KR102161426B1 - Method for producing lubricant base oil and lubricant base oil - Google Patents

Abstract

It provides a method for producing a base oil for a lubricating oil capable of producing a base oil for a lubricating oil having a high viscosity index in a high yield. One embodiment of the method for producing a base oil for lubricating oil according to the present invention is hydrogenation of petroleum-derived hydrocarbon oil at a reaction temperature of 250 to 420°C in an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa, so that the aromatic hydrocarbon content is 10 And a step of preparing an oil to be treated in an amount of from 25% by mass to a step of performing hydroisomerization of the oil to be treated.

Description

Manufacturing method of base oil for lubricating oil and base oil for lubricating oil {METHOD FOR PRODUCING LUBRICANT BASE OIL AND LUBRICANT BASE OIL}

The present invention relates to a method for producing a base oil for lubricating oil and a base oil for lubricating oil.

In the production of base oil for lubricating oil using petroleum as a raw material, for example, a vacuum distillation process, a solvent extraction process, a hydrodesulfurization process, an isomerization dewaxing process (hydroisomerization process), and a hydrogenation finishing process, etc. are performed in this order. Conduct. Hydrocarbon oils such as vacuum gas oil obtained by vacuum distillation contain aromatic hydrocarbons that impair the oxidation stability of the base oil for lubricating oil. This aromatic hydrocarbon is extracted with a solvent such as furfural and removed from the hydrocarbon oil. In hydrodesulfurization, sulfur or the like, which is a catalyst poison of the catalyst for isomerization dewaxing, is removed from the hydrocarbon oil. By isomerization dewaxing, the wax component (normal paraffin) in the hydrocarbon oil is converted into isoparaffin or the like, thereby improving the low-temperature fluidity of the hydrocarbon oil. The hydrogenation finish improves the quality of the hydrocarbon oil, such as hue and oxidation stability (see, for example, Patent Document 1).

Japanese Patent Publication No. 2001-525861

The present invention has been made in view of the problems of the prior art, and provides a method for producing a base oil for lubricating oil capable of producing a base oil for lubricating oil having a high viscosity index in high yield, and a base oil for lubricating oil obtained by the production method. It aims to provide.

One embodiment of the method for producing a base oil for lubricating oil according to the present invention is hydrogenation of petroleum-derived hydrocarbon oil at a reaction temperature of 250 to 420°C in an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa, so that the aromatic hydrocarbon content is 10 It includes a step of preparing an oil to be treated, which is 25% by mass, and a step of performing hydroisomerization of the oil to be treated.

In one embodiment of the present invention, it is preferable to hydroisomerize the oil to be treated in an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa.

In one embodiment of the present invention, it is preferable to hydroisomerize the oil to be treated at a reaction temperature of 200 to 450°C.

One form of the base oil for lubricating oil according to the present invention is produced by the above production method.

According to the present invention, there is provided a method for producing a base oil for lubricating oil capable of producing a base oil for lubricating oil having a high viscosity index in a high yield, and a base oil for lubricating oil obtained by the production method.

Hereinafter, preferred embodiments of the present invention will be described. However, this invention is not limited at all to the following embodiment.

In the method for producing a base oil for lubricating oil according to the present embodiment, a vacuum distillation step, a solvent extraction step, a hydrogenation treatment step, an isomerization dewaxing step (hydrogenation isomerization step), a hydrogenation finishing step, and a purification step are performed in this order. However, in the case of producing a base oil for lubricating oil having a kinematic viscosity of 1.5 to 3.0 mm 2 /s at 100 °C, and a base oil for lubricating oil having a kinematic viscosity of 3.0 to 5.5 mm 2 /s at 100 °C, distillation under reduced pressure without performing a solution extraction process After the step, a hydrodesulfurization step and a hydroisomerization step may be performed. In addition, when producing a lubricating base oil having a kinematic viscosity of 15.0 to 40.0 mm 2 /s at 100°C, an atmospheric distillation process, a reduced pressure distillation process, a solvent deasphalting process, a solvent extraction process, a hydrogenation treatment process, an isomerization dewaxing process (hydroisomerization process ), hydrogenation finishing process and purification process may be performed in this order.

(Pressure distillation process)

In the vacuum distillation step, petroleum-derived hydrocarbon oil (hereinafter referred to as "hydrocarbon oil") such as vacuum gas oil (VGO) is obtained by vacuum distillation of petroleum-based raw material oil such as atmospheric residual oil. do.

(Solvent extraction process)

In the solvent extraction step, a part of the aromatic hydrocarbon in the hydrocarbon oil is extracted into the solvent using an extraction column and removed. By the solvent extraction process, the color, viscosity index, and oxidation stability of the base oil for lubricating oil can be improved. The solvent is not particularly limited as long as it selectively dissolves the component to be extracted (the component to be extracted), has high solubility of the component to be extracted, is easy to separate from the component to be extracted, and has little toxicity and corrosion. Specific examples of the solvent include furfural, phenol, N-methyl-2-pyrrolidinone, tetrahydrofuran, and the like. Among these solvents, it is preferable to use furfural for extraction of aromatic hydrocarbons. The operating conditions of the extraction tower using furfural are controlled by the solvent ratio (the volume of the solvent when the volume of hydrocarbon oil is 100) and the extraction temperature. The solvent ratio may be about 100 to 400, and the extraction temperature may be about 30 to 150°C.

(Solvent deasphalting process)

In the solvent deasphalting step, the asphalt component in the residual oil (reduced pressure residual oil) from the reduced pressure distillation column is removed. By a solvent deasphalting process, a heavy oil component suitable for a high viscosity lubricating oil and an asphalt component are separated to produce a lubricant raw material. A common solvent deasphalting method is a propane deasphalting process (PDA). In the PDA method, raw material oil is supplied to the upper portion of the deasphalt tower, and propane (liquid) as a solvent is supplied to the lower portion of the deasphalt tower. Since there is a specific gravity difference between the raw material oil and the propane, light propane rises in the tower while absorbing oil suitable for the lubricating oil, and asphalt powder that is not absorbed by the propane falls. In the deasphalting tower, a baffle plate or a rotating disk is used to mix the raw material oil and propane, and deasphalting is efficiently performed. The solvent ratio (the ratio of propane added to the raw material oil) in the solvent deasphalting step is 300 to 600%, and the temperature of the extraction column is about 50 to 85°C. Deasphalted oil (suitable for high-viscosity lubricating oil) absorbed by propane is extracted from the upper part of the deasphalted tower, and asphalt is extracted from the lower part of the deasphalted tower. By separating propane from each of the deasphalted oil and asphalt extracted from the extraction tower in a solvent absorption system, desired deasphalted oil and asphalt are produced.

(Hydrogenation treatment process)

<Characteristics of hydrocarbon oil>

In the hydrotreating process, hydrogenation treatment of hydrocarbon oils having different properties is performed according to the specifications of the target base oil for lubricating oil. Hydrocarbon oil having a desired property can be prepared by selection of a petroleum-based raw material oil, a vacuum distillation step or a solvent extraction step.

Base oils for lubricating oils suitable for Group II standards determined by API (American Petroleum Institute) are as follows. Among the base oils for lubricating oils that satisfy this standard, for example, lubricating base oils having properties of the following lubricating base oil fractions 1 to 5 can be produced by the present embodiment.

[Classification of base oil by API (Group II)]

Viscosity Index (VI): 80 or more and less than 120

Saturated content: 90% by mass or more

Sulfur content: 0.03% by mass or less

In addition, VI means Viscosity Index.

<<Lubricating oil fraction 1>>

The kinematic viscosity of the lubricating oil fraction 1 at 100°C is 1.5 to 3.0 mm 2 /s, preferably 2.0 to 3.0 mm 2 /s. In addition, the viscosity index (VI) of the lubricating oil fraction 1 is preferably 90 or more, more preferably 95 or more, and particularly preferably 100 or more. The pour point of the lubricating oil fraction 1 is preferably -10.0°C or less, and more preferably -15.0°C or less. It is preferable that the boiling point range of the lubricating oil fraction 1 is 330 to 390°C.

<<Lubricant oil 2>>

The kinematic viscosity of the lubricating oil fraction 2 at 100°C is 3.0 to 5.5 mm 2 /s, preferably 3.5 to 5.0 mm 2 /s. Further, the viscosity index (VI) of the lubricating oil fraction 2 is preferably 90 or more, and more preferably 100 or more. The pour point of the lubricating oil fraction 2 is preferably -5.0°C or less, and more preferably -10.0°C or less. It is preferable that the boiling point range of the lubricating oil fraction 2 is 390 to 450°C. Lubricant oil fraction 2 may meet the viscosity standard of SAE-10 oil fraction of engine oil specified by the Society of Automotive Engineers (SAE).

<<Lubricant oil 3>>

The kinematic viscosity at 100° C. of the lubricating oil fraction 3 is 5.5 to 9.0 mm2/s, preferably 6.0 to 8.5 mm2/s. Further, the viscosity index (VI) of the lubricating oil fraction 3 is preferably 90 or higher, and more preferably 100 or higher. The pour point of the lubricating oil fraction 3 is preferably -5.0°C or less, more preferably -10.0°C or less. The boiling point range of the lubricating oil fraction 3 is preferably 450 to 480°C. Lubricating oil fraction 3 can meet the viscosity standard of SAE-20 oil, which is an engine oil regulated by SAE.

<<Lubricating oil fraction 4>>

The kinematic viscosity at 100° C. of the lubricating oil fraction 4 is 9.0 to 15.0 mm 2 /s, preferably 9.5 to 13.0 mm 2 /s. Further, the viscosity index (VI) of the lubricating oil fraction 4 is preferably 90 or higher, and more preferably 100 or higher. The pour point of the lubricating oil fraction 4 is preferably -5.0°C or less, more preferably -10.0°C or less. It is preferable that the boiling point range of lubricating oil fraction 4 is 480 to 550°C. Lubricating oil fraction 4 can meet the viscosity specifications of SAE-30 oil, which is an engine oil regulated by SAE.

<<Lubricant oil 5>>

The kinematic viscosity at 100° C. of the lubricating oil fraction 5 is 15.0 to 40.0 mm 2 /s, preferably 20.0 to 35.0 mm 2 /s. Further, the viscosity index (VI) of the lubricating oil fraction 5 is preferably 90 or more, and more preferably 100 or more. The pour point is preferably -5.0°C or less, and more preferably -10.0°C or less. The boiling point range is preferably 550°C or higher.

(Hydrogenation treatment process)

In this embodiment, it is preferable to perform hydrogenation treatment of hydrocarbon oil having a boiling point range of 310 to 680°C, and more preferably performing hydrogenation treatment of hydrocarbon oil having a boiling point range of 320 to 650°C.

For example, when producing a lubricating oil base oil corresponding to the lubricating oil fractions 1 to 5, it is more preferable to perform hydrogenation treatment of a hydrocarbon oil having the following properties.

In the case of producing the base oil for lubricating oil of lubricating oil fraction 1, it is preferable to perform hydrogenation treatment of hydrocarbon oil having the following properties.

Boiling point range: 310 to 490°C, preferably 320 to 480°C.

10% outflow temperature (T10): 345 to 385°C.

90% outlet temperature (T90): 415 to 455°C.

Kinematic viscosity (Vis) at 100°C: 1.5 to 4.0 mm 2 /s.

Viscosity Index (VI): 50 to 130.

In the case of producing the base oil for lubricating oil of lubricating oil fraction 2, it is preferable to perform hydrogenation treatment of hydrocarbon oil having the following properties.

Boiling point range: 320 to 490°C, preferably 330 to 480°C.

10% outlet temperature (T10): 365-405°C.

90% outlet temperature (T90): 445 to 475°C.

Kinematic viscosity (Vis) at 100°C: 3.0 to 6.5 mm 2 /s.

Viscosity Index (VI): 50 to 130.

In the case of producing the base oil for lubricating oil of lubricating oil fraction 3, it is preferable to perform hydrogenation treatment of a hydrocarbon oil having the following properties.

Boiling point range: 340 to 530°C, preferably 350 to 520°C.

10% outlet temperature (T10): 410 to 450°C.

90% outlet temperature (T90): 475 to 505°C.

Kinematic viscosity at 100°C (Vis): 5.5 to 10.0 mm 2 /s.

Viscosity Index (VI): 50 to 130.

In the case of producing the base oil for lubricating oil of lubricating oil fraction 4, it is preferable to perform hydrogenation treatment of hydrocarbon oil having the following properties.

Boiling point range: 360 to 600°C, preferably 370 to 590°C.

10% outlet temperature (T10): 435 to 475°C.

90% outlet temperature (T90): 545 to 575°C.

Kinematic viscosity (Vis) at 100°C: 5.0 to 10.0 mm 2 /s.

Viscosity Index (VI): 50 to 130.

In the case of producing the base oil for lubricating oil of lubricating oil fraction 5, it is preferable to perform hydrogenation treatment of hydrocarbon oil having the following properties.

Boiling point range: 380 to 680°C, preferably 390 to 650°C.

10% outlet temperature (T10): 515 to 545°C.

90% outlet temperature (T90): 625 to 645°C.

Kinematic viscosity (Vis) at 100°C: 15.0 to 41.0 mm 2 /s.

Viscosity Index (VI): 50 to 130.

<Different conditions of the hydrogenation process>

In the hydrogenation process, hydrocarbon oil is brought into contact with the hydrogenation catalyst at a reaction temperature of 250 to 420°C in an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa. Thereby, the oil to be treated having an aromatic hydrocarbon content of 10 to 25% by mass is prepared. The content of the aromatic hydrocarbon in the oil to be treated is preferably 10.0 to 18.0% by mass.

In addition, the "hydrogenation treatment" in this embodiment mainly aims at adjusting the content of the aromatic hydrocarbon in the hydrocarbon oil within the above range by hydrogenation of the aromatic hydrocarbon. However, in the hydrogenation process, reactions such as desulfurization and denitrification may proceed. By such a reaction, sulfur content or nitrogen content, which is a catalyst poison of the hydroisomerization catalyst, is removed from the hydrocarbon oil, and the life of the hydroisomerization catalyst is improved. In addition, in the hydrotreating process, in addition to the hydrogenation of the aromatic hydrocarbon, hydrocracking and hydroisomerization of the wax component in the hydrocarbon oil may proceed.

