JPH07316567A - Dewaxing method and dewaxing aid for lubricating oil fraction - Google Patents

Abstract

(57) [Abstract] [Purpose] Not only relatively high-viscosity oil with SAE of 30 or more,
A dewaxing auxiliary agent effective for SAEs 20 to 10 having relatively low viscosity oil and a dewaxing method using the same are proposed. [Structure] (A) A multi-component ester copolymer of a mixture of an aliphatic alcohol having an alkyl group having a carbon number in the range of 6 to 16 and acrylic acid, the mass average molecular weight of which is 5,0.
It is a multi-component ester copolymer of acrylic acid with a mixture of 100 to 700,000 and (B) an alkyl group having an alkyl group having a carbon number in the range of 17 to 30, and a mass average molecular weight of A mixture of 5,000 to 700,000 and 25 to 75% by mass: 75 to 25% by mass, or a polycondensate of chlorinated paraffin and biphenyl having a mass average molecular weight of 2,000 to 60,
000 and the above mixture are mixed in a ratio of 25 to 75% by mass: 75 to 25% by mass as a dewaxing aid.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for dewaxing a wax-containing lubricating oil fraction using a dewaxing aid and a dewaxing aid.
More specifically, a mixture of two kinds of multi-component ester copolymers of a mixture of an aliphatic alcohol having an alkyl group having a carbon number within a specific range and acrylic acid, or a polycondensate of a chlorinated paraffin and biphenyl and the above The present invention relates to a method for dewaxing a wax-containing lubricating oil fraction and a dewaxing auxiliary, characterized by using a mixture with the mixture as a dewaxing auxiliary.

[0002]

2. Description of the Related Art Generally, in order to produce a lubricating base oil from crude oil, first, the crude oil is distilled under atmospheric pressure, and the residual oil is further distilled under reduced pressure to obtain various wax-containing lubricating oil fractions from low viscosity to high viscosity. Separate into minutes and vacuum distillation bottoms. A wax-containing bright stock, which is a wax-containing lubricating oil fraction having the highest viscosity, can be produced by further removing the asphalt content from the vacuum distillation residual oil by solvent deasphalting treatment.

The wax-containing lubricating oil fractions of various viscosities thus obtained are subjected to a series of solvent extraction, hydrorefining and dewaxing combinations, or hydrocracking, solvent extraction, hydrorefining and dewaxing combinations, etc. It is subjected to a treatment process and becomes a lubricating base oil.

The dewaxing step of the manufacturing steps is a step of removing the wax content in the lubricating oil fraction to produce a low pour point lubricating base oil.

In particular, the lubricating oil fraction produced from paraffin base crude oil contains a large amount of wax, but the lubricating base oil obtained by dewaxing this has a high viscosity index, oxidation stability and heat stability. Since it has good properties, it is widely used as a base oil for high-grade lubricating oils for industrial and engine applications. The dewaxing method includes a method of decomposing the wax and a method of selectively separating and removing the wax with a solvent, and the present invention relates to the latter, that is, the solvent dewaxing method.

There are various methods for solvent dewaxing,
According to the dewaxing solvent used, there are the following methods. That is, in a lubricating oil fraction containing a wax, a ketone having a low solubility in wax such as methyl ethyl ketone (MEK), methyl isobutyl ketone, and acetone, or an aromatic hydrocarbon having a high solubility in a wax such as toluene and benzene is used. In this method, a solvent consisting of a mixture is added, or a low molecular weight hydrocarbon such as propane or butane is added as a solvent, and the oil component and the wax component are separated by the difference in solubility in the solvent. In any of these methods, these solvents are first added to the wax-containing lubricating oil fraction, heated and dissolved, and then cooled to an appropriate temperature. Since the wax is precipitated and solidified by cooling, the wax is filtered by a vacuum rotary filter or the like to separate the wax.

