JP2002295797A - Adsorption sheet for gas storage, and pressure vessel for gas storage with the sheet accommodated therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a technology of easily filling an adsorbent for gas storage in a pressure vessel at high density without scattering the adsorbent. SOLUTION: An adsorbent sheet for gas storage which is formed of a powder adsorbent for gas storage formed in a sheet shape is wound in a roll, or adsorbent sheet pieces obtained by cutting the adsorbent sheet to the sectional shape of a gas storage unit of the pressure vessel are stacked to form a laminate, and the roll or the laminate is filled in the gas storage unit of the pressure vessel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an adsorbent for gas storage and a pressure vessel for gas storage filled with the adsorbent.

[0002]

2. Description of the Related Art As a method of storing gas, such as gaseous fuel such as hydrogen or methane, at a higher density than conventional compression cylinders, a specific gas such as activated carbon or a hydrogen storage alloy is adsorbed in a pressure vessel. A pressure vessel for filling a material to be occluded has been proposed.

[0003] A pressure vessel filled with such a gas adsorbent stores the same amount of gas as a conventional cylinder at the same volume and a smaller pressure as compared with the conventional one, or at the same pressure and a smaller volume as compared to a conventional cylinder. can do. Also, with the same volume and pressure as the conventional cylinder, a larger amount of gas can be stored than the conventional cylinder.

However, when the adsorbent is filled in the pressure vessel, the powder or granular adsorbent is filled as it is or is formed into an arbitrary pellet.

When the powdery adsorbent is directly charged into the pressure vessel, there are problems such as scattering of the powdery adsorbent and deterioration of the working environment. Had to be put into the pressure vessel little by little, and much labor and time had to be spent.

[0006] A method has also been proposed in which the adsorbent is formed into an arbitrary pellet shape and filled into a pressure vessel. According to this method, the adsorbent can be easily filled into the pressure vessel without being distracted by the scattering of the adsorbent, but since the degree of freedom of the shape of the molded adsorbent is low, the adsorbent is placed in the pressure vessel. The packing could not be performed in a high-density state, and the effect of increasing the gas storage amount of the pressure vessel by filling the adsorbent was not so large.

On the other hand, it has also been proposed to mold the adsorbent into a shape and size corresponding to the shape and size of the gas storage portion of the pressure vessel in order to fill the formed adsorbent into the pressure vessel at a high density. I have. However, in this case, it is necessary to precisely measure the shape and dimensions of the gas storage portion of the pressure vessel,
This requires a lot of effort and time. Further, if the shape and size of the pressure vessel are different, it is necessary to mold an adsorbent having a new shape and size corresponding to the shape and size. Therefore, it is difficult to form a molded body having a general-purpose shape and dimensions that can be filled in a pressure vessel in a high-density state, and it has not been possible to reduce costs in producing a molded body.

[0008]

SUMMARY OF THE INVENTION The main object of the present invention is to develop a technology which makes it possible to easily and densely pack an adsorbent into a pressure vessel without causing the problem of scattering. is there.

[0009]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have achieved the above object by forming an adsorbent into a sheet and forming an adsorbent sheet. I found that.

That is, the present invention provides the following adsorbent sheet, gas storage pressure vessel, method for filling a gas storage adsorbent into a pressure vessel, gas storage pressure vessel, and gas storage method.

Item 1 A gas storage adsorbent sheet comprising a powdery adsorbent capable of storing and releasing gas and a binder and having flexibility.

Item 2. The adsorbent sheet according to item 1, wherein the powdery adsorbent is at least one selected from the group consisting of a carbonaceous adsorbent, a hydrogen storage alloy, and a zeolite.

Item 3. The adsorbent sheet according to item 1, wherein the ratio S / T is 100/1 or more when the area of one side of the sheet is S (cm ² ) and the thickness is T (cm).

Item 4 is a gas storage pressure vessel filled with an adsorbent capable of storing and releasing gas, wherein the adsorbent is obtained by winding the adsorbent sheet according to any one of Items 1 to 3 above. It is a roll-shaped material or obtained by stacking adsorbent sheet pieces obtained by cutting the adsorbent sheet according to any one of items 1 to 3 according to the cross-sectional shape of the gas storage section of the pressure vessel. A pressure vessel for gas storage, which is a laminate.

