TWI611015B - Hydrodesufurization catalyst for hydrocarbon oil - Google Patents

Abstract

Provided is a hydrogenation desulfurization catalyst for a hydrocarbon oil, which is a catalyst which is supported on a composite oxide carrier containing 80 to 99% by mass of alumina and 1 to 20% by mass of HY zeolite, on a catalyst basis and The oxide conversion meter contains 3 to 6 mass% of cobalt, 16 to 24 mass% of molybdenum, and 0.8 to 4.5 mass% of phosphorus, a specific surface area of 210 to 280 m ² /g, and a pore volume of 0.3 to 0.6 ml/g. The average pore diameter under the pore distribution is 75~95 , average pore diameter ± 15 The pore volume of the range accounts for at least 75% of the total pore volume. In the above HY zeolite: (a) SiO ₂ /Al ₂ O ₃ (mole ratio) is 3-10; (b) lattice constant is 2.435~2.465 Nm; (c) the molar ratio of Al to total Al in the zeolite framework is 0.2 to 0.9 and (d) the crystallite diameter is 30 to 100 nm.

Description

Hydrocarbon desulfurization catalyst for hydrocarbon oil Field of invention

This invention relates to a hydrodesulfurization catalyst for a hydrocarbon oil. More specifically, it relates to a hydrodesulfurization catalyst which can reduce the sulfur component in a hydrocarbon oil such as a lamp oil, a light oil, a vacuum gas oil or the like under a relatively mild condition and has excellent activity.

Background of the invention

The hydrocarbon oil fraction obtained by distillation or decomposition of crude oil generally contains a sulfur compound, and when such oil is used as a fuel, atmospheric pollutants such as sulfur oxides caused by the sulfur compound are released into the atmosphere. Therefore, in the awareness of environmental issues, the regulation of air pollution has become more stringent, and there is a strong demand to reduce the sulfur content contained in fuel oil.

As a technique for reducing the sulfur compound contained in the fuel oil, a catalyst having desulfurization activity is usually used, and the raw material hydrocarbon oil is subjected to hydrodesulfurization treatment by a hydrodesulfurization apparatus, and various desulfurization catalysts are proposed. For example, as a desulfurization catalyst, a hydrogenation-active metal component such as molybdenum or tungsten, cobalt or nickel is used in an inorganic oxide carrier such as alumina, and in order to further improve the performance of the catalyst, it is also reviewed. The improvement of the carrier, the review of the loaded component, and the method of loading the loaded component (for example, see JP-A-2000-342976).

If it is a known level of desulfurization (0.2 to 0.05% by mass of oil sulfur component), it can be easily achieved in the current desulfurization technology, but the sulfur component is desulphurized to a lower level (the oil sulfur component is formed at 0.04). The mass% or less) is eager to become difficult. This is because sulfur compounds such as 4-methyldibenzothiophene (4-MDBT) or 4,6-dimethyldibenzothiophene (4,6-DMDBT) are located at the sulfur atom due to the position of the alkyl substituent. In the vicinity, when it comes into contact with the desulfurization active point of the catalyst, steric hindrance is caused, and desulfurization becomes extremely difficult.

Under this circumstance, the development of desulfurization technology for removing more sulfur components in light oil has been increasingly emphasized. In general, in order to increase the amount of sulfur component in the light oil, operating conditions such as reaction temperature and liquid space velocity of the hydrodesulfurization are severely performed. However, once the reaction temperature is raised, the carbonaceous material is precipitated on the catalyst, and the activity of the catalyst is rapidly lowered. Once the liquid space velocity is lowered, the desulfurization energy is increased, but the refining treatment capacity is lowered, which makes it necessary to expand the scale of the equipment. Moreover, such severe operating conditions also have an adverse effect on the traits such as hue or storage stability. Therefore, the development of a catalyst having particularly excellent desulfurization activity is the best method for achieving light oil desulfurization under relatively loose conditions without stringent operating conditions.

On the other hand, depending on the use condition of kerosene or gas oil, a catalyst having a desulfurization activity capable of securing a predetermined ratio of desulfurization rate and capable of being used for a long period of time, that is, a catalyst having a long life, is required. In addition, if the same catalyst can be used for desulfurization of kerosene and light oil or even decompression light oil, the catalyst or device can be managed more effectively.

It is an object of the present invention to provide a catalyst which has a predetermined desulfurization activity and longevity, and which can hydrotreat a wide range of hydrocarbon oils such as naphtha to vacuum gas oil under milder desulfurization conditions.

Invented subject

Under the above-described circumstances, the inventors of the present invention have further studied the following aspects by hydrolyzing and desulfurizing a zeolite having various physical properties on a carrier based on alumina as a result of intensive research, and obtained the following novel findings: That is, in various zeolites, HY zeolite having specific physical properties can be more efficiently hydrogenated and desulfurized with respect to various hydrocarbon oils such as kerosene, light oil, and heavy light oil, as compared with other zeolites. As a result of further investigation based on the above findings, it has been found that the above-described object can be attained by recombining a HY zeolite having a predetermined physical property with an alumina-based carrier and controlling the catalyst properties such as an average pore diameter.

，平均細孔直徑±15

範圍之細孔容積在總細孔容積佔至少75%，前述HY沸石中：(a)SiO₂/Al₂O₃(莫耳比)為3~10； (b)晶格常數為2.435~2.465nm；(c)沸石骨架內Al相對於總Al之莫耳比為0.2~0.9；及(d)微晶徑為30~100nm。 That is, the first aspect of the present invention is a hydrodesulfurization catalyst for a hydrocarbon oil which is obtained by compounding cobalt, molybdenum and phosphorus in an alumina containing 80 to 99% by mass of alumina and 1 to 20% by mass of HY zeolite. The catalyst for the oxide carrier is determined by a nitrogen adsorption method in which, in terms of a catalyst, 3 to 6 mass% of cobalt, 16 to 24 mass% of molybdenum, and 0.8 to 4.5 mass% of phosphorus are contained in terms of an oxide. The specific surface area is 210-280 m ² /g, the pore volume measured by the mercury intrusion method is 0.3-0.6 ml/g, and the average pore diameter under the pore distribution measured by the mercury intrusion method is 75. ~95

, average pore diameter ± 15

The pore volume of the range accounts for at least 75% of the total pore volume. In the above HY zeolite: (a) SiO ₂ /Al ₂ O ₃ (mole ratio) is 3 to 10; (b) The lattice constant is 2.435 to 2.465. Nm; (c) the molar ratio of Al to total Al in the zeolite framework is 0.2 to 0.9; and (d) the crystallite diameter is 30 to 100 nm.

