JP2011225410A - Hydrogen generating apparatus, fuel cell system with the same and method of operating hydrogen generating apparatus - Google Patents

Abstract

An object of the present invention is to provide a hydrogen generator capable of further suppressing performance deterioration of a shift catalyst when operation is stopped.
A hydrogen generator comprising a reformer for generating a hydrogen-containing gas by reforming a raw material, and a shift generator having a shift catalyst for reducing carbon monoxide in the hydrogen-containing gas by a shift reaction; The raw material supplier 1 that supplies the raw material to the reformer 6 and the hydrogen that supplies hydrogen to the raw material that flows into the transformer 8 when the raw material supplier 1 purges the interior of the hydrogen generator 100A with the raw material when stopped A hydrogen generator comprising a supplier 15.
[Selection] Figure 1

Description

  The present invention relates to a reformer that generates a hydrogen-containing gas by a reforming reaction, a hydrogen generator that includes a converter that reduces carbon monoxide in the hydrogen-containing gas, a fuel cell system including the hydrogen generator, and an operation of the hydrogen generator. Regarding the method.

  Since the conventional fuel cell system does not have an infrastructure for supplying hydrogen as a fuel gas, the conventional fuel cell system usually includes a hydrogen generation device that generates a hydrogen-containing gas by a reforming reaction using a raw material containing hydrocarbons.

  The hydrogen generator includes a reformer that generates a hydrogen-containing gas from a raw material by a reforming reaction, and a heater that supplies heat required for the reforming reaction to the reformer. The reformer is provided with a reforming catalyst. In addition, as the raw material, a raw material containing a hydrocarbon such as natural gas, LPG, naphtha, gasoline, kerosene, or an organic compound containing at least carbon and hydrogen as constituent elements as exemplified by alcohol such as methanol is used.

  In the reforming reaction, carbon monoxide (hereinafter referred to as CO) is generated as a subcomponent, and the hydrogen-containing gas sent from the reformer contains about 10 to 15% of CO. Since the CO contained in the hydrogen-containing gas poisons the electrode catalyst of the fuel cell and lowers the power generation capacity, the hydrogen generator used in the fuel cell system has a hydrogen-containing gas produced by the reformer. Means have been taken to reduce the CO concentration.

  As one of the methods for reducing the CO concentration, a shift reaction is generally used in which CO and water vapor are reacted to convert to hydrogen and carbon dioxide. More specifically, the hydrogen generator has a shifter that shifts CO and water vapor in the hydrogen-containing gas downstream of the reformer, and this shifter is provided with a shift catalyst. . In many cases, this transformer reduces the CO concentration in the hydrogen-containing gas to about 0.5% or less.

  Furthermore, in order to reduce CO in the hydrogen-containing gas, a CO remover provided with an oxidation catalyst or a methanation catalyst is provided downstream of the converter, and when an oxidation catalyst is used, air is supplied into the CO remover. By doing so, CO in the hydrogen-containing gas is oxidized, and the CO concentration in the hydrogen-containing gas is reduced to 100 ppm, preferably 10 ppm or less. Electricity is generated by supplying a hydrogen-containing gas mainly containing hydrogen discharged from the CO remover to the fuel cell.

  By the way, at the time of the shutdown operation of the hydrogen generator, the temperature of the reforming catalyst is lowered while supplying the raw material and water, and when the temperature of the reforming catalyst becomes a predetermined temperature or less, the supply of water is stopped, A method of purging with a raw material has been proposed (see, for example, Patent Document 1).

  In addition, after purging with water vapor during the shutdown operation of the hydrogen generator, after the temperature of the reforming catalyst layer falls below the temperature at which the raw material gas does not thermally decompose and falls below the water vapor condensation temperature, the raw material gas Has been proposed (see, for example, Patent Document 2).

JP 2000-95504 A JP 2002-151124 A

  In the inventions described in Patent Documents 1 and 2, by purging the raw material, water vapor remaining inside the hydrogen generator is scavenged to suppress water condensation in the hydrogen generator. No consideration is given to catalyst degradation.

  The present invention provides a hydrogen generator, a fuel cell system including the hydrogen generator, and a method of operating the hydrogen generator that can suppress performance deterioration of the shift catalyst due to a raw material purge in consideration of the problems of the conventional hydrogen generator. The purpose is to do.

