Method and system for preparing polyalphaolefin lubricating oil base oil

Abstract

Provided in the present invention are a method and system for preparing a polyalphaolefin lubricating oil base oil. The method comprises: performing a first splitting on a Fischer-Tropsch synthesis product to obtain a first mixture containing C9-C11 hydrocarbon compounds; wherein the Fischer-Tropsch synthesis product comprises hydrocarbon compounds having 8-20 carbon atoms; performing a first deoxygenation treatment on the first mixture to obtain a first deoxygenated product; using a first distillation column to carry out a second splitting on the first deoxygenated product, so as to obtain a second mixture containing C10 hydrocarbon compounds; wherein the pressure at the top of the first distillation column is 2-6 kPa, and the temperature at the top of the first distillation column is 55-75°C; carrying out a second deoxygenation treatment on the second mixture, so as to obtain a second deoxygenated product; wherein the second deoxygenated product comprises 1-decene; and under the catalysis of a catalytic system, carrying out a polymerization reaction on the second deoxygenated product, so as to obtain a polyalphaolefin lubricating oil base oil. The second deoxygenated product has a simple composition and has high content of 1-decene, which improves the quality of the PAO lubricating oil base oil and reduces costs.

Description

Process and system for producing poly-alpha olefin lubricating oil base oil

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202410641416.5, filed May 22, 2024, the contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of lubricating oil base oil, in particular to a process and system for producing poly-alpha olefin lubricating oil base oil. BACKGROUND

[0004] Poly-alpha olefin, as a kind of base oil with excellent performance, has the advantages of wide liquid phase range, low pour point, high viscosity index, good viscosity-temperature performance, high flash point, good low-temperature flowability, good oxidation stability and thermal stability, and small evaporation loss, and is widely used in harsh environments such as high-viscosity industrial gear oil, extreme cold hydraulic oil, screw compressor and refrigerator oil. At present, the average annual consumption growth rate of poly-alpha olefin in China is about 5%. The proportion of high-quality lubricating oil demand in the overall demand for lubricating oil is increasing year by year, and the demand for high-end lubricating oil products will drive the growth of poly-alpha olefin demand.

[0005] PAO lubricating oil base oil (poly-alpha olefin lubricating oil base oil) as a type IV synthetic lubricating oil base oil is favored by the high-end lubricating oil market due to its regular molecular structure, excellent viscosity-temperature performance, low-temperature flowability, high-temperature oxidation resistance, low volatility and cleaning properties. The alpha olefin for producing PAO in China is mainly obtained by paraffin cracking method. Because the composition of the raw material produced by the paraffin cracking method is complex, the distillation range is wide, and the alpha olefin content is low, the quality of the PAO finished product prepared by the paraffin cracking method is poor. At present, the medium and low-grade lubricating oils and most high-grade lubricating agents produced by paraffin cracking products in China are being eliminated. The raw material base oil for domestic synthetic lubricating oil base oil has long relied on imports, resulting in high production cost of high-quality PAO lubricating oil base oil.

[0006] Coal indirect liquefaction is a production technology for producing liquid hydrocarbons as the main oil product by Fischer-Tropsch synthesis of synthesis gas (mixed gas of CO and H2) under suitable conditions and catalysts. The proportion of alpha-olefins in the Fischer-Tropsch synthesis intermediate oil product is nearly 70wt%, in addition to oxygen-containing compounds mainly composed of n-alkanes and alcohols. Using the Fischer-Tropsch synthesis intermediate oil product to produce PAO lubricating oil base oil can improve the product quality of PAO lubricating oil base oil, reduce the production cost, and improve the economic benefit of the whole process.

[0007] The prior art (Publication No. CN116590048A) discloses a method for preparing high-viscosity PAO lubricating oil base oil, comprising: deoxygenating a Fischer-Tropsch synthesis intermediate oil product to obtain a Fischer-Tropsch oxygen-containing compound and a deoxygenated Fischer-Tropsch synthesis intermediate oil product; then, the deoxygenated Fischer-Tropsch synthesis intermediate oil product is subjected to fractionation, and the medium-temperature fraction oil and the high-temperature fraction oil obtained therefrom are subjected to polymerization reaction under the action of a polymerization catalyst AlCl3, and the product is further treated to obtain high-viscosity PAO lubricating oil base oil. The catalyst consumption of the process technology is large, and the solid waste discharge is large.

[0008] The prior art (Publication No. CN1633402A) discloses a method for preparing high-viscosity poly-alpha-olefin using a liquid acidic ionic oligomerization catalyst without organic diluent. The process method uses 1-decene and 1-dodecene as raw materials to produce high-viscosity PAO products, and the product production cost is expensive.

[0009] In the existing method for synthesizing coal-based poly-alpha-olefin, the catalyst system is mostly AlCl3 as the catalyst. Although it has high conversion rate, there are problems such as large amount of catalyst, difficult separation of reaction product and catalyst, large amount of solid waste discharge causing environmental pollution, etc.

[0010] In summary, it is necessary to research and develop a method and system for preparing poly-alpha-olefin lubricating oil base oil capable of obtaining poly-alpha-olefin lubricating oil base oil with a single number of carbon atoms. SUMMARY

[0011] The main purpose of the present application is to provide a method and system for preparing poly-alpha-olefin lubricating oil base oil, to solve the problem that the carbon number distribution of the poly-alpha-olefin lubricating oil base oil prepared by using the Fischer-Tropsch synthesis product as raw material is wide, and a single number of carbon atoms of the poly-alpha-olefin lubricating oil base oil cannot be obtained.

[0012] In order to achieve the above-mentioned purpose, the present application provides a method for preparing poly-alpha-olefin lubricating oil base oil, which comprises: step S1, cutting a Fischer-Tropsch synthesis product to obtain a first mixture containing C 11 The Fischer-Tropsch synthesis product comprises hydrocarbon compounds with a number of carbon atoms of 8-20; step S2, subjecting the first mixture to first deoxygenation treatment to obtain a first deoxygenation product; step S3, using a first distillation column to cut the first deoxygenation product to obtain a second mixture containing C 10The second mixture of hydrocarbon compounds; the first distillation column has a top pressure of 2-6 kPa and a top temperature of 55-75℃; step S4, the second mixture is subjected to a second deoxygenation treatment to obtain a second deoxygenated product; the second deoxygenated product includes 1-decene; step S5, the second deoxygenated product is subjected to a polymerization reaction under the catalysis of a catalytic system to obtain a poly-alpha-olefin lubricating oil base oil.

[0013] Further, the second cutting in step S3 is a first reduced pressure distillation; preferably, the first reduced pressure distillation has a top temperature of 61-63℃ and a reflux ratio of (20-40):1.

[0014] Further, the content of 1-decene in the second mixture is ≥90% by weight percentage; preferably, the second deoxygenated product includes 90-95% 1-decene, 3-5% internal olefins and 2-5% n-decane by weight percentage.

[0015] Further, step S5 includes: the second deoxygenated product is subjected to a polymerization reaction under the catalysis of a catalytic system to obtain a poly-alpha-olefin lubricating oil base oil crude product, and a second distillation column is used to perform a second reduced pressure distillation on the poly-alpha-olefin lubricating oil base oil crude product to obtain a poly-alpha-olefin lubricating oil base oil; preferably, the second distillation column has a top pressure of 3-5 kPa, a top temperature of 250-350℃ and a reflux ratio of (5-10):1.

[0016] Further, the weight percentage content of 1-decene in the Fischer-Tropsch synthesis product is 6-8%; and / or, the first mixture includes 3-5% 1-nonene, 8-12% nonane, 60-70% 1-decene and 5-7% decane by weight percentage.

