Adsorption unit and production method therefor

Abstract

Provided is an adsorption unit having a novel form. An adsorption unit 100 comprises: a roll object 20 formed by spirally winding a sheet material comprising a base and an adsorbent supported on the base; and a cylindrical case 10 containing the roll object 20. The roll object 20 is contained in the case 10 so that the winding-axis direction thereof coincides with the cylinder axis direction of the case 10, and is held on the inner wall of the case 10 at least by elastic resorting force in outward radial directions.

Description

Adsorption unit and manufacturing method thereof

[0001] The present invention relates to an adsorption unit and a method for manufacturing the same. This application claims priority to Japanese Patent Application No. 2024-088693, filed on May 31, 2024, the entire contents of which are incorporated herein by reference.

[0002] Conventionally, adsorbents such as activated carbon and zeolite have been used to selectively separate and recover desired components from fluid compositions (e.g., gases) or the environment. In recent years, the use of metal organic frameworks (MOFs) having porous structures as adsorbents has also been considered (e.g., Patent Document 1).

[0003] Japanese Patent Application Publication No. 2022-164183

[0004] Adsorbents are often formed into granules such as pellets or extruded bodies, or supported on a honeycomb substrate to form a honeycomb structure. However, according to the inventors' research, the granules tend to crumble easily due to vibration, impact, etc., which can cause durability issues depending on the application. Furthermore, honeycomb structures can have problems such as an insufficient amount of adsorbent supported depending on the application, and generally tend to have high manufacturing costs.

[0005] The present invention has been made in view of the above points, and its main object is to provide a novel type of adsorption unit that can solve the above problems.

[0006] The present invention provides an adsorption unit comprising one or more roll-formed bodies formed by spirally winding a sheet material having a substrate and an adsorbent supported on the substrate, and a cylindrical case for accommodating the roll-formed bodies. The roll-formed bodies are accommodated in the case with their winding axis oriented in the same direction as the cylindrical axis of the case, and are held against the inner wall of the case by elastic restoring force in at least the radial direction.

[0007] The present invention also provides a method for manufacturing an adsorption unit, comprising one or more roll-formed bodies formed by spirally winding a sheet material having a substrate and an adsorbent supported on the substrate, and a cylindrical case for accommodating the roll-formed bodies. This manufacturing method includes the steps of: preparing the sheet material; spirally winding the sheet material to form a roll-formed body; accommodating the roll-formed body in the case while compressing it radially inward and accommodating it with its axis of winding aligned with the cylindrical axis of the case; and releasing the roll-formed body from its compressed state to generate an elastic restoring force radially outward, and using the elastic restoring force to hold the roll-formed body against the inner wall of the case.

[0008] According to the present invention, a novel type of adsorption unit can be realized that is low cost and highly durable compared to when the adsorbent is formed into granules or supported on a honeycomb substrate.

[0009] FIG. 1 is a cross-sectional view of a suction unit according to one embodiment. FIG. 2 is a front view of a suction unit according to one embodiment. FIG. 3 is a schematic diagram of an accommodation step. FIG. 4A is a cross-sectional view of an insertion jig according to one example. FIG. 4B is a schematic diagram of an accommodation step when the insertion jig of FIG. 4A is used. FIG. 5 is a view corresponding to FIG. 3 according to a first modified example. FIG. 6 is a view corresponding to FIG. 3 according to a second modified example. FIG. 7 is a view corresponding to FIG. 1 according to a third modified example.

[0010] Hereinafter, several embodiments of the present invention will be described with reference to the drawings. It should be noted that the embodiments described here are, of course, not intended to limit the present invention in any particular way. Furthermore, the same reference numerals are used to designate components and parts that perform the same function, and redundant explanations will be omitted or simplified as appropriate. Furthermore, in this specification, the expression "X to Y" (X and Y are arbitrary numerical values) indicating a range encompasses not only the meaning of X or greater and Y or less, but also the meanings of "greater than X" and "smaller than Y."

[0011] <Adsorption unit> Fig. 1 is a cross-sectional view of an adsorption unit 100 according to one embodiment. Fig. 2 is a front view of the adsorption unit 100 according to one embodiment. In Fig. 1 and other figures, the symbol X indicates the cylindrical axis direction of the case 10, and the symbol Y indicates a radial direction perpendicular to the cylindrical axis direction X. The adsorption unit 100 of this embodiment is configured so that a fluid composition (e.g., gas) flows along the cylindrical axis direction X. As shown in Figs. 1 and 2, the adsorption unit 100 includes a cylindrical case 10 and a roll-formed body 20.

[0012] The case 10 is a housing that houses the roll molded body 20. The material of the case 10 is not particularly limited and may be, for example, metal or resin. The case 10 may be entirely or partially (for example, a portion facing the roll molded body 20) made of punched metal, expanded metal, metal mesh (wire netting), or the like.

[0013] The case 10 is hollow and cylindrical. The case 10 extends in the flow direction of the fluid composition (e.g., gas). Here, the case 10 is cylindrical (pipe-shaped) (see also FIG. 3 ). However, the shape of the case 10 is not limited to a cylindrical shape, and in other embodiments, various shapes, such as an elliptical shape or a polygonal shape, may be used. As shown in FIG. 2 , the cross section of the case 10 in the radial direction Y is circular here. This increases the contact area with the roll molded body 20, thereby improving the integrity of the case 10 with the roll molded body 20.

[0014] As shown in FIG. 1 , the case 10 has an internal space 12 therein in which the roll molded body 20 is accommodated. The internal space 12 has an inner diameter corresponding to the outer shape of the roll molded body 20. In this example, the inner diameter of the internal space 12 is the same as the inner diameter of the inlet 10 a and the inner diameter of the outlet 10 b. In the internal space 12, the roll molded body 20 is in direct contact with the inner wall 10 c of the case 10. However, in other embodiments, another member may be interposed between the inner wall 10 c and the roll molded body 20.

