CN116590048B

CN116590048B - A method for preparing high-viscosity PAO lubricant base oil

Info

Publication number: CN116590048B
Application number: CN202310410263.9A
Authority: CN
Inventors: 孙鑫; 高鹏; 陶智超; 牛晓峰; 李国强; 杨勇; 李永旺
Original assignee: Synfuels China Inner Mongolia Co ltd; Zhongke Synthetic Oil Technology Co Ltd
Current assignee: Synfuels China Inner Mongolia Co ltd; Zhongke Synthetic Oil Technology Co Ltd
Priority date: 2023-04-14
Filing date: 2023-04-14
Publication date: 2025-06-06
Anticipated expiration: 2043-04-14
Also published as: CN116590048A

Abstract

The invention provides a method for preparing high-viscosity PAO (poly (lactic acid) lubricating oil base oil, which comprises the steps of deoxidizing Fischer-Tropsch synthesis intermediate oil to obtain Fischer-Tropsch oxygen-containing compound and deoxidized Fischer-Tropsch synthesis intermediate oil, and then fractionating the deoxidized Fischer-Tropsch synthesis intermediate oil, so that the obtained medium-temperature distillate and high-temperature distillate are subjected to polymerization reaction under the action of a polymerization catalyst, and the product is subjected to further treatment to obtain the high-viscosity PAO lubricating oil base oil. The method can effectively utilize the intermediate oil product of Fischer-Tropsch synthesis, improves economic benefit, realizes flexible modulation based on product guidance, and improves the quality and the pluripotency of PAO production raw materials.

Description

Method for preparing high-viscosity PAO (PAO) lubricating oil base oil

Technical Field

The invention belongs to the field of post-processing of Fischer-Tropsch synthesis products, and relates to a method for preparing high-viscosity PAO (poly (arylene ether)) lubricating oil base oil by utilizing coal indirect liquefied intermediate oil, such as Fischer-Tropsch synthesis intermediate oil.

Background

The indirect coal liquefaction is an oil production technology for producing liquid hydrocarbon as a main component by Fischer-Tropsch synthesis of synthesis gas (mixed gas of CO and H ₂) under the condition of a catalyst and a proper condition. The liquid hydrocarbon (also called as 'Fischer-Tropsch synthetic oil') is obtained through the processes of chain initiation, carbon chain growth, carbon chain termination, product desorption and the like. The proportion of alpha-olefin in the Fischer-Tropsch synthesis intermediate oil product is nearly 70wt% of the liquid phase product, and the alpha-olefin is in addition normal alkane and an oxygen-containing compound mainly comprising alcohols. Further processing is carried out on the Fischer-Tropsch synthesis oil product, so that a product with higher economic added value is obtained, and the economic benefit of the whole process is improved.

Currently, lubricating oil faces more severe use conditions in various fields, and the demand for high-quality synthetic lubricating oil with longer oil change period, better lubricating performance, energy conservation and environmental protection is continuously increasing in the future. PAO is favored by the high-end lubricating oil market as IV synthetic lubricating oil base oil because of the advantages of regular molecular structure, excellent viscosity-temperature performance, low-temperature fluidity, high-temperature oxidation resistance, low volatility, cleanliness and the like.

The alpha-olefin for producing PAO is mainly obtained by paraffin cracking method in China, while the foreign alpha-olefin is mainly obtained by ethylene oligomerization process, which has obvious advantages compared with the paraffin cracking method in China, but no ethylene oligomerization production device is available in China at present, and the production technology is monopolyed by several chemical enterprises in foreign countries for a long time. Because the paraffin cracking method produces raw materials with complex composition, wider distillation range and lower alpha-olefin content, the quality of PAO finished products prepared by the method is still greatly different from that of foreign products, and the PAO finished products are imported in China in the field of high-quality PAO base oil for a long time.

As the Fischer-Tropsch synthesis intermediate product has high alpha-olefin content, if the PAO base oil can be produced by using the Fischer-Tropsch synthesis intermediate product, the quality and the pluripotency of PAO production raw materials in China can be improved, and the current situations of poor raw material quality and single variety in the past are made up. In addition, due to the high economic value of the high-quality PAO lubricating oil base oil, the high-quality PAO lubricating oil base oil can promote the healthy and stable development of the coal-to-oil industry, and create larger economic value and social value.

