JP4559676B2 - Hydrocarbon desulfurization catalyst, desulfurization method, and fuel cell system - Google Patents

Description

【００３８】
また、これらの触媒（１）〜（４）をそれぞれ１０ｍｌ反応管に充填し、水素気流中、３００℃で２時間還元した後、灯油の脱硫反応評価を行った。反応評価は、室温、常圧、ＬＨＳＶ０．５ｈ^-1、触媒量１０ｃｍ³、原料灯油中の硫黄濃度３５質量ｐｐｍの条件で行い、２００時間後の生成灯油中の硫黄濃度を表２に示した。
【００３９】
【表２】

【００４０】
（実施例３）
図１の燃料電池システムにおいて、実施例１で得られた触媒（１）を脱硫器５に充填して、灯油を燃料とし、発電試験を行なった。２００時間の運転中、脱硫器は正常に作動し、触媒の活性低下は認められなかった。
このとき水蒸気改質にはＲｕ系触媒を用い、Ｓ／Ｃ＝３、７００℃、ＬＨＳＶ＝５の条件で、ＣＯシフトではＣｕ−Ｚｎ系触媒を用い、２００℃、ＧＨＳＶ＝２０００の条件で、ＣＯ選択酸化工程ではＲｕ系触媒を用い、Ｏ_２／ＣＯ＝３、１５０℃、ＧＨＳＶ＝５０００の条件で運転を行った。燃料電池も正常に作動し電気負荷１５も順調に運転された。
【図面の簡単な説明】
【図１】本発明の燃料電池システムの一例を示す概略図である。
【符号の説明】
１ 水タンク
２ 水ポンプ
３ 燃料タンク
４ 燃料ポンプ
５ 脱硫器
６ 気化器
７ 改質器
８ 空気ブロアー
９ 高温シフト反応器
１０ 低温シフト反応器
１１ 選択酸化反応器
１２ アノード
１３ カソード
１４ 固体高分子電解質
１５ 電気負荷
１６ 排気口
１７ 固体高分子形燃料電池
１８ 加温用バーナー[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydrocarbon desulfurization catalyst. The present invention also relates to a desulfurization method using this catalyst, and further to a fuel cell system provided with a desulfurization apparatus filled with this catalyst.
[0002]
[Prior art]
A fuel cell has a feature that high efficiency can be obtained because a free energy change caused by a combustion reaction of fuel can be directly taken out as electric energy. In addition to the fact that it does not emit harmful substances, it is being developed for various uses. In particular, solid polymer fuel cells are characterized by high power density, compactness, and operation at low temperatures.
[0003]
As a fuel gas for a fuel cell, a gas containing hydrogen as a main component is generally used, and the raw materials thereof include natural gas, hydrocarbons such as LPG, naphtha and kerosene, alcohol such as methanol, ethanol, and dimethyl ether. Ether or the like is used. These carbon and hydrogen raw materials are reformed by treating them with steam at a high temperature on a catalyst, or they are partially oxidized with an oxygen-containing gas, or a self-heat recovery type reforming reaction in a system in which steam and an oxygen-containing gas coexist. The hydrogen and carbon monoxide obtained by performing the above are basically used as fuel hydrogen for fuel cells.
[0004]
However, since elements other than hydrogen exist in these raw materials, it is inevitable that impurities derived from carbon are mixed in the fuel gas to the fuel cell. Among these, carbon monoxide poisons platinum-based noble metals used as electrode catalysts for fuel cells. Therefore, if carbon monoxide is present in the fuel gas, sufficient power generation characteristics cannot be obtained. In particular, a fuel cell operated at a low temperature has a stronger carbon monoxide adsorption and is more susceptible to poisoning. Therefore, in a system using a polymer electrolyte fuel cell, it is indispensable that the concentration of carbon monoxide in the fuel gas is reduced.
