A catalyst, poly-α-olefin PAO and its preparation method

Abstract

This application discloses a catalyst, polyalphaolefin (PAO), and its preparation method, relating to the field of PAO technology, and aims to solve the problem of the small molecular weight of PAO. The viscosity-average molecular weight of this PAO ranges from 6 million g / mol to 25 million g / mol. And / or, the activity range of the PAO is 450 gPAO / gCat to 900 gPAO / gCat; it can be applied to drag reduction in oil pipelines.

Description

Technical Field

[0001] This application relates to the field of polyalphaolefin (PAO) technology, and more particularly to a catalyst, polyalphaolefin (PAO) and its preparation method. Background Technology

[0002] High molecular weight polyalphaolefin (PAO) is the main component of oil drag reducers. Generally, PAO with a viscosity-average molecular weight exceeding 5 million g / mol can significantly reduce frictional resistance along the pipeline and improve the pipeline's elastic transport capacity during oil pipeline transportation. PAO drag reducers are generally composed of homopolymers or copolymers of olefins such as 1-hexene, 1-octene, 1-decene, and 1-dodecene.

[0003] Coal-derived hydrocarbon mixtures are high in α-olefins (containing over 45% C5 and above), diverse in type, and almost entirely free of aromatics. These coal-derived mixed hydrocarbons are byproducts of the Fischer-Tropsch reaction in coal-to-oil production, and are produced in large quantities. They can provide abundant raw materials for PAO drag reducer production while simultaneously increasing the added value of coal-to-oil products.

[0004] However, PAO prepared from coal-to-hydrocarbon mixtures has a relatively small molecular weight, making it difficult to meet the requirements for drag reduction in oil pipelines. Summary of the Invention

[0005] The purpose of this application is to provide a catalyst, poly-α-olefin (PAO), and a method for preparing the same.

[0006] To achieve the above objectives, this application adopts the following technical solution: This application provides a polyalphaolefin (PAO). The viscosity-average molecular weight of the PAO ranges from 6 million g / mol to 25 million g / mol. And / or, the activity range of the PAO is from 450 gPAO / gCat to 900 gPAO / gCat.

[0007] The polyalphaolefin (PAO) provided in this application has a high viscosity index and relatively stable performance, making it suitable for reducing drag in oil pipelines and ensuring economical and efficient oil transportation.

[0008] In some embodiments, the viscosity-average molecular weight of the poly-α-olefin (PAO) ranges from 8 million g / mol to 18 million g / mol, or from 12 million g / mol to 17.7 million g / mol.

[0009] In some embodiments, the activity range of the poly-α-olefin PAO is 490 gPAO / gCat to 850 gPAO / gCat, or 800 gPAO / gCat to 830 gPAO / gCat.

[0010] Secondly, this application provides a method for preparing poly-α-olefin (PAO). The method includes: A coal-to-hydrocarbon mixture containing α-olefins is mixed with a main catalyst and a co-catalyst to carry out a polymerization reaction to obtain the polyα-olefin PAO.

[0011] The main catalyst includes a TiCl3-type Ziegler-Natta catalyst, wherein the TiCl3-type Ziegler-Natta catalyst contains a crystal form regulator with an R1-O-R2 structure. R1 and R2 are each independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl groups; the term "substituted or unsubstituted" means unsubstituted or substituted by one or more groups selected from those that do not participate in and interfere with the polymerization reaction.

[0012] In some embodiments, R1 and R2 are each independently selected from substituted or unsubstituted C2-C. 10 Alkyl, substituted or unsubstituted C3-C 10 Cycloalkyl, or substituted or unsubstituted C6-C 10 Aryl.

[0013] In some embodiments, the term "substituted or unsubstituted" means unsubstituted or substituted with one or more groups selected from alkyl and aryl groups.

[0014] In some embodiments, the term "substituted or unsubstituted" means unsubstituted or selected from C1-C6 alkyl and C6-C6 alkyl groups. 10 One or more groups in the aryl group are substituted.

[0015] In some embodiments, the R1-O-R2 crystal form modifier is selected from any one of methyl phenyl ether, n-butyl phenyl ether, isobutyl phenyl ether, isopentyl phenyl ether, diisopentyl ether, di-n-butyl ether, fluorene diether, and diisobutyl ether.

[0016] In some embodiments, the reactants of the reaction further include a molecular weight regulator; preferably, the molecular weight regulator is hydrogen.

[0017] In some embodiments, the viscosity-average molecular weight of the polyalphaolefin (PAO) ranges from 8 million g / mol to 18 million g / mol, or from 12 million g / mol to 17.7 million g / mol; the activity range of the polyalphaolefin (PAO) is from 490 gPAO / gCat to 850 gPAO / gCat, or from 800 gPAO / gCat to 830 gPAO / gCat.

[0018] In some embodiments, the co-catalyst has the structure (R3). m Al alkylaluminum or with the structure (R3) n AlX (3-n) Alkyl aluminum halide; wherein R3 is a C1-C8 alkyl or C3-C8 cycloalkyl; X is a halogen; m is 3; n is an integer from 1 to 3.

[0019] In some embodiments, the co-catalyst is one or more of trimethylaluminum, triethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, triisobutylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum.

[0020] In some embodiments, the co-catalyst is at least one of triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, or tri-n-octylaluminum.

[0021] In some embodiments, the reactants of the reaction optionally include an external electron donor.

[0022] In some embodiments, the reactants of the reaction further include: silane-based external electron donors.

[0023] In some embodiments, the reactants of the reaction further include those with the structural formula (R4). t Si(OR5) 4-t The silane-based external electron donor; wherein R4 and R5 are each independently selected from substituted or unsubstituted saturated or unsaturated groups; the substituted or unsubstituted means substituted or unsubstituted by one or more substituents selected from heteroatoms or C1-C4 alkyl groups; the value of t is an integer from 0 to 4.

[0024] Preferably, R4 is selected from C1-C 10 Alkyl, C2-C 10 alkenyl, C3-C 10 cycloalkyl, C3-C 10 Cycloalkenyl, C 6- C 10 Any of the aryl groups.

[0025] Preferably, R4 is selected from substituted or unsubstituted C1-C. 10 Alkyl or C6-C 10 Aryl.

[0026] Preferably, R5 is selected from substituted or unsubstituted methyl, ethyl, n-propyl or isopropyl.

[0027] Preferably, t is 1 or 2.

[0028] In some embodiments, the titanium content in the main catalyst is 20wt%~30wt%.

[0029] In some embodiments, the titanium content in the main catalyst is 24wt% to 27wt%.

