JP6506667B2 - Method of producing lubricating base oil - Google Patents

Description

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

  In the petroleum refining process, atmospheric distillation of crude oil gives atmospheric residual oil (AR). Vacuum distillation of this atmospheric residue (bottom oil) gives a vacuum gas oil (VGO: Vacuum Gas Oil). Lubricating oil base oil (base oil for lubricating oil) is obtained by various reactions such as hydrocracking of these feedstock oils. As a hydrocracking catalyst, for example, a catalyst containing an amorphous solid acid (amorphous catalyst) and a catalyst containing a zeolite (zeolitic catalyst) are known. For example, Patent Document 1 listed below describes a hydrocracking catalyst containing amorphous silica alumina as a solid acid.

Japanese Patent Application Publication No. 2006-505403

  When a feedstock oil containing an aromatic hydrocarbon (for example, a vacuum gas oil) is brought into contact with a hydrocracking catalyst, hydrogenation of the aromatic hydrocarbon produces naphthene, and isomerization and ring opening of the naphthene cause viscosity index (VI A product oil is obtained which contains high isoparaffins. The bottom oil obtained by the fractionation of the product oil containing isoparaffin is used as a raw material of a lubricant base oil.

  Amorphous catalysts are excellent in the activity of isomerization and ring opening of naphthene. However, the activity of the amorphous catalyst appears at a temperature higher than the activity of the zeolitic catalyst. That is, in the hydrocracking using an amorphous catalyst, it is necessary to heat the amorphous catalyst at a higher temperature than when using a zeolitic catalyst. And, as the hydrogenolysis is continued, the activity is deteriorated due to coking or the like, and therefore, it is necessary to keep raising the temperature of the amorphous catalyst to compensate for the activity. As a result, in hydrocracking using an amorphous catalyst, the temperature of the amorphous catalyst reaches the upper limit of the heat resistance temperature of the reactor earlier than when using a zeolitic catalyst, and the hydrocracking continues. It will be difficult. That is, the life of the amorphous catalyst is shorter than the life of the zeolite catalyst.

  Zeolite based catalysts are superior to amorphous catalysts in that the activity of hydrocracking is manifested at lower temperatures. Therefore, the catalyst life of the zeolitic catalyst is longer than that of the amorphous catalyst, and the amount of heat (energy) required for hydrocracking using the zeolitic catalyst is more saved than when using the amorphous catalyst.

  However, in the hydrocracking using a zeolitic catalyst, the hydrocracking of paraffin tends to occur in preference to the isomerization and ring opening of naphthene as compared to the hydrocracking using an amorphous catalyst. Therefore, in hydrocracking using a zeolitic catalyst, isomerization and ring opening of naphthene are less likely to occur, and isoparaffin is less likely to occur, as compared to the case of using an amorphous catalyst. As a result, the viscosity index of the product oil obtained using the zeolitic catalyst is lower than the viscosity index of the product oil obtained using the amorphous catalyst.

  As described above, it is difficult to achieve both the long life of the hydrocracking catalyst and the high viscosity index of the lubricating base oil in the conventional method for producing a lubricating base oil.

  The present invention has been made in view of the problems of the prior art, and provides a method for producing a lubricant base oil that extends the life of a hydrocracking catalyst and increases the viscosity index (VI) of the lubricant base oil. The purpose is to

In the method for producing a lubricant base oil according to one aspect of the present invention, a feedstock oil containing an aromatic hydrocarbon is brought into contact with a first hydrocracking catalyst in the presence of hydrogen gas to hydrocrack the feedstock oil. A first step of obtaining a first product oil, and contacting the first product oil with a second hydrocracking catalyst in the presence of hydrogen gas to hydrocrack the first product oil Accordingly, a second step of obtaining a second product oil, comprising a first hydrocracking catalyst contains a zeolite, the second hydrocracking catalyst contains an amorphous solid acid, the first step The hydrocracking of the feedstock oil at this stage includes the formation of naphthenes by hydrogenation of aromatic hydrocarbons in the feedstock oil, and the formation of isoparaffins by the isomerization and ring opening of naphthenes, and the hydrogen of the first oil produced in the second step Cracking is caused by the hydrogenation of aromatic hydrocarbons in the first oil Production of, as well as production of isoparaffins by isomerization and ring opening of naphthenes.

  In one aspect of the present invention, when the volume of the first hydrocracking catalyst is V1 and the volume of the second hydrocracking catalyst is V2, 100 · V1 / (V1 + V2) is 5 to 50, Good.

