JP2009057421A - Liquid fuel desulfurization agent and liquid fuel desulfurization method - Google Patents

Abstract

The present invention provides a desulfurization agent and a desulfurization method capable of efficiently desulfurizing a sulfur compound in a liquid fuel to a very low concentration that can be used as a fuel for hydrogen generation in a fuel cell at a temperature of 80 ° C. or less. .
A desulfurization agent used when desulfurizing a liquid fuel at 80 ° C. or lower, mainly composed of alumina carrying a metal component belonging to Group VI of the periodic table, and having an ammonia adsorption amount at 100 ° C. A desulfurization agent for liquid fuel that is 310 μmol / g or more per gram of desulfurization agent, and a desulfurization method for liquid fuel using the desulfurization agent.
[Selection figure] None

Description

  The present invention relates to a liquid fuel desulfurization agent, a liquid fuel desulfurization method using the desulfurization agent, a hydrogen production method, and a fuel cell system.

In recent years, fuel cells, which are attracting attention as a new energy technology due to environmental problems, convert chemical energy into electrical energy by electrochemically reacting oxygen with hydrogen and flammable substances such as CO and methane. Therefore, since it has the feature of high energy use efficiency, practical research has been actively conducted for consumer use, industrial use or automobile use. In this fuel cell, as a hydrogen source, liquefied natural gas mainly composed of methanol and methane, city gas mainly composed of this natural gas, synthetic liquid fuel made from natural gas, LP gas, and petroleum-based gas The use of hydrocarbon oils such as naphtha and kerosene has been proposed.
When fuel cells are used for consumer use or automobiles, the hydrocarbons other than methane, liquefied natural gas, city gas, and liquefied petroleum gas are liquid at room temperature and normal pressure, and are easy to store and handle. In particular, petroleum-based products are advantageous as a hydrogen source because their supply systems such as gas stations and dealers have been established. However, such hydrocarbon oil has a problem that the content of sulfur is higher than that of methanol or natural gas. In the case of producing hydrogen using a hydrocarbon oil, generally, a method of reforming the hydrocarbon oil 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 below a predetermined value over a long period of time.

As a desulfurization method for petroleum hydrocarbons, many studies have been made so far. For example, Patent Document 1 describes a sulfur removal method using a desulfurization agent carrying an active metal component such as Ni, Zn, Cu or the like. Patent Document 2 describes a hydrocarbon compound desulfurization agent having a specific amount of Ag held in a porous carrier, and Patent Document 3 discloses a fuel containing a composite compound composed of a metal component and an inorganic oxide or activated carbon. A method for treating fuel oil using an oil treating agent is described. Further, Patent Document 4 discloses that liquid hydrocarbon is brought into contact with an adsorbent such as an oxide-based transition metal-carrying alumina adsorbent and contained in the liquid hydrocarbon. A desulfurization method for removing a specific organic sulfur compound is described, and Patent Document 5 describes that alumina-supported molybdenum is used as a normal temperature desulfurization agent for kerosene and gasoline.
However, none of the desulfurization agents described in the above-mentioned patent documents has yet been sufficient in desulfurization performance.

JP 2006-117721 A JP 2006-176721 A JP 2002-249787 A JP 2005-2317 A JP 2005-270855 A

  An object of the present invention is to efficiently desulfurize sulfur in liquid fuels such as kerosene, light oil, methanol, ethanol, etc. at a temperature of 80 ° C. or less to a very low concentration that can be used as a fuel for hydrogen generation in fuel cells. An object of the present invention is to provide a desulfurization agent and a desulfurization method. Another object of the present invention is to provide a method for producing hydrogen by reforming a liquid fuel desulfurized using the desulfurizing agent, and a fuel cell system using the hydrogen.

