JP2017159290A - Desulfurization method, desulfurization apparatus and fuel cell power generation system - Google Patents

Abstract

The present invention provides a desulfurization method and a desulfurization apparatus that can use a hydrodesulfurization agent with high activity stably in a long period of time while having a simple apparatus configuration, and thus to a fuel gas utilization apparatus such as a fuel cell power generation system. To enable stable supply of fuel gas from which sulfur components have been removed. Platinum and iridium are mainly used as a steam reforming catalyst 2b for performing a reforming reaction in which steam is added to a fuel gas P containing a sulfur component and hydrogen gas is generated from the fuel gas P in the presence of steam. A sulfur-resistant steam reforming catalyst in which at least one noble metal component selected from ruthenium, rhodium, and palladium is supported on an inorganic oxide carrier together with a catalytic metal component as a component, and a sulfur compound from a fuel gas containing a sulfur compound The sulfur component in the fuel gas P is removed by sequentially passing through the hydrodesulfurizing agent 2a that removes. [Selection] Figure 1

Description

  The present invention relates to a desulfurization method, a desulfurization apparatus, and a fuel cell power generation system.

  As the fuel gas for the steam reforming process, various hydrocarbons such as natural gas, coal gas (COG), liquefied petroleum gas (LPG), and naphtha are used, and these generally contain a sulfur content. Yes. Since this sulfur content poisons the reforming catalyst used in the reforming process and the surrounding process catalyst and lowers the catalytic activity, it is necessary to desulfurize the fuel gas in advance.

  In such a case, a copper oxide-zinc oxide desulfurization agent impregnated and supported with nickel is known as a desulfurization agent that efficiently removes an odorant component composed of a sulfur component (see Patent Document 1). And in patent document 1, it was discovered that the life of the copper oxide-zinc oxide-based desulfurization agent impregnated and supported by nickel is significantly increased by adding a small amount of hydrogen to the fuel gas supplied to the desulfurization agent. ing.

  Therefore, when a copper oxide-zinc oxide desulfurization agent impregnated and supported with nickel is used in a fuel cell, the fuel gas is reformed into a gas containing hydrogen as a main component with a steam reforming catalyst, and then the reformed gas is used. It is considered that a part of the slag is returned to the desulfurization agent and recycled as a hydrogen source. However, this method requires a recycling pipe for returning the reformed gas, which complicates the apparatus configuration and increases the cost, and when water vapor in the gas is condensed in the recycling pipe, There was a problem that there was a possibility that it could not be stably recycled, and there was room for improvement.

  In Patent Document 2, when a Ni-based desulfurizing agent having activity for a reforming reaction is used, by adding water vapor to the fuel gas supplied to the desulfurizing agent, the desulfurizing agent removes hydrocarbons in the presence of water vapor. It has been shown that the following reforming reaction (and partial modification reaction) that converts to hydrogen occurs, and that the life of the desulfurization agent itself can be improved by using the hydrogen generated there as a hydrogen source. It was necessary, and it was expected that hydrogen could be stably supplied at a low cost.

(Reforming reaction)
CmHn + mH ₂ O → (m + n / 2) H ₂ + mCO
(Metamorphic reaction)
CO + H ₂ O → H ₂ + CO ₂

  Here, the life of the desulfurizing agent is extended because sulfur in the sulfur compound is fixed inside the desulfurizing agent via hydrogen sulfide in the presence of hydrogen, and this series of reactions is performed when hydrogen is not present. This is based on the reason that only sulfur in the sulfur compound proceeds faster than the reaction directly fixed inside the catalyst.

Japanese Patent Laid-Open No. 11-61154 JP 2011-184549 A

  However, in the technique disclosed in Patent Document 2, by generating hydrogen in the desulfurizing agent, it is possible to adopt a configuration that does not require recycled piping, but the amount of hydrogen generation is insufficient, and the life of the desulfurizing agent is sufficiently effective. However, there is a need for further improvement.

  Therefore, in view of the above circumstances, the present invention provides a desulfurization method and a desulfurization apparatus that can use a desulfurization agent in a long-term stably and with high activity while having a simple apparatus configuration. An object of the present invention is to enable stable supply of fuel gas from which sulfur components have been removed to a utilization device.

  The desulfurization method according to the present invention is characterized in that platinum is a steam reforming catalyst that performs a reforming reaction in which steam is added to a fuel gas containing a sulfur component and hydrogen gas is generated from the fuel gas in the presence of steam. A sulfur-resistant steam reforming catalyst in which at least one noble metal component selected from ruthenium, rhodium, and palladium is supported on an inorganic oxide carrier together with a catalyst metal component mainly composed of iridium, and a fuel gas containing a sulfur compound The hydrodesulfurization agent which removes a sulfur compound from is passed in order to remove the sulfur component in the fuel gas.

  According to the above configuration, the fuel gas is first contacted with the steam reforming catalyst while being mixed with the steam. Since the reforming reaction of the fuel gas occurs on the steam reforming catalyst, a part of the fuel gas is converted into hydrogen, and the fuel gas contains steam and hydrogen. When the fuel gas thus converted is passed through a hydrodesulfurization agent that removes sulfur compounds and has an activity for reforming reaction, the sulfur component contained in the fuel gas is hydrodesulfurized, and is contained in the fuel gas. The sulfur component contained is removed with high accuracy.

  When hydrodesulfurization is carried out with a hydrodesulfurizing agent, the fuel gas contains a sufficient amount of hydrogen generated by the steam reforming catalyst, so that the life of the hydrodesulfurizing agent is further improved. Can be increased.

  In other words, the steam reforming catalyst makes it possible to stably supply hydrogen to the hydrodesulfurization agent without providing a separate hydrogen gas supply facility. Additive desulfurization agents can be used with high activity. Therefore, by simply changing the configuration, the adsorption capacity of the hydrodesulfurization agent can be increased and the life can be extended, and the amount of hydrodesulfurization agent charged in the desulfurization apparatus can be reduced, or the hydrodesulfurization agent can be reduced. The desulfurization equipment filled to the specified capacity can be used over a long period of time, or the number of replacements of the hydrodesulfurization agent filled in the desulfurization equipment can be reduced within a predetermined period. I was able to plan.

  When the fuel gas is city gas, methane is the main component and an odorant is included. Therefore, desulfurization may be performed on dimethylsulfide, tetrahydrothiophene and t-butyl mercaptan as odorants. The above-mentioned desulfurization reaction can be caused by a general-purpose hydrodesulfurization agent.

Further, since the steam reforming catalyst is directly supplied with a fuel gas containing a sulfur component, sulfur poisoning resistance (long-term durability) is required. As this steam reforming catalyst, it is considered that a sulfur-resistant steam reforming catalyst in which a catalytic metal component mainly composed of platinum and iridium is supported on an inorganic oxide carrier is preferably used. As a result of intensive research, as such a steam reforming catalyst, in addition to a catalytic metal component mainly composed of platinum and iridium, at least one noble metal component (third component) selected from ruthenium, rhodium, and palladium, It has been found that when a sulfur-resistant steam reforming catalyst supported on an inorganic oxide support is selected, the steam activity is particularly high and the sulfur durability is high.
For this reason, even though it is an environment in which undesulfurized fuel gas is circulated upstream of the desulfurization section, it can be used stably over a long period of time.

