JP2011178625A - Metal-supporting fibrous activated carbon and method for producing the same, and desulfurizing unit using the same and method for desulfurizing hydrocarbon oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing metal-supporting fibrous activated carbon reducing occurrence of irregularities caused in the stream of hydrocarbon oil such as kerosene and also effectively using a space in a desulfurizing unit. <P>SOLUTION: The method for producing metal-supporting fibrous activated carbon includes: a process of causing an immersing liquid containing a metal component to permeate into the fibrous activated carbon of which the specific surface area is 800 to 4,000 m<SP>2</SP>/g and the total micropore volume is 0.5 to 1.5 cm<SP>3</SP>/g; a process of leaving the fibrous activated carbon in which the immersion liquid is permeated as it is at a temperature of 0 to 40°C for 12 to 36 h; and a subsequent process of firing the fibrous activated carbon in which the metal component is permeated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a metal-supported fibrous activated carbon, a method for producing the metal-supported fibrous activated carbon, a desulfurizer using the metal-supported fibrous activated carbon, and a hydrocarbon oil desulfurization method using the desulfurizer, The present invention relates to a desulfurizer that can adsorb and remove sulfur compounds from hydrocarbon oils such as kerosene using metal-supported fibrous activated carbon as part or all of the adsorbing desulfurizing agent.

And CO ₂ gas as a greenhouse gas, from the viewpoint of reducing the emissions of automotive exhaust gases, such as NO _X, further reduction of sulfur content in the fuel, he is strongly desired by society. In Japan, sulfur has already been regulated to 10 mass ppm or less since 2007 for diesel and gasoline since 2008. On the other hand, recent technological innovations in fuel cells are remarkable. When the hydrogen source is determined for petroleum-based fuel, if the sulfur content in the fuel oil is not reduced to the ppb level, the fuel cell reformer and the electrode catalyst are poisoned by the sulfur content, and the fuel cell system Thus, the desired life is not obtained. Against this background, desulfurization technology for obtaining ultra-low sulfur petroleum fuel oil has been actively researched.

  Most of the difficult desulfurization compounds that are difficult to remove by conventional hydrodesulfurization methods are thiophenes, benzothiophenes, and dibenzothiophenes. In the case of kerosene, the ratio of thiophenes and benzothiophenes is particularly large, and the ratio of thiophenes and benzothiophenes to the total sulfur compounds is often 70% or more as the sulfur content. However, dibenzothiophenes with a low content are more difficult to remove, and in particular, alkyl dibenzothiophenes having a large number of alkyl groups are very difficult to remove. On the other hand, there is a demand for a method that can be easily and efficiently desulfurized by a simple operation. For example, no reduction treatment or hydrogen is required, no pressure is required, and room temperature to about 150 ° C. Therefore, a desulfurization agent that can efficiently remove dibenzothiophenes at a relatively low temperature is desired.

  Activated carbon having a specific pore structure, particularly fibrous activated carbon, has been reported to have high removal performance with respect to dibenzothiophenes contained in light oil and kerosene (see Patent Document 1). However, since fibrous activated carbon is cotton-like, the packing density cannot be increased, so there are problems that the adsorption performance per unit volume is not high, and that the manufacturing process is complicated and the manufacturing cost is extremely high and not economical. To do.

  It has also been reported that hydrocarbon oil desulfurization agents containing a copper component and a silver component can efficiently remove thiophenes and benzothiophenes at temperatures from room temperature to about 150 ° C. (Patent Literature) 2). However, there is a problem that the adsorption removal performance of dibenzothiophenes is limited.

  Furthermore, a hydrocarbon oil containing at least one sulfur compound selected from the group consisting of thiophenes, benzothiophenes and dibenzothiophenes, or a hydrocarbon oil further containing an aromatic hydrocarbon, and a solid acid and / or transition metal Hydrocarbon oil desulfurization method for desulfurization by contacting activated carbon carrying oxide (see Patent Document 3), and hydrocarbon oil containing benzothiophenes and dibenzothiophenes as solid acid desulfurization agent and activated carbon system A hydrocarbon oil desulfurization method (see Patent Document 4) in which a desulfurization treatment is performed in combination with a desulfurization agent is also reported. However, if it is intended to be applied as a kerosene desulfurizer in a stationary fuel cell system for home use or the like, the volume of desulfurization agent necessary to ensure a life of about one year becomes too large. There is a problem that the speed is reduced and the flow of kerosene is uneven.

International Publication No. 2003/097771 International Publication No. 2007/020800 International Publication No. 2005/073348 International Publication No. 2007/015391

  Therefore, the present invention is suitable for a hydrocarbon oil desulfurizer in a stationary fuel cell system for home use and the like, and can reduce the occurrence of unevenness in the flow of hydrocarbon oil such as kerosene, and can also save space in the desulfurizer. It is an object of the present invention to provide a metal-supported fibrous activated carbon that can be effectively used and a method for producing the metal-supported fibrous activated carbon. The present invention also provides a desulfurizer that can efficiently adsorb and remove sulfur compounds in hydrocarbon oil such as kerosene using the metal-supported fibrous activated carbon, such as a stationary fuel cell for home use. It is an object of the present invention to provide a desulfurizer suitable for a system and a hydrocarbon oil desulfurization method using the desulfurizer.

