JP2003206101A - Hydrogen production apparatus and fuel cell system using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen production apparatus capable of operating a fuel cell by well controllably producing a large volume of hydrogen at a room temperature under low pressure environment and working an injection control mechanism with a small energy in the hydrogen production apparatus used for the fuel cell. <P>SOLUTION: The hydrogen production apparatus is provided with an injection vessel containing a liquid such as water or alcohol, a hydrogen production vessel containing a hydride capable of producing hydrogen by the reaction with the water or the alcohol, a connection part for connecting the injection vessel and the hydrogen production vessel to each other and the injection control mechanism for injecting the liquid to the hydrogen production vessel through the connection part. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for generating hydrogen, and more particularly to a device for generating hydrogen supplied to a fuel cell.

[0002]

2. Description of the Related Art In recent years, fuel cell technology has been actively developed for application to fuel cell automobiles, stationary fuel cells, and portable fuel cells from the viewpoint of environmental and energy problems. There are various types of fuel cells, and among them, polymer electrolyte fuel cells using hydrogen as fuel and air or oxygen have been commercialized.

This hydrogen supply method includes a method of generating hydrogen or a method of storing hydrogen. As a method of generating hydrogen, there are a method of electrolyzing water and a method of reforming fossil fuel. The method by electrolysis of water is a method of generating hydrogen by supplying large electric power from the outside, and the method by reforming fossil fuel is, for example, in a high temperature environment of about 300 ° C. for methanol and 800 ° C. for methane gas. This is a method of generating hydrogen by causing a reforming reaction.

Further, as a method of storing hydrogen, there is storage of high pressure hydrogen or liquid hydrogen, or storage by a hydrogen storage alloy. Storage of high-pressure hydrogen is a method of storing hydrogen in a pressure vessel under a high-pressure environment of several hundred atmospheric pressure. Liquid hydrogen storage is
This is a method of storing liquid hydrogen under an extremely low temperature environment of −253 ° C. Storage with a hydrogen-absorbing alloy shows that vanadium-based alloys store 2.5% by weight of hydrogen at room temperature.
Magnesium stores about 7% by weight of hydrogen in a high temperature operation above ℃. Since the operating conditions of these hydrogen supply methods are different from each other, it is the present situation that they can be appropriately used according to the usage pattern of the fuel cell.

[0005]

However, for widespread use of fuel cells, hydrogen that can operate as a hydrogen supply method at room temperature and in a low-pressure environment, has a high capacity, and requires almost no external energy supply. Feeding equipment is essential. Particularly, in a fuel cell vehicle and a portable fuel cell, a hydrogen supply device having such performance is effective.

However, considering the conventional hydrogen supply method,
The method by electrolysis of water operates at room temperature and low pressure environment to obtain high capacity hydrogen, but it is necessary to supply a large amount of electric power from the outside. The method based on fossil fuel reforming operates in a low-pressure environment and gives a high volume of hydrogen.
It is necessary to operate in a high temperature environment and externally supply heat energy.

The high-pressure hydrogen storage method operates in a room temperature environment and does not require external energy, but requires a high pressure of several hundreds of atmospheres to increase the capacity. The liquid hydrogen storage method operates in a low pressure environment, obtains a high volume of hydrogen, and basically requires no external energy, but is placed in a cryogenic environment. On the other hand, the storage method using a hydrogen storage alloy operates in a low-pressure environment at room temperature and requires almost no external energy, but the amount of hydrogen stored in the alloy is small and a high capacity cannot be obtained.

The present invention has been made especially in view of the above problems of the hydrogen supply device used in the fuel cell, and in a room temperature and low pressure environment, a large amount of hydrogen is generated with good control, and injection control with small energy is performed. An object of the present invention is to provide a hydrogen generator capable of operating a fuel cell by operating a mechanism.

[0009]

The hydrogen generator of the present invention comprises an injection container containing a liquid of water or alcohol, a hydrogen generation container containing a hydride that reacts with water or alcohol to generate hydrogen, and the injection container. It is characterized in that it is provided with a connecting portion for connecting with the hydrogen generating container.