[0015] As shown in FIG. 1 , the case 10 has an inlet 10a through which a fluid composition (e.g., gas) flows from the outside into the internal space 12 during use of the adsorption unit 100, and an outlet 10b through which the fluid composition (e.g., gas) flows from the internal space 12 to the outside. Here, the inlet 10a is provided at a first end (the right end in FIG. 1 ) of the case 10 in the cylindrical axis direction X. Here, the outlet 10b is provided at a second end (the left end in FIG. 1 ) of the case 10 in the cylindrical axis direction X. During use of the adsorption unit 100, the fluid composition (e.g., gas) flows from the inlet 10a toward the outlet 10b. Note that the positions of the inlet 10a and the outlet 10b are not particularly limited. In another embodiment, for example, the inlet 10a may be provided on a side surface of the case 10 near the first end in the cylindrical axis direction X, and the outlet 10b may be provided on a side surface of the case 10 near the second end in the cylindrical axis direction X. The positions of the inlet 10a and the outlet 10b may also be reversed.

[0016] As shown in FIG. 1 , the inner wall 10c of the case 10 is provided with a locking portion that restricts movement of the roll molded body 20 in the cylindrical axis direction X. In this embodiment, a groove 14 is provided in the inner wall 10c of the case 10, and the locking portion is composed of a locking member 15 fitted into the groove 14. An end 20e of the roll molded body 20 in the winding axis direction can abut against the locking member 15, for example, during manufacturing or when a fluid composition (e.g., gas) flows in during use of the adsorption unit 100. By providing the locking portion on the inner wall 10c of the case 10, positioning of the roll molded body 20 in the cylindrical axis direction X is facilitated. Furthermore, even if the elastic restoring force RF of the roll molded body 20, which will be described later, decreases due to, for example, aging, the position of the roll molded body 20 in the cylindrical axis direction X is less likely to shift.

[0017] The locking member 15 is a separate, generally C-shaped member. The locking member 15 is, for example, a retaining ring or a snap ring. The locking member 15 is fixed to the inner wall 10c of the case 10 (more specifically, the groove 14) by tension in the radially outward direction. By configuring the locking portion as the locking member 15 (a separate member), productivity and workability can be improved.

[0018] The locking portion is preferably disposed closer to the end 20e on the outlet 10b side than to the end on the inlet 10a side of the roll molded body 20. The locking portion is preferably disposed closer to the outlet 10b side than to the roll molded body 20. This makes it difficult for the roll molded body 20 to move in the cylindrical axis direction X even if a fluid composition (e.g., gas) flows in forcefully from the inlet 10a when the adsorption unit 100 is in use.

[0019] The roll molded body 20 has a function of selectively separating and recovering a desired component from a fluid composition or the environment. The roll molded body 20 is accommodated in the internal space 12 of the case 10. In this embodiment, one roll molded body 20 is accommodated in one case 10. However, the number of roll molded bodies 20 accommodated in one case 10 is not particularly limited. As will be shown in a modified example described later, the number of roll molded bodies 20 accommodated in one case 10 may be more than one (two or more).

[0020] In the technology disclosed herein, as shown in FIG. 1 , the roll molded body 20 is housed in the case 10 with the direction in which the winding axis WL extends (winding axis direction) coinciding with the cylindrical axis X of the case 10. Also, as shown in FIG. 2 , the roll molded body 20 is held to the inner wall 10c of the case 10 by an elastic restoring force RF in at least the outer diameter direction. By utilizing the elastic restoring force RF, the roll molded body 20 can be easily fixed to the case 10. This can improve productivity and workability, and ultimately reduce costs.

[0021] In this specification, "held on the inner wall of the case by the elastic restoring force" means that, for example, when the roll molded body 20 is inserted into the case 10 from the insertion opening and supported on the inner wall 10c of the case 10 by only the elastic restoring force RF, and the case 10 is placed in this state with the insertion opening facing downward in the vertical direction, the roll molded body 20 does not fall off from the case 10. The elastic restoring force RF of the roll molded body 20 can be adjusted by, for example, the number of windings and properties (e.g., thickness, porosity, etc.) of the sheet material described below, the structure and type of the base material constituting the sheet material (e.g., type of fiber material constituting the base material), etc.

[0022] In some embodiments, it is preferable that the roll molded body 20 is fixed to the inner wall 10c of the case 10 only by the elastic restoring force RF (only physical force). In other words, it is preferable that the roll molded body 20 is not adhered to the case 10 by chemical forces via adhesives, tape, or the like. This can further improve productivity and workability. Furthermore, since the roll molded body 20 can be detachably disposed in the case 10, even if the adsorption ability of the roll molded body 20 decreases with use, for example, work such as replacement can be easily performed.

[0023] As shown in FIG. 1 , the roll molded body 20 is configured by spirally winding a sheet material having a substrate and an adsorbent around a winding axis WL. By supporting the adsorbent on the substrate and using it in the form of a sheet material, durability is improved compared to granulated materials such as pellets or extrusion molded bodies. It also enables a thinner and lighter product. Furthermore, by winding the sheet material into a roll, a larger surface area can be secured compared to, for example, a honeycomb structure, and the amount of adsorbent supported per unit volume can be increased. Therefore, the adsorption capacity of the roll molded body 20 can be improved.

