JP2001023673A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately circulate unreacted gas exhausted from a fuel cell in the fuel cell and sufficiently avoid catalyst poisoning of the fuel cell without decreasing energy efficiency as the whole system in a fuel cell system constituted so as to supply mixed gas obtained by reforming a hydrogen-containing compound to the fuel cell. SOLUTION: This fuel cell system has a reformer 2 for obtaining hydrogen- rich mixed gas by reforming a hydrogen-containing compound; and a fuel cell 4 for producing electromotive force by the reaction of hydrogen and oxygen. A hydrogen permeable membrane is arranged between the reformer 2 and the fuel cell 4, and a hydrogen separator 3 for separating hydrogen gas from mixed gas obtained with the reformer 2 is installed. Preferably, as the hydrogen permeable membrane, a palladium alloy permeable membrane or a solid polymer hollow thread membrane is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell system for selectively extracting hydrogen gas from a hydrogen-rich mixed gas obtained from a hydrogen-containing compound and reacting it with oxygen gas in a fuel cell to generate an electromotive force. .

[0002]

2. Description of the Related Art In a fuel cell, hydrogen as a negative electrode active material is brought into contact with a catalyst such as platinum (platinum) to dissociate it into electrons and protons. The reaction mechanism is based on a reaction mechanism in which water is obtained by reacting with oxygen. That is, in the fuel cell, an electromotive force is generated by the movement of electrons released from hydrogen on the negative electrode side.

[0003] Based on such a principle, a chemical energy change can be directly converted into electric energy, so that the energy efficiency is extremely high as compared with other power generation methods. This means that the fuel cell has less energy loss than the internal combustion engine based on the Carnot cycle, and is useful as a power source for a motor for an electric vehicle, which is an alternative to the internal combustion engine. In a fuel cell, the exhaust gas is mainly water vapor, and harmful gases such as nitrogen compounds, hydrocarbons, and carbon monoxide are not emitted as in an internal combustion engine. Practical use of the electric vehicle as a source is desired.

[0004] Normally, a fuel cell is not used alone, but constitutes a fuel cell system together with means for supplying hydrogen gas to the fuel cell. As a means for supplying hydrogen to the fuel cell, for example, a method of pumping hydrogen filled in a cylinder or a method of pumping hydrogen gas obtained by reforming a hydrogen-containing compound can be mentioned. The method of filling a cylinder with hydrogen gas and using it as a hydrogen source has many advantages, such as a relatively simple system. On the other hand, filling hydrogen requires a high pressure and a long time, and there are also problems in the infrastructure such as a filling station, which poses a serious obstacle to the practical use of electric vehicles powered by fuel cells. ing. From such a viewpoint, it is advisable to adopt a method of reforming the hydrogen-containing compound. As a method of reforming the hydrogen-containing compound to take out hydrogen, for example, a method of bringing methanol into contact with steam or a method of partially oxidizing methanol (partial oxidation method) is generally used.

However, in these methods, a trace amount of carbon monoxide gas is produced as a by-product together with carbon dioxide, and hydrogen gas is obtained as a mixed gas containing these gases. As described above, platinum (Pt) is preferably used as a catalyst on the negative electrode side. However, platinum has a problem that its activity is gradually reduced due to poisoning by carbon monoxide gas.
Supplying hydrogen gas to the fuel cell in the state of a mixed gas containing carbon monoxide gas shortens the catalyst life of platinum. For this reason, in order to prevent platinum poisoning, a method has been adopted in which after the carbon monoxide gas in the mixed gas is converted into carbon dioxide gas in the presence of a catalyst, the mixed gas after the treatment is supplied to the fuel cell. Have been. In general, a multi-stage metamorphic system in which carbon monoxide is first oxidized at a high temperature and the remaining carbon monoxide is oxidized at a lower temperature is employed.

[0006]

However, in a fuel cell, not all of the supplied hydrogen gas is consumed. Therefore, in order to make effective use of the hydrogen gas, a method of circulating the unreacted gas as it is to the fuel cell. Has also been taken. However, since the concentration of hydrogen gas in the circulated unreacted gas is lower than that before supply to the fuel cell, the hydrogen gas supplied to the fuel cell is particularly not unlike the method of reforming a hydrogen-containing compound. When the purity of the gas is low, there is a problem that gas other than hydrogen gas, for example, carbon dioxide is concentrated by circulating, and the efficiency is continuously reduced,
Technically it did not hold. Therefore, the unreacted gas from the fuel cell can only be used as a heating fuel for raising the temperature of the hydrogen-containing compound and water sent to the reformer, and the energy of the hydrogen gas is effectively used. We could not say that we used.