  The present inventors have found that the shift catalyst deteriorates when the raw material purge is performed at a high temperature of about 300 ° C. Therefore, the present inventors have intensively studied and found that, even when the shift catalyst is at a high temperature, purging with coexisting hydrogen as a raw material suppresses the deterioration of the shift catalyst, and the configuration described below is provided. It has been found that adoption is very effective in achieving the object of the present invention, and the present invention has been conceived.

  That is, in order to solve the above-described problem, the hydrogen generator of the first aspect of the present invention includes a reformer that generates a hydrogen-containing gas by reforming a raw material, and carbon monoxide in the hydrogen-containing gas by a shift reaction. A hydrogen generator including a shifter having a shift catalyst to be reduced, a raw material supplier that supplies the raw material to the reformer, and when the hydrogen generator is purged with the raw material by the raw material supplier when stopped And a hydrogen supply device for supplying hydrogen to the raw material flowing into the transformer.

The hydrogen generator of the second aspect of the present invention is characterized in that the hydrogen supplier is a valve that is opened when supply of hydrogen is started from a hydrogen generator that generates hydrogen by electrolysis of water. The hydrogen generator of the third aspect of the present invention is characterized in that the hydrogen supplier is a valve that is opened when the supply of hydrogen is started from a hydrogen reservoir that stores hydrogen.

  A hydrogen generator according to a fourth aspect of the present invention includes a hydrodesulfurizer that removes sulfur compounds in a raw material supplied to the reformer, and a feed from the hydrogen generator to the raw material that flows into the hydrodesulfurizer. A return gas flow path for supplying a hydrogen-containing gas, wherein the hydrogen supplier is a valve provided in the return gas flow path and opening the return gas flow path. .

  The hydrogen generator of the fifth aspect of the present invention is characterized in that the shift catalyst contains Cu and Zn as constituent elements.

  A fuel cell system according to a first aspect of the present invention includes the hydrogen generation device and a fuel cell that generates power using a hydrogen-containing gas supplied from the hydrogen generation device.

  The operation method of the hydrogen generator according to the first aspect of the present invention includes a reformer that generates a hydrogen-containing gas by reforming a raw material, and a shift catalyst that reduces carbon monoxide in the hydrogen-containing gas by a shift reaction. A method for operating a hydrogen generator including a hydrogen generator including a transformer, wherein hydrogen is supplied to the raw material flowing into the transformer when the inside of the hydrogen generator is purged with the raw material when stopped.

  According to the present invention, it is possible to suppress the deterioration of the shift catalyst during the raw material purge as compared with the conventional hydrogen generator and fuel cell system.

FIG. 1 is a schematic diagram showing a schematic configuration of a hydrogen generator in Embodiment 1. FIG. 2 is a graph showing temperature characteristics of the shift catalyst when a raw material or a mixed gas of raw material and hydrogen is passed through the shift catalyst. FIG. 3 is an operation flowchart when the hydrogen generator in Embodiment 1 is stopped. FIG. 4 is a schematic diagram illustrating a schematic configuration of the hydrogen generator according to the first modification of the first embodiment. FIG. 5 is a schematic diagram illustrating a schematic configuration of the hydrogen generator according to the second modification of the first embodiment.

  Below, the hydrogen generator of embodiment of this invention, a fuel cell system provided with the same, and the operating method of a hydrogen generator are demonstrated.

  The hydrogen generator of the present embodiment includes a reformer that reforms a raw material to generate a hydrogen-containing gas, and a hydrogen that includes a shifter that has a shift catalyst that reduces carbon monoxide in the hydrogen-containing gas by a shift reaction. A generator, a raw material supplier for supplying the raw material to the reformer, and a hydrogen supply for supplying hydrogen to the raw material flowing into the shifter when the hydrogen generator is purged with the raw material by the raw material supplier when the raw material is stopped And a vessel.

  The fuel cell system of the present embodiment includes the hydrogen generator of the above embodiment and a fuel cell that generates electric power using the hydrogen-containing gas supplied from the hydrogen generator.