Item 5 is a method of filling the gas storage adsorbent into a pressure vessel, wherein the gas storage adsorbent is used as described in the above item 1 to item 1.
3. The roll-shaped material obtained by winding the adsorbent sheet according to any one of the above items 3 or the adsorbent sheet according to any one of the above items 1 to 3 is cut in accordance with the sectional shape of the gas storage section of the pressure vessel. A method comprising filling a pressure vessel in the form of a laminate obtained by laminating adsorbent sheet pieces obtained by the above method.

Item 6. A gas storage pressure container according to Item 4, wherein the gas is filled in the gas storage pressure container.

Item 7 A gas storage method characterized by filling the gas storage pressure container according to Item 4 with a gas.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Powdery adsorbent As the powdery adsorbent used in the present invention, any of those used for gas storage can be used. For example, activated carbon, carbon materials including carbon nanotubes, activated carbon Examples include carbonaceous adsorbents such as carbon fibers, hydrogen storage alloys, zeolites, and the like. Among these, carbonaceous adsorbents such as activated carbon and carbon materials including carbon nanotubes are particularly preferred.

As the activated carbon, various types of carbons conventionally used for gas storage can be used.

The carbon material containing the carbon nanotube is preferably a carbon material containing 50% by weight or more, particularly about 90 to 100% by weight of the carbon nanotube. Such a carbon material may be manufactured by any method that can synthesize carbon nanotubes, such as arc discharge, laser ablation, and thermal CVD. As the carbon nanotube contained in the carbon material, various diameters can be used as long as gas can be stored.
Those having a size of about m to 100 nm are preferred. In addition, the content of the carbon nanotube in the carbon material is measured by a scanning electron microscope and an organic matter combustion decomposition method.

The average particle diameter of the powdery adsorbent is as follows:
0.01 as measured by gravity sedimentation and centrifugal sedimentation
It is preferable that the thickness is about 1000 μm, particularly about 0.02 to 500 μm.

The powdery adsorbent adsorbs various gases, for example, hydrogen, methane, nitrogen, helium, argon and the like under pressure, and releases the gases when the pressure is reduced. Therefore, it is suitable for storing these gases.

Examples of the binder used in the binder present invention is intended to form a sheet having flexibility bonded to each other particles of the powdered adsorbent, within a wide range can be used.

Examples of the binder include clays such as Kibushi, frog eyes, bentonite and the like, starches such as dextrin and corn starch, proteins such as casein and gelatin, tar and asphalt and the like, methylcellulose, ethylcellulose, carboxycellulose and hydroxy. Cellulose derivatives such as ethyl cellulose and cyanoethyl cellulose, natural rubber, polyvinyl alcohol, polyethylene, polyester, vinyl acetate, phenolic resin, epoxy resin, furan resin, alkyd resin, styrene butadiene resin, butadiene resin, chloroprene resin, butyl resin, acrylonitrile, acrylic Examples thereof include natural or synthetic resins such as resins, and isocyanates. Among these binders, polyvinyl alcohol, methyl cellulose and the like can be preferably used.

The amount of the binder to be used can be selected from a wide range as long as the powdery adsorbent can be formed into a sheet shape.
The solid content is preferably about 0.5 to 20 parts by weight, particularly preferably about 1 to 10 parts by weight.

The above-mentioned binder can be used after being diluted with a diluting medium such as alcohols such as water, methanol, ethanol and propanol.

Adsorbent Sheet In the present invention, the above powdery adsorbent is formed into a flexible sheet and used as an adsorbent sheet. The adsorbent sheet has, for example, a property that it is not damaged even when bent at an acute angle or wound in a roll shape (herein, referred to as “flexible”).

Further, in the adsorbent sheet of the present invention, the area of one surface of the adsorbent sheet is S (cm ² ), and the thickness is T (c).
m) and the ratio S / T is 100/1 or more, especially 20
It is preferably about 0/1 to 100000/1.

In general, the thickness of the adsorbent sheet of the present invention is not particularly limited, but from the viewpoint of strength and ease of processing,
About 0.001 to 1000 mm, especially 0.01 to 500
It is preferably about mm.

In the adsorbent sheet of the present invention, first, a powdered adsorbent and the above-mentioned predetermined amount of the binder are uniformly mixed to obtain a raw material of a compact, which is formed into a sheet, and the obtained sheet is dried. Can be manufactured.