[0030] In some embodiments, the titanium content in the main catalyst is 25.4 wt% to 26.2 wt%.

[0031] In some embodiments, the molar ratio of Al in the co-catalyst to Ti in the main catalyst ranges from 2 to 50.

[0032] In some embodiments, the molar ratio of Al in the co-catalyst to Ti in the main catalyst ranges from 20 to 50.

[0033] In some embodiments, the molar ratio of Al in the co-catalyst to Ti in the main catalyst is in the range of 20 to 30.

[0034] In some embodiments, the molar ratio of Si in the external electron donor to Ti in the main catalyst ranges from 0 to 15.

[0035] In some embodiments, the molar ratio of Si in the external electron donor to Ti in the main catalyst is in the range of 5 to 15.

[0036] In some embodiments, the molar ratio of Si in the external electron donor to Ti in the main catalyst is in the range of 9 to 12.

[0037] In some embodiments, the temperature range of the polymerization reaction is -30°C to 50°C.

[0038] In some embodiments, the temperature range of the polymerization reaction is -20°C to 5°C.

[0039] In some embodiments, the temperature range of the polymerization reaction is -20°C.

[0040] In some embodiments, the polymerization reaction time ranges from 1 hour to 200 hours.

[0041] In some embodiments, the polymerization reaction time ranges from 100 hours to 168 hours.

[0042] In some embodiments, the polymerization reaction takes place over a period of 168 hours.

[0043] In some embodiments, the coal-to-hydrocarbon mixture contains C7-C. 15 Olefins and optional C7-C 15 Alkanes; based on the molar amount of the coal-derived hydrocarbon mixture, C7-C 15 The molar content of α-olefins is 60 mol% to 100 mol%.

[0044] In some embodiments, the coal-to-hydrocarbon mixture consists of C7-C 15 Olefin composition.

[0045] In some embodiments, the pure product of the coal-to-hydrocarbon mixture has an ultraviolet absorbance of less than 0.5 / cm in the 250nm~300nm wavelength range and a moisture content of less than 10ppm.

[0046] In some embodiments, the preparation method of the polyα-olefin PAO further includes: at a temperature of 100℃ to 200℃, 10 -5 Pa~10 3 Vacuum distillation is performed under a vacuum of Pa to remove unreacted hydrocarbon compounds.

[0047] Thirdly, this application provides a catalyst. The catalyst comprises: a TiCl3-type Ziegler-Natta catalyst. The TiCl3... 3 The Ziegler-Natta catalyst contains a crystal form regulator with the structure R1-O-R2; wherein R1 and R2 are each independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl groups; the term "substituted or unsubstituted" means unsubstituted or substituted by one or more groups selected from those that do not participate in and do not interfere with the polymerization reaction.

[0048] In some embodiments, the R1-O-R2 crystal form modifier is selected from any one of methyl phenyl ether, n-butyl phenyl ether, isobutyl phenyl ether, isopentyl phenyl ether, diisopentyl ether, di-n-butyl ether, fluorene diether, and diisobutyl ether.

[0049] In some embodiments, the mass content of the R1-O-R2 crystal form regulator in the TiCl3-type Ziegler-Natta catalyst is 2.0wt%~10.0wt%.

[0050] Fourthly, this application provides a polyalphaolefin (PAO). The polyalphaolefin PAO is prepared by the method described in any one of the above embodiments; or, the polyalphaolefin PAO is prepared via an olefin polymerization reaction using the catalyst described in the above embodiments. Attached Figure Description

[0051] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 A flowchart of a method for preparing poly-α-olefin (PAO) is provided for embodiments of this application. Detailed Implementation

[0053] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0054] In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0055] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0056] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0057] An embodiment of this application provides a polyalphaolefin (PAO) with a viscosity-average molecular weight ranging from 6 million g / mol to 25 million g / mol.

[0058] In some embodiments, the viscosity-average molecular weight of polyalphaolefin (PAO) ranges from 8 million g / mol to 18 million g / mol.

[0059] In some embodiments, the viscosity-average molecular weight of polyalphaolefin (PAO) ranges from 12 million g / mol to 17.7 million g / mol.

[0060] For example, the viscosity-average molecular weight of polyalphaolefin (PAO) can be 6 million g / mol, 6.5 million g / mol, 7 million g / mol, 7.5 million g / mol, 8 million g / mol, 8.97 million g / mol, 9 million g / mol, 9.5 million g / mol, 10 million g / mol, 10.57 million g / mol, 11 million g / mol, 11.5 million g / mol, 12 million g / mol, 12.86 million g / mol, 13 million g / mol, 13.5 million g / mol, 14 million g / mol, 14.64 million g / mol, 15.5 million g / mol, 16 million g / mol, 16.5 million g / mol, 17 million g / mol, 17.7 million g / mol, 20 million g / mol, or 25 million g / mol, etc., and there is no limitation here.

[0061] Here, the viscosity-average molecular weight of polyalphaolefin (PAO) is measured using the Ubbelohde viscosity method.

[0062] In this application, the viscosity-average molecular weight test method for polyalphaolefin (PAO) includes: dissolving approximately 5 mg to 10 mg of PAO sample completely in 100 mL of cyclohexane or toluene, testing the pure solvent first at 30°C, and then placing the sample in the solvent to test the viscosity-average molecular weight.

[0063] Based on the relationship between the viscosity of poly(α-olefin) (PAO) solutions and the relative molecular weight of the polymer, the viscosity-average relative molecular mass of polymers can be determined using the Mark-Houwink formula: Where k and α are Mark-Houwink constants, and in toluene k = 4.14 × 10⁻⁶. -4 mL / g, α=0.625, [η] is the intrinsic viscosity; the intrinsic viscosity can be obtained according to the following formulas (1) to (3):

[0064]

[0065] ; Where, η sp η0 represents the specific viscosity; η0 is the solvent viscosity, η is the polymer solution viscosity, and η is the specific viscosity. r ρ is the relative viscosity; A is the instrument constant; ρ is the polymer density; t and t0 represent the outflow time of the solution and the pure solvent, respectively.

[0066] In some embodiments, the activity range of polyalphaolefin (PAO) is 450 g PAO / g Cat to 900 g PAO / g Cat.

[0067] In some embodiments, the activity range of polyalphaolefin (PAO) is 490 gPAO / gCat to 850 gPAO / gCat.

[0068] In some embodiments, the activity range of polyalphaolefin (PAO) is 800 gPAO / gCat to 830 gPAO / gCat.

