JP2004290728A - Method for manufacturing hydrogenation catalyst for light oil and hydrogenation method for light oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a hydrogenation catalyst capable of performing the ultra-deep desulfurization of a sulfur component in light oil and at the same time capable of reducing a nitrogen component in the light oil by a simple means without requiring a severe operation condition, and a hydrogenation method for light oil using the obtained catalyst. <P>SOLUTION: The hydrogenation catalyst for light oil is manufactured by supporting 10-40 mass% of a Group VI metal in terms of an oxide on a catalyst basis, 1-15 mass% of a Group VIII metal and 0.8-8 mass% of phosphorus on an inorganic oxide carrier having a predetermined specific surface area, a predetermined pore volume and a predetermined mean pore size using a solution containing a compound which contains at least one of Group VIII metals, a compound which contains at least one of Group VI metals, an organic acid, a polyhydric alcohol and phosphoric acid, and drying the supported carrier at 200°C or below. The obtained catalyst is used in a hydrogenation method for light oil. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００５３】
〔直留軽油の水素化処理反応〕
上記の実施例及び比較例で調製した触媒Ａ、Ｂ、Ｃ、Ｄ、ａ、ｂを用い、以下の要領にて、下記性状の直留軽油の水素化処理を行った。
先ず、触媒を高圧流通式反応装置に充填して固定床式触媒層を形成し、下記の条件で予備硫化処理した。
次に、反応温度に加熱した原料油と水素含有ガスとの混合流体を、反応装置の上部より導入して、下記の条件で水素化反応を進行させ、生成油とガスの混合流体を、反応装置の下部より流出させ、気液分離器で生成油を分離した。
【００５４】
予備硫化処理条件：原料油による液硫化を行った。
圧力（水素分圧）；４．９ＭＰａ
雰囲気；水素及び原料油（液空間速度１．５ｈｒ^−１、水素／オイル比２００ｍ^３（ｎｏｒｍａｌ）／ｋｌ）
温度 ；常温約２２℃で水素及び原料油を導入し、２０℃／ｈｒで昇温し、３００℃にて２４ｈｒ維持、次いで反応温度である３５０℃まで２０℃／ｈｒで昇温
【００５５】
水素化反応条件：
反応温度 ；３５０℃
圧力（水素分圧）；４．９ＭＰａ
液空間速度 ；１．５ｈｒ^−１
水素／オイル比 ；２００ｍ^３（ｎｏｒｍａｌ）／ｋｌ
【００５６】
原料油の性状：
油種 ；中東系直留軽油
密度（１５／４℃）；０．８６０９
蒸留性状 ；初留点が２１１．５ ℃、５０％点が３１４．０℃、９０％点が３６５．０℃、終点が３８３．５℃
硫黄成分 ；１．３７質量％
窒素成分 ；２１０質量ｐｐｍ
動粘度（＠３０℃）；６．５７０ｃＳｔ
流動点 ；５．０℃
くもり点 ；６．０℃
セタン指数 ；５４．５
セイボルトカラー ；−１１
【００５７】
反応結果については、以下の方法で解析した。
３５０℃で反応装置を運転し、６日経過した時点で生成油を採取し、その性状を分析した。
・脱硫反応速度定数（Ｋｓ）：
生成油の硫黄分（Ｓｐ）の減少量に対して、１．３次の反応次数を得る反応速度式の定数を脱硫反応速度定数（Ｋｓ）とする。
なお、反応速度定数が高い程、触媒活性が優れていることを示している。これらの結果は、表２の通りであった。
【００５８】
脱硫反応速度定数＝〔１／（Ｓｐ）^{１．３−１}−１／（Ｓｆ）^{１．３−１}〕×（ＬＨ
ＳＶ）
式中、Ｓｆ：原料油中の硫黄分（質量％）
Ｓｐ：反応生成油中の硫黄分（質量％）
ＬＨＳＶ：液空間速度（ｈｒ^−１）
比活性（％）＝各脱硫反応速度定数／比較触媒ａの脱硫反応速度定数×１００
【００５９】
【表２】

【００６０】
以上の結果から明らかなように、本発明による触媒は、従来の軽油水素化処理の場合とほぼ同じ水素分圧や反応温度等の条件下で、超深度脱硫領域での軽油の脱硫反応に対して、極めて優れた活性を有することが判る。
【００６１】
【発明の効果】
本発明によれば、次のような効果を奏することができる。
（１）高い脱硫及び脱窒素活性を有するため、軽油中の硫黄分及び窒素分の含有率を、大幅に低減させることができる。
（２）反応条件を従来の水素化処理の際の反応条件とほぼ同じとすることができるため、従来の装置を大幅改造することなく転用できる。
（３）硫黄含有量及び窒素含有量の少ない軽油基材を、容易に供給することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a gas oil hydrotreating catalyst and a method for hydrotreating gas oil using the obtained catalyst.Specifically, when hydrotreating gas oil, the sulfur content in gas oil is conventionally reduced. The present invention relates to a method for producing a catalyst having excellent activity which can be reduced as compared with the case of using this kind of catalyst, and a hydrotreating method using the obtained catalyst.
