JPH04359994A - Turbine oil composition - Google Patents

Abstract

PURPOSE:To provide a turbine oil composition based on a mineral oil having high viscosity index and excellent oxidation stability and thermal stability. CONSTITUTION:A turbine oil composition based on an oil composed mainly of a mineral oil of which the total aromatic matter content is 2-15wt.%, the total content of the isoparaffin and monocyclic naphthene in the saturated matter is at least 60wt.%, the alkylbenzene content of the total aromatic matter is at least 30wt.%, and the total content of the tricyclic aromatic matter and tetracyclic aromatic matter in the total aromatic matter is at most 4wt.% and which has a viscosity index of 105 or higher and a pour point of -10 deg.C or lower.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbine oil composition useful as a lubricating oil for general turbine power generation equipment such as thermal, nuclear, and hydroelectric power plants.

0002

BACKGROUND OF THE INVENTION In recent years, the operating systems of turbine power generation equipment have become more diverse, and the thermal load on turbine oil has also tended to increase. For this reason, turbine oils that support the highly reliable operation of power generation equipment are now required to have quality that can withstand these harsh conditions and long-term use. For this reason, various high performance lubricant base oils have been developed.

Among these high-performance lubricating base oils, hydrocracked base oils are known as typical mineral oil base oils. Although this base oil is an excellent base oil with a high viscosity index and low pour point, it contains a large amount of undesirable polycyclic naphthenes as a base oil component, and also dissolves additives and sludge generated during the use of lubricating oil. It has the disadvantage of being bad. As a result of repeated research to solve the above problems, the present inventors discovered that a mineral oil-based lubricating base oil with a specific composition and properties has a high viscosity index and excellent oxidation stability and thermal stability. , we have completed the present invention. An object of the present invention is to provide a turbine oil composition using mineral oil as a base oil, which has a specific composition, a high viscosity index, and excellent oxidative stability and thermal stability.

0004

[Means for Solving the Problems] That is, the present invention has a total aromatic content of 2 to 15% by weight, a total content of isoparaffins and monocyclic naphthenes in the saturated content of 60% by weight or more,
It has a composition in which the alkylbenzene content in the total aromatic content is 30% by weight or more, the total content of tricyclic aromatics and tetracyclic aromatics in the total aromatic content is 4% by weight or less, and the viscosity index is 105 or higher and a pour point of -10°C or lower as a main component of the base oil. Hereinafter, the content of the present invention will be explained in more detail.

The base oil of the turbine oil composition according to the present invention is
Total aromatic content from 2 to 15% by weight, preferably from 3 to 10
The total content of isoparaffins and monocyclic naphthenes in the saturated content is 60% by weight or more, preferably 65% by weight or more, and the alkylbenzene content in the total aromatic content is 30% by weight.
or more, preferably 40% by weight or more, the total content of tricyclic aromatics and tetracyclic aromatics in the total aromatic content is 4% by weight or less,
It preferably has a composition of 3% by weight or less, a viscosity index of 105 or more, preferably 110 or more, and a pour point of -1.
The main component is mineral oil having a temperature of 0°C or lower, preferably -15°C.

[0006] When the total aromatic content is less than 2% by weight, additives and sludge generated during the use of turbine oil are not sufficiently dissolved, and when it exceeds 15% by weight, excellent Oxidative stability cannot be obtained. The total aromatic content in the present invention means a value measured in accordance with ASTM D2549, and the total aromatic content usually includes alkylbenzene, alkylnaphthalene, anthracene, phenanthrene, alkylated products thereof, and four or more rings. In addition to compounds with fused benzene rings, phenols, naphthols, etc., it also includes heterocyclic compounds such as pyridines and quinolines.

Next, regarding the total content of isoparaffins and monocyclic naphthenes in the saturated content, if the amount is less than 60% by weight, the turbine oil has excellent oxidative stability and thermal stability. I can't do it. The total amount of isoparaffins and monocyclic naphthenes mentioned here is determined by gas chromatography and mass spectrometry. Also,
When the alkylbenzene content in the total aromatic content is less than 30% by weight, the solubility of additives and sludge generated during use of the turbine oil decreases. What is alkylbenzene?
Refers to a compound in which one or more alkyl groups are bonded to a benzene ring. Furthermore, when the total content of tricyclic aromatics and tetracyclic aromatics in the total aromatic content exceeds 4% by weight, excellent oxidative stability and thermal stability cannot be obtained.

