JP2013029180A - Composite container for hydrogen storage, and method for filling hydrogen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite container for hydrogen storage where a large quantity of hydrogen is stored, little or no precooling is required when filled with hydrogen, and hydrogen is more readily filled than in a conventional container.SOLUTION: In the composite container for hydrogen storage, a liner 2 is reinforced with fibers and resin 4, wherein a filler material of 1-25 vol.% which has a hydrogen absorption capacity of less than 0.5 mass% when a temperature is 303 K and an equilibrium pressure of hydrogen is 35 MPa, is present.

Description

  The present invention relates to a composite container for hydrogen storage and a hydrogen filling method. More specifically, the present invention relates to a hydrogen storage composite container that does not require precooling or requires little precooling during hydrogen filling, and a hydrogen filling method.

  At present, in consideration of the environment, development of a fuel cell vehicle (FCV) that uses hydrogen as energy and generates and runs on a fuel cell, and development of a hydrogen station infrastructure that fills the FCV with hydrogen are in progress. There are two types of hydrogen stations: on-site type that reforms city gas, LPG, kerosene, etc. to produce hydrogen, and off-site type that produces hydrogen at a refinery etc. and transports hydrogen. There are two possible types.

In the off-site type, a large amount of hydrogen is produced and purified, so that carbon dioxide (CO ₂ ) generated at that time can be separated and collected and stored (CCS: Carbon Dioxide Capture and Storage). ₂ High expectations are placed on reduction.

  As one means for transporting hydrogen, hydrogen is compressed to a pressure of about 35 to 45 MPa and filled into a high-pressure container for hydrogen, and dozens of the containers are curled together and transported by a trailer. .

  The hydrogen transport trailer container made of steel and having a capacity of 19.6 MPa is currently in practical use. However, since the steel container is heavy, the load on the trailer is limited, and there is a problem in the amount of hydrogen transport in the future FCV diffusion period. Therefore, transportation with a trailer using a composite container (CFRP container) using a lightweight aluminum liner or resin liner is being studied.

  By the way, regarding the handling of the high-pressure hydrogen container, there is an allowable temperature defined by laws and regulations, and the general high-pressure gas safety regulations stipulate that the temperature of hydrogen be 40 ° C. or lower during storage. However, since the CFRP (carbon fiber reinforced resin) container has a low thermal conductivity of the resin liner layer and the CFRP layer, the hydrogen temperature may exceed the legally allowable temperature (40 ° C) when filling with hydrogen. There is sex.

  For example, when filling a 200 L aluminum liner CFRP container at an external temperature of 25 ° C. over 90 minutes up to 40 MPa at a constant pressure, it reaches about 40 ° C. in 20 minutes and immediately after filling up to 40 MPa in 90 minutes. The temperature is about 53 ° C. In this case, in order to fully fill the hydrogen while keeping the temperature of the hydrogen at 40 ° C. or lower, it is necessary to lengthen the filling time or to perform precooling to lower the hydrogen temperature before filling.

  Increasing the filling time is not practical during the FCV diffusion period. On the other hand, when pre-cooling is performed, the equipment cost and running cost increase, and the hydrogen supply cost increases. In addition, a large amount of power is consumed when precooling is performed, and an increase in power consumption is predicted when a commercial hydrogen infrastructure currently under study is realized. In addition, pre-cooling is easily affected by outside air temperature, and it is not preferable from the viewpoint of energy saving effect and environmental load reduction effect because it requires 1.5 times as much electric power as winter in the summer when electricity demand is large. This can be said (see Non-Patent Document 1).

  As a solution to this problem, in Patent Document 1, when a pipe-like container containing a hydrogen-adsorbing alloy that has adsorbed hydrogen is inserted from one end of the liner and hydrogen is introduced from multiple ends, hydrogen is desorbed from the hydrogen-absorbing alloy. A method for preventing the temperature rise by utilizing the endothermic heat of the is disclosed. In the invention disclosed in Patent Document 2, a large number of composite tubes in which a hydrogen gas filter for introducing hydrogen from the outside is spirally wound around a heat medium tube are arranged in a storage container, and the heat medium tube is filled with hydrogen. The temperature rise is hindered by flowing cooling water through.

  However, since the above-described prior art requires both large devices for cooling and complicated operations, further improvements are required in terms of cost, convenience, and versatility.

JP 2004-162812 A JP 2000-55300 A

“2009 Hydrogen and Fuel Cell Demonstration Project JHFC Seminar”, New Energy and Industrial Technology Development Organization, p. 41, 52, 77, March 2, 2010

  Under the circumstances as described above, there is a demand for a hydrogen storage composite container that can store (transport) as much hydrogen as possible and that can be filled more easily than conventional filling when filling with hydrogen. Therefore, the present invention can store as much hydrogen as possible and does not require precooling at the time of hydrogen filling, or requires less precooling, and can be filled with hydrogen more easily than before. And it aims at providing the hydrogen filling method.