According to the hydrodesulfurization catalyst for a hydrocarbon oil of the present invention, since the desulfurization activity is high, the content of the sulfur component in the gas oil fraction can be greatly reduced.

Further, since the hydrodesulfurization catalyst of the hydrocarbon oil of the present invention can set the reaction conditions to be substantially the same as or milder than the reaction conditions in the conventional hydrogenation treatment, it is not necessary to substantially modify the conventional apparatus, and it is possible to A hydrodesulfurization catalyst that has been used.

Further, by using the hydrodesulfurization catalyst of the hydrocarbon oil of the present invention, a light oil base material having a small sulfur content can be easily provided.

Fig. 1 is a graph showing the relationship between the crystallite diameter (nm) of the zeolite contained in the catalyst and the desulfurization reaction rate constant (Ks) in the catalysts A to D and the catalyst X.

Form for implementing the invention

The hydrodesulfurization catalyst of the hydrocarbon oil of the present invention (hereinafter sometimes referred to as "the catalyst of the present invention") is such that cobalt, molybdenum and phosphorus are supported on a composite oxide carrier containing alumina and HY zeolite having specific physical properties. A catalyst, and a specific surface area or pore volume, and a hydrodesulfurization catalyst of a hydrocarbon oil having an average pore diameter within a specific range. An alumina carrier having a specific physical property of HY zeolite, and a specific surface area or a pore volume, and an average pore diameter The degree of control is within a specific range, whereby a hydrodesulfurization catalyst which can be subjected to hydrogenation treatment at a sufficient desulfurization rate and has a long life can be obtained even under milder desulfurization conditions.

<HY zeolite>

The HY zeolite used in the catalyst of the present invention has the following physical properties (a) to (d).

(a) SiO ₂ /Al ₂ O ₃ (mole ratio) is 3 to 10; (b) lattice constant is 2.435 to 2.465 nm; (c) molar ratio of Al to total Al in the zeolite framework is 0.2~ 0.9; and (d) the crystallite diameter is 30 to 100 nm.

(a) SiO ₂ /Al ₂ O ₃ (Morby)

SiO ₂ /Al ₂ O ₃ (mole ratio) can be determined by chemical composition analysis by ICP analysis.

The overall SiO ₂ /Al ₂ O ₃ (mole ratio) obtained from the chemical composition analysis of the HY zeolite used in the catalyst of the present invention is 3 to 10, and preferably 5 to 8. When SiO ₂ /Al ₂ O ₃ (mole ratio) is 3 or more, a sufficient amount of active sites can be provided, and the heterogeneity of the alkyl group of the hard-to-remove substance and the hydrogenation of the benzene ring can be sufficiently performed. Further, when SiO ₂ /Al ₂ O ₃ (mole ratio) is 10 or less, decomposition of the feedstock oil (hydrocarbon oil) is difficult to proceed, and the decrease in liquid yield can be suppressed.

The HY zeolite used in the present invention has substantially the same crystal structure as the natural faujasite, and has the composition shown below as an oxide.

[Chemical 1] (0.02 ~ 1.0) R ₂ / mO. Al ₂ O ₃ . (5~11) SiO ₂ . (5~8) H ₂ OR: atomic number of Na, K, other alkali metal ions, alkali ± metal ions m: R

(b) lattice constant

The lattice constant (unit lattice size) of the HY zeolite can be determined by an X-ray diffraction device (XRD). Here, the "lattice constant of HY zeolite" means the unit cell size constituting the zeolite.

The lattice constant of the HY zeolite used in the present invention is 2.435 to 2.465 nm, and is preferably 2.440 to 2.460 nm. When the lattice constant is 2.435 nm or more, the number of Al (amount of aluminum) required for promoting the heterogeneity of the alkyl group of the hard-to-treat substance and the hydrogenation of the benzene ring is an appropriate amount; if it is 2.435 nm or less, the acid moiety can be suppressed. The raw material oil is decomposed and can inhibit the carbon deposition of the main factor of the decrease in activity.

(c) Mohr ratio of Al to total Al in the zeolite framework

The molar number of aluminum atoms in the zeolite framework of the zeolite relative to the total aluminum atom can be calculated from the SiO ₂ /Al ₂ O ₃ ratio and the lattice constant by chemical composition analysis using the following formulas (A) to (D). . Further, the formula (A) is a formula described in HKBeyeretal., J. Chem. Soc., Faraday Trans. 1, (81), 2899 (1985).

Formula (A): N _Al = (ao-2.425) / 0.000868

In the formula (A), ao: lattice constant / nm; N _Al : number of Al atoms per unit lattice; 2.425: lattice constant when the total Al atom in the unit lattice skeleton is separated from the skeleton; 0.000868: The calculated value obtained by the experiment is the slope of ao and N _Al in a one-dimensional equation (ao=0.000868N _Al +2.425).

Formula (B): [(Si/Al) calculation formula] = (192-N _Al ) / N _Al

In the formula (B), 192: the number of atoms of (Si + Al) per lattice constant of the Y-type zeolite.

Formula (C): [(Si/Al) chemical composition analysis value] = [(SiO ₂ /Al ₂ O ₃ ) molar ratio]/2

Formula (D): [Al in the zeolite framework] / [Total Al] = [(Si/Al) chemical composition analysis value] / [(Si / Al) calculation formula]

The molar ratio of the aluminum atom to the total aluminum atom in the zeolite framework of the HY zeolite used in the present invention ([Al in the zeolite framework] / [total Al]) is 0.2 to 0.9, and preferably 0.4 to 0.7. By setting the [Al in the zeolite framework] / [Total Al] molar ratio within this range, an acid point which can be appropriately anisotropic or hydrogenated can be formed to obtain a desired desulfurization activity.

(d) microcrystalline diameter

The microcrystalline diameter of the HY zeolite used in the catalyst of the present invention is measured by an X-ray diffraction apparatus and is defined by the following (1) to (4).

(1) The diffraction peak of the zeolite was calculated by an X-ray diffraction device.

(2) The half value width of each surface is calculated from the peak corresponding to the (533) plane, the (642) plane, and the (555) plane.

(3) The half-value widths of the (533) plane, the (642) plane, and the (555) plane are brought into the Scherrer equation (formula (E)), and the dimensions of the respective faces are obtained.

(4) The average value of the three faces obtained by the above (3) is defined as the zeolite crystal diameter.

Formula (E): D = Kλ / βcos θ

)；K：Sherrer常數；λ：X射線波長(nm)；β：半值寬度(rad)；θ：繞射角(°)。 In formula (E), D: the crystallite diameter of the zeolite (

K: Sherrer constant; λ: X-ray wavelength (nm); β: half-value width (rad); θ: diffraction angle (°).