CN105368489B discloses a PAO preparation method for Fischer-Tropsch synthetic oil, in the method, light oil generated by indirect liquefaction of coal is used as a raw material, the polymerization reaction pressure is 10.0-15.0MPa, the reaction temperature is 300-400 ℃, a catalyst is a Lewis acid catalyst, and the PAO product is obtained through polymerization intermittent reaction and fixed bed hydrofining. However, the reaction conditions are harsh, the requirements on equipment are too high, and the obtained product has relatively single brand and cannot meet the market demands.

CN104560193a discloses a method for preparing a lubricant base oil, which comprises the steps of carrying out polymerization reaction in the presence of Lewis acid catalyst, and carrying out hydrofining and/or hydroisomerization reaction on the polymerization product, but the process adopts a bulk polymerization method, so that the viscosity of the product is lower, and only a product with low viscosity can be obtained.

Therefore, there is a need to develop a process for producing PAO lubricant base oils that is different from the prior art to address the deficiencies in the existing counts.

Disclosure of Invention

In order to solve the above problems in the prior art, the present inventors have studied to provide a method for preparing a high viscosity PAO lubricant base oil, which uses a fischer-tropsch synthesis intermediate oil as a raw material, and obtains the high viscosity PAO lubricant base oil by polymerizing a specific fraction oil therein with a polymerization catalyst containing an oxygen-containing compound and then performing subsequent treatments. The method can flexibly adjust the composition of the reaction raw materials and the catalyst according to the requirements, can realize the reutilization of the oxygen-containing compounds in the raw materials, improves the economic benefit, is environment-friendly and can greatly reduce the energy consumption.

The invention relates to a method for preparing high-viscosity PAO lubricating oil base oil, which comprises the following steps:

(1) Deoxidizing the Fischer-Tropsch synthesis intermediate oil product to obtain a Fischer-Tropsch oxygen-containing compound and a deoxidized Fischer-Tropsch synthesis intermediate oil product;

(2) Fractionating the deoxidized Fischer-Tropsch synthesis intermediate oil product to obtain low-temperature distillate oil, medium-temperature distillate oil and high-temperature distillate oil;

(3) Mixing an additive with a portion of the optional fischer-tropsch oxygenate to provide a polymerization catalyst containing 0.01wt% to 10wt% oxygenate, wherein the additive comprises AlCl ₃, C5-C10 alkane solvent, and optionally oxygenate, the oxygenate being at least one selected from alcohols, aldehydes, ketones, acids or ethers;

(4) Mixing the medium-temperature distillate oil and the high-temperature distillate oil with the polymerization catalyst to perform polymerization reaction, and performing post-treatment on a reaction product to obtain a product to be hydrogenated and a recycled catalyst;

(5) Carrying out hydrofining reaction on the product to be hydrogenated and polymerized to obtain a crude product of polymerized oil;

(6) Fractionating the crude product of the polymerized oil to obtain the high-viscosity PAO lubricating oil base oil.

The methods provided herein for preparing high viscosity PAO lubricant base oils from fischer-tropsch synthesis intermediate oils may, for example, have the following beneficial effects and further other advantages:

1. the quality and the pluripotency of PAO production raw materials are improved, and the current situations of poor quality and single variety of domestic raw materials are made up;

2. Flexible modulation based on product guidance is realized, and multidimensional matching between products, raw materials and conditions is formed;

3. the polymerization catalyst is prepared by effectively utilizing the oxygen compound contained in the Fischer-Tropsch synthesis intermediate oil product, such as Fischer-Tropsch light oil, thereby improving economic and ecological benefits.

Drawings

The accompanying drawings are included to provide a further explanation of the invention, together with the description, and are not intended to limit the scope of the invention.

FIG. 1 illustrates a flow chart of an exemplary process for preparing a high viscosity PAO lube base stock using a coal-to-liquids product.

The description of the reference numerals is as follows:

1, fischer-Tropsch synthesis intermediate oil product, 2, fischer-Tropsch oxygen-containing compound, 3, deoxidized Fischer-Tropsch synthesis intermediate oil product, 4, extracted oxygen-containing compound, 5, additive, 6, low-temperature distillate oil, 7, middle-temperature distillate oil, 8, high-temperature distillate oil and 9, high-viscosity PAO lubricating oil base oil;

I, deoxidizing unit, II, polymerization catalyst preparation unit, III, raw material fractionation unit, IV, storage unit, V, kettle reactor 1, VI, kettle reactor 2, VII, post-treatment unit, VIII, hydrofining unit, IX, product rectification unit.

