JP5478450B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system.

  As techniques for reforming organic compounds such as hydrocarbon compounds to convert them into synthesis gas or hydrogen, methods such as a steam reforming method, a partial oxidation method, and an autothermal reforming method are known. Among them, the steam reforming method has already been put into practical use, but since it is a reaction with a relatively large endotherm, the heat supply system such as a heat exchanger has a heavy load and takes time to start up. There is a problem. On the other hand, the partial oxidation method has a very short start-up time as opposed to the steam reforming method. However, since the heat generated by the oxidation is large, the partial oxidation method is difficult to control and has problems such as suppression of soot generation. In contrast, the autothermal reforming method, which combines the oxidation reaction and steam reforming reaction, balances the reaction heat by advancing steam reforming with the heat generated at this time while oxidizing part of the fuel. Since the start-up time is relatively short and control is easy, it has recently been attracting attention as a method for producing hydrogen for fuel cells.

As a catalyst used in such an autothermal reforming method, a catalyst in which a noble metal is supported on γ-alumina, such as Rh / γ-Al ₂ O ₃ , has been conventionally known (for example, Patent Document 1). reference). However, when such an expensive noble metal is used, the cost of the catalyst increases, which is economically disadvantageous. With the recent widespread use of fuel cells, there is a need to reduce the cost of the catalyst. Therefore, it is conceivable to use inexpensive Ni instead of a noble metal such as Rh.

JP 2002-336702 A

However, when a catalyst made of Ni / γ-Al ₂ O _{3 in} which Ni is supported on γ-alumina instead of Rh is used, Ni is oxidized by the oxidation treatment and the steam reforming activity is lost. There is. When such a catalyst is used as an autothermal reforming catalyst, Ni in the reformer is oxidized at the stage of partial oxidation reforming reaction, and the reforming reaction is performed at the stage of steam reforming reaction. There will be less catalyst to contribute. Therefore, when a catalyst made of Ni / γ-Al ₂ O ₃ is used, there is a problem that sufficient reforming reaction is not performed and the performance cannot be sufficiently exhibited as an autothermal reforming fuel cell system. Alternatively, in order to perform a sufficient reforming reaction, it is necessary to increase the amount of catalyst in the reformer in order to secure a catalyst that can contribute to the steam reforming reaction without being oxidized by Ni. When the amount of the catalyst is increased, the reformer becomes larger, the cost increases, and there is a problem that the start of the fuel cell system is delayed due to the time required for heating in the reformer.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a fuel cell system capable of sufficiently ensuring performance even when a Ni-based catalyst is used. To do.

Here, as a result of earnest research, the inventors of the present invention have obtained from La _1-x Sr _x AlO ₃ (x = 0.05 to 0.3) obtained by replacing Sr with perovskite oxide LaAlO _3. It was found that the oxidation of Ni can be suppressed when a catalyst having 0.05 to 20% by mass of Ni supported on the carrier is used. Further, it has been found that the performance of an autothermal reforming fuel cell system can be sufficiently secured by using such a catalyst.

Accordingly, a fuel cell system according to the present invention includes a reformer having an autothermal reforming catalyst that converts fuel gas into a reformed gas containing carbon monoxide and hydrogen, a fuel cell that generates power using the reformed gas, and The autothermal reforming catalyst is La _1-x Sr _x AlO ₃ (x = 0.05 to 0.3) obtained by replacing Sr with perovskite oxide LaAlO _3. The reformer is supplied with fuel gas and oxygen-containing gas and heated to carry out a partial oxidation reforming reaction, and is supported by water. Is supplied, and an autothermal reforming reaction is performed, and a steam reforming reaction is performed by stopping the supply of the oxygen-containing gas.

