JP2024000532A - Composite inorganic membrane, fluid separation membrane module, fluid separation membrane plant and purified fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite inorganic membrane where the occurrence of breaking and breakage of the inorganic membrane at modularization and a module operation can be suppressed by reducing hooking to a module producing device and a module member.

SOLUTION: In a composite inorganic membrane including a hollow fiber inorganic membrane and a fibrous resin composition, coefficient of static friction of mutual resin compositions measured by JIS L 1095(2010) is 0.01 or more and 0.60 or less, and a part of the surface of the inorganic membrane is coated with the resin composition.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to an inorganic membrane, a fluid separation membrane module using the same, a fluid separation membrane plant, and a purified fluid.

A membrane separation method is known as a separation method for selectively separating and purifying specific components from various mixed gases and mixed liquids. Because the membrane separation method uses pressure differences and concentration differences, it has the advantage of using less thermal energy than other separation and purification methods. Although polymer membranes and inorganic membranes are known as separation membranes used in membrane separation methods, inorganic membranes are preferably used particularly in applications where heat resistance and chemical resistance are required. At this time, in order to increase the membrane area per unit volume, a membrane module is used in which a plurality of inorganic membranes are housed in a vessel.

Regarding membrane modules containing inorganic membranes, so far, a hollow fiber bundle (1) reinforced by wrapping a filamentous substance around the outer periphery of a bundle consisting of a plurality of hollow fiber separation membranes, and a large number of hollow fiber bundles (1) have been developed. A hollow fiber separation membrane element (e.g. , see Patent Document 1) has been proposed.

Japanese Patent Application Publication No. 2001-300267

Patent Document 1 discloses that by using a hollow fiber bundle (1) reinforced by wrapping a filamentous material around the outer periphery of a bundle consisting of a plurality of hollow fiber separation membranes, damage or breakage of the hollow fiber separation membranes during module production can be prevented. A method to prevent this is disclosed. However, in the method of Patent Document 1, when producing a hollow fiber bundle, modularizing the hollow fiber bundle, and operating the module, the hollow fiber separation membrane and the hollow fiber bundle are removed from the module manufacturing equipment or module members (adjacent hollow fiber bundles, etc.). There was a problem that the hollow fiber separation membrane could get caught on the housing (such as the housing), causing breakage or damage to the hollow fiber separation membrane.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an inorganic membrane that is easy to handle and suppresses the possibility of getting stuck during modularization or module operation.

In order to solve the above problems, the present invention has the following configuration. That is, the present invention provides a composite inorganic membrane in which a part of the surface of a hollow fiber-like inorganic membrane is coated with a fibrous resin composition, and the resin composition has the same composition as the resin composition measured in accordance with JIS L 1095 (2010). It is a composite inorganic film having a coefficient of static friction between objects of 0.01 or more and 0.60 or less.

Since the composite inorganic membrane of the present invention is less likely to get caught in module manufacturing equipment or module members, it is possible to suppress the occurrence of rupture or damage to the inorganic membrane during modularization or module operation.

FIG. 1 is a schematic diagram showing one embodiment of a composite inorganic membrane of the present invention. FIG. 3 is a schematic diagram showing another embodiment of the composite inorganic membrane of the present invention. FIG. 1 is a schematic diagram showing a cross section of one embodiment of a fluid separation membrane module having an inlet and an outlet of the present invention.

The composite inorganic membrane of the present invention is a composite inorganic membrane in which a part of the surface of a hollow fiber-like inorganic membrane is coated with a fibrous resin composition, and the resin composition is measured according to JIS L 1095 (2010). It is characterized in that the coefficient of static friction between the resin compositions is 0.01 or more and 0.60 or less.
As mentioned above, in the conventional technology, inorganic membranes have the problem of breaking or being damaged due to catching on module manufacturing equipment or module components (adjacent inorganic membranes, casings, etc.) during modularization or module operation. Ta. The surface of the composite inorganic membrane of the present invention is partially coated with a resin composition having a small coefficient of static friction, so that the slipperiness of the surface of the composite inorganic membrane is improved. The membrane is less likely to get caught in the module manufacturing equipment or module members (adjacent inorganic membrane, casing, etc.), and rupture or damage of the inorganic membrane can be suppressed.

The resin composition of the present invention is characterized in that the coefficient of static friction between the resin compositions (hereinafter also simply referred to as "coefficient of static friction") measured in accordance with JIS L 1095 (2010) is 0.01 or more and 0.60 or less. shall be. When the static friction coefficient of the resin composition is 0.60 or less, the slipperiness of the surface of the composite inorganic film can be improved. The static friction coefficient of the resin composition is more preferably 0.50 or less, and even more preferably 0.40 or less. On the other hand, the lower limit of the static friction coefficient of the resin composition is not particularly limited, but is preferably 0.01 or more.

The present invention will be described below by way of example with reference to the drawings. However, the present invention is not to be construed as limited to the examples.

The composite inorganic membrane of the present invention is an inorganic membrane whose surface is partially coated with a fibrous resin composition. Here, the aspect in which a part of the surface is "covered" refers to an aspect in which a part of the outer surface of the inorganic film is visually blocked by the resin composition and cannot be seen. Examples of such embodiments include, for example, an embodiment in which a fibrous resin composition is spirally wound around a hollow fiber-shaped inorganic membrane, and an embodiment in which a fibrous resin composition and a hollow fiber-shaped inorganic membrane are aligned. This has the effect of improving the slipperiness of the inorganic membrane surface without impairing fluid permeability.

Regarding the aspect of "coating", if a coating layer or a resin composition different from the resin composition of the present invention (hereinafter sometimes referred to as "another resin composition") is present on the surface of the inorganic film. It's okay. In such an embodiment, the resin composition of the present invention is preferably placed in the outermost layer of the composite inorganic membrane, thereby improving the handling properties of the composite inorganic membrane while also preventing the resin composition from forming a coating layer or another resin. It becomes possible to improve the functionality of a composite inorganic membrane using the composition.

FIG. 1 shows a schematic diagram of one embodiment of the present invention. FIG. 1 is a schematic diagram showing a composite inorganic membrane in which a fibrous resin composition 2 is spirally wound around an inorganic membrane 1 with a pitch of 3. In FIG. 1, a part of the outer surface of the inorganic film 1 is blocked by the resin composition 2 and cannot be seen.

