WO2004085307A1

WO2004085307A1 - Hydrogen gas generator

Info

Publication number: WO2004085307A1
Application number: PCT/KR2004/000675
Authority: WO
Inventors: Seung Sik Cha; Jeong Gun Park
Original assignee: Temco Co., Limited
Priority date: 2003-03-28
Filing date: 2004-03-25
Publication date: 2004-10-07
Also published as: US20060185242A1; DE112004000485T5; JP2006521277A

Abstract

Disclosed is a self-regulating hydrogen gas generator for a hydrogen fuel cell. The self-regulating hydrogen gas generator includes a fuel tank, defining an inner space having a designated volume, provided with a hydrogen outlet communicating the inner space, a fuel solution, containing a hydrogen storing material, stored in the fuel tank, and a catalyst contacting the fuel solution for generating hydrogen gas, wherein the catalyst fills a catalytic reactor, provided with a closed portion for interrupting the contact between the catalyst and the fuel solution, and an opened portion contacting the fuel solution, so that the generation and interruption of hydrogen gas are actively regulated based on the increase and decrease of the pressure of the fuel tank.

Description

HYDROGEN GAS GENERATOR

[Technical Field]

The present invention relates to a self-regulating hydrogen gas

generator, and more particularly to a hydrogen gas generator for actively

regulating the generation of hydrogen gas due to variation in pressure of a

fuel tank based on the amount of hydrogen gas generated in the fuel tank

regardless of any external force.

I Background Art!

Recently, industrial development has improved quality of life, but the

rapid increase of energy demand causes serious problems such as

environmental pollution and exhaustion of fossil fuels.

All the countries of the world put forth great effort into the

development of alternative energy sources to protect against possible

exhaustion of fossil fuels, including petroleum. Particularly, the conventional

use of fossil fuels causes serious environmental (air) pollution, thereby

accelerating global warming and the destruction of environment. It is known

that the main factors contaminating the atmosphere are nitric oxides,

hydrocarbons and carbon dioxide exhausted from factories or vehicles.

These exhaust gases destroy the ozone layer, thereby causing various natural hazards, such as the direct transmission of harmful rays of the sun to

the surface of the earth and the generation of climatic change, the

destruction of the ecosystem, and various diseases.

In order to reduce the air pollution generated due to the use of fossil

fuels, development of clean-burning fuels has been accelerated.

Particularly, the development of alternative clean energy using hydrogen as

an energy source is suggested. Hydrogen, which an abundant earth

resource, reacts with oxygen to generate a great deal of energy and only

water as a by-product, thus being the only measure for simultaneously

solving the problems of the exhaustion of energy resources and

environmental pollution.

However, in order to use hydrogen as an energy resource, technical

problems caused by the generation of hydrogen and the safe storage and

carriage of the generated hydrogen must be solved. Particularly, in case

that hydrogen is used as the fuel for mobile equipment such as a hydrogen

engine or hydrogen fuel cell applied to a vehicle, or a hydrogen fuel cell

applied to small-sized IT (Information Technology) electronic devices, since

the amount of fuel stored in the equipment is restricted, a technique of

minimizing the volume and weight of a fuel tank for maintaining a high energy

density is essentially required.

Particularly, in case that hydrogen is used as fuel of the hydrogen

fuel cell for vehicles and IT electronic devices, the performances of the

vehicles and IT electronic devices are influenced by the storage method of the fuel and the capacity of the fuel tank. Thus, the generation and storage

methods of hydrogen are considered as leading techniques. A liquid

hydrogen storage method, a gaseous hydrogen storage method and a solid

hydrogen storage method are used as the hydrogen storage methods, which

are suggested now.

The liquid hydrogen storage method is advantageous in that

hydrogen is liquefied by maintaining cryotemperatures to greatly increase the

stored density of hydrogen. However, natural loss of the liquefied hydrogen

must be reduced and energy loss due to the cryogenic cooling must be

considered.

In the gaseous hydrogen storage method, high pressure is applied to

hydrogen and the compressed hydrogen is then stored. In order to obtain

an energy density suitable for mobile equipment, several hundreds of

atmospheres must be applied to the hydrogen, thus increasing energy

consumption and requiring a safe storage method for the super high-

pressure hydrogen.

The solid hydrogen storage method is advantageous in that it is usable at room-temperature and low-pressure and is excellent in terms of

safety and reduces energy loss, but is disadvantageous in that it has a low

energy density per unit weight due to the high density of a hydrogen storing

material. For example, a hydrogen fuel cell vehicles, which command public

attention recently, use hydrogen instead of gasoline or light gas oil as fuel.

In order to use hydrogen as the fuel of the hydrogen fuel cell vehicle, a large amount of hydrogen must be stored in a storage container. In case that the

conventional solid hydrogen storage method is applied to the above

hydrogen fuel cell vehicle, the hydrogen fuel cell vehicle has a travel range

half of that of a vehicle using gasoline as its fuel source, thus causing a

difficulty in commercially using the conventional solid hydrogen storage

method. In accordance with one solid hydrogen storage method for solving

of the above problem, a catalyst contacts a fuel solution obtained by

dissolving a hydrogen storing material, thus generating hydrogen. Since it is

possible to store hydrogen in a liquid state at approximately atmospheric

pressure, this method has high stability and high hydrogen storing capacity,

thus being capable of being applied to mobile equipment.

The above method generates hydrogen by means of the reaction

between the fuel solution and the catalyst. Accordingly, in order to start or

stop the generation of hydrogen, the method requires a process for bringing

the catalyst into contact with the fuel solution or separating the catalyst from

the fuel solution by supplying the fuel solution to the catalyst or preventing

the supply of the fuel solution using a pump, or by moving the catalyst to the

fuel solution or separating the catalyst from the fuel solution using a motor.

Particularly, in case that the above method is used in mobile equipment

provided with a hydrogen fuel cell, when an amount of hydrogen exceeding

the requirements of the mobile equipment is generated, hydrogen is

accumulated in the hydrogen fuel cell and increases the pressure in the

system. In this case, in order to maintain the pressure in the system below a designated value, apparatuses, for exhausting the accumulated hydrogen,

measuring the pressure and the supplied amount of hydrogen using a

sensor, regulating the reacting amount of the catalyst by separating the

catalyst from the fuel solution using external mechanical energy, and/or

variably regulating the supplied amount of the fuel solution containing the

hydrogen storing material, are additionally installed in the system, thereby

complicating the structure of the system and increasing the volume of the

system. Thus, the use of the system is restricted.