[0024] The roll molded body 20 has a curved outer surface. The outer surface of the roll molded body 20 is flat. This relatively increases the contact area with the inner wall 10c of the case 10 compared to an outer surface having an uneven surface, such as a corrugated surface, thereby improving the unity with the case 10. The roll molded body 20 here has a cylindrical outer shape (see also FIG. 3 ). However, in other embodiments, it may have an elliptical shape, etc. In this case, substantially the entire outer surface of the roll molded body 20 abuts against the inner wall 10c of the case 10. The number of turns of the sheet material is preferably changed as appropriate depending on, for example, the thickness of the sheet material and the application of the adsorption unit 100. Therefore, although not particularly limited, from the viewpoint of increasing the contact area per unit volume with the adsorption target (e.g., gas) to improve adsorption ability and from the viewpoint of obtaining a high elastic restoring force RF, the number of turns of the sheet material is preferably 5 or more, and more preferably 10 or more.

[0025] The sheet material is configured to be elastically deformable at least in the thickness direction. This allows an elastic restoring force RF in the outer diameter direction to be generated in the internal space 12 of the case 10. The sheet material is preferably porous (sponge-like) with pores that communicate in a three-dimensional network pattern. This improves the permeability of the fluid composition (e.g., gas) during use of the adsorption unit 100, thereby reducing pressure loss when the fluid composition passes through the adsorption unit 100. The porous sheet material preferably has multiple openings that communicate with the outside. This allows air to easily enter and exit the porous material through the openings, making it easier to obtain a high elastic restoring force RF.

[0026] Although not particularly limited, the average thickness of the sheet material in an uncompressed state is preferably 0.1 to 2 mm, more preferably 0.2 to 0.5 mm. By making the thickness equal to or greater than a predetermined value, a high elastic restoring force RF is easily obtained. Furthermore, by making the thickness equal to or greater than a predetermined value, it becomes easier to form into a roll shape. The porosity of the sheet material is preferably 30 to 80%, more preferably 50 to 70%. By making the porosity within the above range, a high elastic restoring force RF is easily obtained. In this specification, "porosity" refers to the porosity determined using a commercially available mercury intrusion porosimeter (e.g., a PoreMaster mercury intrusion pore distribution analyzer manufactured by Quantachrome) with a cell stem volume of 0.5 cc, over a pressure range from a measurement start pressure of 0.2 psi to an ultimate pressure of 50 psi.

[0027] In some embodiments, it is preferable that the average thickness of the sheet material of the roll molded body 20 is equal to or greater than a predetermined value (e.g., 0.2 to 0.5 mm), the porosity of the sheet material is within a predetermined range (e.g., 30 to 80%), and the number of turns of the sheet material is equal to or greater than a predetermined value (e.g., 10 or more). This makes it easier to achieve a particularly stable and high elastic restoring force RF, and makes it easier to exhibit the effects of the technology disclosed herein at a higher level.

[0028] The sheet material has a substrate and an adsorbent supported on the substrate. The substrate constitutes the skeleton of the sheet material. As the substrate, various materials conventionally used for this type of application can be used as long as they are configured to be elastically deformable at least in the thickness direction. The substrate preferably has a porous structure. This makes it easier to obtain a high elastic restoring force RF while increasing the amount of adsorbent supported.

[0029] In some embodiments, the substrate preferably includes a fibrous material. That is, the substrate is preferably a so-called paper substrate made of a paper material. Among these, a nonwoven fabric obtained by a wet papermaking method or the like is preferable. In a nonwoven fabric, the irregularly entangled fibrous material tends to form a spring-like shape, and this, combined with the voids secured between the fibrous material, makes it easier to obtain a higher elastic restoring force RF than, for example, a regular structure such as a woven fabric.

[0030] The fiber material may be inorganic or organic, or may contain both. Examples of inorganic fibers include glass fibers, metal fibers, ceramic fibers, and carbon fibers. Examples of organic fibers include natural fibers and chemically synthesized synthetic fibers (artificial fibers). Examples of natural fibers include plant fibers such as pulp fibers, animal fibers, and mineral fibers. Examples of chemical fibers include recycled fibers, semi-synthetic fibers, and synthetic fibers. Examples of chemical fibers include cellulose fibers, aramid fibers, polyester fibers, polyethylene fibers, polypropylene fibers, acrylic fibers, rayon fibers, polyamide fibers, and polyimide fibers.

[0031] In some embodiments, the fiber material is preferably composed mainly of organic fibers (a component occupying 50% or more by mass; the same applies hereinafter) from the viewpoint of increasing the elastic restoring force RF. Among these, it is preferable that the fiber material is composed mainly of chemical fibers, and cellulose fibers or aramid fibers are more preferable.

[0032] In some embodiments, the substrate is made of a nonwoven fabric containing a fibrous material, and the fibrous material preferably contains organic fibers in an amount of 50% or more by mass, which makes it easier to achieve a particularly stable and high elastic recovery force RF and makes it easier to achieve the effects of the technology disclosed herein at a higher level.

[0033] Although not particularly limited, the average length of the fiber material is preferably 0.01 μm to 30 mm. The average diameter of the fiber material is preferably 1 nm to 0.1 mm. The aspect ratio of the fiber material (ratio of average length to average diameter (average length / average diameter)) is preferably approximately 10 or more, for example, 100 or more, 1000 or more. The average length and average diameter can be number-average values ​​obtained by measurements based on electron microscope observation.

[0034] The adsorbent is supported on a substrate and has the function of selectively adsorbing desired components. The adsorbent is typically solid. There are no particular limitations on the adsorbent, and any material conventionally used for this type of application can be appropriately adopted depending on, for example, the components to be adsorbed and the application of the adsorption unit 100. Examples include metal-organic frameworks, activated carbon, silica gel, zeolites, and amorphous aluminum silicates. Among these, it is preferable to include a metal-organic framework. Note that the term "metal-organic framework" here is synonymous with a porous coordination polymer (PCP) and a porous metal complex.