  In one aspect of the present invention, a first catalyst bed containing a first hydrocracking catalyst and a second catalyst bed containing a second hydrocracking catalyst are fixed in one fixed bed reactor. In the first step, the feedstock oil may be flowed to the first catalyst layer to obtain a first product oil, and in the second step, the first product oil may be flowed from the first catalyst layer to the second catalyst layer , Second product oil may be obtained.

In one aspect of the present invention, the feedstock oil may be vacuum gas oil.
In one aspect of the present invention, the hydrocracking of the feedstock oil in the first step may proceed at a lower temperature than the hydrocracking of the first product oil in the second step .

  According to the present invention, there is provided a process for producing a lubricant base oil that extends the life of the hydrocracking catalyst and increases the viscosity index (VI) of the lubricant base oil.

FIG. 1 is a schematic cross-sectional view in the vertical direction of a reactor used in a method for producing a lubricant base oil according to an embodiment of the present invention.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to FIG. In FIG. 1, equivalent components are given the same reference numerals. X, Y and Z shown in FIG. 1 mean three coordinate axes orthogonal to each other. The Z axis is vertical and the X and Y axes are horizontal. The present invention is not limited to the following embodiments.

  In the method for producing a lubricant base oil according to the present embodiment, a fixed bed reactor 10 shown in FIG. 1 is used. The fixed bed reactor 10 is a tower reactor extending in the vertical direction Z. In the fixed bed reactor 10, a first catalyst layer 1 and a second catalyst layer 2 are fixed. The first catalyst layer 1 and the second catalyst layer 2 are aligned in the vertical direction Z. The first catalyst layer 1 is disposed above the second catalyst layer 2. In the fixed bed reactor 10, a filler may be filled in a region where the above catalyst layer (1, 2) is not disposed.

  The first catalyst layer 1 contains a first hydrocracking catalyst. The first catalyst layer 1 may be composed of only the first hydrocracking catalyst. The first hydrocracking catalyst contains a zeolite. Hereinafter, the first hydrocracking catalyst may be referred to as a zeolitic catalyst. The second catalyst layer 2 contains a second hydrocracking catalyst. The second catalyst layer 2 may be composed of only the second hydrocracking catalyst. The second hydrocracking catalyst contains an amorphous (amorphous) solid acid. Hereinafter, the second hydrocracking catalyst may be referred to as an amorphous catalyst.

  The feedstock oil 4 used for producing the lubricating base oil contains an aromatic hydrocarbon. The feedstock oil 4 may be, for example, a fraction obtained in the process of distillation of crude oil. The crude oil may be, for example, at least one selected from the group consisting of petroleum, condensate, synthetic crude oil derived from oil sands, and bitumen reformed oil. The feedstock oil 4 may be, for example, at least one selected from the group consisting of heavy oil (normal residual oil), vacuum gas oil, vacuum residual oil, and deasphalted oil. Heavy oil (atmospheric residual oil) is obtained by atmospheric distillation of crude oil. Vacuum gas oil and vacuum residue are obtained by vacuum distillation of atmospheric residue. The deasphalted oil is obtained by deasphalting of the vacuum residue.

When the feedstock oil 4 is a vacuum gas oil, the effects according to the present invention are remarkable. The properties of the vacuum gas oil may be, for example, as follows.
Density: 0.92 to 0.94.
Aromatic hydrocarbon content: 45 to 60% by mass.
Sulfur content: 2.2 to 3.0% by mass.
Content of nitrogen content: 600 to 1200 mass ppm.
Initial boiling point: 210-260 ° C.
5% distillation temperature: 300 to 330 ° C.
95% distillation temperature: 550-590 ° C.
Final boiling point: 590-650 ° C.

  The method for producing a lubricant base oil according to the present embodiment comprises a first step and a second step. In the present embodiment, first, the feedstock oil 4 is supplied from the upper part of the fixed bed reactor 10 to the inside of the fixed bed reactor 10. Hydrogen gas is also supplied to the inside of the fixed bed reactor 10.

