WO2022209849A1

WO2022209849A1 - Membrane reactor, chemical plant, and method for manufacturing fluid

Info

Publication number: WO2022209849A1
Application number: PCT/JP2022/011582
Authority: WO
Inventors: 柿山創; 三原崇晃
Original assignee: 東レ株式会社
Priority date: 2021-03-30
Filing date: 2022-03-15
Publication date: 2022-10-06
Also published as: JPWO2022209849A1

Abstract

The present invention addresses the problem of providing a membrane reactor with which a processing amount and a processing speed are achieved simultaneously, the gist of the present invention lying in a membrane reactor including, in a vessel, fluid separating membranes, and a fibrous material present between the fluid separating membranes, wherein the fibrous material supports a catalyst.

Description

MEMBRANE REACTOR, CHEMICAL PLANT AND FLUID MANUFACTURING METHOD

The present invention relates to membrane reactors.

A chemical process generally consists of a reaction process and a purification process. A reaction process is a process of obtaining a product from a reactant, optionally using a catalyst. In order to increase the yield of the reaction process, it is necessary to improve the reaction rate, but the reaction rate has an upper limit governed by chemical equilibrium, and the reaction rate cannot be increased to suppress side reactions. In some cases. On the other hand, the purification process is a process of separating the product from unreacted substances and by-products after the reaction. Distillation, which is a typical refining process, requires temperature and pressure to fluctuate, resulting in a large energy loss.

Therefore, in a chemical process that can be purified by membrane separation, a membrane reactor that integrates the reaction process and the purification process has been proposed. In the membrane reactor, a catalyst is placed on the surface of the separation membrane and between the separation membranes, and the reaction process proceeds in the space where the separation membrane exists. In parallel, products or by-products generated in the reaction process are removed from the reaction system via the separation membrane, thereby shifting the equilibrium to the product side and improving the reaction rate. In addition, by using energy (pressure and heat) at the time of reaction, energy-saving refinement can be achieved. In a membrane reactor, as a method of efficiently supplying the removed components to the separation membrane, a method of arranging a spacer or a rectifying plate in the reaction chamber is known (see, for example, Patent Documents 1 and 2).

Japanese Patent Application Laid-Open No. 2004-34025 JP-A-2001-213611

WO 2005/010303 has at least at least one bundle of ceramic capillaries (9) and a housing surrounding the bundle, said capillaries being joined at their (both) ends by a perforated plate, and The housing has an inlet tube and/or an outlet tube connected to the interior of the capillaries for the first material stream and connected to the gap between the capillaries for the second material stream. A separation module is disclosed, having inlet and/or outlet tubes, characterized in that the distance between the capillaries is kept constant by spacers (6). However, in the method of Patent Document 1, when the number of ceramic capillaries housed in the housing is increased, the spacers for generating forced flow become dead spaces in the separation module and partially cover the surfaces of the ceramic capillaries. Also, there was a problem of filling the storage space for the catalyst. Due to the dead space, there is concern about a decrease in productivity and an increase in equipment size.

Patent Document 2 discloses a selectively permeable membrane reactor in which a raw material gas flowing from the inlet of the reactor reacts in a reaction chamber filled with a catalyst in the reactor, and the product gas produced is discharged into the reactor. In a selectively permeable membrane reactor in which the by-product gas is discharged from an outlet and is allowed to permeate the selectively permeable membrane and flow out of the reaction chamber, the reactor is provided with a porous tube having a selectively permeable membrane formed on its surface. a catalyst layer is provided in the gap between the inner wall of the reactor and the porous tube to form a reaction chamber; A selectively permeable membrane reactor is disclosed, which is characterized in that it is provided in a reaction chamber. However, in the method of Patent Document 2, when a plurality of porous tubes are housed in the reaction chamber, the distance between the porous tubes must be larger than the width of the rectifying plate, so the filling rate of the porous tubes is increased. Therefore, it was difficult to increase the surface area of the permselective membrane per unit volume of the reaction chamber. In addition, when the number of porous tubes increases, the arrangement of the rectifying plates becomes complicated, making manufacturing difficult.

In order to solve the above problems, the present invention has the following configuration. That is, the present invention is a membrane reactor comprising, in a vessel, fluid separation membranes for separating a fluid to be separated, and fibrous materials existing between the fluid separation membranes, wherein the fibrous materials contain a catalyst. It is a supported membrane reactor.

In the membrane reactor of the present invention, since the fibrous material supports at least part of the catalyst, it is possible to supply the removed components to the fluid separation membrane while minimizing the dead space, thereby improving the productivity of the target product. It is possible to

FIG. 2 is a schematic diagram showing a cross section including a fluid inlet and outlet of one embodiment of the membrane reactor of the present invention. Figure 2 is a schematic diagram showing two compartments of the membrane reactor of Figure 1; 1 is a schematic diagram showing one mode of arrangement of a fluid separation membrane and a fibrous material of the present invention. FIG. FIG. 4 is a schematic diagram showing another aspect of the arrangement of the fluid separation membrane and fibrous material of the present invention.

The membrane reactor of the present invention is a membrane reactor comprising, in a vessel, a fluid separation membrane for separating a fluid to be separated and a fibrous material existing between the fluid separation membranes, wherein the fibrous material is characterized by carrying a catalyst.

The present invention will be described below with reference to the drawings. However, the present invention should not be construed as being limited to the examples shown in the drawings.

FIG. 1 shows a schematic cross-sectional view of one embodiment of the membrane reactor of the present invention. FIG. 1 is a schematic cross-sectional view of a membrane reactor in which fluid separation membranes, which are hollow fiber membranes, are housed, including fluid inlets and outlets. The term "fluid" as used herein refers to a feed fluid, a fluid to be separated, a permeating fluid, or a non-permeating fluid. A feed fluid is a fluid containing a reactant. A fluid to be separated is a mixture of reactants, products, by-products, impurities, sweep gases, and the like. A permeate fluid is a fluid that has permeated a fluid separation membrane. Non-permeate fluid is fluid that exits the membrane reactor without permeating the fluid separation membrane.