[0017] Further, the second deoxidization treatment comprises: physically adsorbing the second mixture by using an adsorbent to obtain a second deoxidization product; or, treating the second mixture by using a deoxidization agent to remove the compounds containing hydroxyl and / or carboxyl groups in the second mixture to obtain a second deoxidization product; preferably, the weight ratio of the second mixture to the adsorbent is (5-50):(1-5); preferably, the weight ratio of the second mixture to the deoxidization agent is (10-60):(1-2); preferably, the adsorbent is selected from one or more of the group consisting of white clay, silica gel, 3A molecular sieve, 4A molecular sieve, 5A molecular sieve and 13X molecular sieve; preferably, the deoxidization agent comprises a molecular sieve, a modifier and a binder; preferably, the molecular sieve is selected from one or more of the group consisting of ZSM-5, ZSM-48 and TS-1; preferably, the modifier is one or more of the group consisting of ZrO2, BaO and MgO; preferably, the binder is selected from one or more of the group consisting of silicon dioxide, aluminum oxide and sesbania powder; more preferably, the weight ratio of the molecular sieve, the modifier and the binder is (20-60):(5-15):(15-50).

[0018] Further, the first deoxidization treatment comprises: physically adsorbing the first mixture by using an adsorbent to obtain a first deoxidization product; or, treating the first mixture by using a deoxidization agent to remove the compounds containing hydroxyl and / or carboxyl groups in the first mixture to obtain a first deoxidization product; preferably, the weight ratio of the first mixture to the adsorbent is (5-50):1; preferably, the weight ratio of the first mixture to the deoxidization agent is (10-60):1; preferably, the deoxidization agent comprises a molecular sieve, a modifier and a binder; preferably, the molecular sieve is selected from one or more of the group consisting of ZSM-5, ZSM-48 and TS-1; preferably, the modifier is one or more of the group consisting of ZrO2, BaO and MgO; preferably, the binder is selected from silicon dioxide and / or aluminum oxide; more preferably, the weight ratio of the molecular sieve, the modifier and the binder is (20-60):(5-15):(15-50).

[0019] Further, in step S5, the catalytic system comprises a metallocene catalyst and a co-catalyst; preferably, the metallocene catalyst is a bridged bimetallic catalyst; preferably, the co-catalyst is selected from alkylaluminoxane and / or organoboron; preferably, the weight ratio of the metallocene catalyst to the co-catalyst is (1-5):(10-60).

[0020] Further, step S5 further comprises: after the polymerization reaction is completed, mixing the reaction system with a quenching agent to end the polymerization reaction to obtain a crude product of poly-alpha-olefin lubricating oil base oil; preferably, the quenching agent is selected from one or more of the group consisting of hydrochloric acid ethanol solution, lye and water; more preferably, the quenching agent is a hydrochloric acid ethanol solution with a mass concentration of 5-10%.

[0021] Further, in step S1, the first cutting is performed by using a normal pressure distillation column to obtain the first mixture; preferably, the normal pressure distillation column has a top temperature of 144-165°C, preferably 150-160°C, and a reflux ratio of (10-40):1.

[0022] To achieve the above object, the present application further provides a system for implementing the method for preparing poly-alpha-olefin lubricating oil base oil, which comprises a first distillation device, a first deoxygenation device, a second distillation device, a second deoxygenation device and a polymerization reaction device. The first distillation device is used for performing first cutting on the Fischer-Tropsch synthesis product to obtain a first mixture; the first distillation device is provided with a Fischer-Tropsch synthesis product inlet and a first mixture outlet; the first deoxygenation device is used for performing first deoxygenation treatment on the first mixture to obtain a first deoxygenation product; the first deoxygenation device is provided with a first mixture inlet and a first deoxygenation product outlet; the first mixture inlet is in communication with the first mixture outlet; the second distillation device is used for performing second cutting on the first deoxygenation product to obtain a second mixture; the second distillation device is provided with a first deoxygenation product inlet and a second mixture outlet; the first deoxygenation product inlet is in communication with the first deoxygenation product outlet; the second distillation device is a first distillation column; the second deoxygenation device is used for performing second deoxygenation treatment on the second mixture to obtain a second deoxygenation product; the second deoxygenation device is provided with a second mixture inlet and a second deoxygenation product outlet; the second mixture inlet is in communication with the second mixture outlet; the polymerization reaction device is used for performing polymerization reaction on the second deoxygenation product under the catalysis of a catalytic system to obtain poly-alpha-olefin lubricating oil base oil; the polymerization reaction device is provided with a catalytic system inlet, a second deoxygenation product inlet and a first poly-alpha-olefin lubricating oil base oil outlet; the second deoxygenation product inlet is in communication with the second deoxygenation product outlet.

[0023] Further, the first deoxygenation device is further provided with a first deoxygenation agent inlet or a first adsorbent inlet; and / or, the second deoxygenation device is further provided with a second deoxygenation agent inlet or a second adsorbent inlet.

[0024] Further, the polymerization reaction device is further provided with a quenching agent inlet; and / or, the polymerization reaction device is selected from a stirred tank reactor or a microfluidic reactor.

[0025] Further, the system further comprises a third distillation device, which is used for performing second vacuum distillation on the poly-alpha-olefin lubricating oil base oil crude product to obtain poly-alpha-olefin lubricating oil base oil; the third distillation device is provided with a poly-alpha-olefin lubricating oil base oil crude product inlet and a second poly-alpha-olefin lubricating oil base oil outlet; the poly-alpha-olefin lubricating oil base oil crude product inlet is in communication with the first poly-alpha-olefin lubricating oil base oil outlet.

[0026] Further, the first distillation device is a normal pressure distillation column; and / or, the second distillation device is a first distillation column, preferably a first reduced pressure distillation column; and / or, the third distillation device is a second distillation column, preferably a second reduced pressure distillation column.

[0027] By using the technical solution of the present application, the existing method usually only performs one cutting and one deoxidization on the Fischer-Tropsch synthesis product to obtain a product for polymerization reaction. The one cutting process is prone to cause cracking of the raw material, and it is difficult to obtain a product with a single component. Compared with the existing method, the Fischer-Tropsch synthesis product is subjected to two cuttings and two deoxidizations in the present application, and the first deoxidization product is not prone to cracking in the second cutting process, thereby improving the content of C 10 The content of the component, so that the second deoxidization product has a single component and a high content of 1-decene. Using the above preparation method of the present application can inhibit the decrease in product quality of PAO lubricating oil base oil caused by cracking. Moreover, compared with using a high-purity a-olefin as a raw material for polymerization reaction, using the above Fischer-Tropsch synthesis product as a starting raw material in the present application can significantly reduce the cost of raw materials. On this basis, using the above preparation method provided by the present application can improve the product quality of PAO lubricating oil base oil while reducing the cost.

[0028] The pressure and temperature of the second cutting include but are not limited to the above range, and limiting them within the above range is beneficial to inhibit the cracking of the raw material during the cutting process, to improve the content of 1-decene in the second deoxidization product, and to improve the product quality of PAO lubricating oil base oil. BRIEF DESCRIPTION OF DRAWINGS

[0029] The drawings accompanying the specification of the present application serve to provide a further understanding of the present application, and the illustrative embodiments of the present application and their descriptions serve to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0030] FIG. 1 shows a structure schematic diagram of a preparation system of poly-a-olefin lubricating oil base oil in an embodiment of the present application;

[0031] FIG. 2 shows a structure schematic diagram of a preparation system of poly-a-olefin lubricating oil base oil in another embodiment of the present application;

[0032] FIG. 3 shows a structure schematic diagram of a preparation system of poly-a-olefin lubricating oil base oil in another embodiment of the present application.

[0033] wherein the above figure comprises the following reference signs: 100, first distillation device; 101, Fischer-Tropsch synthesis product inlet; 102, first mixture outlet; 200, first deoxygenation device; 201, first mixture inlet; 202, first deoxygenation product outlet; 203, first deoxygenation agent inlet; 204, first adsorbent inlet; 300, second distillation device; 301, first deoxygenation product inlet; 302, second mixture outlet; 400, second deoxygenation device; 401, second mixture inlet; 402, second deoxygenation product outlet; 403, second deoxygenation agent inlet; 404, second adsorbent inlet; 500, polymerization reaction device; 501, catalytic system inlet; 502, second deoxygenation product inlet; 503, first poly-alpha-olefin lubricating oil base oil outlet; 504, quenching agent inlet; 600, third distillation device; 601, poly-alpha-olefin lubricating oil base oil crude product inlet; 602, second poly-alpha-olefin lubricating oil base oil outlet. DETAILED DESCRIPTION

[0034] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments.

