating an example of the functional configuration of a control panel. [Figure 3] 3A to 3C are diagrams illustrating the relationship between the temperature of the separation membrane and the permeability of components contained in gas. [Figure 4] FIG. 10 is a flow chart illustrating an example of a process for controlling the flow rate of a heat medium. [Figure 5] 5A and 5B are diagrams illustrating an example of the configuration of the heat exchanger. [Figure 6]FIG. 2 is a diagram illustrating a modified example of the configuration of the gas processing system according to the first embodiment. [Figure 7] FIG. 10 is a diagram illustrating a configuration example of a gas processing system according to a second embodiment. [Figure 8] FIG. 10 is a diagram illustrating a modified example of a heat transfer medium flow path in the gas processing system according to the second embodiment. [Figure 9] FIG. 10 is a diagram illustrating a configuration example of a gas processing system according to a third embodiment. [Figure 10] FIG. 10 is a diagram illustrating a modified example of a heat transfer medium flow path in the gas processing system according to the third embodiment. [Figure 11] FIG. 10 is a diagram illustrating a configuration example of a gas processing system according to a fourth embodiment. [Figure 12] FIG. 10 is a diagram illustrating a configuration example of a gas processing system according to a fifth embodiment. [Figure 13] FIG. 10 is a diagram illustrating a configuration example of a gas processing system according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. A gas processing system 1 exemplified in the following description may be a system that performs a treatment process to selectively separate and recover desired components contained in gas emitted by a gas emission source. In this specification, the system is described as recovering CO2 (carbon dioxide) contained in gas, but the components to be recovered are not limited to a specific component. The components to be recovered may be, for example, CH4 (methane) contained in natural gas flowing through the system, or CH4 and CO2 contained in biogas.

[0010] [First embodiment] Fig. 1 is a diagram illustrating an example of the configuration of a gas processing system according to a first embodiment. The gas processing system 1 illustrated in Fig. 1 includes a processing system 2 in which a process for separating and capturing CO2 from a CO2-containing gas (hereinafter referred to as a "raw material gas") to be processed (captured) is carried out, and a heat medium flow path 3 including a heat exchanger 303 that exchanges heat with a separation membrane module 11 of the processing system 2.

[0011] The treatment system 2 includes a pretreatment unit 10, a separation membrane module 11, and a capture unit (not shown). A first-state raw material gas introduced into the treatment system 2 through a supply port 200 is supplied to the pretreatment unit 10 via a flow path 201. The pretreatment unit 10 performs several processes on the first-state raw material gas to make it suitable for CO2 separation by the separation membrane module 11. The first-state raw material gas may be gas emitted from a gas emission source. The gas emission source may be a device that burns fossil fuels or fuels derived from fossil fuels and emits gases containing CO2 (carbon dioxide) and the like, such as a diesel engine, a gasoline engine, a gas turbine, or a gas boiler. This type of gas emission source may be applied, for example, to power ships, power generation equipment, and power generation equipment in various plants. The gas emission source may be, for example, an incinerator in a waste incineration facility, a device that collects natural gas from natural gas, or a device that generates (produces) biogas. The pretreatment unit 10 may include, for example, a heat removal unit for lowering the temperature of the gas, a dust removal unit for removing impurities such as dust contained in the gas, a selective catalytic reduction (SCR) unit for removing NOx (nitrogen oxides), an exhaust gas recirculation (EGR) system, and an economizer for utilizing exhaust gas waste heat. The second-state raw material gas discharged from the pretreatment unit 10 is supplied to the separation membrane module 11 through a flow path 202. In the following description, the raw material gas supplied to the separation membrane module 11, such as the second-state raw material gas, will be simply referred to as the "raw material gas."

[0012] The separation membrane module 11 is a process device equipped with a separation membrane 12 that selectively allows CO2 contained in a supplied raw material gas to permeate. The separation membrane module 11 has a first flow space 13 and a second flow space 14 separated by the separation membrane 12. The raw material gas is supplied into the first flow space 13. As the raw material gas flows in the flow direction along the separation membrane 12, CO2 contained in the raw material gas selectively permeates through the separation membrane 12, resulting in separation into a permeated gas and a retentate gas. The permeated gas is a gas containing CO2 that has permeated through the separation membrane 12, while the retentate gas is a gas containing components of the raw material gas that have not permeated through the separation membrane 12. The separated retentate gas and permeate gas are separately discharged from the separation membrane module 11 (see FIG. 3A). Specifically, the retentate gas is discharged into a flow path 203 connected to the downstream end of the first flow space 13, and the permeate gas is discharged into a flow path 205 connected to the downstream end of the second flow space 14. The permeated gas discharged to flow path 205 has a higher CO2 concentration than the retentate gas discharged to flow path 203, and is therefore supplied to a recovery unit (not shown) through permeated gas outlet 206. The retentate gas has a lower CO2 concentration, and is therefore released directly into the atmosphere through retentate gas outlet 204, for example.

[0013] The separation membrane 12 in the separation membrane module 11 used in the gas processing system 1 of this embodiment is not limited to a specific structure or to being made of a specific material. Suitable membranes are those with temperature-dependent CO2 permeability, such as organic membranes driven by differential pressure or facilitated transport membranes driven by adsorption and desorption. The separation membrane 12 is not limited to membranes that selectively permeate and separate only CO2 contained in the feed gas, but may also be membranes that allow other components contained in the feed gas to permeate at lower permeability than CO2. As described below, when multiple separation membrane modules 11 are arranged in the processing system 2, the separation membranes 12 of all separation membrane modules 11 do not need to have the same composition. The multiple separation membrane modules 11 may include separation membrane modules 11 that exchange heat with the heat medium in the heat medium flow path 3 and separation membrane modules 11 that do not exchange heat. The separation membrane 12 in the separation membrane module 11 that does not exchange heat with the heat medium in the heat medium flow path 3 may be an inorganic membrane or other membrane whose CO2 permeability is not, or is considered to be substantially, temperature-dependent.

[0014] 1 includes a first temperature detection means 220 and a second temperature detection means 221. The first temperature detection means 220 detects the temperature T G1 The second temperature detection means 221 detects the temperature T G2The first temperature detecting means 220 and the second temperature detecting means 221 may be known piping temperature sensors. The above-described first temperature detecting means 220 and second temperature detecting means 221 may be examples of means for detecting the temperature of the upstream end and the downstream end of the separation membrane 12 in the direction of gas flow along the separation membrane 12, respectively. The first temperature detecting means 220 is preferably disposed so as to detect the temperature of the feed gas at a position as close as possible to the separation membrane module 11 in the flow path 202, and the second temperature detecting means 221 is preferably disposed so as to detect the temperature of the retentate gas at a position as close as possible to the separation membrane module 11 in the flow path 203. The second temperature detecting means 221 may detect the temperature of the permeate gas discharged to the flow path 205. Alternatively, the second temperature detecting means 221 for detecting the temperature of the retentate gas discharged to the flow path 203 and another temperature detecting means (not shown) for detecting the temperature of the permeate gas discharged to the flow path 205 may be disposed. Furthermore, the first temperature detecting means 220 and the second temperature detecting means 221 may directly detect the temperature of the upstream end and the downstream end of the separation membrane 12, respectively, for example.

[0015] 1 is a flow path in which the heat medium supplied from the supply port 300 passes through the heat exchanger 303 and is discharged from the discharge port 305. The heat medium supplied (introduced) from the supply port 300 to the flow path 301 is supplied through the flow control valve 310 at a flow rate Q H The heat medium flows through the flow path 302 and is supplied to the heat exchange section 303. The flow rate control valve 310 controls the flow rate Q of the heat medium to be circulated through the heat exchange section 303. H The valve opening of the flow control valve 310 is controlled by a control panel 8 as described below. In order to control the valve opening of the flow control valve 310, the heat medium flow path 3 is provided with a flow rate detection means 330 that detects the flow rate of the heat medium in the flow path 302 upstream of the heat exchanger 303. The flow rate detection means 330 may be a well-known piping flow rate sensor.