At present, the MEK dewaxing method and the propane dewaxing method are widely adopted. In such a dewaxing method, needle-like or plate-like particles precipitated by cooling a mixture of a wax-containing lubricating oil fraction and a dewaxing solvent are used. Crystalline or non-crystalline wax causes obstacles such as clogging of filter cloth at the time of filtration, slowing down filtration speed, or oil content being included in wax crystals to lower the yield of dewaxed oil. There is. Such a situation depends on the type, amount and cooling rate of the dewaxing solvent, the feed oil, and the like.

In such a dewaxing method, a dewaxing method in which a dewaxing auxiliary agent is added has been proposed as a method for improving the dewaxing efficiency.
"New edition petroleum product additives", Koshobo (1986), etc.)
It is described in.

[0009]

However, the conventionally known dewaxing aids do not necessarily improve the dewaxing efficiency of all the waxes. For example, S
In the case of a wax-containing oil having a relatively low viscosity of AE20 or less,
Even when these dewaxing aids are used, the dewaxed oil is still contained in the wax and tends to remain as an oil, and thus the yield of the lubricating base oil and the filtration rate cannot be said to be sufficiently improved.

The object of the present invention is to use a dewaxing aid which is effective not only for relatively high-viscosity oils of SAE 30 or higher but also for relatively low-viscosity oils such as SAE 20 to SAE 10 equivalent oils.
That is, the present invention is to search for a dewaxing auxiliary agent that further reduces the oil content contained in the wax or to improve the filtration rate, and propose a dewaxing method using the same.

[0011]

As a result of various studies to solve the above problems, the present inventors have found that a mixture of a specific aliphatic alcohol mixture and a multi-component ester copolymer of acrylic acid is a wax. Reduce the amount of oil contained in it,
It was found to improve the filtration rate.

That is, the present invention uses a mixture of two polyacrylates having a weight average molecular weight and the number of carbon atoms of an alkyl group within a specific range as a filter aid to dewax a wax-containing wax fraction. A dewaxing aid comprising the method and the above mixture.

The dewaxing aid according to the present invention comprises the following two types of copolymers A and B: A: B = 25 to 75% by mass: 75 to 25
A mixture obtained by mixing in a mass% ratio or a polycondensation product of chlorinated paraffin and biphenyl and having a mass average molecular weight of 2,000.
The dewaxing aid (D) according to claim 1 in the range of 0 to 60,000 (C) and C: D = 25 to 75% by mass: 7
The mixture is a mixture of 5 to 25% by mass.

A: A multi-component ester copolymer of a mixture of an aliphatic alcohol having an alkyl group having 6 to 16 carbon atoms and acrylic acid, having a mass average molecular weight of 5,
000 to 700,000 B: A multi-component ester copolymer of a mixture of an aliphatic alcohol having an alkyl group having a carbon number in the range of 17 to 30 and acrylic acid and having a mass average molecular weight of 5,000. ~ 7
In the dewaxing step, as the mixture of the wax-containing lubricating oil fraction and the dewaxing solvent is cooled in the dewaxing step, plate-shaped, needle-shaped or non-crystalline solids of the wax are precipitated. Dewaxing is performed by filtering and separating the wax component.

However, a phenomenon occurs in which a three-dimensional network structure is formed depending on the shape and the deposition state of the deposited wax and the oil is included in the network. For this reason, the state of precipitation of the wax content has a great influence on the dewaxed oil yield and filtration rate.

A mixture of two kinds of multicomponent ester copolymers of aliphatic alcohol and acrylic acid used in the present invention,
Alternatively, by using a mixture of the polycondensation product of chlorinated paraffin and biphenyl with the above mixture as a dewaxing aid, the dewaxing aid is adsorbed to the crystals of the wax, or co-crystallized with the wax to precipitate the wax. Change. As a result, the dewaxed oil yield and filtration rate are improved.

The addition amount of the copolymer as a dewaxing aid varies depending on the wax-containing lubricating oil fraction to be dewaxed and the filtration conditions. 50-3,000 mass ppm based on the oil fraction
It is preferably in the range of 100 to 500 mass ppm. If the amount added is too small, the sufficient effect will not be obtained, and on the other hand, if added more than necessary, the effect will not be improved, and on the contrary, it may decrease. The solvent dewaxing method can be applied as long as it is a solvent dewaxing method having appropriate refrigeration equipment, filtration equipment and the like such as the MEK dewaxing method using the above solvent or the propane dewaxing method.