The membrane reactor of FIG. has a compartment 2 which is the inner compartment of the . The two partitions will be explained using FIG. FIG. 2 is a schematic diagram of FIG. 1 with the fibrous material removed. The interior of the membrane reactor is divided into a compartment 1 (reference numeral 13) that is an outer compartment of the fluid separation membrane 1 and a compartment 2 (reference numeral 14) that is an inner compartment of the fluid separation membrane 1. FIG. Compartment 1 has an inlet 8 for the feed fluid and an outlet 9 for the non-permeate fluid, and compartment 2 has an outlet 10 for the permeate fluid that has permeated the fluid separation membrane 1 and an outlet 10 for the permeate fluid and a sweep gas for sweeping the permeate fluid. It has an inlet 11 . The non-permeating fluid outlet 9 and the permeating fluid outlet 10 are connected to an external channel (not shown), and the non-permeating fluid and the permeating fluid are recovered.

A fibrous material 3 exists between the fluid separation membranes 1 in the compartment 1, and the fibrous material 3 carries a catalyst 4 (not shown). The fibrous material 3 may be present in places other than between the fluid separation membranes 1 (for example, between the fluid separation membrane and the vessel), and the catalyst 4 may be present on the surfaces of the fluid separation membranes 1 and in the gaps 5 between the fluid separation membranes. may also exist. In the membrane reactor of FIG. 1, the fibrous material 3 spirally covers the periphery of one fluid separation membrane 1, and the fluid separation membranes 1 bundled in parallel have both ends at potting sites 7. Fixed (potted) to each other and fixed to the vessel 12 , the fluid separation membrane 1 passes through the potting site 7 .

Chemical processes to which the membrane reactor of the present invention can be applied are not particularly limited. Examples include hydrogen production by steam reforming of methane, hydrogen production from methylcyclohexane, methane synthesis from carbon dioxide and hydrogen, and methanol synthesis and the like.

In the membrane reactor of the present invention, the cross-sectional shape of the vessel is preferably oval or circular, more preferably circular, from the viewpoint of improving the pressure resistance of the vessel. Here, the cross section of the vessel refers to the cross section of the vessel perpendicular to the length direction of the fluid separation membrane. Materials for the vessel include, for example, metal, resin, fiber reinforced plastic (FRP), and the like, and can be appropriately selected according to the environment of the installation site and the usage situation. In applications where pressure resistance and heat resistance are required, metals having both strength and moldability are preferred, and stainless steel and the like are more preferred.

The supply fluid inlet of the vessel has the function of guiding the supply fluid into the membrane reactor. The reactants contained in the feed fluid chemically react in the membrane reactor to form products, and the feed fluid becomes the fluid to be separated. When the fluid separation membrane is used in a dead end filtration system, the compartment 1 may have an inlet for the feed fluid, and when used in a cross-flow filtration system, the compartment 1 serves as an inlet for the feed fluid. Preferably, each has an outlet for the non-permeating fluid. A plurality of inlets for the feed fluid and outlets for the non-permeating fluid (hereinafter referred to as "outflow inlets") may be provided within the range of maintaining the mechanical strength of the vessel. In this case, it is preferable to place a cloth such as a mesh or felt between the inlet and the fluid separation membrane within a range that does not hinder the passage of the fluid, which has the effect of diffusing the fluid and protecting the fluid separation membrane. On the other hand, the compartment 2 may have an outlet for the permeating fluid, but may also have an inlet for the sweep gas for actively entraining the permeating fluid.

In the membrane reactor of the present invention, the method of fixing the fluid separation membrane to the vessel includes a method of fixing the fluid separation membrane directly to the inner surface of the vessel with a potting material, and a separation membrane in which a plurality of fluid separation membranes are fixed with a potting material. A method of fixing the element in the vessel via an adapter or the like (for example, an O-ring or the like) capable of ensuring liquid tightness or airtightness can be used. Since only the separation membrane element can be replaced when the performance of the separation membrane element deteriorates over time, it is preferable to fix it in the vessel via an adapter or the like.

The potting portion of the membrane reactor or the separation membrane element may be at one or a plurality of locations, but from the viewpoint of sufficiently fixing the position of the fluid separation membrane and maintaining the effective surface area of the fluid separation membrane Preferably, two ends of a plurality of fluid separation membranes bundled in a substantially straight line are fixed with a potting material. Moreover, in a state in which a plurality of bundled fluid separation membranes are bent in a U shape, both ends of the fluid separation membranes may be fixed at one place with a potting material, or only one end of the fluid separation membranes may be fixed with a potting material, The other end may be sealed by means other than potting material.

Further, as one aspect of the present invention, the separation membrane element may have a casing (hereinafter referred to as "element casing") separate from the vessel. The element casing preferably has an inlet and outlet for fluid. The shape of the element casing is not particularly limited as long as it does not interfere with housing in the vessel. Materials for the element casing include, for example, metals, resins, fiber reinforced plastics (FRP), and the like, and can be appropriately selected according to the conditions of use. For applications requiring high temperature operation, metals are preferred due to their high heat resistance. Resin is preferable from the viewpoint of high followability to curing shrinkage of potting material, and since it has both moldability and chemical resistance, polyphenylene sulfide, polytetrafluoroethylene, polyethylene, polypropylene, polyether ether ketone, polyphenylene ether, polyether More preferred are imides, polyamideimides and polysulfones.

Potting materials include organic adhesives and inorganic adhesives. In applications requiring high-temperature operation, inorganic adhesives are preferred due to their high heat resistance.

Examples of organic adhesives include thermoplastic resins and thermosetting resins. Furthermore, the organic adhesive may contain other additives.

Thermoplastic resins suitable as organic adhesives include, for example, polyethylene, polyethersulfone, polystyrene, polyphenylene sulfide, polyarylate, polyester, liquid crystal polyester, polyamide, and polymethyl methacrylate. Examples of thermosetting resins include epoxy resins, unsaturated polyester resins, urethane resins, urea resins, phenol resins, melamine resins, and silicone resins. You may use 2 or more types of these. Among these resins, epoxy resins and urethane resins are preferable from the viewpoint of balance of moldability, curing time, adhesiveness, hardness, and the like.