  As a result of intensive studies to achieve the above object, the present inventors put fibrous activated carbon in a container, sprayed with an impregnating liquid containing a metal component, left at room temperature for 12 to 36 hours, and then dried and fired. Thus, it has been found that a metal-supported fibrous activated carbon in which a metal component is uniformly supported can be obtained, and further, the hydrocarbon supported by filling the metal-supported fibrous activated carbon in the vicinity of the hydrocarbon oil inlet of the desulfurizer. It has been found that the occurrence of unevenness in the oil flow can be reduced and the space in the desulfurizer can be used effectively, and the present invention has been completed.

That is, the present invention includes the following inventions.
(1) A fibrous activated carbon having a specific surface area of 800 to 4,000 m ² / g and a total pore volume of 0.5 to 1.5 cm ³ / g is impregnated with an impregnating solution containing a metal component, and 0 to A method for producing a metal-supported fibrous activated carbon, wherein the activated carbon is allowed to stand at 40 ° C. for 12 to 36 hours, and then the fibrous activated carbon infiltrated with the metal component is baked.
(2) The fibrous activated carbon has a specific surface area of 2,000 to 3,000 m ² / g, a total pore volume of 1.0 to 1.3 cm ³ / g, and an average thickness of 5 to 30 μm. And the average length is 0.1-200 mm, The manufacturing method of the metal carrying | support fibrous activated carbon as described in said (1) characterized by the above-mentioned.
(3) The metal-carrying fiber according to (1) or (2), wherein the impregnating liquid containing the metal component is an aqueous solution containing 0.1 to 50 g of metal component per kg of the impregnating liquid. A method for producing activated carbon.
(4) The method for producing a metal-supported fibrous activated carbon according to any one of (1) to (3), wherein the metal component is copper.
(5) A metal-supported fibrous activated carbon obtained by the production method according to any one of (1) to (4) above.
(6) A desulfurizer for desulfurizing the hydrocarbon oil by flowing a hydrocarbon oil therein, wherein the metal-supported fibrous activated carbon described in the above (5) is filled in the desulfurizer. Desulfurizer.
(7) The desulfurizer according to (6), wherein the metal-supported fibrous activated carbon is disposed at least in the vicinity of an inlet of the hydrocarbon oil.
(8) The desulfurizer according to (6), wherein the hydrocarbon oil is kerosene or light oil.
(9) Further, a desulfurizer filled with a solid acid adsorbent, wherein the hydrocarbon oil is brought into contact with the metal-supported fibrous activated carbon, and then contacted with the solid acid adsorbent, The desulfurizer according to (6) above, wherein the sulfur compound is adsorbed and removed from the hydrocarbon oil.
(10) A hydrocarbon oil desulfurization method using the desulfurizer according to any one of (6) to (9) above, wherein a temperature at which the hydrocarbon oil flows through the desulfurizer is −30 to 100. A method for desulfurizing a hydrocarbon oil, characterized by being in the range of ° C.

  According to the method for producing a metal-supported fibrous activated carbon of the present invention, the unevenness of the metal component supported by the fibrous activated carbon is small and uniformly supported, thereby reducing the occurrence of unevenness in the flow of hydrocarbon oil such as kerosene. Further, it is possible to provide a metal-supported fibrous activated carbon that can effectively use the space in the desulfurizer. Also, using such metal-supported fibrous activated carbon, it is suitable for desulfurizers that can efficiently adsorb and remove sulfur compounds in hydrocarbon oils such as kerosene, for example, stationary fuel cell systems for home use, etc. A desulfurizer and a hydrocarbon oil desulfurization method using the desulfurizer can be provided.

It is sectional drawing of an example of the conventional desulfurizer. It is sectional drawing of the other example of the conventional desulfurizer. It is sectional drawing of an example of the desulfurizer of this invention. It is sectional drawing of the other example of the desulfurizer of this invention. It is a graph which shows the relationship between a copper content rate and a frequency ratio.

[Fibrous activated carbon]
Fibrous activated carbon is obtained by using carbon fibers such as PAN (polyacrylonitrile) fiber, strong rayon, petroleum pitch, pitch fiber melt-spun pitch fiber, etc. as the activated carbon raw material, compared with granular activated carbon The adsorbing speed is very high, and it can be processed into various shapes such as cloth and felt. Fibrous activated carbon is a thin fiber of about 10 μm, and when filled in a desulfurizer, the packing density is about 0.05 to 0.3 g / ml, and the packing density is lower than granular activated carbon. Unevenness in the flow of hydrocarbon oil passing through the vessel can be reduced. In addition, fibrous activated carbon itself has adsorptive desulfurization performance for dibenzothiophenes, but if it carries a metal, the adsorptive desulfurization performance for dibenzothiophenes can be further improved, and adsorption to mercaptans, thiophenes, and benzothiophenes. It is also possible to add desulfurization performance.

The fibrous activated carbon used in the present invention has a specific surface area of 800 to 4,000 m ² / g, particularly preferably 2,000 to 3,000 m ² / g, in order to ensure high performance as an adsorptive desulfurization agent. . Here, when the specific surface area is less than 800 m ² / g, the adsorption site of the sulfur is not sufficiently ensured because the adsorption site of the sulfur compound is remarkably small. On the other hand, when the specific surface area exceeds 4,000 m ² / g, the density is remarkably low and the handling is not easy due to scattering or the like. The fibrous activated carbon used in the present invention has a total pore volume of 0.5 to 1.5 cm ³ / g, particularly preferably 1.0 to 1.3 cm ³ / g. Here, if the total pore volume is less than 0.5 cm ³ / g, the route through which the sulfur compound in the hydrocarbon oil diffuses to the adsorption site becomes narrow, and the adsorption rate decreases. On the other hand, when the total pore volume exceeds 1.5 cm ³ / g, the density is remarkably low and the handling is not easy due to scattering or the like.

