JP5275771B2 - Desulfurizer, and fuel cell cogeneration system and desulfurization system including the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a desulfurizer which reduces a sulfur content of a hydrocarbon oil containing benzothiophenes and/or dibenzothiophenes, and in which a desulfurization agent can be used for a long period up to the very limit of the service life because the replacement time of the desulfurization agent can be judged, and can exhibit the intrinsic performance of the desulfurizer by reducing the uneven flow etc. in the desulfurizer. <P>SOLUTION: The desulfurizer is filled with the desulfurization agent containing a solid acid-based desulfurization agent inside, and the desulfurization agent reduces a sulfur content of a hydrocarbon oil containing at least one sulfur compound selected from the group consisting of benzothiophenes and dibenzothiophenes. The replacement time of the desulfurization agent can be judged by a change in the color of the solid acid-based desulfurization agent. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a desulfurizer, and a fuel cell cogeneration system and a desulfurization system equipped with the desulfurizer, and in particular, a liquid raw fuel used in a fuel cell cogeneration system, particularly benzothiophenes and / or dibenzothiophenes. The present invention relates to a desulfurizer for reducing the sulfur content of hydrocarbon oils containing selenium.

  As a desulfurization method for hydrocarbon oils such as kerosene used in stationary fuel cells for home use and commercial use, a chemisorption desulfurization method using a nickel-based desulfurizing agent at around 200 ° C. has been studied. However, the chemisorption desulfurization method consumes energy for heating, takes time to start up, needs to be performed under pressurized conditions to prevent vaporization of hydrocarbon oil, and decomposes methane and the like. A gas-liquid separation device is required to generate gas, a residence time in the desulfurization agent layer must be shortened to suppress the generation of cracked gas, and carbon deposition is intense, resulting in rapid activation. In addition, the carbon deposition is unavoidable if the exposure time is long, so even if the volume of the desulfurizing agent is increased, the effect of extending the service life is small. There was a problem such as. Further, the nickel-based desulfurizing agent to which copper is added has a certain activity even at a lower temperature of about 150 ° C., but has not yet been solved. Furthermore, nickel-based desulfurization agents need to be subjected to reduction treatment in advance. However, nickel-based desulfurization agents that have undergone reduction treatment are subject to rapid exothermic reaction due to contact with oxygen, and the activity decreases. There was also a problem in the method (see Patent Documents 1 to 13).

  As described above, the desulfurizing agent is replaced for a fixed time such as 4,000 hours or after processing a fixed amount of hydrocarbon oil. Since the remaining desulfurization activity differs depending on the type of desulfurization agent, it was necessary to replace the desulfurization agent as soon as possible in order to prevent leakage of the sulfur content downstream. On the other hand, various methods for managing the replacement timing of the desulfurizing agent have been proposed so as not to waste the desulfurizing agent having the remaining desulfurizing activity as much as possible. (See Patent Documents 14 to 16).

  On the other hand, as a desulfurization method for hydrocarbon oils, a physical adsorption desulfurization method using zeolite, activated carbon or the like at around room temperature is also being studied. However, commercially available kerosene contains aromatic compounds that compete with sulfur compounds, and there is no physical adsorbent with high removal performance, especially for benzothiophenes, which account for the majority of sulfur compounds. It is not practical because a very large volume of adsorbent is required to reduce the amount of the catalyst (see Patent Documents 17 to 19).

  For example, most of the types of sulfur compounds contained in commercially available kerosene are benzothiophenes and dibenzothiophenes, and especially the ratio of benzothiophenes is large. The ratio of benzothiophenes to the total sulfur compounds is the sulfur content. Often 70% or more. However, removal of dibenzothiophenes is more difficult than removal of benzothiophenes, and it is known that removal of alkyldibenzothiophenes is particularly difficult (see Patent Documents 20 to 22).

  Accordingly, a liquid raw fuel for a fuel cell cogeneration system that can be desulfurized relatively easily at a temperature from about room temperature to about 150 ° C. that does not require reduction treatment or hydrogen, and that does not require pressurization. A desulfurizer was sought.

  In contrast, the present inventors have developed a desulfurization method that combines chemical reaction and physical adsorption because sufficient desulfurization performance cannot be obtained by a simple physical adsorption method. Further, the present inventors have found that the thiophene ring has high reactivity and reacts with the benzene ring in the presence of an acidic catalyst even at 100 ° C. or lower to produce a heavier compound. The higher the temperature, the higher the reaction rate of the chemical reaction, but it was confirmed that the reaction proceeds even at a lower temperature by using a solid superacid catalyst having a high acid strength. And it turned out that the solid acid desulfurization agent with a large specific surface area can physically adsorb | suck the heavy sulfur compound which is a reaction product. In addition, by combining a chemical reaction and physical adsorption using a solid acid desulfurization agent with a large specific surface area, benzothiophenes contained in hydrocarbon oils such as commercially available kerosene can be obtained at near room temperature in the absence of hydrogen. I figured out that it could be removed. However, these solid acid-based desulfurization agents are mainly Bronsted acid, and have a problem that desulfurization performance deteriorates quickly with respect to alkyldibenzothiophenes having many alkyl groups (Patent Document 23). reference).

  The present inventors have also proposed an activated carbon-based desulfurization agent having high desulfurization performance for alkyldibenzothiophenes. However, the adsorption mechanism of the activated carbon-based desulfurization agent is a π-electron adsorption mechanism between the graphite structure partially present in the activated carbon and the benzene ring, so the greater the number of alkyl groups in the alkyldibenzothiophenes, the greater the contribution ratio of the benzene ring. Will fall relatively. For this reason, the activated carbon-based desulfurization agent also has a problem that the desulfurization performance is rapidly reduced with respect to alkyldibenzothiophenes having a large number of alkyl groups (see Patent Document 17).

Japanese Examined Patent Publication No. 6-65602 Japanese Patent Publication No.7-115842 Japanese Patent No. 3410147 Japanese Patent No. 3261192 Japanese Patent No. 39144949 Japanese Patent No. 4041636 JP 2007-070502 A JP 2007-262149 A JP 2008-016340 A JP 2008-036523 A JP 2008-043855 A JP 2008-045018 A JP 2008-063448 A JP 2007-193694 A JP 2007-1993979 A JP 2008-044830 A International Publication No. 2003/097771 Pamphlet JP 2003-49172 A JP 2005-2317 A JP 2001-294874 A JP 2004-319400 A JP 2007-31143 A International Publication No. 2005/073348 Pamphlet

  Furthermore, the present inventors have found an alumina-based desulfurization agent fired at a high temperature, which has a high desulfurization performance with respect to alkyldibenzothiophenes. This alumina-based desulfurizing agent is mainly Lewis acidic, and it is estimated that the alkyldibenzothiophenes can be adsorbed by the π-electron adsorption mechanism with the benzene ring of the alkyldibenzothiophenes. By using these alumina-based desulfurization agents, it is possible to relatively easily remove hydrocarbon oil at a temperature from about room temperature to about 150 ° C., which does not require reduction treatment or hydrogen, and does not require pressurization. It became possible to desulfurize. However, even when the desulfurizing agent is used, it is impossible to determine the replacement timing of the desulfurizing agent, so it cannot be used for a long time until the desulfurizing agent has reached its end of life. In some cases, the performance could not be fully exhibited.