  The operation method of the hydrogen generator according to the present embodiment includes a reformer that reforms a raw material to generate a hydrogen-containing gas, and a shift converter that includes a shift catalyst that reduces carbon monoxide in the hydrogen-containing gas by a shift reaction. A hydrogen generator comprising: a hydrogen generator comprising: a raw material supplier that supplies a raw material to the reformer; and a hydrogen supplier that supplies hydrogen to the raw material flowing into the shifter, When purging the inside of the hydrogen generator with the raw material supplied from the raw material supply device, hydrogen is supplied to the raw material flowing into the transformation device from the hydrogen supply device.

  Thereby, compared with the conventional hydrogen generator and fuel cell system, it becomes possible to suppress deterioration of the shift catalyst during the raw material purge.

  Here, the hydrogen supplier is an on-off valve provided in a hydrogen supply path through which hydrogen supplied from a hydrogen supply source flows.

  Examples of the hydrogen supply path include a form in which a hydrogen supply source and a raw material supply path through which a raw material supplied to the reformer flows are connected. The form is arbitrary as long as hydrogen can be supplied to the raw material flowing into the vessel.

  Examples of the hydrogen supply source include a hydrogen storage container, a hydrogen generator that generates hydrogen by electrolysis of water, and the hydrogen generator described above. However, the hydrogen supply source is not limited to this example. If it functions as, the form is arbitrary.

(Embodiment 1)
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted. The other components are not shown. Furthermore, the present invention is not limited to the following embodiment.

  FIG. 1 is a schematic diagram showing a schematic configuration of a hydrogen generator according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the hydrogen generator 100 according to Embodiment 1 of the present invention includes a reformer 6 that generates a hydrogen-containing gas using raw materials, and a hydrogen-containing gas generated by the reformer 6. Hydrogen generator 100A having a shifter 8 having a shift catalyst for reducing carbon monoxide in the shift reaction, a raw material supplier 1 for supplying the raw material to the reformer 6, and hydrogen generation by the raw material supplier when stopped An on-off valve 15 is provided as a hydrogen supplier for supplying hydrogen to the raw material flowing into the transformer when purging the inside of the reactor with the raw material.

  Here, the raw material contains an organic compound having at least carbon and hydrogen as constituent elements, and raw materials exemplified by hydrocarbons such as natural gas, LPG, naphtha, gasoline, kerosene, and alcohols such as methanol are preferably used. It is done.

  Here, a reforming catalyst is disposed inside the reformer 6. With this reforming catalyst, the reforming reaction proceeds and a hydrogen-containing gas can be generated from the raw material and water. Heat required for the reforming reaction is supplied from the combustor 11. In general, as the reforming catalyst, at least one selected from the group consisting of noble metal catalysts such as Pt, Ru and Rh and Ni is preferably used.

  Further, a shift catalyst is disposed inside the transformer 8. With this shift catalyst, the shift reaction proceeds, and hydrogen and carbon dioxide can be generated from carbon monoxide and water in the hydrogen-containing gas discharged from the reformer 6. Generally, at least one selected from the group consisting of noble metal catalysts such as Pt, Ru, Rh, Cu—Zn catalysts, and Fe—Cr catalysts is preferably used as the shift catalyst. .

  The raw material supplier 1 is a device that adjusts the flow rate of the raw material supplied to the reformer 6, and in the present embodiment, includes a booster and a flow rate adjustment valve. In addition, the raw material supply device 1 is not limited to this example, You may employ | adopt the form which provides any one of a pressure | voltage riser and a flow regulating valve.

  In the hydrogen generator of the present embodiment, only the reformer 6 and the transformer 8 are provided in the hydrogen generator 100A. However, the present invention is not limited to this example. Alternatively, a configuration may be adopted in which a CO remover that reduces carbon monoxide in the hydrogen-containing gas discharged from the transformer 8 downstream of the gas by an oxidation reaction or a methanation reaction may be employed. In addition, although the oxidation catalyst or methanation catalyst is arrange | positioned inside the said CO removal device, generally a Pt type catalyst or a Ru type catalyst is used suitably.

