JP2012007098A - Hydrorefining method of hydrocarbon oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrorefining method using a hydrodesulfurization catalyst improved so as to exhibit a high desulfurization activity in the case of being used for a hydroprocessing reaction of a hydrocarbon oil, especially a straight gasoil.SOLUTION: The hydrodesulfurization catalyst is used which is prepared by subjecting an initial hydrodesulfurization catalyst to a preparatory sulfurization treatment and has a molybdenum disulfide layer(s) after the preparatory sulfurization treatment having an average length of >3.5 mm and ≤7 mm and an average laminating number of >1.0 and ≤1.9, wherein the initial hydrodesulfurization catalyst is obtained by containing a metal component(s) (including molybdenum as an essential component) selected from the periodic table VIA group and VIII group together with a chelate agent or further a phosphorus compound in a silica-alumina-titania carrier in which the total of a diffraction peak area indicating a crystal structure of anatase-type titania (101) plane and a diffraction peak area indicating a crystal structure of rutile-type titania (110) plane, as measured by X-ray diffractometry, is ≤1/4 the diffraction peak area indicating an aluminum crystal structure assigned to a γ-alumina (400) plane.

Description

  The present invention relates to a method for hydrorefining hydrocarbon oil using a catalyst having high desulfurization activity.

  In recent years, quality control of fuel oil sulfur content has been strengthened from the viewpoint of environmental protection. In particular, the sulfur content in gasoline and light oil is strictly regulated. For this reason, the development of a catalyst exhibiting high desulfurization performance in order to meet this regulation is in progress.

  The active point of the desulfurization catalyst is caused by the sulfide of the active metal supported on the support, and is mainly at the edge of the molybdenum disulfide crystal layer (hereinafter also referred to as “molybdenum disulfide layer”) having a laminated structure. It is considered to exist. For example, in Patent Document 1, the average value of the number of laminated molybdenum disulfide layers is 2.5 to 5, and the average length (average value length) in the plane direction of the crystal layer is 1 to 3.5 nm. It is described that the hydrotreating catalyst is a high gas oil desulfurization performance.

  In addition, titania support is known to exhibit higher desulfurization performance than alumina support, and a hydrotreating catalyst using titania support is expected to be a catalyst that can meet the demand. However, titania generally has a problem that its specific surface area is small and its thermal stability at high temperature is low. In order to solve this problem, a porous titania obtained by adding a particle growth inhibitor or the like that suppresses particle growth during firing to a hydrosol or hydrogel of hydrous titanium oxide or a dried product thereof, followed by drying and firing. Has been developed (see, for example, Patent Document 2). However, when only this porous titania is used as a carrier, there is a problem that the catalyst becomes expensive. Therefore, a hydrotreating catalyst using an alumina-titania carrier prepared by supporting a water-soluble titania compound on an alumina carrier has also been developed (see, for example, Patent Document 3). However, this hydrotreating catalyst can be reduced in price, but has the disadvantage that the performance of the catalyst is low because titania can be supported only by the water absorption rate of the carrier. In addition, a hydrotreating catalyst using an alumina-titania support prepared by highly dispersing titania in alumina by mixing titania during alumina preparation has been developed (see, for example, Patent Document 4). However, this carrier can highly disperse titania in alumina. However, as the titania content increases, the specific surface area decreases and the titania aggregates, so that the sharpness of the pore distribution deteriorates and the performance of the catalyst decreases. There was a drawback of lowering.

JP 2003-299960 A JP 2005-336053 A JP 2005-262173 A Japanese Patent Laid-Open No. 10-118495

  An object of the present invention is to provide a hydrorefining method for hydrocarbon oil using a hydrodesulfurization catalyst that shows a high desulfurization performance at low cost, using a silica-alumina-titania support in which titania is highly dispersed.

  As a result of intensive studies, the present inventors have impregnated a support containing silica, alumina and titania having a specific structure (hereinafter referred to as “silica-alumina-titania support”) with a metal component containing at least molybdenum together with a chelating agent. The hydrodesulfurization catalyst prepared by supporting the molybdenum disulfide crystal layer with an average length of more than 3.5 nm and not more than 7 nm, and an average number of layers exceeding 1.0 and not more than 1.9 The hydrodesulfurization catalyst obtained by the presulfidation treatment (in this specification, the hydrodesulfurization catalyst obtained by the presulfidation treatment is referred to as “presulfided It has been found that by using "hydrodesulfurization catalyst" for hydrorefining of hydrocarbon oil, the desulfurization performance of hydrocarbon oil can be greatly improved and the above-mentioned problems can be achieved. It is those that completed.

That is, the present invention provides [1] a support containing silica, alumina and titania and at least one metal component selected from Groups VIA and VIII of the periodic table supported on the support (however, molybdenum is essential) Containing)
The carrier is the total area of the diffraction peak area showing the crystal structure of the anatase titania (101) plane and the diffraction peak area showing the crystal structure of the rutile titania (110) plane as measured by X-ray diffraction analysis (titania diffraction). Peak area) is 1/4 or less with respect to a diffraction peak area (alumina diffraction peak area) indicating an aluminum crystal structure belonging to the γ-alumina (400) plane,
Obtaining a hydrodesulfurization catalyst a in which the metal component is contained in a carrier together with a chelating agent or further a phosphorus compound;
By pre-sulfiding the hydrodesulfurization catalyst a, the molybdenum is crystallized as molybdenum disulfide and arranged in a layer on the carrier, and the molybdenum disulfide crystal layer is a surface of the crystal layer. A pre-sulfurized hydrodesulfurization catalyst in which the average length in the direction exceeds 3.5 nm, 7 nm or less, and the average number of layers exceeds 1.0 and is 1.9 or less;
The present invention relates to a hydrorefining method for hydrocarbon oil, characterized by hydrotreating a hydrocarbon oil in a hydrogen atmosphere using the presulfided hydrodesulfurization catalyst.