[0008] Proceeding to explain the method for producing mineral oil which is the base oil component of the turbine oil composition, the mineral oil used in the present invention can be produced by any method. However, vacuum distillation distillate oil (WVGO), mild hydrocracking treated oil (HIX) of WVGO, deasphalted oil (DAO),
Using either DAO's mild hydrocracking treated oil or a mixture of these oils as feedstock, this feedstock was heated to a total pressure of 150 kg/cm2 in the presence of a hydrocracking catalyst.
Below, temperature 360-440℃, LHSV 0.5hr-1
Under the following reaction conditions, hydrocracking is carried out so that the decomposition rate is 40% by weight or more, and the resulting product is used as it is, or after recovering the lubricating fraction from it, it is then subjected to dewaxing treatment, followed by dearomatization treatment. It is preferable that the product be manufactured by performing a dewaxing treatment after performing a aromatization treatment or a dearomatization treatment.

[0009] WVGO is a distillate oil obtained by distilling the atmospheric distillation residue of crude oil under reduced pressure, preferably at 360°C to 5°C.
It has a boiling point of 30°C. HIX is a heavy vacuum gas oil obtained by mild hydrocracking treatment (MHC treatment) of WVGO. 450℃,
Preferably 400-430°C, LHSV 0.5-4.
Relatively mild hydrogen decomposition with a decomposition rate of the 360°C+ fraction in the range of 20-30% by weight, carried out under reaction conditions of 0 hr-1, preferably 1.0-2.0 hr-1. means.

As a catalyst for MHC treatment, a complex oxide carrier such as alumina, silica alumina, alumina boria, etc.
A sulfurized material supported with a group VI metal or a group VIII metal can be used. A promoter, such as a phosphorus compound, may be added to the alumina. The supported amount of the metal is 5 to 30% by weight, preferably 10 to 25% by weight for Group VI metals, such as molybdenum, tungsten, and chromium, and 1 to 10% by weight for Group VIII metals, such as cobalt and nickel, based on the oxide. % by weight, preferably from 2 to
It is in the range of 10% by weight. When WVGO and HIX are mixed and used as feedstock, more than 50% of the feedstock is HIX.
It is preferable that DOA is an oil substantially free of asphaltene, obtained by distilling the residue of crude oil under reduced pressure and treating the resulting residual oil with a propane deasphalting method or the like.

[0011] Hydrocracking of feedstock oil is carried out in the presence of a hydrocracking catalyst at a medium to low total pressure of 150 kg/cm2 or less, preferably 100 to 130 kg/cm2, and at a temperature of 360 to 440°C, preferably 370°C. ~430°C, LHSV is low LHSV of 0.5 hr-1 or less, preferably 0.2-0.3 hr-1, and hydrogen to feedstock ratio is 1,000-6,000 s. c. f/bbl-
Raw material oil, preferably 2,500 to 5,000 s. c. f
/bbl-stock oil under reaction conditions. When hydrocracking feedstock oil, the temperature in the feedstock oil is 360℃+
The reaction conditions are adjusted so that the decomposition rate of the fraction is 40% by weight or more, preferably 45% by weight or more, and more preferably 50% by weight or more. In addition, when HIX is used as the feedstock oil, the total decomposition rate of MHC treatment and hydrocracking is 6
It is 0% by weight or more, preferably 70% by weight or more. Furthermore, when part of the undecomposed oil is recycled, the decomposition rate here refers to the decomposition rate per fresh feed, not the decomposition rate including recycled oil.

[0012] The catalyst used for hydrogenolysis preferably has a dual function; specifically, for example, a hydrogenation site consisting of a group VIb metal and a group VIII iron group metal; A catalyst having a decomposition site composed of a composite oxide of Group III, Group IV, and Group V elements is used. Generally, tungsten and molybdenum are used as group VIb metals, and nickel, cobalt, and iron are used as group VIII iron group metals, and these are supported on a composite oxide support and ultimately converted into sulfides. is customary. Composite oxides used for carriers include:
Silica alumina, silica zirconia, silica titania,
Examples include silica magnesia, silica alumina zirconia, silica alumina titania, and silica alumina magnesia. Crystalline silica alumina (zeolite), crystalline alumina phosphate (ALPO), and crystalline silica alumina phosphate (SAPO) are also sometimes used as carriers. . The amount of the metal supported on the composite oxide is 5 to 30% by weight, preferably 10 to 25% by weight for group VIb metals, and 1 to 20% by weight for group VIII iron group metals, based on the oxide.
% by weight, preferably in the range of 5 to 15% by weight.

