JP7430539B2 - Gas adsorption device, method of manufacturing an adsorption unit, and method of manufacturing a gas adsorption device - Google Patents

Description

The technology disclosed in this application relates to a gas adsorption device that captures gas molecules using a porous body.

In a gas adsorption device that uses a porous adsorbent to capture gas molecules, the adsorbent is held in a predetermined region within a gas passage by various methods. For example, in the method disclosed in International Publication No. 2018/062504, MOF (Metal Organic Framework)/PCP (Porous Coordination Polymer), which is a type of porous material, is The MOF/PCP is retained in the marshmallow gel by introducing the powder into the marshmallow gel in a state in which it is dispersed in a suitable solvent and removing the solvent by drying. Japanese Unexamined Patent Publication No. 2017-198884 discloses a filter that captures VOC (volatile organic compounds) generated from an electrophotographic image forming apparatus. In this filter, MOF/PCP is retained by filling a cloth bag or mixing it with a synthetic resin.

International Publication No. 2018/062504 pamphlet Japanese Patent Application Publication No. 2017-198884

In the technique of International Publication No. 2018/062504, the marshmallow gel is expensive, and a drying process is required to remove the solvent used for introducing MOF/PCP from the marshmallow gel. Moreover, when the marshmallow gel comes into contact with some kind of liquid, the MOF/PCP is easily expelled from the marshmallow gel. In the filter disclosed in Japanese Unexamined Patent Publication No. 2017-198884, MOF/PCP is held in a predetermined position by filling a cloth bag or mixing it into a synthetic resin support. Since the MOF/PCP placed in the flow path, such as by being filled in a cloth bag, blocks the gas flow path, pressure loss is large. Further, if the porous body expands in volume during gas adsorption, the support such as a cloth bag may be damaged and the porous body may leak out. Therefore, it is desirable to solve at least one of the above problems.

One embodiment of the technology disclosed in this application is a gas adsorption device, which includes at least one adsorption unit in a gas flow path, and each adsorption unit includes a porous adsorbent that adsorbs gas molecules, and a porous adsorbent that adsorbs gas molecules. and an air-permeable container that accommodates an adsorbent, and the container is configured to be able to follow changes in the volume of the adsorbent. In some embodiments, the interior of the container has a void larger than the volumetric expansion that occurs in the adsorbent under the usage environment. In some embodiments, the container is formed from a flexible material. In some embodiments, at least a portion of the container includes a bellows structure. This provides the effect that, for example, the container will not be damaged even if the volume of the adsorbent changes.

In some embodiments, the container includes a protrusion on its outer surface to ensure a clearance around the suction unit. In some embodiments, the protrusion is a plurality of planar protrusions, and each protrusion is provided in a different direction. This prevents the containers from being too crowded together and the pressure loss of the gas flow from becoming excessive.

In some embodiments, the adsorption unit includes a through hole that is separated from the internal space of the container. In some embodiments, the gas adsorption device further comprises an adsorption layer, and the adsorption unit is arranged adjacent to the adsorption layer and the through-hole is oriented in the direction of gas flow. According to this, it can be used as a partition member for partitioning the adsorption layer, and the adsorption performance of the device can be improved. In addition, by appropriately designing the through holes, it is possible to control gas flow and adjust ventilation resistance.

In some embodiments, the adsorption unit may include the steps of putting a predetermined amount of adsorbent into a long bag with one end open, and sealing the bag so that the adsorbent is enclosed to form the adsorption unit. and a step of separating the suction unit. In some embodiments, the adsorption unit includes the steps of setting a first sheet so that a depression is formed, putting an adsorbent into the depression, and stacking a second sheet on the first sheet. and sealing the two sheets around the adsorbent so that the adsorbent is encapsulated. Adsorption units can be easily formed using these methods.

It is a sectional view showing an adsorption unit as one embodiment. FIG. 2 is a sectional view of a gas adsorption device as one embodiment using the adsorption unit of FIG. 1. FIG. It is a figure explaining the effect|action of the protrusion part of a suction unit. FIG. 2 is a cross-sectional view showing a container swollen due to volumetric expansion of the adsorbent of the adsorption unit of FIG. 1. FIG. FIG. 3 is a perspective view showing a perforated plate that can be used for manufacturing an adsorption unit. FIG. 3 is a cross-sectional view showing a process of putting an adsorbent into the recesses of a first sheet set on a perforated plate. FIG. 3 is a cross-sectional view showing a process of thermally welding two sheets around an adsorbent. FIG. 3 is a cross-sectional view showing a process of separating individual adsorption units. 1 is a perspective view of a grooved plate that can be used in manufacturing elongated suction units; FIG. FIG. 3 is a perspective view showing a suction unit having planar protrusions formed in different directions. FIG. 2 is a perspective view showing a suction unit having a cross-shaped planar protrusion. It is a figure explaining another method of manufacturing an adsorption unit. FIG. 7 is a sectional view showing an adsorption unit using a container having a bellows structure as another embodiment. FIG. 7 is a sectional view showing an adsorption unit having a through hole as another embodiment. 15 is a sectional view taken along the line XV-XV of the suction unit in FIG. 14. FIG. FIG. 15 is a sectional view of a gas adsorption device as one embodiment using the adsorption unit of FIG. 14.