Further, the present invention is [2] wherein the carrier, with the carrier reference, the range silica is 1 to 10% by mass as SiO _2, range titania of 3 to 40% by mass as TiO _2, alumina _Al 2 _{O 3} The method for hydrorefining a hydrocarbon oil according to [1], wherein the hydrocarbon oil is contained in a range of 50% by mass or more.
In the present invention, [3] the metal component is in the range of 1 to 35% by mass as an oxide on the catalyst basis, and the molybdenum is in the range of 1 to 25% by mass on the catalyst basis as MoO _3. The present invention relates to a method for hydrorefining a hydrocarbon oil according to the above [1] or [2].

[4] The present invention provides [4], wherein the hydrocarbon oil is selected from straight-run gas oil, vacuum gas oil, catalytic cracking gas oil, hydrocracked gas oil, and pyrolysis gas oil. ] The hydrorefining method of the hydrocarbon oil in any one of these.
The present invention also relates to [5] the method for hydrorefining a hydrocarbon oil according to any one of [1] to [4], wherein the chelating agent is citric acid or malic acid.

In addition, the present invention provides [6] wherein the product oil obtained by hydrotreating the hydrocarbon oil has a sulfur content of 10 ppm by mass or less and a nitrogen content of 3 ppm by mass or less. The present invention relates to a method for hydrorefining hydrocarbon oil according to any one of 1] to [5].
The present invention also provides [6] a reaction pressure of 1 to 12 MPa, a liquid space velocity of 0.1 to 4.0 h ⁻¹ , a hydrogen / oil ratio of 80 to 500 NL / L, and a reaction temperature of 250 to 400 ° C. The hydrocarbon hydrorefining method according to any one of [1] to [6], wherein

  The presulfided hydrodesulfurization catalyst used in the present invention has an average length of the molybdenum disulfide molybdenum layer that is an active point of desulfurization exceeding 3.5 nm, 7 nm or less, and an average number of layers exceeding 1.0, Since it is 1.9 or less, the active point of desulfurization can be increased. In addition, by chelating molybdenum with a chelating agent contained in the impregnation solution, the interaction between the molybdenum disulfide layer and the carrier can be weakened, and even the first molybdenum disulfide exhibits high desulfurization performance. Is possible. In addition, since the hydrodesulfurization catalyst used in the present invention has a high dispersion of titanium in the support, it can exhibit high desulfurization performance with a relatively small amount of expensive titanium as compared with alumina and silica.

FIG. 3 is a diagram showing the result of X-ray diffraction analysis of carrier a in Example 1. It is a transmission electron microscope (TEM) photograph of a presulfided hydrodesulfurization catalyst. It is an image figure which shows the lamination number and length of the surface direction of the crystal layer of molybdenum disulfide.

Hereinafter, preferred embodiments of the present invention will be described in detail.
The hydrodesulfurization catalyst used in the hydrorefining method of hydrocarbon oil of the present invention is a silica-alumina-titania support having a specific structure, at least one metal selected from Group VIA and Group VIII of the periodic table. This is a hydrodesulfurization catalyst obtained by further preliminarily sulfiding a hydrodesulfurization catalyst supporting a component (including at least molybdenum) to form a molybdenum disulfide crystal layer having a specific structure.

  The silica-alumina-titania support used in the hydrodesulfurization catalyst according to the present invention has a diffraction peak area and a rutile-type titania (110) showing the crystal structure of the anatase-type titania (101) plane measured by X-ray diffraction analysis. A diffraction peak area (hereinafter, referred to as “a titania diffraction peak area”) indicating the crystal structure of the plane is represented by an aluminum crystal structure belonging to the γ-alumina (400) plane. It is necessary to be 1/4 or less, preferably 1/5 or less, and more preferably 1/6 or less.

Here, when the titania diffraction peak area with respect to the alumina diffraction peak area (titania diffraction peak area / alumina diffraction peak area) is larger than 1/4, it indicates that the crystallization of titania is progressing, and is effective for desulfurization reaction. Holes are reduced. Therefore, in this case, even if the amount of titania contained in the support is increased, the resulting hydrodesulfurization catalyst does not exhibit desulfurization performance corresponding to its economic efficiency, and does not become an inexpensive and high-performance catalyst.
The diffraction peak showing the crystal structure of the anatase-type titania (101) plane was measured at 2θ = 25.5 °, and the diffraction peak showing the crystal structure of the rutile-type titania (110) plane was 2θ = 27. It is measured at 5 °. The diffraction peak showing the aluminum crystal structure attributed to the γ-alumina (400) plane is measured at 2θ = 45.9 °.

  Each diffraction peak area is calculated by fitting the graph obtained by X-ray diffraction analysis using the least square method and correcting the baseline to obtain the height from the maximum peak value to the baseline (peak intensity W). The peak width (half width) at the half value (W / 2) of the obtained peak intensity was determined, and the product of this half width and peak intensity was taken as the diffraction peak area. From each obtained diffraction peak area, “titania diffraction peak area / alumina diffraction peak area” was calculated (see FIG. 1).

The carrier preferably contains 1 to 10% by mass of silica as SiO ₂ on a carrier basis, more preferably 2 to 7% by mass, and still more preferably 2 to 5% by mass. When the silica content is less than 1% by mass, the specific surface area is lowered and the titania particles are easily aggregated during firing during the production of the carrier (hereinafter referred to as “second step” described below. The same applies hereinafter). The total area of diffraction peaks indicating the crystal structures of anatase titania and rutile titania measured by X-ray diffraction analysis is increased. On the other hand, when the content of silica exceeds 10% by mass, the sharpness of the pore distribution of the obtained carrier is deteriorated and the desired desulfurization activity may not be obtained.

Further, the carrier preferably contains 3 to 40% by mass of titania as TiO _{2 based} on the carrier, more preferably 15 to 35% by mass, and further preferably 15 to 25% by mass. When the titania content is less than 3% by mass, the addition effect of the titania component is small, and the resulting catalyst may not obtain the desired catalytic activity. In addition, when the titania content is more than 40% by mass, the mechanical strength of the catalyst may be lowered, and the specific surface area is increased because the crystallization of titania particles easily proceeds during firing during the production of the support. The catalyst performance becomes low and the catalyst performance corresponding to the economic efficiency corresponding to the increase in the amount of titania is not exhibited, and it is not preferable because it does not become an inexpensive and high-performance catalyst.