Detailed Description

The following describes specific embodiments of the present invention in detail. The specific embodiments described herein are offered by way of illustration and explanation only, and are not intended to limit the invention.

Aiming at the problems existing in the prior art, the invention provides a method for preparing high-viscosity PAO lubricating oil base oil, which comprises the following steps:

In some embodiments, in step (1), the Fischer-Tropsch synthesis intermediate oil is a Fischer-Tropsch light oil having a distillation range of less than 350 ℃, preferably less than 280 ℃. In some preferred embodiments, the Fischer-Tropsch light oil contains 0.1wt% to 10wt% of oxygenates. Wherein the oxygen-containing compound contained in the Fischer-Tropsch light oil is one or more selected from alcohol, aldehyde, ketone, acid or ether oxygen-containing compounds of C1-C12.

In some embodiments, in step (1), the deoxygenation may be performed using methods conventional in the art, such as, but not limited to, using any one selected from the group consisting of extraction, physical adsorption, chemisorption, or hydrogenation.

In some embodiments, in step (2), the fractionation may be performed using methods conventional in the art. In some preferred embodiments, the fractionation may be performed by atmospheric distillation and vacuum distillation. Wherein the atmospheric distillation and the reduced pressure distillation are carried out under the conventional conditions in the art, for example, the vacuum degree of the reduced pressure distillation may be 10-150torr (e.g., 30-100), the column top temperature may be 150-250 ℃, the column bottom temperature may be 200-300 ℃ and the column plate number may be 40-60, the column top temperature of the atmospheric distillation may be 80-150 ℃, the column bottom temperature may be 200-280 ℃ and the column plate number may be 40-60.

In some embodiments, the low temperature distillate, medium temperature distillate and high temperature distillate described in step (2) are respectively a distillate with a final distillation point <125 ℃ (< C8), a distillate with a final distillation point between 126 ℃ and 216 ℃ (C8-C12), and a distillate with a final distillation point between 217 ℃ and 280 ℃ (C13-C14).

In this document, unless otherwise indicated, the term "a portion" refers to any value in the range of greater than 0% and less than 100% relative to the total amount of the subject to which it modifies.

In some embodiments, in step (3), the polymerization catalyst contains 1wt% to 5wt% (e.g., 1.5wt% to 3wt%, 1.8wt% to 2.5 wt%) of the oxygenate.

In this context, the additive is a mixture of AlCl ₃, a C5-C10 alkane solvent, and optionally an oxygenate. In some embodiments, in step (3), the oxygenate contained in the additive comprises at least one of an alcohol, an aldehyde, a ketone, an acid, and an ether. Preferably, the alcohols include n-propanol, n-butanol, n-pentanol, iso-pentanol, n-hexanol, iso-hexanol, n-heptanol, iso-heptanol, n-octanol, 2-dimethylbutanol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, trimethylol propane, glycerol, pentaerythritol, 2-phenyl-2-propanol, the aldehydes include propionaldehyde, butyraldehyde, the ketones include acetone, butanone, the acid is acetic acid, and the ethers are diethyl ethers.

In some embodiments, in step (3), the C5-C10 alkane solvent comprises one or more of hexane, cyclohexane, heptane, octane, nonane, decane (e.g., heptane, octane, nonane, decane, or any mixture thereof).

In some embodiments, in step (3), the additive comprises 5wt% to 20wt% AlCl ₃, 0.5wt% to 5wt% oxygenate, 80wt% to 90wt% C5-C10 alkane solvent. In some preferred embodiments, the additive comprises 10wt% to 15wt% AlCl ₃, 1wt% to 2wt% of an oxygenate, 85wt% to 90wt% of a C5-C10 alkane solvent, wherein the oxygenate is at least one selected from n-pentanol, iso-pentanol, n-hexanol, iso-hexanol, propanal, butanal, and the C5-C10 alkane solvent comprises one or more of heptane, octane, nonane, decane.

In some embodiments, in step (4), the medium temperature distillate and the high temperature distillate are mixed in a mass ratio of 0:1 to 15:1 (e.g., 2:1 to 15:1, 5:1 to 15:1, or 5:1 to 13:1).

In some embodiments, in step (4), the medium temperature distillate and the high temperature distillate are mixed with the polymerization catalyst at a mass ratio of distillate to polymerization catalyst of 100:3 to 100:15 (e.g., 100:5 to 100:15, 100:6 to 100:13, or 100:60 to 100:12).