The hydrogen generator of the present invention comprises an injection container containing an alkaline solution of a hydride that reacts with water or alcohol to generate hydrogen, a hydrogen generation container containing a catalyst for promoting the decomposition reaction of the hydride, It is characterized by comprising a connecting portion for connecting the injection container and the hydrogen generation container.

[0011] by reaction with water or alcohol is a hydride to generate hydrogen, the formula A _x B _y H _z (A is an alkali metal or alkaline earth metal, B is boron or aluminum, H
Is hydrogen, 0 ≦ x ≦ 10, 0 ≦ y ≦ 20, 1 ≦ z ≦
30 except that both x and y are 0).

Furthermore, an injection control mechanism for injecting water or an alkaline solution of alcohol or hydride into the hydrogen generating container is provided, and the injection control mechanism is a mechanism for utilizing expansion and contraction of the piezoelectric material, or water by heating the injection container. Alkaline solution of water or alcohol, or hydride by a mechanism that utilizes expansion of an alkaline solution of alcohol or hydride, or by a mechanism that pressurizes water or alcohol in a cylindrical injection container or alkaline solution of hydride with a piston. Is preferably a mechanism for injecting into the hydrogen generation container.

The connecting portion for connecting the injection container and the hydrogen generating container is composed of a plurality of connecting pipes provided with valves, and the injection control mechanism uses the plurality of valves for the hydrogen generating container according to the hydrogen supply amount. A mechanism for controlling the flow rate of water or alcohol, or an alkaline solution of hydride injected into the container is preferable.

The fuel cell system of the present invention comprises a hydrogen generator having the above-mentioned structure, and a fuel cell for generating electricity using a fuel gas containing an oxidant gas and hydrogen supplied from the hydrogen generator. It is characterized by that.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A hydrogen generator according to the present invention includes an injection container containing a liquid of water or alcohol, a hydrogen generation container containing a hydride that reacts with water or alcohol to generate hydrogen, the injection container and the hydrogen generation device. It is characterized by comprising a connecting portion for connecting with a container.

The alcohol contained in the injection container is
Examples thereof include methyl alcohol and the like, but are not particularly limited. Examples of hydrides that react with water or alcohol to generate hydrogen include LiBH ₄ , LiAlH ₄ , and N.
Examples include aBH ₄ and NaAlH ₄ .

Further, the hydrogen generator includes an injection control mechanism for injecting a liquid of water or alcohol into the hydrogen generation container containing the hydride through the connecting portion, and the injection control mechanism expands and contracts the piezoelectric material. A mechanism that utilizes expansion of water or alcohol by heating the injection container, or a mechanism that pressurizes water or alcohol in a cylindrical injection container with a piston to inject water or alcohol into the hydrogen generation container. Preferably there is.

Further, the connecting portion for connecting the injection container and the hydrogen generation container is composed of a plurality of connecting pipes provided with valves, and the injection control mechanism uses the plurality of valves to supply hydrogen depending on a hydrogen supply amount. A mechanism for controlling the flow rate of water or alcohol injected into the generation container is preferable.

In the injection control mechanism provided with the valve as described above, it is necessary to pressurize the water or alcohol in the injection container. Examples of the method of pressurizing water or alcohol include a method of utilizing expansion of water or alcohol by heating. For this, the heating container provided in the injection container may heat the injection container, or the heating device may be installed in the injection container to directly heat the liquid. In addition, there is a method in which a piezoelectric material is provided in the upper part of the injection container and its expansion and contraction are used, or a cylinder-shaped injection container is used to push the piston downward.

Further, there is a method in which a container made of an elastic material such as rubber is used as the material of the injection container and the contracting force is utilized. A container made of an elastic material can be filled with water or alcohol and expanded by the following method. A container containing water or alcohol is connected to the container made of an elastic material. Then, by the above-mentioned pressurizing method or the like, pressure is applied to water or alcohol in the container,
Water or alcohol is poured into a container made of an elastic material.
In this way, water or alcohol can be injected into a container made of an elastic material to expand the container, and the contracting force of the elastic material can be used to apply pressure to the water or alcohol.

