JP2005146055A - Desulfurizing method and manufacturing method of hydrogen for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently removing sulfur compounds in hydrocarbon raw materials to a very low concentration for a long period of time, and a method which can keep catalysts for a reforming apparatus in a highly reactive state and can efficiently manufacture hydrogen for fuel cells when applied to a fuel cell system. <P>SOLUTION: The desulfurizing method comprises removing sulfur in the hydrocarbon raw materials using a desulfurizing agent comprising a metal component containing at least nickel supported on a carrier, where the desulfurizing conditions satisfy expressions (I) and (II): 1.06×P<SB>ope</SB><SP>0.44</SP><T<SB>ope</SB>/T<SB>50</SB><1.78×P<SB>ope</SB><SP>0.22</SP>(I); and T<SB>ope</SB>≥230 (II). In the formulae, T<SB>ope</SB>is an operation temperature (°C); P<SB>ope</SB>is an operation pressure (MPa); and T<SB>50</SB>is a 50% distillation temperature obtained by the ordinary pressure distillation test method prescribed in JIS K 2254 petroleum product-distillation test method. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a desulfurization method and a method for producing hydrogen for fuel cells. Specifically, the sulfur content in the hydrocarbon raw material can be efficiently removed to a very low concentration over a long period of time, and the hydrocarbon raw material that has been desulfurized using this desulfurization method is reformed to produce a fuel. The present invention relates to a method for producing hydrogen for batteries.

  In recent years, new energy technology has attracted attention due to environmental problems, and fuel cells are attracting attention as one of the new energy technologies. This fuel cell converts chemical energy into electrical energy by electrochemically reacting hydrogen and oxygen, and has a feature of high energy use efficiency. Alternatively, research into practical use is actively conducted for automobiles and the like. For this fuel cell, types such as a phosphoric acid type, a molten carbonate type, a solid oxide type, and a solid polymer type are known depending on the type of electrolyte used. On the other hand, as a hydrogen source, liquefied natural gas mainly composed of methanol and methane, city gas mainly composed of this natural gas, synthetic liquid fuel using natural gas as a raw material, and carbonization of petroleum naphtha and kerosene, etc. The use of hydrogen oil has been studied.

When the fuel cell is used for consumer use or automobile use, the hydrocarbon oil is liquid at room temperature and normal pressure, and is easy to store and handle. Since the supply system is maintained, it is advantageous as a hydrogen source. However, such hydrocarbon oil has a problem that the content of sulfur is higher than that of methanol or natural gas. When hydrogen is produced using this hydrocarbon oil, generally, a method of subjecting the hydrocarbon oil to steam reforming or partial oxidation reforming in the presence of a reforming catalyst is used. In such reforming treatment, the reforming catalyst is poisoned by the sulfur content in the hydrocarbon oil. Therefore, from the viewpoint of catalyst life, the hydrocarbon oil is subjected to desulfurization treatment to reduce the sulfur content. It is necessary to reduce it to 0.2 mass ppm or less over a long period of time.
In addition, when hydrogen is directly mounted on an automobile, it has been studied to add an odorant to hydrogen from the viewpoint of safety, and it is also possible to reduce the concentration of an odorant consisting of sulfur compounds present in feedstock as much as possible. It is important to.

As a desulfurization method for petroleum hydrocarbons, many studies have been made so far. For example, a hydrodesulfurization catalyst such as Co-Mo / alumina or Ni-Mo / alumina and a hydrogen sulfide adsorbent such as ZnO are usually used. A method of hydrodesulfurizing at a temperature of 200 to 400 ° C. under a pressure of 5 MPa · G is known. This method performs hydrodesulfurization under harsh conditions and removes sulfur by converting it to hydrogen sulfide. For small-scale distributed fuel cells, safety and environmental considerations, high-pressure gas control methods, etc. It is not preferable in relation to related laws and regulations. That is, for fuel cells, a desulfurization agent that can desulfurize fuel for a long time under a condition of less than 1 MPa · G is desired.
On the other hand, a nickel-based adsorbent has been proposed as a desulfurizing agent that adsorbs and removes sulfur in fuel oil under mild conditions (for example, see Patent Documents 1 to 12), and an improved nickel-copper system. Adsorbents have been proposed (see, for example, Patent Document 11 or 13).
However, the techniques disclosed in these documents are not at a practical level from the viewpoint of the life of the desulfurizing agent, are difficult to put into practical use, and further improvements have been desired.

