JPS6310081B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydrogen storage method and storage container.

Hydrogen is widely used in various industrial fields, and there is a need for efficient, safe, and easy storage and transportation of hydrogen. Traditionally, hydrogen has been stored and transported in containers as high-pressure hydrogen gas or liquid hydrogen, but because it requires a large amount of energy to achieve high pressure or ultra-low temperature, recently hydrogen storage alloys have been used. Attempts to use are being actively considered.

A hydrogen storage alloy is an alloy that has the ability to store hydrogen H ₂ .There are various hydrogen storage alloys that are already known. When it is depressurized and heated, it releases hydrogen and absorbs heat. Note that when the hydrogen storage alloy is brought into contact with pressurized hydrogen, it absorbs hydrogen and becomes a metal hydride. Usually, to make a hydrogen storage alloy absorb hydrogen, it is sufficient to contact it with high-pressure hydrogen at room temperature, and to release hydrogen from a metal hydride, a heat medium such as hot water is passed between the metal hydrides.

Hydrogen storage methods and storage containers using hydrogen storage alloys that have been studied to date include the following.

In order to bring the hydrogen storage alloy into sufficient contact with hydrogen, it is housed in a porous metal container such as a wire mesh, punched metal, or foamed metal, and a plurality of these porous metal containers are arranged at predetermined intervals in the container. There are many voids within the container, and the space within the container is reduced by the metal enclosure itself. When a hydrogen storage alloy absorbs hydrogen, its volume expands by about 30%, so the container needs to have a porosity of 50 to 40%. Furthermore, since high pressure is required when storing hydrogen, a high-pressure container is used. Furthermore, by repeatedly absorbing and desorbing hydrogen in the hydrogen storage alloy, the lumpy hydrogen storage alloy becomes finely powdered, and the hydrogen passage holes in the porous metal storage body become clogged, and the heat generated during storage causes the fine powder to become pulverized. Solidification occurs due to sintering, leading to a decrease in reaction efficiency.

Therefore, in view of the above circumstances, the present invention aims to reduce the porosity as much as possible, prevent the consolidation of the hydrogen storage alloy, and increase the storage speed so that it can be used practically. This hydrogen storage alloy is made to absorb hydrogen by contacting it with hydrogen. Furthermore, if the hydrogen storage or desorption reaction is carried out only in the falling space, the container can be manufactured as a low-pressure container, and the exothermic or endothermic reaction heat in this region can be incorporated into the heat exchange system and utilized. It is also possible to do so.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

As shown in FIGS. 1 and 2, the container 1 is made of, for example, an aluminum alloy and has a conical shape with a large diameter at the top and a small diameter at the bottom, and four supporting legs 2 are hung from the bottom surface of the container 1. fixes the square tube fork guide 3. A hydrogen storage alloy inlet 4 is opened in the upper part of the container 1 and can be opened and closed with a cover plate 5. A discharge port 6 for the hydrogen storage alloy is opened in the lower part of the container 1, a porous bottom plate 7 made of a grid or punched metal is provided to cover the discharge port 6, and a gate valve is provided above the porous bottom plate 7 to open and close the discharge port 6. 8 is slidably provided. The porous bottom plate 7 and the gate valve 8 can be omitted if they are not necessary due to the shape of the container 1 or the like. In addition, the discharge port 6
A hydrogen supply pipe 9 is connected to the lower part of the porous bottom plate 7, and a heat medium passage pipe 10 for hot water, heated air, steam, etc. is arranged in a spiral shape inside the container 1, and its inlet pipe part 10a and outlet pipe part 10b are arranged in a spiral manner. It is made to protrude from the top surface of the container 1.

Next, the operation will be explained.