The target feedstock is a lubricating oil fraction having a wide range of viscosity from SAE10 to bright stock,
Especially for a lubricating oil fraction having a viscosity from SAE 20 to bright stock, the application of the dewaxing method according to the present invention has a favorable effect particularly on the dewaxed oil yield.

The dewaxing solvent is not particularly limited. For example, ketones having a low solubility in wax such as MEK, methylisobutylketone, and acetone, or aromatic carbonization having a high solubility in wax such as toluene and benzene. A mixture with hydrogen or a low molecular weight hydrocarbon such as propane or butane is used.

The method of adding the dewaxing aid according to the present invention is not particularly limited as long as it is uniformly dissolved in the wax-containing lubricating oil fraction before cooling, and it is necessary to dissolve it in the dewaxing solvent in advance. Is also preferable in terms of work efficiency. The dewaxing aid according to the present invention may contain a third component as long as the effect of the present invention is not impaired.

[0021]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 SAE10 wax-containing lubricating oil fraction (density 0.861 g, produced by treating crude oil suitable for lubricating oil production by processes such as atmospheric distillation, vacuum distillation, furfural solvent extraction, hydrorefining, etc.
/ Cm ³ @ 15 ° C, kinematic viscosity 4.54 mm ² / sec @ 100
C., 50% distillation temperature 425.degree. C.) 300 ml of MEK-toluene mixed solvent (55% by volume of MEK, 45% by volume of toluene; the same applies hereinafter) as a primary solvent and 300 ml of the following E and F as dewaxing aids. 300 mass ppm of the equal mass mixture was mixed.

E: A multi-component ester copolymer of a mixture of an aliphatic alcohol having an alkyl group having 8 to 16 carbon atoms and acrylic acid, having a mass average molecular weight of 11
50,000 F: A multi-component ester copolymer of a mixture of an aliphatic alcohol having an alkyl group having a carbon number in the range of 18 to 24 and acrylic acid, and having a mass average molecular weight of 240,000.
This mixture was heated to 60 ° C., mixed well, put in a cooling bath, and cooled to −21 ° C. at a constant rate (2 ° C./min). MEK that has been cooled to -21 ° C in advance after cooling
-Add 300 ml of toluene mixed solvent as a secondary solvent,
Filtration was performed with a vacuum filter using a filter cloth while suctioning at a reduced pressure of 160 mmHg. When the filtration was almost completed, 200 ml of the MEK-toluene mixed solvent which had been cooled to -21 ° C. was added to wash the wax on the filter cloth.

The results of dewaxed oil yield and filtration rate of this lubricating oil fraction are shown in Table 1. The filtration rate indicates the amount of filtrate per unit time.

Example 2 SAE20 wax-containing lubricating oil fraction produced in the same process as in Example 1 (density 0.875 g / cm ³ @ 15 ° C., kinematic viscosity 6.49 mm ² / sec @ 100 ° C., 50%) Distillation temperature 457
℃) 300ml, primary solvent 300ml, secondary solvent 30
0 ml, tertiary solvent 290 ml, other conditions are in Example 1
A dewaxing experiment was conducted in the same manner as in. The results of dewaxed oil yield and filtration rate of this lubricating oil fraction are also shown in Table 1.

Example 3 A SAE30 wax-containing lubricating oil fraction produced in the same manner as in Example 1 (density 0.880 g / cm ³ @ 15 ° C., kinematic viscosity 9.86 mm ² / sec @ 100 ° C., 50%) Distillation temperature 499
℃) 300ml, primary solvent 390ml, secondary solvent 45
0 ml, tertiary solvent 390 ml, other conditions are in Example 1
A dewaxing experiment was conducted in the same manner as in. The results of dewaxed oil yield and filtration rate of this lubricating oil fraction are also shown in Table 1.