[0002]
[Prior art]
2. Description of the Related Art In recent years, quality regulation values of light oil have tended to be stricter worldwide in order to improve the atmospheric environment. In particular, the sulfur content in light oil may affect the durability of post-treatment devices such as oxidation catalysts, nitrogen oxide (NOx) reduction catalysts, and continuous regeneration type diesel exhaust particulate removal filters, which are expected as measures against exhaust gas. Therefore, there is a demand for reducing the sulfur content of light oil.
[0003]
Under such circumstances, the development of an ultra-deep desulfurization technology that significantly removes the sulfur content in light oil is gaining importance. As a technique for reducing the sulfur content in light oil, it is generally considered that operating conditions for hydrodesulfurization, for example, reaction temperature, liquid hourly space velocity and the like are made severe. However, when the reaction temperature is increased, carbonaceous materials are precipitated on the catalyst, and the activity of the catalyst is rapidly decreased.When the liquid hourly space velocity is decreased, the desulfurization ability is improved, but the purification treatment capacity is decreased, so that the equipment capacity is reduced. Need to scale up.
Therefore, the best way to achieve ultra-deep desulfurization of gas oil without severe operating conditions is to develop a catalyst with excellent desulfurization activity.
In recent years, many studies have been conducted on various types of active metals, methods of impregnating active metals, improvement of catalyst carriers, control of pore structure of catalysts, activation methods, and the like. It has been reported.
[0004]
For example, Patent Literature 1 discloses that a γ-alumina support includes a compound belonging to Group 8 of the periodic table (hereinafter simply referred to as “group 8 metal”) and a metal belonging to Group 6 of the periodic table (hereinafter simply referred to as “group 6 metal”). A method comprising the steps of: impregnating an impregnating solution containing a compound and phosphoric acid, further adding a diol or an ether to the impregnating solution, and drying the impregnated solution at 200 ° C. or lower. I have.
[0005]
Patent Literature 2 discloses a method in which a support is impregnated with a solution containing a Group 6 metal compound, a phosphorus component, a Group 8 metal compound, and citric acid, followed by baking.
[0006]
Further, in Patent Document 3, an oxide carrier is impregnated with a solution comprising a Group 6 metal compound, a Group 8 metal compound, and phosphoric acid, and a catalyst dried at 200 ° C. or lower is obtained. A method of impregnating a solution of an organic acid and drying at 200 ° C. or lower is disclosed.
[0007]
On the other hand, a method for producing a catalyst that is impregnated with an organic acid twice has been proposed.
For example, in Patent Document 4, an oxide carrier is impregnated with a solution composed of a Group 6 metal compound, a Group 8 metal compound, an organic acid, and phosphoric acid, and a catalyst dried at 200 ° C. or lower is obtained. A method of impregnating a solution of a polyhydric alcohol and drying at 200 ° C. or lower is disclosed.
[0008]
However, in some of the above-mentioned catalyst production methods, the steps are complicated or the obtained catalyst is not suitable for performing ultra-deep desulfurization of light oil. For these reasons, at present, there is a demand for the development of a technology for obtaining a catalyst having a higher desulfurization activity than the conventional one, which can realize ultra-deep desulfurization of gas oil by a simpler method and without severe operating conditions. I have.
[0009]
[Patent Document 1]
Japanese Patent No. 2900771
[Patent Document 2]
Japanese Patent No. 2832033
[Patent Document 3]
JP-A-4-244238
[Patent Document 4]
JP-A-6-339635
[0010]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a simple means and without the need for severe operating conditions, to enable ultra-deep desulfurization of sulfur in light oil and simultaneously reduce hydrogen content of light oil which can reduce nitrogen content. It is an object of the present invention to provide a method for producing a hydrotreating catalyst, and to provide a method for hydrotreating a gas oil fraction with high efficiency using the obtained catalyst.
[0011]
[Means for Solving the Problems]
The present inventors have conducted studies to achieve the above object. As a result, the inorganic oxide carrier having certain physical properties includes a Group 6 metal compound, a Group 8 metal compound, an organic acid, a polyhydric alcohol, and phosphoric acid. A high-performance desulfurization catalyst capable of easily achieving an ultra-deep desulfurization reaction without severe reaction conditions by impregnating the solution, supporting a predetermined amount of these components, and drying at a temperature of 200 ° C. or less. Was obtained.
That is, the method for producing a gas oil hydrotreating catalyst according to the present invention has a specific surface area of 200 to 500 m.²/ G, a compound containing at least one selected from Group 8 metals on an inorganic oxide support having a pore volume of 0.5 to 0.9 m1 / g and an average pore diameter of 60 to 120 °, Using a solution containing at least one selected compound, an organic acid, a polyhydric alcohol, and phosphoric acid, 10 to 40% by mass of Group 6 metal and 1 of Group 8 metal in terms of oxide on a catalyst basis. -15% by mass, and 0.8 to 8% by mass of phosphorus, and dried at 200 ° C. or less.
In addition, the hydrotreating method for ultra-deep desulfurization of gas oil according to the present invention comprises a hydrogen partial pressure of 3 to 8 MPa, a treatment temperature of 300 to 420 ° C., and a liquid space in the presence of the catalyst obtained by the above-described catalyst production method. Speed 0.3-5hr^-1The contact reaction of the light oil fraction is carried out under the following conditions.