That is, the present invention
(1) A desulfurization agent used when desulfurizing liquid fuel at 80 ° C. or lower, mainly composed of alumina carrying a metal component belonging to Group VI of the periodic table, and having an ammonia adsorption amount at 100 ° C. of desulfurization A desulfurization agent for liquid fuel that is 310 μmol / g or more per gram of the agent.
(2) A liquid fuel desulfurization method, wherein the liquid fuel is desulfurized at a temperature of 80 ° C. or lower using the desulfurization agent described in (1) above.
(3) A method for producing hydrogen, wherein the liquid fuel is desulfurized by the method described in (2) above, and then the desulfurized fuel is subjected to partial oxidation reforming, autothermal reforming or steam reforming, and (4) the above (3) A fuel cell system using hydrogen obtained by the production method as described above,
Is to provide.

  According to the present invention, sulfur compounds in liquid fuels such as kerosene, light oil, methanol, and ethanol are efficiently desulfurized at a temperature of 80 ° C. or lower to an extremely low concentration that can be used as a fuel for hydrogen generation in fuel cells. A desulfurizing agent that can be provided can be provided. Further, hydrogen can be produced by reforming the liquid fuel desulfurized using the desulfurizing agent, and a fuel cell system can be provided using the hydrogen.

[Desulfurization agent for liquid fuel]
The desulfurizing agent of the present invention is used when desulfurizing a liquid fuel at 80 ° C. or lower, and is mainly composed of alumina supporting a metal component belonging to Group VI of the periodic table, and the ammonia adsorption amount at 100 ° C. is desulfurized. The amount is 310 μmol / g or more per gram of the agent.
Examples of the metal component belonging to Group VI of the periodic table include molybdenum, tungsten, chromium, and the like, and molybdenum and tungsten are preferable from the viewpoint of low activity and toxicity.
The supported amount of the metal component is preferably 0.5 to 80% by mass, more preferably 5 to 70% by mass, and still more preferably 5 to 50% by mass. However, in the impregnation method, when the metal component loading is 50% by mass or less, the dispersibility of the supported metal component particles can be maintained, and sufficient desulfurization performance can be obtained.

  When the metal component belonging to Group VI of the periodic table is a molybdenum component, the molybdenum component source is molybdenum ethylhexanoate, hexacarponyl molybdenum, molybdenum oxide, 12 molybdophosphoric acid hydrate, 12 molybdosilicic acid hydration. Products, ammonium molybdate hydrate, 12 molybdophosphate triammonium hydrate, and the like. Among these, 12 molybdophosphate hydrate, ammonium molybdate hydrate are preferred from the viewpoint of availability. It is a thing.

When the metal component belonging to Group VI of the periodic table is a tungsten component, the tungsten source includes ammonium tungstate hydrate, tungsten ammonium hydrate, tungstophosphate ammonium hydrate, tungsten ethoxide, hexacarboxyl. Nyl tungsten, tungsten oxide, tungsten phosphide, sodium tungsten citrate, 12 tungstophosphoric acid hydrate, 12 tungsto silicic acid hydrate, and the like. Among these, from the point of availability, preferably 12 Tungstosilicic acid hydrate, ammonium tungstate hydrate.
When the metal component belonging to Group VI of the periodic table is a chromium component, chromium sources include chromium chloride, chromium oxide, chromium phosphate, chromium acetate, chromium formate, chromium nitrate, chromium bromide, chromium carbonate, chromium hydroxide, etc. Is mentioned.

Moreover, as the alumina which is the carrier of the desulfurizing agent according to the present invention, it is preferable that the substrate substantially consists only of alumina. Here, “substantially” means that a small amount of other components may be included within a range that does not affect the effects of the present invention, and includes those composed only of alumina. In addition, if the alumina support contains boria, the Lewis acid point may be reduced. Therefore, in the present invention, it is preferable that the alumina support, that is, the desulfurization agent of the present invention does not contain boria.
In the present invention, alumina having any structure such as α, κ, θ, δ, γ, η, χ, and ρ can be used as the alumina, but γ alumina is used because of its large surface area and easy availability. Is preferably used.

  The desulfurizing agent of the present invention is mainly composed of alumina carrying a metal component belonging to Group VI of the periodic table, wherein the “main component” includes at least 50% by mass of alumina. Meaning, preferably 80% by mass or more, more preferably 90% by mass or more, and including substantially 100% by mass.