[0016] The heat exchanger 303 is a component that performs heat exchange to adjust the temperature of the downstream end of the separation membrane module 11 relative to the temperature of the upstream end so that the temperature difference (temperature gradient) between the temperatures of the upstream end and the downstream end of the separation membrane 12 becomes a predetermined temperature gradient. The heat exchanger 303 is disposed so that a heat medium flows from the downstream end to the upstream end of the separation membrane module 11 (more specifically, in the direction of gas flow along the separation membrane 12). That is, the heat exchanger 303 is disposed so that the heat medium inlet is located at the downstream end of the separation membrane module 11 and the heat medium outlet is located closer to the upstream end of the separation membrane module 11 than the heat medium inlet. The heat exchanger 303 may have, for example, a jacket shape that can be attached to the outer surface of the separation membrane module 11, but is not limited to a specific shape. The heat exchange method used by the heat exchanger 303 may be a well-known method and is not limited to a specific method. The heat medium flowing through the heat medium flow path 3 is not limited to a specific type (composition). The heat medium may be a liquid or a gas. For example, when the gas processing system 1 of the present embodiment is applied to a ship, seawater or freshwater present around the ship while sailing can be used as the heat medium. The heat medium flow path 3 may be covered with a heat insulating material, for example, to suppress a decrease in the temperature of the heat medium due to factors other than the heat exchange with the separation membrane module 11 by the heat exchanger 303. The heat medium that has flowed through the heat exchanger 303 is discharged from the outlet 305 via the flow path 304.

[0017] In the gas processing system 1 according to the present embodiment, the temperature T H1 and a third temperature detecting means 320 for detecting the temperature T of the heat medium in the flow path 304 downstream of the heat exchange section 303. H2and a fourth temperature detecting means 321 that detects the temperature of the heat medium at the upstream end of the heat exchange section 303. The third temperature detecting means 320 and the fourth temperature detecting means 321 may be known piping temperature sensors. The above-mentioned third temperature detecting means 320 and the fourth temperature detecting means 321 may be examples of means for detecting the temperature of the heat medium at the upstream end of the heat exchange section 303 and means for detecting the temperature of the heat medium at the downstream end of the heat exchange section 303, respectively. It is preferable that the third temperature detecting means 320 detects the temperature of the heat medium at a position as close as possible to the heat exchange section 303 in the flow path 302, and the fourth temperature detecting means 321 detects the temperature of the heat medium at a position as close as possible to the heat exchange section 303 in the flow path 304. Note that the third temperature detecting means 320 and the fourth temperature detecting means 321 may directly detect the temperatures at the upstream end and downstream end of the heat exchange section 303, respectively, for example.

[0018] The treatment process in gas treatment system 1 is controlled by a control panel 8. Fig. 2 is a block diagram illustrating an example of the functional configuration of the control panel. Control panel 8 illustrated in Fig. 2 includes a control unit 800, a storage unit 810, a communication unit 820, and an operation unit 830, which are interconnected by a bus 840.

[0019] The control unit 800 generates control signals for controlling the operation of the pretreatment unit 10, the valve opening degree of the flow control valve 310, etc., in accordance with the programs and control information stored in the memory unit 810 and various information related to the treatment process of the gas treatment system 1 acquired via the communication unit 820. The communication unit 820 receives signals indicating temperatures detected by the first temperature detection means 220, the second temperature detection means 221, the third temperature detection means 320, and the fourth temperature detection means 321, as well as detection signals indicating the flow rate of the heat medium detected by the flow rate detection means 330. The control unit 800 transmits the generated control signals to the pretreatment unit 10 and the valve opening adjustment mechanism of the flow control valve 310 via the communication unit 820. The functions of the control unit 800 are provided by a processor such as a CPU (Central Processing Unit) that executes a program. The memory unit 810 stores a control program that causes the control unit 800 to execute processes related to the control of the gas treatment system 1, including the processes described below with reference to FIG. 4, as well as set values ​​811 referenced by the control unit 800. The set value 811 is, for example, the upper limit temperature T M , the set value ΔT of the temperature gradient of the separation membrane module 11 SV The storage device that provides the functions of the storage unit 810 includes a ROM (Read Only Memory) and a RAM (Random Access Memory) as main storage devices. The storage device that provides the functions of the storage unit 810 may also include auxiliary storage devices such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive).

[0020] Operation unit 830 receives and displays inputs such as setting information related to the operation (control) of gas processing system 1. The functions of operation unit 830 are provided by, for example, various switches arranged on an operation panel, input devices such as a keyboard, and display devices such as a liquid crystal display, a seven-segment display, pilot lamps, etc. arranged on the operation panel. Some or all of the functions of operation unit 830 may be provided by, for example, a single piece of hardware that combines the functions of an input device, such as a touch panel display, and the functions of a display device.

[0021] The control panel 8 is not limited to a specific hardware configuration. The control panel 8 may be designed and manufactured as a control device dedicated to controlling the gas processing system 1, or may be a combination of a general-purpose computer such as a personal computer and a control program recorded on a computer-readable recording medium. The hardware of the control panel 8 may include a single piece of hardware that provides the functions shown by multiple blocks in FIG. 2, for example, hardware that integrates a processor as the control unit 800 and a memory as the storage unit 810. The control panel 8 may also include multiple pieces of hardware that provide the function shown by a single block in FIG. 2. For example, as described above, the hardware (storage device) that functions as the storage unit 810 may include multiple separate storage devices. For example, the processor that functions as the control unit 800 may include multiple separate processors.

[0022] 3A to 3C are diagrams illustrating the relationship between the temperature of the separation membrane and the permeability of components contained in gas.

[0023] 3A shows a schematic diagram of how a feed gas is separated into a retentate gas and a permeate gas in a separation membrane module 11. As the feed gas flows from a flow path 202 into the first flow space 13 of the separation membrane module 11 in the gas flow direction along the separation membrane 12, components to be captured, such as CO2, contained in the feed gas selectively permeate the separation membrane 12 and flow through the second flow space 14. The retentate gas, which contains components of the feed gas that did not permeate the separation membrane 12, is discharged into a flow path 203 connected to the first flow space 13, while the permeate gas that permeated the separation membrane 12 is discharged into a flow path 205 connected to the second flow space 14. The permeate gas discharged into the flow path 205 has a higher CO2 concentration than the retentate gas discharged into the flow path 203, and is therefore supplied to a capture module (not shown) via the flow path 205 and other channels.

[0024] The raw material gas in the first state introduced into the pretreatment unit 10, such as the gas discharged from the gas discharge source, is heated to a temperature higher than the heat-resistant temperature (upper limit temperature T M) in the pretreatment unit 10. Therefore, the temperature T G1 is the upper limit temperature T M As the raw material gas flows through the separation membrane module 11, the temperature of the gas flowing through the separation membrane module 11 gradually decreases from the upstream end to the downstream end due to heat radiation to the container of the separation membrane module 11 and expansion caused by permeation through the separation membrane 12. As the gas temperature decreases, a temperature gradient occurs in the separation membrane 12 that comes into contact with the gas. Figure 3B shows a tabular diagram illustrating an example of the temperature gradient of the separation membrane 12 in a certain type of separation membrane module 11 investigated by the inventors of the present application. In the illustrated separation membrane module 11, as the gas flow rate increases, the temperature gradient (T G1 -T G2 ) and the temperature gradient of the permeating gas (T G1 -T G0 ) is smaller, but the temperature gradient within the range of gas flow rates in the typical process illustrated in Figure 3B is 25°C or more.

