CN112920874B

CN112920874B - Preparation method of polyolefin synthetic oil

Info

Publication number: CN112920874B
Application number: CN202110033386.6A
Authority: CN
Inventors: 魏东初; 叶健
Original assignee: Abbott Science And Technology Hangzhou Co ltd
Current assignee: Abbott Science And Technology Hangzhou Co ltd
Priority date: 2021-01-11
Filing date: 2021-01-11
Publication date: 2023-01-10
Anticipated expiration: 2041-01-11
Also published as: CN112920874A

Abstract

The invention discloses a preparation method of polyolefin synthetic oil, which can prepare synthetic oil products with low viscosity grade. The method comprises the steps of premixing a cocatalyst and a main catalyst or respectively adding the cocatalyst and the main catalyst into a polymerization reactor containing a reaction medium, introducing low-carbon olefin as a main polymerization monomer, controlling proper reaction temperature and reaction pressure, and preparing the polyolefin synthetic oil (mAPO) by homopolymerization of the low-carbon olefin or copolymerization of the low-carbon olefin and alpha-olefin prepared by an ethylene oligomerization method or alpha-olefin prepared by a Fischer-Tropsch method. The invention takes the olefin with rich and cheap sources in China as the main raw material, can reduce the cost of the raw material and reduce the dependence on imported high-carbon alpha-olefin. Meanwhile, the invention can prepare a series of low-viscosity synthetic oil base oil with high conversion rate, and has excellent product performance, wide viscosity range and flexible adjustment.

Description

Preparation method of polyolefin synthetic oil

Technical Field

The invention relates to a preparation technology of synthetic lubricating oil base oil, relates to a preparation method of polyolefin synthetic oil, and particularly relates to a method for preparing low-viscosity polyolefin synthetic oil base oil through low-carbon olefin polymerization.

Background

The fully synthetic base oil is a high-quality lubricating oil raw material, and particularly, the synthetic oil of Poly-Alpha-olefin (PAO) has the best comprehensive performance. PAO mainly composed of C ₈ ～C ₁₂ The linear alpha-olefin has better low-temperature fluidity, higher viscosity index (generally more than 135), better oxidation resistance and thermal stability, and higher shear resistance under heavy-load mechanical shear stress compared with mineral oilAnd the volatility is lower, and the method has the advantages of environmental friendliness, energy conservation, safety, no toxicity, lower comprehensive use cost and the like.

PAOs can be classified primarily into three grades of low, medium and high viscosity. Generally, the low viscosity PAO has a kinematic viscosity at 100 ℃ of less than 10cSt, the medium viscosity PAO has a kinematic viscosity at 100 ℃ of 10-40cSt, the high viscosity PAO has a kinematic viscosity at 100 ℃ of more than 40cSt, and the high viscosity PAO is called an ultra-high viscosity PAO when the kinematic viscosity at 100 ℃ is more than 100 cSt. Depending on the viscosity, PAOs are widely used in industrial and automotive fields, and play an important role in many fields such as automobile engine oils, gear oils, hydraulic transmission oils, hydraulic oils, aircraft engine oils, aircraft lubricating oils, heat transfer oils, and insulating oils. For example, medium and low viscosity PAOs have important applications in the automotive field, while ultra-high viscosity synthetic lubricating oils have extremely important applications in dynamic and static lubrication of heavy duty, low or ultra-low speed moving parts used in high-speed rail, aircraft carriers, nuclear powered submarines, heavy duty vehicles, heavy armored tanks, and in such fields as the ocean going vessel industry, the steel industry, and the cement industry.

The viscosity and performance of PAOs is closely related to the catalyst and polymerization process employed. The existing mainstream PAO production process mostly adopts BF ₃ Or AlCl ₃ And the like Lewis acid type catalysts, but can only produce medium and low viscosity products with irregular side chains. In 2010, exxon mobil corporation first introduced a new generation of PAO synthetic oils based on metallocene catalyst technology. The Metallocene catalyst is a catalytic system which takes IVB group transition metal elements (such as Ti, zr, hf and the like) complexes (ligands contain cyclopentadienyl rings or derivatives thereof) as a main catalyst, has the characteristic of a single active center, has higher activity when catalyzing alpha-olefin polymerization, and can produce mPAO (Metallocene-PAO) with regular comb-shaped structure and uniform polymerization degree. Currently, only five foreign companies, exxonMobil, snowdrop (Chevron Phillips), infringes (Ineos), langson (Lanxess) and sheen (Idemitsu), are internationally producing high viscosity mPAO products with kinematic viscosities of 40-300 cSt, but none are turning outside the assignee.

