Method and apparatus for inspecting gas separation membrane module

Abstract

To provide an inspection method and an inspection device for specifying a generation part or confirming the degree of deterioration or the like with respect to abnormality such as the deterioration, damage or leak of a gas separation membrane module.SOLUTION: Measuring a characteristic of at least one of a non-permeated gas and a permeated gas of the gas separation membrane for each of divided regions divided in a flow direction of the at least one of the non-permeated gas and the permeated gas of the gas separation membrane module, and determining a characteristic of a reference non-permeated gas and a characteristic of a reference permeated gas for each of the divided regions in advance, the gas supplied to the gas separation membrane module being composed of one or two or more gases; Comparing at least one of the measured operating characteristics of the non-permeated gas and the measured operating characteristics of the permeated gas with the determined characteristics of the reference non-permeated gas and the determined characteristics of the reference permeated gas, and determining the presence or absence of an abnormality in the separation membrane module on the basis of predetermined state determination criteria for the separation membrane module whose state is to be determined.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. Therefore, there is a concern that the separation membrane elements may be damaged, broken, or deteriorated. It is important to quickly detect the occurrence of an abnormality in the separation membrane module, identify the location of the abnormality as quickly as possible, and take early measures.

[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. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6643223 [Patent Document 2] International Publication No. 2020 / 071507 Summary of the Invention [Problem to be solved by the invention]

[0007] 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.

[0008] Therefore, the present invention provides an inspection device and an inspection method for gas separation membrane modules that can improve these problems, examine parts of separation membrane modules where performance has deteriorated, confirm the degree of performance deterioration, and obtain information for performance recovery such as repairs. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention has the following configuration.

[0010] (1) A method for inspecting a gas separation membrane module, in which the gas supplied to the gas separation membrane module is composed of one or more types of gas, and for at least one of the non-permeate gas or permeate gas of the gas separation membrane, the characteristics of at least one of the non-permeate gas or permeate gas are measured for each divided region obtained by dividing the gas separation membrane module in the flow direction of at least one of the non-permeate gas or permeate gas, the characteristics of a reference non-permeate gas and the characteristics of a reference permeate gas for each divided region are determined in advance, and at least one of the measured operating characteristics of the non-permeate gas and the operating characteristics of the permeate gas are compared with the determined characteristics of the reference non-permeate gas and the characteristics of the reference permeate gas, and the presence or absence of an abnormality in the separation membrane module is determined based on predetermined condition judgment criteria for the separation membrane module whose condition is to be judged.

[0011] (2) The method for inspecting a gas separation membrane module according to (1), wherein the gas separation membrane is a flat membrane.

[0012] (3) A method for inspecting a gas separation membrane module according to (1) or (2), in which the gas separation membrane, the supply side flow path material, and the permeation side flow path material are wound around a central tube that collects the permeated gas of the gas separation membrane.

[0013] (4) A method for inspecting a gas separation membrane module according to any one of (1) to (3), 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.

[0014] (5) A method for inspecting a gas separation membrane module according to any one of (1) to (4), wherein the supply gas is composed of two or more types of gases, 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.

[0015] (6) A method for inspecting a gas separation membrane module according to any one of (1) to (5), 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. [Effects of the Invention]

[0016] 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 and can also confirm the degree of deterioration. [Brief explanation of the drawings]

[0017] [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] 1 is a schematic diagram showing an example of a gas separation membrane module of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention relates to a method and an apparatus for inspecting a gas separation membrane module, 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 of the gas separation membrane are measured at a location on the gas separation membrane module.

[0019] Hereinafter, embodiments of the present invention will be described in detail.

[0020] 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.

[0021] <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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] When the pressure is increased in the storage means to liquefy only the water vapor, the liquefied water can be separated and removed.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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 within a certain range, since this makes it easier to grasp the degree of abnormality. Specifically, it is preferable that the ratio is 1.05 or more and 2.60 or less. More preferably, it is 1.10 or more and 2.55 or less, and even more preferably, it is 1.20 or more and 2.50 or less. When selecting the type of gas, permeability may be used as an index. For example, when gases with different permeabilities are supplied, if there is a portion where the gas with lower permeability permeates more, while the permeability of the gas with higher permeability remains unchanged, the degree of abnormality can be grasped.

[0034] 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.

[0035] 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 and the gas with the lower permeability can be calculated by the formula (1), and is preferably 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 term "feed gas composed of two or more types of gases" means that the feed gas contains each of the gases at 0.001 mol % or more when analyzed using a mass spectrometer or the like.

[0036] 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.

[0037] 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.

[0038] <Gas separation membrane module> In the present invention, at least one gas permeates the separation membrane in the separation membrane module.

