KR100560442B1 - Fuel cell system - Google Patents

Abstract

The present invention relates to a fuel cell system, and more particularly to a fuel cell system that effectively reduces the carbon monoxide concentration of the reformed gas.

To this end, the fuel cell system according to the present invention includes a reforming unit for generating a hydrogen-rich reformed gas from a liquid fuel containing hydrogen, and an electrochemical reaction of the reformed gas and oxygen with an operating temperature of 100 to 150 ° C. Electrochemical chemicals of a first stack that generates electricity by a phosphorus reaction and an unreacted gas discharged from the first stack in an unreacted state with an operating temperature condition of less than 100 ° C. lower than that of the first stack. A second stack for generating electricity by a phosphorus reaction, a carbon monoxide removal unit disposed between the first stack and the second stack and connected to the first stack and the second stack, and supplying liquid fuel to the reforming unit And a fuel supply unit for supplying external air to the first and second stacks and the carbon monoxide removing unit.

Fuel cell, fuel supply, air supply, reformer, first stack, second stack, electricity generator, electrode-electrolyte composite, bipolar plate, carbon monoxide remover, carbon monoxide selective oxidation, catalyst layer

Description

Fuel Cell System {FUEL CELL SYSTEM}

1 is a schematic diagram showing an overall configuration of a fuel cell system according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a portion of the carbon monoxide removing unit illustrated in FIG. 1.

The present invention relates to a fuel cell system, and more particularly to a fuel cell system that effectively reduces the carbon monoxide concentration of the reformed gas.

In general, a fuel cell is a power generation system that directly converts chemical energy into electrical energy by an electrochemical reaction generated by using hydrogen and oxygen or air containing oxygen as fuel in a hydrocarbon-based material such as methanol, ethanol or natural gas. to be. In particular, the fuel cell is characterized in that it can simultaneously use electricity generated by the electrochemical reaction of hydrogen and oxygen and heat as a byproduct thereof without a combustion process.

Such fuel cells are phosphoric acid fuel cells operating near 150-200 ° C., molten carbonate fuel cells operating at high temperatures 600-700 ° C. and solid oxide types operating at high temperatures 1000 ° C. or higher depending on the type of electrolyte used. It is classified into fuel cell, polymer electrolyte type and alkaline type fuel cell operating at room temperature to below 100 ° C. Each of these fuel cells operates on the same principle, but the type of fuel, operating temperature, catalyst and electrolyte Are different.

Among these, polymer electrolyte fuel cells (PEMFCs), which have been recently developed, have excellent output characteristics, low operating temperatures, fast start-up and response characteristics compared to other fuel cells, and methanol and ethanol. By using hydrogen produced by reforming natural gas, etc. as a fuel, it has a wide range of applications such as mobile power sources such as automobiles, as well as distributed power sources such as houses and public buildings, and small power sources such as electronic devices.

In order for the polymer electrolyte fuel cell as described above to basically have a system configuration, a fuel cell body (hereinafter referred to as a stack for convenience) called a stack, a fuel tank, and a fuel tank are supplied from the fuel tank to the stack. A fuel pump for this purpose is needed. Further, a reformer for reforming the fuel to generate hydrogen gas and supplying the hydrogen gas to the stack is further included in the process of supplying the fuel stored in the fuel tank to the stack. Therefore, the polymer electrolyte fuel cell supplies the fuel stored in the fuel tank to the reformer by the pumping force of the fuel pump, the reforming unit reforms the fuel to generate hydrogen gas, and the stack electrochemically reacts the hydrogen gas with oxygen. Electric energy is produced.

