JP2006306974A - Catalyst for hydrotreating hydrocarbon oil, method for producing the same and method for hydrotreating hydrocarbon oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst for hydrodesulfurizing a hydrocarbon oil which exhibits minimal degradation of catalytic activity caused by coke degradation and is capable of removing sulfur compounds in a light oil fraction such as a vacuum light oil at a high efficiency for a long period, a method for producing the same and a method for hydrodesulfurizing the vacuum light oil. <P>SOLUTION: The catalyst for hydrotreating the hydrocarbon oil comprises 10-30% by mass of a group 6 metal in the periodic table, 1-15% by mass of a group 8 metal in the periodic table, 2-14% by mass of carbon, 0.05-1% by mass of lithium and 0.8-8% by mass of phosphorus wherein a distribution of the phosphorus atoms obtained by line analysis in the width direction of a section through a center line with an electron prove micro-analysis instrument satisfies a specific equation. The method for producing the same and the method for hydrodesulfurizing the vacuum light oil are also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydrotreating catalyst for hydrocarbon oil, a method for producing the same, and a hydrotreating method for hydrocarbon oil using the catalyst, and more particularly to a hydrocarbon oil, particularly a light oil fraction such as vacuum gas oil. When hydrotreating the catalyst, the sulfur content and nitrogen content in the hydrocarbon oil can be reduced as compared with the conventional use of this type of catalyst, and the catalyst has an excellent activity, and a method for producing the same. And a hydrotreating method using this catalyst.

  There is a large amount of heavy oil such as atmospheric residue obtained by treating crude oil with an atmospheric distillation device, heavy oil such as vacuum gas oil and vacuum residue obtained by further treating atmospheric residue with a vacuum distillation device. Contains sulfur compounds. When these heavy oils are used as fuel without being desulfurized, sulfur oxides (SOx) are discharged into the atmosphere.

Therefore, conventionally, hydrodesulfurization treatment of heavy oil fractions by indirect desulfurization equipment and direct desulfurization equipment has been incorporated as one of the processes for producing various petroleum products from crude oil, and sulfur compounds can be removed. The hydrodesulfurization catalyst for the purpose of removing sulfur compounds in heavy oils is composed of molybdenum, tungsten, tungsten of group VIII, cobalt and nickel of the periodic table as active active ingredients, which are alumina, magnesia. Those supported on an inorganic oxide carrier such as silica and titania have been developed.
In recent years, awareness of global environmental issues has increased and regulations on the quality of various fuel oils have become stricter. The development of desulfurization technology that further reduces the sulfur content of vacuum gas oil, which is a major gasoline base stock, is awaited. As a technique for reducing the sulfur content in vacuum gas oil, it is usually considered that the operating conditions of the hydrodesulfurization apparatus, for example, the reaction temperature, the liquid space velocity, etc. are made severe.
However, when the reaction temperature is increased, carbonaceous matter is deposited on the catalyst and the activity of the catalyst is rapidly reduced (hereinafter referred to as coke deterioration). Since the processing capacity decreases, it is necessary to expand the scale of the facility.
Therefore, the best way to achieve ultra-deep desulfurization of vacuum gas oil without harsh operating conditions is to develop a catalyst that has excellent desulfurization activity and can suppress carbonaceous deposition.

  In recent years, many studies have been conducted on the types of active metals, impregnation methods of active metals, improvement of catalyst support, control of pore structure of catalysts, activation methods, etc. Is reported and known.

  For example, a method is known in which an alumina or silica carrier is impregnated with a solution comprising an organic compound having a nitrogen-containing ligand as a complexing agent and an active metal and dried at 200 ° C. or lower (see Patent Document 1). ).

  Further, on the γ-alumina support, a Group 8 metal (hereinafter simply referred to as “Group 8 metal”) compound and a Group 6 metal (hereinafter simply referred to as “Group 6 metal”) compound of the Periodic Table; Further, there is known a method characterized by impregnating an impregnating solution containing phosphoric acid with an impregnating solution obtained by further adding a diol or ether and drying the impregnating solution at 200 ° C. or lower (see Patent Document 2). ).

  Further, an invention is known in which a carrier is impregnated with a solution composed of a Group 6 metal compound, a phosphorus component, a Group 8 metal compound, and citric acid, and then fired (see Patent Document 3).

  Furthermore, a catalyst comprising a group 6 metal compound, a group 8 metal compound, and phosphoric acid is supported on an oxide carrier to obtain a catalyst dried at 200 ° C. or lower, and a solution of an organic acid represented by a specific chemical formula is supported on the catalyst. And the method of drying at 200 degrees C or less is known (refer patent document 4).

On the other hand, a method for producing a catalyst in which an organic acid is impregnated twice is also known.
For example, an oxide carrier is impregnated with a solution consisting of a Group 6 metal compound, a Group 8 metal compound, an organic acid, and phosphoric acid to obtain a catalyst dried at 200 ° C. or lower, and further impregnated with an organic acid solution. A method of drying at a temperature of 0 ° C. or lower is known (see Patent Document 5).

  In addition, a technique for manufacturing a catalyst by impregnating an inorganic oxide support with a Group 8 metal compound and a heteropolyacid of a Group 6 metal and drying it is also known (see Patent Document 6).

Further, a method for producing a catalyst is known in which an oxide carrier is impregnated with a solution comprising molybdenum, tungsten, a group 8 metal compound, mercaptocarboxylic acid, and phosphoric acid (see Patent Document 7).
The main purpose of this method is to form a coordination compound of mercaptocarboxylic acid and molybdenum, tungsten, or a group 8 metal compound and highly disperse it on the catalyst support.
However, in this method, molybdenum and tungsten are highly dispersed on the support, making it difficult to laminate molybdenum disulfide as in the present invention described later. Type II (refers to Co, Ni active points present at the edge of the second layer or more of molybdenum disulfide, Type I refers to Co, Ni active points present at the edge of the first layer of molybdenum disulfide, type It is speculated that there is no formation of (lower activity than II).
Moreover, the mercaptocarboxylic acid contains sulfur, and if it exists in the vicinity of the group 8 metal (Co, Ni) or forms a coordination, it does not become a desulfurization active site (CoMoS phase, NiMoS phase). In addition, there is a possibility of becoming inactive Co ₉ S ₈ species or Ni ₃ S ₂ species.

  Further, it is known that organic acid is added and molybdenum disulfide is laminated to improve desulfurization performance (see Patent Document 8). However, this catalyst is required to further improve the coke deterioration.

  Regarding lithium, it is known that when a hydrogenolysis is carried out using a catalyst in which a hydrogenation active metal is supported on a carrier containing lithium oxide, an excellent conversion rate can be obtained without increasing the precipitate. (See Patent Document 9) However, this catalyst requires further improvement in desulfurization activity.

  Further, a catalyst is known in which an alkali metal or an alkaline earth metal is added to a catalyst carrier having a total Brnsted acid amount of 50 μmol / g or more by TPD measurement to carry a hydrogenation active metal (see Patent Document 10). This catalyst is also required to be further improved to suppress coke deterioration.

  Further, a catalyst in which the amount of acid is controlled by adding lithium is also known (see Patent Document 11), but this catalyst is also required to be further improved to improve the desulfurization activity.

  The above catalysts have problems such as insufficient desulfurization performance with respect to vacuum gas oil and short catalyst life. For this reason, it is currently required to develop a catalyst having higher desulfurization activity and longer catalyst life than the conventional one that can realize advanced desulfurization of vacuum gas oil without harsh operating conditions. .