  Therefore, the present invention is a desulfurizer for reducing the sulfur content of a hydrocarbon oil containing benzothiophenes and / or dibenzothiophenes, and the desulfurizing agent can be used for a long period of time until the end of its life by judging the replacement timing of the desulfurizing agent. It is another object of the present invention to provide a desulfurizer that can be used and that can exhibit the original performance of the desulfurizing agent by reducing drift in the desulfurizer.

  The inventors of the present invention have made extensive studies to solve the above-mentioned problems, and paid attention to the fact that the alumina-based desulfurization agent changes from the initial white color to brown as the sulfur content is adsorbed. We found a desulfurizer that can determine the replacement time based on the color change. In addition, the filling method for exhibiting the original performance of the desulfurizing agent was examined in detail, and a desulfurizer having high desulfurization performance and high convenience for the user was found and the present invention was conceived. That is, the desulfurizer of the present invention, and the fuel cell cogeneration system and desulfurization system including the desulfurizer are as follows.

(1) Hydrocarbon oil which is filled with a desulfurizing agent containing a solid acid desulfurizing agent and contains at least one sulfur compound selected from the group consisting of benzothiophenes and dibenzothiophenes. The sulfur content of the desulfurization agent can be determined from the change in color of the solid acid desulfurization agent, and the particle size of the desulfurization agent charged in the desulfurization device is 0.1 to 10. The desulfurizer is 2.0 mm, and a part or all of the desulfurizing agent is slurried with hydrocarbon oil having a sulfur content of 20 mass ppb or less and charged into the desulfurizer.
(2) The desulfurizer according to (1), wherein the solid acid desulfurizing agent is a Lewis acid desulfurizing agent.
(3) The desulfurizer according to (1) or (2), wherein the sulfur content is reduced at a temperature of -30 to 100 ° C.
(4) The hydrocarbon oil is kerosene or light oil, and the sulfur content of the hydrocarbon oil is 0.1 to 10 ppm by mass, according to any one of (1) to (3) above Desulfurizer.
(5) A part or all of the desulfurizer is transparent or translucent, and the color of the solid acid desulfurizing agent can be identified from the outside, and the color of the solid acid desulfurizing agent has a wavelength of 400 to 550 nm by a sensor. The desulfurizer according to any one of the above (1) to (4), further comprising detection means for detecting light by measuring light.
(6) The desulfurizer includes a cylindrical main body container and flanges provided at the inlet and the outlet of the main body container, respectively, and the diameter of the inlet and the outlet of the main body container is a cylindrical portion of the main body container. The desulfurizer according to (1) above, which has an inner diameter of 0.1 to 1.0 times.
(7) The desulfurizer according to any one of (1) to (6) above, wherein the sulfur content of the hydrocarbon oil with reduced sulfur content is 5 mass ppb or less.

(8) A fuel cell cogeneration system comprising the desulfurizer according to any one of the above (1) to (7) and a fuel cell, wherein the hydrocarbon oil reduced in sulfur content is used as a raw material for the fuel cell. A fuel cell cogeneration system that is used as a fuel.
(9) The fuel cell cogeneration system according to (8) , wherein the desulfurizer is installed outside a housing containing the fuel cell and a fuel processing device.
(10) The fuel cell cogeneration system according to (9) , wherein the desulfurizer includes a heat storage agent jacket.

(11) Desulfurizer A for reducing sulfur content at a temperature of −30 to 100 ° C. described in any of (1) to (7 ) above, and 110 to 300 ° C. disposed downstream of the desulfurizer A A desulfurization system comprising a high-temperature desulfurizer B that reduces sulfur content at a temperature of 5 ° C.
(12) The desulfurization system according to (11) , wherein the internal volume of the desulfurizer A is 2 to 100 times the internal volume of the high temperature desulfurizer B.

  The desulfurizer of the present invention can efficiently and economically reduce the sulfur content of hydrocarbon oil to 5 mass ppb or less near normal temperature, and the replacement time can be determined by the color change of the desulfurizing agent. It is convenient for the user and can be suitably used for desulfurization of liquid raw fuel for a fuel cell cogeneration system.

  The present invention is described in detail below. The desulfurizer of the present invention is filled with a desulfurizing agent, and the desulfurizing agent contains a sulfur content of a hydrocarbon oil containing at least one sulfur compound selected from the group consisting of benzothiophenes and dibenzothiophenes. Reduce. Here, the desulfurization agent filled in the desulfurizer of the present invention includes a solid acid desulfurization agent, and the replacement time can be determined by a change in the color of the solid acid desulfurization agent. Further, as the solid acid desulfurizing agent, an alumina desulfurizing agent is preferable in that the color change is large.

  The alumina-based desulfurizing agent is white in a dry state, but becomes slightly yellow when it is filled in the desulfurizer and the hydrocarbon oil is circulated, and changes from brown to brown when the sulfur content is adsorbed. The alumina-based desulfurization agent gradually changes from upstream to brown as the sulfur content is adsorbed, and the brown portion spreads downstream, while the upstream side changes to brown. In the alumina-based desulfurization agent, sulfur is adsorbed at the stage of changing from yellow to brown, and the amount of adsorbed sulfur is increased while changing from brown to brown. Therefore, the replacement timing of the desulfurizing agent can be determined from the change in the color of the desulfurizing agent. In addition, when the sulfur content at the outlet of the desulfurizer needs to be extremely low, the brown portion needs to be replaced before reaching the outlet. Then, by observing or measuring the color of the desulfurizing agent at a certain distance from the outlet of the desulfurizer, it can be determined that it is time to replace the desulfurizing agent when a specific threshold value is reached.

  In the above-mentioned alumina-based desulfurizing agent, the reason why the color of the desulfurizing agent changes from white to slightly yellow, brown, or brown is unknown, but due to the interaction between the adsorbed polycyclic aromatics and sulfur and the desulfurizing agent, light It is thought that the absorption of is occurring.