[0035] The metal-organic framework is composed of metal ions and organic ligands capable of bonding to the metal ions. The metal-organic framework is typically a porous metal complex having a highly regular lattice structure (a porous three-dimensional structure) composed of metal ions and organic ligands, and having a plurality of pores capable of accommodating specific molecules. The type of metal ion is preferably selected depending on, for example, the component to be adsorbed and the application of the adsorption unit 100. Metal-organic frameworks are typically very small in size, making them difficult to handle, and may easily fall off the substrate if not firmly fixed to the substrate. However, according to the technology disclosed herein, the adsorption performance of the metal-organic framework can be fully utilized by forming it into a sheet, and by arranging it in the case 10 as a roll-formed body, it is possible to prevent the metal-organic framework from falling off the substrate. Therefore, excellent adsorption performance can be easily exhibited.

[0036] The adsorbent preferably contains a metal-organic framework as a main component, more preferably contains 80 mass % or more of the metal-organic framework, further preferably contains 95 mass % or more of the metal-organic framework, and particularly preferably contains substantially the metal-organic framework (98 mass % or more of the metal-organic framework).

[0037] In some embodiments, when the substrate has a porous structure, the adsorbent is preferably unevenly distributed within the substrate. In other words, it is preferable that the adsorbent is disposed in a greater amount, by mass, within the substrate than on the exterior (surface) of the substrate. This prevents the adsorbent from falling off due to friction between the sheet materials when the sheet material is wound into a spiral during production. Therefore, the desired adsorption performance is more likely to be stably exhibited. Note that a sheet material in which the adsorbent is unevenly distributed within the substrate can be manufactured by incorporating a fibrous material and an adsorbent using a wet papermaking method, as described in the manufacturing method below.

[0038] Although not particularly limited, when the entire sheet material is taken as 100% by mass, the adsorbent content is preferably 50% by mass or more, and more preferably 60% by mass or more. By setting the adsorbent content to a predetermined value or more, the amount of adsorbent carried per unit volume can be increased, thereby improving the adsorption capacity of the roll molded body 20. The adsorbent content is preferably 90% by mass or less, and more preferably 80% by mass or less, from the viewpoint of, for example, ensuring voids and increasing the elastic restoring force RF.

[0039] In some embodiments, the roll molded body 20 preferably has a porous substrate, the adsorbent is unevenly distributed within the substrate, and the adsorbent content is 50% by mass or more when the entire sheet material is taken as 100% by mass. If the adsorbent content is a predetermined value or more, the probability of the adsorbent being exposed on the outer surface of the roll molded body 20 increases, making the adsorbent more likely to fall off. By unevenly disposing the adsorbent within the substrate, even if the adsorbent content is high, for example, 50% by mass or more, the adsorbent is less likely to be exposed on the outer surface. Therefore, applying the technology disclosed herein is highly effective.

[0040] Furthermore, in some embodiments, the roll-formed body 20 has a substrate with a porous structure, and the adsorbent includes at least a metal-organic framework and is unevenly distributed within the substrate. More preferably, the adsorbent content is 50% by mass or more when the entire sheet material is taken as 100% by mass. Metal-organic frameworks are typically very small in size and therefore tend to fall off the substrate more easily than other adsorbents. By unevenly disposing the adsorbent within a porous substrate, even if the adsorbent includes a metal-organic framework and the adsorbent content is high, for example, 50% by mass or more, the adsorbent (especially the metal-organic framework, which is prone to falling off) is less likely to be exposed to the outer surface. Therefore, applying the technology disclosed herein is particularly effective. Ultimately, the adsorption performance of the metal-organic framework can be fully utilized, making it easier to stably exhibit excellent adsorption ability.

[0041] The sheet material may further contain other optional components, such as additives, as needed. Additives may be one or more of those known to be useful for this type of application, and may be used to improve various properties of the sheet material, such as mechanical strength and durability. Specific examples include inorganic additives such as inorganic binders and inorganic fillers, and organic additives such as organic binders, dispersants, antioxidants, preservatives, lubricants, stabilizers, and colorants (pigments, dyes, etc.). The total proportion of these additives is preferably 10% by mass or less, and more preferably 5% by mass or less, when the entire sheet material is taken as 100% by mass.

[0042] In some embodiments, as shown in Fig. 2, when the cross-sectional area of ​​the case 10 is taken as 100 area %, in a cross-sectional view in a direction (radial direction Y) perpendicular to the cylindrical axis direction X, the roll molded body 20 preferably occupies 80 area % or more, more preferably 90 area % or more, and particularly preferably 95 area % or more. This increases the amount of adsorbent carried per unit volume, thereby improving the adsorption ability of the roll molded body 20. Furthermore, from the viewpoint of improving the permeability of a fluid composition (e.g., gas), when the cross-sectional area of ​​the case 10 is taken as 100 area %, the proportion occupied by the roll molded body 20 is preferably 99 area % or less, more preferably 98 area % or less.

[0043] In some embodiments, a hollow portion may be provided in the center of the roll-formed body 20 in a cross-sectional view in a direction perpendicular to the cylindrical axis direction X (radial direction Y) due to the manufacturing method described below (see also FIG. 2 ). The hollow portion is a cylindrical space formed by winding a sheet material around a winding core and then removing the winding core. The presence of the hollow portion can improve the permeability of a fluid composition (e.g., gas) when the adsorption unit 100 is in use. In other embodiments, a core member (typically, the winding core used in the manufacturing method described below) may be disposed in the center of the roll-formed body 20 in a cross-sectional view in a direction perpendicular to the cylindrical axis direction X (radial direction Y). In this case, the core member is preferably made of punched metal, expanded metal, metal mesh (wire netting), or the like, and has a plurality of holes at predetermined intervals along the axial and circumferential directions.