[0069] For example, the activity of polyalphaolefin (PAO) can be 450 g PAO / gCat, 492 g PAO / gCat, 500 g PAO / gCat, 550 g PAO / gCat, 600 g PAO / gCat, 650 g PAO / gCat, 700 g PAO / gCat, 702.8 g PAO / gCat, 711 g PAO / gCat, 750 g PAO / gCat, 792 g PAO / gCat, 798 g PAO / gCat, 827 g PAO / gCat, 738 g PAO / gCat, 850 g PAO / gCat, or 900 g PAO / gCat, etc., and there is no limitation here.

[0070] Understandably, the aforementioned polyalphaolefin (PAO) has better lubrication performance, a higher viscosity index, and more stable properties, making it suitable for reducing drag in oil pipelines and ensuring economical and efficient oil transportation.

[0071] Embodiments of this application provide a method for preparing polyα-olefin (PAO). For example... Figure 1 As shown, the preparation method of poly-α-olefin PAO includes: S1.

[0072] S1: A coal-to-hydrocarbon mixture containing α-olefins is mixed with a main catalyst and a co-catalyst to carry out a polymerization reaction to obtain polyα-olefin (PAO).

[0073] The main catalyst includes a TiCl3-type Ziegler-Natta catalyst, which contains a crystal form regulator with an R1-O-R2 structure.

[0074] R1 and R2 are each independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl groups; the term "substituted or unsubstituted" means unsubstituted or substituted by one or more groups selected from those that do not participate in and interfere with the polymerization reaction.

[0075] Understandably, coal-derived hydrocarbons are rich in α-olefins (such as ethylene, propylene, and butene), and the raw materials for coal-derived hydrocarbons are widely available, which helps reduce production costs and improve the economics of the preparation process. The poly-α-olefin (PAO) prepared by the above method can significantly reduce raw material costs and PAO drag-reducing agent product costs, better meeting current pipeline transportation needs.

[0076] The main catalyst is a MgCl2-supported TiCl4 Ziegler-Natta catalyst, which is a coordination polymerization catalyst with many active centers. It can promote the efficient polymerization of olefins and form high molecular chains. It can precisely control the chain growth process of α-olefin polymerization in coal-to-hydrocarbons. The co-catalyst can effectively activate the main catalyst. The two work together to realize the preparation of poly-α-olefin PAO with high controllability and stable PAO product performance.

[0077] The main catalyst contains a specific crystal form regulator with a structure of R1-O-R2 (ether compounds). These ether compounds significantly enhance the isotropic activity of the active centers of the main catalyst. Furthermore, during the preparation of high molecular weight PAO, the main catalyst allows for the coordination insertion of α-olefins from coal-to-olefins into the highly oriented active centers of the catalyst, resulting in continuous chain elongation and the formation of extremely high molecular weight long-chain molecules, thus yielding poly-α-olefin PAO.

[0078] In other words, different alkyl, cycloalkyl, or aryl groups can be independently selected through the R1 and R2 groups in the crystal form regulator. This provides a large number of possibilities to adjust the structure and performance of the catalyst. By changing these groups, the catalyst performance can be optimized, the orientation ability and activity of the catalyst can be significantly improved, and chain transfer can be effectively inhibited, thus successfully preparing polyalphaolefin (PAO). Moreover, it makes the microstructure of PAO more regular, giving it better lubrication performance, higher viscosity index and more stable performance, making it suitable for drag reduction in oil pipelines.

[0079] In some embodiments, R1 and R2 are each independently selected from substituted or unsubstituted C2-C. 10 Alkyl, substituted or unsubstituted C3-C 10 Cycloalkyl, or substituted or unsubstituted C6-C 10 Aryl.

[0080] In yet another embodiment, the term "substituted or unsubstituted" means unsubstituted or substituted with one or more groups selected from alkyl and aryl groups.

[0081] In yet other embodiments, the term "substituted or unsubstituted" refers to unsubstituted or substituted compounds selected from C1-C6 alkyl and C6-C6 alkyl groups. 10 One or more groups in the aryl group are substituted.

[0082] In some embodiments, the R1-O-R2 crystal form modifier is selected from any one of methyl phenyl ether, n-butyl phenyl ether, isobutyl phenyl ether, isopentyl phenyl ether, diisopentyl ether, di-n-butyl ether, fluorene diether, and diisobutyl ether.

[0083] Understandably, the aforementioned specific ether compounds—methyl phenyl ether, n-butyl phenyl ether, isobutyl phenyl ether, isopentyl phenyl ether, diisopentyl ether, di-n-butyl ether, and diisobutyl ether—can coordinate with the active center of titanium during the synthesis of the main catalyst, insert into the lattice of TiCl3, and stabilize the crystal form of the main catalyst. In the preparation of polyalphaolefin (PAO), the polymerization reaction can proceed more stably and orderly, allowing the polymer chains to grow continuously, thereby obtaining polyalphaolefin (PAO) with extremely high molecular weight and regular structure. This further results in PAO products having better lubrication properties, higher viscosity index, and more stable performance.

[0084] In some embodiments, the cocatalyst has the structure (R3). m Al alkylaluminum or with the structure (R3) n AlX (3-n) Alkyl aluminum halide; wherein R3 is a C1-C8 alkyl or C3-C8 cycloalkyl; X is a halogen; m is 3; n is an integer from 1 to 3.

[0085] For example, the value of n can be 1, 2, or 3, etc.

[0086] In some embodiments, the co-catalyst is one or more of trimethylaluminum, triethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, triisobutylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum.

[0087] In some embodiments, the co-catalyst is at least one of triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, or tri-n-octylaluminum.

[0088] Understandably, co-catalysts such as alkylaluminum or alkylaluminum halide can alkylate and reduce the main catalyst, ensuring that the co-catalyst can effectively activate the main catalyst. Meanwhile, R3 is selected from C1-C8 alkyl groups, allowing for selection based on the characteristics of different alkyl groups to achieve the dual purpose of ensuring activation efficiency while inhibiting chain transfer; and, when the co-catalyst is selected from alkylaluminum halide, the halogenated group helps stabilize the active center and promotes the coordination of olefin monomers.

[0089] Furthermore, there is an interaction between the main catalyst and the co-catalyst. By selecting a suitable alkyl group, the main catalyst can be flexibly activated, forming a favorable microenvironment around the active center, which is beneficial for realizing poly-α-olefin PAO.

[0090] In some embodiments, the reactants of the reaction optionally include an external electron donor.

[0091] In some embodiments, the reactants of the reaction further include: silane-based external electron donors.

[0092] In some embodiments, the reactants of the reaction further include those with the structural formula (R4). t Si(OR5) 4-t The silane-based external electron donor; wherein R4 and R5 are each independently selected from substituted or unsubstituted saturated or unsaturated groups; substituted or unsubstituted means substituted or unsubstituted by one or more substituents selected from heteroatoms or C1-C4 alkyl groups; the value of t is an integer from 0 to 4.

