JP2003286001A - Method of activating hydrogen absorbing body, method of housing hydrogen absorbing body in hydrogen storage apparatus and hydrogen storage apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of simply activating a hydrogen absorbing alloy before a hydrogen absorbing body containing the hydrogen absorbing alloy is housed in a hydrogen storage apparatus. <P>SOLUTION: The method of activating the hydrogen absorbing body is constituted so as to include a hydrogen absorbing body preparing process for preparing the hydrogen absorbing body containing the hydrogen absorbing alloy and an inert gas treating process for housing the hydrogen absorbing body in a treating vessel and holding at ≥100°C under an inert gas atmosphere. The hydrogen absorbing alloy is easily activated by carrying out the inert gas treatment even if an activation treatment at a high temperature under the pressurizing of hydrogen is not carried out. It is needless to carry out the conventional activation in the hydrogen storage apparatus by housing the hydrogen absorbing body treated with the insert gas in the hydrogen storage apparatus as the hydrogen absorbing body is under the inert gas atmosphere. Then, a heating apparatus is unnecessary in the hydrogen storage apparatus to realize a small sized lightweight hydrogen storage apparatus. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an activation treatment method for activating a hydrogen storage body containing a hydrogen storage alloy, a method for accommodating a hydrogen storage body in a hydrogen storage device and a hydrogen storage using the activation treatment method. Regarding the device.

[0002]

2. Description of the Related Art Hydrogen energy is expected to be used in various applications such as fuel cells used as power sources for electric vehicles. In order to put hydrogen energy into practical use, technology for safely storing and transporting hydrogen is important. As a technique for storing hydrogen, for example, there is a method of filling a container with a material capable of storing and releasing hydrogen and storing the hydrogen by storing hydrogen in the material. Here, as a material capable of storing and releasing hydrogen, for example, a hydrogen storage alloy that stores hydrogen in a solid state called a hydride under predetermined conditions and releases hydrogen under another condition is known. ing.

When a hydrogen storage alloy comes into contact with a substance other than hydrogen such as air or water, a gas such as oxygen is adsorbed on the surface of the hydrogen storage alloy to form a film such as an oxide. descend. Therefore, when the hydrogen storage alloy is used as a hydrogen storage material, after storing the hydrogen storage alloy in a container in the hydrogen storage device, high temperature inside the container,
It is necessary to increase the hydrogen storage capacity of the hydrogen storage alloy by carrying out so-called activation treatment such as high pressure by hydrogen pressure. The activation treatment of the hydrogen storage alloy differs depending on the type of the alloy, but, for example, in JP-A-11-311400,
A method is shown in which the TiCrV alloy is evacuated and held at a temperature of 60 ° C. for 1 hour, and then held under hydrogen pressure of about 1 MPa and 0 ° C. for 1 hour, which is repeated three times. Further, in Japanese Patent Laid-Open No. 9-31585, Ti is
As a method of activating the VMn alloy, a method of performing it at a high temperature of about 500 ° C. is shown.

[0004]

The conventional activation treatment described above is performed after the hydrogen storage alloy is housed in the hydrogen storage device. For this reason, the hydrogen storage device requires auxiliary equipment such as a heating device and a cooling device for heating / cooling the container for activation treatment, in addition to the container for storing the hydrogen storage alloy. That is, the hydrogen storage device itself becomes large and heavy. This becomes a big problem when it is assumed that the hydrogen storage device is mounted on a moving body such as an automobile.

The present invention has been made in view of the above circumstances, and can be carried out before the hydrogen storage device containing the hydrogen storage alloy is housed in the hydrogen storage device, and the hydrogen storage alloy can be easily activated. It is an object to provide a method that can be realized. Another object of the present invention is to provide a method for accommodating a hydrogen storage body containing a hydrogen storage alloy in a hydrogen storage device that does not require activation treatment after the hydrogen storage body is stored in the hydrogen storage device. Another object of the present invention is to provide a compact and lightweight hydrogen storage device that does not require a heating device for heating a container containing a hydrogen storage body.

[0006]

A method for activating a hydrogen storage material according to the present invention comprises a hydrogen storage material preparing step of preparing a hydrogen storage material containing a hydrogen storage alloy, and the hydrogen storage material being housed in a processing container. And an inert gas treatment step of maintaining the temperature at 100 ° C. or higher in an inert gas atmosphere.