Additives contained in organic adhesives include, for example, fillers, surfactants, silane coupling agents, and rubber components. Examples of fillers include silica, talc, zeolite, calcium hydroxide, calcium carbonate, and the like, and have effects such as suppression of curing heat generation, strength improvement, and thickening. Further, the surfactant and the silane coupling agent provide effects such as improvement of handleability when mixing the potting material and improvement of infiltration between the fluid separation carbon films when the potting material is injected. In addition, the rubber component has the effect of improving the toughness of the hardened and molded potting material. The rubber component may be contained in the form of rubber particles.

　Inorganic adhesives include, for example, ceramics and cement. You may use 2 or more types of these. Furthermore, other additives may be contained.

The membrane reactor of the present invention is characterized in that there are fibrous substances present between the fluid separation membranes, and the fibrous substances carry a catalyst. Here, "the state in which the fibrous material supports the catalyst" does not mean that the surface of the fibrous material and the catalyst particles, etc. are simply in contact with each other and can be easily removed with a brush or the like. represents the state in which the catalyst is chemically or physically fixed. As described above, in the conventional technology, the membrane reactor in which the spacer for efficiently supplying the fluid to be separated to the separation membrane is arranged inside the membrane reactor, the spacer itself becomes a dead space in the membrane reactor, and the fluid separation membrane There was a problem of partially covering the surface of the catalyst and filling the storage space of the catalyst. In the membrane reactor of the present invention, the fibrous material placed between the fluid separation membranes supports the catalyst, thereby minimizing the dead space while supplying the removed components to the fluid separation membranes. Productivity can be improved. In addition, since both the permeability of the fluid and the high filling of the fluid separation membrane can be achieved in the membrane reactor, the equipment can be made compact.

A fluid separation membrane is a membrane that has a higher permeability for specific components (permeable components) contained in the fluid to be separated than for other components (non-permeable components). The shape of the fluid separation membrane is not particularly limited, and may be a flat membrane or a hollow fiber membrane. Preferably, the membrane is a hollow fiber membrane.

When the fluid separation membrane is a hollow fiber membrane, the inner diameter of the hollow fiber membrane is preferably 10 µm or more and 2,000 µm or less. Fluid permeability can be improved by setting the inner diameter of the hollow fiber membrane to 10 μm or more. The inner diameter of the hollow fiber membrane is more preferably 20 µm or more, more preferably 50 µm or more. On the other hand, by setting the inner diameter of the hollow fiber membrane to 2,000 μm or less, the outer diameter of the hollow fiber membrane can be reduced, so that the membrane area of the fluid separation membrane per unit volume when used as a membrane reactor can be increased. can. The inner diameter of the fluid separation membrane is more preferably 1,000 μm or less, and even more preferably 500 μm or less.

If the inner diameter of the hollow fiber membrane, which is the fluid separation membrane, is 10 μm or more and 2,000 μm or less, a portion where the distance between the membranes is small occurs, and the flow of the fluid to be separated becomes uneven, and the surface utilization efficiency of the fluid separation membrane tends to decrease. In one aspect of the present invention, since the fibrous material secures the inter-membrane distance, the fluid separation membrane can be highly filled while maintaining the membrane utilization efficiency.

When the hollow fiber membrane includes a support, which will be described later, the inner diameter of the hollow fiber membrane represents the diameter of the hollow portion of the hollow fiber membrane. When the shape of the hollow portion is not circular, the diameter of the maximum inscribed circle that fits in the hollow portion is regarded as the inner diameter of the hollow fiber membrane.

Examples of fluid separation membranes include zeolite membranes, metal organic framework (MOF) membranes, inorganic membranes such as carbon membranes, and polymer membranes. When the membrane reactor is operated under severe reaction conditions such as high temperature and acidity and basicity, an inorganic membrane with excellent heat resistance and chemical resistance is preferable, and the inorganic membrane is more preferably a zeolite membrane or a carbon membrane. preferable.

Zeolite membranes include membranes made of aluminosilicates such as NaX type (FAU), ZSM-5, MOR, silicalite, and A type. You may use 2 or more types of these. The zeolite seeds preferably have a Si/Al ratio comparable to that of those secondary grown by hydrothermal synthesis reaction.

MOF films include, for example, Cu-BTC, MOF-5, IRMOF-3, MIL-47, MIL-53, MIL-96, MMOF, SIM-1, ZIF-7, ZIF-8, ZIF-22, ZIF -69, ZIF-90 and the like. You may use 2 or more types of these.

Examples of carbon films include polyphenylene oxide, polyvinyl alcohol, polyacrylonitrile, phenol resin, wholly aromatic polyester, unsaturated polyester resin, alkyd resin, melamine resin, urea resin, polyimide resin, diallyl phthalate resin, lignin resin, and urethane resin. etc. is carbonized. You may use 2 or more types of these.

Polymer membranes include, for example, aromatic polyimide, cellulose acetate, polysulfone, aromatic polyamide, polyetherimide, polyethersulfone, polyacrylonitrile, polyphenylene sulfide, polyetheretherketone, polytetrafluoroethylene, polyvinylidene fluoride, poly (1-trimethylsilylpropyne), polydimethylsiloxane, polyvinyltrimethylsilane, poly(4-methylpentene), ethylcellulose, natural rubber, poly(2,6-dimethylphenylene oxide), low-density polyethylene, high-density polyethylene, styrene, Examples include films made of polyethyl methacrylate, polycarbonate, polyester, aliphatic polyamide, polymethyl methacrylate, polyvinyl alcohol, silicone, and the like. You may use 2 or more types of these.

Nanoparticles and the like can be added to the fluid separation membrane to improve the permeability of permeable components. Examples of nanoparticles include silica, titania, zeolites, metal oxides, metal organic frameworks (MOF), carbon nanotubes (CNT), and the like.

As one aspect of the present invention, the fluid separation membrane may contain a support. More preferably, when the fluid separation membrane of the present invention comprises a support, the support is located on only one surface of the fluid separation membrane.

Examples of the support include porous inorganic materials such as alumina, silica, cordierite, zirconia, titania, Vycor glass, zeolite, magnesia, sintered metals, polysulfone, polyethersulfone, polyamide, polyester, cellulose-based polymers, Porous organic materials containing at least one polymer selected from the group consisting of homopolymers and copolymers such as vinyl polymers, polyphenylene sulfides, polyphenylene sulfide sulfones, polyphenylene sulfones, and polyphenylene oxides; Examples include porous carbon materials obtained by carbonizing materials. Carbonizable resins include, for example, polyphenylene oxide, polyvinyl alcohol, polyacrylonitrile, phenol resin, wholly aromatic polyester, unsaturated polyester resin, alkyd resin, melamine resin, urea resin, polyimide resin, diallyl phthalate resin, lignin resin, urethane resin, Resin etc. are mentioned. You may use 2 or more types of these.