In some embodiments, in step (4), the medium temperature distillate and the high temperature distillate are polymerized at a reaction temperature of 0 to 60 ℃ (preferably 10 ℃ to 50 ℃) and a reaction pressure of 0 to 1.0MPa (preferably 0.1 to 1.0MPa, 0.1 to 0.9MPa, 0.1 to 0.8 MPa).

In some embodiments, in step (4), the post-treatment comprises filtration (to recover the catalyst), caustic wash, optionally water wash. Preferably, the alkaline wash may be performed with, for example, ca (OH) ₂ powder, for example, at 300-400 ℃ (e.g., 300-350 ℃).

In some embodiments, in step (4), the recycled catalyst may be recycled to the polymerization reaction for reuse.

In some embodiments, in step (5), the hydrofinishing reaction is conducted by means of fixed bed hydrogenation. In some preferred embodiments, the product to be hydrogenated is heated and then enters from the top of the fixed bed, hydrogen and the product to be hydrogenated are fully mixed and reacted in the catalyst bed, and then are separated by an oil-gas separator, and the obtained crude product of the polymerized oil is discharged from the bottom (for example, the product can enter a finished product tank through a constant pressure valve). In some preferred embodiments, the hydrofinishing reaction is conducted at a reaction pressure of 8.0 to 15.0MPa (e.g., 8.0 to 12.0 MPa), a reaction temperature of 300 to 400 ℃ (e.g., 300 to 350 ℃), a space velocity of 0.5 to 2.0h ^-1 (e.g., 0.5 to 1.0h ^-1), and the catalyst is a Ni-Mo based catalyst.

Herein, the high viscosity PAO lubricant base oil is a product having a viscosity of greater than or equal to 100mm ²/s at 100 ℃. In some embodiments, in step (6), the high viscosity PAO lubricating oil base oil is identified as PAO100, PAO150, PAO200, or the like.

Exemplary embodiments of the present invention are illustrated by the following numbered paragraphs:

1. a method of making a high viscosity PAO lubricating oil base oil comprising:

2. The method of paragraph 1, wherein in step (1), the Fischer-Tropsch synthesis intermediate oil product is Fischer-Tropsch light oil, and the distillation range is less than 350 ℃.

3. The method of paragraph 2 wherein the Fischer-Tropsch light oil contains 0.1wt% to 10wt% of oxygenates.

4. The method according to any one of paragraphs 1 to 3, wherein in step (1), the deoxidation is performed by any one selected from the group consisting of extraction, physical adsorption, chemical adsorption and hydrogenation.

5. The method according to any one of paragraphs 1-4, wherein in step (2), the fractionating is performed by atmospheric distillation and vacuum distillation.

6. The method as in paragraph 5, wherein the atmospheric distillation has a top temperature of 80 ℃ to 150 ℃, a bottom temperature of 200 ℃ to 280 ℃ and a number of plates of 40 to 60, and the vacuum distillation has a vacuum of 10 to 150torr, a top temperature of 150 ℃ to 250 ℃, a bottom temperature of 200 ℃ to 300 ℃ and a number of plates of 40 to 60.

7. The process of any of paragraphs 1-6, wherein in step (3), the polymerization catalyst contains 1 to 5wt% of the oxygenate.

8. The method according to any one of paragraphs 1-7, wherein in step (3), the alcohol comprises n-propanol, n-butanol, n-pentanol, iso-pentanol, n-hexanol, iso-hexanol, n-heptanol, iso-heptanol, n-octanol, 2-dimethylbutanol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, trimethylolpropane, glycerol, pentaerythritol, 2-phenyl-2-propanol, the aldehyde comprises propionaldehyde, butyraldehyde, the ketone comprises acetone, butanone, the acid is acetic acid, and the ether is diethyl ether.

9. The method of any of paragraphs 1-8, wherein in step (3), the C5-C10 alkane solvent comprises one or more of hexane, cyclohexane, heptane, octane, nonane, decane.

10. The process of any one of paragraphs 1-9, wherein in step (3), the additive comprises 5wt% to 20wt% AlCl ₃, 0.5wt% to 5wt% oxygenate, 80wt% to 90wt% C5-C10 alkane solvent.