As described above, when the hydrogen storage alloy constituting the hydrogen storage body is exposed to air or the like, oxygen and nitrogen in the air are adsorbed on the surface, and a film such as an oxide is formed on the surface. Formed, the hydrogen storage capacity is reduced. In the activation treatment method of the present invention, the reduced hydrogen storage capacity of the hydrogen storage alloy is recovered by treating the hydrogen storage body containing the hydrogen storage alloy under predetermined conditions such as an inert gas atmosphere. That is, the hydrogen storage alloy is activated. Although the mechanism of the activation treatment method of the present invention is not clear, the hydrogen storage material containing the hydrogen storage alloy is held at a temperature of 100 ° C. or higher in an inert gas atmosphere (referred to as “inert gas treatment” in the present specification). Represents)),
It is considered that oxygen and the like adsorbed on the surface of the hydrogen storage alloy are removed. Further, it is considered that fine cracks (cracks) are generated on the surface of the hydrogen storage alloy by performing the above-mentioned inert gas treatment. When cracks occur, the hydrogen storage alloy is likely to crack when the hydrogen storage alloy later stores and releases hydrogen. As a result, pulverization of the hydrogen storage alloy is promoted, and many active surfaces having high hydrogen storage / release capacity are exposed, resulting in high hydrogen storage / release capacity. As described above, by performing the inert gas treatment, the hydrogen storage alloy can be easily activated without performing the activation treatment under high temperature and hydrogen pressure as in the conventional case.

The method for accommodating a hydrogen storage device in a hydrogen storage device according to the present invention comprises a hydrogen storage device preparation step of preparing a hydrogen storage device containing a hydrogen storage alloy, and the hydrogen storage device not being stored in a processing container. An inert gas treatment step of maintaining the temperature at 100 ° C. or higher in an active gas atmosphere, and a hydrogen storage material accommodation step of accommodating the hydrogen storage material subjected to the inert gas treatment in the hydrogen storage device in the inert gas atmosphere. It is characterized by including.

That is, according to the method for accommodating the hydrogen storage device of the present invention, the hydrogen storage body subjected to the inert gas treatment in the activation treatment method of the present invention is accommodated in the hydrogen storage device in an inert gas atmosphere. Is the way to do. By storing the hydrogen storage alloy contained in the hydrogen storage body in the hydrogen storage device in the inert gas atmosphere, the activated state of the hydrogen storage alloy is maintained. In other words, it is not necessary to carry out activation treatment under high temperature and hydrogen pressure as in the prior art after accommodating the hydrogen absorber in the hydrogen storage device. Therefore, according to the method of accommodating the hydrogen storage device of the present invention, in addition to being able to easily activate the hydrogen storage alloy, it is not necessary to perform activation treatment of the hydrogen storage alloy after accommodating in the hydrogen storage device, It is possible to reduce the size and weight of the hydrogen storage device.

Further, the hydrogen storage device of the present invention is a hydrogen storage device comprising a storage container and a hydrogen storage material housed in the storage container, wherein the hydrogen storage material is 100% in an inert gas atmosphere. It is characterized by containing a hydrogen storage alloy held at a temperature of ℃ or more.

That is, the hydrogen storage device in the hydrogen storage device of the present invention contains the hydrogen storage alloy that has been subjected to the inert gas treatment in the activation treatment method of the present invention. That is, since the hydrogen storage alloy that constitutes the hydrogen storage body has already been activated, it is not necessary to perform the activation treatment in the state of being stored in the hydrogen storage device. Therefore, the heating device conventionally required becomes unnecessary. For example, when a titanium-based alloy is used as the hydrogen storage alloy, hydrogen can be stored and released at room temperature. In this case, the hydrogen storage device of the present invention can be used at room temperature, and is a compact and lightweight hydrogen storage device. The hydrogen storage device of the present invention having such advantages is particularly suitable for use in a mobile body such as an automobile. When the hydrogen storage device is mounted on an automobile, it is assumed that the hydrogen storage device is used in a temperature range of -30 to 60 ° C. In the present specification, when it can be used at room temperature, it means that it can be used in the above temperature range.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The method for activating the hydrogen storage material, the method for accommodating the hydrogen storage material in the hydrogen storage device, and the hydrogen storage device according to the present invention will be described in detail below. The embodiment to be described is only one embodiment, and the activation processing method of the hydrogen storage material, the method for accommodating the hydrogen storage material in the hydrogen storage device, and the hydrogen storage device of the present invention are limited to the following embodiments. Not something. The present invention can be implemented in various forms including modifications and improvements that can be made by those skilled in the art, including the following embodiment.

<Method for activating hydrogen storage body> The method for activating the hydrogen storage body of the present invention comprises a hydrogen storage body preparation step and an inert gas treatment step. Hereinafter, each step will be described.

(1) Hydrogen Storage Body Preparation Step This step is a step of preparing a hydrogen storage body containing a hydrogen storage alloy. The type of the hydrogen storage alloy forming the hydrogen storage body is not particularly limited, and a known hydrogen storage alloy may be used. For example, titanium-based alloys, rare earth-based alloys, magnesium-based alloys, etc. may be mentioned. Above all, it is desirable to use a titanium-based alloy because hydrogen can be stored and released at room temperature. Specifically, for example, TiFe, TiCo, TiNi, TiM
N ₂ , TiCr ₂ , TiV, TiCrV, TiCrMn and the like are suitable.