[0012]
As the oil to be treated in the present invention, for example, gas oil fractions such as straight-run gas oil, catalytic cracking gas oil, pyrolysis gas oil, hydrogenated gas oil, desulfurized gas oil, and vacuum distilled gas oil (VGO) are suitable.
Typical properties of these feedstocks include those having a boiling range of 150 to 450 ° C. and a sulfur content of 5% by mass or less.
[0013]
The method for producing a catalyst according to the present invention provides a solution comprising a compound containing at least one Group 6 metal, a compound containing at least one Group 8 metal, an organic acid, a polyhydric alcohol, and phosphoric acid on an inorganic oxide carrier. Is carried out, and the components contained in the impregnating solution are supported and dried. Specifically, for example, the method is carried out by immersing an inorganic oxide carrier in a solution containing these compounds and the like, and drying. .
[0014]
As the inorganic oxide carrier used in the catalyst of the present invention, alumina alone can be used, but in order to further improve the desulfurization activity, it is preferable to use a composite oxide containing alumina as a main component.
As the alumina, various aluminas such as α-alumina, β-alumina, γ-alumina, δ-alumina, and alumina hydrate can be used.Alumina which is porous and has a high specific surface area is preferable. -Alumina is suitable. Alumina having a purity of about 98% by mass or more, preferably about 99% by mass or more is suitable.
As impurities in alumina, S0₄ ^2-, Cl⁻, Fe₂O₃, Na₂O and the like are mentioned, but it is desirable that these impurities are as small as possible, and the total amount of impurities is 2% by mass or less, preferably 1% by mass or less.₄ ^2-<1.5% by mass, Cl⁻, Fe₂O₃, Na₂Preferably, O <0.1% by mass.
[0015]
The oxide component to be complexed with alumina is preferably at least one selected from zeolite, boria, silica, and zirconia.
Among them, zeolite has an average particle diameter of about 2.5 to 6 μm, preferably about 3 to 5 μm, more preferably about 3 to 5 μm as measured by a coal counter method (1 wt% NaCl aqueous solution, aperture 30 μ, ultrasonic treatment for 3 minutes). ４4 μm. The zeolite has a particle diameter of 6 μm or less occupying about 70 to 98%, preferably about 75 to 98%, and more preferably about 80 to 98% of all the zeolite particles.
Such physical properties of the zeolite are preferable for precisely controlling the pore diameter in order to facilitate diffusion of the hardly desulfurizable substance into the pores.For example, the average particle diameter is too large, or the content of the large particle diameter is large. If the amount is large, the alumina hydrate (alumina precursor) at the time of heating and sintering due to differences in the amount of water absorbed and the crystallinity of the alumina hydrate (alumina precursor) and zeolite in the process of preparing the composite oxide carrier The zeolite has a different shrinkage ratio, and relatively large meso or macropores tend to be generated as pores of the composite oxide carrier. In addition, these large pores not only reduce the surface area, but also facilitate the internal diffusion of metal components that can be a catalyst poison in the case of treating residual oil, and eventually desulfurization, denitrification and decomposition. Produces a tendency to reduce activity.
[0016]
In the present invention, preferred zeolites to be complexed with alumina include faujasite X-type zeolite, faujasite Y-type zeolite, β zeolite, mordenite-type zeolite, and ZSM zeolite (ZSM-4, 5, 8, 11, 12). , 20, 21, 23, 34, 35, 38, 46, etc.), MCM-41, MCM-22, MCM-48, SSZ-33, UTD-1, CIT-5, VPI-5, TS-1. , TS-2 and the like can be used, and Y-type zeolite, stabilized Y zeolite and β zeolite are particularly preferable. Further, the zeolite is preferably a proton type.
As the above-mentioned boria, silica and zirconia, those generally used as a carrier component of this type of catalyst can be used.
[0017]
The above zeolite, boria, silica, and zirconia can be used alone or in combination of two or more.
The mixing amount of these components is not particularly limited, but the alumina is more than about 80% by mass and 99.5% by mass or less in the composite oxide carrier, and is about 0.5% by mass or more and less than 20% by mass. Preferably, the alumina is about 0.5-15% by weight, based on about 85-99.5% by weight, and more preferably, the alumina is about 0.5-10% by weight, based on about 90-99.5% by weight. It is.
If these components are too small or too large, it is difficult to control the pore diameter. If too small, the application of Bronsted acid sites or Lewis acid sites becomes insufficient. Mo tends to be difficult to be highly dispersed.
[0018]
The specific surface area, pore volume, and average pore diameter of the inorganic oxide carrier are 200 to 500 m in order to make the catalyst having a high hydrodesulfurization activity for hydrocarbon oil.²/ G, preferably 270-450 m²/ G, a pore volume of 0.5 to 0.9 ml / g, preferably 0.65 to 0.8 ml / g, and an average pore diameter of 60 to 120 °, preferably 65 to 110 °.
[0019]
The reason is as follows.
The specific surface area of the carrier is 200m²Is less than / g, it becomes difficult to highly disperse the metal due to the bulkiness of the complex formed by the Group 6 metal or Group 8 metal during the impregnation. Presumably, precise control of point formation becomes difficult.
