Inspection method and inspection device for gas separation membrane module

Abstract

To provide an inspection device that identifies the location of occurrence of an abnormality including deterioration, damage, or leakage in a gas separation membrane module, or confirms the extent of such deterioration or the like.SOLUTION: An inspection method and an inspection device for a gas separation membrane module are provided. In the inspection method for the gas separation membrane module, supply gas to the gas separation membrane module is composed of one or more types of gas, and at a portion of the gas separation membrane module, at least one characteristic of either the non-permeated gas or the permeated gas is measured.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an inspection method and an inspection device for measuring the properties of at least one of a non-permeating gas and a permeating gas at a site of a gas separation membrane module. [Background technology]

[0002] In recent years, there has been a demand for the development of technology that can efficiently separate specific gases from a gas mixture. As a method for efficiently separating specific gases from a gas mixture, membrane separation, which utilizes differences in the gas permeability of materials to selectively allow the target component to pass through, has attracted attention. Separation membranes have been developed for a variety of gases, including helium, hydrogen, carbon dioxide, nitrogen, sulfur hexafluoride, water vapor, and rare gases. Gas separation using separation membranes is expected to be a technology that can achieve energy and space savings.

[0003] When a separation membrane is used in an actual separation process, for example, a flat membrane, it is used as a spiral module. If there is a defect in the adhesive joint during module fabrication or if the separation membrane is damaged, or if the separation membrane deteriorates due to acidic gases during use of the separation membrane module, there is a concern that the feed gas will leak to the permeate side or that separation performance will decrease. In some cases, chemical cleaning may be performed in addition to normal operation. This raises concerns that abnormalities such as damage, rupture, or deterioration of the separation membrane elements may occur, making it important to quickly detect abnormalities in the separation membrane module, identify the location of the abnormality as quickly as possible, and take early action.

[0004] Patent Document 1 discloses a method and device for evaluating the quality of a separation membrane, which measures the actual separation coefficient of a mixed gas.

[0005] Patent Document 2 discloses a method for measuring the flow rate and water quality of multiple permeates from multiple separation membrane modules arranged in series, in order to address concerns about breakage or deterioration when cleaning the separation membranes of separation membrane modules used in water treatment processes with chemicals.

[0006] Patent Document 3 discloses a method for identifying damaged hollow fiber membranes by pressing a ventilation device against the outer surface of the adhesive fixing part at the open end of the membrane of a hollow fiber membrane module having a damaged membrane, changing or narrowing the specified range into which pressurized gas is fed, and repeating the detection operation. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6643223 [Patent Document 2] International Publication No. 2020 / 071507 [Patent Document 3] Japanese Patent Application Laid-Open No. 2009-078243 Summary of the Invention [Problem to be solved by the invention]

[0008] It is important to check for abnormalities in separation membrane modules used in actual separation processes, i.e., to inspect separation membrane modules. While conventional methods for inspecting separation membrane modules can detect performance degradation in the entire separation membrane module, it is difficult to determine which part of the separation membrane module is defective, whether it is a partial or global defect. This makes it difficult to determine the cause of the performance degradation.

[0009] Therefore, the present invention provides an inspection device and an inspection method for a gas separation membrane module equipped with a hollow tubular separation membrane that can solve these problems, examine the parts of the separation membrane module where performance has deteriorated, confirm the degree of performance deterioration, and obtain information for performance recovery such as repairs. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention has the following configuration.

[0011] (1) A method for inspecting a gas separation membrane module, in which the gas supplied to the gas separation membrane module having a hollow tubular separation membrane is composed of one or more types of gas, and the characteristics of at least one of the non-permeating gas or the permeating gas are measured at a location in the gas separation membrane module.

[0012] (2) The method for inspecting a gas separation membrane module according to (1), wherein the characteristics of at least one of the non-permeating gas and the permeating gas are measured at two or more locations in the gas separation membrane module.

[0013] (3) A method for inspecting a gas separation membrane module according to (1) to (2), in which a gas separation membrane module having hollow tubular separation membranes is formed by potting a plurality of separation membranes with one or both ends open, a gas is passed through the separation membrane module, and the gas collected from a predetermined area on the outer surface of the open potting portion is inspected for abnormalities, and the predetermined area through which the gas is passed is changed or narrowed and the detection operation is repeated to identify the inspection area, and then the characteristics of at least one of the non-permeating gas or the permeating gas are measured at a location in the gas separation membrane module.

[0014] (4) A method for inspecting a gas separation membrane module according to any one of (1) to (3), in which a gas separation membrane module having hollow tubular separation membranes is potted with one or both ends of a plurality of separation membranes open, gas is vented from a predetermined area on the outer surface of the open potting portion, the gas collected from inside the separation membrane module is inspected for abnormalities, the predetermined area for collecting gas is changed or narrowed and the detection operation is repeated to identify the inspection area, and then the characteristics of at least one of the non-permeating gas or the permeating gas are measured at a location in the gas separation membrane module.

[0015] (5) A method for inspecting a gas separation membrane module according to any one of (1) to (4), wherein the rate of decrease in the flow rate of the non-permeated gas or permeated gas discharged from the separation membrane module relative to the flow rate of the supply gas is 1% or more and 99% or less.

[0016] (6) A method for inspecting a gas separation membrane module according to any one of (1) to (5), wherein the supply gas is composed of two or more types of gases, and the ratio of the kinetic molecular diameters of the other gases to the gas with the smallest kinetic molecular diameter is 1.05 or more and 2.60 or less.

[0017] (7) A method for inspecting a gas separation membrane module according to any one of (1) to (6), wherein the supply gas is composed of two or more types of gas, and the ratio of the permeability of the gases contained in the supply gas having a higher permeability to the permeability of the gas having a lower permeability is 1.1 or more and 2000 or less.

[0018] (8) A method for inspecting a gas separation membrane module according to any one of (1) to (7), which measures one or more characteristics of the volumetric flow rate, mass flow rate, composition, temperature, pressure, and thermal conductivity of at least one of the non-permeating gas and the permeating gas.

[0019] (9) An inspection device for a gas separation membrane module, comprising: a supply means for supplying a supply gas composed of one or more types of gases to a gas separation membrane module having a hollow tubular separation membrane; the gas separation membrane module for separating the supply gas composed of one or more types of gases into a non-permeate gas and a permeate gas; a non-permeate gas discharge means and a permeate gas discharge means for discharging the non-permeate gas and the permeate gas, respectively, from the gas separation membrane module; and a means for measuring the characteristics of at least one of the non-permeate gas or the permeate gas at a location of the gas separation membrane module.

[0020] (10) A method for inspecting a gas separation membrane module according to any one of (1) to (9), characterized in that the module is used in at least one process selected from the following: separation of gases in the manufacturing process of optical fibers, semiconductors, and electrical appliances; separation of gases produced by reactions such as natural gas, city gas, biogas, and methanation, separation of gases containing unreacted raw materials and by-products; separation of gases generated from water electrolysis equipment, and separation of gases for concentrating a target gas from a mixed gas.

[0021] (11) A method for manufacturing an optical fiber, characterized by using the method for inspecting a gas separation membrane module according to any one of (1) to (9).

[0022] (12) A method for manufacturing a semiconductor, characterized by using the method for inspecting a gas separation membrane module according to any one of (1) to (9).

[0023] (13) A method for manufacturing an electrical appliance, characterized by using the gas separation membrane module inspection method according to any one of (1) to (9).

[0024] (14) A gas production method characterized by using the inspection method for a gas separation membrane module described in (1) to (9), which separates at least one gas selected from gases produced by reactions such as natural gas, city gas, biogas, and methanation, gases containing unreacted raw materials and by-products, gases from fermentation and enzyme reaction processes, and gases generated from water electrolysis devices.

[0025] (15) An optical fiber, characterized by being produced using a gas separation membrane module whose performance has been tested by the method described in (1) to (9).

[0026] (16) A semiconductor manufactured using a gas separation membrane module whose performance has been tested by the method according to any one of (1) to (9).

[0027] (17) An electrical product, characterized by being manufactured using a gas separation membrane module whose performance has been tested by the method described in (1) to (9).

[0028] (18) A gas separation device characterized by using a gas separation membrane module whose performance has been tested by the method described in (1) to (9), which separates at least one gas selected from natural gas, city gas, biogas, gases produced by methanation reactions, gases containing unreacted raw materials and by-products, gases produced in fermentation or enzymatic reaction processes, and gases produced from water electrolysis devices. [Effects of the Invention]

[0029] The present invention provides a method and apparatus for inspecting gas separation membrane modules that can identify the location of abnormalities such as deterioration, damage, and leaks in gas separation membrane modules equipped with hollow tubular separation membranes, and can also confirm the degree of deterioration. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a schematic diagram showing an example of an inspection device for a gas separation membrane module according to the present invention. [Figure 2] FIG. 2 is a schematic diagram showing another example of an inspection device for a gas separation membrane module according to the present invention. [Figure 3] FIG. 2 is a schematic diagram showing another example of an inspection device for a gas separation membrane module according to the present invention. [Figure 4] FIG. 2 is a schematic diagram showing another example of an inspection device for a gas separation membrane module according to the present invention. [Figure 5] FIG. 2 is a schematic diagram showing another example of an inspection device for a gas separation membrane module according to the present invention. [Figure 6] FIG. 2 is a schematic diagram showing another example of an inspection device for a gas separation membrane module according to the present invention. [Figure 7] FIG. 2 is a schematic diagram showing another example of an inspection device for a gas separation membrane module according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention relates to a method and an apparatus for inspecting a gas separation membrane module having a hollow tubular separation membrane, in which the gas supplied to the gas separation membrane module is composed of one or more types of gas, and the characteristics of at least one of the non-permeating gas or the permeating gas are measured at a location in the gas separation membrane module.

[0032] Hereinafter, embodiments of the present invention will be described in detail.

[0033] The gas separation membrane module inspection device of the present invention comprises: (1) A supply means for supplying a feed gas consisting of one or more gases to a gas separation membrane module. (2) A gas separation membrane module that separates a feed gas consisting of one or more gases into a non-permeate gas and a permeate gas. (3) A non-permeate gas discharge means and a permeate gas discharge means for respectively discharging the non-permeate gas and the permeate gas from the gas separation membrane module. (4) A means for measuring the properties of at least one of the non-permeating gas and the permeating gas at the site of the gas separation membrane module. It has.