The desulfurizing agent of the present invention has an ammonia adsorption amount at 100 ° C. of 310 μmol / g or more per 1 g of the desulfurizing agent.
The ammonia adsorption amount means a value obtained by measuring the ammonia adsorption amount by mass spectrometry when 0.5% NH ₃ / He is circulated at 100 ° C. for 1 hour. It can be measured by the method. The desulfurization agent of the present invention has an ammonia adsorption amount of 310 μmol / g or more per 1 g of the desulfurization agent. From the viewpoint of desulfurization performance, the adsorption amount is preferably 330 μmol / g or more, more preferably 350 μmol. / G or more, more preferably 370 μmol / g or more. Although the upper limit is not particularly limited, the periodic table Group VI metal component-supported alumina is usually 1000 μmol / g.
As the desulfurization agent of the present invention, those having an ammonia adsorption amount in the above range are used, but those which satisfy the above range by heat treatment such as calcination and reduction are preferably included.

The method for supporting the metal component on alumina is not particularly limited, and any known method such as an impregnation method, a coprecipitation method, a kneading method, a physical mixing method, a vapor deposition method, and an ion exchange method can be employed. From the viewpoint of simplicity, an impregnation method, a coprecipitation method, and an ion exchange method are preferable, and an impregnation method is more preferable.
In the impregnation method, a metal chloride, nitrate, sulfate, acetate, carbonate, etc. and a solution of these hydrates are impregnated into a support and dried at a temperature of about 80 to 150 ° C. overnight, preferably By baking at a temperature of about 200 to 1000 ° C., more preferably the same temperature as the above heat treatment temperature, a desired desulfurizing agent can be obtained.

  In the coprecipitation method, first, an acidic aqueous solution or dispersion of a metal source and an aluminum source and a basic aqueous solution containing an inorganic base are prepared. For the former metal source, the salts shown in the above impregnation method and hydrates thereof can be used. As the aluminum source, alumina hydrates such as aluminum nitrate, pseudoboehmite, boehmite alumina, bayerite, dibsite, and γ-alumina can be used. 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 desulfurization agent in which the metal component is supported on the alumina support is obtained by firing the dried treatment product thus obtained, preferably at a temperature of 200 to 1000 ° C., more preferably at the same temperature as the heat treatment temperature. can get.

The method for producing a desulfurization agent of the present invention is not particularly limited as long as it satisfies the above ammonia adsorption amount, but from the viewpoint of desulfurization performance, the catalyst precursor is preferably heat-treated at 550 to 850 ° C. The catalyst precursor is preferably mainly composed of alumina carrying a metal component belonging to Group VI of the periodic table.
In this invention, it is preferable to heat-process at 550-850 degreeC when using as a desulfurization agent from a viewpoint of desulfurization performance. When the heat treatment temperature is lower than the above range, the amount of ammonia adsorbed decreases, and the desulfurization effect may be reduced. If it is higher than the above range, a part of the porous structure of the alumina support is broken, the surface area is narrowed, and the desulfurization effect may be inferior. From the above viewpoint, the heat treatment temperature is more preferably 600 to 800 ° C.
The heat treatment time may be appropriately selected depending on the treatment temperature, but is usually 30 minutes to 10 hours, preferably 1 to 5 hours.