11. The method of paragraph 10, wherein the additive comprises 10wt% to 15wt% AlCl ₃, 1wt% to 2wt% of an oxygenate, 85wt% to 90wt% of a C5-C10 alkane solvent, the oxygenate being at least one selected from n-pentanol, iso-pentanol, n-hexanol, iso-hexanol, propanal, butanal, the C5-C10 alkane solvent comprising one or more of heptane, octane, nonane, decane.

12. The method of any of paragraphs 1-11, wherein in step (4), the medium temperature distillate and the high temperature distillate are mixed at a mass ratio of 0:1 to 15:1.

13. The method according to any one of paragraphs 1-12, wherein in step (4), the medium temperature distillate and the high temperature distillate are mixed with the polymerization catalyst at a mass ratio of distillate to polymerization catalyst of 100:3 to 100:15.

14. The method according to any one of paragraphs 1-13, wherein in step (4), the polymerization is conducted at a reaction temperature of 0-60℃and a reaction pressure of 0-1.0MPa.

15. The method of any of paragraphs 1-14, wherein in step (4), the post-treatment comprises filtration, caustic washing, optionally water washing.

16. The method of paragraph 15 wherein the alkaline wash is performed with Ca (OH) ₂ powder.

17. The method of paragraph 15 or 16, wherein the alkaline wash is performed at 300 ℃ to 400 ℃.

18. The process of any one of paragraphs 1-17, wherein in step (4), the recycled catalyst is recycled to the polymerization reaction for reuse.

19. The process of any one of paragraphs 1-18, wherein in step (5), the hydrofinishing reaction is conducted by means of fixed bed hydrogenation.

20. The method of paragraph 19, wherein in step (5), the product to be hydrogenated is heated and then enters from the top of the fixed bed, the hydrogen and the product to be hydrogenated are fully mixed and reacted in the catalyst bed, and then separated by an oil-gas separator, and the obtained crude product of the polymerized oil is discharged from the bottom.

21. The process according to any one of paragraphs 1 to 20, wherein in step (5), the hydrofining reaction is carried out under the conditions of a reaction pressure of 8.0 to 15.0MPa, a reaction temperature of 300 to 400 ℃ and a space velocity of 0.5 to 2.0h ^-1, and the catalyst is a Ni-Mo-based catalyst.

22. The method of any of paragraphs 1-21, wherein in step (6), the high viscosity PAO lubricant base oil is identified as PAO100, PAO150 or PAO200.

The following detailed description will further illustrate the aspects of the present invention, but the scope of the present invention is not limited thereto.

And removing the oxygen-containing compound from the Fischer-Tropsch intermediate oil (such as Fischer-Tropsch light oil) by any one method selected from an extraction method, a physical adsorption method, a chemical adsorption method or a hydrogenation method to obtain the Fischer-Tropsch oxygen-containing compound and a deoxidized Fischer-Tropsch synthesis intermediate oil. Wherein, the deoxidized Fischer-Tropsch synthesis intermediate oil is distilled under normal pressure and reduced pressure under normal conditions (for example, the vacuum degree can be 10-150 torr) to obtain low-temperature distillate oil (< C8) with the final distillation point of <125 ℃, medium-temperature distillate oil (C8-C12) with the final distillation point of 126-216 ℃ and high-temperature distillate oil (C13-C14) with the final distillation point of 217-280 ℃, and a part of the optional Fischer-Tropsch oxygen-containing compound is mixed with an additive to obtain a polymerization catalyst, wherein, the AlCl ₃ content in the additive is 5-20 wt%, the oxygen-containing compound content is 0.5-5 wt% and the content of the C5-C10 alkane solvent is 80-90 wt%.

Mixing the medium-temperature distillate oil and the high-temperature distillate oil with the polymerization catalyst, carrying out polymerization reaction at the reaction temperature of 0-60 ℃ and the reaction pressure of 0-1.0MPa, and filtering the reaction product to recover the catalyst, carrying out alkaline washing, optional water washing and other post-treatments to obtain the product to be hydrogenated and the recycled catalyst, wherein the recycled catalyst can be reused in the polymerization reaction preferably.

And (3) carrying out hydrofining reaction on the product to be hydrogenated in a fixed bed hydrogenation reactor under the conditions that the reaction pressure is 8.0-15.0MPa, the reaction temperature is 300-400 ℃ and the space velocity is 0.5-2.0h ^-1, and the catalyst is a Ni-Mo catalyst to obtain a crude product of the polymerized oil with stable properties. Specifically, in the hydrofining reaction process, the product to be hydrogenated and polymerized enters from the top of a fixed bed after being heated, hydrogen and the product to be hydrogenated and polymerized are fully mixed and reacted in a catalyst bed layer, then are separated by an oil-gas separator, and the crude product of polymerized oil is discharged from the bottom and enters into a finished product tank through a constant pressure valve. Fractionating the polymer oil crude product with stable properties to obtain the high-viscosity PAO lubricating oil base oil.