In order to produce a raw material for a molded article, the whole may be stirred and uniformly mixed while adding the binder or the binder diluted in the diluting medium to the powdery adsorbent.

In order to mold the thus obtained molded body raw material, a method in which the molded body raw material is supplied between two rotating rollers and extruded from the rollers can be exemplified. By drying the sheet thus formed, the particles of the powdery adsorbent are adhered to each other by the binder, and the adsorbent sheet of the present invention is obtained. Since the amount of the binder used is small enough to adhere the particles of the powdery adsorbent to each other, the gas storage capacity of the powdery adsorbent is not significantly impaired.

In the present invention, the powdery adsorbent is formed into a flexible sheet which is not damaged even when bent at an acute angle as described above or wound into a roll, and used as an adsorbent sheet. Things. Preferably, the adsorbent sheet comprises a powdered adsorbent and a binder and is recommended to be in the form of a self-supporting film. Here, “independence” means that the sheet retains the form of the sheet without using a support.

Method of Filling Pressure Vessel A typical example of the pressure vessel used in the present invention is a pressure vessel having a cylindrical main body, and various pressure vessels conventionally used are used. it can.

According to the present invention, the powdery adsorbent is formed into a sheet to form an adsorbent sheet 1 as shown in FIG.
By winding this into a roll as shown in FIG. 2, a roll 2 having a cylindrical outer shape can be manufactured.

When filling the gas storage portion of the cylindrical pressure vessel, the number of turns of the adsorbent sheet can be changed to easily produce a roll-shaped material that matches the inner diameter of the gas storage portion. . Therefore, regardless of the size of the gas storage portion of the pressure vessel, if the adsorbent sheet or sheet-like molded body of the present invention is used, the adsorbent can be densely packed in the pressure vessel simply by changing the number of turns of the sheet. Can be filled.

That is, in the present invention, if the sheet-shaped molded article or the adsorbent sheet 1 of the present invention is prepared in advance as a general-purpose product, the inner diameter of the cylindrical pressure vessel can be any size. The roll-shaped material 2 according to the above can be easily prepared, and the adsorbent can be filled at a high density.

Further, even when the length of the pressure vessel is greater than the width of the adsorbent sheet 1 of the present invention, that is, when the length of the pressure vessel is greater than the height of the roll-shaped material 2. Even so, the space of the gas storage portion in the pressure vessel can be filled by using a plurality of the roll-shaped materials 2 arranged vertically.

Further, the above-mentioned roll-shaped material can be accommodated in a pressure vessel having a shape other than the cylindrical shape. For example,
A number of relatively small-diameter rolls 2 can be arranged in parallel to form a bundle and filled without leaving a space in the pressure vessel.

According to another embodiment of the present invention, the adsorbent sheet 1 of the present invention is cut in accordance with the cross-sectional shape of the gas storage portion of the pressure vessel to obtain an adsorbent sheet piece. Can be used.

For example, when the gas storage unit is housed in a cylindrical pressure vessel, as shown in FIG. 4, the adsorbent sheet of the present invention is cut into a circle having a diameter slightly smaller than the inner diameter of the pressure vessel. The obtained circular sheets 3 are stacked so as to have a predetermined height as shown in FIG. 5 to produce a cylindrical laminate 4, which can be stored in the gas storage portion of the pressure vessel.

Also in this embodiment, it is only necessary to stack the adsorbent sheet pieces 3 obtained by cutting the adsorbent sheet according to the shape of the gas storage portion of the pressure vessel, so that the inner diameter of the cylindrical pressure vessel is reduced. Regardless of the dimensions, the adsorbent sheet pieces 3 and the laminate 4 obtained by stacking the adsorbent sheet pieces 3 can be easily prepared, and the adsorbent can be filled at a high density.

Regardless of the length of the pressure vessel, the space of the gas storage portion in the pressure vessel can be substantially completely adjusted by adjusting the number of the adsorbent sheet pieces 3 to be stacked. Can be filled.

The above-mentioned adsorbent sheet pieces according to the shape can also be stacked and filled in a pressure vessel having a shape other than the cylindrical shape.