Furthermore, the carrier preferably contains 50 to 96% by mass of alumina as Al ₂ O _{3 based} on the carrier, more preferably 58 to 83% by mass, and even more preferably 70 to 83% by mass. Here, when the content of alumina is less than 50% by mass, catalyst deterioration tends to increase, such being undesirable. Moreover, when there is more content of alumina than 96 mass%, since there exists a tendency for catalyst performance to fall, it is unpreferable.

The metal component supported on the silica-alumina-titania support is selected from Group VIA (IUPAC Group 6) and Group VIII (IUPAC Groups 8 to 10) of the periodic table. However, it is essential to contain at least molybdenum.
As the metal component of Group VIA of the periodic table, tungsten can be preferably used in addition to molybdenum, and as the metal component of Group VIII of the periodic table, cobalt and nickel are preferably used.
The total content of metal components selected from Group VIA and Group VIII of the periodic table is preferably in the range of 1 to 35% by mass, more preferably in the range of 15 to 30% by mass as an oxide, based on the catalyst. Among these, the content of the metal component (including molybdenum) of Group VIA of the periodic table is preferably in the range of 1 to 30% by mass, more preferably in the range of 13 to 24% by mass as an oxide, The content of the metal component of Group VIII of the periodic table is preferably in the range of 1 to 10% by mass, more preferably in the range of 2 to 6% by mass as an oxide. The content of molybdenum contained as an essential component is preferably in the range of 1 to 25% by mass, more preferably in the range of 10 to 22% by mass, as an oxide.

  When the metal component is supported on the silica-alumina-titania support in the hydrodesulfurization catalyst used in the present invention, it is important that the metal component is contained in the support together with a chelating agent or further a phosphorus compound.

Examples of chelating agents include citric acid, malic acid, tartaric acid, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), polyethylene glycol (PEG), and tetraethylene glycol (TEG). Malic acid is preferably used. The chelating agent is preferably contained in an amount of 35 to 75% by mass with respect to molybdenum oxide, and more preferably in the range of 55 to 65% by mass. Here, when the content of the chelating agent exceeds 75% by mass with respect to molybdenum oxide, the viscosity of the impregnating liquid containing the metal component increases, which makes the impregnation step in production difficult, and is less than 35% by mass. This is not preferable because the stability of the impregnating solution is deteriorated and the catalyst performance tends to be lowered.
The impregnation liquid preferably further contains a phosphorus compound. The chelating agent and phosphorus compound can be brought into contact with the carrier by conventional means (impregnation method, immersion method, etc.).

As the phosphorus compound, preferably, orthophosphoric acid (hereinafter, also simply referred to as “phosphoric acid”), ammonium dihydrogen phosphate, diammonium hydrogen phosphate, trimetaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, and more preferably, Orthophosphoric acid can be used.
The phosphorus compound is preferably contained in an amount of 3 to 25% by mass in terms of oxide with respect to molybdenum oxide, and more preferably in the range of 5 to 15% by mass. If the content of the phosphorus compound exceeds 25% by mass with respect to molybdenum oxide, the performance of the presulfided hydrodesulfurization catalyst tends to decrease, and if it is less than 3% by mass, the stability of the impregnating solution deteriorates. It is not preferable.

  The method for incorporating the metal component, chelating agent or further phosphorus compound into the carrier is not particularly limited, and known methods such as impregnation method (equilibrium adsorption method, pore filling method, initial wetting method, etc.), ion exchange method and the like. This method can be used. Here, the impregnation method is a method in which a support is impregnated with an impregnation liquid containing an active metal and then dried. In the impregnation method, the metal component is preferably supported simultaneously. If the metals are separately supported, the desulfurization activity or denitrification activity may be insufficient.

Next, the manufacturing method of the hydrodesulfurization catalyst used by this invention is demonstrated.
The method for producing a hydrodesulfurization catalyst used in the present invention includes a mixed aqueous solution of a titanium mineral acid salt and an acidic aluminum salt (hereinafter also simply referred to as “mixed aqueous solution”), and a basic aluminum salt in the presence of silicate ions. A first step of obtaining a hydrate by mixing an aqueous solution so that the pH is 6.5 to 9.5, and a step of obtaining a carrier by sequentially washing, molding, drying and baking the hydrate. Two steps, wherein the carrier is contacted with an impregnation liquid containing at least one metal component selected from Group VIA and Group VIII of the periodic table (however, molybdenum is essential) and a chelating agent or further a phosphorus compound. 3 steps and a fourth step of obtaining the hydrodesulfurization catalyst by drying the support brought into contact with the impregnating liquid in the third step. Hereinafter, each process will be described.

(First step)
First, in the presence of silicate ions, a mixed aqueous solution of a titanium mineral acid salt and an acidic aluminum salt (this is an acidic aqueous solution) and a basic aqueous aluminum salt solution (this is an alkaline aqueous solution), Mixing so that the pH is 6.5 to 9.5, preferably 6.5 to 8.5, more preferably 6.5 to 7.5, to obtain a hydrate containing silica, titania and alumina. .

In this step, (1) a mixed aqueous solution may be added to the basic aluminum salt aqueous solution containing silicate ions, and (2) a basic aluminum salt aqueous solution may be added to the mixed aqueous solution containing silicate ions.
Here, in the case of (1), the silicate ion contained in the basic aluminum salt aqueous solution can be basic or neutral. As the basic silicate ion source, a silicate compound that generates silicate ions in water such as sodium silicate can be used. In the case of (2), the silicate ions contained in the mixed solution of the titanium mineral acid salt and the acidic aluminum salt aqueous solution can be acidic or neutral. As the acidic silicate ion source, a silicate compound that generates silicate ions in water such as silicic acid can be used.