JP 61-114737 A Japanese Patent No. 2900771 Japanese Patent No. 2832033 JP-A-4-244238 JP-A-6-339635 JP-A-6-31176 JP-A-1-228552 JP 2003-299960 A JP-A-7-256106 JP 2000-8050 A JP 2003-103175 A

  An object of the present invention is to provide a hydrodesulfurization catalyst that is less likely to reduce catalyst activity due to coke degradation and can remove sulfur compounds in hydrocarbon oils, particularly gas oil fractions such as vacuum gas oil, over a long period of time and with high efficiency. It is another object of the present invention to provide a method for producing the hydrodesulfurization catalyst and a hydrodesulfurization method for vacuum gas oil using the hydrodesulfurization catalyst.

The inventors of the present invention have studied to achieve the above object, and found that the catalyst contains a predetermined amount of Group 6 metal compound, Group 8 metal compound, organic acid, phosphorus, lithium in the periodic table, and at least By impregnating a solution containing a Group 6 metal compound, a Group 8 metal compound and an organic acid and drying at a temperature of 200 ° C. or less, a highly active desulfurization active site (CoMoS) is formed without forming inert cobalt and nickel species. Phase, NiMoS phase, etc.) can be controlled to a high degree, and the acidity of the catalyst can be controlled to a suitable value, so that coke deposition can be suppressed. As a result, since the desulfurization reaction proceeds efficiently, it is possible to obtain a high-performance desulfurization catalyst that can easily achieve advanced desulfurization of hydrocarbon oil such as vacuum gas oil without making the reaction conditions severe. And gained knowledge.
That is, according to the present invention, the above object has been achieved by the following hydrocarbon oil hydrogenation catalyst, a method for producing the catalyst, and a hydrocarbon oil hydrotreating method.
1. 10 to 30% by mass of at least one selected from Group 6 metals of the periodic table, 1 to 15% by mass of at least one selected from Group 8 metals of the periodic table, 2 to 14% by mass of carbon, Phosphorus obtained by line analysis in the cross-sectional width direction passing through the center line using an electron probe microanalysis (EPMA) apparatus of this phosphorus atom containing 0.05 to 1% by mass of lithium and 0.8 to 8% by mass of phosphorus A hydrocarbon oil hydrotreating catalyst characterized in that the distribution of atoms satisfies the following formula (1): In addition, the said mass% is a catalyst reference | standard and oxide conversion.

S = exp (0.04 × Iave. + 0.013 × Imax.−0.143 × Imin.) ≦ 1 Equation (1)

(In Formula (1), Imax. Is the maximum value of the phosphorus atom concentration measured by EPMA line analysis, Imin. Is the minimum value of the phosphorus atom concentration measured value by EPMA line analysis, and Iave. Is the EPMA line. (This is the average value of phosphorus atom concentration measured by analysis.)
2. ^2. The hydrocarbon oil hydrotreating catalyst according to 1 above, having a specific surface area of 110 to 300 m ² / g, a pore volume of 0.35 to 0.6 m1 / g, and an average pore diameter of 65 to 180 mm.
3. 3. The hydrocarbon according to the above 1 or 2, characterized in that it has an acid point which generates an ammonia adsorption heat of 100 to 200 kJ / mol measured by a microcalorimetry method in a range of 270 to 380 μmol per 1 g of the catalyst. Oil hydrotreating catalyst.
4). The carbonization according to any one of 1 to 3 above, wherein the catalyst has an average number of laminated molybdenum disulfide phases of 2.5 to 5 observed by a transmission electron microscope after preliminary sulfidation. Hydrogen oil hydrotreating catalyst.
5. On an inorganic oxide support having a specific surface area of 160 to 500 m ² / g, a pore volume of 0.55 to 0.9 m1 / g, and an average pore diameter of 60 to 150 mm, at least selected from Group 8 metals of the periodic table A compound containing at least one kind selected from a compound containing at least one selected from the group 6 metals in the periodic table, a solution containing an organic acid, phosphorus and lithium, based on the catalyst standard and oxide conversion, and a group 6 metal in the periodic table To 10 to 30% by mass, 1 to 15% by mass of Group 8 metal of the periodic table, 0.05 to 1% by mass of lithium, 2 to 14% by mass of carbon, and 0.8 to 8% by mass of phosphorus. The method for producing a hydrocarbon oil hydrotreating catalyst according to any one of the above 1 to 4, wherein the catalyst is dried at 200 ° C. or lower.
6). Inorganic oxidation containing phosphorus having a specific surface area of 160 to 500 m ² / g, a pore volume of 0.55 to 0.9 m1 / g, and an average pore diameter of 60 to 150 mm on a catalyst basis, 0.8 to 8% by mass in terms of oxide A solution containing a compound containing at least one selected from Group 8 metals of the periodic table, a compound containing at least one selected from Group 6 metals of the periodic table, an organic acid, and lithium on a physical support , 10-30% by mass of periodic group 6 metal in terms of oxide, 1-15% by mass of group 8 metal in the periodic table, 0.05-1% by mass of lithium, 2% of carbon The method for producing a hydrocarbon oil hydrotreating catalyst according to any one of the above 1 to 4, wherein the catalyst is supported so as to be 14% by mass and dried at 200 ° C or lower.
7). 7. The hydrocarbon oil hydrotreating catalyst according to the above 6, wherein the phosphorus-containing inorganic oxide support is prepared by a kneading method in which an inorganic oxide support raw material and a phosphorus raw material are kneaded. Method 8. In the presence of the catalyst according to any one of 1 to 4 above, a catalytic reaction of a hydrocarbon oil fraction under conditions of a hydrogen partial pressure of 3 to 8 MPa, a temperature of 300 to 420 ° C., and a liquid space velocity of 0.3 to 5 hr ^−1. Hydrocarbon oil hydrotreating method characterized by performing.

  According to the present invention, a catalyst having a specific composition and a specific physical property using the group 6 metal and the group 8 metal as an active metal is used, and a decrease in catalytic activity due to coke deterioration is small. The sulfur compound in the gas oil fraction such as can be removed with high efficiency over a long period of time.

The present invention can widely use hydrocarbon oils as processing target oils, but can be suitably applied to the processing of light oil fractions such as vacuum gas oils.
Typical examples of the properties of the feedstock to which the present invention can be suitably applied include those having a boiling range of 150 to 550 ° C. and a sulfur content of 5% by mass or less.

In the catalyst of the present invention, various inorganic oxide carriers such as alumina, silica, zirconia, titania, boria and the like can be used, and among them, an inorganic oxide carrier whose main component is an alumina carrier is preferable. The production method of the alumina carrier is not particularly limited, and a normal method can be adopted. That is, by neutralizing a water-soluble aluminum compound such as aluminum sulfate, nitrate or chloride with a base such as ammonia, or neutralizing an alkali metal aluminate with an acidic aluminum salt or acid, etc. The produced aluminum hydrogel or hydrosol can be produced by applying a general formulation such as washing, aging, molding, drying, and baking. In the catalyst of the present invention, an inorganic oxide carrier containing a predetermined amount of phosphorus oxide in the inorganic carrier can also be used, and a carrier containing a phosphorus compound in an inorganic oxide mainly composed of alumina is used. It can be particularly preferably used.
The method for producing this phosphorus-containing alumina carrier is not particularly defined as a preparation method, and can be produced by an equilibrium adsorption method, a coprecipitation method, a kneading method, etc., but a catalyst having a high desulfurization activity can be obtained. It is particularly preferable to use a kneading method. In that case, it is preferable that the raw material of phosphorus oxide is aqueous solution.
Various compounds can be used as a raw material for the phosphorous oxide used in the catalyst of the present invention. Examples thereof include orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, and tetraphosphoric acid. preferable.