In the membrane reactor of the present invention, the bending radius of the fluid separation membrane is preferably 0.1 cm or more and 100 cm or less. By setting the bending radius to 100 cm or less, breakage of the fluid separation membrane during fabrication or operation of the membrane reactor can be suppressed. The bending radius 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 fluid separation membrane is not particularly limited, it is preferably 0.1 cm or more because self-sustainability can be imparted to the fluid separation membrane when the bending radius is 0.1 cm or more.

In one aspect of the present invention, a fluid separation membrane having a bending radius of 100 cm or less can be wound around a rigid fibrous material or conform to a complex shape of a vessel or fibrous material. This is preferable because the degree of freedom in reactor design can be improved.

The bending radius of the fluid separation membrane is such that when a fluid separation membrane of 10 cm or more is sampled from the membrane reactor and the sampled fluid separation membrane is wound 360° or more along the normal direction of the cylinder, the fluid separation membrane does not break. It can be obtained from the radius. When the bending radius of the fluid separation membrane is 1.5 cm or more, the angle at which the sampled fluid separation membrane is wound along the normal direction of the cylinder is appropriately reduced for evaluation, and the radius of the cylinder at which the fluid separation membrane does not break is determined. , can be regarded as the bending radius of the fluid separation membrane.

When the fluid separation membrane supports a catalyst, the bending radius of the fluid separation membrane supporting the catalyst is regarded as the bending radius of the fluid separation membrane.

In one aspect of the present invention, the water permeability of the fluid separation membrane is preferably 100 μL/(hr·m ² ·Pa) or less. A fluid separation membrane having a water permeability of 100 μL/(hr·m ² ·Pa) or less can be suitably used as a membrane reactor that requires gas separation because the pore size of the separation functional layer is small. The water permeability of the fluid separation membrane is more preferably 10 μL/(hr·m ² ·Pa) or less, and even more preferably 1 μL/(hr·m ² ·Pa) or less.

The water permeability of the fluid separation membrane is determined by the amount of permeated water recovered from the permeate fluid outlet of the membrane reactor when pure water is supplied from the feed fluid inlet of the membrane reactor, and the following (Equation 1) can be calculated by

Water permeability (μL / (hr m ² Pa)) = Q _w / (P × T × A) (Equation 1)
[In Equation 1, Qw represents the amount of permeated water (μL), P represents the pressure of the feed water (Pa), T represents the water permeation time (hr), and A represents the membrane area of the fluid separation membrane (m ² ). ]
The fibrous substances are present between the fluid molecular membranes in the compartment 1 to secure the distance between the fluid separation membranes and guide the fluid to be separated to the fluid separation membranes. Examples of fibrous materials include fibers, nonwoven fabrics, woven fabrics, and knitted fabrics. You may combine 2 or more types of these.

　Fiber refers to a form whose length is 100 times or more its diameter, and examples include organic fibers and inorganic fibers. Examples of organic fibers include synthetic fibers, semi-synthetic fibers, and regenerated fibers, and examples of inorganic fibers include metal fibers, carbon fibers, glass fibers, and rock fibers. Inorganic fibers are preferably used because of their high heat resistance. In addition, non-woven fabric, woven fabric, and knitted fabric represent forms in which fibers are processed on a plane.

When the fluid separation membrane is a hollow fiber membrane, the fibrous material is preferably a fiber because it can be easily arranged between the fluid separation membranes. A woven or knitted fabric is preferred. Moreover, when the fluid separation membranes are hollow fibers, the fibrous material may spirally cover one or more fluid separation membranes, or may be arranged in parallel with the fluid separation membranes. From the viewpoint of enabling the spacers to be arranged uniformly around the fluid separation membranes, it is preferable that the spacers spirally cover the circumference of one or more fluid separation membranes. A parallel arrangement is preferred.

The fiber length is preferably 0.1 to 2.0 times the length of the fluid separation membrane. When the fiber length is 0.1 times or more the length of the fluid separation membranes, it becomes easier to secure the distance between the fluid separation membranes. The fiber length is preferably at least 0.5 times the length of the fluid separation membrane, more preferably at least 0.75 times. On the other hand, when the fiber length is 2.0 times or less the length of the fluid separation membrane, the volume occupied by the fiber in the membrane reactor can be suppressed and the membrane packing rate can be improved. The length of the fibers is more preferably 1.5 times or less, and even more preferably 1.1 times or less, the length of the fluid separation membrane. When discussing the length of fibers and fluid separation membranes in the present invention, the fibers and fluid separation membranes present in compartment 1 are targeted, and the fibers and fluid separation membranes present in compartment 2 penetrating the potting site and potting site Does not include membrane.

3 and 4 show schematic diagrams of one embodiment in which the fluid separation membrane is spirally coated with a fibrous material. FIG. 3 is a schematic diagram of one embodiment in which one fluid separation membrane 1 is spirally coated with one fibrous material 3 at a pitch of 12, and FIG. FIG. 2 is a schematic diagram of an embodiment in which two fibrous materials 3 are spirally coated on a separation membrane 1 with a pitch of 12 between them. In FIGS. 3 and 4, fibrous material 3 carries catalyst 4 (not shown).

The fibrous covering may be a single covering in which the fibrous material is wrapped around the fluid separation membrane, or a double covering in which the fibrous material is wrapped twice. Further, a multi-stage covering may be used in which a fibrous material is further spirally wound around a plurality of fluid separation membranes wrapped with a fibrous material. Examples of fibrous substances include polyesters, nylons, polyolefins, fluororesins, polyacetals, thermoplastic elastomers, metal oxides, and metals. You may use 2 or more types of these.

In addition, when the fibrous material is a fiber, the fibrous material may be a monofilament or a multifilament. preferable. Further, it is more preferable to use a false-twisted textured yarn because it has high bulkiness and can easily secure the distance between the fluid separation membranes.