  In the fibrous activated carbon used in the present invention, the average thickness is preferably 5 to 30 μm, particularly preferably 6 to 15 μm. Here, if the average thickness is thinner than 5 μm, the elasticity at the time of filling is too high, so that the possibility that the filled portion moves in the desulfurizer increases. On the other hand, if the average thickness is larger than 30 μm, the distance from the activated carbon surface to the center becomes longer, so it takes time for the sulfur compound to diffuse to the center, and the adsorption rate may decrease. In the fibrous activated carbon used in the present invention, the average length is preferably from 0.1 to 200 mm, particularly preferably from 1 to 20 mm. Here, if the average length is less than 0.1 mm, the activated carbon moves to the downstream side of the desulfurizer and may cause a differential pressure increase. On the other hand, when the average length exceeds 200 mm, the activated carbons are entangled with each other, and handling by a single unit is not easy, and it may be necessary to form a cloth or the like. In particular, short fibers (fibrous activated carbon having an average length of 0.1 to 200 mm) are preferable because they are easy to handle in the process of supporting a metal and are easy to uniformly fill the desulfurizer. The fibrous activated carbon formed into a cloth shape or felt shape can be cut and filled in a circle according to the diameter of the desulfurizer, or can be used after being rounded to the same thickness as the diameter of the desulfurizer.

  The specific surface area and the total pore volume are usually measured by a nitrogen adsorption method. The nitrogen adsorption method is simple and commonly used, and is described in various documents. Examples of such documents include Kazuhiro Hagio, Shimazu review, 48 (1), 35-49 (1991), ASTM (American Society for Testing and Materials) Standard Test Method D 4365-95, and the like. The average thickness is measured, for example, by observing with a scanning electron microscope (SEM) or the like, and the average length is measured, for example, by arbitrarily collecting 100 samples. Measured by determining the value.

(Impregnating liquid)
The impregnating liquid used in the present invention contains a metal component and is characterized in that the metal component is infiltrated into the fibrous activated carbon. The metal component may be dissolved or dispersed in the impregnation liquid. In the present invention, the impregnating liquid containing a metal component is preferably an aqueous solution containing 0.1 to 50 g, more preferably 0.5 to 20 g of a metal component per 1 kg of the impregnating liquid. Here, when the content of the metal component per 1 kg of the impregnating liquid is less than 0.1 g, the amount of metal supported as the metal-supported fibrous activated carbon is too small, so that the effect of improving the adsorptive desulfurization performance by the metal support cannot be obtained sufficiently. There is a case. In addition, since the fibrous activated carbon has a high water absorption rate, when the content of the metal component per 1 kg of the impregnating liquid exceeds 50 g, if the amount of the impregnating liquid used is too high, the amount of metal supported on the fibrous activated carbon is too large. The pores may be blocked to inhibit the diffusion of the sulfur compound, and the effect of improving the adsorptive desulfurization performance may not be sufficiently obtained. On the other hand, when the amount of the impregnation liquid used is small, a portion where the metal is supported and a portion where the metal is not supported may be generated due to uneven impregnation. In this case, uniform adsorptive desulfurization performance cannot be obtained.

Examples of the metal component contained in the impregnating liquid include copper, silver, manganese, zinc, nickel and the like, and copper is particularly preferable. Moreover, these metal components may be used individually by 1 type, and may be used in combination of 2 or more type. Copper is inexpensive and relatively high in safety, and in a wide temperature range from near room temperature to about 300 ° C., and the copper is in a monovalent or divalent oxidation state, such as copper oxide (CuO) or sub-oxidation. Even in the case of copper (Cu ₂ O), it exhibits excellent performance in adsorption of sulfur compounds even in the oxidized state without performing a reduction treatment, and even in the absence of hydrogen. The copper is preferably copper oxide (CuO) or cuprous oxide (Cu ₂ O). Further, the metal component contained in the impregnating agent can be used in the form of a metal salt in addition to a simple metal or an oxide, and the metal salt is not particularly limited as long as it is a water-soluble salt, such as nitrate, Examples thereof include sulfates, chlorides, and organic acid salts. An aqueous solution of nitrate is preferred because it is less affected by residual components.

  Moreover, it does not specifically limit as a component which dissolves or disperse | distributes the said metal component in an impregnation liquid, Water, methanol, etc. are mentioned. Water is preferred because it is safe and easy to handle.

[Method for producing metal-supported fibrous activated carbon]
In the method for producing a metal-supported fibrous activated carbon according to the present invention, the fibrous activated carbon is impregnated with an impregnating solution containing the metal component and left at 0 to 40 ° C. for 12 to 36 hours, after which the metal component has penetrated. Fibrous activated carbon is calcined, whereby a fibrous activated carbon in which a metal component is uniformly supported (that is, a metal-supported fibrous activated carbon) is obtained. In addition, in this invention, normal temperature means the temperature of the range of 0-40 degreeC, and leaving at 0-40 degreeC is synonymous with leaving at normal temperature. The standing time for allowing the impregnating solution to uniformly penetrate into the fibrous activated carbon is 12 to 36 hours, but preferably 16 to 24 hours. Here, if the standing time is shorter than 12 hours, the metal component does not permeate uniformly, resulting in uneven support. On the other hand, even if the standing time is longer than 36 hours, the effect of uniformly infiltrating the metal component is small and the time required for production becomes long and is not efficient. In the method for producing a metal-supported fibrous activated carbon of the present invention, the means for impregnating the impregnating liquid is not particularly limited, but for example, a method of spraying the impregnating liquid on the fibrous activated carbon is preferable. A method in which fibrous activated carbon is put in a container and the impregnating solution is uniformly dropped is exemplified. Moreover, in the manufacturing method of this invention, in order to make a metal component adhere firmly to fibrous activated carbon, it is necessary to bake this fibrous activated carbon. Here, the firing can be performed by a known method, but it is preferably performed in a nitrogen gas atmosphere, and the firing temperature is preferably 300 to 500 ° C, more preferably 350 to 450 ° C, and the firing time is 0.5 to 3 hours are preferable, and 0.7 to 2 hours are more preferable. In addition, in the manufacturing method of this invention, in order to remove the component which melt | dissolves or disperse | distributes a metal component in an impregnation liquid, you may dry the fibrous activated carbon which the metal component osmose | permeated before the baking process. Here, the drying temperature is preferably 100 to 150 ° C, more preferably 120 to 140 ° C, and the drying time is preferably 12 to 36 hours, and more preferably 16 to 30 hours.