  In order to obtain a carrier having structural properties suitable as a catalyst, a pH when making an alumina gel by adding a precipitating agent, a neutralizing agent, etc., the concentration, time, temperature, etc. of these agents may be appropriately adjusted. If the pH during gel formation is on the acidic side, the specific surface area increases. In the present invention, it is preferable that the pH is about 4 to 8 and the temperature is about 15 to 90 ° C.

After the gel is formed, aging, cleaning and removing impurities, and dehydration drying are performed. Aging is preferably carried out at a pH of 4 to 9, 15 to 90 ° C. for 1 to 25 hours. Within the range of these aging conditions, impurities in the alumina gel can be easily removed, and the surface area of the alumina gel increases.
The dehydration drying is performed by adjusting the water content without applying heat to the alumina gel. For example, it is dehydrated and dried by a method such as natural filtration at about 15 to 90 ° C. and about 0.01 to 2 MPa, suction filtration, pressure filtration, etc., so that the water content after dehydration drying is about 60 to 90% by mass. It is preferable to make it. By adjusting the water content without applying extra heat to the alumina gel, the surface structure of the support can be controlled and the hydrodesulfurization activity of the catalyst can be improved.

  The carrier is formed after dehydration and drying. The molding method is not particularly limited, and a general method such as extrusion molding, tableting molding, or granulation in oil can be used. The pore volume and pore distribution, which are structural physical properties of the carrier, can also be controlled by adjusting the pressure and speed during molding.

  The shape of the support is preferably cylindrical, trilobal, quadrilobal, dumbbell, or ring-shaped pellets in consideration of the distribution of the heavy oil fraction catalyst layer. A shape with a small pressure loss (pressure difference) is selected. Similarly, the pellet diameter is preferably in the range of 1 to 2 mm so that pressure loss does not increase before and after the catalyst layer under the reaction conditions. In addition, a pellet diameter is represented by the long diameter of the cross section of the thickest part except what the shape of a pellet is a cylinder.

  After molding, the support can be obtained by drying at room temperature to 150 ° C. for 3 to 24 hours, and subsequently firing at 200 to 600 ° C. for 3 to 24 hours.

  As described later, the catalyst of the present invention is prepared by simply drying at 200 ° C. or lower after an active ingredient is supported on an inorganic oxide carrier. Close-packed bulk density, etc.) can be obtained by firing an inorganic oxide support. The support is fired in consideration of its mechanical strength, specific surface area, pore volume, average pore diameter, and the like. It is preferable to carry out at a temperature of from 700 ° C. to 700 ° C. for 0.5 to 10 hours, particularly preferably from 500 ° C. to 630 ° C. for 2 hours to 5 hours. When the drying temperature and time are within the above ranges, the catalyst can obtain sufficient mechanical strength, and the specific surface area, pore volume and average pore diameter are also appropriate, and a catalyst with high desulfurization activity can be obtained. In addition, the above effects can be obtained economically without waste.

The specific surface area of the inorganic oxide support, pore volume, average pore diameter, in order to high hydrodesulfurization activity for hydrocarbon oils catalysts, specific surface area of 160~500m ² / g, preferably 175～450M ² / G, a pore volume of 0.55 to 0.9 ml / g, preferably 0.65 to 0.8 ml / g, and an average pore diameter of 60 to 150 mm, preferably 65 to 110 mm.

The reason is as follows.
In the impregnating solution, the group 6 metal and the group 8 metal are considered to form a complex (the group 6 metal is coordinated with phosphoric acid to form a heteropolyacid, and the group 8 metal is coordinated to an organic acid to form an organometallic complex). Therefore, if the specific surface area of the support is 160 m ² / g or more, it becomes easy to highly disperse the complex during impregnation, and as a result, when the resulting catalyst is sulfided, the above active sites (CoMoS phase, NiMoS) Presumably, precise control of the formation will be possible.
A specific surface area of 500 m ² / g or less is preferable because the pore diameter does not become extremely small, so that the sulfur compound can diffuse into the catalyst pores and the desulfurization activity can be prevented from being lowered.

  If the pore volume is 0.55 ml / g or more, when preparing the catalyst by the usual impregnation method, the solvent that enters the pore volume is sufficient, and the solubility of the active metal compound is not impaired. It is preferable because high dispersibility can be maintained, and a pore volume of 0.9 ml / g or less is preferable because the specific surface area does not become extremely small and the dispersibility of the active metal can be maintained.

  When the average pore diameter is 60 mm or more, high desulphurization activity can be maintained because the diffusibility of the sulfur compound into the catalyst pores is not impaired. If the average pore diameter is 150 mm or less, the specific surface area of the catalyst necessary for highly dispersing the active metal can be maintained, and therefore the catalyst has a high desulfurization activity. In order to increase the effective number of pores satisfying the above average pore diameter condition, the pore distribution of the catalyst, that is, the ratio of pores having an average pore diameter of ± 15 mm is preferably 20 to 90%, preferably 35 to 85%. If it is 20% or more, pores not related to desulfurization of hydrocarbon oil do not increase, and as a result, desulfurization activity does not significantly decrease, which is preferable. If it is 90% or less, the compound to be desulfurized is not limited to a specific compound and is preferable because it can be uniformly desulfurized.

Moreover, in order to improve the dispersibility of the group 6 metal and the 8 metal, which will be described later, a phosphor oxide may be supported on the carrier. As the raw material for the phosphorus oxide to be supported, the same materials as those used for preparing the carrier are preferable. Examples thereof include orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, and tetraphosphoric acid, and orthophosphoric acid is preferred. In addition, as a method of supporting the phosphorus compound, there is a method of impregnating a carrier with these phosphorus compound raw materials.
The amount of phosphorus oxide to be supported is such that the total amount including the amount of phosphorus oxide used at the time of preparing the carrier is in the range of 0.8 to 8% by mass in terms of catalyst and oxide. For example, when the carrier is prepared by kneading an inorganic oxide and a phosphorous oxide, a part of the phosphorous oxide used in the kneading method is used for the supporting phosphorous oxide. In addition, for example, when molybdenum is used for the active metal, the mass ratio of phosphorus oxide to molybdenum ([(P ₂ O ₅ ) / (MoO ₃ )]), preferably 0.01 to 1. 5, more preferably 0.05 to 1, and still more preferably 0.1 to 0.5. If this mass ratio is 0.01 or more, CoMoS can be integrated with Co and Mo, and after sulfiding, lamination of molybdenum disulfide can be achieved. Phase, NiMoS phase type II is easily obtained, and a highly active catalyst is easily obtained. If it is 1.5 or less, there is no significant decrease in the surface area and pore volume of the catalyst, the activity of the catalyst does not decrease, and the amount of excess acid does not increase, and carbon deposition can be suppressed. This is preferable because it is difficult to cause.

The Group 6 metal contained in the catalyst of the present invention is preferably molybdenum or tungsten, and particularly preferably molybdenum.
The content of the Group 6 metal is 10 to 30% by mass, preferably 16 to 28% by mass in terms of catalyst and oxide.
If it is 10% by mass or more, the effect due to the Group 6 metal can be sufficiently exhibited, and if it is 30% by mass or less, the Group 6 metal compound is aggregated in the impregnation (supporting) process of the Group 6 metal. Without any problem, because the Group 6 metal can be efficiently dispersed.

