JP2001068136A - Solid high-polymer fuel cell system and operating method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for operating a solid high-polymer fuel cell system, in which power generating efficiency can be enhanced and the trouble of sulfur poisoning in a system can be overcome, and a system capable of achieving such an operating state. SOLUTION: In a method for operating a solid high-polymer fuel cell system 100 in which raw fuel including mainly hydrocarbon and containing sulfur is reformed with steam so as to prepare reformed gas containing mainly hydrogen which then acts as anode gas for a solid high-polymer type fuel cell, the content of sulfur contained in the raw fuel 2 is desulfurized to 1 vol.ppb or less (preferably, 0.1 vol.ppb or less), followed by steam reforming, thereby obtaining reformed gas. The reformed gas is supplied to the solid high-polymer type fuel cell, thus allowing the solid high-polymer fuel cell system 100 to be operated. The steam reforming is performed in a reformer in S/C of 0.7-3.0 in the case where the number of mol of steam per 1 mol of carbon in the raw fuel 2 is represented by S/C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a polymer electrolyte fuel cell in which a reformed gas obtained by steam reforming a raw fuel such as natural gas or naphtha is supplied to the anode side of a polymer electrolyte fuel cell. The present invention relates to an operation method of a polymer electrolyte fuel cell system that generates electricity by operating a fuel cell, and also relates to such a polymer electrolyte fuel cell system.

2. Description of the Related Art Conventionally, in a polymer electrolyte fuel cell system using a raw fuel mainly composed of a hydrocarbon such as natural gas or naphtha, a desulfurizer, a reformer, a CO shift converter, a CO Equipped with a removal device, the raw fuel from which the sulfur component has been removed by the desulfurization device is introduced into the reforming device, and converted into a reformed gas containing hydrogen as a main component by a steam reforming reaction. C in the reformed gas by the device
The fuel cell is operated by supplying a reformed gas having a reduced O concentration to the fuel electrode of the polymer electrolyte fuel cell to generate power. However, such a conventional method has many problems as described below. Typical desulfurization process taking place in the conventional desulfurization apparatus, after hydrogenolysis of organic sulfur of the raw fuel in the presence of a Ni-Mo-based or Co-Mo catalyst, ZnO the resulting H ₂ S In the hydrodesulfurization process, if the raw fuel contains a certain amount or more of organic sulfur, especially unresolved organic sulfur such as thiophene, undecomposed The object does not slip and is not adsorbed to ZnO but passes through.
In addition, in this adsorption desulfurization, for example,

[0002]

Embedded image Due to the equilibrium represented by, the amounts of H ₂ S, COS, and the like do not fall below a certain value. This tendency is remarkable especially when H ₂ O and CO ₂ are present. In addition, activation of the device,
If the desulfurization system is unstable at the time of shutdown or the like, sulfur may be scattered from the hydrodesulfurization device and the adsorption desulfurization catalyst, and the sulfur concentration in the purified product may increase. Therefore, in the desulfurization process in the current steam reforming process, the sulfur concentration in the refined raw fuel is several vol. ppm to 0.1 vol. p
pm.

[0003] The raw fuel mainly composed of hydrocarbons desulfurized as described above is then subjected to Ni-based,
It is subjected to steam reforming in the presence of a Ru-based catalyst or the like. However, McCarty et al; J. Chem.Phys.
vol72. No.12.6332, 1980: J. Chem.Phys.vol74. No.10.
5877, 1981), the sulfur adsorption power of Ni and Ru is strong, so even if the sulfur content in the raw fuel is extremely small, most of the catalyst surface is Covered. Specifically, at the inlet conditions of a general steam reforming process (around 450 ° C.), the current best level of sulfur content of 0.1 vol. In a state of about ppm, about 90% of the surface of the Ni or Ru catalyst is covered with sulfur in a short time. This means that sulfur poisoning of the catalyst in the steam reforming process cannot be prevented with the conventional desulfurization level of the raw fuel.

[0004]

On the other hand, the use of a polymer electrolyte fuel cell as a fuel cell has been proposed today. Here, since the solid polymer fuel cell is small in size and has features such as easy start and stop, it is used as a home power source, a portable power source, a small-scale stationary power source, a vehicle power source, and the like. For this reason, miniaturization of the system is a very important issue. Since the operating temperature of such a polymer electrolyte fuel cell is as low as about 80 ° C., steam cannot be obtained by the exhaust heat. For this reason, a system that supplies a polymer-rich fuel cell with a hydrogen-rich reformed gas obtained by steam-reforming a raw fuel such as natural gas to a polymer electrolyte fuel cell generates electricity, and the steam required for steam-reforming the raw fuel is converted into natural gas. It is necessary to generate the heat of combustion of raw fuel such as gas or the heat of combustion of hydrogen which is off-gas of a fuel cell. In this case, since natural gas is consumed as an energy source for generating steam, a polymer electrolyte fuel cell system that uses hydrocarbons such as natural gas as a raw fuel reduces the power generation efficiency as a whole. This is one of the major factors that cause it. Also, when hydrogen that is an off-gas is used, it is necessary to reduce the hydrogen utilization rate of the fuel cell, which also causes a reduction in the power generation efficiency of the system. For this reason, in the reformer, it is preferable to lower the S / C (steam / carbon ratio) when steam-reforming a raw fuel such as natural gas to reduce the energy for steam generation. Then, it was found that the reformer had the following problems. Conventionally used 0.1 vol. In a steam reforming method of raw fuel using a desulfurizing agent having a desulfurization level of about ppm as it is, a small amount of a sulfur component slips to a steam reforming device at a subsequent stage of the desulfurizing device to poison the steam reforming catalyst. Conventionally, usually,
In the reformer of the phosphoric acid fuel cell, the S / C is 3 to 3.5.
If the steam reforming reaction is performed at a lower S / C than the extent, carbon tends to precipitate, and the steam reforming reaction cannot be performed for a long time under the low S / C conditions. That is, S
/ C must be set higher than 3 to 3.5. Furthermore, 0.1 vol. In the steam reforming method of raw fuel using a desulfurizing agent with a desulfurization level of about ppm, it is necessary to fill the steam reforming unit with a reforming catalyst that can maintain the performance even if the steam reforming catalyst is poisoned by slipping. Therefore, the size of the apparatus cannot be reduced substantially.