The composite inorganic membrane of the present invention is preferably an inorganic membrane in which a fibrous resin composition (hereinafter sometimes referred to as "covering thread") is wound helically. By doing so, the covering thread is loosely wound around the inorganic membrane, improving resistance to external forces and vibrations during modularization and module operation. In addition, by controlling the covering pitch, the slipperiness of the composite inorganic film can be uniformly improved.

It is preferable that the pitch of the covering yarn satisfies the following formula 1.

r<L<2(2Rr+ ^r2 ) ^0.5 ...Formula 1
[In the formula, L represents the pitch of the resin composition, r represents the outer diameter of the resin composition, and R represents the bending radius of the inorganic film. ]
When L is 2 (2Rr+r ² ) ^0.5 or less, even when the inorganic film is bent to the bending radius, the surface of the inorganic film is not exposed to the external plane, and the surface of the inorganic film and the module are It is possible to reduce the possibility of getting caught in manufacturing equipment or module members. More preferably, L is less than 1.6(2Rr+r ² ) ^0.5 . On the other hand, when L exceeds r, overlapping of the covering yarns is suppressed, so that handling as a composite inorganic membrane can be improved without impairing the filling rate during modularization. L is preferably 2r or more, and even more preferably 5r or more.

Examples of the embodiment in which the covering thread is wound spirally include the embodiment in which one or more covering threads are wound around one inorganic membrane, and the embodiment in which one or more covering threads are wound around two or more inorganic films. An example is a spirally wound form. From the viewpoint of further reducing catching between inorganic membranes, a preferred embodiment is one in which one or more covering threads are wound helically around one inorganic membrane. On the other hand, from the viewpoint of reinforcing the inorganic membrane, it is preferable that one or more covering threads are spirally wound around two or more inorganic membranes, and a part of the surface is covered with the resin composition in the form of particles. An embodiment in which one or more covering threads are wound spirally around a plurality of coated inorganic membranes, or an embodiment in which covering threads are wound in multiple stages (hereinafter referred to as "multi-stage covering"). is more preferable.

Multi-stage covering refers to a mode in which one or more covering threads are further spirally wound around a plurality of inorganic membranes around which covering threads are spirally wound. FIG. 2 shows a schematic diagram of two-stage covering as one embodiment of multi-stage covering. In FIG. 2, the resin composition 11 in the first stage, which is a fiber, is further arranged in a core thread in which five inorganic films 1 are wound spirally at intervals of pitch 13, and the resin composition 11 in the second stage, which is fibers, is further arranged. FIG. 2 is a schematic diagram of a multi-stage covering composite inorganic film 10 in which a composition 12 is spirally wound with a pitch 14. FIG. By adopting a multi-stage covering mode, it is possible to improve the strength of the inorganic film bundle while reducing the chance of the inorganic films getting caught with each other. Note that the multistage covering may be three or more stages, and the lower stage may include an uncovered inorganic film.

In addition, in an embodiment in which two or more types of covering threads are wound around one or more inorganic membranes, it is preferable to arrange the covering thread, which is the resin composition of the present invention, in the outermost layer. By doing so, it is possible to improve the ease of handling as a composite inorganic membrane while ensuring bulkiness etc. with the covering yarn of the inner layer made of another resin composition.

Examples of methods for reducing the coefficient of static friction between resin compositions include a method of using a resin composition having a low-friction resin on at least a portion of the surface, and a method of treating the covering yarn with an oil agent or the like. It is preferable to use a resin composition containing a fluororesin that is chemically stable and has a small coefficient of friction on at least part of the surface because it can enlarge the process window of the modularization process and module operation, and the fluororesin described below is preferably used. It is more preferable.

The resin composition of the present invention comprises at least one member selected from the group consisting of polytetrafluoroethylene (hereinafter referred to as PTFE), perfluoroethylene propene copolymer (hereinafter referred to as FEP), and perfluoroalkoxyalkane (hereinafter referred to as PFA). It is preferable that the resin composition contains the following fluororesin. PFA represents a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether. Examples of perfluoroalkyl vinyl ether include perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, and the like.

The resin composition of the present invention may contain a resin other than a fluororesin (hereinafter referred to as a "non-fluororesin") or a composition other than a resin (hereinafter referred to as a "non-resin"). The non-fluororesin or non-resin is preferably coated with the above-mentioned fluororesin, and by doing so, it is possible to impart slipperiness to the surface of the resin composition while taking advantage of the characteristics of the non-fluororesin or non-resin. Can be done. Examples of the above-mentioned non-fluororesin include polyester, nylon, polyolefin, polyacetal, thermoplastic elastomer, and the like. When the resin composition is a fiber, from the viewpoint of easy control of properties, polyester is preferable, and polyethylene terephthalate is more preferable. On the other hand, examples of the non-resin include metals and metal oxides, which have the effect of improving the strength of the resin composition.

In one embodiment of the present invention, the composite inorganic membrane preferably has a coating layer on at least a portion of the surface of the inorganic membrane. That is, it is preferable that a part of the outer surface of the inorganic film having a coating layer on at least a part of the surface is blocked by the resin composition and cannot be seen. By doing this, the fluid permeation performance of the inorganic membrane can be controlled by the coating layer, while reducing the chance of the inorganic membrane getting caught between the module components (adjacent inorganic membranes, casing, etc.) during module production, thereby reducing the amount of waste generated during module production. This makes it possible to achieve both high efficiency and module separation performance. Furthermore, in this embodiment, the resin composition of the present invention is preferably placed in the outermost layer of the composite inorganic membrane. That is, it is preferable that the resin composition of the present invention does not have a coating layer.

Examples of the coating layer include a layer containing a silicone resin or a microporous polymer (hereinafter referred to as PIM). It is more preferable that the coating layer contains a silicone resin since micro defects on the surface of the inorganic film can be repaired and coating is easy. Since the composite inorganic film of the present invention has improved slipperiness due to the resin composition, it can be suitably used even as a coating layer with high friction.

A module having a coating layer on a part of the surface of an inorganic membrane can be produced by, for example, forming a coating layer on the surface of the inorganic membrane after modularizing the inorganic membrane, or by modularizing an inorganic membrane having a coating layer on a part of the surface. It can be manufactured by the following method.