In the fuel cell system as described above, the stack for generating electricity has a structure in which several to tens of unit cells composed of an electrode-electrolyte assembly (MEA) and a bipolar plate are stacked. The electrode-electrolyte composite has a structure in which an anode electrode and a cathode electrode are attached with an electrolyte membrane interposed therebetween. The bipolar plate simultaneously serves as a passage for supplying oxygen and hydrogen gas required for the reaction of the fuel cell and a conductor connecting the anode electrode and the cathode electrode of each electrode-electrolyte composite in series. Therefore, hydrogen gas is supplied to the anode electrode by the bipolar plate, while oxygen is supplied to the cathode electrode. In this process, an oxidation reaction of hydrogen gas occurs at the anode electrode, and a reduction reaction of oxygen occurs at the cathode electrode, and electricity, heat, and water can be obtained together due to the movement of generated electrons.

The reformer is a device that not only converts hydrogen-containing liquid fuel and water into hydrogen gas necessary for generating electricity in the stack by the reforming reaction, but also removes harmful substances such as carbon monoxide, which poison the fuel cell and shorten its life. .

Typically, the reformer includes a portion for reforming fuel to generate hydrogen gas and a portion for removing carbon monoxide from the hydrogen gas. That is, the reformer converts the above-described fuel into a hydrogen-rich reformed gas through catalytic reactions such as steam reforming, partial oxidation, and autothermal reaction, and purifies hydrogen using a catalytic reaction or separation membrane such as a water gas conversion method or a selective oxidation method. Carbon monoxide is removed from the reformed gas in the same manner. Such a reformer produces a reformed gas containing no carbon monoxide when the above reactions are carried out substantially completely, but in practice, it is difficult to completely carry out the reaction for removing carbon monoxide, thereby generating a reforming gas containing carbon monoxide. .

Meanwhile, as described above, a fuel cell system for reducing the carbon monoxide concentration of the reformed gas generated from the reformer has been proposed in US Pat. No. 6294278.

The above-described conventional fuel cell system comprises a stack having operating conditions of high temperature (above 100 ° C) and a separate stack having operating conditions of low temperature (less than 100 ° C). Therefore, the reformed gas generated from the reformer may be supplied to the high temperature stack to reduce the concentration of carbon monoxide contained in the reformed gas, and the reformed gas having the reduced concentration of carbon monoxide may be supplied to the low temperature stack to generate electricity. That is, when the reformed gas is supplied to a high temperature stack having an operating temperature condition of 100 ° C. or higher, the catalyst layer of the anode electrode of the electrode-electrolyte composite is made of a material having poisoning resistance of carbon monoxide and has a catalytic activity at high temperatures. The concentration of carbon monoxide contained in the reformed gas can be reduced.

However, in the conventional fuel cell system, even if the carbon monoxide concentration of the reformed gas generated from the reformer is reduced by using the stack under high temperature operating conditions, the reformed gas finally supplied to the stack under low temperature operating conditions contains a small amount of carbon monoxide. Therefore, due to such poisoning of carbon monoxide, there was a problem in that the stack performance under low temperature operating conditions is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object thereof is to provide a fuel cell system that can further improve the performance of the overall system by maximizing the efficiency of reducing the concentration of carbon monoxide generated from the reformer.

The fuel cell system according to the present invention for achieving the above object is a reforming unit for producing a hydrogen-rich reformed gas from a liquid fuel containing hydrogen, and the reforming having an operating temperature condition of 100 to 150 ℃ A first stack that generates electricity by an electrochemical reaction of gas and oxygen, and a reforming that is discharged unreacted from the first stack with an operating temperature condition of less than 100 ° C., which is relatively lower than the first stack. A second stack that generates electricity by an electrochemical reaction of gas and oxygen, a carbon monoxide removal unit disposed between the first stack and the second stack and connected to the first stack and the second stack, and the reforming And a fuel supply unit supplying liquid fuel to the air, and an air supply unit supplying external air to the first and second stacks and the carbon monoxide removing unit.

In the fuel cell system according to the present invention, the fuel supply unit comprises: a first tank for storing liquid fuel containing hydrogen; A second tank for storing water; And a fuel pump connected to the first tank and the second tank, respectively, and the air supply unit may include an air pump for sucking external air.