[0034] <Means for Supplying Gas to Separation Membrane Module> The present invention has a supply means for supplying a supply gas composed of one or more gases to a separation membrane module. In this supply means, a pipe or the like is connected to a flow path on the supply gas side of the separation membrane module, and the supply gas is passed through the supply means.

[0035] When the feed gas is passed through, the non-permeation side outlet may be opened or sealed.

[0036] When gas is supplied and vented to a separation membrane module with the non-permeate side open, particularly if it is supplied continuously, a large amount of gas is used, but the performance of the separation membrane module can be confirmed over time to ensure that membrane separation is stable. Especially when evaluating a mixed gas, it is preferable to open the non-permeate side for testing, because the compositions of the non-permeate and permeate sides change gradually until they stabilize. Furthermore, by changing the flow rate or composition of the supply gas and supplying it indirectly, the response of the permeate or non-permeate gas to changes in the supply gas can be observed.

[0037] When the non-permeation side is opened, a valve or the like can be provided to adjust the pressure on the non-permeation side.

[0038] When supplying and venting a gas to a separation membrane module with the non-permeate side sealed, it is particularly preferable to vent one type of gas. By sealing the non-permeate side and conducting the inspection while supplying the gas, it is possible to ensure sufficient inspection time to identify the leak location without discharging gas from the non-permeate side outlet, while reducing the amount of gas used.

[0039] When using sealed gas, i.e., after supplying gas into the separation membrane module, the non-permeate and supply sides are sealed and testing is performed using the gas sealed inside the separation membrane module without continuously supplying gas, the gas supply is stopped during testing, so the amount of gas used is reduced. In this case, testing becomes impossible if all the sealed gas is discharged, so the test must be performed before the permeation flow rate stabilizes. In addition, there are cases where the test must be repeated without identifying the leak location.

[0040] The material of the piping and the like can be determined depending on the properties of the gas to be supplied, and for example, metals such as stainless steel and copper, and organic materials such as polypropylene, polyethylene, and fluororesin can be used.

[0041] In addition, instruments such as a flow meter, a pressure meter, a thermometer, and a hygrometer may be provided to monitor the ventilation state of the supply gas.

[0042] Furthermore, a device such as a valve for controlling the flow rate of the supply gas may be provided, and a pressure control device such as a compressor for controlling the pressure of the supply gas may be provided.

[0043] Storage means such as tanks or cylinders may also be provided for storing the supply gas, and these storage means may be temperature and pressure controlled.

[0044] By increasing the pressure in the storage means, at least a part of the supply gas can be stored as a liquid. In this case, a mechanism can be provided to reduce the pressure and convert the liquid into a gas when supplying the gas to the separation membrane module.

[0045] When the pressure is increased in the storage means to liquefy only the water vapor, the liquefied water can be separated and removed.

[0046] In particular, when circulating at least some or all of the non-permeating gas or permeating gas of the separation membrane module in a storage means such as a tank, a stirring blade or the like for mixing the gases can be provided in the storage means such as a tank in order to mix the gases as uniformly as possible with the gas stored in the tank and supply the gas to the separation membrane module.

[0047] The type of gas to be supplied is not particularly limited, and examples thereof include gases such as helium, hydrogen, ammonia, nitrogen, oxygen, argon, methane, carbon dioxide, and water vapor.

[0048] When selecting the type of gas, except for separation membranes in which dissolution and diffusion must be taken into consideration, in the case of gas separation by molecular sieves, the kinetic molecular diameter may be used as an index.

[0049] Gases with smaller kinetic molecular diameters are more likely to permeate the separation membrane, while gases with larger kinetic molecular diameters are less likely to permeate the separation membrane.

[0050] For example, when gases with different kinetic molecular diameters are supplied, if there are areas where gases with smaller kinetic molecular diameters are more permeable, while gases with larger kinetic molecular diameters have no change in permeability, the degree of abnormality can be grasped.

[0051] Therefore, from the viewpoint of grasping the degree of abnormality, when gases with different kinetic molecular diameters are supplied, it is preferable that the ratio of the kinetic molecular diameters of the gas with the larger kinetic molecular diameter to the gas with the smaller kinetic molecular diameter is large, preferably 1.05 or more and 2.60 or less, more preferably 1.10 or more and 2.55 or less, and even more preferably 1.20 or more and 2.50 or less.

[0052] For testing, it is sufficient to treat the substance as a gas. In the case of gases that condense easily, the temperature can be kept constant. It is also possible to adjust the degree of vacuum and test under conditions where the substance exists as a gas.

[0053] When selecting the type of gas, permeability may be used as an index.

[0054] For example, when gases with different permeabilities are supplied, if there are areas where the gas with lower permeability is more permeable, while the permeability of the gas with higher permeability remains unchanged, the extent of the abnormality can be determined.

[0055] In measuring the permeability, the permeability may vary depending on the location of the separation membrane module and due to issues with the accuracy of the measurement method.

[0056] Therefore, from the viewpoint of grasping the degree of abnormality, when gases with different permeabilities are supplied, the ratio of the permeabilities of the gas with the higher permeability to the gas with the lower permeability can be calculated by Equation 1, and the higher the ratio, the more preferable it is, and the more preferable it is 1.1 or more and 2000 or less, more preferably 3 or more and 1500, and even more preferably 10 or more and 1000 or less. Formula 1: Permeability ratio = (permeability of gas with high permeability) ÷ (permeability of gas with low permeability) In this specification, "the supply gas is composed of one type of gas" means that when the test is performed multiple times by analysis using a mass spectrometer or the like, the second component or components in the supply gas supplied in one test are less than 0.001 mol%, and the type of supply gas may be changed for each test throughout the test. Also, in this specification, "the supply gas is composed of two or more types of gases" means that the supply gas contains 0.001 mol% or more of each gas when analyzed using a mass spectrometer or the like.

[0057] Here, the test only requires that the substance be treated as a gas, and in the case of a gas that is prone to condensation, the temperature can be kept constant. Alternatively, the degree of vacuum can be adjusted to test under conditions where the substance exists as a gas. For example, in the case of water, if liquid water adheres to the surface of the separation membrane, it may affect gas separation. Therefore, it is preferable to prevent condensation as much as possible.

[0058] There are no particular limitations on the temperature, pressure, flow rate, etc. of the gas supplied in the supply step, and any conditions that are compatible with the specifications of the supply step and the separation membrane module in the next step can be applied.

[0059] Before supplying the feed gas to the next separation membrane module, the feed gas may be subjected to pretreatment such as filtering, moisture absorption, or humidification.

[0060] <Gas separation membrane module> In the present invention, at least one gas permeates the separation membrane in the separation membrane module.

[0061] (Partial pressure difference) In a membrane separation mechanism, the driving force for separation when a gas permeates through a gas separation membrane is mainly the partial pressure difference between the non-permeation side and the permeation side of the gas separation membrane.

[0062] In the present invention, this partial pressure difference can be generated by reducing the pressure on the permeate side of the separation membrane. The degree of reduction in pressure can be set according to the specifications of the separation membrane, etc., in order to obtain the desired separation efficiency.

[0063] Generally, the greater the degree of vacuum, the greater the partial pressure difference between the non-permeate side and the permeate side, improving separation efficiency. When using a vacuum pump, a degree of vacuum close to vacuum can be achieved, but there are issues such as increased pump load and energy consumption, and high equipment and electricity costs. To reduce the load and energy consumption of the vacuum pump, it is sometimes possible to operate it at around 20 to 50 kPa.

[0064] In the case of reduced pressure, it is not possible to obtain a partial pressure difference equal to or greater than an absolute vacuum, but the non-permeate side can be pressurized to obtain the desired partial pressure difference.

[0065] In the present invention, the supply gas may contain water vapor, but the partial pressure difference is limited by the vapor pressure of water at the operating temperature. For example, a water vapor pressure of approximately 3 kPa occurs at a water temperature of 25°C, and approximately 2 kPa occurs at a water temperature of 20°C. However, if the pressure is reduced to about 90 kPa, a partial pressure difference almost equal to that of an absolute vacuum can be obtained.

[0066] Alternatively, both the pressure on the permeation side of the separation membrane and the pressure on the supply side of the feed gas may be applied. The degree of pressure application can be set according to the specifications of the separation membrane in order to obtain the permeability of the feed gas composed of one or more gases through the separation membrane, and either method can be applied.

[0067] As a method for pressurization, any commonly used method such as a compressor can be applied.

[0068] Any of the above means can create the necessary partial pressure difference.

[0069] (separation membrane) In the present invention, various hollow tubular separation membranes can be used.

[0070] The separation membrane can be appropriately selected depending on the type of gas and the conditions of use. As the separation membrane, those commonly used in the technical field can be used without any particular limitation, and examples thereof include hollow fibers and tubular membranes.

[0071] The separation membrane may be made of any material, including, for example, rubber-like polymer materials such as silicone resin and polybutadiene resin, polymer membranes such as aromatic polyimide, cellulose acetate, polysulfone, aromatic polyamide, polyetherimide, polyamideimide, polycarbonate, polyethersulfone, polyacrylonitrile, polyphenylene sulfide, polyetheretherketone, polytetrafluoroethylene, and polyvinylidene fluoride, and inorganic membranes containing metals such as zeolite, silica, and palladium.

[0072] The separation membrane may be any of a homogeneous membrane, an asymmetric membrane consisting of a homogeneous layer and a porous layer, a microporous membrane, etc. It may be any of a hollow fiber membrane having an asymmetric structure in which the homogeneous layer is 10 nm to 200 nm thick, the porous layer is 20 μm to 200 μm thick, and an inner diameter of approximately 30 μm to 500 μm, and a tubular membrane having an asymmetric structure in which the homogeneous layer is 0.05 mm to 0.4 mm thick, the porous layer is 0.1 mm to 0.5 mm thick, and an inner diameter of approximately 10 mm to 15 mm.

[0073] When allowing relatively small gases such as hydrogen and helium to pass through, polyamide membranes, polyimide membranes, silica membranes, carbon membranes, zeolite membranes, graphene membranes, polyimide resins, fluorine-based ion exchange membranes, polyetherimide resins, polysulfone-based resins, etc. can be used.

[0074] (Separation membrane module) In the separation membrane module, the feed gas is passed through the inlet of the separation membrane module and continuously passed toward the outlet of the separation membrane module, where separation occurs through the separation membranes.