By the way, various desulfurization conditions have been proposed for the desulfurization method of kerosene using the nickel-based or nickel-copper-based desulfurizing agent. However, although the quality of kerosene used as a raw material varies depending on the production method, the relationship between the quality of kerosene used as a raw material and the optimum desulfurization treatment conditions has not been clarified, and the performance of the desulfurizing agent has not been clarified. It has not yet reached its full potential. Moreover, the details of the case where a gasoline fraction or a light oil fraction is used as a raw material are not disclosed.
In addition, for example, a method for desulfurizing kerosene using a nickel-based desulfurizing agent without adding hydrogen has been proposed, and reaction conditions for desulfurization have also been proposed specifically (see, for example, Patent Documents 1 to 4). The details of the optimum desulfurization conditions according to the above are not described, and the relationship between the quality of fuel such as kerosene and the optimum desulfurization conditions according to the fuel quality has not been found.

Japanese Examined Patent Publication No. 6-65602 Japanese Patent Publication No.7-115842 Japanese Patent Laid-Open No. 1-188405 Japanese Patent Publication No.7-115843 JP-A-2-275701 JP-A-2-204301 Japanese Patent Laid-Open No. 5-70780 Japanese Patent Laid-Open No. 6-80972 JP-A-6-91173 JP-A-6-228570 JP 2001-279259 A JP 2001-342465 A JP-A-6-315628

  Under such circumstances, the present invention provides a desulfurization method capable of efficiently removing sulfur content in a fuel to a very low concentration over a long period of time, and desulfurization treatment was performed using this desulfurization method. It is an object of the present invention to provide a method for producing hydrogen for fuel cells by subjecting fuel to steam reforming, partial oxidation reforming or autothermal reforming.

As a result of repeating various studies to achieve the above object, the present inventors have found that there is a certain relationship between the distillation characteristics of fuel such as kerosene and the optimum desulfurization conditions corresponding to the distillation characteristics. The present invention has been completed by finding that the above problems can be solved by applying to a method of removing sulfur content in fuel using a desulfurizing agent.
That is, the present invention
(1) A desulfurization method for removing sulfur in a hydrocarbon raw material using a desulfurization agent formed by supporting a metal component containing at least nickel on a carrier, wherein the desulfurization conditions are represented by the following formulas (I) and (II): A desulfurization method characterized by satisfaction,
1.06 × P _ope ^0.44 <T _ope / T ₅₀ <1.78 × P _ope ^0.22 (I)
T _ope ≧ 230 (II)
(Where T _ope is the operating temperature (° C.), P _ope is the operating pressure (MPa), and T ₅₀ is the 50% distillation determined by the atmospheric distillation test method defined in JIS K2254 Petroleum Products-Distillation Test Method. This is the distillation temperature when leaving.)
(2) The desulfurization method according to the above (1), wherein 95 mol% or more of the metal component is in a metal state,
(3) The desulfurization method according to the above (1) or (2), wherein the content of nickel in the desulfurizing agent is in the range of 50 to 90% by mass as the converted amount of NiO (nickel oxide),
(4) The desulfurization method according to any one of (1) to (3), wherein the metal component further contains copper, and the copper content is 40% by mass or less in terms of CuO (copper oxide),
(5) The desulfurization method according to any one of (1) to (4), wherein the carrier contains at least one selected from silica, alumina, and silica-alumina.
(6) The desulfurization method according to any one of (1) to (5), wherein the hydrocarbon raw material is at least one selected from kerosene, light oil, naphtha, and gasoline,
(7) A method for producing hydrogen for a fuel cell, comprising desulfurizing a hydrocarbon raw material by the desulfurization method according to any one of (1) to (6) above, followed by reforming,
(8) The method for producing hydrogen for a fuel cell according to (7), wherein the reforming is steam reforming, partial oxidation reforming, or autothermal reforming,
(9) The method for producing hydrogen for fuel cells according to (7) or (8) above, wherein the catalyst used for reforming is a ruthenium catalyst or a nickel catalyst.
(10) The method for producing hydrogen for fuel cells as described in (9) above, wherein the carrier component of the catalyst used for reforming contains at least one selected from manganese oxide, cerium oxide, and zirconium oxide.
(11) A fuel cell system using hydrogen produced by the method according to any one of (7) to (10) above,
Is to provide.