In order to solve the above-described problems and since an

embodiment for increasing a contact area between a fuel solution and a

catalyst attached to a catalyst-fixing portion is insufficient, the development of

various embodiments is required. Further, technical solution and means, for

preventing moisture contained in hydrogen gas in a foam state from closing fine air holes of a gas-liquid separating film, when the hydrogen gas

containing fine moisture particles generated in the fuel tank collides with the

gas-liquid separating film, are required. Further, technical means, for

preventing moisture contained in hydrogen gas in the foam state from closing

fine air holes of the gas-liquid separating film, in case that hydrogen gas

flowing out of the fuel solution, which contains fine moisture particles, collides

with the gas-liquid separating film, and improving performance of an apparatus, is required.

[Disclosure of the Invention] Therefore, the present invention has been made in view of the

above problems, and it is an object of the present invention to provide a

self-regulating hydrogen gas generator, which is actively self-operated at an

initial stage without an external energy source, and generates and supplies

hydrogen gas serving as an energy source, thereby allowing the hydrogen

gas to be used as clean alternative energy, preventing environmental

pollution and increasing the utility of the hydrogen gas.

It is another object of the present invention to provide a self-

regulating hydrogen gas generator, which has a simple structure and a

minimal volume, thereby commercially applying hydrogen gas to

apparatuses, systems and mobile equipment using hydrogen as fuel.

It is yet another object of the present invention to provide a self-

regulating hydrogen gas generator, in which a catalyst-fixing member,

provided with a catalyst attached thereto, contacting a fuel solution to

generate hydrogen gas has various shapes for generating a large amount

of hydrogen gas, and a fixed fuel tank, mobile and portable equipment has

a structure such that hydrogen gas generated in the fuel tank is efficiently

exhausted and passes through a gas-liquid separating film, thus having an

improved performance.

In accordance with the present invention, the above and other

objects can be accomplished by the provision of a self-regulating hydrogen

gas generator, for a hydrogen fuel cell, comprising: a fuel tank, defining an inner space having a designated volume, provided with a hydrogen outlet

communicating the inner space; a fuel solution, containing a hydrogen

storing material, stored in the fuel tank; and a catalyst contacting the fuel

solution for generating hydrogen gas, wherein the catalyst fills a catalytic

reactor, provided with a closed portion for interrupting the contact between

the catalyst and the fuel solution to stop the generation of hydrogen gas in

case that a pressure of the fuel tank increases due to the generation of

hydrogen gas by the contact between the catalyst and the fuel solution, and

an opened portion contacting the fuel solution for generating hydrogen gas

in case that the pressure of the fuel tank decreases due to the use of the

generated hydrogen gas by the fuel cell, so that the generation and

interruption of hydrogen gas are actively regulated based on the increase

and decrease of the pressure of the fuel tank.

Preferably, the catalytic reactor may include elastic means having a

designated compressing and restoring force for moving the catalyst toward

the closed or opened portion, based on the increase and decrease of the

pressure of the fuel tank due to the generation of hydrogen gas, to regulate

the generation of hydrogen gas, and the catalyst may be combined with a

catalyst-fixing member, which is movable in the catalytic reactor.

Further, preferably, the fuel tank may include gas-liquid separating

means for separating the generated hydrogen gas from the fuel solution in a

liquid state and exhausting the separated hydrogen gas to the outside.

More preferably, the gas-liquid separating means may be a gas-liquid separating film having various shapes fixedly installed in the fuel tank so

that a designated space between the inner hole of the outlet and the fuel

solution is defined to easily exhaust the hydrogen gas through the outlet.

Preferably, the gas-liquid separating means may include a collector

floating on the fuel solution filling a designated level of the fuel tank, a

collection hole protruded from the collector and exposed to the upper

surface of the fuel solution for introducing the hydrogen gas generated in

the fuel tank to the collector therethrough, and a drain hose connecting the

other side of the collector, opposite to the collection hole, and the outlet, for

exhausting the hydrogen gas collected by the collector. Further,

preferably, the fuel tank may include hydrogen gas retaining means for

converting hydrogen gas in a fine foarn state, generated by the contact of

the fuel solution and the catalyst, into large-sized hydrogen gas bubbles

and allowing the obtained large-sized gas bubbles to pass through the gas-

liquid separating means. Moreover, preferably, at least one collision

member for preventing hydrogen gas in a fine foam state, generated in the

fuel tank, containing moisture, from directly contacting the gas-liquid

separating film, may be interposed between the fuel solution and the gas-

liquid separating film.

[Brief Description of the Drawings]

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed

description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a partially exploded perspective view of a hydrogen gas

generator in accordance with a first embodiment of the present invention;

Figs. 2 and 3 are partially exploded perspective views illustrating

the operation of a catalytic reactor applied to the hydrogen gas generator in

accordance with the first embodiment of the present invention;

Fig. 4 is an exploded perspective view of the catalytic reactor of

Figs. 2 and 3;

Figs. 5 and 6 are partially exploded perspective views of another

catalytic reactor having a shape differing from that of the catalytic reactor of

Figs. 2 and 3;

Figs. 7 to 13 illustrate various embodiments of a catalyst-fixing

member, to which a catalyst is connected; Figs. 14 to 18 illustrate various embodiments of gas-liquid separating means provided in a fuel tank;

Figs. 19 and 20 illustrate hydrogen gas retaining means formed on

the external surface of the catalytic reactor filled with a fuel solution;

Figs. 21 and 22 illustrate a collision member interposed between

the fuel solution of the fuel tank and a gas-liquid separating film;

Figs. 23 to 28 are each schematic views of hydrogen gas

generators in accordance with second, third and fourth embodiments of the present invention; and Fig. 29 is a schematic view of the hydrogen gas generator of the

present invention used as a fuel feed system of a portable telephone.

[Best Mode for Carrying Out the Invention]

Now, preferred embodiments of the present invention will be

described in detail with reference to the annexed drawings. Hereinafter, the

description of conventional peripheral devices of a hydrogen gas generator

will be omitted.

