A method for preparing high-viscosity PAO lubricant base oil

Abstract

The present invention provides a method for preparing a high-viscosity PAO lubricant base oil, comprising: deoxygenating a Fischer-Tropsch synthesis intermediate oil product to obtain a Fischer-Tropsch oxygenated compound and a deoxygenated Fischer-Tropsch synthesis intermediate oil product; then, fractionating the deoxygenated Fischer-Tropsch synthesis intermediate oil product, subjecting the obtained medium-temperature distillate oil and high-temperature distillate oil to polymerization reaction under the action of a polymerization catalyst, and further treating the product to obtain a high-viscosity PAO lubricant base oil. The method described in the present invention can effectively utilize the Fischer-Tropsch synthesis intermediate oil product, improve economic benefits, realize flexible modulation based on product orientation, and improve the quality and diversity of PAO production raw materials.

Description

Technical Field

[0001] The present invention belongs to the field of post-processing of Fischer-Tropsch synthesis products, and relates to a method for preparing high-viscosity PAO lubricant base oil by using coal indirect liquefaction intermediate oil products, such as Fischer-Tropsch synthesis intermediate oil products. Background Art

[0002] Indirect coal liquefaction is the synthesis gas (CO and H 2 A technology that uses a mixed gas (of a mixture of carbon and carbon) to carry out Fischer-Tropsch synthesis under a catalyst and suitable conditions to produce oil products mainly in the form of liquid hydrocarbons. Liquid hydrocarbons (also called "Fischer-Tropsch synthetic oils") are obtained through processes such as chain initiation, carbon chain growth, carbon chain termination and product desorption. In the intermediate oil products of Fischer-Tropsch synthesis, α-olefins account for nearly 70wt% of the liquid phase products, and the rest are normal alkanes and oxygen-containing compounds mainly alcohols. Further processing of Fischer-Tropsch synthetic oils to obtain products with higher economic added value helps to improve the economic benefits of the entire process.

[0003] At present, lubricants are facing more demanding operating conditions in various fields. In the future, the demand for high-quality synthetic lubricants with longer oil change cycles, better lubrication performance, energy saving and environmental protection will continue to increase. PAO, as a Class IV synthetic lubricant base oil, is favored by the high-end lubricant market due to its regular molecular structure, excellent viscosity-temperature performance, low-temperature fluidity, high-temperature oxidation resistance, low volatility and cleanliness.

[0004] The α-olefins used to produce PAO in my country are mainly obtained through paraffin cracking, while foreign α-olefins are mainly obtained through ethylene polymerization. This process has obvious advantages over my country's paraffin cracking, but there is currently no ethylene polymerization production equipment in China, and its production technology has long been monopolized by several foreign chemical companies. Due to the complex composition, wide distillation range and low α-olefin content of the raw materials produced by the paraffin cracking method, the quality of the PAO finished products prepared by it is still far behind that of foreign countries, resulting in my country's long-term reliance on imports in the field of high-quality PAO base oils.

[0005] Since the intermediate products of Fischer-Tropsch synthesis have a high α-olefin content, if they can be used to produce PAO base oil, it will be able to improve the quality and diversity of raw materials for PAO production in my country, making up for the current situation of poor quality and single variety of raw materials. In addition, due to the high economic value of high-quality PAO lubricant base oil, it can promote the healthy and stable development of the coal-to-oil industry and create greater economic and social value.

[0006] CN105368489B discloses a method for preparing PAO from Fischer-Tropsch synthetic oil products, in which light oil generated by indirect liquefaction of coal is used as raw material, the polymerization reaction pressure is 10.0-15.0MPa, the reaction temperature is 300-400°C, the catalyst is a Lewis acid catalyst, and the PAO product is obtained through intermittent polymerization reaction and fixed bed hydrofining. However, the reaction conditions are harsh, the equipment requirements are too high, and the obtained product brand is relatively single, which cannot meet market demand.

[0007] CN104560193A discloses a method for preparing a lubricating base oil, which includes a polymerization reaction in the presence of a Lewis acid catalyst, and subjecting the polymerization product to hydrogenation refining and / or hydrogenation isomerization reaction. However, the process adopts a bulk polymerization method, resulting in a low viscosity of the product, and only a low-viscosity product can be obtained.

[0008] Therefore, it is necessary to develop a method for producing PAO lubricant base oil that is different from the prior art to address the deficiencies in the prior art. Summary of the invention

[0009] In order to solve the above problems existing in the prior art, the inventors have provided a method for preparing a high-viscosity PAO lubricant base oil through research, which uses Fischer-Tropsch synthesis intermediate oil as raw material, and obtains a high-viscosity PAO lubricant base oil by polymerizing a specific fraction oil therein with a polymerization catalyst containing oxygen-containing compounds and subsequent treatment. The method can flexibly adjust the composition of the reaction raw materials and catalysts according to demand, and can realize the reuse of oxygen-containing compounds in the raw materials, thereby improving economic benefits, and the method is environmentally friendly and can significantly reduce energy consumption.