[0044] <Use of Adsorption Unit> The adsorption unit 100 is configured to extract a specific gas component (e.g., CO ) from a mixed gas to be treated. ２ The present invention can be suitably used in gas adsorption apparatuses that separate and recover various components. In particular, the present invention can be suitably used in adsorption apparatuses that use pressure swing adsorption (PSA), which uses a pressure difference to perform adsorption and desorption, or thermal swing adsorption (TSA), which uses a temperature difference to perform adsorption and desorption. In such adsorption apparatuses, there is a demand for separating and recovering a larger amount of a specific component with a single application of pressure or heat. Therefore, applying the technology disclosed herein is particularly effective.

[0045] <Method of Manufacturing Suction Unit> Next, a method of manufacturing the above-described suction unit 100 will be described. The manufacturing method of this embodiment includes, in this order, a preparation step (step S10), a molding step (step S20), a housing step (step S30), and a fixing step (step S40). The manufacturing method disclosed herein may further include other steps at any stage.

[0046] The preparation step (step S10) is a step of preparing a sheet material. The sheet material has a substrate and an adsorbent supported on the substrate. The sheet material may be purchased commercially or may be prepared by hand using a conventionally known method. In some embodiments, it is preferable to prepare the sheet material by dispersing a fibrous material and an adsorbent in a solvent to prepare a slurry, and then forming the slurry into a sheet using a wet papermaking method. The wet papermaking method can suitably produce a nonwoven substrate in which the adsorbent and voids are uniformly distributed. Furthermore, since the adsorbent can be incorporated into the substrate containing the fibrous material, a sheet material in which the adsorbent is unevenly distributed within the substrate can be suitably produced.

[0047] In some embodiments, it is preferable to prepare at least a metal-organic framework as the adsorbent. As an example, when the adsorbent is a metal-organic framework, a fiber material and a precursor of the metal-organic framework (e.g., metal ions and organic ligands constituting the metal-organic framework) are first added to a solvent and mixed to prepare a slurry. The organic ligands bond with the metal ions in the slurry to form the lattice structure of the metal-organic framework. The solvent is typically water, but a mixed solvent mainly composed of water may also be used. As a solvent other than water that constitutes the mixed solvent, an organic solvent that is uniformly miscible with water, such as lower alcohols such as methanol, ethanol, and propanol, or lower ketones, may be used. Various additives may also be added to the slurry as long as they do not significantly impair the effects of the technology disclosed herein. For mixing, a conventional stirring and mixing device such as a magnetic stirrer, a planetary mixer, or a disperser may be used as appropriate.

[0048] Next, wet papermaking can be performed using, for example, a conventionally known papermaking machine. The papermaking conditions may be the same as conventional ones. In one example, first, the solvent contained in the slurry is roughly removed, and the solid content in the slurry is made (molded) into a sheet. This results in a wet paper. Next, the obtained wet paper is dried, and the solvent is further removed. This causes a metal-organic framework containing metal ions and organic ligands to precipitate, and a sheet material can be obtained in which the metal-organic framework is supported on a substrate containing a fibrous material.

[0049] In some embodiments, it is preferable to prepare a sheet material in which the substrate has a porous structure and the adsorbent is unevenly distributed within the substrate. In some embodiments, it is more preferable to prepare a sheet material in which the substrate has a porous structure, the adsorbent is unevenly distributed within the substrate, and the adsorbent content is 50% by mass or more when the entire sheet material is taken as 100% by mass.

[0050] The forming step (step S20) is a step of spirally winding the sheet material prepared in the preparation step (step S10) into a roll-shaped formed body (roll formed body). In one example, first, a rod-shaped winding core is prepared, and the end of the sheet material is aligned with the winding core. Next, the sheet material is wound around the winding core a predetermined number of times. It is preferable to wind the sheet material around the winding core until the outer diameter becomes larger than the inner diameter of the internal space 12 of the case 10 to be used. From the viewpoint of preventing loosening of the winding, the end of the winding may be clamped with a jig or temporarily fixed to the outer surface with tape or the like. This improves the handleability of the roll formed body 20. After winding of the sheet material is completed, the winding core is typically pulled out. However, the winding core may also be held in place. In this manner, the roll formed body 20 can be obtained.

[0051] The accommodation step (step S30) is a step of accommodating the roll molded body 20 in the case 10. In one embodiment, first, the cylindrical case 10 as described above is prepared. Next, the outer peripheral portion of the roll molded body 20 produced in the molding step (step S20) is compressed in the inner diameter direction of the roll molded body 20. As a result, the outer diameter of the roll molded body 20 is made smaller than the inner diameter of the inlet 10a of the case 10, which serves as an insertion opening, and the inner diameter of the internal space 12 in which the roll molded body 20 is accommodated. Then, with the roll molded body 20 in a compressed state, as shown in FIG. 3 , the roll molded body 20 is inserted (accommodated) into the internal space 12 from the inlet 10a of the case 10 with the winding axis direction aligned with the cylindrical axis direction X of the case 10.

[0052] While the compression of the roll molded body 20 and its insertion into the case 10 can be performed manually, it is preferable to use an insertion jig, for example, when the size of the roll molded body 20 is large. FIG. 4A is a cross-sectional view of an example insertion jig 200. As shown in FIG. 4A, the insertion jig 200 has a cylindrical (pipe-shaped) outer diameter and a tapered inner wall surface 200c configured so that the inner diameter gradually decreases from a first end 200a (the end on the right side in FIG. 4A ) in the cylindrical axis direction X to a second end 200b (the end on the left side in FIG. 4A ). The inner diameter of the first end 200a of the insertion jig 200 is the same as or larger than the outer diameter of the roll molded body 20 (before compression) produced in the molding step (step S20). The first end 200a is configured to accommodate the roll molded body 20 (before compression) produced in the molding step (step S20). The inner diameter of the second end 200b of the insertion jig 200 is the same as or smaller than the outer diameter of the case 10. The second end 200b is configured so that one end of the case 10 can be inserted therein. The second end 200b has a stepped portion 200d to which one end of the case 10 is attached. The insertion jig 200 is configured so that the roll molded body 20 can be deformed from a large diameter state (first state) to a small diameter state (second state) in which the roll molded body 20 is compressed in the inner diameter direction.