The hydrogen generating apparatus having the above-described structure includes an injection container containing an alkaline solution of hydride instead of water or alcohol, and a hydrogen generating container containing a catalyst for promoting a decomposition reaction of hydride instead of hydride. May be used. NaOH, KOH or the like is used as the alkaline solution. Examples of the catalyst include precious metal elements such as Ru, Rh,
Pd, Os, Ir, Pt, Au or the like is used.

[0022]

EXAMPLES The present invention will be specifically described based on examples, but the present invention is not limited thereto.

<< Embodiment 1 >> FIG. 1 shows a block diagram of a hydrogen generator in this embodiment. Reference numeral 1 denotes an injection container containing a liquid of water or alcohol, which is connected via a connecting portion 4 to a hydrogen generation container 2 containing a hydride that reacts with water or alcohol to generate hydrogen. The connection part 4 is provided with an injection control mechanism 3 that controls the injection of water or alcohol liquid into the hydrogen generation container 2 in response to a signal S1 output from the control part of the fuel cell device 5. The hydrogen generation container 2 is provided with a hydrogen supply pipe 6 for supplying the generated hydrogen to the fuel cell device 5. The pneumatic dispenser has a mechanism for controlling pressurization of water or alcohol liquid in the injection container 1 by a signal S2 sent from the control unit of the fuel cell device 5. Compressed air is sent to the injection container 1 by a pneumatic dispenser.

The operation of the hydrogen generator having the structure shown in FIG. 1 will be described below. When the operation switch of the control unit of the fuel cell device 5 is pressed, the control unit sends a signal S2 for sending compressed air to the pneumatic dispenser. Thereby, the compressed air is sent into the injection container 1, and the water or alcohol in the injection container 1 is pressurized. At the same time, a signal S1 for opening the outlet of the injection container 1 is sent from the control unit to the injection control mechanism 3. As a result, the outlet of the injection container 1 is opened and the water or alcohol pressurized in the injection container 1 is pushed out and injected into the hydrogen generation container 2. The hydride in the hydrogen generation container 2 undergoes a decomposition reaction by the injected water or alcohol to generate hydrogen. Then, this hydrogen is sent to the fuel cell device 5 through the hydrogen supply pipe 6, and the fuel cell operates.

When the stop switch of the control unit of the fuel cell device 5 is pressed, the control unit sends a signal S2 to stop sending compressed air to the pneumatic dispenser. This stops sending the compressed air into the injection container 1. At the same time, a signal S1 for closing the outlet of the injection container 1 is sent from the control unit to the injection control mechanism 3. This allows
The outlet of the injection container 1 is closed, and the injection of water or alcohol into the hydrogen generation container 2 is blocked. The decomposition reaction of hydride with water or alcohol stops and hydrogen is not generated. Therefore, the supply of hydrogen gas to the fuel cell is stopped and the fuel cell is stopped.

Hydrogen was generated using the hydrogen generator having the above structure. At this time, the injection control mechanism was operated by the storage battery built in the control unit of the fuel cell device. The built-in battery is charged by the fuel cell at any time during operation of the fuel cell. LiB as hydride
_{H 4, LiAlH 4, NaBH 4} , and was used NaAlH _4. And each said hydride was put into the hydrogen generation container, and water was put into the injection container, respectively, and each said hydride and water were made to react, and hydrogen was generated. High-capacity hydrogen of 10 wt%, 8 wt%, 8 wt%, and 7 wt% was obtained for the mixture of hydride and water, respectively.

Further, each of the above hydrides is placed in a hydrogen generating container.
Methyl alcohol was placed in each of the injection containers, and each of the above hydrides was reacted with methyl alcohol to generate hydrogen. 10 wt%, 9 wt%, 9 wt%, and 8 wt for the mixture of hydride and methyl alcohol, respectively
% And a high volume of hydrogen was obtained. As described above, by using the hydrogen generator having the configuration shown in FIG. 1, a high-capacity hydrogen is generated with good control under a low-pressure environment at room temperature, and the injection control mechanism is operated with a small amount of energy, so that the fuel cell Can be up and running.