  The effect of the present invention can be obtained by using a hydrocarbon oil containing at least one sulfur compound selected from the group consisting of benzothiophenes and dibenzothiophenes as the raw material hydrocarbon oil.

  In the absence of hydrogen, benzothiophenes are obtained by a solid acid desulfurization agent, particularly a solid acid desulfurization agent having Bronsted acidity (hereinafter also referred to as a Bronsted acid desulfurization agent), particularly an alumina desulfurization agent. It can be efficiently removed at a temperature from normal temperature (0 to 40 ° C.) to about 150 ° C. that does not require pressurization. The temperature is more preferably about 40 to 120 ° C., but it has desulfurization performance even near room temperature, although its life is slightly shortened.

  On the other hand, for dibenzothiophenes, especially alkyldibenzothiophenes with many alkyl groups, the above-mentioned Bronsted acid solid acid desulfurization agent has low activity and it is difficult to maintain desired desulfurization performance for a long period of time. . For such dibenzothiophenes, it is efficient to use an activated carbon desulfurization agent at a temperature of 100 ° C. or lower, particularly 0 to 80 ° C. The activated carbon desulfurization agent has low removal performance of benzothiophenes but high removal performance of dibenzothiophenes. Since the activated carbon desulfurization agent has a Freundlich type adsorption isotherm, the higher the concentration of the sulfur compound, the larger the amount of adsorption, and the larger the specific surface area, the larger the amount of saturated adsorption.

  Alternatively, solid acid desulfurization agent having Lewis acidity (hereinafter also referred to as Lewis acid desulfurization agent), especially alumina desulfurization agent, also has high adsorption performance for dibenzothiophenes, especially alkyldibenzothiophenes having many alkyl groups. Have The solid acid desulfurization agent having Lewis acidity has a relatively small specific surface area than the activated carbon desulfurization agent, so the saturated adsorption amount is not large, but the adsorption isotherm is Langmuir type due to its strong adsorption power, and the sulfur compound Even when the concentration is low, the amount of adsorption is large. A solid acid desulfurization agent having Lewis acidity is also considered to have a π electron adsorption mechanism, and it is efficient to use it at a temperature of 100 ° C. or less.

The ratio between the Lewis acid amount and the Bronsted acid amount of a solid acid desulfurizing agent, particularly an alumina desulfurizing agent, can generally be relatively compared by pyridine adsorption Fourier transform infrared spectrophotometry (FT-IR). Peak of an absorbance attributed to a Lewis acid site in the vicinity of 1450 cm ^-1, around 1540 cm ^-1 peak absorbance attributable to Bronsted acid sites, a peak of an absorbance attributed to both a Lewis acid and a Bronsted acid 1490cm Detected around ^-1 . Thus, the Lewis acid point peak height (1450 cm around ^-1) I _1450, the Bronsted acid sites of the peak height of the (1540 cm around ^-1) and I _1540, the ratio of the Bronsted acid amount to the amount Lewis acids I _A relative comparison of ₁₅₄₀ / I _{1450 reveals} the difference in acid properties. In the present invention, the Bronsted acid-based desulfurizing agent refers to a desulfurizing agent having an I ₁₅₄₀ / I ₁₄₅₀ of more than 0.120, and the Lewis acid-based desulfurizing agent refers to an I ₁₅₄₀ / I ₁₄₅₀ of 0.120. The following desulfurization agents are indicated.

As the Lewis acid desulfurization agent of the present invention, an alumina desulfurization agent having I ₁₅₄₀ / I ₁₄₅₀ of 0.120 or less, preferably 0.010 or less is preferable. The Bronsted acid point, which is a weak acid point, plays an important role in catalysis in the reaction of producing heavy sulfur compounds from thiophenes and benzothiophenes, but hardly contributes to the adsorption removal of dibenzothiophenes. On the other hand, the Lewis acid point, which is a strong acid point, has high physical adsorption performance for dibenzothiophenes due to π electron interaction with the benzene ring, so when removing dibenzothiophenes rather than thiophenes and benzothiophenes, A smaller amount of Bronsted acid points is preferred.

  In the desulfurizer of the present invention, an activated carbon desulfurizing agent and / or a Bronsted acid desulfurizing agent is disposed upstream, and a Lewis acid desulfurizing agent is disposed downstream, whereby benzothiophenes and / or dibenzothiophenes are disposed. The sulfur content of the hydrocarbon oil contained can be effectively reduced. As the Bronsted acid desulfurizing agent and the Lewis acid desulfurizing agent, an alumina desulfurizing agent is preferable.

  When the desulfurizer of the present invention is filled with a desulfurization agent having a high desulfurization performance even at a room temperature of −30 to 100 ° C., that is, an activated carbon desulfurization agent and / or a Bronsted acid desulfurization agent, and further a Lewis acid desulfurization agent The sulfur content of the hydrocarbon oil can be reduced at a temperature of -30 to 100 ° C, preferably -10 to 80 ° C, particularly 0 to 50 ° C.

  The hydrocarbon oil that the desulfurizer of the present invention reduces the sulfur content typically includes commercially available kerosene and commercially available light oil, and those obtained by blending light hydrocarbon oil such as naphtha with kerosene, kerosene A blend of heavy hydrocarbon oils such as diesel oil, those with a narrower boiling range than commercially available kerosene, those obtained by removing specific components such as aromatics from commercially available kerosene, and light oils such as kerosene It may be obtained by blending a simple hydrocarbon oil, one having a narrower boiling range than commercially available light oil, or one obtained by removing a specific component such as an aromatic component from a commercially available light oil. In particular, commercially available kerosene and commercially available light oil that are easily available are preferred. Moreover, the range of 0.1-10 mass ppm is preferable for the sulfur content of the hydrocarbon oil to be used. If the sulfur content is 0.1 mass ppm or more, desulfurization is necessary as the raw fuel of the fuel cell, and the performance of the desulfurizer is important, but the desulfurizer of the present invention is more normal temperature than other desulfurizers. In the vicinity, the sulfur content of hydrocarbon oil can be efficiently and economically reduced to 5 mass ppb or less, and the replacement time can be determined by the change in the color of the desulfurizing agent. The effect that it can be suitably used for desulfurization of liquid raw fuel for a fuel cell cogeneration system is more apparent. On the other hand, if it is 10 mass ppm or less, it is practical to use the desulfurizer of the present invention because it is not necessary to replace the desulfurizing agent for a long time.