As shown in FIG. 6, a bottom 10 having a shape conforming to the cross-sectional shape of the pressure vessel or the gas storage section of the pressure vessel, and the bottom 10 Post 11 standing at or near the center
Using a support member 12 provided with, a hole is formed in the center of the adsorbent sheet piece 3 or in the vicinity thereof and a hole is passed through a support to produce a cylindrical laminate, and the obtained laminate is pressed together with the support member into a pressure vessel or The pressure vessel may be filled.

Further, as shown in FIG. 7, a bottom 15 and a plurality of columns 16, 16 'and 1 standing upright around the bottom.
The suction sheet pieces 3 may be stacked using the support 17 having 6 ″, and the obtained laminate may be filled in a pressure vessel or a pressure vessel together with the support 17.

Gas Storage Pressure Vessel As described above, the pressure vessel used in the present invention is, for example, as shown in FIG. 8 because of the filling of a roll or a laminate obtained from the adsorbent sheet of the present invention. In addition, a type including a main body 22 having the same inner diameter d1 of the gas storage unit 20 and an inner diameter of the opening 21 thereof, and a lid 23 can be exemplified as an example. There are through holes 24, 24 'through which bolts are passed around the lid 23 and the upper flange of the main body 22, so that the container can be hermetically sealed using an appropriate packing. Further, the lid portion 23 of the pressure vessel is provided with a gas introduction / extraction port (not shown) for storing and extracting gas. Such pressure vessels are known in the field of gas storage.

The roll or laminate obtained from the adsorbent sheet of the present invention is filled in the gas storage section 20 in the main body 22. At the time of filling, it is preferable to fill so that the space of the gas storage unit 20 is as small as possible. Next, the main body 22 and the lid 23 are hermetically joined by a method known per se. Thus, the gas storage pressure vessel of the present invention is obtained.

Gas Storage Method and Gas Storage Pressure Vessel In order to store gas in the gas storage pressure vessel of the present invention obtained above, pressurized gas may be injected into the pressure vessel using a compressor. Thus, a pressure vessel storing the gas of the present invention is obtained. Examples of the gas that can be stored include hydrogen, methane, helium, nitrogen, and argon.

When removing the gas from the pressure vessel of the present invention in which the gas is stored, a pressure reducing valve may be attached and the pressure may be reduced to a required pressure.

The removal of the gas from the pressure vessel storing the gas of the present invention and the storage of the gas can be carried out repeatedly.

[0052]

The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1 Activated carbon was used as a gas adsorbent. This activated carbon is a powder having an average particle diameter of 100 μm. This activated carbon powder 1
While adding an aqueous solution of polyvinyl alcohol (concentration: 1% by weight) to 00 parts by weight as a binder, the whole is stirred and uniformly mixed to prepare a molded material containing 2 parts by weight of a binder after drying.

A strip-shaped adsorbent sheet having a thickness of 1 mm and having flexibility was prepared from the raw material of the molded body. That is, the above-mentioned raw material for the compact is injected into a contact portion between two rollers having a width of 30 cm and formed into a sheet having a width of 30 cm and a thickness of 1 mm. The sheet immediately after being extruded from the roller is 150
It is introduced into a drying oven set at a temperature of ° C. and dried. The dried sheet is rolled and collected by a winder. By performing this operation continuously, the width is 30 cm,
An adsorbent sheet having a thickness of 1 mm and a length of 10 m was prepared.

The adsorbent sheet was rolled up into a roll to prepare a cylindrical roll having a diameter equal to the inner diameter of the pressure vessel into which the adsorbent sheet was to be filled. As a result, the adsorbent could be filled into the pressure vessel at a high density, and the filling operation could be easily performed without scattering the adsorbent.

Example 2 An adsorbent sheet of the present invention was obtained in the same manner as in (a) and (b) of Example 1 except that a carbon material containing 50% or more of carbon nanotubes was used instead of activated carbon. The obtained adsorbent sheet had flexibility.

The adsorbent sheet was rolled up into a roll, and a columnar roll having a diameter equal to the inner diameter of the pressure vessel into which the adsorbent sheet was to be filled was prepared.

As a result, the adsorbent could be filled into the pressure vessel at a high density, and the filling operation could be easily performed without scattering the adsorbent.

Comparative Example 1 The same activated carbon used in Example 1 was extruded.
It was formed into pellets with a diameter of 10 mm by the high-speed rolling method .