Example 2 LiBH ₄ as a hydride,
LiAlH ₄ , NaBH ₄ , and NaAlH ₄ are used,
20: 60: 2 sodium hydroxide, water and each hydride
The mixture was mixed at a molar ratio of 0 to obtain alkaline solutions of hydride. Then, using the same hydrogen generator as in Example 1, alkaline solutions of the above hydrides were placed in the injection container, and Ru was placed as a catalyst in the hydrogen generation container. Then, the operation switch of the fuel cell device was pushed to generate hydrogen. At this time, the injection control mechanism was operated in the same manner as in Example 1. 7 wt%, 6 wt%, 6 wt%, and 5 with respect to the alkaline solution of hydride, respectively.
A high hydrogen content of wt% was obtained.

As described above, an injection container containing an alkaline solution of hydride was used in place of water or alcohol, and a hydrogen generation container containing a catalyst for promoting the decomposition reaction of hydride was used in place of hydride. A hydrogen generator having the same configuration as in Example 1 was used except for this. By using the hydrogen generator having such a configuration, a high-capacity hydrogen can be generated with good control under a room temperature and low pressure environment, and the injection control mechanism can be operated with a small amount of energy to operate the fuel cell.

<< Embodiment 3 >> FIG. 2 shows a block diagram of a hydrogen generator in this embodiment. A pressure mechanism including the piezoelectric material 7 is provided on the top of the injection container 1. The piezoelectric material 7 has a mechanism for controlling voltage application by a signal S3 sent from the control unit of the fuel cell device 5.

The operation of the hydrogen generator having the configuration shown in FIG. 2 will be described below. When the operation switch of the control unit of the fuel cell device 5 is pressed, the control unit sends a signal S3 for applying a voltage to the piezoelectric material 7. As a result, a voltage is applied to the piezoelectric material 7 to expand the piezoelectric material 7, water or alcohol in the injection container 1 is pushed out, and injected into the hydrogen generation container 2.

When the stop switch of the control unit of the fuel cell device 5 is pressed, the control unit sends a signal S3 for canceling the voltage application to the piezoelectric material 7. As a result, no voltage is applied to the piezoelectric material 7, the piezoelectric material 7 contracts, the water or alcohol in the injection container 1 is not pressurized, and the injection of water or alcohol into the hydrogen generation container 2 is blocked.

<Embodiment 4> FIG. 3 shows a block diagram of a hydrogen generator in this embodiment. A pressure mechanism including a heater 8 is provided on the outer periphery of the injection container 1. The heater 8 is provided with a signal S4 sent from the control unit of the fuel cell device 5.
Thus, a mechanism for controlling the power source of the heater 8 is provided.

The operation of the hydrogen generator having the structure shown in FIG. 3 will be described below. When the operation switch of the control unit of the fuel cell device is pushed, a signal S for turning on the heater 8 from the control unit is sent.
4 is sent. As a result, the heater 8 is turned on and the temperature of water or alcohol in the injection container 1 rises. Then, water or alcohol expands, is pushed out, and is injected into the hydrogen generation container 2. When the stop switch of the control unit of the fuel cell is pressed, the control unit sends a signal S4 for turning off the power to the heater 8. This allows
The heater 8 is turned off, and the temperature of water or alcohol drops. Then, the water or alcohol contracts, and the injection of water or alcohol into the hydrogen generation container 2 is blocked.

<Embodiment 5> FIG. 4 shows a block diagram of a hydrogen generator in this embodiment. Reference numeral 9 is a cylindrical injection container containing a liquid of water or alcohol, and is connected via a connecting portion 4 to a hydrogen generation container 2 containing a hydride that reacts with water or alcohol to generate hydrogen. Inside the cylindrical injector 9, a pressurizing mechanism including a pushing portion 10 is provided. The push-in section 10 has a mechanism for controlling the drive by a signal S5 sent from the control section of the fuel cell device 5.

The operation of the hydrogen generator having the structure shown in FIG. 4 will be described below. When the operation switch of the control unit of the fuel cell device 5 is pushed, a signal S5 for driving the pushing unit 10 downward is sent from the control unit to the pushing unit 10. As a result, the pushing portion 10 is driven downward, and the water or alcohol in the injection container 1 is pushed out and injected into the hydrogen generation container 2.