An inorganic membrane is a membrane in which the permeability of a specific component (permeable component) contained in a fluid to be separated is higher than that of other components (non-permeable component).

As for the shape of the inorganic membrane, a hollow fiber membrane is used because it facilitates increasing the membrane area per unit volume of the module and improves fluid permeability when used as a fluid separation membrane module. The outer diameter of the hollow fiber inorganic membrane is preferably 50 μm or more and 2,000 μm or less. By setting the outer diameter of the inorganic membrane to 50 μm or more, fluid permeability can be improved. The outer diameter of the inorganic membrane is more preferably 100 μm or more, and even more preferably 200 μm or more. On the other hand, by setting the outer diameter of the inorganic membrane to 2,000 μm or less, it is possible to increase the membrane area of the inorganic membrane per unit volume when used as a fluid separation membrane module. The outer diameter of the inorganic membrane is more preferably 1,000 μm or less, and even more preferably 500 μm or less. Note that as the outer diameter of the inorganic membrane becomes smaller, the frequency of contact between the surface of the inorganic membrane and its surroundings increases, increasing the risk of breakage or damage, but the composite inorganic membrane of the present invention can reduce snagging, so it is suitable Can be used.

Examples of the material of the inorganic membrane include a zeolite membrane, a silica membrane, a metal-organic framework (MOF) membrane, and a carbon membrane. It is preferable to use a carbon film as the inorganic film since it has both heat resistance and chemical resistance.

Examples of carbon membranes include polyphenylene oxide, polyvinyl alcohol, polyacrylonitrile, phenol resin, fully aromatic polyester, unsaturated polyester resin, alkyd resin, melamine resin, urea resin, polyimide resin, diallyl phthalate resin, lignin resin, and urethane resin. Examples include carbonized films. Two or more types of these may be used.

In one embodiment of the present invention, the inorganic membrane may include a support. When the inorganic membrane of the present invention includes a support, it is more preferable that the support is disposed only on one surface of the inorganic membrane.

Examples of the support include porous inorganic materials such as alumina, silica, cordierite, zirconia, titania, Vycor glass, zeolite, magnesia, and sintered metal, polysulfone, polyethersulfone, polyamide, polyester, cellulose polymer, A porous organic material containing at least one polymer selected from the group consisting of homopolymers and copolymers such as vinyl polymers, polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfone, and polyphenylene oxide; a porous organic material comprising a carbonizable resin; Examples include porous carbon materials obtained by carbonizing materials. Examples of carbonizable resins include polyphenylene oxide, polyvinyl alcohol, polyacrylonitrile, phenol resin, fully aromatic polyester, unsaturated polyester resin, alkyd resin, melamine resin, urea resin, polyimide resin, diallyl phthalate resin, lignin resin, and urethane. Examples include resin. Two or more types of these may be used.

The inorganic film of the present invention preferably has a bending radius of 0.1 cm or more and 100 cm or less. When the bending radius of the inorganic film is 100 cm or less, the inorganic film can be curved, so external stress can be relaxed and breakage and damage can be suppressed. Furthermore, since the composite inorganic membrane of the present invention can suppress catching, it can prevent catching when curved. The bending radius of the inorganic film is more preferably 10 cm or less, and even more preferably 1 cm or less. Although the lower limit of the bending radius of the inorganic film is not particularly limited, it is preferably 0.1 cm or more, since self-supporting properties can be imparted to the inorganic film if the bending radius is 0.1 cm or more.

The bending radius of the inorganic film can be determined from the radius of the cylinder at which the inorganic film does not break when the inorganic film of 10 cm or more is wrapped at 360° or more along the normal direction of the cylinder. If the bending radius of the inorganic film is 1.5 cm or more, evaluate by appropriately reducing the angle at which the inorganic film is wrapped along the normal direction of the cylinder, and determine the radius of the cylinder at which the inorganic film does not break. It can be considered as a radius.

The fluid separation membrane module of the present invention (hereinafter sometimes simply referred to as a "module") is a module in which a plurality of composite inorganic membranes of the present invention are housed. The number of composite inorganic membranes housed in the module is preferably 100 or more and 1,000,000 or less. When the number of composite inorganic membranes housed in the module is 100 or more, the membrane area per unit volume can be increased, and a certain amount of the fluid to be separated can be processed. The number of composite inorganic membranes housed in a module is more preferably 1,000 or more, and even more preferably 10,000 or more. The number of composite inorganic membranes housed in the module is not particularly limited, but if it is 1,000,000 or less, the module can be easily transported.

In the module of the present invention, the filling rate of the inorganic membrane is preferably 30% or more and 70% or less. Here, the filling rate of the inorganic membrane represents the ratio of the cross-sectional area of the inorganic membrane to the internal cross-sectional area of the module. The internal cross-sectional area of the module represents the internal cross-sectional area excluding the wall surfaces of the vessel and element housing in the cross section of the module perpendicular to the longitudinal direction of the inorganic membrane. The cross-sectional area of an inorganic membrane refers to the cross-sectional area of all the inorganic membranes housed in the module in the cross section of the module (the area surrounded by the outer surface including the hollow part, including the support if it has a support). area), and does not include the area of the resin composition. When the filling rate of the inorganic membrane is 30% or more, the membrane area per unit volume of the module can be secured. More preferably, the filling rate of the inorganic membrane is 40% or more. On the other hand, by setting the filling rate of the inorganic membrane to 70% or less, it is possible to suppress breakage and damage to the inorganic membrane due to overfilling. More preferably, the filling rate of the inorganic membrane is 60% or less. Since the composite inorganic membrane of the present invention has improved surface slipperiness due to the resin composition, the filling rate can be improved even if the inorganic membrane is easily damaged.

FIG. 3 shows a schematic cross-sectional view of one embodiment of the module of the present invention. Figure 3 shows a cross section of a module containing a plurality of composite inorganic membranes in which a resin composition is spirally wound around an inorganic membrane that is a hollow fiber membrane and has a coating layer on its surface, including an inlet and an inlet for a fluid to be separated. FIG.