The group 8 metal is preferably cobalt or nickel.
The content of the group 8 metal is 1 to 15% by mass, preferably 3 to 8% by mass in terms of catalyst and oxide.
If it is 1% by mass or more, the active sites belonging to the group 8 metal can be sufficiently obtained, and if it is 15% by mass or less, the group 8 metal compound is aggregated in the step of containing (supporting) the group 8 metal. In addition to maintaining the dispersibility of the Group 8 metal, inert cobalt, Co ₉ S ₈ species that are nickel species, CoO species that are precursors of Ni ₃ S ₂ species, NiO species, and the like, It is preferable to suppress the generation of Co spinel species, Ni spinel species, and the like incorporated in the lattice.

In the above-described contents of the Group 8 metal and the Group 6 metal, the optimum mass ratio between the Group 8 metal and the Group 6 metal is preferably [Group 8 metal] / [Group 8 metal + Group 6 metal] (in terms of oxide) ( The mass ratio is 0.1 to 0.25.
When this value is in the above range, a CoMoS phase, NiMoS phase, etc., which are considered as active sites for desulfurization, are generated to improve the desulfurization activity, and the above-described inert cobalt, nickel species (Co ₉ S ₈ species, Ni ₃ S ₂ type) is generated little and the catalytic activity is not substantially reduced.

The phosphorus content is 0.8 to 8% by mass, preferably 1 to 6% by mass, and more preferably 1.2 to 5% by mass in terms of catalyst and oxide. Phosphorus may be contained at the time of preparing the carrier, or may be supported by an impregnation method or the like after the carrier is prepared. The phosphorus content is the sum of the amount contained during carrier preparation and the amount supported after carrier preparation.
If it is 0.8 mass% or more, it is estimated that a highly dispersed MoS ₂ phase can be formed in the group 6 metal in the preliminary sulfidation step, and the above desulfurization active sites can be sufficiently arranged. In particular, in order to form the molybdenum disulfide layer on the catalyst after the preliminary sulfidation so that the average number of layers is 2.5 to 5, the content is preferably 0.8% by mass or more. On the other hand, if it is 8 mass% or less, it is estimated that excess phosphorus does not cover a desulfurization active site as a poisonous substance, which is preferable.

  In the present invention, a basic element is used to control the acid properties of the catalyst. The basic element is preferably an alkali metal or alkaline earth metal, more preferably an alkali metal, particularly lithium. In the present invention, lithium is used, and the supported amount is preferably 0.05 to 1% by mass in terms of oxide based on the catalyst. By making the amount of lithium supported in the above range, it is possible to control the desired acid properties and the amount of acid, and it is possible to obtain a catalyst in which coke deterioration hardly occurs while maintaining high activity.

The carbon content is 2 to 14% by mass, preferably 3 to 10% by mass in terms of catalyst and element.
This carbon is derived from an organic acid, preferably citric acid, and if it is 2% by mass or more, the group 8 metal and the organic acid can sufficiently form a complex compound on the catalyst surface. Since the uncomplexed group 8 metal is not sulfided prior to the sulfidation of the group 6 metal, desulfurization active sites (CoMoS phase, NiMoS phase, etc.) can be sufficiently formed, and inactive cobalt, It is presumed that nickel species such as Co ₉ S ₈ species and Ni ₃ S ₂ species are not formed.
If it is 14% by mass or less, the group 8 metal can sufficiently form a complex compound with the organic acid on the catalyst surface, and many of the above desulfurization active sites can be obtained in the preliminary sulfidation process, and excess carbon is poisoned. It is preferable because it covers a desulfurization active site as a substance and does not cause a decrease in activity.

  Regarding the amount of metal supported, “display in terms of oxide based on the catalyst” means that the mass of all metal species contained in the catalyst is calculated as the oxide of each metal, and the total mass of each metal It means to display with the value (mass% display) which divided the oxide mass of. Aluminum was trivalent, molybdenum was hexavalent, nickel and cobalt were bivalent, and lithium was monovalent metal. The amount of metal supported was measured by ICP spectroscopy (inductively coupled high-frequency plasma spectroscopy) after dissolving the catalyst in a mixed acid and displayed in terms of catalyst-based metal oxide.

The catalyst of the present invention has the above composition in order to increase the hydrodesulfurization activity for hydrocarbon oils, particularly gas oil fractions such as vacuum gas oil, and the specific surface area, pore volume and average pore diameter are as follows: Must be the value of.
The specific surface area (specific surface area measured by the nitrogen adsorption method (BET method)) is 110 to 300 m ² / g.
If it is 110 m ² / g or more, the group 6 metal and group 8 metal considered to form a complex are sufficiently highly dispersed on the catalyst surface. It is inferred that precise control of the active site formation becomes possible. If it is 300 m ² / g or less, the pore diameter does not become extremely small, so that it is possible to maintain the diffusion of the sulfur compound into the catalyst pores during the hydrotreatment.

  The pore volume measured by the mercury intrusion method is 0.35 to 0.6 m1 / g, preferably 0.38 to 0.55 m1 / g. If it is 0.35 m1 / g or more, it is effective for the diffusion of sulfur compounds in the catalyst pores during the hydrogenation treatment, and if it is 0.6 m1 / g or less, the specific surface area of the catalyst becomes extremely small. This is preferable because the dispersibility of the active metal is not lowered.

The average pore diameter in the pore distribution measured by mercury porosimetry is 65 to 180 mm, preferably 70 to 145 mm. If it is 65 mm or more, the reactants easily diffuse into the pores, so that the desulfurization reaction proceeds efficiently, and if it is 180 mm or less, the effective specific surface area of the catalyst can be maintained.
Further, in order to increase the effective number of pores satisfying the above pore conditions, the pore size distribution of the catalyst, that is, the proportion of pores having an average pore size of ± 15 mm is 40% or more, preferably 50 % Or more, more preferably 60% or more. If it is 40% or more, pores not related to desulfurization of hydrocarbon oil do not increase, and as a result, desulfurization activity does not decrease significantly, which is preferable.

In the catalyst of the present invention, the dispersion state of phosphorus atoms is controlled. When the EPMA line analysis of the phosphorus atom was performed from one surface to the opposite surface through the cross section of the catalyst, the S value indicating the dispersion state of the phosphorus atom represented by the following formula (1) was 1 or less, Preferably it is 0.8 or less, More preferably, it is 0.6 or less. The smaller the S value, the more uniformly the distribution of phosphorus atoms is controlled. When the S value is 1 or less, the distribution uniformity of the phosphorus oxide in the catalyst is maintained. Dispersibility in the lateral direction of the surface is improved, and desulfurization activity can be improved.
In Formula (1), Imax. Is the maximum value of the measured concentration of phosphorus atoms by EPMA line analysis, and Imin. Is the minimum value of the measured concentration of phosphorus atoms by EPMA line analysis. Iave. Is the average value of phosphorus atom concentration measured by EPMA line analysis.
S = exp (0.04 × Iave. + 0.013 × Imax.−0.143 × Imin.) ≦ 1 Equation (1)

  It is preferable that the catalyst of the present invention has an acid point that generates an ammonia adsorption heat of 100 to 200 KJ / mol by a microcalorimetry method in a range of 270 to 380 μmol, preferably 290 to 380 μmol, per 1 g of the catalyst. The heat of adsorption generated when ammonia is adsorbed on the acid sites on the catalyst surface varies depending on the acid properties of the acid sites. A catalyst having an acid point with an adsorption heat of 100 to 200 KJ / mol in the above range has a sufficient active site in hydrodesulfurization reaction of vacuum gas oil, has very little deterioration with time, and can suppress coke formation. . When the acid point is 270 μmol / g or more, the catalyst activity can be sufficiently exerted, and when it is 380 μmol / g or less, desired coke formation can be suppressed.