[0025] As shown in FIG. 3C, the permeability of the separation membrane 12 used in the separation membrane module 11 to the desired component to be separated (e.g., CO2) decreases as the membrane temperature decreases. That is, when a feed gas is separated into a retentate gas and a permeate gas using a separation membrane module 11 that does not perform heat exchange with the heat exchange section 303 of the heat medium flow path 3, as shown in FIG. 3A, the permeability of the desired component near the downstream end is lower than the permeability near the upstream end. Therefore, the amount of CO2 that does not permeate the separation membrane 12 near the downstream end increases relatively, resulting in a decrease in the amount of CO2 recovered from the permeate gas (CO2 recovery rate). Patent Document 1 discloses a technology for improving the CO2 recovery rate by heating the separation membrane with a heater to suppress condensation of moisture in the gas due to expansion when the gas permeates the separation membrane. However, the energy required to operate the heater increases, which can increase operating costs. Furthermore, Patent Document 2 discloses a technology for improving the CO2 recovery rate by supplying water vapor to the second flow space 14 through which the gas that has permeated the separation membrane 12 flows. However, there is a risk that the water vapor will condense due to expansion when permeating the separation membrane, causing blockage of the separation membrane.

[0026] In the gas processing system 1 of this embodiment, unlike the techniques disclosed in Patent Documents 1 and 2, the temperature gradient along the flow direction of the gas flowing through the first flow space 13 of the separation membrane module 11 is reduced by heat exchange with the heat exchange section 303 of the heat medium flow path 3, thereby reducing the temperature gradient along the flow direction of the gas of the separation membrane 12. For example, when heat exchange with the heat exchange section 303 of the heat medium flow path 3 is not performed (i.e., in the conventional case), the membrane temperature T D1 and the film temperature T at the downstream end (position X2) D213C. In contrast to this, in the gas processing system 1 of the present embodiment, the temperature of the gas in the first flow space 13 of the separation membrane module 11 is increased by heat exchange with the heat exchange section 303 of the heat medium flow path 3. At this time, the flow of the heat medium in the heat exchange section 303 is oriented from the downstream end to the upstream end of the separation membrane module 11, thereby facilitating the increase in the gas temperature by heat exchange at a position close to the downstream end of the separation membrane module 11 (a position where the gas temperature is lower). As a result, in the gas processing system 1 of the present embodiment, for example, the membrane temperature at the downstream end (position X2) of the separation membrane module 11 is increased to the membrane temperature T D22 (>T D21 ) can be obtained. Therefore, the membrane temperature T D1 This reduces the temperature difference between the upstream end and downstream end of separation membrane 12, thereby reducing the difference in permeability between the upstream end and downstream end of separation membrane 12. Therefore, according to gas processing system 1 of this embodiment, it is possible to suppress a relative increase in the amount of CO2 that does not permeate separation membrane 12 near the downstream end, and it is possible to increase the amount of CO2 recovered from the permeating gas (i.e., improve the CO2 recovery rate). The membrane temperature T D1 and the downstream end film temperature T D21 and T D22 are the temperatures T of the raw material gas detected by the first temperature detection means 220, respectively. G1 and the temperature T of the non-permeated gas detected by the second temperature detection means 221. G2 The relationship between the temperature gradient of the film temperature and the transmittance of CO2, O2 (oxygen gas), and N2 (nitrogen gas), as exemplified in Figure 3C, will be described later.

[0027] Fig. 4 is a flow diagram illustrating an example of a process for controlling the flow rate of the heat medium. In gas processing system 1 of the present embodiment, in order to reduce the temperature gradient in the gas flow direction of separation membrane module 11, the flow rate of the heat medium in heat exchange section 303 that exchanges heat with separation membrane module 11 is controlled according to the flow illustrated in Fig. 4. The process according to the flow illustrated in Fig. 4 is mainly performed by control section 800 of control panel 8.

[0028] The control unit 800 first calculates the measured value ΔT of the temperature gradient of the separation membrane module 11. PV (Step S1), and the measured value of the temperature gradient ΔT PV and the temperature gradient setting value ΔT SV The relationship between PV =ΔT SV In step S1, the control unit 800 determines whether the temperature T detected by the first temperature detection means 220 is equal to or greater than the predetermined temperature (step S2). G1 and the temperature T detected by the second temperature detection means 221 G2 Obtain the temperature gradient measurement ΔT PV =T G1 -T G2 The temperature gradient setting value ΔT is calculated. SV is stored in the storage unit 810 (see FIG. 2) as one of the set values ​​811. In the following description of this specification, the measured value of the temperature gradient ΔT PV The temperature gradient ΔT PV " or "Measurement value ΔT PV " and the temperature gradient setting value ΔT SV Set the "Setting value ΔT SV " Setting value ΔT SV can be set according to the desired CO2 recovery rate in the gas processing system 1, and may be "0" or another value. SV is a negative value (ΔT SV <0), but T G2 >T G1 In this case, the temperature at the downstream end of the separation membrane 12 exceeds the upper limit temperature T M Since there is a risk that it will be higher than ΔT SV In step S2, for example, taking into consideration a measurement error that depends on the accuracy of the temperature detection means (temperature sensors) 220 and 221, for example, ΔT SV +0.1(℃)≧ΔT PV (℃)≧ΔT SV When -0.1 (℃), ΔT PV =ΔT SV It may be determined that ΔT PV =ΔT SVIf it is determined that this is the case (step S2; YES), the control unit 800 ends the process of controlling the flow rate of the heat medium.

[0029] ΔT PV =ΔT SV If it is determined that the difference is not ΔT (step S2; NO), the control unit 800 next PV >ΔT SV It is determined whether ΔT PV >ΔT SV If , the measured temperature gradient ΔT PV is the set value ΔT SV If the temperature T G1 and the temperature at the downstream end T G2 The temperature difference between the two is the desired temperature difference (e.g., the temperature difference T in Figure 3C). D1 -T D22 ) is greater than ΔT PV >ΔT SV If it is determined that G2 is lower than the temperature corresponding to the desired transmittance. PV >ΔT SV If so (step S3; YES), the control unit 800 increases the valve opening of the flow control valve 310 to reduce the temperature gradient, thereby reducing the flow rate Q of the heat medium in the heat exchange unit 303. H (Step S4). PV >ΔT SV If it is determined that this is not the case (step S3; NO), the control unit 800 reduces the valve opening of the flow control valve 310 to increase the flow rate Q of the heat medium in the heat exchange unit 303 in order to increase the temperature gradient. H In steps S4 and S5, the control unit 800 reduces the flow rate Q of the heat medium in the heat exchange unit 303 based on, for example, equation (1-2) derived from the relationship in equation (1-1) below. H Calculate the calculated flow rate Q H and the flow rate Q of the heat transfer medium detected by the flow rate detection means 330. HPV The valve opening of the flow control valve 310 is adjusted so that the flow rate and the pressure are equal to each other.

number

[0030] After step S4 or S5, the control unit 800 adjusts the temperature T G1 and the upper limit temperature T M Relationship with T G1 ≦T M It is determined whether or not T G1 ≦T M If it is determined that the temperature is not T G1 (Step S7). After that, the control unit 800 performs the processes from step S1 onwards again. G1 ≦T M If it is determined that ΔT PV =ΔT SV4 continues until it is determined that the control unit 800 has executed the control according to the flow illustrated in Fig. 4. For example, the control unit 800 may execute the control according to the flow illustrated in Fig. 4 periodically or irregularly based on a predetermined condition (trigger).

[0031] As described above, in the gas processing system 1 of the present embodiment, the temperature gradient in the gas flow direction in the separation membrane 12 is adjusted by adjusting the temperature of the gas flowing through the separation membrane module 11 through heat exchange with the heat medium flowing through the heat exchange section 303 of the heat medium flow path 3. This makes it possible to increase the amount of CO2 contained in the permeable gas that has permeated the separation membrane 12 and increase the CO2 recovery rate from the permeable gas without introducing water vapor into the second flow space 14 and / or the first flow space 13 of the separation membrane module 11. Therefore, the gas processing system 1 of the present embodiment is less likely to clog the separation membrane 12 than the system of Patent Document 2, allowing for stable operation of the gas processing system 1.