The industrialization of the Chinese synthetic oil base oil is started late and is always in the state of fallingThe later situation and the structural contradiction of the product are more and more prominent, the domestic main productivity is concentrated on the middle and low-end product, and the research and development of mPAO still has a larger gap with the international advanced level. Production of PAO generally employs C ₈ ～C ₁₂ Is used as the starting material. However, there is currently a lack of high quality olefin feedstocks for polymerization in the country, where only partial production of hexene-1, and C is possible ₈ And above LAOs depend entirely on imports. Since LAO producers are 99% concentrated in Europe and America, C ₈ ～C ₁₂ The supply of olefins has been very short and scarce, with the supply of high purity decene-1 being more limited and very expensive. Before solving the problem of olefin source in China, C is adopted ₈ ～C ₁₂ The PAO synthetic oil prepared by using olefin as a raw material has high production cost and is easily produced by people.

Generally, the reasons why China is in a relatively laggard position in the industrialization of high-performance mPAO synthetic oil are mainly that the synthesis aspect is limited by upstream raw material supply, catalysts and production processes. Therefore, to realize the autonomous development of the high-performance mPAO synthetic oil, domestic research institutions need to further increase research and development investment in the aspects of raw materials, catalysts, polymerization processes and the like.

Disclosure of Invention

In order to reduce the cost of raw materials and reduce the dependence on imported high-carbon alpha-olefin, the invention takes the low-carbon olefin such as ethylene, propylene or 1-butylene which are abundant and cheap in China and the alpha-olefin prepared by an ethylene oligomerization method or the alpha-olefin prepared by a Fischer-Tropsch method as main raw materials, adopts a Metallocene CGC catalyst system to prepare polyolefin synthetic oil (mAPO, metallocene Apalene-Poly-Olefins), breaks through the supply limit of market raw materials and greatly reduces the product cost.

The preparation method of the polyolefin synthetic oil is characterized in that a cocatalyst and a main catalyst are premixed or respectively added into a polymerization reactor containing a reaction medium, low-carbon olefin is introduced as a main polymerization monomer, the reaction temperature is controlled to be above 100 ℃, the reaction pressure is controlled to be below 1MPa, and the polyolefin synthetic oil is prepared by homopolymerization of the low-carbon olefin or copolymerization of the low-carbon olefin and Fischer-Tropsch alpha-olefin.

According to a preferred embodiment of the invention, the procatalyst is selected from the group of metallocene CGC catalysts having a defined geometric configuration.

The main catalyst has the following structural general formula:

wherein the content of the first and second substances,

i) L is a heteroatom coordination group such as N, O, P, S and the like, and is used for replacing one Cp ring in the traditional double Cp metal catalyst, L is connected with another Cp through a bridging group E, E can be C, si, ge or Sn, N is an integer more than or equal to 1;

ii)R ₁ and R ₂ Same or different, each independently selected from hydrogen, saturated or unsaturated C ₁ To C ₂₀ Hydrocarbyl, saturated or unsaturated C ₁ To C ₂₀ Halogenated hydrocarbon groups, saturated or unsaturated C ₁ To C ₂₀ Hydrocarbyloxy, saturated or unsaturated C ₃ To C ₂₀ Cycloalkyl radical, C ₆ To C ₂₀ Aryl radicals or C ₆ To C ₂₀ A heterocyclic aromatic hydrocarbon group; r is ₁ 、R ₂ Can also be reacted with E _n Together form a benzene ring, a heterocycle or other aromatic ring;

iii)R ₃ selected from hydrogen, saturated or unsaturated C ₁ To C ₂₀ Hydrocarbyl, saturated or unsaturated C ₁ To C ₂₀ Halogenated hydrocarbon groups, saturated or unsaturated C ₁ To C ₂₀ Hydrocarbyloxy, saturated or unsaturated C ₃ To C ₂₀ Cycloalkyl radical, C ₆ To C ₂₀ Aryl radicals or C ₆ To C ₂₀ A heterocyclic aromatic hydrocarbon group;

iv)R ₄ 、R ₅ 、R ₆ and R ₇ Identical or different, each independently selected from hydrogen, halogen, saturated or unsaturated C ₁ To C ₁₀ Hydrocarbyl, saturated or unsaturated C ₁ To C ₁₀ Halogenated hydrocarbon group, saturated or unsaturated C ₁ To C ₁₀ Hydrocarbyloxy, saturated or unsaturated C ₃ To C ₁₀ Cycloalkyl radical, C ₆ To C ₁₀ Aryl radicals or C ₆ To C ₁₀ A heterocyclic aromatic hydrocarbon group;

v) or, R ₄ And R ₅ 、R ₅ And R ₆ Or R ₆ And R ₇ Can form a new cyclopentadienyl ring, a benzene ring, a heterocyclic ring or other complex aromatic rings together with the carbon atoms connected with Cp;

vi) M is Ti, zr or Hf;

vii)X ₁ and X ₂ Identical or different, each independently selected from hydrogen, halogen, saturated or unsaturated C ₁ To C ₂₀ A hydrocarbyl group.

In the CGC catalyst, a space multi-membered ring configuration with geometric tension is formed between a cyclopentadienyl ring Cp-bridging group E-coordination heteroatom L-central metal M, the free rotation of Cp around a metal center is limited by the structure, so that the catalyst structure has rigidity, and the existence of a bridging group enables the metal active center of the CGC catalyst to be opened only in one direction, thereby achieving the purpose of limiting the geometric configuration. In the CGC, the occlusion angle of Cp-M-L is smaller than that of a metallocene bridged complex Cp-M-Cp, so that the space left by an active center for coordination of olefin is larger, and a large-volume alpha-olefin can be more sufficiently close to the active center to facilitate coordination and insertion of the alpha-olefin, thereby endowing the CGC catalyst with extremely strong copolymerization capability.