A hydrogen gas generator (H) of the present invention is

characterized in that the generation of hydrogen gas and the interception of

the hydrogen gas are repeatedly performed without using external energy.

More specifically, the hydrogen gas generator (H) of the present

invention comprises a fuel tank 10 having a designated size for maintaining a

hermetically sealed space, a hydrogen storing material fuel solution 17 contained in the fuel tank 10, and a catalyst 21 contacting the hydrogen

storing material fuel solution 17 for generating hydrogen gas. The catalyst

21 fills a catalyst reactor 20 having a designated shape. Fig. 1 is a

perspective view of the hydrogen gas generator, in which the fuel tank 10 is partially exploded in accordance with a first embodiment of the present invention.

As shown in Fig. 1, the fuel tank 10 has the designated size for

containing the fuel solution having a certain volume, and the size and shape of the fuel tank 10 vary according to the purpose and kind of the fuel tank

10. An outlet 12 for discharging hydrogen generated in the fuel tank 10 is

formed in one side surface of the fuel tank 10, and a valve, such as a quick

connector 15, is installed on the outlet 12 and is combined with a hydrogen

fuel cell.

The fuel tank is filled with the hydrogen storing material fuel solution

17 having a certain volume, when the fuel tank 10 is initially manufactured,

and is then hermetically sealed so that the fuel tank cannot be recharged

and discharged. Alternately, a hole 14 is formed through one side of the

fuel tank 10 so that the fuel solution 17, after use, is discharged from the

fuel tank 10 through the hole 14 and new fuel solution 17 fills the fuel tank

10 through the hole 14, and a vent hole 13 serving as a safety measure is

formed through one side of the fuel tank 10 so that hydrogen is discharged

from the inside of the fuel tank 10 to the outside.

The hydrogen storing material fuel solution 17 applied to the

embodiment of the present invention contains NaBH₄ 20%, KOH 8% and

H₂0 72%. The catalyst 21 is made of a material, which efficiently generates hydrogen by contact with the fuel solution 17. In the present

invention, the catalyst 21 is made of Raney Ni.

Figs. 2 and 3 are partially exploded perspective views illustrating

the operation of the catalytic reactor 20 applied to the hydrogen gas

generator (H) in accordance with the first embodiment of the present

invention. Fig. 4 is an exploded perspective view of the catalytic reactor 20 of Figs. 2 and 3.

The catalytic reactor 20 of the hydrogen gas generator (H) of the

present invention has a structure such that the contact or isolation between

the catalyst 21 and the fuel solution 17 of the fuel tank 10 is automatically

controlled by the pressure of hydrogen generated in the fuel tank 10. In

this embodiment of the present invention, the catalytic reactor 20 is

positioned at the inside of the fuel tank 10 such that hydrogen is generated

due to the contact between the fuel solution 17 and the catalyst 21 under

the condition that the catalytic reactor 20 is dipped in the fuel solution 10.

In other embodiments of the present invention, the catalytic reactor 20 is

positioned at the outside of the fuel tank 1 , and will be described in brief

later.

That is, as shown in Figs. 2 and 3 and Fig. 4, it is preferable that the

catalytic reactor 20 is a tube including a main body 29 provided with an opened portion 28 positioned at one end thereof and communicated with the outside and a closed portion 27 positioned at the other end thereof.

The opened portion 28 is obtained by opening one end of the main body 29

or forming a cutting portion at the side surface of one end of the main body

29, and has a structure such that the catalyst 21 is exposed to the outside

through the opened portion 28 and contacts the fuel solution 17.

Further, elastic means 24 having an excellent restoring force is positioned at the inside of the closed portion 27 formed at the end of the

main body 29, and the catalyst 21 is attached to a catalyst-fixing member 22 reciprocating in the closed portion 27. In case that the pressure in the

fuel tank 10 increases, the catalyst-fixing member 22 moves toward the

closed portion 27 so as to prevent the catalyst 21 from contacting the fuel

solution 17, and in case that the pressure in the fuel tank 10 decreases, the

catalyst-fixing member 22 moved toward the closed portion 27 is returned to

an initial position toward the opened portion 28 by the elastic means 24 so

as to cause the catalyst 21 to contact the fuel solution 17 through the

opened portion 28 to generate hydrogen.

The catalyst 21 is a powder or lump type. In case that the catalyst

21 is a powder type, the powdery catalyst 21 is introduced into a net made

of various materials, which does not pass powder but passes the fuel

solution 17 and the hydrogen gas, or is attached to the net or a substrate

using an adhesive agent, and is then attached to the catalyst-fixing member

22. Alternately, in this case, the powdery catalyst 21 is processed to have

a designated shape suitably for the structure of the catalyst-fixing member

22, is sintered, and is then attached to the catalyst-fixing member 22.

More specifically, Raney Ni used as the catalyst 21 of the

embodiment of the present invention has a large surface area, thus being

stored in distilled water, and is characterized in that Raney Ni

spontaneously combusts when exposed to air. Accordingly, in order to use

Raney Ni as the catalyst 21, only the surface of Raney Ni is oxidized so that

Raney Ni is stably used in the atmosphere. This method reduces the

hydrogen generating capacity of the catalyst 21. Thus, in embodiments of the present invention, the catalyst 21 is manufactured by two methods, in

which the surface of Raney Ni is not oxidized. In the first method, Raney

Ni is attached to a magnet, and is then used. That is, the magnet is

attached to the catalyst-fixing member 22 (with reference to Fig. 12), and

then Raney Ni is attached to the magnet attached to the catalyst-fixing

member 22.

In the second method, Raney Ni is attached to a net or substrate

made of various materials in an aqueous solution such as distilled water.

Since Raney Ni is stored in distilled water, when Raney Ni stored in the

distilled water is manufactured into the catalyst 21 , it is possible to prevent

the reduction of the hydrogen generating capacity of the catalyst 21 due to

the surface oxidation. In the embodiment of the present invention, the

catalyst 21 is manufactured by fixing Raney Ni to a nickel mesh using

urethane foam.