[0032] Furthermore, in the gas processing system 1 of the present embodiment, the heat medium in the heat exchange unit 303 that exchanges heat with the gas flowing through the separation membrane module 11 is circulated from the downstream end side to the upstream end side of the separation membrane module 11, and the flow rate of the heat medium flowing through the heat exchange unit 303 is adjusted, thereby reducing the temperature gradient ΔT PV =T G1 -T G2 , and the temperature T of the supplied raw material gas G1 Therefore, for example, by adjusting the flow rate of the heat medium so that the temperature (membrane temperature) of the separation membrane 12 becomes high overall, the transmittance of the component (e.g., CO2) contained in the raw gas that is the target of recovery increases, improving the CO2 recovery rate, as described above with reference to FIG.

[0033] Note that the separation membrane 12 can allow other components (e.g., O2, N2, etc.) to permeate along with the component to be recovered (CO2). When such a separation membrane 12 is used, increasing the membrane temperature also increases the permeability of O2, N2, etc., which are not the target components to be recovered, as illustrated in FIG. 3C. In the graph of FIG. 3C, the permeability of O2 and N2 at a certain temperature is lower than that of CO2, but as the temperature of the separation membrane 12 increases, the differences between the permeability of CO2 and each of the permeability of O2 and N2 become smaller. In other words, as the temperature of the separation membrane 12 increases, the ratio of the amount of permeation of CO2 to the total amount of permeation of CO2, O2, and N2 that permeated the separation membrane 12 (CO2 selectivity) decreases, and the component concentration of CO2 in the permeated gas decreases. In contrast, in the gas processing system 1 of this embodiment, the temperature T of the supplied raw material gas increases. G1 , and the measured value of the temperature gradient of the separation membrane 12 ΔT PV =T G1 -T G2 By controlling the temperature gradient ΔT of the separation membrane 12, the difference between the CO permeability and each of the O permeability and the N permeability can be increased, thereby increasing the CO selectivity of the separation membrane 12. PV =T G1 -T G2 Set value ΔT is greater than 0 SV By controlling the CO selectivity of separation membrane 12 to be higher from the upstream end to the downstream end, the CO selectivity of separation membrane 12 can be adjusted from the upstream end to the downstream end. Gas processing system 1 of the present embodiment, which is capable of adjusting the CO selectivity of separation membrane 12 along the gas flow direction in first flow space 13, can reduce the concentrations of components other than CO in the permeated gas and improve the CO recovery rate compared to that of Patent Document 1.

[0034] The process of controlling the flow rate of the heat medium described above with reference to FIG. 4 is carried out by adjusting the measured value ΔT of the temperature gradient of the separation membrane module 11 (separation membrane 12). PV =T G1 -T G2 The measured value of the temperature gradient ΔT in the gas processing system 1 of this embodiment is merely an example of a process for controlling the temperature gradient ΔT PVFor example, if the opening of the flow control valve 310 is already at its maximum (fully open) when step S4 in FIG. 4 is performed, the temperature T of the retentate gas detected downstream of the separation membrane module 11 can be increased by a method other than increasing the opening (for example, by increasing the temperature of the heat medium). G2 may be set to be higher.

[0035] 5A is a diagram illustrating an example of the configuration of a shell-shaped heat exchanger, and FIG. 5B is a diagram illustrating an example of the configuration of a jacket-shaped heat exchanger. In gas processing system 1 of the present embodiment, heat exchanger 303 of heat medium flow path 3 is not limited to a specific shape as long as the heat medium flows from the downstream end to the upstream end of separation membrane module 11.

[0036] The shell-shaped heat exchanger 303 illustrated in FIG. 5A has a container 341 having a space large enough to accommodate the separation membrane module 11. The container 341 is provided with a heat medium inlet 342, a heat medium outlet 343, and through-holes (not shown) through which the flow paths (pipes) 202, 203, and 205 connected to the separation membrane module 11 are inserted. The heat medium inlet 342 is located near the downstream end of the separation membrane module 11, and the heat medium outlet 343 is located near the upstream end of the separation membrane module 11. The gaps between the through-holes (not shown) of the container 341 and the flow paths (pipes) 202, 203, and 205 connected to the separation membrane module 11 and inserted through the through-holes are sealed with a sealant to prevent leakage of the heat medium flowing through the container 341. The shell-shaped heat exchanger 303 preferably has baffle plates 344A to 344E located within the container 341 to prevent uneven flow of the heat medium within the container 341. The baffle plates 344A to 344E are arranged alternately from the downstream end to the upstream end of the separation membrane module 11. The baffle plates 344A, 344C, and 344E extend from a first region toward a second region of the inner wall surface of the container 341, and the baffle plates 344B and 344D extend from the second region toward the first region. When viewed from the downstream end of the separation membrane module 11, each of the baffle plates 344A to 344E extends from the first region or the second region by a length that creates an overlapping region. The heat transfer medium flowing through the container 341 provided with such baffle plates 344A to 344E flows from the downstream end to the upstream end of the separation membrane module 11 while meandering along the baffle plates 344A to 344E. This makes it possible to prevent, for example, heat exchange from being promoted only in a specific portion of the separation membrane module 11 due to uneven flow of the heat medium. Note that the installation conditions, such as the number and spacing of the baffles 344 in the container 341 of the shell-shaped heat exchanger 303, are not limited to specific conditions. Furthermore, the shell-shaped heat exchanger 303 may have, for example, a flow path formed in the container 341 through which the heat medium flows spirally around the separation membrane module 11 from the downstream end to the upstream end of the separation membrane module 11.

[0037] 5B, heat exchange with the gas flowing through the first flow space 13 is performed in a section from an intermediate position X3 downstream of the upstream end (position X1) of the separation membrane module 11 to a position X4 near the downstream end (position X2). In this case, the temperature T G1 and the temperature of the gas flowing through the first flow space 13 at the intermediate position X3 may differ to some extent depending on the distance (length) from position X1 to the intermediate position X3. Therefore, if heat exchange is not performed in the section from the upstream end (position X1) of the separation membrane module 11 to the intermediate position X3, the temperature T G1 Instead, the temperature T of the raw material gas at a portion of the separation membrane module 11 upstream of the intermediate position X3 and close to the intermediate position X3 G3 may be detected by the fifth temperature detection means 222. In this way, by adjusting the section in which heat exchange with the heat exchanger 303 takes place, the CO2 permeability or selectivity of the separation membrane 12 can be adjusted more flexibly.

[0038] Fig. 6 is a diagram illustrating a modified configuration of the gas processing system according to the first embodiment. Fig. 6 shows an enlarged example of the configuration of the separation membrane module 11 and the heat exchanger 303 of the heat medium passage 3 in the gas processing system 1. The relationship between the separation membrane module 11 and the heat exchanger 303 in the gas processing system 1 of this embodiment is not limited to a one-to-one relationship, and may be a many-to-one relationship. Fig. 6 shows an example in which six separation membrane modules 11A to 11F are housed in one shell-shaped heat exchanger 303.