The catalyst of the present invention preferably has an average value of the number of laminated molybdenum disulfide layers of 2.5 to 5 when observed with a transmission electron microscope after sulfiding.
That is, this molybdenum disulfide layer is formed on the inorganic oxide support and serves to increase the contact area of the catalyst, and active points such as a CoMoS phase and a NiMoS phase are formed in the layer. In a catalyst having an average value of 2.5 or more, the proportion of type II of highly active CoMoS phase or NiMoS phase is increased to express high activity, and if it is 5 or less, highly active CoMoS phase or NiMoS. Since the absolute number of active points can be maintained while forming phase type II, high activity is exhibited.

  In order to obtain the catalyst of the present invention having the above characteristics, it is preferable to use the method of the present invention described below. That is, an inorganic oxide carrier comprising the above-described components and having the above-described physical properties, a compound containing at least one group 6 metal, a compound containing at least one group 8 metal, an organic acid, lithium, By using a solution containing phosphoric acid, a group 6 metal, a group 8 metal, phosphorus, lithium, and carbon are supported so as to have the above-described contents and dried.

Examples of the compound containing a Group 6 metal used in the impregnation solution include molybdenum trioxide, molybdophosphoric acid, ammonium molybdate, molybdic acid, and the like, and preferably molybdenum trioxide and molybdophosphoric acid.
The amount of these compounds added to the impregnation solution is such that the Group 6 metal is contained in the resulting catalyst within the above-described range.

Examples of the compound containing a group 8 metal include cobalt carbonate, nickel carbonate, cobalt citrate compound, nickel citrate compound, cobalt nitrate hexahydrate, nickel nitrate hexahydrate, and preferably cobalt carbonate and nickel carbonate. , Cobalt citrate compounds and nickel citrate compounds. Particularly preferred are cobalt citrate compounds and nickel citrate compounds, which have a lower decomposition rate than cobalt carbonate and nickel carbonate.
That is, when the decomposition rate is high, apart from the molybdenum disulfide layer, cobalt or nickel forms a unique layer, and the formation of a highly active CoMoS phase or NiMoS phase becomes insufficient. When the speed is low, these highly active phases can be sufficiently formed at the rim-edge portion of molybdenum disulfide.

As cobalt citrate, cobalt citrate (Co ₃ (C ₆ H ₅ O ₇ ) ₂ ), cobalt hydrogen citrate (CoHC ₆ H ₅ O ₇ ), cobalt citrate oxysalt (Co ₃ (C ₆ H ₅ O ₇ ) ₂ .CoO) and the like, and nickel citrate includes nickel citrate (Ni ₃ (C ₆ H ₅ O ₇ ) ₂ ), nickel hydrogen citrate (NiHC ₆ H ₅ O) ₇ ), nickel citrate oxysalt (Ni ₃ (C ₆ H ₅ O ₇ ) ₂ .NiO) and the like.
For example, in the case of cobalt, this method of producing a citric acid compound of cobalt and nickel can be obtained by dissolving cobalt carbonate in an aqueous solution of citric acid. You may use for the catalyst preparation as it is, without removing the water | moisture content of the citric acid compound obtained by such a manufacturing method.
The amount of these compounds added to the impregnation solution is such that the group 8 metal is contained within the above-described range in the resulting catalyst.

Organic acids include citric acid monohydrate, anhydrous citric acid, isocitric acid, malic acid, tartaric acid, oxalic acid, succinic acid, glutaric acid, adipic acid, benzoic acid, phthalic acid, isophthalic acid, salicylic acid, malonic acid, etc. And citric acid monohydrate is preferred. It is important that these organic acids use compounds that are substantially free of sulfur.
When citric acid is used as the organic acid, citric acid alone or a citric acid compound with cobalt or nickel (group 8 metal) described above may be used.
The addition amount of the organic acid is not particularly limited, but it is important that the amount of carbon remaining in the obtained catalyst is such that the carbon remains, and the organic acid / It is preferable to set it as group 8 metal = 0.2-1.2. If this molar ratio is in the range of 0.2 to 1.2, the active sites attributed to the Group 8 metal can be obtained sufficiently, and the impregnating liquid has a low viscosity, so that no time is required for the supporting step.
When a group 8 metal citrate compound is used, an organic acid is further added when the amount of the organic acid is insufficient.

  Various compounds can be used to add the phosphorus oxide by the impregnation liquid. Specific examples include orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, tetraphosphoric acid, polyphosphoric acid, and orthophosphoric acid is particularly preferable. Moreover, molybdophosphoric acid which is a compound with a group 6 metal can also be used, and it can also be used together with a phosphorus compound.

  Various types of lithium can be used. Specific examples include lithium hydroxide, lithium nitrate, lithium oxalate, lithium sulfate, lithium chloride, lithium carbonate, and lithium acetate, with lithium hydroxide, lithium nitrate, and lithium acetate being preferred.

On the other hand, the desulfurization activity and coke deterioration of the prepared catalyst are greatly affected by the lithium loading method. The impregnation method is preferable because the acid amount and acid properties on the catalyst surface can be efficiently controlled.
The active metal and lithium may be supported in any order. That is, the active metal and lithium may be supported simultaneously, or the active metal may be supported after the lithium is supported and then dried and fired to form a metal oxide.
Particularly preferred is a method in which both of the active metal and lithium are supported by the impregnation method. In this case, the active metal and lithium may be impregnated simultaneously or individually. Moreover, when impregnating individually, the impregnation order is impregnated with lithium first, dried and fired to obtain a metal oxide, and then impregnated with an active metal.

  If the above Group 6 metal compound or Group 8 metal compound is not sufficiently dissolved in the impregnation solution, an acid (nitric acid, organic acid << citric acid, malic acid, tartaric acid, etc. >>) together with these compounds May be used, preferably an organic acid is used. When an organic acid is used, carbon from the organic acid may remain in the resulting catalyst. It is important to be within range.

In the above impregnation solution, the solvent used for dissolving each of the above components is water.
If the amount of the solvent used is too small, the support cannot be sufficiently impregnated, and if it is too large, the dissolved active metal does not impregnate on the support and adheres to the edge of the impregnation solution container. Therefore, the impregnation amount of the active metal into the carrier is 50 to 90 g, preferably 60 to 85 g, with respect to 100 g of the carrier.

  The above components are dissolved in the solvent to prepare an impregnation solution. The temperature at this time is preferably higher than 0 ° C. and not higher than 100 ° C. If the temperature is within this range, the components are added to the solvent. Can be dissolved well.

  The pH of the impregnating solution is preferably less than 5. When it is 5 or more, hydroxide ions increase, the coordination ability between the organic acid and the group 8 metal is weakened, and complex formation of the group 8 metal is suppressed. As a result, the number of desulfurization active points (CoMoS phase, NiMoS phase) cannot be increased significantly.