  As the basic aluminum salt, sodium aluminate, potassium aluminate or the like is preferably used. Further, as the acidic aluminum salt, aluminum sulfate, aluminum chloride, aluminum nitrate and the like are preferably used, and as the titanium mineral acid salt, titanium tetrachloride, titanium trichloride, titanium sulfate, titanium nitrate and the like are exemplified. Titanium is preferably used because it is inexpensive.

  For example, a basic aluminum salt aqueous solution containing a predetermined amount of basic silicate ions is placed in a tank equipped with a stirrer, and is usually kept at 40 to 90 ° C., preferably 50 to 70 ° C., and the temperature of this solution ± A mixed aqueous solution of a predetermined amount of a titanium mineral acid salt and an acidic aluminum salt aqueous solution heated to 5 ° C., preferably ± 2 ° C., more preferably ± 1 ° C. has a pH of 6.5 to 9.5, preferably 6.5. It is added continuously in 5 to 20 minutes, preferably 7 to 15 minutes so as to be ˜8.5, more preferably 6.5 to 7.5, to form a precipitate, thereby obtaining a hydrate slurry. Here, the addition of the mixed aqueous solution to the basic aluminum salt aqueous solution is preferably 15 minutes or less because undesirable crystals such as bayerite and gibbsite may be generated in addition to pseudoboehmite as time goes on. More preferably less than a minute. Bayerite and gibbsite are not preferred because their specific surface area decreases when fired.

(Second step)
The hydrate slurry obtained in the first step is aged as desired, and then washed to remove by-product salts to obtain a hydrate slurry containing silica, titania and alumina. The obtained hydrate slurry is further heat-aged if desired, and then, by a conventional means, for example, heat-kneaded to form a kneaded product, and then molded into a desired shape by extrusion molding or the like. In general, after drying at 70 to 150 ° C., preferably 90 to 130 ° C., it is further calcined at 400 to 800 ° C., preferably 450 to 600 ° C., for 0.5 to 10 hours, preferably 2 to 5 hours to obtain silica. A silica-alumina-titania support containing alumina and titania is obtained.

(Third step)
The resulting silica-alumina-titania support is impregnated with at least one metal component selected from Group VIA and Group VIII of the periodic table (provided that molybdenum is essential), a chelating agent or further a phosphorus compound. As described above, the liquid is brought into contact with the carrier by conventional means (impregnation method, dipping method, etc.).
As the raw material for the metal component, for example, molybdenum trioxide, ammonium molybdate, ammonium metatungstate, ammonium paratungstate, tungsten trioxide, nickel nitrate, nickel carbonate, cobalt nitrate, cobalt carbonate and the like are preferably used.

(4th process)
The carrier carrying the metal component obtained by contacting with the impregnation liquid in the third step is hydrodesulfurized by drying at 200 ° C. or less, preferably 110 to 150 ° C. for 0.5 to 3 hours, preferably 1 to 2 hours. A catalyst is obtained.
In addition, when drying or baking is performed at a temperature exceeding 200 ° C., the chelating agent is thermally decomposed, and the supported metal component is aggregated, which is not preferable.

In the hydrorefining method for hydrocarbon oil of the present invention, the above-mentioned hydrodesulfurization catalyst is presulfided, and the molybdenum in the catalyst is crystallized as molybdenum disulfide and arranged in a layer on the support. In the crystal layer of molybdenum disulfide, the average length of the crystal layer in the plane direction exceeds 3.5 nm and is 7 nm or less, preferably 3.6 nm or more and 6.5 nm or less, more preferably 3.7 nm or more, 5 Preliminary in which the average number of layers exceeds 1.0 and is 1.9 or less, preferably 1.1 nm or more and 1.7 nm or less, more preferably 1.2 nm or more and 1.5 nm or less. There is a need to obtain a sulfurized hydrodesulfurization catalyst.
Here, in the case where the average length in the surface direction of the molybdenum disulfide layer is 3.5 nm or less, the crystallinity of molybdenum disulfide is reduced and the interaction with the carrier is likely to occur, and the average length is greater than 7 nm. Then, since the number of active sites decreases, the resulting presulfided hydrodesulfurization catalyst does not exhibit high desulfurization activity. Moreover, when the average number of laminated molybdenum disulfide layers exceeds 1.9, molybdenum disulfide is not highly dispersed, so that sufficient desulfurization performance is not exhibited.

The average number of laminated molybdenum disulfide crystal layers and the average value length are values obtained by the following method.
After the presulfurization is completed, the presulfided hydrodesulfurization catalyst is cooled to room temperature and stored in a nitrogen atmosphere. A part of this presulfided hydrodesulfurization catalyst is pulverized to, for example, 20 mesh or less, and a transmission electron microscope (TEM) photograph of the obtained powder is taken (see FIG. 2).
The average number of molybdenum disulfide crystal layers in the presulfided hydrodesulfurization catalyst is, for example, about 20, preferably 50, more preferably 100 or more molybdenum disulfide layers from the obtained TEM photograph. Then, the number N of the respective layers is measured (see FIG. 3), and the average value thereof is calculated.
Further, the length of the molybdenum disulfide layer is calculated by measuring the length L of each molybdenum disulfide layer from the TEM photograph in the same manner as the average number of layers, and calculating the average value thereof.

The preliminary sulfidation treatment according to the present invention refers to the hydrodesulfurization catalyst and the mixed oil of hydrocarbon oil and sulfiding agent, or hydrogen sulfide brought into contact at a temperature of 200 to 400 ° C. and contained in the hydrodesulfurization catalyst. This refers to a process for converting a metal component into a sulfide state.
More specifically, (1) a hydrodesulfurization catalyst, a petroleum distillate containing a sulfur compound (“hydrocarbon oil” in the present invention) and a mixed oil mixed with a sulfiding agent, or (2 ) The hydrosulfurization catalyst and hydrogen sulfide are contacted in a hydrogen atmosphere at 200 to 400 ° C., preferably 240 to 340 ° C., at a normal pressure or a hydrogen partial pressure, and subjected to preliminary sulfidation treatment and pre-sulfided. A hydrodesulfurization catalyst is obtained.
Here, when the temperature of the preliminary sulfidation treatment is less than 200 ° C., the degree of sulfidation of the supported metal is low, and therefore the desulfurization activity tends to decrease, and when the temperature exceeds 400 ° C., it is not preferable. This is not preferable because the number of laminated molybdenum sulfide crystal layers is remarkably increased and the desulfurization activity tends to decrease. Here, when the mixed oil is brought into contact with the hydrodesulfurization catalyst, it is preferable that the initial temperature be in the range of room temperature to 120 ° C. Here, when the mixed oil is brought into contact after exceeding 120 ° C., the effect of the chelating agent decreases, and as a result, the desulfurization activity tends to decrease.