[Metal-supported fibrous activated carbon]
The metal-supported fibrous activated carbon of the present invention is obtained by the above-described production method, and since the metal component is uniformly supported, the occurrence of unevenness in the flow of hydrocarbon oil is reduced, and excellent adsorption It is possible to exert desulfurization performance. In the present invention, the amount of the metal component supported on the metal-supported fibrous activated carbon is not particularly limited, and varies depending on the type of metal component, but on the basis of the metal element relative to the finished metal-supported fibrous activated carbon, 0.1-10 mass% is preferable, and 0.3-5 mass% is especially preferable. If the loading amount of the metal is less than 0.1% by mass, the loading effect is not sufficiently obtained. On the other hand, if the loading amount exceeds 10% by mass, the amount of the metal having a weak bond with the activated carbon as the carrier increases. May be detached. The amount of metal supported on the metal-supported fibrous activated carbon can be measured with an ICP-AES (inductively coupled plasma emission spectrometer) after dissolving the sample in an alkali solution in an acidic solution. The physical properties of the metal-supported fibrous activated carbon such as the specific surface area, total pore solution, average thickness, average length, etc. can be said to be the same as those of the fibrous activated carbon as a raw material, but the production method of the present invention The metal-supported fibrous activated carbon obtained by the above has the same physical properties as the fibrous activated carbon that is the raw material.

[Desulfurizer]
The desulfurizer of the present invention is a desulfurizer that desulfurizes the hydrocarbon oil by flowing hydrocarbon oil therein, and the desulfurizer is filled with the above-mentioned metal-supported fibrous activated carbon. . Here, according to the desulfurizer of the present invention, the metal-supported fibrous activated carbon exhibiting excellent adsorptive desulfurization performance is reduced while reducing the occurrence of unevenness in the flow of hydrocarbon oil. The sulfur compound can be efficiently adsorbed and removed, and is suitable for a stationary fuel cell system for home use or the like.

[Filling position of metal-supported fibrous activated carbon in desulfurizer]
Generally, in order to make the flow of hydrocarbon oil passing through the adsorbing desulfurizing agent filled in the desulfurizer uniform, as shown in FIG. 1, the adsorbed near the hydrocarbon oil inlet 2 in the desulfurizer 1. By providing a portion 4 not filled with the desulfurizing agent 3, or by providing a portion 5 in which the vicinity of the hydrocarbon oil inlet 2 is narrowed by rounding the corner of the desulfurizer 1, as shown in FIG. There is known a method of dispersing hydrocarbon oil at the time of inflow in the direction perpendicular to the length direction of the desulfurizer. However, stationary fuel cell systems for home use and the like are required to be made as compact as possible. As in conventional desulfurizers, a portion 4 not filled with the adsorbent desulfurizing agent 3 is provided, or the desulfurizer 1 The provision of the narrowed portion 5 by rounding off the corners of the fuel cell wastes the volume in the desulfurizer (and thus in the fuel cell system), which may hinder the compactness of the fuel cell system. There is also. Therefore, in a preferred embodiment of the desulfurizer of the present invention, the above-described metal-supported fibrous activated carbon is disposed in the vicinity of at least the hydrocarbon oil inlet. As described above, the metal-supported fibrous activated carbon of the present invention can reduce the occurrence of unevenness in the flow of hydrocarbon oil, in addition to being able to adsorb and remove sulfur compounds in hydrocarbon oil. It is also possible to maintain a uniform flow of hydrocarbon oil passing through the activated carbon, thus eliminating the above-mentioned useless volume and making effective use of the space in the desulfurizer. That is, as shown in FIG. 3, the desulfurizer of the present invention is a desulfurizer 1 for desulfurizing hydrocarbon oil by flowing the hydrocarbon oil through a hydrocarbon oil supply line 6. The desulfurizer 1 in which the metal-supported fibrous activated carbon 7 is disposed in the vicinity of the hydrocarbon oil inlet 2 is preferable. Further, in the desulfurizer 1 shown in FIG. 3, an adsorbing desulfurizing agent 8 other than the metal-supported fibrous activated carbon charged downstream from the metal-supported fibrous activated carbon 7 as viewed in the flow direction of the hydrocarbon oil is disposed. In the present invention, the vicinity of the hydrocarbon oil inlet means that the distance from the hydrocarbon oil inlet 2 is (1/4) when the distance from the hydrocarbon oil inlet 2 to the outlet 9 is D. ) It means the area up to D.