In the present invention, as described above, the Lewis acid of alumina increases by heat treatment at a high temperature. As a result, the ammonia adsorption amount increases, and as a result, the desulfurization performance of the liquid fuel using the desulfurization catalyst is improved.
In the present invention, the heat treatment may be carried out for any purpose as long as it is carried out at the above temperature, but any one of the catalyst baking treatment, reduction treatment described later, and pretreatment carried out before desulfurization treatment, etc. These steps can also be performed, or a combination thereof may be performed. The heat treatment can be performed in any atmosphere of air, nitrogen, hydrogen, helium and a mixture of two or more of them. It is also possible to perform this process in a vacuum. In this case, the desulfurization agent of the present invention can be obtained by performing at least one of the treatments at 550 to 850 ° C. The atmosphere described above is preferably air from the standpoint of gas availability and simplicity. However, since the adsorption performance is higher when the group VI metal is in a metal state under desulfurization conditions, it is preferable to perform heat treatment with hydrogen in that respect. For example, after heat treatment with air, heat treatment with hydrogen can be performed.
Moreover, it is preferable that the desulfurization agent of this invention performs a desulfurization process by making it contact with liquid fuel, without making it contact substantially with water or water vapor | steam after the said heat processing. After the heat treatment, for example, even when it comes into contact with moisture contained in the air, the Lewis acid sites on the catalyst surface may decrease, resulting in a decrease in the amount of ammonia adsorbed on the catalyst and desulfurization performance. Therefore, it is preferable that the desulfurizing agent of the present invention is not substantially brought into contact with water or water vapor after the heat treatment so that the value in the ammonia adsorption amount range can be maintained. Specifically, the desulfurizing agent is put into a desulfurizer and heat-treated while attached to the fuel cell system, and used for desulfurization as it is, or the desulfurizing agent put into the desulfurizer is heat-treated and sealed with an inert gas or kerosene. It can also be stored and used in a fuel cell system when used. In addition, it is also effective to fill and seal the desulfurizer in the desulfurizer as soon as possible after the heat treatment, or to fill it in dry gas.
The shape of the desulfurization agent is preferably a powder, crushed, pellet, tablet, honeycomb, sphere, or a state where powder is coated on another honeycomb.

[Method of desulfurization of liquid fuel]
In the liquid fuel desulfurization method of the present invention, the liquid fuel is desulfurized using the desulfurizing agent at a temperature of 80 ° C. or lower.
In the present invention, the sulfur-containing liquid fuel to be desulfurized using the desulfurizing agent is not particularly limited. For example, alcohol, ether, naphtha, gasoline, kerosene, light oil, heavy oil, coal liquefied oil, GTL oil, Examples thereof include one selected from waste plastic oil and biofuel (biomass fuel), or a combination thereof. Among these, as a liquid fuel suitable for applying the desulfurizing agent of the present invention, kerosene, light oil, gasoline, methanol or ethanol is preferable from the viewpoint of availability, and the sulfur content is 80 mass ppm or less. The above liquid fuel is more preferable, and JIS No. 1 kerosene having the above sulfur content is more preferable.

In the desulfurization method of the present invention, the sulfur compound contained in the liquid fuel as a sulfur content to be removed includes, for example, mercaptans, chain sulfides, cyclic sulfides, thiophenes, benzothiophenes, dibenzothiophenes, and the like. A sulfur compound is mentioned.
As a method of desulfurizing a sulfur-containing liquid fuel using the desulfurizing agent according to the present invention, a method in which the liquid fuel is circulated through the desulfurizing agent, or the liquid fuel is allowed to stand or stir in a container such as a tank having the desulfurizing agent fixed therein. Is preferred.
In the desulfurization method in the present invention, the desulfurization temperature is preferably 80 ° C. or less. If this desulfurization temperature is 80 degrees C or less, energy cost is low and it is economically advantageous. The lower limit of the desulfurization temperature is not particularly limited, and is appropriately selected in consideration of the fluidity of the liquid fuel to be desulfurized and the desulfurization activity of the desulfurizing agent. When the liquid fuel to be desulfurized is kerosene, the lower limit is about −40 ° C. from the viewpoint of fluidity. A preferable desulfurization temperature is −30 to 60 ° C., and more preferably 0 to 40 ° C.

The desulfurization conditions other than the temperature are not particularly limited, and can be appropriately selected according to the properties of the liquid fuel to be desulfurized. Specifically, when a hydrocarbon such as JIS No. 1 kerosene as a fuel is passed through a desulfurization tower filled with the desulfurization agent according to the present invention in a liquid phase in an upward or downward flow, the desulfurization temperature is about room temperature, the pressure is atmospheric圧乃Itaru 1 MPa · G about, liquid hourly hourly space velocity (LHSV) can be 30 hr ^-1 or less, more 20 hr ^-1 or less, and more preferably to desulfurization treatment with 5 hr ^-1 following conditions. At this time, if necessary, a small amount of hydrogen may coexist.
By the desulfurization treatment, in the present invention, the sulfur content of the liquid fuel can be reduced to, for example, 10 mass ppm or less, preferably less than 1 mass ppm.