  In order to achieve the above object, the present invention is a composite container in which a liner is reinforced with fibers and a resin, and has a hydrogen storage capacity of 0.5 mass% when the temperature is 303 K and the hydrogen equilibrium pressure is 35 MPa. Provided is a composite container for hydrogen storage in which less than 1 to 25% by volume of filler material is present.

  According to the composite container for hydrogen storage of the present invention, when the filling material is present inside, the filling material absorbs the heat of compression of hydrogen when the hydrogen is compressed and filled in the container. The rise can be suppressed. In addition, by using a filling material with poor hydrogen storage capacity that is less than 0.5 mass%, the heat of adsorption generated when hydrogen is adsorbed on the packing material can be suppressed, and the temperature of the hydrogen increases. Can be further suppressed. Furthermore, although the space in the container is reduced by the volume of the filling material, the temperature of hydrogen can be kept low by the presence of the filling material, so the same without performing precooling as compared to the case without the filling material. It is possible to increase the amount of hydrogen stored when hydrogen is filled with pressure. Therefore, according to the hydrogen storage container of the present invention, it is possible to store as much hydrogen as possible in a limited time, and it is possible to eliminate precooling or reduce precooling during hydrogen filling.

Here, the filling material preferably has a density of 2 g / cm ³ or less and a specific heat of 0.1 cal / (K · g) or more. Since such a filling material has a high specific heat, the temperature rise due to the compression heat generated when compressing and filling hydrogen can be suppressed more sufficiently. Further, since the density is low, it is scattered by the air flow generated during hydrogen filling. It is easy to flow and heat exchange can be performed efficiently.

  Moreover, it is preferable that the said filling material contains at least 1 sort (s) selected from the group which consists of a thermosetting resin, a thermoplastic resin, and a carbonaceous material.

  Moreover, it is preferable that the shape of the said filling material is the shape thinned to thickness 10-1000 micrometers, or the shape refined | miniaturized to diameter 1-1000 micrometers. The filling material having such a shape can be more easily flown or scattered by an air flow generated during hydrogen filling, and can increase the surface area, so that heat exchange during filling can be performed more efficiently.

  The composite container for hydrogen storage according to the present invention further includes a porous carbon material having a hydrogen storage capacity of 0.5% by mass or more at a temperature of 303 K and an equilibrium pressure of hydrogen of 35 MPa in total with the above filling material. It is preferable that the amount is 25% by volume or less. By coexisting the filling material and the porous carbon material, it is possible to achieve both high temperature suppression and hydrogen storage amount at the time of hydrogen filling.

Here, the porous carbon material preferably has a specific surface area measured by the BET method of 800 to 3000 m ² / g and a micropore volume of 0.5 to 2 cc / g. Moreover, it is preferable that the said porous carbon material is activated carbon derived from the plant raw material formed through two or more activation processes. Furthermore, the porous carbon material is preferably activated carbon containing Li atoms. By using a porous carbon material that satisfies these conditions, it is possible to achieve both higher levels of suppression of temperature rise and hydrogen storage during hydrogen filling.

  The present invention also provides a composite container in which a liner is reinforced with fibers and a resin, in which a filling material having a hydrogen storage capacity of less than 0.5% by mass at a temperature of 303 K and a hydrogen equilibrium pressure of 35 MPa is provided. Provided is a hydrogen filling method in which hydrogen is compressed and filled into a composite container for hydrogen storage that is present at -25% by volume. According to such a hydrogen filling method, since the filling material is present in the inside, it is possible to suppress an increase in temperature at the time of hydrogen filling, and precooling is not required or reduced at the time of hydrogen filling. And as much hydrogen as possible can be stored.

  According to the present invention, a hydrogen storage composite container that can store as much hydrogen as possible and does not require precooling when filling with hydrogen, or requires less precooling, and can be filled with hydrogen more easily than before. And a hydrogen filling method can be provided.

It is a general | schematic fragmentary sectional view of the composite container for hydrogen storage which concerns on one Embodiment of this invention. It is a general | schematic fragmentary sectional view of the composite container for hydrogen storage which concerns on one Embodiment of this invention. It is a general | schematic fragmentary sectional view of the composite container for hydrogen storage which concerns on one Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

  1 to 3 are each a schematic partial cross-sectional view of a composite container for hydrogen storage according to an embodiment of the present invention. As shown in FIGS. 1 to 3, the hydrogen storage composite container 1 includes a container portion 6 in which a liner 2 is reinforced with fibers and a resin 4.

  The liner 2 is a cylindrical body having both end portions formed in a dome shape (hemisphere), the inside is hollow, and has a structure for filling at least one end portion with hydrogen. The cylindrical portions other than the both end portions may be formed with a constant diameter, but may have a structure in which the diameter of the central portion is somewhat larger. The material constituting the liner 2 may be any material as long as a certain strength can be obtained, such as a metal such as stainless steel or aluminum, or a plastic such as polyethylene.