A typical commercial kerosene is mainly a hydrocarbon having about 12 to 16 carbon atoms, a density (15 ° C.) of 0.790 to 0.850 g / cm ³ and a boiling point range of about 150 to 320 ° C. It is. Commercial kerosene contains a large amount of paraffinic hydrocarbons, but 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 specified in Japanese Industrial Standard JIS K2203 is used as a fuel for lighting, heating, and kitchen. The No. 1 kerosene has a flash point of 40 ° C. or higher, a 95% distillation temperature of 270 ° C. or lower, a sulfur content of 0.008 mass% (80 mass ppm) or lower, a smoke point of 23 mm or higher (21 mm for cold weather) Above), copper plate corrosion (50 ° C., 3 hours) 1 or less, color (Saebold) +25 or more. Commercial kerosene usually contains a sulfur content of several ppm to 80 ppm by mass and a nitrogen content of several ppm to 10 ppm by mass.

A typical commercial light oil is a hydrocarbon oil mainly composed of a hydrocarbon having about 16 to 20 carbon atoms, and has a density (15 ° C.) of 0.820 to 0.880 g / cm ³ and a boiling point range of 140 to 390. Although it contains a large amount of paraffinic hydrocarbons at about 0 ° C., it contains about 0-30% by volume of aromatic hydrocarbons and about 0-10% by volume of polycyclic aromatic compounds. In addition, the standard property of commercially available light oil is generally defined as “light oil” in JIS K2204 as fuel for automobile diesel engines.

  For example, the main sulfur compounds contained in the kerosene fraction are benzothiophenes and dibenzothiophenes, but include thiophenes, mercaptans (thiols), sulfides, disulfides, carbon disulfide, inorganic sulfur, etc. In some cases.

  The types and concentrations of sulfur compounds contained in the raw material hydrocarbon oil are gas chromatograph (GC) -flame photometric detector (FPD), GC-atomic emission detector (AED), GC -Analysis can be performed using a sulfur chemiluminescence detector (SCD), a GC-inductively coupled plasma mass spectrometer (ICP-MS), and the analysis equipment is particularly limited. Although not intended, GC-ICP-MS is most preferred for mass ppb level analysis.

  The hydrocarbon oil in which the sulfur content is reduced by the desulfurizer of the present invention can be used as a raw fuel for producing hydrogen which is a fuel for a fuel cell. As fuel cells, phosphoric acid fuel cells (PAFC), molten carbonate fuel cells (MCFC), solid oxide fuel cells (SOFC, also known as solid electrolyte fuel cells), polymer electrolyte fuel cells (PEFC) Among them, solid oxide fuel cells are preferable because they have higher power generation efficiency than solid polymer fuel cells.

  The desulfurizer of the present invention can be suitably used for a fuel cell cogeneration system including a desulfurizer and a fuel cell. Here, since the desulfurizer of the present invention can be used near room temperature, heating is unnecessary, so it is not always necessary to install it inside the fuel cell main body (housing) of the fuel cell cogeneration system, and the degree of freedom of installation location is improved. To do. That is, the desulfurizer of the present invention can be installed outside the housing containing the fuel cell and fuel processing device of the fuel cell cogeneration system. For example, the hydrocarbon oil is stored under a tank that stores the hydrocarbon oil. It can be installed in the middle of the hydrocarbon oil piping from the storage tank to the fuel cell cogeneration system. The housing refers to a fuel processor that produces hydrogen from raw fuel such as kerosene by a steam reforming reaction, a fuel cell, a heat exchanger that recovers heat generated in the fuel cell with warm water, a pump, a valve, and the like. Refers to a container that contains a container.

  The desulfurizer of the present invention can be used near room temperature, but it must be installed in a place where direct sunlight hits a high temperature of 50 ° C or higher, or a location where the temperature becomes 0 ° C or lower in a cold region. When it is necessary to install the heat exchanger, the desulfurizer can be covered with a heat storage agent jacket, and temperature fluctuation can be suppressed with the heat storage agent jacket. As the heat storage agent, in particular, a heat storage agent using a long-chain normal paraffin is suitable. As the long-chain normal paraffin, tetradecane (melting point 278.95K), pentadecane (melting point 283.05K), hexadecane (melting point 291.25K). ), Heptadecane (melting point 295.05K), octadecane (melting point 301.25K) nonadecane (melting point 305.15K), and the like.

  In the desulfurizer of the present invention, it is preferable that part or all of the desulfurizer is transparent or translucent, and the color of the desulfurizing agent can be identified from the outside. By making a part or all of the desulfurization agent filling part of the desulfurizer transparent or translucent, it is possible to easily confirm the deterioration status and replacement time of the desulfurization agent, and for the purpose of preventing drifting, It is also possible to check the filling state.

  Furthermore, it is more preferable that the desulfurizer of the present invention is provided with a mechanism for detecting the color of the desulfurizing agent with a sensor and informing the outside of the replacement timing of the desulfurizing agent. As a sensor, a color sensor that identifies and distinguishes the color of an object by illuminating each color light source of red, blue, and green on the light projecting side and detecting the amount of each reflection by a light receiving unit, a white light A monochromatic light sensor that turns on and transmits reflected light through a filter to measure a specific wavelength, or a structure in which a light emitting element and a light receiving element face the same direction. A reflective photosensor that receives and detects incoming light by a light receiving element can be used. By detecting the color of the desulfurizing agent that changes from white to brown, it is possible to determine that it is time to replace the desulfurizing agent when it is below a specific threshold value, and to notify the outside. The wavelength of the light to be measured is preferably from 380 to 700 nm, more preferably from 400 to 550 nm, and particularly preferably from 450 to 500 nm, from which the color change of the desulfurizing agent can be easily confirmed. In addition, it is preferable that the desulfurizer of this invention is provided with the detection means which detects the color of a solid acid type | system | group desulfurization agent by measuring the light of wavelength 400-550 nm, especially 450-500 nm with a sensor. When the wavelength of the light to be measured is 400 to 550 nm, particularly 450 to 500 nm, the measurement error is small and the replacement timing of the desulfurizing agent can be determined more reliably.

The size of the desulfurizing agent particles filled in the desulfurizer of the present invention is 0.1 to 2.0 mm in diameter when it is spherical , and 0.1 to 2 mm in diameter when it is cylindrical. It is 0 mm , and the length is preferably 0.5 to 5 times the diameter, particularly 1 to 2 times the diameter. However, when such small particles are filled in a dry state, the packing density decreases. In addition, if the hydrocarbon oil is filled after filling, a gas reservoir is formed, and it is difficult to remove the gas later, and drift may occur. Therefore, by filling a part or all of the desulfurizing agent in a slurry with hydrocarbon oil having a sulfur content of 20 mass ppb or less and filling the desulfurizer, the packing density is improved and the formation of a gas reservoir is prevented . Further, after filling with the desulfurizing agent, the desulfurization agent is filled with a hydrocarbon oil having a sulfur content of 20 mass ppb or less, and the hydrocarbon oil is circulated at a large flow rate of 5 to 100 ml / min, preferably 10 to 50 ml / min. It is also possible to perform.