When the stop switch of the control unit of the fuel cell device 5 is pressed, a signal S5 for stopping the driving of the pushing unit 10 is sent from the control unit. As a result, the pushing unit 10 is stopped, and the injection of water or alcohol into the hydrogen generation container 2 is blocked.

In any of Examples 3 to 5, water or alcohol can be injected with good control, there is no variation in the injection amount per time, and hydrogen can be stably generated and supplied to the fuel cell. As described above, with any of the hydrogen generators having the configurations shown in FIGS. 2 to 4, under a room temperature and low pressure environment, a large amount of hydrogen can be generated with good control, and the injection control mechanism can be operated with a small amount of energy. By this, the fuel cell can be operated.

<Embodiment 6> FIG. 5 shows a block diagram of a hydrogen generator in this embodiment. The connecting portion 4 is provided with an opening / closing valve 11 that controls injection and shutoff of water or alcohol by a signal S6 sent from the fuel cell device 5.
The injection container 1 contains water or alcohol which is expanded and pressurized by the heating of the heater.

The operation of the hydrogen generator having the structure shown in FIG. 5 will be described below. When the operation switch of the control unit of the fuel cell device 5 is pushed, a signal S6 for opening the valve is sent from the control unit to the on-off valve 11. As a result, the valve is opened, and the pressurized water or alcohol in the injection container 1 is pushed out and injected into the hydrogen generation container 2. When the stop switch of the control unit of the fuel cell is pressed, a signal S6 for closing the valve is sent from the control unit to the on-off valve 11. As a result, the valve is closed and the injection of water or alcohol into the hydrogen generation container 2 is blocked.

Therefore, the liquid of water or alcohol can be injected with good control, the amount of injection per hour does not vary, and hydrogen can be stably generated and supplied to the fuel cell. As described above, by using the hydrogen generator having the configuration shown in FIG. 5, a high-capacity hydrogen can be generated with good control under a low-pressure environment at room temperature, and the injection control mechanism can be operated with a small amount of energy. Can be up and running.

<Embodiment 7> FIG. 6 shows a configuration diagram of a hydrogen generator in this embodiment. Injection container 1 and hydrogen generation container 2
A plurality of connecting portions 4 are provided to connect and. Each connecting portion 4 is provided with an on-off valve 11 that controls the flow rate of water or alcohol injected into the hydrogen generation container according to the hydrogen supply amount. The injection container 1 contains water or alcohol which is expanded and pressurized by the heating of the heater.

The operation of the hydrogen generator having the structure shown in FIG. 6 will be described below. Depending on the amount of hydrogen to be supplied to the fuel cell device 5 set by the control unit of the fuel cell device 5, the control unit outputs a signal S6 for opening or closing the valves to the plurality of on-off valves 11. The opening / closing valve 11 to which the signal S6 for opening the valve is sent from the control unit of the fuel cell device 5 opens, and the pressurized water or alcohol in the injection container 1 is pushed out and injected into the hydrogen generation container 2. . On the other hand, the on-off valve 11 to which the signal S6 for closing the valve is sent is closed and the injection of water or alcohol is cut off. In this way, the amount of water or alcohol injected into the hydrogen generation container is controlled according to the set hydrogen supply amount. That is, it is possible to control the amount of hydrogen supplied to the fuel cell device 5 by adjusting the amount of water or alcohol to be injected into the hydrogen generation container 2 with the plurality of open / close valves 11.

As described above, by using the hydrogen generator having the structure shown in FIG. 6, a high volume of hydrogen can be generated with good control under a room temperature and low pressure environment, and the injection control mechanism can be operated with a small amount of energy. Can operate the fuel cell.

[0045]

As described above, according to the present invention, at room temperature and low pressure environment, a high volume of hydrogen is generated with good control, and the injection control mechanism is operated with a small amount of energy.
A hydrogen generator capable of operating a fuel cell can be provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a hydrogen generator in Embodiments 1 and 2 of the present invention.