[0035] As described in the background, the raw material production cost of high-quality PAO lubricating oil base oil is high, and the existing coal-based synthesis poly-alpha-olefin method is difficult to obtain a single carbon atom number poly-alpha-olefin lubricating oil base oil. In order to solve the above technical problems, the present application provides a preparation method of poly-alpha-olefin lubricating oil base oil, which comprises the following steps: S1, performing first cutting on a Fischer-Tropsch synthesis product to obtain a first mixture of hydrocarbon compounds containing C 11 The Fischer-Tropsch synthesis product comprises hydrocarbon compounds with a carbon atom number of 8-20; S2, performing first deoxygenation treatment on the first mixture to obtain a first deoxygenation product; S3, performing second cutting on the first deoxygenation product by using a first distillation column to obtain a second mixture of hydrocarbon compounds containing C 10 The first distillation column has a top pressure of 2-6 kPa and a temperature of 55-75°C; S4, performing second deoxygenation treatment on the second mixture to obtain a second deoxygenation product; the second deoxygenation product comprises 1-decene; S5, under the catalysis of a catalytic system, performing polymerization reaction on the second deoxygenation product to obtain a poly-alpha-olefin lubricating oil base oil.

[0036] The present application takes the second deoxygenation product obtained by sequentially performing first cutting, first deoxygenation treatment, second cutting and second deoxygenation treatment on the Fischer-Tropsch synthesis product as a raw material, and obtains a poly-alpha-olefin lubricating oil base oil after polymerization reaction under the catalysis of a catalytic system. Specifically, the Fischer-Tropsch synthesis product with specific components is subjected to first cutting to obtain a first mixture of hydrocarbon compounds containing C 11the first mixture of hydrocarbon compounds; the first mixture of hydrocarbon compounds is subjected to a first deoxygenation treatment to remove oxygen-containing compounds therein to obtain a first deoxygenated product; the first deoxygenated product is subjected to a second cutting to obtain a second mixture of hydrocarbon compounds containing C 10 the second mixture of hydrocarbon compounds is subjected to a second deoxygenation treatment to obtain a second deoxygenated product; and the second deoxygenated product is used as a raw material for preparing a PAO lubricating oil base oil, and is subjected to a polymerization reaction under catalysis of a catalytic system to obtain a poly-alpha-olefin lubricating oil base oil.

[0037] The existing method usually only performs one cutting and one deoxygenation on the Fischer-Tropsch synthesis product, and the one cutting process is prone to cause cracking of the raw material, and it is difficult to obtain a product with a single component. Compared with the existing method, the Fischer-Tropsch synthesis product is subjected to two cuttings and two deoxygenation treatments in the present application, and the first deoxygenated product is not prone to cracking in the second cutting process, so that the content of C 10 components in the second mixture of hydrocarbon compounds can be improved, the second deoxygenated product obtained has a single component and a high content of 1-decene, and the use of the above preparation method of the present application can inhibit the decrease in product quality of the PAO lubricating oil base oil caused by cracking. Moreover, compared with using an alpha-olefin with a higher purity as a raw material for a polymerization reaction, the use of the above Fischer-Tropsch synthesis product as a starting raw material in the present application can significantly reduce the cost of the raw material. On this basis, the use of the above preparation method provided by the present application can improve the product quality of the PAO lubricating oil base oil while reducing the cost.

[0038] The pressure and temperature of the second cutting include but are not limited to the above range, and limiting them within the above range is beneficial to inhibit the cracking of the raw material in the cutting process to cause a complex product component, improve the content of 1-decene in the second deoxygenated product, and thus improve the product quality of the PAO lubricating oil base oil.

[0039] In order to further improve the content of 1-decene in the product, the present application uses a vacuum distillation method to perform a second cutting treatment on the first deoxygenated product. In a preferred embodiment, the second cutting in step S3 is a first vacuum distillation. The first deoxygenated product is prone to cracking at high temperatures, and compared with atmospheric distillation, vacuum distillation can reduce the boiling point of the separated substance by reducing the pressure, which is beneficial to inhibit side reactions and decomposition of substances caused by high temperatures, further improve the content of 1-decene, and thus further improve the product quality of the PAO lubricating oil base oil. Moreover, the first vacuum distillation is simple to operate.

[0040] In order to further improve the content of 1-decene, and thus further improve the product quality of the PAO lubricating oil base oil, preferably, the overhead temperature of the first vacuum distillation is 61-63℃, and the reflux ratio is (20-40):1.

[0041] In a preferred embodiment, the content of 1-decene in the second mixture is ≥ 90% by weight percentage of the second mixture. Compared with other ranges, limiting the content of 1-decene in the second mixture in the above range is advantageous for further improving the product quality of the PAO lubricating oil base oil.

[0042] In a preferred embodiment, the second deoxidized product comprises 90-95% of 1-decene, 3-5% of internal olefins and 2-5% of n-decane by weight percentage of the second deoxidized product. Compared with other ranges, limiting the components and contents in the second deoxidized product in the above ranges is advantageous for reducing the content of oxygen-containing compounds, obtaining a PAO lubricating oil base oil with a single carbon number, and further improving the viscosity index, oxidation stability and photo-oxidation stability and other comprehensive performances of the PAO lubricating oil base oil.

[0043] In a preferred embodiment, the step S5 comprises: under the catalysis of the catalytic system, subjecting the second deoxidized product to a polymerization reaction to obtain a poly-α-olefin lubricating oil base oil crude product, and using a second distillation column to perform a second vacuum distillation on the poly-α-olefin lubricating oil base oil crude product to obtain a poly-α-olefin lubricating oil base oil. The above second vacuum distillation can purify the obtained poly-α-olefin lubricating oil base oil crude product, thereby reducing the impurity content therein and being advantageous for obtaining a poly-α-olefin lubricating oil base oil with higher performance. Meanwhile, the second vacuum distillation has high separation efficiency, is simple to operate and has low energy consumption, and can be applied to large-scale industrial production. Compared with other purification methods, the vacuum distillation method can effectively remove the unreacted monomers and by-products in the polymerization reaction, and has better separation effect on chemical substances that are difficult to separate.

[0044] In order to further remove the unreacted monomers and by-products in the polymerization reaction and further improve the purity and quality of the prepared poly-α-olefin lubricating oil base oil, preferably, the overhead pressure of the second distillation column is 3-5 kPa, the overhead temperature is 250-350°C, and the reflux ratio is (5-10):1.

[0045] The present application uses a Fischer-Tropsch synthesis product with specific components as a starting material to produce a poly-α-olefin lubricating oil base oil. In a preferred embodiment, the weight percentage content of 1-decene in the Fischer-Tropsch synthesis product is 6-8%.

[0046] In a preferred embodiment, the first mixture comprises 3-5% of 1-nonene, 8-12% of nonane, 60-70% of 1-decene and 5-7% of decane by weight percentage of the first mixture. Using the Fischer-Tropsch synthesis product with specific components as a starting material to produce a poly-α-olefin lubricating oil base oil and performing the first cutting can obtain the first mixture containing the above specific components, and the content of 1-decene is significantly improved relative to the starting material.