The fuel cell system according to the present invention uses an autothermal forming catalyst that can suppress oxidation despite being Ni-based. Therefore, even when the partial oxidation reforming reaction is performed in the reformer, it is possible to prevent the steam reforming activity from being lost due to oxidation of Ni of the autothermal reforming catalyst in the reformer. For example, when an autothermal reforming catalyst made of Ni / γ-Al ₂ O ₃ is used, there is an autothermal reforming catalyst that cannot contribute to the steam reforming reaction due to oxidation of Ni in the partial oxidation reforming reaction, When the autothermal reforming catalyst according to the present invention (also referred to as “Ni-supported perovskite autothermal reforming catalyst”) is used, reforming is achieved by suppressing the oxidation of Ni in the partial oxidation reforming reaction. The autothermal reforming catalyst over almost the entire region in the vessel can contribute to the steam reforming reaction. As a result, even if an inexpensive autothermal reforming catalyst containing Ni is used, sufficient performance can be exhibited as an autothermal reforming fuel cell system. In addition, since the autothermal reforming catalyst over almost the entire region in the reformer can contribute to the steam reforming reaction, when using an autothermal reforming catalyst made of Ni / γ-Al ₂ O ₃ that easily oxidizes Ni. In comparison, the amount of catalyst in the reformer can be reduced. As a result, it is possible to reduce the size of the reformer and reduce the cost. In addition, by reducing the amount of catalyst, heating in the reformer can be performed in a short time. In an autothermal reforming fuel cell system, heat is exchanged inside the reformer itself (for example, the reformer itself is heated by heat generated by the partial oxidation reforming reaction). By reducing the amount of catalyst, such heat exchange can be easily performed. Therefore, the fuel cell system can be started up quickly.

  According to the present invention, sufficient performance can be ensured even when a Ni-based catalyst is used.

1 is a schematic block diagram showing a fuel cell system according to an embodiment of the present invention. It is a flowchart which shows the system starting method in the fuel cell system 1 of this invention. A reactor autothermal reforming catalyst is filled consisting _{Ni / γ-Al 2 O 3} , autothermal reforming catalyst according to the present embodiment is a schematic diagram showing the reaction in the reactor filled.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

<System configuration>
FIG. 1 is a schematic block diagram showing a fuel cell system according to an embodiment of the present invention. As shown in FIG. 1, the fuel cell system 1 according to the present embodiment includes a reformer 2, a fuel cell 3, a supply unit 4, temperature sensors 5 and 6, and a control unit 7. . The fuel cell system 1 according to the present embodiment performs partial oxidation reforming (POX: Partial Oxdation) and auto thermal reforming (ATR: Auto Thermal Reforming) in the reformer 2 at the start-up of the system. It shifts to quality (SR: Steam Reforming) and generates electricity with the fuel cell 3.

  The reformer 2 converts the fuel gas supplied from the supply unit 4 into a reformed gas containing carbon monoxide and hydrogen, and supplies the reformed gas to the fuel cell 3. The reformer 2 includes a reactor filled with a Ni-supported perovskite autothermal reforming catalyst that converts fuel gas into reformed gas. The autothermal reforming catalyst according to the present embodiment can suppress the oxidation of Ni in the catalyst even at the stage of partial oxidation reforming, and can perform steam reforming in substantially the entire region of the reactor. Is. A detailed description of the autothermal reforming catalyst will be described later.

  The fuel gas supplied to the reformer 2 is composed of hydrocarbon compounds and preferably contains 70% by volume or more of hydrocarbon compounds having 4 or less carbon atoms, more preferably 80% by volume or more, and 85% by volume. %, More preferably 90% by volume or more. Specific examples of the hydrocarbon compound having 4 or less carbon atoms include saturated aliphatic hydrocarbons such as methane, ethane, propane, and butane, and unsaturated aliphatic hydrocarbons such as ethylene, propylene, and butene. In view of the above, methane can be preferably mentioned. The fuel gas according to the present invention is not particularly limited as long as it contains 70% by volume or more of a hydrocarbon compound having 4 or less carbon atoms, but may contain nitrogen gas, carbon dioxide gas, or the like. The fuel gas according to the present invention preferably contains 70% by volume or more of a hydrocarbon compound having 4 or less carbon atoms, and examples thereof include materials that can be obtained industrially at low cost such as natural gas and LPG.

  The fuel cell 3 generates power using the reformed gas supplied from the reformer 2. In the fuel cell system 1 according to the present embodiment, a solid oxide fuel cell (SOFC) is used as the fuel cell 3. The reformed gas from the reformer 2 is supplied to the anode of the fuel cell 3, and the oxygen-containing gas is supplied to the cathode. As the oxygen-containing gas, an oxygen-containing gas such as air or oxygen gas can be used, but air is preferably used from the viewpoint of ease of handling. The fuel cell 3 can supply heat HT to the reformer 2 by igniting and combusting combustible gas discharged from the anode with an igniter or the like. For example, the fuel cell 3 can heat the reformer 2 by burning anode off gas. Further, at the time of start-up, the fuel cell 3 heats the reformer 2 by discharging the fuel gas and air supplied from the supply unit 4 via the reformer 2 and igniting and burning them with an igniter or the like. can do.