In the module of the present invention, it is preferable that a portion of the surface of the inorganic membrane is coated with a resin composition, and that at least a portion of the surface of the inorganic membrane has a coating layer. In other words, the inorganic membrane 1 having the hollow part 21 in FIG. 3 has the resin composition 2 spirally wound around it and at the same time has the coating layer 22 on the surface. Both ends of the inorganic membranes 1 bundled in parallel are fixed (potted) to each other at a potting site 23 and also fixed to a vessel 24 . The vessel 24 has an inlet/outlet 25 for the fluid to be separated and a recovery port 26 for the permeated fluid, and is connected to an external channel (not shown) (a supply channel for the fluid to be separated, a channel for recovering non-permeated fluid and permeated fluid, etc.). Connected.

Although the mixed gas and mixed liquid to be separated by the module of the present invention are not particularly limited, they are preferably used in applications that require heat resistance and chemical resistance by taking advantage of the heat resistance and chemical resistance of the inorganic membrane. be able to. Applications that require heat resistance and chemical resistance include, for example, carbon dioxide separation and storage systems from exhaust gas from power plants and blast furnaces, removal of sulfur components from gasified fuel gas in coal gasification combined cycle power generation, Examples include the purification of biogas and natural gas, and the purification of hydrogen from organic hydrides. In the module of the present invention, since the inorganic membrane is coated with a highly slippery resin composition, during module operation, the inorganic membrane and module members (adjacent inorganic membrane, casing, etc.) are less likely to get caught, and complicated It can be suitably used for fluid separation on the ocean, which requires operation under severe oscillations.

In the module of the present invention, the cross-sectional shape of the vessel is preferably elliptical or circular, and more preferably circular, from the viewpoint of improving the pressure resistance of the vessel. Here, the cross section of the vessel refers to a cross section of the vessel perpendicular to the length direction of the inorganic film. Examples of the material of the vessel include metal, resin, fiber-reinforced plastic (hereinafter referred to as FRP), and can be appropriately selected depending on the environment of the installation site and the usage situation. In applications requiring pressure resistance and heat resistance, metals that have both strength and moldability are preferred, and stainless steel and the like are more preferred.

The inlet and outlet located in the vessel have the function of guiding fluid to the inorganic membrane. When an inorganic membrane is used in a total volume filtration system, it is sufficient to have one inlet and outlet, and when it is used in a cross-flow filtration system, it may have two or more inflow and outflow ports in total. preferable. A plurality of inlets and outlets may be provided as long as the mechanical strength of the vessel is maintained. In this case, it is preferable to place a mesh, felt, or other fabric between the inlet and/or outlet and the inorganic membrane to the extent that it does not impede the passage of the fluid. play.

In the module of the present invention, the number of membrane elements housed in one vessel may be one or more, but in the case of applications requiring a large membrane area, multiple membrane elements may be housed in one vessel. It is preferable to store it inside. A plurality of membrane elements may be connected in series or in parallel.

The membrane element constituting the module of the present invention is an inorganic membrane fixed with a potting material, and is preferably fixed to the inner surface of a vessel. Methods for fixing the membrane element to the inner surface of the vessel include, for example, directly fixing it to the inner surface of the vessel using the potting material itself, or using an adapter that can ensure liquid-tightness or air-tightness (for example, an O-ring, etc.). Examples include a method of fixing it inside the vessel through a holder. Since only the membrane element can be replaced when the performance of the membrane element deteriorates over time, it is preferable to fix it in the vessel via an adapter or the like.

The potting part of the membrane element may be placed in one place or in multiple places, but from the viewpoint of sufficiently fixing the position of the inorganic membrane and maintaining the effective surface area of the inorganic membrane, it is preferable to bundle it in a substantially straight line. It is preferable to fix two ends of the plurality of inorganic membranes with a potting material. Alternatively, a plurality of bundled inorganic membranes may be bent into a U-shape and fixed at both ends with potting material, or only one end of the inorganic membrane may be fixed with potting material and the other end may be fixed with potting material. It may be sealed by other means.

Examples of the potting material include thermoplastic resins and thermosetting resins. Furthermore, other additives may be contained.

Examples of the thermoplastic resin include polyethylene, polyether sulfone, polystyrene, polyphenylene sulfide, polyarylate, polyester, liquid crystal polyester, polyamide, and polymethyl methacrylate. Examples of the thermosetting resin include epoxy resin, unsaturated polyester resin, urethane resin, urea resin, phenol resin, melamine resin, and silicone resin. Two or more types of these may be used. Among these, epoxy resins and urethane resins are preferred from the viewpoint of balance of moldability, curing time, adhesiveness, hardness, and the like.

Examples of additives include fillers, surfactants, silane coupling agents, rubber components, and the like. Examples of the filler include silica, talc, zeolite, calcium hydroxide, and calcium carbonate, which have effects such as suppressing curing heat generation, improving strength, and increasing viscosity. In addition, the surfactant and silane coupling agent have effects such as improved handling when mixing the potting material and improved infiltration between inorganic films when the potting material is injected. Furthermore, the rubber component has effects such as improving the toughness of the hardened and molded potting material. The rubber component may be contained in the form of rubber particles.

Moreover, as one aspect of the present invention, the membrane element may have a casing (hereinafter referred to as "element casing") separate from the vessel. By having the element casing, the inorganic membrane is protected even during replacement or transportation when the membrane element is not housed in a vessel, and the handling of the membrane element is improved. The element casing has an opening for supplying the fluid to be separated to the inorganic membrane. The openings in the element casing are preferably located at positions corresponding to the inlet and outlet of the vessel, thereby allowing the supply of the fluid to be separated to the inorganic membrane and the collection of non-permeable components from inside the membrane element. becomes easier. The shape of the element casing is not particularly limited as long as it does not prevent storage into the vessel. Examples of the material for the element casing include metal, resin, FRP, etc., and can be appropriately selected depending on the usage situation. Resins are preferred because they have a high ability to follow curing shrinkage of potting materials, and polyphenylene sulfide, polytetrafluoroethylene, polyethylene, polypropylene, polyether ether ketone, polyphenylene ether, polyether are preferred because they have both moldability and chemical resistance. More preferred are imide, polyamideimide, and polysulfone.