[0010] The present invention relates to a method for preparing a high-viscosity PAO lubricant base oil, comprising:

[0011] (1) deoxygenating the Fischer-Tropsch synthesis intermediate oil product to obtain a Fischer-Tropsch oxygenated compound and a deoxygenated Fischer-Tropsch synthesis intermediate oil product;

[0012] (2) fractionating the deoxygenated Fischer-Tropsch synthesis intermediate oil to obtain low-temperature distillate oil, medium-temperature distillate oil and high-temperature distillate oil;

[0013] (3) mixing an additive with a portion of the optional Fischer-Tropsch oxygenate to obtain a polymerization catalyst containing 0.01 wt % to 10 wt % of the oxygenate, wherein the additive comprises AlCl 3 , a C5-C10 alkane solvent, and an optional oxygen-containing compound, wherein the oxygen-containing compound is at least one selected from alcohol, aldehyde, ketone, acid or ether;

[0014] (4) mixing the medium-temperature distillate oil and the high-temperature distillate oil with the polymerization catalyst to carry out a polymerization reaction, and post-treating the reaction product to obtain a polymerization product to be hydrogenated and a recycled catalyst;

[0015] (5) subjecting the to-be-hydrogenated polymer product to a hydrofining reaction to obtain a crude polymer oil product;

[0016] (6) fractionating the crude polymerized oil product to obtain a high-viscosity PAO lubricant base oil.

[0017] The method for preparing a high viscosity PAO lubricating oil base oil from a Fischer-Tropsch synthesis intermediate oil provided herein may, for example, have the following beneficial effects and further other advantages:

[0018] 1. Improve the quality and diversity of raw materials for PAO production to make up for the current situation of poor quality and single variety of domestic raw materials;

[0019] 2. Realize flexible adjustments based on product orientation and form multi-dimensional matching between products, raw materials and conditions;

[0020] 3. Effectively utilize oxygen compounds contained in Fischer-Tropsch synthesis intermediate oils, such as Fischer-Tropsch light oil, to prepare polymerization catalysts, thereby improving economic and ecological benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are a part of the specification and together with the detailed description provide further explanation of the present invention, but are not intended to limit the scope of the present invention.

[0022] Figure 1 A flow chart of an exemplary process for preparing high viscosity PAO lubricant base oil using coal indirect liquefaction products is shown.

[0023] Description of the reference numerals is as follows:

[0024] 1. Fischer-Tropsch synthesis intermediate oil; 2. Fischer-Tropsch oxygenated compounds; 3. Deoxygenated Fischer-Tropsch synthesis intermediate oil; 4. Extracted oxygenated compounds; 5. Additives; 6. Low-temperature distillate oil; 7. Medium-temperature distillate oil; 8. High-temperature distillate oil; 9. High-viscosity PAO lubricant base oil;

[0025] I, deoxygenation unit; II, polymerization catalyst preparation unit; III, raw material fractionation unit; IV, storage unit; V, tank reactor 1; VI, tank reactor 2; VII, post-processing unit; VIII, hydrofining unit; IX, product distillation unit. DETAILED DESCRIPTION

[0026] The specific embodiments of the present invention are described in detail below. The specific embodiments described here are only used to illustrate and explain the present invention, but are not used to limit the present invention.

[0027] In view of the problems existing in the prior art, the present invention provides a method for preparing a high-viscosity PAO lubricant base oil, comprising:

[0028] (1) deoxygenating the Fischer-Tropsch synthesis intermediate oil product to obtain a Fischer-Tropsch oxygenated compound and a deoxygenated Fischer-Tropsch synthesis intermediate oil product;

[0029] (2) fractionating the deoxygenated Fischer-Tropsch synthesis intermediate oil to obtain low-temperature distillate oil, medium-temperature distillate oil and high-temperature distillate oil;

[0030] (3) mixing an additive with a portion of the optional Fischer-Tropsch oxygenate to obtain a polymerization catalyst containing 0.01 wt % to 10 wt % of the oxygenate, wherein the additive comprises AlCl 3 , a C5-C10 alkane solvent, and an optional oxygen-containing compound, wherein the oxygen-containing compound is at least one selected from alcohol, aldehyde, ketone, acid or ether;

[0031] (4) mixing the medium-temperature distillate oil and the high-temperature distillate oil with the polymerization catalyst to carry out a polymerization reaction, and post-treating the reaction product to obtain a polymerization product to be hydrogenated and a recycled catalyst;

[0032] (5) subjecting the to-be-hydrogenated polymer product to a hydrofining reaction to obtain a crude polymer oil product;

[0033] (6) fractionating the crude polymerized oil product to obtain a high-viscosity PAO lubricant base oil.