[0093] For example, the heteroatom can be a halogen, S, N, or O.

[0094] For example, the value of t can be 0, 1, 2, 3 or 4.

[0095] Preferably, R4 is selected from C1-C 10 Alkyl, C2-C 10 alkenyl, C3-C 10 cycloalkyl, C3-C 10 Cycloalkenyl, C 6- C 10 Any of the aryl groups.

[0096] Preferably, R4 is selected from substituted or unsubstituted C1-C. 10 Alkyl or C6-C 10 Aryl.

[0097] Preferably, R5 is selected from substituted or unsubstituted methyl, ethyl, n-propyl or isopropyl.

[0098] Preferably, t is 1 or 2.

[0099] Understandably, external electron donors further optimize and supplement the binary system of main catalyst and co-catalyst. Silane-based external electron donors can selectively coordinate with co-catalysts or main catalysts. This is because the solid components of the internal electron donors in the main catalyst have already modified some active centers during the catalyst preparation stage. However, during polymerization, some active centers may undergo structural changes or be exposed due to the effect of alkyl aluminum. The additional silane external electron donors can further modify the non-selective active centers that the solid components of the internal electron donors in the main catalyst fail to cover or that are newly generated during polymerization. They can also undergo reversible complexation reactions with alkyl aluminum to adjust the concentration of free alkyl aluminum in the system, thereby mitigating non-selective chain transfer reactions that may be caused by excessive alkyl aluminum.

[0100] Furthermore, R4 is selected from substituted or unsubstituted C1-C. 10 Alkyl or C6-C 10Aryl, R5 is preferably a small molecule alkyl such as methyl or ethyl, and m is preferably 1 or 2. It can finely balance the polymerization activity and molecular weight, and optimize the polymerization effect for the specific composition of coal-to-olefins.

[0101] In some embodiments, the titanium content of the main catalyst is 20wt%~30wt%.

[0102] In some embodiments, the titanium content of the main catalyst is 24wt%~27wt%.

[0103] In some embodiments, the titanium content of the main catalyst is 25.4 wt% to 26.2 wt%.

[0104] For example, the titanium content of the main catalyst can be 20wt%, 22wt%, 24wt%, 24.7wt%, 25.2wt%, 25.4wt%, 26.2wt%, 28wt%, or 30wt%, etc., and there is no limitation here.

[0105] Understandably, in TiCl3-type Ziegler-Natta catalysts, titanium (Ti) is the active center for the polymerization reaction. Controlling the titanium content to 20wt%~30wt% ensures a sufficiently high density of titanium atoms per unit mass of catalyst, providing ample active sites for the polymerization reaction. This results in a higher active center density during the preparation of poly-α-olefins (PAO), enabling the simultaneous initiation of more olefin molecular chains under the same conditions, thus improving the catalyst's polymerization activity (i.e., the amount of polymer produced per unit mass of catalyst) and achieving a higher product yield within a certain timeframe. Furthermore, a high titanium content (e.g., greater than 30wt%) may lead to overcrowding of active centers, triggering chain transfer; conversely, a low titanium content (e.g., less than 20wt%) may result in insufficient activity, failing to support the continued growth of polymer chains.

[0106] In this application, the method for determining the titanium content in the main catalyst includes steps (1) and (2).

[0107] (1) The titanium compound in the supported catalyst reacts with hydrogen peroxide to form a yellow complex, which exhibits maximum absorbance at a wavelength of 410 nm. At this wavelength, within a certain concentration range, the absorbance-concentration curve conforms to the Lambert-Beer law. A standard curve for titanium is plotted according to this law, and a linear equation is obtained through linear fitting: In this equation A Absorbance B The value represents the Ti element content, expressed in μg / mL.

[0108] (2) In an argon atmosphere, weigh 0.1000~0.2000g of catalyst and place it in an Erlenmeyer flask. Add 20mL of sulfuric acid (30%) to dissolve it. Heat to ensure complete reaction. Filter into a 50mL volumetric flask and dilute to volume with sulfuric acid (10%). Mix thoroughly. Pipette 5mL of the above solution into a 25mL volumetric flask and dilute to volume with sulfuric acid (10%). Mix thoroughly. Using the blank solution as a reference solution, determine the absorbance using spectrophotometry (wavelength 410nm) on a 722S spectrophotometer. A Finally, the Ti element content (Y) in the catalyst is calculated using the following equation: .

[0109] In some embodiments, the molar ratio of Al in the co-catalyst to Ti in the main catalyst ranges from 2 to 50.

[0110] In some embodiments, the molar ratio of Al in the co-catalyst to Ti in the main catalyst ranges from 20 to 50.

[0111] In some embodiments, the molar ratio of Al in the co-catalyst to Ti in the main catalyst ranges from 20 to 30.

[0112] For example, the molar ratio of Al in the co-catalyst to Ti in the main catalyst can be 2, 5, 10, 20, 30, 40, or 50, etc., and there is no limitation here.

[0113] Understandably, the above setup ensures that there are enough alkylaluminum molecules to activate each titanium active center, while avoiding the negative effects of excessive alkylaluminum or halogenated alkylaluminum.

[0114] In some embodiments, the molar ratio of Si in the external electron donor to Ti in the main catalyst ranges from 0 to 15.

[0115] In some embodiments, the molar ratio of Si in the external electron donor to Ti in the main catalyst ranges from 5 to 15.

[0116] In some embodiments, the molar ratio of Si in the external electron donor to Ti in the main catalyst ranges from 9 to 12.

[0117] For example, the molar ratio of Si in the external electron donor to Ti in the main catalyst can be 0, 2, 4, 6, 8, 10, 12, 14 or 15, etc., and there is no limitation here.

[0118] Understandably, the above settings can suppress non-selective centers that lead to chain transfer, enabling the molecular weight to reach the ultra-high molecular weight level while ensuring the activity of reactive centers.

[0119] In summary, by setting the above two key molar ratios, the optimal ratio range for synergistic effect among the main catalyst (Ti), co-catalyst (Al), and external electron donor (Si) was formed, jointly constructing a highly efficient and durable chain growth environment, and ultimately successfully preparing poly-α-olefin PAO.

[0120] In some embodiments, the polymerization reaction temperature range is -30°C to 50°C.

[0121] In some embodiments, the temperature range of the polymerization reaction is -20°C to 5°C.

[0122] In some embodiments, the polymerization reaction occurs at a temperature range of -20°C.