[0075] In this case, if the feed gas contains two or more types of gas, some components will permeate the permeation side of the separation membrane, and the components that do not or have difficulty permeating the separation membrane will be concentrated on the non-permeation side as they are passed from the feed inlet to the outlet of the separation membrane module.The partial pressure of the components that permeate the separation membrane decreases, making it more difficult for the gas to permeate as it approaches the concentrated outlet of the separation membrane module.

[0076] Even when the feed gas is a single type of gas, as it passes from the feed inlet to the outlet of the separation membrane module, some of it permeates the separation membrane and becomes a permeated gas, while the rest is discharged from the separation membrane module as a non-permeated gas.

[0077] Here, it is preferable to eliminate the concentration polarization on the membrane surface, which becomes the permeation resistance, by increasing the flow rate of the supply gas, while taking into consideration the diffusion of the supply gas.

[0078] The separation membrane module may have a structure in which the permeate gas flows in a parallel or countercurrent direction to the feed gas, a cross-flow structure in which the feed gas and permeate gas flow in different directions by 90°, or a structure in which the feed gas and permeate gas flow in the same direction. Furthermore, a combination of these may also be used, and any of these flow channel structures can be applied.

[0079] The separation membrane may be modularized and housed in a container for use. The form of the separation membrane module may be a cylindrical type using hollow fiber membranes or a tubular type using tubular membranes, as long as the membranes are hollow tubular.

[0080] (Hollow fiber gas separation membrane module) 1, 2, and 3, a hollow fiber gas separation membrane module 100 according to one embodiment of the present invention may be configured by mounting one or more hollow fiber membranes 0. Examples of such modules include a module in which tens to hundreds of thousands of hollow fiber membranes 0 are bundled together to form a U-shape within the module, a module in which one end of the hollow fiber membrane bundle is sealed together with an appropriate adhesive, a module in which one end of the hollow fiber membrane bundle is sealed individually with an appropriate adhesive in an unfixed state (free state), and a module in which both ends of the hollow fiber bundle are fixed with an adhesive or the like.

[0081] The hollow fiber gas separation membrane module 100 is configured such that hollow fiber membranes 0 are packed in a container 7 having a supply gas inlet 1, a permeate gas outlet 2, and a non-permeate gas outlet 3. The hollow fiber membranes 0 are embedded in a first potting 4 and a second potting 5, both ends of which are fixed with an adhesive, and the first potting 4 and the second potting 5 are fixed to the container 7. The first potting 4 and the second potting 5 may have sealed ends of the embedded hollow fiber membranes 0, or may have a plurality of through-holes for venting gas.

[0082] The first potting 4 and the second potting 5, to which the plurality of hollow fiber membranes 0 are fixed, refer to the areas where the gaps between the bundled hollow fiber membranes 0 are filled with adhesive. The potting is preferably formed at the end of the hollow fiber membrane bundle.

[0083] The potting resin, which is the main component of the adhesive, is preferably an epoxy resin, a polyurethane resin, or a silicone resin, which have excellent adhesion to the hollow fiber membrane, heat resistance, and chemical durability. The adhesive may also contain additives such as silica, talc, mica, clay, calcium carbonate, glass, or rubber in addition to the potting resin.

[0084] The first potting part 4 only needs to be fixed in position so that it does not move due to the flow of the supply gas, and may have a structure in which it is adhesively fixed to the container 7, or a removable cartridge structure. There are no particular specifications for the structure for fixing the position, and it can be selected as appropriate, such as a structure that fixes the position between the container 7 and the first potting part 4, or a structure that fixes the position between the second potting part 5 and the first potting part 4.

[0085] The container 7 of the separation membrane module can be made of either resin or metal.

[0086] There is no particular limitation on the shape of the container 7, and a cylindrical shape or the like can be used.

[0087] (Arrangement of separation membrane modules) A single separation membrane module or multiple modules may be used. When multiple separation membrane modules are used for each, the separation membrane modules may be arranged in parallel or series, or may be arranged in a tree configuration in which the number of separation membrane modules in the second feed stage is reduced from the number of separation membrane modules in the first feed stage. Furthermore, these separation membrane modules may be provided with a circulation flow in which at least one of the non-permeate gas or permeate gas of some or all of the separation membrane modules is combined with the supply gas of the separation membrane module or the supply gas of the separation membrane module in the preceding stage.

[0088] (Pressure of gas supplied to separation membrane module) In the present invention, the supply gas to the separation membrane module may be pressurized. By pressurizing the supply gas and supplying it to the separation membrane module, the non-permeation side is pressurized. This generates a pressure difference between the permeation side and the non-permeation side, providing a driving force for permeation through the separation membrane.

[0089] The gas to be supplied may be pressurized using a device such as a compressor, or the gas may be supplied from a high-pressure container such as a cylinder.

[0090] (Depressurization on the permeation side of the separation membrane module) In the present invention, the permeate side of the separation membrane module may be depressurized. A vacuum pump may be used for depressurization. Alternatively, an aspirator or ejector may be used. However, it is necessary to consider the possibility that the gas permeating through the separation membrane may come into contact with the driving fluid of the aspirator or ejector, resulting in mixing or dissolution.

[0091] The vacuum pump, aspirator, and ejector may be the same as those commonly used in the art without any particular limitations.

[0092] The vacuum pump may be of any type, such as a diaphragm type or an oil type.

[0093] Aspirators and ejectors are known to be made of metal or resin. The material can be selected based on the durability and temperature of the gas used. When the driving fluid of an aspirator or ejector is a liquid, various liquids such as water, an aqueous solution of dissolved salts, silicone, or a mixture of these can be used. When the driving fluid of an aspirator or ejector is a gas, various gases or a mixture of these can be used.

[0094] The degree of pressure reduction is preferably set within a range in which most of the permeation-side gas does not condense. A large degree of pressure reduction is also preferable because it increases the driving force for separation when the gas permeates through the gas separation membrane. The degree of pressure reduction may be adjusted, including the possibility of pressurizing the supply gas.

[0095] In the present invention, a gas is supplied to the separation membrane module, the non-permeation side is sealed, and then at least one of pressurization and depressurization is carried out.

[0096] If the separation membrane has a defect, the amount of permeation through the membrane will be higher than that of a normal separation membrane. Also, if there is a defect in a part of the separation membrane module, such as the adhesive joint, gas will leak from that part, causing more gas to move to the permeation side and increasing the flow rate.

[0097] In the present invention, when at least one of pressurization and decompression of the separation membrane module is performed, the pressure that serves as the driving force for the separation membrane can be set taking into consideration the permeability of a predetermined gas, the characteristics of the separation membrane, etc., and either pressurization only, decompression only, or both pressurization and decompression can be selected.

[0098] In the present invention, when depressurizing the separation membrane module, the permeation side of the separation membrane module is depressurized by a vacuum pump while continuously supplying gas and with the permeation side valve open, and membrane separation is carried out using the pressure as a driving force.

[0099] In the present invention, when pressurizing a separation membrane module, first, a gas is supplied to the separation membrane module as described above, and the non-permeate side is sealed. Next, the permeate side valve is left open, and the same gas as that supplied to the module is supplied to pressurize the module. The degree of pressurization can be adjusted by the supply flow rate and the opening of the permeate side valve.

[0100] <Non-permeate gas discharge means and permeate gas discharge means> The present invention has non-permeate gas and permeate gas discharge means 102 for discharging the non-permeate gas and permeate gas, respectively, from the gas separation membrane module. In this non-permeate gas and permeate gas discharge means 102, piping or the like is connected to a flow path on the non-permeate gas discharge side and a flow path on the permeate gas discharge side of the separation membrane module, and all or a portion of at least one of the non-permeate gas or the permeate gas is vented to a means for measuring the properties of at least one of the non-permeate gas or the permeate gas.

[0101] The material of the piping and the like can be determined depending on the properties of the gas to be supplied, and for example, metals such as stainless steel and copper, and organic materials such as polypropylene, polyethylene, and fluororesin can be used.

[0102] In addition, instruments such as a flow meter, a pressure meter, a thermometer, and a hygrometer may be provided to monitor the ventilation state of at least one of the non-permeating gas and the permeating gas.

[0103] Furthermore, a device such as a valve for controlling the flow rate of at least one of the non-permeate gas and the permeate gas may be provided, and a pressure control device such as a compressor for controlling the pressure of at least one of the non-permeate gas and the permeate gas may be provided.

[0104] Storage means such as a tank or cylinder may be provided for storing at least one of the non-permeating gas and the permeating gas, and these storage means may be capable of controlling the temperature and pressure.

[0105] By increasing the pressure in the storage means, at least a portion of the non-permeating gas or at least one of the permeating gas can be stored as a liquid. In this case, a mechanism can be provided to reduce the pressure and convert the liquid into a gas when the non-permeating gas or at least one of the permeating gas is supplied to a means for measuring the properties of the non-permeating gas or at least one of the permeating gas.

[0106] When the pressure is increased in the storage means to liquefy only the water vapor, the liquefied water can be separated and removed.

[0107] In particular, when circulating at least some or all of the non-permeating gas or permeating gas of the separation membrane module in a storage means such as a tank, the storage means such as a tank may be provided with an agitator blade or the like for mixing the gases so that the gases can be mixed as uniformly as possible with the gas stored in the tank or the like and supplied to a means for measuring the properties of at least one of the non-permeating gas or permeating gas.

[0108] There are no particular limitations on the temperature, pressure, flow rate, etc., at the time of discharging at least one of the non-permeating gas and the permeating gas, and any conditions that meet the specifications of the means for measuring the properties of at least one of the non-permeating gas and the permeating gas can be applied.

[0109] Furthermore, the feed gas may be subjected to pretreatment such as filtering, moisture absorption, or humidification before being supplied to a means for measuring the properties of at least one of the non-permeating gas and the permeating gas.

[0110] <Means for measuring the properties of at least one of non-permeating gas and permeating gas> In the present invention, a means 103 for measuring the properties of at least one of the non-permeating gas and the permeating gas is provided at the site of the gas separation membrane module.

[0111] (Properties of at least one of non-permeable gas and permeable gas) In the present invention, the separation membrane module is diagnosed by measuring at least one of the properties of the non-permeating gas or the permeating gas. Examples of at least one of the properties of the non-permeating gas or the permeating gas include volumetric flow rate, mass flow rate, temperature, pressure, composition, thermal conductivity, odor, weight, specific gravity, specific heat, color, liquefaction temperature, liquefaction pressure, radiation, diffusion coefficient, solubility in water and water containing solutes, pH at dissolution, solubility in organic solvents, etc., heat of combustion, calorific value, recovery rate of a specific gas, and pressure on the permeating gas side. The module has a means for measuring at least one of these properties.