[0034] In some embodiments, in step (1), the Fischer-Tropsch synthesis intermediate oil is a Fischer-Tropsch light oil, and its distillation range is less than 350° C., preferably less than 280° C. In some preferred embodiments, the Fischer-Tropsch light oil contains 0.1wt%-10wt% of oxygen-containing compounds. The oxygen-containing compounds contained in the Fischer-Tropsch light oil are one or more oxygen-containing compounds selected from C1-C12 alcohols, aldehydes, ketones, acids or ethers.

[0035] In some embodiments, in step (1), the deoxygenation can be performed by conventional methods in the art, for example, but not limited to, any one selected from extraction, physical adsorption, chemical adsorption or hydrogenation.

[0036] In some embodiments, in step (2), the fractionation can be carried out by conventional methods in the art. In some preferred embodiments, the fractionation can be carried out by atmospheric distillation and vacuum distillation. Among them, the atmospheric distillation and vacuum distillation are carried out under conventional conditions in the art. For example, the vacuum degree of the vacuum distillation can be 10-150 torr (such as 30-100), the top temperature can be 150°C - 250°C, the bottom temperature can be 200°C - 300°C, and the number of trays can be 40-60; the top temperature of the atmospheric distillation can be 80°C - 150°C, the bottom temperature can be 200°C - 280°C, and the number of trays can be 40-60.

[0037] In some embodiments, in step (2), the low-temperature fraction oil, medium-temperature fraction oil, and high-temperature fraction oil are fraction oils with an end boiling point < 125°C (<C8), fraction oils with an end boiling point between 126°C - 216°C (C8-C12), and fraction oils with an end boiling point between 217°C - 280°C (C13-C14), respectively.

[0038] In this article, unless otherwise specified, the term "a part" refers to any value within the range of greater than 0% and less than 100% relative to the total amount of the object it modifies.

[0039] In some embodiments, in step (3), the polymerization catalyst contains 1 wt% to 5 wt% (such as 1.5 wt% to 3 wt%, 1.8 wt% to 2.5 wt%) of oxygen-containing compounds.

[0040] In this article, the additive is a mixture of AlCl 3 , a C5-C10 alkane solvent, and an optional oxygen-containing compound. In some embodiments, in step (3), the oxygen-containing compounds included in the additive include at least one of alcohols, aldehydes, ketones, acids, and ethers. Preferably, the alcohols include n-propanol, n-butanol, n-pentanol, isopentanol, n-hexanol, isohexanol, n-heptanol, isoheptanol, n-octanol, 2,2-dimethylbutanol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, trimethylolpropane, glycerol, pentaerythritol, 2-phenyl-2-propanol; the aldehydes include propionaldehyde, butyraldehyde; the ketones include acetone, butanone; the acid is acetic acid; the ether is diethyl ether.

[0041] In some embodiments, in step (3), the C5-C10 alkane solvent includes one or more of hexane, cyclohexane, heptane, octane, nonane, and decane (such as heptane, octane, nonane, decane, or any mixture thereof).

[0042] In some embodiments, in step (3), the additive contains 5 wt% - 20 wt% of AlCl 3, 0.5wt%-5wt% of oxygen-containing compound, 80wt%-90wt% of C5-C10 alkane solvent. In some preferred embodiments, the additive comprises 10wt%-15wt% of AlCl 3 , 1wt%-2wt% of oxygen-containing compounds, 85wt%-90wt% of C5-C10 alkane solvents, wherein the oxygen-containing compound is at least one selected from n-pentanol, isopentanol, n-hexanol, isohexanol, propionaldehyde, and butyraldehyde, and the C5-C10 alkane solvent includes one or more of heptane, octane, nonane, and decane.

[0043] In some embodiments, in step (4), the medium-temperature distillate oil and the high-temperature distillate oil are mixed in a mass ratio of 0:1 to 15:1 (eg, 2:1 to 15:1, 5:1 to 15:1, or 5:1 to 13:1).

[0044] In some embodiments, in step (4), the medium-temperature distillate oil and the high-temperature distillate oil are mixed with the polymerization catalyst according to a mass ratio of distillate oil: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).

[0045] In some embodiments, in step (4), the medium-temperature distillate oil and the high-temperature distillate oil are polymerized under the following conditions: the reaction temperature is 0-60°C (preferably 10°C-50°C), and the reaction pressure is 0-1.0 MPa (preferably 0.1-1.0 MPa, 0.1-0.9 MPa, 0.1-0.8 MPa).

[0046] In some embodiments, in step (4), the post-treatment includes filtration (to recover the catalyst), alkaline washing, and optional water washing. Preferably, the alkaline washing can be carried out using, for example, Ca(OH) 2 The alkali washing is performed on the powder, for example, at 300°C-400°C (eg 300°C-350°C).