  In the present embodiment, the liner 2 is reinforced with fibers and a resin 4. Although the method of reinforcement is arbitrary, the container part 6 is manufactured by winding the carbon fiber impregnated with resin around the liner 2, for example. In this case, the liner 2 is reinforced by a carbon fiber layer (reinforcing layer) containing carbon fibers and a resin. The winding method is arbitrary. For example, a tow prepreg in which a carbon fiber or the like is impregnated with a resin in advance is used, or a liquid resin is impregnated in a liquid resin at the time of winding. The resin used is generally a thermosetting resin, and a typical one is an epoxy resin. Examples of the winding method include a method of winding continuously and densely by hoop winding, helical winding or the like. Such a resin is wound around the liner 2 and then heated and cured.

  The thickness of the reinforcing layer including the fibers and the resin 4 varies depending on the hydrogen filling pressure, but is generally 5 mm to 10 cm and is about 3% to 20% of the diameter of the liner 2.

  As shown in FIG. 1, the structure filled with hydrogen provided at at least one end of the liner 2 is generally composed of a base 12 and a hydrogen supply pipe 14 extending in a nozzle shape outside the liner 2. The hydrogen supply pipe 14 may also extend inside the liner 2 as shown in FIG. In that case, the portion (inner nozzle) extending into the liner 2 of the hydrogen supply pipe 14 is, for example, a filter-like pipe having innumerable holes, and hydrogen is uniformly blown by the inner nozzle, and The air flow may occur throughout the liner 2.

  Moreover, as a hydrogen supply pipe | tube, you may use a short thing like the hydrogen supply pipe | tube 16 shown in FIG. In this case, the portion (inner nozzle) extending inside the liner 2 of the hydrogen supply pipe 16 may be in a state in which the opening at the tip is covered with a filter or the like, or similar to the hydrogen supply pipe 14 shown in FIG. Alternatively, a filter-like tube having innumerable holes may be used. Thereby, it is possible to prevent the filling material 20 from being ejected to the outside through the hydrogen supply pipe when hydrogen is released.

  In the present invention, when the temperature is 303 K and the hydrogen equilibrium pressure is 35 MPa in the container portion 6 in which the liner 2 is reinforced with fibers and the resin 4, the hydrogen storage capacity is less than 0.5 mass%. 1 to 25% by volume of filler material 20 is present. Here, the hydrogen storage capacity of the filling material 20 is preferably 0.4% by mass or less, and more preferably 0.2 to 0.3% by mass. When the hydrogen storage capacity is 0.5% by mass or more, hydrogen is easily adsorbed by the filling material 20, and the effect of suppressing the temperature rise of hydrogen is reduced due to the generation of heat of adsorption.

The density of the filler material 20, it preferably at 2 g / cm ³ or less, more preferably 0.5 to 1.5 g / cm ^3, a 0.7 to 1.2 g / cm ³ Is more preferable. When the density exceeds 2 g / cm ³ , the filling material 20 is not scattered at the time of hydrogen filling and tends to be densely gathered at the bottom of the liner 2, so that efficient heat exchange tends to be difficult. Further, if the density is too high, the inner wall of the liner 2 may be damaged by the filling material 20, which is not preferable. On the other hand, when the density is less than 0.5 g / cm ³ , it tends to be difficult to fill the filling material 20 into the container. In the present specification, the density is measured by dry density measurement.

  The specific heat of the filling material 20 is preferably 0.1 cal / (K · g) or more, more preferably 0.2 cal / (K · g) or more, and 0.2 to 0.5 cal / (K). More preferably, g). When the specific heat is less than 0.1 cal / (K · g), a large amount of the filler 20 is necessary to sufficiently suppress the temperature rise of hydrogen, and when the specific heat exceeds 0.5 cal / (K · g). The heat dissipation of the filling material 20 tends to take time.

  The amount of the filling material 20 is determined by the relationship between the amount of heat generated when filling with hydrogen and the amount of heat absorbed by the filling material 20, and the temperature of the hydrogen filled in the container portion 6 is the resin constituting the container portion 6 and It is desirable to adjust the temperature so as to be equal to or lower than the heat-resistant temperature of the filling material 20 or the temperature defined by laws and regulations. The temperature stipulated by laws and regulations is, for example, 40 ° C., which is the upper limit of the temperature of a container or hydrogen during hydrogen filling under the regulations of the current general high-pressure gas safety regulations.