The HY zeolite used in the present invention obtained by the formula (E) has a crystallite diameter of 30 to 100 nm, and desirably 45 to 95 nm. By setting the microcrystal diameter of the zeolite within the above range, the function of promoting the heterogeneity or hydrogenation can be prevented, and the carbon deposition of the main factor of the decrease in activity can be suppressed, and the decrease in the liquid yield due to the decomposition reaction can be suppressed.

<Composite oxide carrier>

The catalyst of the present invention as a carrier has a main component of alumina and an inorganic oxide containing the above-mentioned HY zeolite. Specifically, the catalyst of the present invention contains cobalt (Co), molybdenum (Mo), and phosphorus in an amount of 80 to 99% by mass of alumina and 1 to 20% by mass of the above-mentioned HY based on the carrier. A catalyst for a composite oxide support of zeolite.

The blending amount of the HY zeolite of the composite oxide carrier is preferably from 2 to 10% by mass, and more preferably from 4 to 8% by mass, based on the carrier. The amount of the HY zeolite blended is too small or too large to easily form the catalyst. Further, if the amount is too small, the supply of the acidic portion of the catalyst, that is, the acidic portion of the Brunsten or the acidic portion of the Lewis is insufficient, and if it is too large, the high dispersion of Mo is suppressed.

The alumina used for the carrier of the catalyst of the present invention may be various aluminas such as α-alumina, β-alumina, γ-alumina, δ-alumina, and preferably porous and high specific surface area alumina. Among them, γ-alumina is suitable. The purity of alumina is about 98% by mass or more, and preferably about 99% by mass or more. As the impurities in the alumina, there are, for example, SO ₄ ^2- , Cl ^- , Fe ₂ O ₃ , Na ₂ O, etc., and it is preferable to use such impurities as small as possible. Specifically, it is preferably 2% by mass or less and preferably 1% by mass or less, based on the total amount of impurities, and SO ₄ ^2- <1.5% by mass and Cl-, Fe ₂ O ₃ , Na ₂ O per component. <0.1% by mass is preferred.

且理想約在65~90

者為適合。 The specific surface area, pore volume, and average pore diameter of the alumina carrier (composite oxide carrier) containing the HY zeolite are not particularly limited, and a specific surface area is used to produce a catalyst having high hydrodesulfurization activity relative to light oil. It is about 240~500m ² /g and ideally about 300~450m ² /g, the pore volume is about 0.55~0.9ml/g and the ideal is about 0.65~0.8ml/g, and the average pore size is about 60~120.

And ideal about 65~90

Suitable for those who are suitable.

In the composite oxide carrier, the specific surface area is about 240 m ² /g or more, whereby the dispersibility of the active metal can be improved and a catalyst having high desulfurization activity can be obtained. Further, when the pore diameter of the catalyst is small, the diffusion of the sulfur compound into the pores of the catalyst is insufficient to reduce the desulfurization activity, but by making the specific surface area be about 500 m ² /g or less, The pore diameter becomes extremely small, and the pore diameter of the catalyst does not become too small.

In the composite oxide carrier, when the amount of the solvent permeating into the pore volume is too small, the solubility of the active metal compound is deteriorated and the metal dispersibility is lowered to become a low-activity catalyst. When the catalyst is prepared by a usual impregnation method by a pore volume of about 0.55 ml/g or more, a sufficient amount of solvent can be infiltrated into the pore volume. Also, in order to enhance the dissolution of the active metal compound The solution is a method in which a large amount of an acid such as nitric acid is added. However, when the amount of the acid added is too large, the specific surface area of the carrier may be extremely lowered to lower the desulfurization performance. By having a pore volume of the composite oxide carrier of about 0.9 ml/g or less, a catalyst having a sufficient specific surface area, excellent dispersibility of the active metal, and high desulfurization activity can be obtained.

以上，使活性金屬受載即可獲得細孔直徑為充分大小的催化劑。另一方面，催化劑的比表面積一小，即有活性金屬分散性變差使脫硫活性降低之虞。藉由複合氧化物載體的細孔直徑約在120

以下，可獲得具有充分的比表面積之催化劑。 Further, when the pore diameter of the catalyst is small, the diffusion of the sulfur compound into the pores of the catalyst is insufficient and the desulfurization activity is lowered. The pore diameter of the composite oxide carrier is about 60

In the above, a catalyst having a pore diameter of a sufficient size can be obtained by subjecting the active metal to a load. On the other hand, the specific surface area of the catalyst is small, that is, the dispersion of the active metal is deteriorated to lower the desulfurization activity. The pore diameter of the composite oxide carrier is about 120

Hereinafter, a catalyst having a sufficient specific surface area can be obtained.

In the composite oxide carrier, in addition to the alumina and the HY zeolite, inorganic oxidation such as boron oxide, cerium oxide, cerium oxide-alumina, titanium oxide, and zirconium oxide may be contained in the range satisfying the physical properties of the carrier or the final physical properties of the catalyst. Things.

<Hydrogen Desulfurization Catalyst for Hydrocarbon Oil>

The Co compound to be supported on the composite oxide carrier may, for example, be a carbonate, an acetate, a nitrate, a sulfate or a chloride, preferably a carbonate or an acetate, and more preferably a carbonate.

The Mo compound to be supported on the composite oxide carrier may, for example, be molybdenum trioxide, molybdenum phosphate, ammonium molybdate or molybdic acid, and is preferably molybdenum phosphate or molybdenum trioxide.

In the case of the phosphorus supported on the composite oxide carrier, such as molybdenum and phosphorus When a phosphorus-containing compound (phosphorus compound) is used as the Co compound or the Mo compound, an acid or the like may be a phosphorus derived from the phosphorus compound. Further, when a phosphorus compound is not used as the Co compound or the Mo compound, if only phosphorus derived from the phosphorus compound is insufficient in the amount of phosphorus specified, another phosphorus source is additionally used. Examples of the other phosphorus source include various phosphoric acids, and specific examples thereof include orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, tetraphosphoric acid, and polyphosphoric acid. Particularly, orthophosphoric acid is preferred.

In the active component, the Co content is from 3 to 6% by mass, and preferably from about 3.5 to 6% by mass, based on the catalyst. When the Co content is too small, the active point attributed to Co may not be sufficiently obtained; when the Co content is too large, not only the dispersion of the active metal may be deteriorated due to coagulation of the Co compound, but also an inert precursor such as Co ₃ O may be formed. _four species (or in the sulfided catalyst as a hydrotreating Co ₉ S ₈ species present) or to pull Co spinel lattice species in the carrier, thereby reducing the risk of catalyst activity. By setting the Co content within the above range, it is possible to obtain a catalyst having a sufficient amount of active sites belonging to Co, a good dispersibility of Co, a low content of an inert Co compound, and a high desulfurization activity.