In the desulfurizer of the present invention, the height of the metal-supported fibrous activated carbon layer (portion filled with the metal-supported fibrous activated carbon) is preferably 500 to 50,000 times the moving distance of hydrocarbon oil per second. In particular, 1,000 to 10,000 times are preferable. The moving distance per second of the hydrocarbon oil is called (apparent) linear velocity [m / sec], and the flow rate [m ³ / sec] is divided by the cross-sectional area [m ² ] perpendicular to the flow. Represented by value.

  The shape of the desulfurizer of the present invention does not need to be rounded in consideration of dispersion of hydrocarbon oil, and may be a cylinder or a square column. Further, the flow direction of the hydrocarbon oil in the desulfurizer is preferably from the bottom to the top (up flow) in order to ensure a uniform flow. Further, the hydrocarbon oil inlet (inlet 2) provided in the desulfurizer may be in any direction and position as long as it is a lower part of the desulfurizer. Therefore, as shown in FIG. 3, the inlet 2 does not have to be located at the bottom of the desulfurizer 1, and may be located at the side of the lower part of the desulfurizer, for example, as shown in FIG.

[Adsorption desulfurization agents other than metal-supported fibrous activated carbon]
The desulfurizer of the present invention can be filled with an adsorbing desulfurizing agent other than the metal-supporting fibrous activated carbon (hereinafter also simply referred to as adsorptive desulfurizing agent) in addition to the metal-supporting fibrous activated carbon. More preferably, the adsorbing desulfurization agent is filled downstream from the flow direction of the hydrocarbon oil. In the case of the desulfurizer having such a structure, the sulfur oil can be adsorbed and removed from the hydrocarbon oil by bringing the hydrocarbon oil into contact with the metal-supported fibrous activated carbon and then contacting with the adsorbing desulfurizing agent. . That is, the hydrocarbon oil that has flowed in from the inlet of the hydrocarbon oil in the desulfurizer is first dispersed in the metal-supported fibrous activated carbon layer in a direction perpendicular to the length direction of the desulfurizer, and then flows in the length direction of the desulfurizer. Therefore, the adsorbing desulfurization agent layer located on the downstream side of the metal-supported fibrous activated carbon layer is uniformly contacted. Therefore, an adsorptive desulfurizing agent having a higher adsorptive desulfurizing performance per unit volume than the metal-supported fibrous activated carbon can be used as the adsorptive desulfurizing agent, and a solid acid adsorbent is preferable. Adsorbing desulfurization agent, which is a combination of a solid acid desulfurization agent and an activated carbon desulfurization agent proposed by J. Org., Is preferred (see International Publication No. 2007/015391).

As the solid acid adsorbent, an adsorbent containing a solid super strong acid is particularly preferable. The solid super strong acid means a solid acid having a higher acid strength than 100% sulfuric acid having a Hammett acidity function H ₀ of −11.93. Specifically, silicon, aluminum, titanium, zirconium, tungsten , A carrier made of hydroxide or oxide such as molybdenum or iron, graphite, ion exchange resin, or the like, to which sulfate radical, antimony pentafluoride, tantalum pentafluoride, boron trifluoride or the like is attached or supported, Zirconium oxide (ZrO ₂ ), stannic oxide (SnO ₂ ), titania (TiO ₂ ), ferric oxide (Fe ₂ O ₃ ) or the like carrying tungsten oxide (WO ₃ ), and further fluorinated sulfone An acid resin etc. can be illustrated (refer international publication 2005/073348). Among these, sulfate group alumina proposed by the present inventors is preferable (see International Publication No. 2009/031613). An adsorbent in which copper, silver, gallium or the like is supported on the sulfate radical alumina is also preferably used.

[Desulfurization method of hydrocarbon oil]
The hydrocarbon oil desulfurization method of the present invention uses the above-described desulfurizer to adsorb the sulfur compound from the hydrocarbon oil by bringing the hydrocarbon oil flowing through the desulfurizer into contact with the metal-supported fibrous activated carbon. Preferably, the sulfur compound contained in the hydrocarbon oil is adsorbed and removed by first contacting the hydrocarbon oil with the metal-supported fibrous activated carbon, and then contacting with the adsorbing desulfurizing agent. Thus, the sulfur compound remaining in the hydrocarbon oil is removed by adsorption. Since the flow of the hydrocarbon oil is made uniform by the metal-supported fibrous activated carbon, the sulfur compound can be efficiently adsorbed and removed by the adsorptive desulfurization agent. Thereby, the sulfur content in the hydrocarbon oil flowing out from the desulfurizer can be reduced to 20 mass ppb or less.

As conditions for bringing the hydrocarbon oil into contact with the metal-supported fibrous activated carbon (including the conditions for bringing the hydrocarbon oil into contact with the adsorptive desulfurizing agent when using an adsorptive desulfurizing agent), the pressure is preferably normal pressure to 1.0 MPaG. Normal pressure to 0.1 MPaG is more preferable, and 0.001 to 0.03 MPaG is particularly preferable. Flow rate is preferably 0.001～100Hr ^-1 at a liquid hourly space velocity (LHSV), 0.01~10hr ^-1 are more preferred. The apparent linear velocity ^{is, 1 × 10 -7 ~1 × 10} -1 m / sec, even ^{5 × 10 -7 ~1 × 10 -2} m / sec, in particular 1 × ¹⁰ -6 ~1 × ^{10 - 3} m / sec is preferred. If the apparent linear velocity is high, the moving speed of the liquid phase itself passing through the packed bed of adsorbent is faster than the adsorption speed (moving speed from the liquid phase to the solid phase), and the liquid phase reaches the outlet of the adsorbing layer. By this time, the adsorbate cannot be completely removed, and the hydrocarbon oil tends to flow out from the outlet while containing the adsorbate that is not removed. Conversely, if the apparent linear velocity is low, the cross-sectional area of the adsorbent layer is relatively large, so the hydrocarbon oil dispersion state is poor, and the hydrocarbon passes through a cross section perpendicular to the flow direction of the adsorbent layer. The oil flow rate (flow rate) is likely to be uneven, and the adsorbate adsorbed in the cross section of the adsorbent layer is likely to be distributed (unevenness), resulting in uneven load on the adsorbent and desulfurization sufficiently efficiently. I can't.