  In addition to the above configuration, the hydrogen generator 100 of the present embodiment further includes a water supply unit 3 that supplies water to the reformer 6 for use in the reforming reaction, and a temperature of the reformer 6. A temperature detector 7 to detect, a first on-off valve 12 provided in a first path 31 through which a hydrogen-containing gas supplied from a hydrogen generator 100A to a hydrogen-using device flows, and a combustor that heats the reformer 6 11, the second on-off valve 13 provided in the second path 32 for supplying the hydrogen-containing gas sent from the hydrogen generator 100 </ b> A to the combustor 11 by bypassing the hydrogen-using device 10, and the hydrogen generation And a controller 200 for controlling the operation of the apparatus 100.

  Here, the controller 200 includes a microprocessor, a CPU, and the like, and includes not only a single controller but also a controller group in which a plurality of controllers cooperate to execute control. Therefore, the controller 200 does not need to be composed of a single controller, and a plurality of controllers are distributed and configured to control the operation of the hydrogen generator 100 in cooperation with each other. May be.

  In addition to the hydrogen generator 100 having the above-described configuration, a hydrogen supply source that supplies hydrogen to the raw material supplied to the hydrogen utilization device 10 and the reformer 6 that use the hydrogen-containing gas generated by the hydrogen generator 100. A hydrogen generator 5 is shown in FIG.

  In the present embodiment, the hydrogen using device 10 is a fuel cell. The hydrogen generator 100 and the fuel cell constitute a fuel cell system. In addition, a hydrogen utilization apparatus is not limited to this example, The form will be arbitrary if it is an apparatus using hydrogen, such as a hydrogen storage container.

  The hydrogen generator 5 is a device that generates hydrogen by electrolyzing water. As an example, a water tank is provided with a positive electrode and a negative electrode, and a voltage is applied to both electrodes from an external power source to electrolyze water. As another example, an electrode using platinum black or the like, a solid polymer membrane as an electrolyte membrane, and applying an electric voltage from an external power source to the electrode and electrolyzing while allowing one water to flow therethrough can be mentioned. Moreover, it is good also as a structure which uses a polymer electrolyte fuel cell as a fuel cell, applies a voltage from an external power source to the positive electrode and the negative electrode, and generates hydrogen, and serves as a hydrogen generator and hydrogen utilization apparatus.

Next, the stop operation of the hydrogen generator 100 having the above configuration will be described.
[Hydrogen generation operation]
Hereinafter, an operation example of the hydrogen generation operation of the hydrogen generator 100 will be described. These operations are performed by being controlled by the controller 200.

  The raw material supplier 1 is controlled so that the raw material is supplied from the raw material supply path 2 to the reformer 6.

Further, the water supplier 3 is controlled to supply water to the reformer 6. The water supply flow rate is, for example, a flow rate at which the molar amount ratio (S / C) of C atoms in the raw material flow rate per unit time / mole amount of H ₂ O molecules in the water supply rate per unit time is about 3. Is preferred.

  Then, the reformer 6 is heated by the combustor 11 so as to maintain a temperature suitable for the steam reforming reaction (reforming reaction temperature). The adjustment of the heating temperature is performed based on the temperature detected by the temperature detector 7. In the present embodiment, it is preferable to use a Ru catalyst as the reforming catalyst and to heat the combustor 11 so that the temperature detected by the temperature detector 7 is about 650 ° C.

  By the above control, the reformer 6 efficiently generates a hydrogen-containing gas by the steam reforming reaction.

  The hydrogen-containing gas produced by the reformer 6 is supplied to the transformer 8, and the carbon monoxide concentration of the hydrogen-containing gas is reduced by the shift reaction. During the hydrogen generation operation, the transformer 8 is configured to have a temperature suitable for the shift reaction (shift reaction temperature). Specifically, the temperature of the transformer 8 may be adjusted using heat transfer from the combustion exhaust gas of the combustor 11 or may be performed using a heater such as an electric heater. It may be configured as follows.

  In this embodiment, a Cu—Zn shift catalyst is used as the shift catalyst, and the shift reaction temperature is designed to be about 250 to 350 ° C.

The hydrogen-containing gas delivered from the hydrogen generator 100 </ b> A is supplied to the hydrogen utilization device 10 via the first path 31. In the present embodiment, since the hydrogen utilization device 10 is a fuel cell, the power generation operation is performed using the supplied hydrogen-containing gas and an oxidant gas supplied from an oxidant gas supply device (not shown).
[Stop processing]
Next, an operation when the hydrogen generator 100 that is performing the hydrogen generation operation is stopped will be described.