  The sulfurizing agent used for the preliminary sulfiding treatment is not particularly limited, but in addition to carbon disulfide, hydrogen sulfide, etc., organic sulfur compounds such as thiophene, dimethyl sulfide, dimethyl disulfide, dioctyl polysulfide, dialkylpentasulfide, dibutyl polysulfide, and the like. And dimethyl sulfide, dimethyl disulfide, carbon disulfide, hydrogen sulfide and the like are generally used.

  In the hydrorefining method of hydrocarbon oil of the present invention, the hydrotreating of hydrocarbon oil is performed in a hydrogen atmosphere using the pre-sulfided hydrodesulfurization catalyst. The hydrogenation treatment is not particularly limited, but is carried out under a high-temperature and high-pressure condition in a hydrogen atmosphere by filling a flow-through fixed bed reactor with a catalyst.

As the hydrocarbon oil used in the present invention, straight-run kerosene obtained from an atmospheric distillation apparatus of crude oil, straight-run light oil, straight-run heavy oil obtained from an atmospheric distillation apparatus or residual oil is obtained with a vacuum distillation apparatus. Gasoline diesel oil obtained by catalytic cracking of reduced pressure light oil, vacuum heavy gas oil or desulfurized heavy oil obtained by treatment, or hydrocracked kerosene obtained by hydrocracking contact cracked light oil, vacuum heavy gas oil or desulfurized heavy oil Or hydrocracked kerosene obtained from a pyrolysis device such as hydrocracked gas oil or coker, or pyrolyzed gas oil, and the like, and a fraction containing 80% by volume or more of a fraction having a boiling point of 180 to 390 ° C. The oil to be treated in the atmospheric distillation apparatus is not particularly limited, and examples thereof include petroleum crude oil, synthetic crude oil derived from oil sand, coal liquefied oil, bitumen reformed oil, and the like.
In addition, the value of distillation property (boiling point) here is a value measured according to the method described in JIS K2254 “Petroleum product-distillation test method”.

The method for hydrorefining hydrocarbon oil according to the present invention is preferably carried out under the following reaction conditions.
The hydrogen partial pressure (reaction pressure) is not particularly limited, but is preferably 1 to 12 MPa. When the reaction pressure is less than 1 MPa, desulfurization and denitrogenation activities tend to be remarkably lowered, and therefore, 1 MPa or more is preferable and 3 MPa or more is more preferable. On the other hand, when the reaction pressure exceeds 12 MPa, hydrogen consumption increases and the operating cost increases, which is not preferable. Therefore, the pressure is preferably 12 MPa or less, more preferably 10 MPa or less, and even more preferably 7 MPa or less.
But not liquid hourly space velocity particularly limited, is preferably a 0.1～4H ^-1, more preferably 0.5~2h ^-1. If the liquid space velocity is less than 0.1 h ⁻¹ , the throughput is low and the productivity is low, which is not practical. Further, if the liquid space velocity exceeds 4 h ⁻¹ , the reaction temperature is increased, and the catalyst deterioration is accelerated.
The hydrogen / oil ratio is not particularly limited, but is preferably 80 to 500 NL / L, and more preferably 150 to 350 NL / L. A hydrogen / oil ratio of less than 80 NL / L is not preferable because the desulfurization rate decreases. Moreover, even if it exceeds 500 NL / L, since there is no big change in desulfurization activity and only an operating cost increases, it is not preferable.
Although reaction temperature in particular is not restrict | limited, It is preferable that it is 250-400 degreeC, More preferably, it is 300-380 degreeC. If the reaction temperature is less than 250 ° C., the desulfurization and denitrification activities tend to be remarkably lowered, which is not practical. On the other hand, when the reaction temperature exceeds 400 ° C., the catalyst is remarkably deteriorated and the catalyst life is shortened.