  In the hydrocarbon oil desulfurization method of the present invention, the temperature at which the hydrocarbon oil circulates in the desulfurizer, that is, the temperature at which the adsorptive deflow is performed, or the temperature at which the hydrocarbon oil is brought into contact with the metal-supported fibrous activated carbon (the adsorptive desulfurizing agent is used. In the case, the temperature at which the hydrocarbon oil is brought into contact with the adsorptive desulfurization agent) is preferably -30 to 100 ° C, particularly preferably 0 to 80 ° C. When the temperature is lower than −30 ° C., the diffusion rate of the adsorbed substance (adsorbate) in the hydrocarbon oil is remarkably small, and it takes a long time to be adsorbed. Further, since the viscosity of the hydrocarbon oil increases, the pressure loss in the desulfurizer increases, and the desulfurizer inlet pressure needs to be increased. In general, 0 ° C. or higher is particularly preferable. On the other hand, when the temperature exceeds 100 ° C., the adsorption of dibenzothiophenes is physical adsorption, so that the adsorption amount at equilibrium is remarkably reduced. The higher the temperature, the higher the adsorption rate. However, since the amount of dibenzothiophenes adsorbed at the time of equilibrium decreases, 80 ° C. or lower is particularly preferable.

[Hydrocarbon oil]
Examples of the hydrocarbon oil to which the desulfurizer of the present invention is applied include hydrocarbon oils containing at least one sulfur compound selected from the group consisting of thiophenes, benzothiophenes, and dibenzothiophenes. Specific examples include kerosene and light oil, and particularly kerosene for fuel cells that needs to be highly desulfurized (deep).

  For qualitative and quantitative analysis of these sulfur compounds, Gas Chromatograph (GC) -Flame Photometric Detector (FPD), GC-Atomic Emission Detector (AED), GC- Sulfur Chemiluminescence Detector (SCD), GC-Inductively Coupled Plasma Mass Spectrometer (ICP-MS), etc. can be used, but GC-ICP is used for mass ppb level analysis. -MS is most preferable (see JP 2006-145219 A).

Kerosene is an oil having mainly a hydrocarbon having about 12 to 16 carbon atoms, a density (15 ° C.) of 0.79 to 0.85 g / cm ³ , and a boiling point range of about 150 to 320 ° C. Although it contains a lot of paraffinic hydrocarbons, it contains about 0 to 30% by volume of aromatic hydrocarbons and about 0 to 5% by volume of polycyclic aromatics. In general, No. 1 kerosene defined in Japanese Industrial Standard JIS K2203 is used as a fuel for lighting, heating, and kitchen. Quality: flash point 40 ° C or higher, 95% distillation temperature 270 ° C or lower, sulfur content 0.008% by mass or lower, smoke point 23mm or higher (21mm or higher for cold weather), copper plate corrosion (50 ° C, 3 hours) ) There are provisions of 1 or less and color (Saebold) +25 or more. Usually, the sulfur content is from several ppm to 80 ppm by mass and the nitrogen content is from several ppm to 10 ppm by mass.

The light oil is an oil having mainly a hydrocarbon having about 16 to 20 carbon atoms, a density (15 ° C.) of 0.82 to 0.88 g / cm ³ , and a boiling point range of about 140 to 390 ° C. Although it contains a lot of paraffinic hydrocarbons, it also contains about 10-30% by volume of aromatic hydrocarbons and about 1-10% by volume of polycyclic aromatics. Sulfur is contained from several ppm to 100 ppm by mass, and nitrogen is contained from several ppm to several tens of ppm.

Thiophenes are heterocyclic compounds containing one or more sulfur atoms as heteroatoms, and the heterocyclic ring is a five-membered or six-membered ring and has aromaticity (has two or more double bonds in the heterocyclic ring). ) Sulfur compounds and derivatives thereof, including compounds in which the heterocycles are condensed with each other. Thiophene, also called thiofuran, is a sulfur compound having a molecular weight of 84.1 that can be represented by the molecular formula C ₄ H ₄ S. Other typical thiophenes, methylthiophene (thiotolene, molecular formula C ₅ H ₆ S, molecular weight 98.2), thiopyran (penthiophene, molecular formula C ₅ H ₆ S, molecular weight 98.2), thiophthene (molecular formula C ₆ H ₄ S ₂ , molecular weight 140), tetraphenylthiophene (thionesal, molecular formula C ₂₀ H ₂₀ S, molecular weight 388), dithienylmethane (molecular formula C ₉ H ₈ S ₂ , molecular weight 180) and derivatives thereof.