[0039] In the container 341 of the shell-shaped heat exchanger 303 illustrated in FIG. 6, a set of three separation membrane modules 11A-11C connected in series and a set of three separation membrane modules 11D-11F connected in series are arranged, and these two sets are connected in parallel. The term "series" used to describe the connection of separation membrane modules refers to the connection between a separation membrane module and another separation membrane module to which the permeate gas discharged from the separation membrane module is supplied as a raw gas. The term "parallel" used to describe the connection of separation membrane modules refers to the connection between a separation membrane module and another separation membrane module to which the raw gas is supplied via a branch channel branched from the channel that supplies the raw gas to the separation membrane module. In the heat exchanger 303 illustrated in FIG. 6, the installation conditions, such as the number and spacing of baffles 344 in the container 341, are not limited to specific conditions. Furthermore, the number of separation membrane modules 11 exchanging heat with one heat exchanger 303 is not limited to six, as illustrated in FIG. 6. The plurality of separation membrane modules 11 exchanging heat with one heat exchange section 303 may be, for example, all of the separation membrane modules 11 connected in series, or all of the separation membrane modules 11 connected in parallel. Furthermore, the heat exchange section 303 may be configured to exchange heat with some of the separation membrane modules 11, including the separation membrane module 11 in the final stage, among the plurality of separation membrane modules 11 connected in series, but not with some of the separation membrane modules 11, including the separation membrane module 11 in the initial stage.

[0040] [Second embodiment] Fig. 7 is a diagram illustrating an example of the configuration of a gas processing system according to a second embodiment. Fig. 8 is a diagram illustrating a modified example of a heat transfer medium flow path in the gas processing system according to the second embodiment. As illustrated in Figs. 7 and 8, gas processing system 1 according to this embodiment has a configuration in which two separation membrane modules 11A and 11B connected in series via first gas delivery means 15A in processing system 2 exchange heat with separate heat exchange sections 303A and 303B.

[0041] In the gas processing system 1 of FIGS. 7 and 8, a raw material gas supplied to the first separation membrane module 11A of two serially connected separation membrane modules 11A and 11B is separated into a permeate gas and a retentate gas. The retentate gas is discharged into a flow path 203 and, for example, discharged into the atmosphere through an outlet 204A. The permeate gas is discharged into a flow path 205, and then the flow rate, pressure, etc. are adjusted by a first gas delivery means 15A such as a vacuum pump or a blower, and then sent to a flow path 207. The permeate gas sent to a flow path 207 is supplied to the second separation membrane module 11B as a raw material gas, where it is separated into a permeate gas and a retentate gas. The retentate gas is discharged into a flow path 208 and, for example, discharged into the atmosphere through an outlet 204B. The permeate gas is discharged into a flow path 209, and then the flow rate, pressure, etc. are adjusted by a second gas delivery means 15B such as a vacuum pump or a blower, and then sent to a flow path 210. The permeable gas sent to the flow path 210 is supplied through the permeable gas outlet 206 to a capture unit (not shown) that captures CO2 from the permeable gas. The raw material gas supplied to the subsequent separation membrane module 11B is the permeable gas with an increased CO2 concentration discharged from the previous separation membrane module 11A, and therefore the permeable gas discharged from the subsequent separation membrane module 11B has an even higher CO2 concentration than the permeable gas discharged from the previous separation membrane module 11A. Therefore, by supplying the permeable gas discharged from the subsequent separation membrane module 11B to a capture unit to capture CO2, the CO2 capture rate can be increased.

[0042] The gas processing system 1 illustrated in FIG. 7 includes a first heat medium flow path 3A and a second heat medium flow path 3B, which may be independent heat medium flow paths. The first heat medium flow path 3A includes a heat exchange section 303A that exchanges heat with the upstream separation membrane module 11A, and the second heat medium flow path 3B includes a heat exchange section 303B that exchanges heat with the downstream separation membrane module 11B. The first heat medium flow path 3A and the second heat medium flow path 3B may each have the same configuration as the heat medium flow path 3 illustrated in FIG. 1. In the gas processing system 1 illustrated in FIG. 7, the valve aperture of the flow control valve 310A of the first heat medium flow path 3A, the valve aperture of the flow control valve 310B of the second heat medium flow path 3B, and the processing of the pretreatment unit 10 are controlled by a control panel 8 (see FIGS. 1 and 2).

[0043] The control panel 8 controls the temperature T of the raw material gas supplied to the upstream separation membrane module 11A. G11 and the temperature of the discharged retentate gas T G12 The temperature difference (i.e., the temperature gradient) between PV =T G11 -T G12 ) is the set value ΔT SV The control unit 800 of the control panel 8 adjusts the valve opening of the flow control valve 310A of the first heat medium flow path 3A so that the temperature T G11 , the temperature of the retentate gas T G12 , the temperature T of the heat medium upstream of the heat exchange section 303A H11 , and the temperature T of the heat medium downstream of the heat exchange section 303A H12 and the flow rate Q of the heat medium upstream of the heat exchange section 303A is obtained. HPV is the flow rate Q derived from equation (1-2) H The valve opening of the flow control valve 310A is adjusted so that the temperature of the raw material gas T G11 and the temperature of the retentate gas, T G12 The temperature of the heat medium T is detected by a first temperature detection means 220A installed in the flow path 202 between the pretreatment unit 10 and the upstream separation membrane module 11A, and a second temperature detection means 221A installed in the flow path 203 through which the retentate gas discharged from the upstream separation membrane module 11A flows. H11 and T H12 The temperature is detected by a third temperature detecting means 320A installed in the flow path 302A on the upstream side of the heat exchanger 303A and a fourth temperature detecting means 321A installed in the flow path 304A on the downstream side.

[0044] The control unit 800 of the control panel 8 controls the temperature T G21 and the temperature of the discharged retentate gas T G22 The temperature difference (i.e., the temperature gradient) between PV =T G21 -T G22 ) is the set value ΔT SVThe control unit 800 adjusts the valve opening of the flow control valve 310B of the second heat medium flow path 3B so that the temperature T G21 , the temperature of the discharged retentate gas T G22 , the temperature T of the heat medium upstream of the heat exchange section 303B H21 , and the temperature T of the heat medium downstream of the heat exchange section 303B H22 and the flow rate Q of the heat medium upstream of the heat exchange section 303B is obtained. HPV is the flow rate Q derived from equation (1-2) H The valve opening of the flow control valve 310B is adjusted so that the temperature of the permeated gas T G21 and the temperature of the retentate gas, T G22 The temperature of the heat medium T is detected by a first temperature detection means 220B installed in the flow path 207 between the first gas delivery means 15A and the subsequent separation membrane module 11B, and a second temperature detection means 221B installed in the flow path 208 for the retentate gas discharged from the subsequent separation membrane module 11B. H21 and T H22 The temperature is detected by a third temperature detecting means 320B installed in the flow path 302A upstream of the heat exchanger 303B and a fourth temperature detecting means 321B installed in the flow path 304B downstream of the heat exchanger 303B.

[0045] In this way, in the gas processing system 1 illustrated in FIG. 7, the temperature gradient ΔT PV and a heat exchanger 303A that adjusts the temperature gradient ΔT PV In this gas processing system 1, the temperature gradient ΔT of the separation membrane 12 in the upstream separation membrane module 11A is adjusted by the temperature gradient ΔT of the separation membrane 12 in the upstream separation membrane module 11A. PV and the temperature gradient ΔT of the separation membrane 12 of the subsequent separation membrane module 11B. PV and can be controlled separately (independently), making it easy to adjust the amount of CO2 contained in the permeate gas discharged from each of the separation membrane modules 11A and 11B.

[0046] On the other hand, in the gas processing system 1 illustrated in Fig. 8, a heat exchange section 303A that exchanges heat with the upstream separation membrane module 11A and a heat exchange section 303B that exchanges heat with the downstream separation membrane module 11B are provided in one heat medium flow path 3C. That is, in the gas processing system 1 illustrated in Fig. 8, the heat medium used for heat exchange with the upstream separation membrane module 11A in the first heat exchange section 303A is also used for heat exchange with the downstream separation membrane module 11B in the second heat exchange section 303B.