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In the fuel cell system according to the present invention, the carbon monoxide removing unit includes a reaction chamber connected to the first and second stacks, and a carbon monoxide selective oxidation (PROX) catalyst layer formed in the reaction chamber. In this case, the carbon monoxide selective oxidation catalyst layer is preferably made of Pt or Ru.

In the fuel cell system according to the present invention, the fuel supply unit and the reforming unit may be connected by a first supply line, and the reforming unit and the first stack may be connected by a second supply line.

In the fuel cell system according to the present invention, the first stack and the carbon monoxide remover may be connected by a third supply line, and the carbon monoxide remover and the second stack may be connected by a fourth supply line.

In the fuel cell system according to the present invention, the first stack and the air supply is connected by a fifth supply line, the second stack and the air supply is connected by a sixth supply line, the carbon monoxide removing unit and the air The supply part may be connected by a seventh supply line.

The fuel cell system according to the present invention is made of a polymer electrolyte fuel cell (PEMFC) method.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

This system generates a reformed gas rich in hydrogen by reforming a fuel containing hydrogen, and converts the chemical energy produced by electrochemical reaction of the reformed gas with oxygen to a polymer electrolyte fuel cell (Polymer Electrode). Membrane Fuel Cell (PEMFC) is adopted.

In the fuel cell system according to the present invention, the fuel for generating electricity further includes water and oxygen in addition to hydrocarbon or alcohol-based liquid fuels such as methanol, ethanol and natural gas, among which liquid fuels are used. And water are defined as mixed fuels for convenience in the following description. As the oxygen fuel, pure oxygen gas stored in a separate storage means may be used, and air containing oxygen may be used as it is. However, below, the example which uses external air as an oxygen fuel is demonstrated.

1 is a schematic diagram showing an overall configuration of a fuel cell system according to an embodiment of the present invention.

Referring to FIG. 1, the fuel cell system 100 according to the present invention basically includes a reforming unit 30 for generating hydrogen-rich reforming gas from the mixed fuel and a reforming unit generated by the reforming unit 30. The first stack 10 and the unreacted from the first stack 10 to produce electricity by primarily reducing the carbon monoxide concentration of the gas and converting the chemical reaction energy of the reformed gas and the outside air into electrical energy. The second stack 20 converts the chemical reaction energy of the reformed gas and the outside air discharged in the state into electrical energy to produce electricity, and the fuel supply unit 50 supplying the mixed fuel to the reforming unit 30. And an air supply unit 70 for supplying external air to the first and second stacks 10 and 20.

The fuel supply unit 50 is installed in connection with the reforming unit 30, the first tank 51 for storing the liquid fuel containing hydrogen, the second tank 52 for storing water, and the first And a fuel pump 53 connected to the second tanks 51 and 52, respectively.

As described above, the air supply unit 70 is connected to the first and second stacks 10 and 20 and includes an air pump 71 having a conventional structure for sucking external air with a predetermined pumping force. At this time, the air supply unit 70 and the first stack 10 may be connected by the fifth supply line (85). In addition, the air supply unit 70 and the second stack 20 may be connected and installed by the sixth supply line 86.

The reforming unit 30 has a structure of a conventional reforming unit for reforming a mixed fuel supplied from the fuel supply unit 50 to generate a hydrogen-rich reforming gas. The reforming unit 30 is a reforming gas containing carbon dioxide and hydrogen by simultaneously performing the decomposition reaction of the mixed fuel and the modification reaction of carbon monoxide (also referred to as a "shift reaction") through a steam reformer (SR) reaction. The reforming reaction part 31 which produces | generates is provided. Here, the reforming reaction unit 31 and the first and second tanks 51 and 52 of the fuel supply unit 50 may be connected by the first supply line 81. In addition, the fuel pump 53 of the fuel supply unit 50 may be installed on the first supply line 81.