The hydrogen storage body may be made of only the hydrogen storage alloy, or may contain other materials in addition to the hydrogen storage alloy. For example, it is desirable to adopt an aspect including a porous carbon material as the hydrogen storage material. It is considered that the inclusion of the porous carbon material further promotes the activation of the hydrogen storage alloy. That is, in the subsequent inert gas treatment step, the hydrogen storage alloy is activated by treating the hydrogen storage body with the inert gas. In this case, if the hydrogen storage material contains the porous carbon material, a reducing atmosphere is easily formed. Therefore, oxygen and the like adsorbed on the surface of the hydrogen storage alloy are easily removed. Further, the gas such as carbon dioxide and oxygen adsorbed on the surface of the hydrogen storage alloy is also adsorbed and removed by the gas adsorption function of the porous carbon material.

As the porous carbon material, for example, activated carbon, carbon nanotube, graphite nanofiber or the like can be used. In particular, the specific surface area is 1000m because of its high adsorption capacity for carbon dioxide and oxygen.
It is preferably ² / g or more. For example, it is suitable to use activated carbon. In this specification, the specific surface area is
The value measured by the BET adsorption method is adopted. Specifically, the porous carbon material to be measured is put in a sample tube, and N ₂
A mixed gas of He and He is caused to flow to adsorb N ₂ . Then, the N ₂ adsorption amount of the porous carbon material is detected by a thermal conductivity cell, and the specific surface area of the porous carbon material is calculated from the adsorption isotherm assumed by the BET theory. When the embodiment containing the porous carbon material as the hydrogen storage material is adopted, the content ratio of the porous carbon material in the hydrogen storage material is 5% by weight.
It is preferably 50% by weight or more. This is because when the content ratio of the porous carbon material is less than 5% by weight, the above effect due to the inclusion of the porous carbon material cannot be sufficiently obtained. On the other hand, if the content ratio of the porous carbon material exceeds 50% by weight, the bulk as a whole becomes bulky and not practical.

Further, it is possible to adopt a mode in which the hydrogen storage body contains a binder for binding the hydrogen storage alloy and the porous carbon material. By including the binder, it is possible to maintain a uniform mixed state of the hydrogen storage alloy and the porous carbon material. Further, when the hydrogen storage body is formed into a predetermined shape, there is an advantage that the formation becomes easy. The type of the binder is not particularly limited. For example, polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVD)
Fluororesin such as F), ethylene-propylene-diene copolymer, styrene-butadiene rubber, carboxycellulose and the like can be used. The hydrogen storage body is heated in a subsequent inert gas treatment step. Therefore, in consideration of being heated, when the binder is included, it is desired that the binder has a certain degree of heat resistance. From this point of view, high heat resistance among those exemplified above,
It is desirable to use a fluororesin, which has advantages such as easier molding. In particular, polytetrafluoroethylene (PTFE) is suitable because it can be mixed without using a solvent. The content ratio of the binder in the hydrogen storage material is preferably 10% by weight or less. Since the binder does not have the ability to absorb and release hydrogen, the content ratio of the binder is 1
This is because if it exceeds 0% by weight, the hydrogen storage amount of the hydrogen storage material decreases. More preferably, it is 5% by weight or less. Further, in order to effectively exert the above effects obtained by containing the binder, the content ratio is preferably 0.2% by weight or more.

When the hydrogen storage material contains a hydrogen storage alloy and a porous carbon material, for example, the powder hydrogen storage alloy and the porous carbon material are mixed, and both are dispersed to form the hydrogen storage material. Just prepare. The mixing may be performed using, for example, a ball mill, a rocking mill or the like. Alternatively, the hydrogen storage alloy in powder form and the individual particles of the porous carbon material may be bonded together by mechanical shearing force to prepare the hydrogen storage body in a composite form. In this case, for example, the hydrogen absorbing alloy and the porous carbon material may be compounded by a method such as mechanical alloying or mechanofusion. Furthermore, a mixed material of a hydrogen storage alloy and a porous carbon material or the like can be subjected to a high pressure compression treatment to obtain a hydrogen storage body. In this case, the hydrogen storage material is cylindrical, spherical,
It may be formed into pellets such as rugby balls. By forming the hydrogen storage body into pellets in advance, the hydrogen storage alloy and the porous carbon material can be uniformly dispersed when the hydrogen storage body is housed in a processing container or the like. The high-pressure compression treatment is not particularly limited in its method and conditions. For example, it can be performed by compressing a mixed material of a hydrogen storage alloy and a porous carbon material under a predetermined pressure and temperature. The processing pressure may be 100 MPa or more and 2000 MPa or less. The high-pressure compression treatment may be performed at room temperature,
It may be performed at a high temperature up to about 200 ° C. Further, it may be carried out in air or in an inert gas atmosphere.
The processing time may be about several seconds to 10 minutes as the time for holding the processing pressure after reaching the processing pressure. The number of times of treatment depends on the treatment conditions and the like, but may be about 1 to 50 times. The high-pressure compression process may be performed using a compression molding machine such as a hydraulic press.