Specific surface area is 500m²If it is larger than / g, the pore diameter becomes extremely small, so that the diameter of the catalyst also becomes small. If the pore diameter of the catalyst is small, the diffusion of the sulfur compound into the pores of the catalyst becomes insufficient, and the desulfurization activity decreases.
[0020]
When the pore volume is less than 0.5 ml / g, a small amount of solvent enters the pore volume when preparing a catalyst by a usual impregnation method. When the amount of the solvent is small, the solubility of the active metal compound is deteriorated, the dispersibility of the metal is reduced, and the catalyst has low activity. In order to increase the solubility of the active metal compound, there is a method of adding a large amount of an acid such as nitric acid. However, if it is added too much, the surface area of the carrier is reduced, which is a main cause of a decrease in desulfurization performance.
When the pore volume is larger than 0.9 ml / g, the specific surface area becomes extremely small, the dispersibility of the active metal becomes poor, and the catalyst has a low desulfurization activity.
[0021]
When the pore diameter is less than 60 °, the pore diameter of the catalyst supporting the active metal also becomes small. If the pore diameter of the catalyst is small, the diffusion of the sulfur compound into the pores of the catalyst becomes insufficient, and the desulfurization activity decreases.
When the pore diameter is larger than 120 °, the specific surface area of the catalyst becomes small. If the specific surface area of the catalyst is small, the dispersibility of the active metal becomes poor, resulting in a catalyst having low desulfurization activity.
[0022]
The group 6 metal contained in the catalyst of the present invention is preferably molybdenum or tungsten, and particularly preferably molybdenum.
Examples of the compound containing a Group 6 metal to be used include molybdenum trioxide, molybdophosphoric acid, ammonium molybdate, molybdic acid, and the like, and preferably molybdenum trioxide and molybdophosphoric acid.
The content of the Group 6 metal is from 10 to 40% by mass, preferably from 16 to 30% by mass, in terms of an oxide on a catalyst basis.
If the amount is less than 10% by mass, it is insufficient to exhibit the effect due to the Group 6 metal, and if it exceeds 40% by mass, the Group 6 metal compound is aggregated in the step of containing (supporting) the Group 6 metal, Not only is the dispersibility of the Group 6 metal deteriorated, but the catalytic activity is not improved because the content of the Group 6 metal that efficiently disperses is exceeded, or the surface area of the catalyst is significantly reduced.
[0023]
The group 8 metal is preferably cobalt or nickel.
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 the like. , A cobalt citrate compound and a nickel citrate compound.
[0024]
As the above cobalt citrate compound, cobaltous citrate (Co₃(C₆H₅O₇)₂), Cobalt hydrogen citrate (CoHC)₆H₅O₇), Cobalt citrate oxysalt (Co₃(C₆H₅O₇)₂.CoO) and the like. Nickel citrate compounds include nickel nickel citrate (Ni₃(C₆H₅O₇)₂), Nickel hydrogen citrate (NiHC₆H₅O₇), Nickel citrate oxysalt (Ni₃(C₆H₅O₇)₂NiO) and the like.
For example, in the case of cobalt, the method for producing these citric acid compounds of cobalt and nickel is obtained by dissolving cobalt carbonate in an aqueous solution of citric acid. The water of the citric acid compound obtained by such a production method may be used as it is for catalyst preparation without removing it.
[0025]
The content of the Group 8 metal is 1 to 15% by mass, and preferably 3 to 8% by mass in terms of an oxide in terms of a catalyst.
When the amount is less than 1% by mass, the active sites belonging to the Group 8 metal cannot be sufficiently obtained. When the amount exceeds 15% by mass, the Group 8 metal compound is aggregated in the step of containing (supporting) the Group 8 metal, and the Group 8 metal In addition to the poor dispersibility of Co, the inert cobalt and nickel species Co₉S₈Seed, Ni₃S₂It is thought that CoO species, NiO species, etc., which are the precursors of the species, and Co spinel species, Ni spinel species, etc. incorporated in the lattice of the carrier are generated. Decreases.
[0026]
In the above content ranges of the Group 8 metal and the Group 6 metal, the optimum mass ratio of the Group 8 metal to the Group 6 metal is preferably [Group 8 metal] / [Group 8 metal + Group 6 metal] in terms of oxide. Is about 0.1 to 0.25.
If this value is less than about 0.1, the formation of CoMoS phase, NiMoS phase and the like, which are considered to be the active points of desulfurization, is suppressed, and the degree of improvement of the desulfurization activity does not increase so much. Of inert cobalt and nickel species (Co₉S₈Seed, Ni₃S₂), And tends to suppress the improvement in the catalytic activity.
[0027]
Examples of the phosphoric acid include various phosphoric acids, specifically, orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, tetraphosphoric acid, polyphosphoric acid, and the like, with orthophosphoric acid being particularly preferred.
The content of phosphorus is 0.8 to 8% by mass, preferably 2 to 5% by mass in terms of oxide on a catalyst basis.