The Mo content is 16 to 24% by mass in terms of oxide based on the catalyst, and is preferably about 18 to 22% by mass. When the Mo content is too small, it is insufficient to exhibit the effect derived from Mo. On the other hand, when the Mo content is too large, not only the dispersibility of the active metal is deteriorated by Mo coagulation, but also the limit of the active metal content which is efficiently dispersed, or the surface area of the catalyst is largely lowered, and the catalyst activity is not improved. When the Mo content is within the above range, a sufficient effect derived from Mo can be exhibited, and the dispersibility of Mo is good, and a catalyst having a sufficient catalyst surface area and high desulfurization activity can be obtained.

Phosphorus is added as a component which enhances the desulfurization activity per active metal amount, and enhances the qualitative improvement of the active point, and has a function of precisely creating a highly active Co-Mo-S phase (desulfurization active point). That is, in the case where phosphorus acts to increase the acid properties of the catalyst to cause the catalyst to exhibit a value of an appropriate acid property, the dispersibility of the active component can be improved, and the amount of the acidic portion on the carrier can be optimized to promote the optimum value. The adsorption of the sulfur compound enhances the hydrodesulfurization activity of the sulfur compound.

The phosphorus content is 0.8 to 4.5% by mass in terms of oxide based on the catalyst, and is preferably about 1.0 to 4% by mass. When the phosphorus content is too small, the effect of the above-mentioned phosphorus may not be sufficiently exhibited, and the sulphur component in the gas oil fraction may not be efficiently removed. On the other hand, when the phosphorus content is too large, the action of the above phosphorus is saturated to further reduce the surface area of the catalyst or the pore volume, and the desulfurization activity is lowered. By setting the phosphorus content within the above range, the surface area of the catalyst or the decrease in the pore volume can be suppressed, and the action of the above phosphorus can be sufficiently exerted.

Among the above contents of Co, Mo, and phosphorus, the optimum mass ratio of Co to Mo of the active metal is preferably about 0.12 to 0.24 in terms of [CoO] / [CoO + MoO ₃ ], and Mo of the active metal. The optimum mass ratio of phosphorus to the acid-promoting component of the catalyst is preferably from about 0.05 to 0.25, based on the value of [P ₂ O ₅ ]/[MoO ₃ ].

The mass ratio of Co to Mo is the value of [CoO]/[CoO+MoO ₃ ]. When the value is too small, the Co-Mo-S phase which is considered to be the active point of desulfurization cannot be sufficiently formed, and thus cannot be lifted off. Sulfur activity. On the other hand, when the value is too large, a Co species (Co ₉ S ₈ or a Co spinel in the crystal lattice of the carrier) which is not related to the activity is generated, and the catalyst activity is further generated. reduce. By setting the mass ratio of Co to Mo to about 0.12 to 0.24 in terms of the above value, generation of an inert Co species can be suppressed, and a Co-Mo-S phase can be sufficiently formed, whereby a catalyst having high desulfurization activity can be obtained.

The mass ratio of phosphorus to Mo is the value of [P ₂ O ₅ ]/[MoO ₃ ]. When the value is too small, it will not be able to map the integration of Co and Mo, and finally it will be difficult to obtain the Co-Mo of the desulfurization active point. -S phase, which becomes a catalyst with low activity. On the other hand, when the value is too large, not only the surface area of the catalyst and the pore volume are reduced, but also the activity of the catalyst is lowered, and the amount of acid is increased to cause carbon deposition, which tends to cause deterioration of activity. By the mass ratio of phosphorus to Mo being about 0.05 to 0.25 in the above-mentioned value, the surface area of the catalyst and the pore volume reduction or carbon deposition can be suppressed, and the Co-Mo-S phase can be sufficiently formed, so that the desulfurization activity can be obtained. High catalyst.

The catalyst of the present invention can be prepared by first compounding the HY zeolite with alumina, and then impregnating the solution prepared by dissolving the compound of the above components into a solvent such as water or an acid. The composite oxide carrier is used for modulation.

A method of combining alumina with the above-mentioned HY zeolite may be, for example, a coprecipitation method or a kneading method.

It is preferred that the components of Co, Mo, and phosphorus are impregnated into the composite oxide carrier so that the components are simultaneously impregnated. Since it is seen from the aspect of the catalyst characteristics such as the desulfurization activity point, the acid property, the pores, or the operability, it is considered that the one-stage impregnation method is advantageous. That is, according to a one-stage impregnation method, Co and Mo can be integrally introduced into the carrier, so that the Co-Mo-S phase of the desulfurization active point can be greatly increased. At this time, as long as the phosphorus component is present in the impregnation solution, the integration of Co and Mo can be promoted. In contrast, in the method of infiltrating Co and Mo in two stages, Co and Mo may not be sufficiently integrated, and finally it is difficult to form a Co-Mo-S phase of a desulfurization active point. For example, Co may inactive precursor into the Co ₃ O ₄ is led into one or into the support crystal lattice and is not associated with the activity of the spinel Co species.

A specific method of supporting Co and Mo on a carrier is as follows.

First, a solution containing each of Co, Mo, and phosphorus (when the Mo compound contains phosphorus, no phosphorus compound or an appropriate amount of a phosphorus compound) is prepared. In order to promote the dissolution of the compounds, the solution may be heated (about 30 to 100 ° C) or added with an acid. The acid may, for example, be an organic acid such as nitric acid or citric acid, acetic acid, malic acid or tartaric acid.

Next, the prepared solution was slowly added to be impregnated into the composite oxide carrier and made uniform. The infiltration time is about 1 minute to 5 hours and is preferably about 5 minutes to 3 hours, the temperature is about 5 to 100 ° C and the ideal is about 10 to 80 ° C, and the environment is not particularly limited, in the atmosphere, in nitrogen, Suitable for use in vacuum.

After impregnation, the water is removed to a certain extent under normal temperature to about 80 ° C, nitrogen flow, air flow or vacuum (to make LOI "Loss on ignition loss" is less than 50%), It is dried in a drying oven and air flow at about 80 to 150 ° C for about 10 minutes to 10 hours. Next, it is baked in a baking furnace and air flow at about 300 to 700 ° C for about 10 minutes to 10 hours.

The distribution state of the active metal in the catalyst of the present invention is preferably a uniform type in which the active metal is uniformly distributed in the catalyst.

The catalyst of the present invention prepared by the above method must have a specific surface area, a pore volume, and an average pore diameter as follows in order to increase the hydrogenation activity and desulfurization activity with respect to kerosene or light oil, heavy light oil fraction, and the like. The value.