Hereinafter, various embodiments of the technology disclosed in this application will be described with reference to the drawings. It should be noted that portions of the following embodiments that are not substantially different from each other are given similar reference numerals to avoid repetition of description.

FIG. 1 shows an adsorption unit 10 that can be used in a gas adsorption device as one embodiment, and FIG. 2 shows a gas adsorption device 12 that uses a large number of such adsorption units 10. Gas adsorption device 12 captures desired gas molecules from the gas passed into the casing. Examples of gas adsorption devices include charcoal canisters and vapor collectors that adsorb fuel vapor generated from a fuel tank of an automobile to prevent it from being released into the atmosphere. It is also possible to switch between adsorption and desorption by reversing the gas flow direction. The gas adsorption device 12 includes at least one adsorption unit 10, and each adsorption unit 10 has a porous adsorbent 14 (porous body) and a container 16 that accommodates the adsorbent 14.

The porous adsorbent 14 is, for example, MOF/PCP, COF (Covalent Organic Framework), activated carbon, zeolite, porous polymer, porous alumina, porous silica, molecular sieve, or any of these. Can be any combination. A person skilled in the art can select an appropriate porous material depending on the application of the gas adsorption device. For the adsorbent 14, a material that changes in volume each time it adsorbs and desorbs gas molecules or changes in volume over time due to repeated adsorption and desorption can also be selected. MOF/PCP is, for example, Cu(bpy) ₂ (BF ₄ ) ₂ (bpy=4,4'-bipyridine) (commonly known as ELM-11) or Fe(OH)(BDC) (BDC=1,4-benzenedidine). carboxylate) (commonly known as MIL-53(Fe)). In all of these examples, the volume increases due to adsorption of gas molecules, and the volume decreases due to desorption. Adsorbent 14 can be in powder form.

Although not shown, in addition to the porous adsorbent 14, the container 16 can also contain a heat storage agent for absorbing heat generated from the porous adsorbent 14 during adsorption.

As shown in FIGS. 1 and 4, the container 16 has air permeability and is configured to follow changes in the volume of the adsorbent 14. For example, the container 16 can be formed from a flexible material, such as an elastic material. In this way, even if the adsorbent 14 expands in volume, the container 16 will not be damaged. It is preferable that the interior of the container 16 has a void larger than the amount of volumetric expansion that occurs in the adsorbent 14 under the usage environment. Moreover, when the heat storage agent is contained in the container 16, the heat transfer efficiency is increased by increasing the contact area between the heat storage agent and the porous adsorbent 14 due to contraction of the container 16. The container 16 can be made of a material such as a nonwoven fabric, a net, a film, or a membrane made of a synthetic resin such as polypropylene, polyethylene, PET (polyethylene terephthalate), polyamide (nylon, etc.) or a polymer such as cellulose. The materials constituting the container 16, such as nonwoven fabrics, have a large number of holes (voids) in a mesh pattern. The hole is made larger than the size of the gas molecule to be adsorbed (for example, a hydrocarbon of butane or higher in the case of a canister) so that the gas molecule can come into contact with the adsorbent 14 in the container 16. Further, the hole is made smaller than the size of the adsorbent 14 before its volume increases so that the adsorbent 14 inside the container 16 does not leak out of the container 16. Those skilled in the art can select an appropriate material that satisfies the above conditions depending on the application of the gas adsorption device.

As shown in FIG. 13, as another embodiment, the bellows structure 18 may be provided on at least a portion of the container 316 of the adsorption unit 310. In this way, even if the adsorbent 14 expands in volume, the container 316 will expand and will not be damaged.

As shown in FIG. 1, the container 16 of the suction unit 10 can be provided with a protrusion 20 on the outer surface to ensure a clearance around the container 16. As can be seen from FIG. 3, the presence of this protrusion 20 becomes an obstacle to the suction units 10 coming into close contact with each other or the suction units 10 and surrounding objects. Therefore, gas pressure loss can be reduced and adsorption efficiency can be increased. As shown in FIG. 10, as another embodiment, a plurality of planar protrusions 120 may be provided in the suction unit 110 in different directions. As shown in FIG. 11, as yet another embodiment, the suction unit 210 may be provided with a cross-shaped planar protrusion 220. The protrusions 20, 120, 220 described above may also be formed by welds formed when sealing the container 16, as described below.