Although not bound by theory, this can be explained as follows.
That is, it is assumed that platinum and iridium are adjacent metals in the periodic table, and therefore make a very stable alloy. On the other hand, platinum has a property that it is difficult to form a compound with sulfur, and iridium has a relatively high steam reforming activity. Therefore, in particular, since the steam reforming catalyst in which platinum and iridium are supported on an inorganic oxide can stably obtain desirable properties of each metal in an alloy or composite of platinum and iridium, High durability against sulfur while maintaining reforming activity. Furthermore, by containing at least one noble metal component selected from ruthenium, rhodium, and palladium having high steam reforming activity, the preferable properties of each metal are further stabilized in an alloy or composite of platinum and iridium. It is thought that it is expressed.

  In addition, it eliminates the need for hydrogen recycling pipes for systems that use hydrodesulfurization agents (for example, fuel cell power generation systems) and contributes to cost reductions in implementing desulfurization methods and downsizing of equipment configuration. In addition, since a simple configuration change is sufficient, it can be applied to various systems.

  As a result, fuel gas from which sulfur components have been accurately removed can be stably generated over a long period of time, so that high-quality fuel gas can be supplied in applications such as desulfurization of fuel gas in fuel cells.

The desulfurization apparatus according to the present invention is characterized in that a desulfurization system is provided with a supply unit for adding and supplying water vapor to a fuel gas containing a sulfur component, and a hydrodesulfurization agent for removing the sulfur compound from the fuel gas containing a sulfur compound A desulfurization apparatus comprising a part,
As a steam reforming catalyst for performing a reforming reaction for generating hydrogen gas from the fuel gas supplied by the supply unit in the presence of steam on the upstream side in the fuel gas flow direction of the desulfurizing agent, platinum and iridium are main components. And a hydrogen generation part provided with a sulfur-resistant steam reforming catalyst in which at least one noble metal component selected from ruthenium, rhodium and palladium is supported on an inorganic oxide carrier. .

  According to the above configuration, steam is added to the fuel gas containing the sulfur component in the supply unit, and the fuel gas is supplied to the hydrodesulfurization agent in the desulfurization unit. Here, since the hydrogen generator is provided on the upstream side of the hydrodesulfurization agent in the fuel gas flow direction, the fuel gas first contacts the steam reforming catalyst in a state of being mixed with the steam. Since the reforming reaction of the fuel gas occurs on the steam reforming catalyst, a part of the fuel gas is converted into hydrogen, and the fuel gas contains steam and hydrogen. When the fuel gas thus converted is supplied to the desulfurization section, the sulfur component contained in the fuel gas is hydrodesulfurized by the hydrodesulfurization agent provided in the desulfurization section and is contained in the fuel gas. Sulfur components are removed with high accuracy.

  When hydrodesulfurization is performed in the desulfurization section, the fuel gas contains a sufficient amount of hydrogen generated in the hydrogen generation section, so that the effect of improving the life of the hydrodesulfurization agent is further enhanced. Can do.

Further, since the steam reforming catalyst is directly supplied with a fuel gas containing a sulfur component, sulfur poisoning resistance (long-term durability) is required. As this steam reforming catalyst, it is considered that a sulfur-resistant steam reforming catalyst in which a catalytic metal component mainly composed of platinum and iridium is supported on an inorganic oxide carrier is preferably used. As a result of intensive research, as such a steam reforming catalyst, in addition to a catalytic metal component mainly composed of platinum and iridium, at least one noble metal component (third component) selected from ruthenium, rhodium, and palladium, It has been found that when a sulfur-resistant steam reforming catalyst supported on an inorganic oxide support is selected, the steam activity is particularly high and the sulfur durability is high.
For this reason, even though it is an environment in which undesulfurized fuel gas is circulated upstream of the desulfurization section, it can be used stably over a long period of time.

  In other words, the hydrogen generator can stably supply hydrogen to the desulfurization unit without providing a separate hydrogen gas supply facility, and there is no need for a complicated route such as a recycle route. The hydrodesulfurization agent can be used with high activity stably over the long term. Therefore, by simply changing the configuration, the adsorption capacity of the hydrodesulfurization agent can be increased and the life can be extended, and the amount of hydrodesulfurization agent charged in the desulfurization apparatus can be reduced, or the hydrodesulfurization agent can be reduced. The desulfurization equipment filled to the specified capacity can be used over a long period of time, or the number of replacements of the hydrodesulfurization agent filled in the desulfurization equipment can be reduced within a predetermined period. I was able to plan.

  In addition, it eliminates the need for hydrogen recycling piping for systems that use hydrodesulfurization agents (for example, fuel cell power generation systems) and contributes to cost reductions in the construction of desulfurization equipment and compact equipment construction. In addition, since a simple configuration change is sufficient, it can be applied to various systems.

  As a result, fuel gas from which sulfur components have been accurately removed can be stably generated over a long period of time, so that high-quality fuel gas can be supplied in applications such as desulfurization of fuel gas in fuel cells.

  The said structure WHEREIN: The said hydrogen production | generation part may be formed in the small capacity | capacitance compared with the said desulfurization part.

  As the desulfurization equipment, the main reaction is hydrodesulfurization of sulfur components in the fuel gas out of the gas flowing through the desulfurization section, and the size of the desulfurization section is set to an appropriate size according to the amount of fuel gas supplied. Can be set. On the other hand, the reaction for generating hydrogen gas to be supplied to the desulfurization unit in the hydrogen generation unit can be suppressed to the minimum necessary for extending the life of the hydrodesulfurization agent in the desulfurization unit. Then, while the desulfurization part is set to a size capable of processing a sufficient amount of fuel gas, the capacity of the hydrogen generation part necessary for generating hydrogen gas to be supplied to the desulfurization part is theoretically larger than that of the desulfurization part. A sufficiently small capacity is acceptable. Therefore, by forming the hydrogen generation part in a small capacity relative to the desulfurization part, hydrogen purification by the hydrogen generation part can be performed in a well-balanced manner, and the desulfurization apparatus can be configured without increasing the size more than necessary.

  Further, the hydrodesulfurization agent can be a nickel-based desulfurization agent mainly composed of copper oxide and zinc oxide impregnated and supported by nickel.