[0053] When inserting the roll molded body 20 into the case 10 using the insertion jig 200, as shown in FIG. 4B , first, the step portion 200d of the insertion jig 200 is attached to one end of the case 10 (here, the inlet 10a), and the internal space of the insertion jig 200 is connected to the internal space 12 of the case 10 via the second end 200b. Next, the (uncompressed) roll molded body 20 produced in the molding step (step S20) is inserted into the insertion jig 200 from the first end 200a. The roll molded body 20 inserted into the insertion jig 200 is fed in the cylindrical axis direction X while being compressed along the tapered inner wall surface 200c in the internal space of the insertion jig 200, and is then pushed out from the second end 200b in the direction of the arrow. As a result, the roll molded body 20 is inserted (housed) in the case 10 in a compressed state.

[0054] The fixing step (step S40) is a step of holding the roll molded body 20 on the inner wall 10c of the case 10 by an elastic restoring force RF. In one embodiment, after the roll molded body 20 is accommodated in the internal space 12 of the case 10, the insertion jig is removed. This releases the roll molded body 20 from its compressed state, and the roll molded body 20 returns to its original large diameter state inside the case 10. As a result, an elastic restoring force RF in the outer diameter direction is generated in the roll molded body 20, and the roll molded body 20 is held on the inner wall 10c of the case 10 by this elastic restoring force RF. In this manner, the suction unit 100 can be manufactured.

[0055] As described above, the technology disclosed herein employs a novel form known as a "roll-molded body," thereby improving the durability of the adsorbent relative to when it is molded into a granulated product such as pellets or an extrusion molded body. Specifically, the granulated product is a product in which particulate adsorbent is compressed under pressure, and the particulate adsorbent is exposed on the outer surface of the granulated product (the inner wall of the case or the area where the granulated products come into contact with each other). Therefore, when vibrations or impacts are applied during use, for example, and the outer surface is rubbed due to contact with the inner wall of the case or contact between the granulated products, the adsorbent is likely to fall off the granulated product.

[0056] In contrast, the roll molded body 20 disclosed herein has a base material and the sheet material is spirally wound, so that the proportion of adsorbent present (exposed) on the outer surface (the inner wall of the case or the outermost peripheral portion where the roll molded bodies contact each other) is relatively small compared to the granulated material. Therefore, even if the outer surface is rubbed due to vibration, impact, etc. during use, the adsorbent is relatively less likely to fall off. Therefore, the roll molded body 20 has the effect of being relatively less likely to collapse due to vibration, impact, etc. compared to the granulated material. Therefore, the technology disclosed herein makes it possible to realize an adsorption unit 100 that is relatively less likely to have durability issues and is highly versatile.

[0057] Furthermore, the technology disclosed herein employs a novel form known as a "roll-formed body," thereby enabling a relative reduction in manufacturing costs compared to when an adsorbent is supported on a honeycomb substrate. Specifically, when manufacturing a honeycomb structure, an adsorption unit is generally manufactured through the following steps (see, for example, Japanese Patent Application Publication No. 2024-057201, which is a well-known technique at the time of filing this application). (Step 1: Sheet Material Preparation Step) A plurality of sheet-like substrates supporting an adsorbent are prepared. (Step 2: Corrugating Step) A first sheet-like substrate is processed into a corrugated (wave-shaped) shape to prepare a corrugated substrate. (Step 3: Adhesive Application Step) An adhesive is applied to the peaks of the corrugated shape of the corrugated substrate prepared in Step 2. (Step 4: Adhesion Step) The sheet-like substrate and the corrugated substrate are bonded together to obtain a laminate of two types of substrates. (Step 5: Winding Step) The laminate is wound to obtain a honeycomb structure. (Step 6: Housing Step) The honeycomb structure is housed in a case.

[0058] In contrast, the suction unit 100 disclosed herein can be manufactured by the following steps, as described above: (Step S10: Preparation Step) Prepare a sheet material carrying an adsorbent; (Step S20: Forming Step) Wind the sheet material into a spiral shape to obtain a roll molded body; (Step S30: Accommodation Step) Accommodation the roll molded body in a case and hold it against the inner wall of the case by its elastic restoring force. In other words, (Step 2: Corrugating Step), (Step 3: Adhesive Application Step), and (Step 4: Adhesion Step) in the above-described honeycomb structure manufacturing process can be omitted. Therefore, the roll molded body 20 requires fewer steps than a honeycomb (corrugated) molded body, thereby improving productivity and workability. Therefore, the technology disclosed herein relatively reduces manufacturing costs, allowing the suction unit 100 to be realized at low cost.

[0059] Although the preferred embodiments of the present invention have been described above, the above-described embodiments are merely examples, and the present invention can be embodied in various other forms.

[0060] <Modifications> In the above-described embodiment, one roll molded body 20 is accommodated in one case 10. However, this is not limited to this. The number of roll molded bodies 20 accommodated in one case 10 may be plural.

[0061] FIG. 5 is a diagram corresponding to FIG. 3 for the first modified example. In this modified example, a case 50 is used instead of the case 10. Furthermore, there are multiple (specifically, two) roll molded bodies 20. In this modified example, as shown in FIG. 5, the multiple roll molded bodies 20 are inserted (housed) through the inlet 50a of the case 50 with their winding axes aligned with the cylindrical axis direction X of the case 50. As a result, the multiple roll molded bodies 20 are arranged in series along the cylindrical axis direction X of the case 50. By arranging the multiple roll molded bodies 20 in series, it is possible to prevent the roll molded bodies 20 from rubbing against each other and causing the adsorbent to fall off, even if vibrations or impacts are applied during use. Furthermore, since a single locking member 15 can restrict movement of the multiple roll molded bodies 20 in the cylindrical axis direction X, productivity and workability can be improved, thereby achieving cost reduction.