  The amount of the filling material 20 necessary to achieve the above object is 1 to 25% by volume, preferably 5 to 25% by volume, based on the total volume inside the liner 2. When the filling amount is less than 1% by volume, the effect of suppressing the temperature rise of hydrogen cannot be sufficiently obtained. When the filling amount exceeds 25% by volume, hydrogen in the liner 2 is stored depending on the volume of the filling material 20. Space is reduced and hydrogen storage is greatly reduced. By setting the amount of the filling material 20 within the above range, for example, when filling an aluminum liner composite container having an internal volume of 200 L and a filling pressure of 40 MPa, the hydrogen temperature is suppressed to 40 ° C. or lower while the hydrogen is reduced to 60 ° C. It can be filled in about ~ 100 minutes. In addition, when using together the porous carbon material mentioned later, the quantity of the filling material 20 is 1 volume% or more and less than 25 volume%, it is preferable that it is 1-20 volume%, and it is 5-17 volume%. More preferred.

The filling material 20 preferably has a specific surface area measured by the BET method of 1000 m ² / g or less, and more preferably 500 to 1000 m ² / g. By setting the BET specific surface area within the above range, the contact area with hydrogen increases, so that more efficient heat exchange is possible and the temperature rise of hydrogen can be more sufficiently suppressed.

  Examples of the filling material 20 include a thermosetting resin, a thermoplastic resin, and a carbon-based material. Particularly preferable materials are a thermosetting resin and a thermoplastic resin having a high heat capacity, and a carbon-based material such as activated carbon. It is.

  Examples of the thermosetting resin having a high heat capacity include phenol resin, melamine resin, allyl resin, unsaturated polyester resin, epoxy resin, polyimide resin, polyurethane resin, and the like. Examples of the thermoplastic resin having a high heat capacity include polymethyl methacrylate resin, polystyrene resin, polyamide resin, and polycarbonate resin. Examples of carbon-based materials such as activated carbon include those obtained by carbonizing and activating wood, rice husks, coal, and the like, PAN-based / pitch-based carbon fibers, and those obtained by activating them. However, the filling material 20 in the present invention is not limited to these. The filler material 20 can be used alone or in combination of two or more.

  In the present invention, when the filling material 20 is present inside the container portion 6, the filling material 20 can be present in any form. Examples of the shape of the filling material 20 include a thinned shape and a refined (micronized) shape.

  When making the filling material 20 into the shape made into the thin layer, it is preferable that the thickness of a thin layer is 10-1000 micrometers, and it is more preferable that it is 50-100 micrometers. The method of thinning is arbitrary. For example, when a resin is used as the filling material 20, there is a method in which a resin as a raw material is dissolved in a solvent, thinly spread on a mold, and then the solvent is dried. The shape of the thin layer is not particularly limited as long as it is a size that can be introduced from the base 12 into the liner 2 except for the above thickness. For example, the filling material 20 may be a ribbon-like (strip-like) shape that is narrow enough to be introduced from the base 12 and has a long vertical length, and is a sheet having a vertical and horizontal length longer than the width of the base 12. The shape may be a shape, or may be a shape that is fragmented to such an extent that it can be introduced from the base 12. When the filling material 20 has a sheet shape, for example, the filling material 20 can be rolled into a cylindrical shape or folded and introduced into the liner 2 from the base 12. In this case, after the filling material 20 is introduced into the liner 2, the filled material 20 may be unrolled and spread out. Among them, the filling material 20 preferably has a shape that scatters when filled with hydrogen, preferably about 1 cm square or less, more preferably about 0.3 to 0.5 mm square. It is preferable that

  When making the filling material 20 into the refined shape, it is preferable to refine | miniaturize to 1-1000 micrometers in diameter, and it is more preferable to refine | miniaturize to 10-100 micrometers in diameter. When the filling material 20 has a refined shape, it is preferable because it easily scatters during hydrogen filling. Although it does not specifically limit as a refined | miniaturized shape, It is preferable that it is particulate form and it is more preferable that it is spherical particle form. In the present specification, the diameter of the refined filling material 20 means an average diameter measured by optical microscope observation.

  As the filling material 20, one kind of filling material may be used alone, or two or more kinds of filling materials having different materials, physical properties, shapes and the like may be used in combination.

  Furthermore, in the present invention, the porous carbon material 8 can be used in combination with the filler material 20 as shown in FIG. Since the porous carbon material 8 has a large surface area and can adsorb a large amount of hydrogen molecules, the amount of hydrogen stored can be further increased by using this. In addition, although adsorption heat is generated during hydrogen adsorption, in addition to the heat capacity of the porous carbon material 8 itself, the heat capacity of the filler material 20 is effectively suppressed, and the hydrogen is kept at a low temperature. The hydrogen storage amount can be further increased by the synergistic effect of the combined use of the porous carbon material 8 and the filling material 20.