  In the first step, the feedstock oil 4 is flowed to the first catalyst layer 1 in the presence of hydrogen gas. That is, in the first step, the feedstock oil 4 is brought into contact with the first hydrocracking catalyst in the first catalyst layer 1 to hydrocrack the feedstock oil 4. By hydrocracking the feedstock oil 4, a first product oil 5A is obtained. The hydrocracking in the first step implies the formation of naphthene by hydrogenation of aromatic hydrocarbon in the feedstock oil 4 and the formation of isoparaffin by isomerization and ring opening of naphthene. The hydrocracking depends on the acid nature of the first hydrocracking catalyst.

  In the second step, the first product oil 5A obtained in the first step is allowed to flow from the first catalyst layer 1 to the second catalyst layer 2 in the presence of hydrogen gas. That is, in the second step, the first product oil 5A is brought into contact with the second hydrocracking catalyst in the second catalyst layer 2 to hydrocrack the first product oil 5A. By hydrogenolysis of the first product oil 5A, a second product oil 5B is obtained. The hydrogenolysis in the second step implies the formation of naphthene by hydrogenation of aromatic hydrocarbon in the first oil 5A, and the formation of isoparaffin by isomerization and ring opening of naphthene. The hydrocracking depends on the acid nature of the second hydrocracking catalyst. The second product oil 5B itself may be used as a lubricant base oil. The lubricating oil base oil may be obtained by performing hydrofinishing of the second product oil 5B and subsequent vacuum distillation.

  Since the feedstock oil 4, the first product oil 5A and the second product oil 5B respectively flow vertically downward by gravity, the first step and the second step proceed continuously and automatically. The details of the first step and the second step are as follows.

  In the first step, the feedstock oil 4 supplied into the fixed bed reactor 10 flows downward by gravity and contacts the amorphous catalyst in the first catalyst layer 1. As a result, hydrocracking of the feedstock oil 4 occurs and reaction heat of hydrocracking is generated. The first product oil 5A heated by the heat of reaction flows from the first catalyst layer 1 to the second catalyst layer 2. Therefore, the temperature of the second catalyst layer 2 tends to be higher than the temperature of the first catalyst layer 1. In other words, the hydrocracking of the feedstock oil 4 in the first catalyst layer 1 proceeds at a lower temperature than the hydrocracking of the first oil 5A in the second catalyst layer 2. In the present embodiment, a zeolitic catalyst which is more excellent in activity at a lower temperature than an amorphous catalyst is disposed in the first catalyst layer 1. Therefore, the hydrocracking of the feedstock oil 4 can be sufficiently advanced in the low temperature first catalyst layer 1. In addition, due to the excellent activity of the zeolite catalyst at low temperature, the amount of heat (energy) required for hydrocracking in the first catalyst layer 1 is also saved.

  Since the zeolitic catalyst is disposed in the first catalyst layer 1 which is at a lower temperature than the second catalyst layer 2, the isomerization and opening of naphthenes by the zeolitic catalyst can be carried out while suppressing the overdecomposition of paraffin by the zeolitic catalyst to some extent. It becomes possible to cause a ring (formation of isoparaffin). That is, by arranging the zeolitic catalyst in the low temperature region (the first catalyst layer 1), the decrease in the viscosity index of the lubricating base oil due to the overcracking of paraffin is suppressed. In addition, by arranging the zeolitic catalyst in the low temperature region (the first catalyst layer 1), the decrease in the yield of the lubricating base oil due to the overcracking of paraffin is also suppressed. If the zeolite-based catalyst is disposed in the second catalyst layer 2 whose temperature is higher than that of the first catalyst layer 1, paraffin decomposition in the second catalyst layer 2 has priority over naphthene isomerization and ring opening. It happens. As a result, the viscosity index of the second product oil 5B decreases, and the yield of the lubricating base oil also decreases.

  In the second step, hydrogenation of aromatic hydrocarbon (formation of naphthene) and isomerization and opening of naphthene (formation of isoparaffin) in the first oil 5A are further promoted by the amorphous catalyst. That is, the aromatic hydrocarbon which remained without reacting in the first step and naphthene are reacted in the second step to further produce isoparaffin. As a result, the viscosity index of the second product oil 5B is increased.

  The temperature required to express the activity of the amorphous catalyst is higher than that of the zeolite catalyst. However, the amorphous catalyst disposed in the second catalyst layer 2 is sufficiently heated by the first product oil 5A supplied from the first catalyst layer 1. As a result, the activity of the amorphous catalyst is sufficiently developed in the second catalyst layer 2. If the amorphous catalyst is disposed in the first catalyst layer 1 whose temperature is lower than that of the second catalyst layer 2, the temperature of the amorphous catalyst is adjusted to compensate for the activity of the amorphous catalyst that degrades with time. I have to keep raising. As a result, the temperature of the amorphous catalyst rapidly reaches the upper limit value of the heat resistant temperature of the fixed bed reactor 10.