The catalyst of the present invention has a specific surface area (BET specific surface area) measured by a nitrogen adsorption method (BET "Braunauer-Emmett-Teller specific surface area") of 210 to 280 m ² /g and preferably about 220 to 250 m ² /g. . When the BET specific surface area is too small, the dispersibility of the active metal is deteriorated, and the desulfurization activity is lowered. When the BET specific surface area is too large, the pore diameter becomes extremely small, so that the pore diameter of the catalyst is also small, and At the time of the hydrotreatment, the diffusion of the sulfur compound into the pores of the catalyst becomes insufficient to lower the desulfurization activity. When the BET specific surface area of the catalyst is set within the above range, the dispersibility of the active metal is good, and the pore diameter can be made sufficiently large, whereby a catalyst having high desulfurization activity can be obtained.

The pore volume of the catalyst of the present invention measured by the mercury intrusion method is 0.3 to 0.6 ml/g and desirably about 0.35 to 0.5 ml/g. When the pore volume is too small, the diffusion of the sulfur compound in the pores of the catalyst during the hydrogenation treatment becomes insufficient and the desulfurization activity is insufficient; when the pore volume is too large, the specific surface area of the catalyst becomes extremely small, and the activity is made active. The dispersibility of the metal is lowered to become a catalyst for low desulfurization activity. By setting the pore volume of the catalyst within the above range, the sulfur compound can be sufficiently diffused in the pores of the catalyst, and a catalyst having a sufficient specific surface area and high desulfurization activity can be obtained.

且理想約在80~90

。平均 細孔直徑過小時，反應物質將難以擴散至細孔內而無法有效率地進行脫硫反應；平均細孔直徑過大時，細孔內的擴散性雖佳但細孔內表面積會減少，因此催化劑的有效比表面積會減少且活性降低。藉由將催化劑的平均細孔直徑設定在前述範圍內，可使催化劑的有效比表面積夠寬廣，且反應物質容易擴散，故可獲得得以在高效率下進行脫硫反應的催化劑。 The average pore diameter of the catalyst of the present invention under the pore distribution measured by the mercury intrusion method is 75 to 95.

And ideal about 80~90

. When the average pore diameter is too small, the reaction material is difficult to diffuse into the pores and the desulfurization reaction cannot be efficiently performed. When the average pore diameter is too large, the diffusibility in the pores is good, but the surface area in the pores is reduced. The effective specific surface area of the catalyst is reduced and the activity is lowered. By setting the average pore diameter of the catalyst within the above range, the effective specific surface area of the catalyst can be broadened and the reaction material is easily diffused, so that a catalyst capable of performing a desulfurization reaction at a high efficiency can be obtained.

之細孔徑的細孔比率，係設定在總細孔容積之至少75%且理想約在80%以上。 Further, in order to increase the effective number of pores satisfying the aforementioned pore condition, the pore diameter distribution of the catalyst has an average pore diameter ± about 15

The pore ratio of the pore diameter is set to be at least 75% of the total pore volume and desirably about 80% or more.

Moreover, the pore distribution is preferably a single mode. The pore size distribution of the catalyst is such that the sharpness has less pores which are not related to the activity, and a higher desulfurization activity can be obtained.

The shape of the catalyst of the catalyst of the present invention is not particularly limited, and various shapes such as a columnar shape, a trilobal type, a four-leaf type, and the like which are used in such a catalyst can be usually used. The size of the catalyst of the present invention is usually about 1 to 2 mm in diameter and about 2 to 5 mm in length.

The mechanical strength of the catalyst of the present invention is preferably about 2 lbs/mm or more in terms of side crush strength (SCS: Side crush strength). When the SCS is smaller than this value, the catalyst charged in the reaction apparatus is crushed, and a differential pressure is generated in the reaction apparatus, so that the hydrogenation treatment operation cannot be continued. The compact density (CBD: Compacted Bulk Density) of the catalyst of the present invention is preferably about 0.6 to 1.2.

<Hydrogenation treatment method using hydrodesulfurization catalyst>

The catalyst of the present invention can be used for hydrogenation treatment of a hydrocarbon oil in the same manner as other desulfurization catalysts. The catalyst of the invention has very high desulfurization activity, and can not only greatly reduce the content of sulfur components in hydrocarbon oils, especially light oil fractions, under the reaction conditions substantially the same as those in the conventional hydrogenation treatment, even in comparison. Under mild reaction conditions, the content can also be greatly reduced.

For example, the catalyst of the present invention is contacted with a hydrocarbon oil containing a sulfur compound (for example, a gas oil fraction, etc.) under a hydrogen partial pressure of about 3 to 8 MPa, about 300 to 420 ° C, and a liquid space velocity of about 0.3 to 5 h ^-1 . Desulfurization is carried out, whereby the sulfur compound containing a hardly desulfurized sulfur compound in the hydrocarbon oil can be reduced.

The content of the sulfur component of the oil produced by hydrogenation treatment using the catalyst of the present invention is 500 ppm or less, more specifically about 20 to 300 ppm. Although depending on the properties of the raw material oil, by using the catalyst of the present invention, the oil of the sulfur component content which is the same level as the conventional one can be obtained under a relatively mild hydrogenation treatment condition for a long period of time.

The target oil (raw material oil) to be subjected to hydrogenation treatment by the catalyst of the present invention may be a hydrocarbon-containing oil, for example, a straight-run lamp oil, a straight-run light oil, a contact decomposed light oil, a thermally decomposed light oil, or a hydrogenation treatment. Lamp oil or light oil fractions such as oil, desulfurization light oil, vacuum distillation light oil (VGO) are suitable. Representative examples of such raw material oils include those having a boiling point range of 150 to 450 ° C and a sulfur component of 5% by mass or less.

To carry out a hydrotreating process using the catalyst of the present invention on a commercial scale, a fixed bed, a moving bed, or a fluidized bed catalyst layer of the catalyst of the present invention is formed in a reaction apparatus, and in the reaction apparatus The raw material oil is introduced, and the hydrogenation reaction may be carried out under the above conditions. The most common method is to form a fixed bed catalyst layer in the reaction device, introduce the feedstock oil to the upper part of the reaction device, pass the fixed bed from top to bottom, and generate a stream from the lower part of the reaction device; or conversely, the raw material The oil is introduced into the lower portion of the reaction device, and the fixed bed is passed from bottom to top, and the product is discharged from the upper portion of the reaction device.

The hydrotreating process may be a one-stage hydrotreating process in which the catalyst of the present invention is charged to a separate reaction apparatus, or may be a multi-stage continuous hydrotreating process, that is, filling into a plurality of reaction apparatuses.