  The desulfurizer of the present invention includes a cylindrical main body container 1 as shown in FIG. 1 and flanges 2 and 3 provided at the inlet and the outlet of the main body container, respectively. A desulfurizer in which the outlet diameter D1 is 0.1 to 1.0 times the inner diameter D2 of the cylindrical portion of the main body container 1 is preferable. Then, the diameter D1 of the inlet and outlet of the main body container 1 (portion filled with the desulfurizing agent) of the desulfurizer (not the diameter of the pipe, but the diameter of the portion where the main body container 1 is squeezed) is set to The inner diameter D2 of the portion is set to 0.1 to 1.0 times, preferably 0.2 to 0.5 times, and after degassing, the connection joints 4 and 5 with the pipes are attached to the flanges 2 and 3. Is preferred. In addition, even when a part or all of the desulfurizing agent is slurried with hydrocarbon oil having a sulfur content of 20 mass ppb or less and charged into the desulfurizer, the diameter of the inlet of the main body container 1 of the desulfurizer is large. Can be filled.

  In addition, since the flow rate during normal use is a low flow rate of about 0.5 to 5 ml / min, the pipe connected to the desulfurizer is thin and the pressure loss increases. Even when degassing is performed by circulating hydrocarbon oil at a large flow rate, the diameter D1 of the inlet and outlet of the main body container 1 of the desulfurizer is set to 0. 0 of the inner diameter D2 of the cylindrical portion of the main body container 1 of the desulfurizer. It is preferable to set the joints 4 and 5 to the flanges 2 and 3 to be connected to the flanges 2 and 3 after degassing by 1 to 1.0 times, preferably 0.2 to 0.5 times.

  Thus, by filling the desulfurizer with the activated carbon-based desulfurizing agent and / or the Bronsted acid-based desulfurizing agent, and further the Lewis acid-based desulfurizing agent, the sulfur content of the hydrocarbon oil is 500 mass ppb or less at room temperature, preferably 50 The mass can be reduced to ppb or less, more preferably 20 mass ppb or less, and even more preferably 5 mass ppb or less.

  A high-temperature desulfurizer B used such as a nickel-based desulfurization agent that reduces the sulfur content at a temperature of 110 to 300 ° C. is disposed downstream of the desulfurizer of the present invention (hereinafter referred to as desulfurizer A for convenience). The desulfurization system is also a preferred embodiment of the present invention. In the desulfurization system including the desulfurizer A and the high-temperature desulfurizer B, a small amount of sulfur may leak from the desulfurizer A. For example, the desulfurizer A desulfurizes to 500 mass ppb, and the desulfurizer of the present invention. The replacement frequency of A may be reduced.

  In the desulfurization system, the internal volume of the desulfurizer A, that is, the amount of the desulfurizing agent to be filled is 2 to 100 times, preferably 3 to 20, the internal volume of the high temperature desulfurizer B, that is, the amount of the high-temperature desulfurizing agent to be filled. More preferably, by setting it to 4 to 10 times, the replacement frequency of the high-temperature desulfurizing agent that is difficult to replace can be reduced, and preferably no replacement is required. In addition, by reducing the size of the high-temperature desulfurizer B, it is possible to suppress a decrease in energy efficiency due to heat radiation from the high-temperature desulfurizer B.

  The activated carbon desulfurization agent has a Freundlich type adsorption isotherm. Therefore, the higher the concentration of the sulfur compound, the larger the adsorption amount. Since desulfurization using a solid acid desulfurization agent having Bronsted acidity is adsorptive desulfurization accompanied by a reaction, the influence of the concentration of the sulfur compound is small. The solid acid desulfurization agent having Lewis acidity has a large amount of adsorption even if the concentration of the sulfur compound is low because the adsorption isotherm is Langmuir type as described above. Therefore, it is efficient to dispose the activated acid desulfurizing agent and the solid acid desulfurizing agent having Bronsted acid upstream and the solid acid desulfurizing agent having Lewis acidity downstream. In particular, an activated carbon-based desulfurizing agent is used as the first desulfurizing agent, then a solid acid-based desulfurizing agent having Bronsted acidity is used as the second desulfurizing agent, and then Lewis acidity is used as the third desulfurizing agent. It is preferable to use a solid acid desulfurizing agent because the concentration of the sulfur compound is an area where the desulfurizing agent is good.

  In addition, when the sulfur content of the hydrocarbon oil to be treated is originally low, such as 1 to 5 ppm by mass, it is not always necessary to use an activated carbon desulfurizing agent, and a solid acid system having Bronsted acidity as the first desulfurizing agent A desulfurizing agent may be used, and then a solid acid desulfurizing agent having Lewis acidity may be used as the second desulfurizing agent.

  In addition, when desulfurizing gas oil and the like not containing benzothiophenes, it is not always necessary to use a solid acid desulfurizing agent having Bronsted acidity, and an activated carbon desulfurizing agent is used as the first desulfurizing agent, and then A solid acid desulfurizing agent having Lewis acidity may be used as the second desulfurizing agent.

  Specific examples of the solid acid desulfurization agent include solid acid such as zeolite, silica / alumina, activated clay, sulfate zirconia, sulfate radical alumina, sulfate radical tin oxide, sulfate radical iron oxide, tungstate zirconia, Mention may also be made of solid superacids such as tin tungstate oxide. These often have both Bronsted acidity and Lewis acidity, and can be used as a Bronsted acid-based desulfurization agent because of particularly strong Bronsted acidity. Among these, an alumina-based desulfurizing agent such as sulfate radical alumina is preferable.

  The Bronsted acid desulfurizing agent is preferably at least one zeolite selected from proton type faujasite type zeolite, proton type mordenite and proton type β zeolite. In particular, these zeolites preferably have a silica / alumina ratio of 100 mol / mol or less, more preferably 30 mol / mol or less, because the smaller the silica / alumina ratio, the greater the amount of acid that becomes an adsorption site. It is preferable.

The zeolite has the general formula: xM _{2 / n} O.Al ₂ O ₃ .ySiO ₂ .zH ₂ O (where n is the valence of the cation M, x is a number of 1 or less, and y is a number of 2 or more. , Z is a general term for a crystalline hydrous aluminosilicate represented by 0 or more). The zeolite holds charge compensating cations such as alkali metals and alkaline earth metals in the pores and cavities. The charge compensating cation in the zeolite can be easily exchanged for another cation such as a proton. In addition, the acid treatment increases the SiO ₂ / Al ₂ O ₃ molar ratio, increases the acid strength, and decreases the amount of solid acid. Since acid strength does not significantly affect the adsorption of sulfur compounds, it is preferable not to reduce the amount of solid acid.