Test Example 1 As a method of filling the adsorbent without scattering, a method of filling the sheet-shaped adsorbent of Example 1 into a pressure vessel and a method of filling the adsorbent into spherical pellets of Comparative Example 1 There is a method of filling the pressure vessel into the pressure vessel. In these two methods, the amount of the adsorbent that can be filled in the pressure vessel was compared.

The volume fraction occupied by the adsorbent in the molded article was 0.62 for both the adsorbent sheet of the present invention and the conventional spherical pellet. When the adsorbent sheet of the present invention was spirally wound up and filled in a pressure vessel as a roll, the volume fraction occupied by the roll in the pressure vessel volume was almost 1.

On the other hand, when the spherical pellets were packed in a pressure vessel in a hexagonal close-packed form, the volume fraction of the molded body in the volume of the pressure vessel was 0.74.

From the above, it can be seen that if the adsorbent is formed into a sheet, more adsorbents can be filled in the pressure vessel than can be formed into a sphere, so that more gas can be stored.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an adsorbent sheet of the present invention.

FIG. 2 is a schematic view showing a state in which the adsorbent sheet of the present invention is wound up into a roll.

FIG. 3 is a schematic view showing a roll-shaped material obtained by winding the adsorbent sheet of the present invention into a roll.

FIG. 4 is a plan view of an adsorbent sheet piece obtained by cutting the adsorbent sheet of the present invention into a circle.

FIG. 5 is a schematic view showing a laminate formed by stacking a large number of adsorbent sheet pieces obtained by cutting the adsorbent sheet of the present invention into a circular shape.

FIG. 6 is a schematic diagram showing an example of a support for forming a laminate by stacking a large number of adsorbent sheet pieces obtained by cutting the adsorbent sheet of the present invention into a circular shape.

FIG. 7 is a schematic view showing another example of a support for forming a laminate by stacking a large number of adsorbent sheet pieces obtained by cutting the adsorbent sheet of the present invention into a circular shape.

FIG. 8 is a longitudinal sectional view of a pressure vessel for filling a roll formed of the adsorbent sheet of the present invention or a laminate formed by stacking a large number of adsorbent sheet pieces obtained by cutting the adsorbent sheet of the present invention into a circle. FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 adsorbent sheet 2 roll 3 adsorbent sheet piece 4 laminate 10 bottom 11 support 12 support 15 bottom 16 support 16 'support 16 "support 17 support 20 gas storage 22 main body 23 lid

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hitoshi Nishino 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka Gas Co., Ltd. (reference) 3E072 AA10 EA01 EA02 EA05 4D012 BA02 BA03 CA20 CB03 CD07 CG01 CH10 CK10

Claims (7)

[Claims] An adsorbent sheet for gas storage, comprising a powdery adsorbent capable of storing and releasing gas and a binder, and having flexibility. 2. The adsorbent sheet according to claim 1, wherein the powdery adsorbent is at least one selected from the group consisting of a carbonaceous adsorbent, a hydrogen storage alloy and zeolite. 3. An area of one side of a sheet is S (cm ² ),
2. The adsorbent sheet according to claim 1, wherein the ratio S / T when the thickness is T (cm) is 100/1 or more. 4. A gas storage pressure vessel filled with an adsorbent capable of storing and releasing gas, wherein the adsorbent is obtained by winding the adsorbent sheet according to claim 1. It is obtained by stacking the adsorbent sheet pieces obtained by cutting the adsorbent sheet according to any one of claims 1 to 3 in a roll shape or according to the cross-sectional shape of the gas storage section of the pressure vessel. A pressure vessel for gas storage, which is a laminate. 5. A method for filling a gas storage adsorbent into a pressure vessel, wherein the gas storage adsorbent is obtained by winding the adsorbent sheet according to claim 1. The form of a laminate obtained by laminating adsorbent sheet pieces obtained by cutting the adsorbent sheet according to any one of claims 1 to 3 according to the cross-sectional shape of the gas storage part of the pressure vessel And filling the pressure vessel. 6. A gas storage pressure vessel, wherein the gas storage pressure vessel according to claim 4 is filled with a gas. 7. A gas storage method, wherein the gas storage pressure vessel according to claim 4 is filled with a gas.