Naphthenes are produced by hydrogenation of aromatic hydrocarbons. Naphthene has a lower kinematic viscosity than aromatic hydrocarbons having the same carbon number as this. Therefore, as the content of the aromatic hydrocarbon in the hydrogenated hydrocarbon oil (oil to be treated) decreases, the content of naphthene in the oil to be treated increases, and the kinematic viscosity of the oil to be treated tends to decrease. For the same reason, the kinematic viscosity of the lubricating base oil fraction finally obtained through various processes (hydroisomerization process, hydrogenation finishing process and refining process) after the hydrogenation process is also lowered. For example, in the case of manufacturing a base oil for lubricating oil having a high kinematic viscosity such as the lubricating oil fraction 4, by introducing a light oil having a low kinematic viscosity to the final lubricating base oil fraction, a base oil for lubricating oil whose kinematic viscosity is adjusted to a value suitable for the standard There are cases. However, when the kinematic viscosity of the final lubricating base oil fraction is low, the kinematic viscosity of the lubricating base oil fraction is likely to be lower than the standard value by mixing with light oil. Accordingly, the lower the kinematic viscosity of the final lubricating oil base oil fraction, the less the amount of light oil that can be contained in the lubricating oil base oil fraction, thereby reducing the yield of the target lubricating oil base oil. In other words, as the content of the aromatic hydrocarbon in the hydrocarbon oil (oil to be treated) after hydrogenation is lower, the yield of the base oil for lubricating oil having a high kinematic viscosity tends to decrease.

However, in the present embodiment, since the content of the aromatic hydrocarbon in the oil to be treated obtained after the hydrogenation process is 10% by mass or more, the above problems are solved, and a base oil for a lubricating oil having a desired high kinematic viscosity is produced in a high yield. It becomes possible.

Naphthene produced by hydrogenation of an aromatic hydrocarbon has a higher viscosity index than that of an aromatic hydrocarbon having the same carbon number as this. Therefore, as the content of the aromatic hydrocarbon in the hydrogenated hydrocarbon oil (oil to be treated) increases, the content of naphthene in the oil to be treated decreases, and the VI of the oil to be treated tends to decrease. Accordingly, the higher the content of aromatic hydrocarbons in the hydrocarbon oil (oil to be treated) after the hydrogenation treatment, the lower the VI of the base oil for lubricating oil finally obtained through various steps after the hydrogenation treatment process.

However, in this embodiment, since the content of the aromatic hydrocarbon in the oil to be treated obtained after the hydrogenation process is 25% by mass or less, the above problems are solved, and the base oil for lubricating oil having a desired high VI can be produced in a high yield. It becomes possible. In addition, since the aromatic hydrocarbon serves as a catalyst poison for the catalyst for hydroisomerization performed after the hydrogenation process, poisoning of the catalyst for hydroisomerization can be suppressed by the content of the aromatic hydrocarbon in the oil to be treated is 25% by mass or less.

In the hydrogenation process, a hydrocarbon oil is brought into contact with a catalyst for hydrogenation in an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa. The partial pressure of hydrogen is preferably 11.1 to 19.5 MPa, more preferably 11.1 to 19 MPa.

When the hydrogen partial pressure in the hydrogenation process is too low, the hydrogenation reaction of the aromatic hydrocarbon is difficult to occur, and the content of the aromatic hydrocarbon in the oil to be treated tends to exceed the above upper limit. In addition, when the partial pressure of hydrogen in the hydrogenation process is low, there is a tendency that a desulfurization reaction and a denitrification reaction are less likely to occur. On the other hand, when the hydrogen partial pressure is too high, the hydrogenation of the aromatic hydrocarbon is excessively accelerated, and the content of the aromatic hydrocarbon in the oil to be treated after the hydrogenation tends to be lower than the above lower limit.

In the hydrotreating process, hydrocarbon oil is brought into contact with the hydrotreating catalyst at a reaction temperature of 250 to 420°C. The reaction temperature is preferably 260 to 420°C, more preferably 270 to 410°C, and particularly preferably 280 to 400°C. The reaction temperature may be 300 to 365°C or 330 to 365°C. On the other hand, the reaction temperature is, for example, the temperature of the catalyst layer composed of a catalyst for hydrogenation.

When the reaction temperature in the hydrogenation process is too low, the hydrogenation reaction of the aromatic hydrocarbon is difficult to occur, and the content of the aromatic hydrocarbon in the oil to be treated tends to exceed the above upper limit. In addition, when the reaction temperature in the hydrogenation process is too low, there is a tendency that the desulfurization reaction and the denitrification reaction are less likely to occur. On the other hand, when the reaction temperature is too high, the hydrogenation of the aromatic hydrocarbon is excessively accelerated, and the content of the aromatic hydrocarbon in the oil to be treated after the hydrogenation tends to be lower than the above lower limit. In addition, when the reaction temperature is too high, the decomposition of the wax component in the hydrocarbon oil into the light component proceeds excessively, and the yield of the intermediate fraction and the heavy component decreases.

As described above, with respect to the increase or decrease in the content of the aromatic hydrocarbon in the oil to be treated, the kinematic viscosity and yield of the base oil for lubricating oil have a trade-off relationship. In this embodiment, by preparing the oil to be treated having an aromatic hydrocarbon content of 10 to 25% by mass by the hydrogenation process, it becomes possible to achieve both high VI and high yield of the base oil for lubricating oil. In this embodiment, especially in the case of manufacturing the base oil for lubricating oil of SAE-30, the product of the viscosity index (VI) and the yield (Y) (VI Y) can be produced in the range of 6000 to 7500 lube base oil. It becomes. In this case, the viscosity index (VI) is preferably 100 to 150, and the yield (Y) is preferably 55 to 100% by mass.

In addition, the yield (Y) (unit: mass %) of the base oil for lubricating oil is defined by the following equation, for example.

Y=(V _L /V _R )×100

In the above equation, V _L is the mass of the finally obtained base oil for lubricating oil. V _R is the mass of the oil to be treated obtained in the hydrogenation step, and is the mass of the oil to be treated before the hydroisomerization step. For example, when Y is the yield of the base oil for lubricating oil of the lubricating base oil fraction 4, V _L is, among the oils obtained by the hydrotreating process, hydroisomerization process, hydrogenation finishing process, and distillation process (refining process), the lubricant base oil It is the mass of the base oil fraction of fraction 4.

The content of the aromatic hydrocarbon in the hydrocarbon oil before the hydrogenation process is preferably 25 to 50% by mass, more preferably 26 to 48% by mass. In this case, it becomes easy to adjust the content of the aromatic hydrocarbon in the oil to be treated obtained in the hydrogenation step within the range of 10 to 25% by mass. The content of the aromatic hydrocarbon in the hydrocarbon oil before the hydrotreating process is freely controlled by selection of the petroleum-based raw material oil or by various processes before the hydrotreating process (for example, a solvent extraction process).

The content of the sulfur content in the oil to be treated obtained in the hydrogenation step is preferably 1 to 100 ppm by mass, more preferably 3 to 80 ppm by mass, and particularly preferably 6 to 65 ppm by mass. When the content of the sulfur content is within the above range, the effect of the present invention becomes remarkable. When the content of the sulfur content is within the above range, deactivation of the hydroisomerization catalyst is suppressed. When the content of the sulfur content is within the above range, it becomes easy to obtain a base oil for lubricating oil having a low content of the sulfur content. On the other hand, the content of the sulfur content in the oil to be treated may be measured by, for example, a method prescribed by JIS K2541 or the like.

The content of the sulfur content in the hydrocarbon oil before the hydrogenation process is preferably 50 to 30000 ppm by mass, more preferably 100 to 25000 ppm by mass. In this case, it becomes easy to adjust the content of the sulfur content in the oil to be treated obtained in the hydrotreating step within the above numerical range. The content of the sulfur content in the hydrocarbon oil before the hydrogenation process depends on the composition of the petroleum-based raw material oil.

The kinematic viscosity at 100°C of the oil to be treated obtained in the hydrogenation process is preferably about 1.5 to 40.0 mm 2 /s, more preferably 2.0 to 38.0 mm 2 /s. The viscosity index (VI) of the oil to be treated is preferably 85 to 140, more preferably 90 to 130. When the kinematic viscosity and viscosity index of the oil to be treated are within the above numerical ranges, it becomes easy to obtain a base oil for lubricating oil having a desired kinematic viscosity and viscosity index in high yield.

The liquid space velocity (LHSV) of the hydrocarbon oil in the hydrogenation process is about 0.1 to 4h ^-1 , preferably 0.25 to 3h ^-1 . When the LHSV is less than 0.1h ^-1 , the throughput is low, resulting in poor productivity and not practical. On the other hand, when the LHSV exceeds 4h ^-1 , since it is necessary to increase the reaction temperature, the catalyst for hydrogenation treatment is liable to deteriorate.

The hydrogen/hydrocarbon ratio in the hydrogenation process is about 100 to 2000 Nm 3 /m 3, and preferably 200 to 1000 Nm 3 /m 3. When the hydrogen/oil ratio is less than 100Nm3/m3, the desulfurization activity of the catalyst for hydrogenation treatment tends to decrease. On the other hand, when the hydrogen/oil ratio exceeds 2000 Nm 3 /m 3, there is no significant change in the desulfurization activity, but the operating cost increases.

In the present embodiment, after the hydrogenation process, in a state in which the pressure in the reactor subjected to the hydrogenation treatment is adjusted to be less than or equal to the pressure during the hydrogenation treatment, more preferably, in a state in which the pressure during the hydrogenation treatment is lowered by 1 MPa or more, the features in the reactor It is preferable to remove gaseous substances (hydrogen sulfide, ammonia, steam, etc.) from the oil. After removal of the gaseous substance, it is preferable to perform a hydroisomerization process.

On the other hand, in order to obtain lubricating oil base oil fractions 1 to 5, it is preferable to perform a hydrogenation treatment step under the following conditions.

<Conditions of the hydrogenation process in the case of lubricant base oil fraction 1>

In order to obtain a lubricating oil base oil fraction having a kinematic viscosity of 1.5 to 3.0 mm 2 /s at 100°C, a viscosity index of 90 or more, and 0.03 mass% or less of a sulfur content from a hydrocarbon oil obtained by solvent extraction of the vacuum gas oil obtained in the vacuum distillation step, in the hydrogenation treatment step, In an atmosphere where the partial pressure of hydrogen is 11 to 20 MPa, it is preferable to contact a hydrocarbon oil at a reaction temperature of 280 to 420°C with a catalyst for hydrogenation. More preferably, the partial pressure of hydrogen is 11 to 15 MPa, and the reaction temperature is 280 to 400°C. This makes it possible to prepare an oil to be treated having an aromatic hydrocarbon content of 10 to 25% by mass, preferably 10 to 18% by mass. LHSV is about 0.1 to 4h ^-1 , preferably 0.5 to 2h ^-1 . The hydrogen/hydrocarbon ratio in the hydrogenation process is about 100 to 2000 Nm 3 /m 3, and preferably 200 to 1000 Nm 3 /m 3.

A lubricating oil base oil fraction having a kinematic viscosity at 100°C of 1.5 to 3.0 mm 2 /s, a viscosity index of 90 or more, and a sulfur content of 0.03 mass% or less is obtained from a hydrocarbon oil obtained by solvent extraction of the vacuum gas oil obtained in the vacuum distillation step without performing the solvent extraction step. In order to do this, in the hydrogenation process, it is preferable to bring the hydrocarbon oil into contact with the hydrogenation catalyst at a reaction temperature of 280 to 420°C in an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa. More preferably, the partial pressure of hydrogen is 15 to 18 MPa, and the reaction temperature is 280 to 400°C. This makes it possible to prepare an oil to be treated having an aromatic hydrocarbon content of 10 to 25% by mass, preferably 10 to 18% by mass. LHSV is about 0.1 to 4h ^-1 , preferably 0.5 to 2h ^-1 . The hydrogen/hydrocarbon ratio in the hydrogenation process is about 100 to 2000 Nm 3 /m 3, and preferably 200 to 1000 Nm 3 /m 3.

<Conditions of the hydrogenation process in the case of lubricant base oil fraction 2>

In the case of obtaining a lubricating base oil fraction having a kinematic viscosity of 3.0 to 5.5 mm 2 /s at 100°C, a viscosity index of 90 or more, and 0.03 mass% or less of a sulfur content from a hydrocarbon oil obtained by solvent extraction of the vacuum gas oil obtained in the distillation process, in the hydrogenation process, hydrogen In an atmosphere in which the partial pressure of is 11 to 20 MPa, the hydrocarbon oil is preferably brought into contact with the catalyst for hydrogenation at a reaction temperature of 300 to 420°C. More preferably, the partial pressure of hydrogen is 11 to 15 MPa, and the reaction temperature is 310 to 360°C. This makes it possible to prepare an oil to be treated having an aromatic hydrocarbon content of 10 to 25% by mass, preferably 10 to 18% by mass. LHSV is about 0.1 to 4h ^-1 , preferably 0.5 to 2h ^-1 . The hydrogen/hydrocarbon ratio in the hydrogenation process is about 100 to 2000 Nm 3 /m 3, and preferably 200 to 1000 Nm 3 /m 3.

When obtaining a lubricating base oil fraction having a kinematic viscosity of 3.0 to 5.5 mm 2 /s at 100°C, a viscosity index of 90 or more, and a sulfur content of 0.03% by mass or less from the hydrocarbon oil of the reduced pressure gas oil fraction obtained in the vacuum distillation step without performing the solvent extraction step , In the hydrogenation process, it is preferable to contact the hydrocarbon oil with the hydrogenation catalyst at a reaction temperature of 300 to 420°C in an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa. More preferably, the partial pressure of hydrogen is 15 to 18 MPa, and the reaction temperature is 340 to 400°C. This makes it possible to prepare an oil to be treated having an aromatic hydrocarbon content of 10 to 25% by mass, preferably 10 to 18% by mass. LHSV is about 0.1 to 4h ^-1 , preferably 0.5 to 2h ^-1 . The hydrogen/hydrocarbon ratio in the hydrogenation process is about 100 to 2000 Nm 3 /m 3, and preferably 200 to 1000 Nm 3 /m 3.