[0039] (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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] As a method for pressurization, any commonly used method such as a compressor can be applied.

[0046] Any of the above means can create the necessary partial pressure difference.

[0047] (separation membrane) In the present invention, various separation membranes can be used.

[0048] The separation membrane can be appropriately selected depending on the type of gas and the conditions of use. Separation membranes similar to those commonly used in the relevant technical field can be used without particular limitation. Examples include polymer membranes made of rubber-like polymer materials such as silicone resin and polybutadiene resin, cellulose acetate, polysulfone, aromatic polyamide, polyethersulfone, polyacrylonitrile, polyphenylene sulfide, polyetheretherketone, polytetrafluoroethylene, and polyvinylidene fluoride, as well as inorganic membranes containing metals such as zeolite, silica, and palladium.

[0049] 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, and the like.

[0050] When relatively small gases such as hydrogen and helium are to be permeated, polyamide 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.

[0051] The separation membrane may also have a coating layer. Separation membranes have a small number of regions with significantly high gas permeability, such as coarse pores and defects. In these regions, the contribution of molecular sieving to separation is small, and the selective separation ability for gases with small molecular diameters, such as hydrogen, helium, water vapor, and ammonia, is low. Reducing the contribution of regions with low selective separation ability, such as coarse pores and defects, is preferable for improving the selective separation ability of the entire membrane, and forming a coating layer on the separation membrane can suppress gas permeation through coarse pores and defects. While the permeation of oxygen, nitrogen, methane, etc. is significantly suppressed, the effect on the permeation of light gases such as hydrogen and helium is small, thereby significantly improving the selective separation ability.

[0052] The coating layer does not necessarily need to cover the entire surface of the separation membrane; there may be cases where the coating layer is partially missing due to unevenness in the coating when the coating layer is formed, or where the coating layer is formed only on surfaces with particularly many coarse pores or defects.

[0053] The coating layer can be made of any material commonly used in the art, without any particular limitations, including organic materials such as silicone resin, polyolefin resin, polyvinyl alcohol, and polyurethane, as well as metal-organic frameworks (MOFs), and metal-based materials using palladium or palladium alloys as hydrogen-permeable materials.

[0054] (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 it is filtered by the separation membrane.

[0055] 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 become concentrated 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.

[0056] 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.

[0057] Here, the concentration polarization on the membrane surface, which becomes the permeation resistance, is preferably eliminated by increasing the flow rate of the supply gas while taking into consideration the diffusion of the supply gas. Examples of the means for this include a method of thinning the supply-side channel material, or, in the case of a flat membrane, a method of feeding the supply gas from the end face of the separation membrane module and discharging it from the outer periphery.

[0058] 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.

[0059] The separation membrane may be modularized and housed in a container for use. The separation membrane module may be of any type, such as a flat membrane type, a plate and frame type, a spiral type, a hollow fiber membrane type, a tubular type, or a pipe type.

[0060] (Spiral-wound gas separation membrane module) 1, 2, 3, and 4, a spiral-wound gas separation membrane module 100 according to one embodiment of the present invention comprises a central tube 6, a separation membrane leaf wrapped around the central tube 6, a feed-side channel material 2, and a permeate-side channel material 3. This separation membrane module 100 is used by being loaded into a pressure vessel 7. The x-axis direction in FIG. 4 is the longitudinal direction of the central tube 6. The y-axis direction is perpendicular to the longitudinal direction of the central tube 6.

[0061] The central tube 6 is a hollow (cylindrical) member that is open at least at the downstream end so that the permeate gas described below can be discharged. When multiple gas separation membrane modules 100 are connected, a central tube 6 that is open at both ends is used. Multiple holes are provided on the side surface of the central tube 6 (the side surface of the cylindrical shape).

[0062] The separation membrane leaf has a feed-side surface and a permeate-side surface, and includes a plurality of separation membranes 1 arranged with their feed-side surfaces facing each other and their permeate sides facing each other, and a feed-side channel material 2 arranged between the feed-side surfaces of the separation membranes 1. Note that, for example, one membrane is folded with its permeate or feed side surface facing inward and wrapped around a central tube 6. This also includes the case where a plurality of membranes are each folded with their permeate or feed side surface facing inward and wrapped around a central tube 6.

[0063] Furthermore, a permeate-side channel material 3 is disposed between the permeate-side surfaces of the separation membranes 1 and is wrapped around a central tube 6 together with the separation membrane leaves to form a gas separation membrane module 100 .

[0064] A supply gas 201 is supplied from one end face of the gas separation membrane module 100. The supply gas 201 is separated while moving in the longitudinal direction of the central tube 6 of the gas separation membrane module 100, and permeated gas 202 that has permeated the separation membrane passes through the interior of the central tube 6 from holes in the side of the central tube 6 and is discharged from its end. The supply gas that has not been filtered is discharged from the other end face of the gas separation membrane module 100 as non-permeated gas 203.