  According to the desulfurization method of the present invention, the sulfur content in the hydrocarbon raw material can be efficiently removed to a very low concentration over a long period of time. By applying this desulfurization method to the production of hydrogen for fuel cells, a reforming catalyst for producing hydrogen from a hydrocarbon raw material can function effectively, and the life of the reforming catalyst can be extended. it can.

The desulfurization agent used in the desulfurization method of the present invention is characterized in that a metal component containing at least nickel is supported on a carrier. Examples of the nickel component include nickel oxide, metallic nickel obtained by reducing the nickel oxide, nickel carbonate, nickel nitrate, nickel chloride, nickel sulfate, nickel acetate and the like. In the desulfurization agent of this invention, it is preferable that 95 mol% or more of the metal component containing nickel is a metal state. When 95 mol% or more of metal components are in a metal state, the number of active sites on the surface of the desulfurizing agent is large, and higher desulfurization activity can be obtained.
As content of nickel, it is preferable that it is the range of 50-90 mass% as NiO (nickel oxide) conversion amount based on the desulfurization agent whole quantity. When the nickel content is 50% by mass or more, a high desulfurization activity is obtained. When the nickel content is 90% by mass or less, the content of the carrier, which will be described in detail later, is ensured, so that the surface area of the desulfurizing agent becomes sufficient. Will not drop. From this viewpoint, the nickel content is preferably in the range of 60 to 90% by mass, and more preferably in the range of 65 to 85% by mass.

Moreover, it is preferable that the desulfurization agent of this invention contains copper further as a metal component. The supported amount of the copper component is preferably 40% by mass or less in terms of CuO (copper oxide) based on the total amount of the desulfurizing agent. When the copper content is 40% by mass or less, the function as a desulfurizing agent can be sufficiently exhibited without inhibiting the effect of the nickel. From the viewpoints described above and from the viewpoint of increasing the degree of reduction of the coexisting nickel, the copper content is more preferably in the range of 0.1 to 40% by mass, and particularly in the range of 0.1 to 30% by mass. It is preferable.
Furthermore, in the desulfurization agent of the present invention, the total amount of NiO and CuO is preferably in the range of 60 to 90% by mass based on the total amount of the desulfurization agent. When the total amount is within this range, the number of active points necessary for desulfurization is sufficient, and higher desulfurization performance is obtained, and since the ratio of the carrier described later is sufficient, the surface area of the desulfurization agent is reduced, and the desulfurization performance There is no inconvenience that becomes low. From the above viewpoint, the total amount of NiO and CuO is preferably in the range of 70 to 90% by mass.

  The carrier used in the present invention is not particularly limited within the scope of the effects of the present invention, but a porous inorganic oxide is particularly preferable, and specifically, silica, alumina, silica-alumina, titania, zirconia, magnesia. , Zinc oxide, white clay, clay and diatomaceous earth. These may be used alone or in combination of two or more. Of these, silica, alumina, silica-alumina and mixtures thereof are particularly preferable. In the present invention, the metal component to be supported on these carriers essentially includes the above-described nickel component, and optionally contains the above-described copper component. Moreover, you may mix a small amount of other metal components, such as cobalt, iron, manganese, and chromium, if desired.