  The method of allowing the porous carbon material 8 to be present inside the liner 2 is arbitrary. For example, after the powder of the porous carbon material 8 is dispersed in an evaporable organic solvent, it is formed on a flexible sheet such as paper. There is a method in which the side surface of the cylinder and the other end dome member are formed after casting and wrapping around an internal nozzle that is integrally formed with the end dome member and from which gas can be ejected. Moreover, you may affix the sheet | seat which cast the powder of the porous carbon material 8 on the cylindrical part of the liner 2, or the inner surface of an edge dome member. In particular, as shown in FIG. 3, it is preferable that the porous carbon material 8 is present on the inner surface of the liner 2 in a certain amount because a heat insulation effect is produced in addition to the effect of suppressing the temperature rise due to the heat capacity. Although this manufacturing method is arbitrary, for example, the porous carbon material 8 may be attached to the inner surface of the liner 2 using a binder such as a resin, or the powder of the porous carbon material 8 is easily evaporated. After being dispersed in an organic solvent capable of being cast, it may be cast on the surface inside the liner 2 and held by pressing with a breathable net-like material. In FIG. 3, the hydrogen supply pipe 14 may be replaced with a short hydrogen supply pipe 16 as shown in FIG.

  As the porous carbon material 8, a material having a hydrogen storage capacity of 0.5 mass% or more, preferably 0.6 to 3 mass% when the temperature is 303 K and the hydrogen equilibrium pressure is 35 MPa is used. be able to. The porous carbon material 8 is preferably present in the liner 2 in an amount of 5 to 24% by volume in a range in which the total amount with the filler material 20 is 25% by volume or less based on the total volume inside the liner 2; More preferably, 8 to 15% by volume is present. When the amount of the porous carbon material 8 is less than 5% by volume, the effect of improving the hydrogen storage amount tends to decrease. When the amount exceeds 24% by volume, the hydrogen in the liner 2 is reduced by the volume of the porous carbon material 8. There is a tendency for the storage space to decrease and the hydrogen storage amount to decrease.

  Further, the total amount of the filler material 20 and the porous carbon material 8 present in the liner 2 is preferably 25% by volume or less based on the total volume inside the liner 2, and is preferably 10-25% by volume. More preferred. When the total amount of the filling material 20 and the porous carbon material 8 exceeds 25% by volume, the space for storing hydrogen inside the liner 2 is reduced by the volume of the filling material 20 and the porous carbon material 8, and the hydrogen storage amount Tends to decrease.

  The porous carbon material 8 may be a general one, but particularly preferred is an activated carbon derived from a plant raw material having a high hydrogen storage capacity and formed through two or more activation steps. Furthermore, the porous carbon material 8 is preferably activated carbon containing Li atoms.

  The activated carbon derived from a plant material formed through two or more activation steps is activated by activating two or more times after carbonizing plant materials such as coconut shells, rice straw, bamboo, and wood chips. The activated carbon thus obtained is an activated carbon having a large surface area and capable of storing hydrogen, and having developed micropores, and is an activated carbon having a high level of hydrogen storage capacity when a plant-derived component other than carbon acts favorably.

  In the present invention, the plant raw material as it is or carbonized at a temperature of 300 to 1,000 ° C. is subjected to the first stage activation treatment. If necessary, the plant material may be pulverized before activation.

  The activation method includes steam activation, alkali activation and the like, and any activation method may be used, but an activation method using an alkali metal or alkaline earth metal hydroxide is particularly preferable.

  For example, 0.2 to 5 parts by mass of an alkali metal hydroxide is added to 1 part by mass of a carbide obtained by carbonizing a plant material, and the treatment is performed at a temperature of about 500 to 800 ° C. for about 0.1 to 5 hours. Do. At this time, potassium hydroxide is particularly preferable as the alkali metal hydroxide. Thereafter, unreacted alkali metal hydroxide is removed by washing. In washing, it is possible to remove alkali using hydrochloric acid or the like as necessary. Then, after making it dry, it activates again. At this time, steam activation may be performed, or an alkali metal hydroxide may be reacted in the same manner. In this case, potassium hydroxide may be used, or lithium hydroxide may be used because micropores are easily formed, and some alkali metal hydroxides may be used in combination. Thereafter, similarly, it is washed if necessary and dried. Furthermore, activation may be repeated.

The plant material-derived activated carbon thus produced has a specific surface area of 800 to 3000 m ² / g and a micropore volume of 0.5 to ² cc / g measured by the BET method.

  Plants contain components other than carbon even when carbonized, and have better hydrogen storage capacity than simple activated carbon due to interaction with hydrogen. On the other hand, components other than carbon may hinder activation, and by activating twice or more, preferable activation and pore formation are possible.

  The activated carbon containing Li atoms is a general activated carbon in which Li ions are bonded (supported) to oxygen functional groups on the surface. Here, the oxygen-containing functional group is preferably at least one selected from the group consisting of a phenolic hydroxyl group, a quinone group, a lactone carboxyl group, and a carboxyl group.