Examples

The reagents, materials, and apparatus involved in the following examples are commercially available as is conventional in the art, unless otherwise indicated, and conventional procedures involved in the following examples can be found in patents, patent applications, publications, and the like, which are published in the art (e.g., he Yongde, main code, handbook of modern coal chemical industry, chemical industry Press, 2003, but are not limited thereto).

The PAO lubricating oil base oil performance test method in the invention is as follows:

(1) Petroleum product motion viscosity measuring method GB/T265

(2) Petroleum product viscosity index calculation method GB/T1995

(3) Pour Point determination of Petroleum products GB/T3535

(4) The method for measuring the flash point of the lubricating oil is GB/T3536-2008.

The relevant properties of the raw material, fischer-Tropsch light oil, used in the examples below are shown in the following table:

example 1

And (3) removing the oxygen-containing compound from the Fischer-Tropsch light oil by an extraction method (the extractant is sulfolane, the volume ratio of the sulfolane to the Fischer-Tropsch light oil is 1:1, and the extraction time is 2 h), so as to obtain the Fischer-Tropsch oxygen-containing compound and deoxidized Fischer-Tropsch light oil. Wherein, the deoxidized Fischer-Tropsch light oil is distilled under normal pressure (the tower top temperature is 110 ℃, the tower bottom temperature is 230 ℃ and the tower plate number is 50) and distilled under reduced pressure (the vacuum degree is 100torr, the tower top temperature is 220 ℃, the tower bottom temperature is 280 ℃ and the tower plate number is 50), and the medium-temperature distillate oil and the high-temperature distillate oil are obtained. Mixing 0.5wt% of the obtained Fischer-Tropsch oxygenate with additives to obtain a polymerization catalyst (the mass percentage of the oxygenate in the polymerization catalyst is 1.8%). The additive comprises 13.5wt% of AlCl ₃, 1.0wt% of oxygen-containing compound n-hexanol and 85.5wt% of solvent n-octane.

Mixing the medium temperature distillate and the high temperature distillate according to the mass ratio of 13:1, adding 12wt% (relative to the mass sum of the medium temperature distillate and the high temperature distillate) of the polymerization catalyst, carrying out polymerization under the conditions of the reaction temperature of 10 ℃ and the reaction pressure of 0.1MPa, filtering the reaction product to recover the catalyst, and carrying out alkali washing treatment to be neutral by using Ca (OH) ₂ powder at 340 ℃ to obtain the product to be hydrogenated and the recycled catalyst.

The product to be hydrogenated is subjected to hydrofining reaction in a fixed bed hydrogenation reactor under the conditions that the reaction pressure is 10.0MPa, the reaction temperature is 300 ℃, the space velocity is 0.5h ^-1, the catalyst is a Ni-Mo catalyst (wherein, the Ni content is 2.9wt percent, the Mo content is 23.2wt percent, and the balance is an aluminum oxide carrier), so as to obtain a crude product of the polymerized oil with stable property, and then the crude product is subjected to fractional distillation by adopting a true boiling point device under the condition that the vacuum degree is 2torr, so that the PAO-200 lubricating oil base oil product is obtained, and the specific results are shown in table 1.

Example 2

And removing the oxygen-containing compound from the Fischer-Tropsch light oil by a physical adsorption method (the adsorbent is aluminum oxide, and the adsorption time is 5 h) to obtain the Fischer-Tropsch oxygen-containing compound and deoxidized Fischer-Tropsch light oil. Wherein, the deoxidized Fischer-Tropsch light oil is distilled under normal pressure (the tower top temperature is 110 ℃, the tower bottom temperature is 230 ℃ and the tower plate number is 50) and distilled under reduced pressure (the vacuum degree is 100torr, the tower top temperature is 220 ℃, the tower bottom temperature is 280 ℃ and the tower plate number is 50), and the medium-temperature distillate oil and the high-temperature distillate oil are obtained. Mixing 0.7wt% of the obtained Fischer-Tropsch oxygenate with an additive to obtain a polymerization catalyst (the mass percentage of the oxygenate in the polymerization catalyst is 2%). The additive comprises 12wt% of AlCl ₃, 1.3wt% of oxygen-containing compound isoamyl alcohol and 86.7wt% of solvent heptane.