[0047] In a preferred embodiment, the second deoxygenation treatment comprises: using an adsorbent to physically adsorb the second mixture to obtain a second deoxygenated product; or, using a deoxygenation agent to treat the second mixture to remove the hydroxyl and / or carboxyl containing compounds therein to obtain a second deoxygenated product. Oxygen-containing compounds can affect the yield of olefin polymerization to prepare poly-alpha-olefins and the selectivity of the catalyst. After the second deoxygenation treatment using the above method, not only is it beneficial to remove oxygen-containing compounds, but it is also beneficial to inhibit the decrease in the content of alpha-olefins after deoxygenation, thereby facilitating the obtaining of a second deoxygenated product containing a single carbon number, which is used as a raw material for polymerization, and further facilitating the improvement of the comprehensive performance of the PAO lubricating oil base oil prepared, such as the viscosity index, oxidation stability, and photo-oxidation stability.

[0048] To further improve the removal rate of oxygen-containing compounds, preferably, the weight ratio of the second mixture to the adsorbent is (5-50):(1-5).

[0049] The physical adsorption method is simple to operate and can achieve deep impurity removal, is suitable for complete removal of trace amounts of oxygen-containing compounds, is commonly used in the fine removal link, and mainly uses the polarity difference between hydrocarbons and oxygen-containing compounds to remove oxygen-containing compounds in hydrocarbons. The solid particles used as the adsorbent usually have a large specific surface area and a special microporous structure. To further improve the adsorption efficiency and further improve the removal rate of oxygen-containing compounds, preferably, the adsorbent comprises one or more of the group consisting of, but not limited to, white clay, silica gel, 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, and 13X molecular sieve.

[0050] In a preferred embodiment, the deoxygenation agent used in the second deoxygenation treatment process comprises a molecular sieve, a modifier, and a binder. The molecular sieve acts as the main component of the deoxygenation agent to remove oxygen-containing compounds. The introduction of the modifier can activate the molecular sieve, introduce active metal centers on the molecular sieve, thereby exerting the catalytic activity of the molecular sieve, facilitating the dehydration reaction of the oxygen-containing compounds, converting them into components such as olefins, and further facilitating the deoxygenation agent to more effectively remove the oxygen-containing compounds in the Fischer-Tropsch synthesis.

[0051] To further improve the removal rate of oxygen-containing compounds, preferably, the weight ratio of the second mixture to the deoxygenation agent is (10-60):(1-2).

[0052] The preparation method of the deoxygenation agent suitable for the above-mentioned second deoxygenation treatment of the present application comprises: modifying the molecular sieve using a modifier, kneading through a binder, and obtaining the deoxygenation agent after drying and calcination.

[0053] To further improve the deoxygenation performance of the deoxygenation agent prepared for the second deoxygenation treatment, preferably, the drying temperature is 200-300°C, and the time is 2-24h.

[0054] In order to further improve the deoxidation performance of the prepared deoxidizer for the second deoxidation treatment, preferably, the calcination temperature is 500-600°C, and the time is 4-8h.

[0055] In a preferred embodiment, the molecular sieve includes one or more of the group consisting of ZSM-5, ZSM-48 and TS-1. The use of the above-mentioned types of molecular sieve is conducive to improving the removal effect of the deoxidizer on the oxygen-containing compounds in the second mixture, thereby facilitating the obtaining of a second deoxidation product containing a single carbon number as a raw material for the polymerization reaction, and further facilitating the improvement of the comprehensive performance of the prepared PAO lubricating oil base oil, such as viscosity index, oxidation stability and photo-oxidation stability.

[0056] In a preferred embodiment, the modifier includes one or more of the group consisting of ZrO2, BaO and MgO. The use of the above-mentioned types of modifier is conducive to better activating the molecular sieve and improving the catalytic activity of the molecular sieve, thereby improving the removal effect of the deoxidizer on the oxygen-containing compounds in the second mixture.

[0057] The addition of the binder is conducive to improving the structural stability of the deoxidizer and improving the modification effect of the modifier on the molecular sieve, thereby improving the removal effect of the deoxidizer on the oxygen-containing compounds in the second mixture, and preferably, the binder includes one or more of the group consisting of silicon dioxide, aluminum oxide and amaranth powder.

[0058] In a preferred embodiment, the weight ratio of the molecular sieve, the modifier and the binder is (20-60):(5-15):(15-50). The weight ratio of the molecular sieve, the modifier and the binder includes but is not limited to the above-mentioned range, and the limitation within the above-mentioned range is conducive to further improving the removal efficiency of the oxygen-containing compounds, thereby further inhibiting the adverse effects of the oxygen-containing compounds on the catalytic system in the polymerization reaction, and further improving the comprehensive performance of the PAO lubricating oil base oil, such as viscosity index, oxidation stability and photo-oxidation stability.

[0059] In a preferred embodiment, the first deoxidation treatment includes: using an adsorbent to physically adsorb the first mixture to obtain a first deoxidation product; or, using a deoxidizer to treat the first mixture to remove the compounds containing hydroxyl and / or carboxyl groups therein to obtain a first deoxidation product. The presence of the oxygen-containing compounds will affect the yield of the poly-alpha-olefin prepared by the polymerization of olefins and the selectivity of the catalyst, and after the first deoxidation treatment by the above-mentioned method, it is conducive to improving the fine removal effect of the second deoxidation treatment, thereby facilitating the obtaining of a second deoxidation product containing a single carbon number as a raw material for the polymerization reaction, and further facilitating the improvement of the comprehensive performance of the prepared PAO lubricating oil base oil, such as viscosity index, oxidation stability and photo-oxidation stability.

[0060] To further improve the adsorption efficiency of the oxygen-containing compounds in the first mixture, and further improve the removal rate of the oxygen-containing compounds, preferably, the weight ratio of the first mixture to the adsorbent is (5-50): 1.

[0061] In a preferred embodiment, the deoxidizer used in the first deoxidation process comprises a molecular sieve, a modifier and a binder. The molecular sieve as the main component of the deoxidizer plays a role in removing oxygen-containing compounds, the introduction of the modifier can activate the molecular sieve, introduce active metal centers on the molecular sieve, thereby playing the catalytic activity of the molecular sieve, which is beneficial to the dehydration reaction of the oxygen-containing compounds to convert them into olefins and other components, and further beneficial to the deoxidizer to more effectively remove the oxygen-containing compounds in the Fischer-Tropsch synthesis.

[0062] To further improve the removal rate of the oxygen-containing compounds, preferably, the weight ratio of the first mixture to the deoxidizer is (10-60): 1.

[0063] The preparation method of the deoxidizer suitable for the above-mentioned first deoxidation process of the present application comprises: modifying the molecular sieve with a modifier, kneading by a binder, and obtaining the deoxidizer after drying and calcination.

[0064] To further improve the deoxidation performance of the prepared deoxidizer for the first deoxidation process, preferably, the drying temperature is 200-300°C, and the time is 2-24h.

[0065] To further improve the deoxidation performance of the prepared deoxidizer for the first deoxidation process, preferably, the calcination temperature is 500-600°C, and the time is 4-8h.

[0066] In a preferred embodiment, the molecular sieve includes but is not limited to one or more of the group consisting of ZSM-5, ZSM-48 and TS-1. The use of the above-mentioned types of molecular sieve is beneficial to improve the removal effect of the deoxidizer on the oxygen-containing compounds in the first mixture, and is beneficial to subsequent processing.

[0067] In a preferred embodiment, the modifier is one or more of the group consisting of ZrO2, BaO and MgO. The use of the above-mentioned types of modifier is beneficial to better activate the molecular sieve, thereby improving the removal effect of the deoxidizer on the oxygen-containing compounds in the first mixture, and is beneficial to subsequent processing.

[0068] To better mix and contact the molecular sieve and the modifier, improve the modification effect of the modifier on the molecular sieve, and thereby improve the removal effect of the deoxidizer on the oxygen-containing compounds in the first mixture, preferably, the binder includes but is not limited to silica and / or alumina.

[0069] In a preferred embodiment, the weight ratio of the molecular sieve, the modifier and the binder is (20-60):(5-15):(15-50). The weight ratio of the molecular sieve, the modifier and the binder includes but is not limited to the above range, which is limited in the above range to further improve the removal efficiency of the oxygen-containing compounds, to improve the fine removal effect of the second deoxygenation treatment, thereby to further remove the oxygen-containing compounds, and to further improve the purity and the comprehensive performance of the PAO lubricating oil base oil.