On the other hand, it has been found that the following problems occur downstream of the steam reformer. Since the operating temperature of polymer electrolyte fuel cells is as low as about 80 ° C,
When a reformed gas obtained by reforming a hydrocarbon such as natural gas is used as the anode gas, the electrode catalyst of the anode is poisoned by CO in the reformed gas. For this reason, a CO removal device for performing a selective oxidation reaction of CO is disposed at a stage subsequent to the CO shift device to reduce CO in the reformed gas to 100 vol. less than ppm,
Preferably 10 vol. The fuel is supplied to the fuel cell after being removed to less than ppm. In a CO selective oxidation reaction mainly performed in a CO removal device, an oxidizing agent such as air is added to a reformed gas in which a CO concentration is reduced to about 1% by a CO shift device, and a CO selective oxidation reactor is used. CO to C
Oxidation to O ₂ reduces the CO concentration to 10 vol. ppm
It has been reduced to below. Conventionally, the amount of the oxidizing agent added during the CO selective oxidation reaction is [O ₂ ] / [C
O] The molar ratio is about 3. Amount of oxygen required to completely selective oxidation of CO _alone, because it is 0.5 [O 2] / [CO] molar ratio, oxygen [O _2] / [CO] molar ratio 3 When adding CO to remove CO, approximately C
Combustion loss of hydrogen five times that of O results. Hydrogen loss due to excessive addition of oxidizing agent in the CO removing device is one of the factors that lower the power generation efficiency of the polymer electrolyte fuel cell system. [O ₂ ] / [C
Various studies have been made to lower the [O] molar ratio. However, under conditions where the S / C of the steam reforming reaction in the reformer is greater than 3 and up to 3.5, the equilibrium of the CO shift reaction is reduced by CO because the steam partial pressure in the subsequent CO shift device is relatively high. , And the CO concentration at the outlet of the CO converter becomes low. For this reason, the oxidizing agent addition amount ([O ₂ ] / [CO] molar ratio) in the CO removing device is reduced,
Even if the hydrogen combustion loss of the side reaction is reduced, the effect is not so large, and the power generation efficiency of the polymer electrolyte fuel cell system cannot be significantly improved. On the other hand, when the S / C of the steam reforming reaction in the reformer is set to 3 or less, the equilibrium of the CO shift reaction proceeds in a direction disadvantageous to the CO reduction because the steam partial pressure in the subsequent CO shift device becomes lower, In order to increase the CO concentration at the outlet of the CO converter,
It is very effective to reduce the amount of the oxidizing agent added ([O ₂ ] / [CO] molar ratio) in the CO removing device and reduce the hydrogen combustion loss of the side reaction. For this reason, the advantage of reducing the energy for generating steam in the steam reforming reaction and the advantage of reducing CO2
The power generation efficiency of the polymer electrolyte fuel cell system is increased by the synergistic effect of reducing the oxidizing agent addition amount ([O ₂ ] / [CO] molar ratio) in the removal device and reducing the hydrogen combustion loss of the side reaction. In order to achieve the improvement, it has been an important issue to reduce the S / C of the steam reforming reaction in the reformer for realizing a highly efficient polymer electrolyte fuel cell system. In addition, CO used in the CO removal device
As the removal catalyst, a noble metal catalyst such as Ru is mainly used. However, like the reforming catalyst, these catalysts are also poisoned by a small amount of sulfur, and the performance is reduced. That is, 0.1 vol. When a desulfurizing agent having a desulfurization level of about ppm is used, when the catalyst is used for a long period of thousands or tens of thousands of hours, 0.1 vol. The sulfur component slipped at about ppm lowers the CO removal performance and significantly degrades the cell performance of the polymer electrolyte fuel cell.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the state of the art as described above, and as a result, have determined that the sulfur content in the raw fuel supplied for steam reforming is 1 vol. ppb
Hereinafter, more preferably 0.1 vol. When the level is as low as ppb or less, the S / C
Can be operated at a relatively low level, and as a result, it is possible to improve the power generation efficiency of the system, and to improve the efficiency, downsizing, and start / stop performance of the polymer electrolyte fuel cell system. It has been found that not only becomes possible, but also the protection of the catalyst disposed in the system upstream of the polymer electrolyte fuel cell becomes possible. That is, in the present invention, a reformed gas containing hydrogen as a main component is produced by steam reforming a raw fuel containing a hydrocarbon as a main component and containing a sulfur component by a reformer, and the reformed gas is converted into a solid polymer. In the operation of a polymer electrolyte fuel cell system operated as anode gas of a fuel cell, as described in claim 1, the sulfur content in the raw fuel is 1 vol. After desulfurization to ppb or less, in relation to the amount of hydrocarbons contained in the raw fuel and the amount of steam supplied in the reformer, the number of moles of steam per mole of carbon in the raw fuel is expressed by S / C, the S / C in the reformer is set to 0.7 to 3.0 to operate the reformer to perform steam reforming to obtain the reformed gas. It is to be supplied to the polymer electrolyte fuel cell. Here, the lower the sulfur content after desulfurization by the desulfurization device, the better, but the actual lower limit of analysis is 0.1 vol.
l. ppb, which is this value if the lowest value of the upper limit after desulfurization is specified. By doing so, as described above, it is possible to operate the reformer at a relatively low S / C, and the above-described effects can be obtained.

[0007] In this configuration, the desulfurization apparatus may have a sulfur content of the raw fuel of 0.1 vol. It is preferable to perform steam reforming after reducing the pressure to ppb or less. In this way, the problem of sulfur poisoning of the steam reforming catalyst can be further reduced significantly, so that not only the amount of the reforming catalyst can be significantly reduced, but also the low S / C condition which has been difficult in the past. Long-term operation is possible below. Further, the problem of sulfur poisoning of the CO removal catalyst can be solved. As described in claim 3, the range of the S / C in the reforming apparatus is set at 2.
It is preferable to perform the steam reforming by operating the reformer at 0 to 2.8 to obtain the reformed gas. By doing so, it is easy to maintain a favorable state as the operating condition of the reformer, and stable operation can be performed for a long period of time. In this case, if the S / C is smaller than 2, the amount of water vapor decreases, so that the equilibrium of the CO shift reaction shifts to the CO generation side, and there is a problem that the CO concentration in the reformed gas at the outlet of the CO shift device increases. Cheap. On the other hand, when S / C is larger than 2.8, a problem that the energy required for generating steam becomes large tends to occur.

