JP2000185231A - Catalyst for hydrogenation refining of base oil of lubricating oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst for hydrogenation refining for refining a base oil of lubricating oils advantageously used as a base oil to be a main component of various types of lubricating oils such as engine oils, gear oils for gasoline engines and diesel engines and the likes, working fluids, rolling oils, turbine oils to be employed for various purposes for various types of apparatuses such as construction and machining machinery and the likes. SOLUTION: This catalyst comprises an inorganic oxide containing alumina main component as a carrier, not less than 2 mass % to less than 9 mass % of nickel in conversion into oxide, 18-28 mass % of molybdenum in conversion into oxide, and more than 2 mass % and not more than 9 mass % of phosphorus in conversion into oxide deposited on the carrier. The deposition ratio of nickel/ phosphorus in conversion into oxides is not lower than 0.7 and less than 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to engine oils and gear oils for gasoline engines and diesel engines, and hydraulic oils, rolling oils, and turbine oils used for various purposes in various devices such as construction and machine tools. And a hydrorefining catalyst for refining a lubricating base oil which is advantageously used as a base oil as a main component of various lubricating oils.

[0002]

BACKGROUND ART Various lubricating oils as described above are prepared by mixing various additives with a base oil, and most of the base oils are produced by refining heavy components of petroleum. The refining technology for producing lubricating base oil is a technology in which dewaxed (partially furfural-extracted) feedstock is subjected to catalytic hydrogenation under high temperature and high pressure. This hydrogenation enables desulfurization and denitrification.・ Performs hydrogenation saturation reaction of aroma.

[0003] The performance required of a base oil includes heat and oxidation stability, because a required characteristic of a lubricating oil itself is a high viscosity index with a small change in viscosity with temperature. Therefore, it is necessary to remove aromatic hydrocarbons having a low viscosity index from the base oil. Recently, as a technology for producing a lubricating base oil having a high viscosity index, a method of combining a hydrocracking method with a solvent refining method, and a hydrotreating method with a dewaxing treatment has been proposed. Attempts have been made to reduce or control the aroma content to increase the viscosity index and at the same time to improve the stability against heat, oxidation, etc. (JP-A-3-223392 and JP-A-4-36391). However, none of these methods can efficiently reduce the aroma content.

In recent years, as a part of environmental regulations, strengthening of regulations on carcinogenic substances has been studied, and in particular, polycyclic aromatic compounds (hereinafter abbreviated as PCA) in base oils have been reduced to less than 3% by mass. Reducing it has become a social need. In order to produce such a base oil compatible with low PCA, the conventional catalyst system responds by raising the reaction temperature above the normal operating temperature and reducing the oil flow rate. Is significantly up. Further, it is expected that the life of the catalyst will be shortened as the severity increases.

[0005] By the way, as a hydrorefining catalyst for producing such a low-aromatic base oil, a catalyst in which a metal oxide such as nickel, molybdenum, phosphorus, and tungsten is supported on an alumina carrier, or a catalyst that is supported on a carrier is generally used. A catalyst supporting a noble metal is used.

[0006] A method for producing a lubricating base oil comprises using a catalyst in which at least one metal component selected from nickel, cobalt, molybdenum and tungsten and, if desired, phosphorus are supported on a refractory inorganic oxide carrier. A method for reducing the amount of a four-membered condensed polycyclic aromatic component having a pyrene ring has been proposed (JP-A-8-3571). Further, a proposal is made to produce a lubricating base oil in a fixed bed flow reactor using a catalyst in which 12% by mass of molybdenum, 3% by mass of nickel, and 2.5% by mass of phosphorus are supported on an alumina carrier (Japanese Patent Application Laid-Open (JP-A) No) No. 6-41548). Further, a catalyst system containing nickel and molybdenum on an alumina carrier and alumina +
There is also a proposal for producing a lubricating base oil by hydrocracking in the presence of a catalyst system containing nickel and molybdenum in a Y-type zeolite (Japanese Patent Application Laid-Open No. 8-259974). However, none of these proposals suggests that the amount of supported metal or the supported ratio of the catalyst is optimized, and that the dearomatic activity is insufficient.

