JPH0652119B2 - Mass activation method of metal hydride - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for mass activation of metal hydrides.

2. Description of the Related Art It is known that a certain kind of metal or alloy exothermically absorbs hydrogen to form a metal hydride, and this metal hydride reversibly endothermally releases hydrogen. In recent years, various devices utilizing the characteristics of these metal hydrides have been proposed,
In addition, it has been put to practical use in some cases. As such a device, for example, a hydrogen storage device or a transportation device that uses the property that a metal hydride can store a large amount of hydrogen, a hydrogen purification device that uses the property that a metal hydride selectively stores hydrogen,
Examples include heat pumps and heat storage devices that utilize heat absorption and absorption when metal hydride absorbs and releases hydrogen, temperature sensors and actuators that utilize the property that metal hydride has a constant hydrogen equilibrium pressure at a constant temperature. it can.

In the various devices as described above, after a certain amount of metal hydride is charged into a reactor having a structure or form suitable for the purpose, the metal hydride is activated or incorporated into a required device. After that, a method of individually activating each reactor is adopted, and conventionally, a method of simultaneously activating a large amount of metal hydrides charged in a large number of reactors has not been known. Therefore, the larger the apparatus including a large number of reactors, the longer the activation time of the metal hydride charged in each reactor, and the more expensive the processing cost. It was

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention has been made to solve the above-mentioned problems in activation of a metal hydride filled in a container, in which metal hydrides in a plurality of containers are simultaneously and It is an object to provide a method for activating a large amount in a batch.

Means for Solving the Problems In the method for activating large amounts of metal hydride according to the present invention, a plurality of containers having openings are filled with metal hydride, and these containers are collectively placed in a pressure resistant container, and at the same time metal It is characterized by activating a hydride.

Hereinafter, the method of the present invention will be described in detail with reference to FIG.

According to the method of the present invention, a large number of containers 2 each having an opening 1 serving as a hydrogen inlet / outlet are filled with a metal hydride 3 respectively, and these are collectively housed in a pressure-resistant container 4, and the metal hydrides in a large number of containers are filled. Are activated at the same time. The pressure-resistant container is provided with a vacuum exhaust pipe 5 connected to an appropriate vacuum device (not shown), an inlet pipe 6 for filling hydrogen into the pressure-resistant container, and an exhaust pipe 7 for exhaust. Further, in order to heat or cool the pressure resistant container, a heating / cooling pipe 8 for a heat medium or a refrigerant is arranged around the pressure resistant container.

In the method of the present invention, activation of the metal hydride includes
Firstly, a method of introducing hydrogen into the pressure vessel after applying a vacuum and then pressurizing it, making a vacuum in the second pressure vessel while heating, and then introducing and pressurizing hydrogen, and thirdly A method of introducing hydrogen into the pressure vessel, pressurizing it, and then discharging hydrogen repeatedly can be adopted.

In the case of the first method, after the vacuum vessel is evacuated by the vacuum exhaust pipe, hydrogen is introduced under pressure up to about 10 kg / cm ² or several tens of kg / cm ^{2, and} then left for a certain period of time. repeat. In the case of the second method, after the pressure vessel is evacuated, a high-temperature heating medium is circulated through the heating tube to heat the metal hydride, and then preferably cooled to room temperature, and then the above-mentioned is placed in the pressure vessel. Similarly to the above, hydrogen is introduced under pressure. According to the third method, without introducing a vacuum inside the pressure vessel, hydrogen is repeatedly introduced into the vessel under pressure to replace the inside of the pressure vessel with hydrogen and activate the metal hydride.

After activating the metal hydrides in the respective reactors as described above, if these are taken out from the pressure vessel, a metal hydride reactor filled with the metal hydrides in an activated state is obtained. be able to. But, for example, when the reactor is integrated into the device by welding,
When exposed to fire or high temperature, there is a risk of ignition of hydrogen, so after completing the activation of the metal hydride in each container as described above in the pressure vessel, vacuum the pressure vessel, After dehydrogenating the metal hydride, it is preferable to introduce an inert gas such as argon or helium into the container, replace the inside of the reactor with the inert gas, and take out from the pressure resistant container.

Further, according to the present invention, it is possible to easily obtain a metal hydride reactor in which a predetermined amount of hydrogen is stored in the metal hydride in the container. That is, after activating the metal hydride in the container by the method described above, so that the metal hydride hydrogen equilibrium pressure corresponding to the desired hydrogen storage amount is equal to atmospheric pressure,
Set and hold the temperature of the metal hydride. FIG. 2 shows the relationship between the hydrogen storage amount (H / M) in the metal hydride and the hydrogen equilibrium pressure (P). For example, in the case where the metal hydride stores hydrogen in the amount shown at point A, The temperature of the metal hydride may be maintained so that the point A is atmospheric pressure. Explaining in a specific example, when the metal hydride is LaNi ₅ , the pressure proof container is maintained at about 10 ° C., and hydrogen is introduced under pressure at a pressure of atmospheric pressure or higher into the pressure proof container to form a metal hydride. If hydrogen is naturally discharged from the pressure-resistant container up to atmospheric pressure after occluding hydrogen in, the LaNi ₅ occludes hydrogen corresponding to approximately point A.