  In addition, after removing sulfur in the liquid fuel by the above-described desulfurization method of the present invention, sulfur is removed to 0.5 mass ppm or less using a clean-up desulfurization agent, thereby efficiently desulfurizing the sulfur-containing liquid fuel. The poisoning of the reforming catalyst in the subsequent stage due to the sulfur content can be suppressed as much as possible, and it can function stably for a long period of time. The cleanup desulfurizing agent is not particularly limited as long as the sulfur content can be reduced to 0.5 ppm or less, and any known adsorptive desulfurizing agent or hydrodesulfurizing agent may be used.

[Method for producing hydrogen]
Next, in the present invention, the fuel desulfurized as described above is subjected to steam reforming, partial oxidation reforming or autothermal reforming, and more specifically, a steam reforming catalyst, partial oxidation reforming catalyst or Hydrogen for fuel cells is produced by contacting with 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 or 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 ruthenium (hereinafter referred to as ruthenium-based catalyst) or those supporting rhodium are preferable.
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. These have a great effect of suppressing carbon deposition during steam reforming, partial oxidation reforming or autothermal reforming.

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 10% 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 economy, the more preferable loading of ruthenium is 0.05 to 5% 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 .
Note that CO in the hydrogen-containing gas obtained by steam reforming, partial oxidation reforming or autothermal reforming is further converted to H ₂ and CO ₂ by a shift reaction at a later stage to further increase the hydrogen concentration. . 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.

[Fuel cell system]
The present invention also provides a fuel cell system using hydrogen obtained by the production method. The fuel cell system of the present invention will be described below with reference to FIG.
FIG. 1 is a schematic flowchart showing an example of the fuel cell system of the present invention. According to FIG. 1, the fuel in the fuel tank 21 flows into the desulfurizer 23 via the fuel pump 22. The desulfurizer is filled with the desulfurizing agent according to the present invention. As described above, this desulfurization is performed in two stages, and the desulfurization agent of the present invention can be filled in the first stage. The fuel desulfurized in the desulfurizer 23 is mixed with water from the water tank via the water pump 24, introduced into the vaporizer 1, vaporized, and then fed into the reformer 31.
The inside of the reformer 31 is filled with the above-described reforming catalyst, and the above-described steam reforming reaction is performed from the fuel mixture (mixed gas containing steam and desulfurized liquid fuel) fed into the reformer 31. Hydrogen is produced.

The hydrogen produced in this way is reduced through the CO converter 32 and the CO selective oxidizer 33 to such an extent that the CO concentration does not affect the characteristics of the fuel cell. Examples of catalysts used in these reactors include an iron-chromium catalyst, a copper-zinc catalyst or a noble metal catalyst in the CO converter 32, and a ruthenium catalyst, a platinum catalyst, or a noble metal catalyst in the CO selective oxidizer 33. The mixture etc. can be mentioned.
The fuel cell 34 is a solid polymer fuel cell including a polymer electrolyte 34C between a negative electrode 34A and a positive electrode 34B. The hydrogen-rich gas obtained by the above method is introduced into the negative electrode side, and the air sent from the air blower 35 is introduced into the positive electrode side after performing appropriate humidification treatment as necessary (humidifier not shown). Is done.
At this time, a reaction in which hydrogen gas becomes protons and emits electrons proceeds on the negative electrode side, and a reaction in which oxygen gas obtains electrons and protons to become water proceeds on the positive electrode side, and a direct current is generated between both electrodes 34A and 34B. . Platinum black, activated carbon-supported Pt catalyst or Pt-Ru alloy catalyst is used for the negative electrode, and platinum black, Pt catalyst supported on activated carbon is used for the positive electrode.