[0047] In some embodiments, in step (4), the recycled catalyst can be recycled to the polymerization reaction for repeated use.

[0048] In some embodiments, in step (5), the hydrofining reaction is carried out by fixed bed hydrogenation. In some preferred embodiments, the polymer product to be hydrogenated is heated and then enters from the top of the fixed bed. After the hydrogen and the polymer product to be hydrogenated are fully mixed and reacted in the catalyst bed, they are separated by an oil-gas separator, and the obtained polymer oil crude product is discharged from the bottom (for example, the product can enter the finished product tank through a constant pressure valve). In some preferred embodiments, the hydrofining reaction is carried out under the following conditions: the reaction pressure is 8.0-15.0MPa (for example, 8.0-12.0MPa), the reaction temperature is 300℃-400℃ (for example, 300℃-350℃), and the space velocity is 0.5-2.0h -1 (e.g. 0.5-1.0h -1 ), the catalyst is a Ni-Mo catalyst.

[0049] In this article, the high viscosity PAO lubricant base oil has a viscosity greater than or equal to 100 mm at 100°C. 2 In some embodiments, in step (6), the main grades of the high-viscosity PAO lubricant base oil are PAO100, PAO150 or PAO200.

[0050] The exemplary technical solutions of the present invention are described by the contents shown in the following numbered paragraphs:

[0051] 1. A method for preparing a high-viscosity PAO lubricant base oil, comprising:

[0052] (1) deoxygenating the Fischer-Tropsch synthesis intermediate oil product to obtain a Fischer-Tropsch oxygenated compound and a deoxygenated Fischer-Tropsch synthesis intermediate oil product;

[0053] (2) fractionating the deoxygenated Fischer-Tropsch synthesis intermediate oil to obtain low-temperature distillate oil, medium-temperature distillate oil and high-temperature distillate oil;

[0054] (3) mixing an additive with a portion of the optional Fischer-Tropsch oxygenate to obtain a polymerization catalyst containing 0.01 wt % to 10 wt % of the oxygenate, wherein the additive comprises AlCl 3 , a C5-C10 alkane solvent, and an optional oxygen-containing compound, wherein the oxygen-containing compound is at least one selected from alcohol, aldehyde, ketone, acid or ether;

[0055] (4) mixing the medium-temperature distillate oil and the high-temperature distillate oil with the polymerization catalyst to carry out a polymerization reaction, and post-treating the reaction product to obtain a polymerization product to be hydrogenated and a recycled catalyst;

[0056] (5) subjecting the to-be-hydrogenated polymer product to a hydrofining reaction to obtain a crude polymer oil product;

[0057] (6) fractionating the crude polymerized oil product to obtain a high-viscosity PAO lubricant base oil.

[0058] 2. The method as described in paragraph 1, wherein in step (1), the Fischer-Tropsch synthesis intermediate oil product is Fischer-Tropsch light oil, and its distillation range is less than 350°C.

[0059] 3. The method as described in paragraph 2, wherein the Fischer-Tropsch light oil contains 0.1 wt%-10 wt% of oxygen-containing compounds.

[0060] 4. The method as described in any one of paragraphs 1 to 3, wherein in step (1), the deoxygenation is carried out by any one selected from extraction, physical adsorption, chemical adsorption or hydrogenation.

[0061] 5. The method as described in any one of paragraphs 1 to 4, wherein in step (2), the fractionation is performed by atmospheric distillation and reduced pressure distillation.

[0062] 6. The method as described in paragraph 5, wherein the top temperature of the atmospheric distillation is 80°C-150°C, the bottom temperature is 200°C-280°C, and the number of plates is 40-60; the vacuum degree of the reduced pressure distillation is 10-150 torr, the top temperature is 150°C-250°C, the bottom temperature is 200°C-300°C, and the number of plates is 40-60.

[0063] 7. The method as described in any of paragraphs 1 to 6, wherein in step (3), the polymerization catalyst contains 1 wt% to 5 wt% of an oxygen-containing compound.

[0064] 8. The method of any one of paragraphs 1 to 7, wherein in step (3), the alcohol comprises n-propanol, n-butanol, n-pentanol, isopentanol, n-hexanol, isohexanol, n-heptanol, isoheptanol, n-octanol, 2,2-dimethylbutanol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, trimethylolpropane, glycerol, pentaerythritol, 2-phenyl-2-propanol; the aldehyde comprises propionaldehyde and butyraldehyde; the ketone comprises acetone and butanone; the acid is acetic acid; and the ether is diethyl ether.

[0065] 9. The method as described in any of paragraphs 1 to 8, wherein in step (3), the C5-C10 alkane solvent comprises one or more of hexane, cyclohexane, heptane, octane, nonane, and decane.