Further, in the above-described structure, the selective removal of CO is performed by adding an oxidizing agent to the CO removing device, so that the CO is removed from the reformed gas. The amount of the oxidizing agent added by the CO removing device to the CO in the reformed gas introduced into the CO removing device by using a CO selective oxidizer for removing CO is [O ₂ ] / [CO] as oxygen. The molar ratio is preferably in the range of 0.5 to 3. In this case, as described above, the oxidizing agent addition amount ([O ₂ ] / [C
O] molar ratio), the partial pressure of steam is reduced in the preceding CO shift apparatus, and the equilibrium of the CO shift reaction is reduced.
In a case where the process proceeds in a direction disadvantageous to the reduction of O and the CO concentration at the outlet of the CO shift device becomes high, reducing the hydrogen combustion loss of the side reaction works very effectively. As a result, the advantage of reducing the energy for generating steam in the steam reforming reaction,
The power generation efficiency of the polymer electrolyte fuel cell system is improved by the synergistic effect of reducing the amount of the oxidant added ([O ₂ ] / [CO] molar ratio) in the CO removal device and reducing the hydrogen combustion loss of the side reaction. It can be greatly improved. In addition, a favorable situation can be achieved after poisoning the anode electrode of the polymer electrolyte fuel cell with CO. If the [O ₂ ] / [CO] molar ratio is larger than the upper limit of 3, the amount of hydrogen lost by the oxidation reaction, which is a side reaction, increases, and the efficiency of the fuel cell system tends to decrease. On the other hand, when the lower limit is less than 0.5, the tendency that CO cannot be removed to a level that can sufficiently avoid CO poisoning of the anode electrode of the polymer electrolyte fuel cell increases. Further, as described in claim 5,
When the molar ratio of [O ₂ ] / [CO] is in the range of 0.5 to 2, it is more advantageous in terms of efficiency of the fuel cell system and poisoning of the anode of the polymer electrolyte fuel cell. .

[0009] As described in claim 6,
In the CO removal device, a CO selective oxidizer that removes CO in the reformed gas by performing a selective oxidation reaction of CO by adding an oxidizing agent is used in a plurality of stages, and the CO in the reformed gas introduced into the CO removal device is used. The sum of the oxidizing agents added to CO in all CO selective oxidizers is [O ₂ ] / [CO] as oxygen.
Preferably, the molar ratio is in the range of 0.5 to 2. This is preferable in terms of system efficiency, and the CO of the anode electrode of the polymer electrolyte fuel cell is preferable.
After poisoning, a favorable situation can be achieved. [O
₂ ] / [CO] molar ratio, when the upper limit is higher than 2,
The amount of hydrogen lost by the oxidation reaction of hydrogen, which is a side reaction, increases, and the efficiency of the fuel cell system decreases. On the other hand, if the lower limit is lower than 0.5, the CO is reduced to a level that can sufficiently avoid CO poisoning of the anode electrode of the polymer electrolyte fuel cell.
Cannot be removed. Even in this case, as described in claim 7, the [O ₂ ] / [CO]
When the molar ratio is in the range of 0.5 to 1.5, it is further advantageous in terms of efficiency of the fuel cell system and poisoning of the anode electrode of the polymer electrolyte fuel cell.

[0010] Further, as described in claim 8, the CO removal device comprises two stages of a CO selective methanator and a CO selective oxidizer, and a CO selective methanation reaction for performing a CO selective methanation reaction in a preceding stage. A methanizer, and a CO selective oxidizer that performs a selective oxidation reaction of CO by adding an oxidizing agent in the subsequent stage,
CO in the reformed gas introduced into the CO removal device is C
When the amount of the oxidizing agent added in the O removing device is [O 2
[ ₂ ] / [CO] molar ratio is preferably 2 or less. By doing so, the amount of hydrogen consumed can be reduced by reducing the amount of the oxidizing agent added to the system. If it is higher than the above upper limit, the amount of hydrogen lost by the oxidation reaction of hydrogen as a side reaction increases, and the efficiency of the fuel cell system decreases. [O ₂ ] / [CO]
The lower limit of the molar ratio is about 0.05. In this case, as described in claim 9, the [O ₂ ] / [C
[O] The molar ratio is preferably in the range of 0.5 or less, and a decrease in the efficiency of the fuel cell system can be further suppressed.

[0011] As a system adopting the driving method described in claim 1, as described in claim 10,
A desulfurization device for desulfurizing the raw fuel, a steam reforming device for reforming the desulfurized raw fuel to a reformed gas containing hydrogen as a main component,
In a polymer electrolyte fuel cell system having at least a CO removing device for reducing the CO concentration in the reformed gas, the sulfur content of the raw fuel is 1 vol. a desulfurization device for desulfurization to ppb or less, and a relationship between the amount of hydrocarbons contained in the raw fuel and the amount of steam supplied to the reformer provided in the downstream of the desulfurization device, In the case where the number of moles of water vapor per mole of carbon is represented by S / C, a reformer operated with the S / C set to 0.7 to 3.0 is provided. Thus, a polymer electrolyte fuel cell system capable of obtaining the functions and effects described in the method of the first aspect can be obtained. Further, a system using the method described in claim 2 includes claim 1.
As described in 1, the sulfur content of the fuel is reduced to 0.1 vol. ppb or less,
The system can be constructed by performing steam reforming. As the desulfurization device used in such a system, as described in claim 12, copper-
A desulfurizer filled with a zinc-based desulfurizing agent can be used. Further, as described in claim 13, the desulfurization apparatus may be constituted by a hydrodesulfurizer and a desulfurizer filled with a copper-zinc desulfurizing agent. This is because the desulfurization performance is excellent. Here, the desulfurization device may be a seventeenth aspect.
As described in the desulfurization apparatus copper-zinc-based desulfurization agent, a desulfurization agent obtained by hydrogen reduction of a copper oxide-zinc oxide mixture prepared by a coprecipitation method using a copper compound and a zinc compound, Alternatively, a desulfurizing agent obtained by hydrogen reduction of a copper oxide-zinc oxide-aluminum oxide mixture prepared by a coprecipitation method using a copper compound, a zinc compound and an aluminum compound is preferable. The choice of such a desulfurizing agent,
This is because the combination can provide a desulfurization device that easily realizes the desulfurization performance required by the present application. On the other hand, as the reformer, a reformer filled with a Ru-based catalyst or a Ni-based catalyst can be used. Further, as the CO removing device, Ru, Pt,
A single-stage or multiple-stage CO selective oxidizer filled with a catalyst supporting a metal containing at least one of Rh and Pd can be employed. In this case, there is an advantage that CO poisoning of the anode catalyst of the polymer electrolyte fuel cell can be sufficiently prevented.
As such a CO removing device, the CO removing device may be Ru, Pt, R
a CO selective methanator packed with a catalyst supporting a metal containing at least one of h, Pd and Ni,
It is preferable that a CO selective oxidizer filled with a catalyst supporting a metal containing at least one of Ru, Pt, Rh, and Pd is used in a subsequent stage. In this case, C
It is possible to reduce the amount of the oxidizing agent supplied to the O removing device, and consequently suppress the hydrogen consumption, thereby contributing to the improvement of the efficiency of the system. In the present invention, the unit “vol.ppb” indicating the sulfur concentration means (capacity ppb).