An example of the structure of a part of the surface of the porous carbon material and the phenolic hydroxyl group formed on the surface is shown in the following chemical formula (1).

An example of the structure of a part of the surface of the porous carbon material and the quinone group formed on the surface is shown in the following chemical formula (2).

An example of the structure of a part of the surface of the porous carbon material and the lactone carboxyl group formed on the surface is shown in the following chemical formula (3).

An example of the structure of a part of the surface of the porous carbon material and the carboxyl group formed on the surface is shown in the following chemical formula (4).

The following chemical formula (5) shows a state in which Li is not bonded to a part of the surface of the porous carbon material in which carboxyl groups and hydroxyl groups are formed as oxygen-containing functional groups. The following chemical formula (6) shows a state where Li is bonded to a part of the surface of the porous carbon material shown in the following chemical formula (5).

  As shown in the chemical formulas (5) and (6), it is preferable that Li is bonded to oxygen contained in the oxygen-containing functional group to form a LiO group. The LiO group has a property of strongly adsorbing hydrogen molecules. Therefore, when the LiO group is formed on the surface of the porous carbon material, the adsorption density of hydrogen molecules in the hydrogen storage material is increased, and the hydrogen storage capacity is significantly improved as compared with the conventional case.

  The oxygen-containing functional group is particularly preferably a phenolic hydroxyl group among the functional groups described above. In order to improve the hydrogen storage capacity, Li bonded to a phenolic hydroxyl group is more preferable than Li bonded to other oxygen-containing functional groups.

  The amount of Li contained in the hydrogen storage material may be about 0.1 to 3 mmol / g. However, the amount of Li contained in the hydrogen storage material is not limited to this range. The larger the amount of Li introduced into the hydrogen storage material, the better the hydrogen storage capacity.

  As the activated carbon supporting Li, activated carbon derived from a plant material activated two or more times as described above may be used.

Further, as the porous carbon material 8, an activated product of a fibrous raw material may be used. The activated material of the fibrous raw material is preferably activated PAN (polyacrylonitrile). The activated material of the fibrous raw material is manufactured by a manufacturing method including two steps of “carbonization” and “activation” in the same manner as the activated carbon derived from the plant raw material described above. It is preferable that the activated fiber material is also activated two or more times. Moreover, it is preferable that the activated material of a fibrous raw material is what carried Li as mentioned above. The fibrous material activation product thus produced also has a specific surface area of 800 to 3000 m ² / g and a micropore volume of 0.5 to ² cc / g as measured by the BET method.

  It is possible to fill the liner 2 with a material other than the filling material 20 and the porous carbon material 8 as long as the effects of the present invention are not impaired. Examples of such other materials include a hydrogen storage alloy. However, in the case of a container containing a hydrogen storage alloy, usually, heat is required for releasing hydrogen, and a heating device such as a heater disposed inside or outside the container is required. It becomes complicated. Therefore, from the viewpoint of cost, convenience, and versatility, it is preferable that the hydrogen storage composite container of the present invention does not contain a hydrogen storage alloy.

  When filling the hydrogen storage composite container 1 with hydrogen, the hydrogen is compressed and filled into the liner 2 from the hydrogen supply pipe. At this time, the heat capacity of the filling material 20 and optionally the porous carbon material 8 absorbs the heat of adsorption of hydrogen and the compression heat of hydrogen that is not adsorbed, so that the temperature of the hydrogen filled in the liner 2 is increased. It is desirable to adjust the filling conditions so that the temperature is equal to or lower than the heat resistance temperature of the resin and the filling material 20 constituting the container portion 6 or the temperature stipulated by laws and regulations. For example, when the composite container 1 for hydrogen storage of the present invention is used, it is possible to fill a container with an internal volume of 200 L with hydrogen to 40 MPa in about 60 to 100 minutes while keeping the temperature of hydrogen at 40 ° C. or lower. is there.

  The preferred embodiment of the composite container for hydrogen storage and the hydrogen filling method of the present invention has been described above, but the present invention is not limited to the above embodiment.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

  In this example, the hydrogen temperature was examined so as to be kept at 40 ° C. or lower, which is a regulation of the general high-pressure gas safety regulations. In addition, it confirmed that there was no influence on the used filling material (heat-resistant temperature of 120 degreeC or more) at this temperature.

  In addition, the hydrogen storage capacity of each material in the following examples and comparative examples is obtained by using a hydrogen storage amount measuring device manufactured by Reska Co., Ltd., in a state where the sample tube portion containing the measurement sample is immersed in a 303K water tank, This is obtained by measuring the hydrogen storage amount when the equilibrium pressure of hydrogen is 35 MPa.

Example 1
A CFRP container made of an aluminum liner provided with a filter-like hydrogen supply pipe having innumerable holes of 1 μm or less was produced. The specifications of the produced container were an internal volume of 10 L, an inner diameter of 160 mm, a length of 520 mm, and a minimum burst pressure of 180 MPa.