[0065] The gas separation membrane module of the present invention includes a feed-side channel material and a permeate-side channel material. Examples of such channel materials include nets and nonwoven fabrics, as well as knitted fabrics such as tricot, woven fabrics such as plain weave mesh, and porous sheets with protrusions, such as textured sheets. The protrusions that function as the channel material may be fixed to the feed-side or permeate-side surface of the separation membrane.

[0066] The feed-side channel material and the permeate-side channel material may be the same or different in material, shape, and average pore size.

[0067] As a material for molding or forming the feed-side channel material and the permeate-side channel material, a thermoplastic resin is preferred from the viewpoint of moldability, and polyester, nylon, polyphenylene sulfide, polyethylene, polypropylene, polysulfone, polyethersulfone, polylactic acid, ABS (acrylonitrile-butadiene-styrene) resin, or UV-curable resin is more preferred from the viewpoint of suppressing damage to the separation membrane.

[0068] The ends of the separation membrane sandwiching the feed-side channel material are appropriately sealed together. Examples of the "sealing" method include adhesion using an adhesive or hot melt, fusion using heat or a laser, or sandwiching a rubber sheet, but simple sealing by adhesion is preferred.

[0069] There are no particular limitations on the shape of the central tube 6, but as mentioned above, a cylindrical shape can be used, and the outer periphery has one or more holes through which gas can pass. Alternatively, a partition wall may be provided inside the central tube 6, so that gas supplied from one end cannot move to the other end, but instead passes through the holes provided on the outer periphery.

[0070] (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.

[0071] (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.

[0072] The vacuum pump, aspirator, and ejector may be the same as those commonly used in the art without any particular limitations.

[0073] The vacuum pump may be of any type, such as a diaphragm type or an oil type.

[0074] 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.

[0075] 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.

[0076] <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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] When the pressure is increased in the storage means to liquefy only the water vapor, the liquefied water can be separated and removed.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] <Means for measuring the properties of at least one of non-permeating gas and permeating gas> The present invention has means 103 for measuring the properties of at least one of the non-permeating gas and the permeating gas of the gas separation membrane at the site of the gas separation membrane module.

[0087] (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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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 or not there is a defect. Furthermore, by measuring the permeate volumetric flow rate at each site within the separation membrane module and comparing the normal separation membrane module with the 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 composition of the permeate gas 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 the normal separation membrane module with that of a defective separation membrane module.

[0092] (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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] The advantage is that it is easy to put on and the position of the device can be easily adjusted.

[0100] 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.

[0101] 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, rather than attaching the scale or marking to the separation membrane itself, the scale or marking may be attached to the pressure vessel in which the separation membrane is loaded or, in the case of a spiral-type separation membrane module, inside the central pipe which is the flow path for the permeate gas.

[0102] 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.

[0103] A transparent or translucent pressure vessel may be prepared to identify and mark the insertion position of the sensor.

[0104] 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.

[0105] At least one of the non-permeated gas and the permeated gas is preferably collected at two or more locations in the separation membrane module.

[0106] A plurality of pipes for collecting gas may be arranged inside the separation membrane module.

[0107] 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.

[0108] 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 measurement is performed at that location. The presence or absence of an abnormality can be determined by comparing with a product that is not abnormal. For example, in the case of a spiral-wound separation membrane module, if a defect in the adhesive that seals the separation membrane is assumed, the adhesive can be measured.

[0109] When collecting gas, it is preferable to avoid mixing it with gas from other sites as much as possible.

[0110] For example, when sampling permeated gas in a spiral separation membrane module, the position of the gas sampling port may be changed along the length of the central tube 6, and the gas may be sampled through a gas sampling pipe. In this case, if the gas sampling port is sealed to fit the inner diameter of the central tube 6, almost all of the gas flowing into the central tube 6 can be sampled.

[0111] For sealing, commonly used sealing materials can be used, such as O-rings and packing made of silicone, butyl rubber, Teflon (registered trademark), etc.

[0112] In this case, almost all of the permeable gas passing through from the upstream of the central tube 6 is sampled, but by sampling the gas from the most upstream part and checking the characteristics of that gas, any abnormal areas along the way can be identified.

[0113] Depending on the structure of the separation membrane module, it may be difficult to insert a pipe for gas sampling. 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 hundred μm may be used.

[0114] 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.

[0115] Depending on the structure of the central tube 6 of the separation membrane module and the nozzle of the container in which the separation membrane module is installed, the sealing member may be expanded by passing air or the like through the central tube 6 after installing the gas sampling tube. Alternatively, the separation membrane module may be installed in the container after installing the gas sampling tube. When measuring the flow rate or flow velocity of gas, sampling may be performed using a Pitot tube.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] However, if 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 flow rate of the gas supplied to the separation membrane module to be inspected will be large.