The fluid separation membrane plant of the present invention (hereinafter sometimes simply referred to as "plant") is a plant that includes the fluid separation membrane module of the present invention. In addition to the modules, the plant preferably includes pretreatment equipment, purified fluid recovery equipment, byproduct fluid recovery equipment, and the like. The pretreatment equipment is equipment for removing impurities from the fluid to be separated before separation or adjusting the composition of the fluid to be separated before separation. The purified fluid recovery facility is a facility for recovering purified fluid from which unnecessary components have been removed from a fluid to be separated before separation, and further refining the fluid as necessary or supplying it to a pipeline or the like. The by-product fluid recovery equipment is equipment that collects the by-product fluid removed from the fluid to be separated before separation and, for example, discharges it after rendering it harmless. In the plant of the present invention, the module, the pretreatment equipment, the purified fluid recovery equipment, and the byproduct fluid recovery equipment are connected by piping, etc., and the fluid to be separated before separation is continuously separated into the purified fluid and the byproduct fluid. is preferred.

Preferably, the plant includes a plurality of modules depending on the throughput of the fluid to be separated. The plurality of modules may be connected in series or in parallel with respect to the fluid to be separated. From the viewpoint of module production efficiency, it is preferable that the modules be connected in series, and from the viewpoint of allowing partial replacement of modules, it is preferable that the modules be connected in parallel. A preferred embodiment of the plant of the present invention is one in which modules are connected in series, and the modules connected in series are further connected in parallel. By doing so, it is possible to achieve both the advantages of connecting modules in series and the advantages of connecting them in parallel.

The mixed gases and mixed liquids to be separated by the plant of the present invention are not particularly limited, but include, for example, carbon dioxide separation and storage systems from exhaust gas from power plants and blast furnaces, gas in coal gasification combined cycle power generation, etc. Examples include removing sulfur components from converted fuel gas, refining biogas and natural gas, and refining hydrogen from organic hydrides. In the plant of the present invention, since the inorganic membrane is coated with a highly slippery resin composition, during module operation, catching between the inorganic membrane and module members (adjacent inorganic membrane, casing, etc.) is reduced, resulting in complicated It can be suitably used for fluid separation on the ocean, which requires operation under severe oscillations. That is, the plant of the present invention is preferably installed offshore.

In an embodiment in which the resin composition has at least one fluororesin selected from the group consisting of polytetrafluoroethylene, perfluoroethylene propene copolymer, and perfluoroalkoxyalkane on at least a portion of the surface, the resin composition is supplied to the composite inorganic membrane. The gas to be separated preferably contains a liquid component. Examples of liquid components include water, benzene, toluene, hexane, etc., and also include cases where components supplied in the form of gas condense and liquefy within the module. In the above embodiment, since the water- and oil-repellent resin composition can suppress the retention of the liquid component between the inorganic membranes, separation performance can be maintained even when the gas to be separated contains a liquid component. It is possible. Therefore, it is possible to reduce the pretreatment load for removing liquid components.

The purified fluid of the present invention is a fluid purified by the fluid separation membrane module of the present invention. The purified fluid may be purified by including another purification process or an additional process before or after the purification process in the module of the present invention, or may be used in combination with a purified fluid purified in a different purification process. Examples of other or different purification steps include distillation, adsorption, absorption, and the like. Additionally, examples of additional steps include component adjustment for mixing with another fluid.

Since the purified fluid of the present invention is purified using the module of the present invention that has both durability and separation performance, energy consumption in module production and the above-mentioned additional steps is suppressed, and it can be used in various industries as a purified fluid with a low environmental impact. It can be suitably used in various applications.

Next, regarding the method for manufacturing the module of the present invention, an example will be described in which a carbon membrane is first manufactured, a fiber resin composition is wound spirally, and then the carbon membrane is inserted into an element casing or a vessel and fixed with a potting material. Explain.

Examples of methods for producing a carbon membrane include methods such as first forming a polymer membrane using a carbonizable resin, drying it, performing an infusible treatment such as oxidation treatment as necessary, and then carbonizing it in an inert atmosphere. It will be done.

Examples of the method for forming the polymer membrane include melt spinning, dry spinning, dry-wet spinning, and wet spinning, which can be appropriately selected depending on the type of carbonizable resin. Furthermore, an appropriate solvent can be used during film formation.

As a method for forming a carbon membrane in the form of a hollow fiber membrane, for example, a solution containing a carbonizable resin is extruded from the outer tube of a hollow fiber membrane spinning nozzle with a double tube structure, and air, nitrogen, etc. are extruded from the inner tube of the spinning nozzle. Examples include a method of extruding a gas, the same solvent as the spinning dope, a solution in which the disappearing resin is dissolved, a nonsolvent, or a mixture thereof, passing it through a coagulation bath, and then removing the solvent by drying, etc. . Examples of the coagulating liquid include water, alcohol, saturated saline, and a mixed solvent of these and an organic solvent.

The preferred method for carbonizing a polymer film is to heat it in an inert gas atmosphere.The polymer film is continuously fed into a heating device kept at a constant temperature using a roller, conveyor, etc. and heated. It is more preferable to do so. Here, the inert gas refers to a gas that is chemically inert during heating, and includes, for example, helium, neon, nitrogen, argon, krypton, xenon, carbon dioxide, and the like. Among these, nitrogen and argon are preferred. The heating temperature is preferably 500°C or more and 1,000°C or less.

Subsequently, a resin composition in the form of fibers is spirally wound around the obtained carbon film using a covering device. Examples of the covering device include a covering twisting machine, a double covering twisting machine, and the like.

Subsequently, a plurality of carbon membranes are bundled and inserted into an element casing or a vessel, and one or both ends of the carbon membranes are potted with a potting material. Potting methods include, for example, centrifugal potting, which uses centrifugal force to infiltrate the potting material between the carbon membranes, and stationary potting, which uses a metering pump or head to feed the potting material in a fluidized state to infiltrate between the carbon membranes. Laws etc.

It is preferable to cut the potted carbon film at the potting site to open the carbon film. It is preferable to attach a cap as a pipe joint member to the cut surface of the carbon membrane module so that it can be connected to an external channel (such as a channel for recovering fluid that has passed through the carbon membrane).

The present invention will be described in detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Evaluations in each Example and Comparative Example were performed by the following method.

(Durability of composite inorganic membrane)
Approximately 10 cm of the inorganic membranes of Examples and Comparative Examples were placed on a smooth stainless steel plate, and with the inorganic membrane pressed down with a melamine sponge from above, the melamine sponge was moved back and forth 10 times in a direction parallel to the fiber axis of the inorganic membrane. , the inorganic film was rubbed on a stainless steel plate. Subsequently, one end of the inorganic membrane was sealed with an epoxy resin, and the other end was fixed to a tube so that the inorganic membrane was not sealed, thereby producing an evaluation sample.