  In the present embodiment, after the hydrogenolysis (first step) by the zeolite catalyst having excellent activity, the hydrogenolysis (second step) by the amorphous catalyst is performed. As a result, in the present embodiment, the load of the amorphous catalyst is reduced as compared to the conventional hydrocracking using only the amorphous catalyst. That is, even if the temperature of the amorphous catalyst in the second step is lower than that of the conventional hydrocracking using only the amorphous catalyst, the second product oil 5B having a viscosity index equal to that of the conventional is equivalent to that of the conventional It can be obtained in a yield. Since the temperature of the amorphous catalyst in the second step can be reduced, the time (life) until the temperature of the amorphous catalyst reaches the upper limit value of the heat resistant temperature of the fixed bed reactor 10 can be extended. As in the case of the amorphous catalyst, in the present embodiment, the load of the zeolite catalyst can be reduced as compared to the conventional hydrocracking using only the zeolite catalyst. As a result, even if the temperature of the zeolitic catalyst in the first step is lower than that of conventional hydrocracking using only the zeolitic catalyst, the second product oil 5B having a viscosity index equal to that of the conventional is equivalent to that of the conventional Can be obtained in a yield of The temperature of the zeolitic catalyst in the first step can be reduced. Therefore, the time (life) until the temperature of the zeolite-based catalyst reaches the upper limit value of the heat resistant temperature of the fixed bed reactor 10 can be extended. From the above, in the present embodiment, the life of the hydrocracking catalyst (zeolite based catalyst and amorphous based catalyst) is extended as compared with the prior art. In other words, when the hydrocracking according to the present embodiment is performed under the same reaction conditions (for example, reaction temperature) as the conventional hydrocracking, in the present embodiment, sufficient viscosity is obtained for a longer time than in the conventional Lubricating base oils having indices can continue to be produced with substantially constant yields.

  When the volume of the first hydrocracking catalyst is V1 and the volume of the second hydrocracking catalyst is V2, 100 · V1 / (V1 + V2) is, for example, 5 to 75, 5 to 50, or 25 to 50. It may be. When 100 · V1 / (V1 + V2) is 5 or more, the decomposition activity by the catalyst is easily improved as compared with the case where only the second hydrocracking catalyst (amorphous catalyst) is used, and the same decomposition is performed at a lower reaction temperature. There is a tendency for rates to be achieved. This tendency is accompanied by an increase of 100 · V1 / (V1 + V2). When 100 · V1 / (V1 + V2) is 50 or less, the viscosity index of the lubricating base oil tends to be high. This tendency is accompanied by a decrease of 100 · V1 / (V1 + V2). V1 may be rephrased as the volume of the first catalyst layer 1. V2 may be reworded as the volume of the second catalyst layer 2. Even if 100 · V1 / (V1 + V2) is out of the above range, the effect of the present invention can be obtained.

The temperature of the feedstock oil 4 may be, for example, 300 to 380 ° C. The temperature of the feedstock oil 4 may be adjusted in advance to the above range. The partial pressure of hydrogen gas in the reaction system (inside of fixed bed reactor 10) may be, for example, 5 to 20 MPa. The liquid hourly space velocity (LHSV) may be, for example, 0.1 to 1.5 h ⁻¹ . The hydrogen / oil ratio (flow rate of hydrogen gas / flow rate of feedstock 4) may be, for example, 300 to 2500 Nm ³ / m ³ . The temperature of the first catalyst layer 1 (first hydrocracking catalyst) may be, for example, 340 to 400 ° C. The temperature of the second catalyst layer 2 (second hydrocracking catalyst) may be, for example, 360 to 420 ° C.

  The fixed bed reactor 10 may be equipped with a mechanism (a control mechanism of various catalytic reactions) for controlling various reaction conditions as described above. The control mechanism may be, for example, means for heating and cooling of each catalyst layer (1, 2), control of hydrogen partial pressure, venting, and flow adjustment of feedstock oil 4 and second product oil 5B. Cooling may be, for example, quenching by the introduction of hydrogen gas. The shape of the fixed bed reactor 10 is not particularly limited, but may be, for example, cylindrical. When the fixed bed reactor 10 is cylindrical, the fixed bed reactor 10 is excellent in pressure resistance.