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the polymer electrolyte fuel cell system of the present invention will be described below with reference to the drawings.
FIG. 1 shows a polymer electrolyte fuel cell system 100 in which a desulfurizer 5, a heat exchanger 6,
Reforming device 3 for performing steam reforming, CO shift device 7 and CO
With the removal device 8, the generated hydrogen-rich gas is
It is configured to supply to the anode 1a side of the polymer electrolyte fuel cell 1. Further, a water circulation system 20 for steam reforming and cooling water is provided, and water from the water tank 21 is supplied to the reforming device 3 for reforming steam (in the reforming device 3, water is In the state of heated and steam, steam reformer 3
a) is supplied, and is supplied as cooling water for the polymer electrolyte fuel cell 1. As described above, since the operating temperature of this polymer electrolyte fuel cell is about 80 ° C., it is difficult for the polymer electrolyte fuel cell to directly produce reforming steam by exhaust heat of the fuel cell. Can not do. This is
This is one of the factors that lowers the power generation efficiency of the system.

Hereinafter, the outline of each device constituting the system 100 and the operation state thereof will be described. 1 Desulfurization unit 5 This desulfurization unit 5 converts a raw fuel containing hydrocarbon as a main component and a sulfur content to a sulfur content of 1 vol. ppb or less, more preferably 0.1 vol. The purpose is to reduce it to ppb or less. Such desulfurization is called higher desulfurization. Such a high-order desulfurization method is disclosed in JP-A-1-123627.
And desulfurization using a copper-zinc-based and copper-zinc-aluminum-based desulfurizing agent disclosed in JP-A-2001-123628 and JP-A-1-123628. In this type of desulfurization apparatus 5, a high-order desulfurizer 5a in which a desulfurizing agent as described below is stored in a reaction vessel (not shown) is used. The example shown in FIG. 2A is an example using only the high-order desulfurizer 5a, and FIG. 2B is an example using both the high-order desulfurizer 5a and the adsorber 5b. Fig. 2 (b)
The example in which the hydrodesulfurizer 5c is used in combination with the above configuration is shown.

The desulfurizing agent used in the high-order desulfurizer 5a is prepared by the following method. (1) Copper-zinc desulfurizing agent An aqueous solution containing a copper compound (eg, copper nitrate, copper acetate, etc.) and a zinc compound (eg, zinc nitrate, zinc acetate, etc.) and an alkaline substance (eg, sodium carbonate, potassium carbonate, etc.)
Is formed by a conventional coprecipitation method using an aqueous solution of The purified precipitate is dried and calcined at about 300 ° C. to obtain a copper oxide-zinc oxide mixture (generally copper: zinc = 1: about 0.3 to 10, preferably 1: about 0.5 to 3,
More preferably 1: after obtaining about 1 to 2.3), an inert gas (for example, nitrogen gas or the like) such that the hydrogen content becomes 6% by volume or less, more preferably about 0.5 to 4% by volume. The mixture is reduced at about 150 to 300 ° C. in the presence of hydrogen gas diluted by the above method. The copper-zinc desulfurizing agent thus obtained may contain a certain metal oxide such as chromium oxide as another carrier component. (2) Copper-zinc-aluminum desulfurizing agent Copper compound (eg, copper nitrate, copper acetate, etc.), zinc compound (eg, zinc nitrate, zinc acetate, etc.) and aluminum compound (eg, aluminum nitrate, sodium aluminate, etc.) And an aqueous solution of an alkaline substance (for example, sodium carbonate, potassium carbonate, etc.) containing water is used to cause precipitation by a common coprecipitation method. The formed precipitate is dried and calcined at about 300 ° C. to obtain copper oxide-zinc oxide-
An aluminum oxide mixture (generally copper: zinc: aluminum = 1: about 0.3-10: about 0.05-2, more preferably 1: about 0.6-3: about 0.3-1) After obtaining, the hydrogen content is 6% by volume or less, more preferably 0.5 to
The mixture is reduced at about 150 to 300 ° C. in the presence of hydrogen gas diluted to about 4% by volume with an inert gas. The copper-zinc-aluminum desulfurizing agent thus obtained may contain a certain metal oxide, for example, chromium oxide, as another carrier component.

The copper desulfurizing agent obtained by the above methods (1) and (2) is characterized in that fine-particle copper having a large surface area is uniformly dispersed in zinc oxide (and aluminum oxide), and It is in a highly active state due to chemical interaction with zinc (and aluminum oxide). Therefore, as shown in FIG. 2 (a), even when these desulfurizing agents are simply used, the sulfur content in the raw fuel mainly containing hydrocarbons is 1 vol. ppb or less, and easily under 0.1 vol. ppb or less, and it is also possible to reliably remove hardly decomposable sulfur compounds such as thiophene. In particular, in the case of a copper-zinc-aluminum desulfurizing agent, there is obtained an advantage that due to the action of aluminum oxide, heat resistance is excellent, and a decrease in strength at a high temperature and a decrease in sulfur adsorption power can be remarkably reduced.

The high-order desulfurization using the above-mentioned copper-based desulfurizing agent is usually performed at room temperature to about 400 ° C., preferably 200 to 350 ° C.
° C, pressure normal pressure-about 50 kg / cm ² · G, GHSV =
Under conditions of about 5000 / h or less, usually 0.1 vo
l. It can be desulfurized to ppb or less.