[Manufacture of adsorption unit]
The adsorption unit 10 described above can be easily manufactured by the method described below. As shown in FIGS. 6 to 8, in one embodiment, first, a first plate made of a non-woven fabric made of resin, for example, is placed on a base such as a plate 22 having a plurality of holes 24 (or recesses) as shown in FIG. set the sheet 26. Next, a predetermined amount of adsorbent 14 is placed in the depression 32 of the sheet 26 formed at the location of the hole 24 of the plate 22 (FIG. 6). The adsorbent 14 can also be introduced into each recess 32 from multiple nozzles 28 at the same time. Next, a second sheet 30 made of a similar non-woven fabric is superimposed on the first sheet 26, and the two sheets 26, 30 are thermally welded to each other around each hole 24 to form the container 16, and the adsorbent 14 is (Figure 7). The sheets 26 and 30 are cut at the welded portion 34 to separate the individual suction units 10 (FIG. 8). The welded portion 34 after cutting becomes a continuous planar protrusion 20 surrounding the outer periphery of the container 16 as shown in FIGS. 1 to 4 described above. Although not shown, as another embodiment, it is also possible to use a stand without holes in place of the plate 22 having the holes 24 described above, and to place the adsorbent 14 at a predetermined position on the first sheet 26 without relying on the depressions. It is. As shown in FIG. 9, as another embodiment, it is also possible to manufacture an elongated adsorption unit 10 (not shown) by using a plate 122 having grooves 36 and placing the adsorbent 14 while moving the nozzle. be.

As shown in FIG. 12, in another embodiment, first, a predetermined amount of adsorbent 14 is put into a long bag 38 with one end open. Next, a bag 38 is thermally welded to the upper end of the charged adsorbent 14 to form a closed container 16, and the adsorbent 14 is sealed inside. By repeating this process, a plurality of suction units 110 partitioned by welded portions 34 are formed. Finally, the bag 38 is cut at the welded portion (as shown by the broken line) to separate the individual suction units 110. In this case as well, the welded portion 34 becomes the protrusion 120 on the outer surface of the container 16 described above. By welding adjacent welding parts 34 in different directions, planar protrusions 120 in different directions as shown in FIG. 10 described above are formed. Further, by thermally welding three or more hot plates against each other, it is also possible to form a cross-shaped protrusion 220 as shown in FIG. 11, for example.

Although not shown, in yet another embodiment, the container 16 may be sealed using a welding method other than thermal welding or an adhesive.

[Through hole]
As shown in FIGS. 14 and 15, the adsorption unit 410 can be provided with at least one through hole 40 that is separated from the internal space of the container 416. Thereby, ventilation resistance and pressure loss can be easily adjusted by appropriately designing the number, size, and shape of the through holes 40. The through hole 40 can be formed by thermal welding in the same manner as the sealing of the container 16 described above.

[Use of suction unit]
The adsorption units 10, 110, 210, 310, and 410 described above can be used in various ways in the casing 44 of the gas adsorption device 12 provided in the gas passage 42. As shown in FIG. 2, in one embodiment, the adsorption units 10 of the gas adsorption device 12 can be arranged as an assembly within the casing 44 (only some adsorption units are depicted in the figure). The white arrow indicates the direction of gas flow during the adsorption operation. The assembly of suction units 10 is held by, for example, being sandwiched between urethane sheets 46 and 48 from both sides to prevent outflow, and further by being sandwiched between pressing members 50 and 52 from both sides. The holding members 50 and 52 are, for example, resin members (referred to as plates) having large gaps so as not to obstruct the flow of gas. The holding members 50 and 52 that sandwich the assembly of the suction units 10 are supported within the casing 44 by, for example, a rib 54 protruding from the inner surface of the casing 44 on one side, and are allowed to be displaced using a compression spring 56 on the other side. while being elastically supported. Compared to the case where the adsorbent 14 is directly aggregated and arranged as an adsorption layer, since the adsorbent 14 is subdivided into a large number of adsorption units 10, more gaps are created between the adsorption units 10. Therefore, the pressure loss of gas can be reduced and the efficiency of adsorption and desorption can be increased.