[0123] For example, the polymerization temperature can be -30℃, -20℃, -10℃, 0℃, 10℃, 20℃, 30℃, 40℃ or 50℃, etc., and there is no limitation here.

[0124] In some embodiments, the polymerization reaction time ranges from 1 hour to 200 hours.

[0125] In some embodiments, the polymerization reaction time ranges from 100 hours to 168 hours.

[0126] In some embodiments, the polymerization reaction takes place over a period of 168 hours.

[0127] For example, the polymerization reaction time can be 1 hour, 50 hours, 100 hours, 110 hours, 120 hours, 130 hours, 140 hours, 150 hours, 160 hours, 168 hours, 180 hours, 190 hours or 200 hours, etc., and there is no limit here.

[0128] Understandably, the above setup ensures the fluidity of the reaction system, allowing the polymer chains to grow continuously, thus ensuring the operability and basic activity of the reaction system; and provides sufficient time for the chain growth reaction of the polymerization reaction, enabling the molecular weight to reach ultra-high molecular weight through continuous accumulation.

[0129] In some embodiments, coal-to-hydrocarbon mixtures contain C7-C. 15 Olefins and optional C7-C 15 Alkanes; in molar amounts of coal-derived hydrocarbon mixtures, C7-C 15 The molar content of α-olefins is 60 mol% to 97 mol%.

[0130] For example, the mass content of α-olefins can be 60 mol%, 70 mol%, 80 mol%, 90 mol%, or 97 mol%, and there is no limitation here.

[0131] In yet other embodiments, the coal-to-hydrocarbon mixture is composed of C7-C... 15 Olefin composition.

[0132] Understandably, the raw material is a mixture of hydrocarbons from C7 to C15, that is, olefins with medium chain length are selected as polymerization monomers. After polymerization, the side chain length of α-olefins in this carbon number range is moderate, which can give the final PAO good low-temperature fluidity and provide a high viscosity index. It is an ideal raw material range for preparing high-performance lubricating oil base oil.

[0133] In Ziegler-Natta catalytic polymerization, only α-olefins (olefins with double bonds at the ends) can effectively insert into the active center for directional polymerization. The above-mentioned α-olefin content is beneficial for preparing poly-α-olefin PAO using coal-derived mixtures.

[0134] In some embodiments, the pure product of the coal-to-hydrocarbon mixture has an ultraviolet absorbance of less than 0.5 / cm in the 250nm~300nm wavelength range and a moisture content of less than 10ppm.

[0135] For example, the ultraviolet absorbance of a pure coal-derived hydrocarbon mixture in the 250nm~300nm wavelength range can be 0.5 / cm, 0.4 / cm, 0.3 / cm, 0.2 / cm or 0.1 / cm, etc., and there is no limitation here.

[0136] For example, the moisture content of a pure coal-to-hydrocarbon mixture in the 250nm~300nm wavelength range can be 10ppm, 8ppm, 6ppm, 4ppm, 2ppm or 1ppm, etc., and there is no limit here.

[0137] Setting the pure product of coal-derived hydrocarbon mixtures to have an ultraviolet absorbance of less than 0.5 / cm in the 250nm~300nm wavelength range and a moisture content of less than 10ppm ensures that the active centers can maintain their activity for a long time, which is beneficial to the continuous chain growth of PAO during the preparation of poly-α-olefin PAO.

[0138] In some embodiments, the preparation method of polyα-olefin (PAO) further includes: at a temperature of 100°C to 200°C, 10 - 5 Pa~10 3 Vacuum distillation is performed under a vacuum of Pa to remove unreacted hydrocarbon compounds.

[0139] For example, the temperature can be 100℃, 120℃, 140℃, 160℃, 180℃ or 200℃, etc., and there is no limitation here.

[0140] For example, the vacuum level can be 10. -5 Pa, 10 -3 Pa, 10 -1Pa, 1 Pa, 10 1 Pa or 10 3 Pa, etc., are not limited here.

[0141] Understandably, by controlling the temperature within the range of 100℃ to 200℃, thermal degradation or chain breakage of the synthesized polyalphaolefin (PAO) can be avoided during subsequent heat treatment; and by utilizing 10 -5 With a wide vacuum range of Pa to 10³ Pa, the boiling point of unreacted olefins and alkanes is significantly reduced, allowing them to be effectively vaporized and removed under mild conditions of 100℃ to 200℃. This achieves efficient separation, completely removes unreacted low-molecular-weight hydrocarbons, and greatly improves the purity, flash point, and viscosity index of PAO products, enabling them to meet the performance requirements of high-end lubricating oil base oils.

[0142] Embodiments of this application provide a catalyst comprising: a TiCl3-type Ziegler-Natta catalyst. The TiCl3-type Ziegler-Natta catalyst contains a crystal form regulator with the structure R1-O-R2; wherein R1 and R2 are each independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl groups; the term "substituted or unsubstituted" means unsubstituted or substituted by one or more groups selected from those that do not participate in and interfere with the polymerization reaction.

[0143] In some embodiments, the R1-O-R2 crystal form modifier is selected from any one of methyl phenyl ether, n-butyl phenyl ether, isobutyl phenyl ether, isopentyl phenyl ether, diisopentyl ether, di-n-butyl ether, fluorene diether, and diisobutyl ether.

[0144] In some embodiments, the TiCl3-type Ziegler-Natta catalyst and the R1-O-R2 crystal form modifier are in solid form.

[0145] In some embodiments, the mass content of the R1-O-R2 crystal form regulator in the TiCl3 type Ziegler-Natta catalyst is 2.0wt%~10.0wt%.

[0146] For example, the mass content of the R1-O-R2 crystal form regulator in the TiCl3 type Ziegler-Natta catalyst can be 2.0wt%, 4.0wt%, 6.0wt%, 8.0wt%, or 10.0wt%, etc., and there is no limitation here.

[0147] In some embodiments, the preparation method of the above-mentioned TiCl3 type Ziegler-Natta catalyst includes: steps (1) to (2).

[0148] (1) Mix diethylaluminum chloride (DEAC) solution with a portion of TiCl4 solution, react at a lower temperature first, then heat the reaction, and filter to obtain the first filtrate.

[0149] (2) Add R1-O-R2 crystal form regulator solution to the first filtrate, heat the reaction, and filter to obtain the second filtrate.

[0150] (3) Add the remaining TiCl4 solution to the second filtrate, heat the reaction, filter to obtain the third filtrate, and then dry the third filtrate to obtain the TiCl3 type Ziegler-Natta catalyst.