[0007]

The object of the present invention is to provide a high-performance hydrorefining catalyst having a high hydrogenation activity for aroma and PCA and a long catalyst life in order to produce a lubricating base oil having a low aroma. The purpose is to do.

[0008]

SUMMARY OF THE INVENTION The inventors of the present invention have conducted various studies to achieve the above-mentioned object, and as a result, among the catalysts for hydrorefining for producing a low-aromatic base oil, an inorganic oxide containing alumina as a main component was used. For catalyst systems that support nickel, molybdenum, and phosphorus oxides using the product as a carrier, it is generally thought that the higher the amount of each metal supported, the higher the activity is, whereas the higher the amount of nickel supported, the higher the activity. Is low and the loading ratio of nickel and phosphorus has a predetermined value, dearomatization and deaeration of PCA
It was found that the activity was dramatically improved.

The catalyst for hydrorefining a lubricating base oil according to the present invention is based on this finding, and comprises an inorganic oxide containing alumina as a main component and a nickel loading of 2% by mass in terms of oxide. Not less than 9% by mass, the amount of molybdenum supported is 18 to 28% by mass in terms of oxide, the amount of phosphorus supported is more than 2% by mass and not more than 9% by mass in terms of oxide, and the mass ratio in terms of oxide. And the loading ratio of nickel / phosphorus is 0.7
It is characterized by being less than 1 or more.

In the present invention, various inorganic oxides containing alumina as a main component as a carrier can be used, for example, alumina, silica-alumina, alumina-alumina.
Zirconia, alumina-titania, alumina-boria,
Alumina-chromia, silica-alumina-tria, silica-alumina-zirconia, silica-alumina-magnesia and the like, preferably, alumina, silica-alumina, alumina-boria, alumina-titania, alumina-zirconia, and more Alumina is preferred, and γ-alumina is particularly preferred as alumina.
These can be used alone or in combination of two or more. The alumina content of the inorganic oxide containing alumina as a main component is 85% by mass or more, preferably 90% by mass or more.

The specific surface area of the carrier comprising these components is as follows:
In the present invention, although not particularly limited, it is preferably 200 m ² / g or more, more preferably 200 to 200 m ² / g.
600m ² / g, particularly preferably 250~500m ² /
g. The pore volume of the carrier is also not particularly limited, but is preferably 0.5 to 0.8 cc / g. The average pore diameter of the carrier is also not particularly limited, but is preferably 50 to 80 °.
It is.

The metal component contained in the carrier is nickel,
Molybdenum. The amount of nickel supported is 2% by mass or more and less than 9% by mass, preferably 3% by mass or more and 9% by mass in terms of oxide.
It is less than 3% by mass, more preferably 3 to 6% by mass, particularly preferably 3 to 5% by mass. If the amount is less than 2% by mass, the active sites attributed to nickel cannot be sufficiently obtained. If the amount is 9% by mass or more, the catalytic activity is not improved because the catalyst surface area and pore volume are significantly reduced. The amount of molybdenum supported is 18 to 28% by mass in terms of oxide, preferably 21 to 28% by mass.
It is 27% by mass, more preferably 22 to 27% by mass, particularly preferably 22 to 26% by mass. If the content is less than 18% by mass, the active sites attributed to molybdenum cannot be sufficiently obtained,
If the content is more than 28% by mass, not only does molybdenum agglomerate and the dispersibility of the active metal deteriorates, but also the catalyst surface area and pore volume are significantly reduced, so that the activity of the catalyst is not improved.

Further, in the present invention, a hydrogenation active component selected from other Group 6A and Group 8 metals of the periodic table can be carried together with the above-mentioned metals.