[0070] In a preferred embodiment, in step S5, the catalytic system comprises a metallocene catalyst and a cocatalyst. Compared with the catalytic system containing AlCl3, the catalytic system containing the metallocene catalyst is used to catalyze the polymerization reaction, which is advantageous to significantly reduce the amount of catalyst and the amount of solid waste. The catalytic system of the present application also contains a cocatalyst, which can activate the metallocene catalyst to form a single active coordination center with a vacancy. Therefore, compared with other catalysts, the catalytic activity of the metallocene catalyst is more single, and the selectivity is higher, so that the relative molecular mass, structure and composition of the obtained poly-alpha-olefin product are more uniform and regular, thereby further improving the performance of the obtained lubricating oil base oil.

[0071] In a preferred embodiment, the metallocene catalyst is a bridged bis-metallocene catalyst. Compared with a mono-metallocene catalyst, the use of the bridged bis-metallocene catalyst is advantageous to increase the relative molecular mass and the regularity of the structure of the poly-alpha-olefin molecular chain in the PAO lubricating oil base oil, thereby improving the performance of the product.

[0072] In order to better activate the metallocene catalyst and improve the activity and selectivity of the catalytic system, preferably, the cocatalyst includes but is not limited to alkylaluminoxane (MAO) and / or organoboride.

[0073] In order to further improve the activity and selectivity of the catalytic system and further improve the yield of the polymerization reaction, preferably, the weight ratio of the metallocene catalyst to the cocatalyst is (1-5):(10-60).

[0074] In a preferred embodiment, step S5 further comprises: after the completion of the polymerization reaction, mixing the reaction system with a quenching agent to end the polymerization reaction, to obtain a crude product of the poly-alpha-olefin lubricating oil base oil. The above method is advantageous to inhibit the side reaction of the excess unreacted monomer with other substances, thereby improving the yield of the polymerization reaction.

[0075] In order to further improve the quenching efficiency, preferably, the quenching agent includes but is not limited to one or more of the group consisting of an ethanol hydrochloric acid solution, an aqueous solution of an alkaline compound and water.

[0076] In order to further improve the quenching efficiency of the polymerization reaction, preferably, the quenching agent is a 5-10% mass concentration hydrochloric acid ethanol solution.

[0077] In a preferred embodiment, in step S1, the first mixture is obtained by using a normal pressure distillation column for the first cutting of the Fischer-Tropsch synthesis product. The first cutting of the Fischer-Tropsch synthesis product by using normal pressure distillation is low in cost and simple in operation, and only simple heating and cooling are needed to realize the separation of substances, which is suitable for large-scale industrial production.

[0078] In order to improve the yield of the first mixture and increase the content of 1-decene therein, preferably, the overhead temperature of the normal pressure distillation column is 144-165°C, more preferably 150-160°C, and the reflux ratio is (10-40):1.

[0079] The second aspect of the present application also provides a system for implementing the above-mentioned method for preparing poly-alpha-olefin lubricating oil base oil, as shown in FIG. 1, FIG. 2 or FIG. 3, which comprises a first distillation device 100, a first deoxygenation device 200, a second distillation device 300, a second deoxygenation device 400 and a polymerization reaction device 500. The first distillation device 100 is used for the first cutting of the Fischer-Tropsch synthesis product to obtain a first mixture; the first distillation device 100 is provided with a Fischer-Tropsch synthesis product inlet 101 and a first mixture outlet 102; the first deoxygenation device 200 is used for the first deoxygenation treatment of the first mixture to obtain a first deoxygenation product; the first deoxygenation device 200 is provided with a first mixture inlet 201 and a first deoxygenation product outlet 202; the first mixture inlet 201 communicates with the first mixture outlet 102; the second distillation device 300 is used for the second cutting of the first deoxygenation product to obtain a second mixture; the second distillation device 300 is provided with a first deoxygenation product inlet 301 and a second mixture outlet 302; the first deoxygenation product inlet 301 communicates with the first deoxygenation product outlet 202; the second distillation device 300 is a first distillation column; the second deoxygenation device 400 is used for the second deoxygenation treatment of the second mixture to obtain a second deoxygenation product; the second deoxygenation device 400 is provided with a second mixture inlet 401 and a second deoxygenation product outlet 402; the second mixture inlet 401 communicates with the second mixture outlet 302; the polymerization reaction device 500 is used for the polymerization reaction of the second deoxygenation product under the catalysis of a catalytic system to obtain poly-alpha-olefin lubricating oil base oil; the polymerization reaction device 500 is provided with a catalytic system inlet 501, a second deoxygenation product inlet 502 and a first poly-alpha-olefin lubricating oil base oil outlet 503; the second deoxygenation product inlet 502 communicates with the second deoxygenation product outlet 402.

[0080] Compared with the traditional process, the first distillation device 100, the first deoxygenation device 200, the second distillation device 300 and the second deoxygenation device 400 are arranged in the application, the Fischer-Tropsch synthesis product can be cut twice and deoxygenated twice, and the first deoxygenated product is not easy to crack during distillation in the second distillation device 300, which is beneficial to improve the content of C 10 The content of the component, the component of the second deoxygenated product obtained after the second deoxygenation device 400 treatment is single and the content of 1-decene is high, which can further inhibit the product quality of PAO lubricating oil base oil caused by cracking. Compared with using high-purity a-olefin as a starting material for polymerization reaction, using the above-mentioned system provided by the application to prepare the second deoxygenated product with single component and high content of 1-decene as the raw material of PAO lubricating oil base oil can improve the product quality of PAO lubricating oil base oil while reducing the cost.

[0081] In a preferred embodiment, the first deoxygenation device 200 is further provided with a first deoxygenation agent inlet 203 or a first adsorbent inlet 204 for adding deoxygenation agent and adsorbent respectively to remove oxygen-containing compounds in the first mixture, which is beneficial to inhibit the influence of oxygen-containing compounds on the yield of poly-a-olefin prepared by polymerization reaction and the selectivity of the catalyst, and further improve the performance of PAO lubricating oil base oil.

[0082] In a preferred embodiment, the second deoxygenation device 400 is further provided with a second deoxygenation agent inlet 403 or a second adsorbent inlet 404 for adding deoxygenation agent and adsorbent respectively to remove oxygen-containing compounds in the second mixture, which is beneficial to inhibit the influence of oxygen-containing compounds on the yield of poly-a-olefin prepared by olefin polymerization and the selectivity of the catalyst, and further improve the performance of PAO lubricating oil base oil.

[0083] In a preferred embodiment, the polymerization reaction device 500 is further provided with a quenching agent inlet 504 for adding a quenching agent to end the polymerization reaction. The arrangement of the quenching agent inlet 504 facilitates the addition of the quenching agent, which is beneficial to inhibit the side reaction of unreacted monomers with other substances, thereby improving the yield of the polymerization reaction product.

[0084] In a preferred embodiment, the polymerization reaction device 500 includes but is not limited to a stirred tank reactor or a microfluidic reactor. Compared with other types of reactors, the stirred tank reactor has a larger volume and can accommodate more reaction substances, and the operation is flexible and simple, while the microfluidic reactor has higher reaction efficiency, which is beneficial to improve the yield of the product and reduce the exposure risk of the operator. Both of these two reactors are suitable for large-scale industrial production.

[0085] In a preferred embodiment, the system of the method for preparing polyalphaolefin lubricating oil base oil of the present application further comprises a third distillation device 600, which is used for performing a second vacuum distillation on the polyalphaolefin lubricating oil base oil crude product to obtain the polyalphaolefin lubricating oil base oil; the third distillation device 600 is provided with a polyalphaolefin lubricating oil base oil crude product inlet 601 and a second polyalphaolefin lubricating oil base oil outlet 602; the polyalphaolefin lubricating oil base oil crude product inlet 601 is in communication with the first polyalphaolefin lubricating oil base oil outlet 503. The third distillation device 600 is provided to facilitate the purification of the polyalphaolefin lubricating oil base oil crude product, so as to reduce the impurity content therein, and the treatment by the third distillation device 600 is conducive to obtaining polyalphaolefin lubricating oil base oil with better performance.