  The supply unit 4 supplies fuel gas to the reformer 2. In addition, the supply unit 4 can supply the fuel gas by mixing an oxygen-containing gas, water, or both. The supply unit 4 can start and stop the supply of the oxygen-containing gas and water at a predetermined timing. As the oxygen-containing gas, air or oxygen gas can be used in the same manner as that supplied to the cathode.

  The temperature sensor 5 acquires a temperature at a predetermined position (such as the reformer inlet temperature and the reformer outlet temperature) of the reformer 2. The temperature sensor 6 acquires the temperature at a predetermined position of the fuel cell 3. The temperature sensor 5 can be provided at a plurality of positions with respect to the reformer 2, and the temperature sensor 6 can be provided at a plurality of positions with respect to the fuel cell 3. The temperature sensors 5 and 6 output the acquired temperature to the control unit 7.

  The control unit 7 has a function of controlling the entire fuel cell system 1. For example, a device that performs electronic control (for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), And a device configured to include an input / output interface). The control unit 7 is electrically connected to the supply unit 4, the temperature sensors 5 and 6, and other sensors and auxiliary devices (not shown), and inputs and outputs signals. The control unit 7 controls the supply / stop of the fuel gas, the oxygen-containing gas, and water by outputting a control signal to the supply unit 4.

<System startup method>
FIG. 2 is a flowchart showing a system activation method in the fuel cell system 1. As shown in FIG. 2, at the time of system startup, the control unit 7 supplies a fuel gas and air to the fuel cell 3 via the reformer 2 by outputting a control signal to the supply unit 4 (steps). S100). At this time, the fuel gas and air discharged from the fuel cell 3 are ignited by an igniter or the like, and combustion is started (step S110). Heat (HT) is supplied to the reformer 2 by the combustion and heated. When the temperature of the reformer becomes about 200 ° C., the reformer 2 starts a partial oxidation reforming reaction in the autothermal reforming catalyst (step S120). At this time, an oxidizing atmosphere is formed in the reactor of the reformer 2, but when the Ni-supported perovskite autothermal reforming catalyst according to the present embodiment is used, oxidation of Ni is suppressed. Further, since the partial oxidation reforming reaction is an exothermic reaction, the reformer 2 is also heated by the heat generated by itself.

  The control unit 7 monitors the inlet temperature of the reformer 2 based on the output result from the temperature sensor 5, and detects that the inlet temperature of the reformer 2 has become equal to or higher than the first threshold (step S130). . Thereby, the control unit 7 detects that the temperature in the system has increased to a temperature at which water does not condense. The first threshold value is set to a temperature at which the reformer 2 can cause an autothermal reforming reaction, and is set to 300 ° C., for example. When the inlet temperature of the reformer 2 becomes equal to or higher than the first threshold value, the control unit 7 supplies water to the reformer 2 by outputting a control signal to the supply unit 4. The autothermal reforming reaction is started (step S140).

  The control unit 7 monitors the inlet temperature of the reformer 2 based on the output result from the temperature sensor 5, and detects that the inlet temperature of the reformer 2 is equal to or higher than the second threshold (step S150). . The second threshold is set to a temperature at which the reformer 2 can cause a steam reforming reaction, and is set to 500 ° C., for example. When the inlet temperature of the reformer 2 becomes equal to or higher than the second threshold value, the control unit 7 stops supplying air to the reformer 2 by outputting a control signal to the supply unit 4, thereby reforming. The vessel 2 moves to the steam reforming reaction (step S160). Thereafter, when the temperature of the fuel cell 3 becomes 600 ° C. or higher, power generation is started in the fuel cell 3 (step S170). The system startup process shown in FIG. 2 is completed as described above, and thereafter, the reformer 2 continues to supply the reformed gas to the fuel cell 3 by the steam reforming reaction.

  The system startup method described above is merely an example, and the specific procedure is appropriately determined as long as the reforming reaction is caused in the order of partial oxidation reforming reaction, autothermal reforming reaction, and steam reforming reaction. It is possible to change. For example, the temperature related to the first threshold value and the second threshold value can be changed as appropriate. Moreover, you may consider the temperature in parts other than the reformer inlet temperature.

<Autothermal reforming catalyst>
The autothermal reforming catalyst of the present invention is a compound represented by La _1-X Sr _x AlO ₃ (x = 0.05 to 0.3) obtained by substituting Sr for perovskite oxide LaAlO ₃ (hereinafter referred to as “0.05” to “0.3”). A catalyst carrier made of Sr-substituted perovskite oxide is supported on Ni as an active metal. The catalyst support may be in the form of an Sr-substituted perovskite oxide supported on an alumina support.