[0013] Just to be sure, when hydrocracking feedstock oil, a pretreatment catalyst with high desulfurization and/or denitrification ability should be packed upstream of the hydrocracking catalyst packed bed. Can be done. As this type of pretreatment catalyst, a sulfurized catalyst having a group VI metal and a group VIII metal supported on a carrier such as alumina or alumina boria can be used. A promoter, such as a phosphorus compound, may be added to alumina or alumina boria.

After hydrocracking the raw material oil, a lubricating oil fraction is recovered from the cracked product by a conventional distillation operation, if necessary. In this case, the lubricating oil fraction that can be recovered is:
70 pail fraction with a boiling point range of 343°C to 390°C,
SAE-10 fraction, 390°C to 445°C, 445°C
~500°C SAE-20 fraction, even 500°C
There are SAE-30 fractions that are ~565°C. The hydrocracked product from which the lubricating oil fraction has been separated and recovered as necessary is then subjected to a dewaxing treatment and then a dearomatization treatment, or
Alternatively, after aromatization treatment, dewaxing treatment is performed.

[0015] As the dewaxing treatment, a solvent dewaxing treatment or a catalytic dewaxing treatment can be adopted. The solvent dewaxing treatment can be performed by a conventional method such as the MEK method. M.E.
Method K uses a mixed solvent of benzene, toluene and acetone, or a mixed solvent of benzene, toluene and methyl ethyl ketone (MEK) as a solvent. As for processing conditions, the cooling temperature is adjusted so that the dewaxed oil reaches a predetermined pour point. The solvent/oil volume ratio is between 0.5 and 5.0, preferably 1
．． 0~4.5, temperature is -5~-45℃, preferably -1
The temperature is 0 to -40°C. Catalytic dewaxing treatment can be carried out in a conventional manner. For example, pentasil-type zeolite is used as a catalyst and the reaction temperature is adjusted so that the dewaxed oil reaches a predetermined pour point under hydrogen flow, but the reaction conditions Generally, the total pressure is 10 to 70 kg/cm2, preferably 20 to 50 kg/cm2.
kg/cm2 and the temperature is 240-400℃
, preferably in the range of 260 to 380°C. LHSV
is 0.1 to 3.0 hr-1, preferably 0.5 to 2.0
It is in the range of hr-1.

As the dearomatization treatment, either a solvent dearomatization treatment or a high-pressure hydrodearomatization treatment can be employed, but a solvent dearomatization treatment is preferred. Although solvents such as furfural and phenol are usually used in solvent dearomatization treatment, it is preferable to use furfural in the present invention. The conditions for the solvent dearomatization treatment include a solvent/oil volume ratio of 4 or less, preferably 3 or less, more preferably 2 or less, a temperature of 90 to 150°C, and a raffinate yield of 60% by volume or more, preferably 70% by volume. It is operated so that it is at least 85% by volume, more preferably at least 85% by volume. The dearomatization treatment by high-pressure hydrogenation reaction is usually carried out at a total pressure of 150 to 200 kg/kg in the presence of a sulfurized catalyst containing group VIb metals and iron group VIII metals supported on an alumina carrier.
cm2, preferably 70-200 kg/cm2, temperature 280-350°C, preferably 300-330°C, L
HSV0.2-2.0hr-1, preferably 0.5-1
．． It is carried out under the condition of 0hr-1. The amount of metal supported on the catalyst is based on the oxide, such as Group VIb metals, such as molybdenum,
For tungsten and chromium, it is 5 to 30% by weight, preferably 10 to 25% by weight, and for Group VIII iron group metals, such as cobalt and nickel, it is 1 to 10% by weight, preferably 2 to 10% by weight.

When a solvent dearomatization treatment is used as the dearomatization treatment, a hydrogenation treatment can be performed after this treatment if necessary. This hydrotreating is carried out at a total reaction pressure of 50 kg/cm2 or less, preferably 2
The hydrogenation reaction is carried out under low pressure hydrogenation reaction conditions of 5 to 40 kg/cm2 by contacting a group VIb metal and a group VIII iron group metal supported on an alumina carrier with a sulfurized hydrogenation catalyst. The supported amount of the metal is in accordance with VIb based on the oxide.
Group metals such as molybdenum, tungsten, chromium in the range 5 to 30% by weight, preferably 10 to 25% by weight, group VIII iron group metals such as cobalt,
1-10% by weight for nickel, preferably 2-1
It is in the range of 0% by weight. Such hydrogenation treatment under relatively low pressure dramatically improves the photostability of solvent-dearomatized oils.