Example 4 Wax-containing bright stock (density: 0.904 g) produced by treating the crude oil used in Example 1 by processes such as atmospheric distillation, vacuum distillation, propane deasphalting, furfural solvent extraction, hydrorefining and the like. / Cm ³ @ 15 ° C, kinematic viscosity 29.0 mm ²
/ Sec @ 100 ℃, 50% distillation temperature 588 ℃) 300ml
1,200 ml primary solvent, no secondary solvent, 3 tertiary solvent
A dewaxing experiment was conducted in the same manner as in Example 1 except that the amount was 00 ml and other conditions. The results of dewaxed oil yield and filtration rate of this lubricating oil fraction are also shown in Table 1.

Example 5 The filter aid used in Example 2 and a polycondensation product of chlorinated panrafine and biphenyl and having a mass average molecular weight of 30,000.
A dewaxing experiment was conducted under the same conditions as in Example 2 except that a dewaxing aid was prepared by mixing the above materials in equal mass. The results of dewaxed oil yield and filtration rate of this lubricating oil fraction are shown in Table 2.

Example 6 Using the SAE30 wax-containing lubricating oil fraction used in Example 3,
Except for that, the dewaxing experiment was conducted under the same conditions as in Example 5. The results of dewaxed oil yield and filtration rate of this lubricating oil fraction are also shown in Table 2.

Example 7 Using the SAE20 wax-containing lubricating oil fraction used in Example 2,
A dewaxing experiment was carried out under the same conditions as in Example 2 using a mixture obtained by mixing two kinds of E and F copolymers at a ratio of 70% by mass to 30% by mass as a dewaxing aid. The results of dewaxed oil yield and filtration rate of this lubricating oil fraction are shown in Table 3.

Example 8 Using the SAE20 wax-containing lubricating oil fraction used in Example 2,
A dewaxing experiment was carried out under the same conditions as in Example 2, using a mixture obtained by mixing two kinds of E and F copolymers at a ratio of 30% by mass: 70% by mass as a dewaxing aid. The results of dewaxed oil yield and filtration rate of this lubricating oil fraction are also shown in Table 3.

Example 9 Using the SAE30 wax-containing lubricating oil fraction used in Example 3,
A dewaxing experiment was carried out under the same conditions as in Example 3, using a mixture obtained by mixing two kinds of E and F copolymers at a ratio of 70% by mass to 30% by mass as a dewaxing aid. The results of dewaxed oil yield and filtration rate of this lubricating oil fraction are also shown in Table 3.

Example 10 Using the SAE30 wax-containing lubricating oil fraction used in Example 3,
A dewaxing experiment was carried out under the same conditions as in Example 3, using a mixture obtained by mixing the copolymers of two kinds of E and F at a ratio of 30 mass%: 70 mass% as a dewaxing aid. The results of dewaxed oil yield and filtration rate of this lubricating oil fraction are also shown in Table 3.

Comparative Examples 1 to 4 SAE10 wax-containing lubricating oil fraction used in Example 1 (Comparative Example 1), SAE20 wax-containing lubricating oil fraction (Comparative Example 2), SA
E30 wax-containing lubricating oil fraction (Comparative Example 3) and wax-containing bright stock (Comparative Example 4) were subjected to dewaxing experiments under the same conditions as in Examples 1 to 4 without adding a dewaxing aid. .
The results of dewaxed oil yield and filtration rate of these lubricating oil fractions are shown in Table 4.

Comparative Example 5 Using the SAE20 wax-containing lubricating oil fraction used in Example 2,
A dewaxing experiment was conducted under the same conditions as in Example 2 using as a dewaxing aid a mixture obtained by mixing two kinds of E and F copolymers at a ratio of 10% by mass: 90% by mass. The results of dewaxed oil yield and filtration rate of this lubricating oil fraction are shown in Table 5.