The impregnating solution thus prepared is impregnated with the inorganic oxide carrier, and the components in the solution are supported on the inorganic oxide carrier.
Various conditions can be adopted as the impregnation conditions. Usually, the impregnation temperature is preferably 5 ° C. to less than 100 ° C., more preferably 10 to 50 ° C., further preferably 15 to 30 ° C., and the impregnation time is The reaction time is preferably 30 minutes to 3 hours, more preferably 30 minutes to 2 hours, and even more preferably 30 minutes to 1 hour. An excessively high temperature is not preferable because drying occurs during impregnation and the degree of dispersion becomes uneven. Moreover, it is preferable to stir during the impregnation.

After the impregnation with the solution, water is removed (so that LOI << Loss on ignition >> is 50% or less) at room temperature to 80 ° C, in a nitrogen stream, in an air stream, or in a vacuum. In a nitrogen stream or in vacuum, drying is performed at 200 ° C. or less, preferably 80 to 200 ° C. for 3 hours to 24 hours, more preferably 100 to 150 ° C. for 5 to 20 hours.
When drying is performed at a temperature of 200 ° C. or lower, an organic acid that is considered to be complexed with a metal does not leave the surface of the catalyst. Therefore, the resulting catalyst is subjected to sulfidation treatment to obtain the above active sites (CoMoS phase, NiMoS phase, etc.). ) The formation can be precisely controlled, and the formation of inert cobalt, nickel species such as Co ₉ S ₈ species and Ni ₃ S ₂ species can be suppressed. Moreover, since it is estimated that the average lamination number of molybdenum disulfide can also be 2.5 or more, it is preferable.

In the present invention, the shape of the catalyst is not particularly limited, and various shapes usually used for this type of catalyst, for example, a cylindrical shape, a trilobal type, a four-leaf type, and the like can be adopted. The size of the catalyst is usually preferably about 1 to 2 mm in diameter and about 2 to 5 mm in length.
The mechanical strength of the catalyst is preferably 2 lbs / mm or more in terms of side surface breaking strength (SCS << Side crash strength >>). By doing so, it is avoided that the catalyst charged in the reactor is destroyed, a differential pressure is generated in the reactor, and the hydration operation cannot be continued.
The close-packed bulk density (CBD) of the catalyst is preferably 0.6 to 1.2 g / ml.
The distribution state of the active metal in the catalyst is preferably a uniform type in which the active metal is uniformly distributed in the catalyst.

The hydrotreating method of the present invention is a hydrocarbon oil containing the above catalyst and sulfur compound under the conditions of a hydrogen partial pressure of 3 to 8 MPa, 300 to 420 ° C., and a liquid space velocity of about 0.3 to 5 hr ^−1. However, it is a method of reducing sulfur compounds including a hardly desulfurizable sulfur compound in the hydrocarbon oil by desulfurization by contacting with a light oil fraction such as vacuum gas oil. The product oil obtained by the process of the present invention can be less sulfur and nitrogen than by the prior art.

In order to carry out the hydrotreating method of the present invention on a commercial scale, a fixed bed, moving bed or fluidized bed type catalyst layer of the catalyst of the present invention is formed in the reactor, and the feedstock is introduced into the reactor. The hydrogenation reaction may be performed under the above conditions.
Most commonly, a fixed bed catalyst layer is formed in the reactor, feedstock is introduced into the top of the reactor, the fixed bed is passed from bottom to top, and the product is drained from the top of the reactor. Is.
Further, it may be a one-stage hydrotreating method in which the catalyst of the present invention is filled in a single reactor, or a multi-stage continuous hydrotreating method in which several reactors are filled. Good.

Note that the catalyst of the present invention is activated by, for example, sulfiding in a reaction apparatus before use (that is, prior to performing the hydrotreating method of the present invention). This sulfidation treatment is carried out at 200 to 400 ° C., preferably 250 to 350 ° C. under a hydrogen atmosphere of normal pressure or higher, and a petroleum distillate containing sulfur compounds, dimethyl disulfide, carbon disulfide, etc. It is carried out using a material added with a sulfurizing agent or hydrogen sulfide.
By this sulfidation treatment, the catalyst of the present invention forms a molybdenum disulfide layer having an average number of layers of 2.5 to 5 as described above, and a highly active CoMoS is formed on the rim-edge portion of the molybdenum disulfide. The active point of the phase or NiMoS phase is formed.

(Preparation of catalyst)
Example 1
After 0.37 g of lithium nitrate was dissolved in 41 g of ion-exchanged water and dropped into 50 g of alumina pellets (specific surface area of 318 m ² / g, pore volume of 0.71 ml / g, average pore diameter of 71 kg) in an eggplant type flask, Soaked for 5 hours. Then, it air-dried in nitrogen stream for 5 hours, and baked at 500 degreeC for about 4 hours in the muffle furnace, and obtained the lithium carrying | support alumina support | carrier. Further, 29.8 g of molybdophosphoric acid, 7.7 g of cobalt carbonate, 3.8 g of orthophosphoric acid, and 8.4 g of citric acid monohydrate were dissolved in 33 g of ion-exchanged water. All of this aqueous solution was dropped into the lithium-supported alumina in the eggplant-shaped flask and then immersed for 5 hours at room temperature. Thereafter, it was air-dried in a nitrogen stream for 5 hours and dried in a muffle furnace at 120 ° C. for about 16 hours to obtain Catalyst A.

Example 2
An aqueous orthophosphoric acid solution was added to the alumina gel, and the properties of P ₂ O ₅ content (support equivalent) 4.4 mass%, specific surface area 315 m ² / g, pore volume 0.7 ml / g, and average pore diameter 71 mm were obtained. A phosphorus-containing alumina support having was prepared.
Next, an aqueous solution in which 0.36 g of lithium nitrate was dissolved in 41 g of ion-exchanged water was dropped into 50 g of this phosphorus-containing alumina carrier, and then immersed for 3 hours at room temperature. Then, it air-dried in nitrogen stream for 5 hours, and baked at 500 degreeC for 4 hours in the muffle furnace, and obtained the lithium carrying | support phosphorus atom containing alumina support | carrier. Further, an aqueous solution prepared by dissolving 28.1 g of molybdophosphoric acid, 7.2 g of cobalt carbonate and 8.1 g of citric acid monohydrate in 41 g of ion-exchanged water was added dropwise to this lithium-supporting phosphorus-containing alumina carrier, and then at room temperature for 3 hours. Soaked. Then, it air-dried in nitrogen stream for 5 hours, and was dried at 120 degreeC in the muffle furnace for 16 hours, and the catalyst B was obtained.

Example 3
3.8 g of orthophosphoric acid was dissolved in 41 g of ion-exchanged water and dropped into 50 g of alumina pellets having a specific surface area of 318 m ² / g, a pore volume of 0.71 ml / g and an average pore diameter of 71 kg in an eggplant type flask, Soaked for 24 hours. Then, it air-dried in nitrogen stream for 5 hours, and baked at 500 degreeC for 4 hours in the muffle furnace, and prepared the phosphorus containing alumina support | carrier. An aqueous solution in which 0.36 g of lithium nitrate was dissolved in 38 g of ion-exchanged water was added dropwise to 50 g of this phosphorus-containing alumina carrier, and then immersed for 3 hours at room temperature. Then, it air-dried in nitrogen stream for 5 hours, and baked at 500 degreeC in the muffle furnace for 4 hours, and obtained lithium carrying | support phosphorus containing alumina support | carrier. Further, an aqueous solution prepared by dissolving 28.1 g of molybdophosphoric acid, 7.2 g of cobalt carbonate and 8.1 g of citric acid monohydrate in 41 g of ion-exchanged water was added dropwise to this lithium-supporting phosphorus-containing alumina carrier, and then at room temperature for 3 hours. Soaked. Then, it air-dried in nitrogen stream for 5 hours, and was dried at 120 degreeC in the muffle furnace for 16 hours, and the catalyst C was obtained.