Further, the amount of phosphorus to be carried together with the metal component is more than 2% by mass and not more than 9% by mass, preferably 4 to 8% by mass, more preferably 4 to 7% by mass, particularly preferably 4 to 7% by mass in terms of oxide. Is 4 to 6.8% by mass. When the content is 2% by mass or less, the active sites attributed to phosphorus cannot be sufficiently obtained,
If the content is more than 9% by mass, not only the dispersibility of the active component is deteriorated, but also the catalyst surface area and the pore volume are significantly reduced, so that the activity of the catalyst is not improved.

Among the above metal components, the loading ratio of nickel / phosphorus (mass ratio in terms of oxide) is 0.7 or more and less than 1, preferably more than 0.7 and less than 1. If it is less than 0.7, sufficient activity cannot be obtained due to insufficient active sites attributed to nickel, and if it is 1 or more, the active sites attributed to phosphorus are insufficient to improve the acidity of the catalyst. Is insufficient, and sufficient activity cannot be obtained.

The catalyst of the present invention is produced by impregnating the above-mentioned carrier with a solution containing the compound of each of the above-mentioned components, and carrying the active component. The following can be used as these compounds. Examples of the molybdenum compound include molybdophosphoric acid, ammonium molybdate, molybdenum oxide, and the like.As the nickel compound,
For example, nickel carbonate, acetate and phosphate may be mentioned, and these may be used alone or in combination of two or more. Examples of the phosphorus compound include various phosphoric acids, and specific examples include orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, tetraphosphoric acid, and polyphosphoric acid.

The solvent for dissolving the metal compound and phosphoric acid is not particularly limited, and various solvents can be used. Examples thereof include water, alcohols, ethers, ketones, and aromatics. , Preferably, water, acetone,
Examples include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, hexanol, benzene, toluene, xylene, diethyl ether, tetrahydrofuran, dioxane and the like, and more preferably water.

The method of loading the active ingredient may be a single-stage loading method in which each component is loaded at once, or a multi-stage loading method in which each component is loaded in multiple stages. The single-stage supporting method is a method of impregnating the carrier with a solution obtained by dissolving the compounds of the respective components at one time, and drying and calcining. Is carried out in multiple stages.

The impregnation conditions may be various conditions in any one-stage or multi-stage loading method.
The temperature is preferably 90 ° C, particularly preferably 70 to 80 ° C, and the impregnation time is preferably 30 minutes or more under this temperature condition. Also,
An impregnation operation with stirring is preferred. In addition, drying, air drying,
It can be performed by various drying methods such as hot air drying, heat drying, and freeze drying. Further, as for the firing conditions, the temperature may be appropriately selected, but generally, preferably 400 to 550 ° C, particularly preferably 450 to 500 ° C, and the firing time is preferably 2 to 10 hours under this temperature condition, and particularly preferably 3 to 3 hours. ~ 5 hours are preferred.

The specific surface area and pore volume of the catalyst of the present invention prepared as described above are not particularly limited as long as they can function as a catalyst. In order to efficiently remove even aroma substances and even hard-to-remov PCA substances, the specific surface area is 160-30.
0 m < ² > / g is preferable, More preferably, it is 180-250.
m ² / g, particularly preferably 180~230m ² / g, pore volume, 0.3~0.8cc / g are preferred,
More preferably, it is 0.3 to 0.6 cc / g.

The average pore size of the catalyst is 60 to 120.
Although it may be about {}, it is preferably 70 to 90 °, more preferably 73 to 80 °. If the average pore size is too large,
Although the diffusivity of the reactants into the pores is good, the effective surface area of the catalyst is small, so that the hydrogenation activity is reduced. If the average pore diameter is too small, difficulties arise in the production of the catalyst, such as insufficient mechanical strength, in order to obtain physical properties (specific surface area, pore volume) necessary for functioning as a catalyst.