[0047] The heat medium that has passed through the first heat exchange unit 303A in the heat medium flow path 3C is cooled by heat exchange with the preceding separation membrane module 11A. In contrast, the permeate gas discharged from the preceding separation membrane module 11A (i.e., the permeate gas supplied to the following separation membrane module 11B) has a higher temperature due to heat exchange with the first heat exchange unit 303A than the permeate gas in a conventional gas processing system 1 that does not involve heat exchange. For this reason, when adjusting the temperature gradient of the following separation membrane module 11B by heat exchange with the heat medium that has passed through the first heat exchange unit 303A and flowed into the second heat exchange unit 303B, it is preferable to increase the temperature of the heat medium that has passed through the first heat exchange unit 303A using the temperature increasing means 350 before flowing it into the second heat exchange unit 303B. The temperature raising means 350 illustrated in Fig. 8 is configured to raise the temperature of the heat medium flowing through the flow path 304 by heat exchange between a relatively high-temperature heat medium flowing through the flow path 301 upstream of the first heat exchange unit 303A and a relatively low-temperature heat medium flowing through the flow path 304 connecting the downstream end of the first heat exchange unit 303A and the second flow control valve 310B. In the heat medium flow path 3C illustrated in Fig. 8, the flow rate Q of the heat medium for the heat exchange by the first heat exchange unit 303A adjusted by the process described above with reference to Fig. 4 is H1 and the flow rate Q of the heat medium for heat exchange by the second heat exchange section 303B. H2 The relationship between Q and H1 >Q H2 For this reason, the heat transfer medium flow path 3C has a H1 >Q H2In order to prevent an increase in pressure in the flow path 304 due to an excess of the heat medium exceeding the flow rate of the heat medium required to supply to the second heat exchange section 303B, it is preferable to provide a branch flow path 306 that branches off from the flow path 304 to the heat medium outlet 305 without passing through the second heat exchange section 303B.

[0048] The control unit 800 of the control panel 8 in the gas processing system 1 illustrated in FIG. 7 or 8 can perform the processes described above with reference to FIG. 4 to control the temperature gradient of the upstream separation membrane module 11A and the temperature gradient of the downstream separation membrane module 11B. The set value ΔT of the temperature gradient in the process of controlling the temperature gradient of the upstream separation membrane module 11A is SV and the set value ΔT of the temperature gradient in the process of controlling the temperature gradient of the subsequent separation membrane module 11B. SV For example, the set value ΔT of the temperature gradient of the separation membrane module 11A in the upstream stage may be SV is a positive value (ΔT SV >0), the temperature T of the raw material gas supplied to the subsequent separation membrane module 11B G21 is the upper limit temperature T M In this case, the process for controlling the temperature gradient of the subsequent separation membrane module 11B may be a process in which steps S6 and S7 in the flow of FIG. 4 are omitted.

[0049] 7 and 8 illustrate a treatment system 2 in which two separation membrane modules 11A and 11B are connected in series, but the number (number of stages) of separation membrane modules 11 connected in series in the treatment system 2 may be three or more. From the viewpoint of improving the CO2 recovery rate, the heat transfer medium flow path 3 combined with the treatment system 2 in which multiple separation membrane modules 11 are connected in series is preferably configured to exchange heat with all of the separation membrane modules 11, but is not limited to such a configuration. The heat transfer medium flow path 3 may be configured to exchange heat with one or more of the multiple separation membrane modules 11, and conditions such as the position, number, and combination of the separation membrane modules 11 to be heat exchanged within the treatment system 2 are not limited to specific conditions.

[0050] [Third embodiment] Fig. 9 is a diagram illustrating a configuration example of a gas processing system according to a third embodiment. Fig. 10 is a diagram illustrating a modified example of a heat medium flow path in the gas processing system according to the third embodiment.

[0051] The heat medium supplied to the heat medium flow path 3 described above with reference to FIG. G2 3. The temperature of the heat medium supplied through the supply port 300 is higher than that of the heat medium supplied through the supply port 300, and is heated by some heating means as necessary before being supplied to the heat medium flow path 3. In contrast, as illustrated in FIGS. 9 and 10, the heat medium flow path 3 in the gas processing system 1 according to the third embodiment uses a temperature increasing means 351 to increase the temperature of the heat medium supplied through the supply port 300 before being supplied to the heat exchanger 303. The temperature increasing means 351 illustrated in FIGS. 9 and 10 is configured to increase the temperature of the heat medium by heat exchange between the heat medium flowing through the flow path 301 upstream of the heat exchanger 303 (more specifically, the flow control valve 310) and the raw material gas flowing through the flow path 201 between the supply port 200 and the pretreatment unit 10 in the processing system 2. The temperature of the raw material gas supplied through the flow path 201 to the pretreatment unit 10 is determined based on the temperature T of the raw material gas supplied from the pretreatment unit 10 to the separation membrane module 11. G1 Therefore, by performing heat exchange using the temperature raising means 351 upstream of the pre-treatment unit 10, the temperature of the heat medium flowing through the flow path 301 can be easily raised to the temperature T G2Moreover, since the temperature of the heat medium can be increased by the heat of the raw material gas exhausted by the pretreatment unit 10, the cost for increasing the temperature of the heat medium can be reduced compared to, for example, heating using an electric heating sheet as in Patent Document 1, and an increase in the operating cost of the gas treatment system 1 can be suppressed.

[0052] 10, when heat exchange between the heat medium and the raw material gas is performed in the flow path 301 of the heat medium flow path 3, a flow control valve 312 may be provided upstream of the heat exchange section 301a where heat exchange is performed in the flow path 301 of the heat medium flow path 3 to adjust the flow rate of the heat medium in the heat exchange section 301a. By adjusting the flow rate of the heat medium in the heat exchange section 301a with the flow control valve 312, the amount of heat transferred from the raw material gas to the heat medium in the heat exchange section 301a is adjusted, and the temperature T H1 Therefore, for example, when the valve opening degree of the flow control valve 310 cannot be increased in step S4 of FIG. 4 or when the valve opening degree of the flow control valve 310 cannot be decreased in step S5, the valve opening degree of the flow control valve 312 can be adjusted to adjust (control) the temperature T H1 The measured temperature gradient ΔT of the separation membrane module 11 (separation membrane 12) can be adjusted. PV can be controlled.

[0053] 8, in the heat medium flow path 3 having the flow control valve 312 illustrated in Fig. 10, the flow rate of the heat medium in the flow path 301 between the flow control valve 312 and the flow control valve 310, which corresponds to the valve opening of the flow control valve 312, may be greater than the flow rate of the heat medium downstream of the flow control valve 310, which corresponds to the valve opening of the flow control valve 310. For this reason, when the flow control valve 312 is provided, it is preferable to provide a branch flow path 306 that branches off from the flow path 301 to the heat medium outlet 305 without passing through the heat exchanger 303, as illustrated in Fig. 10, in order to prevent an increase in pressure in the flow path 301 due to an excess flow of heat medium exceeding the flow rate of the heat medium required to supply to the heat exchanger 303.

[0054] Furthermore, the temperature increasing means 351 in the gas processing system 1 according to the third embodiment described above with reference to Figures 9 and 10 may also be applied to the gas processing system 1 in which multiple separation membrane modules 11 described in the second embodiment are heat exchanged using separate heat exchange sections 303.

[0055] [Fourth embodiment] FIG. 11 is a diagram illustrating an example of the configuration of a gas processing system according to the fourth embodiment.