  The charge-compensating cation of the zeolite used for the desulfurization means is a proton, that is, hydrogen, and the cation content other than protons such as sodium, potassium, magnesium and calcium is preferably 5% by mass or less, more preferably 3 It is not more than mass%, more preferably not more than 1 mass%.

As the properties of the above zeolite crystals, the crystallinity is preferably 80% or more, particularly 90% or more, the crystallite diameter is preferably 5 μm or less, particularly 1 μm or less, and the average particle diameter is 30 μm or less, particularly The specific surface area is preferably 300 m ² / g or more, more preferably 400 m ² / g or more.

  Moreover, a solid superacid catalyst is also mentioned as a Bronsted acid desulfurization agent and a Lewis acid desulfurization agent. The acid property of the solid superacid catalyst can be adjusted by its calcination temperature. When baked at a high temperature of 800 ° C. or higher, Bronsted acidity is lowered and Lewis acidity is improved. A solid superacid catalyst calcined at a high temperature of 800 ° C. or higher can be suitably used as the Lewis acid desulfurization agent of the present invention.

The solid super strong acid catalyst is a catalyst made of a solid acid having a higher acid strength than 100% sulfuric acid having a Hammett acidity function H ₀ of −11.93. Silicon, aluminum, titanium, zirconium, tungsten, Hydroxides or oxides such as molybdenum and iron, or a support made of graphite, ion exchange resin, etc., with sulfate radical, antimony pentafluoride, tantalum pentafluoride, boron trifluoride etc. attached or supported, oxidation Zirconium (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 sulfonic acid Resin etc. can be illustrated. Among these, in particular, zirconia, alumina, tin oxide, iron oxide or titania sulfate zirconia treated with sulfuric acid, sulfate radical alumina, sulfate radical tin oxide, sulfate radical iron oxide, sulfate radical titania, or a plurality of metal water It is preferable to use zirconia tungstate, tin oxide tungstate, or the like obtained by kneading and mixing oxides and / or hydrated oxides (for example, Japanese Patent Publication Nos. 59-6181 and 59-40056). No. 4, JP 04-187239 A, JP 04-187241 A, Patent 2566814, Patent 2929772, Patent 3251313, Patent 3328438, Patent 3342694, Patent 3517696, Patent No. 3553878 and Japanese Patent No. 3568372).

The acid strength (H ₀ ) is defined by the ability of the acid points on the catalyst surface to give protons to the base (Bronsted acidity) or the ability to receive electron pairs from the base (Lewis acidity), and is expressed by the pKa value. It can be measured by a known indicator method or gas base adsorption method. For example, the acid strength of the solid acid desulfurization agent can be directly measured using an acid-base conversion indicator having a known pKa value. p-nitrotoluene (pKa value; -11.4), m-nitrotoluene (pKa value; -12.0), p-nitrochlorobenzene (pKa value; -12.7), 2,4-dinitrotoluene (pKa value; -13.8), 2,4-dinitrofluorobenzene (pKa value; -14.5), 1,3,5-trichlorobenzene (pKa value; -16.1), etc. When the color change of the indicator on the catalyst surface to the acidic color is observed, the value is the same as or lower than the pKa value at which the color changes to the acidic color. When the catalyst is colored, it cannot be measured with an indicator, so it has been reported that it can be estimated from the isomerization activity of butane and pentane ["Studies in Surface Science and Catalysis" Vol. 90, ACID-BASE CATALYSIS II , p.507 (1994)].

  As the solid acid desulfurizing agent, the above-mentioned zeolite and solid super strong acid catalyst can be used as they are, but a compact containing 30% by mass or more, particularly 60% by mass or more of these zeolite or solid super strong acid catalyst is preferably used. It is done. As the shape, in order to increase the concentration gradient of the sulfur compound, in the case of the flow type, a small shape, particularly a spherical shape, is preferable as long as the differential pressure before and after the container filled with the desulfurizing agent does not increase. In the case of a spherical shape, the diameter is preferably 0.05 to 4 mm, particularly preferably 0.1 to 2 mm. In the case of a cylindrical shape, the diameter is preferably 0.05 to 4 mm, particularly 0.1 to 2 mm, and the length is preferably 0.5 to 5 times, particularly 1 to 2 times the diameter.

Since the specific surface area of the solid acid desulfurization agent greatly affects the adsorption capacity of the sulfur compound, including the case of the solid superacid catalyst, it is preferably 100 m ² / g or more, more preferably 200 m ² / g or more, particularly 300 m. ² / g or more is preferable. In order to increase the adsorption capacity of the sulfur compound, the pore volume having a pore diameter of 10 mm or less is preferably 0.10 ml / g or more, particularly preferably 0.20 ml / g or more. The pore volume with a pore diameter of 10 mm or more and 0.1 μm or less may be 0.05 ml / g or more, particularly 0.10 ml / g or more in order to increase the diffusion rate of sulfur compounds in the pores. preferable. The pore volume having a pore diameter of 0.1 μm or more is preferably 0.3 ml / g or less, particularly preferably 0.25 ml / g or less, in order to increase the mechanical strength of the molded product. In general, the specific surface area and the total pore volume are measured by a nitrogen adsorption method, and the macropore volume is measured by a mercury intrusion method.

  When zeolite is used as a molded product, as described in JP-A-4-198011, a semi-finished product may be molded and then dried and calcined. The binder may be mixed and molded, and then dried and fired.

  Examples of the binder include clays such as alumina and smectite, and inorganic binders such as water glass. These binders should just be used in the quantity which can be shape | molded, and although it does not specifically limit, It is normally used in the quantity of about 0.05-30 mass% with respect to a raw material. Mixing inorganic particles such as silica, alumina, other zeolites and organic matter such as activated carbon, improving the adsorption performance of sulfur compounds that are difficult to adsorb zeolite, increasing the abundance of mesopores and macropores, You may improve the diffusion rate of a sulfur compound. Moreover, you may improve adsorption | suction performance by compounding with a metal. In particular, Lewis acidity may be improved by supporting Ga or the like. It is preferable that the breaking strength of the particles is 0.5 kg / pellet or more, particularly 1.0 kg / pellet or more because cracking of the desulfurization agent does not occur. Usually, the breaking strength is measured by a compressive strength measuring device such as a Kiya-type tablet breaking strength measuring device (Toyama Sangyo Co., Ltd.).