[0112] These properties can be temporarily changed by varying one or more of the following: volumetric flow rate, mass flow rate, temperature, pressure, composition, thermal conductivity, odor, weight, specific gravity, specific heat, color, liquefaction temperature, liquefaction pressure, radiation, diffusion coefficient, solubility in water and water containing solute, pH and electrical conductivity at dissolution, solubility in organic solvents, heat of combustion, calorific value, recovery rate of specific gas, and pressure on the permeate gas side. For example, a step response may be used to change the properties and measure the response.

[0113] The water containing the solute may be a salt such as sodium chloride, magnesium sulfate, or ammonium chloride, an ionic liquid, or an organic substance such as glucose, or may be a mixture with an organic solvent such as ethanol, hexane, carbon tetrachloride, benzene, or acetone.

[0114] Considering the necessary equipment, cost, ease of measurement, quantitativeness, etc., one or more of the following characteristics are preferred: volumetric flow rate, mass flow rate, composition, temperature, pressure, and thermal conductivity.

[0115] For example, in a defective separation membrane module, the permeate volumetric flow rate is higher than normal at the defective site. Therefore, by measuring the permeate volumetric flow rate at the outlet of the separation membrane module after a predetermined time and comparing it with that of a normal separation membrane module, it is possible to determine whether a defect exists. Furthermore, by estimating the permeate volumetric flow rate at each site within the separation membrane module and comparing a normal separation membrane module with a defective separation membrane module, it is possible to infer the location of the defect. Furthermore, when two or more types of gases are used, it is possible to determine the presence or absence of a defect by measuring the permeate gas composition at the outlet of the separation membrane module and comparing it with that of a normal separation membrane module. Furthermore, it is possible to infer the location of the defect by measuring the composition at each site within the separation membrane module and comparing the composition of a normal separation membrane module with that of a defective separation membrane module.

[0116] (measurement means) In the present invention, the volumetric flow rate, mass flow rate, temperature, pressure, composition, thermal conductivity, odor, weight, specific gravity, specific heat, color, liquefaction temperature, liquefaction pressure, radiation, diffusion coefficient, solubility in water and water containing solute, pH at dissolution, solubility in organic solvents, etc., heat of combustion, calorific value, recovery rate of specific gas, and pressure on the permeating gas side can be measured by commonly known methods and are not limited to any particular technique.

[0117] In the case of producing a separation membrane module, taking into consideration the necessary equipment, cost, ease of measurement, quantitativeness, etc., one or more of the following characteristics are preferred: volumetric flow rate, mass flow rate, composition, temperature, pressure, and thermal conductivity.

[0118] For volumetric flow, flow meters such as float type and soap film type can be applied. For mass flow, flow meters such as mass flow meters can be applied. For composition, gas chromatography can be applied. Gas chromatography using a thermal conductivity detector can also be applied. For temperature, both contact and non-contact types can be applied. For contact types, thermocouples, platinum resistance thermometers, thermistor thermometers, bimetal thermometers, liquid-filled thermometers, and mercury thermometers can be applied. For non-contact types, radiation temperature sensors and color temperature sensors can be applied. For pressure, diaphragm types, piezoelectric types, piezo-resistance types, Pitot tube types, and manometers that detect differential pressure can be applied. Any sensor for absolute pressure, gauge pressure, or differential pressure can be applied.

[0119] The more characteristics that are measured, the better from the viewpoint of determining the presence or absence of abnormalities and their severity. On the other hand, it is preferable to select the items to be measured, since this makes the analysis complicated and it is difficult to determine the purity when only one type of gas is supplied.

[0120] Here, when measuring each characteristic, a sensor may be provided inside the separation membrane module for measurement, or a wireless tag (RFID tag), sensor, or the like may be provided.

[0121] Here, the sensor may be attached to the separation membrane module at the time of manufacturing the separation membrane module, or may be attached at the time of measurement.

[0122] When the sensor is attached during the manufacture of the separation membrane module, the change in the sensor may be measured in real time, or, for example, the adsorbent may be placed inside the module and removed at intervals to measure the amount of adsorption.

[0123] The advantage is that it is easy to put on and the position of the device can be easily adjusted.

[0124] When attached during measurement, the sensor is inserted into the structure of the separation membrane module, so it is preferable that the sensor is small and has low rigidity so as not to damage the structures inside the separation membrane module, such as the separation membrane and flow path material. The sensor may be attached while visually observing the inside of the separation membrane module using a small camera commonly used in medical applications.

[0125] As is common to the following examples, a scale or marking may be attached inside the separation membrane module to enable confirmation of the sensor position. In this case, the scale or marking may be attached to the container in which the separation membrane is loaded, rather than to the separation membrane itself.

[0126] Furthermore, a scale or markings may be attached to the outside of the separation membrane module, in which case the length of the inserted wiring or the like can be checked from outside the separation membrane module, thereby enabling the position to be confirmed.

[0127] A transparent or translucent pressure vessel may be prepared to identify and mark the insertion position of the sensor.

[0128] Furthermore, since there is a space limitation inside the separation membrane module, at least one of the non-permeated gas and the permeated gas may be sampled inside the separation membrane module and discharged to the outside of the separation membrane module for measurement.

[0129] At least one of the non-permeated gas and the permeated gas is preferably sampled at two or more locations in the separation membrane module.

[0130] A plurality of pipes for collecting gas may be arranged inside the separation membrane module.

[0131] Alternatively, one or a limited number of pipes or the like may be arranged within the separation membrane module, and the position within the separation membrane module may be changed to allow gas to be sampled at a plurality of locations.

[0132] The location where the non-permeating gas or permeating gas is sampled may be one location. In this case, the cause of the abnormality is assumed to some extent, and the measurement is made at that location, and the presence or absence of an abnormality can be determined by comparing with a product that does not have an abnormality.

[0133] When collecting gas, it is preferable to avoid mixing it with gas from other sites as much as possible.

[0134] Filtration methods using hollow fiber membrane modules include total filtration (dead-end filtration), in which the entire amount of supply gas is filtered, and circulating filtration (cross-flow filtration), in which the treatment liquid is flowed in a direction parallel to the membrane surface and a portion of it is extracted as permeated gas. Either of these filtration methods can be used in the present invention.

[0135] Furthermore, in each filtration method, there are external pressure filtration methods, in which one or more feed gases are supplied to the outer surface of the membrane and the permeated gas is removed from the inner surface, and internal pressure filtration methods, in which the feed gas is supplied to the inner surface of the membrane and the permeated gas is removed from the outer surface. Therefore, there are four membrane filtration methods that combine total filtration and circulating filtration: external pressure total filtration, internal pressure total filtration, external pressure circulating filtration, and internal pressure circulating filtration.

[0136] In the present invention, either filtration method can be used, but by changing the position of the gas sampling port along the length of the hollow fiber membrane and sampling gas through a gas sampling pipe, it is possible to accurately narrow down the abnormal part of the hollow fiber membrane and also to significantly reduce the time required to identify the abnormal part.

[0137] 4 and 5, when the separation membrane module 100 is an internal pressure circulation filtration type, the tip of the gas vent device 9 is pressed against the potting part at the membrane end opening, gas is vented into approximately one-fourth of the potting part, the presence or absence of an abnormality within that venting range is determined, and the position of the gas vent device 9 is shifted or replaced to change the gas venting range or narrow the venting range until the diameter of the potting part is 10 mm or less, thereby identifying the range of the abnormal part. Also, when the separation membrane module 100 is an external pressure circulation filtration type, the tip of the gas collector device 10 is pressed against the potting part at the membrane end opening, gas is collected into approximately one-fourth of the potting part, the presence or absence of an abnormality within that collection range is determined, and the position of the gas collector device 10 is shifted or replaced to change the gas collection range or narrow the collection range until the diameter of the potting part is 10 mm or less, thereby identifying the range of the abnormal part.

[0138] After identifying the range of the abnormal area, when sampling the permeable gas or non-permeable gas from each hollow fiber membrane, the permeable gas and non-permeable gas passing through the hollow fiber membrane from the upstream side are sampled. By sampling the gas from the most upstream part and checking the characteristics of the gas, it is possible to confirm any abnormal areas along the hollow fiber membrane.

[0139] In addition, one or more types of gas are introduced into a predetermined area on the outer surface of the first potting portion 4 where the membrane end of the separation membrane module is opened, and a detection operation is performed to determine whether or not there is an abnormality within that area.Furthermore, by changing or narrowing the predetermined area through which the gas is ventilated and repeating the detection operation, it is possible to narrow down the hollow fiber membrane 0 that has an abnormality.

[0140] Depending on the structure of the hollow fiber membrane module, it may be difficult to insert a pipe for gas sampling, etc. In such cases, a thin silicone tube with an outer diameter of about 1 mm or a hollow fiber tube with an outer diameter of several tens to several hundred μm may be used.

[0141] In the case of such a thin tube, it may take time to collect the gas, so it may be possible to use a vacuum pump or the like to suck the gas.

[0142] When measuring both non-permeating and permeating gases, if there are no gas-related reactions inside the separation membrane module and the effects of adsorption to the separation membrane module structure can be ignored, confirmation can be made from each measurement data, taking into account material balance. When there is a large error in the characteristics of the gas, such as flow rate or composition, this is more preferable because it allows for complementary data to be obtained. This is particularly effective when there is a concern that there may be a large error in measuring the gas flow rate or composition.

[0143] Considering gas sampling operations, etc., the flow rates of the supply gas, non-permeate gas, and permeate gas are preferably at least a certain level, and the rate of decrease of the flow rate of the non-permeate gas or permeate gas relative to the flow rate of the supply gas is preferably small. Even when the gas flow rate is low, the flow rate of the gas can be increased and backflow of the gas can be reduced by reducing the cross-sectional area of ​​the flow path of the piping, etc. through which the gas discharged from the separation membrane module flows. If the ventilation resistance becomes large, assistance such as a vacuum pump may be used. Gases generally have a larger diffusion coefficient than liquids. Therefore, it is preferable that the flow of gases, including the supply gas, non-permeating gas, and permeating gas of a separation membrane module, is dominant until the gases are discharged from the separation membrane module. It is preferable to appropriately set the flow rate, flow velocity, temperature, viscosity, and other parameters of the gases.