[0056] The heat medium flow path 3 in the gas processing system 1 according to the first to third embodiments has a heat medium supply port 300 and a heat medium discharge port 305, as illustrated in FIG. 1 and other figures, and the heat medium used for heat exchange with the separation membrane module 11 in the heat exchange section 303 is discharged from the discharge port 305. Such a heat medium flow path 3 is particularly useful when a large amount of heat medium can be easily procured at low cost. In contrast, in the gas processing system 1 according to the fourth embodiment, as illustrated in FIG. 11, for example, the heat medium flow path 3 has a closed flow path configuration in which the heat medium circulates. The heat medium flow path 3 illustrated in FIG. 11 has a configuration in which the heat medium discharge port 305 in the heat medium flow path 3 described above with reference to FIG. 9 is connected to the heat medium supply port 300 via a heat medium delivery means 360 such as a pump or a blower. That is, the heat medium whose temperature has been reduced by heat exchange with the separation membrane module 11 in the heat exchange section 303 is supplied to the heat medium delivery means 360 through the flow path 304, and the flow rate, pressure, etc. are adjusted in the heat medium delivery means 360 before being delivered to the flow path 301. The heat medium delivered to the flow path 301 has its temperature increased by heat exchange with the raw material gas in the temperature increasing means 351 (heat exchange section 301a), and is then used again for heat exchange with the separation membrane module 11 in the heat exchange section 303. By circulating the heat medium in the heat medium flow path 3 in this way, it is possible to reduce costs required for procuring, discharging, etc. the heat medium.

[0057] The heat medium flow path 3 in the gas processing system 1 of this embodiment is not limited to the configuration exemplified in Fig. 11. The heat medium flow path 3 for circulating the heat medium may also be applied to the gas processing system 1 in which the plurality of separation membrane modules 11 described in the second embodiment exchange heat using separate heat exchange units 303.

[0058] [Fifth embodiment] FIG. 12 is a diagram illustrating an example of the configuration of a gas processing system according to a fifth embodiment. As illustrated in FIG. 12, the heat medium flow path 3 in the gas processing system 1 of the fifth embodiment may be configured to circulate a portion of the raw material gas in the processing system 2 as the heat medium. The heat medium supply port in the heat medium flow path 3 illustrated in FIG. 12 is provided by branching off from a flow path 201 that supplies the raw material gas in the processing system 2 to the pretreatment unit 10. For this reason, the heat medium (raw material gas) supplied to the heat medium flow path 3 is circulated at a temperature T G2 9 and the like is not required. The raw material gas supplied to the heat medium flow path 3 may pass through a heat exchanger 303 and then be returned to the flow path 201 that supplies the raw material gas in the processing system to the pre-treatment unit 10 through a flow path 304, as shown in FIG. 12. The position in the flow path 201 that supplies the raw material gas to the pre-treatment unit 10, where the heat medium (raw material gas) of the heat medium flow path 3 is returned, is preferably upstream of the position where the heat medium (raw material gas) is supplied to the heat medium flow path 3, as shown in FIG. 12, but is not limited to a specific position. The heat medium (raw material gas) supplied to the heat medium flow path 3 may be discharged into the atmosphere, etc., without being returned to the flow path 201 that supplies the raw material gas to the pre-treatment unit 10.

[0059] [Sixth embodiment] Fig. 13 is a diagram illustrating an example of the configuration of a gas processing system according to Embodiment 6. The gas processing system 1 illustrated in Fig. 13 has a recycle flow path 211 that supplies the retentate gas discharged from the latter separation membrane module 11B of the two separation membrane modules 11A and 11B in the processing system 2 back to the former separation membrane module 11A.

[0060] In the gas processing system 1 of FIG. 13, a mixing header 17 is disposed between the pretreatment unit 10 and the upstream separation membrane module 11A. The retentate gas discharged from the downstream separation membrane module 11B is supplied to a delivery means 16, such as a recycle pump or a blower, through a flow path 208. The delivery means 16 adjusts the flow rate, pressure, and the like before delivering the retentate gas to a recycle flow path 211. The retentate gas delivered to the recycle flow path 211 is mixed with the raw material gas discharged from the pretreatment unit 10 in the mixing header 17 and delivered to the upstream separation membrane module 11A. Therefore, in the gas processing system 1 illustrated in FIG. 13, CO2 remaining in the retentate gas discharged from the downstream separation membrane module 11B can be separated and recovered again in the separation membrane modules 11A and 11B. Note that the heat transfer flow path 3 in the gas processing system 1 having the recycle flow path 211 illustrated in FIG. 13 may include a heat exchanger 303B that exchanges heat with the downstream separation membrane module 11B, as described above with reference to FIGS. 7 and 8. The gas processing system 1 may also include, for example, a flow path that returns the retentate gas discharged from the upstream separation membrane module 11A to the mixing header 17. Furthermore, the gas processing system 1 may include another separation membrane module to which the permeate gas discharged from the downstream separation membrane module 11B is supplied as a raw material gas.

[0061] The embodiments of the gas processing system 1 according to the present invention are not limited to the above-described embodiments, and may be variously modified, substituted, or altered without departing from the spirit of the technical concept. Furthermore, the gas processing system 1 may be a combination of configurations described separately in multiple embodiments. Furthermore, if the technical concept can be realized in a different way due to technological advances or derived technologies, the system may be implemented using that method. Therefore, the claims cover all embodiments that may fall within the scope of the technical concept.

[0062] The features of the above-described embodiment will be summarized below. The gas processing system according to the above-described embodiment includes a separation membrane module in which a separation membrane for separating a desired component contained in a raw material gas containing the desired component is disposed; a first temperature detection means for detecting the temperature of the separation membrane at an upstream end in a gas flow direction along the separation membrane; a second temperature detection means for detecting the temperature of the separation membrane at a downstream end in the gas flow direction; a heat medium flow path for circulating a heat medium that exchanges heat with the separation membrane module; and a control unit for controlling the flow rate of the heat medium in the heat medium flow path. The separation membrane module is provided with a heat exchange section that circulates the heat medium from the downstream end to the upstream end in the flow direction of the raw material gas within the membrane module and exchanges heat with the gas flowing within the separation membrane module, a third temperature detection means that detects the temperature of the heat medium at the upstream end of the heat exchange section, a fourth temperature detection means that detects the temperature of the heat medium at the downstream end of the heat exchange section, and a control valve that is arranged upstream of the heat exchange section and adjusts the flow rate of the heat medium supplied to the heat exchange section, and the control section controls the opening degree of the control valve based on the temperatures detected by each of the temperature detection means.

[0063] In the gas processing system according to the above embodiment, the control unit derives the flow rate of the heat medium to be supplied to the heat exchange unit based on a predetermined temperature gradient between the temperature at the upstream end and the temperature at the downstream end of the separation membrane, a first temperature detected by the first temperature detection means, a second temperature detected by the second temperature detection means, a third temperature detected by the third temperature detection means, and a fourth temperature detected by the fourth temperature detection means, and adjusts the opening degree of the control valve so that the temperature difference between the first temperature and the second temperature becomes the set temperature gradient.

[0064] In the gas processing system according to the above embodiment, the control unit adjusts the opening of the control valve in an opening direction when the temperature difference between the first temperature and the second temperature is large relative to the set temperature gradient, and adjusts the opening of the control valve in a closing direction when the temperature difference between the first temperature and the second temperature is small relative to the set temperature gradient.

[0065] In the gas processing system according to the above embodiment, the heat exchange unit has a shell shape that covers the entire separation membrane module.

[0066] In the gas processing system according to the above embodiment, the heat exchange section is disposed so that heat exchange occurs between the downstream end of the separation membrane module and an intermediate position between the upstream end and the downstream end.

[0067] The gas processing system according to the above embodiment includes a plurality of separation membrane modules, and the heat medium flow path is configured to exchange heat with one or more of the plurality of separation membrane modules.

[0068] In the gas processing system according to the above embodiment, the separation membrane module separately discharges a permeate gas containing the desired component that has permeated the separation membrane and a retentate gas containing the component of the raw material gas that has not permeated the separation membrane, and the gas processing system comprises a flow path that supplies the permeate gas discharged by the first separation membrane module to a second separation membrane module as a raw material gas, and a recycle flow path that supplies the retentate gas discharged by the second separation membrane module again to the first separation membrane module.

[0069] The gas processing system according to the above embodiment includes a second heat exchange section that increases the temperature of the heat medium by heat exchange between the heat medium flowing upstream of the heat exchange section in the heat medium flow path and the raw material gas supplied to the separation membrane module.