The surplus hydrogen can be used as fuel by connecting the burner 31A of the reformer 31 to the negative electrode 34A side. Further, in the steam separator 36 connected to the positive electrode 34B side, water and exhaust gas generated by the combination of oxygen and hydrogen in the air supplied to the positive electrode 34B side are separated, and the water is used to generate water vapor. Can be used.
In the fuel cell 34, since heat is generated with power generation, an exhaust heat recovery device 37 can be attached to recover the heat for effective use. The exhaust heat recovery device 37 includes a heat exchanger 37A that takes away the heat generated during the reaction, a heat exchanger 37B that exchanges heat taken by the heat exchanger 37A with water, a cooler 37C, and these heat exchanges. The hot water obtained in the heat exchanger 37B can be effectively used in other facilities. The pumps 37A and 37B and the pump 37D circulate the refrigerant to the cooler 37C.

In this example, each property was measured and evaluated as follows.
[Measurement of metal component loading]
The measurement was performed using a multi-type plasma emission spectrometer (ICP, SPS5100 manufactured by ESI Nanotechnology Inc.) that satisfies the general rules of JISK 0116.

[Measurement of ammonia adsorption amount]
(1) The desulfurization agent 0.1g which performed to the part corresponding to "baking" of the heat processing conditions shown in Table 1 in an electric furnace, and was pulverized and sized to 22-36 mesh (0.7-1.2 mm) after that. Was filled in a cell for measuring the amount of adsorbed ammonia, and the portion corresponding to “reduction” of the heat treatment conditions shown in Table 1 was carried out in this cell to produce desulfurizing agents 1 to 24. Thereafter, the temperature is lowered to 100 ° C., and after the temperature is stabilized, 0.5% NH ₃ / He is circulated in the cell at 100 ° C. for 1 hour. After 1 hour, purge with He. After the baseline becomes stable, the temperature is increased to 710 ° C. at 20 ° C./min, and ammonia desorption is measured by mass spectrometry. Calibration uses 0.5% NH ₃ / He.
(2) Except not adsorbing ammonia, the data obtained by performing the same operation as in (1) above was used as the background, and the value subtracted from the value obtained in (1) was taken as the ammonia adsorption amount. The results are shown in Table 1.

[Measurement of sulfur content in liquid fuel]
In accordance with the microcoulometric titration method defined in JIS K 2541-2, the amount was determined using a TS-03 apparatus manufactured by Mitsubishi Chemical Corporation. The calibration curve was prepared by measuring a toluene solution of dibutyl sulfide (purity 99% or more). The sample was measured in the same manner as the calibration curve solution, and the sulfur content (wtppm) in the sample was calculated from the sulfur amount (μg) obtained from the calibration curve and the sample injection amount (mg).

Examples 1 and 2 [Production of desulfurizing agents 1 and 2 (alumina-supported molybdenum)]
12 g of 12 molybdophosphoric acid hydrate was dissolved in ion-exchanged water to make 48 cc, and impregnated on 50 g of alumina carrier (containing no boria, the same in the following examples). After drying in a dryer at 40 ° C. for 3 hours, it was dried at 120 ° C. overnight. The dried product was put in a desulfurizer and subjected to a reduction heat treatment at 600 ° C. and 800 ° C. for 3 hours under hydrogen before the desulfurization treatment to obtain desulfurization agents 1 and 2, respectively. The molybdenum loading at this time was 10% by mass.
The obtained desulfurizing agent was evaluated for the desulfurization performance described later without being taken out from the desulfurizer.

Examples 3 and 4 [Production of desulfurizing agent 3, 4 (alumina-supported molybdenum)]
12 g of 12 molybdophosphoric acid hydrate was dissolved in ion exchange water to make 48 cc, and impregnated in 50 g of alumina carrier. After drying in a dryer at 40 ° C. for 3 hours, it was dried at 120 ° C. overnight. After the drying, it was baked at 400 ° C. for 3 hours in an air using an electric furnace. Before the desulfurization treatment, the calcined product was put in a desulfurizer and subjected to reduction heat treatment at 600 ° C. and 800 ° C. for 3 hours under hydrogen to obtain desulfurization agents 3 and 4, respectively. The molybdenum loading at this time was 10% by mass.
The obtained desulfurizing agent was evaluated for the desulfurization performance described later without being taken out from the desulfurizer.