As conditions for circulating hydrocarbon oil in the desulfurizer of the present invention, the pressure is normal pressure to 5 MPaG, preferably normal pressure to 1 MPaG, particularly 0.01 to 0.3 MPaG, and the temperature is -30 to 100 ° C. Preferably, it is −10 to 80 ° C., particularly 0 to 50 ° C., and LHSV is 0.001 to 10 hr ⁻¹ , preferably 0.01 to ¹ hr ⁻¹ , particularly 0.02 to 0.5 hr ⁻¹ . The apparent linear velocity (value obtained by dividing the flow rate of hydrocarbon oil by the cross-sectional area of the desulfurizing agent layer) is 0.001 to 10 cm / min, preferably 0.05 to 1 cm / min, particularly 0.01 to 0.00. 5 cm / min is preferred. If the apparent linear velocity is high, the liquid phase itself moves faster than the adsorption speed (the liquid phase to the solid phase movement speed), and the sulfur component is completely removed before the liquid phase reaches the adsorption layer outlet. Therefore, a problem of flowing out from the outlet while containing a sulfur component that is not removed easily occurs. On the other hand, if the apparent linear velocity is low, the cross-sectional area of the desulfurizing agent layer becomes large at the same flow rate, so that the liquid dispersion state becomes poor and the hydrocarbon passes through a cross section perpendicular to the flow direction of the desulfurizing agent layer. Since the oil flow rate (flow rate) is uneven and the sulfur content adsorbed in the cross section of the desulfurizing agent layer is distributed, the load on the desulfurizing agent becomes non-uniform and the desulfurization cannot be performed sufficiently efficiently. The direction of flow is preferably from bottom to top (upflow) because the flow can be made uniform.

  It is preferable that the desulfurization agent removes a small amount of adsorbed moisture in advance as a pretreatment. If moisture or the like is adsorbed, not only the adsorption of the sulfur compound is inhibited, but moisture desorbed from the desulfurizing agent immediately after the start of introduction of the hydrocarbon oil is mixed into the hydrocarbon oil. In particular, the Lewis acid desulfurization agent decreases the Lewis acidity when moisture is adsorbed, so it is necessary to prevent moisture from being adsorbed. The desulfurization agent not containing carbonaceous materials such as Bronsted acid desulfurization agent and Lewis acid desulfurization agent is preferably dried at 200 to 980 ° C, preferably 300 to 900 ° C, more preferably 400 to 800 ° C. The activated carbon-based desulfurization agent is preferably dried at about 100 to 200 ° C., preferably about 120 to 150 ° C. in an oxidizing atmosphere such as air. The activated carbon-based desulfurization agent is not preferable at 200 ° C. or higher because it reacts with oxygen and decreases in mass. On the other hand, the activated carbon-based desulfurization agent can be dried at about 100 to 800 ° C. in a non-oxidizing atmosphere such as nitrogen. Further, the activated carbon-based desulfurization agent is particularly preferable when heat treatment is performed at 400 to 800 ° C., because organic substances and contained oxygen are removed and the adsorption performance is improved.

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

Example 1
A column made of a transparent pressure-resistant glass having an internal volume of 10 ml, an alumina-based desulfurizing agent (sulfuric acid-alumina, alumina content 99.5% by mass, spectroscopic peak ratio I ₁₅₄₀ / I ₁₄₅₀ 0.000, specific surface area as a Lewis acid desulfurizing agent 10 ml of 295 m ² / g, pore volume 0.67 ml / g, sulfur content 0.5 mass%, particle size 0.1-0.6 mm) was filled. The filling was performed in a slurry form with desulfurized kerosene having a sulfur content of 20 mass ppb or less.

In the absence of hydrogen, kerosene was circulated from bottom to top at a flow rate of 0.12 ml / min (LHSV 0.72 hr ⁻¹ , apparent linear velocity 0.11 cm / min), all at normal temperature and normal pressure. The sulfur compound therein was analyzed by GC-ICP-MS.

  Kerosene (manufactured by Japan Energy) has a boiling range of 158.0-275.0 ° C, 5% distillation point 172.0 ° C, 10% distillation point 175.5 ° C, 20% distillation point 183.0 ° C, 30% distillation point 190.0 ° C, 40% distillation point 197.0 ° C, 50% distillation point 205.0 ° C, 60% distillation point 214.0 ° C, 70% distillation point 223.0 ° C, 80% distillation point 233.5 ° C, 90% distillation point 247.0 ° C, 95% distillation point 259.5 ° C, 97% distillation point 269.0 ° C, density (15 ° C) 0.7941 g / ml 17.0 vol% aromatic content, 83.0 vol% saturation content, 6.3 mass ppm sulfur content, 1 mass ppb sulfur content derived from a lighter sulfur compound than benzothiophene, heavier than thiophene and thiophene And a sulfur content of 5.3 mass derived from a lighter sulfur compound than 4-methyldibenzothiophene pm, was used 4-methyl dibenzothiophene and sulfur content 1.0 wt ppm derived from the heavy sulfur compounds than 4-methyl-dibenzothiophene, the following: nitrogen content of 1 mass ppm.

  The change with time of the sulfur content at the outlet is shown in FIG. As can be seen from FIG. 2, the sulfur content at the outlet was 5 mass ppb or less until 2,500 minutes, 20 mass ppb or less until 3,600 minutes, and about 200 mass ppb at 7,000 minutes.

  Moreover, the external appearance after 1,170 minutes, 2,550 minutes, and 4,080 minutes is shown in FIG. The white portion remained at the stage where the sulfur content at the outlet was 5 mass ppb or less, but the brown portion gradually spread downstream, and the whole became brown when the sulfur content at the outlet was 20 mass ppb.

(Comparative Example 1)
Into a stainless steel column having an internal volume of 13.5 ml, an alumina-based desulfurizing agent (sulfuric acid-alumina, alumina content 99.5% by mass, spectroscopic analysis peak ratio I ₁₅₄₀ / I _{1450 is} used as a Lewis acid desulfurizing agent as in Example 1. 13.5 ml of 0.000, specific surface area 287 m ² / g, pore volume 0.66 ml / g, sulfur content 0.5 mass%, particle size 0.1 to 0.4 mm). The filling is not made into a slurry with desulfurized kerosene having a sulfur content of 20 mass ppb or less, and is not filled with a hydrocarbon oil having a sulfur content of 20 mass ppb or less during and / or after filling with the desulfurizing agent. Distribution started.

In the absence of hydrogen, the same amount of kerosene as in Example 1 was applied from below at a flow rate of 0.10 ml / min (LHSV 0.44 hr ⁻¹ , apparent linear velocity of 0.11 cm / min) at normal temperature and normal pressure. The sulfur compounds in the spilled kerosene were analyzed by GC-ICP-MS.