Further, the catalyst of the present invention is activated by a vulcanization treatment in a reaction apparatus before use (that is, before the hydrotreatment treatment). The vulcanization treatment is carried out by using a petroleum distillate containing a sulfur compound or adding dimethyl sulfide or the like in a hydrogen atmosphere of about 200 to 400 ° C and preferably about 250 to 350 ° C and a hydrogen partial pressure of a normal pressure or higher. The vulcanizing agent such as carbon disulfide or hydrogen sulfide is used.

Example

Next, the embodiments of the present invention and the effects thereof will be further described in detail by way of examples and comparative examples, but the invention is not limited by the examples.

First, the analysis methods of the physical properties and chemical compositions of the catalysts in the examples and comparative examples are shown below.

<specific surface area>

The specific surface area is measured by the BET method using nitrogen adsorption. As the nitrogen adsorption device, a surface area measuring device (BELSORP 28) manufactured by BEL Co., Ltd., was used.

<Pore volume, average pore diameter, and pore distribution> (using the machine)

The pore volume, average pore diameter, and pore distribution were measured by mercury intrusion. The mercury intrusion device used was a porosimeter (MICROMERITICS AUTO-PORE 9200: manufactured by Shimadzu Corporation).

(measurement principle)

The mercury intrusion method is based on the capillary phenomenon. In the case of mercury and cylindrical pores, the law is expressed by the following formula (F). In the formula (F), D is a pore diameter, P is an applied pressure, γ is a surface tension, and θ is a contact angle. The volume of mercury entering the pores is measured as a function of the applied pressure P. On the other hand, the surface tension of the fine pore mercury of the catalyst was set to 484 dyne/cm, and the contact angle was set to 130 degrees.

Formula (F): D=-(1/P) ⁴ γcosθ

The pore volume is the total mercury volume per gram of catalyst that has entered the pores. The average pore diameter is the average value of D calculated as a function of P.

The pore distribution is the distribution of D calculated by P as a function.

(measurement order)

(1) The power supply of the vacuum heating degasser was inserted, and it was confirmed that the temperature was 400 ° C and the degree of vacuum was 5 × 10 ^-2 Torr or less.

(2) The sample burette is installed in an empty tube to a vacuum heating degasser.

(3) The degree of vacuum is one to 5 × 10 ^-2 Torr or less, that is, the plug is closed and the sample burette is separated from the vacuum heating degasser, and the weight is measured after cooling.

(4) A sample (catalyst) is placed in the sample burette.

(5) The sample burette equipped with the sample is placed in a vacuum heating deaerator, and is maintained for 1 hour or more after the degree of vacuum is 5 × 10 ^-2 Torr or less.

(6) The sample burette containing the sample was separated from the vacuum heating degasser, and after cooling, the weight was measured to determine the weight of the sample.

(7) The sample was placed in the slot of the AUTO-PORE 9200.

(8) Measurement was performed by AUTO-PORE 9200.

<Chemical composition analysis> (using machines and analytical methods)

The metal analysis in the catalyst was carried out by inductively coupled plasma emission spectrometry (ICPS-2000: manufactured by Shimadzu Corporation).

The quantification of the metal is carried out by the absolute detection line method.

(measurement order)

(1) 0.05 g of a catalyst, 1 ml of hydrochloric acid (50% by volume), one drop of hydrofluoric acid, and 1 cc of pure water were placed in UNISEAL, and dissolved by heating.

(2) After dissolving, transfer to a polypropylene measuring flask (50 ml), add pure water, and weigh to 50 ml.

(3) The solution was measured by ICPS-2000.

[Manufacturing Example 1] Modulation of zeolite

The zeolite 1 used in the following examples and the like was prepared by the following method.

To 230 g of a 21.7% by mass aqueous sodium hydroxide solution which had been placed in an autoclave vessel, 29 g of sodium aluminate containing 17.0% by mass of Na ₂ O and 22.0% by mass of Al ₂ O ₃ was added while stirring. While stirring the solution obtained by adding sodium aluminate, it was added to 232 g of No. 3 water glass having a SiO ₂ concentration of 24% by mass, and after sufficiently stirring, it was subjected to heating and aging at 95 ° C for 12 hours. After completion of the aging, the temperature was cooled to 70 ° C or lower, and the synthesized product was taken out, filtered, washed, and dried to prepare a Na-Y type seed crystal. The composition of the obtained seed composition was Na ₂ O/Al ₂ O ₃ = 16, SiO ₂ /Al ₂ O ₃ = 15, and H ₂ O/Al ₂ O ₃ = 330 in terms of oxide molar ratio.

Next, 220 g of a sodium citrate solution having a SiO ₂ concentration of 29% by mass, 31.7 g of sodium aluminate containing 33.0% by mass of Na ₂ O and 36.5 mass % of Al ₂ O ₃ , and 6 g of sodium hydroxide were placed in the autoclave vessel. 747.0 g of pure water was added, and after stirring well, 8.0 g of the above-mentioned crystals were added (dry basis), and after sufficiently stirring, the mixture was heated and aged at 95 ° C for 12 hours. After the completion of the aging, the temperature was cooled to 70 ° C or lower, and the synthetic product was taken out, filtered, washed, and dried to obtain Na-Y type zeolite 1.

Thereafter, Na-Y type zeolite 1 was placed in a 5 mass% aqueous ammonium nitrate solution, and stirred under a certain condition of 60 ° C for 20 minutes, followed by filtration and ion exchange treatment. After repeating the ion exchange treatment twice, it was dried at 120 ° C for 12 hours, whereby NH 3 -type Y zeolite 1 was obtained.

Then, the obtained NH3 type Y zeolite 1 was calcined at 600 ° C for 4 hours under air flow to obtain H-type Y zeolite 1 (hereinafter simply referred to as "zeolite 1"). Further, in the reaction mixture, the amount of the seed Al ₂ O ₃ relative to the total Al ₂ O ₃ was 0.098 mol%.

The zeolite 2 to zeolite 5 were also prepared in accordance with the method of the above zeolite 1.

SiO ₂ /Al ₂ O ₃ (mole ratio) of zeolite 1 to zeolite 5, lattice constant, molar ratio of Al to total Al in zeolite framework ([Al in zeolite framework]/[total Al]) and micro The crystal diameter is shown in Table 1.

Here, SiO ₂ /Al ₂ O ₃ (mole ratio) was measured from chemical composition analysis by ICP analysis. The lattice constant is measured in accordance with ASTM D3906 using an X-ray analysis apparatus (XRD). The molar ratio of Al to the total Al atom in the zeolite framework was calculated from the chemical composition analysis value and the XRD measurement value. The details are carried out as described above.