<Conditions of the hydrogenation process in the case of lubricant base oil fraction 3>

In order to obtain a lubricating oil base oil fraction having a kinematic viscosity of 5.5 to 9.0 mm 2 /s at 100°C, a viscosity index of 90 or more, and a sulfur content of 0.03 mass% or less from the hydrocarbon oil obtained by solvent extraction of the vacuum gas oil obtained in the vacuum distillation step, in the hydrogenation treatment step, In an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa, it is preferable to contact the hydrocarbon oil with the catalyst for hydrogenation at a reaction temperature of 300 to 420°C. More preferably, the partial pressure of hydrogen is 11 to 15 MPa, and the reaction temperature is 310 to 360°C. This makes it possible to prepare an oil to be treated having an aromatic hydrocarbon content of 10 to 25% by mass, preferably 10 to 18% by mass. LHSV is about 0.1 to 4h ^-1 , preferably 0.5 to 1.5h ^-1 . The hydrogen/hydrocarbon ratio in the hydrogenation process is about 100 to 2000 Nm 3 /m 3, and preferably 200 to 1000 Nm 3 /m 3.

<Conditions of the hydrogenation process in the case of lube base oil fraction 4>

In order to obtain a lubricating oil base oil fraction having a kinematic viscosity of 9.0 to 15.0 mm 2 /s at 100°C, a viscosity index of 90 or more, and 0.03 mass% or less of a sulfur content from a hydrocarbon oil obtained by solvent extraction of the vacuum gas oil obtained in the vacuum distillation step, in the hydrogenation treatment step, In an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa, it is preferable to contact the hydrocarbon oil with the catalyst for hydrogenation at a reaction temperature of 300 to 420°C. More preferably, the partial pressure of hydrogen is 11 to 17 MPa, and the reaction temperature is 320 to 370°C. This makes it possible to prepare an oil to be treated having an aromatic hydrocarbon content of 10 to 25% by mass, preferably 10 to 18% by mass. LHSV is about 0.1 to 4h ^-1 , preferably 0.5 to 1.5h ^-1 . The hydrogen/hydrocarbon ratio in the hydrogenation process is about 100 to 2000 Nm 3 /m 3, and preferably 200 to 1000 Nm 3 /m 3.

<Conditions of the hydrogenation process in the case of lubricant base oil fraction 5>

A lubricating oil having a kinematic viscosity of 15.0 to 40.0 mm2/s at 100°C, a viscosity index of 90 or more, and a sulfur content of 0.03% by mass or less from a hydrocarbon oil obtained through a solvent deasphalting process followed by a solvent extraction process. In order to obtain the base oil fraction, in the hydrogenation step, it is preferable to contact the hydrocarbon oil with the hydrogenation catalyst at a reaction temperature of 300 to 420°C in an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa. More preferably, the partial pressure of hydrogen is 11 to 19 MPa, and the reaction temperature is 350 to 400°C. This makes it possible to prepare an oil to be treated having an aromatic hydrocarbon content of 10 to 25% by mass, preferably 10 to 18% by mass. LHSV is about 0.1 to 4h ^-1 , preferably 0.5 to 1.5h ^-1 . The hydrogen/hydrocarbon ratio in the hydrogenation process is about 100 to 2000 Nm 3 /m 3, and preferably 200 to 1000 Nm 3 /m 3.

<Catalyst for hydrogenation treatment>

The catalyst for hydrogenation treatment is not particularly limited. As a specific example of the catalyst for hydrotreating, a carrier made of a porous inorganic oxide containing two or more elements selected from aluminum, silicon, zirconium, boron, titanium and magnesium, and the periodic table groups 6, 8, and And a catalyst carrying a metal selected from elements of groups 9 and 10.

As a carrier for the catalyst for hydrogenation, a porous inorganic oxide composed of two or more elements selected from aluminum, silicon, zirconium, boron, titanium and magnesium is suitably used. The carrier is generally a porous inorganic oxide containing alumina, and other carrier components include silica, zirconia, boria, titania, magnesia, and the like. A preferred carrier is a composite oxide containing at least one or more selected from alumina and other constituents, and examples thereof include silica-alumina and the like.

A raw material that becomes a precursor of silica, zirconia, boria, titania, and magnesia, which are carrier components other than alumina, is not particularly limited, and a solution containing general silicon, zirconium, boron, titanium or magnesium may be used. For example, as a raw material containing silicon, silicic acid, water glass, silica sol, or the like can be used. As a raw material containing titanium, titanium sulfate, titanium tetrachloride, various alkoxide salts, and the like can be used. As a raw material containing zirconium, zirconium sulfate, various alkoxide salts, etc. can be used. As the raw material containing boron, boric acid or the like can be used. As a raw material containing magnesium, magnesium nitrate or the like can be used. As the raw material containing phosphorus, phosphoric acid or an alkali metal salt of phosphoric acid can be used.

It is preferable that the raw materials for the carrier constituent components other than alumina are added to the raw material (alumina) of the carrier in any one step prior to the firing of the carrier. For example, after the carrier constituents are added to the aluminum aqueous solution in advance, an aluminum hydroxide gel containing these carrier constituents may be prepared. You may add a carrier component to the prepared aluminum hydroxide gel. Alternatively, to a commercial alumina intermediate or boehmite powder, a carrier component may be added together with water or an acidic aqueous solution, and these may be kneaded. Preferably, in the step of preparing the aluminum hydroxide gel, the carrier components are coexisted. Although the mechanism for expressing the effects of these carrier components other than alumina has not been elucidated, it is considered that carrier components other than alumina form a complex oxide state with aluminum. This is considered to be m, which affects the activity by increasing the surface area of the carrier or causing some kind of interaction with the active metal.

The active metal of the catalyst for hydrogenation treatment is preferably at least one metal selected from Group VIA (IUPAC Group 6) and Group VIII (IUPAC Groups 8 to 10) of the periodic table, and more preferably Is two or more types of metals selected from groups 6 and 8 to 10. Further, a hydrotreating catalyst containing at least one metal selected from Group 6 and at least one metal selected from Groups 8 to 10 as active metals is also suitable. As a combination of active metals, Co-Mo, Ni-Mo, Ni-Co-Mo, Ni-W, etc. are mentioned, for example. During the hydrogenation treatment, these metals may be converted to a sulfide state and used.

As the catalyst for hydrogenation treatment, the total area of the diffraction peak area indicating the crystal structure of the anatase-type titania (101) plane measured by X-ray diffraction analysis and the diffraction peak area indicating the crystal structure of the rutile-type titania (110) plane is, At least one metal selected from Group VIA and Group VIII of the periodic table in a silica-titania-alumina carrier having a diffraction peak area of 1/4 or less with respect to the diffraction peak area showing an aluminum crystal structure belonging to the γ-alumina 400 plane Hydrodesulfurization catalyst for hydrocarbon oil obtained by supporting a component, (a) a specific surface area (SA) of 150 m 2 /g or more, (b) a total pore volume (PVo) of 0.30 ml/g or more, (c) an average pore diameter ( PD) is in the range of 6 to 15 nm (60 to 150 Å), and (d) the ratio of the pore volume (PVp) of the pore diameter of the average pore diameter (PD) ± 30% is not less than 70% of the total pore volume (PVo) Catalysts for hydrotreating hydrocarbon oils are particularly preferred. This catalyst is hereinafter referred to as "catalyst A".

Among the catalysts for hydrotreating, when catalyst A is used, in particular, hydrogenation of hydrocarbon oil is likely to proceed at a relatively low reaction temperature in an atmosphere with a relatively high hydrogen partial pressure, so that the oil to be treated having an aromatic hydrocarbon content of 10 to 25% by mass is easily obtained. It can be prepared.

<Specific form of catalyst A>

The silica-titania-alumina carrier in the catalyst A uses silica as SiO _{2 in} an amount of preferably 1 to 10% by mass, more preferably 2 to 7% by mass, and particularly preferably 2 to 5% by mass based on the support. Contains. When the silica content is less than 1% by mass, the specific surface area is lowered, and titania particles tend to agglomerate when the carrier is calcined, indicating the crystal structures of anatase-type titania and rutile-type titania measured by X-ray diffraction analysis. The diffraction peak area increases. In addition, when the content of silica exceeds 10% by mass, the sharpness of the pore distribution of the obtained carrier deteriorates, and the desired desulfurization activity may not be obtained.

The silica-titania-alumina carrier of the catalyst A contains titania as TiO _{2 in} an amount of preferably 3 to 40 mass%, more preferably 15 to 35 mass%, particularly preferably 15 to 25 mass%, based on the carrier. . When the content of titania is less than 3% by mass, the effect of the addition of the titania component is small, and the resulting catalyst may not obtain a desired desulfurization activity. In addition, when the content of titania is more than 40% by mass, the mechanical strength of the catalyst may be lowered, and crystallization of titania particles tends to proceed when the support is calcined, so that the specific surface area is lowered, resulting in an increase in the amount of titania. Desulfurization performance is not exhibited enough to meet the cost.

The silica-titania-alumina carrier of the catalyst A uses alumina as Al ₂ O _{3 in} an amount of preferably 50 to 96% by mass, more preferably 58 to 83% by mass, particularly preferably 70 to 83% by mass, based on the support. Contains. Here, when the content of alumina is less than 50% by mass, catalyst deterioration tends to increase, which is not preferable. Further, when the alumina content is more than 96% by mass, the catalyst performance tends to decrease, which is not preferable.

Catalyst A is one in which at least one metal component selected from Group VIA and Group VIII of the periodic table is supported on the silica-titania-alumina support. Examples of the metal component of Group VIA in the periodic table include molybdenum (Mo), tungsten (W), and the like. Examples of the metal component of Group VIII in the periodic table include cobalt (Co), nickel (Ni), and the like. One of these metal components may be used alone, or two or more metal components may be used in combination. From the viewpoint of catalytic performance, as the combination of metals, nickel-molybdenum, cobalt-molybdenum, nickel-molybdenum-cobalt, nickel-tungsten, cobalt-tungsten, nickel-tungsten-cobalt, etc. are preferable, and in particular, nickel-molybdenum, cobalt -Molybdenum and nickel-molybdenum-cobalt are more preferable.

The amount of the metal component supported as the metal oxide is preferably 1 to 35% by mass, more preferably 15 to 30% by mass, based on the catalyst. In particular, the supported amount of a metal component of Group VIA of the periodic table as a metal oxide is preferably 10 to 30% by mass, more preferably 13 to 24% by mass. The supported amount of the metal component of Group VIII of the periodic table as a metal oxide is preferably 1 to 10% by mass, more preferably 2 to 6% by mass.

When the catalyst A contains a metal component of Group VIA in the periodic table, it is preferable to dissolve the metal component using an acid. As the acid, it is preferable to use phosphoric acid and/or organic acid. When phosphoric acid is used, preferably 3 to 25% by mass (in terms of phosphorus oxide), more preferably 10 to 15% by mass of phosphoric acid is supported with respect to 100% by mass of the metal component of Group VIA in the periodic table. When the supported amount exceeds 25% by mass, the catalyst performance tends to decrease, which is not preferable. When the amount is less than 3% by mass, the stability of the supported metal solution is deteriorated, which is not preferable. In addition, when an organic acid is used, preferably 35 to 75 mass% of organic acid, more preferably 55 to 65 mass% of organic acid is supported with respect to the metal component of Group VIA of the periodic table. When the supported amount of the organic acid exceeds 75% by mass with respect to the metal component of Group VIA of the periodic table, the viscosity of the solution containing the metal component (hereinafter, also referred to as "supported metal-containing solution") increases, and impregnation in production. This is not preferable because the process becomes difficult. When the amount of the organic acid supported is less than 35% by mass, the stability of the supported metal-containing solution tends to deteriorate, and the catalyst performance tends to decrease, which is not preferable.

The method of supporting and containing the metal component, phosphorus and/or organic acid on the carrier is not particularly limited. Known methods such as an impregnation method (equilibrium adsorption method, pore filling method, initial wetting method) and ion exchange method using a compound containing the above metal component or a compound containing additional phosphorus and/or an organic acid can be used. Here, the impregnation method refers to a method in which a carrier is impregnated with a solution containing an active metal, and then dried and fired. In the impregnation method, it is preferable to simultaneously support a metal component of Group VIA of the periodic table and a metal component of Group VIII of the periodic table. When the metal is individually supported, the desulfurization activity or denitrification activity may become insufficient. In the case of carrying out the support by impregnation method, the dispersibility of the metal component of Group VIA in the periodic table on the carrier becomes high, and the desulfurization activity and denitrification activity of the resulting catalyst become higher. Therefore, the impregnation method is carried out in the presence of an acid, preferably in the presence of phosphoric acid or organic acid. In that case, it is preferable to add 3 to 25% by mass of phosphoric acid or 35 to 75% by mass of organic acid with respect to 100% by mass of the metal component of Group VIA in the periodic table. As the organic acid, a carboxylic acid compound is preferable, and specifically citric acid, malic acid, tartaric acid, gluconic acid, and the like are mentioned.

The specific surface area of the catalyst A measured by the BET method is 150 m 2 /g or more. More preferably, the specific surface area of the catalyst A is 170 m 2 /g or more. When the specific surface area is less than 150 m 2 /g, there is a possibility that the active point of the desulfurization reaction decreases, and the desulfurization performance decreases. On the other hand, when the specific surface area exceeds 250 m 2 /g, the mechanical strength of the catalyst tends to decrease. Therefore, the specific surface area is preferably 250 m 2 /g or less, and more preferably 230 m 2 /g or less. The specific surface area of the catalyst A is calculated by the following method. First, a pretreatment for removing moisture adsorbed on the catalyst A is performed. In the pretreatment, for example, by heating the inside of the sealed container in which the catalyst A is disposed and exhausting the inside of the container, the catalyst A may be held in a vacuum at 300°C for 5 hours. The adsorption and desorption isotherms of the gas in the catalyst A after this pretreatment are automatically measured by the constant capacity method. As the gas, nitrogen may be used. The temperature of nitrogen may be liquid nitrogen temperature (-196°C). As the measuring device, BELSORP-max manufactured by Nippon Bell Corporation may be used. For analysis of the measurement data, it is recommended to use analysis software (BELMaster ^TM ) attached to the device. The measured nitrogen adsorption and desorption isotherms are automatically analyzed by the equation of BET, and the surface area per unit mass of catalyst A (m 2 /g) is calculated.