Pellet-shaped phenol resin (trade name: Admer, manufactured by Mitsui Chemicals, Inc.) was pulverized with a pulverizer to obtain a particulate filler. The average diameter of the finely divided phenol resin particles is 100 μm, the specific heat is 0.43 cal / (K · g), the density is 1.3 g / cm ³ , and the BET specific surface area is almost 0 m ² / g (below the measurement limit of nitrogen adsorption amount). ) When the temperature was 303 K and the hydrogen equilibrium pressure was 35 MPa, the hydrogen storage capacity was almost 0% by mass (below the measurement limit of the hydrogen storage amount).

  3 kg (23.1% by volume) of the filling material was introduced into the produced container to obtain a composite container for hydrogen storage. In this hydrogen storage composite container, hydrogen having an initial temperature of 25 ° C. was filled up to 40 MPa in 5 minutes (assuming that a 200 L container is filled in 100 minutes). The temperature of hydrogen in the container immediately after filling was 38 ° C. The hydrogen filling amount was 0.2 kg.

(Example 2)
A pellet-shaped polystyrene resin (trade name: G900, manufactured by Nippon Polystyrene Co., Ltd.) is dissolved in toluene to a concentration of 10% by mass, poured into a 300 mm × 300 mm flat tray at 180 cm ³ , and then decompressed at 50 ° C. The toluene was removed. The film thickness of the obtained sheet-like polystyrene resin was about 200 μm. This sheet-like polystyrene resin was subdivided into about 0.5 mm square by a cutting machine. This operation was repeated to obtain a filling material. The specific heat of this filling material is 0.32 cal / (K · g), the density is 1.0 g / cm ³ , the BET specific surface area is almost 0 m ² / g (below the measurement limit of nitrogen adsorption amount), the temperature is 303 K, and the hydrogen equilibrium The hydrogen storage capacity when the pressure was 35 MPa was approximately 0% by mass (below the measurement limit of the hydrogen storage capacity).

  2.5 kg (23.8% by volume) of this filling material was introduced into a container having the same specifications as in Example 1 to obtain a composite container for hydrogen storage. The hydrogen storage composite container was filled with hydrogen at an initial temperature of 25 ° C. to 40 MPa in 5 minutes. The temperature of hydrogen in the container immediately after filling was 40 ° C. The hydrogen filling amount was 0.2 kg.

(Example 3)
Hydrogen storage capacity of 0.25 mass when specific heat is 0.21 cal / (K · g), density is 0.8 g / cm ³ , BET specific surface area is 950 m ² / g, temperature is 303 K, and hydrogen equilibrium pressure is 35 MPa. 4 kg of granular activated carbon (Kuraray Chemical Co., Ltd., trade name: PDX) is introduced into a container having the same specifications as in Example 1 (18.2% by volume based on the total volume inside the container) for hydrogen storage. A composite container was obtained. The hydrogen storage composite container was filled with hydrogen at an initial temperature of 25 ° C. to 40 MPa in 5 minutes. The temperature of hydrogen in the container immediately after filling was 35 ° C. The hydrogen filling amount was 0.23 kg.

Example 4
A filler material was obtained in the same manner as in Example 2 using a pellet-shaped polystyrene resin (trade name: G900, manufactured by PS Japan Corporation). 1 kg of this filling material was introduced into a container having the same specifications as in Example 1 (9.5% by volume based on the total volume inside the container).

On the other hand, coconut palm was baked at 700 ° C., 0.05 mol of KOH was added per 1 g of baked palm tree, and activation treatment was performed at 750 ° C. for 2 hours in an inert gas atmosphere. Then, activation treatment was performed again at 750 ° C. in an inert gas atmosphere with 0.1 mol of LiOH per gram of activated palm, and Li was introduced into the material. The amount of introduced Li was 0.3% by mass. The obtained porous carbon material had a specific surface area measured by the BET method of 2118 m ² / g and a micropore volume of 1.402 cc / g. The hydrogen storage capacity of the obtained porous carbon material was 1.3 mass% at an equilibrium pressure of hydrogen of 35 MPa and a temperature of 30 ° C. (303 K).

  2 kg (8% by volume) of this porous carbon material was further introduced into the container to obtain a hydrogen storage composite container.

  The hydrogen storage composite container was filled with hydrogen at an initial temperature of 25 ° C. to 40 MPa in 5 minutes. The temperature of hydrogen in the container immediately after filling was 40 ° C. The hydrogen filling amount was 0.25 kg.

(Comparative Example 1)
Without filling the container with the same specifications as in Example 1, hydrogen at an initial temperature of 25 ° C. was filled up to 40 MPa in 5 minutes. The temperature of hydrogen in the container immediately after filling was 58 ° C. Further, the hydrogen pressure when the temperature of hydrogen in the container reached 40 ° C. was 22 MPa. The hydrogen filling amount was 0.2 kg.