[0122] Therefore, the reduction rate of the flow rate of the non-permeating gas or permeating gas relative to the flow rate of the supply gas is preferably 1% or more and 95% or less, more preferably 5% or more and 95% or less, even more preferably 10% or more and 80% or less, and particularly preferably 20% or more and 60% or less.

[0123] 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.

[0124] 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.

[0125] In the present invention, the flow velocities of the feed gas, non-permeate gas, and permeate gas are preferably 1 cm / min or more and 6000 m / min or less, more preferably 5 cm / min or more and 600 m / min or less, and even more preferably 18 cm / min or more and 300 m / min or more.

[0126] (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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] (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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] (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.

[0137] 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.

[0138] 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.

[0139] 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. 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] Here, it is preferable that the reference separation membrane module is not in contact with gases that may deteriorate the separation membranes.

[0144] It is also preferable to measure the membrane characteristics of the feed gas in the divided regions in advance and compare them with the characteristics of the separation membrane itself. It is even more preferable to configure it with a single type of gas and measure it. 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] Examples of inspection methods for the separation membrane module to be inspected are given below, but the methods are not limited to the following.

[0149] 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.

[0150] 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. 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] By taking the above measures, it will be possible to operate the separation membrane process stably.

[0157] For example, compared to a standard separation membrane module, particularly when two or more types of gases are supplied, there is an increase in the permeation flow rate of gases that have a large dynamic molecular diameter and are difficult to permeate through the membrane, resulting in a decrease in the purity of the permeated gas for gases that are easy to permeate through the membrane. In a separation membrane module such as that shown in Figure 1, when permeated gas is discharged from one end of the central tube 6, the permeated gas from the end opposite the discharge side is accumulated and discharged.

[0158] When there is no abnormality in the separation membrane, the purity of the permeated gas in the divided region is almost constant, but when there is an abnormality in the separation membrane, the purity of the permeated gas gradually increases or decreases, an inflection point appears, and then the purity of the permeated gas gradually decreases or increases. From the position of such an inflection point, it is possible to determine the divided region where an abnormality exists.

[0159] 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.

[0160] 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.

[0161] 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.

[0162] 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.

[0163] 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]

[0164] The present invention will be described in more detail below with reference to examples, in which the separation membrane module is of a spiral type, but the present invention is not limited to these examples.

[0165] A. Device mechanism 1 and 2 are schematic diagrams showing an example of an inspection device for a gas separation membrane module of the present invention.

[0166] 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.

[0167] 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.

[0168] B. Fabrication of Gas Separation Membranes Unless otherwise specified below, the temperature conditions are room temperature (25°C).

[0169] (gas separation membrane) Nonwoven fabric made of polyester fiber produced by papermaking method (air permeability 1.0cc / cm 2 A 18% by mass solution of polysulfone in dimethylformamide (DMF) was cast onto the nonwoven fabric substrate (1000 nm / sec) at room temperature (25°C) to a coating thickness of 190 μm, and then the substrate was immediately immersed in pure water for 5 minutes to form a porous support layer on the nonwoven fabric substrate.

[0170] Next, the substrate with the porous support layer formed thereon was immersed in an aqueous solution containing 4.0% by mass of m-phenylenediamine for 1 minute, and then nitrogen was sprayed from an air nozzle to remove excess aqueous solution. Subsequently, an n-undecane solution containing 0.2% by mass of trimesoyl chloride heated to 45°C was uniformly applied to the surface of the porous support and dried in an oven at 100°C for 60 seconds. This was then left in an air atmosphere for 1 minute to obtain a separation functional layer (polyamide membrane). The resulting separation membrane was held vertically to drain the liquid and washed with pure water at 60°C for 2 minutes to obtain a gas separation membrane.

[0171] C. Separation membrane module (Separation membrane module P) The gas separation membrane was cut to a width of 300 mm, air-dried in a greenhouse at 25°C, and then folded in two. A feed-side channel material (Diomesh PET-Screen 100-55PT (manufactured by Innovex)) was sandwiched between the folded separation membrane. A permeation-side channel material (Diomesh PET-Screen 100-55PT (manufactured by Innovex)) was placed on the permeation side of the gas separation membrane, and adhesive was applied to the three edges of the permeation-side channel material. The laminate (effective membrane area 1.0 m) was then formed. 2) was spirally wound around an ABS resin water collection pipe (length: 300 mm, diameter: 17 mm, 80 holes arranged in a straight line on the wall in two rows) to prepare a separation membrane module with a diameter of 2.5 inches.