The total pore volume (PVo) of the catalyst A measured by the mercury intrusion method (contact angle of mercury: 135 degrees, surface tension: 480 dyn/cm) is 0.30 ml/g or more. Preferably, PVo is at least 0.35 ml/g. On the other hand, since the catalyst strength tends to decrease when the total pore volume (PVo) exceeds 0.60 ml/g, PVo is preferably 0.60 ml/g or less, and more preferably 0.50 ml/g or less.

The average pore diameter (PD) of catalyst A is 6 to 15 nm (60 to 150 Å). Preferably the PD is 6.5 to 11 nm. When the average pore diameter (PD) is less than 6 nm, since the pores are small, the reactivity with the raw material oil may deteriorate. In addition, a catalyst having a PD exceeding 15 nm is difficult to manufacture, and the specific surface area of the catalyst tends to decrease, resulting in poor catalyst performance. On the other hand, the total pore volume (PVo) represents pores having a pore diameter of 4.1 nm (41 Å) or more, which is the quantitative limit of measurement, and the average pore diameter (PD) is a pore diameter corresponding to 50% of the total pore volume (PVo). Represents.

In the catalyst A, the ratio (PVp/PVo) occupied with respect to the total pore volume (PVo) of the pore volume (PVp) having a pore diameter of the average pore diameter (PD)±30% is 70% or more. Its pore distribution is sharp. PVp/PVo is preferably 80% or more. When PVp/PVo is less than 70%, the pore distribution of the catalyst becomes broad, and the desired desulfurization performance may not be obtained.

In the carrier of the catalyst A, the "titania diffraction peak area" measured by X-ray diffraction analysis is 1/4 or less, preferably 1/5 or less, and 1/6 or less with respect to the "alumina diffraction peak area". More preferable. The "titania diffraction peak area" is the total area of the diffraction peak area showing the crystal structure of the anatase type titania (101) plane and the diffraction peak area showing the crystal structure of the rutile type titania (110) plane. The "alumina diffraction peak area" is a diffraction peak area indicating an aluminum crystal structure attributable to the γ-alumina 400 plane. When the ratio of the titania diffraction peak area to the alumina diffraction peak area (titania diffraction peak area/alumina diffraction peak area) is greater than 1/4, crystallization of titania proceeds and pores effective for reaction are reduced. For this reason, desulfurization performance comparable to the cost accompanying the increase in titania amount is not exhibited. On the other hand, as a measuring device for X-ray diffraction analysis, RINT2500 manufactured by Rigaku Corporation may be used. As the source, a Cu-Kα line (50 kV, 200 mA) may be used.

The diffraction peak showing the crystal structure of the anatase-type titania (101) plane was measured as 2θ = 25.5°. The diffraction peak showing the crystal structure of the rutile titania (110) plane was measured at 2θ = 27.5°. In addition, the diffraction peak showing the aluminum crystal structure attributed to the γ-alumina 400 plane was measured at 2θ = 45.9°. In the calculation method of each diffraction peak area, a graph obtained by X-ray analysis diffraction with an X-ray diffraction apparatus is fitted by the least squares method to perform base line correction. Then, the height from the maximum peak value of the graph to the baseline (peak intensity (W)) is obtained. The peak width (half width) at the half value (W/2) of the obtained peak intensity is determined. The product of the half-width and peak intensity is the diffraction peak area. From each obtained diffraction peak area, "titania diffraction peak area/alumina diffraction peak area" is calculated.

Catalyst A is prepared by the following method. In the method for producing catalyst A, in the presence of silicate ions, a mixed aqueous solution of a titanium inorganic acid salt and an acidic aluminum salt (hereinafter, also simply referred to as a “mixed aqueous solution”) and a basic aluminum salt aqueous solution are mixed so that the pH becomes 6.5 to 9.5. A first step of obtaining a hydrate by means of a method; a second step of obtaining a carrier by sequentially performing washing, shaping, drying, and firing of the hydrate; and a periodic table Group VIA (IUPAC Group 6) And a third step of supporting at least one metal component selected from Group VIII (IUPAC Groups 8 to 10). Hereinafter, each process is demonstrated.

[Step 1]

In the presence of silicate ions, a mixed aqueous solution of a titanium inorganic acid salt and an acidic aluminum salt (acidic aqueous solution) and a basic aluminum salt aqueous solution (alkaline aqueous solution) have a pH of 6.5 to 9.5, preferably 6.5 to 8.5, more preferably Mixing so as to be 6.5 to 7.5, a hydrate containing silica, titania and alumina is obtained.

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

As the basic aluminum salt, sodium aluminate, potassium aluminate, and the like are suitably used. Moreover, as the acidic aluminum salt, aluminum sulfate, aluminum chloride, aluminum nitrate, etc. are used suitably. Examples of the titanium inorganic acid salt include titanium tetrachloride, titanium trichloride, titanium sulfate, and titanium nitrate, and titanium sulfate is particularly suitably used because it is inexpensive.

For example, an aqueous basic aluminum salt solution containing a predetermined amount of basic silicate ions is introduced into a tank equipped with a stirrer, and maintained by heating at 40 to 90°C, preferably 50 to 70°C. A mixed aqueous solution of a predetermined amount of a titanium inorganic acid salt and an aqueous acidic aluminum salt solution is heated to a temperature of ±5°C, preferably ±2°C, and more preferably ±1°C of the basic aluminum salt solution. The heated mixed aqueous solution is continuously added to the basic aluminum salt aqueous solution for 5 to 20 minutes, preferably 7 to 15 minutes, to generate a precipitate to obtain a hydrate slurry. A mixed aqueous solution is added to the basic aluminum salt aqueous solution so that the pH of the hydrate slurry is 6.5 to 9.5, preferably 6.5 to 8.5, more preferably 6.5 to 7.5. If the addition time of the mixed aqueous solution to the basic aluminum salt aqueous solution is prolonged, undesirable crystals such as bierite or gibsite may be formed in addition to pseudo boehmite. Since the specific surface area of a viarite or a gibbsite decreases when fired, it is not preferable. Therefore, the addition time is preferably 15 minutes or less, more preferably 13 minutes or less.

[2nd process]

The slurry of the hydrate obtained in the first step is aged and washed to remove by-product salts, and a slurry of the hydrate containing silica, titania and alumina is obtained. The resulting hydrate slurry is further heat-aged and then heat-kneaded to obtain a moldable dough. The dough is molded into a desired shape by extrusion molding or the like. After drying the molded article at usually 70 to 150°C, preferably 90 to 130°C, it is fired at 400 to 800°C, preferably at 450 to 600°C, for 0.5 to 10 hours, preferably 2 to 5 hours. By these processes, a silica-titania-alumina carrier containing silica, titania and alumina is obtained.

[3rd process]

After supporting at least one metal component selected from Group VIA and Group VIII of the periodic table on the silica-titania-alumina carrier by the above method, a carrier carrying the metal component is usually 400 to 800°C. , Preferably 450 to 600°C, 0.5 to 10 hours, preferably 2 to 5 hours. By the above process, catalyst A is produced. As a preferred raw material for the metal component, for example, nickel nitrate, nickel carbonate, cobalt nitrate, cobalt carbonate, molybdenum trioxide, ammonium molybdate, ammonium paratungstate, and the like are used.

(Hydrogenation isomerization process)

The oil to be treated obtained in the hydrogenation process contains normal paraffin having 10 or more carbon atoms. In the hydroisomerization step, part or all of the oil to be treated containing normal paraffin is converted to isoparaffin by contacting the oil to be treated and the hydroisomerization catalyst.

On the other hand, hydroisomerization refers to a reaction in which the number of carbon atoms (molecular weight) of the hydrocarbon in the oil to be treated is not changed, and only the molecular structure of the hydrocarbon oil is changed. The decomposition of hydrocarbon oil refers to a reaction accompanied by a decrease in the number of carbon atoms (molecular weight) of the hydrocarbon oil. In the catalytic dewaxing reaction using a hydroisomerization catalyst, not only isomerization but also the decomposition reaction of hydrocarbon oil and isomerization product may occur to some extent. If the carbon number (molecular weight) of the decomposition reaction product falls within a predetermined range capable of constituting the target base oil, there is no problem. That is, the decomposition product may be a constituent component of the base oil.

The reaction conditions of the hydroisomerization process are as follows.

In the hydroisomerization step, it is preferable to hydroisomerize the oil to be treated in an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa. Preferably, the partial pressure of hydrogen in the hydroisomerization step is 11 to 19 MPa. When the reaction pressure is 11 MPa or more, coke formation is suppressed and the catalyst life tends to be prolonged. When the reaction pressure is less than 11 MPa, deterioration of the catalyst due to coke formation tends to be accelerated. On the other hand, when the reaction pressure exceeds 20 MPa, since pressure resistance is required for the reaction device, the cost of constructing the device increases, and there is a tendency that it is difficult to realize an economical process. However, even when the partial pressure of hydrogen is out of the above range, the effect of the present invention is achieved.

The reaction temperature in the hydroisomerization step is preferably 200 to 450°C, more preferably 260 to 400°C. When the reaction temperature is equal to or higher than the lower limit, reduction and removal of the wax component by isomerization of the normal paraffin contained in the oil to be treated is promoted. On the other hand, when the reaction temperature is below the above upper limit, excessive decomposition of the raw material oil is suppressed, and the yield of the target hydrocarbon tends to be remarkably improved. However, even when the reaction temperature of the hydroisomerization reaction is out of the above range, the effect of the present invention is achieved.

Note that the raw material liquid space velocity in the hydrogenation-isomerization reaction, the it is preferred from 0.1 to 10h ^-1, more preferably from 0.5 to 5h ^-1. When the liquid space velocity is more than the above lower limit, excessive decomposition of the raw material oil is suppressed, and the yield of the target base oil for lubricating oil tends to be remarkably improved. On the other hand, when the liquid space velocity is less than or equal to the above upper limit, reduction and removal of wax components by isomerization of normal paraffin contained in the raw material oil is promoted.

In the hydroisomerization reaction, the supply ratio of hydrogen to the oil to be treated (the ratio of hydrogen/oil to be treated) is preferably 50 to 2000 Nm 3 /m 3, more preferably 100 to 1500 Nm 3 /m 3. It is particularly preferably 200 to 800 Nm 3 /m 3. When the feed rate is less than 50Nm3/m3, hydrogen sulfide, ammonia gas, and water generated by desulfurization, denitrification, and deoxygenation reactions that occur concurrently with the isomerization reaction are adsorbed to the active metals on the catalyst and poison the catalyst. In addition, there is a tendency that the hydrogenation of impurities such as trace amounts of olefins produced by side reactions is insufficient, and catalyst deactivation due to coking occurs. On the other hand, when the supply ratio exceeds 2000 Nm 3 /m 3, since a hydrogen supply facility with high capability is required, an economical process tends to be difficult to realize. However, even when the hydrogen supply ratio is out of the above range, the effect of the present invention is achieved.

The conversion rate of normal paraffin by the hydroisomerization reaction is freely controlled by adjusting reaction conditions such as reaction temperature according to the application of the obtained hydrocarbon.

According to the above hydroisomerization process, normal paraffin isomerized (i.e., dewaxed) is proceeded while sufficiently suppressing hardening of normal paraffin contained in the oil to be treated, and a base oil having a high content of isomers having a branched chain structure is obtained. It can be obtained in high yield.

<Hydrogenation isomerization catalyst>

The hydroisomerization catalyst (isomerization dewaxing catalyst) used in the hydroisomerization step is not particularly limited, and a known catalyst can be used in the present embodiment. However, as a hydroisomerization catalyst, it is preferable to use the following hydroisomerization catalyst, which is given characteristics by being produced by a specific method. Hereinafter, the hydrogenation isomerization catalyst will be described in accordance with its preferred form of production.

The method for producing the hydrogenation isomerization catalyst of the present embodiment is a solution containing an organic template and a zeolite having a one-dimensional pore structure (organic template-containing zeolite) containing an organic template and containing a 10-membered ring, and an ammonium ion and/or a proton. In a first step of obtaining an ion exchange zeolite by ion exchange in, and heating a mixture containing the ion exchange zeolite and a binder at a temperature of 250 to 350°C in an N ₂ atmosphere to obtain a carrier precursor, and platinum in the carrier precursor. A catalyst precursor containing a salt and/or a palladium salt is calcined at a temperature of 350 to 400° C. in an atmosphere containing molecular oxygen to provide a carrier containing zeolite and platinum and/or palladium supported on the carrier. And a second step of obtaining a hydroisomerization catalyst.

The organic template-containing zeolite used in the present embodiment has a one-dimensional pore structure consisting of a 10-membered ring from the viewpoint of achieving high isomerization activity and suppressed decomposition activity at a high level in the hydroisomerization reaction of normal paraffin. Examples of such zeolites include AEL, EUO, FER, HEU, MEL, MFI, NES, TON, MTT, WEI, *MRE and SSZ-32. On the other hand, each of the three letters of the alphabet refers to a framework structure code given by The Structure Commission of The International Zeolite Association for each structure of the classified molecular zeolite. Also, zeolites having the same topology are generically referred to by the same code.

As the organic template-containing zeolite, among the zeolites having a 10-membered one-dimensional pore structure described above, from the viewpoint of high isomerization activity and low decomposition activity, zeolite having TON, MTT structure, and zeolite having *MRE structure (ZSM-48 Zeolite), and SSZ-32 zeolite are preferred. As the zeolite having a TON structure, ZSM-22 zeolite is more preferable, and as a zeolite having an MTT structure, ZSM-23 zeolite is more preferable.