(Comparative Example 2)
When the specific heat is 0.1 cal / (K · g), the density is 6 g / cm ³ , the BET specific surface area is almost 0 m ² / g (below the measurement limit of nitrogen adsorption amount), the temperature is 303 K, and the hydrogen equilibrium pressure is 35 MPa. 2.4 kg of vanadium (Aldrich) having a hydrogen storage capacity of 0.55 mass% is introduced into a container having the same specifications as in Example 1 (3.9% by volume based on the total volume inside the container), and hydrogen A composite container for storage was obtained. The hydrogen storage composite container was filled with hydrogen at an initial temperature of 25 ° C. to 40 MPa in 5 minutes. The temperature of hydrogen in the container immediately after filling was 53 ° C. The hydrogen filling amount was 0.2 kg.

(Comparative Example 3)
A filler material was obtained in the same manner as in Example 2 using a pellet-shaped polystyrene resin (trade name: G900, manufactured by PS Japan Corporation). 5 kg (47.6% by volume) of this filling material was introduced into a container having the same specifications as in Example 1 (47.6% by volume based on the total volume inside the container) to obtain a composite container for hydrogen storage. The hydrogen storage composite container was filled with hydrogen at an initial temperature of 25 ° C. to 40 MPa in 5 minutes. The temperature of hydrogen in the container immediately after filling was 45 ° C. In this example, it is considered that the amount of the filling material is too large, heat is not efficiently absorbed by the filling material, and the endothermic effect is not sufficiently obtained, so that the temperature of hydrogen is increased. The hydrogen filling amount was 0.12 kg.

  As is clear from the results of Examples and Comparative Examples, according to the composite container for hydrogen storage of the present invention, the temperature of hydrogen can be suppressed to 40 ° C. or less without performing precooling at the time of hydrogen filling. Hydrogen can be easily charged and a sufficient amount of hydrogen can be stored.

  The composite container for hydrogen storage of the present invention can be used as a container for transporting hydrogen in the coming hydrogen society, or used as a fuel tank for an engine incorporated in a hydrogen vehicle. Moreover, it can be used as a former propane gas cylinder as a container for storing hydrogen as fuel for household fuel cells. That is, even if it does not have complicated and expensive equipment, it becomes possible to supply hydrogen from the composite container for hydrogen storage, and the present invention greatly contributes to the spread of hydrogen as energy. It is clear that the implementation of the present invention can contribute to the environment and contribute to the realization of a sustainable society.

  DESCRIPTION OF SYMBOLS 1 ... Composite container for hydrogen storage, 2 ... Liner, 4 ... Fiber and resin, 8 ... Porous carbon material, 12 ... Base, 14, 16 ... Hydrogen supply pipe, 20 ... Filling material.

Claims (9)

A composite container in which a liner is reinforced with fibers and resin,
A hydrogen storage composite container in which 1 to 25% by volume of a filling material having a hydrogen storage capacity of less than 0.5% by mass at a temperature of 303K and a hydrogen equilibrium pressure of 35 MPa is present. 2. The hydrogen storage composite container according to claim 1, wherein the filling material has a density of 2 g / cm ³ or less and a specific heat of 0.1 cal / (K · g) or more.   The hydrogen storage composite container according to claim 1, wherein the filling material includes at least one selected from the group consisting of a thermosetting resin, a thermoplastic resin, and a carbon-based material.   The hydrogen storage according to any one of claims 1 to 3, wherein the shape of the filling material is a shape thinned to a thickness of 10 to 1000 µm or a shape refined to a diameter of 1 to 1000 µm. Composite container.   Further, a porous carbon material having a hydrogen storage capacity of 0.5 mass% or more at a temperature of 303 K and an equilibrium pressure of hydrogen of 35 MPa is set so that the total amount of the porous carbon material and the filling material is 25 volume% or less. The composite container for hydrogen storage according to any one of claims 1 to 4, which is present. The said porous carbon material is for hydrogen storage of Claim 5 whose specific surface area measured by BET method is 800-3000 m < ² > / g, and whose micropore volume is 0.5-2 cc / g. Composite container.   The said porous carbon material is a composite container for hydrogen storage of Claim 5 or 6 which is the activated carbon derived from the plant raw material formed through the activation process of 2 times or more.   The composite container for hydrogen storage according to any one of claims 5 to 7, wherein the porous carbon material is activated carbon containing Li atoms.   1 to 25% by volume of a filling material having a hydrogen storage capacity of less than 0.5% by mass when the liner is reinforced with fibers and resin and the temperature is 303K and the equilibrium pressure of hydrogen is 35 MPa. A hydrogen filling method, in which hydrogen is compressed and filled into a hydrogen storage composite container.

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