As the higher the temperature is, the greater the hydrogen

generating capacity of the catalyst 21, including Raney Ni, is. In case that

a worker wants to generate a large amount of hydrogen using a small

amount of the catalyst 21 , a heating medium, such as a hot wire, for heating

the catalyst 21 or the fuel by itself or by an external power supply source is

installed in at least one of the fuel tank 10, the catalytic reactor 20 and the

catalyst-fixing member 22. The above method using the heating medium

increases the solubility of the hydrogen storing material and its by-product,

thus causing the hydrogen storing material and the by-product to store a large amount of hydrogen.

The catalyst-fixing member 22 has a structure or shape for allowing

the catalyst 21 to be easily attached thereto and effectively preventing the

fuel solution 17 from being introduced thereinto when the catalyst 21 enters

into and leaves the inside of the main body 29. The catalyst-fixing member

22 of the embodiment of the present invention includes both wings 23 and

23', and a catalyst fixing section 23c, having various shapes for receiving

the catalyst 21, interposed between the wings 23 and 23'.

When the catalyst-fixing member 22 moves toward the inside and

outside of the closed portion 27 of the main body 29, in order to prevent the

fuel solution 17 in a liquid state from being introduced into the closed

portion along the outer surface of the catalyst-fixing member 22, fuel

solution interception members 23a and 23b are respectively and

simultaneously formed between both ends of the catalyst-fixing member 22 and the inner surface of the main body 29 or between the catalyst-fixing

member 22 and the elastic means 24. An installation groove 25a is formed

on the inner circumference of the main body 29, and a subsidiary

interception member 25 having a ring shape is inserted into the installation

groove 25a so as to prevent the fuel solution from being introduced into the

main body 29 along the external circumference of the catalyst-fixing member 22 when the catalyst-fixing member 22 provided with the catalyst

21 attached thereto moves. Fig. 4 illustrates the above components of the catalytic reactor 20. Figs. 5 and 6 are partially exploded perspective views of another

catalytic reactor 20 having a shape differing from that of the above catalytic

reactor 20. Here, the opened portion 28 is formed at one end of the main

body 29, the catalyst 21 is attached to the catalyst fixing section 23c such

that the catalyst 21 surrounds the overall external circumference of the

catalyst fixing section 23c to enlarge the contact area between the catalyst

21 and the fuel solution, thereby increasing the amount of the generated

hydrogen. Other elements of the catalytic reactor 20 are the same as

those of the above-described catalytic reactor.

Preferably, the elastic means 24 applied to this embodiment of the

present invention is made of compressed gas and elastomer for restoring

the catalyst-fixing member 22 to an initial position when the catalyst-fixing

member 22 is forcibly introduced into the inside of the closed portion 27 and

hydrogen filling the fuel tank 10 is exhausted through the outlet 12 using a

hydrogen fuel cell so that the pressure in the fuel tank 10 decreases in case

that the exposed state of the catalyst 21 positioned on the catalyst-fixing

member 22 is maintained at the atmospheric pressure and the pressure in the fuel tank 10 increases to higher than the atmospheric pressure and the

increased pressure is applied to one side surface of the catalyst-fixing

member 22 exposed to the opened portion 28 of the catalytic reactor 20.

In this embodiment of the present invention, the elastic means 24 is made of a compressed coil spring.

Figs. 7 to 13 illustrate various embodiments of the catalyst-fixing member 22. The various embodiments of the catalyst-fixing member 22

serve to improve the structure of the catalyst-fixing section 23c, to which the

catalyst 21 is attached, so as to maximally increase the contact area between

the catalyst 21 and the fuel solution 17.

That is, the catalyst-fixing member 22 applied to the embodiment of

the present invention includes the wings 23 and 23' sliding on the inner

surface of the main body 29 and the catalyst-fixing section 23c, having

various shapes for receiving the catalyst 21 , interposed between the wings

23 and 23'. Particularly, the catalyst-fixing section 23c has a multi-layered

structure comprising a plurality of stacked plates, or various structures such

as fan, conical, circular structures, etc., so that a large amount of the

catalyst 21 is attached to the surface of the catalyst-fixing section 23c. A

magnet 23d may be attached to one side surface or both side surfaces of

the catalyst-fixing section 23c so that the metallic catalyst 21 can be

attached to the catalyst-fixing section 23c without any separate process

(with reference to Fig. 12).

Hereinafter, a process for generating hydrogen by the hydrogen gas

generator (H) of the present invention will be described in detail. The fuel

solution 17 in an amount of 10mA is introduced into the fuel tank 10, and the

catalyst 17 in an amount of 0.1g made of Raney Ni is introduced into the

fuel tank 10. Then, the fuel tank 10 generates hydrogen gas at the rate,

corresponding to 12SCCM (Standard Cubic Centimeter per Minute) at room

temperature or 1W of the fuel cell, for approximately 10 hours. The hydrogen gas generated in the fuel tank 10 is supplied to an external

system, such as a hydrogen engine, using hydrogen as a fuel, or a

hydrogen fuel cell, through the outlet 12 of the fuel tank 10. In case that

the amount of the hydrogen gas required by the external system is less than

12SCCM, or the hydrogen gas is not exhausted by cutting off the power, the

generated hydrogen gas is accumulated in the fuel tank 10 and the

pressure in the fuel tank 10 increases to 1.5 atmospheres (P1).

There is generated a difference of pressures between the fuel tank

10 and the main body 29 of the catalytic reactor 20, and the increased

pressure in the fuel tank 10 presses one end of the opened portion 28 of the

main body 29 of the catalytic reactor 20. When the catalyst-fixing member

22 moves toward the closed portion 27 of the main body 29 of the catalytic

reactor 20, the catalyst 21 exposed to the fuel solution 17 made of the hydrogen storing material gradually enters into the main body 29 so that the

contact area between the catalyst 21 and the fuel solution 17 is reduced,

thereby reducing the generation of hydrogen gas and then stopping the

generation of hydrogen gas.

When the external system again uses hydrogen gas, the generated

hydrogen gas is exhausted from the fuel tank 10. Then, the pressure in

the fuel tank 10 is reduced, the difference of pressures between the fuel

tank 10 and the main body 29 of the catalytic reactor 20 decreases, and the

elastic means 24 positioned in the main body 29 is returned to the initial

position so that the catalyst-fixing member 22 moves toward the opened portion 28 and the catalyst 21 again contacts the fuel solution 17.

Thereby, the hydrogen gas generator (H) of the present invention

intermittently generates hydrogen gas.