  The first hydrocracking catalyst may contain a carrier and an active metal supported on the carrier. The first hydrocracking catalyst contains zeolite as a carrier. The zeolite contained in the first hydrocracking catalyst may be, for example, at least one selected from the group consisting of HY-type zeolite, ultra-stabilized Y-type (USY-type) zeolite, mordenite, and β-zeolite. Among these, USY-type zeolite is preferred.

  USY-type zeolite is obtained by superstabilizing Y-type zeolite by at least any treatment of hydrothermal treatment or acid treatment. USY-type zeolite has the fine pore structure that Y-type zeolite originally has. The fine pore structure is a structure composed of micropores having a pore diameter of 2 nm or less. Moreover, in addition to the said fine pore structure, the new pore whose pore diameter is 2-10 nm is further formed in the USY-type zeolite.

  The average particle size of the USY-type zeolite may be, for example, 1.0 μm or less, or 0.5 μm or less. In addition, the molar ratio of silica / alumina (molar ratio of silica to alumina) in USY-type zeolite may be 10 to 200, 15 to 100, or 20 to 60.

  The first hydrocracking catalyst may further contain an amorphous metal oxide in addition to the zeolite as a carrier. Amorphous metal oxides include alumina, silica, boria, zirconia, titania, magnesia, alumina-silica, alumina-boria, alumina-titania, alumina-zirconia, alumina-magnesia, alumina-silica-boria, alumina-silica-zirconia And at least one selected from the group consisting of alumina-silica-titania and alumina-titania-zirconia. The first hydrocracking catalyst may further contain an additive element such as phosphorus or chlorine.

  The first hydrocracking catalyst may contain a USY-type zeolite and an amorphous metal oxide as a carrier. The content of USY-type zeolite in the support of the first hydrocracking catalyst may be 0.1 to 80% by mass, 10 to 80% by mass, or 30 to 70% by mass, based on the total amount of the support. The content of the amorphous metal oxide in the support of the first hydrocracking catalyst may be 0.1 to 60% by mass based on the total amount of the support.

  The support of the first hydrocracking catalyst is produced, for example, by forming a composition containing a USY-type zeolite and a binder and then calcining the composition. In the case of producing a carrier containing an amorphous composite metal oxide, for example, a composition containing a raw material to be an amorphous composite metal oxide may be fired. The firing temperature of the composition may be, for example, 400-550 ° C, 470-530 ° C, or 490-530 ° C. By firing at such a firing temperature, the carrier is given sufficient solid acidity and mechanical strength.

  The active metal contained in the first hydrocracking catalyst is, for example, at least one metal selected from the group consisting of Group 6 elements, Group 8 elements, Group 9 elements and Group 10 elements of the periodic table You may Here, the periodic table is a periodic table of long-period elements according to the regulations of IUPAC (International Pure Applied Chemistry Association). The active metal contained in the first hydrocracking catalyst may be, for example, at least one selected from the group consisting of platinum, palladium, rhodium, ruthenium, iridium, osmium, cobalt, nickel, molybdenum, tungsten, and iron. . The active metal contained in the first hydrocracking catalyst may be, for example, at least one selected from the group consisting of platinum, palladium, nickel, cobalt, molybdenum and tungsten. The active metal contained in the first hydrocracking catalyst is preferably at least one selected from the group consisting of cobalt, nickel, molybdenum and tungsten. The first hydrocracking catalyst may contain a plurality of active metals. The combination of active metals can be, for example, platinum-palladium, cobalt-molybdenum, nickel-molybdenum, nickel-cobalt-molybdenum, or nickel-tungsten. The active metal may be supported on the above mentioned carrier, for example by impregnation or ion exchange. The content of the active metal in the first hydrocracking catalyst may be, for example, 1.0 to 40 parts by mass, or 10 to 30 parts by mass with respect to 100 parts by mass of the carrier.

  The second hydrocracking catalyst may contain a support and an active metal supported on the support. The second hydrocracking catalyst contains an amorphous solid acid as a carrier. The amorphous solid acid contained in the second hydrocracking catalyst is, for example, silica-alumina, silica-zirconia, alumina-boria, silica-titania, silica-magnesia, kaolinite, aluminophosphate, silica-aluminophosphato It may be at least one selected from the group consisting of Fate and alumina-silica-zirconia. The second hydrocracking catalyst does not contain zeolite as a carrier.