[0086] In a preferred embodiment, the first distillation device 100 is a normal pressure distillation column; the second distillation device 300 is a first distillation column, preferably a first vacuum distillation column; and the third distillation device 600 is a second distillation column, preferably a second vacuum distillation column. The first distillation device 100 can adopt a normal pressure distillation column commonly used in the art. Compared with other types of distillation columns, the second distillation device 300 is a first vacuum distillation column, which can reduce the boiling point of the first deoxygenated product by reducing the pressure, and is also conducive to inhibiting the occurrence of cracking reaction, so as to facilitate the increase of the content of C 10 Compared with other types of distillation columns, the third distillation device 600 is a second vacuum distillation column, which is conducive to improving the purity and comprehensive performance of the PAO lubricating oil base oil. In addition, the normal pressure distillation and vacuum distillation operation is simple and has low energy consumption, and is suitable for large-scale industrial production.

[0087] The present application will be further described in detail below in combination with specific examples, which should not be understood as limiting the scope of the present application.

[0088] It should be noted that the polyalphaolefin lubricating oil base oil prepared in all examples and comparative examples of the present application is subjected to viscosity test, pour point test and flash point test. (1) The viscosity is measured according to the method in GB / T265-1988 and by using a full-automatic kinematic viscosity analyzer (Anton Paar, SVM3001); (2) The pour point is measured according to the method in GB / T3535-2006 and by using a pour point tester (Dalian Beiyu Analysis Instrument Co., Ltd., BY-12); (3) The flash point is measured according to the method in GB / T3536-2008 and by using an open flash point and fire point tester (Anton Paar, CLA5); and (4) The evaporation loss is measured according to the method in ASTM D5800 and by using a lubricating oil evaporation loss tester (ISL Co., Ltd. under the PAC flag, NCK2 5G).

[0089] The preparation method of the first deoxygenating agent used in all the examples and comparative examples of the present application comprises the following steps: taking ZSM-5 as a molecular sieve, ZrO2 as a modifier, and SiO2 as a binder, weighing 40 g of ZSM-5 molecular sieve and 10 g of ZrO2, stirring uniformly, then adding 50 g of SiO2 for kneading, and then sequentially drying at 250 ℃ for 24 h and calcining at 550 ℃ for 8 h to obtain the first deoxygenating agent.

[0090] Example 1

[0091] A preparation method of a poly-alpha-olefin lubricating oil base oil, which is prepared by using a preparation system of a poly-alpha-olefin lubricating oil base oil as shown in FIG. 1, comprises the following steps:

[0092] (1) preparing a Fischer-Tropsch synthesis product as a starting material, which comprises 42.99% of alpha-olefins, 46.98% of n-alkanes, 3.45% of oxygen-containing compounds, and 6.58% of other hydrocarbons; and feeding the Fischer-Tropsch synthesis product into an atmospheric distillation column for first cutting (the column top pressure is atmospheric pressure, the column top temperature is 154-156 ℃, and the reflux ratio is 20:1) to obtain a first mixture of hydrocarbon compounds containing C9-C 11 hydrocarbon compounds, wherein the content of alpha-olefins in the first mixture is 82 wt% in terms of the weight percentage content of the first mixture, and the first mixture comprises 4% of 1-nonene, 10% of nonane, 70% of 1-decene, and 3% of decane;

[0093] (2) feeding the first mixture into a first deoxygenating device 200, adding a first deoxygenating agent for first deoxygenation treatment to obtain a first deoxygenated product; wherein the weight ratio of the first mixture to the first deoxygenating agent is 10:1;

[0094] (3) feeding the first deoxygenated product into a first distillation column for second cutting (the column top pressure is 2 kPa, the column top temperature is 65 ℃, and the reflux ratio is 40:1) to obtain a second mixture of hydrocarbon compounds containing C 10 hydrocarbon compounds, wherein the weight percentage content of 1-decene in the second mixture is 95%;

[0095] (4) feeding the second mixture into a second deoxygenating device 400, adding 13X molecular sieve (adsorbent) for second deoxygenation treatment to obtain a second deoxygenated product; wherein the weight ratio of the second mixture to the 13X molecular sieve is 1:1; and the second deoxygenated product comprises 95% of 1-decene, 3% of internal olefins, and 2% of n-decane in terms of the weight percentage content of the second deoxygenated product;

[0096] (5) 50 g of the second deoxygenated product, 0.005 g of ethylene bridged bis-indenyl zirconium dichloride, and 0.015 g of MAO were added into a kettle-type stirring reactor to perform a polymerization reaction at 70°C for 2 h; after the reaction was completed, 10% hydrochloric acid ethanol solution was added into the reaction system to quench, and the system was centrifuged for 1-2 times, and then a crude poly-alpha-olefin lubricating oil base product was obtained after filtration;

[0097] (6) The crude poly-alpha-olefin lubricating oil base product was sent into a second distillation column to perform a second vacuum distillation (the column top pressure was 3 kPa, the column top temperature was 300°C, and the reflux ratio was 5:1), and a PAO 150 base oil was obtained.

[0098] Example 2

[0099] The difference from Example 1 is that the column top pressure of the first distillation column in step (3) is 6 kPa, and the column top temperature is 55°C, and the other steps are the same as those in Example 1. The content of 1-decene in the second mixture is 95% by weight percentage.

[0100] Example 3

[0101] The difference from Example 1 is that the column top temperature of the first distillation column in step (3) is 61°C, and the reflux ratio is 20:1, and the other steps are the same as those in Example 1. The content of 1-decene in the second mixture is 96% by weight percentage.

[0102] Example 4

[0103] The difference from Example 1 is that the column top temperature of the first distillation column in step (3) is 63°C, and the reflux ratio is 40:1, and the other steps are the same as those in Example 1. The content of 1-decene in the second mixture is 97% by weight percentage.

[0104] Example 5

[0105] The difference from Example 1 is that the reflux ratio of the first distillation column in step (3) is 15:1, and the other steps are the same as those in Example 1. The content of 1-decene in the second mixture is 89% by weight percentage.

[0106] Example 6

[0107] The difference from Example 1 is that the column top pressure of the second distillation column in step (6) is 3 kPa, the column top temperature is 350°C, and the reflux ratio is 5:1, and the other steps are the same as those in Example 1.

[0108] Example 7

[0109] The difference from Example 1 is that the overhead pressure of the second distillation column in step (6) is 5 kPa, the overhead temperature is 250℃, and the reflux ratio is 10:1, and the remaining steps are the same as Example 1.

[0110] Example 8

[0111] The difference from Example 1 is that the overhead pressure of the second distillation column in step (6) is 2 kPa, the overhead temperature is 200℃, and the reflux ratio is 15:1, and the remaining steps are the same as Example 1.

[0112] Example 9

[0113] The difference from Example 1 is that the weight ratio of ethylene-bridged bis-indenyl zirconium dichloride to MAO in step (5) is 1:60, and the remaining steps are the same as Example 1.

[0114] Example 10

[0115] The difference from Example 1 is that the weight ratio of ethylene-bridged bis-indenyl zirconium dichloride to MAO in step (5) is 1:2, and the remaining steps are the same as Example 1.

[0116] Example 11

[0117] The difference from Example 1 is that the weight ratio of ethylene-bridged bis-indenyl zirconium dichloride to MAO in step (5) is 1:1, and the remaining steps are the same as Example 1.

[0118] Example 12

[0119] The difference from Example 1 is that AlCl3 catalyst is selected for the polymerization reaction in step (5), and the amount of AlCl3 catalyst used is 1.5 g, and 5 g of NaOH is added to quench the polymerization reaction, and the remaining steps are the same as Example 1. After quenching with NaOH, a large amount of aluminum salt is produced, resulting in a large amount of solid waste.