Mixing the medium temperature distillate and the high temperature distillate according to the mass ratio of 10:1, adding 8wt% (relative to the mass sum of the medium temperature distillate and the high temperature distillate) of the polymerization catalyst, carrying out polymerization under the conditions of the reaction temperature of 30 ℃ and the reaction pressure of 0.5MPa, recovering the catalyst of the reaction product, and carrying out alkaline washing treatment to neutrality by using Ca (OH) ₂ powder at the temperature of 330 ℃ to obtain the product to be hydrogenated and the recycled catalyst.

The product to be hydrogenated is subjected to hydrofining reaction in a fixed bed hydrogenation reactor under the conditions of reaction pressure of 12MPa, reaction temperature of 350 ℃, space velocity of 1h ^-1 and catalyst of Ni-Mo series catalyst (wherein Ni content is 3.5wt%, mo content is 26.3wt% and the rest is aluminum oxide carrier), so as to obtain a crude product of polymerized oil with stable property, and then the crude product is subjected to fractional distillation by adopting a real boiling point device under the condition of vacuum degree of 10torr to obtain a PAO-150 lubricating oil base oil product, wherein specific results are shown in table 1.

Example 3

And removing the oxygen-containing compound from the Fischer-Tropsch light oil by a chemical adsorption method (the adsorbent is a microporous molecular sieve, and the adsorption time is 3 h), so as to obtain the Fischer-Tropsch oxygen-containing compound and deoxidized Fischer-Tropsch light oil. Wherein, the deoxidized Fischer-Tropsch light oil is distilled under normal pressure (the tower top temperature is 115 ℃, the tower bottom temperature is 240 ℃ and the tower plate number is 50) and distilled under reduced pressure (the vacuum degree is 30torr, the tower top temperature is 175 ℃, the tower bottom temperature is 216 ℃ and the tower plate number is 45), and the medium-temperature distillate oil and the high-temperature distillate oil are obtained. Mixing 0.6wt% of the obtained Fischer-Tropsch oxygenate with additives to obtain a polymerization catalyst (the mass percentage of the oxygenate in the polymerization catalyst is 2.5%). The additive comprises 10wt% of AlCl ₃, 1.5wt% of oxygen-containing compound butyraldehyde and 88.5wt% of solvent decane.

Mixing the medium temperature distillate and the high temperature distillate according to the mass ratio of 5:1, adding 6.5wt% (relative to the mass sum of the medium temperature distillate and the high temperature distillate) of the polymerization catalyst, carrying out polymerization reaction under the conditions of 50 ℃ and 0.8MPa of reaction temperature, filtering the reaction product to recover the catalyst, and carrying out alkali washing treatment to be neutral with Ca (OH) ₂ powder at 320 ℃ to obtain the product to be hydrogenated and the recycled catalyst.

And (3) carrying out hydrofining reaction on the product to be hydrogenated in a fixed bed hydrogenation reactor under the conditions that the reaction pressure is 8MPa, the reaction temperature is 330 ℃, the space velocity is 1h ^-1, the catalyst is a Ni-Mo catalyst (wherein, the Ni content is 3.5wt%, the Mo content is 28wt% and the balance is an aluminum oxide carrier), so as to obtain a polymer oil crude product with stable properties, and then fractionating by adopting a true boiling point device under the condition that the vacuum degree is 10torr, so as to obtain the PAO-100 lubricating oil base oil product.

Table 1 results of analysis of the products of the examples

Examples	Number plate	Viscosity at 100℃of mm ²/s	Viscosity index	Pour point/° C
					Example 1	PAO-200	205.3	216	<-30
Example 2	PAO-150	149.2	208	<-40
					Example 3	PAO-100	102.3	203	<-45

Claims

1. A method of making a high viscosity PAO lubricating oil base oil comprising:

(3) Mixing an additive with a portion of the Fischer-Tropsch oxygenate to obtain a polymerization catalyst containing 0.01wt% to 10wt% of oxygenate, wherein the additive comprises AlCl ₃, a C5-C10 alkane solvent, and an oxygenate, the oxygenate being at least one selected from alcohols, aldehydes, ketones, acids or ethers;

2. The method of claim 1, wherein in the step (1), the fischer-tropsch synthesis intermediate oil is a fischer-tropsch light oil with a distillation range of less than 350 ℃.