[0172] (Separation membrane module Q) The gas separation membrane was cut to a width of 300 mm, air-dried in a greenhouse at 25°C, and then folded in two. A feed-side channel material (Diomesh PET-Screen 100-55PT (manufactured by Innovex)) was sandwiched between the folded separation membrane. A permeation-side channel material (Diomesh PET-Screen 100-55PT (manufactured by Innovex)) was placed on the permeation side of the gas separation membrane, and adhesive was applied to the three edges of the permeation-side channel material. The laminate (effective membrane area 1.0 m) was then formed. 2 ) was spirally wound around an ABS resin water collection pipe (length: 300 mm, diameter: 17 mm, 80 holes arranged in a straight line on the wall in two rows) to prepare a separation membrane module with a diameter of 2.5 inches.

[0173] When applying the adhesive, a portion of about 1 cm long where no adhesive was applied was provided near the center of both ends in the length direction of the permeate side channel material.

[0174] (Separation Membrane Module R) The gas separation membrane was cut to a width of 300 mm, and 5 ml of an aqueous solution prepared by adding 100 ppm sodium hypochlorite to pure water and adjusting the pH to 7 was dropped onto the widthwise center of the separation membrane sheet. After 1 hour, the membrane was washed with pure water and air-dried in a greenhouse at 25°C. The membrane was then folded in half, and a feed-side channel material (Diomesh PET-Screen 100-55PT (Innovex)) was sandwiched between the folded membrane. A permeation-side channel material (Diomesh PET-Screen 100-55PT (Innovex)) was placed on the permeation side of the gas separation membrane, and adhesive was applied to the three edge sides of the permeation-side channel material. The resulting laminate (effective membrane area 1.0 m) was then assembled. 2 ) was spirally wound around an ABS resin water collection pipe (length: 300 mm, diameter: 17 mm, 80 holes arranged in a straight line on the wall in two rows) to prepare a separation membrane module with a diameter of 2.5 inches.

[0175] (Reference separation membrane module 1) A feed gas (7 L / min) containing 50 mol % helium and 50 mol % oxygen was supplied using the gas separation membrane module inspection device configured as shown in Figure 1. The supply pressure was adjusted to 0.02 MPa.

[0176] Here, the separation membrane module 100 used was the separation membrane module P produced above, and was installed in a pressure vessel (ROPV, R25C1000E, 2514). Here, the supply gas ventilation side of the central tube 6 was sealed. 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. 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.

[0177] To collect permeated gas at each location, a silicone tube (outer diameter 5 mm, inner diameter 3 mm) was inserted from the permeated gas outlet side of the central tube 6. To collect all permeated gas vented from the upstream of the central tube 6, a silicone sheet molded to seal the inner diameter (10 mm) of the central tube 6 was attached around the silicone tube near the inserted end.

[0178] The end of the silicon tube was moved to a point 6 cm from the innermost end of the central tube 6 from the permeation gas outlet side of the central tube 6, and permeation gas sampling began. After that, the end of the silicon tube was moved every 3 cm in the direction of the permeation gas flow toward the end of the central tube 6 (flow direction), and permeation gas sampling was completed at a point 6 cm from the permeation gas outlet side of the central tube 6.

[0179] Here, the point 6 cm from the permeate gas outlet side of the central tube 6 was the end of the separation membrane 1 wrapped around the periphery of the central tube 6 .

[0180] For the non-permeated gas, a silicone tube was inserted into the non-permeated gas outlet of the separation membrane module. The end of the silicone tube was moved every 3 cm in the flow direction from the supply gas inlet to the non-permeated gas outlet, as in the case of the permeated gas, and the non-permeated gas was sampled.

[0181] Here, a hollow fiber tube (manufactured by Art Photonics, core 50 μm) was used on the non-permeation side because a flow path material was placed there. Because the hollow fiber tube was thin and gas sampling was slow, measurements were performed while suctioning with a vacuum pump (manufactured by KNF, absolute pressure 20 kPa).

[0182] The oxygen concentrations of the non-permeating gas and the permeating gas collected at each point were measured using an oxygen concentration meter 12 (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).

[0183] The measurement results for 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 characteristics of the non-permeate gas and permeate gas. The results for this reference separation membrane module 1 were determined as the characteristics of the reference non-permeate gas and reference permeate gas for each divided region. The condition criterion for determining deterioration of the separation membrane module was set to a change of 1% or more.

[0184] [Table 1]

[0185] Example 1 A gas containing 50 mol % helium and 50 mol % oxygen (7 L / min) was supplied to the gas separation membrane module inspection device shown in Figure 1 in the same manner as the reference separation membrane module 1, except that the separation membrane module 100 was replaced with the prototype separation membrane module Q. The supply pressure was adjusted to 0.02 MPa.