[0005]
Therefore, a method is adopted in which carbon monoxide in the reformed gas obtained by reforming the raw material is reacted with water vapor to convert it into hydrogen and carbon dioxide, or a small amount of remaining carbon monoxide is removed by selective oxidation. .
Finally, the fuel hydrogen removed until the carbon monoxide concentration is sufficiently low is introduced into the cathode of the fuel cell where it is converted into protons and electrons on the electrocatalyst. The produced protons move to the anode side in the electrolyte, react with oxygen together with the electrons that have passed through the external circuit, and produce water. Electrons generate electricity by passing through an external circuit.
[0006]
The catalyst used for the reforming of raw materials until the production of fuel hydrogen for fuel cells, the removal of carbon monoxide, and the cathode electrode is often used in a reduced state such as noble metal or copper. When sulfur coexists, it becomes a catalyst poison, which reduces the catalytic activity of the hydrogen production process or the battery itself, and reduces the efficiency.
Therefore, it is considered that it is indispensable to sufficiently remove the sulfur content contained in the fuel in order to use the catalyst used in the hydrogen production process and further the electrode catalyst in its original performance.
The so-called desulfurization process, which basically removes sulfur, takes place at the very beginning of the hydrogen production process. Although it is necessary to reduce the sulfur concentration to a level at which the catalyst used in the reforming step immediately after that functions sufficiently, it is usually 0.1 ppm or less.
[0007]
Until now, the sulfur content of fuel cell raw materials has been removed by hydrodesulfurizing difficult-to-desulfurize organic sulfur compounds with a desulfurization catalyst, once converted to hydrogen sulfide that can be easily adsorbed and removed, and treated with an appropriate adsorbent. Seems to be suitable. However, a general hydrodesulfurization catalyst is used at a high hydrogen pressure. However, when it is used in a fuel cell system, since the technological development is limited to atmospheric pressure or at most 1 MPa, an ordinary desulfurization catalyst is used. The current situation is that the system cannot handle it.
[0008]
Therefore, an invention relating to a sorbent that sufficiently exhibits a desulfurization function even in a low-pressure system has been proposed, and various catalyst systems have been introduced so far. For example, JP-A-1-188404 and JP-A-1-188405 report a method for producing hydrogen by steam reforming kerosene desulfurized with a nickel-based desulfurizing agent. However, in this case, the temperature range in which desulfurization is possible under good conditions is 150 to 300 ° C., and there is a restriction on the process. The inlet temperature of the steam reformer in the subsequent stage of desulfurization is 400 to 500 ° C., and the desulfurization temperature is preferably close to this temperature in terms of the process. JP-A-2-302302 and JP-A-2-302303 disclose copper-zinc-based desulfurization agents. However, even if this catalyst is used at a relatively high temperature, carbon deposition is small. However, since the desulfurization activity is lower than that of nickel, light hydrocarbons such as natural gas, LPG and naphtha can be desulfurized. Is insufficient.
Japanese Patent Application Laid-Open No. 1-143155 discloses a method using activated carbon or a chemical solution for desulfurization. However, this catalyst has been shown to be effective for desulfurization at room temperature at start-up, but the raw material is limited to a gas body at room temperature and has no effect on naphtha and kerosene.
[0009]
[Problems to be solved by the invention]
As described above, noble metal or copper is often used in a reduced state as the catalyst used for the reforming of raw materials until the production of fuel hydrogen for fuel cells, the removal of carbon monoxide, and the cathode electrode. In such a state, when sulfur coexists, it becomes a catalyst poison, which reduces the catalytic activity of the hydrogen production process or the battery itself, and reduces the efficiency.
Therefore, it is indispensable to sufficiently remove the sulfur contained in the fuel in order to use the catalyst used in the hydrogen production process and further the electrode catalyst in its original performance. In addition, it is necessary to effectively desulfurize hardly desulfurization substances under low pressure conditions.