In such a nickel-based desulfurization agent, the reforming reaction and hydrogenolysis reaction by nickel and the adsorption reaction by copper oxide and zinc oxide exhibit a balanced activity, and as a whole exhibit a high desulfurization activity. Since the nickel-based desulfurization agent has activity for the reforming reaction, hydrogen is generated by reforming the fuel gas, and the hydrogen-based desulfurization agent itself has the effect of improving the life of the nickel-based desulfurization agent. Also functions to assist the supply of hydrogen to the unit.
Moreover, there is little deterioration by water vapor | steam, and it becomes the structure which can maintain high desulfurization activity over a long term.

  The inorganic oxide carrier may be composed mainly of at least one selected from the group consisting of zirconia, alumina, and titania.

  The inorganic oxide carrier can be selected from alumina such as α-alumina and γ-alumina, silica, zirconia, titania, and mixtures thereof. Among them, α-alumina, zirconia and titania have high heat resistance and are heated. It can be said that it is particularly suitable for the use conditions of the steam reforming catalyst of the hydrocarbon compounds of the present invention, which is assumed to be used for a long time in the state.

  In addition, it is experimentally clarified that the steam reforming catalyst using zirconia has high activity from the examples described later, and is considered to be particularly preferable.

  Further, the inorganic oxide carrier may contain lanthanum or neodymium.

  By modifying the inorganic oxide with lanthanum or neodymium, the sulfur resistance of the sulfur-resistant steam reforming catalyst is enhanced, and the hydrogen concentration supplied to the desulfurization section is maintained high for a long time, leading to higher activity. It is thought that.

The characteristic configuration of the fuel cell system of the present invention includes the desulfurization device,
A reformer for reforming the fuel gas desulfurized by the desulfurizer to generate a reformed gas mainly composed of hydrogen;
A fuel cell that generates electricity using the reformed gas supplied from the reformer as a fuel;
It is in the point with.

  That is, according to the above configuration, the desulfurization device is provided as a component of the fuel cell power generation system, and the fuel gas from the desulfurization device can be reformed by the reformer to produce hydrogen as fuel for the fuel cell. Then, the fuel cell can be operated with the hydrogen to generate a power.

  As described above, in the desulfurization apparatus, the desulfurization reaction can be performed in the presence of water vapor. Further, since the hydrodesulfurization agent is accommodated in the desulfurization part, a reforming reaction also occurs inside the desulfurization part, and the desulfurization reaction is performed in the presence of hydrogen gas. Further, the desulfurization apparatus includes a steam reforming catalyst that performs a reforming reaction for generating hydrogen gas from the fuel gas supplied by the supply unit in the presence of steam in the upstream of the hydrodesulfurization agent in the fuel gas flow direction. Since the provided hydrogen generator is provided, the fuel gas reforming reaction occurs on the steam reforming catalyst, so that part of the fuel gas is converted to hydrogen, and the fuel gas contains steam and hydrogen. become. When the fuel gas converted in this way is supplied to the desulfurization section, the hydrodesulfurization reaction by the hydrodesulfurization agent proceeds, so the sulfur component is adsorbed on the hydrodesulfurization agent as hydrogen sulfide, High desulfurization performance is exhibited and the life of the hydrodesulfurization agent can be extended.

  Therefore, by simply changing the configuration, the adsorption capacity of the hydrodesulfurization agent can be increased and the life can be extended, and the amount of hydrodesulfurization agent charged in the desulfurization apparatus can be reduced, or the hydrodesulfurization agent can be reduced. The desulfurization equipment filled to the specified capacity can be used over a long period of time, or the number of replacements of the hydrodesulfurization agent filled in the desulfurization equipment can be reduced within a predetermined period. I was able to plan. Therefore, the fuel cell power generation system can contribute to stable operation and the like such as less maintenance.

  Therefore, the present invention provides a desulfurization method and a desulfurization apparatus that can use a hydrodesulfurization agent with high activity stably over a long period of time while having a simple apparatus configuration. The fuel gas from which components have been removed can be stably supplied.

Schematic configuration diagram of a fuel cell power generation system Schematic configuration diagram of exhaust heat recovery mechanism and heating means

  Below, the desulfurization method concerning embodiment of this invention is demonstrated, exemplifying the desulfurization apparatus 2 used for the fuel cell power generation system S. In addition, although suitable examples are described below, these examples are described in order to more specifically illustrate the present invention, and various modifications can be made without departing from the spirit of the present invention. The present invention is not limited to the following description.

[Fuel cell power generation system]
As shown in FIG. 1, the fuel cell power generation system S is desulfurized by the fuel gas supply unit 10, the desulfurization device 2 for removing sulfur compounds from the fuel gas P containing sulfur compounds, and the desulfurization device 2. A reformer 3 that reforms the fuel gas P to generate a reformed gas R containing hydrogen as a main component, and a fuel cell 6 that generates electricity using the reformed gas R supplied from the reformer 3 as fuel. And.

[Desulfurization equipment]
The desulfurization apparatus 2 removes sulfur compounds from the fuel gas P containing sulfur compounds. The desulfurization apparatus 2 includes a supply unit 20 that supplies a fuel gas P mainly composed of hydrocarbons such as methane and propane. The supply unit 20 contains a sulfur component supplied from the fuel gas supply unit 10. The fuel gas P is provided with a water vapor supply unit 11 for adding water vapor.

  In the present embodiment, methane, propane or the like used as the fuel gas P is supplied in the form of city gas, LPG, or the like. City gas, LPG, and the like generally contain a sulfur compound such as dimethyl sulfide (DMS) as an odorant. The fuel gas P is desulfurized from the supply unit 20 in a state where water vapor is added from the water vapor supply unit 11 after passing through the gas flow rate adjusting valve 12 for adjusting the flow rate and the pump 13 for energizing the flow of the fuel gas P. Supplied to the device 2. The desulfurization apparatus 2 includes a desulfurization unit 21 provided with a nickel-based desulfurization agent (an example of a hydrodesulfurization agent 2a) having an activity for a reforming reaction that generates hydrogen gas from the fuel gas P in the presence of water vapor. Steam reforming that performs a reforming reaction for generating hydrogen gas from the fuel gas P supplied by the supply unit 20 in the presence of steam on the upstream side in the flow direction of the fuel gas P inside the vessel constituting the desulfurization apparatus 2 A hydrogen generator 22 provided with a catalyst 2b is provided.

  Further, the water vapor supply unit 11 is configured to supply water vapor to the fuel gas P from a separately provided water vapor generator 14 by a water vapor flow rate adjusting valve 11a. The steam flow rate adjusting valve 11a has a water vapor addition amount of 5% by volume to 20% by volume with respect to the volume of the fuel gas P based on a detection value of a water vapor sensor Se1 provided between the water vapor supply unit 11 and the desulfurization device 2. It is controlled to be maintained.