Pressurized air at a pressure of 0.2 MPaG was supplied from the tube side of the evaluation sample, and the entire inorganic membrane was immersed in water while the hollow part of the inorganic membrane was pressurized. After immersion for 1 minute, the number of bubbles attached to the surface of the inorganic film in water was counted visually, and the number of defects per unit length was calculated by dividing by the length of the inorganic film in water. The measurement was performed five times, and the average of the five measurements was taken as the number of defects in the inorganic film. The durability of the inorganic membrane is judged as "unsatisfactory" if the inorganic membrane breaks or severe bubbles occur continuously in one of the five evaluations, and if the inorganic membrane breaks or continues to generate severe bubbles in all five evaluations. If no defects occur, it is "fair" if the number of defects is more than 10/cm, "good" if the number of defects is more than 3/cm and less than or equal to 10, and "good" if the number of defects is more than 0/cm and less than or equal to 3/cm. It was rated as "excellent" if there was one, and rated as "excellent" if no defects were found in all five evaluations.

(bending radius of inorganic membrane)
The radius of the cylinder at which the inorganic film would not break when approximately 30 cm of the inorganic film of the production example was wound over 360 degrees along the normal direction of the cylinder was determined.

(Static friction coefficient between resin compositions)
The static friction coefficient between the resin compositions was measured in accordance with the method described in JIS L 1095 (2010) General Spun Yarn Test Method, and the average value of the results of N=30 was used in each case. The specific measurement method is shown below. First, resin compositions were sampled from the modules of Examples and Comparative Examples and measured using a YR-1 radar method friction coefficient measuring device (manufactured by Intec Corporation) at an initial load of 5 cN.

(Module durability)
The modules of Examples and Comparative Examples were fixed to a micromixer E-36 (manufactured by TAITEC) and shaken at 2,5000 rpm for one day.

A pressure gauge and a vacuum pump were connected to the permeate fluid collection port of the module via an adapter. Next, operate the vacuum pump to reduce the pressure on the permeate side of the membrane module, and stop the vacuum pump when the pressure on the permeate side of the module becomes 100 Pa or less, and after the vacuum pump stops, the pressure on the permeate side of the module increases to 10,000 Pa or more. The pressure rise time was measured. The pressure rise time was measured in the same manner for the module before shaking.

The durability of the module is judged as "poor" if the pressure rise time before shaking is less than 10 seconds, and if the pressure rise time before shaking is more than 10 seconds, the durability of the module is determined by the ratio of the pressure rise time before and after shaking (" "Pressure rise time after shaking"/"Pressure rise time before shaking") is 0.02 or less as "fair", more than 0.02 and less than 0.1 as "good", more than 0.1 and less than 0.9 The score was rated "Excellent" and the score above 0.9 was rated "Excellent."

(Module performance when supplying gas to be separated including liquid components)
A mixed gas of CO ₂ =50 vol% and CH ₄ =50 vol% was supplied to the modules of Examples and Comparative Examples, and the CH ₄ concentration in the purified gas was evaluated. A gas separation evaluation was conducted using a supply gas containing water vapor of 95RH% under operating conditions that allowed the _CH4 concentration in the purified gas to be concentrated to 90vol% when the humidity of the supplied gas was 0%. _4. The case where the concentration was 85% or more was judged as "pass", and the case where it was below 85% was judged as "fail".

(Production example 1: Preparation of carbon film with outer diameter of 300 μm)
10 parts by weight of polyacrylonitrile (weight average molecular weight: 150,000) manufactured by Polyscience, 10 parts by weight of polyvinylpyrrolidone (weight average molecular weight: 40,000) manufactured by Sigma-Aldrich, and 80 parts by weight of dimethyl sulfoxide (hereinafter referred to as DMSO) manufactured by Fujifilm Wako Pure Chemical Industries. The components were mixed and stirred at 100°C to prepare a spinning dope.

After cooling the obtained spinning stock solution to 25°C, using a concentric triple cap, a 80% by weight DMSO aqueous solution was poured into the inner tube, the above spinning stock solution was poured into the middle tube, and a 90% by weight DMSO solution was poured into the outer tube. After being simultaneously discharged, the mixture was introduced into a coagulation bath made of pure water at 25° C. and wound around a roller to obtain a raw yarn. After washing the obtained yarn with water, it was dried at 25° C. for 24 hours using a circulating dryer to produce a precursor of a porous carbon membrane in the form of a hollow fiber membrane.

The obtained porous carbon membrane precursor was passed through an electric furnace at 250° C. and heated in an air atmosphere for 1 hour to perform an infusible treatment to obtain an infusible thread. Subsequently, the infusible yarn was carbonized at a carbonization temperature of 650° C. to obtain the inorganic membrane of Production Example 1, which was a carbon membrane with an outer diameter of 300 μm and an inner diameter of 100 μm. As a result of evaluation by the method described above, the bending radius of the inorganic film of Production Example 1 was 10 cm.

(Production Example 2: Preparation of carbon membrane with silicone resin layer on the surface)
The inorganic membrane of Production Example 1 was immersed in a 10 wt% hexane solution (hereinafter referred to as PDMS solution) of Silgard (manufactured by DuPont-Toray), and after the outer surface of the inorganic membrane was sufficiently immersed in the PDMS solution, the PDMS solution was removed. After drying, the film was heated in an oven at 70° C. for 30 minutes to produce an inorganic film of Production Example 2 having a coating layer made of silicone resin on at least a portion of the surface. As a result of evaluation using the method described above, the bending radius of the inorganic film of Production Example 2 was 15 cm.

(Manufacturing example 3: Preparation of carbon film with outer diameter of 1 cm)
The spinning stock solution of Production Example 1 was dip-coated onto an alumina porous tube having an average pore diameter of 100 nm to 250 nm, an outer diameter of 1 cm, and a length of 10 cm as a support. After coating, it was washed with a coagulation bath consisting of pure water at 25° C., and dried at 25° C. for 24 hours using a circulating dryer to produce a precursor of a porous carbon membrane in the form of a hollow fiber membrane.