The present invention provides a catalyst that satisfies such difficult conditions and a fuel cell system based on the catalyst.
[0010]
[Means for Solving the Problems]
The present inventor has found a catalyst for efficiently desulfurizing a sulfur compound contained in a raw material through intensive research, and has completed the present invention.
That is, the present invention relates to a hydrocarbon desulfurization catalyst obtained by loading 0.1 to 50% by mass of a rare earth element or a rare earth compound as an element on a Y-type zeolite.
The Y-zeolite has a caivan ratio of preferably 4 or more and 11 or less.
The rare earth element is preferably La or Y.
[0011]
The present invention also relates to a method for desulfurizing a hydrocarbon raw material containing sulfur to a sulfur concentration of 0.1 ppm or less using the catalyst described above.
Furthermore, the present invention relates to a desulfurization apparatus for desulfurizing a hydrocarbon raw material containing sulfur, in which a hydrocarbon desulfurization catalyst in which 0.1 to 50% by mass of a rare earth element or a rare earth compound is supported on Y-type zeolite is loaded. And a fuel cell system having at least a reforming device for reforming the hydrocarbon raw material desulfurized by the desulfurization device into a fuel gas containing hydrogen as a main component.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
The present invention relates to a hydrocarbon desulfurization catalyst obtained by loading 0.1 to 50% by mass of a rare earth element or rare earth compound as an element on a Y-type zeolite.
It is preferable that the Y-zeolite serving as a support has a quartz-ban ratio (SiO ₂ / Al ₂ O ₃ ratio) of 4 or more and 11 or less. Particularly preferably, it is 5 or more and 6 or less. When the Y-zeolite has a Caubanium ratio of less than 4, the carrier performance is not exhibited, and when it is greater than 11, the acid point decreases and stable support becomes difficult.
The surface area of the Y-type zeolite is not particularly limited, but the upper limit is preferably 1000 m ² / g, particularly preferably 800 m ² / g, and the lower limit is preferably 50 m ² / g, particularly preferably 200 m ^2. / G.
The shape, size, and molding method of the carrier are not particularly limited. An appropriate binder may be added at the time of molding to improve the moldability. The binder is not particularly limited, and alumina, silica, titania, zirconia, or a composite oxide thereof can be used. The addition amount of the binder is not particularly limited as long as the upper limit is 50% by mass, preferably 30% by mass, and the lower limit is not particularly limited as long as the function as a binder can be exhibited. For example, 1% by mass, preferably 5% by mass. It is.
[0013]
As the rare earth element, La, Y, Ce, Sc, Yb, Gd, Sm and the like can be used, and La or Y is particularly preferable.
As the rare earth compound, chlorides, nitrates, sulfates, organic acid salts and the like of rare earth elements such as La, Y, Ce, Sc, Yb, Gd, and Sm can be used. A compound of La or Y is particularly preferable.
[0014]
There is no particular limitation on the method for supporting the rare earth element, and a known method such as a normal impregnation method or an ion exchange method can be used. For example, in the impregnation method, the rare earth compound is dissolved in a solvent such as water, ethanol or acetone, particularly preferably water, and impregnated on the support. Thereafter, the supported catalyst is obtained by drying, calcination and the like. The rare earth compound is not particularly limited as long as it is soluble in a solvent, and examples thereof include various chlorides, nitrates, sulfates, organic acid salts, and the like. Specifically, lanthanum nitrate, lanthanum chloride, yttrium nitrate, yttrium chloride Etc. can be used.
[0015]
The supported amount of the rare earth element or rare earth compound as an element is 0.1 to 50% by mass, preferably 5 to 45% by mass, particularly preferably 10 to 40% by mass. When the supported amount is less than 0.1% by mass, the catalyst performance is not exhibited, and when the supported amount exceeds 50% by mass, not only the dispersibility of the rare earth element is lowered but also from the economical aspect. It is not preferable.