[0120] Example 13

[0121] The difference from Example 1 is that the weight ratio of the second mixture to 13X molecular sieve in step (4) is 50:1, and the remaining steps are the same as Example 1. The second deoxygenated product includes 95% 1-decene, 3% internal olefins, and 2% n-decane, based on the weight percentage of the second deoxygenated product.

[0122] Example 14

[0123] The difference from Example 1 is that the weight ratio of the second mixture to 13X molecular sieve in step (4) is 1:10, and the remaining steps are the same as Example 1. The second deoxygenated product includes 88% 1-decene, 5% internal olefins, and 7% n-decane, based on the weight percentage of the second deoxygenated product.

[0124] Example 15

[0125] The difference from Example 1 is that the preparation is carried out using the system shown in Figure 2, the second mixture is subjected to deoxidation treatment using a second deoxidizing agent in step (4), and the weight ratio of the second mixture to the second deoxidizing agent is 30:1, and the remaining steps are the same as those in Example 1, wherein the preparation method of the second deoxidizing agent is as follows: ZSM-48 is used as a molecular sieve, ZrO2 is used as a modifier, and alumina is used as a binder, 50g of ZSM-48 molecular sieve and 15g of ZrO2 are weighed, stirred uniformly, and then 40g of alumina is added for kneading, and then the second deoxidizing agent is obtained after drying at 250℃ for 24h and calcining at 550℃ for 8h. The second deoxidizing product includes 94% 1-decene, 3% internal olefins, and 3% n-decane in terms of weight percentage.

[0126] Example 16

[0127] The difference from Example 1 is that the second mixture is subjected to deoxidation treatment using a second deoxidizing agent in step (4), and the weight ratio of the second mixture to the second deoxidizing agent is 2:1, and the remaining steps are the same as those in Example 1. The second deoxidizing product includes 88% 1-decene, 7% internal olefins, and 5% n-decane in terms of weight percentage.

[0128] Comparative Example 1

[0129] The difference from Example 1 is that steps (3) and (4) in Example 1 are omitted, and the first deoxidizing product prepared in step (2) is directly sent into a stirred tank reactor for polymerization reaction, and the remaining steps are the same as those in Example 1.

[0130] Comparative Example 2

[0131] The difference from Example 1 is that the overhead pressure of the first distillation column in step (3) is 8kPa, and the overhead temperature is 85℃, and the remaining steps are the same as those in Example 1. The content of 1-decene in the second mixture is 83% in terms of weight percentage.

[0132] The test results are shown in Table 1.

[0133] Table 1

[0134] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0135] Comparing Example 1 and Comparative Example 1, it can be seen that the prior method usually only performs one cutting on the Fischer-Tropsch synthesis product and one deoxidation on the product obtained to perform a polymerization reaction, and the one cutting process is prone to cause cracking of the raw material, and it is difficult to obtain a product with a single component. In comparison with the prior method, the Fischer-Tropsch synthesis product is subjected to two cuttings and two deoxidations in the present application, and the first deoxidation product is not prone to cracking in the second cutting process, so that the content of C 10 The content of the components, so that the second deoxidation product obtained has a single component and a high content of 1-decene, and the above preparation method can inhibit the decrease in product quality of the PAO lubricating oil base oil caused by cracking.

[0136] Comparing Example 1, 2 and Comparative Example 2, it can be seen that the pressure and temperature of the second cutting in the present application include but are not limited to the above range, and limiting them in the above range is beneficial to inhibit the cracking of the raw material in the cutting process to cause a complex product component, to improve the content of 1-decene in the second deoxidation product, and thus to improve the product quality of the PAO lubricating oil base oil.

[0137] Comparing Example 1 and Examples 3 to 5, it can be seen that the overhead temperature and reflux ratio of the first distillation column include but are not limited to the above range, and limiting them in the above range is beneficial to further improve the content of 1-decene in the second mixture, so as to obtain a PAO lubricating oil base oil with a single carbon number, and thus to improve the viscosity and other comprehensive properties of the PAO lubricating oil base oil.

[0138] Comparing Example 1 and Examples 6 to 8, it can be seen that, compared with other ranges, limiting the overhead pressure, overhead temperature and reflux ratio of the second distillation column in the above range is beneficial to improve the separation efficiency of the PAO lubricating oil base oil and the unreacted monomers and by-products, to reduce the impurity content in the product, and thus to obtain a PAO lubricating oil base oil with higher performance.

[0139] Comparing Example 1 and Examples 9 to 11, it can be seen that the weight ratio of the metallocene catalyst to the co-catalyst in the present application includes but is not limited to the above range, and limiting it in the above range is beneficial to better activate the metallocene catalyst by the co-catalyst, so as to further improve the activity and selectivity of the catalytic system, and thus to further improve the polymerization reaction yield and the comprehensive properties of the PAO lubricating oil base oil prepared.

[0140] Comparing Example 1 and Example 12, it can be seen that the present application uses a catalytic system containing a metallocene catalyst to catalyze the polymerization reaction, which is beneficial to significantly reduce the amount of catalyst and solid waste emissions compared with the catalytic system containing AlCl3.

[0141] As can be seen from Comparative Examples 1, 13 and 14, the weight ratio of the second mixture to the second adsorbent in the present application includes but is not limited to the above range, and limiting it within the above range is beneficial to improve the removal rate of the oxygen-containing compounds, thereby being beneficial to obtain a second deoxygenated product containing a single carbon number as a raw material for polymerization reaction, and further being beneficial to improve the comprehensive performance of the prepared PAO lubricating base oil in viscosity and the like.

[0142] As can be seen from Comparative Examples 1, 15 and 16, the second mixture in the present application can also be subjected to deoxygenation treatment by using a second deoxygenation agent, and the weight ratio of the second mixture to the second deoxygenation agent in the present application includes but is not limited to the above range, and limiting it within the above range is beneficial to improve the removal effect of the deoxygenation agent on the oxygen-containing compounds in the second mixture, thereby improving the purity and the comprehensive performance of the PAO lubricating base oil.

[0143] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the terms thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that described herein.

[0144] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A process for the production of a poly-alpha-olefin lubricating oil base oil, characterized by, The method for preparing the poly-alpha-olefin lubricating oil base oil comprises: Step S1, performing first cutting on the Fischer-Tropsch synthesis product to obtain a first mixture containing C9~C 11 hydrocarbon compounds; the Fischer-Tropsch synthesis product comprises hydrocarbon compounds with carbon atom number of 8~20; Step S2, performing first deoxygenation treatment on the first mixture to obtain a first deoxygenation product; Step S3, using a first distillation column to perform second cutting on the first deoxygenated product to obtain a C 10 a second mixture of hydrocarbon compounds; wherein the first distillation column has a top pressure of 2-6 kPa and a top temperature of 55-75°C; Step S4, performing second deoxygenation treatment on the second mixture to obtain a second deoxygenation product; the second deoxygenation product comprises 1-decene; Step S5, under catalysis of a catalytic system, performing polymerization reaction on the second deoxygenation product to obtain the poly-alpha-olefin lubricating oil base oil.

2. The process for producing poly-alpha-olefin lubricating oil base oil according to claim 1, characterized by, The second cutting in the step S3 is first vacuum distillation; Preferably, the overhead temperature of the first vacuum distillation is 61-63℃, and the reflux ratio is (20-40):

1.

3. The process for producing poly-alpha-olefin lubricating oil base oil according to claim 1 or 2, characterized by, Preferably, the content of 1-decene in the second mixture is ≥90% in terms of weight percentage of the second mixture; Preferably, the second deoxygenation product comprises 90-95% 1-decene, 3-5% internal olefins and 2-5% n-decane in terms of weight percentage of the second deoxygenation product.