If the amount is less than 0.8% by mass, the Group 6 metal cannot form a heteropolyacid on the catalyst surface, so that MoS which is highly dispersed in₂Is not formed, and it is estimated that the above-mentioned desulfurization active sites cannot be sufficiently arranged. If the content is more than 8% by mass, the Group 6 metal forms a heteropolyacid sufficiently on the catalyst surface, so that the high-quality desulfurization active site is formed by the pre-sulfurization treatment, but excess phosphorus is a poisoning substance. It is presumed to be the main cause of activity decrease because of covering the desulfurization active sites.
As the phosphoric acid, molybdophosphoric acid, which is a compound with a Group 6 metal, can be used. In this case, if the resulting catalyst does not contain phosphorus at the above content, phosphoric acid needs to be further added. There is.
[0028]
Examples of the organic acid include citric acid monohydrate, citric anhydride, isocitric acid, malic acid, tartaric acid and the like.
When citric acid is used as the organic acid, it may be citric acid alone or a citric acid compound with the above-mentioned cobalt or nickel (group 8 metal).
The amount of the organic acid to be added is not particularly limited, but it is preferable that the molar ratio of the organic acid to the group 8 metal is 0.2 to 1.2. When the molar ratio is less than 0.2, the active sites belonging to the group 8 metal may not be sufficiently obtained. When the molar ratio exceeds 1.2, the impregnating liquid has a high viscosity, so that the supporting step requires time. Will be.
When a citrate compound of a Group 8 metal is used, an organic acid is further added when the amount of the organic acid is insufficient.
[0029]
Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, trimethylene glycol, diethylene glycol, trimethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and polyethylene glycol (molecular weight of 1 to 10,000,000).
The amount of the polyhydric alcohol to be added is not particularly limited, but is preferably from 0.1 to 2 in a molar ratio to the active metal. Further, it is preferable that the molar ratio of polyhydric alcohol / group 8 metal to the group 8 metal is 0.1 to 2. When the molar ratio is less than 0.1, the active sites attributed to the Group 8 metal may not be sufficiently obtained. When the molar ratio is more than 2, the impregnating liquid has a high viscosity, so that the supporting step requires time. Become.
[0030]
The organic acid and the polyhydric alcohol are preferably added at the above-mentioned preferable amount, and the content of carbon on the catalyst resulting therefrom is preferably 14% by mass or less, more preferably 10% by mass or less, based on the catalyst. .
If the content is more than 14% by mass, it is presumed that excess carbon covers the desulfurization active sites as a poisoning substance, thereby causing a decrease in activity.
[0031]
In the case where the above-mentioned Group 6 metal compound or Group 8 metal compound is not sufficiently dissolved in the impregnating solution, an acid (nitric acid, organic acid (citric acid, malic acid, tartaric acid, etc.)) is added together with these compounds. It is preferable to use an organic acid, and when an organic acid is used, the carbon obtained by the organic acid may remain in the obtained catalyst. It is important to stay within the range.
[0032]
In the above impregnating solution, the solvent used to dissolve each of the above components is water.
If the amount of the solvent used is too small, the carrier cannot be sufficiently impregnated. If the amount is too large, the solution becomes excessive and the entire amount of the active metal solution cannot be completely impregnated into the carrier. Therefore, the amount of the solvent to be used is appropriately 50 to 90 g, preferably 60 to 85 g, per 100 g of the carrier.
[0033]
The respective components are dissolved in the solvent to prepare an impregnation solution. The temperature at this time may be higher than 0 ° C. and equal to or lower than 100 ° C. If the temperature is within this range, the respective components are preferably dissolved in the solvent. Can be dissolved.
[0034]
The pH of the impregnating solution is preferably less than 5. If it is 5 or more, hydroxyl 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, desulfurization active sites (CoMoS phase, NiMoS phase) Can not be increased significantly.
[0035]
The impregnating solution thus prepared is impregnated on the above-mentioned inorganic oxide carrier, and the above-mentioned components in these solutions are supported on the above-mentioned inorganic oxide carrier.
The impregnation conditions can employ various conditions, and usually, the impregnation temperature is preferably higher than 0 ° C and lower than 100 ° C, more preferably 10 to 50 ° C, and still more preferably 15 to 30 ° C. Is preferably 15 minutes to 3 hours, more preferably 20 minutes to 2 hours, and still more preferably 30 minutes to 1 hour.
If the temperature is too high, drying occurs during the impregnation, and the degree of dispersion is biased.
During the impregnation, it is preferable to stir.
[0036]
After impregnating the impregnating solution on the inorganic oxide carrier as described above and supporting each component therein, a certain amount of water (LOI) is applied at room temperature to about 80 ° C. in a nitrogen stream, an air stream, or a vacuum. << Loss on ignition >> so as to be about 50% or less), and then, in an air stream, a nitrogen stream, or a vacuum, at 200 ° C. or lower, preferably at about 80 to 200 ° C. for about 10 minutes to 24 hours. The drying is carried out at a temperature of about 100 to 150 ° C. for about 5 to 20 hours.
When the drying is performed at a temperature higher than 200 ° C., the organic acid which seems to be complexed with the metal is separated from the surface of the catalyst. As a result, even when the obtained catalyst is subjected to the sulfurating treatment, the above-mentioned active sites (CoMoS phase, It becomes difficult to precisely control the formation of NiMoS phase, etc.₉S₈Seed, Ni₃S₂Seeds and the like are formed, resulting in a catalyst with low desulfurization activity.