Next, a manufacturing method in the case where a carrier is used and a metal component such as nickel is supported thereon will be described in detail below.
The method for supporting nickel, which is an essential component, copper, which is an optional component, and other metal components, is not particularly limited, and any known method such as an impregnation method, a coprecipitation method, or a kneading method is employed. can do. A desulfurization agent in which nickel-copper is supported on a silica-alumina support, which is one of the preferred desulfurization agents of the present invention, can be produced, for example, by a coprecipitation method as shown below. In this coprecipitation method, first, an acidic aqueous solution or acidic aqueous dispersion containing a nickel source, an aluminum source, and a copper source, and a basic aqueous solution containing a silicon source and an inorganic base are prepared. Examples of the nickel source used in the former acidic aqueous solution or acidic aqueous dispersion include nickel chloride, nickel nitrate, nickel sulfate, nickel acetate, nickel carbonate, and hydrates thereof. Examples of the copper source include copper chloride, copper nitrate, copper sulfate, copper acetate, and hydrates thereof. Furthermore, examples of the aluminum source include alumina hydrates such as aluminum nitrate, pseudoboehmite, boehmite alumina, bayerite, and dibsite, and γ-alumina.

  On the other hand, the silicon source used in the basic aqueous solution is not particularly limited as long as it is soluble in an alkaline aqueous solution and becomes silica upon firing. For example, orthosilicic acid, metasilicic acid and their sodium salts A potassium salt, water glass, etc. are mentioned. Examples of the inorganic base include alkali metal carbonates and hydroxides. Next, the acidic aqueous solution or aqueous dispersion thus prepared and the basic aqueous solution are each heated to about 50 to 90 ° C., mixed together, and further maintained at a temperature of about 50 to 90 ° C. Complete the reaction. Next, the produced solid is sufficiently washed and separated into solid and liquid, or the produced solid is separated into solid and liquid and washed sufficiently, and then this solid is obtained at a temperature of about 80 to 150 ° C. by a known method. Dry at a temperature of The dried product thus obtained is preferably calcined at a temperature in the range of 200 to 400 ° C. to obtain a desulfurization agent having a metal component supported on a silica-alumina support.

  When a carrier other than alumina-silica is used as the carrier, it can be carried out according to the above method as appropriate. Further, the desulfurization agent obtained by the above method is further reduced, and the reduction degree of the metal component (mass ratio of the metal state in the metal component) is within the scope of the present invention. Methods are used as appropriate. In the production of hydrogen for a fuel cell, the reduction treatment is performed immediately before the desulfurization treatment step or after the desulfurization agent production step is completed. When the reduction is performed after the production of the desulfurizing agent, it is preferable that the desulfurizing agent is stabilized using air, diluted oxygen, carbon dioxide, or the like. When this stabilizing treatment desulfurizing agent is used, it is necessary to perform reduction treatment again after filling the desulfurization reactor. After performing the reduction treatment, it may be sealed with an inert gas or desulfurized kerosene.

Next, the desulfurization method of the present invention is characterized in that the desulfurization conditions satisfy the following formulas (I) and (II).
1.06 × P _ope ^0.44 <T _ope / T ₅₀ <1.78 × P _ope ^0.22 (I)
T _ope ≧ 230 (II)
Here, in the formula, T _ope is the operating temperature (° C.), P _ope is the operating pressure (MPa), and T ₅₀ is determined by the atmospheric pressure distillation test method specified in JIS K2254 petroleum product-distillation test method. % Is the distillation temperature at the time of distillation.
T ₅₀ is one parameter indicating the distillation characteristics of the fuel used. Based on this, by determining the desulfurization treatment conditions from the above formula, it is possible to determine the optimum desulfurization conditions according to the distillation properties of the liquid hydrocarbon.
When T _ope / T ₅₀ falls below the lower limit (1.06 × P _ope ^0.44 in the above formula (I)), the desulfurization reaction rate becomes slow, so the desulfurization performance decreases. Further, if the upper limit (1.78 × P _ope ^0.22 in the above formula (I)) is exceeded, the amount of coke precursor or coke increases, so the desulfurization performance of the desulfurizing agent should be maintained for a long time. Can not be.
At this time, if necessary, a small amount of hydrogen may coexist. By appropriately selecting the desulfurization conditions within the above range, it is possible to obtain a fuel such as hydrocarbon having a very low concentration of sulfur.