The perovskite type oxide is an oxide having a perovskite type structure represented by the chemical composition of ABO ₃ (A: rare earth element or alkaline earth metal element, B: transition metal element). In the present invention, LaAlO ₃ A compound represented by La _1-X Sr _x AlO ₃ obtained by substituting Sr at the A site is used as a catalyst support. Here, the substitution rate (x) of Sr is preferably 0.05 to 0.3, and particularly preferably 0.2 to 0.3. When x is 0.4 or more, the perovskite structure is destroyed and the effect of Sr substitution is lost, which is not preferable. Moreover, when x is less than 0.05, the conversion rate of hydrocarbon compounds becomes insufficient.

The perovskite oxide used in the present invention can be produced by a known method and is not particularly limited. Further, the method of substituting Sr for the A site of LaAlO ₃ is not particularly limited, and a known method such as a solid phase reaction method, a hydrolysis method, a sol-gel method, a hydrothermal method, or a spray pyrolysis method may be used. What is necessary is just to synthesize | combine the oxide which employ | adopts and has an above-described composition. For example, a compound containing a metal element contained in the above composition formula (for example, oxide, carbonate, organic substance, etc.) is used as a starting material, mixed so as to have the same metal element ratio as the target oxide, and fired. Can be synthesized.

  In addition, when obtaining a catalyst carrier in which an Sr-substituted perovskite oxide is supported on an alumina carrier, it can be synthesized by impregnating the alumina carrier with a metal nitrate solution having the above-mentioned predetermined composition and firing.

In the present invention, an example of a method for preparing La _1-X Sr _x AlO ₃ by a sol-gel method is illustrated below. First, La (NO ₃ ) ₃ · 6H ₂ O, Sr (NO ₃ ) ₂ , Al (NO ₃ ) ₃ · 9H ₂ O, citric acid, ethylene glycol, and pure water having a predetermined composition ratio may be mixed and stirred. After that, it is heated to remove moisture. Next, after maintaining the temperature at about 300 ° C. to 500 ° C. for about 1 to 5 hours to decompose the nitrate, the temperature is maintained at about 700 to 900 ° C. for about 5 to 20 hours to burn and remove citric acid and ethylene glycol. Thus, La _1-X Sr _x AlO ₃ can be obtained.

  In the present invention, the catalyst carrier can be calcined in air or an oxygen atmosphere before supporting the active metal. As a calcination temperature at this time, 500-1500 degreeC is preferable normally, Preferably 700-1200 degreeC is desirable. Further, for the purpose of increasing the mechanical strength of the catalyst carrier, a small amount of a binder such as silica or cement can be added to the catalyst carrier.

  The autothermal reforming catalyst of the present invention can be obtained by supporting an active metal on the Sr-substituted perovskite oxide support. As the active metal, inexpensive nickel is used because it exhibits high activity, coking resistance, and oxidation resistance.

  The method for supporting the active metal on the catalyst carrier is not particularly limited, and can be easily performed by applying a known method. For example, an impregnation method, a deposition method, a coprecipitation method, a kneading method, an ion exchange method, a pore filling method and the like can be mentioned, and the impregnation method is particularly desirable. The active metal starting material for producing the catalyst varies depending on the above-mentioned supporting method and can be selected as appropriate. Usually, active metal chlorides and nitrates are used. For example, when the impregnation method is applied, a method of preparing a solution (usually an aqueous solution) of an active metal salt, impregnating the catalyst support, drying, and calcining as necessary can be exemplified. Firing is usually performed in an air or nitrogen atmosphere, and the temperature is not particularly limited as long as it is equal to or higher than the decomposition temperature of the salt, but it is usually 200 to 800 ° C, preferably about 300 to 600 ° C. The treatment time depends on the temperature, but is usually 1 to 30 hours, preferably about 5 to 20 hours. In the present invention, an autothermal reforming catalyst is usually prepared by supporting an active metal on a catalyst carrier and then reducing it at 400 to 1000 ° C., preferably 400 to 700 ° C. in a reducing atmosphere (usually a hydrogen atmosphere). It is preferably adopted.