  The hydrogen generating apparatus 100 of the present embodiment performs a raw material purging operation for purging the inside of the hydrogen generator 100A with the raw material gas at the time of stoppage. The influence on the characteristics of the shift catalyst at that time is described in the present invention. They studied.

  First, the present inventors installed a shift catalyst in the fixed bed flow reactor shown below, and compared the characteristics before and after the flow of the raw material at a high temperature. FIG. 2 is a graph showing the results. That is, FIG. 2 examines the characteristics (temperature characteristics) of the shift catalyst with respect to the temperature of the carbon monoxide concentration in the hydrogen-containing gas after passing the reforming simulation gas corresponding to the reformer through the shift catalyst. It is a graph which shows the test result.

  A commercially available Cu—Zn-based catalyst was used as the shift catalyst, and it was packed in a 20 cc reaction tube. The temperature characteristic of the shift catalyst is a reaction in which the reforming simulation gas (hydrogen: 57%, carbon monoxide: 9%, carbon dioxide: 8%, water: 26%) is circulated at 300 mL / min and the shift catalyst is filled. This was carried out by lowering the set temperature of the electric furnace for applying heat to the tube and measuring the concentration of carbon monoxide in the gas discharged from the reaction tube.

  First, the shift catalyst filled in the reaction tube was subjected to reduction treatment to initialize the shift catalyst, and then the carbon monoxide concentration was measured under the above conditions. The result (initial temperature characteristic) is a graph plotted with white circles in FIG.

  Next, in order to verify the influence of the raw material purge on the temperature characteristics, the reaction tube is heated by an electric furnace so that the temperature of the shift catalyst becomes 300 ° C. Using the desulfurized city gas, the reaction tube was circulated at a flow rate of 100 mL / min for 12 hours. After the city gas flow, the reformed simulated gas was passed through the shift catalyst and the temperature property was measured in the same manner as when the initial temperature property was measured. The result is shown in a plot (black triangle) “13A” in FIG.

  From this result, when the shift catalyst is in the initial state, for example, when the catalyst temperature was 190 ° C., CO could be reduced to about 0.2 dry%, but after the city gas flow, about 1 dry even at the same catalyst temperature. % Could not be reduced. That is, it was shown that the shift catalyst deteriorates due to the raw material purge.

  Next, the shift catalyst is replaced, the reduction treatment is performed, the temperature characteristic test is performed, and the initial characteristic of the replaced shift catalyst is equal to the above-described characteristic (the plot of the “initial temperature characteristic” indicated by the white circle in FIG. 2). I confirmed that there was.

  Thereafter, the reaction tube was heated in an electric furnace so that the temperature of the shift catalyst was 300 ° C., and a mixed gas obtained by adding 10 mL / min of hydrogen to 100 mL / min of desulfurized city gas was allowed to flow through the reaction tube for 12 hours. . Thereafter, the reforming simulation gas was passed through the shift catalyst, and the temperature characteristics were measured. This result is shown in a plot (black square) “13A + hydrogen” in FIG. As shown in FIG. 2, it is understood that when hydrogen is added to the city gas, the temperature characteristics of the shift catalyst are hardly deteriorated.

  As described above, based on the results of FIG. 2, the present inventors have found that it is preferable to add hydrogen when the raw material is circulated to suppress deterioration of the catalytic performance of the shift catalyst.

  Next, an example of the operation when the hydrogen generator 100 is stopped, which is a feature of the hydrogen generator of the present embodiment, will be described.

  FIG. 3 is a flowchart showing an example of the operation when the hydrogen generator of the present embodiment is stopped.

  As described above, during the hydrogen generation operation of the hydrogen generator 100, control is performed such that the reforming temperature is 650 ° C. and the transformation temperature is 350 ° C.