4. The process for producing poly-alpha-olefin lubricating oil base oil according to any one of claims 1 to 3, characterized by, The step S5 comprises: Under catalysis of the catalytic system, performing the polymerization reaction on the second deoxygenation product to obtain a poly-alpha-olefin lubricating oil base oil crude product, performing second vacuum distillation on the poly-alpha-olefin lubricating oil base oil crude product by using a second distillation column to obtain the poly-alpha-olefin lubricating oil base oil; Preferably, the overhead pressure of the second distillation column is 3-5kPa, the overhead temperature is 250-350℃, and the reflux ratio is (5-10):

1.

5. The process for producing poly-alpha-olefin lubricating oil base oil according to claim 4, characterized by, The weight percentage of 1-decene in the Fischer-Tropsch synthesis product is 6-8%; and / or, the first mixture comprises 3-5% 1-nonene, 8-12% nonane, 60-70% 1-decene and 5-7% decane in terms of weight percentage of the first mixture.

6. The process for producing poly-alpha-olefin lubricating oil base oil according to claim 5, characterized by, The second deoxygenation treatment comprises: performing physical adsorption on the second mixture by using an adsorbent to obtain the second deoxygenation product; or, performing treatment on the second mixture by using a deoxygenation agent to remove the compounds containing hydroxyl and / or carboxyl groups therein to obtain the second deoxygenation product; Preferably, the weight ratio of the second mixture to the adsorbent is (5-50):(1-5); Preferably, the weight ratio of the second mixture to the deoxygenation agent is (10-60):(1-2); Preferably, the adsorbent is selected from one or more of the group consisting of white clay, silica gel, 3A molecular sieve, 4A molecular sieve, 5A molecular sieve and 13X molecular sieve; Preferably, the deoxygenation agent comprises a molecular sieve, a modifier and a binder; Preferably, the molecular sieve is selected from one or more of the group consisting of ZSM-5, ZSM-48 and TS-1; Preferably, the modifier is one or more of the group consisting of ZrO2, BaO and MgO; Preferably, the binder is selected from one or more of the group consisting of silicon dioxide, aluminum oxide and sesbania powder; More preferably, the weight ratio of the molecular sieve, the modifier and the binder is (20-60):(5-15):(15-50).

7. The process for producing poly-alpha-olefin lubricating oil base oil according to claim 5, characterized by, The first deoxygenation treatment comprises: using an adsorbent to perform physical adsorption on the first mixture to obtain the first deoxygenation product; or using a deoxygenation agent to treat the first mixture to remove the compounds containing hydroxyl and / or carboxyl groups therein to obtain the first deoxygenation product; Preferably, the weight ratio of the first mixture to the adsorbent is (5-50):1; Preferably, the weight ratio of the first mixture to the deoxygenation agent is (10-60):1; Preferably, the deoxygenation agent comprises a molecular sieve, a modifier and a binder; Preferably, the molecular sieve is selected from one or more of the group consisting of ZSM-5, ZSM-48 and TS-1; Preferably, the modifier is one or more of the group consisting of ZrO2, BaO and MgO; Preferably, the binder is selected from silica and / or alumina; More preferably, the weight ratio of the molecular sieve, the modifier and the binder is (20-60):(5-15):(15-50).

8. The process for producing poly-alpha-olefin lubricating oil base oil according to any one of claims 1 to 7, characterized by, In the step S5, the catalytic system comprises a metallocene catalyst and a cocatalyst; Preferably, the metallocene catalyst is a bridged bimetallic catalyst; Preferably, the cocatalyst is selected from alkyl aluminoxane and / or organoboron compound; Preferably, the weight ratio of the metallocene catalyst to the cocatalyst is (1-5):(10-60).

9. The process for preparing poly-alpha-olefin lubricating oil base oil according to claim 4, characterized by, After the polymerization reaction is completed, the reaction system is mixed with a quenching agent to end the polymerization reaction, to obtain the crude product of the poly-alpha-olefin lubricating oil base oil; Preferably, the quenching agent is selected from one or more of the group consisting of hydrochloric acid ethanol solution, lye and water; More preferably, the quenching agent is hydrochloric acid ethanol solution with a mass concentration of 5-10%.

10. The process for producing poly-alpha-olefin lubricating oil base oil according to claim 1, characterized by, In the step S1, the first mixture is obtained by performing the first cutting using a normal pressure distillation column; Preferably, the top temperature of the normal pressure distillation column is 144-165°C, preferably 150-160°C, and the reflux ratio is (10-40):

1.

11. A system for carrying out the process for producing the poly-alpha-olefin lubricating oil base oil according to claim 1, characterized by The system comprises: a first distillation device (100) configured to perform first cutting on a Fischer-Tropsch synthesis product to obtain a first mixture; the first distillation device (100) is provided with a Fischer-Tropsch synthesis product inlet (101) and a first mixture outlet (102); a first deoxygenation device (200) configured to perform first deoxygenation treatment on the first mixture to obtain a first deoxygenation product; the first deoxygenation device (200) is provided with a first mixture inlet (201) and a first deoxygenation product outlet (202); the first mixture inlet (201) is in communication with the first mixture outlet (102); a first deoxygenation device (200) configured to perform first deoxygenation treatment on the first mixture to obtain a first deoxygenation product; the first deoxygenation device (200) is provided with a first mixture inlet (201) and a first deoxygenation product outlet (202); the first mixture inlet (201) is in communication with the first mixture outlet (102); a second distillation device (300) for performing a second cut on the first deoxygenated product to obtain a second mixture; the second distillation device (300) is provided with a first deoxygenated product inlet (301) and a second mixture outlet (302); the first deoxygenated product inlet (301) is in communication with the first deoxygenated product outlet (202); the second distillation device (300) is a first distillation column; a second deoxygenation device (400) for performing a second deoxygenation treatment on the second mixture to obtain a second deoxygenated product; the second deoxygenation device (400) is provided with a second mixture inlet (401) and a second deoxygenated product outlet (402); the second mixture inlet (401) is in communication with the second mixture outlet (302); a polymerization reaction device (500) for performing a polymerization reaction on the second deoxygenated product under the catalysis of a catalytic system to obtain the poly-alpha-olefin lubricating oil base oil; the polymerization reaction device (500) is provided with a catalytic system inlet (501), a second deoxygenated product inlet (502), and a first poly-alpha-olefin lubricating oil base oil outlet (503); the second deoxygenated product inlet (502) is in communication with the second deoxygenated product outlet (402).

12. The system for the production of poly-a-olefin lubricating oil base oil according to claim 11, characterized by, The first deoxygenation device (200) is further provided with a first deoxygenating agent inlet (203) or a first adsorbent inlet (204); and / or, the second deoxygenation device (400) is further provided with a second deoxygenating agent inlet (403) or a second adsorbent inlet (404).

13. The system for the production of poly-a-olefin lubricating oil base oil according to claim 11, characterized by, The polymerization reaction device (500) is further provided with a quenching agent inlet (504); and / or, the polymerization reaction device (500) is selected from a kettle-type stirred reactor or a microfluidic reactor.

14. The system for the production of poly-alpha-olefin lubricating oil base oil according to any one of claims 11 to 13, characterized by, The system further comprises: a third distillation device (600) for performing a second vacuum distillation on the poly-alpha-olefin lubricating oil base oil crude product to obtain the poly-alpha-olefin lubricating oil base oil; the third distillation device (600) is provided with a poly-alpha-olefin lubricating oil base oil crude product inlet (601) and a second poly-alpha-olefin lubricating oil base oil outlet (602); the poly-alpha-olefin lubricating oil base oil crude product inlet (601) is in communication with the first poly-alpha-olefin lubricating oil base oil outlet (503).

15. The system for the process for the preparation of poly-a-olefin lubricating oil base oils according to any one of claims 14, characterized by the fact that, The first distillation device (100) is a normal-pressure distillation column; and / or, The second distillation device (300) is a first distillation column, preferably a first vacuum distillation column; and / or, The third distillation device (600) is a second distillation column, preferably a second vacuum distillation column.

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