The sulfur content of the product oil obtained by the hydrorefining method for hydrocarbon oil according to the present invention is preferably 10 ppm by mass or less, more preferably 8 ppm by mass or less, and 7 ppm by mass or less. Is more preferable. Moreover, it is preferable that the nitrogen content of produced | generated oil is 3 mass ppm or less, and 1 mass ppm or less is more preferable. In the present invention, it is possible to highly reduce the sulfur content concentration and nitrogen content of the product oil by hydrotreating the hydrocarbon oil using the above-mentioned specific hydrodesulfurization catalyst.
In addition, the value of sulfur content here (sulfur content concentration) is a value measured according to the method described in JIS K2541 “Crude oil and petroleum products—sulfur content test method”. Moreover, the value of nitrogen content (nitrogen content concentration) is a value measured according to the method described in JIS K2609 “Crude oil and petroleum products—Test method for nitrogen content”.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Preparation of catalyst A]
A tank with a steam jacket with a capacity of 100 L is charged with 8.16 kg of 22 mass% sodium aluminate aqueous solution in terms of Al ₂ O ₃ concentration, diluted with 41 kg of ion-exchanged water, and then 5 mass% silicic acid in terms of SiO ₂ concentration. 1.80 kg of sodium solution was added with stirring and heated to 60 ° C. to prepare a basic aluminum salt aqueous solution. Further, 10 kg of an acidic aluminum salt aqueous solution obtained by diluting 7.38 kg of an aluminum sulfate aqueous solution of 7% by mass in terms of Al ₂ O ₃ concentration with 13 kg of ion-exchanged water, and 1.82 kg of 33% by mass of titanium sulfate in terms of TiO ₂ concentration. The aqueous solution of titanium mineral salt dissolved in the ion-exchanged water was mixed and heated to 60 ° C. to prepare a mixed aqueous solution. Water containing silica, titania, and alumina is added to the tank containing the basic aqueous aluminum salt solution at a constant rate using a roller pump until the pH is 7.2 (addition time: 10 minutes). A Japanese slurry a was prepared.
The obtained hydrate slurry a was aged at 60 ° C. for 1 hour with stirring, dehydrated using a flat plate filter, and further washed with 150 L of a 0.3 mass% aqueous ammonia solution. The cake-like slurry after washing was diluted with ion-exchanged water so as to be 10% by mass in terms of Al ₂ O ₃ concentration, and then the pH was adjusted to 10.5 with 15% by mass ammonia water. This was transferred to an aging tank equipped with a reflux machine and aged at 95 ° C. for 10 hours with stirring. The slurry after completion of aging was dehydrated and concentrated and kneaded to a predetermined moisture content while kneading with a double-arm kneader equipped with a steam jacket. The obtained kneaded product was molded into a cylindrical shape having a diameter of 1.8 mm by an extrusion molding machine and dried at 110 ° C. The dried molded product was baked in an electric furnace at a temperature of 550 ° C. for 3 hours to obtain a carrier a. As for the carrier a, silica is 3% by mass in terms of SiO ₂ (support standard), titania is 20% by mass in terms of TiO ₂ (support standard), and aluminum is 77% by mass in terms of Al ₂ O ₃ concentration (support standard). Contained.

  Further, the carrier a was subjected to X-ray diffraction analysis with an X-ray diffraction apparatus RINT2100 manufactured by Rigaku Corporation (the same applies to the following examples). The result is shown in FIG. Here, the obtained graph was fitted by the least square method, the baseline was corrected, and the half width of the peak attributed to the anatase-type titania (101) surface indicated by 2θ = 25.5 ° was obtained. And the peak intensity from the baseline was defined as the anatase titania diffraction peak area. Similarly, the half value of the peak attributed to the rutile-type titania (110) plane shown at 2θ = 27.5 ° is obtained, and the product of this half-value and the peak intensity from the baseline is the rutile-type titania diffraction peak area. did. Here, the total area of the anatase type titania diffraction peak area and the rutile type titania diffraction peak area was defined as the titania diffraction peak area. In carrier a, no rutile-type titania peak was detected. Further, the half value of the peak attributed to the γ-alumina (400) plane shown at 2θ = 45.9 ° was determined, and the product of this half value and the peak intensity from the baseline was defined as the alumina diffraction peak area. In carrier a, the diffraction peak area showing the crystal structure of anatase titania and rutile type titania was 1/8 of the diffraction peak area showing the crystal structure belonging to aluminum (titania diffraction peak area / alumina). Diffraction peak area = 1/8.

After suspending 232 g of molybdenum trioxide and 97 g of cobalt carbonate in 500 ml of ion-exchanged water and heating this suspension at 95 ° C. for 5 hours so as not to reduce the liquid volume, malic acid was heated. 145 g was added and dissolved to prepare impregnating solution a. The impregnating liquid a was impregnated with 1000 g of support a and then dried at 110 ° C. for 1 hour to obtain Catalyst A. The metal component of the catalyst A was 18% by mass of MoO ₃ (catalyst reference) and 4.5% by mass of CoO (catalyst reference).

[Preparation of catalyst B]
The same carrier a as in Example 1 was used as the carrier. After suspending 235 g of molybdenum trioxide and 98 g of cobalt carbonate in 500 ml of ion-exchanged water and heating this suspension at 95 ° C. for 5 hours so that the liquid volume does not decrease, phosphoric acid is added. 21 g and 147 g of citric acid were added and dissolved to prepare impregnating solution b. The impregnating liquid b was spray impregnated on 1000 g of the carrier a and then dried at 110 ° C. for 1 hour to obtain a catalyst B. The metal component of catalyst B was 18% by mass (catalyst reference) for MoO ₃ , 4.5% by mass (catalyst reference) for CoO, and 1.0% by mass (catalyst reference) for P ₂ O ₅ . Properties of catalyst B are shown in Table 1.

[Preparation of catalyst C]
The same carrier a as in Example 1 was used as the carrier. After suspending 235 g of molybdenum trioxide and 107 g of nickel carbonate in 500 ml of ion-exchanged water and heating this suspension at 95 ° C. for 5 hours so that the liquid volume does not decrease, phosphoric acid is added. 21 g and 147 g of citric acid were added and dissolved to prepare impregnating solution c. The impregnating solution c was spray impregnated on 1000 g of the carrier a and then dried at 110 ° C. for 1 hour to obtain a catalyst C. The metal component of the catalyst C was 18% by mass of MoO ₃ (based on catalyst), 4.5% by mass of NiO (based on catalyst), and 1.0% by mass of P ₂ O ₅ (based on catalyst). The properties of catalyst C are shown in Table 1.

[Preparation of catalyst D]
Add 8.82 kg of 22 wt% sodium aluminate aqueous solution in terms of Al ₂ O ₃ concentration, dilute with 34 kg of ion-exchanged water, and add 1.80 kg of 5 wt% sodium silicate solution in terms of SiO ₂ concentration with stirring. A basic aluminum salt aqueous solution prepared by heating to 60 ° C., an acidic aluminum salt aqueous solution obtained by diluting 13.86 kg of an aluminum sulfate aqueous solution of 7% by mass in terms of Al ₂ O ₃ concentration with 25 kg of ion-exchanged water, It differs from Example 1 in that the hydrate slurry d was prepared by adding the solution until the pH reached 7.2.
In the same manner as in Example 1, carrier d was prepared from hydrate slurry d. In the carrier d, the SiO ₂ concentration was 3% by mass (carrier standard), the TiO ₂ concentration was 0% by mass (carrier standard), and the aluminum was 97% by mass in terms of Al ₂ O ₃ concentration (carrier standard).
In addition, as a result of X-ray diffraction analysis (not shown) as in Example 1, the titania diffraction peak area / alumina diffraction peak area was 0.
Further, in the same manner as in Example 1, catalyst D was produced from carrier d and impregnating liquid a. Catalyst D contained 18% by mass (based on catalyst) of MoO ₃ and 4.5% by mass (based on catalyst) of CoO. Table 1 shows the properties of the catalyst D.