As described above, the reactor containing the activated metal hydride is taken out of the pressure vessel, and then the opening of the reactor is caulked or brazed to be incorporated in a predetermined metal hydride device.

EFFECTS OF THE INVENTION As described above, according to the method of the present invention, it is possible to activate a large amount of metal hydrides respectively filled in a large number of containers at once, and, as in the conventional case, the metal hydrides can be activated for each container. Compared with the method of activating a hydride, the activation time and labor can be significantly reduced. In particular, according to the method of the present invention, after activating the metal hydride, it is possible to obtain a reactor containing a metal hydride in which a predetermined amount of hydrogen has been occluded. Can be immediately incorporated into a given metal hydride device.

Furthermore, according to the method of the present invention, the container filled with the metal hydride is activated in the pressure-resistant container, and therefore there is no pressure difference between the inside and the outside of the container during this activation.
Even when high-pressure hydrogen is particularly required for activation of the metal hydride, there is an advantage that the wall thickness of the container may be thin.

Examples Examples of the present invention will be given below.

Example 1 (Implementation in manufacturing hydrogen storage device) As shown in FIG. 3, a ceramic porous tube 10 having an outer diameter of 10 mm was placed inside a copper container 9 having an outer diameter of 19.05 mm and a length of 300 mm with one end sealed. was arranged as a hydrogen circulation material, a LaNi _{4. 8} Al _{0. 2} was 160g filled as a metal hydride. Twenty-one such containers are placed in a pressure resistant container, vacuum treated for 30 minutes while heating to 80 ° C, hydrogen is introduced to a pressure of 10 kg / cm ² and cooled to 20 ° C, and then left for 10 hours. did. Then, after vacuum treatment at a temperature of 80 ° C. for 30 minutes,
Hydrogen was introduced at a temperature of 20 ° C. at 10 kg / cm ² , and then 30
The operation of leaving for a minute was repeated 5 times.

In this way, 21 reactors could be obtained all at once by taking out the reactor from the pressure vessel with hydrogen stored in the activated metal hydride. As shown in FIG. 4, nine reactors 11 are attached to the hydrogen branch header 13 with a joint 12 and the reactor is hermetically covered with an outer shell 14 so that the inside of the outer shell has a heat medium flow path. A hydrogen storage and refining apparatus having a capacity of 15 was constructed.

According to this apparatus, while cooling the metal hydride in the reactor, hydrogen can be stored by storing hydrogen in the reactor, while heating the metal hydride,
Hydrogen can be released.

Example 2 (Implementation in Fabrication of Temperature Sensitive Drive) Twenty containers 17 having openings 16 filled with TiCo as a metal hydride were placed in a pressure resistant container, and the first activation was performed in the same manner as in Example 1. After that, hydrogen was introduced under pressure at a pressure of 2 kg / cm ² at a temperature of 20 ° C. to occlude hydrogen in the metal hydride. Next, after evacuating hydrogen from the pressure resistant container to atmospheric pressure, the reactor was taken out of the pressure resistant container and the opening 16
Crimped and brazed.

The reactor thus obtained was used as a temperature sensing tube for detecting the temperature, and was connected to a bellows 19 having one of the electrical contacts 18 at the end in the expansion / contraction direction by a thin tube 20 as shown in FIG. According to this temperature-sensitive drive device, the bellows expands and contracts according to the temperature sensed by the temperature-sensitive cylinder, so that the expansion and contraction can be utilized to open and close the electrical contact 18, for example.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a pressure resistant container and a number of containers filled with metal hydride for explaining the method of the present invention, and FIG. 2 generally shows the relationship between hydrogen storage amount and hydrogen equilibrium pressure in metal hydride. The graph which shows, FIG. 3 is sectional drawing which shows an example of a reactor, FIG. 4 is sectional drawing which shows an example of a hydrogen storage device, 5th.
The figure is a cross-sectional view showing an example of the temperature-sensitive drive device. 1 ... container opening, 2 ... container, 3 ... metal hydride, 4
...... Pressure resistant container, 5 ...... vacuum exhaust pipe, 6 ...... hydrogen inlet pipe,
7 ... Hydrogen discharge pipe, 8 ... Heating / cooling pipe.

Claims (1)

[Claims] 1. A method for mass-activating metal hydride, which comprises filling a plurality of containers having openings with metal hydride, placing the containers in a pressure resistant container, and simultaneously activating the metal hydride. .