Figs. 14 to 18 illustrate various embodiments of gas-liquid

separating means 40 provided in the fuel tank 10.

The gas-liquid separating means 40 serves to prevent the hydrogen

in a gas state generated in the fuel tank 10 filled with the water-soluble fuel

solution 17 from being exhausted together with the exhaustion of the fuel

solution in a liquid state, and is more usable in a mobile or portable fuel cell

rather than a fixed fuel cell.

That is, each of the gas-liquid separating means 40 shown in Figs.

14 to 16 includes a gas-liquid separating film 42. The gas-liquid separating

film 42 is made of hydrophobic silicon rubber, which is more permeable to

hydrogen gas than water, a porous non-metal such as Teflon, or metal

having selective permeability to hydrogen. In Fig. 14, the gas-liquid

separating film 42 installed in the fuel tank 10 is separated from the inner

hole of the outlet 12 by a designated interval. An implant member 43

provided with air holes or hydrogen paths, for preventing the movement of

the gas-liquid separating film 42 and efficiently exhausting hydrogen when

the pressure in the fuel tank 10 increases due to the generation of the

hydrogen gas or the fuel tank 10 moves, is interposed between the inner

surface of the fuel tank 10, where the outlet 12 is positioned, and the gas-

liquid separating film 42. The gas-liquid separating film 42 may have other structures without the implant member 43 so that the gas-liquid separating

film 42 is fixed to the inner surface of the fuel tank 10 and the generated

hydrogen gas is efficiently exhausted.

In Fig. 15, the hermetically sealed type gas-liquid separating film 42,

which is positioned in the fuel tank 10, has the same shape as that of the

fuel tank 10 and a size slightly smaller than that of the fuel tank 10, and is

separated from the inner wall of the fuel tank 10. Also, the implant

member 43, for preventing the contact of the inner wall of the fuel tank 10

and the gas-liquid separating film 42 due to the increased pressure or

movement of the fuel tank 10 and allowing the hydrogen gas to smoothly

move, is interposed between the inner wall of the fuel tank 10 and the gas-

liquid separating film 42. In Fig. 16, the gas-liquid separating film 42 is U-

shaped, and is positioned in the fuel tank 10 such that the central area of

the gas-liquid separating film 42 is disposed under the inner hole of the outlet 12.

In Figs. 17 and 18, the gas-liquid separating means 40 includes a

collector 44, made of a material floating on the fuel solution 17 in the liquid

state, for collecting generated gas and then exhausting the gas to the

outside. A collection hole 46 for introducing the hydrogen gas from the fuel

tank 10 thereinto is protruded from one side of the collector 40, and a drain

hose 48 for exhausting the hydrogen gas collected by the collector 44 to the

outlet 12 connects the other side of the collector 40 opposite to the collection hole 46 and the outlet 12. The above-described various structures of gas-liquid separating

means 40 may be properly selected based on characteristics of equipment

using hydrogen fuel, and the collector 44 may be made of any material

having specific gravity lower than that of water.

Figs. 19 and 20 illustrate hydrogen gas retaining means 50 for

temporarily collecting the hydrogen gas generated in the catalytic reactor 20

filled with the fuel solution 17 in the fuel tank 10 and for converting small-

sized hydrogen bubbles in a fine foam state into large-sized hydrogen

bubbles. The hydrogen gas retaining means 50 has various structures for

indirectly cutting off the circumference of the catalytic reactor 20, thus

allowing the hydrogen bubbles in the fine foam state to be temporarily

aggregated and then exhausted to the outside.

When the fuel solution 17 filling the fuel tank 10 contacts the

catalyst 21 of the catalytic reactor 20 to exhaust the fine hydrogen foam, the

hydrogen gas retaining means 50 serves to collect the fine hydrogen foam

and convert the foam into large-sized hydrogen bubbles and then to allow

the large-sized hydrogen bubbles to pass through the gas-liquid separating

film 42. In case that the small-sized hydrogen bubbles in the fine foam

state directly reach the gas-liquid separating film 42, the small-sized

hydrogen bubbles in the fine foam state close fine air holes of the gas-

liquid, thus causing a difficulty of efficiently exhausting the hydrogen gas.

Accordingly, the hydrogen gas retaining means 50 prevents the above problem. Particularly, the hydrogen gas generator (H) of the present invention

can be applied to fixed, mobile or portable articles using a hydrogen fuel

cell. Even though the fuel tank 10 is disposed at any position of the article,

the hydrogen gas generated in the fuel tank 10 must be efficiently

exhausted. Thus, the gas-liquid separating film 42 can be installed at any

portion, i.e., left, right, upper and lower portions, of the inside of the fuel

tank 10. In the embodiments of the present invention shown in Figs. 19

and 20, the gas-liquid separating means 42 are respectively installed at the

upper and lower portions of the inside of the fuel tank 10, and a connection

pipe 54 connects both spaces obtained by the upper and lower gas-liquid

separating means 42. Although the fuel tank 10 stands at any position,

spaces cut off from the fuel solution by the gas-liquid separating films 42

are connected to each other through the connection pipe 54 so that the

hydrogen gas bubbles generated in the fuel tank 10 communicate between

the spaces, thereby efficiently exhausting the hydrogen gas bubbles to the

outside through the outlet 12. The hydrogen gas retaining means 50 is

formed integrally with the fuel tank 10, or the catalytic reactor 20 is formed

integrally with the hydrogen gas retaining means 50.

Figs. 21 and 22 respectively illustrate embodiments, in which a

collision member 52 is interposed between the fuel solution 17 of the fuel

tank 10 and the gas-liquid separating film 42. That is, the collision member

52 serves to prevent the fine hydrogen foam, generated in the fuel tank 10,

containing moisture, from directly contacting the gas-liquid separating film 42. When the hydrogen gas rises and collides with the collision member

52, the moisture contained by the hydrogen gas due to the fuel solution 17

is separated from the hydrogen gas. Thereby, only the obtained pure

hydrogen gas passes through the gas-liquid separating film 42. In the

same manner as the above-described hydrogen gas retaining means 50,

the collision member 52 may have various structures based on installation

types of the fuel tank 10 or applied articles.

Figs. 23 to 28 are each schematic views of hydrogen gas

generators in accordance with second, third and fourth embodiments of the

present invention. In these embodiments of the present invention, the

hydrogen gas generator is a fuel tank external installation type, in which the

catalytic reactor 20 is detachably attached to the outer surface of the fuel

tank 10.