A catalyst increases the reaction rate of a chemical process in a membrane reactor by lowering the activation energy of the reaction.

The membrane reactor of the present invention is characterized in that the catalyst is supported on a fibrous material. The catalyst may be coated on the surface of the fibrous material or attached to the surface of the fibrous material. It is more preferable to be supported. Any outer surface of the fibrous material includes the inner surface of pores when the fibrous material is porous and the outer surface of all single fibers when the fibrous material is multifilament.

The catalyst loading amount of the fibrous material of the present invention is preferably 0.01% by mass or more and 10% by mass or less with respect to 100% by mass of the fibrous material containing the catalyst. When the fibrous material supports a catalyst in an amount of 0.01% by mass or more, the fibrous material tends to exhibit its catalytic function for a long period of time. The catalyst loading amount of the fibrous material is more preferably 0.1% by mass or more, further preferably 1% by mass or more. Although the upper limit of the amount of catalyst supported on the fibrous material is not particularly limited, it is preferably 10% by mass or less because the surface area of the fibrous material can be effectively used.

The amount of catalyst supported on the fibrous material is expressed by the ratio of the weight of the catalyst supported on the fibrous material to the weight of the fibrous material containing the catalyst, and can be calculated from the weight of the fibrous material before and after supporting the catalyst. Also, the weight of the catalyst supported on the fibrous material can be estimated by completely eluting the catalyst from the fibrous material and measuring the obtained eluate by inductively coupled plasma mass spectrometry (ICP-MS). be.

Wet plating and dry plating are examples of methods for supporting catalysts on fibrous materials. Examples of wet plating include electrolytic plating and electroless plating, and examples of dry plating include vapor deposition and sputtering.

In the membrane reactor of the present invention, the catalyst not supported on the fibrous material may be arranged on the surface of the fluid separation membranes or between the fluid separation membranes. It is preferably arranged on the surfaces of the fluid separation membranes from the viewpoint of not inhibiting passage of the fluid, and preferably arranged between the fluid separation membranes from the viewpoint of increasing the contact surface area of the catalyst. The catalyst may be placed both on the surface of the fluid separation membranes and between the fluid separation membranes.

The type of catalyst is not particularly limited, and is appropriately selected according to the reaction that occurs within the membrane reactor.

It is preferable that the membrane reactor of the present invention has an electric circuit, and the electric circuit is arranged so that an electric current can flow through the fibrous material, but this aspect will be explained. There is no particular limitation on the method of applying an electric current to the fibrous material, and the fibrous material may be provided with individual electric circuits, or a plurality of fibrous materials may be incorporated into one electric circuit. From the viewpoint of simplifying the wiring, it is preferable to incorporate a plurality of fibrous materials into one electrical circuit. be done. The fibrous material and the current collector, and the current collector and the power source may be directly connected, or may be connected via a conductor such as a lead wire.

In one aspect of the present invention, the electrical resistivity of the fibrous material is preferably 0.1 µΩ·m or more and 1000 µΩ·m or less. When the electrical resistivity of the fibrous material is 0.1 μΩ·m or more, resistance heating occurs when an electric current is applied to the fibrous material, and the fibrous material can be used as a heating element, and the fibrous material can be used as a heating element. Even if the reaction of is endothermic, the inside of the membrane reactor can be directly heated. In resistance heating, all the power consumed by the resistance is converted into heat, so the inside of the membrane reactor can be efficiently heated. The electrical resistivity of the fibrous material is more preferably 0.5 μΩ·m or more, and still more preferably 1 μΩ·m or more. When the electrical resistivity of the fibrous material is 1000 μΩ·m or less, resistance heating can be generated even if the fibrous material is thinned, so that the volume of the fibrous material in the membrane reactor can be suppressed. can. The electrical resistivity of the fibrous material is more preferably 100 μΩ·m or less, and even more preferably 10 μΩ·m or less.

Examples of fibrous materials having an electrical resistivity of 0.1 μΩ·m or more and 1000 μΩ·m or less include iron, chromium, aluminum, nickel, platinum, molybdenum, tantalum, tungsten, alloys thereof, and carbon.

In one aspect of the present invention, the fibrous material preferably has an insulating layer on its surface. Since the insulating layer on the surface of the fibrous material suppresses corrosion of the fibrous material when the fibrous material is used as a heating element, it can be used as a heating element for a long time.

The membrane reactor of the present invention preferably has a heat source or a cooling source and is arranged so that the fibrous material and the heat source or the cooling source are in contact with each other, but this aspect will be explained. The method of heating or cooling the fibrous material, that is, the heating method or the cooling method of the heat source or the cooling source arranged so as to be in contact with the fibrous material is not particularly limited, and the fibrous material is directly connected to the heat source or the cooling source. may be connected via a heat conductor. From the viewpoint of simplifying wiring, it is preferable to connect a plurality of fibrous materials to a heat conductor before connecting them to a heat source or a cooling source. In this case, the fibrous materials are arranged so as to contact the heat conductor. and the heat conductor is connected with a heat source or a cooling source.

In one aspect of the present invention, the thermal conductivity of the fibrous material is preferably 1 W/(m·K) or more and 1000 W/(m·K) or less. When the fibrous material has a thermal conductivity of 1 W/(m·K) or more, the inside of the membrane reactor can be heated or cooled by heating or cooling the fibrous material. Whether the reaction is endothermic or exothermic, the temperature in the membrane reactor can be easily controlled. The thermal conductivity of the fibrous material is more preferably 10 W/(m·K) or more, more preferably 100 W/(m·K) or more.

The fibrous material having a thermal conductivity of 1 W/(m·K) or more and 1000 W/(m·K) or less includes silver, copper, iron, chromium, aluminum, nickel, platinum, molybdenum, tantalum, tungsten, and These alloys etc. are mentioned.

In other words, it is easy to adjust when controlling the electrical resistivity to 0.1 μΩ · m or more and 1000 μΩ · m or less, or the thermal conductivity to 1 W / (m · K) or more and 1000 W / (m · K) or less. From the viewpoint of durability, the fibrous material preferably contains at least one selected from the group consisting of iron, chromium, aluminum, nickel, platinum, molybdenum, tantalum, tungsten, alloys thereof, and carbon.