The organic template-containing zeolite is obtained by hydrothermal synthesis using a silica source, an alumina source, and an organic template added to construct the predetermined pore structure as raw materials.

The organic template is an organic compound having an amino group, an ammonium group, or the like, and is selected according to the structure of the zeolite to be synthesized. It is preferable that the organic template is an amine derivative. Specifically, the organic template is selected from the group consisting of alkylamine, alkyldiamine, alkyltriamine, alkyltetramine, pyrrolidine, piperazine, aminopiperazine, alkylpentamine, alkylhexamine and derivatives thereof. It is more preferable that it is at least 1 type.

The molar ratio ([Si]/[Al]) (hereinafter referred to as “Si/Al ratio”) of the silicon and aluminum elements constituting the organic template-containing zeolite having a 10-membered one-dimensional pore structure is 10 to 400. It is preferable and it is more preferable that it is 20-350. When the Si/Al ratio is less than 10, the activity for conversion of normal paraffin increases, but the selectivity for isomerization to isoparaffin decreases, and the increase in the decomposition reaction accompanying the increase in the reaction temperature tends to rapidly increase. Can't. On the other hand, when the Si/Al ratio exceeds 400, it is difficult to obtain a catalytic activity required for conversion of normal paraffin, which is not preferable.

The organic template-containing zeolite synthesized, preferably washed and dried, usually has an alkali metal cation as a pair cation, and an organic template is contained in the pore structure. The zeolite containing an organic template used in the production of the hydroisomerization catalyst according to the present embodiment is one in such a synthesized state, that is, it is not subjected to a sintering treatment to remove the organic template contained in the zeolite. desirable.

The zeolite containing the organic template is then ion-exchanged in a solution containing ammonium ions and/or protons. By ion exchange treatment, the bication contained in the zeolite containing the organic template is exchanged for ammonium ions and/or protons. In addition, at the same time, a part of the organic template contained in the zeolite containing the organic template is removed.

The solution used for the ion exchange treatment is preferably a solution using a solvent containing at least 50% by volume of water, and more preferably an aqueous solution. Further, examples of the compound for supplying ammonium ions into the solution include various inorganic and organic ammonium salts such as ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium phosphate and ammonium acetate. On the other hand, as the compound for supplying the proton into the solution, inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid are usually used. Ion-exchange zeolite (here, ammonium type zeolite) obtained by ion-exchanging an organic template-containing zeolite in the presence of ammonium ions releases ammonia at the time of later firing, and the bication becomes a proton and becomes a Brensted acid site. Ammonium ions are preferable as cationic species used for ion exchange. The content of ammonium ions and/or protons contained in the solution is preferably set to be 10 to 1000 equivalents based on the total amount of the dication and organic template contained in the organic template-containing zeolite to be used.

The ion exchange treatment may be performed on a zeolite carrier containing a powdery organic template. In addition, prior to the ion exchange treatment, an inorganic oxide as a binder may be blended with the zeolite containing an organic template, and the resulting molded article may be subjected to an ion exchange treatment. However, if the above molded article is subjected to ion exchange treatment without firing, the problem of disintegration and differentiation of the molded article is liable to occur. Therefore, it is preferable to provide a zeolite containing a powdery organic template for ion exchange treatment.

The ion exchange treatment is preferably performed by a normal method, that is, a method of immersing a zeolite containing an organic template in a solution containing ammonium ions and/or protons, preferably an aqueous solution, and stirring or flowing this. In addition, the stirring or flow is preferably performed under heating in order to increase the efficiency of ion exchange. In this embodiment, a method of heating the aqueous solution and performing ion exchange under boiling or reflux is particularly preferred.

In addition, from the viewpoint of enhancing the efficiency of ion exchange, during ion exchange of zeolite by solution, it is preferable to exchange the solution with a new one or two or more times, and it is more preferable to exchange the solution with a new one or two times. desirable. When the solution is exchanged once, for example, a zeolite containing an organic template is immersed in a solution containing ammonium ions and/or protons, heated to reflux for 1 to 6 hours, and then the solution is replaced with a new one, By heating and refluxing again for 6 to 12 hours, it becomes possible to increase the ion exchange efficiency.

By ion exchange treatment, it is possible to exchange almost all of the pair cations such as alkali metals in the zeolite with ammonium ions and/or protons. On the other hand, with respect to the organic template contained in the zeolite, a part of it is removed by the ion exchange treatment described above, but even if the same treatment is repeated, it is generally difficult to remove all of it, and a part of it is contained inside the zeolite. Remain.

In this embodiment, the mixture containing the ion exchange zeolite and the binder is heated to a temperature of 250 to 350°C in a nitrogen atmosphere to obtain a carrier precursor.

The mixture containing the ion-exchange zeolite and the binder is preferably molded into a composition obtained by mixing the ion-exchange zeolite obtained by the above method with an inorganic oxide as a binder. The purpose of blending the inorganic oxide into the ion exchange zeolite is to improve the mechanical strength of the carrier (particularly, the particulate carrier) obtained by firing the molded article to a degree that can withstand practical use. It has been found that the choice of is affecting the isomerization selectivity of the hydroisomerization catalyst. From this point of view, as the inorganic oxide, at least one inorganic oxide selected from alumina, silica, titania, boria, zirconia, magnesia, ceria, zinc oxide and phosphorus oxide, and a composite oxide consisting of a combination of two or more thereof is used. do. Among these, silica or alumina is preferred, and alumina is more preferred from the viewpoint of further improving the isomerization selectivity of the hydroisomerization catalyst. In addition, the "composite oxide composed of a combination of two or more of these" is a composite oxide composed of at least two components of alumina, silica, titania, boria, zirconia, magnesia, ceria, zinc oxide, and phosphorus oxide. A composite oxide containing 50% by mass or more of an alumina component based on the composite oxide (alumina-based composite oxide) is preferred, and among them, alumina-silica is more preferred.

The blending ratio of the ion exchange zeolite and the inorganic oxide in the composition is a ratio of the mass of the ion exchange zeolite: the mass of the inorganic oxide, preferably 10:90 to 90:10, more preferably 30:70 to 85 :15. When this ratio is smaller than 10:90, since there is a tendency that the activity of the hydroisomerization catalyst becomes insufficient, it is not preferable. On the other hand, when the ratio exceeds 90:10, it is not preferable because the mechanical strength of the carrier obtained by molding and firing the composition tends to become insufficient.

The method of mixing the above inorganic oxide with the ion exchange zeolite is not particularly limited, for example, adding a liquid such as water in an appropriate amount to both powders to prepare a viscous fluid, and kneading the fluid with a kneader, etc. It is possible to adopt a commonly practiced method of.

The composition containing the ion-exchange zeolite and the inorganic oxide, or the viscous fluid containing the same, is molded by a method such as extrusion molding, and is preferably dried to form a particulate molded body. Although it does not specifically limit as a shape of a molded object, For example, a cylindrical shape, a pellet shape, a spherical shape, a deformed shape having a three-leaf or four-leaf cross section, etc. are mentioned, for example. The size of the molded article is not particularly limited. From the viewpoints of ease of handling and packing density into the reactor, for example, it is preferable that the long axis of the molded body is 1 to 30 mm, and the short axis of the molded body is about 1 to 20 mm.

In this embodiment, it is preferable that the molded article obtained as described above is heated to a temperature of 250 to 350°C in an N ₂ atmosphere to obtain a carrier precursor. Regarding the heating time, 0.5 to 10 hours are preferable, and 1 to 5 hours are more preferable.

In the present embodiment, when the heating temperature is lower than 250°C, a large amount of the organic template remains, and the zeolite pores are blocked by the remaining template. The isomerization active point is considered to exist in the vicinity of the pore pore mouse, and in the above case, the reactive substrate does not diffuse into the pore due to pore occlusion, and the active point is covered, making the isomerization reaction difficult to proceed, and the conversion rate of normal paraffin This tends to become difficult to obtain sufficiently. On the other hand, when the heating temperature exceeds 350° C., the isomerization selectivity of the obtained hydroisomerization catalyst is not sufficiently improved.

The lower limit temperature when heating the molded article to form a carrier precursor is preferably 280°C or higher. In addition, the upper limit temperature is preferably 330°C or less.

In this embodiment, it is preferable to heat the mixture so that a part of the organic template contained in the molded article remains. Specifically, the micropore volume per unit mass of the hydroisomerization catalyst obtained through calcination after metal support to be described later is 0.02 to 0.12 cc/g, and the micropore volume per unit mass of the zeolite contained in the catalyst is 0.01 to It is preferable to set the heating conditions to be 0.11 cc/g.

Next, a catalyst precursor containing a platinum salt and/or a palladium salt in the carrier precursor is prepared at 350 to 400°C, preferably 380 to 400°C, and more preferably 400°C in an atmosphere containing molecular oxygen. By firing at temperature, a hydrogenation isomerization catalyst in which platinum and/or palladium is supported on a zeolite-containing carrier is obtained. On the other hand, "under an atmosphere containing molecular oxygen" means a gas containing oxygen gas, preferably air. The firing time is preferably 0.5 to 10 hours, more preferably 1 to 5 hours.

Examples of the platinum salt include chloroplatinic acid, tetraammine dinitroplatinum, dinitroaminoplatinum, tetraammine dichloroplatinum, and the like. Since the chloride salt generates hydrochloric acid during the reaction and the hydrochloric acid may corrode the device, tetraammine dinitroplatinum, which is a platinum salt in which platinum is highly dispersed, is preferable in addition to the chloride salt.

As a palladium salt, palladium chloride, tetraammine palladium nitrate, diamino palladium nitrate, etc. are mentioned, for example. Since the chloride salt generates hydrochloric acid during the reaction and the hydrochloric acid may corrode the apparatus, tetraammine palladium nitrate, which is a palladium salt in which palladium is highly dispersed, is preferable in addition to the chloride salt.

The amount of active metal supported in the zeolite-containing carrier according to the present embodiment is preferably 0.001 to 20% by mass, and more preferably 0.01 to 5% by mass, based on the mass of the carrier. When the supported amount is less than 0.001 mass%, it becomes difficult to impart a predetermined hydrogenation/dehydrogenation function to the catalyst. On the other hand, when the supported amount exceeds 20% by mass, hardening due to decomposition of hydrocarbons on the active metal is likely to proceed, and the yield of the target oil tends to decrease, resulting in an increase in catalyst cost. It is not desirable because it tends to do.

In addition, when the hydroisomerization catalyst according to the present embodiment is used for hydroisomerization of a hydrocarbon oil containing a large amount of a sulfur-containing compound and/or a nitrogen-containing compound, from the viewpoint of persistence of catalytic activity, the catalyst is an active metal, and nickel-cobalt , Nickel-molybdenum, cobalt-molybdenum, nickel-molybdenum-cobalt, nickel-tungsten-cobalt, and the like. The supported amount of these metals is preferably 0.001 to 50% by mass, more preferably 0.01 to 30% by mass, based on the mass of the carrier.

In this embodiment, it is preferable to fire the catalyst precursor so that the organic template remaining in the carrier precursor remains. Specifically, heating so that the micropore volume per unit mass of the obtained hydroisomerization catalyst is 0.02 to 0.12 cc/g, and the micropore volume per unit mass of the zeolite contained in the catalyst is 0.01 to 0.11 cc/g. It is desirable to set the conditions.

The micropore volume per unit mass of the hydroisomerization catalyst is calculated by the following method called nitrogen adsorption measurement. First, a pretreatment for removing moisture adsorbed on the hydroisomerization catalyst is performed. In the pretreatment, for example, by heating the inside of the sealed container in which the hydroisomerization catalyst is disposed and evacuating the container, the hydroisomerization catalyst may be maintained in a vacuum at 300°C for 5 hours. The adsorption and desorption isotherms of the gas in the hydroisomerization catalyst after this pretreatment are automatically measured by the constant capacity method. As the gas, nitrogen may be used. The temperature of nitrogen may be liquid nitrogen temperature (-196°C). As the measuring device, BELSORP-max manufactured by Nippon Bell Corporation may be used. For analysis of the measurement data, it is recommended to use analysis software (BELMaster ^TM ) attached to the device. The measured nitrogen adsorption and desorption isotherms are automatically analyzed by the t-plot method, and the micropore volume per unit mass of the catalyst is calculated. Further, the volume of micropores per unit mass of zeolite contained in the catalyst is also calculated by the above nitrogen adsorption measurement.

The micropore volume per unit mass of the zeolite contained in the catalyst (V _z ) is, for example, when the binder does not have a micropore volume, the value of the micropore volume per unit mass of the hydroisomerization catalyst (V _c ) and , It can be calculated from the zeolite content ratio (M _z ) (mass %) in the catalyst according to the following equation.

[Equation]

V _z =V _c /M _z ×100

It is preferable that the hydroisomerization catalyst according to the present invention has been subjected to a reduction treatment following the above firing treatment (preferably after being charged into a reactor for carrying out the hydroisomerization reaction). Specifically, in an atmosphere containing molecular hydrogen (preferably in the flow of hydrogen gas), preferably at 250 to 500°C (more preferably 300 to 400°C), about 0.5 to 5 hours, a hydroisomerization catalyst It is preferable that a reduction treatment is applied to. By such a process, a high activity for dewaxing of hydrocarbon oil can be imparted to the catalyst more reliably.

Another embodiment of the hydroisomerization catalyst comprises a zeolite having a one-dimensional pore structure containing a 10-membered ring and a carrier containing a binder, and platinum and/or palladium supported on the carrier, and microparticles per unit mass of the catalyst. A hydroisomerization catalyst having a pore volume of 0.02 to 0.12 cc/g, wherein the zeolite contains an organic template and contains an organic template having a 10-membered one-dimensional pore structure in a solution containing ammonium ions and/or protons. It is derived from an ion exchange zeolite obtained by ion exchange, and the micropore volume per unit mass of the zeolite contained in the catalyst is 0.01 to 0.11 cc/g.