In addition, since the reactions performed in the reforming reaction part 31 are endothermic reactions as a whole, the reforming part 30 includes a combustion part 32 that provides the amount of heat required for the reaction of the reforming reaction part 31.

The combustion unit 32 is an exothermic portion for supplying a heat source necessary for the generation of the reformed gas to the reforming reaction unit 31, and burns liquid fuel and external air by a catalytic oxidation reaction to generate heat of combustion at a predetermined temperature. . The combustion unit 32 receives liquid fuel from the fuel supply unit 50 and also receives external air from the air supply unit 70. Here, the combustion unit 32 and the first tank 51 of the fuel supply unit 50 may be connected by the eighth supply line 88. The combustion unit 32 and the air supply unit 70 may be connected by the ninth supply line 89.

The reforming unit 30 having the structure as described above generates a reformed gas containing no carbon monoxide when the reactions are substantially completely performed. However, in the actual reforming unit, it is difficult to completely perform the carbon monoxide modification reaction. It produces a reformed gas containing carbon monoxide as a by-product.

According to the present embodiment, the reformed gas containing carbon monoxide may be supplied to the first stack 10 to reduce the carbon monoxide concentration of the reformed gas through the catalytic activity caused by the high temperature condition of the stack itself.

In order to reduce the concentration of the carbon monoxide contained in the reformed gas, the first stack 10 is controlled in a range of 100 ° C to 150 ° C. The operating temperature of the first stack 10 may be controlled by the supply amount of the reformed gas supplied from the reforming unit 30 and the external air supplied from the air supply unit 70. The first stack 10 also has a unique function of generating electrical energy by inducing an oxidation / reduction reaction between the reformed gas generated from the reformer 30 and the outside air.

The first stack 10 includes a plurality of electricity generating units 11 including an electrode-electrode assembly (MEA) 12 and a bipolar plate 16.

The electricity generating unit 11 has the electrode-electrolyte composite 12 in the center and bipolar plates 16 are disposed on both sides thereof. As a result, the stack 10 is configured by continuously arranging the plurality of electricity generating units 11 as described above.

The electrode-electrolyte composite 12 has a structure of a conventional MEA (membrane electrode assembly) in which an electrolyte membrane is interposed between an anode electrode and a cathode electrode forming both sides.

The anode electrode receives a reformed gas rich in hydrogen through the bipolar plate 16, and includes a catalyst layer for converting hydrogen contained in the reformed gas into electrons and hydrogen ions by an oxidation reaction, and smooth movement of the electrons and hydrogen ions. Gas diffusion layer (GDS).

The cathode electrode is a portion to which air is supplied through the bipolar plate 16, and is composed of a catalyst layer for converting oxygen in the air into electrons and oxygen ions by a reduction reaction, and a gas diffusion layer for smooth movement of electrons and oxygen ions. Here, the catalyst layer of the anode electrode is made of Pt or an alloy of Pt and Ru having poisoning resistance of carbon monoxide.

The electrolyte membrane is a solid polymer electrolyte having a thickness of 50 to 200 µm, and has an ion exchange function for transferring hydrogen ions generated in the catalyst layer of the anode electrode to the catalyst layer of the cathode electrode.

Therefore, the first stack 10 is formed of a catalyst layer made of Pt or an alloy of Pt and Ru on the anode electrode side of the electrode-electrolyte composite 12, and the operating temperature condition of the stack is maintained in the range of 100 ° C to 150 ° C As a result, the carbon monoxide concentration in the reformed gas supplied from the reforming unit 30 can be reduced. In other words, the higher the operating temperature of the catalyst layer, the higher the operating temperature of the stack, the catalyst activity is accelerated, so the carbon monoxide concentration is reduced.

The bipolar plate 16 described above has the function of a conductor that connects the anode electrode and the cathode electrode of the electrode-electrolyte composite 12 in series. The bipolar plate 16 also has a function of a passage for supplying the reforming gas and air necessary for the oxidation / reduction reaction of the electrode-electrolyte composite 12 to the anode electrode and the cathode electrode.