FIG. 2B shows that the total sulfur compound content is 10%.
vol. ppm or more, but the content of the hardly decomposable organic sulfur compound is 10 vol. The case corresponding to the raw fuel which is less than ppm is shown. In this case, first, the raw fuel is subjected to primary adsorption desulfurization (performed in the adsorber 5b) by a conventional method using, for example, a ZnO-based desulfurizing agent. The conditions at this time are not particularly limited, but in order to maximize the sulfur compound adsorption effect in the subsequent high-order desulfurization step, the sulfur content in the hydrocarbon is set to 1 to 0.1 vol. It is desirable to reduce it to about ppm. Therefore, in the primary adsorptive desulfurization, a temperature of 250 to 400 in the presence of a ZnO-based desulfurizing agent is used.
℃, pressure normal pressure ~ 10kg / cm ² · G, GHS
It is preferable to employ a condition of about V1000 / h, but it is of course possible to employ other conditions. Next, the raw fuel after the first adsorptive desulfurization was sent to the same high-order desulfurization step as described above to reduce the sulfur content to 1 vol. ppb or less, preferably 0.1 vol. After reducing to ppb or less, steam reforming is performed by a conventional method.

FIG. 2 (c) shows that the content of all sulfur compounds mainly composed of hardly decomposable organic sulfur compounds is 10 vol. ppm
This is a configuration for coping with the case of the raw fuel described above.
In this case, first, the raw fuel is heated to a temperature of 350 to 400 in the presence of a catalyst such as a Ni-Mo system according to a conventional method.
℃, pressure normal pressure ~ 10kg / cm ² · G, GHS
Hydrodesulfurization is performed under the condition of about V3000 / h or less (this is performed by the hydrodesulfurizer 5c). Subsequently, FIG.
After performing the same primary adsorptive desulfurization as described in relation to (b), high-order desulfurization is performed to reduce the sulfur content in the hydrocarbon to 1 v.
ol. ppb or less, preferably 0.1 vol. ppb or less. At this time, since the hydrocarbon subjected to the adsorption desulfurization treatment has a high temperature, it is preferable to perform a high-order desulfurization using a copper-zinc-aluminum desulfurizing agent having excellent heat resistance.

The raw fuel desulfurized as described above is preheated in the heat exchanger 6 and then guided to the steam reformer 3. 2. Steam Reforming Apparatus 3 The steam reforming apparatus 3 is a conventional one and includes a steam reformer 3a having a steam reforming catalyst (Ru catalyst, Ni catalyst, etc.) therein, and a catalyst filling section. And a steam reformer burner 3b for heating the steam. The steam reformer burner 3b has a configuration in which raw fuel and air are supplied for combustion. Further, the steam reformer 3a is configured to be supplied with the steam described above. Here, the reforming conditions (reaction conditions) in the steam reformer 3a are a temperature of about 400 to 800 ° C., a normal pressure of about 10 kg / cm ² · G, a GHSV of 5000 / h.
The condition is less than or equal to. By this step, hydrocarbons can be reformed to hydrogen. The reformed gas is used for preheating the raw fuel supplied to the steam reformer 3 in the heat exchanger 6,
The CO is supplied to the CO conversion device 7 and the CO removal device 8 in order.

3 CO shift unit 7 In the CO shift unit 7, CO remaining in the reformed gas
Is converted to CO ₂ . The CO shift apparatus 7 is a common type and is operated under normal conditions. In the present application, a catalyst such as a copper / zinc catalyst is used as the catalyst.

4 CO Removal Device 8 As the CO removal device 8, a CO selective methanator (1) and / or a CO selective oxidation device (2) are used.

(1) CO selective methanation reactor In the CO selective methanation reactor, one or more metals selected from Ru, Pt, Rh, Pd, and Ni are used as a selective methanation reaction catalyst such as alumina. 0.1-5% for carrier
The supported catalyst is stored. Here, GHSV (Gas Hourly Space Vel) in the catalytic reaction is used.
ocity: flow rate of gas to be treated / catalyst volume (1 / h))
Is 500 to 100000 / h (preferably 3000 to
Selective methanation of CO is performed by setting the reaction temperature (° C.) within a range of 160 to 230 ° C. (setting which is practically appropriate).

(2) CO selective oxidizer In the CO selective oxidizer, Ru, Pt,
A catalyst in which 0.1 to 5% of one or more metals selected from Rh, Pd, and Ni are supported on a carrier such as alumina is stored. Here, GHSV (Gas Hourly S) in an oxidation catalytic reaction under the supply of air as an oxidizing agent.
(space velocity: flow rate of gas to be treated / catalyst volume (1 / h)) is set in the range of about 500 to 100,000 / h, and the reaction temperature (° C.) is set in the range of 50 to 250 ° C. (practically). (Appropriate setting for practical use) to perform selective oxidation of CO while supplying an oxidizing agent. In the present application, when the CO selective methanizer (1) and the CO selective oxidizer (2) are used in combination as described above, the configuration is such that the former is disposed in the former stage and the latter is disposed in the latter stage, thereby removing CO. The amount of the oxidizing agent required for the entire apparatus can be reduced. In this way, the system is operated by receiving the desulfurization treatment and supplying the hydrogen-rich reformed gas having a low CO concentration to the anode 1a of the polymer electrolyte fuel cell.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. Hereinafter, the present invention will be described in more detail based on examples and comparative examples, but the present invention is not limited to these examples.