(2) Inert gas treatment step In this step, the hydrogen storage material prepared in the hydrogen storage material preparation step is placed in a processing container and 100 ° C. in an inert gas atmosphere.
This is a process of holding at the above temperature. The material of the processing container is not particularly limited as long as it has good heat resistance and airtightness. For example, a container made of quartz glass or stainless steel may be used. The storage container in the hydrogen storage device can also be used as the processing container. In this case, a container made of aluminum alloy or the like may be used as the processing container for reasons such as light weight. It is desirable to install a valve in the processing container in order to introduce an inert gas into the processing container and maintain an inert gas atmosphere. Further, for example, it is desirable to provide a heat source such as a heater outside the processing container so that the hydrogen storage body can be heated and held.

After accommodating the hydrogen storage material in the processing container, an inert gas is introduced to make the inside of the processing container an inert gas atmosphere. In this case, the inert gas may be caused to flow at a predetermined flow rate, or the processing container previously evacuated may be filled with the inert gas. In the case of the former, the flow rate of the inert gas is not particularly limited, and for example, the volume is 500 m.
A flow rate of about 20 to 50 ml / min may be applied to a processing container of about 1 l. As the inert gas, argon, nitrogen, neon, xenon, krypton or the like may be used. In particular, it is desirable to use argon because it is easily available and easy to handle.

The processing container containing the hydrogen storage material is heated and kept at a temperature of 100 ° C. or higher. When the processing container is heated by the heater or the like, the temperature on the outer wall surface of the processing container may be 100 ° C. or higher. From the viewpoint of further activating the hydrogen storage alloy, the holding temperature is preferably higher, and the holding temperature is preferably 200 ° C. or higher. A temperature of 300 ° C. or higher is more preferable, and 500
It is more preferable that the temperature is not less than ° C. Hold temperature is 100 ℃
There is no particular limitation as long as it is at least the above, but it is desirable that the melting point be not higher than the melting point of the hydrogen storage alloy. For example, when titanium-based alloy TiCr ₂ is used as the hydrogen storage alloy, the temperature is preferably 700 ° C. or lower. The holding time depends on the amount of the hydrogen storage material to be treated, but for example, when processing 50 g or less of the hydrogen storage material, it may be about 1 hour. When treating 100 g or more of a hydrogen storage material, it is desirable that the time is 2 hours or more.

After performing the inert gas treatment, the hydrogen storage body may be naturally cooled in the treatment container. Cooling is preferably performed while flowing an inert gas. In this case, the cooling time may be about 2 to 3 times the holding time.

<Accommodating Method of Hydrogen Absorber in Hydrogen Storage Device> The method of accommodating the hydrogen absorbing device in the hydrogen storage device of the present invention comprises a hydrogen absorber preparing step, an inert gas treatment step, and a hydrogen absorber accommodating step. It is configured to include. The hydrogen storage body preparation step and the inert gas treatment step are omitted because they are the same as the steps in the hydrogen storage body activation treatment method of the present invention, and the hydrogen storage body accommodation step will be described here.
In addition, also in the method for accommodating the hydrogen storage body of the present invention in the hydrogen storage device, it is desirable to employ the preferred aspect of the method for activating the hydrogen storage body of the present invention described above.

The step of accommodating the hydrogen storage material in the hydrogen storage device according to the present invention is a step of accommodating the hydrogen storage material subjected to the inert gas treatment in the hydrogen storage device in an inert gas atmosphere. is there. The hydrogen storage alloy contained in the hydrogen storage body subjected to the inert gas treatment is already activated. Therefore, in order to maintain its activity, the hydrogen storage material is housed in the hydrogen storage device in an inert gas atmosphere. In addition, in the inert gas treatment step, since the hydrogen storage body is heated, it is desirable to flow the inert gas to cool the hydrogen storage body before storing it. The method for accommodating the hydrogen storage device in the hydrogen storage device is not particularly limited as long as an inert gas atmosphere is ensured at the time of storage. For example, the hydrogen storage material may be transferred from the processing container after the inert gas treatment to the storage container of the hydrogen storage device in the glove box in the inert gas atmosphere. Further, the storage container of the hydrogen storage device is kept in an inert gas atmosphere, and the storage container and the processing container are connected in a joined state in which the outside air is completely shut off,
The hydrogen storage material in the reaction container may be transferred to the storage container.

Further, in the case where the hydrogen storage body adopts a mode containing a porous carbon material and the like in addition to the hydrogen storage alloy, the porous carbon material and the like are removed after the inert gas treatment step, and only the hydrogen storage alloy is obtained. A mode in which the hydrogen storage device is housed can also be adopted. By adopting this mode, activation of the hydrogen storage alloy can be promoted in the inert gas treatment even when only the hydrogen storage alloy is stored in the hydrogen storage device as the hydrogen storage body.