More specifically, the bipolar plate 16 is disposed on both sides thereof with the electrode-electrolyte composite 12 interposed therebetween, and is in close contact with the anode electrode and the cathode electrode of the electrode-electrolyte composite 12. The bipolar plate 16 is a flow channel (not shown) for supplying a reforming gas to the anode electrode and supplying air to the cathode electrode on a close contact surface which is in close contact with the anode electrode and the cathode electrode of the electrode-electrolyte composite 12, respectively. ).

Meanwhile, the first stack 10 includes a first supply pipe 13a for supplying the reformed gas generated from the reforming unit 30 to the electrode-electrolyte composite 12, and external air to the electrode-electrolyte composite 12. In the second supply pipe (13b) for supplying the furnace, the first discharge pipe (13c) for discharging the remaining unreacted reformed gas in the plurality of electricity generating section 11, and in the electricity generating section (11) Finally, the second discharge pipe 13d for discharging the unreacted and remaining air is provided. Here, the first supply pipe 13a and the reforming unit 30 may be connected to each other by the second supply line 82. In addition, the second supply pipe 13b and the air supply unit 70 may be connected to each other by the fifth supply line 85 as described above.

The second stack 20 is reformed gas whose concentration of carbon monoxide is reduced by the catalytic activity due to the reformed gas discharged from the first stack 10 in an unreacted state, that is, an operating temperature condition of the first stack 10. It induces oxidation / reduction reaction of gas and outside air to generate electrical energy. The second stack 20 is controlled to have an operating temperature of less than 100 ° C. The operating temperature of the second stack 20 may be controlled by the supply amount of the unreacted reformed gas discharged from the first stack 10 and the external air supplied from the air supply unit 70.

The second stack 20 as described above includes a first supply pipe 23a for supplying the reformed gas discharged from the first stack 10 in an unreacted state to the electrode-electrolyte composite 22 and external air. A second supply pipe 23b for supplying the electrolyte composite 22, a first discharge pipe 23c for discharging the reformed gas remaining unreacted in the plurality of electricity generating units 21, and the aforementioned A second discharge pipe 23d for discharging the remaining unreacted air in the electricity generating unit 21 is provided. Here, the second supply pipe 23b and the air supply unit 70 may be connected by the sixth supply line 86 as described above.

Since the remaining components of the second stack 20 are the same as the first stack 10 described above, a detailed description thereof will be omitted.

Upon operation of the present system 100 as described above, the reforming generated from the reforming portion 30 by the operating temperature conditions of the first stack 10 and the catalytic activity of the anode electrode side catalyst layer of the electrode-electrolyte composite 12 Even if the carbon monoxide concentration of the gas is reduced to some extent, since the unreacted reformed gas discharged through the first discharge pipe 13c is mixed with a small amount of carbon monoxide, the performance of the second stack 20 may be degraded.

Accordingly, according to an embodiment of the present invention, the carbon monoxide removal unit 90 for secondly reducing the concentration of carbon monoxide from the unreacted reformed gas discharged from the first stack 10 includes the first stack 10 and the second stack. Disposed between the stacks 20.

FIG. 2 is a cross-sectional view illustrating a portion of the carbon monoxide removing unit illustrated in FIG. 1.

Referring to FIGS. 1 and 2, the carbon monoxide removing unit 90 performs a catalytic reaction of the reformed gas discharged from the unreacted state from the first stack 10 with external air (Preferential CO Oxidation (PROX)). By oxidizing the carbon monoxide in the reformed gas preferentially over hydrogen, the carbon monoxide concentration of the reformed gas can be reduced.

The carbon monoxide removal unit 90 for this purpose is a reaction chamber 91 substantially connected to the first stack 10 and the second stack 20 and a carbon monoxide of Pt or Ru formed inside the reaction chamber 91. A selective oxidation (PROX) catalyst layer 93 is included.