Example 1 A test was conducted using a polymer electrolyte fuel cell system having a desulfurization device 5 shown in FIG. As the desulfurization device 5, an aqueous solution of sodium carbonate was added as an alkaline substance to a mixed aqueous solution containing copper nitrate, zinc nitrate and aluminum nitrate, and the resulting precipitate was washed and filtered. 1
錠 inch tablet size, fired at about 400 ° C., and then fired (copper oxide 45%, zinc oxide 45%,
300% of a copper-zinc-aluminum desulfurizing agent obtained by reducing aluminum oxide (10%) at a temperature of about 200 ° C. using a nitrogen gas containing 2% by volume of hydrogen, and obtaining a commercial Ni
300 cc of Mo-based hydrodesulfurization catalyst and ZnO adsorption desulfurizer 6
A desulfurization unit charged on the downstream side of 00 cc was used. Also,
As a steam reformer 3, a Ru catalyst (Ru 2 wt%, A
A steam reformer filled with 300 cc (l ₂ O ₃ supported) was used. As raw fuel 2, a city gas 13A (0.18 m ³ / h) composed of the components shown in Table 1 below was preheated to about 380 ° C., and then 2% by volume of the recycled fuel based on the raw fuel (ie, The fuel gas (recycled from the CO shift unit 7) was introduced into the desulfurization unit 5 for desulfurization.
The desulfurized gas is converted to S / C (carbon 1 in raw fuel hydrocarbons).
(Moles of water vapor per mol) = 2.2, reaction temperature 450
° C (inlet) and 665 ° C (outlet), reaction pressure 0.2 kg
/ Cm ² · G and subjected to a steam reforming reaction. The steam reformed fuel gas passes through a CO shifter 7 and a CO remover 8, and is led to the anode 1a of the polymer electrolyte fuel cell main body, where it reacts with oxygen in the air introduced into the cathode 1b. , Took out the electrical energy. In this case, as the CO removal device 8, a Ru catalyst or the like (Rulwt
%, Al ₂ O ₃ supported)
O ₂ was used at 3,168 ° C. In the above test,
The sulfur content in the gas at the outlet of the desulfurization device 5 was measured over time, and even after 1000 hours, the sulfur content was 0.1 vol.
l. ppb or less. In addition, the steam reforming catalyst comprises 1
Even after the elapse of 000 hours, no deterioration in the catalytic activity was observed, and the activity was maintained the same as immediately after the start of the reaction, and the polymer electrolyte fuel cell operated normally.

[0026]

Table 1 Methane 86.9% by volume Ethane 8.1% by volume Propane 3.7% by volume Butane 1.3% by volume Odorant Dimethyl sulfide 3mg-S / Nm ³ t-Butyl mercaptan 2mg-S / Nm ³

Comparative Example 1 The procedure of Example 1 was repeated except that a desulfurizing apparatus 5 was used in which the same amount of a commercially available ZnO adsorption desulfurizing agent was used instead of the copper-zinc-aluminum desulfurizing agent of Example 1.
An experiment similar to that of Example 1 was performed using a polymer electrolyte fuel cell system (FIG. 1) similar to that of Example 1. As a result, the sulfur content of the gas at the outlet of the desulfurization device immediately after the start of the reaction was 0.1%.
2 vol. ppm, which remained almost unchanged after that, but after 500 hours, the slip of methane increased at the outlet of the steam reformer 3 and the electric output of the polymer electrolyte fuel cell 1 began to decrease. I had to stop. At this time, the reforming catalyst was almost completely degraded.

Example 2 As raw fuel 2, 0.18 L of full-range naphtha (sulfur content: 100 vol. Ppm)
/ H was vaporized and preheated to 380 ° C., and then introduced into a desulfurization apparatus 5 similar to that of Example 1 together with 2% by volume of a recycled reforming gas with respect to the raw fuel for desulfurization. The desulfurized gas was subjected to a steam reforming reaction or the like in the same manner as in Example 1 to operate a polymer electrolyte fuel cell. In the above test, the sulfur content in the gas at the outlet of the desulfurization device was measured over time.
After the elapse of time, the sulfur content is 0.1 vol. ppb or less. The steam reforming catalyst did not show any deterioration in catalytic activity even after 1000 hours, and maintained the same activity as immediately after the start of the reaction, and the polymer electrolyte fuel cell operated normally.

Comparative Example 2 Using the same system as in Comparative Example 1, the same test as in Example 2 was performed. As a result, the sulfur content of the gas at the outlet of the desulfurization device immediately after the start of the reaction was 0.1%.
4 vol. ppm, which was almost unchanged after that, but after 200 hours, the slip of the raw hydrocarbons increased at the outlet of the steam reformer 3, and the electric output of the polymer electrolyte fuel cell 1 began to decrease, and eventually I had to stop the system. At this time, the reforming catalyst was almost completely degraded.

Example 3 As raw material 2, 0.18 L / h of LPG (sulfur content: 5 vol. Ppm) was vaporized.
After preheating to 380 ° C., the raw fuel was introduced into a desulfurization apparatus 5 similar to that of Example 1 together with 2% by volume of a recycled reformed gas for desulfurization. The desulfurized gas was subjected to a steam reforming reaction or the like in the same manner as in Example 1, and the polymer electrolyte fuel cell 1 was operated. In the above test, the sulfur content in the gas at the outlet of the desulfurization mechanism was measured over time, and even after 1000 hours, the sulfur content was 0.1 vol. ppb or less. In addition, the catalyst activity of the steam reforming catalyst was not deteriorated even after 1000 hours, and the activity was maintained the same as immediately after the start of the reaction. Thus, the polymer electrolyte fuel cell 1 operated normally.

Comparative Example 3 Using the same system as in Comparative Example 1, the same test as in Example 3 was performed. As a result, the gas sulfur content at the desulfurizer outlet immediately after the start of the reaction was 0.2
vol. ppm, which was almost unchanged after that, but after 500 hours, the slip of the raw material hydrocarbons increased at the outlet of the steam reformer 3, and the electric output of the polymer electrolyte fuel cell 1 began to decrease. I had to stop the equipment. At this time, the reforming catalyst was almost completely degraded.

Example 4 In Example 1, as a desulfurizer 5, an aqueous solution of sodium carbonate was added as an alkaline substance to a mixed aqueous solution containing copper nitrate, zinc nitrate and aluminum nitrate, and the resulting precipitate was washed and filtered. Thereafter, it is tablet-molded to a size of 1/8 inch high x 1/8 inch diameter, fired at about 300 ° C, and then fired (copper oxide 45
%, Zinc oxide 45%, aluminum oxide 10%) using a nitrogen gas containing 2% by volume of hydrogen at a temperature of about 200 ° C. to obtain a copper-zinc-aluminum desulfurizing agent 300
The same test as in Example 1 was performed using a desulfurization apparatus filled with only cc. As a result, as in Example 1, the sulfur content in the gas at the outlet of the desulfurizer was set to 0.1 vol. It was found that desulfurization could be carried out to ppb or less and deterioration of the steam reforming catalyst could be suppressed, and the polymer electrolyte fuel cell 1 operated normally.