  When the fuel gas P is supplied from the supply unit 20 to the desulfurization apparatus 2, methane, propane, and the like contained in the fuel gas P are provided in the hydrogen generation unit 22 together with a catalytic metal component mainly composed of platinum and iridium, Part of the steam reforming reaction is caused by a sulfur-resistant steam reforming catalyst (an example of the steam reforming catalyst 2b) in which at least one noble metal component selected from ruthenium, rhodium and palladium is supported on an inorganic oxide carrier. Then, after being converted into hydrogen and carbon monoxide (and carbon dioxide), it is supplied to the desulfurization section 21. On the other hand, the sulfur compound contained in the fuel gas P does not react even when it comes into contact with the steam reforming catalyst 2b in the hydrogen generation unit 22, and is a nickel-based desulfurization agent provided in the desulfurization unit 21 (an example of a hydrodesulfurization agent 2a). Is removed by adsorption. Thus, the fuel gas P is desulfurized when passing through the desulfurization apparatus 2. The fuel gas P desulfurized by the desulfurization device 2 is supplied to the reformer 3. Also, in the desulfurization section 21, a nickel-based desulfurization agent having an activity for a reforming reaction that generates hydrogen gas from the fuel gas P in the presence of water vapor is used as the hydrodesulfurization agent 2a. Methane, propane, and the like partly undergo a steam reforming reaction and are converted into hydrogen and carbon monoxide (and carbon dioxide).

  In addition, the hydrogen generated in the hydrogen generation unit 22 and the hydrogen generated in the desulfurization unit 21 are efficiently desulfurized by the hydrodesulfurization reaction in the desulfurization unit 21 to improve the performance of the hydrodesulfurization agent 2a and extend the life. It has a structure that contributes. From the experimental examples described later, it was found that the hydrodesulfurization agent 2a filled in the desulfurization part 21 can maintain high desulfurization activity over a long lifetime.

Further, the desulfurization apparatus 2 includes a heating unit 23 that heats the hydrodesulfurization agent 2 a in the desulfurization section 21. The heating means 23 is maintained and controlled so that the hydrodesulfurization agent 2a is heated to 200 ° C. to 400 ° C. based on the temperature detection value of the temperature sensor Se2 provided in the desulfurization apparatus 2.
Thereby, it is possible to maintain the desulfurization performance satisfactorily for a long time in the hydrodesulfurization agent 2a. As a result, replacement of the hydrodesulfurizing agent 2a over a predetermined lifetime can be made unnecessary or limited.

  Further, it has been found that the steam reforming catalyst 2b generates sufficient hydrogen to activate the hydrodesulfurization agent 2a even when the amount is sufficiently smaller than that of the hydrodesulfurization agent 2a. In the following embodiments, the steam reforming catalyst 2b and the hydrodesulfurization agent 2a are used at a volume ratio (steam reforming catalyst 2b: hydrodesulfurization agent 2a) at a ratio of (1: 2). This ratio is actually set to about (1: 1) to (1: 5).

[Hydrogen desulfurization agent]
The hydrodesulfurization agent 2a filled in the desulfurization part may be any hydrodesulfurization agent such as nickel-molybdenum, cobalt-molybdenum, nickel, etc. A copper oxide-zinc oxide desulfurization agent impregnated and supported by nickel is preferably used.

[Production method of nickel-based desulfurization agent]
A mixed aqueous solution containing a copper salt, a zinc salt and an aluminum salt in a predetermined ratio is added dropwise to an aqueous solution of sodium carbonate maintained at a predetermined temperature while stirring to form a precipitate, and then the precipitate is thoroughly washed with water. , Filtered and dried.

  Next, the dried precipitate was calcined, added to water to form a slurry, filtered, dried, added with a molding aid, and extruded.

  Next, the resulting molded product was impregnated with an aqueous nickel salt solution, dried and fired to obtain a desulfurization agent precursor. A hydrogen-containing desulfurizing agent 2a was obtained by flowing nitrogen gas containing hydrogen through the desulfurizing part 21 filled with the desulfurizing agent precursor and reducing it under heating conditions.

[Steam reforming catalyst]
The steam reforming catalyst 2b provided in the hydrogen generation part 22 has at least one noble metal component selected from ruthenium, rhodium and palladium in addition to a catalytic metal component mainly composed of platinum and iridium, which will be described below. Is used as a sulfur-resistant steam reforming catalyst supported on an inorganic oxide support.

[Inorganic oxide support]
As the inorganic oxide carrier for supporting the noble metal component, sintered inorganic oxides such as zirconia, alumina and titania can be used as they are, or other components such as lanthanoid elements such as lanthanum and neodymium can be used. It may be contained. As a method of adding other components to the inorganic oxide carrier, it is possible to add it by mixing elements such as lanthanum and neodymium with inorganic oxides such as zirconia, alumina, and titania and then manufacturing them by sintering or the like. Alternatively, the inorganic oxide carrier can contain other components by previously supporting an element such as lanthanum or neodymium on an inorganic oxide such as zirconia, alumina, or titania.

[Method for producing steam reforming catalyst]
A granular inorganic oxide support was impregnated with a mixed aqueous solution of a platinum salt, an iridium salt, and a salt of at least one noble metal component selected from ruthenium, rhodium, and palladium as a third component, and dried. This was immersed in an aqueous NaOH solution and subjected to a liquid phase reduction treatment with an aqueous hydrazine solution.
Thereafter, after washing with pure water, drying was performed to obtain a steam reforming catalyst 2b.

[Reformer]
The reformer 3 reforms the fuel gas P desulfurized by the desulfurizer 2 to generate a reformed gas R mainly composed of hydrogen. The reformer 3 has a reforming catalyst (not shown) such as ruthenium, nickel, or platinum. Further, the steam generated by the steam generator 14 is supplied to the reformer 3 in a form mixed with the fuel gas P after the desulfurization process by the desulfurizer 2. The amount of water vapor mixed with the fuel gas P is adjusted by the water vapor flow rate adjusting valve 14a. The reformer 3 reforms the fuel gas P into a reformed gas R containing hydrogen, carbon monoxide, and carbon dioxide. When the fuel gas P is a gas containing methane as a main component, methane and water vapor undergo a reforming reaction and reformed to a reformed gas R containing hydrogen, carbon monoxide, and carbon dioxide.

  The reformed gas R reformed by the reformer 3 is supplied to the carbon monoxide shifter 4.

[Carbon monoxide conversion equipment]
The carbon monoxide shifter 4 performs processing so as to reduce carbon monoxide contained in the reformed gas R that has been reformed by the reformer 3. The carbon monoxide shifter 4 has a carbon monoxide shift catalyst (not shown) such as iron-chromium or copper-zinc. In the carbon monoxide shifter 4, the carbon monoxide and water vapor remaining in the reformed gas R generated by the reformer 3 are, for example, about 200 ° C. to 300 ° C. due to the catalytic action of the carbon monoxide shift catalyst. The carbon monoxide is converted to carbon dioxide by a modification reaction at the reaction temperature of

  The reformed gas R modified by the carbon monoxide modification device 4 is supplied to the carbon monoxide removal device 5.