[Example 1]

)。 2.0 g of zeolite 1 and 109.4 g of alumina hydrate were kneaded and extruded, and then calcined at 600 ° C for 2 hours to obtain a zeolite-alumina composite carrier having a columnar shaped body of 1/16 inch in diameter ( Zeolite/alumina mass ratio = 7/93, pore volume = 0.63 ml/g, specific surface area = 336 m ² /g, average pore diameter = 69

).

An infiltration solution in which 5.51 g of cobalt carbonate, 19.02 g of molybdenum phosphate, and 2.46 g of orthophosphoric acid (85% aqueous solution) were dissolved in 40.0 g of ion-exchanged water was prepared separately.

50.0 g of the above zeolite-alumina composite carrier was placed in an eggplant type flask, and the total amount of the above-mentioned impregnation solution was added thereto by a pipette, and immersed at about 25 ° C for 1 hour. Thereafter, it was air-dried in a nitrogen stream, dried in a high-temperature furnace at 120 ° C for about 1 hour, and calcined at 500 ° C for 4 hours to obtain a catalyst A.

。 Catalyst A has a specific surface area of 227 m ² /g, a pore volume of 0.40 ml/g, and an average pore diameter of 80.

.

[Embodiment 2]

)。 2.0 g of zeolite 2 and 109.4 g of alumina hydrate were kneaded and extruded, and then fired at 600 ° C for 2 hours to obtain a zeolite-alumina composite carrier having a columnar shaped body of 1/16 inch in diameter ( Zeolite/alumina mass ratio = 7/93, pore volume = 0.61 ml/g, specific surface area = 342 m ² /g, average pore diameter = 68

).

An infiltration solution in which 5.51 g of cobalt carbonate, 19.02 g of molybdenum phosphate, and 2.46 g of orthophosphoric acid (85% aqueous solution) were dissolved in 40.0 g of ion-exchanged water was prepared separately.

50.0 g of the above zeolite-alumina composite carrier was placed in an eggplant type flask, and the total amount of the above-mentioned impregnation solution was added thereto by a pipette, and immersed at about 25 ° C for 1 hour. Thereafter, it was air-dried in a nitrogen stream, dried in a high-temperature furnace at 120 ° C for about 1 hour, and calcined at 500 ° C for 4 hours to obtain a catalyst B.

。 Catalyst B has a specific surface area of 223 m ² /g, a pore volume of 0.43 ml/g, and an average pore diameter of 81.

.

[Example 3]

)。 2.0 g of zeolite 3 and 109.4 g of alumina hydrate were kneaded and extruded, and then fired at 600 ° C for 2 hours to obtain a zeolite-alumina composite carrier having a columnar shaped body of 1/16 inch in diameter ( Zeolite/alumina mass ratio = 7/93, pore volume = 0.63 ml/g, specific surface area = 333 m ² /g, average pore diameter = 69

).

In this way, 40.0 g of ion-exchanged water was separately prepared to dissolve infiltration of 5.51 g of cobalt carbonate, 19.02 g of molybdenum phosphate, and 2.46 g of orthophosphoric acid (85% aqueous solution). Solution.

50.0 g of the above zeolite-alumina composite carrier was placed in an eggplant type flask, and the total amount of the above-mentioned impregnation solution was added thereto by a pipette, and immersed at about 25 ° C for 1 hour. Thereafter, it was air-dried in a nitrogen stream, dried in a high temperature furnace at 120 ° C for about 1 hour, and calcined at 500 ° C for 4 hours to obtain a catalyst C.

。 Catalyst C has a specific surface area of 220 m ² /g, a pore volume of 0.38 ml/g, and an average pore diameter of 83.

.

[Example 4]

)。 2.0 g of zeolite 4 and 109.4 g of alumina hydrate were kneaded and extruded, and then calcined at 600 ° C for 2 hours to obtain a zeolite-alumina composite carrier having a columnar shaped body of 1/16 inch in diameter ( Zeolite/alumina mass ratio = 7/93, pore volume = 0.64 ml/g, specific surface area = 330 m ² /g, average pore diameter = 70

).

An infiltration solution in which 5.51 g of cobalt carbonate, 19.02 g of molybdenum phosphate, and 2.46 g of orthophosphoric acid (85% aqueous solution) were dissolved in 40.0 g of ion-exchanged water was prepared separately.

50.0 g of the above zeolite-alumina composite carrier was placed in an eggplant type flask, and the total amount of the above-mentioned impregnation solution was added thereto by a pipette, and immersed at about 25 ° C for 1 hour. Thereafter, it was air-dried in a nitrogen stream, dried in a high temperature furnace at 120 ° C for about 1 hour, and calcined at 500 ° C for 4 hours to obtain a catalyst D.

。 Catalyst D has a specific surface area of 224 m ² /g, a pore volume of 0.39 ml/g, and an average pore diameter of 81.

.

[Comparative Example 1]

)。將該沸石-氧化鋁複合載體50.0g投入至茄型燒瓶中，對其與實施例1同樣地以與實施例1同樣的方式添加浸滲用溶液之總量並進行浸漬後，以與實施例1同樣的方式進行風乾、乾燥、燒成而獲得催化劑X。 A zeolite-alumina composite carrier having the same shape as that of Example 1 was obtained in the same manner as in Example 1 except that the zeolite 1 of Example 1 was replaced with zeolite 5 (mass ratio of zeolite/alumina = 7/93, pores). Volume = 0.63 ml / g, specific surface area = 334 m ² / g, average pore diameter = 71

). 50.0 g of the zeolite-alumina composite carrier was placed in an eggplant type flask, and the total amount of the solution for impregnation was added and immersed in the same manner as in Example 1 in the same manner as in Example 1, and the examples were carried out. 1 In the same manner, air drying, drying, and firing were carried out to obtain a catalyst X.

。 Catalyst X has a specific surface area of 223 m ² /g, a pore volume of 0.37 ml/g, and an average pore diameter of 82.

.

)，「PSD」表示細孔分布(於MPD±15

含有佔總細孔容積中幾%之細孔容積)(%)，且「CBD」表示最密充填嵩密度(g/ml)。如表2及3顯示，催化劑A~D及催化劑X之化學組成及物理形狀皆大致為相同程度。 The elemental analysis values of Catalysts A to D and Catalyst X are shown in Table 2, and the catalyst information is shown in Table 3. The symbols in Table 3 are respectively: "SA" represents the specific surface area (m ² /g), "PV" represents the pore volume (ml/g), and "MPD" represents the average pore diameter (

), "PSD" means pore distribution (at MPD ± 15)

Contains a pore volume (%) which accounts for a few percent of the total pore volume, and "CBD" indicates the density of the densest packed crucible (g/ml). As shown in Tables 2 and 3, the chemical compositions and physical shapes of Catalysts A to D and Catalyst X were approximately the same.