Example 5 A test was performed using the fuel cell power generation system shown in FIG. 1 having the desulfurization device 5 shown in FIG. In addition, as a desulfurization device 5, an aqueous solution of sodium carbonate was added as an alkaline substance to a mixed aqueous solution containing copper nitrate, zinc nitrate and aluminum nitrate, and the resulting precipitate was washed and filtered.
錠 inch tablet, baked at about 300 ° C., and then baked (copper oxide 45%, zinc oxide 45%,
A desulfurization apparatus filled with 300 cc of only a copper-zinc-aluminum desulfurizing agent obtained by reducing aluminum oxide (10%) at a temperature of about 200 ° C. using nitrogen gas containing 2% by volume of hydrogen was used. Further, as the steam reformer 3, Ru
A steam reformer packed with 300 cc of a catalyst (Ru ₂ wt%, loaded with Al ₂ O ₃ ) was used. As raw fuel 2, city gas 13A (0.18 m ³ /
h) was preheated to about 300 ° C., and then introduced into the desulfurizer 5 to desulfurize. The desulfurized gas was subjected to S / C (moles of water vapor per mole of carbon in the raw fuel hydrocarbon) = 2.2,
The steam reforming reaction was performed under the conditions of a reaction temperature of 450 ° C. (inlet) and 665 ° C. (outlet) and a reaction pressure of 0.2 kg / cm ² · G. The steam reformed fuel gas passes through a CO shift device 7 and a CO removing device 8 and is led to the anode 1a of the polymer electrolyte fuel cell 1, where it reacts with oxygen in the air introduced into the cathode 1b. , Took out the electrical energy. Here, the CO conversion device 7 and the CO removal device 8 used were those used in Example 1. In the above test, the sulfur content in the gas at the outlet of the desulfurization device was measured with time, and even after 1000 hours, the sulfur content was 0.1 v
ol. ppb or less. Also, the steam reforming catalyst is
No deterioration of the catalyst activity was observed even after 1000 hours, and the same activity as that immediately after the start of the reaction was maintained, and the polymer electrolyte fuel cell 1 operated normally.

Example 6 A CO removing apparatus 8 for performing selective oxidation of CO by adding air corresponding to [O ₂ ] / [CO] (molar ratio) = 2 using a 1 wt% Ru / Al ₂ O ₃ catalyst. In the polymer electrolyte fuel cell system similar to that of Example 5 using city gas 13A as a raw fuel, the condition of S / C = 2.5 is smaller than that of S / C = 3.5. The power generation efficiency (DC end, LHV) improved by about 1.2%. (Power generation efficiency improved from 40.8% to 42.0%)

[Embodiment 7] CO removal device 8 is 1 wt% R
It consists of a two-stage CO selective oxidizer using a u / Al ₂ O ₃ catalyst, and the sum of the amount of air added by the first-stage CO selective oxidizer and the amount of air added by the second-stage CO selective oxidizer is [O ₂ ] / [CO] (molar ratio) = 1.2 with respect to the CO concentration at the inlet of the CO removing device (CO concentration at the outlet of the CO shift converter 7).
In a polymer electrolyte fuel cell system similar to that of Example 5 using city gas 13A as a raw fuel and capable of removing CO by adding air corresponding to , S / C = 3.5, the power generation efficiency (DC end, LHV) was improved by about 1.7%. (Power generation efficiency improved from 41.0% to 42.7%)

[Embodiment 8] The CO removing device 8 has two stages of a CO selective methanator and a CO selective oxidizer, and in the first stage, CO selective methane using a 1 wt% Ru / Al ₂ O ₃ catalyst. In the second stage, CO is selectively oxidized using a 1 wt% Ru / Al ₂ O ₃ catalyst, thereby reducing the CO concentration at the inlet of the CO remover (CO concentration at the outlet of the CO shift converter 7) by [O ₂ ] / [CO] (molar ratio) = Solid polymer fuel cell similar to Example 5 using city gas 13A as a raw fuel and capable of removing CO by adding air corresponding to 0.2 with a CO removing device In the system, under the condition of S / C = 2.2,
Compared to the condition of S / C = 3.5, the power generation efficiency (DC end, L
HV) improved by about 2.1%. (Power generation efficiency is 41.1%
→ Improved to 43.2%)

[Embodiment 9] In a polymer electrolyte fuel cell system using natural gas as fuel, a sulfur content of 1 vol. When steam reforming was performed after desulfurization to ppb or less, the amount of the steam reforming catalyst could be reduced to about 2/3 when a conventional desulfurizing agent was used.

[Other Embodiments] In the present invention, natural gas, ethane, propane, butane, LPG
(Liquefied petroleum gas), light naphtha, heavy naphtha, light kerosene, coke oven gas, various city gases, and the like.

[0039]

According to the present invention, the S / C of the reformer for performing steam reforming can be reduced,
The power generation efficiency of the entire system could be improved. Further, since sulfur poisoning of the steam reforming catalyst and deposition of carbon on the catalyst are extremely effectively prevented, the required amount of steam can be reduced. That is, in the conventional steam reforming method, in order to perform the operation for a long time, the S / C (the number of moles of steam per mole of carbon in the hydrocarbon) is 3 to 3.
Although it was necessary to be higher than 5, according to the method of the present invention,
Even when the S / C is 0.7 to 3.0, stable operation can be performed for a long time, and a highly efficient polymer electrolyte fuel cell system using a hydrocarbon such as natural gas as a raw fuel can be realized. It became. Further, since the sulfur poisoning of the steam reforming catalyst and the deposition of carbon on the catalyst are extremely effectively prevented, the required amount of the reforming catalyst is required to greatly reduce the sulfur poisoning content of the steam reforming catalyst. And the size of the conventional polymer electrolyte fuel cell system using a hydrocarbon or the like as a raw fuel can be further reduced. Further, the sulfur content in the hydrocarbon is 1 vol. If a high-order desulfurizing agent capable of desulfurizing to ppb or less is used, even if the catalyst is used for a long period of thousands or tens of thousands of hours, the slip of sulfur can be suppressed. Therefore, CO removal using a noble metal catalyst such as Ru is required. The performance of the vessel can be maintained over a long period of time.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a configuration of a polymer electrolyte fuel cell system of the present application.