Comparative Example 6 Using the SAE30 wax-containing wax fraction used in Example 3,
A dewaxing experiment was carried out under the same conditions as in Example 3, using a mixture obtained by mixing two kinds of E and F copolymers at a ratio of 90% by mass: 10% by mass as a dewaxing aid. The results of dewaxed oil yield and filtration rate of this lubricating oil fraction are also shown in Table 5.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

[Table 4]

[0041]

[Table 5]

[0042]

INDUSTRIAL APPLICABILITY According to the present invention, by adding the dewaxing aid of the present invention to a wax-containing lubricating oil fraction having a viscosity of SAE 10 or more to remove the wax, the yield of the dewaxed oil can be increased. +2.1 points for wax lubricant fraction, SAE20
+2.1 to +2.8 points for the wax-containing lubricating oil fraction, +2.4 to + for the SAE30 wax-containing lubricating oil fraction
2.7 points, plus for wax-included bright stock
2.9 points, each improved, filtration speed SA
E10 brazing oil fraction 1.8 times, SAE20
2.2 to 2.3 times in case of wax-containing lubricating oil fraction, SAE3
In the case of 0 wax-containing lubricating oil fraction, the improvement is 1.5 to 1.6 times, and in the case of wax-containing bright stock, it is 1.1 times.

As described above, by adding the dewaxing aid of the present invention to dewax, the dewaxed oil yield and the filtration rate are improved, and particularly for relatively high viscosity oils equivalent to SAE 30 or higher. In addition, SAE20 equivalent oils and SAs which have not always been sufficiently effective with conventional dewaxing aids
It has an effect of improving the dewaxing oil yield and the filtration rate even for a relatively low viscosity oil such as E10 equivalent oil. This is a particular advantage of the present invention.

Claims (6)

[Claims] 1. A: B = 2 copolymers of the following two types A and B:
A method for dewaxing a wax-containing lubricating oil fraction, which comprises using a mixture mixed at a ratio of 5 to 75% by mass: 75 to 25% by mass as a dewaxing aid. A: A multi-component ester copolymer of a mixture of an aliphatic alcohol having an alkyl group having 6 to 16 carbon atoms and acrylic acid, and having a mass average molecular weight of 5,000 to 70.
50,000 B: A multi-component ester copolymer of a mixture of an aliphatic alcohol having an alkyl group having a carbon number in the range of 17 to 30 and acrylic acid, and having a weight average molecular weight of 5,000 to 7.
The one of 0,000 2. A polycondensate of chlorinated paraffin and biphenyl having a mass average molecular weight in the range of 2,000 to 60,000 (C) and a dewaxing aid (D) according to claim 1 as C A method for dewaxing a wax-containing lubricating oil fraction, which comprises using a mixture of D: 25 to 75% by mass: 75 to 25% by mass as a dewaxing aid. 3. A wax fraction containing a dewaxing aid for 5 wax fractions.
The dewaxing method of the wax-containing lubricating oil fraction according to claim 1 or 2, wherein 0 to 3,000 mass ppm is added. 4. A dewaxing aid-containing wax fraction containing 1 wax.
The method according to claim 1 or 2, wherein the amount is 0.00 to 500 mass ppm.
A method for dewaxing the wax-containing lubricating oil fraction described. 5. The following two types of copolymers A and B are used as A: B = 2.
Dewaxing aid for lubricating oil fractions consisting of a mixture of 5 to 75% by mass: 75 to 25% by mass. A: A multi-component ester copolymer of a mixture of an aliphatic alcohol having an alkyl group having 6 to 16 carbon atoms and acrylic acid, and having a mass average molecular weight of 5,000 to 70.
50,000 B: A multi-component ester copolymer of a mixture of an aliphatic alcohol having an alkyl group having a carbon number in the range of 17 to 30 and acrylic acid, and having a weight average molecular weight of 5,000 to 7.
The one of 0,000 6. A polycondensate of chlorinated paraffin and biphenyl having a mass average molecular weight in the range of 2,000 to 60,000 (C) and a dewaxing aid (D) according to claim 5 as C : D = 25 to 75% by mass: Dewaxing aid for a lubricating oil fraction, which is composed of a mixture mixed in a ratio of 75 to 25% by mass.