The present invention was conceived under the circumstances described above, and is directed to a fuel cell system in which a mixed gas obtained by reforming a hydrogen-containing compound is supplied to a fuel cell. The unreacted gas discharged from the fuel cell can be appropriately circulated to the fuel cell,
It is an object of the present invention to avoid poisoning of the fuel cell catalyst without deteriorating the energy efficiency of the entire system.

[0008]

DISCLOSURE OF THE INVENTION In order to solve the above-mentioned problems, the present invention takes the following technical means. That is, the fuel cell system provided by the present invention includes a reformer that reforms a hydrogen-containing compound to obtain a hydrogen-rich mixed gas, and a fuel cell that generates an electromotive force by a reaction between hydrogen and oxygen. A fuel cell system comprising a hydrogen permeable membrane between the reformer and the fuel cell, and separating a hydrogen gas from a mixed gas obtained by the reformer to separate the fuel gas. It is characterized in that a hydrogen separation device for obtaining the same is provided.

In this fuel cell system, the mixed gas obtained by the reformer is separated into high-purity hydrogen gas by a hydrogen separator using a hydrogen permeable membrane and then supplied to the fuel cell. . For this reason, a fuel gas having a high purity of hydrogen gas is supplied to the fuel cell, and a certain amount of hydrogen gas is consumed. Can be kept constant. Therefore, the unreacted gas can be circulated as a fuel gas for the fuel cell without any problem, and the utilization efficiency of hydrogen gas, particularly the energy conversion efficiency, can be improved.

Here, as the hydrogen-containing compound serving as the reforming raw material, any of an organic compound and an inorganic compound can be suitably used.

Examples of the organic compound include hydrocarbons, natural gas or petroleum containing hydrocarbons as a main component, or derivatives of hydrocarbons as base materials, in which some of the hydrogen atoms are replaced with oxygen functional groups, or nitrogen functional groups. A substituted derivative or a derivative substituted with a sulfur functional group is exemplified. Derivatives substituted with an oxygen functional group include alcohols, phenols, aldehydes, carboxylic acids, ketones, ethers, and the like, and derivatives substituted with a nitrogen functional group include nitro compounds and amines. Examples of the substituted derivative include thiol and sulfonic acid. On the other hand, examples of the inorganic compound include carbonic acid, ammonia, and hydrazine.

In consideration of the energy efficiency of the entire system, it is preferable to employ a compound which can be reformed with relatively small energy (low temperature), high safety, good industrial supply stability, and the like. Easy handling is also required. For this reason, methanol, dimethyl ether, propane, methane, and natural gas are preferred as reforming raw materials.

The hydrogen permeable membrane may be, for example, a polymer-based one in addition to a metal-based one.

Examples of the metal-based hydrogen permeable membrane include those utilizing a metal having a high hydrogen absorbing property, for example, palladium or a palladium alloy. In a hydrogen-permeable membrane made of these materials, hydrogen molecules first adhere to
Dissociates into two hydrogen atoms. The hydrogen atoms emit electrons into the permeable membrane and are absorbed as protons in the permeable membrane, and move to the lower hydrogen partial pressure in the permeable membrane. Note that components other than hydrogen molecules do not become protons and are not occluded or transmitted through the permeable membrane. Then, the protons that reach the membrane surface by the movement receive electrons from the permeable membrane and become hydrogen atoms, and then become hydrogen molecules again. In other words, the hydrogen molecules on the side of the raw material to be separated, that is, the side with the higher hydrogen partial pressure, move through the membrane as protons due to the difference in the hydrogen partial pressure, and permeate to the side with the lower hydrogen partial pressure to be separated. Other components therein cannot pass through the permeable membrane and remain on the raw material side.

Here, examples of the palladium alloy include various known alloys, for example, an alloy composed of palladium and at least one metal selected from the group consisting of silver, gold and ruthenium. That is, an alloy of palladium and silver (Pd-Ag alloy), an alloy of palladium and silver and gold (Pd-Ag-Au alloy), or an alloy of palladium and silver, gold and ruthenium (Pd-Ag-Au)
-Ru alloy) or the like is preferably used. This Pd-Ag
As the alloy, those having a silver content of 20 to 30 wt% are preferably used, and for the Pd-Ag-Au alloy, the silver content is particularly 20 to 30 wt% and the gold content is 5 to 10 wt%. Are preferably used, and Pd-A
The g-Au-Ru alloy has a silver content of especially 20%.
Those having a content of ３０30 wt%, a gold content of 5-10 wt%, and a ruthenium content of 1-5 wt% are preferably used.