That is, the catalytic reactor 20 provided with the elastic means 24

and the catalyst-fixing member 22 positioned therein is inserted into an installation groove 60 formed in one outer surface of the fuel tank 10.

More specifically, in the second embodiment shown in Figs. 23 and

24, a stopper 60a is protruded from one end of the catalytic reactor 20, and

a stopper-fixture 60b for fixing the stopper 60a is formed in the front end of

the inside of the installation groove 60. A through hole 62 communicating

with the inside of the fuel tank 10 is formed at a designated position of the

inner circumference of the installation groove 60, the elastic means 24 is

positioned on the bottom of the installation groove 60 inside the through hole 62, a through hole sealing member 26 for sealing the through hole 62

is combined with the elastic means 24, a hydrogen generation regulating

hole 64 communicating with the inside of the fuel tank 10 for introducing a

fluid of the fuel tank 10 is formed through the bottom of the installation

groove 60, and the gas-liquid separating film 42 is installed in front of the

hydrogen generation regulating hole 64 in the fuel tank 10.

As shown in Fig. 23, before the catalytic reactor 20 is inserted into

the installation groove 60 of the fuel tank 10, the through hole sealing

member 26 positioned in the installation groove 60 seals the through hole

62. Then, as shown in Fig. 24, when the catalytic reactor 20 is inserted

into the installation groove 60 of the fuel tank 10, the through hole sealing

member 26 presses the elastic means 24 so that the through hole 62 is

exposed to the outer circumference of the catalytic reactor 20, and when

the catalytic reactor 20 is fully inserted into the installation groove 60 of the

fuel tank 10, the through hole 62 contacts the catalyst 21 provided on the

catalytic reactor 20, thereby allowing hydrogen gas to be generated.

When the inner pressure of the fuel tank 10 rises due to the generation of hydrogen gas and exceeds a designated level (in case that

the hydrogen gas is not used), a part of the hydrogen gas accumulated in

the fuel tank 10 is introduced into the installation groove 60 through the

hydrogen generation regulating hole 64 formed through the bottom of the

installation groove 60, and the inner pressure of the installation groove 60

rises. Then, the through hole sealing member 26 pushes the catalyst- fixing member 22 of the catalytic reactor 20, and releases its force from the

elastic means 24. As the elastic means 24 is stretched, the contact area

between the catalyst 21 and the fuel solution 17 gradually decreases and

the through hole 62 is fully sealed by the through hole sealing member 26,

thereby stopping the generation of hydrogen gas. When the external

system uses the generated hydrogen gas, the pressure of hydrogen in the

fuel tank 10 is decreased and the fluid in the installation groove 60 is

directed into the fuel tank 10. Then, the elastic means 24 positioned on

the catalytic reactor 20 is constricted and the catalyst-fixing member 22

pushes the through hole sealing member 26 so that the catalyst 21 contacts

the fuel solution 17. By automatically achieving the generation of the

hydrogen gas and the interruption of the hydrogen gas by means of

repeating the above-described operation, the hydrogen gas generator (H) of

the present invention generates and supplies hydrogen gas required by a hydrogen fuel cell, etc. The hydrogen generation regulating hole 64 can

be disposed at any position, which allows the fluid of the fuel tank 10 to be

introduced into the installation groove due to the increased inner pressure

of the fuel tank 10 to push the through hole sealing member 26 or the

catalyst-fixing member 22 of the catalytic reactor 20.

In the third embodiment shown in Figs. 25 and 26, a catalyst exposure regulating portion 66 having a sealed space is extended from the

end of the above-described catalytic reactor 20, i.e., the outer surface of the

catalyst-fixing member 22. A hydrogen generation regulating hole 64', which coincides with the hydrogen generation regulating hole 64 when the

catalytic reactor 20 is inserted into the installation groove 60 and regulates

the generation of hydrogen gas by moving the catalyst-fixing member 22

based on the increase and decrease of the inner pressure of the fuel tank

10, is formed through a designated position of the catalyst exposure

regulating portion 66.

The hydrogen gas generator (H) of the third embodiment is the

same as the hydrogen gas generator (H) of the second embodiment in that

the generation of the hydrogen gas and the interruption of the hydrogen gas

are achieved by the increase and decrease of the inner pressure of the fuel

tank 10. However, in the third embodiment, when the inner pressure of the

fuel tank 10 increases, the fluid in a high pressure state is introduced into

the catalyst exposure regulating portion 66 formed at the inner front end of

the catalytic reactor 20, and pushes the catalyst-fixing member 22 of the

catalytic reactor 20. On the other hand, when the inner pressure of the

fuel tank 10 decreases, the fluid having introduced into the catalyst

exposure regulating portion 66 is exhausted, and pushes the catalyst-fixing

member 22 by means of the elastic means 24 positioned in the catalytic

reactor 20 so that the catalyst 21 contacts the fuel solution 17, thereby

allowing hydrogen gas to be generated.

In the fourth embodiment shown in Figs. 27 and 28, elastic means

is not provided in the catalytic reactor 20 combined with the installation

groove 60, and the catalyst-fixing member 22 is provided only on the front end of the main body 29 of the catalyst-fixing member 22. A stopper 61a,

serving as fixing means, is popped into and out of the outer surface of the

main body 29 by an elastic spring 67 positioned in an installation hole 65

formed in the central area of the main body 29, and a stopper-fixture 61b for

fixing the stopper 61a to prevent the catalytic reactor 20 from being

separated from the installation groove 60 after the catalytic reactor 20 is

inserted into the installation groove 60.

As shown in Fig. 28, when the catalytic reactor 20 is forcibly

inserted into the installation groove 60, the stopper 61a formed on the outer

circumference of the catalytic reactor 20 is caught by the stopper-fixture 61b

so that the catalytic reactor 20 is fixed into the installation groove 60.