In the present invention, the hydrocarbon raw material to be desulfurized using a desulfurizing agent is not particularly limited, and examples thereof include kerosene, light oil, naphtha, gasoline, and the like, or a mixture thereof. Among these, kerosene is preferable as a fuel suitable for applying the desulfurizing agent of the present invention, and JIS No. 1 kerosene having a sulfur content of 80 mass ppm or less is particularly preferable. This JIS No. 1 kerosene is obtained by desulfurizing crude kerosene obtained by atmospheric distillation of crude oil. The crude kerosene usually has a high sulfur content, and as such, it does not become JIS No. 1 kerosene, Need to be reduced. As a method for reducing the sulfur content, it is preferable to perform a desulfurization treatment by a hydrorefining method which is generally carried out industrially. In this case, as a desulfurization catalyst, usually a mixture of transition metals such as nickel, cobalt, molybdenum, tungsten, etc., mixed at an appropriate ratio is supported on a carrier mainly composed of alumina in the form of metal, oxide, sulfide or the like. Things are used. As the reaction conditions, for example, the reaction temperature is 250 to 400 ° C., the pressure is 2 to 10 MPa · G, the hydrogen / oil molar ratio is 2 to 10, and the liquid hourly space velocity (LHSV) is ^{1 to 5} hr ⁻¹ .

Next, in the method for producing hydrogen for a fuel cell according to the present invention, the fuel desulfurized as described above is subjected to steam reforming, partial oxidation reforming or autothermal reforming, more specifically steam reforming. Hydrogen for fuel cells is produced by contacting with a catalyst, a partial oxidation reforming catalyst or an autothermal reforming catalyst.
There is no restriction | limiting in particular as a reforming catalyst used here, Arbitrary things can be suitably selected and used from the well-known things conventionally known as a hydrocarbon reforming catalyst. As such a reforming catalyst, for example, a catalyst in which noble metal such as nickel, zirconium, ruthenium, rhodium or platinum is supported on a suitable carrier can be exemplified. The supported metal may be one kind or a combination of two or more kinds. Among these catalysts, those supporting nickel (hereinafter referred to as nickel-based catalyst) and those supporting ruthenium (hereinafter referred to as ruthenium-based catalyst) are preferable. The effect of suppressing carbon deposition during quality treatment or autothermal reforming treatment is great.
The carrier for supporting the reforming catalyst preferably contains manganese oxide, cerium oxide, zirconium oxide or the like, and particularly preferably a carrier containing at least one of these.

In the case of a nickel-based catalyst, the supported amount of nickel is preferably in the range of 3 to 60% by mass based on the carrier. When the supported amount is within the above range, the activity of the steam reforming catalyst, the partial oxidation reforming catalyst or the autothermal reforming catalyst is sufficiently exhibited, and it is economically advantageous. In view of catalyst activity and economy, the more preferable amount of nickel is 5 to 50% by mass, and particularly preferably 10 to 30% by mass.
In the case of a ruthenium-based catalyst, the supported amount of ruthenium is preferably in the range of 0.05 to 20% by mass based on the carrier. When the supported amount of ruthenium is within the above range, the activity of the steam reforming catalyst, the partial oxidation reforming catalyst or the autothermal reforming catalyst is sufficiently exhibited and it is economically advantageous. Considering catalytic activity and economic efficiency, the more preferable loading of ruthenium is 0.05 to 15% by mass, and particularly preferably 0.1 to 2% by mass.