The pore size distribution of the catalyst (that is, the proportion of pores having a pore size of average pore size ± 15 °) is preferably at least 70%, more preferably at least 80%. If the value of the pore size distribution is small and the distribution curve is broad, even if the average pore size is an ideal value, the number of effective pores for the reaction is relatively small, and a highly active catalyst No.

The shape of the catalyst is not particularly limited, and may be various shapes usually used for this type of catalyst, for example, various shapes such as a columnar shape and a four-leaf type. The size is usually 1/10 to 1/22 inch in diameter and 3.0 to 3.6 m in length.
m is preferred.

Examples of the feedstock using the catalyst of the present invention include various lubricating oil fractions obtained by further distilling a distillate obtained by further distilling a crude distillation residue from a normal pressure distillation under reduced pressure from a low viscosity to a high viscosity;
A heavy lubricating oil fraction obtained by further removing the asphalt component by subjecting the vacuum distillation residue to a solvent demarcation treatment; a lubricating oil fraction of various viscosities including the heavy lubricating oil fraction; a lubricating oil of various viscosities The fraction may further be treated oil such as solvent extraction and solvent dewaxing; and the like, and these may be used alone or in combination of two or more.

These feedstocks have a boiling point range of 200 to 6
00 ° C, preferably 250 to 580 ° C, more preferably 270 to 550 ° C, and the aroma content is 30% by mass or less, preferably 25% by mass or less, more preferably 23.
The amount is preferably 5% by mass or less, and the PCA content is 20% by mass or less, preferably 15% by mass or less, more preferably 13.5% by mass or less.

The conditions for the hydrogenation reaction of the above feedstock using the catalyst of the present invention are such that the pressure (hydrogen partial pressure) is 130 to 160 kg /
cm ² , preferably 140-150 kg / cm ² , temperature 290-360 ° C., preferably 300-350 ° C., more preferably 320-350 ° C., liquid hourly space velocity (LHS
V) is 0.2 to 1.0 hr ^-1 , preferably 0.3 to 1.0 hr ^-1
0.8 hr ^-1 , more preferably 0.4 to 0.6 hr
^-1 and a hydrogen / oil ratio of 500 to 1600 L / L, preferably 850 to 1100 L / L.

[0027] When the pressure (hydrogen partial pressure) is less than 130 kg / cm ^2, can not be removed until the flame de aroma substances and flame de PCA material, it exceeds 160 kg / cm ^2, the flame de Aroma Not only does the removal efficiency of the substance and the hardly-removable PCA substance become saturated, but also expensive equipment that can withstand such a high pressure is required, which is uneconomical. If the temperature is less than 290 ° C., it is not possible to remove the hard-to-desorb aroma substance and the hard-to-reach PCA substance. It is uneconomical.
If the LHSV exceeds 1.0 hr ⁻¹ , the contact time between the catalyst and the feed oil becomes too short, and the hard-to-desorb aroma substance and hard-to-desorb P
Unable to remove even the CA substance, 0.2 hr
^If it is less than ^-1 , the contact time becomes excessively long, and the processing efficiency is reduced.

The reaction conditions are as follows: the aroma content in the product oil is 2.7 to 3.2% by mass, and the PCA content in the product oil is 2.
It is preferable to select a condition that gives 5 to 3% by mass. Under such conditions, the life of the catalyst is equal to or longer than the life of a typical conventional catalyst, and the catalyst can be used for four years or more in an actual device.

Using the catalyst of the present invention,
To carry out hydrorefining under the above conditions on a commercial scale, the catalyst of the present invention is used in a suitable reactor as a fixed bed, a moving bed or a fluidized bed, and the feedstock is introduced into the reactor. The processing may be performed under predetermined conditions. Most commonly, the catalyst of the present invention is maintained as a fixed bed, with feedstock passing through the fixed bed from top to bottom. Further, the catalyst of the present invention may be used in a single reactor or may be used in several continuous reactors.