[0016]
Although it does not specifically limit as a drying method, For example, natural drying in the air, deaeration drying under reduced pressure, etc. can be used. Although it does not specifically limit as a baking method, Usually, it is desirable to carry out at 250-650 degreeC as a temperature at air atmosphere, Preferably it is 400-550 degreeC, As time, it is 0.1 to 10 hours, Preferably it is 0.00. It is desirable to carry out for 5 to 5 hours.
When the catalyst prepared by the above method is used, it can be subjected to the reaction as it is, but a reduction treatment with hydrogen or the like may be performed as a pretreatment. As the conditions, the temperature is 150 to 500 ° C., preferably 250 to 400 ° C., and the time is 0.1 to 10 hours, preferably 0.5 to 5 hours.
[0017]
The shape of the catalyst is not particularly limited. For example, a catalyst formed by tableting and pulverized to an appropriate range, an extruded catalyst, an extruded catalyst added with an appropriate binder, a powdered catalyst, etc. Can be used. The binder is not particularly limited, and alumina, silica, titania, zirconia, or a composite oxide thereof can be used. Alternatively, a metal is supported on a carrier formed by tableting and pulverized to an appropriate range, an extruded carrier, a powder or a carrier formed into an appropriate shape such as a sphere, ring, tablet, cylinder, or flake. Used catalysts can be used.
[0018]
The present invention also relates to a method for desulfurizing a hydrocarbon raw material containing sulfur to a sulfur concentration of 0.1 ppm or less using the catalyst described above.
The hydrocarbon raw material containing sulfur used in the present invention is not particularly limited, and examples thereof include methane, ethane, propane, butane, natural gas, LPG, naphtha, gasoline, kerosene, and mixtures thereof. . In addition, hydrogen may be contained in the raw material.
These hydrocarbon raw materials used in the present invention usually contain 0.1 to 100 ppm by mass of sulfur.
[0019]
The pressure in the desulfurization reaction is preferably a low pressure in the range of normal pressure to 1 MPa, and more preferably normal pressure to 0.2 MPa in consideration of the economics and safety of the fuel cell system. The reaction temperature is not particularly limited as long as it is a temperature that lowers the sulfur concentration. ˜450 ° C. is preferred. More preferably, room temperature to 350 ° C., particularly preferably room temperature to 300 ° C. is employed. If the SV is too high, the desulfurization reaction does not proceed easily. On the other hand, if the SV is too low, the apparatus becomes large.
When using a liquid material is preferably in the range of 0.01～15H ^-1, more preferably in the range of 0.05～5H ^-1, range 0.1～3H ^-1 it is particularly preferred. In the case of using a gas fuel, preferably in the range of 100～10000H ^-1, more preferably in the range of 200～5000H ^-1, range 300～2000H ^-1 it is particularly preferred.
[0020]
Although the form of the desulfurization apparatus filled with the desulfurization catalyst of the present invention is not particularly limited, for example, a flow-type fixed bed system can be used. The shape of the desulfurization device can be any known shape depending on the purpose of each process, such as a cylindrical shape or a flat plate shape.
[0021]
By using the desulfurization catalyst of the present invention, the sulfur concentration can be reduced to 0.1 ppm or less from the hydrocarbon raw material containing sulfur.
The hydrocarbon raw material desulfurized to a sulfur concentration of 0.1 ppm or less can then be used as a fuel for fuel cells by passing through a reforming step, a shift step, a carbon monoxide selective oxidation step, etc. .
Although it does not specifically limit as a reforming process, steam reforming which reforms raw materials with steam at a high temperature treatment on a catalyst, partial oxidation with oxygen-containing gas, and steam and oxygen-containing gas coexist For example, autothermal reforming that performs a self-heat recovery type reforming reaction in the system can be used.