As a reaction condition in the steam reforming treatment, steam / carbon (molar ratio), which is a ratio of steam and carbon derived from fuel oil, is usually selected in the range of 1.5 to 10. When the steam / carbon (molar ratio) is 1.5 or more, the amount of hydrogen generated is sufficient, and when it is 10 or less, excess water vapor is not required, so heat loss is small and hydrogen production can be performed efficiently. . From the above viewpoint, the steam / carbon (molar ratio) is preferably in the range of 1.5 to 5, and more preferably in the range of 2 to 4.
Moreover, it is preferable to perform steam reforming while maintaining the inlet temperature of the steam reforming catalyst layer at 630 ° C. or lower. If the inlet temperature is 630 ° C. or lower, thermal decomposition of the fuel oil does not occur, so that carbon deposition on the catalyst or reaction tube wall via the carbon radical is unlikely to occur. From the above viewpoint, the inlet temperature of the steam reforming catalyst layer is preferably 600 ° C. or lower. The catalyst layer outlet temperature is not particularly limited, but is preferably in the range of 650 to 800 ° C. When the temperature is 650 ° C. or higher, the amount of hydrogen generated is sufficient, and when it is 800 ° C. or lower, the reaction apparatus does not need to be made of a heat-resistant material, which is economically preferable.

As reaction conditions in the partial oxidation reforming treatment, the pressure is usually normal pressure to 5 MPa · G, the temperature is 400 to 1100 ° C., the oxygen (O ₂ ) / carbon (molar ratio) is 0.2 to 0.8, and the liquid The space-time velocity (LHSV) is 0.1 to 100 hr ⁻¹ .
As reaction conditions in the autothermal reforming treatment, the pressure is usually normal pressure to 5 MPa · G, the temperature is 400 to 1100 ° C., the steam / carbon (molar ratio) is 0.1 to 10, and oxygen (O ₂ ). / Carbon (molar ratio) is 0.1 to 1, liquid hourly space velocity (LHSV) is 0.1 to 2 hr ⁻¹ , and gas hourly space velocity (GHSV) is 1000 to 100,000 hr ⁻¹ .
In addition, since CO obtained by the steam reforming, partial oxidation reforming or autothermal reforming adversely affects hydrogen generation, it is preferable to convert CO to CO ₂ by reaction and remove it. Thus, according to the method of the present invention, hydrogen for fuel cells can be produced efficiently.
A fuel cell system using a liquid fuel is usually composed of a fuel supply device, a desulfurization device, a reforming device, and a fuel cell, and the hydrogen produced by the method of the present invention is supplied to the fuel cell.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
(Physical property measurement method)
Degree of reduction (%)
The degree of reduction was calculated from the amount of hydrogen consumption measured using a temperature programmed reduction (TPR) “TP2000” manufactured by Okura Riken Co., Ltd.
The sample tube was filled with 20 mg of the desulfurization agent (before reduction treatment) produced in each production example, and 100% argon gas was passed for 1 hour to replace the air. Thereafter, a mixed gas of hydrogen (65%) / argon (35%) was circulated at 20 cm ³ / min and held at room temperature for 90 minutes. Next, the hydrogen consumption was measured with a TCD detector (heat conduction type detector) while heating to 827 ° C. at a rate of temperature increase of 10 ° C./min. FIG. 1 is a TPR profile of a desulfurization agent (before reduction treatment), and the peak area A shown in FIG. 1 indicates the amount of hydrogen necessary for the total reduction of the metal component from the oxide to the metal state.
Next, after reducing and stabilizing the desulfurizing agent produced in each Example and Comparative Example, the hydrogen consumption of the desulfurizing agent was measured in the same manner as described above. The result shows the TPR profile shown in FIG. 2, and the hydrogen consumed in the vicinity of 400 K (127 ° C.) in FIG. 2 (corresponding to the peak area C) is due to re-reduction of the surface oxidized portion by the stabilization treatment. The hydrogen consumed in the vicinity of 770 K (497 ° C.) (corresponding to the peak area B) is due to the reduction of the unreduced portion after the reduction treatment. From these, the degree of reduction was determined by the following equation.
Degree of reduction (%) = 100 × (area A−area B) / area A