<Hydrogen Storage Device> The hydrogen storage device of the present invention is a hydrogen storage device including a storage container and a hydrogen storage material housed in the storage container, wherein the hydrogen storage material is an inert gas atmosphere. The hydrogen storage alloy is kept at a temperature of 100 ° C. or higher. The storage container is not particularly limited as long as it can be used under high pressure. It is possible to use various pressure vessels such as aluminum alloy pressure vessels and cylinders that are commonly used. Further, as described above, the storage container can also be used as the processing container for performing the inert gas processing.

Since the hydrogen storage device of the present invention accommodates a hydrogen storage body containing an activated hydrogen storage alloy, a heating device for conventional activation treatment under high temperature and hydrogen pressure is required. Absent. Depending on the type of hydrogen storage alloy used, the hydrogen storage device of the present invention can be used at room temperature,
Further, it is desirable that the working pressure is about 1 to 35 MPa. The hydrogen storage device of the present invention may be configured to include, for example, a cooling device for reducing heat generation due to hydrogen storage of the hydrogen storage alloy, a vacuum pump for reducing the pressure in the storage container, and the like.

Also for the hydrogen storage material constituting the hydrogen storage device of the present invention, it is desirable to adopt the preferred embodiment of the above-described hydrogen storage material activation treatment method of the present invention.
Usually, a hydrogen storage alloy tends to be pulverized and agglomerated when storing and releasing hydrogen. For this reason, there is a possibility that the temperature locally rises due to heat generation when hydrogen is absorbed.
Therefore, when the hydrogen storage material is configured to include the porous carbon material, the porous carbon material has high heat conduction,
Diffusion of heat generated when the hydrogen storage alloy stores hydrogen is facilitated and the temperature rise due to the heat generation can be suppressed. Further, since the porous carbon material is a material capable of storing and releasing hydrogen, the hydrogen storage amount of the hydrogen storage body also becomes large.

[0029]

Example Based on the above-mentioned embodiment, various hydrogen storage materials were subjected to the activation treatment of the present invention. After that, each hydrogen storage body was housed in a hydrogen storage / release amount measuring device in an inert gas atmosphere, and the degree of activation was evaluated by measuring each hydrogen storage / release amount. Hereinafter, the activation treatment of the hydrogen storage body, the measurement of the hydrogen storage / release amount of the hydrogen storage body, and the evaluation of the degree of activation will be described.

<Activation Treatment of Hydrogen Storage Body> (1) Hydrogen Storage Body of # 1 As a hydrogen storage alloy, TiCrV which is a titanium-based alloy,
Activated carbon MSC30 (manufactured by Kansai Thermal Chemical Co., Ltd., specific surface area: about 3200 m ² / g) was used as a porous carbon material to obtain a hydrogen storage material. For TiCrV, an ingot of about 20 g was produced by arc melting in a argon gas using a water-cooled copper hearth, and the ingot was crushed into several millimeters square in air and used. 1 g of TiCrV and 1 g of activated carbon MSC30 were mixed in a weight ratio of 1: 1 and T
A powdery hydrogen storage material composed of iCrV and activated carbon MSC30 was prepared. Mixing was performed in an argon gas atmosphere for about 5 minutes using a mortar. The prepared hydrogen storage body was housed in a quartz tube (outer diameter 30 mm, inner diameter 25 mm, length 600 m) as a processing container, and treated with an inert gas. For the inert gas treatment, argon gas was flown into the quartz tube at a flow rate of 50 ml /
The temperature was kept at 200 ° C. for 1 hour while flowing at min. The holding temperature is the temperature of the outer wall surface of the quartz tube when the vicinity of the center of the quartz tube is heated from the outside by a heater. After the treatment with the inert gas, the mixture was left to cool for about 2 hours while flowing argon gas. The hydrogen storage material activated by this activation treatment method was designated as # 1 hydrogen storage material.

(2) Hydrogen absorbers # 2 to # 5 In the activation treatment method described in (1) above, the holding temperature for the inert gas treatment is 100 ° C, 150 ° C, 300 ° C,
The hydrogen storage material was activated in the same manner except that the temperature was changed to 500 ° C. The activated hydrogen storage bodies were designated as # 2 to # 5 hydrogen storage bodies in ascending order of holding temperature.

(3) Hydrogen storage body of # 6 In the activation treatment method described in the above (1), the mixing amount of the hydrogen storage alloy and the porous carbon material was changed to 2.5 g.
Except that TiCrV and 0.5 g of activated carbon MSC30 were mixed at a weight ratio of 5: 1 to form a hydrogen storage material, and the hydrogen storage material was activated in the same manner. The activated hydrogen storage material was designated as # 6 hydrogen storage material.

(4) Hydrogen storage body of # 7 In the activation treatment method described in (1) above, the mixing amount of the hydrogen storage alloy and the porous carbon material was changed to obtain 3 g of T.
1 weight ratio of iCrV and 0.3 g of activated carbon MSC30
Except that a hydrogen storage material was prepared by mixing so as to be 0: 1.
The hydrogen storage material was activated in the same manner. The activated hydrogen storage material was designated as # 7 hydrogen storage material.