[0062] In this modification, the roll molded body 20 includes a first roll molded body and a second roll molded body, and the first roll molded body and the second roll molded body may have different types of adsorbents. This allows the fluid composition (e.g., gas) to pass through the first roll molded body and the second roll molded body sequentially during use of the adsorption unit 100, allowing multiple types of components to be separated and recovered in a single adsorption unit. This improves convenience.

[0063] FIG. 6 is a view corresponding to FIG. 3 for a second modified example. In this modified example, a case 60 is used instead of the case 10. Furthermore, there are multiple (specifically, three or more) roll molded bodies 20. In this modified example, as shown in FIG. 6, when the multiple roll molded bodies 20 are inserted into the case 60, they are preferably held by, for example, an insertion jig (not shown) and grouped as a group of roll molded bodies 28. Here, the multiple roll molded bodies 20 are grouped so that their cylindrical axes are approximately parallel. Here, the group of roll molded bodies 28 (the multiple roll molded bodies 20) is inserted (accommodated) through the inlet 60a of the case 60 with the case 60 standing upright (the cylindrical axis direction X of the case 60 is aligned vertically). The multiple roll molded bodies 20 are arranged in parallel along the cylindrical axis direction X of the case 60. By arranging the multiple roll molded bodies 20 in parallel, the height of the suction unit (the dimension in the cylindrical axis direction X) can be reduced. However, the arrangement of the plurality of roll molded bodies 20 is not limited to being parallel, and they may be stacked in the cylinder axis direction X, for example, in multiple series or multiple parallel arrangements.

[0064] In this modification, it is preferable that all or part of the case 60 is made of punched metal, expanded metal, metal mesh (wire netting), etc. This improves the permeability of the fluid composition (e.g., gas) when the adsorption unit 100 is in use, and reduces the pressure loss when the fluid composition passes through the adsorption unit 100.

[0065] In the above-described embodiment, the case 10 is cylindrical (pipe-shaped) and has a substantially uniform inner diameter. However, this is not limiting. FIG. 7 is a view corresponding to FIG. 1 of a third modified example. In this modified example, a case 70 is used instead of the case 10. The case 70 has an accommodation space 72 for accommodating the roll molded body 20 therein and a flow path portion 73 communicating with the accommodation space 72 in the cylindrical axis direction X. Here, the flow path portion 73 is provided on both the inlet 70a side and the outlet 70b side of the case 70. The inner diameter D3 of the flow path portion 73 is smaller than the inner diameter D2 of the accommodation space 72 (D3<D2). The inner diameter D3 of the flow path portion 73 is typically smaller than the outer diameter of the roll molded body 20. Providing the accommodation space 72 facilitates positioning of the roll molded body 20 during manufacturing. Furthermore, even if the elastic restoring force of the roll molded body 20 decreases due to, for example, aging, the position of the roll molded body 20 in the cylindrical axis direction X is less likely to shift. In this case, the case 70 does not need to be provided with a locking portion (locking member 15).

[0066] In the above-described embodiment, the locking portion that restricts the movement of the roll molded body 20 in the cylindrical axis direction X is configured as the locking member 15. However, this is not limited to this. The locking member 15 may be a part of the case 10. The locking member 15 may be provided on the inner wall 10c of the case 10, for example, and may be configured as a protruding portion (protrusion, claw portion) that protrudes in a direction perpendicular to the cylindrical axis direction X.

[0067] As described above, specific aspects of the technology disclosed herein include those described in the following items. Item 1: An adsorption unit including one or more roll-formed bodies formed by spirally winding a sheet material having a substrate and an adsorbent supported on the substrate, and a cylindrical case accommodating the roll-formed body, wherein the roll-formed body is accommodated in the case with a winding axis direction aligned with the cylindrical axis of the case, and is held against the inner wall of the case by an elastic restoring force at least in the outer diameter direction. Item 2: The adsorption unit according to Item 1, wherein the substrate is made of a nonwoven fabric containing a fibrous material. Item 3: The adsorption unit according to Item 1 or 2, wherein the substrate has a porous structure, and the adsorbent is unevenly distributed within the substrate. Item 4: The adsorption unit according to any one of Items 1 to 3, wherein the adsorbent includes at least one of a metal-organic framework, activated carbon, silica gel, zeolite, and amorphous aluminum silicate. Item 5: The adsorption unit according to any one of Items 1 to 4, wherein the adsorbent includes a metal-organic framework. Item 6: The suction unit according to any one of Items 1 to 5, wherein the adsorbent content is 50% by mass or more when the entire sheet material is taken as 100% by mass. Item 7: The suction unit according to any one of Items 1 to 6, wherein, in a cross-sectional view perpendicular to the cylindrical axis direction, the roll molded body occupies 80% by area or more when the cross-sectional area of ​​the case is taken as 100% by area. Item 8: The suction unit according to any one of Items 1 to 7, wherein there are a plurality of roll molded bodies, and the plurality of roll molded bodies are arranged in series along the cylindrical axis direction of the case. Item 9: The suction unit according to Item 8, wherein the plurality of roll molded bodies include a first roll molded body and a second roll molded body, and the first roll molded body and the second roll molded body have different types of adsorbent. Item 10: The suction unit according to any one of Items 1 to 9, wherein the inner wall of the case is provided with a locking portion that restricts movement of the roll molded body in the cylindrical axis direction. Item 11: An adsorption unit described in any one of items 1 to 10, wherein a groove portion is provided on the inner wall of the case, and the locking portion is composed of a locking member fitted into the groove portion.Item 12: The adsorption unit according to any one of Items 1 to 11, wherein the case has a storage space in which the roll molded body is stored and a flow path portion that is in communication with the storage space in the cylindrical axis direction and has an inner diameter smaller than that of the storage space. Item 13: The adsorption unit according to any one of Items 1 to 12, which is used in an adsorption device that uses pressure swing adsorption or temperature swing adsorption. Item 14: A method for manufacturing an adsorption unit including one or more roll-formed bodies formed by spirally winding a sheet material having a substrate and an adsorbent supported on the substrate, and a cylindrical case for accommodating the roll-formed body, the method including: a preparation step of preparing the sheet material, a forming step of spirally winding the sheet material and shaping it into a roll-formed body, a housing step of compressing the roll-formed body in the inner diameter direction and accommodating it inside the case with the winding axis direction aligned with the cylindrical axis of the case, and a fixing step of releasing the roll-formed body from the compressed state to generate an elastic restoring force in the outer diameter direction and holding the roll-formed body against the inner wall of the case by the elastic restoring force. Item 15: The manufacturing method according to Item 14, wherein in the preparation step, a fibrous material and an adsorbent are dispersed in a solvent to prepare a slurry, and the slurry is formed into a sheet by a wet papermaking method to produce the sheet material. Item 16: A manufacturing method according to Item 14 or 15, wherein in the accommodating step, an insertion jig having a tapered inner wall surface configured so that the inner diameter gradually decreases from the first end toward the second end is prepared, the second end of the insertion jig is attached to one end of the case in the cylindrical axis direction, and the roll molded body is inserted from the first end of the insertion jig in a state in which the internal space of the insertion jig is connected to the internal space of the case, and the roll molded body is moved along the tapered inner wall surface to be compressed in the internal diameter direction, and the roll molded body is extruded from the second end and accommodated inside the case.