The above hydroisomerization catalyst can be produced by the method described above. The micropore volume per unit mass of the catalyst and the micropore volume per unit mass of the zeolite contained in the catalyst are the amount of the ion exchange zeolite blended in the mixture containing the ion exchange zeolite and the binder, and the heating conditions of the mixture under N ₂ atmosphere , The catalyst precursor can be within the above range by appropriately adjusting the heating conditions in an atmosphere containing molecular oxygen.

(Hydrogenation finishing process)

In the present embodiment, the product oil obtained by the hydroisomerization step may be subjected to hydrofinishing. In the hydrogenation finish, the product oil is brought into contact with a metal-supported hydrogenation catalyst in the presence of hydrogen. Examples of the hydrogenation catalyst include alumina and silica alumina on which platinum and/or palladium are supported. The hydrogenation finish improves the color, oxidation stability, etc. of the reaction product (product oil) obtained in the hydroisomerization process (dewaxing process), and the quality of the product can be improved. A catalyst layer for hydrogenation finishing may be provided on the downstream side of the catalyst layer of the hydroisomerization catalyst installed in the reactor performing the hydroisomerization step, and hydrogenation finishing may be performed following the dewaxing step. The hydrogenation finishing may be performed in a reaction facility different from the dewaxing process.

(Refining process)

In this embodiment, the product oil obtained by the hydrogenation finishing step may be distilled under reduced pressure to purify the base oil. The heavy fraction obtained by distillation under reduced pressure may be further distilled under reduced pressure. For example, you may separate the raw material oil for hydrorefining into a plurality of light fractions having a lower kinematic viscosity than the raw material oil for hydrorefining by a refining process. With respect to these base oils, if necessary, light oil having a low kinematic viscosity is mixed, and properties such as kinematic viscosity and viscosity index (VI) of each fraction are adjusted to suit each standard, thereby preparing a desired base oil for lubricating oil.

The reaction equipment for performing the above-described hydrogenation treatment step and the reaction equipment for performing the hydroisomerization step are not particularly limited. As each facility, a known one can be used. Each of the facilities may be any of a continuous distribution type, a batch type, and a semi-batch type, but from the viewpoint of productivity and efficiency, it is preferable that they are a continuous distribution type. The catalyst layer of each facility may be any of a fixed bed, a fluidized bed, and an agitated bed, but it is preferably a fixed bed from the viewpoint of equipment cost and the like. The reaction phase is preferably a gas-liquid mixed phase.

Example

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless departing from the technical idea of the present invention.

<Preparation of catalyst for hydrogenation treatment>

Into a tank equipped with a steam jacket with a capacity of 100L, 8.16kg of sodium aluminate aqueous solution having a concentration of 22% by mass in terms of Al ₂ O ₃ was added, diluted with 41 kg of ion-exchanged water, and then silicic acid having a concentration of 5% by mass in terms of SiO ₂ 1.80 kg of sodium solution was added while stirring, and it heated to 60 degreeC, and the basic aluminum salt aqueous solution was prepared. In addition, 10 kg of an acidic aluminum salt aqueous solution obtained by diluting 7.38 kg of an aqueous solution of aluminum sulfate having a concentration of 7 mass% in terms of Al ₂ O ₃ with 13 kg of ion-exchanged water and 1.82 kg of titanium sulfate having a concentration of 33 mass% in terms of TiO ₂ A titanium inorganic acid salt aqueous solution dissolved in ion-exchanged water was mixed, and heated to 60°C to prepare a mixed aqueous solution. A mixed aqueous solution was added to the tank containing the aqueous basic aluminum salt solution for 10 minutes at a constant rate until the pH reached 7.2 using a roller pump to prepare a hydrate slurry a containing silica, titania, and alumina.

After the hydrate slurry a was aged for 1 hour at 60°C while stirring, it was dehydrated using a flat plate filter, and further washed with 150 L of a 0.3% by mass aqueous ammonia solution. The washed cake-like slurry was diluted with ion-exchanged water so that the concentration of Al ₂ O ₃ became 10% by mass, and then the pH was adjusted to 10.5 with 15% by mass aqueous ammonia. This was transferred to an aging tank equipped with a reflux and aged for 10 hours at 95°C while stirring. The aged slurry was dehydrated, and kneaded with a twin arm type kneader equipped with a steam jacket, and kneaded to a predetermined moisture content. The obtained kneaded product was molded into a cylindrical shape having a diameter of 1.8 mm by a pressure molding machine, and dried at 110°C. The dried molded article was baked in an electric furnace at a temperature of 550° C. for 3 hours to obtain a carrier a. The concentration of silica relative to the total mass of the carrier a was 3% by mass in terms of SiO ₂ . The concentration of titania relative to the total mass of the carrier a was 20% by mass in terms of TiO ₂ . The concentration of aluminum relative to the total mass of the carrier a was 77 mass% in terms of Al ₂ O ₃ .

The X-ray diffraction analysis of the carrier a was performed using an X-ray diffraction apparatus RINT2500 manufactured by Rigaku Corporation. As a source, a Cu-Kα ray (50 kV, 200 mA) was used. In the X-ray diffraction pattern of the carrier a, the diffraction peak area showing the crystal structures of anatase-type titania and rutile-type titania was 1/8 with respect to the diffraction peak area showing the crystal structure attributed to aluminum. That is, the value of (titania diffraction peak area/alumina diffraction peak area) was 1/8.

306 g of molybdenum trioxide and 68 g of cobalt carbonate were suspended in 500 ml of ion-exchanged water, and the suspension was heated at 95° C. for 5 hours under appropriate reflux so as not to decrease the liquid amount. To the suspension after heating, 68 g of phosphoric acid was added and dissolved, to prepare an impregnation liquid. This impregnation liquid was sprayed onto 1000 g of the carrier a and impregnated, and then dried at 250°C. The dried carrier a was calcined in an electric furnace at 550° C. for 1 hour to obtain a hydrogenation catalyst a (hereinafter, also referred to as “catalyst a”). The concentration of MoO ₃ relative to the total mass of the catalyst a was 22% by mass. The concentration of CoO relative to the total mass of the catalyst a was 3% by mass. The concentration of P ₂ O ₅ relative to the total mass of the catalyst a was 3% by mass.

<Preparation of hydrogenation isomerization catalyst>

ZSM-22 zeolite (hereinafter sometimes referred to as "ZSM-22") made of crystalline aluminosilicate having a Si/Al ratio of 45 was prepared by hydrothermal synthesis by the following procedure.

First, the following four types of aqueous solutions were prepared.

Solution A: 1.94 g of potassium hydroxide dissolved in 6.75 ml of ion-exchanged water.

Solution B: 1.33 g of 18 hydrated aluminum sulfate was dissolved in 5 mL of ion-exchanged water.

Solution C: 4.18 g of 1,6-hexanediamine (organic template) diluted with 32.5 mL of ion-exchanged water.

Solution D: 18 g of colloidal silica (Lodox AS-40 manufactured by Grace Davison) was diluted with 31 mL of ion-exchanged water.

Next, the mixed solution in which Solution A was added to Solution B was stirred until the aluminum component was completely dissolved. Solution C was added to this mixed solution. A mixture of solutions A, B, and C was poured into solution D to this mixture with vigorous stirring at room temperature. Separately synthesized and after synthesis, 0.25 g of powder of ZSM-22, which has not been subjected to any special treatment, was added to the mixture of Solutions A, B, C and D as "seed crystals" to promote crystallization, to obtain a gel material. Obtained.

The gel material was transferred to a stainless steel autoclave reactor having an inner volume of 120 mL, and the autoclave reactor was rotated on a tumbling device at a rotation speed of about 60 rpm for 60 hours in an oven at 150°C to perform hydrothermal synthesis reaction. After the reaction was completed, the reactor was cooled and opened, and dried overnight in a dryer at 60°C to obtain ZSM-22 having a Si/Al ratio of 45.

Regarding the obtained ZSM-22, ion exchange treatment was performed with an aqueous solution containing ammonium ions by the following operation.

The above-described ZSM-22 was taken in a flask, and 100 mL of 0.5N-ammonium chloride aqueous solution per 1 g of ZSM-22 zeolite was added to ZSM-22, and the liquid was heated to reflux for 6 hours. After the refluxed liquid was cooled to room temperature, the supernatant was removed and the crystalline aluminosilicate was washed with ion-exchanged water. To this, 0.5N-ammonium chloride aqueous solution in the same amount as above was added again, and heated to reflux for 12 hours.

After heating and refluxing for 12 hours, the solid content was collected by filtration, washed with ion-exchanged water, and dried overnight in a dryer at 60°C to obtain ion-exchanged NH ₄ type ZSM-22. This ZSM-22 was ion-exchanged in a state containing an organic template.

The above NH ₄ type ZSM-22 and alumina as a binder were mixed at a mass ratio of 7:3, and a small amount of ion-exchanged water was added to the mixture and kneaded. The obtained viscous fluid was filled into an extruder and molded, and a cylindrical molded body having a diameter of about 1.6 mm and a length of about 10 mm was obtained. This molded article was heated at 300° C. for 3 hours in an N ₂ atmosphere to obtain a carrier precursor.

Tetraammine dinitroplatinum [Pt(NH ₃ ) ₄ ](NO ₃ ) ₂ was dissolved in ion-exchanged water corresponding to the amount of absorption of the carrier precursor measured in advance to obtain an impregnation solution. This solution was impregnated with the above carrier precursor by an initial wetting method, and platinum was supported on the ZSM-22 zeolite so that the content of platinum relative to the mass of the ZSM-22 zeolite was 0.3% by mass. Next, the obtained impregnated material (catalyst precursor) is dried overnight in a dryer at 60° C., and then calcined at 400° C. for 3 hours under flow of air to obtain a hydroisomerization catalyst b (hereinafter, also referred to as “catalyst b”). Obtained.

(Example 1)

Hydrocarbon oil of Example 1 (hydrocarbon oil before hydrogenation) was obtained by extracting and removing part of the aromatic hydrocarbons in the gas oil fraction under reduced pressure in furfural using an extraction tower. Table 1 shows the boiling point range of the hydrocarbon oil before hydrogenation in Example 1, T10, T90, the aromatic hydrocarbon content in the hydrocarbon oil, the sulfur content in the hydrocarbon oil, the kinematic viscosity at 100°C of the hydrocarbon oil, and the viscosity index of the hydrocarbon oil. Write. On the other hand, the density at 15°C of the hydrocarbon oil before hydrogenation in Example 1 was 0.8683 g/cm 3. The content of nitrogen content in the hydrocarbon oil before hydrogenation of Example 1 was 23 mass ppm.

In the hydrogenation process of Example 1, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 1, the hydrocarbon oil of Example 1 was brought into contact with the catalyst a at the reaction temperature shown in Table 1, The oil to be treated was obtained. On the other hand, in the hydrogenation process, the ratio of hydrogen/hydrocarbon oil was adjusted to 253 Nm 3 /m 3. In the hydrogenation process, the liquid space velocity of the hydrocarbon oil with respect to the catalyst a was adjusted to the value shown in Table 1. Table 1 shows the content of aromatic hydrocarbons in the oil to be treated obtained in the hydrogenation step of Example 1, the content of sulfur content in the oil to be treated, the kinematic viscosity of the oil to be treated, and the viscosity index (VI) of the oil to be treated.

In the hydrogenation isomerization step of Example 1, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 2, the oil to be treated in Example 1 was brought into contact with the catalyst b at the reaction temperature shown in Table 2, The resulting oil was obtained. On the other hand, in the hydroisomerization process, the ratio of hydrogen/hydrocarbon oil was adjusted to 506 Nm 3 /m 3. In the hydroisomerization step, the liquid space velocity of the hydrocarbon oil with respect to the catalyst b was adjusted to the value shown in Table 2. The reaction temperature in the hydroisomerization step of Example 1 is the lowest temperature at which the pour point of the following base oil fraction b for lubricating oil ("main base oil fraction" in Table 2) becomes -12.5°C or less. Table 2 shows the content of aromatic hydrocarbons in the product oil of Example 1, the content of sulfur content in the product oil, and the yield (X) of Example 1. On the other hand, the yield (X) in Table 2 is a value expressed by the following equation.

[Equation]

X=(V _L /V _R )×100

In the above equation, V _L is the sum of the masses of the base oil fractions for lubricating oils (final base oil fractions). The final base oil fraction is obtained by distilling the product oil of the hydroisomerization step into naphtha, kerosene oil, and heavy fraction having a target kinematic viscosity. V _R is the mass of the oil to be treated obtained in the hydrogenation step, and is the mass of the oil to be treated before the hydroisomerization step. Table 3 shows the final base oil fractions of Example 1 and the following Examples and Comparative Examples.

In the purification process of Example 1 (pressure-sensitive distillation process), the product oil obtained in the hydroisomerization process was classified into naphtha, kerosene oil, and heavy oil. Further, by classifying the heavy oil fraction, the following base oil fraction a for lubricating oil (base oil fraction 1 in Table 3) and the base oil fraction b for lubricating oil (base oil fraction 2 in Table 3) were obtained. The base oil fraction b for lubricating oil in Example 1 corresponds to the "main base oil fraction" in Table 2.

[Base oil fraction for lubricating oil a]

Kinematic viscosity at 100°C: 2.71 mm 2 /s.

Boiling point range: 341 to 385°C.

[Base oil fraction for lubricating oil b]

Table 2 shows the yield (Y), pour point, kinematic viscosity, viscosity index (VI), and (VI×Y) of the base oil fraction b (main base oil fraction) for lubricating oil. Further, the mass of the main base oil yield (Y) of the oil is, V _L is the main base oil fraction, as a target in mind the mass is V _R is obtained in the hydrogenation step, when the target significant mass prior to hydrogenation-isomerization step, ( It is a value expressed as V _L /V _R )×100. The boiling point range of the main base oil fraction of Example 1 was 395 to 421°C.