  The support of the second hydrocracking catalyst is produced, for example, by forming a mixture containing a solid non-crystalline acid and a binder and then calcining the mixture. The content of the solid acid in the carrier may be, for example, 5 to 90% by mass, or 8 to 70% by mass, based on the total amount of the carrier. The binder may be, for example, at least one selected from the group consisting of alumina (such as boehmite), silica, silica alumina, titania, and magnesia. The binder is preferably alumina. The content of the binder in the carrier may be, for example, 10 to 90% by mass, or 20 to 80% by mass, based on the total amount of the carrier. The calcination temperature of the mixture containing the amorphous solid acid and the binder may be, for example, 300 to 600 ° C., 400 to 550 ° C., or 430 to 500 ° C.

  The active metal contained in the second hydrocracking catalyst may be, for example, at least one selected from the group consisting of platinum, palladium, nickel, cobalt, molybdenum and tungsten. The active metal contained in the second hydrocracking catalyst is preferably at least one selected from the group consisting of cobalt, nickel, molybdenum and tungsten, for example. The second hydrocracking catalyst may contain a plurality of active metals. The combination of active metals can be, for example, platinum-palladium, cobalt-molybdenum, nickel-molybdenum, nickel-cobalt-molybdenum, or nickel-tungsten. The active metal may be supported on the above mentioned carrier, for example by impregnation or ion exchange. The content of the active metal in the first hydrocracking catalyst may be, for example, 1.0 to 40 parts by mass, or 10 to 30 parts by mass with respect to 100 parts by mass of the carrier.

  The support of the first hydrocracking catalyst may, for example, be shaped. The shape of the shaped carrier may, for example, be spherical, cylindrical, cylindrical or disc-shaped. The shape of the carrier may be cylindrical or columnar having a three-leaf or four-leaf cross section. The method of molding the carrier may be, for example, extrusion molding or tableting molding. The support of the second hydrocracking catalyst may also be shaped similarly to the support of the first hydrocracking catalyst. The shape of the support of the second hydrocracking catalyst and the forming method may be the same as in the case of the support of the first hydrocracking catalyst.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited at all to the said embodiment.

  For example, in a horizontally extending fixed bed reactor, the first catalyst layer and the second catalyst layer may be horizontally aligned. The first catalyst layer and the second catalyst layer may not be disposed in the same fixed bed reactor. For example, after the first step is carried out in the first fixed bed reactor in which the first catalyst layer is disposed, the first product oil obtained in the first fixed bed reactor is thermally insulating. The second step is carried out in the second catalyst bed disposed in the second fixed bed reactor, supplied to the second fixed bed reactor via the transport path (tube) having heat retention property. May be In advance, demetallization of the feedstock oil or hydrorefining (for example, hydrodesulfurization and hydrodenitrogenation) of the feedstock oil may be performed.

  Hereinafter, the contents of the present invention will be described in more detail using examples and comparative examples, but the present invention is not limited to the following examples.

Example 1
The first catalyst layer 1 and the second catalyst layer 2 were fixed in a column-shaped fixed bed reactor 10 as shown in FIG. The first catalyst layer 1 and the second catalyst layer 2 were arranged in the vertical direction Z. The first catalyst layer 1 was disposed above the second catalyst layer 2.

The first catalyst layer 1 was composed only of a commercially available zeolite-based catalyst (first hydrocracking catalyst). The zeolitic catalyst contained USY-type zeolite as a carrier. The content of USY-type zeolite was 50% by mass with respect to the entire zeolite-based catalyst. The ratio [SiO ₂ ] / [Al ₂ O ₃ ] of the number of moles [SiO ₂ ] of silica constituting the USY-type zeolite and the number of moles [Al ₂ O ₃ ] of alumina constituting the USY-type zeolite is 30 there were. The average particle size of the zeolite catalyst was 0.4 μm. The zeolitic catalyst contained nickel and tungsten as an active metal supported on a carrier.

  The second catalyst layer 2 was composed only of a commercially available amorphous catalyst (second hydrocracking catalyst). The amorphous catalyst contained an amorphous solid acid (alumina-silica-zirconia) as a carrier. The amorphous catalyst contained nickel and tungsten as an active metal supported on a carrier. The amorphous catalyst did not contain zeolite.