Examples 5 to 7 [Production of desulfurizing agent 5 to 7 (alumina-supported molybdenum)]
12 g of 12 molybdophosphoric acid hydrate was dissolved in ion exchange water to make 48 cc, and impregnated in 50 g of alumina carrier. After drying in a dryer at 40 ° C. for 3 hours, it was dried at 120 ° C. overnight. After the drying was completed, a heat treatment was performed for 3 hours at 600 ° C. in air using an electric furnace. The calcined product was put in a desulfurizer and subjected to reduction heat treatment at 450 ° C., 600 ° C., and 800 ° C. for 3 hours under hydrogen to obtain desulfurizing agents 5 to 7, respectively. The molybdenum loading at this time was 10% by mass.
The obtained desulfurizing agent was evaluated for the desulfurization performance described later without being taken out from the desulfurizer.

Examples 8 and 9 [Production of desulfurization agents 8 and 9 (alumina-supported molybdenum)]
12 g of 12 molybdophosphoric acid hydrate was dissolved in ion exchange water to make 48 cc, and impregnated in 50 g of alumina carrier. After drying in a dryer at 40 ° C. for 3 hours, it was dried at 120 ° C. overnight. After the drying was completed, a heat treatment was performed in an electric furnace at 800 ° C. for 3 hours using an electric furnace. The calcined product was put in a desulfurizer and subjected to reduction heat treatment at 600 ° C. and 800 ° C. for 3 hours under hydrogen to obtain desulfurization agents 8 and 9, respectively. The molybdenum loading at this time was 10% by mass.
The obtained desulfurizing agent was evaluated for the desulfurization performance described later without being taken out from the desulfurizer.

Examples 10 to 18 [Production of desulfurizing agent 10 to 18 (alumina-supported tungsten)]
In each of Examples 1 to 9, desulfurizing agent 10 corresponding to each of desulfurizing agents 1 to 9 was similarly used except that 8 g of 12 tungstosilicic acid hydrate was used instead of 12 g of 12 molybdophosphoric acid hydrate. ~ 18 were obtained respectively. In this case, the amount of tungsten supported was 10% by mass.
The obtained desulfurizing agent was evaluated for the desulfurization performance described later without being taken out from the desulfurizer.

Comparative Examples 1 and 2 [Production of Desulfurization Agents 19 and 20 (Alumina-Supported Iron)]
22 g of iron nitrate hydrate was dissolved in ion exchange water to make 15 cc, and 27 g of alumina support was impregnated. After drying for 2 hours in a dryer at 60 ° C., it was dried overnight at 110 ° C. After the drying was completed, a heat treatment was performed for 3 hours at 400 ° C. in air using an electric furnace. The calcined product was put in a desulfurizer and subjected to reduction heat treatment at 450 ° C. and 600 ° C. for 3 hours under hydrogen to obtain desulfurization agents 19 and 20, respectively. At this time, the iron loading was 10% by mass.
The obtained desulfurizing agent was evaluated for the desulfurization performance described later without being taken out from the desulfurizer.

Comparative Examples 3 and 4 [Production of Desulfurization Agents 21 and 22 (Alumina-Supported Copper)]
In each of Comparative Examples 1 and 2, desulfurization agents 21 and 22 were obtained in the same manner except that 22 g of iron nitrate hydrate was replaced with 12 g of copper nitrate hydrate. In this case, the amount of copper supported was 10% by mass.
The obtained desulfurizing agent was evaluated for the desulfurization performance described later without being taken out from the desulfurizer.