The obtained porous carbon membrane precursor was passed through an electric furnace at 250° C. and heated in an air atmosphere for 1 hour to perform an infusible treatment to obtain an infusible thread. Subsequently, the infusible yarn was carbonized at a carbonization temperature of 650° C. to obtain an inorganic membrane of Production Example 3, which was a carbon membrane with an outer diameter of 1 cm. As a result of evaluation using the method described above, the bending radius of the inorganic film of Production Example 3 was 200 cm or more.

(Production example 4: Preparation of carbon film with outer diameter of 3 cm)
Manufacturing except that an alumina porous tube with an average pore diameter of 100 nm to 250 nm, an outer diameter of 3 cm, and a length of 10 cm was used instead of an alumina porous tube with an average pore diameter of 100 nm to 250 nm, an outer diameter of 1 cm, and a length of 10 cm. In the same manner as in Example 3, an inorganic membrane of Production Example 4 was obtained. As a result of evaluation by the method described above, the bending radius of the inorganic film of Production Example 4 was 200 cm or more.

(Example 1)
One inorganic membrane from Production Example 1 was used as a core thread, and PTFE fibers such as "Toyoflon" (manufactured by Toray Industries, Inc.) with a total fineness of 220 dtex were wound in the Z direction at a pitch of 1 cm, so that the PTFE fibers were wound in a spiral shape. The composite inorganic membrane of Example 1 was manufactured. As a result of evaluation by the above-mentioned method, the coefficient of static friction between TOYOFLON was 0.39, the pitch was within the range of formula 1, and the durability of the composite inorganic film of Example 1 was "excellent".

(Example 2)
A composite inorganic membrane of Example 2 was produced in the same manner as Example 1 except that the pitch was changed from 1 cm to 5 cm. As a result of evaluation by the above-mentioned method, the coefficient of static friction between TOYOFLON was 0.39, the pitch was within the range of formula 1, and the durability of the composite inorganic film of Example 2 was "good".

(Example 3)
A composite inorganic membrane of Example 3 was produced in the same manner as Example 1 except that the pitch was changed from 1 cm to 10 cm. As a result of evaluation by the above-mentioned method, the coefficient of static friction between TOYOFLON was 0.39, the pitch was outside the range of formula 1, and the durability of the composite inorganic film of Example 3 was "fair".

(Example 4)
A composite inorganic membrane of Example 4 was produced in the same manner as Example 1 except that the inorganic membrane of Production Example 2 was used instead of the inorganic membrane of Production Example 1. As a result of evaluation by the above-mentioned method, the coefficient of static friction between TOYOFLON was 0.39, the pitch was within the range of formula 1, and the durability of the composite inorganic film of Example 4 was "good".

(Example 5)
A composite inorganic membrane of Example 5 was produced in the same manner as Example 1 except that the inorganic membrane of Production Example 3 was used instead of the inorganic membrane of Production Example 1. As a result of evaluation by the above-mentioned method, the coefficient of static friction between TOYOFLON was 0.39, the pitch was within the range of formula 1, and the durability of the composite inorganic film of Example 5 was "good".

(Example 6)
A composite inorganic membrane of Example 6 was produced in the same manner as in Example 1 except that the inorganic membrane of Production Example 4 was used instead of the inorganic membrane of Production Example 1. As a result of evaluation by the above-mentioned method, the coefficient of static friction between TOYOFLON was 0.39, the pitch was within the range of formula 1, and the durability of the composite inorganic film of Example 6 was "fair".

(Example 7)
A composite inorganic membrane of Example 7 was produced in the same manner as in Example 1, except that polyvinylidene fluoride fiber No. 4 "Seeger" (manufactured by Kureha Corporation) was used instead of Toyoflon. As a result of evaluation by the above-mentioned method, the coefficient of static friction between Seagers was 0.63, the pitch was within the range of formula 1, and the durability of the composite inorganic film of Example 7 was "fair".

(Example 8)
One hundred composite inorganic membranes of Example 1 were bundled and housed in an acrylic pipe (inner diameter 5 mm) having an inlet, and each end of the acrylic pipe was potted using epoxy resin. After the epoxy resin had hardened, the potting site at one end was cut with a rotary saw to open the inorganic membrane to obtain a module of Example 8. As a result of evaluation by the above-mentioned method, the durability of the module of Example 8 was "excellent", and the module performance when the gas to be separated containing a liquid component was supplied was "pass".

(Example 9)
A module was produced in the same manner as in Example 8. Subsequently, a 10 wt % hexane solution (hereinafter referred to as PDMS solution) of Silgard (manufactured by DuPont-Toray) was injected from the inlet of the module. After sufficiently immersing the outer surface of the inorganic membrane in the PDMS solution, the PDMS solution is discharged from the inlet of the module, and after drying, the solution is heated in an oven at 70°C for 30 minutes to completely immerse at least a portion of the surface of the inorganic membrane. A module of Example 9 was manufactured with a coating layer made of silicone resin. As a result of evaluation by the above-mentioned method, the durability of the module of Example 9 was "good", and the module performance when the gas to be separated containing a liquid component was supplied was "pass".

(Example 10)
A module of Example 10 was produced in the same manner as Example 8 except that the composite inorganic membrane of Example 2 was used instead of the composite inorganic membrane of Example 1. As a result of evaluation by the above-mentioned method, the durability of the module of Example 10 was "good", and the module performance when supplying a gas to be separated containing a liquid component was "pass".

(Example 11)
A module of Example 11 was produced in the same manner as Example 8, except that the composite inorganic membrane of Example 3 was used instead of the composite inorganic membrane of Example 1. As a result of evaluation by the above-mentioned method, the durability of the module of Example 11 was "good", and the module performance when supplying a gas to be separated containing a liquid component was "pass".

(Example 12)
A module of Example 12 was produced in the same manner as Example 8, except that the composite inorganic membrane of Example 4 was used instead of the composite inorganic membrane of Example 1. As a result of evaluation by the above-mentioned method, the durability of the module of Example 12 was "fair", and the module performance when the gas to be separated containing a liquid component was supplied was "fail".

(Example 13)
A module of Example 13 was produced in the same manner as Example 8 except that the composite inorganic membrane of Example 7 was used instead of the composite inorganic membrane of Example 1. As a result of evaluation by the above-mentioned method, the durability of the module of Example 13 was "fair", and the module performance when supplying a gas to be separated containing a liquid component was "pass".