3. The method of claim 2, wherein the fischer-tropsch light oil comprises 0.1wt% to 10wt% oxygenates.

4. A process according to any one of claims 1 to 3, wherein in step (1) the deoxygenation is carried out using any one selected from the group consisting of extraction, physical adsorption, chemisorption and hydrogenation.

5. A process according to any one of claims 1 to 3, wherein in step (2) the fractionation is carried out by atmospheric distillation and vacuum distillation.

6. The process according to claim 5, wherein the atmospheric distillation has a top temperature of 80 to 150 ℃, a bottom temperature of 200 to 280 ℃ and a number of trays of 40 to 60, and the vacuum distillation has a vacuum of 10 to 150torr, a top temperature of 150to 250 ℃, a bottom temperature of 200 to 300 ℃ and a number of trays of 40 to 60.

7. A process according to any one of claims 1 to 3, wherein in step (3) the polymerization catalyst contains 1 to 5wt% of an oxygenate.

8. The process of any of claims 1-3, wherein in step (3), the alcohol comprises n-propanol, n-butanol, n-pentanol, iso-pentanol, n-hexanol, iso-hexanol, n-heptanol, iso-heptanol, n-octanol, 2-dimethylbutanol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, trimethylol propane, glycerol, pentaerythritol, 2-phenyl-2-propanol, the aldehyde comprises propionaldehyde, butyraldehyde, the ketone comprises acetone, butanone, the acid is acetic acid, and the ether is diethyl ether.

9. A process according to any one of claims 1 to 3, wherein in step (3) the C5-C10 alkane solvent comprises one or more of hexane, cyclohexane, heptane, octane, nonane, decane.

10. The process of any one of claims 1-3, wherein in step (3), the additive comprises 5wt% to 20wt% AlCl ₃, 0.5wt% to 5wt% oxygenate, 80wt% to 90wt% C5-C10 alkane solvent.

11. The method of claim 10, wherein the additive comprises 10wt% to 15wt% AlCl ₃, 1wt% to 2wt% of an oxygenate, 85wt% to 90wt% of a C5-C10 alkane solvent, the oxygenate being at least one selected from n-pentanol, iso-pentanol, n-hexanol, iso-hexanol, propanal, butanal, the C5-C10 alkane solvent comprising one or more of heptane, octane, nonane, decane.

12. A process according to any one of claims 1 to 3, wherein in step (4) the medium temperature distillate and the high temperature distillate are mixed in a mass ratio of 0:1 to 15:1.

13. A process according to any one of claims 1 to 3, wherein in step (4) the medium temperature distillate and the high temperature distillate are mixed with the polymerization catalyst in a mass ratio of distillate to polymerization catalyst of 100:3 to 100:15.

14. A process as claimed in claim 1 to 3, wherein in step (4), the polymerization is carried out at a reaction temperature of from 0 to 60℃and a reaction pressure of from 0 to 1.0MPa.

15. A method according to any one of claims 1 to 3, wherein in step (4), the post-treatment comprises filtration, caustic washing.

16. The method of claim 15, wherein in step (4), the post-treatment further comprises water washing.

17. The method of claim 15, wherein the alkaline washing is performed with Ca (OH) ₂ powder.

18. The method of claim 15, wherein the alkaline wash is performed at 300-400 ℃.

19. A process according to any one of claims 1 to 3 wherein in step (4) the recycled catalyst is recycled to the polymerization reaction for reuse.

20. A process according to any one of claims 1 to 3, wherein in step (5) the hydrofinishing reaction is carried out by means of fixed bed hydrogenation.

21. The method according to claim 20, wherein in the step (5), the product to be hydrogenated is heated and enters from the top of the fixed bed, hydrogen and the product to be hydrogenated are fully mixed and reacted in the catalyst bed, and then separated by an oil-gas separator, and the obtained crude product of the polymerized oil is discharged from the bottom.

22. The process according to any one of claims 1 to 3, wherein in the step (5), the hydrorefining reaction is carried out under the conditions of a reaction pressure of 8.0 to 15.0MPa, a reaction temperature of 300 to 400 ℃ and a space velocity of 0.5 to 2.0h ^-1, and the catalyst is a Ni-Mo-based catalyst.

23. A method according to any one of claims 1 to 3, wherein in step (6) the high viscosity PAO lubricating oil base oil is identified by the brand name PAO100, PAO150 or PAO200.