FIG. 2 is a diagram showing an embodiment of a desulfurization device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 solid polymer fuel cell 2 raw fuel 4 air 5 desulfurization device 6 heat exchanger 7 CO conversion device 8 CO removal device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Minoru Suzuki, Inventor Minoru Suzuki 4-1-2, Hirano-cho, Chuo-ku, Osaka, Osaka Inside Osaka Gas Co., Ltd. (72) Inventor Osamu Yamazaki 4-chome, Hirano-cho, Chuo-ku, Osaka-shi, Osaka 1-2-2 Osaka Gas Co., Ltd. (72) Inventor Takeshi Ken Tabata 4-1-2 Hirano-cho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka Gas Co., Ltd. 4G040 EA03 EA06 EB01 EB03 EB16 EB32 EB43 EC03 4H060 AA01 BB08 BB12 CC18 FF02 GG02 5H026 AA06 5H027 AA06 BA01 BA09 BA16 BA17 CC06

Claims (16)

[Claims] 1. A desulfurization device for desulfurizing raw fuel, a reforming device for reforming desulfurized raw fuel into a reformed gas containing hydrogen as a main component, and a CO removing device for reducing a CO concentration in the reformed gas A solid polymer fuel cell system having at least a sulfur content of the raw fuel in a desulfurization device of 1 vol.
After desulfurization to ppb or less, in relation to the amount of hydrocarbons contained in the raw fuel and the amount of steam supplied to the reformer, the number of moles of steam per mole of carbon in the raw fuel is S / C, the S / C in the reformer is set to 0.7 to 3.0, the reformer is operated to perform steam reforming, and the reformed gas is obtained to obtain a solid. A method for operating a solid polymer fuel cell system, wherein the method is supplied to a polymer fuel cell. 2. The desulfurization device reduces the sulfur content of the raw fuel to 0.1 vol. 2. The method for operating a polymer electrolyte fuel cell system according to claim 1, wherein steam reforming is performed after the pressure is reduced to ppb or less. 3. The S / C in the reformer,
The reformed gas is obtained by performing steam reforming by operating a reformer at 2.0 to 2.8 to obtain the reformed gas.
An operation method of the polymer electrolyte fuel cell system according to the above. 4. A reformer introduced into a CO removal device, wherein the CO removal device is provided with a CO selective oxidizer that removes CO in a reformed gas by performing a selective oxidation reaction of CO by adding an oxidizing agent. the amount of oxidizing agent added in CO remover for CO in the _{gas, [O 2] / [CO} ] claims, characterized in that in the range of 0.5 to 3 in molar ratio 1 as an oxygen 4. The method for operating the polymer electrolyte fuel cell system according to 3. 5. The [O ₂ ] / [CO] molar ratio is 0.5
5. The operating method for a polymer electrolyte fuel cell system according to claim 4, wherein 6. A CO selective oxidizer for removing CO in a reformed gas by performing a selective oxidation reaction of CO by adding an oxidizing agent to the CO removing device and introducing the CO into the CO removing device. All CO for the CO in the reformed gas
The total amount of the oxidizing agent added in the selective oxidizer is [O
_The method for operating a polymer electrolyte fuel cell system according to any one of claims 1 to 3, wherein the molar ratio of [ ₂ ] / [CO] is in the range of 0.5 to 2. 7. The [O ₂ ] / [CO] molar ratio is 0.5
7. The operating method for a polymer electrolyte fuel cell system according to claim 6, wherein the range is from 1.5 to 1.5. 8. The CO removal device is composed of a CO selective methanator and a CO selective oxidizer in two stages, a CO selective methanator for performing a selective methanation reaction of CO in a preceding stage, and an oxidizing agent in a latter stage. A CO selective oxidizer for performing a selective oxidation reaction of CO is disposed, and CO in the reformed gas introduced into the CO removing device is disposed.
Adding a CO remover to the amount of the oxidizing _{agent, [O 2] / [CO} ] a polymer electrolyte fuel cell of claim 1, wherein the molar ratio is equal to or is 2 or less as an oxygen How the system operates. 9. The [O ₂ ] / [CO] molar ratio is 0.5
The method for operating a polymer electrolyte fuel cell system according to claim 8, wherein the range is as follows. 10. A desulfurization device for desulfurizing raw fuel, a reforming device for reforming desulfurized raw fuel into a reformed gas containing hydrogen as a main component, and CO removal for reducing the CO concentration in the reformed gas A solid polymer fuel cell system having at least a sulfur content of 1 vol. pp
b, a desulfurization device for desulfurizing the raw fuel, and a desulfurization device provided downstream of the desulfurization device, wherein the amount of hydrocarbons contained in the raw fuel and the amount of steam supplied to the reforming device, The number of moles of water vapor per mole of carbon in S / C
A polymer electrolyte fuel cell system comprising a reformer operated at a S / C of 0.7 to 3.0 when expressed by: 11. The desulfurization device reduces the sulfur content of the fuel to 0.1 vol. The polymer electrolyte fuel cell system according to claim 10, wherein steam reforming is performed after the pressure is reduced to ppb or less. 12. The desulfurizer according to claim 1, wherein the desulfurizer is a desulfurizer filled with a copper-zinc desulfurizing agent.
The polymer electrolyte fuel cell system according to 0,11. 13. The polymer electrolyte fuel cell system according to claim 10, wherein said desulfurization device comprises a hydrodesulfurizer and a desulfurizer filled with a copper-zinc desulfurizing agent. . 14. The desulfurizing apparatus, wherein the copper-zinc desulfurizing agent is:
Copper oxide prepared by a coprecipitation method using a copper compound and a zinc compound-a desulfurization agent obtained by hydrogen reduction of a zinc oxide mixture, or copper oxide prepared by a coprecipitation method using a copper compound, a zinc compound and an aluminum compound- 14. The polymer electrolyte fuel cell system according to claim 12, which is a desulfurizing agent obtained by reducing a zinc oxide-aluminum oxide mixture with hydrogen. 15. The device for removing CO, Ru, Pt, R
15. The polymer electrolyte fuel cell according to claim 10, wherein the CO selective oxidizer packed with a catalyst supporting a metal containing at least one of h and Pd is composed of one or more stages. system. 16. The device for removing CO, Ru, Pt, R
a CO selective methanator packed with a catalyst supporting a metal containing at least one of h, Pd and Ni,
The CO selective oxidizer packed with a catalyst supporting a metal containing at least one of Ru, Pt, Rh, and Pd is used in a subsequent stage, and is configured by using a subsequent stage.
5. The polymer electrolyte fuel cell system according to 4.