Example 4
Except that the amount of lithium nitrate was 2.96 g, everything was prepared in the same manner as in Example 1 to obtain Catalyst D.

Example 5
0.3 g of lithium nitrate was dissolved in 37 g of ion-exchanged water and dropped into 50 g of alumina pellets (specific surface area 191 m ² / g, pore volume 0.71 ml / g, average pore diameter 102 mm) in an eggplant type flask. Soaked for 5 hours. Then, it air-dried in nitrogen stream for 5 hours, and baked at 500 degreeC for about 4 hours in the muffle furnace, and obtained the lithium carrying | support alumina support | carrier. Further, 21.5 g of molybdophosphoric acid, 5.1 g of cobalt carbonate, 2.8 g of orthophosphoric acid, and 6.6 g of citric acid monohydrate were dissolved in 30 g of ion-exchanged water. All of this aqueous solution was dropped into the lithium-supported alumina in the eggplant-shaped flask and then immersed for 5 hours at room temperature. Then, it air-dried for 5 hours in nitrogen stream, and it was made to dry at 120 degreeC in a muffle furnace for about 16 hours, and the catalyst E was obtained.

Comparative Example 1
0.37 g of lithium nitrate was dissolved in 41 g of ion-exchanged water, dropped in 50 g of alumina pellets used in Example 1 in an eggplant type flask, and then immersed for 5 hours at room temperature. Then, it air-dried in nitrogen stream for 5 hours, and baked at 500 degreeC for 4 hours in the muffle furnace, and obtained the lithium carrying | support alumina support | carrier. Furthermore, 29.81 g of molybdophosphoric acid, 7.68 g of cobalt carbonate, 3.8 g of orthophosphoric acid, and 8.40 g of citric acid monohydrate were dissolved in 33.0 g of ion-exchanged water. All of this aqueous solution was dropped into the lithium-supported alumina in the eggplant-shaped flask and then immersed for 10 minutes at room temperature. Then, it air-dried for 1 hour in nitrogen stream, and it was made to dry at 120 degreeC in a muffle furnace for 1 hour, and the catalyst a was obtained.

Comparative Example 2
In an eggplant-shaped flask, 50 g of the alumina pellets used in Example 1, 41 g of ion-exchanged water, 21.5 g of molybdophosphoric acid, 5.1 g of cobalt carbonate, 2.9 g of orthophosphoric acid, and 6.6 g of citric acid monohydrate. Dissolved. All of this aqueous solution was dropped into alumina in an eggplant-shaped flask and then immersed at room temperature for 5 hours. Then, it air-dried for 5 hours in nitrogen stream, and it was made to dry at 120 degreeC in a muffle furnace for about 16 hours, and the catalyst b was obtained.

Comparative Example 3
0.37 g of lithium nitrate was dissolved in 41 g of ion-exchanged water, dropped in 50 g of alumina pellets used in Example 1 in an eggplant type flask, and then immersed for 5 hours at room temperature. Then, it air-dried in nitrogen stream for 5 hours, and baked at 500 degreeC for 4 hours in the muffle furnace, and obtained the lithium carrying | support alumina support | carrier. Furthermore, 23.5 g of molybdophosphoric acid, 5.6 g of cobalt carbonate, and 3.2 g of orthophosphoric acid were dissolved in 33 g of ion-exchanged water. All of this aqueous solution was dropped into alumina in an eggplant-shaped flask and then immersed at room temperature for 5 hours. Then, it air-dried in nitrogen stream for 5 hours, and dried at 120 degreeC in the muffle furnace for about 16 hours, and the catalyst c was obtained.

[Catalyst properties]
The chemical properties of the catalysts obtained in Examples 1 to 5 and Comparative Examples 1 to 3 are shown in Table 1, with physical properties after calcining at 500 ° C. for 4 hours, and S values obtained by EPMA line analysis, using a microcalorimetric method. Table 2 shows the amounts of acid sites (per 1 g of the catalyst) that generate ammonia adsorption heat of 100 to 200 kJ / mol and the structural properties of the catalyst.
A method for analyzing these properties is shown below.

[Analysis of chemical and physical properties]
-The carbon mass was combusted at 950 ° C using a CHN analyzer (MT-5) manufactured by Yanagimoto Co., Ltd. after grinding the catalyst in a mortar, and the combustion product gas was measured with a differential thermal conductivity meter. It was measured.
The S value, which is an index of the distribution state of phosphorus atoms, is obtained by using an electron probe microanalysis (EPMA: JXA-8200 manufactured by JEOL Ltd.), passing the cross section of the catalyst from one surface to the center, and the opposite surface. Until now, EPMA line analysis of phosphorus atoms was performed under the following conditions.
1. Sample preparation A catalyst sample was embedded in MMA resin, and after a smooth catalyst cross section was obtained by a cutting method, carbon deposition was performed on the surface.
2. Measurement conditions Measurement is acceleration voltage 15 kV, irradiation current 1 × 10 ⁻⁷ ampere, data points 250 points.
The specific surface area was measured by a nitrogen adsorption method (BET method) using a surface area measuring device (BELSORP28) manufactured by Nippon Bell Co., Ltd. after vacuum degassing of the catalyst at 400 ° C. for 1 hour. The pore diameter was measured by mercury porosimetry using AUTOPORE-9520 manufactured by Shimadzu Corporation for the catalyst treated in the same manner.
-The lamination | stacking number of the molybdenum disulfide layer was measured in the following way using the transmission electron microscope (TEM: JEOL Co., Ltd. product JEM-2010).
1. The catalyst is packed in a flow-type reaction tube, kept in a nitrogen stream at room temperature for 5 minutes, the atmospheric gas is switched to H ₂ S (5% by volume) / H ₂ , the temperature is increased at a rate of 5 ° C./min, and the temperature reaches 400 ° C. After reaching, it was held for 1 hour. Thereafter, the temperature was lowered to 200 ° C. under the same atmosphere, the atmosphere gas was switched to nitrogen, the temperature was lowered to room temperature, and the sulfiding treatment was completed.
2. The catalyst after the sulfurization treatment was pulverized in an agate mortar.
3. A small amount of the ground catalyst was dispersed in acetone.
4). The obtained suspension was dropped on a microgrid and dried at room temperature to prepare a sample.
5. The sample was set in the measurement part of TEM and measured at an acceleration voltage of 200 kV. The direct magnification was 200,000 times and 5 fields of view were measured.
6). The photograph was stretched to 2 million times (size: 16.8 cm × 16.8 cm), and the number of laminated molybdenum disulfide layers visible on the photograph was measured.
・ In the microcalorimetry method, a predetermined amount of sample (here, catalyst) is filled in an adsorption tube, ammonia gas is introduced in a certain amount of pulses at a predetermined temperature and adsorbed on the sample, and the adsorption that occurs during this adsorption It is a method of measuring heat and specifying acid strength and acid amount. Here, the heat of adsorption corresponds to the acid strength, and the adsorption amount (introduction amount) corresponds to the acid amount.
In the present invention, the measurement conditions of the microcalorimetry method in which the measurement was performed are as follows.
That is, as a measuring device, a surface analysis device CSA-450G manufactured by Tokyo Riko Co., Ltd. was used, and the catalyst (sample) was vacuum-dried at 400 ° C. for 4 hours. Then, ammonia gas was introduced and the heat of adsorption was measured using a Tian-Calvet calorimeter.