[0068] REFERENCE SIGNS LIST 10 Case 10c Inner wall 12 Internal space 14 Groove 15 Locking member 20 Roll-formed body 100 Suction unit

Claims

1. An adsorption unit comprising: one or more roll-formed bodies formed by spirally winding a sheet material having a substrate and an adsorbent supported on the substrate; and a cylindrical case that houses the roll-formed bodies, wherein the roll-formed bodies are housed in the case with the direction of their winding axis coinciding with the cylindrical axis of the case, and are held against the inner wall of the case by elastic restoring force at least in the direction of their outer diameter.

2. The adsorption unit according to claim 1, wherein the substrate is made of a nonwoven fabric containing a fibrous material.

3. The adsorption unit according to claim 1 or 2, wherein the substrate has a porous structure, and the adsorbent is unevenly distributed inside the substrate.

4. The adsorption unit according to claim 1 or 2, wherein the adsorbent material comprises at least one of a metal-organic framework, activated carbon, silica gel, zeolite, and amorphous aluminum silicate.

5. The adsorption unit according to claim 1 or 2, wherein the adsorbent comprises a metal-organic framework.

6. The adsorption unit according to claim 5, wherein the content of the adsorbent is 50% by mass or more when the entire sheet material is taken as 100% by mass.

7. The suction unit according to claim 1 or 2, wherein, in a cross-sectional view perpendicular to the cylindrical axis direction, the roll-formed body occupies 80% or more of the cross-sectional area of ​​the case, where the cross-sectional area of ​​the case is 100%.

8. The suction unit according to claim 1 or 2, wherein there are a plurality of the roll-formed bodies, and the plurality of roll-formed bodies are arranged in series along the cylindrical axis direction of the case.

9. The adsorption unit according to claim 8, wherein the plurality of roll molded bodies include a first roll molded body and a second roll molded body, and the first roll molded body and the second roll molded body have different types of adsorbent material.

10. The suction unit according to claim 1 or 2, wherein the inner wall of the case is provided with a locking portion that restricts movement of the roll-formed body in the axial direction of the cylinder.

11. The suction unit according to claim 10, wherein a groove is provided on the inner wall of the case, and the locking portion is composed of a locking member fitted into the groove.

12. An adsorption unit as described in claim 1 or 2, wherein the case has: a storage space in which the roll molded body is stored; and a flow path portion that is connected to the storage space in the cylindrical axis direction and has an inner diameter smaller than that of the storage space.

13. The adsorption unit according to claim 1 or 2, which is used in an adsorption apparatus utilizing pressure swing adsorption or temperature swing adsorption.

14. A method for manufacturing an adsorption unit comprising one or more roll-formed bodies formed by spirally winding a sheet material having a substrate and an adsorbent supported on the substrate, and a cylindrical case for accommodating the roll-formed bodies, the method comprising: a preparation step for preparing the sheet material; a forming step for spirally winding the sheet material and shaping it into a roll-formed body; a housing step for compressing the roll-formed body in the inner diameter direction and accommodating it inside the case with the winding axis direction aligned with the cylindrical axis direction of the case; and a fixing step for releasing the roll-formed body from its compressed state to generate an elastic restoring force in the outer diameter direction, and for holding the roll-formed body against the inner wall of the case by the elastic restoring force.

15. The manufacturing method according to claim 14, wherein in the preparation step, a fibrous material and an adsorbent are dispersed in a solvent to prepare a slurry, which is then formed into a sheet by a wet papermaking method to produce the sheet material.

16. A manufacturing method as described in claim 14 or 15, wherein the accommodation step comprises preparing an insertion jig having a tapered inner wall surface configured so that the inner diameter gradually decreases from the first end toward the second end, attaching the second end of the insertion jig to one end of the case in the cylindrical axis direction, and, with the internal space of the insertion jig connected to the internal space of the case, inserting the roll molded body from the first end of the insertion jig, moving the roll molded body along the tapered inner wall surface to compress it in the inner diameter direction, and pushing the roll molded body out from the second end to accommodate it inside the case.

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