The polymer-based hydrogen permeable membrane is a rigid amorphous polymer having a high glass transition temperature and a high order (stereoscopic) structure in order to satisfy high hydrogen permeability and high separability. It is preferably made of a polymer material having a void for selectively transmitting atoms or molecules having a size of about a molecule. For example, cellulose acetate, polysulfone,
Those using polyimide or polyamide are preferable, and polyimide is particularly preferable. In these polymer-based hydrogen permeable membranes, the pressure difference between both sides of the membrane causes
Only hydrogen molecules in the mixed gas selectively permeate through the membrane and are separated.

The form of the membrane includes a flat membrane, a hollow fiber, and a tubular membrane for both the metal-based and polymer-based hydrogen permeable membranes.

Examples of the hydrogen separation apparatus include, for example, a structure in which a flat membrane is formed into a spiral shape together with a porous support, or a structure in which a number of tubular membranes or hollow fibers are bundled into a tube to form a module. Can be

For reforming the hydrogen-containing compound in the reformer, a steam-reforming method in which the hydrogen-containing compound is brought into contact with steam to change into carbon monoxide and hydrogen, or a method in which a part of the hydrogen-containing compound is burned. A partial oxidation method for obtaining carbon oxide and hydrogen is preferably employed. Of course, the steam reforming method and the partial oxidation method may be used in combination.

In the case of utilizing the steam reforming method, the reforming apparatus includes, for example, a steam generating section for heating water to be vaporized, and a combustion section for burning a predetermined fuel to heat the steam generating section. And a reforming section that reacts the steam generated by the steam generating section with the hydrogen-containing compound to obtain a hydrogen-rich mixed gas.

In this configuration, a mixed gas (bleed gas) from which hydrogen has been separated by the hydrogen separation device may be used as fuel for the combustion section. In the reforming unit, in addition to hydrogen gas, carbon monoxide and carbon dioxide are generated.If hydrogen is extracted from the mixed gas in the hydrogen separator, unseparated hydrogen gas in addition to carbon monoxide and carbon dioxide is generated. The contained bleed gas is obtained. Therefore, the bleed gas not only can be effectively used as a fuel for combustion, but also has an advantage that toxic carbon monoxide is oxidized by the combustion to be converted into non-toxic carbon dioxide.

The fuel cell constituting the fuel cell system of the present invention has a positive electrode part, a negative electrode part, and an electrolytic part as in a normal cell. For example, the fuel cell has a configuration in which these are sandwiched between a pair of plates. Is done.

The positive electrode portion and the negative electrode portion have, for example, a structure including a catalyst layer and a current collector, or have both a function as a catalyst layer and a function as a current collector, and correspond to a catalyst layer and a current collector. Is integrally formed.

In a configuration in which the catalyst layer and the current collector are formed separately, the catalyst layer may be configured, for example, such that a catalyst is supported on a porous carrier. It may be applied directly to the surface of the part.

The catalyst layer having the former configuration is formed by solidifying a catalyst matrix in which catalyst powder is preliminarily supported on conductive particles such as carbon particles to form a porous matrix, or by solidifying conductive particles such as carbon particles to form a porous matrix. Is formed, the porous matrix is impregnated with a solution containing a catalyst component, heat-treated, and the catalyst is supported on the matrix.

The latter catalyst layer is formed by screen-printing an ink which is a paste or suspension of a carbon powder as a carrier supporting the catalyst with an organic solvent or a mixture of the catalyst and the carbon powder with an organic solvent. It is formed by applying to the electrolytic part by such a method as described above and evaporating the solvent component. Further, a carbon thin film to be a catalyst layer may be formed on a water-repellent sheet made of a fluororesin or the like by a method such as screen printing and drying, and then this may be thermally transferred to an electrolytic portion to form a catalyst layer.

Since it is necessary to react oxygen gas with hydrogen ions in the catalyst layer of the positive electrode portion, for example, platinum is preferably used as a catalyst constituting the catalyst layer. On the other hand, in the catalyst layer of the negative electrode portion, since it is necessary to dissociate hydrogen gas into hydrogen ions and electrons, for example, platinum, ruthenium or the like is employed as a catalyst constituting the catalyst layer.