[0022]
The reaction conditions for the reforming are not limited, but the reaction temperature is preferably 200 to 1000 ° C, particularly preferably 500 to 850 ° C. The reaction pressure is preferably from normal pressure to 1 MPa, and particularly preferably from normal pressure to 0.2 MPa. LHSV is preferably 0.01 to 40 h ⁻¹ , particularly preferably 0.1 to 10 h ⁻¹ .
The mixed gas containing carbon monoxide and hydrogen obtained at this time can be used as a fuel for a fuel cell as it is in the case of a solid oxide fuel cell. Further, when removal of carbon monoxide is required as in a phosphoric acid fuel cell or a polymer electrolyte fuel cell, it can be suitably used as a raw material for hydrogen for the fuel cell.
[0023]
The production of hydrogen for a fuel cell can employ a known method, and can be carried out, for example, by treating in a shift step and a carbon monoxide selective oxidation step. The shift step is a step of reacting carbon monoxide with water to convert it into hydrogen and carbon dioxide, and a catalyst containing a mixed oxide of Fe—Cr, a mixed oxide of Zu—Cu, platinum, ruthenium, iridium, etc. The carbon monoxide content is reduced to 2 vol% or less, preferably 1 vol% or less, more preferably 0.5 vol% or less. Although the reaction conditions for the shift reaction are not necessarily limited by the reformed gas composition or the like as a raw material, the reaction temperature is preferably 120 to 500 ° C, and particularly preferably 150 to 450 ° C. The pressure is preferably normal pressure to 1 MPa, particularly preferably normal pressure to 0.2 MPa. GHSV is preferably 100~50000h ^-1, especially 300～10000H ^-1 are preferred. Usually, in the phosphoric acid fuel cell, the mixed gas in this state can be used as fuel.
[0024]
On the other hand, in the polymer electrolyte fuel cell, since it is necessary to further reduce the carbon monoxide concentration, it is desirable to provide a process for removing carbon monoxide. Although this process is not particularly limited, an adsorption separation method, a hydrogen separation membrane method, a carbon monoxide selective oxidation step, or the like can be used. A carbon monoxide selective oxidation step is preferable from the viewpoint of compactness of the apparatus and economical efficiency. In this step, using a catalyst containing iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, silver, gold, etc., 0.5 to 10 times the remaining number of moles of carbon monoxide The carbon monoxide concentration is reduced by selectively converting carbon monoxide to carbon dioxide by adding mol, preferably 0.7 to 5 times mol, more preferably 1 to 3 times mol of oxygen. Although the reaction conditions of this method are not limited, the reaction temperature is preferably 80 to 350 ° C., particularly preferably 100 to 300 ° C., and the pressure is preferably normal pressure to 1 MPa, particularly preferably normal pressure to 0.2 MPa. , GHSV is preferably from 1000~50000h ^-1, particularly preferably selected respectively in the range of 3000~30000h ^-1. In this case, the carbon monoxide concentration can be reduced by reacting with the coexisting hydrogen simultaneously with the oxidation of carbon monoxide to generate methane.
[0025]
The present invention also relates to a desulfurization apparatus for desulfurizing a hydrocarbon raw material containing sulfur, in which a hydrocarbon desulfurization catalyst in which 0.1 to 50% by mass of a rare earth element or a rare earth compound is supported on Y-type zeolite is filled. And a fuel cell system having at least a reforming device for reforming the hydrocarbon raw material desulfurized by the desulfurization device into a fuel gas containing hydrogen as a main component.
[0026]
An example of this fuel cell system will be described below with reference to FIG.
The raw fuel in the fuel tank 3 flows into the desulfurizer 5 through the fuel pump 4. At this time, if necessary, the hydrogen-containing gas from the selective oxidation reactor 11 can be added. The desulfurizer 5 is filled with a desulfurization catalyst in which 0.1 to 50% by mass of a rare earth element as an element is supported on a Y-type zeolite. The fuel desulfurized in the desulfurizer 5 is mixed with water from the water tank 1 through the water pump 2, introduced into the vaporizer 6, and sent into the reformer 7.