[Preparation of catalyst E]
Catalyst E was obtained by the same carrier a and the same preparation method as in Example 1 except that malic acid was not used in the impregnating liquid a. Properties of catalyst E are shown in Table 1.

[Preparation of catalyst F]
Add 7.09 kg of 22% by mass sodium aluminate aqueous solution in terms of Al ₂ O ₃ concentration, dilute with 47 kg of ion-exchanged water, and add 1.80 kg of 5% by mass sodium silicate solution in terms of SiO ₂ concentration with stirring. In a basic aluminum salt aqueous solution prepared by heating to 60 ° C., a titanium mineral acid aqueous solution in which 4.09 kg of 33% by mass of titanium sulfate in terms of TiO ₂ concentration was dissolved in 23 kg of ion-exchanged water was added at a constant rate. The difference from Example 1 is that the hydrate slurry f was prepared by adding until the pH reached 7.2.
In the same manner as in Example 1, the carrier f was prepared from the hydrate slurry f. In the carrier f, the SiO ₂ concentration was 3% by mass (carrier standard), the TiO ₂ concentration was 45% by mass (carrier standard), and the aluminum was 52% by mass (carrier standard) in terms of Al ₂ O ₃ concentration.
In addition, as a result of X-ray diffraction analysis (not shown) as in Example 1, the titania diffraction peak area / alumina diffraction peak area was 1/3.
Further, in the same manner as in Example 1, catalyst F was produced from carrier f and impregnating liquid f (the amount of molybdenum trioxide in impregnating liquid a was changed from 232 g to 256 g). Catalyst F contained 20% by mass of MoO ₃ (based on catalyst) and 4.5% by mass of CoO (based on catalyst). Table 1 shows the properties of the catalyst F.

[Example 1]
A flow-through fixed bed reactor was charged with 200 ml of Catalyst A. Pre-sulfurization feeds straight run gas oil adjusted to a sulfur content of 2.0 wt% and dimethyl disulfide from normal temperature, pressure 5.0 MPa, liquid space velocity 2.0 h ⁻¹ , hydrogen / oil ratio 200 NL / L. Then, the reaction was completed by maintaining the reaction temperature at 250 ° C. for 8 hours and further at 320 ° C. for 5 hours.
Using a transmission electron microscope apparatus H-800 manufactured by Hitachi, Ltd., a TEM photograph of catalyst A (pre-sulfided hydrodesulfurization catalyst A) after the pre-sulfidation treatment was taken, and from the obtained TEM photograph, 50 two The molybdenum sulfide layer was observed, the number of layers and the length of each molybdenum disulfide layer were measured, and the average number of layers and the average value length were calculated. (The same applies to the following examples). The regulation of the number N and the length L of molybdenum disulfide is shown in FIG. The average number of layers of molybdenum disulfide of the presulfided hydrodesulfurization catalyst was 1.3, and the average value length was 4.4 nm.
After preliminary sulfidation, the raw material oil is switched to straight-run gas oil (boiling point 220-385 ° C., sulfur content 1.27% by mass), pressure 6.0 MPa, liquid space velocity 1.5 h ⁻¹ , hydrogen / oil ratio 200 NL / L, The catalyst was evaluated for desulfurization activity (hydrorefining experiment) at a reaction temperature of 340 ° C. Table 1 shows the sulfur content of the product oil.

[Example 2]
The same presulfidation and desulfurization activity evaluation as in Example 1 was performed except that the catalyst B was used instead of the catalyst A. The average number of layers of molybdenum disulfide in the presulfided hydrodesulfurization catalyst was 1.3, and the average value length was 4.3 nm. Table 1 shows the sulfur content of the product oil.

[Example 3]
The same preliminary sulfidation and desulfurization activity evaluation as in Example 1 was performed except that the catalyst C was used instead of the catalyst A. The average number of layers of molybdenum disulfide of the presulfided hydrodesulfurization catalyst was 1.3, and the average value length was 3.7 nm. Table 1 shows the sulfur content of the product oil.

[Comparative Example 1]
The same presulfidation and desulfurization activity evaluation as in Example 1 was performed except that catalyst D was used instead of catalyst A. The average number of layers of molybdenum disulfide of the presulfided hydrodesulfurization catalyst was 1.2, and the average value length was 4.7 nm. Table 1 shows the sulfur content of the product oil.

[Comparative Example 2]
The same preliminary sulfidation and desulfurization activity evaluation as in Example 1 was performed except that the catalyst E was used instead of the catalyst A. The average number of layers of molybdenum disulfide of the presulfided hydrodesulfurization catalyst was 2.8, and the average value length was 7.2 nm. Table 1 shows the sulfur content of the product oil.

[Comparative Example 3]
The same preliminary sulfidation and desulfurization activity evaluation as in Example 1 was performed except that the catalyst F was used instead of the catalyst A. The average number of layers of molybdenum disulfide of the presulfided hydrodesulfurization catalyst was 1.8, and the average value length was 7.1 nm. Table 1 shows the sulfur content of the product oil.

[Comparative Example 4]
The preliminary sulfidation and desulfurization activity evaluation was carried out in the same manner as in Example 1 except that the preliminary sulfidation was held at 320 ° C for 5 hours instead of being held at 410 ° C for 5 hours. The average number of layers of molybdenum disulfide of the presulfided hydrodesulfurization catalyst was 3.8, and the average value length was 4.5 nm. Table 1 shows the sulfur content of the product oil.