[0151] In some examples, TiCl3-type Ziegler-Natta catalysts can be prepared by the following method: (1) Slowly add a hexane solution of diethylaluminum chloride (DEAC) to a portion of a hexane solution of TiCl4 (TiCl4 concentration = 1.73 g / mL), and react for 15 minutes at a stirring speed of 100 rpm and a temperature of -20 °C. Then raise the temperature of the reaction solution to 75 °C and continue to react at this temperature for 1 hour. Stop stirring, then filter to obtain the first filtrate. Wash the first filtrate 5 times with 50 mL of hexane.

[0152] (2) Add 18.6 mL of di-n-butyl ether in hexane (concentration of 0.14% by volume) to the reactor containing the first filtrate through a dropping funnel, mix well, and then stir at 200 rpm and maintain the reaction at 35°C for 1 hour. Stop stirring, filter to obtain the second filtrate, and wash the second filtrate 5 times with 50 mL of hexane.

[0153] (3) Add the remaining 8.5 mL of TiCl4 hexane solution (volume concentration of 40%) to the second filtrate, stir and heat to 65 °C, stop stirring after reacting at this temperature for 2 hours, filter to obtain the third filtrate, wash the third filtrate with dry hexane (50 mL × 5), and then vacuum dry to obtain TiCl3 type Ziegler-Natta catalyst, package it under nitrogen atmosphere and store it in a desiccator.

[0154] It is understood that the beneficial effects of the catalysts provided in the above embodiments of this application can be referred to the beneficial effects of the preparation method of poly-α-olefin PAO described above, and will not be repeated here.

[0155] The embodiments of this application provide a polyalphaolefin (PAO). The polyalphaolefin (PAO) is prepared by any of the methods described in the above embodiments; or, the polyalphaolefin (PAO) is prepared by olefin polymerization using the catalyst described in the above embodiments.

[0156] It is understood that the beneficial effects of the poly-α-olefin PAO provided in the above embodiments of this application can be referred to the beneficial effects of the preparation method of poly-α-olefin PAO described above, and will not be repeated here.

[0157] Experimental Example The technical solution of this application will be further illustrated below through specific embodiments and comparative examples.

[0158] Example 1 Example 1 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: Under nitrogen atmosphere, 16.6 g of 10 wt% diethylaluminum chloride (DEAC) hexane solvent was slowly added to 7.5 mL of TiCl4 hexane solution (concentration = 1.73 g / mL). The mixture was stirred at 100 rpm at a reaction temperature of -20 °C for 15 minutes. Then, the temperature was raised to 75 °C and the reaction was continued at this temperature for 1 hour. After stirring, the mixture was stopped, filtered, and washed 5 times with 50 mL of hexane. 18.6 mL of n-butylphenyl ether hexane solution (concentration, volume concentration = 0.14%) was added, stirred evenly, and added to the reactor through a dropping funnel. The mixture was stirred at 200 rpm, heated to 35 °C, and maintained at this temperature for 1 hour. After stirring, the mixture was stopped, filtered, and washed 5 times with 50 mL of hexane. 8.5 mL of TiCl4 hexane solution (volume concentration = 40%) was added, and the mixture was stirred and heated to 65 °C. The reaction was continued at this temperature for 2 hours. Stop stirring, filter out the filtrate and wash with dry hexane (50 mL × 5), vacuum dry the catalyst, seal it under a nitrogen atmosphere and store it in a desiccator. The titanium content of the catalyst is 24.7 wt%.

[0159] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a -20 °C cold bath. Under nitrogen protection, 60 mL of 1-octene (α-olefin content of 96 mol%) and 10 mL of triethylaluminum hexane solution co-catalyst (concentration of 1 mmol / mL) and 2 mL of cyclohexylmethyldimethoxysilane hexane solution (concentration of 1 mmol / mL) were added in sequence. The mixture was stirred and matured thoroughly. Then, about 50 mg of the above main catalyst was added and stirred continuously at 500 rpm. The reaction was continued at this temperature for 100 hours. The reaction product was terminated with ethanol and dried under vacuum at 120 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 792.0 g PAO / g Cat. The viscosity-average molecular weight of PAO was 8.57 million g / mol.

[0160] Example 2 Example 2 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: Under nitrogen atmosphere, 16.6 g of 10 wt% diethylaluminum chloride (DEAC) hexane solvent was slowly added to 7.5 mL of TiCl4 hexane solution (concentration = 1.73 g / mL). The mixture was stirred at 100 rpm at a reaction temperature of -20 °C for 15 minutes. Then, the temperature was raised to 75 °C and the reaction was continued at this temperature for 1 hour. After stirring, the mixture was stopped, filtered, and washed 5 times with 50 mL of hexane. 16.3 mL of isobutylphenyl ether hexane solution (concentration, volume concentration = 0.14%) was added, stirred evenly, and added to the reactor through a dropping funnel. The mixture was stirred at 200 rpm, heated to 35 °C, and maintained at this temperature for 1 hour. After stirring, the mixture was stopped, filtered, and washed 5 times with 50 mL of hexane. 12.5 mL of TiCl4 hexane solution (volume concentration = 40%) was added, and the mixture was stirred and heated to 65 °C. The reaction was continued at this temperature for 2 hours. Stop stirring, filter out the filtrate and wash with dry hexane (50 mL × 5), vacuum dry the catalyst, seal it under a nitrogen atmosphere and store it in a desiccator. The titanium content of the catalyst is 25.2 wt%.

[0161] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in an ice-water bath at 0 °C. Under nitrogen protection, 60 mL of mixed α-olefin C8-12 (α-olefin content of 85 mol%) and 5 mL of triisobutylaluminum hexane solution co-catalyst (concentration of 1 mmol / mL) and 3 mL of dicyclopentyldimethoxysilane hexane solution (concentration of 1 mmol / mL) were added sequentially. The mixture was stirred and matured thoroughly. Then, about 50 mg of the above main catalyst was added and stirred continuously at 300 rpm. The reaction was continued at this temperature for 150 hours. The reaction product was terminated with ethanol and dried under vacuum at 120 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 827.0 g PAO / g Cat. The viscosity-average molecular weight of PAO was 10.57 million g / mol.