The manufacturing method of the membrane reactor of the present invention is not particularly limited. A manufacturing method (hereinafter referred to as manufacturing method 2) in which, after manufacturing a membrane reactor containing a fibrous material, the catalyst is charged into the membrane reactor to fill the space between the fluid separation membranes with the catalyst, and at the same time, the fibrous material supports the catalyst. It's okay. Manufacturing method 1 is more preferable because the catalyst can be reliably supported on the fibrous material.

The chemical plant of the present invention (hereinafter sometimes simply referred to as "plant") is a plant including the membrane reactor of the present invention. In addition to the membrane reactor, the plant preferably includes pretreatment equipment, purified fluid recovery equipment, by-product fluid recovery equipment, and the like. The pretreatment equipment is equipment for adjusting the composition of the reaction fluid supplied to the membrane reactor. Purified fluid recovery equipment is equipment for recovering a purified fluid that has permeated through a fluid separation membrane, further purifying the fluid if necessary, and supplying it to a pipeline or the like. The by-product fluid recovery facility is a facility for recovering unreacted reaction fluids and by-product fluids, reusing the unreacted reaction fluids, and discharging the by-product fluids after rendering them harmless. In the plant of the present invention, the membrane reactor, the pretreatment equipment, the purified fluid recovery equipment, and the by-product fluid recovery equipment are preferably connected by piping or the like so that the purified fluid is continuously produced from the reaction fluid.

The plant preferably includes multiple membrane reactors according to the throughput of the fluid to be separated. A plurality of membrane reactors may be connected in series or in parallel with respect to the reaction fluid. From the viewpoint of production efficiency of the membrane reactor, the membrane reactors are preferably connected in series, and from the viewpoint of partial replacement of the membrane reactors, the membrane reactors are preferably connected in parallel. A preferred embodiment of the plant of the present invention includes a mode in which the membrane reactors are connected in series, and the membrane reactors connected in series are further connected in parallel. By doing so, it is possible to achieve both the advantages of connecting the membrane reactors in series and the advantages of connecting them in parallel.

Chemical processes to which the plant of the present invention can be applied are not particularly limited, but examples include hydrogen production by steam reforming of methane, hydrogen production from methylcyclohexane, methane synthesis and methanol synthesis from carbon dioxide and hydrogen, and the like. is mentioned.

The fluid production method of the present invention is a fluid production method using the membrane reactor of the present invention and includes at least the following steps.

Step 1 where a catalyst present in the membrane reactor produces products from the reactants in the feed stream, and a fluid separation membrane present in the membrane reactor concentrates the products from the resulting fluid to be separated from step 1 above. Step 2 to do.

The product produced from the reactants may contain by-products in addition to the desired product, but the product produced in step 1 and the product concentrated in step 2 are both It refers to the desired product.

Furthermore, before and after the

steps

1 and 2, another purification step or an additional step may be included. Alternative purification steps include, for example, distillation, adsorption, absorption, and the like. Moreover, as an additional process, component adjustment etc. which mix with another fluid are mentioned, for example.

According to the fluid production method of the present invention, the membrane reactor enables continuous production from a small scale.

The present invention will be described in detail below with examples and comparative examples, but the present invention is not limited to these. Evaluation in each example and comparative example was performed by the following methods.

(Bending radius of fluid separation membrane)
Five fluid separation membranes with a length of 10 cm or more were cut out from the fabricated membrane reactor, and the radius of the cylinder where the fluid separation membrane did not break when the cut fluid separation membrane was wound 360° or more along the normal direction of the cylinder was determined. The bending radius of the fluid separation membrane was obtained by expressing the average value of the radii of the obtained cylinders with one significant figure.

(inner diameter of fluid separation membrane)
Five fluid separation membranes with a length of 10 cm or more were cut out from the produced membrane reactor and split in a direction orthogonal to the fiber axis direction. The fractured surface was observed with a digital microscope (VHX-D500 manufactured by Keyence Corporation), and the diameter of the maximum inscribed circle that fits in the hollow portion was measured. The average value of the diameters of the obtained inscribed circles was expressed with one significant digit as the inner diameter of the fluid separation membrane.

(Ratio of fiber length to fluid separation membrane length)
Five fibers were sampled from section 1 of the membrane reactor of the example, the length was measured in a straight state with a non-stretching force, and the average value was obtained to obtain the length of the fiber. Here, when one end or both ends of the fiber existed in the potting site, the fiber was cut at the surface of the potting site in Section 1 and sampled. The length of the fluid separation membrane was the length between the compartment 1 side surface of the potting site at one end of the membrane reactor and the compartment 1 side surface of the potting site at the other end of the membrane reactor. The ratio of the length of the fiber to the length of the fluid separation membrane was expressed as "length of the fiber/length of the fluid separation membrane" with two significant figures.

(Electrical resistivity of fibrous material)
The electrical resistivity of fibrous materials was measured by a four-probe method. The electrical resistivity was measured by measuring the potential difference between two points on the surface of the fibrous material while applying electricity to the fibrous material, and calculating the resistivity β by the following formula 1. A DC power supply (PAD55-20L manufactured by Kikusui Electronics), a voltmeter (3878A multimeter manufactured by Hewlett-Packard) and an ammeter (DT4252 manufactured by Hioki Denki) were used for the measurement of electrical resistivity. The measurement was carried out three times, and the average value represented by two significant figures was taken as the electrical resistivity (μΩ·m) of the fibrous material.

β=ΔU・S/(I・d) Equation 1
[In the formula, ΔU is the measured potential difference, I is the current flowing through the fibrous material, S is the cross-sectional area of the fibrous material, and d is the distance between the two electrodes for measuring the potential. ]
(Thermal conductivity of fibrous material)
The thermal conductivity of fibrous materials was measured by the laser flash method. The thermal conductivity was measured by molding the bundled fibrous material into a block and measuring the thermal conductivity with a thermal conductivity measuring device (TC-7000H manufactured by Avantek Riko Co., Ltd.). The measurement was carried out three times, and the average value represented by two significant figures was defined as the thermal conductivity (W/(m·K)) of the fibrous material.