As described above, the catalyst 21 of the catalytic reactor 20

combined with the fuel tank 10 contacts the fuel solution 17 filling the fuel

tank 10, thus generating hydrogen gas. When the inner pressure of the

fuel tank 10 increases more than a designated value, the fluid at an

increased pressure of the fuel tank 10 is introduced into the installation

groove 60 through the hydrogen generation regulating hole 64 formed through the bottom of the installation groove 60 and pushes the through

hole sealing member 26. Then, the through hole sealing member 26

applies pressure to the catalytic reactor 20 contacting the through hole

sealing member 26, and the stopper 61a formed on the outer circumference of the catalytic reactor 20 is popped into the installation hole 65 by pressing

the elastic spring 67 provided in the installation hole 65, and is then separated from the stopper-fixture 61b. Thereby, the hydrogen gas

generator (H) in accordance with this embodiment of the present invention

generates hydrogen gas by a user forcibly inserting the catalytic reactor 20

into the installation groove 60. As shown in Fig. 29, the hydrogen gas generator (H) of the present

invention may be used in a hydrogen fuel cell of a portable telephone (P).

As described above, the hydrogen gas generator (H) of the present

invention actively self-regulates the generation and interruption of hydrogen

gas based on the pressure of the generated hydrogen gas without any

external force, thus having a simple structure and reducing production

costs. Further, the hydrogen gas generator (H) of the present invention

has reduced volume and weight, thereby greatly increasing energy density

per volume and weight of a fuel cell serving as an energy source for various

equipment. After all hydrogen gas is exhausted from the fuel solution 17, in the

same manner as a conventional fuel cell, the hydrogen gas generator (H) of

the present invention exhausts the waste fuel solution 17 through the hole

14 formed through the fuel tank 10 and is then refilled with a new fuel

solution 17. In case that the hydrogen gas generator (H) is combined with the fuel cell through the quick connector 15 positioned on the outlet 12 of

the fuel tank, the quick connector 15 is opened to supply the hydrogen gas

to the fuel cell, and in case that the hydrogen gas generator (H) is

separated from the fuel cell, the quick connector 15 is closed to prevent the hydrogen gas from being exhausted to the outside so that the pressure of

the fuel tank 10 slightly increases and the reaction between the catalyst 21

and the fuel solution 17 is prevented, thereby stably storing the hydrogen

gas below a designated pressure.

The hydrogen gas generator (H) maximally increases a contact

area between the catalyst 21 and the fuel solution 17 by employing the

various embodiments of the catalyst-fixing member 22, thereby generating

a great amount of hydrogen gas and enlarging the usable range of the

hydrogen fuel cell. Further, the hydrogen gas generator (H) comprises the

hydrogen gas retaining means 50 having various structures, and the

collision member 52 having various structures interposed between the fuel

solution 17 and the gas-liquid separating film 42, so that the hydrogen gas

generated in the fuel tank 10 is efficiently supplied to the outside, thereby

improving the performance of the hydrogen fuel cell. In case that the gas-

liquid separating films 42 are additionally installed in the fuel tank 10, the

hydrogen gas is smoothly circulated through the connection pipe 54.

Thus, various structures of the fuel tank 10 are applied to the hydrogen fuel

cell based on applied products, and extend the usable range of the

hydrogen fuel cell, thereby being capable of effectively using energy.

[Industrial Applicability]

As apparent from the above description, the present invention provides a self-regulating hydrogen gas generator, which is miniaturized,

reduces production cost, volume and weight thereof, thus improving energy

density per unit volume and weight and being applied to mobile or portable

equipment using hydrogen as fuel as well as a large-sized hydrogen fuel

cell device using hydrogen as fuel. Accordingly, the self-regulating

hydrogen gas generator stimulates the use of hydrogen gas as clean

alternative energy, and causes the hydrogen gas to be used as a substitute

for gradually exhausted fossil fuels, thereby preventing air pollution and

providing a clean environment.

Although the preferred embodiments of the present invention have

been disclosed for illustrative purposes, those skilled in the art will

appreciate that various modifications, additions and substitutions are

possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A self-regulating hydrogen gas generator, for a hydrogen fuel

cell, comprising:

a fuel tank, defining an inner space having a designated volume,

provided with a hydrogen outlet communicating the inner space;

a fuel solution, containing a hydrogen storing material, stored in the

fuel tank; and

a catalyst contacting the fuel solution for generating hydrogen gas,

wherein the catalyst fills a catalytic reactor, provided with a closed

portion for interrupting the contact between the catalyst and the fuel solution

to stop the generation of hydrogen gas in case that a pressure of the fuel

tank increases due to the generation of hydrogen gas by the contact

between the catalyst and the fuel solution, and an opened portion

contacting the fuel solution for generating hydrogen gas in case that the

pressure of the fuel tank decreases due to the use of the generated

hydrogen gas by the fuel cell, so that the generation and interruption of

hydrogen gas are actively regulated based on the increase and decrease of the pressure of the fuel tank.

2. The self-regulating hydrogen gas generator as set forth in claim

1 , wherein the catalytic reactor includes elastic means having a designated

compressing and restoring force for moving the catalyst toward the closed or opened portion, based on the increase and decrease of the pressure of

the fuel tank due to the generation of hydrogen gas, to regulate the

generation of hydrogen gas.

3. The self-regulating hydrogen gas generator as set forth in claim

2, wherein a catalyst-fixing member, provided with the catalyst connected

thereto, which is movable in the catalytic reactor, is connected to one end of

the elastic means.

4. The self-regulating hydrogen gas generator as set forth in claim

3, wherein fuel solution interception members, for preventing the fuel

solution from being introduced into the catalytic reactor through the opened

portion when the catalyst-fixing member moves toward the closed portion

due to the increase of the pressure of the fuel tank, are positioned at either

of inner circumferences of the catalyst-fixing member and the catalytic reactor.

5. The self-regulating hydrogen gas generator as set forth in claim

3, wherein fuel solution interception members, for preventing the fuel

solution from being introduced into the catalytic reactor through the opened

portion when the catalyst-fixing member moves toward the closed portion

due to the increase of the pressure of the fuel tank, are positioned between the catalyst-fixing member and the elastic means.

6. The self-regulating hydrogen gas generator as set forth in claim

3, wherein the fuel tank includes gas-liquid separating means for separating

the generated hydrogen gas from the fuel solution in a liquid state and

exhausting the separated hydrogen gas to the outside.