[0030]

In the following Examples and Comparative Examples,
Specific surface area 385 m ² / g, pore volume 0.68 cc / g,
Γ-alumina having an average pore diameter of 61 ° was used.

Example 1 In an Erlenmeyer flask, 5.0 g of nickel carbonate was added to an aqueous solution of phosphoric acid in which 4.0 g of phosphoric acid was dissolved in 39.5 g of water, and the mixture was stirred with a stirrer while maintaining the temperature at 75 ° C. 24.5 g of acid were slowly added. The stirring was performed for 1 hour or more. The obtained solution was impregnated with 50 g of an alumina carrier (γ-alumina) in an eggplant type flask. After impregnation, it is dried (air-dried) at room temperature in a stream of nitrogen, and 120 ° C in a stream of air.
For 1 hour at 500 ° C in a muffle furnace.
Calcination was performed for a period of time to obtain Catalyst A.

Example 2 A catalyst B was obtained in the same manner as in Example 1, except that the phosphoric acid was changed to 5.0 g and the molybdophosphoric acid was changed to 20.5 g.

Comparative Example 1 Phosphoric acid was changed to 0.9 g, nickel carbonate to 7.4 g, and molybdophosphoric acid to 24.2 g. After stirring for 1 hour or more, nitric acid was further added and stirring was performed for 1 hour or more. Example 1
Catalyst C was obtained in the same manner as described above.

Comparative Example 2 A catalyst D was obtained in the same manner as in Comparative Example 1, except that the phosphoric acid was changed to 4.2 g, the nickel carbonate to 7.2 g, and the molybdophosphoric acid to 22.8 g.

Comparative Example 3 Nickel carbonate was 7.8 g of cobalt carbonate, and phosphoric acid was 4.1.
g and molybdophosphoric acid were changed to 31.4 g, and a catalyst E was obtained in the same manner as in Comparative Example 1.

Comparative Example 4 In an Erlenmeyer flask, 7.9 g of nickel nitrate was added to an aqueous phosphoric acid solution in which 0.7 g of phosphoric acid was dissolved in 20 g of water.
The mixture was stirred with a stirrer while maintaining the temperature at 5 ° C., and an aqueous solution in which 30 g of ammonium metatungstate was dissolved in 22 g of water was gradually added. The obtained solution was impregnated with 50 g of an alumina carrier (γ-alumina) in an eggplant type flask.
After impregnation, it is dried (air-dried) at room temperature in a nitrogen stream, dried at 120 ° C. for 1 hour in an air stream, and then dried in a muffle furnace for 50 hours.
Calcination was performed at 0 ° C. for 4 hours to obtain a catalyst F.

[0037]

[Table 1]

[0038]

[Table 2]

[Catalyst Performance Evaluation Example 1] The performances of the catalysts A to F obtained in the above Examples and Comparative Examples were measured using a microreactor reactor under the conditions shown in Table 3 for a dearomatization reaction. Evaluated by relative activity. The results are shown in Table 4.

[0040]

Table 3-Feedstock: Sample for dearoma test Density (15 ° C); 0.8710 g / cm ³ Kinematic viscosity (40 ° C); 33.53 mm ² / s Sulfur content: 0.55 mass% Aroma content: 23 0.5% by mass PCA content; 0.4% by mass Reaction condition: amount of catalyst: 15 cc Hydrogen partial pressure; 14.71 MPa Reaction temperature; 320 to 350 ° C. (heating at every 10 ° C.) LHSV: 0.557 hr ⁻¹ hydrogen / Oil ratio; 1011 L / L ・ Evaluation method: Measure the aroma content of the raw material oil and the aroma content of the product oil obtained by reacting under the above conditions, and calculate the reaction rate from these values based on the equation The constant (k) was determined, and the relative activity of each catalyst was evaluated using this constant.