First, the container 1 containing the hydrogen storage alloy A is placed on top of the empty container 1 at the inlet 4 and outlet 6 of the lower container 1.
Place them so that they are continuous. Next, the gate valve 8 of the upper container 1 is opened, and the hydrogen storage alloy A contained in the upper container 1 is allowed to fall. When a certain hydrogen storage alloy is selected, a pressure higher than the hydrogen equilibrium dissociation pressure is supplied to the hydrogen supply pipe 9. For example, about 7 to 8 kg/cm ² of hydrogen is passed through the metal hydride, which is brought into contact with the falling hydrogen storage alloy A, so that the metal hydride that has stored hydrogen is stored through the inlet 4 of the lower container 1. Even after the hydrogen storage alloy A in the upper container 1 falls and completes its movement to the lower container 1, the pressure above the hydrogen equilibrium dissociation pressure is maintained for a while. Note that it is also possible to remove the heat generated during storage by passing cooling water through the heat medium passage pipe 10 of the lower container 1.
Thereafter, the upper container 1 is lowered and the inlet 4 of the lower container 1 is closed with the lid plate 5 and screwed.

In order to release hydrogen, when a heating medium is passed through the heating medium passage pipe 10 of the container 1 (the lower container 1 mentioned above) which contains the metal hydride which has been turned into hydrogen by storing hydrogen in the hydrogen storage alloy, the metal hydride is released. Hydrogen is released from the hydride,
Hydrogen flows out from the exit side of the hydrogen supply pipe 9.

In FIG. 3, there is no hydrogen circulation, and in FIG. 4, hydrogen is circulated and hydrogen is stored in the hydrogen storage alloy. The containers 1 are placed one above the other with valves 11 such as butterfly valves interposed between them, and in FIG. /
cm ² hydrogen generation source 13, downstream side is needle valve 14
are connected to each. In addition, in Figure 4, if a certain hydrogen storage alloy is selected, there will be 7 to 8 on the upstream side.
Receiver tank 15 for Kg/ ^cm2 , pressure 9-10Kg/
^cm2 compressor 16 is connected, and a flow rate adjustment valve 1 that automatically adjusts the flow rate by detecting the pressure of a pressure gauge 17 provided in the receiver tank 15.
purge tank 19 that accommodates hydrogen with 8 interposed therebetween;
is connected to the compressor 16 via a butterfly valve 20 and a filter 21 on the downstream side.

As described above, the present invention provides a method and a storage container for storing hydrogen by dropping a hydrogen storage alloy and bringing the hydrogen into contact with the falling hydrogen storage alloy. Since hydrogen is absorbed and its volume expands, there is no need for the container to have a large porosity.Also, since hydrogen is absorbed during the fall, it is necessary to provide a porous metal body to absorb hydrogen within the conventional container. The porosity can be further reduced to about 10%, making it possible to efficiently store and transport hydrogen. In addition, since hydrogen only needs to be brought into contact with the falling hydrogen storage alloy, the hydrogen supply pressure is about 7 to 8 kg/cm ² if a certain hydrogen storage alloy is selected, so an expensive high-pressure container is not required, and it is usually It can be stored in a low-pressure container.
Furthermore, since hydrogen is stored while the hydrogen storage alloy is dropped, it prevents the hydrogen storage alloy from solidifying, increases the contact area with hydrogen, accelerates the storage speed, and shortens the time required for storage, making it practical for use. It becomes like this. In this way, since hydrogen is stored when the hydrogen storage alloy falls, there is no need to provide a porous metal storage body or the like in the container, and the structure of the container is extremely simplified and mass production is facilitated. Further, if the containers are used as described above, it becomes possible to replace the hydrogen storage alloy between the containers.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a vertical cross-sectional view of the main part thereof, Fig. 2 is a plan view of Fig. 1, and Fig. 3 is a system for storing hydrogen in a hydrogen storage alloy without circulating hydrogen. 4 are system diagrams for circulating hydrogen and storing hydrogen in a hydrogen storage alloy. A...Hydrogen storage alloy.

Claims (1)

[Scope of Claims] 1. Hydrogen storage characterized by dropping a hydrogen storage alloy from an upper container of the same structure to a lower container, and causing hydrogen to come into contact with the hydrogen storage alloy during the fall so that hydrogen is stored. Method. 2. A container with an input port for the hydrogen storage alloy at the top, a discharge port for the hydrogen storage alloy at the bottom, a gate valve to open and close the discharge port, and a hydrogen supply pipe connected below the gate valve of the discharge port. , the container is stacked vertically, and when the hydrogen storage alloy falls through the discharge port, it comes into contact with the hydrogen supplied from the hydrogen supply pipe and absorbs hydrogen.The hydrogen storage alloy is stored therein. A storage container for hydrogen.