[0186] Here, the separation membrane module Q was loaded into a pressure vessel (ROPV, R25C1000E, 2514), and the supply gas ventilation side of the central tube 6 was sealed. A vacuum pump (diaphragm type, N810.3FT.18(EX) manufactured by KNF) was connected to the permeation side of the separation membrane module Q to reduce the pressure. The measured pressure was 10 kPa. A portion of the gas permeated through the separation membrane of the separation membrane module Q 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 Q.

[0187] To collect permeated gas at each location, a silicone tube (outer diameter 5 mm, inner diameter 3 mm) was inserted from the permeated gas outlet side of the central tube 6. To collect all permeated gas vented from the upstream of the central tube 6, a silicone sheet molded to seal the inner diameter (10 mm) of the central tube 6 was attached around the silicone tube near the inserted end.

[0188] The end of the silicon tube was moved to a point 6 cm from the innermost end of the central tube 6 from the permeation gas outlet side of the central tube 6, and permeation gas sampling began. After that, the end of the silicon tube was moved every 3 cm in the direction of the permeation gas flow toward the end of the central tube 6 (flow direction), and permeation gas sampling was completed at a point 6 cm from the permeation gas outlet side of the central tube 6. The results of measuring 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 in the direction of the permeate gas flow. Regarding the composition of the permeate gas, the helium purity significantly decreased compared to the reference separation membrane module 1 at a point 6 cm from the back of the end of the central tube 6 (referred to as the "6 cm collection point" in Table 1). Furthermore, the helium purity significantly decreased even further at a point 24 cm from the back of the end of the central tube 6 (referred to as the "24 cm collection point" in Table 1).

[0189] The properties of the non-permeable gas were also affected by changes in helium. Comparing the characteristics of the reference non-permeable gas and the reference permeable gas in each divided region of the reference separation membrane module 1, there was a change greater than the established condition criterion (1%) for the deterioration of the separation membrane module.

[0190] From the above, it was estimated that there was an abnormality at both ends of the separation membrane module Q in the width direction.

[0191] As described above, in the separation membrane module Q, there were some areas where the adhesive was not applied, which raised concerns about poor adhesion, but this could be detected using the method of the present invention.

[0192] Example 2 The feed gas was supplied in the same manner as in Example 1, except that the separation membrane module 100 was replaced with the separation membrane module R prototyped above. 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 in the flow direction of the permeate gas. In particular, the helium purity of the permeate gas composition significantly decreased compared to the reference separation membrane module 1, particularly at a point 15 cm from the back of the end of the central tube 6 (referred to as the "15 cm collection point" in Table 1).

[0193] The properties of the non-permeable gas were also affected by changes in helium. Comparing the characteristics of the reference non-permeable gas and the reference permeable gas in each divided region of the reference separation membrane module 1, there was a change greater than the established condition judgment standard (1%) for the deterioration of the separation membrane module. From the above, it was estimated that there was an abnormality near the center of the separation membrane module R in the width direction.

[0194] As mentioned above, in separation membrane module R, there was concern that the separation membrane in the center of the width direction would have its performance deteriorated due to contact with the aqueous sodium hypochlorite solution, but this was detected by the method of the present invention.

[0195] (Reference separation membrane module 2) The feed gas was supplied in the same manner as in the reference separation membrane module 1, except that the feed gas was changed to a feed gas containing 100 mol % helium (3 L / min).

[0196] The measurement results for the non-permeate gas and permeate gas at each point are shown in Table 2. As the permeate gas approaches the outlet port in the direction of flow, the permeate gas flow rate gradually increases, while the non-permeate gas flow rate decreases accordingly. There were no significant changes in the trends in the flow rates of the non-permeate gas and permeate gas. The results for this reference separation membrane module 2 were determined as the characteristics of the reference non-permeate gas and reference permeate gas for each divided region. The status determination criterion for an abnormality in the separation membrane module was set at a change of 0.005 L / min or more.

[0197] [Table 2]

[0198] (Reference separation membrane module 3) The feed gas was supplied in the same manner as in the reference separation membrane module 1, except that the feed gas was changed to a feed gas containing 100 mol % sulfur hexafluoride (1 L / min).

[0199] The measurement results of the non-permeate and permeate gas at each point are shown in Table 2. In the direction of the permeate gas flow, 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. The results of this reference separation membrane module 3 were determined as the characteristics of the reference non-permeable gas and the reference permeable gas for each divided region. As the criterion for determining the state, a change of 0.001 L / min or more was set as an abnormality of the separation membrane.