[Carbon monoxide removal equipment]
The carbon monoxide removing device 5 selectively oxidizes and removes carbon monoxide remaining in the reformed gas R subjected to the modification treatment by the carbon monoxide modifying device 4. The carbon monoxide removal device 5 has a carbon monoxide removal catalyst (not shown) such as ruthenium, platinum, palladium, or rhodium. In the carbon monoxide removal apparatus 5, the carbon monoxide remaining in the reformed gas R at the reaction temperature of about 100 ° C. to 200 ° C. is added to the air in the air to which the carbon monoxide removal catalyst is added. It is selectively oxidized by oxygen. As a result, a hydrogen-rich reformed gas R (fuel) having a low carbon monoxide concentration (for example, 10 ppm or less) is generated. The generated hydrogen-rich reformed gas R is supplied to the fuel cell 6.

〔Fuel cell〕
The fuel cell 6 generates power using the reformed gas R supplied from the reformer 3 as fuel. In the present embodiment, as described above, the reformed gas R supplied from the reformer 3 is in a hydrogen-rich state after passing through the carbon monoxide shifter 4 and the carbon monoxide remover 5, and the fuel cell. 6 performs power generation using the hydrogen-rich reformed gas R as a fuel. Such a fuel cell 6 includes various types such as a polymer electrolyte fuel cell (PEFC), a solid oxide fuel cell (SOFC), a phosphoric acid fuel cell (PAFC), and a molten carbonate fuel cell (MCFC). The system can be adopted. The fuel cell 6 is operated at a temperature higher than room temperature according to each method. In the present embodiment, a polymer electrolyte fuel cell (PEFC) is employed as the fuel cell 6, and the fuel cell 6 is operated at a temperature of 80 to 100 ° C. In the fuel cell 6 according to the present embodiment, in the presence of a platinum catalyst, a reaction between the hydrogen-rich reformed gas R supplied from the carbon monoxide removing device 5 and oxygen (air) supplied from the blower 15, DC power DC is taken out.

  The DC power DC generated and taken out by the fuel cell 6 is sent to the power converter 7. The power converter 7 converts the DC power DC into AC power AC having a predetermined frequency. The AC power AC is configured to be connected to a commercial power system and supplied to a power load (not shown) such as an electric device.

[Exhaust heat recovery mechanism]
In the present embodiment, the heating means 23 is provided in a state where the hydrodesulfurization agent 2a can be heated using the exhaust heat discharged from the fuel cell 6 as a heat source.
As shown in FIG. 2, the fuel cell power generation system S includes an exhaust heat recovery mechanism 8 that recovers exhaust heat exhausted from the fuel cell 6. The exhaust heat recovery mechanism 8 is a mechanism for recovering exhaust heat exhausted from the fuel cell 6 and supplying the recovered heat to the hydrodesulfurization agent 2a. The exhaust heat recovery mechanism 8 includes a heat exchanger 82 for performing heat exchange between the exhaust gas from the fuel cell 6 and the exhaust heat recovery water flowing through the exhaust heat recovery circuit 80. By operating the pump 81, the exhaust heat recovery water flowing through the exhaust heat recovery circuit 80 exchanges heat with the exhaust gas from the fuel cell 6 in the heat exchanger 82. The exhaust heat recovery water heated when passing through the heat exchanger 82 is supplied to the heating means 23 of the desulfurization apparatus 2 to heat the hydrodesulfurization agent 2a in the desulfurization section 21. The exhaust heat recovery water after heating the hydrodesulfurization agent 2 a is stored in a hot water storage tank 83. That is, the recovered heat is stored in the form of the amount of heat that the exhaust heat recovery water stored in the hot water storage tank 83 has.

  The hot water storage tank 83 is configured in a so-called temperature stratification type in which hot water is stored in a form in which high temperature hot water stays in the upper part and low temperature hot water stays in the lower part of the high temperature layer. In the present embodiment, the relatively high temperature exhaust heat recovery water after heating the hydrodesulfurization agent 2 a is supplied to the vicinity of the upper end of the hot water storage tank 83. When the pump 81 is operated, relatively high-temperature hot water is supplied to the heat exchanger 82 as exhaust heat recovery water from the high-temperature layer staying at the upper end of the hot water storage tank 83. By repeating the above operation, it is possible to recover the exhaust heat discharged from the fuel cell 6 and to heat the hydrodesulfurization agent 2a. Even before the fuel cell 6 starts power generation, the heat of the relatively high temperature hot water staying at the upper end of the hot water storage tank 83 is supplied to the hydrodesulfurization agent 2a in the desulfurization section 21, It is possible to heat the hydrodesulfurization agent 2a. That is, the heat stored in the form of the amount of heat of the exhaust heat recovery water in the hot water storage tank 83 is supplied to the hydrodesulfurization agent 2 a in the desulfurization section 21.

  In the present embodiment, the recovered heat is further supplied to the heat load 84. That is, the relatively high temperature hot water staying at the upper end of the hot water storage tank 83 is further supplied to the heat load 84. Thus, the overall energy efficiency of the fuel cell power generation system S is improved by effectively using the exhaust heat accompanying the power generation of the fuel cell 6. The exhaust heat recovery mechanism 8 is also preferably configured to include a backup heater for heating the hot water supplied from the hot water storage tank 83. In this way, when hot water is supplied from the hot water storage tank 83 to the hydrodesulfurization agent 2a and the heat load 84, when the hot water temperature does not reach the temperature required for the desulfurization agent 2a and the heat load 84, Hot water can be heated appropriately.

  Further, since the hydrodesulfurization agent 2a maintains its desulfurization performance well over a long period of time, the reforming catalyst of the reforming device 3 provided in the fuel cell power generation system S in which the desulfurization device 2 is incorporated is DMS. It is also possible to effectively suppress over a long period of time from being poisoned by sulfur compounds such as, etc. and causing performance degradation. Therefore, since the state of the reformer 3 and the fuel cell 6 is maintained in a good state for a long time, the fuel cell power generation system S according to the present embodiment can stably generate power for a long time. It is possible.

〔Control device〕
Next, the configuration of the control device 30 will be described. As shown in FIG. 1, the control device 30 provided in the fuel cell power generation system S functions as a core member that controls the operation of each part of the fuel cell power generation system S, and includes a desulfurization control unit 31 and a system control unit (non-control unit). (Shown in FIG. 1). Further, the control device 30 includes an arithmetic processing device such as a CPU as a core member, and from a random access memory (RAM) configured to be able to read and write data from the arithmetic processing device, and an arithmetic processing device. It has a storage device such as a ROM (Read Only Memory) configured to be able to read data (not shown). Each functional unit of the control device 30 is configured by software (program) stored in a ROM or the like, hardware such as a separately provided arithmetic circuit, or both. Each functional unit is configured to be able to exchange information with each other.