[0037]
In producing the catalyst according to the present invention as described above, in order to increase the desulfurization activity of the resulting catalyst for hydrodesulfurization of gas oil, the specific surface area, pore volume and average pore diameter of the obtained catalyst are in the following ranges. It is preferable that
A preferred range of the specific surface area (specific surface area measured by a nitrogen adsorption method (BET method)) is about 100 to 300 m.²/ G, more preferably about 150-280 m²/ G. About 100m²If it is less than / g, a Group 6 metal (a heteropoly acid coordinating with phosphoric acid) and a Group 8 metal (an organometallic complex coordinating with an organic acid) considered to form a complex on the catalyst surface. However, due to the bulkiness of the complex, the dispersion is not sufficiently high. As a result, even if the sulfuration treatment is performed, it becomes difficult to precisely control the formation of the active sites, and the catalyst becomes a catalyst having a low desulfurization activity.²If it is larger than / g, the pore diameter of the catalyst becomes small, and the diffusion of the sulfur compound into the catalyst pores becomes insufficient during the hydrogenation treatment, and the desulfurization activity decreases.
[0038]
A preferred range of the pore volume measured by the mercury intrusion method is about 0.35 to 0.6 m1 / g, more preferably about 0.38 to 0.55 m1 / g. If it is less than about 0.35 m1 / g, during the hydrogenation treatment, the diffusion of sulfur compounds in the pores of the catalyst will be insufficient, resulting in insufficient desulfurization activity. The specific surface area becomes extremely small, the dispersibility of the active metal decreases, and the catalyst has low desulfurization activity.
[0039]
The preferred range of the average pore diameter in the pore distribution measured by the mercury intrusion method is about 65 to 150 °, more preferably about 70 to 130 °. If it is less than about 65 °, the reactants are less likely to diffuse into the pores, and the desulfurization reaction does not proceed efficiently. If it is larger than about 150 °, the diffusivity in the pores is good, but the surface area in the pores decreases. Therefore, the effective specific surface area of the catalyst decreases, and the activity decreases.
[0040]
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 columnar shape, a three-lobe shape, a four-lobe shape, and the like can be adopted. Usually, the size of the catalyst is preferably about 1-2 mm in diameter and about 2-5 mm in length.
The mechanical strength of the catalyst is preferably about 21 bs / mm or more in side fracture strength (SCS << Side Crush Strength >>). If the SCS is smaller than this, the catalyst charged in the reactor is destroyed, and a differential pressure is generated in the reactor, making it impossible to continue the hydrotreating operation.
The compact bulk density (CBD) of the catalyst is preferably about 0.6 to 1.2 (g / ml).
The distribution of the active metal in the catalyst is preferably a uniform type in which the active metal is uniformly distributed in the catalyst.
[0041]
The hydrotreating method of the present invention comprises a hydrogen partial pressure of about 3 to 8 MPa, about 300 to 420 ° C., and a liquid hourly space velocity of about 0.3 to 5 hr.^-1Under the conditions described above, the catalyst obtained by the above production method of the present invention is brought into contact with a gas oil fraction containing a sulfur compound to perform desulfurization, and the sulfur compound containing a hardly desulfurizable sulfur compound in the gas oil fraction is reduced. Is the way.
The product oil obtained by the process of the present invention can have lower sulfur content than by the prior art.
[0042]
In order to carry out the hydrotreating method of the present invention on a commercial scale, a fixed bed, a moving bed, or a fluidized bed type catalyst layer of the catalyst obtained by the production method of the present invention is formed in a reactor. The feedstock may be introduced into the reactor and the hydrogenation reaction may be performed under the above conditions.
Most commonly, a fixed bed catalyst layer is formed in the reactor, the feedstock is introduced into the upper part of the reactor, the fixed bed is passed from top to bottom, and the product flows out from the lower part of the reactor. Things.
Further, a single-stage hydrotreating method in which the catalyst is charged into a single reactor and a multi-stage continuous hydrotreating method in which the catalyst is charged into several reactors may be used.
[0043]
The catalyst obtained by the production method of the present invention is activated by a preliminary sulfurization treatment in a reactor before use (that is, prior to performing the hydrotreating method of the present invention). This sulfurization treatment is carried out in a hydrogen atmosphere at about 200 to 400 ° C., preferably about 250 to 350 ° C., at atmospheric pressure or a hydrogen partial pressure of normal pressure or higher, a petroleum distillate containing sulfur compounds, dimethyl disulfide or disulfide. This is performed using a substance to which a sulfurizing agent such as carbon is added or hydrogen sulfide.
[0044]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.
[0045]
Example 1
Silica and alumina hydrate are kneaded, extruded, and calcined at 600 ° C. for 2 hours to form a silica-alumina composite carrier (silica / alumina mass ratio = 1/99; Pore volume 0.70m1 / g, specific surface area 359m²/ G, average pore diameter 70 °).
3.31 g of cobalt carbonate and 1.72 g of phosphoric acid (85% aqueous solution) were added to 22.5 g of ion-exchanged water, and the mixture was heated to 80 ° C. and stirred for 10 minutes. Next, 8.33 g of molybdenum trioxide, 1.95 g of citric acid monohydrate and 0.7959 g of diethylene glycol were charged and dissolved, and stirred at the same temperature for 15 minutes to prepare a solution for impregnation.