[0200] Example 3 The separation membrane module 100 was replaced with the separation membrane module Q prototyped above, and the supply gas was changed to 100 mol % helium (3 L / min), but the supply gas was the same as in Example 1. Table 2 shows the measurement results for the non-permeate gas and permeate gas at each point. As the flow direction of the permeate gas approaches the permeate gas outlet, the permeate gas flow rate gradually increases, while the non-permeate gas flow rate decreases accordingly. Furthermore, with regard to the permeate gas flow rate, the helium flow rate significantly increased at a point 6 cm from the back of the end of the central tube 6 (referred to as the "6 cm collection point" in Table 2) compared to the reference separation membrane module 2. Furthermore, the helium flow rate significantly increased even further at a point 24 cm from the back of the central tube 6 (referred to as the "24 cm collection point" in Table 2).

[0201] The characteristics of the non-permeable gas were also similarly affected by changes in the helium flow rate. A comparison of the characteristics of the reference non-permeable gas and the reference permeable gas in each divided region of the reference separation membrane module 2 revealed a change greater than the established condition judgment standard (0.005 L / min) for the deterioration of the separation membrane module. From the above, it was estimated that there was an abnormality at both ends of the separation membrane module Q in the width direction. As described above, in the separation membrane module Q, there were some areas where the adhesive was not applied, which raised concerns about poor adhesion, but this could be detected using the method of the present invention.

[0202] Example 4 The separation membrane module 100 was replaced with the separation membrane module R fabricated above, and the supply gas was changed to 100 mol % helium (3 L / min), but the supply gas was the same as in Example 1. Table 2 shows the measurement results of the non-permeate gas and permeate gas at each point. As the flow direction of the permeate gas approaches the permeate gas outlet, the permeate gas flow rate gradually increases, and the non-permeate gas flow rate decreases accordingly. Furthermore, with regard to the permeate gas flow rate, the helium flow rate significantly increased compared to the reference separation membrane module 2, particularly at a point 15 cm from the back of the end of the central tube 6 (referred to as the "15 cm collection point" in Table 2).

[0203] The characteristics of the non-permeable gas were also similarly affected by changes in the helium flow rate. Comparison with the characteristics of the reference non-permeate gas and the reference permeate gas in each divided region of the reference separation membrane module 2 revealed a change greater than the established condition judgment standard (0.005 L / min) for the deterioration of the separation membrane module.

[0204] From the above, it was estimated that there was an abnormality near the center of the separation membrane module R in the width direction.

[0205] As mentioned above, in separation membrane module R, there was concern that the separation membrane in the center of the width direction would have its performance deteriorated due to contact with the aqueous sodium hypochlorite solution, but this was detected by the method of the present invention.

[0206] Example 5 The separation membrane module 100 was replaced with the separation membrane module Q fabricated above, and the supply gas was changed to a 100 mol % sulfur hexafluoride supply gas (1 L / min), similar to that in Example 1. Table 2 shows the measurement results for the non-permeate and permeate gases at each point. As the flow direction of the permeate gas approaches the permeate gas outlet, the permeate gas flow rate gradually increases, while the non-permeate gas flow rate decreases accordingly. Furthermore, regarding the permeate gas flow rate, the sulfur hexafluoride flow rate significantly increased at a point 6 cm from the end of the central tube 6 (referred to as the "6 cm collection point" in Table 2) compared to the reference separation membrane module 3. Furthermore, the sulfur hexafluoride flow rate significantly increased at a point 6 cm from the end of the central tube 6 (referred to as the "24 cm collection point" in Table 2).

[0207] The characteristics of the non-permeating gas were also affected by changes in the flow rate of sulfur hexafluoride. Comparison with the characteristics of the reference non-permeate gas and the reference permeate gas in each divided region of the reference separation membrane module 3 revealed that there was a change greater than the established condition judgment standard (0.001 L / min) for the deterioration of the separation membrane module.

[0208] From the above, it was estimated that there was an abnormality at both ends of the separation membrane module Q in the width direction.

[0209] As described above, in the separation membrane module Q, there were some areas where the adhesive was not applied, which raised concerns about poor adhesion, but this could be detected using the method of the present invention.

[0210] Example 6 The separation membrane module 100 was replaced with the separation membrane module R fabricated above, and the supply gas was changed to a supply gas containing 100 mol% sulfur hexafluoride (1 L / min), but the supply gas was the same as in Example 1. Table 2 shows the measurement results of the non-permeate gas and permeate gas at each point. As the flow direction of the permeate gas approaches the permeate gas outlet, the permeate gas flow rate gradually increases, and the non-permeate gas flow rate decreases accordingly. Furthermore, with regard to the permeate gas flow rate, the sulfur hexafluoride flow rate significantly increased compared to the reference separation membrane module 3, particularly at a point 15 cm from the back of the end of the central tube 6 (referred to as the "15 cm collection point" in Table 2).