In addition, the fuel cell power generation system S includes a plurality of sensors provided in each part of the system, specifically, a water vapor sensor Se1 and a temperature sensor Se2 including dew point sensors and the like. The water vapor sensor Se <b> 1 is provided in the fuel gas P supply path upstream of the desulfurization unit 21. The water vapor sensor Se1 is a sensor that detects the water vapor amount of the fuel gas P flowing into the desulfurization unit 21, and can be realized using, for example, a capacitance type dew point meter. The temperature sensor Se <b> 2 is provided in the vicinity of the desulfurization unit 21. This temperature sensor Se2 is a sensor for detecting the temperature of the hydrodesulfurization agent 2a accommodated in the desulfurization section 21, and is a non-contact type thermometer such as a radiation thermometer, a contact thermometer such as a surface thermometer, etc. It can be realized using.
Information indicating detection results by the water vapor sensor Se1 and the temperature sensor Se2 is output to the control device 30. Based on the outputs from the water vapor sensor Se1 and the temperature sensor Se2, the control device 30 heats the heating means 23, the amount of water vapor supplied from the water vapor generator 14 (the opening degree of the water vapor flow rate adjusting valves 11a, 14a), and the heating operation of the fuel cell 6. The heating control part 32 which controls is provided.

  The control device 30 is also configured to control the opening of the gas flow rate adjustment valve 12 and the water vapor flow rate adjustment valve 11a, the operation of the pump 13, the operation of the blower 15, the operation of the power converter 7, and the like. .

[Reference Example 1]
(Preparation of sulfur-resistant steam reforming catalyst (1 mass% platinum-1 mass% iridium / zirconia catalyst))
9.8 g of zirconia as a 3 mm diameter x 3 mm long tablet-shaped inorganic oxide carrier was impregnated with 4 mL of a mixed solution of chloroplatinic acid and iridium chloride (platinum and iridium content each 0.1 g), and the mixture was heated at 80 ° C for 3 hours. Dry, soak for 20 hours in 0.375N-NaOH aqueous solution, perform liquid phase reduction treatment with 1% by mass hydrazine aqueous solution, wash with pure water, dry at 80 ° C. for 3 hours, and add 1% by mass to zirconia. A catalyst in which platinum and 1% by mass of iridium were supported (sometimes abbreviated as 1% by mass of platinum-1% by mass of iridium / zirconia catalyst) was obtained.

[Example 1]
(Preparation of sulfur-resistant steam reforming catalyst (1 mass% platinum-1 mass% iridium-1 mass% ruthenium / zirconia catalyst))
9.7 g of zirconia as a 3 mm diameter × 3 mm long tablet-shaped inorganic oxide carrier was impregnated with 4 ml of a mixed aqueous solution of chloroplatinic acid, iridium chloride and ruthenium chloride (0.1 g each of platinum, iridium and ruthenium contents), After drying at 80 ° C. for 3 hours, immersion treatment with 0.375N-NaOH aqueous solution for 20 hours, liquid phase reduction treatment with 1% by mass hydrazine aqueous solution, washing treatment with pure water, drying at 80 ° C. for 3 hours, A catalyst comprising 1% by weight platinum, 1% by weight iridium and 1% by weight ruthenium supported on zirconia was obtained.

[Example 2]
Preparation of sulfur-resistant steam reforming catalyst (1 mass% platinum-1 mass% iridium-1 mass% rhodium / zirconia catalyst) 9.7 g of zirconia as a 3 mm diameter x 3 mm long tablet-shaped inorganic oxide support was added to chloroplatinic acid. , 4 ml of iridium chloride / rhodium chloride mixed aqueous solution (platinum, iridium, rhodium content 0.1 g each) was impregnated in total, dried at 80 ° C. for 3 hours, immersed in 0.375 N-NaOH aqueous solution for 20 hours, 1 mass A catalyst comprising 1% platinum, 1% iridium and 1% rhodium supported on zirconia by drying in a liquid phase with a 1% aqueous hydrazine solution, washing with pure water and drying at 80 ° C. for 3 hours. Obtained.

Example 3
Preparation of sulfur-resistant steam reforming catalyst (1% by weight platinum-1% by weight iridium-1% by weight palladium / zirconia catalyst) 9.7 g of zirconia as a tablet-shaped inorganic oxide support having a diameter of 3 mm × 3 mm was added to chloroplatinic acid. , 4 ml of iridium chloride / palladium chloride mixed aqueous solution (platinum, iridium, palladium content 0.1 g each) was impregnated, dried at 80 ° C. for 3 hours, immersed in 0.375 N-NaOH aqueous solution for 20 hours, 1 mass A catalyst comprising 1% by weight platinum, 1% by weight iridium and 1% by weight palladium supported on zirconia after liquid phase reduction treatment with a 1% hydrazine aqueous solution, washing treatment with pure water, and drying at 80 ° C. for 3 hours. Obtained.

Example 4
Preparation of sulfur-resistant steam reforming catalyst (1 mass% platinum-1 mass% iridium-1 mass% ruthenium / 10 mass% neodymium / zirconia catalyst) 9 g of zirconia as a 3 mm diameter x 3 mm long tablet-shaped inorganic oxide carrier 10% by weight neodymium as an inorganic oxide carrier impregnated with 4 ml of a neodymium nitrate aqueous solution (neodymium content: 1 g), dried at 60 ° C. for 15 hours and then calcined at 800 ° C. for 5 hours to contain a lanthanoid element / A zirconia carrier was obtained. 9.7 g of this inorganic oxide support was impregnated with 4 ml of a mixed aqueous solution of chloroplatinic acid, iridium chloride and ruthenium chloride (0.1 g each of platinum, iridium and ruthenium contents), dried at 80 ° C. for 3 hours, and 0.375 N -Immersion treatment with NaOH aqueous solution for 20 hours, liquid phase reduction treatment with 1 mass% hydrazine aqueous solution, washing treatment with pure water, drying at 80 ° C for 3 hours, 10 mass% neodymium / zirconia with 1 mass% platinum A catalyst having 1% by mass iridium and 1% by mass ruthenium supported thereon was obtained.

Example 5
Preparation of sulfur-resistant steam reforming catalyst (1 mass% platinum-1 mass% iridium-1 mass% ruthenium / 10 mass% lanthanum / zirconia catalyst) 9 g of zirconia as a 3 mm diameter x 3 mm long tablet-shaped inorganic oxide carrier Except impregnated with 4 ml of lanthanum nitrate aqueous solution (1 g of lanthanum content), 10 mass% lanthanum / zirconia was supported by 1 mass% platinum, 1 mass% iridium and 1 mass% ruthenium in the same manner as in Example 4. A catalyst was obtained.

Example 6
Preparation of sulfur-resistant steam reforming catalyst (1% by weight platinum-1% by weight iridium-1% by weight ruthenium / 10% by weight lanthanum / α-alumina catalyst) 9 g α-alumina as an inorganic oxide carrier with a diameter of 3 mm and 4 ml neodymium nitrate aqueous solution Except for impregnating the whole amount of (neodymium content 1 g), a catalyst obtained by supporting 1% by mass of platinum, 1% by mass of iridium and 1% by mass of ruthenium on 10% by mass of lanthanum / α alumina in the same manner as in Example 4 was obtained. It was.