[0162] Example 3 Example 3 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: Under nitrogen atmosphere, 16.6 g of 10 wt% diethylaluminum chloride (DEAC) hexane solvent was slowly added to 7.5 mL of TiCl4 hexane solution (concentration = 1.73 g / mL). The mixture was stirred at 100 rpm, and the reaction temperature was -10℃. After reacting for 15 minutes, the temperature was raised to 65℃ and the reaction was continued at this temperature for 1 hour. Stirring was stopped, the mixture was filtered, and the solution was washed 5 times with 50 mL of hexane. 25 mL of diisopentyl ether hexane solution (concentration / volume percentage 0.14%) was added, stirred evenly, and added to the reactor through a dropping funnel. The mixture was stirred at 200 rpm, heated to 45℃, and maintained at this temperature for 1 hour. Stirring was stopped, the mixture was filtered, and the solution was washed 5 times with 50 mL of hexane. 8.5 mL of TiCl4 hexane solution (volume concentration 40%) was added, and the mixture was stirred and heated to 65℃. The reaction was carried out at this temperature for 2 hours. Stop stirring, filter out the filtrate and wash with dry hexane (50 mL × 5), vacuum dry the catalyst, seal it under a nitrogen atmosphere and store it in a desiccator. The titanium content of the catalyst is 25.4 wt%.

[0163] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a -20 °C cold bath. Under nitrogen protection, 100 mL of 1-decene (α-olefin content of 91 mol%) and 10 mL of tri-n-octyl aluminum hexane solution co-catalyst (concentration of 25 wt%) and 5 mL of diisopropyl dimethoxysilane hexane solution (concentration of 1 mmol / mL) were added sequentially. The mixture was stirred and matured thoroughly. Then, about 50 mg of the above main catalyst was added and stirred continuously at 500 rpm for 168 hours at this temperature. The reaction product was terminated with ethanol and dried under vacuum at 120 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 492.0 g PAO / g Cat. The viscosity-average molecular weight of PAO was 17.7 million g / mol.

[0164] Example 4 Example 4 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: Same as in Example 3; (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a 5 °C cold bath. Under nitrogen protection, 100 mL of mixed α-olefin C9-11 (α-olefin content of 90 mol%), triisobutylaluminum hexane solution and tri-n-octylaluminum hexane solution (concentration of 1 mmol / mL at a volume ratio of 1:1) were added sequentially as 8 mL of co-catalyst, and 2.5 mL of diphenyldimethoxysilane hexane solution (concentration of 1 mmol / mL) were added. The mixture was stirred and matured thoroughly. Then, about 50 mg of the above main catalyst was added and stirred continuously at 500 rpm for 100 hours at this temperature. The reaction product was terminated with ethanol and dried under vacuum at 140 °C to remove unreacted monomers, and solid PAO product was obtained. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 838.0 g PAO / g Cat. The viscosity-average molecular weight of PAO was 14.64 million g / mol.

[0165] Example 5 Example 5 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: Same as in Example 3; (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a 5 °C cold bath. Under nitrogen protection, 100 mL of mixed α-olefin C9-11 (α-olefin content of 90 mol%), triethylaluminum hexane solution and tri-n-octylaluminum hexane solution (concentration of 25 wt% each, volume ratio of 0.5:1.5) were added sequentially as 12 mL of co-catalyst and stirred thoroughly. Then, about 50 mg of the above main catalyst was added and stirred continuously at 500 rpm for 100 hours at this temperature. The reaction product was terminated with ethanol and dried under vacuum at 140 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 798.0 g PAO / g Cat. The viscosity-average molecular weight of PAO was 12.86 million g / mol.

[0166] Example 6 Example 6 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: Under nitrogen atmosphere, 16.6 g of 10 wt% diethylaluminum chloride (DEAC) hexane solvent was slowly added to 7.5 mL of TiCl4 hexane solution (concentration = 1.73 g / mL). The mixture was stirred at 100 rpm at 0 °C for 15 minutes, then heated to 65 °C and reacted at this temperature for 1 hour. After stirring, the mixture was filtered and washed 5 times with 50 mL of hexane. 25 mL of fluorene diether hexane solution (concentration / volume percentage 0.14%) was added and stirred until homogeneous. The solution was then added to the reactor through a dropping funnel, stirred at 200 rpm, heated to 45 °C and maintained at this temperature for 1 hour. After stirring, the mixture was filtered and washed 5 times with 50 mL of hexane. 10 mL of TiCl4 hexane solution (volume concentration 40%) was added, and the mixture was stirred and heated to 65 °C for 2 hours. Stop stirring, filter out the filtrate and wash with dry hexane (50 mL × 5), vacuum dry the catalyst, seal it under a nitrogen atmosphere and store it in a desiccator. The titanium content of the catalyst is 26.2 wt%.

[0167] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a 5 °C cold bath. Under nitrogen protection, 100 mL of mixed α-olefin C9-14 (α-olefin content of 75 mol%), diethylaluminum chloride hexane solution, and triisobutylaluminum hexane solution (concentration of 25 wt% each, volume ratio of 0.5:1.5) were added sequentially as 12 mL of co-catalyst and stirred thoroughly. Then, about 60 mg of the above main catalyst was added and stirred continuously at 300 rpm for 120 hours at this temperature. The reaction product was terminated with ethanol and dried under vacuum at 140 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 702.8 g PAO / g Cat. The viscosity-average molecular weight of PAO was 8.97 million g / mol.

[0168] Example 7 Example 7 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: Same as in Example 3; (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a 5 °C cold bath. Under nitrogen protection, 100 mL of mixed α-olefin C9-11 (α-olefin content of 90 mol%), triisobutylaluminum hexane solution and tri-n-octylaluminum hexane solution (concentration of 25 wt% each, volume ratio of 0.5:1.5) were added sequentially as 12 mL of co-catalyst and stirred thoroughly. Then, about 60 mg of the above main catalyst was added and stirred continuously at 500 rpm for 168 hours at this temperature. The reaction product was terminated with ethanol and dried under vacuum at 140 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 711.0 g PAO / g Cat. The viscosity-average molecular weight of PAO was 14.64 million g / mol.

[0169] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A poly-α-olefin (PAO), characterized in that, The viscosity-average molecular weight of the poly-α-olefin PAO ranges from 6 million g / mol to 25 million g / mol. And / or, the activity range of the poly-α-olefin PAO is 450 g PAO / g Cat to 900 g PAO / g Cat.

2. The poly-α-olefin PAO according to claim 1, characterized in that, The viscosity-average molecular weight of the poly-α-olefin PAO is in the range of 8 million g / mol to 18 million g / mol, or 12 million g / mol to 17.7 million g / mol. And / or, the activity range of the poly-α-olefin PAO is 490 gPAO / gCat to 850 gPAO / gCat, or 800 gPAO / gCat to 830 gPAO / gCat.