Comparative Examples 5 and 6 [Production of Desulfurizing Agents 23 and 24 (Molybdenum on Alumina)]
12 g of 12 molybdophosphoric acid hydrate was dissolved in ion exchange water to make 48 cc, and impregnated in 50 g of alumina carrier. After drying in a dryer at 40 ° C. for 3 hours, it was dried at 120 ° C. overnight. After the drying was completed, the heat treatment was carried out at 350 ° C. for 3 hours in air using an electric furnace. The calcined product was put in a desulfurizer and subjected to a reduction heat treatment at 450 ° C. and 900 ° C. for 3 hours under hydrogen before reaction to obtain desulfurization agents 23 and 24, respectively. The molybdenum loading at this time was 10% by mass.
The obtained desulfurizing agent was evaluated for the desulfurization performance described later without being taken out from the desulfurizer.

Examples 19-36
JIS-1 kerosene having the following properties was passed through the desulfurizers (2.5 cc each) containing the desulfurizing agents 1 to 18 at room temperature (30 ° C.) at a liquid space velocity (LHSV) of 20 / h. The results of measuring the sulfur concentration in the kerosene obtained are shown in Table 1.
JIS-1 kerosene / distillation properties: initial distillation temperature 156 ° C, 10% distillation temperature 170 ° C, 30% distillation temperature 185 ° C, 50% distillation temperature 201 ° C, 70% distillation temperature 224 ° C, 90% distillation Outlet temperature 253 ° C, end point 275 ° C
・ Sulfur content: 14 mass ppm

Comparative Examples 7-12
The same operation as in Examples 19 to 36 was performed except that desulfurizers (2.5 cc each) containing the desulfurizing agents 19 to 24 were used. The results of measuring the sulfur concentration in the kerosene obtained are shown in Table 1.

  The desulfurization agent of the present invention can be used for desulfurization of liquid fuels such as kerosene and light oil because liquid fuel can be efficiently desulfurized to a very low concentration at a temperature of 80 ° C. or lower. Moreover, the liquid processing fuel obtained using this desulfurization agent can be used suitably for manufacture of hydrogen for fuel cells.

It is a schematic flowchart which shows an example of the fuel cell system of this invention.

Explanation of symbols

1: Vaporizer 11: Water supply pipe 12: Fuel introduction pipe 15: Connection pipe 21: Fuel tank 22: Pump 23: Desulfurizer 24: Water pump 31: Reformer 31A: Reformer burner 32: CO converter 33: CO selective oxidizer 34: Fuel cell 34A: Fuel cell negative electrode 34B: Fuel cell positive electrode 34C: Fuel cell polymer electrolyte 35: Air blower 36: Air / water separator 37: Waste heat recovery device 37A: Heat exchanger 37B: Heat exchanger 37C: Cooler 37D: Refrigerant circulation pump

Claims (8)

  A desulfurization agent used when desulfurizing liquid fuel at 80 ° C. or lower, mainly composed of alumina supporting a metal component belonging to Group VI of the periodic table, and the amount of ammonia adsorbed at 100 ° C. per gram of desulfurization agent A liquid fuel desulfurization agent having a concentration of 310 μmol / g or more.   The desulfurization agent according to claim 1, wherein the desulfurization agent does not contain boria.   The desulfurization agent according to claim 1 or 2, which is obtained by supporting a metal component belonging to Group VI of the periodic table on alumina, followed by heat treatment at 550 ° C to 850 ° C in an air atmosphere and / or a hydrogen atmosphere.   The desulfurization agent according to claim 3, wherein the heat treatment is performed in a firing treatment and / or a reduction treatment.   A method for desulfurizing a liquid fuel, wherein the liquid fuel is desulfurized using the desulfurizing agent according to any one of claims 1 to 4 at a temperature of 80 ° C or lower.   The desulfurization method according to claim 5, further comprising a step of bringing the desulfurizing agent according to claim 3 or 4 into contact with liquid fuel without being substantially brought into contact with water or water vapor after the heat treatment.   A method for producing hydrogen, comprising desulfurizing a liquid fuel by the method according to claim 5 and then subjecting the desulfurized fuel to partial oxidation reforming, autothermal reforming, or steam reforming.   A fuel cell system using hydrogen obtained by the production method according to claim 7 as a raw material.

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