In the structure in which the catalyst layer and the current collector are formed separately, the current collector in the positive electrode portion allows oxygen gas to pass therethrough to reach the catalyst layer in the positive electrode portion. It has a function of supplying electrons to the catalyst layer of the part. On the other hand, the current collector of the negative electrode part has a function of passing hydrogen gas to reach the catalyst layer of the negative electrode part and collecting electrons generated in the catalyst layer of the negative electrode part. For this reason, the current collector is required to have an appropriate porosity and be a good electronic conductor. Of course, it is also required to have excellent mechanical strength and to be hardly affected by the electrolyte. As a constituent material of the current collector satisfying such a demand, a carbon-based material (carbon powder such as carbon black, carbon fiber, or the like) is mainly used. This material, for example, if the carbon is in powder form, solidifies the carbon powder into a porous matrix,
In the case of a fiber form, it is preferable to form the current collector as a cloth.

The electrolysis section contains an electrolyte that allows the transfer of hydrogen ions. As the electrolyte, for example, a solid polymer is used.

The solid polymer is formed, for example, in the form of a film or a sheet to form an electrolytic portion. A polystyrene-based cation exchange membrane, for example, a perfluorosulfonic acid polymer is preferably used. This polymer exhibits proton conductivity when wetted with water, and protons (hydrogen ions) generated by dissociation of hydrogen gas in the negative electrode catalyst layer pass through the electrolytic portion by permeation in a hydrated state, It moves to the positive electrode catalyst layer.

A pair of plates sandwiching the electrode portion and the electrolytic portion are provided not only to define and secure a region functioning as a battery between these plates, but also to provide, for example, fuel gas (hydrogen gas) or air. Grooves and through holes for supplying (oxygen gas) are formed and used when supplying fuel gas and air to the positive electrode portion and the negative electrode portion.
For this reason, it is needless to say that it has high conductivity and gas sealing properties, and has excellent heat resistance so that it can cope with heat generated in a portion functioning as a battery, and has high mechanical strength that is not easily corroded by fuel gas or air. In addition, since machining is required to be easy, for example, in addition to a high-density carbon material or a carbon material solidified with phenol resin, various metals and alloys (titanium, stainless steel, titanium alloy, etc.) are used. It is formed.

The fuel cell according to the present invention can be used as a fuel cell stack by stacking a plurality of fuel cells in series. In this fuel cell stack, the same plate is shared between adjacent fuel cells. You can also. In this case, for example, a groove for supplying fuel gas (hydrogen gas) is provided on one side of the shared plate, and a groove for supplying air (oxygen gas) is provided on the other side. In addition, the fuel gas supply grooves of each plate and the air supply grooves communicate with each other through through holes provided in each plate, and if the fuel gas is supplied from one place, all The fuel gas may flow through the fuel gas supply grooves of the plates, and similarly, if air is supplied from one location, the air may flow through the air supply grooves of all the plates. Further, the common plate may be formed of a conductor, and the plate may be configured to conduct to both the positive electrode current collector of one fuel cell and the negative electrode current collector of the other fuel cell. In this configuration, the electrons collected in the negative electrode current collector of the other fuel cell are supplied to the positive electrode current collector of one fuel cell via a shared plate, and the electrons are collected by the positive electrode catalyst layer of the one fuel cell. Will contribute to the water production reaction.

[0033] Other features and advantages of the invention will become more apparent from the detailed description that follows.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be specifically described with reference to FIG. FIG. 1 is a flowchart showing a fuel cell system. In this embodiment, a fuel cell system using methanol as a hydrogen-containing compound as a reforming raw material will be described.

As shown in FIG. 1, the fuel cell system 1
Are a reformer 2 for reforming methanol to obtain a hydrogen-rich mixed gas, a hydrogen separator 3 for separating hydrogen gas from the mixed gas, and a fuel cell for obtaining an electromotive force by a reaction between hydrogen gas and oxygen gas. Fuel cell stack 4 in which is assembled in series
, And is roughly configured.

In the reformer 2, methanol is converted into a hydrogen-rich mixed gas by, for example, a steam reforming method or a partial oxidation (combustion) method. Specifically, the reforming apparatus 2 has a steam generating section 20, a reforming section 21, and a combustion section 22.

Water and methanol are supplied to the steam generating section 20 from the water tank 5 and the methanol tank 6. Then, in the steam generation section 20, the combustion section 2
2 to evaporate water and raise the temperature of methanol to a temperature suitable for reforming. The combustor 22 is provided with a combustor (burner) or a combustion catalyst.
Air is supplied from the air compressor 7 and combustion occurs. Further, a mixed gas (bleed gas) from which hydrogen has been separated in the hydrogen separation device 3 described later is also supplied at the same time and used for combustion in the combustion unit 22.