(Amount of fibrous catalyst supported)
Regarding the fibrous materials of Production Examples 3 to 5, the ratio of the mass of the catalyst to the mass of the fibrous material after supporting the catalyst from the mass of the fibrous material before and after supporting the catalyst ((mass of the fibrous material after supporting the catalyst - catalyst The mass of the fibrous material before loading)/mass of the fibrous material after loading the catalyst) was calculated. The obtained value was expressed as a percentage with one significant figure and used as the amount of catalyst supported on the fibrous material.

(Amount of product produced)
Methylcyclohexane was supplied from the feed fluid inlet of the fabricated membrane reactor. Methylcyclohexane is decomposed into toluene and hydrogen using palladium in the membrane reactor as a catalyst, and hydrogen selectively permeates the fluid separation membrane. Hydrogen was recovered from the inlet and outlet of the permeated fluid of the membrane reactor, and the production amount of hydrogen as a product was evaluated from the flow rate measured with a soap film flow meter and the hydrogen composition ratio obtained by gas chromatography analysis. Regarding the membrane reactors of Examples 2 and 3, the amount of hydrogen produced was also evaluated in a state in which an electric current was passed through the fibrous material and a state in which the fibrous material was heated. The measurement was performed 3 times, and the average value was rounded off to the first decimal place to obtain the production amount of the product.

(Production example 1)
10 parts by weight of polyacrylonitrile (PAN) (MW 150,000) manufactured by Polyscience, 10 parts by weight of polyvinylpyrrolidone (PVP) (MW 40,000) manufactured by Sigma-Aldrich, and 80 parts by weight of dimethyl sulfoxide (DMSO) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. They were mixed and stirred at 100° C. to prepare a spinning dope.

After cooling the obtained spinning stock solution to 25° C., using concentric triple nozzles, an 80% by weight DMSO aqueous solution was introduced from the inner tube, the above spinning stock solution from the middle tube, and a 90% by weight DMSO aqueous solution from the outer tube. After being discharged at the same time, the fibers were introduced into a coagulation bath of pure water at 25° C. and wound around a roller to obtain a raw yarn. After the obtained filament was washed with water, it was dried at 25° C. for 24 hours using a circulating dryer to prepare a hollow fiber-like porous carbon membrane precursor.

The obtained precursor of the porous carbon film was passed through an electric furnace at 250°C and heated in an air atmosphere for 1 hour to perform an infusibilization treatment to obtain an infusibilization thread. Subsequently, the infusible yarn was carbonized at a carbonization temperature of 650° C. to obtain a fluid separation membrane of Production Example 1, which is an inorganic membrane (carbon membrane) having an outer diameter of 300 μm, an inner diameter of 100 μm, and a bending radius of 5 mm.

(Production example 2)
After cutting the fluid separation membrane of Production Example 1 every 10 cm, palladium as a catalyst was sputtered to obtain a palladium-carrying fluid separation membrane of Production Example 2.

(Production example 3)
The 170 dtex polyester textured yarn, which is a fibrous material with an electrical resistivity of 1.0 MΩ·m or more and a thermal conductivity of 0.25 W/(m·K), was sputtered with palladium as a catalyst, and the catalyst was supported. A fibrous material of Production Example 3 was obtained. As a result of evaluation by the method described above, the amount of catalyst supported on the fibrous material of Production Example 3 was 3% by mass.

(Production example 4)
A manufacturing example in which a nichrome wire of φ0.2 mm, which is a fibrous material with an electrical resistivity of 1.0 μΩ·m and a thermal conductivity of 17 W/(m·K), is sputtered with palladium as a catalyst, and the catalyst is supported. 4 filaments were obtained. As a result of evaluation by the method described above, the amount of catalyst carried in the fibrous material of Production Example 4 was 0.02% by mass.

(Production example 5)
A manufacturing example in which a fibrous SUS wire with an electrical resistivity of 0.74 μΩ·m and a thermal conductivity of 16 W/(m·K) is sputtered with palladium as a catalyst to support the catalyst. 5 filaments were obtained. As a result of evaluation by the method described above, the amount of catalyst carried in the fibrous material of Production Example 5 was 0.02% by mass.

(Example 1)
One fluid separation membrane of Production Example 2 was used as a core thread, and the catalyst-supported fibrous material of Production Example 3 was wound in the Z direction at a pitch of 10 mm. 10 fluid separation membranes of Production Example 2 around which the catalyst-supporting fibrous material was wound were bundled, housed in an acrylic pipe (inner diameter 3 mm) having a fluid inlet and outlet, and epoxy resin was applied to both ends of the acrylic pipe. were statically potted one by one. After curing the epoxy resin, the potting portion at one end was cut with a rotating saw to open the fluid separation membrane, and the membrane reactor of Example 1 was obtained. As a result of evaluation by the above-described method, the bending radius of the fluid separation membrane was 5 mm, the inner diameter of the fluid separation membrane was 100 μm, the ratio of the length of the fiber to the length of the fluid separation membrane was 1.0, and the amount of product produced. was 33 mL/min.

(Example 2)
One fluid separation membrane of Production Example 2 was used as a core thread, and the catalyst-supported fibrous material of Production Example 4 was wound in the Z direction at a pitch of 10 mm. 10 fluid separation membranes of Production Example 2 around which the catalyst-supporting fibrous material was wound were bundled, housed in an acrylic pipe (inner diameter 3 mm) having a fluid inlet and outlet, and epoxy resin was applied to both ends of the acrylic pipe. were statically potted one by one. After curing the epoxy resin, the potting portion at one end was cut with a rotating saw to open the fluid separation membrane. Metal perforated plates were installed on the fluid separation membrane opening faces at both ends of the element, and a lead wire and a DC power source were arranged between the two perforated plates to obtain a membrane reactor of Example 2.

The membrane reactor of Example 2 has an electric circuit. As a result of evaluation by the above-described method, the bending radius of the fluid separation membrane was 5 mm, the inner diameter of the fluid separation membrane was 100 μm, the ratio of the length of the fiber to the length of the fluid separation membrane was 1.0, and the amount of product produced. was 17 mL/min. In addition, the production amount of the product was 41 mL/min in the state where the electric current was applied to the fibrous material.