3. A method for preparing poly-α-olefin (PAO), characterized in that, include: A coal-to-hydrocarbon mixture containing α-olefins is mixed with a main catalyst and a co-catalyst to carry out a polymerization reaction to obtain the polyα-olefin PAO; The main catalyst includes a TiCl3-type Ziegler-Natta catalyst, wherein the TiCl3-type Ziegler-Natta catalyst contains a crystal form regulator with an R1-O-R2 structure. R1 and R2 are each independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl groups; the term "substituted or unsubstituted" means unsubstituted or substituted by one or more groups selected from those that do not participate in and interfere with the polymerization reaction.

4. The method for preparing poly-α-olefin (PAO) according to claim 3, characterized in that, R1 and R2 are each independently selected from substituted or unsubstituted C2-C. 10 Alkyl, substituted or unsubstituted C3-C 10 Cycloalkyl, or substituted or unsubstituted C6-C 10 Aryl; And / or, the term "substituted or unsubstituted" means unsubstituted or substituted with one or more groups selected from alkyl and aryl groups; Alternatively, the term "substituted or unsubstituted" refers to unsubstituted or substituted compounds selected from C1-C6 alkyl and C6-C6 alkyl groups. 10 One or more groups in the aryl group are substituted; Alternatively, the R1-O-R2 crystal form regulator is selected from any one of methyl phenyl ether, n-butyl phenyl ether, isobutyl phenyl ether, isopentyl phenyl ether, diisopentyl ether, di-n-butyl ether, fluorene diether, and diisobutyl ether; And / or, the reactants of the reaction further include a molecular weight regulator; preferably, the molecular weight regulator is hydrogen. And / or, the viscosity-average molecular weight of the polyalphaolefin (PAO) is in the range of 8 million g / mol to 18 million g / mol, or 12 million g / mol to 17.7 million g / mol; the activity range of the polyalphaolefin (PAO) is 490 gPAO / gCat to 850 gPAO / gCat, or 800 gPAO / gCat to 830 gPAO / gCat. And / or, the co-catalyst has the structure (R3). m Al alkylaluminum or with the structure (R3) n AlX (3-n) Alkyl aluminum halide; wherein R3 is a C1-C8 alkyl or C3-C8 cycloalkyl; X is a halogen; m is 3; n is an integer from 1 to 3; Alternatively, the co-catalyst may be one or more of trimethylaluminum, triethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, triisobutylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum. Alternatively, the co-catalyst may be at least one of triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, or tri-n-octylaluminum.

5. The method for preparing poly-α-olefin (PAO) according to claim 3, characterized in that, The reactants in the reaction may optionally include an external electron donor; Alternatively, the reactants of the reaction may also include: silane-based external electron donors; Alternatively, the reactants of the reaction may also include those with the structural formula (R4). t Si(OR5) 4-t Silane-based external electron donors; wherein R4 and R5 are each independently selected from substituted or unsubstituted saturated or unsaturated groups; the substituted or unsubstituted refers to being substituted or unsubstituted by one or more substituents selected from heteroatoms or C1-C4 alkyl groups; the value of t is an integer ranging from 0 to 4; Preferably, R4 is selected from C1-C 10 Alkyl, C2-C 10 alkenyl, C3-C 10 cycloalkyl, C3-C 10 Cycloalkenyl, C 6- C 10 Any of the aryl groups; Preferably, R4 is selected from substituted or unsubstituted C1-C. 10 Alkyl or C6-C 10 Aryl; Preferably, R5 is selected from substituted or unsubstituted methyl, ethyl, n-propyl, or isopropyl. Preferably, t is 1 or 2.

6. The method for preparing poly-α-olefin (PAO) according to claim 3, characterized in that, The titanium content in the main catalyst is 20wt%~30wt%; or, the titanium content in the main catalyst is 24wt%~27wt%; or, the titanium content in the main catalyst is 25.4wt%~26.2wt%. And / or, the molar ratio of Al in the co-catalyst to Ti in the main catalyst is in the range of 2 to 50; or, the molar ratio of Al in the co-catalyst to Ti in the main catalyst is in the range of 20 to 50; or, the molar ratio of Al in the co-catalyst to Ti in the main catalyst is in the range of 20 to 30. And / or, the molar ratio of Si in the external electron donor to Ti in the main catalyst is in the range of 0 to 15; or, the molar ratio of Si in the external electron donor to Ti in the main catalyst is in the range of 5 to 15; or, the molar ratio of Si in the external electron donor to Ti in the main catalyst is in the range of 9 to 12.

7. The method for preparing poly-α-olefin (PAO) according to claim 3, characterized in that, The polymerization reaction temperature range is -30℃ to 50℃; or, the polymerization reaction temperature range is -20℃ to 5℃; or, the polymerization reaction temperature range is -20℃. And / or, the polymerization reaction time ranges from 1 hour to 200 hours; or, the polymerization reaction time ranges from 100 hours to 168 hours; or, the polymerization reaction time ranges from 168 hours. And / or, the coal-to-hydrocarbon mixture contains C7-C 15 Olefins and optional C7-C 15 Alkanes; based on the molar amount of the coal-derived hydrocarbon mixture, C7-C 15 The molar content of α-olefins is 60 mol% to 97 mol%; or, the coal-to-hydrocarbon mixture is composed of C7-C... 15 Olefin composition; And / or, the pure product of the coal-to-hydrocarbon mixture has an ultraviolet absorbance of less than 0.5 / cm in the 250nm~300nm wavelength range and a moisture content of less than 10ppm; And / or, the method for preparing the poly-α-olefin PAO further includes: at a temperature of 100℃~200℃, 10 -5 Pa~10 3 Vacuum distillation is performed under a vacuum of Pa to remove unreacted hydrocarbon compounds.

8. A catalyst, characterized in that, The catalyst comprises: a TiCl3-type Ziegler-Natta catalyst; the TiCl3-type Ziegler-Natta catalyst contains a crystal form regulator with an R1-O-R2 structure; R1 and R2 are each independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl groups; the term "substituted or unsubstituted" means unsubstituted or substituted by one or more groups selected from those that do not participate in and interfere with the polymerization reaction.

9. The catalyst according to claim 8, characterized in that, The R1-O-R2 crystal form regulator is selected from any one of methyl phenyl ether, n-butyl phenyl ether, isobutyl phenyl ether, isopentyl phenyl ether, diisopentyl ether, di-n-butyl ether, fluorene diether, and diisobutyl ether; And / or, the mass content of the R1-O-R2 crystal form regulator in the TiCl3 type Ziegler-Natta catalyst is 2.0wt%~10.0wt%.

10. A poly-α-olefin (PAO), characterized in that, The poly-α-olefin PAO is prepared by the method of any one of claims 2 to 7; or, the poly-α-olefin PAO is prepared by olefin polymerization using the catalyst described in claim 8 or 9.

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