(5) Hydrogen Storage Material of # 8 Activated carbon MSC30 was removed from the hydrogen storage material activated by the activation treatment method described in (1) above to obtain a hydrogen storage material consisting of only a hydrogen storage alloy. This hydrogen storage body #
8 was used as the hydrogen storage material.

(6) Hydrogen storage material of # 9 In the activation treatment method described in (1) above, the hydrogen storage material is made of only a hydrogen storage alloy and 1 g of Ti is used.
The hydrogen storage material was activated in the same manner except that CrV was prepared as the hydrogen storage material. The activated hydrogen storage material was designated as # 9 hydrogen storage material.

(7) Hydrogen absorbers # 10 to # 12 In the activation treatment method described in (1) above, the kind of porous carbon material constituting the hydrogen absorber is activated carbon M-1.
5 (Osaka Gas Chemical Co., specific surface area of about 1400 m ² /
g), activated carbon MK-80 (manufactured by Cataler Industry Co., Ltd., specific surface area: about 410 m ² / g), graphitized mesocarbon microbeads (manufactured by Osaka Gas Chemical Co., Ltd., specific surface area: about 10 m ² /
g, hereinafter referred to as "graphitized MCMB". ), And the hydrogen absorbing material was activated in the same manner. The activated hydrogen storage bodies were sequentially designated as # 10 to # 12 hydrogen storage bodies.

(8) Hydrogen storage body of # 13 In the activation treatment method described in (1) above, the type of the hydrogen storage alloy constituting the hydrogen storage body is changed to TiFe (manufactured by Kojundo Chemical Co., Ltd.). , And the hydrogen storage material was activated in the same manner. Activated hydrogen absorbers in order #
Thirteen hydrogen storage bodies were used.

(9) Hydrogen absorber of # 14 The same procedure as in the above-mentioned (1) except that the hydrogen absorber was prepared by molding it into a cylindrical pellet by high-pressure compression treatment. Activated the hydrogen storage material. Specifically, a mixture of 1 g of TiCrV, 1 g of activated carbon MSC30 and PTFE was subjected to a high pressure compression treatment by a compression molding machine to obtain a cylindrical hydrogen storage body having a diameter of about 20 mm. The content ratio of PTFE as a binder is 0.
It was set to 2% by weight. The high-pressure compression treatment was performed once at room temperature at a treatment pressure of 734 MPa. The activated hydrogen storage material was designated as # 14 hydrogen storage material.

(10) Hydrogen absorber of # 21 1 g of the above TiCrV and 1 g of the above activated carbon MSC30
And were mixed at a weight ratio of 1: 1 to obtain a hydrogen storage material. Mixing was performed in an argon gas atmosphere for about 5 minutes using a mortar. This hydrogen absorber was designated as # 21 hydrogen absorber.

(11) Hydrogen absorber of # 22 The hydrogen absorber was made of only 1 g of the above TiCrV, and this hydrogen absorber was designated as the hydrogen absorber of # 22.

(12) Hydrogen absorber of # 23 1 g of the above TiCrV and 1 g of the above activated carbon MSC30
And were mixed at a weight ratio of 1: 1 to obtain a hydrogen storage material. Mixing was performed in an argon gas atmosphere for about 5 minutes using a mortar. Then, the hydrogen storage material was placed in a container and kept at room temperature in an argon gas atmosphere for 12 hours. This hydrogen storage body was designated as # 23 hydrogen storage body.

(13) Hydrogen absorber of # 24 1 g of the above TiCrV and 1 g of the above graphitized MCMB were mixed in a weight ratio of 1: 1 to obtain a hydrogen absorber. Use a mortar for mixing, and use argon gas atmosphere for about 5
I went for a minute. Then, the hydrogen storage material was placed in a container and left at room temperature for 12 hours in an argon gas atmosphere. This hydrogen absorber was designated as # 24 hydrogen absorber.

(14) Hydrogen absorber of # 25 After activating the hydrogen absorber by the activation treatment method described in (1) above, the hydrogen absorber was left in the atmosphere for 1 minute.
This hydrogen absorber was designated as # 25 hydrogen absorber.

<Measurement of Hydrogen Storage / Desorption of Hydrogen Storage and Evaluation of Degree of Activation> (A) Measurement of Hydrogen Storage / Desorption The amount of hydrogen storage / release of each hydrogen storage was measured. # 1 activated by the activation treatment method of the present invention
For the hydrogen absorber of # 14, after the inert gas treatment is completed, the quartz tube is sealed in a state where the quartz tube is filled with argon gas, and the amount of hydrogen absorbed from the quartz tube in the argon gas atmosphere glove box. Each hydrogen storage material was transferred to the measuring device. Similarly, with respect to the hydrogen storage bodies of # 23 and # 24, the hydrogen storage bodies were transferred from the container to the hydrogen storage amount measuring device while maintaining the argon gas atmosphere. #
Regarding the hydrogen storage bodies of 21, # 22 and # 25, the hydrogen storage bodies were housed in the hydrogen storage amount measuring device in the atmosphere. The hydrogen storage / release amount of each hydrogen storage body was measured 3 times at a temperature of about 20 ° C. and a pressure of 0.05 to 9 MPa. Hydrogen storage
The released amount was obtained by the volume method based on the pressure-composition isotherm (PCT line) (JIS H 7201-991).