[0066] 10. The method of any one of paragraphs 1 to 9, wherein in step (3), the additive comprises 5 wt% to 20 wt% of AlCl 3 , 0.5wt%-5wt% of oxygen-containing compounds, and 80wt%-90wt% of C5-C10 alkane solvents.

[0067] 11. The method of paragraph 10, wherein the additive comprises 10 wt% to 15 wt% of AlCl 3 , 1wt%-2wt% of oxygen-containing compounds, 85wt%-90wt% of C5-C10 alkane solvents, wherein the oxygen-containing compounds are at least one selected from n-pentanol, isopentanol, n-hexanol, isohexanol, propionaldehyde, and butyraldehyde, and the C5-C10 alkane solvents include one or more of heptane, octane, nonane, and decane.

[0068] 12. The method as described in any one of paragraphs 1 to 11, wherein in step (4), the medium-temperature distillate oil and the high-temperature distillate oil are mixed in a mass ratio of 0:1 to 15:1.

[0069] 13. The method as described in any one of paragraphs 1 to 12, wherein in step (4), the medium-temperature distillate oil and the high-temperature distillate oil are mixed with the polymerization catalyst according to a mass ratio of distillate oil: polymerization catalyst of 100:3 to 100:15.

[0070] 14. The method as described in any of paragraphs 1 to 13, wherein in step (4), the polymerization reaction is carried out under the following conditions: the reaction temperature is 0-60° C., and the reaction pressure is 0-1.0 MPa.

[0071] 15. The method as described in any of paragraphs 1 to 14, wherein in step (4), the post-treatment comprises filtration, alkali washing, and optionally water washing.

[0072] 16. The method of paragraph 15, wherein the alkaline washing can be carried out by using Ca(OH) 2 Powder made.

[0073] 17. The method of paragraph 15 or 16, wherein the alkali washing is performed at 300°C to 400°C.

[0074] 18. The method as described in any one of paragraphs 1 to 17, wherein in step (4), the recycled catalyst is recycled to the polymerization reaction for repeated use.

[0075] 19. The method as described in any one of paragraphs 1 to 18, wherein in step (5), the hydrotreating reaction is carried out by fixed bed hydrogenation.

[0076] 20. The method as described in paragraph 19, wherein in step (5), the polymer product to be hydrogenated is heated and then enters from the top of the fixed bed, the hydrogen and the polymer product to be hydrogenated are fully mixed and reacted in the catalyst bed, and then separated by an oil-gas separator, and the obtained polymer oil crude product is discharged from the bottom.

[0077] 21. The method as described in any one of paragraphs 1 - 20, wherein in step (5), the hydrofining reaction is carried out under the following conditions: the reaction pressure is 8.0 - 15.0 MPa, the reaction temperature is 300°C - 400°C, and the space velocity is 0.5 - 2.0 h -1 , and the catalyst is a Ni - Mo series catalyst.

[0078] 22. The method as described in any one of paragraphs 1 - 21, wherein in step (6), the main grades of the high - viscosity PAO lubricating oil base oil are PAO100, PAO150 or PAO200.

[0079] The following will further illustrate the solution of the present invention through the following specific embodiments, but the protection scope of the present invention is not limited thereto.

[0080] The oxygen - containing compounds in the Fischer - Tropsch intermediate oil (such as Fischer - Tropsch light oil) are removed by any one method selected from extraction method, physical adsorption method, chemical adsorption method or hydrogenation method to obtain Fischer - Tropsch oxygen - containing compounds and deoxygenated Fischer - Tropsch synthesis intermediate oil. Among them, the deoxygenated Fischer - Tropsch synthesis intermediate oil is subjected to atmospheric distillation and vacuum distillation (for example, the vacuum degree can be 10 - 150 torr) under conventional conditions to obtain a low - temperature distillate oil (<C8) with an end - boiling point <125°C, a medium - temperature distillate oil (C8 - C12) with an end - boiling point of 126°C - 216°C, and a high - temperature distillate oil (C13 - C14) with an end - boiling point of 217°C - 280°C; A part of the optional Fischer - Tropsch oxygen - containing compounds is mixed with an additive to obtain a polymerization catalyst, wherein the AlCl 3 content in the additive is 5 wt% - 20 wt%, the content of oxygen - containing compounds is 0.5 wt% - 5 wt%, and the content of C5 - C10 alkane solvent is 80 wt% - 90 wt%.

[0081] The medium - temperature distillate oil and the high - temperature distillate oil are mixed with the polymerization catalyst, and a polymerization reaction is carried out under the conditions of a reaction temperature of 0 - 60°C and a reaction pressure of 0 - 1.0 MPa. The reaction product is filtered to recover the catalyst, followed by post - treatments such as caustic washing and optional water washing to obtain a product to be hydro - polymerized and a recycled catalyst; Preferably, the recycled catalyst can be reused in the polymerization reaction.