(Comparative example 1)
An inorganic membrane of Comparative Example 1 was produced in the same manner as Production Example 1. As a result of evaluation by the above-mentioned method, the durability of the inorganic film of Comparative Example 1 was "poor".

(Comparative example 2)
An inorganic membrane of Comparative Example 2 was produced in the same manner as Production Example 2. As a result of evaluation by the method described above, the durability of the inorganic film of Comparative Example 2 was "poor".

(Comparative example 3)
An inorganic membrane of Comparative Example 3 was produced in the same manner as Production Example 3. As a result of evaluation by the above-mentioned method, the durability of the inorganic film of Comparative Example 3 was "poor".

(Comparative example 4)
An inorganic membrane of Comparative Example 4 was produced in the same manner as Production Example 4. As a result of evaluation by the method described above, the durability of the inorganic film of Comparative Example 4 was "poor".

(Comparative example 5)
A composite inorganic membrane of Comparative Example 5 was produced in the same manner as in Example 1, except that false-twisted PET fibers with a total fineness of 220 dtex were used instead of Toyoflon. As a result of evaluation by the above-mentioned method, the coefficient of static friction between the false-twisted PET fibers was 0.88, the pitch was within the range of formula 1, and the durability of the composite inorganic film of Comparative Example 5 was "poor".

(Comparative example 6)
A module of Comparative Example 6 was produced in the same manner as Example 8 except that the inorganic membrane of Comparative Example 1 was used instead of the inorganic membrane of Example 1. As a result of evaluation by the above-mentioned method, the durability of the module of Comparative Example 6 was "poor", and the module performance when the gas to be separated containing a liquid component was supplied was "fail".

(Comparative Example 7)
A module was produced in the same manner as Comparative Example 6. Subsequently, a PDMS solution was injected from the inlet of the module. After sufficiently immersing the outer surface of the inorganic membrane in the PDMS solution, the PDMS solution is discharged from the inlet of the module, and after drying, the solution is heated in an oven at 70°C for 30 minutes to completely immerse at least a portion of the surface of the inorganic membrane. A module of Comparative Example 7 was manufactured having a coating layer made of silicone resin. As a result of evaluation by the above-mentioned method, the durability of the module of Comparative Example 7 was "poor", and the module performance when the gas to be separated containing a liquid component was supplied was "fail".

(Comparative example 8)
A module of Comparative Example 8 was produced in the same manner as Example 8 except that the inorganic membrane of Comparative Example 2 was used instead of the inorganic membrane of Example 1. As a result of evaluation by the above-mentioned method, the durability of the module of Comparative Example 8 was "poor", and the module performance when the gas to be separated containing a liquid component was supplied was "fail".

(Comparative Example 9)
A module of Comparative Example 9 was produced in the same manner as Example 8 except that the inorganic membrane of Comparative Example 5 was used instead of the inorganic membrane of Example 1. As a result of evaluation by the above-mentioned method, the durability of the module of Comparative Example 8 was "poor", and the module performance when the gas to be separated containing a liquid component was supplied was "fail".

The carbon membrane module for fluid separation of the present invention is useful for carbon dioxide separation and storage systems from exhaust gas from power plants and blast furnaces, for removing sulfur components from gasified fuel gas in coal gasification combined cycle power generation, and for removing sulfur components from gasified fuel gas in biogas and natural gas. It can be suitably used for gas purification, hydrogen purification from organic hydride, etc.

1: Inorganic film 2: Resin composition 3: Pitch of resin composition 10: Multistage covering composite inorganic film 11: First stage resin composition 12: Second stage resin composition 13: Pitch of first stage resin composition 14: Pitch of second stage resin composition 21: Hollow part of inorganic membrane 22: Coating layer 23: Potting part 24: Vessel 25: Inlet/outlet for fluid to be separated 26: Recovery port for permeated fluid

Claims (14)

A composite inorganic membrane in which a part of the surface of a hollow fiber inorganic membrane is coated with a fibrous resin composition, and the resin composition has a coefficient of static friction between the resin compositions measured according to JIS L 1095 (2010). is 0.01 or more and 0.60 or less. The composite inorganic membrane according to claim 1, wherein the resin composition is spirally wound around the inorganic membrane. The composite inorganic membrane according to claim 2, wherein the pitch of the spirally wound resin composition satisfies the following formula 1.
r<L<2(2Rr+ ^r2 ) ^0.5 ...Formula 1
[In the formula, L represents the pitch of the resin composition, r represents the outer diameter of the resin composition, and R represents the bending radius of the inorganic film. ] The composite inorganic membrane according to claim 1, wherein the resin composition contains at least one fluororesin selected from the group consisting of polytetrafluoroethylene, perfluoroethylene propene copolymer, and perfluoroalkoxyalkane. The composite inorganic membrane according to claim 4, which has a coating layer on at least a part of the surface of the inorganic membrane. The composite inorganic membrane according to claim 5, wherein the coating layer contains a silicone resin. The composite inorganic membrane according to any one of claims 1 to 6, wherein the resin composition is disposed as the outermost layer of the composite inorganic membrane. The composite inorganic membrane according to any one of claims 1 to 6, wherein the inorganic membrane has an outer diameter of 50 μm or more and 2,000 μm or less. The composite inorganic membrane according to any one of claims 1 to 6, wherein the inorganic membrane has a bending radius of 0.1 cm or more and 100 cm or less. The composite inorganic membrane according to any one of claims 1 to 6, wherein the inorganic membrane is a carbon membrane. A fluid separation membrane module containing a plurality of composite inorganic membranes according to any one of claims 1 to 6,
A fluid separation membrane module, wherein a filling rate of the inorganic membrane with respect to an inner cross section of the fluid separation membrane module is 30% or more and 70% or less. An offshore fluid separation membrane plant comprising the fluid separation membrane module according to claim 11. A fluid separation membrane plant comprising a fluid separation membrane module housing a plurality of composite inorganic membranes according to any one of claims 4 to 6,
A fluid separation membrane plant, wherein the gas to be separated that is supplied to the composite inorganic membrane contains a liquid component. A purified fluid purified by the fluid separation membrane module according to claim 11.

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