The reforming section 21 is supplied with steam and methanol from the steam generating section 20, and is supplied with air from the air compressor 7. The reforming section 21 is filled with, for example, a Cu—Zn catalyst or a Pt-based catalyst while being supported on a wire mesh, a honeycomb carrier, or the like, and methanol is reformed to obtain hydrogen gas. Specifically, a steam reforming reaction, which is a reaction between steam and methanol (reaction formula below)
(1)) occurs as a main reaction, and a partial oxidation reaction (reaction formula (2) below), which is a reaction with air (oxygen gas), competes to generate hydrogen gas.

[0039]

Embedded image

As is apparent from the reaction formulas (1) and (2), if a steam reforming reaction or a partial oxidation reaction occurs, carbon dioxide is generated at the same time as hydrogen gas. If the oxidation is insufficient, carbon monoxide is also produced as a by-product, and not all of the supplied methanol is reformed. Thus, in the reforming section 21, the supplied methanol is not only carbon monoxide and carbon dioxide, but also
A hydrogen-rich mixed gas containing methanol and the like is obtained,
This mixed gas is supplied to the hydrogen separation device 3.

The hydrogen separation device 3 is a device for obtaining a fuel gas having an extremely high hydrogen concentration using a hydrogen permeable membrane. The hydrogen separator 3 has a configuration in which, for example, a flat membrane-shaped hydrogen permeable membrane is formed into a spiral with a porous support, or a bundle of a plurality of tubular membranes or hollow fibers is incorporated in a tube to form a module. . The hydrogen permeable film may be a metal-based material such as a palladium alloy or a polymer-based material such as a polyimide resin.

Here, a typical configuration of the hydrogen separator 3 using a palladium alloy membrane is shown in FIGS. 2 (a) and 2 (b).
3 (a) and 3 (b) show typical configurations of the hydrogen separation device 3 using the solid polymer hollow fiber membrane.

In the hydrogen separator 3 shown in FIG. 2, a second tube 33a is accommodated in a first tube 30a, and a plurality of palladium alloy tubes 31 are accommodated in the second tube 33a.
a is accommodated. First tube 30a
Is provided with a supply port 34a for supplying a mixed gas, and the second tube 33a is provided with a first exhaust port 35a for discharging a bleed gas. Each palladium alloy tube 31a has one end closed,
The other end is open and communicates with the space 36a. The space 36a is provided with a second exhaust port 37a for discharging hydrogen gas to the outside.

In this configuration, as is apparent from FIG. 2A, the hydrogen gas supplied from the supply port 34a reaches the second tube 33a, and only the hydrogen gas in the mixed gas selectively passes through the palladium alloy tube. The other gas components reach the inside of the first tube 31a and are discharged as bleed gas from the first exhaust port 35a of the second tube 33a. As is clear from FIG. 2 (b), hydrogen molecules are adsorbed on the surface of the palladium alloy tube 31a, pass through the palladium alloy film in an ionized state, and have a lower hydrogen partial pressure. 3
1a. Then, they become hydrogen molecules and are discharged from the second exhaust port 37a. On the other hand, other components such as carbon monoxide and carbon dioxide cannot pass through the palladium alloy membrane, and are discharged from the first exhaust port 35a.

The hydrogen separator 3 shown in FIG. 3 has a structure in which a plurality of polyimide hollow fibers 31b are accommodated in a tube 30b. The tube 30b is provided with a supply port 34b for supplying the mixed gas, a first exhaust port 35b for discharging the bleed gas, and a second exhaust port 37b for discharging the hydrogen gas. One end of each polyimide hollow fiber 32b is closed, and the other end is open and communicates with the space 36b. This space chamber 36b communicates with the second exhaust port 37b.

In this configuration, as is apparent from FIG. 3A, the hydrogen gas supplied from the supply port 34b reaches the inside of the tube 30b, and each component in the mixed gas comes into contact with each polyimide hollow fiber 31b. At this time, since carbon monoxide, carbon dioxide, and the like having a large molecular diameter cannot pass through the polyimide hollow fiber 31b, they are discharged as bleed gas from the first exhaust port 35b of the tube 30b. FIG.
As apparent from (b), the hydrogen molecules that come into contact with the polyimide hollow fibers 31b pass through the polyimide hollow fibers 31b because of their small molecular diameters, and the polyimide hollow fibers 31b.
reaches the inside of b. The hydrogen gas thus selectively separated is discharged from the second exhaust port 37b.