  The ratio V1 (%) of the volume of the first catalyst layer 1 to the total (100%) of the volume of the first catalyst layer 1 and the volume of the second catalyst layer 2 was adjusted to the value shown in Table 1 below. The ratio V2 (%) of the volume of the second catalyst layer 2 to the total (100%) of the volume of the first catalyst layer 1 and the volume of the second catalyst layer 2 was adjusted to the value shown in Table 1 below.

  As the feedstock oil 4, a vacuum gas oil to which hydrodesulfurization was previously applied was used. The vacuum gas oil was continuously flowed from the upper part of the fixed bed reactor 10 to the inside of the fixed bed reactor 10 to continue passing through the first catalyst layer 1 and the second catalyst layer 2. Also, hydrogen gas was continuously supplied into the fixed bed reactor 10. By these operations, hydrocracking (first and second steps) was continued to obtain a first oil 5A and a second oil 5B. The oil flowing from the first catalyst layer 1 to the second catalyst layer 2 corresponds to the first product oil 5A. The oil flowing out of the second catalyst layer 2 to the lower part of the fixed bed reactor 10 corresponds to the second product oil 5B.

The pressure (pressure of hydrogen gas) in the fixed bed reactor 10 was adjusted to 11.0 MPa. The total LHSV was adjusted to 0.55 h ⁻¹ . The reaction temperature was continuously adjusted over time so that the decomposition rate was maintained at a value close to the target value (65% by mass). That is, the temperatures of the first catalyst layer 1 and the second catalyst layer 2 were continuously adjusted over time so that the decomposition rate was maintained at a value close to the target value (65 mass%). The reaction temperature is a value obtained by averaging the reaction temperature of the first catalyst layer 1 and the reaction temperature of the second catalyst layer 2 by the weight of each catalyst layer. That is, the reaction temperature is the catalyst bed weight average temperature (WABT: Weight Average Bet Temperature). The decomposition rate is defined by the following equation 1. The reaction temperatures of Example 1 are shown in Table 1 below. The reaction temperature shown in the following Table 1 is the reaction temperature 14 days after the start of oil passing (supply of vacuum gas oil into fixed bed reactor 10). The fractions of Example 1 are shown in Table 1 below. In addition, the decomposition rate shown to following Table 1 is a decomposition rate 14 days after starting oil passing.

Rc = {(M1-M2) / M1} × 100 (1)
In Formula 1, Rc is a decomposition rate (unit: mass%). M1 is the mass of a fraction having a boiling point of 360 ° C. or higher, which is contained in the vacuum gas oil (the feedstock oil 4). M2 is the mass of the fraction having a boiling point of 360 ° C. or higher, which is contained in the produced oil (second produced oil 5B). The decomposition rate Rc indicates the degree of reduction of heavy components (fraction having a boiling point of 360 ° C. or more) contained in the vacuum gas oil (the feedstock oil 4).

  Fractionation of the produced oil yielded a light fraction having a boiling point of less than 360 ° C. and a heavy fraction having a boiling point of 360 ° C. or more. The viscosity index (VI) of this heavy fraction (bottom oil) was measured. The VI of the bottom oil obtained in Example 1 is shown in Table 1 below. Bottom oil is used as a raw material of lubricating oil base oil.

(Examples 2 and 3)
In Examples 2 and 3, the ratio of the volume of each of the first catalyst layer 1 and the second catalyst layer 2 was adjusted to the value shown in Table 1 below. The hydrocracking of vacuum gas oil was continued in the same manner as in Example 1 except for this matter, and the resulting oils of Examples 2 and 3 were obtained. The reaction temperatures, decomposition rates, and VIs of the bottom oil of Examples 2 and 3 measured in the same manner as in Example 1 are shown in Table 1 below.

(Comparative example 1)
In Comparative Example 1, both the first catalyst layer 1 and the second catalyst layer 2 consisted of only the above-mentioned zeolite-based catalyst. In Comparative Example 1, the volume ratio of each of the first catalyst layer 1 and the second catalyst layer 2 was adjusted to a value shown in Table 1 below. The hydrocracking of vacuum gas oil was continued in the same manner as in Example 1 except for these matters, and the resulting oil of Comparative Example 1 was obtained. The reaction temperature, decomposition rate, and VI of bottom oil of Comparative Example 1 measured by the same method as in Example 1 are shown in Table 1 below.