Benzothiophenes are heterocyclic compounds containing one or more sulfur atoms as heteroatoms, and the heterocycle is a penta- or hexa-atom ring and has aromaticity (two or more double bonds in the heterocycle). And a sulfur compound in which the heterocyclic ring is condensed with one benzene ring and derivatives thereof. Benzothiophene, also called thionaphthene or thiocoumarone, is a sulfur compound with a molecular weight of 134, which can be represented by the molecular formula C ₈ H ₆ S. Other representative benzothiophenes include methylbenzothiophene, dimethylbenzothiophene, trimethylbenzothiophene, tetramethylbenzothiophene, pentamethylbenzothiophene, hexamethylbenzothiophene, methylethylbenzothiophene, dimethylethylbenzothiophene, trimethylethyl Benzothiophene, tetramethylethylbenzothiophene, pentamethylethylbenzothiophene, methyldiethylbenzothiophene, dimethyldiethylbenzothiophene, trimethyldiethylbenzothiophene, tetramethyldiethylbenzothiophene, methylpropylbenzothiophene, dimethylpropylbenzothiophene, trimethylpropylbenzothiophene , Tetramethylpropylbenzothiophene, penta Chill propyl benzothiophene, methyl ethyl propyl benzothiophene, dimethyl ethyl propyl benzothiophene, trimethyl ethylpropyl benzothiophene, alkyl benzothiophenes such as tetramethyl-ethylpropyl benzothiophene, Chiakuromen (Benzochia -γ- pyran, molecular formula C _{9 H} 8 _S, Molecular weight 148), dithiaphthalene (molecular formula C ₈ H ₆ S ₂ , molecular weight 166) and derivatives thereof.

Dibenzothiophenes are heterocyclic compounds containing one or more sulfur atoms as heteroatoms, and the heterocycle is a penta- or hexa-atom ring and has aromaticity (two or more double bonds in the heterocycle). And a sulfur compound in which a heterocyclic ring is condensed with two benzene rings and derivatives thereof. Dibenzothiophene is also called diphenylene sulfide, biphenylene sulfide, or diphenylene sulfide, and is a sulfur compound having a molecular weight of 184 that can be represented by the molecular formula C ₁₂ H ₈ S. 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene are well known as difficult desulfurization compounds in hydrodesulfurization. Other representative dibenzothiophenes include trimethyldibenzothiophene, tetramethyldibenzothiophene, pentamethyldibenzothiophene, hexamethyldibenzothiophene, heptamethyldibenzothiophene, octamethyldibenzothiophene, methylethyldibenzothiophene, dimethylethyldibenzothiophene, Trimethylethyldibenzothiophene, tetramethylethyldibenzothiophene, pentamethylethyldibenzothiophene, hexamethylethyldibenzothiophene, heptamethylethyldibenzothiophene, methyldiethyldibenzothiophene, dimethyldiethyldibenzothiophene, trimethyldiethyldibenzothiophene, tetramethyldiethyldibenzothiophene, Pentamethyldiethyldibenzo Offene, hexamethyldiethyldibenzothiophene, heptamethyldiethyldibenzothiophene, methylpropyldibenzothiophene, dimethylpropyldibenzothiophene, trimethylpropyldibenzothiophene, tetramethylpropyldibenzothiophene, pentamethylpropyldibenzothiophene, hexamethylpropyldibenzothiophene, heptamethylpropyl Alkyl dibenzothiophenes such as dibenzothiophene, methylethylpropyldibenzothiophene, dimethylethylpropyldibenzothiophene, trimethylethylpropyldibenzothiophene, tetramethylethylpropyldibenzothiophene, pentamethylethylpropyldibenzothiophene, hexamethylethylpropyldibenzothiophene, thianthre (Diphenylene disulfide, molecular formula _C 12 _H 8 _{S 2,} molecular weight 216), thioxanthene (dibenzo thiopyran, diphenylmethane sulfide, molecular formula _C 13 _{H 10} S, molecular weight 198) include and derivatives thereof.

  When hydrocarbon oil is used as a hydrogen source for a fuel cell or the like, sulfur contained in the hydrocarbon oil must be strictly removed because it is a catalyst poison of the reforming catalyst in the hydrogen production process. The desulfurizer of the present invention can reduce sulfur compounds to a very small concentration. Therefore, if the desulfurizer of the present invention is used, hydrogen can be produced and supplied to the fuel cell without poisoning the reforming catalyst for producing hydrogen. Further, the fuel cell system including the desulfurizer of the present invention may be a stationary type or a movable type (for example, a fuel cell vehicle).

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

[Preparation-1 of metal-supported fibrous activated carbon-1]
As the fibrous activated carbon, FR-25 manufactured by Kuraray Chemical Co., Ltd. (specific surface area 2,749 m ² / g, total pore volume 0.96 cm ³ / g, average thickness 10 μm, average length 8 mm) was used.
Copper (II) nitrate trihydrate (2.2 g) was dissolved in ion-exchanged water (69.1 g) to prepare impregnating solution A (71.3 g). 8.1 kg of copper was contained per 1 kg of the impregnation liquid A.
10 g of the above-mentioned fibrous activated carbon is put in a container, and the whole amount of the impregnating liquid A is uniformly dispersed, left at room temperature (about 25 ° C.) for 24 hours, and then dried at 130 ° C. for 12 hours. Activated carbon was obtained. This was divided into 21 parts, and the copper content of each fraction was analyzed. The copper content of the fibrous activated carbon was measured by ICP-AES (inductively coupled plasma emission spectroscopy) after dissolving the sample in an alkali solution in an acidic solution.
Next, while flowing nitrogen gas at a flow rate of 4 L / min, the temperature was raised to 400 ° C. over 1 hour, and the fibrous activated carbon infiltrated with the metal component was fired at 400 ° C. for 1 hour. Metal-supported fibrous activated carbon A was obtained.