[0070] In the gas processing system according to the above embodiment, the control valve of the heat medium flow path is arranged between the heat exchange unit and the second heat exchange unit, and the heat medium flow path further includes a second control valve arranged upstream of the second heat exchange unit, and a branch flow path that branches between the second heat exchange unit and the control valve and connects to a flow path downstream of the heat exchange unit.

[0071] In the gas processing system according to the above embodiment, the control unit adjusts the opening degree of the control valve and the second control valve so that the temperature of the heat medium detected by the third temperature detection means becomes a preset temperature.

[0072] In the gas processing system according to the above embodiment, the heat medium flow path is a closed flow path that circulates the heat medium.

[0073] The gas processing system according to the above embodiment further includes a pre-treatment unit that performs a process of lowering the temperature of the raw material gas supplied to the separation membrane module to a temperature equal to or lower than the heat-resistant temperature of the separation membrane.

[0074] In the gas processing system according to the above embodiment, the first temperature detection means detects the temperature of the raw material gas in a flow path upstream of the separation membrane module, the second temperature detection means detects the temperature of the treated gas discharged from the separation membrane module in a flow path downstream of the separation membrane module, the third temperature detection means detects the temperature of the heat medium in a flow path upstream of the heat exchange unit, and the fourth temperature detection means detects the temperature of the heat medium in a flow path downstream of the heat exchange unit.

[0075] In the gas processing system according to the above embodiment, the separation membrane module separately discharges a permeated gas containing the desired component that has permeated the separation membrane and a retentate gas containing the component of the raw material gas that has not permeated the separation membrane, and the second temperature detection means detects the temperature of the retentate gas discharged from the separation membrane module.

[0076] In the gas processing system according to the above embodiment, the heat transfer medium flow path is configured to branch off from the flow path that supplies the raw material gas to the separation membrane module and to circulate a portion of the raw material gas as the heat transfer medium. [Industrial Applicability]

[0077] As described above, the present invention can improve the recovery rate of desired components in a gas processing system, and is particularly useful in gas processing systems in which the permeability of a separation membrane that selectively permeates and separates specific components such as CO contained in a raw gas is temperature-dependent. [Explanation of symbols]

[0078] REFERENCE SIGNS LIST 1...gas processing system, 2...processing system, 3...heat medium flow path, 8...control panel, 800...control section, 10...pre-processing section, 11...separation membrane module, 12...separation membrane, 303, 303A, 303B...heat exchange section, 220, 220A, 220B...first temperature detection means, 221, 221A, 221B...second temperature detection means, 320, 320A, 320B...third temperature detection means, 321, 321A, 321B...fourth temperature detection means, 310, 310A, 310B, 321...flow rate control valve, 330...flow rate detection means, 350, 351...heating means

Claims

1. a separation membrane module in which a separation membrane for separating a predetermined component contained in a raw material gas containing the predetermined component is disposed; a first temperature detection means for detecting the temperature of an upstream end of the separation membrane in the direction of gas flow along the separation membrane; a second temperature detection means for detecting the temperature of the downstream end of the separation membrane in the direction of gas flow; a heat medium flow path through which a heat medium that exchanges heat with the separation membrane module flows; a control unit that controls the flow rate of the heat medium in the heat medium flow path, The heat transfer medium flow path is a heat exchange section that circulates the heat medium from a downstream end side to an upstream end side in a flow direction of the raw material gas within the separation membrane module and exchanges heat with the gas flowing within the separation membrane module; a third temperature detection means for detecting the temperature of the heat medium at the upstream end of the heat exchange section; a fourth temperature detection means for detecting the temperature of the heat medium at the downstream end of the heat exchange section; a control valve that is disposed upstream of the heat exchange unit and adjusts the flow rate of the heat medium supplied to the heat exchange unit, The control unit controls the opening degree of the control valve based on the temperatures detected by the temperature detection means. Gas treatment system.

2. The control unit a predetermined temperature gradient between the temperature at the upstream end and the temperature at the downstream end of the separation membrane; based on a first temperature detected by the first temperature detecting means, a second temperature detected by the second temperature detecting means, a third temperature detected by the third temperature detecting means, and a fourth temperature detected by the fourth temperature detecting means, deriving a flow rate of the heat medium to be supplied to the heat exchange section; The opening degree of the control valve is adjusted so that the temperature difference between the first temperature and the second temperature becomes the set temperature gradient. The gas processing system of claim 1 .

3. The control unit When the temperature difference between the first temperature and the second temperature is large with respect to the set temperature gradient, the opening degree of the control valve is adjusted in an opening direction; When the temperature difference between the first temperature and the second temperature is small relative to the set temperature gradient, the opening of the control valve is adjusted in the closing direction. The gas processing system of claim 2 .

4. 2. The gas processing system according to claim 1, wherein the heat exchange unit has a shell shape that covers the entire separation membrane module.

5. 2. The gas processing system according to claim 1, wherein the heat exchange section is disposed so that heat exchange occurs between a downstream end of the separation membrane module and an intermediate position between the upstream end and the downstream end.

6. the gas processing system comprises a plurality of separation membrane modules; The heat medium flow path is configured to exchange heat with one or more separation membrane modules among the plurality of separation membrane modules. The gas processing system of claim 1 .

7. The separation membrane module separately discharges a permeated gas containing the predetermined component that has permeated the separation membrane and a non-permeated gas containing a component of the raw material gas that has not permeated the separation membrane, The gas processing system includes a flow path that supplies the permeate gas discharged from a first separation membrane module to a second separation membrane module as a raw material gas, and a recycle flow path that supplies the retentate gas discharged from the second separation membrane module again to the first separation membrane module. The gas processing system of claim 1 .

8. 2. The gas processing system according to claim 1, further comprising a second heat exchange unit that increases the temperature of the heat medium by heat exchange between the heat medium flowing upstream of the heat exchange unit in the heat medium flow path and the raw material gas supplied to the separation membrane module.

9. The control valve of the heat medium flow path is disposed between the heat exchange unit and the second heat exchange unit, The heat medium flow path further includes a second control valve disposed upstream of the second heat exchange unit, and a branch flow path branching between the second heat exchange unit and the control valve and connecting to a flow path downstream of the heat exchange unit. The gas processing system of claim 8 .

10. 10. The gas processing system according to claim 9, wherein the control unit adjusts the opening degrees of the control valve and the second control valve so that the temperature of the heat medium detected by the third temperature detection means becomes a preset temperature.

11. 2. The gas processing system according to claim 1, wherein the heat transfer medium passage is a closed passage for circulating the heat transfer medium.

12. 12. The gas processing system according to claim 1, further comprising a pretreatment unit that performs a process of lowering the temperature of the raw material gas supplied to the separation membrane module to a temperature equal to or lower than the heat-resistant temperature of the separation membrane.

13. the first temperature detection means detects the temperature of the raw material gas in a flow path upstream of the separation membrane module, the second temperature detection means detects the temperature of the treated gas discharged from the separation membrane module in a flow path downstream of the separation membrane module, the third temperature detection means detects the temperature of the heat medium in the flow path upstream of the heat exchanger; The fourth temperature detection means detects the temperature of the heat medium in the flow path downstream of the heat exchanger. The gas processing system of claim 1 .

14. The separation membrane module separately discharges a permeated gas containing the predetermined component that has permeated the separation membrane and a non-permeated gas containing a component of the raw material gas that has not permeated the separation membrane, The second temperature detection means detects the temperature of the retentate gas discharged from the separation membrane module. The gas processing system of claim 1 .

15. 2. The gas processing system according to claim 1, wherein the heat transfer medium flow path is configured to branch off from a flow path that supplies the raw material gas to the separation membrane module and to circulate a portion of the raw material gas as the heat transfer medium.

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