[0144] In particular, the flow rate and flow velocity of the gas are preferably large as long as they do not cause problems with pressure loss in the separation membrane module. Here, the flow velocity of the gas can be calculated from the flow rate of the gas and the cross-sectional area of ​​the flow path in the separation membrane module.

[0145] For example, if the supply gas being aerated is a mixture of helium and oxygen, and we consider a molecular sieve, helium, which has a smaller dynamic molecular diameter, is more likely to permeate the gas separation membrane. If 90% of the supply gas is helium, once the helium recovery rate exceeds 90%, most of the helium will become a permeating gas, and the only non-permeating gas will be the 10% of oxygen in the supply gas that did not permeate the gas separation membrane.

[0146] Here, the helium recovery rate refers to the proportion of helium contained in the feed gas that can be recovered as a non-permeating gas or a permeating gas. In the above example, helium is assumed to permeate the separation membrane more easily than oxygen, so helium was recovered as a permeating gas.

[0147] In this example, if the helium recovery rate increases, in the example of the helium and oxygen system described above, the partial pressure of helium in the non-permeating gas at the outlet side of the separation membrane module will decrease, making it more difficult for it to permeate the separation membrane, resulting in a decrease in the helium purity of the permeating gas. As gas is sampled at each location in the present invention, the amount of data required to determine whether a decrease in helium purity is due to a change in the helium recovery rate or an abnormality in the separation membrane module may increase.

[0148] When the rate of decrease in the flow rate of the non-permeating gas or permeating gas relative to the flow rate of the supply gas is small, the difference from the characteristics of the supply gas is small, and therefore measurement must be performed with high accuracy. Also, the flow rate of the gas supplied to the separation membrane module to be inspected increases.

[0149] For example, if the supply gas is 100 L / min, the non-permeable gas is 99.9 L / min, and the permeable gas is 0.1 L / min, the reduction rate of the non-permeable gas relative to the supply gas flow rate is 0.1%, and the reduction rate of the permeable gas is The decrease rate is 99.9%. The difference between the characteristics of non-permeable gas and the characteristics of the supply gas is small, so it is difficult to judge the difference from the measurement results of the characteristics.

[0150] Therefore, in the test of the present invention, the rate of decrease in the flow rate of the non-permeating gas or permeating gas relative to the flow rate of the supply gas is preferably 1% to 99%, more preferably 5% to 95%, even more preferably 10% to 90%, and particularly preferably 20% to 80%.

[0151] Gases generally have a larger diffusion coefficient than liquids. Therefore, it is preferable that the flow of gases, including the supply gas, non-permeating gas, and permeating gas of a separation membrane module, is dominant until the gases are discharged from the separation membrane module. It is preferable to appropriately set the flow rate, flow velocity, temperature, viscosity, and other parameters of the gases.

[0152] In particular, the flow rate and flow velocity of the gas are preferably large as long as they do not cause problems with pressure loss in the separation membrane module. Here, the flow velocity of the gas can be calculated from the flow rate of the gas and the cross-sectional area of ​​the flow path in the separation membrane module.

[0153] In the present invention, the flow velocities of the feed gas, non-permeating gas, and permeating gas are preferably 1 cm / min to 600 m / min, more preferably 5 cm / min to 500 m / min, and even more preferably 18 cm / min to 300 m / min.

[0154] (Separation membrane module diagnosis: when there is one type of supply gas) Here, the diagnosis of a separation membrane module using the testing device and method of the present invention will be described.

[0155] When diagnosing a separation membrane module using the inspection device of the present invention, if only one type of gas is supplied, the inspection is performed using a gas with a large dynamic molecular diameter or a gas with low permeability, and if there is a region where the permeability is higher than normal, that region is considered to be abnormal.

[0156] In particular, if high permeability is obtained even when a gas that is almost impermeable is supplied, it is possible that there is an abnormality such as physical damage.

[0157] Here, the detection of the above permeability may be performed by, for example, measuring whether there is a region on the permeation side where the flow rate increases, or conversely, measuring whether there is a region on the non-permeation side where the flow rate decreases. The method that is easier to measure may be selected based on the material balance.

[0158] When testing gases with small dynamic molecular diameters or gases with high permeability, the tendency for permeability to increase is similar. However, the type of separation membrane and separation mechanism also have an effect, and since the permeability is originally high, the rate of change may be lower.

[0159] (Separation membrane module diagnosis: when there are two or more types of supply gas) When diagnosing a separation membrane module using the inspection device of the present invention, if there are two or more types of supply gases, In contrast to the knowledge gained when only one type of supply gas is used as described above, it is expected that knowledge will be gained about each of the constituent gases.

[0160] For example, when gases with different kinetic molecular diameters are supplied, if there are areas where gases with smaller kinetic molecular diameters are more permeable, while gases with larger kinetic molecular diameters have no change in permeability, the degree of abnormality can be grasped.

[0161] In measuring the permeability, the permeability may vary depending on the location of the separation membrane module and due to issues with the accuracy of the measurement method.

[0162] Therefore, from the viewpoint of grasping the degree of abnormality, when gases with different permeabilities are supplied, it is preferable that the ratio of the permeabilities of the gas with higher permeability to the gas with lower permeability is large.

[0163] The above-mentioned permeability detection may be performed by, for example, measuring whether there is a region where the flow rate increases on the permeation side, or conversely, measuring whether there is a region where the flow rate decreases on the non-permeation side, and selecting whichever is easier to measure based on the material balance. Preferably, both the permeation side and the non-permeation side may be measured.

[0164] (Analysis of measurement results) In analyzing the measurement results obtained by the above-described measurement, for example, when measuring the flow rate, if the characteristics of the separation membrane of the separation membrane module are approximately constant, the pressure loss within the separation membrane module is almost ignored, and the transmembrane pressure difference, which is the driving force for membrane permeation, is approximately constant, when the supply gas contains multiple gases, the permeation flow rate depends mainly on the partial pressure of each gas.

[0165] The permeation flow rate of a separation membrane module decreases because the partial pressure of the gas that easily permeates gradually decreases as it passes through the separation membrane module. Because of this, the measurement results in the divided regions of the separation membrane module do not necessarily change linearly like a linear function, as they also include the influence of non-permeating or permeating gases flowing from upstream or downstream of the separation membrane module.

[0166] Here, the divided regions are regions divided into two or more in the flow direction of the non-permeating gas or permeating gas in the separation membrane module. The divided regions may be divided evenly in the flow direction, or the length of the division may be changed depending on the purpose. For example, if there is a concern about defects at the ends of the separation membrane module, the ends may be focused on for measurement.

[0167] The greater the number of divisions, the more precisely the location can be identified when determining the presence or absence of deterioration or damage in the separation membrane element to be inspected, the degree of deterioration or damage, and / or the location of the damage. Since a greater number of divisions increases the number of measurements in each divided region, the divided regions may be set according to the purpose. For example, if there is concern about defects at the ends of the separation membrane module, the number of measurements other than at the ends may be reduced.

[0168] The divided regions may be determined on the assumption that measurements will be taken multiple times. For example, the first measurement may divide the region into two, upstream and downstream in the flow direction of the permeating gas, and the second measurement may subdivide the region where abnormalities are suspected.

[0169] When measuring the divided regions divided in the flow direction of the non-permeating gas and the permeating gas of a gas separation membrane module, it is preferable to use the same divided regions for the non-permeating gas and the permeating gas so as to avoid confusion in handling the obtained data and to enable verification of the material balance.

[0170] In the case of gases, the diffusion coefficient is large, and when multiple gases are aerated, they tend to mix easily, so it is preferable to divide the divided regions at a certain length or more, although this depends on the flow rate of the non-permeating gas or permeating gas. Many commercially available separation membrane modules have a length of about 1 m in the direction of flow of the non-permeating gas or permeating gas. Taking the number of measurements into consideration, the divided regions are preferably 1 cm or more and 50 cm or less. More preferably, they are 2 cm or more and 34 cm or less, and even more preferably, they are 5 cm or more and 20 cm or less.

[0171] Therefore, when interpreting the measurement results, the results are compared in advance with the measurement results of a reference separation membrane module to determine at least one of the presence or absence of deterioration or damage in the separation membrane element being inspected, the degree of deterioration or damage, and the location of the damage.

[0172] Here, it is preferable that the reference separation membrane module is not in contact with gases that may deteriorate the separation membranes.

[0173] It is also preferable to measure the membrane characteristics of the feed gas in advance in the divided regions and compare them with the characteristics of the separation membrane itself. It is even more preferable to configure the system with a single type of gas and measure them. The characteristics of the separation membrane can also be calculated for each divided region by creating a permeation model based on conditions such as permeability and transmembrane pressure difference.

[0174] When the supply gas is composed of one type of gas, the partial pressure is constant within the separation membrane module. Therefore, if the pressure loss within the separation membrane module is almost ignored and the transmembrane pressure difference, which is the driving force for membrane permeation, is assumed to be almost constant, the permeability and permeation flow rate of that gas will be almost constant in the divided regions within the separation membrane module.

[0175] Here, when the pressure loss is large, the pressure loss of the separation membrane module is measured in advance, and the transmembrane pressure difference in the divided region is calculated, thereby making it possible to obtain the permeability.

[0176] Furthermore, when the supply gas is made up of a plurality of gases, the flow rate of the supply gas may be increased to reduce the influence of partial pressure.

[0177] Examples of inspection methods for the separation membrane module to be inspected are given below, but the methods are not limited to the following.

[0178] The presence or absence of an abnormality in the separation membrane module being inspected can be determined, for example, by an increase in the membrane permeation flow rate compared to a reference separation membrane module, an increase in the permeation flow rate of gases that have a large dynamic molecular diameter and are difficult to permeate through the membrane, particularly when two or more types of gases are supplied, and as a result, a decrease in the purity of the permeating gas for gases that are easy to permeate through the membrane.

[0179] When the amount of change compared with the reference separation membrane module is greater than a predetermined state determination standard, it can be determined that an abnormality has occurred in the separation membrane module to be inspected.

[0180] The magnitude of the change makes it possible to determine whether the separation membrane has deteriorated or whether the separation membrane module has been damaged.