[Preparation-2 of metal-supported fibrous activated carbon-2]
2.2 g of copper (II) nitrate trihydrate was dissolved in 33.4 g of ion-exchanged water to prepare 35.6 g of impregnation liquid B. 16.2 g of copper was contained per 1 kg of the impregnation liquid B.
A metal-supported fibrous activated carbon B (Example 2) was obtained in the same manner as [Preparation of metal-supported fibrous activated carbon-1] except that the impregnation solution B was used instead of the impregnation solution A. In addition, the fibrous activated carbon before baking which the metal component osmose | permeated was divided into 21 parts, and the copper content rate of each fraction was analyzed.

[Preparation-3 of metal-supported fibrous activated carbon-3]
Prepared in the same manner as [Preparation of metal-supported fibrous activated carbon-1] except that the entire amount of impregnating liquid A was uniformly sprayed, and was not allowed to stand at room temperature, but immediately dried at 130 ° C. for 12 hours. As a result, metal-supported fibrous activated carbon C (Comparative Example 1) was obtained. In addition, the fibrous activated carbon before baking which the metal component osmose | permeated was divided into 21 parts, and the copper content rate of each fraction was analyzed.

[Preparation of metal-supported fibrous activated carbon-4]
Prepared in the same manner as [Preparation of metal-supported fibrous activated carbon-2] except that the entire amount of impregnating solution B was sprayed uniformly and was not left at room temperature at all and immediately dried at 130 ° C. for 12 hours. As a result, metal-supported fibrous activated carbon D (Comparative Example 2) was obtained. In addition, the fibrous activated carbon before baking which the metal component osmose | permeated was divided into 21 parts, and the copper content rate of each fraction was analyzed.

[Distribution of copper content]
In order to evaluate the metal distribution of the metal-supported fibrous activated carbons of Examples 1-2 and Comparative Examples 1-2, the copper content of each fraction in the fibrous activated carbon before firing is classified into 0.5 mass% increments. The frequency distribution of each classification was obtained. The relationship between the copper content and the frequency ratio is shown in FIG. In the case of Example 1 and Example 2 which were allowed to stand at room temperature for 24 hours, the frequency ratio with the copper content of 4.5 to 5.5% by mass was the highest, the spread of the distribution was small, and copper was evenly supported on the fibrous activated carbon. You can see that Moreover, in the case of the comparative example 1 and the comparative example 2 which were not left at room temperature at all, it can be seen that the copper content was widely distributed, and copper carrying unevenness occurred. Since no significant difference was observed between the impregnating liquid A and the impregnating liquid B, the uniform loading of the metal component on the fibrous activated carbon is not the concentration of the metal component in the impregnating liquid, but the standing temperature and It can be seen that the effect of leaving time is large. From the above, it can be seen that the metal-supported fibrous activated carbons of Examples 1 and 2 can reduce the occurrence of unevenness in the flow of hydrocarbon oil such as kerosene because the metal component is uniformly supported.

DESCRIPTION OF SYMBOLS 1 Desulfurizer 2 Hydrocarbon oil inflow port 3 Adsorption desulfurization agent 4 Portion which does not fill with adsorption desulfurization agent 5 Portion where hydrocarbon oil inflow port vicinity is narrowed 6 Hydrocarbon oil supply line 7 Metal-supporting fibrous activated carbon 8 Metal-supporting fiber Adsorbent desulfurization agents other than glassy activated carbon 9 Hydrocarbon oil outlet D Distance from hydrocarbon oil inlet to outlet

Claims (10)

A fibrous activated carbon having a specific surface area of 800 to 4,000 m ² / g and a total pore volume of 0.5 to 1.5 cm ³ / g is impregnated with an impregnating solution containing a metal component at 0 to 40 ° C. A method for producing a metal-supported fibrous activated carbon, wherein the fibrous activated carbon is allowed to stand for 12 to 36 hours, and then the fibrous activated carbon infiltrated with the metal component is fired. The fibrous activated carbon has a specific surface area of 2,000 to 3,000 m ² / g, a total pore volume of 1.0 to 1.3 cm ³ / g, an average thickness of 5 to 30 μm, and an average The method for producing metal-supported fibrous activated carbon according to claim 1, wherein the length is 0.1 to 200 mm.   The method for producing a metal-supported fibrous activated carbon according to claim 1 or 2, wherein the impregnating liquid containing the metal component is an aqueous solution containing 0.1 to 50 g of metal component per kg of the impregnating liquid.   The said metal component is copper, The manufacturing method of the metal carrying | support fibrous activated carbon in any one of Claims 1-3 characterized by the above-mentioned.   A metal-supported fibrous activated carbon obtained by the production method according to claim 1.   A desulfurizer for desulfurizing a hydrocarbon oil by flowing a hydrocarbon oil therein, wherein the desulfurizer is filled with the metal-supported fibrous activated carbon according to claim 5. .   The desulfurizer according to claim 6, wherein the metal-supported fibrous activated carbon is disposed at least in the vicinity of an inlet of the hydrocarbon oil.   The desulfurizer according to claim 6, wherein the hydrocarbon oil is kerosene or light oil.   Further, a desulfurizer filled with a solid acid adsorbent, wherein the hydrocarbon oil is brought into contact with the metal-supported fibrous activated carbon, and then brought into contact with the solid acid adsorbent. The desulfurizer according to claim 6, wherein the sulfur compound is removed by adsorption from the adsorbent.   It is the desulfurization method of hydrocarbon oil using the desulfurizer in any one of Claims 6-9, Comprising: The temperature which the said hydrocarbon oil distribute | circulates in this desulfurizer is the range of -30-100 degreeC. Hydrocarbon oil desulfurization method characterized by the above.

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