Production Example of Desulfurizing Agent 730.2 g of nickel sulfate hexahydrate (special grade, manufactured by Wako Pure Chemical Industries, Ltd.) and 151.3 g of copper sulfate pentahydrate (special grade, manufactured by Wako Pure Chemical Industries, Ltd.) at 80 ° C. was dissolved in ion-exchanged water heated 8L, which pseudoboehmite (C-AP, 67 wt% as Al ₂ O _3, manufactured by catalysts & Chemicals Industries Co., Ltd.) was 16.0g mixed. To this, 300 mL of 1N sulfuric acid was added to adjust the pH to 2, whereby Preparation Solution X was obtained.
Next, 600.0 g of sodium carbonate was dissolved in 8 L of ion-exchanged water heated to 80 ° C. separately, and 180.2 g of water glass (No. J-1, Si concentration 29 mass%, Nippon Chemical Industry Co., Ltd.) Preparation liquid Y was obtained.
While maintaining the temperature of each of the preparation liquids X and Y at 80 ° C., both were mixed and stirred for 1 hour to obtain a precipitation cake. Thereafter, the precipitate cake obtained using 60 L of ion-exchanged water was washed and filtered, and the product was dried for 12 hours in a 120 ° C. blower dryer and then calcined at 350 ° C. for 3 hours. Thereafter, the fired product was molded by tableting and pulverized to obtain a desulfurization agent having an average particle size of 0.8 mm.
The nickel content (NiO equivalent) of the desulfurizing agent is 65% by mass, the copper content (CuO equivalent) is 15% by mass, the amount of silica-alumina as a carrier is 20% by mass, and the Si / Al ratio (atomic ratio) is 5.6.

Example 1
The desulfurizing agent prepared in the above production example was heated to 180 ° C. in a hydrogen stream under normal pressure, held for 6 hours, further heated to 500 ° C. over 30 minutes, held at the temperature for 3 hours, Reduction was performed. Next, the temperature was lowered to room temperature, and the outermost surface oxidation treatment (stabilization treatment) of the desulfurizing agent was performed with diluted oxygen (oxygen concentration 1%). The degree of reduction of the desulfurizing agent subjected to such treatment was measured by the above physical property measurement method, and the degree of reduction was 100%.
A SUS reaction tube having an inner diameter of 17 mm was filled with 15 cm ³ of the desulfurizing agent subjected to the reduction treatment and the stabilization treatment. Under normal pressure, the temperature was raised to 200 ° C. in a hydrogen stream and maintained at that temperature for 2 hours to activate the desulfurizing agent. Next, JIS-1 kerosene having the properties shown in Table 1 was passed through the reaction tube at 250 ° C., pressure 0.6 MPa, and liquid space velocity (SV) 3 h ⁻¹ . The sulfur concentration at the outlet of the reaction tube was analyzed, and the desulfurization performance of the desulfurizing agent was evaluated based on the amount of oil per filled desulfurizing agent until the sulfur concentration increased to 0.2 ppm by mass. Table 2 shows the composition of the desulfurization agent, the reduction conditions and the degree of reduction, and Table 3 shows the evaluation results of the desulfurization performance.

Comparative Example 1
JIS-1 kerosene having the properties shown in Table 1 was passed through the reaction tube at 200 ° C., pressure 0.6 MPa, and liquid space velocity (SV) 3 h ⁻¹ in the same manner as in Example 1 to obtain the desulfurizing agent. Desulfurization performance was evaluated. Table 2 shows the composition of the desulfurization agent, the reduction conditions and the degree of reduction, and Table 3 shows the evaluation results of the desulfurization performance.

Example 2
The desulfurizing agent produced in Production Example 1 was heated to 180 ° C. in a hydrogen stream under normal pressure, held for 6 hours, further heated to 300 ° C. over 30 minutes, held at that temperature for 50 hours, and reduced. Went. Immediately thereafter, the outermost surface oxidation treatment (stabilization treatment) of the desulfurizing agent was performed with diluted oxygen (oxygen concentration 1%). The degree of reduction of the desulfurizing agent subjected to such treatment was measured by the above physical property measurement method and found to be 92%.
With respect to the desulfurization agent subjected to the reduction treatment and the stabilization treatment, JIS-1 kerosene having the properties shown in Table 1 was passed under the same conditions as in Example 1, and the desulfurization performance was similarly evaluated. Table 2 shows the composition of the desulfurization agent, the reduction conditions and the degree of reduction, and Table 3 shows the evaluation results of the desulfurization performance.