[Hydrolysis reaction of vacuum gas oil]
The hydrodesulfurization activity of the catalysts obtained in Examples 1 to 5 and Comparative Examples 1 to 3 was evaluated by the following method using vacuum gas oil as the raw material oil.
First, the catalyst was filled into a high-pressure flow reactor to form a fixed bed catalyst layer, and pretreated under the following conditions.
Next, a mixed fluid of the raw material oil and the hydrogen-containing gas heated to the reaction temperature is introduced from the upper part of the reactor, and the desulfurization reaction proceeds under the following conditions. The product oil was separated by a gas-liquid separator.

Catalyst pretreatment conditions:
Pressure (hydrogen partial pressure); 4.9 MPa
Sulfurizing agent; feedstock oil (Arabyanlite vacuum gas oil) in [Hydrolysis reaction of vacuum gas oil]
Temperature: Step temperature rise of 290 ° C. for 15 hours and then 320 ° C. for 15 hours (temperature rise rate is 25 ° C./hr)

Desulfurization reaction conditions:
Reaction temperature: 360 ° C
Pressure (hydrogen partial pressure); 4.9 MPa
Liquid space velocity; 0.66 hr ^-1
Hydrogen / oil ratio: 500 m ³ (normal) / Kl

Raw oil properties:
Oil type: Arabian light vacuum gas oil Specific gravity (15/4 ° C); 0.9185
Distillation properties: initial boiling point 349.0 ° C, 50% point 449.0 ° C,
90% point is 529.0 ° C, end point is 566.0 ° C
Sulfur component: 2.80% by mass
Nitrogen component: 0.065% by mass
Pour point: 35 ° C. asphaltene; <100 ppm
Aniline point: 82 ° C

The desulfurization activity was analyzed by the following method.
The reaction apparatus was operated at 360 ° C., and the product oil was sampled when 20 days passed, and the desulfurization reaction rate constant (ks) was determined from the sulfur content in the product oil, the sulfur content of the raw material oil, and the liquid space velocity. The method for obtaining this ks value is shown below.
The constant of the reaction rate equation for obtaining a reaction order of 1.5 with respect to the reduction amount of the sulfur content (Sp) of the produced oil is defined as a desulfurization reaction rate constant (ks).
The higher the desulfurization reaction rate constant, the better the catalytic activity.
Desulfurization reaction rate constant = 2 × [1 / (Sp) ^0.5 −1 / (Sf) ^0.5 ] × (LHSV)
In formula, Sf: Sulfur content (mass%) in raw material oil
Sp: Sulfur content (mass%) in reaction product oil
LHSV: Liquid space velocity (hr ^-1 )
Desulfurization specific activity (%) = desulfurization reaction rate constant / desulfurization reaction rate constant of comparative catalyst a × 100

Analysis of the sulfur concentration of the raw material oil and the product oil was obtained with an X-ray sulfur analyzer (RX-610SA) manufactured by Newly Corporation. In addition, it shows that the hydrodesulfurization activity of a catalyst is excellent, so that reaction rate constant is high.
The evaluation results of the catalysts A, B, C, D, E, b and c are shown in Table 3 as relative values when the reaction rate constant of the catalyst a is 100.

  As is apparent from Table 3, it can be seen that Catalyst A to Catalyst E produced by the production method of the present invention have excellent desulfurization performance.

Claims (8)

10 to 30% by mass of at least one selected from Group 6 metals of the periodic table, 1 to 15% by mass of at least one selected from Group 8 metals of the periodic table, 2 to 14% by mass of carbon, Phosphorus obtained by line analysis in the cross-sectional width direction passing through the center line using an electron probe microanalysis (EPMA) apparatus of this phosphorus atom containing 0.05 to 1% by mass of lithium and 0.8 to 8% by mass of phosphorus A hydrocarbon oil hydrotreating catalyst characterized in that the distribution of atoms satisfies the following formula (1): In addition, the said mass% is a catalyst reference | standard and oxide conversion.

S = exp (0.04 × Iave. + 0.013 × Imax.−0.143 × Imin.) ≦ 1 Equation (1)

(In Formula (1), Imax. Is the maximum value of the phosphorus atom concentration measured by EPMA line analysis, Imin. Is the minimum value of the phosphorus atom concentration measured value by EPMA line analysis, and Iave. Is the EPMA line. (This is the average value of phosphorus atom concentration measured by analysis.) ^2. The hydrotreating catalyst for hydrocarbon oil according to claim 1, having a specific surface area of 110 to 300 m ² / g, a pore volume of 0.35 to 0.6 m1 / g, and an average pore diameter of 65 to 180 mm. .   3. The carbonization according to claim 1, which has an acid point which generates an ammonia adsorption heat of 100 to 200 kJ / mol measured by a microcalorimetry method in a range of 270 to 380 μmol per 1 g of the catalyst. Hydrogen oil hydrotreating catalyst.   4. The catalyst according to claim 1, wherein the catalyst has an average number of laminated molybdenum disulfide phases of 2.5 to 5 observed with a transmission electron microscope after preliminary sulfidation. Hydrocarbon oil hydrotreating catalyst. On an inorganic oxide support having a specific surface area of 160 to 500 m ² / g, a pore volume of 0.55 to 0.9 m1 / g, and an average pore diameter of 60 to 150 mm, at least selected from Group 8 metals of the periodic table A compound containing at least one kind selected from a compound containing at least one selected from the group 6 metals in the periodic table, a solution containing an organic acid, phosphorus and lithium, based on the catalyst standard and oxide conversion, and a group 6 metal in the periodic table To 10 to 30% by mass, 1 to 15% by mass of Group 8 metal of the periodic table, 0.05 to 1% by mass of lithium, 2 to 14% by mass of carbon, and 0.8 to 8% by mass of phosphorus. 5. The method for producing a hydrocarbon oil hydrotreating catalyst according to claim 1, wherein the catalyst is dried at 200 ° C. or less. Inorganic oxidation containing phosphorus having a specific surface area of 160 to 500 m ² / g, a pore volume of 0.55 to 0.9 m1 / g, and an average pore diameter of 60 to 150 mm on a catalyst basis, 0.8 to 8% by mass in terms of oxide A solution containing a compound containing at least one selected from Group 8 metals of the periodic table, a compound containing at least one selected from Group 6 metals of the periodic table, an organic acid, and lithium on a physical support , 10-30% by mass of periodic group 6 metal in terms of oxide, 1-15% by mass of group 8 metal in the periodic table, 0.05-1% by mass of lithium, 2% of carbon The method for producing a hydrocarbon oil hydrotreating catalyst according to any one of claims 1 to 4, wherein the catalyst is supported at 14 mass% and dried at 200 ° C or lower.   The hydrocarbon oil hydrotreating catalyst according to claim 6, wherein the inorganic oxide carrier containing phosphorus is prepared by a kneading method in which a raw material of an inorganic oxide carrier and a raw material of phosphorus are kneaded. Production method. Contact of hydrocarbon oil fraction in the presence of the catalyst according to any one of claims 1 to 4 under conditions of a hydrogen partial pressure of 3 to 8 MPa, a temperature of 300 to 420 ° C, and a liquid space velocity of 0.3 to 5 hr ^-1. A method for hydrotreating a hydrocarbon oil, characterized by carrying out a reaction.