(Hydrogen production test)
Using the sulfur-resistant steam reforming catalyst prepared in Examples 1 to 3 and Reference Example 1, a city gas steam reforming test was conducted under the following conditions, and hydrogen in the catalyst outlet gas one hour after gas introduction. Concentration was measured. As a result, it was confirmed that hydrogen was generated. Table 1 shows the hydrogen concentration in the product gas at that time (after 1 hour from the start of the test).

(Hydrogen generation test conditions)
Catalyst temperature: 250 ° C
City gas composition: methane 88.9 vol%, ethane 6.8 vol%, propane 3.1 vol%, butane 1.2 vol%, dimethyl sulfide 2.6 volppm, tertiary butyl mercaptan 1.7 volppm
City gas flow rate: 1 L / min (N)
Water vapor addition amount: 10 mol% with respect to city gas flow rate
Hydrogen concentration analysis method: Shimadzu gas chromatograph with TCD detector

From Table 1, the catalyst prepared in Reference Example 1 has a high ability to perform a reforming reaction that generates hydrogen gas from the fuel gas P in the presence of water vapor, and the hydrodesulfurization agent 2a of the desulfurization section 21 is used at 250 ° C. It can be seen that it has the ability to generate the hydrogen necessary for long-life use. On the other hand, all of the catalysts prepared in Examples 1 to 3 contain noble metal components (ruthenium, rhodium, palladium) as the third component, and the catalyst not containing the third component of Reference Example 1 It was revealed that it has a significantly high hydrogen production capacity. That is, when a sulfur-resistant steam reforming catalyst in which at least one noble metal component selected from ruthenium, rhodium and palladium is supported on an inorganic oxide carrier together with a catalytic metal component mainly composed of platinum and iridium is selected. It was revealed that the water vapor activity is high and the sulfur durability is high.
As the steam reforming catalyst 2b, it is known to use various metal oxides (inorganic oxides) such as zirconia, alumina, and titania as the carrier. Of course, a highly reactive and highly durable catalyst is used. From the viewpoint that it is preferable to employ the inorganic oxide carrier, it is preferable that the inorganic oxide carrier is mainly composed of at least one selected from the group selected from zirconia, alumina, and titania.

Example 7
(Preparation of nickel-based desulfurization agent (nickel / copper-zinc-alumina catalyst))
An aqueous solution of sodium carbonate in which a mixed aqueous solution (concentration is 0.5 mol / L) containing copper nitrate, zinc nitrate and aluminum hydroxide in a ratio (molar ratio) of 1: 1: 0.3 is maintained at about 60 ° C. The mixture was added dropwise with stirring to a concentration of 0.6 mol / L to cause precipitation, and the precipitate was sufficiently washed with water, filtered, and dried. Next, the dried precipitate was calcined at about 280 ° C., added to water to form a slurry, filtered, dried, added with a molding aid (graphite), and extruded to a diameter of 1/8 inch. Next, the obtained molded product was impregnated with an aqueous nickel nitrate solution (Ni concentration 0.2 mol / L), then dried and fired at about 300 ° C. to obtain a desulfurizing agent 2a. The nickel content of the desulfurizing agent 2a was 5% by mass.

(Desulfurization test of city gas)
For the desulfurization apparatus 2 shown in FIG. 1, the above-described nickel-based desulfurization agent (hydrogenated desulfurization agent 2a: filled in the desulfurization section 21) and the sulfur-resistant steam reforming catalyst (steam) prepared in Reference Example 1 and Examples 1-6. Using the reforming catalyst 2b: filling the hydrogen generation unit 22, a city gas desulfurization performance test was performed under the following conditions. In this test, Table 2 shows the time (breakthrough time) until dimethyl sulfide is detected at 0.02 ppm by volume in the desulfurized gas.

(City gas desulfurization test conditions)
Sulfur-resistant steam reforming catalyst: 10 mL (located on the gas inlet side with respect to the hydrodesulfurization agent)
Nickel-based desulfurization agent amount: 20 mL (located on the gas outlet side with respect to the sulfur-resistant steam reforming catalyst)
Pretreatment: Nitrogen gas 1 L / min containing 20% by volume of hydrogen at a temperature of 250 ° C. for 1 hour.
City gas composition: methane 88.9 vol%, ethane 6.8 vol%, propane 3.1 vol%, butane 1.2 vol%, dimethyl sulfide 2.6 volppm, tertiary butyl mercaptan 1.7 volppm
City gas flow rate: 1 L / min (N)
Steam addition amount: 10% by volume relative to city gas flow rate
Sulfur concentration analysis method: Shimadzu gas chromatograph with FPD detector

[Comparative Example 1]
Example 7 is the same as Example 7 except that the hydrogen generating unit 22 filled with the sulfur-resistant steam reforming catalyst 2b is not disposed on the gas inlet side of the desulfurizing unit 21 filled with the nickel-based desulfurizing agent 2a (only the nickel-based desulfurizing agent is used). Under conditions, city gas desulfurization tests were conducted. Table 2 shows the time until 0.02 volume ppm of dimethyl sulfide is detected in the desulfurized gas in this test.

[Comparative Example 2]
A city gas desulfurization test was performed under the same conditions as in Comparative Example 1 except that water was not added. Table 2 shows the time until 0.02 volume ppm of dimethyl sulfide is detected in the desulfurized gas in this test.

  Comparing Example 7 and Comparative Examples 1 and 2 in the city gas desulfurization test, in Comparative Example 2 corresponding to the use form of the conventional desulfurization catalyst, the breakthrough until the odorant breaks through the nickel-based desulfurization agent It cannot be said that the time is sufficiently long, and it is understood that hydrogen hardly acts on the nickel-based desulfurization agent. On the other hand, as in Comparative Example 1, when steam is supplied and no hydrogen generating part is provided by the sulfur-resistant steam reforming catalyst, hydrogen is present as a result of self-hydrogen generation by the nickel-based desulfurizing agent. Although the life extension effect is seen as compared with Example 2, the hydrogen concentration at the time of breakthrough cannot be said to be sufficient, and it can be seen that the life extension effect for the nickel-based desulfurizing agent is not sufficient. On the other hand, as in Example 7, it was found that when a hydrogen generation unit using a sulfur-resistant steam reforming catalyst was provided, the breakthrough time was the longest and the amount of hydrogen generation was sufficiently high. In other words, if a steam reforming catalyst is provided in the hydrogen generation unit and provided upstream of the desulfurization unit, an environment in which a sufficient amount of hydrogen is constantly supplied to the desulfurization unit can be maintained, and the life of the desulfurization agent can be extended. It can be seen that this contributes to

  In addition, if a higher activity catalyst is used as the steam reforming catalyst, hydrogen necessary for maintaining the activity of the nickel-based desulfurization agent can be continuously supplied even if the hydrogen generation part is sufficiently small. As a result, even if a hydrogen generation unit is provided, a desulfurization device that functions sufficiently even if the desulfurization unit is small can be configured. If it is formed, it is clear that it contributes to further downsizing of the entire apparatus. Even if it is assumed that a hydrogen gas supply unit is provided in the supply unit to supply hydrogen for promoting hydrodesulfurization instead of providing a hydrogen generation unit, a hydrogen supply pipe is not required. It is clear that the whole is made compact.