(Example 2)

In Example 2, a hydrogenation treatment step was carried out under the conditions shown in Table 1 to obtain the oil to be treated shown in Table 1. In Example 2, the hydroisomerization step was carried out under the conditions shown in Table 2 to obtain the product oil shown in Table 2. In Example 2, the same purification process as in Example 1 was carried out to obtain the base oil fraction shown in Table 2. Except for these matters, Example 1 and Example 2 are common.

(Example 3)

In Example 3, hydrocarbon oil (hydrocarbon oil before hydrogenation) that has not been subjected to a solvent extraction step was used. Each value of the boiling point range of the hydrocarbon oil before hydrogenation in Example 3, T10, T90, the aromatic hydrocarbon content in the hydrocarbon oil, the sulfur content in the hydrocarbon oil, the kinematic viscosity at 100°C of the hydrocarbon oil, and the viscosity index (VI) of the hydrocarbon oil It is described in Table 1. On the other hand, the density at 15°C of the hydrocarbon oil before hydrogenation in Example 3 was 0.9150 g/cm 3. The content of nitrogen content in the hydrocarbon oil before hydrogenation of Example 3 was 630 mass ppm.

In the hydrogenation process of Example 3, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 1, the hydrocarbon oil of Example 3 was brought into contact with the catalyst a at the reaction temperature shown in Table 1, The oil to be treated was obtained. On the other hand, in the hydrogenation process, the ratio of hydrogen/hydrocarbon oil was adjusted to 844 Nm 3 /m 3. In the hydrogenation process, the liquid space velocity of the hydrocarbon oil with respect to the catalyst a was adjusted to the value shown in Table 1. Table 1 shows the content of aromatic hydrocarbons in the oil to be treated obtained in the hydrogenation step of Example 3, the content of sulfur content in the oil to be treated, the kinematic viscosity of the oil to be treated, and the viscosity index (VI) of the oil to be treated.

In the hydrogenation isomerization step of Example 3, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 2, the oil to be treated of Example 3 was brought into contact with the catalyst b at the reaction temperature shown in Table 2, The resulting oil was obtained. On the other hand, in the hydroisomerization process, the ratio of hydrogen/hydrocarbon oil was adjusted to 506 Nm 3 /m 3. In the hydroisomerization step, the liquid space velocity of the hydrocarbon oil with respect to the catalyst b was adjusted to the value shown in Table 2. The reaction temperature in the hydrogenation isomerization step of Example 3 is the lowest temperature at which the pour point of the following base oil fraction b for lubricating oil ("main base oil fraction" in Table 2) becomes -12.5°C or less. Table 2 shows the content of aromatic hydrocarbons in the product oil of Example 3, the content of sulfur content in the product oil, and the yield (X) of Example 3.

In the purification process (pressure-sensitive distillation process) of Example 3, the product oil obtained in the hydroisomerization process was classified into naphtha, kerosene oil, and heavy oil. Further, by classifying the heavy oil fraction, the following base oil fraction a for lubricating oil (base oil fraction 1 in Table 3) and the base oil fraction b for lubricating oil (base oil fraction 2 in Table 3) were obtained. The base oil fraction b for lubricating oil in Example 3 corresponds to the "main base oil fraction" in Table 2.

[Base oil fraction for lubricating oil a]

Kinematic viscosity at 100°C: 2.70 mm 2 /s.

Boiling point range: 343 to 387°C.

[Base oil fraction for lubricating oil b]

Table 2 shows the yield (Y), pour point, kinematic viscosity, viscosity index (VI), and (VI×Y) of the base oil fraction b (main base oil fraction) for lubricating oil of Example 3. On the other hand, the boiling point range of the main base oil fraction of Example 3 was 392 to 447°C.

(Example 4)

Hydrocarbon oil of Example 4 (hydrocarbon oil before hydrogenation) of Example 4 was obtained by extracting and removing part of the aromatic hydrocarbons in the gas oil fraction under reduced pressure in furfural using an extraction tower. Table 1 shows the boiling point range of the hydrocarbon oil before hydrogenation in Example 4, T10, T90, the aromatic hydrocarbon content in the hydrocarbon oil, the sulfur content in the hydrocarbon oil, the kinematic viscosity of the hydrocarbon oil, and the viscosity index (VI) of the hydrocarbon oil. do. On the other hand, the density at 15°C of the hydrocarbon oil before hydrogenation in Example 4 was 0.8724 g/cm 3. The content of nitrogen content in the hydrocarbon oil before hydrogenation of Example 4 was 58 mass ppm.

In the hydrogenation process of Example 4, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 1, the hydrocarbon oil of Example 4 was brought into contact with the catalyst a at the reaction temperature shown in Table 1, The oil to be treated was obtained. On the other hand, in the hydrogenation process, the ratio of hydrogen/hydrocarbon oil was adjusted to 253 Nm 3 /m 3. In the hydrogenation process, the liquid space velocity of the hydrocarbon oil with respect to the catalyst a was adjusted to the value shown in Table 1. Table 1 shows the content of aromatic hydrocarbons in the oil to be treated obtained in the hydrogenation step of Example 4, the content of sulfur content in the oil to be treated, the kinematic viscosity of the oil to be treated, and the viscosity index (VI) of the oil to be treated.

In the hydrogenation isomerization step of Example 4, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 2, the oil to be treated of Example 4 was brought into contact with the catalyst b at the reaction temperature shown in Table 2, The resulting oil was obtained. On the other hand, in the hydroisomerization process, the ratio of hydrogen/hydrocarbon oil was adjusted to 506 Nm 3 /m 3. In the hydroisomerization step, the liquid space velocity of the hydrocarbon oil with respect to the catalyst b was adjusted to the value shown in Table 1. The reaction temperature in the hydrogenation isomerization step of Example 4 is the lowest temperature at which the pour point of the following base oil fraction c for lubricating oil ("main base oil fraction" in Table 2) becomes -12.5°C or less. Table 2 shows the content of aromatic hydrocarbons in the product oil of Example 4, the content of sulfur content in the product oil, and the yield (X) of Example 4.

In the purification process (pressure-sensitive distillation process) of Example 4, the product oil obtained in the hydroisomerization process was classified into naphtha, kerosene and diesel oil, and heavy oil. In addition, by classifying the heavy oil, the following base oil fraction a for lubricating oil (base oil fraction 1 in Table 3), base oil fraction b for lubricating oil (base oil fraction 2 in Table 3), and base oil fraction c for lubricating oil (base oil fraction 3 in Table 3) Was obtained. The base oil fraction c for lubricating oil in Example 4 corresponds to the "main base oil fraction" in Table 2.

[Base oil fraction for lubricating oil a]

Kinematic viscosity at 100°C: 2.70 mm 2 /s.

Boiling point range: 343 to 387°C.

[Base oil fraction for lubricating oil b]

Kinematic viscosity at 100°C: 4.91 mm 2 /s.

Boiling point range: 395 to 445°C.

[Base oil fraction for lubricating oil c]

Table 2 shows the yield (Y), pour point, kinematic viscosity, viscosity index (VI), and (VI×Y) of the base oil fraction c (main base oil fraction) for lubricating oil of Example 4. On the other hand, the boiling point range of the main base oil fraction of Example 4 was 455 to 472°C.

(Example 5)

Hydrocarbon oil of Example 5 (hydrocarbon oil before hydrogenation) of Example 5 was obtained by extracting and removing part of the aromatic hydrocarbons in the gas oil fraction under reduced pressure in furfural using an extraction tower. Each value of the boiling point range of the hydrocarbon oil before hydrogenation in Example 5, T10, T90, the aromatic hydrocarbon content in the hydrocarbon oil, the sulfur content in the hydrocarbon oil, the kinematic viscosity at 100°C of the hydrocarbon oil, and the viscosity index (VI) of the hydrocarbon oil It is described in Table 1. On the other hand, the density at 15°C of the hydrocarbon oil before hydrogenation in Example 5 was 0.8873 g/cm 3. The content of nitrogen content in the hydrocarbon oil before hydrogenation of Example 5 was 77 mass ppm.

In the hydrogenation process of Example 5, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 1, the hydrocarbon oil of Example 5 was brought into contact with the catalyst a at the reaction temperature shown in Table 1, The oil to be treated was obtained. On the other hand, in the hydrogenation process, the ratio of hydrogen/hydrocarbon oil was adjusted to 253 Nm 3 /m 3. In the hydrogenation process, the liquid space velocity of the hydrocarbon oil with respect to the catalyst a was adjusted to the value shown in Table 1. Table 1 shows the content of aromatic hydrocarbons in the oil to be treated obtained in the hydrogenation step of Example 5, the content of sulfur content in the oil to be treated, the kinematic viscosity of the oil to be treated, and the viscosity index (VI) of the oil to be treated.

In the hydrogenation isomerization step of Example 5, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 2, the oil to be treated of Example 5 was brought into contact with the catalyst b at the reaction temperature shown in Table 2, The resulting oil was obtained. On the other hand, in the hydroisomerization process, the ratio of hydrogen/hydrocarbon oil was adjusted to 506 Nm 3 /m 3. In the hydroisomerization step, the liquid space velocity of the hydrocarbon oil with respect to the catalyst b was adjusted to the value shown in Table 1. The reaction temperature in the hydrogenation isomerization step of Example 5 is the lowest temperature at which the pour point of the following base oil fraction c for lubricating oil ("main base oil fraction" in Table 2) becomes -12.5°C or less. Table 2 shows the content of aromatic hydrocarbons in the product oil of Example 5, the content of sulfur content in the product oil, and the yield (X) of Example 5.

In the purification step of Example 5 (pressure-sensitive distillation step), the product oil obtained in the hydroisomerization step was classified into naphtha, kerosene oil, and heavy oil. In addition, by classifying the heavy oil, the following base oil fraction a for lubricating oil (base oil fraction 2 in Table 3), base oil fraction b for lubricating oil (base oil fraction 3 in Table 3) and base oil fraction c for lubricating oil (base oil fraction 4 in Table 3) Was obtained. The base oil fraction c for lubricating oil in Example 5 corresponds to the "main base oil fraction" in Table 2.

[Base oil fraction for lubricating oil a]

Kinematic viscosity at 100°C: 2.70 mm 2 /s.

Boiling point range: 395 to 447°C.

[Base oil fraction for lubricating oil b]

Kinematic viscosity at 100°C: 4.93 mm 2 /s.

Boiling point range: 457 to 476°C.

[Base oil fraction for lubricating oil c]

Table 2 shows the yield (Y), pour point, kinematic viscosity, viscosity index (VI), and (VI×Y) of the base oil fraction c (main base oil fraction) for lubricating oil of Example 5. On the other hand, the boiling point range of the main base oil fraction of Example 5 was 495 to 535°C.

(Examples 6 to 9)

In Examples 6 to 9, the hydrocarbon oil shown in Table 1 was subjected to hydrogenation treatment under the conditions shown in Table 1 to obtain the oil to be treated shown in Table 1. In Examples 6 to 9, under the conditions shown in Table 2, a hydroisomerization step was performed on the oil to be treated shown in Table 1 to obtain the product oil shown in Table 2. Except for these matters, Examples 6 to 10 and Example 5 are common. Also in Examples 6 to 9, the same purification process as in Example 5 was carried out to obtain base oil fractions shown in Tables 2 and 3.

(Example 10)

The hydrocarbon oil of Example 10 (hydrocarbon oil before hydrogenation) was obtained by extracting and removing part of the aromatic hydrocarbons in the gas oil fraction under reduced pressure into furfural using an extraction tower. Each value of the boiling point range of the hydrocarbon oil before hydrogenation in Example 10, T10, T90, the aromatic hydrocarbon content in the hydrocarbon oil, the sulfur content content in the hydrocarbon oil, the kinematic viscosity at 100°C of the hydrocarbon oil, and the viscosity index (VI) of the hydrocarbon oil It is described in Table 1. On the other hand, the density at 15°C of the hydrocarbon oil before hydrogenation in Example 10 was 0.8589 g/cm 3. The content of nitrogen content in the hydrocarbon oil before hydrogenation of Example 10 was 25 ppm by mass.

In the hydrogenation process of Example 10, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 1, the hydrocarbon oil of Example 10 was brought into contact with the catalyst a at the reaction temperature shown in Table 1, The oil to be treated was obtained. On the other hand, in the hydrogenation process, the ratio of hydrogen/hydrocarbon oil was adjusted to 253 Nm 3 /m 3. In the hydrogenation process, the liquid space velocity of the hydrocarbon oil with respect to the catalyst a was adjusted to the value shown in Table 1. Table 1 shows the content of aromatic hydrocarbons in the oil to be treated obtained in the hydrogenation process of Example 10, the content of sulfur content in the oil to be treated, the kinematic viscosity of the oil to be treated, and the viscosity index (VI) of the oil to be treated.

In the hydrogenation isomerization step of Example 10, in an atmosphere in which the partial pressure of hydrogen is the value shown in Table 2, the oil to be treated of Example 10 was brought into contact with the catalyst b at the reaction temperature shown in Table 2, The resulting oil was obtained. On the other hand, in the hydroisomerization process, the ratio of hydrogen/hydrocarbon oil was adjusted to 506 Nm 3 /m 3. In the hydroisomerization step, the liquid space velocity of the hydrocarbon oil with respect to the catalyst b was adjusted to the value shown in Table 2. The reaction temperature in the hydrogenation isomerization step of Example 10 is the lowest temperature at which the pour point of the following base oil fraction a for lubricating oil ("main base oil fraction" in Table 2) becomes -12.5°C or less. Table 2 shows the content of aromatic hydrocarbons in the product oil of Example 10, the content of sulfur content in the product oil, and the yield (X) of Example 10.

Through the purification step of Example 10 (pressure distillation step), the following base oil fraction a for lubricating oil (base oil fraction 1'in Table 3) was obtained.

[Base oil fraction for lubricating oil a]

Kinematic viscosity at 100°C: 2.702 mm 2 /s.

Boiling point range: 341 to 385°C.

Table 2 shows the yield (Y), pour point, kinematic viscosity, viscosity index (VI), and (VI×Y) of the base oil fraction a (main base oil fraction) of Example 10 for lubricating oil. The boiling point range of the main base oil fraction of Example 10 was 341 to 385°C.