[0027]
The reformer 7 is heated by a heating burner 18. As the fuel for the heating burner 18, the anode off gas of the fuel cell 17 is mainly used, but the fuel discharged from the fuel pump 4 can be supplemented as necessary. As the catalyst filled in the reformer 7, a nickel-based, ruthenium-based, or rhodium-based catalyst can be used.
The gas containing hydrogen and carbon monoxide produced in this way is passed through the high temperature shift reactor 9, the low temperature shift reactor 10, and the selective oxidation reactor 11 in order, so that the carbon monoxide concentration becomes a characteristic of the fuel cell. It is reduced to the extent that it has no effect. Examples of catalysts used in these reactors include an iron-chromium catalyst for the high temperature shift reactor 9, a copper-zinc catalyst for the low temperature shift reactor 10, a ruthenium catalyst for the selective oxidation reactor 11, and the like. be able to.
[0028]
The polymer electrolyte fuel cell 17 comprises an anode 12, a cathode 13, and a solid polymer electrolyte 14, and a fuel gas containing high-purity hydrogen obtained by the above method is provided on the anode side, and an air blower is provided on the cathode side. If necessary, air sent from 8 is introduced after appropriate humidification processing (a humidifier is not shown). At this time, a reaction in which hydrogen gas becomes protons and emits electrons proceeds at the anode, and a reaction in which oxygen gas obtains electrons and protons to become water proceeds at the cathode. In order to promote these reactions, platinum black and Pt catalyst or Pt-Ru alloy catalyst supported on activated carbon are used for the anode, and platinum black and Pt catalyst supported on activated carbon are used for the cathode. Usually, both the anode and cathode catalysts are formed into a porous catalyst layer together with polytetrafluoroethylene, a low molecular weight polymer electrolyte membrane material, activated carbon, and the like as necessary.
[0029]
Next, the porous catalyst layer is laminated on both sides of a polymer electrolyte membrane known by a trade name such as Nafion (manufactured by DuPont), Gore (manufactured by Gore), Flemion (manufactured by Asahi Glass), Aciplex (manufactured by Asahi Kasei). An MEA (Membrane Electrode Assembly) is formed. Further, the fuel cell is assembled by sandwiching the MEA with a separator having a gas supply function, a current collecting function, particularly an important drainage function in the cathode, and the like made of a metal material, graphite, carbon composite and the like. The electric load 15 is electrically connected to the anode and the cathode.
The anode off gas is consumed in the heating burner 18. The cathode off gas is discharged from the exhaust port 16.
[0030]
【The invention's effect】
The catalyst of the present invention can desulfurize a hydrocarbon raw material containing sulfur to reduce the sulfur concentration to 0.1 mass ppm or less, and the obtained fuel gas is a solid polymer fuel cell in particular. It can be suitably used for a fuel cell system.
[0031]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited to these.
[0032]
Example 1
After immersing 20 g of Y-zeolite with a cavern ratio of 5 in 150 ml of a 50% by mass lanthanum nitrate solution and leaving it to stand for 3 hours, it was naturally dried in air, and then calcined for 3 hours in an air atmosphere at 500 ° C. Then, 20% by mass of alumina was added, and a catalyst (1) having a diameter of 1.6 mm was obtained by kneading and extrusion molding. The amount of lanthanum supported was 30% by mass.
[0033]
(Example 2)
After immersing 20 g of Y-zeolite with a Caban ratio of 5 in 150 ml of 50% by mass yttrium nitrate solution and allowing to stand for 3 hours, it was naturally dried in air, and then calcined for 3 hours in an air atmosphere at 500 ° C. Then, 20% by mass of alumina was added, and a catalyst (2) having a diameter of 1.6 mm was obtained by kneading and extrusion molding. The amount of yttrium supported was 30% by mass.