30.0 g of the above-mentioned silica-alumina composite carrier was put into an eggplant-shaped flask, and the entire amount of the above-mentioned impregnating solution was added thereto by a pipette, followed by immersion at about 25 ° C for 3 hours.
Thereafter, it was air-dried in a stream of nitrogen and dried in a muffle furnace at 120 ° C. for about 16 hours to obtain Catalyst A.
[0046]
Example 2
3.31 g of cobalt carbonate, 1.17 g of citric acid monohydrate, 1.11 g of diethylene glycol and 1.73 g of phosphoric acid (85% aqueous solution) were added to 22.5 g of ion-exchanged water, and heated to 80 ° C. Stirred for 10 minutes. Then, 8.33 g of molybdenum trioxide was charged and dissolved, and stirred at the same temperature for 30 minutes to prepare a solution for impregnation. 30.0 g of the same silica-alumina composite carrier as in Example 1 was charged into an eggplant-shaped flask, and the entire amount of the above impregnating solution was added thereto by a pipette, followed by immersion at about 25 ° C. for 3 hours.
Thereafter, it was air-dried in a nitrogen stream and dried in a muffle furnace at 120 ° C. for about 16 hours to obtain a catalyst B.
[0047]
Example 3
To 22.5 g of ion-exchanged water, 3.31 g of cobalt carbonate, 1.95 g of citric acid monohydrate, 8.33 g of molybdenum trioxide, 1.73 g of phosphoric acid, and 0.80 g of triethylene glycol were added, and the mixture was heated to 80 ° C. The mixture was heated and stirred for 30 minutes to prepare a solution for impregnation.
30.0 g of the same silica-alumina composite carrier as in Example 1 was charged into an eggplant-shaped flask, and the entire amount of the above impregnating solution was added thereto by a pipette, followed by immersion at about 25 ° C. for 3 hours.
Thereafter, it was air-dried in a nitrogen stream and dried in a muffle furnace at 120 ° C. for about 16 hours to obtain a catalyst C.
[0048]
Example 4
To 22.5 g of ion-exchanged water, 3.31 g of cobalt carbonate, 1.95 g of citric acid monohydrate, 8.33 g of molybdenum trioxide, 1.73 g of phosphoric acid, and polyethylene glycol 400 ((CH₂CH₂O)_n: Molecular weight 400), and the mixture was heated to 80 ° C. and stirred for 30 minutes to prepare a solution for impregnation.
30.0 g of the same silica-alumina composite carrier as in Example 1 was charged into an eggplant-shaped flask, and the entire amount of the above impregnating solution was added thereto by a pipette, followed by immersion at about 25 ° C. for 3 hours.
Thereafter, it was air-dried in a nitrogen stream and dried in a muffle furnace at 120 ° C. for about 16 hours to obtain Catalyst D.
[0049]
Comparative Example 1
A solution for impregnation was prepared by dissolving 3.31 g of cobalt carbonate, 11.41 g of molybdophosphoric acid, and 1.17 g of orthophosphoric acid in 21.6 g of ion-exchanged water.
Into an eggplant type flask, 30.0 g of a γ-alumina carrier (pore volume 0.69 m1 / g, specific surface area 364 m2 / g, average pore diameter 64 °) is charged, and the entire amount of the above impregnating solution is pipetted there. And soaked at about 25 ° C. for 1 hour.
Thereafter, it was air-dried in a nitrogen stream, dried in a muffle furnace at 120 ° C. for about 1 hour, and calcined at 500 ° C. for 4 hours to obtain a catalyst a.
[0050]
Comparative Example 2
7.45 g of cobalt citrate and 1.17 g of phosphoric acid were added to 20.2 g of ion-exchanged water, heated to 80 ° C., and stirred for 10 minutes. Next, 11.41 g of molybdophosphoric acid was added and dissolved, and the mixture was stirred at the same temperature for 15 minutes to prepare a solution for impregnation.
30.0 g of the same zeolite-alumina composite carrier as in Example 2 was put into an eggplant-shaped flask, and the entire amount of the above impregnating solution was added thereto by a pipette, followed by immersion at about 25 ° C. for 3 hours.
Thereafter, it was air-dried in a nitrogen stream, dried in a muffle furnace at 120 ° C. for about 1 hour, and calcined at 500 ° C. for 4 hours to obtain a catalyst b.
[0051]
Table 1 shows the elemental analysis values and physical properties of the catalysts obtained in the above Examples and Comparative Examples.
The method and analytical equipment used for the analysis of the catalyst are shown below.
[1] Analysis of physical properties
-The specific surface area was measured by the BET method using nitrogen adsorption.
As the nitrogen adsorption device, a surface area measurement device (Bellsorb 28) manufactured by Nippon Bell Co., Ltd. was used.
-The pore volume, average pore diameter, and pore distribution were measured by a mercury intrusion method.
A porosimeter (MICROMERITIC SAUTO-PORE 9200: manufactured by Shimadzu Corporation) was used as a mercury intrusion device.