[0082] The product to be hydro - polymerized is placed in a fixed - bed hydrogenation reactor, under a reaction pressure of 8.0 - 15.0 MPa, a reaction temperature of 300°C - 400°C, and a space velocity of 0.5 - 2.0 h -1, a hydrogenation refining reaction is carried out under the condition that the catalyst is a Ni-Mo catalyst to obtain a crude polymer oil product with stable properties. Specifically, in the process of the hydrogenation refining reaction, the polymer product to be hydrogenated is heated and then enters from the top of the fixed bed. After the hydrogen and the polymer product to be hydrogenated are fully mixed and reacted in the catalyst bed, they are separated by an oil-gas separator, and the crude polymer oil product is discharged from the bottom and enters the finished product tank through a constant pressure valve. The crude polymer oil product with stable properties is fractionated to obtain a high-viscosity PAO lubricant base oil.

[0083] Example

[0084] Unless otherwise specified, the reagents, materials and devices involved in the following examples are all commercially available in the art; the conventional operations involved in the following examples can be found in patents, patent applications and publications disclosed in the art (for example, He Yongde, ed., "Modern Coal Chemical Technology Handbook", Chemical Industry Press, 2003, but not limited thereto).

[0085] The PAO lubricating oil base oil performance test method in the present invention is as follows:

[0086] (1) Determination of kinematic viscosity of petroleum products: GB / T 265

[0087] (2) Calculation method for viscosity index of petroleum products: GB / T 1995

[0088] (3) Pour point determination method for petroleum products: GB / T 3535

[0089] (4) Determination method of flash point of lubricating oil: GB / T 3536-2008.

[0090] The relevant properties of the raw material used in the following examples, Fischer-Tropsch light oil, are shown in the following table:

[0091]

[0092] Example 1

[0093] The Fischer-Tropsch light oil is subjected to an extraction method (the extractant is cyclopentane sulfone, the volume ratio of the extractant to the Fischer-Tropsch light oil is 1:1, and the extraction time is 2 hours) to remove oxygenated compounds to obtain Fischer-Tropsch oxygenated compounds and deoxygenated Fischer-Tropsch light oil. Among them, the deoxygenated Fischer-Tropsch light oil is further subjected to atmospheric distillation (tower top temperature 110°C, tower bottom temperature 230°C, tower plate number 50) and reduced pressure distillation (vacuum degree is 100 torr, tower top temperature 220°C, tower bottom temperature 280°C, tower plate number 50) to obtain medium-temperature distillate oil and high-temperature distillate oil. 0.5wt% of the obtained Fischer-Tropsch oxygenated compounds are mixed with additives to obtain a polymerization catalyst (the mass percentage of the oxygenated compounds in the polymerization catalyst is 1.8%). The AlCl in the additive 3The addition amount of is 13.5wt%, the addition amount of the oxygen-containing compound n-hexanol is 1.0wt%, and the addition amount of the solvent n-octane is 85.5wt%.

[0094] The medium-temperature distillate oil and the high-temperature distillate oil were mixed in a mass ratio of 13:1, and then 12 wt% (relative to the sum of the mass of the medium-temperature distillate oil and the high-temperature distillate oil) of the above-mentioned polymerization catalyst was added thereto, and a polymerization reaction was carried out under the conditions of a reaction temperature of 10° C. and a reaction pressure of 0.1 MPa, and the reaction product was filtered to recover the catalyst, and Ca(OH) 2 The powder was treated with alkali washing at 340°C until it became neutral, thereby obtaining a product to be hydrogenated and a recycled catalyst.

[0095] The polymer product to be hydrogenated is placed in a fixed bed hydrogenation reactor at a reaction pressure of 10.0 MPa, a reaction temperature of 300° C., and a space velocity of 0.5 h -1 , a Ni-Mo catalyst (wherein the Ni content is 2.9wt%, the Mo content is 23.2wt%, and the rest is an aluminum oxide carrier) was used for hydrogenation refining reaction to obtain a crude polymer oil product with stable properties. Thereafter, a true boiling point apparatus was used for fractionation under a vacuum degree of 2 torr to obtain a PAO-200 lubricating oil base oil product. The specific results are shown in Table 1.