(B) Evaluation of degree of activation In the above-mentioned three measurements of hydrogen absorption / desorption amount, 9 MPa
The degree of activation of each hydrogen storage material was determined from the hydrogen storage capacity at. The degree of activation was calculated as a relative value when the hydrogen storage amount was 100% when the hydrogen storage material used was sufficiently activated. For example, TiCrV and activated carbon MSC
In the case of a hydrogen storage material in which 30 and 30 are mixed at a weight ratio of 1: 1, the hydrogen storage capacity is 1. when fully activated.
It becomes 8 wt% (20 ° C., 9 MPa). Therefore, for a hydrogen storage material having the same composition, the degree of activation is calculated by the formula [degree of activation (%) = (hydrogen storage amount / 1.8) × 100]. Table 1 shows the degree of activation of each hydrogen storage material in three measurements of the hydrogen storage capacity.

[0046]

[Table 1]

From Table 1, it can be seen that the hydrogen absorbers # 1 to # 14 activated by the activation treatment method of the present invention have a degree of activation of 70% or more from the first measurement, and other # 2.
It can be seen that the degree of activation is extremely high as compared with the hydrogen absorbers 1 to # 25. That is, according to the activation treatment method of the present invention, it was confirmed that the hydrogen storage body containing the hydrogen storage alloy could be sufficiently activated. Hereinafter, the respective hydrogen storage materials will be compared and examined.

First, focusing attention on the hydrogen storage bodies # 1 to # 5 having different holding temperatures in the inert gas treatment, it can be seen that the activation progresses by 70% or more in the first measurement. It can be seen that the higher the holding temperature, the higher the degree of activation. In particular, with the # 5 hydrogen storage material held at 500 ° C., the activation was 100% from the first measurement,
It can be seen that the activation is sufficient. The hydrogen storage body is gradually activated by storing and releasing hydrogen. Therefore, for example, the # 1 hydrogen storage material held at 200 ° C. was measured at the third measurement with # 4 hydrogen storage material held at 300 ° C.
In the second measurement, the hydrogen storage material of
It became 0%. On the other hand, the hydrogen storage bodies of # 23 and # 24 held at room temperature are both activated at a level of about 50 to 60%, which is low. That is, it is understood that the activation is insufficient only by holding the hydrogen storage body in the inert gas atmosphere. From the above, it was confirmed that when the holding temperature in the inert gas treatment is 100 ° C. or higher, 80% or higher activation can be achieved by repeating hydrogen storage / release 3 times. It was also confirmed that the higher the holding temperature, the higher the degree of activation.

Next, focusing on the hydrogen absorbers # 1, # 6, # 7, and # 9 in which the proportion of the porous carbon material in the hydrogen absorber is different, three types other than the hydrogen absorber # 9 are excluded. It can be seen that the degree of activation of is the same value in any measurement of 1 to 3 times. And in each case, the activation was 100% in the third measurement. On the other hand, the # 9 hydrogen absorber containing no porous carbon material had a slightly lower degree of activation than the other three types of hydrogen absorber containing the porous carbon material. From this result, it is understood that the activation of the hydrogen storage alloy is promoted by including the porous carbon material in the hydrogen storage body. It was also confirmed that in order to accelerate the activation, it is sufficient that the hydrogen storage material contains about 10% by weight of the porous carbon material. Further, the degree of activation of the # 8 hydrogen absorber was also the same as that of the above # 1, # 6, and # 7 hydrogen absorbers. In other words, if the activation treatment is performed with the porous carbon material included, the degree of activation of the hydrogen storage alloy will not change even if the porous carbon material is removed to form a hydrogen storage material. I understand.

Further, the types of porous carbon materials are different.
Focusing on the hydrogen absorbers # 1 and # 10 to # 12, the hydrogen absorbers # 1 and # 10 using the porous carbon material having a specific surface area of 1000 m ² / g or more are porous carbon having a small specific surface area. It can be seen that the degree of activation is higher than that of the # 11 and # 12 hydrogen storage materials using the material. As described above, when a porous carbon material having a large specific surface area is used, it is considered that the activation is further promoted because the adsorption capacity of the gas such as carbon dioxide and oxygen adsorbed on the surface of the hydrogen storage alloy is high. To be In addition, different types of hydrogen storage alloy
When the hydrogen absorber of No. 1 and the hydrogen absorber of # 13 were compared, the degree of activation of the hydrogen absorber of # 13 using TiFe was slightly lower. This is because the ease of activation differs depending on the type of hydrogen storage alloy. The degree of activation of the # 14 hydrogen storage body molded by the high-pressure compression treatment was the same as that of the powdery # 1 hydrogen storage body. From this, it can be seen that the degree of activation does not change regardless of whether the hydrogen storage material is a powder or a molded product.