  The content of Ni as an active metal in the catalyst of the present invention is preferably 0.05 to 20% by mass, more preferably 0.1 to 10% by mass as a metal amount (here, “mass%” "Is a value based on 100% by mass of the whole catalyst). If the content of the active metal is more than 20% by mass, the agglomeration of the metal increases, which is disadvantageous in that the proportion of the active metal that appears on the surface tends to decrease. Since it becomes difficult to exhibit high activity, a large amount of a supported catalyst is required, which is disadvantageous in that the reactor tends to be enlarged.

  Further, the shape of the autothermal reforming catalyst of the present invention is not particularly limited, and can be appropriately selected depending on the form using the autothermal reforming catalyst. For example, an arbitrary shape such as a pellet shape, a granule shape, a honeycomb shape, or a sponge shape is adopted.

<Action and effect>
The fuel cell system 1 according to the present embodiment uses a Ni-supported perovskite autothermal reforming catalyst that can suppress oxidation despite being Ni-based. Therefore, even when the partial oxidation reforming reaction is performed in the reformer 2, it is possible to prevent the steam reforming activity from being lost due to oxidation of Ni of the autothermal reforming catalyst in the reformer 2.

Referring to FIG. 3, the reformer in the case of using the autothermal reforming catalyst made of Ni / γ-Al ₂ O ₃ and the case of using the Ni-supported perovskite autothermal reforming catalyst according to this embodiment. The reaction in the reactor No. 2 will be described. In FIG. 3, the reactor RE1 shown on the upper side is filled with an autothermal reforming catalyst made of Ni / γ-Al ₂ O ₃ . The reactor RE2 shown on the lower side is filled with the Ni-supported perovskite autothermal reforming catalyst according to this embodiment. In the reactor RE1, the autothermal reforming catalyst in the upstream region A in the reactor contributes to the partial oxidation reforming reaction at the stage of the partial oxidation reforming reaction (POX). At this time, the steam reforming activity is lost by oxidizing the Ni of the autothermal reforming catalyst in the region A by the partial oxidation reforming reaction. Therefore, in the reactor RE1, only the autothermal reforming catalyst in the region B where Ni is not oxidized performs the steam reforming reaction (SR), and the autothermal reforming catalyst in the region A contributes to the steam reforming reaction. I can't. As described above, in the reactor RE1 using the autothermal reforming catalyst made of Ni / γ-Al ₂ O ₃ , sufficient reforming reaction is not performed and the fuel cell system of the autothermal reforming type is sufficiently performance. May not be possible. Alternatively, in order to perform a sufficient reforming reaction, it is necessary to increase the amount of the catalyst in the region B in order to secure an autothermal reforming catalyst that can contribute to the steam reforming reaction without oxidizing Ni. When the amount of the catalyst is increased, the reformer becomes larger, the cost increases, and the start of the fuel cell system is delayed due to the time required for heating in the reformer.

  On the other hand, in the reactor RE2, even in the partial oxidation reforming reaction stage, the oxidation of Ni in the autothermal reforming catalyst in the upstream region A is suppressed, so that it is not completely oxidized and steam reforming activity is achieved. I will not lose. Therefore, in the reactor RE2, not only the autothermal reforming catalyst in the region B but also the autothermal reforming catalyst in the region A can contribute to the steam reforming reaction. That is, the autothermal reforming catalyst over substantially the entire region of the reactor RE2 can contribute to the steam reforming reaction. As a result, even if an inexpensive autothermal reforming catalyst containing Ni is used, sufficient performance can be exhibited as an autothermal reforming fuel cell system. Further, since the autothermal reforming catalyst over substantially the entire region in the reactor RE2 of the reformer can contribute to the steam reforming reaction, the amount of catalyst can be reduced as compared with the case where the reactor RE1 is used. As a result, it is possible to reduce the size of the reformer and reduce the cost. In addition, by reducing the amount of catalyst, heating in the reformer can be performed in a short time. Further, in the autothermal reforming fuel cell system 1, heat is exchanged inside the reformer 2 itself. For example, the autothermal reforming catalyst in region A generates heat by the partial oxidation reforming reaction, and the autothermal reforming catalyst in region B is heated by the heat. According to the present embodiment, such heat exchange is facilitated by reducing the amount of catalyst. Therefore, the fuel cell system 1 can be activated quickly.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these Examples at all.