7. The self-regulating hydrogen gas generator as set forth in claim

6, wherein: an installation groove, into which the catalytic reactor from the

outside is detachably inserted, is formed at a designated position of the fuel

tank; and

the installation groove includes:

a through hole for allowing the catalyst of the catalytic

reactor to contact the fuel solution of the fuel tank to generate hydrogen

gas;

elastic means positioned on the bottom of the installation groove;

a through hole sealing member combined with the elastic

means for sealing the through hole and pushing the catalyst-fixing member

of the catalytic reactor connected thereto due to the increase of the

pressure of the fuel tank to the through hole when the catalytic reactor is separated from the installation groove; and

a hydrogen generation regulating hole formed through the bottom of the installation groove defining a closed space by the through

hole sealing member for allowing the hydrogen gas generated in the fuel

tank to enter into and leave the installation groove.

8. The self-regulating hydrogen gas generator as set forth in claim

7, wherein a gas-liquid separating film is installed in the fuel tank provided

with the hydrogen generation regulating hole, and fixing means for fixing the

catalytic reactor to the fuel tank is positioned at the end of the catalytic

reactor and the entrance of the installation groove.

9. The self-regulating hydrogen gas generator as set forth in claim

8, wherein a catalyst exposure regulating portion for defining a sealed

space is extended from the end of the catalytic reactor at the outer surface

of the catalyst-fixing member, and another hydrogen generation regulating

hole, which coincides with the hydrogen generation regulating hole when

the catalytic reactor is inserted into the installation groove and regulates the

generation of hydrogen gas by moving the catalyst-fixing member based on

the increase and decrease of the pressure of the fuel tank, is formed

through a designated position of the catalyst exposure regulating portion.

10. The self-regulating hydrogen gas generator as set forth in any

one of claims 6 to 9, wherein the gas-liquid separating means is a gas-liquid

separating film having various shapes fixedly installed in the fuel tank so that a designated space between the inner hole of the outlet and the fuel

solution is defined to easily exhaust the hydrogen gas through the outlet.

11. The self-regulating hydrogen gas generator as set forth in claim

10, wherein an implant member provided with air holes, for preventing the

movement of the gas-liquid separating film and efficiently exhausting

hydrogen when the pressure in the fuel tank increases due to the

generation of the hydrogen gas or the fuel tank moves, is interposed

between the inner surface of the fuel tank and the gas-liquid separating film.

12. The self-regulating hydrogen gas generator as set forth in claim

11 , wherein the gas-liquid separating film is a completely sealed type, which

includes the catalytic reactor and the fuel solution and separates the outer

surface thereof from the inner wall of the fuel tank by a designated interval.

13. The self-regulating hydrogen gas generator as set forth in any

one of claims 6 to 9, wherein the gas-liquid separating means includes a

collector floating on the fuel solution filling a designated level of the fuel

tank, a collection hole protruded from the collector and exposed to the

upper surface of the fuel solution for introducing the hydrogen gas generated in the fuel tank to the collector therethrough, and a drain hose

connecting the other side of the collector, opposite to the collection hole,

and the outlet, for exhausting the hydrogen gas collected by the collector.

14. The self-regulating hydrogen gas generator as set forth in any

one of claims 3, 6 and 7, wherein the catalyst-fixing member includes:

both wings, formed at both ends thereof, sliding on the inner surface

of a tube; and a catalyst-fixing section interposed between the wings for fixing the

catalyst.

15. The self-regulating hydrogen gas generator as set forth in claim

14, wherein a permanent magnet is attached to the catalyst-fixing section

so that the catalyst made of metal is attached to the catalyst-fixing section

using the permanent magnet without any separate process.

16. The self-regulating hydrogen gas generator as set forth in claim

14, wherein the catalyst-fixing section is divided into plural pieces for

increasing a contact area between the catalyst and the fuel solution to

generate a great amount of hydrogen gas.

17. The self-regulating hydrogen gas generator as set forth in claim

10, wherein the fuel tank includes hydrogen gas retaining means for

converting hydrogen gas in a fine foam state, generated by the contact of

the fuel solution and the catalyst, into large-sized hydrogen gas bubbles

and allowing the obtained large-sized gas bubbles to pass through the gas- liquid separating means.

18. The self-regulating hydrogen gas generator as set forth in claim

10, wherein the catalytic reactor is provided inside the hydrogen gas

retaining means provided with a plurality of holes for converting hydrogen

gas in a fine foam state, generated by the contact of the fuel solution and

the catalyst, into large-sized hydrogen gas bubbles and allowing the

obtained large-sized gas bubbles to pass through the gas-liquid separating

means.

19. The self-regulating hydrogen gas generator as set forth in claim

10, wherein at least one collision member for preventing hydrogen gas in a

fine foam state, generated in the fuel tank, containing moisture, from directly

contacting the gas-liquid separating film, is interposed between the fuel

solution and the gas-liquid separating film.

20. The self-regulating hydrogen gas generator as set forth in claim

10, wherein the fuel tank includes a hole for exhausting the waste fuel

solution or its by-products from the fuel tank therethrough and for filling the

fuel tank with a new fuel solution therethrough.

21. The self-regulating hydrogen gas generator as set forth in claim

10, wherein the fuel tank includes a vent hole for preventing the overpressure of the fuel tank.

22. The self-regulating hydrogen gas generator as set forth in claim

14, wherein the catalyst, which is made of Raney Ni, is attached to a net or

substrate in distilled water or general water using an adhesive agent, which

is solidified in the water without using a separate dry or surface oxidation

process, and is then combined with the catalyst-fixing section.

23. The self-regulating hydrogen gas generator as set forth in any

one of claims 2, 3, 6 and 7, wherein the elastic means includes a

compressed coil spring.

24. The self-regulating hydrogen gas generator as set forth in any

one of claims 2, 3, 6 and 7, wherein the elastic means includes

compressible gas.

25. The self-regulating hydrogen gas generator as set forth in claim

10, wherein, in case that a plurality of spaces not-filled with the fuel solution

are divisionally obtained by respectively installing a plurality of the gas-liquid

separating films at left, right, upper and lower portions, of the inside of the

fuel tank filled with the fuel solution, a connection pipe connects the divided

spaces, not-filled with the fuel solution, in the fuel tank.

26. The self-regulating hydrogen gas generator as set forth in claim

1 or 3, wherein a heating medium for generating heat is installed in at least

one of the fuel tank, the catalytic reactor and the catalyst-fixing member.