(Comparative example 2)
In Comparative Example 2, both the first catalyst layer 1 and the second catalyst layer 2 consisted of only the amorphous catalyst. In Comparative Example 2, the volume ratio of each of the first catalyst layer 1 and the second catalyst layer 2 was adjusted to a value shown in Table 1 below. The hydrocracking of the vacuum gas oil was continued in the same manner as in Example 1 except for these matters, and the produced oil of Comparative Example 2 was obtained. The reaction temperature, the decomposition rate, and the VI of the bottom oil of Comparative Example 2 measured in the same manner as in Example 1 are shown in Table 1 below.

(Comparative example 3)
In Comparative Example 3, the first catalyst layer 1 was composed of only the above-mentioned amorphous catalyst. In Comparative Example 3, the second catalyst layer 2 was composed of only the above-mentioned zeolite-based catalyst. In Comparative Example 3, the ratio of the volume of each of the first catalyst layer 1 and the second catalyst layer 2 was adjusted to the value shown in Table 1 below. The hydrocracking of vacuum gas oil was continued in the same manner as in Example 1 except for these matters, and the resulting oil of Comparative Example 3 was obtained. The reaction temperature, decomposition rate, and VI of bottom oil of Comparative Example 3 measured by the same method as in Example 1 are shown in Table 1 below.

<Evaluation of catalyst life>
The catalyst life of each of Examples 1 to 3 and Comparative Examples 1 to 3 is shown in Table 1 below. The catalyst life is the number of days until the reaction temperature reaches the upper limit value (420 ° C.) of the heat resistant temperature of the fixed bed reactor 10 after the start of oil passage. The catalyst life was estimated by the following method. First, the above-mentioned hydrocracking reaction was continued for a predetermined period (3 to 6 months), and the reaction rate was measured over time. The deterioration rate of the whole of the first catalyst layer 1 and the second catalyst layer 2 was calculated from the temporal transition of the measured values of the reaction rate. The transition of the reaction temperature was obtained by the simulation of the hydrocracking reaction based on this degradation rate. From the transition of the reaction temperature, the time for the reaction temperature to reach 420 ° C. was estimated.

  It is preferable that it is 130 or more, and, as for VI of the said Table 1, it is more preferable that it is 140 or more. The catalyst life described in Table 1 above is preferably 2 years or more.

  According to the present invention, a hydrocracking catalyst can be used to continue producing a lubricant base oil having a high viscosity index for a long time.

  1: first catalyst layer (first hydrocracking catalyst), second catalyst layer (second hydrocracking catalyst), 4: feedstock oil, 5A: first oil, 5B: second oil (lubricant Oil base oil).

Claims (5)

A first step of obtaining a first product oil by contacting an aromatic hydrocarbon-containing feedstock oil with a first hydrocracking catalyst in the presence of hydrogen gas to hydrocrack the feedstock oil; ,
A second step of obtaining a second product oil by contacting the first product oil with a second hydrocracking catalyst in the presence of hydrogen gas to hydrocrack the first product oil ;
Equipped with
The first hydrocracking catalyst contains zeolite,
The second hydrocracking catalyst contains an amorphous solid acid ,
The hydrocracking of the feedstock oil in the first step includes the formation of naphthene by hydrogenation of aromatic hydrocarbon in the feedstock oil, and the formation of isoparaffin by isomerization and ring opening of naphthene,
The hydrocracking of the first product oil in the second step includes the formation of naphthenes by hydrogenation of aromatic hydrocarbons in the first product oil, and the formation of isoparaffins by the isomerization and ring opening of naphthenes.
Method of producing lubricating base oil The volume of the first hydrocracking catalyst is V1;
When the volume of the second hydrocracking catalyst is V2,
100 · V1 / (V1 + V2) is 5 to 50,
A method of producing a lubricant base oil according to claim 1. The first catalyst bed containing the first hydrocracking catalyst and the second catalyst bed containing the second hydrocracking catalyst are fixed in one fixed bed reactor,
In the first step, the feedstock oil is flowed to the first catalyst layer to obtain the first product oil,
In the second step, the first product oil is flowed from the first catalyst layer to the second catalyst layer to obtain the second product oil.
The manufacturing method of lubricating base oil of Claim 1 or 2. The raw material oil is vacuum gas oil,
The manufacturing method of lubricating base oil as described in any one of Claims 1-3. The hydrocracking of the feedstock oil in the first step proceeds at a lower temperature than the hydrocracking of the first product oil in the second step,
The manufacturing method of lubricating base oil as described in any one of Claims 1-4.

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