[0034]
(Comparative Example 1)
After immersing 20 g of Y-zeolite with a Keiban ratio of 5 in 350 ml of a 50% by mass lanthanum nitrate solution, allowing to stand for 3 hours, air-drying in air, and then calcining for 3 hours in an air atmosphere at 500 ° C. Then, 20% by mass of alumina was added, and a catalyst (3) having a diameter of 1.6 mm was obtained by kneading and extrusion molding. The amount of lanthanum supported was 55% by mass.
[0035]
(Comparative Example 2)
After immersing 20 g of Y-zeolite with a Caban ratio of 5 in 350 ml of a 50% by mass yttrium nitrate solution, allowing to stand for 3 hours, air-drying in air, and then calcining for 3 hours in an air atmosphere at 500 ° C. Then, 20% by mass of alumina was added, and a catalyst (4) having a diameter of 1.6 mm was obtained by kneading and extrusion molding. The amount of yttrium supported was 55% by mass.
[0036]
Each of these catalysts (1) to (4) was filled in a 10 ml reaction tube and reduced at 300 ° C. for 2 hours in a hydrogen stream, and then the desulfurization reaction of kerosene was evaluated. The reaction was evaluated under the conditions of 300 ° C., normal pressure, LHSV 1.0 h ⁻¹ , catalyst amount 10 cm ³ , sulfur concentration in raw kerosene 35 ppm by mass, and the sulfur concentration in the generated kerosene after 300 hours is shown in Table 1. It was.
[0037]
[Table 1]

[0038]
Further, each of these catalysts (1) to (4) was filled in a 10 ml reaction tube and reduced at 300 ° C. for 2 hours in a hydrogen stream, and then the desulfurization reaction of kerosene was evaluated. The reaction was evaluated under the conditions of room temperature, normal pressure, LHSV 0.5 h ⁻¹ , catalyst amount 10 cm ³ , sulfur concentration in the raw kerosene of 35 ppm by mass, and the sulfur concentration in the generated kerosene after 200 hours is shown in Table 2. .
[0039]
[Table 2]

[0040]
(Example 3)
In the fuel cell system of FIG. 1, the catalyst (1) obtained in Example 1 was filled in the desulfurizer 5 and kerosene was used as fuel to conduct a power generation test. During the operation for 200 hours, the desulfurizer operated normally and no decrease in the activity of the catalyst was observed.
At this time, a Ru-based catalyst is used for steam reforming, under conditions of S / C = 3, 700 ° C., LHSV = 5, and a CO—Zn-based catalyst is used for CO shift, under conditions of 200 ° C., GHSV = 2000, In the CO selective oxidation step, a Ru-based catalyst was used, and the operation was performed under the conditions of O ₂ / CO = 3, 150 ° C., and GHSV = 5000. The fuel cell also operated normally and the electric load 15 was operated smoothly.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of a fuel cell system of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Water tank 2 Water pump 3 Fuel tank 4 Fuel pump 5 Desulfurizer 6 Vaporizer 7 Reformer 8 Air blower 9 High temperature shift reactor 10 Low temperature shift reactor 11 Selective oxidation reactor 12 Anode 13 Cathode 14 Solid polymer electrolyte 15 Electric load 16 Exhaust port 17 Polymer electrolyte fuel cell 18 Heating burner

Claims (2)

A hydrocarbon desulfurization catalyst for use in a fuel cell system in which 10 to 40 % by mass of La, Y, La compound or Y compound as an element is supported on a Y-type zeolite having a Keiban ratio of 5 to 6 . A desulfurization apparatus for desulfurizing a hydrocarbon raw material containing sulfur, which is filled with the hydrocarbon desulfurization catalyst used in the fuel cell system according to claim 1, to a sulfur concentration of 0.1 mass ppm or less, and desulfurized by the desulfurization apparatus. A fuel cell system having at least a reforming device for reforming the hydrocarbon raw material into a fuel gas containing hydrogen as a main component.

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