The reaction chamber 91 is an airtight container having an internal space of a predetermined volume, and is connected to the first discharge pipe 13c of the first stack 10 and the first supply pipe 23a of the second stack 20, respectively. do. The reaction chamber 91 is connected to the air supply unit 70.

In detail, the reaction chamber 91 may include a first inlet port through which unreacted reformed gas discharged from the first discharge pipe 13c of the first stack 10 in a state in which the concentration of carbon monoxide is reduced is introduced into the internal space. 91a, a second inlet 91b through which the outside air supplied from the air supply unit 70 flows into the above inner space, and a fluid causing a selective oxidation catalytic reaction by the catalyst layer 93 in the above inner space. To the first supply pipe 23a of the second stack 20 to form an outlet 91c. Here, the first discharge pipe 13c of the first stack 10 and the first inlet 91a of the reaction chamber 91 may be connected by the third supply line 83. In addition, the outlet 91c of the reaction chamber 91 and the first supply pipe 23a of the second stack 20 may be connected by the fourth supply line 84. In addition, the second inlet 91b of the reaction chamber 91 and the air supply unit 70 may be connected by the seventh supply line 87.

The carbon monoxide selective oxidation catalyst layer 93 is made of a catalyst material that is typically used for the selective oxidation catalytic reaction and reformed introduced into the internal space of the reaction chamber 91 through the first discharge pipe 13c of the first stack 10. It has the function of reducing the carbon monoxide concentration of the gas.

Referring to the operation of the fuel cell system according to an embodiment of the present invention configured as described above in detail as follows.

First, the fuel pump 53 is operated to supply liquid fuel stored in the first tank 51 to the combustion unit 32 of the reforming unit 30 through the eighth supply line 88. At the same time, the air pump 71 is operated to supply external air to the combustion unit 32 through the ninth supply line 89. Then, the combustion unit 32 generates combustion heat of a predetermined temperature by the catalytic oxidation reaction between the liquid fuel and the air.

Subsequently, the fuel pump 53 is operated to transfer the liquid fuel and water stored in the first tank 51 and the second tank 52 through the first supply line 81 to the reforming reaction unit of the reforming unit 30 ( 31). At this time, the reforming reaction unit 31 receives the combustion heat emitted from the combustion unit 32 and maintains the heating state at a predetermined temperature. Then, the reforming reaction unit 31 performs a reforming reaction of the mixed fuel and a carbon monoxide modification reaction simultaneously through a steam reformer (SR) catalytic reaction to generate a reformed gas containing carbon dioxide and hydrogen. At this time, it is difficult for the reforming reaction unit 31 to completely perform the carbon monoxide modification reaction, thereby generating a reforming gas containing a small amount of carbon monoxide as a minor product.

Next, the reformed gas is discharged from the reforming reaction unit 31 and supplied to the first supply pipe 13a of the first stack 10 through the second supply line 82. At the same time, the air pump 71 is operated to supply external air to the second supply pipe 13b of the first stack 10 through the fifth supply line 85. Then, the electricity generating unit 11 of the first stack 10 generates electric energy by an electrochemical reaction of hydrogen and air contained in the reforming gas. At this time, the operating temperature condition of the first stack 10 is controlled in the range of 100 ° C to 150 ° C by the supply amount of the reformed gas and air.

Therefore, the first stack 10 is contained in the reformed gas while the catalyst layer of the anode electrode of the electrode-electrolyte composite 12 is activated by the operating temperature conditions of the stack itself while generating the electrical energy in the electricity generating unit 11. Primarily reduce the concentration of carbon monoxide.

Subsequently, the unreacted reformed gas, that is, the reformed gas in which the concentration of carbon monoxide is primarily reduced in the electricity generating unit 11 of the first stack 10 is discharged through the first discharge pipe 13c. The reformed gas contains a trace amount of carbon monoxide even if the concentration of carbon monoxide is reduced to some extent by the catalytic activity caused by the operating temperature condition of the first stack 10.