The method for measuring the aroma was as follows. First, a sample diluted in isooctane was measured using an ultraviolet-visible spectrophotometer, and the absorbance at the maximum absorption was measured to determine the extinction coefficient, thereby obtaining a conversion formula correlated with the aroma component. Next, UV measurement of the sample diluted to a specified concentration was performed, and the obtained absorbance was substituted into this conversion formula to calculate an aroma component.

[0042]

K = LHSV × ln (Co / C) k: reaction rate constant Co: aroma content in raw material C: aroma content in product oil

The relative activities in Table 4 are represented by kα / kβ, where α is the target catalyst, β is the reference catalyst,
Here, the catalyst C is used as a reference catalyst, and the activity of the catalyst C is 1
00.

[0044]

[Table 4]

[Catalyst Performance Evaluation Example 2] The performances of the catalysts A to F obtained in the above Examples and Comparative Examples were measured using the microreactor reactor under the conditions shown in Table 5 for the de-PCA reaction. The relative activity was evaluated. The results are shown in Table 6.

[0046]

Table 5-Feedstock: Sample for de-PCA test Density (15 ° C); 0.8885 g / cm ³ Kinematic viscosity (40 ° C); 10.62 mm ² / s Sulfur content; 1.65 mass% PCA content; 13 Reaction conditions: amount of catalyst; 15 cc hydrogen partial pressure; 14.71 MPa reaction temperature; 320 to 350 ° C. (heating every 10 ° C.) LHSV: 0.557 hr- ¹ hydrogen / oil ratio; 1011 L / L Evaluation method: The PCA component of the feedstock oil and the PCA component of the product oil obtained by reacting under the above conditions were measured, and from these values, the reaction rate constant (k) was calculated based on the equation (2). The relative activity of each catalyst was evaluated using constants.

The method for measuring PCA is IP346.
The procedure was performed as specified in

[0048]

K = LHSV × [(1 / C) − (1 / Co)] k: reaction rate constant Co: PCA content in raw material C: PCA content in product oil

The relative activities in Table 6 are represented by kα / kβ, where α is the target catalyst, β is the reference catalyst,
Here, the catalyst C is used as a reference catalyst, and the activity of the catalyst C is 1
00.

[0050]

[Table 6]

[0051]

According to the present invention, dearomatization and dePCA
It is possible to provide a highly active catalyst for hydrorefining lubricating base oils having very high activity. Further, since the reaction temperature can be kept low by increasing the activity of the catalyst, the production of a lubricating base oil can be carried out smoothly using the catalyst of the present invention. Therefore, by using the highly active catalyst of the present invention, the processing capacity can be greatly improved.

Continued on the front page (72) Inventor Hiroshi Mizutani 1134-2, Gongendo, Satte City, Saitama Prefecture Inside the R & D Center of Kosmo Research Institute, Inc. (72) Inventor Koichi Kondo 1134-2, Gongendo, Satte City, Saitama Prefecture Inside the R & D Center of Sumo Research Institute (72) Inventor Takashi Fujikawa 1134-2 Gongendo, Satte City, Saitama Prefecture Inside of the R & D Center Kosumo Research Institute Co., Ltd. (72) Yoshihiro Mizutani 1134- Gongendo, Satte City, Saitama Prefecture 2 F-term in R & D Center, Kosmo Research Institute, Inc. (reference) 4G069 AA03 AA08 BA01A BA01B BB14B BB16B BC59A BC59B BC68A BC68B BD07A BD07B CC02 DA06 FB14 FC08

Claims (1)

[Claims] An inorganic oxide containing alumina as a main component is used as a carrier, and the supported amount of nickel is 2% by mass or more and less than 9% by mass in terms of oxide, and the supported amount of molybdenum is 18% in terms of oxide.
-28% by mass, the amount of phosphorus supported is more than 2% by mass and not more than 9% by mass in terms of oxide, and the supported ratio of nickel / phosphorus is 0.7 or more and less than 1 in terms of mass ratio in terms of oxide. Catalyst for hydrorefining of oil base oil.