FIG. 2 is a configuration diagram of a hydrogen generator according to a third embodiment of the present invention.

FIG. 3 is a configuration diagram of a hydrogen generator according to a fourth embodiment of the present invention.

FIG. 4 is a configuration diagram of a hydrogen generator according to a fifth embodiment of the present invention.

FIG. 5 is a configuration diagram of a hydrogen generator according to a sixth embodiment of the present invention.

FIG. 6 is a configuration diagram of a hydrogen generator according to a seventh embodiment of the present invention.

[Explanation of symbols]

1 infusion container 2 Hydrogen generation container 3 Injection control mechanism 4 connection 5 Fuel cell device 6 Hydrogen supply piping 7 Piezoelectric material 8 heating heater 9 Cylinder shaped injection container 10 Push-in section 11 on-off valve

Claims (9)

[Claims] 1. An injection container containing a liquid of water or alcohol, a hydrogen generation container containing a hydride that reacts with water or alcohol to generate hydrogen, and a connecting portion connecting the injection container and the hydrogen generation container. A hydrogen generator characterized in that. 2. A hydride that reacts with water or alcohol to generate hydrogen has the formula A _x B _y H _z (A is an alkali metal or alkaline earth metal, B is boron or aluminum,
H is hydrogen, 0 ≦ x ≦ 10, 0 ≦ y ≦ 20, 1 ≦ z
The hydrogen generator according to claim 1, which is a compound represented by ≦ 30, except when x and y are both 0). 3. An injection control mechanism for injecting a liquid of water or alcohol into the hydrogen generating container containing the hydride through the connecting portion, wherein the injection control mechanism utilizes expansion and contraction of the piezoelectric material. A mechanism, a mechanism that utilizes expansion of water or alcohol by heating the injection container, or a mechanism that pressurizes water or alcohol in a cylindrical injection container with a piston to inject water or alcohol into the hydrogen generation container. 1. The hydrogen generator according to 1 or 2. 4. The connecting portion connecting the injection container and the hydrogen generation container is composed of a plurality of connecting pipes provided with valves, and the injection control mechanism uses the plurality of valves to adjust the amount of hydrogen supplied.
The hydrogen generator according to claim 1 or 2, which is a mechanism for controlling a flow rate of water or alcohol injected into the hydrogen generation container. 5. An injection container containing an alkaline solution of a hydride that reacts with water or alcohol to generate hydrogen, a hydrogen generation container containing a catalyst that accelerates the decomposition reaction of the hydride,
A hydrogen generator comprising a connecting part for connecting the injection container and the hydrogen generating container. 6. A hydride that reacts with water or alcohol to generate hydrogen has the formula A _x B _y H _z (A is an alkali metal or alkaline earth metal, B is boron or aluminum,
H is hydrogen, 0 ≦ x ≦ 10, 0 ≦ y ≦ 20, 1 ≦ z
6. The hydrogen generator according to claim 5, which is a compound represented by ≦ 30, except when x and y are both 0). 7. An injection control mechanism for injecting an alkaline solution of hydride into the hydrogen generating container containing the catalyst through the connecting portion, wherein the injection control mechanism utilizes expansion and contraction of the piezoelectric material. Injecting the alkaline solution of hydride into the hydrogen generation container by a mechanism that utilizes expansion of the alkaline solution of hydride by heating the injection container or a mechanism that pressurizes the alkaline solution of hydride in the cylindrical injection container with a piston The hydrogen generator according to claim 5 or 6, which is a mechanism. 8. The connecting portion connecting the injection container and the hydrogen generation container is composed of a plurality of connecting pipes provided with valves, and the injection control mechanism uses the plurality of valves to adjust the amount of hydrogen supplied.
7. The hydrogen generator according to claim 5, which is a mechanism for controlling the flow rate of the alkaline solution of hydride injected into the hydrogen generation container. 9. A hydrogen generator according to any one of claims 1 to 8, and a fuel cell for generating electricity using a fuel gas containing an oxidant gas and hydrogen supplied from the hydrogen generator. A fuel cell system characterized by the above.