Next, the reformed gas is supplied to the reaction chamber 91 through the third supply line 83. The reformed gas then flows into the interior space of the reaction chamber 91 through the first inlet 91a. At the same time, the air pump 71 is operated to supply external air to the reaction chamber 91 through the seventh supply line 87. The outside air is then introduced into the internal space of the reaction chamber 91 through the second inlet (91b).

Subsequently, the reformed gas and air introduced into the internal space of the reaction chamber 91 pass through the carbon monoxide selective oxidation catalyst layer 93. Then, the catalyst layer 93 oxidizes the carbon monoxide in the reforming gas preferentially to hydrogen through the selective CO oxidation reaction (PROX) catalysis to secondly reduce the concentration of the carbon monoxide.

Next, the reformed gas having a lower concentration of carbon monoxide as described above is discharged from the internal space of the reaction chamber 91 through the outlet 91c, and the second stack 20 is discharged through the fourth supply line 84. 1 is supplied to the supply pipe 23a. At the same time, the air pump 71 is operated to supply external air to the second supply pipe 23b through the sixth supply line 86.

Therefore, the electricity generating unit 21 of the second stack 20 generates electric energy by an electrochemical reaction of hydrogen and air contained in the reforming gas. At this time, the operating temperature condition of the second stack 20 is controlled to a range of less than 100 ° C by the supply amount of the reformed gas and air.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

According to the fuel cell system according to the present invention, the carbon monoxide concentration of the reformed gas discharged in the unreacted state from the stack and the high temperature operating condition that primarily reduces the carbon monoxide concentration of the reformed gas produced from the reformer is secondary. Since the carbon monoxide removal unit is reduced, the performance of the overall system can be further improved by preventing the carbon monoxide from being poisoned by the carbon monoxide stack which finally generates electricity.

Claims (11)

A reforming unit for generating a hydrogen-rich reformed gas from a liquid fuel containing hydrogen; A first stack generating electricity by an electrochemical reaction of the reformed gas with oxygen while having an operating temperature condition of 100 to 150 ° C .; A second stack generating electricity by an electrochemical reaction of oxygen with a reformed gas discharged unreacted from the first stack while having an operating temperature of less than 100 ° C., which is relatively lower than the first stack; A carbon monoxide removal unit disposed between the first stack and the second stack and connected to the first stack and the second stack; A fuel supply unit supplying a liquid fuel to the reformer; And An air supply unit supplying external air to the first and second stacks and the carbon monoxide removing unit Fuel cell system comprising a. The method of claim 1, The fuel supply unit: A first tank for storing a liquid fuel containing hydrogen; A second tank for storing water; And And a fuel pump connected to the first tank and the second tank, respectively. The method of claim 1, The air supply unit comprises a fuel pump for sucking the outside air. delete delete The method of claim 1, And a carbon monoxide removing unit, a reaction chamber connected to the first and second stacks, and a carbon monoxide selective oxidation (PROX) catalyst layer formed in the reaction chamber. The method of claim 6, And the carbon monoxide selective oxidation catalyst layer is made of Pt or Ru. The method of claim 1, And the fuel supply unit and the reforming unit are connected by a first supply line, and the reforming unit and the first stack are connected by a second supply line. The method of claim 8, And the first stack and the carbon monoxide remover are connected by a third supply line, and the carbon monoxide remover and the second stack are connected by a fourth supply line. The method of claim 9, The first stack and the air supply unit are connected by a fifth supply line, the second stack and the air supply unit are connected by a sixth supply line, and the carbon monoxide removing unit and the air supply unit are connected by a seventh supply line. Fuel cell system. The method of claim 1, The fuel cell system is a fuel cell system comprising a polymer electrolyte fuel cell (PEMFC) method.

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