[Example 4]
In the desulfurization activity evaluation, the same preliminary sulfidation and desulfurization activity evaluation as in Example 1 was performed except that the pressure was 3.7 MPa, the liquid space velocity was 0.5 h ⁻¹ , the hydrogen / oil ratio was 180 NL / L, and the reaction temperature was 320 ° C. . The average number of layers of molybdenum disulfide of the presulfided hydrodesulfurization catalyst was 1.3, and the average value length was 4.4 nm. Table 1 shows the sulfur content of the product oil.

[Comparative Example 5]
The same preliminary sulfidation and desulfurization activity evaluation as in Example 4 was performed except that the catalyst F was used. The average number of layers of molybdenum disulfide of the presulfided hydrodesulfurization catalyst was 1.8, and the average value length was 7.1 nm. Table 1 shows the sulfur content of the product oil.

[Example 5]
A mixed oil (sulfur content: 1.05% by weight) of 80% by weight of straight-run gas oil and fluid catalytic cracking gas oil (boiling point: 170 to 360 ° C., sulfur content: 0.19% by mass) 20% by weight is used as the raw oil for desulfurization activity Except for the above, preliminary sulfidation and desulfurization activity evaluation was performed in the same manner as in Example 4. The average number of layers of molybdenum disulfide of the presulfided hydrodesulfurization catalyst was 1.3, and the average value length was 4.4 nm. Table 1 shows the sulfur content of the product oil.

[Comparative Example 6]
Except that the catalyst D was used, the same preliminary sulfidation and desulfurization activity evaluation as in Example 5 was performed. The average number of layers of molybdenum disulfide of the presulfided hydrodesulfurization catalyst was 1.2, and the average value length was 4.7 nm. Table 1 shows the sulfur content of the product oil.

[Comparative Example 7]
Except that the catalyst E was used, the same preliminary sulfidation and desulfurization activity evaluation as in Example 5 was performed. The average number of layers of molybdenum disulfide of the presulfided hydrodesulfurization catalyst was 2.8, and the average value length was 7.2 nm. Table 1 shows the sulfur content of the product oil.

[Comparative Example 8]
Except that the catalyst F was used, the same preliminary sulfidation and desulfurization activity evaluation as in Example 5 was performed. The average number of layers of molybdenum disulfide of the presulfided hydrodesulfurization catalyst was 1.8, and the average value length was 7.1 nm. Table 1 shows the sulfur content of the product oil.

  From the results of Table 1, the total area of the diffraction peak area showing the crystal structure of the anatase titania (101) plane and the diffraction peak area showing the crystal structure of the rutile titania (110) plane measured by X-ray diffraction analysis is The silica-alumina-titania support, which is 1/4 or less of the diffraction peak area showing the aluminum crystal structure attributed to the γ-alumina (400) plane, is selected from Group VIA and Group VIII of the periodic table. The average length of the disulfide molybdenite layer of the hydrorefining catalyst that is loaded with at least one metal component together with a chelating agent and further subjected to presulfidation treatment is more than 3.5 nm and not more than 7 nm, and High desulfurization activity can be obtained by using a hydrorefining catalyst characterized in that the average number of layers exceeds 1.0 and is 1.9 or less.

  Since the hydrocarbon oil can be highly hydrorefined by the method of the present invention, it is very useful industrially.

Claims (7)

A carrier containing silica, alumina and titania, and at least one metal component selected from Group VIA and Group VIII of the periodic table supported on the carrier (however, molybdenum is contained as an essential component);
The carrier is the total area of the diffraction peak area showing the crystal structure of the anatase titania (101) plane and the diffraction peak area showing the crystal structure of the rutile titania (110) plane as measured by X-ray diffraction analysis (titania diffraction). Peak area) is 1/4 or less with respect to a diffraction peak area (alumina diffraction peak area) indicating an aluminum crystal structure belonging to the γ-alumina (400) plane,
Obtaining a hydrodesulfurization catalyst a in which the metal component is contained in a carrier together with a chelating agent or further a phosphorus compound;
By pre-sulfiding the hydrodesulfurization catalyst a, the molybdenum is crystallized as molybdenum disulfide and arranged in a layer on the carrier, and the molybdenum disulfide crystal layer is a surface of the crystal layer. A pre-sulfurized hydrodesulfurization catalyst in which the average length in the direction exceeds 3.5 nm, 7 nm or less, and the average number of layers exceeds 1.0 and is 1.9 or less;
A method for hydrotreating a hydrocarbon oil, comprising hydrotreating a hydrocarbon oil in a hydrogen atmosphere using the hydrosulfurization catalyst subjected to the presulfurization treatment. In the carrier, silica is in the range of 1 to 10% by mass as SiO ₂ , titania is in the range of ₃ to 40% by mass as TiO ₂ , and alumina is in the range of 50% by mass or more as Al ₂ O ₃ , respectively. The method for hydrorefining hydrocarbon oil according to claim 1, which is contained. The metal component is in a range of 1 to 35% by mass as an oxide on a catalyst basis, and the molybdenum is in a range of 1 to 25% by mass on a catalyst basis as MoO _3. Or the hydrorefining method of the hydrocarbon oil of Claim 2.   The hydrocarbon oil according to any one of claims 1 to 3, wherein the hydrocarbon oil is selected from straight-run gas oil, vacuum gas oil, catalytic cracking gas oil, hydrocracked gas oil, and pyrolysis gas oil. Purification method.   The method for hydrorefining hydrocarbon oil according to any one of claims 1 to 4, wherein the chelating agent is citric acid or malic acid.   The sulfur content of the product oil obtained by hydrotreating the hydrocarbon oil is 10 ppm by mass or less, and the nitrogen content is 3 ppm by mass or less. A method for hydrorefining hydrocarbon oil. The reaction pressure is 1 to 12 MPa, the liquid space velocity is 0.1 to 4.0 h ^-1 , the hydrogen / oil ratio is 80 to 500 NL / L, and the reaction temperature is 250 to 400 ° C. The hydrocarbon hydrotreating method according to any one of 1 to 6.