[0211] The characteristics of the non-permeating gas were also affected by changes in the flow rate of sulfur hexafluoride. Comparison with the characteristics of the reference non-permeate gas and the reference permeate gas in each divided region of the reference separation membrane module 3 revealed that there was a change greater than the established condition judgment standard (0.001 L / min) for the deterioration of the separation membrane module. From the above, it was estimated that there was an abnormality near the center of the separation membrane module R in the width direction.

[0212] As mentioned above, in separation membrane module R, there was concern that the separation membrane in the center of the width direction would have its performance deteriorated due to contact with the aqueous sodium hypochlorite solution, but this was detected by the method of the present invention.

[0213] (Comparative Example 1) The supply gas was the same as in Example 1, 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 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 1, but it was difficult to estimate the location or cause of the abnormality in the separation membrane module.

[0214] (Comparative Example 2) The supply gas was the same as in Example 1, 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 R. 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 1, but it was difficult to estimate the location or cause of the abnormality in the separation membrane module.

[0215] (Comparative Example 3) The supply gas was the same as in Example 3, except that the supply gas was changed to 100 mol % helium (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 throughout the separation membrane module could be determined, and the flow rate of the permeate gas increased as in Example 3, but it was difficult to estimate the location or cause of the abnormality in the separation membrane module.

[0216] Comparative Example 4 The supply gas was the same as in Example 3, except that the supply gas was changed to 100 mol % helium (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 R. The measurement results are shown in Table 2. The characteristics of the non-permeate gas and permeate gas for the entire separation membrane module could be determined, and the flow rate of the permeate gas increased as in Example 3, but it was difficult to estimate the location or cause of the abnormality in the separation membrane module.

[0217] (Comparative Example 5) The supply gas was the same as for the reference separation membrane module 3, except that the supply gas was changed to a supply gas containing 100 mol% sulfur hexafluoride (1 L / min) and the permeate gas was collected from the non-permeate gas and permeate gas discharged from the pressure vessel containing separation membrane module Q. The measurement results are shown in Table 2. The characteristics of the non-permeate gas and permeate gas for the entire separation membrane module could be determined, but the purity of the permeate gas decreased, just as with reference separation membrane module 2, making it difficult to estimate the location or cause of the abnormality in the separation membrane module.

[0218] (Comparative Example 6) The supply gas was the same as in Example 5, except that the supply gas was changed to a supply gas containing 100 mol % sulfur hexafluoride (1 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 R. 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 decreased as in Example 5, making it difficult to estimate the location or cause of the abnormality in the separation membrane module. [Industrial Applicability]

[0219] 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]

[0220] 1 Separation membrane 2 Supply side channel material 3 Permeate side channel material 6 central canal 7. Pressure Vessels 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 Apparatus for measuring the properties of non-permeating and permeating gases 201 Supply gas 202 Permeable Gas 203 Non-permeable gas 204 Sampling Gas

Claims

1. A method for inspecting a gas separation membrane module, in which the gas supplied to the gas separation membrane module is composed of one or more types of gas, and for at least one of the non-permeate gas or permeate gas of the gas separation membrane, the characteristics of at least one of the non-permeate gas or permeate gas are measured for each divided region obtained by dividing the gas separation membrane module in the flow direction of at least one of the non-permeate gas or permeate gas, the characteristics of a reference non-permeate gas and the characteristics of a reference permeate gas for each divided region are determined in advance, and at least one of the measured operating characteristics of the non-permeate gas and the operating characteristics of the permeate gas are compared with the determined characteristics of the reference non-permeate gas and the characteristics of the reference permeate gas, and the presence or absence of an abnormality in the separation membrane module is determined based on predetermined condition determination criteria for the separation membrane module whose condition is to be determined.

2. The method for inspecting a gas separation membrane module according to claim 1 , wherein the gas separation membrane is a flat membrane.

3. 3. The method for inspecting a gas separation membrane module according to claim 1, wherein the gas separation membrane, the supply side flow path material, and the permeation side flow path material are wound around a central tube that collects the permeated gas of the gas separation membrane to form a gas separation membrane module.

4. 4. A method for inspecting a gas separation membrane module according to claim 1, 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.

5. 5. A method for inspecting a gas separation membrane module according to claim 1, 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.

6. 6. A method for inspecting a gas separation membrane module according to claim 1, wherein one or more characteristics of the non-permeating gas or the permeating gas, including volumetric flow rate, mass flow rate, composition, temperature, pressure, and thermal conductivity, are measured.

7. 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.

8. A method for manufacturing optical fibers, semiconductors, and electrical products, comprising using the gas separation membrane module inspection method of claim 1.

9. 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.

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