[0181] The location of the abnormality in the separation membrane module under test can be determined by comparing the divided region of the separation membrane module under test with a reference separation membrane module and determining that the abnormality has occurred at a position where the amount of change is large if the amount of change is greater than a predetermined state determination criterion. Depending on the amount of change, it is possible to determine whether the separation membrane has deteriorated or whether the separation membrane module under test has been damaged.

[0182] The criteria for determining the state may be determined arbitrarily depending on the membrane separation conditions, gas composition, etc. When two or more types of gases are supplied, gases with different kinetic molecular diameters are used, and the deterioration of the separation membrane can be determined according to the kinetic molecular diameter.

[0183] Here, it is more preferable to determine the state judgment criteria taking into consideration the fluctuation range that varies due to measurement errors of membrane separation conditions, gas composition, and the like.

[0184] The separation membrane module inspection method of the present invention may be performed periodically during the operation of the separation membrane module. The presence or absence of abnormalities in the separation membrane module to be inspected can be monitored. If a preset condition criterion is reached, an alarm can be issued, allowing maintenance measures to be taken for the separation membrane module to be inspected and the peripheral equipment systems.

[0185] If the deterioration or damage of the separation membrane progresses to a level where the performance of the separation membrane module being inspected cannot be restored by maintenance or the like, measures such as replacing the module with another separation membrane module can be taken. It is even more preferable if the replacement time can be predicted.

[0186] By taking the above measures, it will be possible to operate the separation membrane process stably.

[0187] For example, when two or more types of gases are supplied to a separation membrane module with an abnormality, the permeation flow rate of gases that have a large dynamic molecular diameter and are difficult to permeate through the membrane increases compared to a reference separation membrane module, resulting in a decrease in the purity of the permeated gas for gases that are easy to permeate through the membrane.

[0188] In a separation membrane module such as that shown in FIG. 1, when permeated gas is discharged from one end of the permeated gas outlet 2, the permeated gas from the end opposite the discharge side is accumulated and discharged.

[0189] When the permeate gas is sampled gradually from the end opposite the discharge side toward the discharge side, if there is no abnormality in the separation membrane, for example, the purity of the permeate gas is almost constant in each divided region. However, if there is an abnormality in the separation membrane, the purity of the permeate gas gradually increases or decreases, creating a region with large changes. After that, the purity of the permeate gas gradually decreases or increases. The divided region with an abnormality can be determined from the position of such a region with large changes.

[0190] Furthermore, multiple separation membrane modules connected in series can also be inspected in the same manner. In this case, they may be inspected one by one, or multiple modules connected in series may be inspected.

[0191] A diagnostic program executed by a computer may be used for the above determinations. When actually inspecting a separation membrane module, it is preferable to inspect it under conditions similar to those of the separation process, in which case there will be multiple inspection conditions. In all cases, it is preferable to actually collect basic data from the separation membrane module, but it is also possible to create a permeation model based on conditions such as its permeability and transmembrane pressure difference, and calculate the characteristics of the separation membrane for each divided region. The diagnostic program may calculate various data that serve as standards for the separation membrane module from the composition, flow rate, temperature, pressure, and time of the supply gas, as well as the permeability and permeation flow rate of each gas through the separation membrane.

[0192] The technology of the present invention can be used in at least one process selected from the following: separation of gases in the manufacturing processes of optical fibers, semiconductors, and electrical products; separation of gases produced by reactions such as natural gas, city gas, biogas, and methanation, separation of gases containing unreacted raw materials and by-products; separation of gases generated from water electrolysis equipment, and separation of gases to concentrate a target gas from a mixed gas.

[0193] The technique of the present invention may be used to inspect a separation membrane module used in the manufacturing process before use. Alternatively, the separation membrane module may be temporarily stopped during use in the manufacturing process and then inspected.

[0194] The technology of the present invention enables efficient testing and confirmation of the performance of separation membrane modules in the production of optical fibers, semiconductors, and electrical products. Various gases can be separated and produced in at least one process selected from natural gas, city gas, biogas, gases containing unreacted raw materials and by-products after reactions such as methanation, gases from fermentation and enzymatic reaction processes, and gases generated from water electrolysis devices. [Example]

[0195] The present invention will be described in more detail below with reference to examples, in which the separation membrane module is of the hollow fiber type, but the present invention is not limited to these examples.

[0196] A.Device mechanism 1, 2, and 3 are schematic diagrams showing an example of an inspection device for a gas separation membrane module of the present invention.

[0197] A feed gas composed of one or more types of gases is supplied to the separation membrane module 100 by the gas supply means 101. In the separation membrane module 100, a portion of the gas permeates through the separation membrane of the separation membrane module and is vented to the permeate gas discharge means 102, and the other gas is vented to the non-permeate gas discharge means 102 of the separation membrane module.

[0198] The permeation side of the separation membrane module 100 may be depressurized by a vacuum pump, which acts as a driving force for the gas to permeate through the membrane. The gas permeation rate in the separation membrane module 100 can be adjusted by the degree of vacuum applied by the vacuum pump.

[0199] B. Preparation of gas separation membranes Unless otherwise specified below, the temperature conditions are room temperature (25°C).

[0200] (gas separation membrane) A separable flask equipped with a stirrer and a nitrogen gas inlet tube was charged with 60 mmol of 1,3-diaminobenzene-4-sulfonic acid (s-BPDA), 40 mmol of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), 60 mmol of 3,7-diamino-2,8-dimethyldibenzothiophene 5,5-dioxide (TSN), and 40 mmol of 3,5-diaminobenzoic acid (DABA) along with NMP as a solvent to a polymer concentration of 18 wt%. While flowing nitrogen gas through the flask, the polymerization-imidization reaction was carried out at a reaction temperature of 180°C for 16 hours with stirring to prepare an aromatic polyimide solution with a polyimide concentration of 18 wt%.

[0201] The aromatic polyimide solution prepared above was filtered through a 400-mesh wire mesh, and this was used as a dope solution. A spinning apparatus equipped with a hollow fiber spinning nozzle (circular opening outer diameter 1200 μm, circular opening slit width 200 μm, core opening outer diameter 600 μm) was used to extrude the dope solution into a hollow fiber form from the hollow fiber spinning nozzle. The extruded hollow fiber was passed through a nitrogen gas atmosphere, then immersed in a primary coagulation solution (0 ° C, 75 wt% ethanol aqueous solution), and further coagulated by reciprocating between guide rolls in a secondary coagulation solution (0 ° C, 75 wt% ethanol aqueous solution) in a secondary coagulation device equipped with a pair of guide rolls. The hollow fiber state was then coagulated by reciprocating between guide rolls, and the hollow fiber membrane was obtained by taking up the membrane at a take-up speed of 25 m / min. The hollow fiber membrane was then wound onto a bobbin, washed with ethanol, and then the ethanol was replaced with isooctane. The mixture was further heated at 100 ° C to evaporate the isooctane and dried, and then further heat-treated at 305 ° C for 30 minutes to obtain a separation membrane.

[0202] C. Separation membrane module (Separation membrane module P) 1,000 gas separation membranes were bundled together and placed in a container (length: 300 mm, inner diameter: 50 mm). One end of each acrylic pipe was statically potted using a urethane adhesive composition SA-7073 (manufactured by Sanyu Rec Co., Ltd.). After the adhesive composition hardened, the adhesive end was cut to open the gas separation membrane, and a gas separation membrane module was produced.

[0203] (Separation membrane module Q) The gas separation membranes were cut to a width of 300 mm, and 5 mL of a sodium hydroxide solution adjusted to a pH of 13 was dripped onto the longitudinal center of 10 gas separation membranes. After 1 hour, the membranes were washed with pure water, and a total of 1,000 gas separation membranes, including those with and without the sodium hydroxide solution dripped on, were bundled together and placed in a container. One end of each acrylic pipe was statically potted using the urethane adhesive composition SA-7073 (manufactured by Sanyu Rec Co., Ltd.). After the adhesive composition cured, the adhesive ends were cut to open the gas separation membranes, and a gas separation membrane module was produced.

[0204] Example 1 A feed gas (3.3 L / min) containing 50 mol % helium and 50 mol % oxygen was supplied using an inspection device for a gas separation membrane module having the configuration shown in Figure 1. The supply pressure was adjusted to 0.02 MPa.

[0205] Here, the separation membrane module 100 used was the separation membrane module P fabricated as above.

[0206] A vacuum pump (diaphragm type, N810.3FT.18(EX) manufactured by KNF) was connected to the permeation side of the separation membrane module P to reduce the pressure. The measured pressure was 10 kPa.

[0207] A portion of the gas permeated through the separation membrane of the separation membrane module P and was vented to the permeate gas discharge means 102, and the other gas was vented to the non-permeate gas discharge means 102 of the separation membrane module P.

[0208] To collect permeated gas at each site, a hollow fiber tube (PMC-C-Blue, manufactured by GLOphotonics) was inserted from the permeated gas outlet side of hollow fiber membrane 0. Because the hollow fiber tube of hollow fiber membrane 0 was thin, gas collection was slow, so measurements were performed while suctioning with a vacuum pump (KNF, absolute pressure 20 kPa).

[0209] Near the end of the hollow fiber tube inserted into the hollow fiber membrane O, a hollow fiber tube molded to fit the inner diameter (300 μm) of the hollow fiber membrane O was attached.

[0210] From the permeate gas outlet side of hollow fiber membrane 0, the end of the hollow fiber tube was moved to a point 6 cm from the end of the innermost hollow fiber membrane 0, and permeate gas sampling began. After that, the end of the hollow fiber tube was moved every 3 cm toward the inserted hollow fiber membrane 0 end, and permeate gas sampling was completed at a point 6 cm from the inserted hollow fiber membrane 0 end.

[0211] For the non-permeate gas, a hollow fiber tube was inserted into the non-permeate gas outlet of the separation membrane module. The end of the hollow fiber tube was moved every 3 cm in the flow direction from the supply gas inlet to the non-permeate gas outlet, just as with the permeate gas, and the non-permeate gas was sampled.

[0212] The oxygen concentrations of the non-permeating gas and the permeating gas collected at each point were measured using an oxygen concentration meter 14 (Gleisinger, G1690). Concentrations other than oxygen were calculated as helium. The flow rate of the permeated gas sampled at each point was measured using a soap film flow meter (HORIBA, SF-U / VP-2, 3, 4).

[0213] The measurement results for the non-permeate and permeate gases at each point are shown in Table 1. As the gas permeates, the helium purity of the non-permeate and permeate gases gradually decreases as they approach the permeate gas outlet. There were no significant changes in the properties of the non-permeate and permeate gases.