[0096] Example 2

[0097] The Fischer-Tropsch light oil is subjected to physical adsorption (the adsorbent is aluminum oxide, and the adsorption time is 5 hours) to remove oxygenated compounds to obtain Fischer-Tropsch oxygenated compounds and deoxygenated Fischer-Tropsch light oil. The deoxygenated Fischer-Tropsch light oil is further subjected to atmospheric distillation (tower top temperature 110°C, tower bottom temperature 230°C, and tower plate number 50) and reduced pressure distillation (vacuum degree is 100 torr, tower top temperature 220°C, tower bottom temperature 280°C, and tower plate number 50) to obtain medium-temperature distillate oil and high-temperature distillate oil. 0.7wt% of the obtained Fischer-Tropsch oxygenated compounds are mixed with additives to obtain a polymerization catalyst (the mass percentage of the oxygenated compounds in the polymerization catalyst is 2%). The AlCl 3 The addition amount of isoamyl alcohol, an oxygen-containing compound, is 1.3 wt %, and the addition amount of heptane, a solvent, is 86.7 wt %.

[0098] The medium-temperature distillate oil and the high-temperature distillate oil were mixed in a mass ratio of 10:1, and then 8 wt% (relative to the sum of the mass of the medium-temperature distillate oil and the high-temperature distillate oil) of the above-mentioned polymerization catalyst was added thereto, and a polymerization reaction was carried out under the conditions of a reaction temperature of 30° C. and a reaction pressure of 0.5 MPa, and the catalyst was recovered from the reaction product, and Ca(OH) 2The powder was treated with alkali washing at 330°C until it became neutral, thereby obtaining a product to be hydrogenated and a recycled catalyst.

[0099] The polymer product to be hydrogenated is placed in a fixed bed hydrogenation reactor at a reaction pressure of 12 MPa, a reaction temperature of 350°C, and a space velocity of 1 h -1 , a Ni-Mo catalyst (wherein the Ni content is 3.5wt%, the Mo content is 26.3wt%, and the rest is an aluminum oxide carrier) was used for hydrogenation refining reaction to obtain a crude polymer oil product with stable properties. Thereafter, a true boiling point apparatus was used for fractionation under a vacuum degree of 10 torr to obtain a PAO-150 lubricating oil base oil product. The specific results are shown in Table 1.

[0100] Example 3

[0101] The Fischer-Tropsch light oil is subjected to chemical adsorption (the adsorbent is a microporous molecular sieve, and the adsorption time is 3 hours) to remove oxygenated compounds to obtain Fischer-Tropsch oxygenated compounds and deoxygenated Fischer-Tropsch light oil. The deoxygenated Fischer-Tropsch light oil is further subjected to atmospheric distillation (tower top temperature 115°C, tower bottom temperature 240°C, and tower plate number 50) and reduced pressure distillation (vacuum degree 30 torr, tower top temperature 175°C, tower bottom temperature 216°C, and tower plate number 45) to obtain medium-temperature distillate oil and high-temperature distillate oil. 0.6wt% of the obtained Fischer-Tropsch oxygenated compounds are mixed with additives to obtain a polymerization catalyst (the mass percentage of the oxygenated compounds in the polymerization catalyst is 2.5%). The AlCl 3 The addition amount of is 10wt%, the addition amount of oxygen-containing compound butyraldehyde is 1.5wt%, and the addition amount of solvent decane is 88.5wt%.

[0102] The medium-temperature distillate oil and the high-temperature distillate oil were mixed in a mass ratio of 5:1, and then 6.5 wt% (relative to the mass sum of the medium-temperature distillate oil and the high-temperature distillate oil) of the above-mentioned polymerization catalyst was added thereto, and a polymerization reaction was carried out under the conditions of a reaction temperature of 50° C. and a reaction pressure of 0.8 MPa, and the reaction product was filtered to recover the catalyst, and Ca(OH) 2 The powder was treated with alkali washing at 320°C until it became neutral, thereby obtaining a product to be hydrogenated and a recycled catalyst.

[0103] The polymer product to be hydrogenated is placed in a fixed bed hydrogenation reactor at a reaction pressure of 8 MPa, a reaction temperature of 330°C, and a space velocity of 1 h -1, a hydrogenation refining reaction is carried out under the conditions of a Ni-Mo catalyst (wherein the Ni content is 3.5wt%, the Mo content is 28wt%, and the rest is an aluminum oxide carrier) to obtain a crude polymer oil product with stable properties, which is then fractionated using a true boiling point apparatus at a vacuum degree of 10torr to obtain a PAO-100 lubricating oil base oil product.