As described above, in the hydrogen separator 3 using the hydrogen permeable membrane, the hydrogen molecules are separated with extremely high selectivity. Therefore, the fuel gas obtained from the hydrogen separator 3 has extremely high hydrogen gas purity. The fuel gas thus obtained is supplied to the fuel cell stack 4, while the bleed gas from which the hydrogen gas has been separated is supplied to the combustion section 2 of the reformer 2.
2 is supplied.

The fuel cell stack 4 is formed by stacking a plurality of fuel cells in series, although not clearly shown in the drawing. Each fuel cell has a positive electrode part, a negative electrode part, and an electrolytic part. Fuel gas is supplied from the hydrogen separator 3 to the negative electrode part, and air from the compressor 7 is supplied to the positive electrode part. At the negative electrode, hydrogen gas in the fuel gas is dissociated into hydrogen ions and electrons (reaction formula (3) below).
Oxygen gas in the air reacts with the electrons and the hydrogen ions moving through the electrolysis part to produce water (reaction formula below)
(4)).

[0049]

Embedded image

The water generated in the negative electrode section is sent to a water recovery device 8 together with air discharged from the fuel cell stack 4 and then stored in a water tank 5. On the other hand, since the purity of the hydrogen gas of the fuel gas supplied to the fuel cell stack 4 itself is extremely high, the purity of the hydrogen gas of the unreacted gas discharged from the fuel cell stack 4 is also high. Therefore, the unreacted gas from the fuel cell stack 4 is circulated and used for the fuel cell stack 4.

[0051]

As described above, in the fuel cell system of the present invention, since the purity of the fuel gas supplied to the fuel cell (stack) is high, the unreacted gas from the fuel cell can be recycled without any problem. can do. For this reason, the utilization efficiency of the fuel gas, in particular, the energy conversion efficiency of the hydrogen gas is increased. Further, since the fuel cell (stack) is supplied with fuel gas having a high purity of hydrogen gas, the problem of catalyst poisoning in the fuel cell can be appropriately avoided.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a fuel cell system.

FIG. 2A is a cross-sectional view illustrating a typical configuration of a hydrogen separation device using a palladium alloy membrane, and FIG. 2B is an enlarged view of a main part thereof.

FIG. 3A is a cross-sectional view illustrating a typical configuration of a hydrogen separation device using a solid polymer hollow fiber membrane, and FIG.
It is the principal part enlarged view.

[Explanation of symbols]

 Reference Signs List 1 fuel cell system 2 reformer 3 hydrogen separator 4 fuel cell stack

Claims (8)

[Claims] 1. A fuel cell system comprising: a reformer for reforming a hydrogen-containing compound to obtain a hydrogen-rich mixed gas; and a fuel cell that generates an electromotive force by a reaction between hydrogen and oxygen, A hydrogen separation device having a hydrogen permeable membrane between the reforming device and the fuel cell and separating the hydrogen gas from the mixed gas obtained by the reforming device to obtain a fuel gas; A fuel cell system, characterized by: 2. The fuel cell system according to claim 1, wherein the unreacted gas discharged from the fuel cell is circulated as fuel gas of the fuel cell. 3. The fuel cell system according to claim 1, wherein the hydrogen-containing compound is selected from methanol, dimethyl ether, propane, and natural gas. 4. The fuel cell system according to claim 1, wherein said hydrogen permeable membrane is a palladium alloy membrane. 5. The palladium alloy film according to claim 1, wherein said palladium alloy film is at least one selected from palladium, silver, gold and ruthenium.
The fuel cell system according to claim 4, comprising an alloy of two metals. 6. The fuel cell system according to claim 1, wherein the hydrogen permeable membrane is a solid polymer hollow fiber. 7. The fuel cell system according to claim 6, wherein the solid polymer hollow fiber is made of polyimide. 8. The steam reforming apparatus according to claim 1, wherein the reformer comprises: a steam generator for heating water to be vaporized; a combustion unit for burning a predetermined fuel to heat the steam generator; and a steam generated by the steam generator. And a reforming section for reacting the hydrogen-containing compound with the hydrogen-containing compound to obtain a hydrogen-rich mixed gas. The mixed gas from which hydrogen has been separated by the hydrogen separation device,
The fuel cell system according to any one of claims 1 to 7, wherein the fuel cell system is used as fuel in the combustion unit.