[0214] [Table 1]

[0215] Example 2 The feed gas was supplied in the same manner as in Example 1, except that only the flow rate of the feed gas was changed (1.8 L / min). The measurement results of the non-permeate gas and permeate gas at each point are shown in Table 1. As the gas permeates, the helium purity of the non-permeate gas and permeate gas gradually decreases as the gas approaches the permeate gas outlet. There were no significant changes in the properties of the non-permeate gas and permeate gas.

[0216] Example 3 The feed gas was supplied in the same manner as in Example 1, except that only the flow rate of the feed gas was changed (0.35 L / min). The measurement results of the non-permeate gas and permeate gas at each point are shown in Table 1. As the gas permeates, the helium purity of the non-permeate gas and permeate gas gradually decreases as the gas approaches the permeate gas outlet. There was no significant change in the composition of the permeate gas, but in the region where the helium recovery rate was high, the characteristics of the permeate gas changed significantly, and the helium purity decreased. Furthermore, the properties of the non-permeable gas were also affected by the decrease in helium permeation.

[0217] Example 4 The feed gas was supplied in the same manner as in Example 1, except that the flow rate of the feed gas was changed (0.28 L / min). The measurement results of the non-permeate gas and permeate gas at each point are shown in Table 1. As the gas permeates, the helium purity of the non-permeate gas and permeate gas gradually decreases as the gas approaches the permeate gas outlet. There was no significant change in the composition of the permeate gas, but in the region where the helium recovery rate was high, the characteristics of the permeate gas changed significantly, and the helium purity decreased. Furthermore, the properties of the non-permeable gas were also affected by the decrease in helium permeation.

[0218] Example 5 A feed gas (3.3 L / min) containing 50 mol % helium and 50 mol % oxygen was supplied using an inspection device for a gas separation membrane module having the configuration shown in Figure 4. The supply pressure was adjusted to 0.02 MPa.

[0219] Here, the separation membrane module 100 used was the separation membrane module Q produced as a prototype above. To identify the presence or absence of damaged membranes and the extent of the damaged membrane, the tip of a silicone gas vent was pressed against the potting part with the membrane end open, and gas was ventilated into an area of ​​approximately one-quarter of the potting part, narrowing down the area of ​​the damaged hollow fiber membrane.

[0220] By shifting or replacing the position of the gas vent, the gas ventilation range was changed or the ventilation range was narrowed until the diameter of the potting part was 10 mm, and the range of the damaged hollow fiber membrane was narrowed, and then the supply gas was supplied in the same manner as in Example 1.

[0221] The results of measuring the non-permeated gas and permeated gas at each point are shown in Table 1. As the gas permeates, the helium purity of the non-permeated gas and permeated gas gradually decreases as the gas approaches the permeated gas outlet. Regarding the composition of the permeated gas, the helium purity significantly decreased compared to Example 1 at a point 6 cm from the innermost end of the inserted hollow fiber membrane. Furthermore, the helium purity significantly decreased even further at a point 6 cm from the outermost end of the inserted hollow fiber membrane.

[0222] The properties of the non-permeable gas were also affected by changes in helium.

[0223] From the above, it was estimated that there was an abnormality at both ends of the separation membrane module Q in the width direction.

[0224] As mentioned above, in the separation membrane module Q, there was concern that the performance of the central portion of the hollow fiber membrane in the longitudinal direction would be reduced due to contact with the aqueous sodium hydroxide solution, but this was detected by the method of the present invention.

[0225] Example 6 Separation membrane module 100 was used to supply a feed gas to the separation membrane module Q fabricated above in the same manner as in Example 5, except that the flow rate of the feed gas was changed (0.35 L / min). The measurement results of the non-permeate gas and permeate gas at each point are shown in Table 1. As the gas permeates, the purity of the non-permeate gas and permeate gas gradually decreases as they approach the permeate gas outlet.

[0226] Regarding the composition of the permeated gas, the helium purity was significantly lower at a point 6 cm from the O end of the inserted hollow fiber membrane compared to Example 1. Furthermore, the helium purity was even more significantly lower at a point 6 cm from the O end of the inserted hollow fiber membrane.

[0227] In the normal separation membrane module, the permeate gas composition changed significantly in the region where the helium recovery rate was high, and the helium purity decreased.

[0228] The properties of the non-permeable gas were also affected by changes in helium.

[0229] From the above, it was estimated that there was an abnormality at both ends of the separation membrane module Q in the width direction.

[0230] As mentioned above, in the separation membrane module Q, there was concern that the performance of the central portion of the hollow fiber membrane in the longitudinal direction would be reduced due to contact with the aqueous sodium hydroxide solution, but this was detected by the method of the present invention.

[0231] Example 7 Separation membrane module 100 was used to supply a feed gas to the separation membrane module Q fabricated above in the same manner as in Example 5, except that the flow rate of the feed gas was changed (0.28 L / min). The measurement results of the non-permeate gas and permeate gas at each point are shown in Table 1. As the gas permeates, the purity of the non-permeate gas and permeate gas gradually decreases as they approach the permeate gas outlet.

[0232] Regarding the composition of the permeated gas, the helium purity was significantly lower at a point 6 cm from the O end of the inserted hollow fiber membrane compared to Example 1. Furthermore, the helium purity was even more significantly lower at a point 6 cm from the O end of the inserted hollow fiber membrane.

[0233] In the normal separation membrane module, the permeate gas composition changed significantly in the region where the helium recovery rate was high, and the helium purity decreased, but the change in this example was even greater.

[0234] The properties of the non-permeable gas were also affected by changes in helium.

[0235] From the above, it was estimated that there was an abnormality at both ends of the separation membrane module Q in the width direction.

[0236] As mentioned above, in the separation membrane module Q, there was concern that the performance of the central portion of the hollow fiber membrane in the longitudinal direction would be reduced due to contact with the aqueous sodium hydroxide solution, but this was detected by the method of the present invention.

[0237] Example 8 The feed gas was supplied in the same manner as in Example 1, except that the feed gas was changed to a feed gas containing 100 mol % helium (3.3 L / min).

[0238] The measurement results for non-permeate and permeate gases at each point are shown in Table 2. As the permeate gas outlet is approached, the permeate gas flow rate gradually increases, while the non-permeate gas flow rate decreases accordingly. There was no significant change in the flow rates of non-permeate and permeate gases.

[0239] [Table 2]

[0240] Example 9 The feed gas was supplied in the same manner as in Example 1, except that the feed gas was changed to a feed gas containing 100 mol % helium (1.8 L / min).

[0241] The measurement results for non-permeate and permeate gases at each point are shown in Table 2. As the permeate gas outlet is approached, the permeate gas flow rate gradually increases, while the non-permeate gas flow rate decreases accordingly. There was no significant change in the flow rates of non-permeate and permeate gases.

[0242] Example 10 The feed gas was supplied in the same manner as in Example 1, except that the feed gas was changed to a feed gas containing 100 mol % helium (0.63 L / min).

[0243] The measurement results of the non-permeate and permeate gas at each point are shown in Table 2. As the permeate gas outlet is approached, the permeate gas flow rate gradually increases, while the non-permeate gas flow rate decreases accordingly. There was no significant change in the permeate gas flow rate.

[0244] Example 11 The feed gas was supplied in the same manner as in Example 1, except that the feed gas was changed to a feed gas containing 100 mol % helium (0.58 L / min).

[0245] The measurement results for non-permeate and permeate gases at each point are shown in Table 2. As the permeate gas outlet is approached, the permeate gas flow rate gradually increases, while the non-permeate gas flow rate decreases accordingly. There was no significant change in the flow rates of non-permeate and permeate gases.

[0246] Example 12 The feed gas was supplied in the same manner as in Example 1, except that the feed gas was changed to a feed gas containing 100 mol % sulfur hexafluoride (3.3 L / min).

[0247] The measurement results for non-permeate and permeate gases at each point are shown in Table 2. As the permeate gas outlet is approached, the permeate gas flow rate gradually increases, while the non-permeate gas flow rate decreases accordingly. There was no significant change in the flow rates of non-permeate and permeate gases.

[0248] Example 13 The feed gas was supplied in the same manner as in Example 1, except that the feed gas was changed to a feed gas containing 100 mol % sulfur hexafluoride (0.3 L / min).

[0249] The measurement results of the non-permeate and permeate gas at each point are shown in Table 2. As the permeate gas outlet is approached, the permeate gas flow rate gradually increases, while the non-permeate gas flow rate decreases accordingly. There was no significant change in the flow rates of the non-permeate and permeate gases.

[0250] Example 14 The feed gas was supplied in the same manner as in Example 1, except that the feed gas was changed to a feed gas containing 100 mol % sulfur hexafluoride (0.14 L / min).

[0251] The measurement results for non-permeate and permeate gases at each point are shown in Table 2. As the permeate gas outlet is approached, the permeate gas flow rate gradually increases, while the non-permeate gas flow rate decreases accordingly. There was no significant change in the flow rates of non-permeate and permeate gases.

[0252] Example 15 The feed gas was supplied in the same manner as in Example 1, except that the feed gas was changed to a feed gas containing 100 mol % sulfur hexafluoride (0.12 L / min).

[0253] The measurement results for non-permeate and permeate gases at each point are shown in Table 2. As the permeate gas outlet is approached, the permeate gas flow rate gradually increases, while the non-permeate gas flow rate decreases accordingly. There was no significant change in the flow rates of non-permeate and permeate gases.

[0254] Example 16 The separation membrane module 100 was replaced with the separation membrane module Q fabricated above, and the feed gas was supplied in the same manner as in Example 1, except that the feed gas was changed to 100 mol % helium (1.8 L / min). The measurement results of the non-permeate gas and permeate gas at each point are shown in Table 2. As the permeate gas exit was approached, the permeate gas flow rate gradually increased, while the non-permeate gas flow rate decreased accordingly. Furthermore, the permeate gas flow rate significantly increased at a point 6 cm from the end of the inserted hollow fiber membrane compared to Example 9. Furthermore, the permeate gas flow rate significantly increased even further at a point 6 cm from the end of the inserted hollow fiber membrane.

[0255] The characteristics of the non-permeating gas were also affected by the change in the flow rate of the permeating gas.

[0256] From the above, it was estimated that there was an abnormality at both ends of the separation membrane module Q in the width direction.