As shown in FIG. 16, as another embodiment, an adsorption unit 410 having a through hole 40 as described above can be used as a partition member or a presser for an original adsorption layer 58 that is separately arranged in a casing 44 of a gas adsorption device 412. It can be used as a member. For example, it can be used as a substitute for (one or both of) the holding members 50 and 52 in the gas adsorption device 12 of FIG. 2 described above. The adsorption layer 58 of the gas adsorption device 412 is made of, for example, an aggregate of granular activated carbon 60 (only some activated carbon particles are shown in the figure). The adsorption unit 410 is formed into a disk shape having a diameter approximately the same as the inner diameter of the casing 44, and is disposed adjacent to the adsorption layer. According to this, gas molecules can be adsorbed even by the partition member or the pressing member containing the adsorbent 14 in this way, and the adsorption performance of the gas adsorption device 412 can be increased. The through hole 40 of the adsorption unit 410 also functions to control the flow of gas within the casing 44. Those skilled in the art can achieve desired flow control by appropriately designing the number, size, and shape of the through holes 40. For example, the through hole 40 is formed so as to face the direction of the gas flow when the adsorption unit 410 is placed in the casing 44 . Furthermore, the surface area of the adsorption unit 410 increases due to the presence of the through holes 40, so that the efficiency of adsorption and desorption is improved.

Although specific embodiments have been described above, the technology disclosed in this application is not limited to these embodiments, and those skilled in the art can make various substitutions, improvements, and changes without departing from the purpose of the technology. It is possible to apply

10 Adsorption unit 12 Gas adsorption device 14 Adsorbent 16 Container 18 Bellows structure 20 Projection portion 22 Plate 24 Hole 26 First sheet 28 Nozzle 30 Second sheet 32 Recess 34 Welded portion 36 Groove 38 Bag 40 Through hole 42 Gas passage 44 Casing 46, 48 Urethane sheets 50, 52 Pressing member 54 Rib 56 Compression spring 58 Adsorption layer 60 Activated carbon

Claims (9)

A gas adsorption device,
Equipped with a collection of multiple adsorption units in the gas flow path,
Each adsorption unit includes a porous adsorbent that adsorbs gas molecules, and a breathable container that houses the adsorbent,
The container is made of a flexible material other than the marshmallow gel and the cloth bag so as to follow the volume change of the adsorbent ,
The container is provided with one or more planar protrusions on the outer surface for securing a gap around the suction units, and the plurality of suction units are arranged in a state where the protrusions are oriented in various directions. A gas adsorption device that forms an aggregate. A gas adsorption device,
Equipped with at least one adsorption unit in the gas flow path,
Each adsorption unit includes a porous adsorbent that adsorbs gas molecules, and a breathable container that houses the adsorbent,
The container is made of a flexible material other than the marshmallow gel and the cloth bag so as to follow the volume change of the adsorbent,
A gas adsorption device including a bellows structure in at least a portion of the container. A gas adsorption device,
Equipped with at least one adsorption unit in the gas flow path,
Each adsorption unit includes a porous adsorbent that adsorbs gas molecules, and a breathable container that houses the adsorbent,
The container is made of a flexible material other than the marshmallow gel and the cloth bag so as to follow the volume change of the adsorbent,
The gas adsorption device includes a through hole in the adsorption unit that is separated from the internal space of the container and formed by thermal welding . 4. The gas adsorption device according to claim 3, further comprising an adsorption layer, wherein the adsorption unit is arranged adjacent to the adsorption layer and the through hole is oriented in the direction of gas flow. 5. The gas adsorption device according to claim 2, wherein the container has one or more planar protrusions on its outer surface for securing a gap around the adsorption unit. 6. The gas adsorption device according to claim 1, wherein the protrusion is a plurality of planar protrusions, and each protrusion is provided in different directions. The gas adsorption device according to any one of claims 1 to 6, wherein the interior of the container has a void larger than the volumetric expansion that occurs in the adsorbent under the usage environment. A method for manufacturing an adsorption unit comprising a porous adsorbent that adsorbs gas molecules and a breathable container that houses the adsorbent, the container being configured to follow changes in the volume of the adsorbent. And,
The container is made of a flexible material except for the marshmallow gel and the cloth bag,
A step of introducing a predetermined amount of adsorbent into a long bag with one end open; and a step of sealing the bag to become the container so that the adsorbent is enclosed to form an adsorption unit. and separating the adsorption unit. A method for manufacturing the gas adsorption device according to claim 1, comprising:
a step of setting a first sheet made of a flexible material excluding marshmallow gel and a cloth bag so as to form a recess; a step of placing an adsorbent in the recess; and a step of placing a marshmallow in the first sheet. The step of stacking a second sheet made of a flexible material excluding the gel and the cloth bag , and sealing the two sheets around the adsorbent so that the adsorbent is encapsulated. forming the adsorption unit having a protrusion on its outer surface, and arranging the thus formed plurality of adsorption units as an assembly in a gas flow path with the protrusion facing various directions; A method comprising:

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