[0018] The above describes an example of the method for producing the lubricating base oil used in the present invention, but in the production process, the lubricating oil fraction was not recovered from the hydrocracked product of the feedstock oil. In this case, the lubricating oil fraction can be recovered by a conventional distillation operation after the dearomatization treatment, dewaxing treatment, or hydrogenation treatment. As in the previous case, the lubricating oil fractions recovered here are the 70 pail fraction with a boiling point range of 343°C to 390°C, the SAE-10 fraction with a boiling point range of 390°C to 445°C, and the 445°C to 800°C boiling oil fraction. SAE-20 fraction, 500
such as the SAE-30 fraction, which is between 565°C and 565°C.

In the present invention, it is preferable to use the above-mentioned mineral oil alone as the base oil of the turbine oil composition, but the composition may also contain a known mineral oil or synthetic oil as a lubricating base oil. . Such mineral oils include, for example:
The lubricating oil fraction obtained by atmospheric distillation and vacuum distillation of crude oil is subjected to solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing,
Examples include paraffinic and naphthenic mineral oils refined by appropriate combinations of purification treatments such as catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment. In addition, as a synthetic oil,
For example, poly-α-olefins (polybutene, 1-octene oligomer, 1-decene oligomer, etc.), alkylbenzenes, alkylnaphthalenes, diesters (ditridecyl glutarate, di-2-ethylhexyl adipate,
diisodecyl adipate, ditridecyl adipate, di3-ethylhexyl sebacate, etc.), polyol esters (trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate, etc.), polyoxyalkylene glycol,
Examples include polyphenyl ether, silicone oil, perfluoroalkyl ether, and mixtures of two or more thereof.

When the above-mentioned conventionally known mineral oil or synthetic oil is mixed with the mineral oil of the present invention, the mineral oil of the present invention is used in an amount of 70% by weight based on the total amount of base oil contained in the turbine oil composition.
It is desirable that the content is preferably 90% by weight or more. In the turbine oil composition of the present invention, the kinematic viscosity of the base oil at 40° C. is 10 to 300 cSt, regardless of whether the above-mentioned conventionally known mineral oil or synthetic oil is mixed therein. Preferably within this range.

Generally, it is desirable that a turbine oil composition has excellent oxidation stability for a long period of time as a lubricating oil for turbine power generation equipment, so the turbine oil composition of the present invention also contains an oxidation inhibitor. Agents can be added. Such antioxidants include, for example, 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, 2,6-di-t-butyl-4-ethylphenol,
, 2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6
-t-butylphenol), 4,4'-methylenebis(
Phenols such as 2,6-di-t-butylphenol), 4,4'-bis(2,6-di-t-butylphenol), and 4,4'-thiobis(6-t-butyl-o-cresol) Antioxidant, diphenylamine, p,p'-dioctyldiphenylamine, p,p'-dinonyldiphenylamine, p,p'-didodecyldiphenylamine,
In addition to amine antioxidants such as phenyl-α-naphthylamine, p-octylphenyl-α-naphthylamine, p-nonylphenyl-α-naphthylamine, and p-dodecylphenyl-α-naphthylamine, sulfur-based antioxidants,
Examples include zinc thiophosphate antioxidants. The blending amount of these antioxidants is 0 based on the total amount of the composition.
．． It is usually selected in the range of 0.01 to 5% by weight, preferably 0.01 to 3% by weight, and more preferably 0.1 to 1% by weight.

Furthermore, the turbine oil composition of the present invention may contain known additives, if necessary, for the purpose of further enhancing its performance. Such additives include, for example, rust inhibitors such as alkenylsuccinic acids or partial esters thereof, petroleum sulfonates, alkylbenzene sulfonates, dinonylnaphthalene sulfonates,
Examples include metal deactivators such as benzotriazole, antifoaming agents such as silicone, viscosity index improvers such as polymethacrylate, polyisobutylene, and polystyrene, pour point depressants, etc. These additives may be used alone or in combination of two or more. can be added. The amount of viscosity index improver added is usually 1 to 5% by weight, and the amount of antifoaming agent added is usually 1 to 5% by weight.
0.0005 to 1 part by weight, the content of the metal deactivator is usually 0.005 to 1% by weight, and the content of other additives is
Each is usually in the range of 0.1 to 5% by weight.