[0257] As mentioned above, in the separation membrane module Q, there was concern that the performance of the central portion of the hollow fiber membrane in the longitudinal direction would be reduced due to contact with the aqueous sodium hydroxide solution, but this was detected by the method of the present invention.

[0258] Example 17 The feed gas was supplied in the same manner as in Example 1, except that separation membrane module 100 was replaced with the prototype separation membrane module Q described above, and the feed gas was changed to a feed gas containing 100 mol % sulfur hexafluoride (0.3 L / min). The measurement results of the non-permeate gas and permeate gas at each point are shown in Table 2. As the permeate gas exit was approached, the permeate gas flow rate gradually increased, and the non-permeate gas flow rate decreased accordingly. Furthermore, the permeate gas flow rate significantly increased compared to Example 13, especially at a point 15 cm from the far end of the inserted hollow fiber membrane 0 end.

[0259] The characteristics of the non-permeating gas were also affected by the change in the flow rate of the permeating gas.

[0260] From the above, it was estimated that there was an abnormality near the center of the separation membrane module Q in the width direction.

[0261] As mentioned above, in the separation membrane module Q, there was concern that the performance of the central portion of the hollow fiber membrane in the longitudinal direction would be reduced due to contact with the aqueous sodium hydroxide solution, but this was detected by the method of the present invention.

[0262] Example 18 The separation membrane module 100 was replaced with the separation membrane module P fabricated above, and the feed gas was changed to 100 mol % helium, the feed pressure was kept constant at 0.02 MPa, and the feed gas was supplied in the same manner as in Example 1, except that the non-permeate gas outlet 3 was sealed. Gas was collected only on the permeate gas side of the hollow fiber membrane 0. The measurement results of the permeate gas at each point are shown in Table 3. The permeate gas flow rate gradually increased as the flow approached the permeate gas outlet. There was no significant change in the trend of the permeate gas flow rate.

[0263] [Table 3]

[0264] Example 19 The separation membrane module 100 was replaced with the separation membrane module Q produced above, and the feed gas was supplied in the same manner as in Example 18. Gas was collected only from the permeate gas side of the hollow fiber membrane 0. The measurement results of the permeate gas at each point are shown in Table 3. The permeate gas flow rate gradually increased as the permeate gas outlet was approached, but the permeate gas flow rate increased significantly compared to Example 18, especially near a point 15 cm from the back side of the inserted hollow fiber membrane 0 end.

[0265] From the above, it was estimated that there was an abnormality near the center of the separation membrane module Q in the width direction.

[0266] As mentioned above, in the separation membrane module Q, there was concern that the performance of the central portion of the hollow fiber membrane in the longitudinal direction would be reduced due to contact with the aqueous sodium hydroxide solution, but this was detected by the method of the present invention.

[0267] (Comparative Example 1) As in Example 5, the permeate gas was collected from the non-permeate gas and permeate gas discharged from the pressure vessel containing the separation membrane module Q. The measurement results are shown in Table 1. The characteristics of the non-permeate gas and permeate gas from the entire separation membrane module could be determined, and the purity of the permeate gas was reduced as in Example 6, but it was difficult to estimate the location or cause of the abnormality in the separation membrane module.

[0268] (Comparative Example 2) The supply gas was the same as in Example 16, except that the permeate gas was collected from the non-permeate gas and permeate gas discharged from the pressure vessel containing the separation membrane module Q. The measurement results are shown in Table 2. The characteristics of the non-permeate gas and permeate gas from the entire separation membrane module could be determined, and the purity of the permeate gas decreased as in Example 16, but it was difficult to estimate the location or cause of the abnormality in the separation membrane module.

[0269] (Comparative Example 3) The supply gas was the same as in Example 17, except that the supply gas was changed to a supply gas containing 100 mol % sulfur hexafluoride (0.3 L / min) and the permeate gas was collected from the non-permeate gas and permeate gas discharged from the pressure vessel containing the separation membrane module Q. The measurement results are shown in Table 2. The characteristics of the non-permeate gas and permeate gas from the entire separation membrane module could be determined, but the purity of the permeate gas was reduced as in Example 17, and it was difficult to estimate the location or cause of the abnormality in the separation membrane module.

[0270] Comparative Example 4 The feed gas was supplied in the same manner as in Example 19, except that the permeate gas was collected from the permeate gas discharged from the pressure vessel containing the separation membrane module Q. The measurement results are shown in Table 3. Although the characteristics of the permeate gas from the entire separation membrane module could be ascertained, it was difficult to estimate the location and cause of the abnormality in the separation membrane module. [Industrial Applicability]

[0271] The gas separation membrane module inspection device of the present invention is an inspection device that measures the characteristics of at least one of the non-permeating gas or permeating gas at two or more locations on the gas separation membrane module, and can provide an inspection device that can identify the location of abnormalities such as deterioration, damage, and leaks in the gas separation membrane module and confirm the degree of deterioration, etc. [Explanation of symbols]

[0272] 0 Hollow fiber membrane 1. Supply gas inlet 2 Permeate gas outlet 3 Non-permeable gas outlet 4. First potting section 5. Second potting section 7 Container 8 Sealed container 9 Gas vent 10 Gas collector 11 Gas sampling tube 12 valves 13 Flow meter 14 Oxygen concentration meter 15 Gas vent pipe 16 Gas Chromatography 17 Conductivity sensor 18 water 100 Separation membrane module 101 Gas supply means 102 Non-permeate gas and permeate gas exhaust means 103 Measurement methods for properties of non-permeating and permeating gases 104 Gas venting means 105 Gas collection means 201 Supply gas 202 Permeable Gas 203 Non-permeable gas 204 Sampling Gas

Claims

1. The gas supplied to the gas separation membrane module having a hollow tubular separation membrane is composed of one or more types of gases, measuring the properties of at least one of the non-permeating gas and the permeating gas at the site of the gas separation membrane module; A method for inspecting a gas separation membrane module.

2. measuring the characteristics of at least one of the non-permeating gas and the permeating gas at two or more locations in the gas separation membrane module; The method for inspecting a gas separation membrane module according to claim 1 .

3. A gas separation membrane module having hollow tubular separation membranes is formed by potting a plurality of separation membranes in an open state at one or both ends thereof, aerating a gas into the separation membrane module and inspecting the gas collected from a predetermined area on the outer surface of the opened potting portion for abnormalities; Furthermore, the predetermined range through which the gas is vented is changed or narrowed down and the detection operation is repeated to specify the inspection range, Then, measuring the properties of at least one of the non-permeated gas and the permeated gas at the site of the gas separation membrane module. The method for inspecting a gas separation membrane module according to claim 1 .

4. A gas separation membrane module having hollow tubular separation membranes is formed by potting a plurality of separation membranes in an open state at one or both ends thereof, aerating a gas through a predetermined area of ​​the outer surface of the opened potting portion, and inspecting the gas collected from inside the separation membrane module for abnormalities; Furthermore, the predetermined range for collecting gas is changed or narrowed down and the detection operation is repeated to specify the inspection range, The method for inspecting a gas separation membrane module according to claim 1 , further comprising the step of measuring the properties of at least one of the non-permeating gas and the permeating gas at a site of the gas separation membrane module.

5. the rate of decrease in the flow rate of the non-permeated gas or permeated gas discharged from the separation membrane module relative to the flow rate of the supply gas is 1% or more and 99% or less; The method for inspecting a gas separation membrane module according to claim 1 .

6. The supply gas is composed of two or more types of gases, and the ratio of the kinetic molecular diameter of the gas having the smallest kinetic molecular diameter to the kinetic molecular diameter of the other gases is 1.05 or more and 2.60 or less. The method for inspecting a gas separation membrane module according to claim 1 .

7. the supply gas is composed of two or more types of gases, and with respect to the permeabilities of the gases contained in the supply gas, the ratio of the permeability of a gas having a higher permeability to the permeability of a gas having a lower permeability is 1.1 or more and 2000 or less; The method for inspecting a gas separation membrane module according to claim 1 .

8. measuring one or more characteristics of the non-permeate gas or the permeate gas, such as volumetric flow rate, mass flow rate, composition, temperature, pressure, or thermal conductivity; The method for inspecting a gas separation membrane module according to claim 1 .

9. a supply means for supplying a feed gas composed of one or more types of gas to a gas separation membrane module having a hollow tubular separation membrane; The gas separation membrane module separates a feed gas composed of one or more types of gases into a non-permeate gas and a permeate gas, a non-permeate gas discharge means and a permeate gas discharge means for discharging the non-permeate gas and the permeate gas, respectively, from the gas separation membrane module; A means for measuring the properties of at least one of the non-permeating gas and the permeating gas at the site of the gas separation membrane module is provided. Gas separation membrane module inspection equipment.

10. 2. The inspection method for a gas separation membrane module according to claim 1, wherein the inspection method is used in at least one process selected from the group consisting of gas separation in the manufacturing processes of optical fibers, semiconductors, and electrical appliances, separation of gases produced by reactions such as natural gas, city gas, biogas, and methanation, separation of gases containing unreacted raw materials and by-products, separation of gases generated from water electrolysis equipment, and separation of gases for concentrating a target gas from a mixed gas.

11. A method for manufacturing an optical fiber, comprising using the method for inspecting a gas separation membrane module according to claim 1.

12. A method for manufacturing a semiconductor, comprising using the method for inspecting a gas separation membrane module according to claim 1.

13. A method for manufacturing an electrical product, comprising using the method for inspecting a gas separation membrane module according to claim 1.

14. A gas production method, characterized by using the gas separation membrane module inspection method of claim 1, for separating at least one gas selected from gases produced by reactions such as natural gas, city gas, biogas, and methanation, gases containing unreacted raw materials and by-products, gases from fermentation and enzymatic reaction processes, and gases generated from water electrolysis devices, etc.

15. An optical fiber manufactured using a gas separation membrane module whose performance has been tested by the method of claim 1.

16. A semiconductor manufactured using a gas separation membrane module whose performance has been tested by the method of claim 1.

17. An electrical product manufactured using a gas separation membrane module whose performance has been tested by the method of claim 1.

18. A gas separation device that uses a gas separation membrane module whose performance has been tested by the method of claim 1, and separates at least one gas selected from natural gas, city gas, biogas, gases produced by methanation reactions, gases containing unreacted raw materials or by-products, gases produced in fermentation or enzymatic reaction processes, and gases generated from water electrolysis devices.

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