(Example 3)
One fluid separation membrane of Production Example 2 was used as a core thread, and the catalyst-supported fibrous material of Production Example 4 was wound in the Z direction at a pitch of 10 mm. 10 fluid separation membranes of Production Example 2 around which the catalyst-supporting fibrous material was wound were bundled, housed in an acrylic pipe (inner diameter 3 mm) having a fluid inlet and outlet, and epoxy resin was applied to both ends of the acrylic pipe. were statically potted one by one. After curing the epoxy resin, the potting portion at one end was cut with a rotating saw to open the fluid separation membrane. Metal perforated plates were placed on the fluid separation membrane opening faces at both ends of the element, and the two perforated plates were connected to respective heat sources to obtain the membrane reactor of Example 3.

The membrane reactor of Example 3 has a heat source. As a result of evaluation by the above-described method, the bending radius of the fluid separation membrane was 5 mm, the inner diameter of the fluid separation membrane was 100 μm, the ratio of the length of the fiber to the length of the fluid separation membrane was 1.0, and the amount of product produced. was 17 mL/min. In addition, when the fibrous material was heated, the amount of product produced was 36 mL/min.

(Example 4)
A membrane reactor of Example 4 was obtained in the same manner as in Example 2 except that the catalyst-supported fibrous material of Production Example 5 was used instead of the catalyst-supported fibrous material of Production Example 4. rice field. The membrane reactor of Example 4 has an electrical circuit. As a result of evaluation by the above-described method, the bending radius of the fluid separation membrane was 5 mm, the inner diameter of the fluid separation membrane was 100 μm, the ratio of the length of the fiber to the length of the fluid separation membrane was 1.0, and the amount of product produced. was 16 mL/min. In addition, the production amount of the product was 23 mL/min when the electric current was applied to the fibrous material.

(Example 5)
A membrane reactor of Example 5 was obtained in the same manner as in Example 3, except that the catalyst-supported fibrous material of Production Example 5 was used instead of the catalyst-supported fibrous material of Production Example 4. rice field. The membrane reactor of Example 5 has a heat source. As a result of evaluation by the above-described method, the bending radius of the fluid separation membrane was 5 mm, the inner diameter of the fluid separation membrane was 100 μm, the ratio of the length of the fiber to the length of the fluid separation membrane was 1.0, and the amount of product produced. was 16 mL/min. In addition, when the fibrous material was heated, the amount of product produced was 34 mL/min.

(Example 6)
The 10 fluid separation membranes of Production Example 2 and the 10 catalyst-supported fibrous materials of Production Example 5 are aligned and bundled so that the fluid separation membranes are not adjacent to each other as much as possible, and an acrylic pipe (inner diameter 3 mm), and each end of the acrylic pipe was statically potted using epoxy resin. After curing the epoxy resin, the potting portion at one end was cut with a rotary saw to open the fluid separation membrane, and the membrane reactor of Example 6 was obtained.

As a result of evaluation by the above-described method, the bending radius of the fluid separation membrane was 5 mm, the inner diameter of the fluid separation membrane was 100 μm, the ratio of the length of the fiber to the length of the fluid separation membrane was 1.0, and the amount of product produced. was 15 mL/min.

(Comparative example 1)
A membrane reactor of Comparative Example 1 was obtained in the same manner as in Example 1, except that a 170 dtex polyester textured yarn was used instead of the catalyst-supported fibrous material of Production Example 3. As a result of evaluation by the method described above, the production amount of the product was 11 mL/min.

1: Fluid separation membrane 2: Hollow part 3: Fiber material 4: Catalyst 5: Gap between fluid separation membranes 7: Potting part 8: Feed fluid inlet 9: Non-permeate fluid outlet 10: Permeate fluid flow Outlet 11: Sweep Gas Inlet 12: Vessel 13: Compartment 1
14: Compartment 2

Claims

A membrane reactor comprising a fluid separation membrane within a vessel and fibrous material interposed between the fluid separation membranes,
A membrane reactor, wherein the fibrous material carries a catalyst.
The membrane reactor according to claim 1, wherein the fluid separation membrane is a hollow fiber membrane and the fibrous material is a fiber.
The membrane reactor according to claim 2, wherein the fibers spirally wrap around one or more of the fluid separation membranes.
The membrane reactor according to claim 2, wherein the fibers are arranged parallel to the fluid separation membrane.
The membrane reactor according to any one of claims 2 to 4, wherein the fiber length is 0.1 to 2.0 times the length of the fluid separation membrane.
The membrane reactor according to any one of claims 2 to 5, wherein the inner diameter of the fluid separation membrane is 10 µm or more and 2,000 µm or less.
The membrane reactor according to any one of claims 2 to 6, wherein the fluid separation membrane has a bending radius of 0.1 cm or more and 100 cm or less.
The membrane reactor according to claim 1, wherein the fluid separation membrane is a flat membrane, and the fibrous material is a nonwoven fabric, a woven fabric, or a knitted fabric.
The membrane reaction according to any one of claims 1 to 8, wherein the fibrous material supports 0.01% by mass or more and 10% by mass or less of the catalyst with respect to 100% by mass of the fibrous material containing the catalyst. vessel.
The membrane reactor further has an electrical circuit,
A membrane reactor according to any one of claims 1 to 9, wherein said electrical circuit is arranged to allow an electric current to flow through said fibrous material.
The membrane reactor according to claim 10, wherein the electrical resistivity of the fibrous material is 0.1 µΩ·m or more and 1000 µΩ·m or less.
The membrane reactor further has a heat source or a cooling source,
The membrane reactor according to any one of claims 1 to 9, wherein said fibrous material and said heat source or cooling source are arranged so as to be in contact with each other.
The membrane reactor according to claim 12, wherein the fibrous material has a thermal conductivity of 1 W/(m·K) or more and 1000 W/(m·K) or less.
Any one of claims 1 to 13, wherein the fibrous material contains at least one selected from the group consisting of iron, chromium, aluminum, nickel, platinum, molybdenum, tantalum, tungsten, alloys thereof, and carbon. A membrane reactor as described in .
A chemical plant comprising the membrane reactor according to any one of claims 1 to 14.
A fluid production method using the membrane reactor according to any one of claims 1 to 14, comprising at least the following steps.
step 1 of producing a product from the reactants in the feed stream with a catalyst present in the membrane reactor;
and step 2 of concentrating said product by means of a fluid separation membrane present in the membrane reactor.