[Table 2]

[Hydrogenation reaction of straight-run light oil 1]

Using the catalysts A to D and the catalyst X prepared in Examples 1 to 4 and Comparative Example 1, the hydrogenation treatment of the straight-run light oil of the following properties was carried out with the following emphasis.

First, the catalyst was charged into a high-pressure flow reactor to form a fixed bed catalyst layer, and pretreatment was carried out under the following conditions.

Next, a mixed fluid of the feedstock oil and the hydrogen-containing gas heated to the reaction temperature is introduced from the upper portion of the reaction apparatus, and a hydrogenation reaction is carried out under the following conditions, and a mixed fluid of the produced oil and gas is discharged from the lower portion of the reaction apparatus to obtain a gas-liquid. The separator will produce oil separation.

Catalyst pretreatment conditions:

Pressure: atmospheric pressure; Environment: hydrogen sulfide (5%) / hydrogen flow; temperature: maintained at 150 ° C for 0.5 hours, followed by a stepwise temperature increase of 350 ° C for 1 hour.

Hydrogenation reaction conditions:

Reaction temperature: 360 ℃ produced oil and the sulfur component becomes 200ppm temperature; pressure (hydrogen partial pressure): 5MPa; Liquid space velocity: 1.2h ^-1; hydrogen / oil ratio: 250m ³ / m ^3.

The properties of raw oil:

Oil species: Middle East straight-run light oil; specific gravity (15/4 ° C): 0.8648; distillation characteristics: initial boiling point is 206.0 ° C, 50% point is 319.0 ° C, 90% point is 372.0 ° C, and the end point is 390.0 ° C; Sulfur component: 1.44% by mass; nitrogen component: 170 ppm; dynamic viscosity (@30 ° C): 6.660 cSt; pour point: 2.5 ° C; cloud point: 3.0 ° C; cetane index: 53.2; color Bochrome: -16; ASTM color: L1.0; aniline point: 74.2 °C.

The reaction results were analyzed by the following methods.

The reaction apparatus was operated at 360 ° C, and oil was taken at a point of 6 days to analyze the properties. Thereafter, the oil is produced in each of the catalysts. The composition was operated at a temperature of 200 ppm for 200 days. In order to suppress the rise of the sulfur component of the produced oil due to deterioration of the catalyst while the generated oil sulfur component is always operating, the operation temperature is compensated while operating.

[1] Desulfurization rate (HDS) (%):

The sulfur component in the raw material is converted into hydrogen sulfide by a desulfurization reaction, and the ratio of the sulfur component which disappears from the raw material oil is defined as the desulfurization rate, and the sulfuric acid analysis value of the raw material oil and the produced oil is calculated by the following formula. .

[2] Desulfurization reaction rate constant (Ks):

The constant of the reaction rate of the number of times of the reaction of 1.5 times is obtained as the desulfurization reaction rate constant (Ks) with respect to the amount of reduction of the sulfur component (Sp) of the oil produced. However, the higher the reaction rate constant, the better the catalyst activity. These results are shown in Table 4.

In the above formula, Sf: a sulfur component (% by mass) in the raw material oil; Sp: a sulfur component (% by mass) in the reaction product oil; and LHSV: a liquid space velocity (h ^-1 ).

[3] A graph in which the desulfurization reaction rate constant (Ks) calculated from [2] with respect to the crystallite diameter of the zeolite is shown in Fig. 1.

[4] Desulfurization reaction rate constant (Ks):

The constant of the reaction rate of the number of times of the reaction of 1.5 times is obtained as the desulfurization reaction rate constant (Ks) with respect to the amount of reduction of the sulfur component (Sp) of the oil produced. However, the higher the reaction rate constant, the better the catalyst activity. The results when the reaction was carried out at 360 ° C are shown in Table 4.

As shown in Table 4, in comparison with the catalyst X of Comparative Example 1, the catalysts A to D of Examples 1 to 4 had a higher desulfurization rate, a higher desulfurization reaction rate constant, and a higher specific activity at 130. %the above. In particular, when the catalyst X is used, the sulfur component of the oil to be produced is about 0.05% by mass, and when the catalysts A to D are used, the sulfur component can be reduced to 0.03% by mass or less.

Further, as shown in Fig. 1, it is understood that the microcrystal diameter of the zeolite contained in the catalyst affects the desulfurization reaction rate constant of the catalyst, and the desulfurization reaction rate constant reaches a peak value near the crystallite diameter of 85 to 95 nm. Once the crystallite diameter is above 100 nm, there is a tendency to decrease sharply.

Further, in Table 5, the operating temperatures after 100 days and after 200 days are shown. When the catalysts A to D of Examples 1 to 4 were used, the difference between the operating temperature on the 100th day and the operating temperature on the 200th day was 1 to 4 ° C, even when oil sulfur was formed. When the sulfonic acid component is always operated for a long period of time, there is still a need to increase the operating temperature. In contrast, when the catalyst X of Comparative Example 1 was used, it was necessary to increase the operating temperature on the 200th day from the 100th day by 10° C. or more. From these results, it is understood that the catalyst of the present invention can maintain stable activity for a long period of time.

As is apparent from the above results, the catalyst of the present invention has extremely excellent activity with respect to the desulfurization reaction of a hydrocarbon oil such as gas oil under conditions such as hydrogen partial pressure and reaction temperature which are substantially the same as those of the conventional gas oil hydrogenation treatment. Therefore, with the catalyst of the present invention, it is possible to easily provide a light oil base material having a very low sulfur content, for example, a light oil base material having a sulfur content of less than 0.05% by mass.

Claims (1)

A hydrodesulfurization catalyst for hydrocarbon oil, which is a catalyst for supporting cobalt, molybdenum and phosphorus on a composite oxide carrier containing 80 to 99% by mass of alumina and 1 to 20% by mass of HY zeolite, based on a catalyst Further, in terms of oxide, 3 to 6 mass% of cobalt, 16 to 24 mass% of molybdenum, and 0.8 to 4.5 mass% of phosphorus are contained, and the specific surface area measured by a nitrogen adsorption method is 210 to 280 m ² /g. The pore volume measured by the mercury intrusion method is 0.3 to 0.6 ml/g, and the average pore diameter under the pore distribution measured by the mercury intrusion method is 75 to 95. , average pore diameter ± 15 The pore volume of the range accounts for at least 75% of the total pore volume. In the above HY zeolite: (a) SiO ₂ /Al ₂ O ₃ (mole ratio) is 3-10; (b) lattice constant is 2.435~2.465 Nm; (c) the molar ratio of Al to total Al in the zeolite framework is 0.2 to 0.9; and (d) the crystallite diameter is 30 to 100 nm.