  When the hydrogen generator 100 is stopped, first, the controller 200 stops the operation of the raw material supplier 1 and the water supplier 3, stops the supply of the raw material gas and water, and stops the combustion operation of the combustor 11. Then, the heating of the reformer 6 is stopped (step S101). When heating in the combustor 11 is stopped, the temperature of the reforming catalyst decreases. Then, the controller 200 determines whether or not the temperature detected by the temperature detector 7 is equal to or lower than a temperature threshold Tth (for example, 400 ° C.) at which carbon does not precipitate from the raw material on the reforming catalyst (step S102). ) When the temperature detected by the temperature detector 7 becomes equal to or lower than Tth (Yes in step S102), the raw material purge of the hydrogen generator 100A is started and the supply of hydrogen to the raw material flowing into the transformer 8 is started ( Step S103). In step S103, specifically, the third on-off valve 15 is opened, and the operations of the raw material supplier 1 and the hydrogen generator 5 are started. Thereby, the raw material gas in the raw material supply path 2 is supplied to the reformer 6 by the operation of the raw material supplier 1, and the hydrogen generated in the hydrogen generator 5 is introduced into the raw material supply path 2, so that the reformer 6 To be supplied. For this reason, the raw material mixed with hydrogen flows through the transformer 8. Further, in the above operation, a voltage is applied to the hydrogen generator 5 to cause electrolysis of water and hydrogen generation operation is executed. However, the hydrogen generator 5 is not operated and remains in the hydrogen generator 5. A form using hydrogen may also be used.

  Next, after starting the raw material purge operation, the controller 200 determines whether or not the amount of raw material supplied to the hydrogen generator 100A is equal to or greater than a predetermined threshold Vth (for example, 10NL) (step S104). When the raw material supply amount becomes Vth (Yes in step S104), the raw material purge of the hydrogen generator 100A and the supply of hydrogen to the raw material flowing into the transformer 8 are stopped (step S105). In step S105, specifically, the third on-off valve 15 is closed, and the operations of the raw material supplier 1 and the hydrogen generator 5 are stopped. Here, the Vth is defined as an amount by which the residual gas in the hydrogen generator 100A can be replaced with the source gas.

In the hydrogen generator 100 of the present embodiment, since the raw material mixed with hydrogen is supplied to the shift converter 8 when the raw material purge of the hydrogen generator 100A is executed at the time of stop as described above, the shift catalyst Even if the temperature is deteriorated when only the raw material is passed, deterioration of the catalytic performance of the shift catalyst can be suppressed as compared with the conventional hydrogen generator. Also, it is obvious that the same effect as described above can be obtained for the fuel cell system including the hydrogen generator 100 of the present embodiment.
[Modification 1]
Next, Modification 1 of the hydrogen generator according to Embodiment 1 will be described. FIG. 4 is a diagram showing a schematic configuration of the hydrogen generator of the present modification.

  As shown in FIG. 4, the hydrogen generator 100 according to the first modification has the same basic configuration as that of the hydrogen generator 100 according to the first embodiment, but a hydrogen reservoir is used instead of the hydrogen generator 5. The difference is that 16 is used as a hydrogen supply source. As the hydrogen storage 16, a tank storing a hydrogen storage alloy, a tank storing hydrogen, or the like is used. Since the operation flow (hydrogen supply operation) when performing the raw material purge of the hydrogen generator 100A when the hydrogen generator 100 is stopped is the same as that of the first embodiment, the description thereof is omitted.

And by the said operation | movement, even if it is the hydrogen generator 100 of this modification 1 similarly to Embodiment 1, compared with the conventional hydrogen generator, the deterioration of the catalyst performance of a shift catalyst can be suppressed. . Further, it is obvious that the same effect as described above can be obtained for the fuel cell system including the hydrogen generator 100 of the first modification.
[Modification 2]
Next, Modification 2 of the hydrogen generator of Embodiment 1 will be described. FIG. 5 is a diagram showing a schematic configuration of the hydrogen generator of the second modification.

  As shown in FIG. 5, the hydrogen generator 100 according to the second modification has the same basic configuration as the hydrogen generator 100 according to the first embodiment, but instead of the hydrogen generator 5 according to the first embodiment. The difference is that the hydrogen-containing gas remaining in the hydrogen generator 100A is used as a hydrogen supply source, and the hydrodesulfurizer 18 is provided. Specifically, in the hydrogen generator 100 according to the second modification, a recycle path 17 that connects the first path 31 and the raw material supply path 2 is provided, and the recycle path 17 is provided with a third hydrogen supply device. An on-off valve 15 is provided. Further, a hydrodesulfurizer 18 is provided on the downstream side of the raw material supplier 1 in the raw material supply path 2. The hydrodesulfurizer 18 is filled with a hydrodesulfurization catalyst, reacts a sulfur compound contained in the raw material with hydrogen, converts it into hydrogen sulfide, and adsorbs this hydrogen sulfide to remove the sulfur compound. It is configured as follows.