(Example 11)

As the hydrocarbon oil (hydrocarbon oil prior to hydrogenation treatment) of Example 11, a vacuum gas oil fraction not subjected to an extraction process with furfural was used. Each value of the boiling point range of the hydrocarbon oil before hydrogenation of Example 11, T10, T90, the content of aromatic hydrocarbons in the hydrocarbon oil, the content of sulfur content in the hydrocarbon oil, the kinematic viscosity at 100°C of the hydrocarbon oil, and the viscosity index (VI) of the hydrocarbon oil It is described in Table 1. On the other hand, the density at 15°C of the hydrocarbon oil before hydrogenation in Example 11 was 0.9054 g/cm 3. The content of nitrogen content in the hydrocarbon oil before hydrogenation in Example 11 was 510 ppm by mass.

In the hydrogenation process of Example 11, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 1, the hydrocarbon oil of Example 11 was brought into contact with the catalyst a at the reaction temperature shown in Table 1, The oil to be treated was obtained. On the other hand, in the hydrogenation process, the ratio of hydrogen/hydrocarbon oil was adjusted to 253 Nm 3 /m 3. In the hydrogenation process, the liquid space velocity of the hydrocarbon oil with respect to the catalyst a was adjusted to the value shown in Table 1. Table 1 shows the content of aromatic hydrocarbons in the oil to be treated obtained in the hydrogenation step of Example 11, the content of sulfur content in the oil to be treated, the kinematic viscosity of the oil to be treated, and the viscosity index (VI) of the oil to be treated.

In the hydrogenation isomerization process of Example 11, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 2, the oil to be treated of Example 11 was brought into contact with the catalyst b at the reaction temperature shown in Table 2, The resulting oil was obtained. On the other hand, in the hydroisomerization process, the ratio of hydrogen/hydrocarbon oil was adjusted to 506 Nm 3 /m 3. In the hydroisomerization step, the liquid space velocity of the hydrocarbon oil with respect to the catalyst b was adjusted to the value shown in Table 2. The reaction temperature in the hydrogenation isomerization step of Example 11 is the lowest temperature at which the pour point of the following base oil fraction a for lubricating oil ("main base oil fraction" in Table 2) becomes -12.5°C or less. Table 2 shows the content of aromatic hydrocarbons in the product oil of Example 11, the content of sulfur content in the product oil, and the yield (X) of Example 11.

Through the purification process of Example 11 (pressure distillation process), the following base oil fraction a for lubricating oil (base oil fraction 1'in Table 3) was obtained.

[Base oil fraction for lubricating oil a]

Kinematic viscosity at 100°C: 2.702 mm 2 /s.

Boiling point range: 341 to 387°C.

Table 2 shows the yield (Y), pour point, kinematic viscosity, viscosity index (VI), and (VI×Y) of the base oil fraction a (main base oil fraction) of Example 11 for lubricating oil. On the other hand, the boiling point range of the main base oil fraction of Example 11 was 341 to 387°C.

(Example 12)

Hydrocarbon oil of Example 12 (hydrocarbon oil before hydrogenation) of Example 12 was obtained by performing solvent deasphalting of the vacuum gas oil fraction after extraction and removal of some of the aromatic hydrocarbons in the reduced pressure gas oil fraction using an extraction tower. I did. Each value of the boiling point range of the hydrocarbon oil before hydrogenation in Example 12, T10, T90, the aromatic hydrocarbon content in the hydrocarbon oil, the sulfur content in the hydrocarbon oil, the kinematic viscosity at 100°C of the hydrocarbon oil, and the viscosity index (VI) of the hydrocarbon oil It is described in Table 1. On the other hand, the density at 15°C of the hydrocarbon oil before hydrogenation in Example 12 was 0.8831 g/cm 3. The content of nitrogen content in the hydrocarbon oil before hydrogenation of Example 12 was 18 mass ppm.

In the hydrogenation process of Example 12, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 1, the hydrocarbon oil of Example 12 was brought into contact with the catalyst a at the reaction temperature shown in Table 1, The oil to be treated was obtained. On the other hand, in the hydrogenation process, the ratio of hydrogen/hydrocarbon oil was adjusted to 253 Nm 3 /m 3. In the hydrogenation process, the liquid space velocity of the hydrocarbon oil with respect to the catalyst a was adjusted to the value shown in Table 1. Table 1 shows the content of aromatic hydrocarbons in the oil to be treated obtained in the hydrogenation step of Example 12, the content of sulfur content in the oil to be treated, the kinematic viscosity of the oil to be treated, and the viscosity index (VI) of the oil to be treated.

In the hydrogenation isomerization step of Example 12, in an atmosphere where the partial pressure of hydrogen is the value shown in Table 2, the oil to be treated of Example 12 was brought into contact with the catalyst b at the reaction temperature shown in Table 2, The resulting oil was obtained. On the other hand, in the hydroisomerization process, the ratio of hydrogen/hydrocarbon oil was adjusted to 506 Nm 3 /m 3. In the hydroisomerization step, the liquid space velocity of the hydrocarbon oil with respect to the catalyst b was adjusted to the value shown in Table 1. The reaction temperature in the hydroisomerization step of Example 12 is the lowest temperature at which the pour point of the following base oil fraction c for lubricating oil ("main base oil fraction" in Table 2) becomes -12.5°C or less. Table 2 shows the content of aromatic hydrocarbons in the product oil of Example 12, the content of sulfur content in the product oil, and the yield (X) of Example 12.

In the purification process (pressure-sensitive distillation process) of Example 12, the product oil obtained in the hydroisomerization process was classified into naphtha, kerosene and diesel oil, and heavy oil. In addition, by classifying the heavy oil, the following base oil fraction a for lubricating oil (base oil fraction 3 in Table 3), base oil fraction b for lubricating oil (base oil fraction 4 in Table 3), and base oil fraction c for lubricating oil (base oil fraction 5 in Table 3) ) Was obtained. The base oil fraction c for lubricating oil in Example 12 corresponds to the "main base oil fraction" in Table 2.

[Base oil fraction for lubricating oil a]

Kinematic viscosity at 100°C: 6.213 mm 2 /s.

Boiling point range: 457 to 476°C.

[Base oil fraction for lubricating oil b]

Kinematic viscosity at 100°C: 10.50 mm 2 /s.

Boiling point range: 497 to 538°C.

[Base oil fraction for lubricating oil c]

Table 2 shows the yield (Y), pour point, kinematic viscosity, viscosity index (VI), and (VI×Y) of the base oil fraction c (main base oil fraction) for lubricating oil of Example 12. On the other hand, the boiling point range of the main base oil fraction of Example 12 was 562 to 610°C.

(Comparative Example 1)

In Comparative Example 1, the hydrocarbon oil shown in Table 1 was subjected to hydrogenation under the conditions shown in Table 1 to obtain the oil to be treated shown in Table 1. In Comparative Example 1, under the conditions shown in Table 2, a hydroisomerization step was performed on the oil to be treated shown in Table 1 to obtain the product oil shown in Table 2. Except for these matters, Comparative Example 1 and Examples 1 and 2 are common. Also in Comparative Example 1, the same purification process as in Examples 1 and 2 was carried out to obtain base oil fractions shown in Tables 2 and 3.

(Comparative Example 2)

In Comparative Example 2, the hydrocarbon oil shown in Table 1 was subjected to hydrogenation treatment under the conditions shown in Table 1 to obtain the oil to be treated shown in Table 1. In Comparative Example 2, under the conditions shown in Table 2, a hydroisomerization step was performed on the oil to be treated shown in Table 1 to obtain the product oil shown in Table 2. Except for these matters, Comparative Example 2, Examples 1 and 2, and Comparative Example 1 are common. Also in Comparative Example 2, the same purification steps as in Examples 1 and 2 and Comparative Example 1 were carried out to obtain base oil fractions shown in Tables 2 and 3.

(Comparative Example 3)

In Comparative Example 3, the hydrocarbon oil shown in Table 1 was subjected to hydrogenation treatment under the conditions shown in Table 1 to obtain the oil to be treated shown in Table 1. In Comparative Example 3, under the conditions shown in Table 2, a hydroisomerization step was performed on the oil to be treated shown in Table 1 to obtain the product oil shown in Table 2. Except for these matters, Comparative Example 3 and Example 3 are common. Also in Comparative Example 3, the same purification process as in Example 3 was carried out to obtain base oil fractions shown in Tables 2 and 3.

(Comparative Example 4)

In Comparative Example 4, the hydrocarbon oil shown in Table 1 was subjected to hydrogenation under the conditions shown in Table 1 to obtain the oil to be treated shown in Table 1. In Comparative Example 4, under the conditions shown in Table 2, a hydroisomerization step was performed on the oil to be treated shown in Table 1 to obtain the product oil shown in Table 2. Except for these matters, Comparative Example 4, Example 3, and Comparative Example 3 are common. Also in Comparative Example 4, the same purification process as in Examples 3 and 3 was carried out to obtain base oil fractions shown in Tables 2 and 3.

(Comparative Example 5)

In Comparative Example 5, under the conditions shown in Table 1, the hydrocarbon oil shown in Table 1 was subjected to hydrogenation treatment to obtain the oil to be treated shown in Table 1. In Comparative Example 5, under the conditions shown in Table 2, a hydroisomerization step was performed on the oil to be treated shown in Table 1 to obtain the product oil shown in Table 2. Except for these matters, Comparative Example 5 and Example 4 are common. Also in Comparative Example 5, the same purification process as in Example 4 was carried out to obtain base oil fractions shown in Tables 2 and 3.

(Comparative Example 6)

In Comparative Example 6, the hydrocarbon oil shown in Table 1 was subjected to hydrogenation under the conditions shown in Table 1 to obtain the oil to be treated shown in Table 1. In Comparative Example 6, under the conditions shown in Table 2, a hydroisomerization step was performed on the oil to be treated shown in Table 1 to obtain the product oil shown in Table 2. Except for these matters, Comparative Example 6 and Examples 5 to 9 are common. Also in Comparative Example 6, the same purification process as in Examples 5 to 9 was performed to obtain base oil fractions shown in Tables 2 and 3.

(Comparative Example 7)

In Comparative Example 7, the hydrocarbon oil shown in Table 1 was subjected to hydrogenation treatment under the conditions shown in Table 1 to obtain the oil to be treated shown in Table 1. In Comparative Example 7, a hydroisomerization step was performed on the oil to be treated shown in Table 1 under the conditions shown in Table 2 to obtain the product oil shown in Table 2. Except for these matters, Comparative Example 7 and Examples 5 to 9 are common. Also in Comparative Example 7, the same purification process as in Examples 5 to 9 was carried out to obtain base oil fractions shown in Tables 2 and 3.

(Comparative Example 8)

In Comparative Example 8, under the conditions shown in Table 1, the hydrocarbon oil shown in Table 1 was subjected to hydrogenation treatment to obtain the oil to be treated shown in Table 1. In Comparative Example 8, under the conditions shown in Table 2, a hydroisomerization step was performed on the oil to be treated shown in Table 1 to obtain the product oil shown in Table 2. Except for these matters, Comparative Example 8 and Examples 5 to 9 are common. Also in Comparative Example 8, the same purification process as in Examples 5 to 9 was carried out to obtain base oil fractions shown in Tables 2 and 3.

(Comparative Example 9)

In Comparative Example 9, the hydrocarbon oil shown in Table 1 was subjected to hydrogenation under the conditions shown in Table 1 to obtain the oil to be treated shown in Table 1. In Comparative Example 9, under the conditions shown in Table 2, a hydroisomerization step was performed on the oil to be treated shown in Table 1 to obtain the product oil shown in Table 2. Except for these matters, Comparative Example 9 and Example 11 are common. Also in Comparative Example 9, the same purification process as in Example 11 was carried out to obtain base oil fractions shown in Tables 2 and 3.

In any of the examples, a main base oil fraction for lubricating oil having a high viscosity index, belonging to the group II lubricating base oil defined by API, could be produced in high yield.

Since the base oil for lubricating oil obtained by the production method according to the present invention has excellent properties as described above, it can be suitably used as a base oil for various lubricating oils. Lubricating oil The use of the base oil is specifically, a lubricating oil used in internal combustion engines such as gasoline engines for passenger cars, gasoline engines for two-wheeled vehicles, diesel engines, gas engines, gas heat pump engines, marine engines, and power generation engines (lubricating oil for internal combustion engines). , Lubricating oil used in drive transmission devices such as automatic transmissions, manual transmissions, continuously variable transmissions, and vertical reduction gears (oil for driving transmission devices), hydraulic hydraulic oil used in hydraulic devices such as shock absorbers, construction machinery, compressor oil, turbine oil, gears Oil, refrigerating machine oil, and an oil for metal processing. By using the lubricating base oil of the present invention for these applications, the viscosity-temperature characteristics of each lubricating oil, thermal/oxidation stability, energy saving, fuel economy, and other characteristics are improved, and the life of each lubricating oil is increased and environmentally harmful substances are reduced. Can be achieved at a high level.

Claims (4)

In an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa, hydrogenation of petroleum-derived hydrocarbon oil is performed at a reaction temperature of 250 to 420°C to prepare an oil to be treated having an aromatic hydrocarbon content of 10 to 25% by mass. Process,
Process of carrying out hydroisomerization of the oil to be treated using zeolite having a 10-membered ring one-dimensional pore structure
And,
The zeolite having a 10-membered one-dimensional pore structure is at least one selected from the group consisting of ZSM-22 zeolite, ZSM-23 zeolite, ZSM-48 zeolite, and SSZ-32 zeolite,
Method for producing base oil for lubricating oil. The method of claim 1, wherein the hydrogenation isomerization of the oil to be treated is carried out in an atmosphere in which the partial pressure of hydrogen is 11 to 20 MPa.
Method for producing base oil for lubricating oil. The method according to claim 1 or 2, wherein the hydroisomerization of the oil to be treated is performed at a reaction temperature of 200 to 450°C,
Method for producing base oil for lubricating oil. A base oil for lubricating oil produced by the method for producing the base oil for lubricating oil according to claim 1 or 2.