The measurement was performed by removing the volatile components from the sample at 400 ° C. for 1 hour in a vacuum atmosphere.
[2] Analysis of carbon in catalyst
The measurement of carbon was carried out using a Yanaco CHN coder MT-5 (manufactured by Yanagimoto Seisakusho).
The measuring method was as follows.
(1) Powdering the catalyst in an agate mortar.
(2) 7 mg of the powdered catalyst is put on a platinum board and placed in a firing furnace.
(3) Burn at 950 ° C.
(4) The combustion product gas is led to a differential thermal conductivity meter, and the amount of carbon in the catalyst is determined.
[0052]
[Table 1]

[0053]
(Hydrotreating reaction of straight gas oil)
Using the catalysts A, B, C, D, a, and b prepared in the above Examples and Comparative Examples, hydrogenation treatment of straight-run gas oil having the following properties was performed in the following manner.
First, the catalyst was charged into a high-pressure flow reactor to form a fixed-bed catalyst layer, and was subjected to a preliminary sulfurization treatment 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 part of the reactor, and the hydrogenation reaction proceeds under the following conditions. It was discharged from the lower part of the device, and the generated oil was separated by a gas-liquid separator.
[0054]
Preliminary sulfurization treatment conditions: Liquid sulfurization with a feed oil was performed.
Pressure (hydrogen partial pressure); 4.9 MPa
Atmosphere: hydrogen and feed oil (liquid hourly space velocity 1.5 hr^-1, Hydrogen / oil ratio 200m³(Normal) / kl)
Temperature: Hydrogen and feedstock are introduced at a normal temperature of about 22 ° C., the temperature is raised at 20 ° C./hr, maintained at 300 ° C. for 24 hours, and then raised to the reaction temperature of 350 ° C. at 20 ° C./hr.
[0055]
Hydrogenation reaction conditions:
Reaction temperature; 350 ° C
Pressure (hydrogen partial pressure); 4.9 MPa
Liquid hourly space velocity: 1.5 hr^-1
Hydrogen / oil ratio: 200m³(Normal) / kl
[0056]
Properties of feedstock:
Oil type: Middle eastern straight gas oil
Density (15/4 ° C); 0.8609
Distillation properties: Initial boiling point: 211.5 ° C, 50% point: 314.0 ° C, 90% point: 365.0 ° C, end point: 383.5 ° C
Sulfur component: 1.37% by mass
Nitrogen component: 210 mass ppm
Kinematic viscosity (@ 30 ° C.); 6.570 cSt
Pour point: 5.0 ° C
Cloud point: 6.0 ° C
Cetane index: 54.5
Saybolt color -11
[0057]
The reaction results were analyzed by the following method.
The reactor was operated at 350 ° C., and after 6 days had passed, the product oil was collected and analyzed for its properties.
-Desulfurization reaction rate constant (Ks):
The constant of the reaction rate equation for obtaining the 1.3 order of the reaction with respect to the decrease in the sulfur content (Sp) of the produced oil is defined as the desulfurization reaction rate constant (Ks).
The higher the reaction rate constant, the better the catalytic activity. The results are shown in Table 2.
[0058]
Desulfurization reaction rate constant = [1 / (Sp)^1.3-1−1 / (Sf)^1.3-1] X (LH
SV)
In the formula, Sf: sulfur content in feedstock (% by mass)
Sp: Sulfur content in reaction product oil (% by mass)
LHSV: liquid hourly space velocity (hr^-1)
Specific activity (%) = desulfurization reaction rate constant / desulfurization reaction rate constant of comparative catalyst a × 100
[0059]
[Table 2]

[0060]
As is evident from the above results, the catalyst according to the present invention is effective for the desulfurization reaction of gas oil in the ultra-deep desulfurization region under the same conditions of hydrogen partial pressure and reaction temperature as in the conventional gas oil hydrotreating. Thus, it is found that the composition has extremely excellent activity.
[0061]
【The invention's effect】
According to the present invention, the following effects can be obtained.
(1) Since it has high desulfurization and denitrification activities, the content of sulfur and nitrogen in gas oil can be significantly reduced.
(2) Since the reaction conditions can be made substantially the same as the reaction conditions in the conventional hydrotreating, the conventional apparatus can be diverted without significant modification.
(3) A light oil base material having a low sulfur content and a low nitrogen content can be easily supplied.

Claims (2)

On an inorganic oxide carrier having a specific surface area of 200 to 500 m ² / g, a pore volume of 0.5 to 0.9 m1 / g, and an average pore diameter of 60 to 120 °, at least one selected from Group 8 metals of the periodic table. Using a compound containing at least one compound, a compound containing at least one selected from Group 6 metals of the periodic table, a solution containing an organic acid, a polyhydric alcohol, and phosphoric acid, the catalyst is used, and the periodic rule is calculated in terms of oxide. It is characterized in that a Group 6 metal is supported at 10 to 40% by mass, a Group 8 metal of the Periodic Table is supported at 1 to 15% by mass, and phosphorus is contained at 0.8 to 8% by mass, and dried at 200C or lower. A method for producing a gas oil hydrotreating catalyst. In the presence of the catalyst obtained by the production method according to claim 1, the catalytic reaction of the gas oil fraction is performed under the 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 diesel oil.