Although the # 25 hydrogen absorber was activated by the activation treatment method of the present invention, the degree of activation was extremely low. The reason is that the storage method in the hydrogen storage amount measuring device is different from that of the hydrogen storage bodies # 1 to # 14. The hydrogen storage bodies # 1 to # 14 were stored in the hydrogen storage amount measuring device in an inert gas atmosphere after the inert gas treatment. On the other hand, the # 25 hydrogen absorber was left in the atmosphere for 1 minute after being treated with an inert gas, and the hydrogen absorber was housed in the hydrogen storage amount measuring device in the atmosphere. Therefore, although the hydrogen storage material was once activated by the activation treatment of the present invention,
It is considered that when it is subsequently placed in the atmosphere, air, water and the like are adsorbed on the surface of the hydrogen storage alloy and deactivated.
That is, it is necessary to maintain an inert gas atmosphere in order to store the hydrogen storage material activated by the activation treatment method of the present invention in a container or the like while maintaining its high activation state. It could be confirmed.

[0052]

According to the method for activating the hydrogen storage alloy of the present invention, the hydrogen storage alloy containing the hydrogen storage alloy is held on the surface of the hydrogen storage alloy at a temperature of 100 ° C. or higher in an inert gas atmosphere. The adsorbed oxygen and the like are removed, and the oxide layer on the surface of the hydrogen storage alloy is easily cracked. Therefore, the hydrogen storage alloy can be easily activated without performing a conventional activation treatment under high temperature and hydrogen pressure.
Further, in the method for accommodating the hydrogen storage device according to the present invention, the hydrogen absorber subjected to the inert gas treatment in the activation treatment method according to the present invention is accommodated in the hydrogen storage device in an inert gas atmosphere. Since the activated hydrogen storage alloy is stored in the hydrogen storage device as it is, it is not necessary to perform activation treatment in the hydrogen storage device as in the conventional case. Therefore, the hydrogen storage device can be reduced in size and weight. Further, the hydrogen storage device of the present invention is one in which a hydrogen storage body containing a hydrogen storage alloy that has been subjected to the inert gas treatment in the activation treatment method of the present invention is stored in a storage container. Since it is not necessary to activate the hydrogen storage alloy in the hydrogen storage device, the heating device conventionally required becomes unnecessary. Therefore, the hydrogen storage device is small and lightweight.

Continued front page    F-term (reference) 3E072 EA10                 4G066 AA02B AA04B AA10D BA26                       CA38 FA18 FA34 FA37 GA14                 4G140 AA02 AA22 AA36 AA43 AA48

Claims (9)

[Claims] 1. A hydrogen storage body preparation step of preparing a hydrogen storage body containing a hydrogen storage alloy, and an inert gas for accommodating the hydrogen storage body in a processing container and holding the hydrogen storage body at a temperature of 100 ° C. or higher in an inert gas atmosphere. A method for activating a hydrogen storage body, the method including: a treatment step. 2. The method for activating a hydrogen storage body according to claim 1, wherein the hydrogen storage body contains a porous carbon material. 3. The specific surface area of the porous carbon material is 100.
The method for activating the hydrogen storage material according to claim 2, wherein the method is 0 m ² / g or more. 4. The method for activating a hydrogen storage material according to claim 2, wherein a content ratio of the porous carbon material in the hydrogen storage material is 5% by weight or more and 50% by weight or more. 5. The hydrogen storage body contains a binder for binding the hydrogen storage alloy and the porous carbon material.
The method for activating the hydrogen storage material according to item 1. 6. The method for activating the hydrogen storage body according to claim 2, wherein the hydrogen storage body is obtained by high-pressure compression treatment. 7. The activation treatment method for a hydrogen storage body according to claim 1, wherein the hydrogen storage alloy is a titanium alloy. 8. A hydrogen storage body preparation step for preparing a hydrogen storage body containing a hydrogen storage alloy, and an inert gas for accommodating the hydrogen storage body in a processing container and holding the hydrogen storage body at a temperature of 100 ° C. or higher in an inert gas atmosphere. A method for accommodating a hydrogen storage device in a hydrogen storage device, comprising: a treatment process; and a hydrogen storage device accommodation process in which the hydrogen storage device subjected to the inert gas treatment is stored in the hydrogen storage device in an inert gas atmosphere. 9. A hydrogen storage device comprising a storage container and a hydrogen storage material housed in the storage container, wherein the hydrogen storage material is held at a temperature of 100 ° C. or higher in an inert gas atmosphere. A hydrogen storage device including a hydrogen storage alloy.