Comparative Example 2
JIS-1 kerosene having the properties shown in Table 1 was passed through the reaction tube at 200 ° C., pressure 0.6 MPa, and liquid space velocity (SV) 3 h ⁻¹ in the same manner as in Example 2 to obtain the desulfurizing agent. Desulfurization performance was evaluated. Table 2 shows the composition of the desulfurization agent, the reduction conditions and the degree of reduction, and Table 3 shows the evaluation results of the desulfurization performance.
Comparative Example 3
JIS-1 kerosene having the properties shown in Table 1 was passed through the reaction tube at 350 ° C., pressure 0.6 MPa, and liquid space velocity (SV) 3 h ⁻¹ in the same manner as in Comparative Example 2 except for the desulfurizing agent. Desulfurization performance was evaluated. Table 2 shows the composition of the desulfurization agent, the reduction conditions and the degree of reduction, and Table 3 shows the evaluation results of the desulfurization performance.

  According to the desulfurization method of the present invention, the sulfur content in the hydrocarbon raw material can be efficiently removed to a very low concentration over a long period of time. Therefore, when applied to a desulfurization method in a desulfurization device of a normal fuel cell system composed of a fuel supply device, a desulfurization device, a reformer, and a fuel cell, the reformer catalyst is in a highly active state for a long period of time. Thus, hydrogen for fuel cells can be produced efficiently.

TPR profile of desulfurizing agent (before reduction treatment) TPR profile of desulfurization agent (after reduction and stabilization)

Claims (11)

A desulfurization method for removing sulfur in a hydrocarbon raw material using a desulfurization agent in which a metal component containing at least nickel is supported on a carrier, and the desulfurization conditions satisfy the following formulas (I) and (II) A desulfurization method characterized by the above.
1.06 × P _ope ^0.44 <T _ope / T ₅₀ <1.78 × P _ope ^0.22 (I)
T _ope ≧ 230 (II)
(Where T _ope is the operating temperature (° C.), P _ope is the operating pressure (MPa), and T ₅₀ is the 50% distillation determined by the atmospheric distillation test method defined in JIS K2254 Petroleum Products-Distillation Test Method. This is the distillation temperature when leaving.)   The desulfurization method according to claim 1, wherein 95 mol% or more of the metal component is in a metal state.   The desulfurization method according to claim 1 or 2, wherein the content of nickel in the desulfurizing agent is in the range of 50 to 90% by mass as a converted amount of NiO (nickel oxide).   The desulfurization method according to claim 1, further comprising copper as a metal component, wherein the copper content is 40% by mass or less in terms of CuO (copper oxide).   The desulfurization method according to any one of claims 1 to 4, wherein the carrier contains at least one selected from silica, alumina, and silica-alumina.   The desulfurization method according to claim 1, wherein the hydrocarbon raw material is at least one selected from kerosene, light oil, naphtha, and gasoline.   A method for producing hydrogen for a fuel cell, wherein the hydrocarbon raw material is desulfurized by the desulfurization method according to claim 1 and then reformed.   The method for producing hydrogen for a fuel cell according to claim 7, wherein the reforming is steam reforming, partial oxidation reforming, or autothermal reforming.   The method for producing hydrogen for a fuel cell according to claim 7 or 8, wherein the catalyst used for reforming is a ruthenium catalyst or a nickel catalyst.   The method for producing hydrogen for a fuel cell according to claim 9, wherein the carrier component of the catalyst used for reforming contains at least one selected from manganese oxide, cerium oxide, and zirconium oxide. 11. A fuel cell system using hydrogen produced by the method according to claim 7.

Images