The turbine oil composition of the present invention can be preferably used as bearing oil, operating oil, etc. in thermal, nuclear, and hydroelectric power plants.

[0024]

EXAMPLES The content of the present invention will be explained in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples in any way.

[0025]

[Table 1] Specific gravity 15/4℃
0.926 viscosity (mm2/s) @ 5
0℃ 62.61100℃
10.44 pour point ℃
40.
0 aniline point ℃
100.2 sulfur content ppm
19000 nitrogen content
ppm 1
000

Base oil production example: WVGO having the properties shown in Table 1 was subjected to hydrocracking treatment, solvent dewaxing treatment, and solvent dearomatization using a furfural solvent under the conditions of medium pressure and low LHSV shown in Table 2. A base oil (A) of a turbine oil composition was produced by subjecting the base oil to a treatment of the following group. The obtained base oil (A) has a high aromatic content of 9.5% by weight,
Therefore, it has excellent solubility of additives and solubility of sludge generated during use. In addition, the total amount of isoparaffins and monocyclic naphthenes with a high viscosity index in the saturated content is 66.1
Since the weight percentage is relatively high, the viscosity index of the base oil is as high as 122. Furthermore, the base oil (A) contains almost no tricyclic aromatics, tetracyclic aromatics, and pentacyclic aromatics that impair its stability, and easily passes the thermal stability test. It also contains a large amount of alkylbenzene, a desirable ingredient.

[0027]

[Table 2]

Using the above base oil (A) and Sumatra hydrorefined base oil (B) and Arabian hydrorefined base oil (C) for comparison, the compositions shown in Table 3 were obtained. Turbine oil compositions were prepared and the performance of each composition was evaluated using the following test methods. The results are shown in Table 3.

Viscosity Index In order to calculate the viscosity index specified in JIS-K-2283 4.2, the kinematic viscosity of each composition was measured at 40°C and 100°C. The compositions of Examples and Comparative Examples were prepared to have substantially the same viscosity at 40°C.

Oxidation stability performance Among the lubricating oil oxidation stability tests specified in JIS-K-2514, the turbine oil oxidation stability test in Section 3.2 and the rotating cylinder oxidation stability test in Section 3.3 were performed. Accordingly, the oxidation life of each composition was measured.

Thermal Stability Performance) The thermal stability of each composition was evaluated in accordance with the lubricating oil thermal stability test specified in JIS-K-2540.

[0032]

[Table 3] ──────────────────────────
────────────

Examples Comparative example 1 Comparative example 2────
──────────────────────────
──────── Base oil used

A B C Additive (
weight%)

Claims (3)

[Claims] Claim 1: The total aromatic content is 2 to 15% by weight, the total content of isoparaffins and monocyclic naphthenes in the saturated content is 60% by weight or more, and the alkylbenzene content in the total aromatic content is 30% by weight or more. , a mineral oil having a composition in which the total content of tricyclic aromatics and tetracyclic aromatics in the total aromatic content is 4% by weight or less, a viscosity index of 105 or more, and a pour point of -10°C or less A turbine oil composition characterized in that the main component of the base oil is: Claim 2: 0.0 antioxidant based on the total amount of the composition.
The turbine oil composition according to claim 1, characterized in that it contains 1 to 5% by weight as an essential component. 3. The mineral oil is a vacuum distillation distillate (WVG).
O), WVGO's mild hydrocracking oil (HIX), deasphalted oil (DAO), DAO's mild hydrocracking oil, and mixed oils thereof are subjected to total pressure in the presence of a hydrocracking catalyst. 15
0kg/cm2 or less, temperature 360-440℃, LHS
Decomposition rate 40% by weight under reaction conditions of V0.5hr-1 or less
Hydrocracking is performed as described above, and the product is used as it is, or after recovering a lubricating fraction from it, and then subjected to dewaxing treatment, followed by dearomatization treatment, or after dearomatization treatment, The turbine oil composition according to claim 1 or 2, characterized in that it is produced by subjecting it to dewaxing treatment.