  The change with time of the sulfur content at the outlet is shown in FIG. As can be seen from FIG. 4, the sulfur content at the outlet was 5 mass ppb or less until 2,920 minutes, but then rose rapidly, about 20 mass ppb at 3,000 minutes, and about 200 at 5,000 minutes. The mass was ppb. In Comparative Example 1, although the amount of the desulfurizing agent was larger than that in Example 1, it was considered that the sulfur content increased rapidly and a drift occurred.

(Example 2)
A desulfurizer having the structure shown in FIG. 1 and having a desulfurizer body container inlet and outlet diameter D1 approximately 0.33 times the desulfurizer body container inner diameter D2 was prepared. It was possible to fill the desulfurizer with a desulfurizing agent, fill it with a hydrocarbon oil having a sulfur content of 20 mass ppb or less, and fill the desulfurizing agent while venting in the middle. Moreover, after filling the desulfurizer with a desulfurizing agent, it was possible to distribute a hydrocarbon oil having a sulfur content of 20 ppb or less at a large flow rate. In any case, formation of a gas reservoir was prevented, and it was confirmed that no drift occurred when kerosene was circulated in the same manner as in Example 1.

(Example 3)
By using the same alumina desulfurizing agent and kerosene as in Example 1 and immersing the alumina desulfurizing agent in kerosene, the colored alumina desulfurizing agent B when the sulfur content of kerosene is 20 mass ppb and 460 mass ppb is used. (Exit sulfur content is equivalent to 20 mass ppb) and C (exit sulfur content is equivalent to 460 mass ppb). Further, an alumina-based desulfurizing agent was immersed in kerosene that had been previously desulfurized to a sulfur content of 30 mass ppb or less to obtain an alumina-based desulfurizing agent A (corresponding to the initial distribution stage) in which the desulfurization performance did not deteriorate. Further, the desulfurization agent near the inlet after the experiment of Example 1 was collected to obtain an alumina-based desulfurization agent D (corresponding to significant deterioration) that was significantly deteriorated.

  The glass vials having an internal volume of 10 ml were filled with desulfurizing agents A to D, respectively, filled with desulfurized kerosene having a sulfur content of 30 mass ppb or less, and the reflectance was measured using a spectrophotometer. The measurement method is a reflection method, the wavelength range is 340 to 800 nm, the scan speed is 120 nm / min, and a white plate is used as a reference. The change of the reflection spectrum is shown in FIG. In the measurement wavelength range of 400 to 600 nm, the reflectance corresponding to the initial distribution of the desulfurizing agent A is about 40%, whereas the desulfurizing agent B whose sulfur content at the outlet has deteriorated to the equivalent of 20 mass ppb has a reflectance. It decreased to about 20-30%. Further, the reflectivity of the desulfurizing agent D after significant deterioration was reduced to about 5%. Since the reflectance clearly decreases depending on the degree of deterioration of the desulfurizing agent, it is possible to easily determine the replacement time by measuring the degree of deterioration of the desulfurizing agent by measuring the reflectance at a measurement wavelength of 400 to 550 nm. It was.

It is a side view of an example of the desulfurizer of this invention. It is the figure which showed the time-dependent change of the exit sulfur content at the time of using the column made from a transparent pressure | voltage resistant glass, and filling the Lewis acid type | system | group desulfurization agent in the slurry form (Example 1). (Example 1) which is the figure which showed the time-dependent change of the hue in the desulfurization agent filling layer at the time of using the column made from a transparent pressure | voltage resistant glass, and filling the Lewis acid type | system | group desulfurization agent in the slurry form. It is the figure which showed the time-dependent change of the exit sulfur content at the time of using the column made from stainless steel, and filling the Lewis' acid type desulfurization agent without making it into a slurry form (comparative example 1). It is a reflection spectrum of the alumina-type desulfurization agent after desulfurization (Example 3).

Explanation of symbols

1 Desulfurizer body container 2, 3 Flange 4, 5 Connection joint

Claims (12)

The sulfur content of the hydrocarbon oil is filled with a desulfurization agent containing a solid acid desulfurization agent and contains at least one sulfur compound selected from the group consisting of benzothiophenes and dibenzothiophenes. A desulfurizer that reduces
The change time of the desulfurization agent can be determined by the change in the color of the solid acid desulfurization agent ,
The particle size of the desulfurizing agent filled in the desulfurizer is 0.1 to 2.0 mm,
A part or all of the desulfurizing agent is slurried with hydrocarbon oil having a sulfur content of 20 mass ppb or less and charged into the desulfurizer.   The desulfurizer according to claim 1, wherein the solid acid desulfurizing agent is a Lewis acid desulfurizing agent.   The desulfurizer according to claim 1 or 2, wherein the sulfur content is reduced at a temperature of -30 to 100 ° C.   The desulfurizer according to any one of claims 1 to 3, wherein the hydrocarbon oil is kerosene or light oil, and the sulfur content of the hydrocarbon oil is 0.1 to 10 ppm by mass.   Part or all of the desulfurizer is transparent or translucent, the color of the solid acid desulfurization agent can be identified from the outside, and the color of the solid acid desulfurization agent is measured with a sensor at a wavelength of 400 to 550 nm The desulfurizer according to any one of claims 1 to 4, further comprising a detecting means for detecting by performing the operation. The desulfurizer comprises a cylindrical main body container and flanges provided at the inlet and the outlet of the main body container,
The desulfurizer according to claim 1 , wherein the diameter of the inlet and outlet of the main body container is 0.1 to 1.0 times the inner diameter of the cylindrical portion of the main body container. The desulfurizer according to any one of claims 1 to 6 , wherein the sulfur content of the hydrocarbon oil with reduced sulfur content is 5 mass ppb or less. A fuel cell cogeneration system comprising the desulfurizer according to any one of claims 1 to 7 and a fuel cell,
A fuel cell cogeneration system, wherein the hydrocarbon oil having a reduced sulfur content is used as a raw fuel for the fuel cell. The fuel cell cogeneration system according to claim 8 , wherein the desulfurizer is installed outside a housing in which the fuel cell and a fuel processing device are built. The fuel cell cogeneration system according to claim 9 , wherein the desulfurizer includes a heat storage agent jacket. The desulfurizer A for reducing sulfur content at a temperature of -30 to 100 ° C according to any one of claims 1 to 7 , and a sulfur content at a temperature of 110 to 300 ° C arranged downstream of the desulfurizer A. A desulfurization system comprising a high-temperature desulfurizer B for reduction. The desulfurization system according to claim 11 , wherein the internal volume of the desulfurizer A is 2 to 100 times the internal volume of the high temperature desulfurizer B.