<Example 1>
(1) Preparation of catalyst support La (NO ₃ ) ₃ · 6H ₂ O, Sr (NO ₃ ) ₂ , Al (NO ₃ ) ₃ · 9H ₂ O, citric acid, ethylene glycol, and pure water may be mixed and stirred well After that, the water was removed by heating. Next, after maintaining the temperature at 400 ° C. for 2 hours to decompose the nitrate, the temperature is maintained at 800 ° C. for 10 hours to burn and remove citric acid and ethylene glycol, whereby La _1-x Sr _x AlO in which x is 0.3. ₃ was prepared.
(2) Preparation of catalyst Next, the support was immersed in an aqueous nickel nitrate solution so that the nickel content was 10 mass% to evaporate water, and then dried at 120 ° C. for 3 hours. Furthermore, it baked at 500 degreeC for 10 hours. Subsequently, this was pressure-molded and then pulverized and sieved to obtain a granulated autothermal reforming catalyst of about 1 to 2 mm. Further, the autothermal reforming catalyst was reduced at 500 ° C. for 3 hours under a hydrogen flow to obtain an autothermal reforming catalyst.
(3) Oxidation treatment The autothermal reforming catalyst was subjected to an oxidation treatment by heating at 600 ° C for 1 hour under air flow.
(4) Steam reforming reaction Using the autothermal reforming catalyst before the oxidation treatment, steam reforming reaction was performed under the following conditions using propane as a raw material. Moreover, the steam reforming reaction was performed under the same conditions using the autothermal reforming catalyst after the oxidation treatment of (3). The propane conversion (%) after 75 hours from the start of the reaction was as shown in Table 1. Furthermore, with respect to the autothermal reforming catalyst after the oxidation treatment of (3), the coke deposition amount after 3 hours from the start of the reaction was as shown in Table 2.
Catalyst amount: 25mg
W / F: 1.7 gh / mol
Reaction temperature: 400 ° C
Steam / carbon ratio: 2.0

<Comparative Example 1>
A steam reforming reaction was carried out in the same manner as in Example 1 except that γ-alumina was used as the catalyst carrier and an autothermal reforming catalyst carrying 10 mass% of nickel was used. The results are shown in Tables 1 and 2.

  As understood from Table 1, the autothermal reforming catalyst according to Comparative Example 1 has steam reforming activity before the oxidation treatment, but loses steam reforming activity after the oxidation treatment. . Thus, in the example shown in FIG. 2, the autothermal reforming catalyst in the region A that contributed to the partial oxidation reforming reaction in the reactor RE1 loses the steam reforming activity and cannot contribute to the steam reforming reaction. It is confirmed. On the other hand, although the autothermal reforming catalyst according to Example 1 has a slight decrease in the conversion rate of propane as compared with that before the oxidation treatment, the oxidation of Ni is suppressed, so that the steam reforming can be performed even after the oxidation treatment. It is understood that quality activity has not been lost. Accordingly, in the example shown in FIG. 2, in the reactor RE1, the autothermal reforming catalyst in the region A that has contributed to the partial oxidation reforming reaction can contribute to the steam reforming reaction without losing the steam reforming activity. It is confirmed.

  In addition, even when the propane conversion rate before the oxidation treatment in Table 1 is compared, the autothermal reforming catalyst according to Example 1 not only has better oxidation resistance than the autothermal reforming catalyst according to Comparative Example 1. It is understood that the propane conversion is also excellent. Furthermore, as understood from Table 2, it is understood that the autothermal reforming catalyst according to Example 1 has a smaller amount of coke deposition than the autothermal reforming catalyst according to Comparative Example 1.

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 2 ... Reformer, 3 ... Fuel cell, 4 ... Supply part, 5, 6 ... Temperature sensor, 7 ... Control part.

Claims (3)

A reformer having an autothermal reforming catalyst that converts fuel gas into reformed gas containing carbon monoxide and hydrogen;
A fuel cell system comprising a fuel cell that generates electric power using the reformed gas,
The autothermal reforming catalyst is formed on a support made of La _1-x Sr _x AlO ₃ (x = 0.05 to 0.3) obtained by substituting Sr for perovskite oxide LaAlO _3. It carries 20 mass% Ni,
The reformer is
The fuel gas and the oxygen-containing gas are supplied and heated to perform a partial oxidation reforming reaction,
Autothermal reforming reaction is performed by supplying water,
A fuel cell system performing a steam reforming reaction by stopping the supply of the oxygen-containing gas.   2. The fuel cell system according to claim 1, wherein the fuel gas contains a hydrocarbon compound having 4 or less carbon atoms in an amount of 70% by volume or more. The fuel cell system according to claim 1 or 2, wherein the fuel gas is selected from natural gas and LPG.

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