  In the hydrogen generator 100 of the second modification, the operation flow when performing the raw material purge of the hydrogen generator 100A is basically the same when stopped, but the Vth in step S104 is the hydrogen generator 100A. It is preferable that the capacity is the same. This is because if the raw material is continuously supplied even after the residual gas in the hydrogen generator 100A is purged with the raw material, the gas flowing into the hydrogen generator 100A via the recycling path 17 changes from the hydrogen-containing gas to the raw material. This is because only the raw material is supplied to the transformer 8, and the shift catalyst may be deteriorated depending on the temperature of the shift catalyst.

  Even in the hydrogen generator of Modification 2 configured as described above, the hydrogen generator 100A supplies a hydrogen to the conventional hydrogen generator in the same manner as in the first embodiment by the hydrogen supply operation during the raw material purge. In comparison, deterioration of the catalyst performance of the shift catalyst can be suppressed. Also, it is obvious that the same effect as described above can be obtained for the fuel cell system including the hydrogen generator 100 of the second modification.

  The hydrogen generator, the operation method of the hydrogen generator, and the fuel cell system of the present invention have the effect of further suppressing the performance deterioration of the shift catalyst when the operation is stopped, and the hydrogen generator and the operation method of the hydrogen generator And it is useful as a fuel cell system.

DESCRIPTION OF SYMBOLS 1 Raw material supply device 2 Raw material supply path 3 Water supply device 5 Hydrogen generator 6 Reformer 7 Temperature detector 8 Transformer 10 Hydrogen utilization equipment 11 Combustor 12 First on-off valve 13 Second on-off valve 15 Third on-off valve 16 Hydrogen storage device 17 Return gas route 18 Hydrodesulfurizer 31 First route 32 Second route 100 Hydrogen generator

Claims (7)

A hydrogen generator comprising a reformer for generating a hydrogen-containing gas by reforming a raw material, and a shifter having a shift catalyst for reducing carbon monoxide in the hydrogen-containing gas by a shift reaction;
A raw material supplier for supplying the raw material to the reformer;
A hydrogen supply device, comprising: a hydrogen supply device that supplies hydrogen to the raw material that flows into the shifter when purging the interior of the hydrogen generator with the raw material by the raw material supply device when stopped.   The hydrogen generator according to claim 1, wherein the hydrogen supplier is a valve that is opened when supply of hydrogen is started from a hydrogen generator that generates hydrogen by electrolysis of water.   The hydrogen generator according to claim 1, wherein the hydrogen supplier is a valve that is opened when supply of hydrogen is started from a hydrogen reservoir that stores hydrogen. A hydrodesulfurizer for removing sulfur compounds in the raw material supplied to the reformer;
A return gas flow path for supplying a hydrogen-containing gas sent from the hydrogen generator to the raw material flowing into the hydrodesulfurizer,
The hydrogen generation apparatus according to claim 1, wherein the hydrogen supply unit is a valve that is provided in the return gas channel and opens the return gas channel.   The hydrogen generator according to any one of claims 1 to 4, wherein the shift catalyst contains Cu and Zn as constituent elements.   A fuel cell system comprising: the hydrogen generator according to claim 1; and a fuel cell that generates electric power using a hydrogen-containing gas supplied from the hydrogen generator. A hydrogen generator comprising a reformer for reforming a raw material to generate a hydrogen-containing gas, a shifter having a shift catalyst for reducing carbon monoxide in the hydrogen-containing gas by a shift reaction, and the reformer A hydrogen generator operating method comprising: a raw material supplier that supplies the raw material; and a hydrogen supplier that supplies hydrogen to the raw material flowing into the transformer,
A hydrogen generator operating method for supplying hydrogen to the raw material flowing from the hydrogen supply device into the shifter when purging the hydrogen generator interior with the raw material supplied from the raw material supply device when stopping .

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