  Further, the sulfur breakthrough time in the desulfurization test of city gas when the hydrogen generating part was filled with a sulfur-resistant steam reforming catalyst using a carrier obtained by adding 10% by mass of neodymium or lanthanum to the zirconia of Examples 4 and 5 is When the sulfur-steam reforming catalyst using only the zirconia support of Example 1 was filled in the hydrogen generation part (see Table 2), the hydrogen generation part was approximately doubled.

This is thought to be because the sulfur resistance of the sulfur-resistant steam reforming catalyst was enhanced by modifying zirconia with lanthanoid elements such as lanthanum and neodymium, and the hydrogen concentration supplied to the desulfurization section was maintained high for a long time. .
A lanthanoid element refers to an element having an atomic number of 57 to 71, and includes, for example, metal elements such as lanthanum, cerium, neodymium, and gadolinium.

  In addition, when α-alumina modified with lanthanum was used as a carrier (Example 6), it was found that the activity was the same as that when zirconia was used (Example 1), and a general-purpose material selected from zirconia, alumina and titania. It is considered that sufficiently high activity can be obtained by using this metal oxide as a carrier.

[Another embodiment]
(1) In the above embodiment, the hydrogen generation unit 22 and the desulfurization unit 21 have been configured to be disposed in an integral container inside the desulfurization apparatus 2, but the hydrogen generation unit 22 and the desulfurization unit 21 are configured separately. You can also In any case, it is sufficient that the hydrogen gas generated in the hydrogen generator 22 is supplied to the desulfurizer 21, and the entire apparatus can be configured more compactly provided in the same container. Yes, when configured separately, it is easy to adopt a configuration in which only the steam reforming catalyst 2b previously deteriorated in the hydrogen generator 22 can be easily replaced, and as the steam reforming catalyst 2b, the sulfur resistance performance is sufficient. It works in an environment where it is not possible to adopt a superior one.

(2) As described above, as the steam reforming catalyst 2b and the hydrodesulfurization agent 2a, various known general-purpose catalysts can be used for the catalyst metal component, the composition of the support, the component, etc. Furthermore, various well-known things can be employed for the shape and production method of the carrier.
That is, instead of adopting a pellet-like (granular) carrier, it may be a powder or a thin film. As a manufacturing method, when the catalyst metal component was supported in the form of fine particles, the sol-gel method was used, the catalyst metal component was supported on the support by the impregnation method, or after the support was supported by wet reduction. However, it is not limited to this. For example, the catalytic metal component can be made fine particles without depending on the sol-gel method, and even if a reduction treatment is performed as a post-treatment, it does not have to be wet. However, the sol-gel method is effective for easily and efficiently producing relatively fine particles, and the impregnation method is simple and versatile when supplying fine particles to a carrier, and is particularly active when wet reduction treatment is performed. It is known that it is effective to support a high-catalyst metal component on a support in a highly dispersed manner.

  The present invention provides a desulfurization method and apparatus that can use a nickel-based desulfurization agent with high activity stably over a long period of time, and is used as a fuel cell power generation system that can stably supply fuel gas from which sulfur components have been removed. can do.

DESCRIPTION OF SYMBOLS 10: Fuel gas supply part 11: Steam supply part 11a: Steam flow rate adjustment valve 12: Gas flow rate adjustment valve 13: Pump 14: Steam generation device 14a: Steam flow rate adjustment valve 15: Blower 2: Desulfurization device 2a: Hydrodesulfurization agent 2b: Steam reforming catalyst 20: Supply unit 21: Desulfurization unit 22: Hydrogen generation unit 23: Heating means 3: Reforming device 30: Control device 31: Desulfurization control unit 32: Heating control unit 4: Carbon monoxide conversion device 5 : Carbon monoxide removal device 6: Fuel cell 7: Power converter 8: Exhaust heat recovery mechanism 80: Exhaust heat recovery circuit 81: Pump 82: Heat exchanger 83: Hot water storage tank 84: Thermal load AC: AC power DC: DC Electric power P: Fuel gas R: Reformed gas S: Fuel cell power generation system Se1: Steam sensor Se2: Temperature sensor

Claims (7)

  Together with a catalytic metal component mainly composed of platinum and iridium, which is a steam reforming catalyst that performs a reforming reaction in which steam is added to a fuel gas containing a sulfur component and hydrogen gas is generated from the fuel gas in the presence of steam. , A sulfur-resistant steam reforming catalyst in which at least one noble metal component selected from ruthenium, rhodium, and palladium is supported on an inorganic oxide carrier, and a hydrodesulfurization agent that removes the sulfur compound from the fuel gas containing the sulfur compound In order to remove the sulfur component in the fuel gas. A desulfurization apparatus comprising a supply unit for adding and supplying water vapor to a fuel gas containing a sulfur component, and a desulfurization unit provided with a hydrodesulfurization agent for removing the sulfur compound from the fuel gas containing a sulfur compound. ,
Platinum and iridium are used as a steam reforming catalyst for performing a reforming reaction for generating hydrogen gas from the fuel gas supplied by the supply unit in the presence of steam on the upstream side in the fuel gas flow direction of the hydrodesulfurization agent. Desulfurization provided with a hydrogen generation part provided with a sulfur-resistant steam reforming catalyst in which at least one noble metal component selected from ruthenium, rhodium and palladium is supported on an inorganic oxide carrier together with a catalytic metal component as a main component apparatus.   The desulfurization apparatus according to claim 2, wherein the hydrogen generation unit is formed with a smaller capacity than the desulfurization unit.   The desulfurization apparatus according to claim 2 or 3, wherein the hydrodesulfurization agent is a nickel-based desulfurization agent mainly composed of copper oxide impregnated with nickel and zinc oxide.   The desulfurization apparatus according to any one of claims 2 to 4, wherein the inorganic oxide support is mainly composed of at least one selected from the group consisting of zirconia, alumina, and titania.   The desulfurization apparatus according to any one of claims 2 to 5, wherein the inorganic oxide support contains lanthanum or neodymium. A desulfurization apparatus according to any one of claims 2 to 6,
A reformer for reforming the fuel gas desulfurized by the desulfurizer to generate a reformed gas mainly composed of hydrogen;
A fuel cell that generates electricity using the reformed gas supplied from the reformer as a fuel;
Fuel cell power generation system equipped with.