[0104] Table 1 Analysis results of products in various embodiments

[0105] Example Brand <![CDATA[Viscosity at 100 °C, mm 2 / s]]> Viscosity Index Pour point / ℃ 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 for preparing a high viscosity PAO lubricant base oil, include: (1) deoxygenating the Fischer-Tropsch synthesis intermediate oil to obtain a Fischer-Tropsch oxygenated compound and a deoxygenated Fischer-Tropsch synthesis intermediate oil; (2) fractionating the deoxygenated Fischer-Tropsch synthesis intermediate oil to obtain low-temperature distillate oil, medium-temperature distillate oil and high-temperature distillate oil; (3) mixing an additive with a portion of the Fischer-Tropsch oxygenate to obtain a polymerization catalyst containing 0.01 wt % to 10 wt % of the oxygenate, wherein the additive comprises AlCl 3 , a C5-C10 alkane solvent, and an oxygen-containing compound, wherein the oxygen-containing compound is at least one selected from alcohol, aldehyde, ketone, acid or ether; (4) mixing the medium-temperature distillate oil and the high-temperature distillate oil with the polymerization catalyst to carry out a polymerization reaction, and post-treating the reaction product to obtain a polymerization product to be hydrogenated and a recycled catalyst; (5) subjecting the to-be-hydrogenated polymer product to a hydrogenation refining reaction to obtain a crude polymer oil product; (6) fractionating the crude polymerized oil product to obtain a high-viscosity PAO lubricant base oil.

2. The method according to claim 1, in, In step (1), the Fischer-Tropsch synthesis intermediate oil product is Fischer-Tropsch light oil, and its distillation range is less than 350°C.

3. The method according to claim 2, in, The Fischer-Tropsch light oil contains 0.1 wt%-10 wt% of oxygen-containing compounds.

4. The method according to any one of claims 1 to 3, in, In step (1), the deoxygenation is carried out by any one method selected from extraction, physical adsorption, chemical adsorption or hydrogenation.

5. The method according to any one of claims 1 to 3, in, In step (2), the fractionation is performed by atmospheric distillation and reduced pressure distillation.

6. The method according to claim 5, in, The top temperature of the atmospheric distillation is 80°C-150°C, the bottom temperature is 200°C-280°C, and the number of plates is 40-60; the vacuum degree of the reduced pressure distillation is 10-150 torr, the top temperature is 150°C-250°C, the bottom temperature is 200°C-300°C, and the number of plates is 40-60.

7. The method according to any one of claims 1 to 3, in, In step (3), the polymerization catalyst contains 1 wt % to 5 wt % of an oxygen-containing compound.

8. The method according to any one of claims 1 to 3, in, In step (3), the alcohol includes n-propanol, n-butanol, n-pentanol, isopentanol, n-hexanol, isohexanol, n-heptanol, isoheptanol, n-octanol, 2,2-dimethylbutanol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, trimethylolpropane, glycerol, pentaerythritol, and 2-phenyl-2-propanol; the aldehyde includes propionaldehyde and butyraldehyde; the ketone includes acetone and butanone; the acid is acetic acid; and the ether is diethyl ether.

9. The method according to any one of claims 1 to 3, in, In step (3), the C5-C10 alkane solvent includes one or more of hexane, cyclohexane, heptane, octane, nonane, and decane.

10. The method according to any one of claims 1 to 3, in, In step (3), the additive comprises 5wt%-20wt% of AlCl 3 , 0.5wt%-5wt% of oxygen-containing compounds, and 80wt%-90wt% of C5-C10 alkane solvents.

11. The method according to claim 10, in, The additive contains 10wt%-15wt% AlCl 3 , 1wt%-2wt% of an oxygen-containing compound, and 85wt%-90wt% of a C5-C10 alkane solvent, wherein the oxygen-containing compound is at least one selected from n-pentanol, isopentanol, n-hexanol, isohexanol, propionaldehyde, and butyraldehyde, and the C5-C10 alkane solvent includes one or more of heptane, octane, nonane, and decane.

12. The method according to any one of claims 1 to 3, in, In step (4), the medium-temperature distillate oil and the high-temperature distillate oil are mixed in a mass ratio of 0:1 to 15:

1.

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

15.

14. The method according to any one of claims 1 to 3, in, In step (4), the polymerization reaction is carried out under the following conditions: reaction temperature is 0-60° C., and reaction pressure is 0-1.0 MPa.

15. The method according to any one of claims 1 to 3, in, In step (4), the post-treatment includes filtration and alkaline washing.

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

17. The method of claim 15, in, The alkaline washing adopts Ca(OH) 2 Powder made.

18. The method of claim 15, in, The alkali washing is performed at 300°C-400°C.

19. The method according to any one of claims 1 to 3, in, In step (4), the recycled catalyst is circulated to the polymerization reaction for repeated use.

20. The method according to any one of claims 1 to 3, in, In step (5), the hydrotreating reaction is carried out by fixed bed hydrogenation.

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

22. The method according to any one of claims 1 to 3, in, In step (5), the hydrofining reaction is carried out under the following conditions: reaction pressure of 8.0-15.0 MPa, reaction temperature of 300°C-400°C, space velocity of 0.5-2.0 h -1 , the catalyst is a Ni-Mo catalyst.

23. The method according to any one of claims 1 to 3, in, In step (6), the grade of the high viscosity PAO lubricating oil base oil is PAO100, PAO150 or PAO200.

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