According to a preferred embodiment of the present invention, the polymerized monomeric lower olefin is selected from ethylene, propylene or butene-1.

According to a preferred embodiment of the present invention, the lower olefin is further preferably ethylene.

According to a preferred embodiment of the present invention, the polyolefin synthetic oil may be prepared by homopolymerization of a lower olefin or copolymerization with an alpha-olefin prepared by an ethylene oligomerization method or with an alpha-olefin prepared by a fischer-tropsch method.

According to a preferred embodiment of the invention, the fischer-tropsch alpha-olefins are alpha-olefins or crude products thereof, converted from coal or natural gas by fischer-tropsch synthesis, wherein the alpha-olefin content may be in the range of 10 to 90%, preferably more than 50%, and the oxygenate content does not exceed 5%.

The polyolefin synthetic oil can be prepared by homopolymerization of low-carbon olefin or copolymerization of alpha-olefin prepared by an ethylene oligomerization method or Fischer-Tropsch alpha-olefin, and can also be a crude product obtained by Fischer-Tropsch synthesis and conversion of coal or natural gas, so that the preparation method can fully utilize raw material resources and greatly reduce the production cost.

According to a preferred embodiment of the invention, the fischer-tropsch alpha-olefin preferably has an alpha-olefin content of more than 60% and an oxygenate content of not more than 2%.

According to a preferred embodiment of the invention, the fischer-tropsch alpha-olefins are used for the preparation of polyolefin synthesis oils after removal of oxygenates.

The CGC catalyst enables a long chain product having a terminal double bond formed in polymerization to be coordinated and inserted again into polymerization to obtain a polymerization product having a long side chain, and also enables α -olefin as a comonomer to participate in polymerization with a high insertion rate to obtain a long side chain polymerization product.

According to a preferred embodiment of the invention, the cocatalyst is an organoaluminium compound, an organoboron compound or a combination of both.

According to a preferred embodiment of the present invention, the organoaluminum compound is selected from one or more of alkylaluminum, alkylaluminum halide, alkylaluminum alkoxide, alkylaluminoxane, or modified alkylaluminoxane.

According to a preferred embodiment of the invention, the organoaluminium compound is selected from C ₁ ～C ₁₀ Alkyl aluminium, halogenated C ₁ ～C ₁₀ Alkyl aluminium, C ₁ ～C ₁₀ Alkoxy aluminium, C ₁ ～～C ₁₀ Alkylaluminoxane or modified C ₁ ～C ₁₀ One or more of alkylaluminoxanes.

According to a preferred embodiment of the present invention, the organoaluminum compound may be specifically selected from any one or more of aluminum compounds such as trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum chloride, ethylaluminum dichloride, ethylaluminum sesquichloride, aluminum isopropoxide, methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, and modified methylaluminoxane and derivatives thereof.

According to a preferred embodiment of the invention, the organoboron compound is selected from the group consisting of boroxines, triethylborane, triphenylborane ammonia complexes, naBH ₄ One or more boron compounds such as tributyl borate, triisopropyl borate, tris (pentafluorophenyl) borane, trityltetrakis (pentafluorophenyl) borate, tris (p-n-octylphenyl) methyltetrakis (pentafluorophenyl) borate, dimethylphenylammonium tetrakis (pentafluorophenyl) borate, diethylphenylammonium tetrakis (pentafluorophenyl) borate, methyldiphenylammonium tetrakis (pentafluorophenyl) borate, ethyldiphenylammonium tetrakis (pentafluorophenyl) borate, methyldioctadecylammonium tetrakis (pentafluorophenyl) borate, trioctylammonium tetrakis (pentafluorophenyl) borate, etc.

According to a preferred embodiment of the invention, the cocatalyst is preferably selected from alkylaluminoxanes, modified alkylaluminoxanes or a combination of alkylaluminums and organic borides.

According to a preferred embodiment of the present invention, in the polymerization reaction system, the molar ratio of aluminum in the cocatalyst to the metal contained in the main catalyst is 20 to 5000: 1.

According to a preferred embodiment of the present invention, in the polymerization reaction system, the molar ratio of aluminum in the cocatalyst to the metal contained in the main catalyst is more preferably 50 to 3000: 1.

According to a preferred embodiment of the present invention, the molar ratio of boron in the organic boron compound to the metal contained in the main catalyst in the polymerization reaction system is 1 to 5:1.

According to a preferred embodiment of the present invention, in the polymerization reaction system, the molar ratio of boron in the organic boron compound to the metal contained in the main catalyst is more preferably 1 to 2: 1.

According to a preferred embodiment of the present invention, the concentration of the main catalyst in the polymerization system is 1X 10 based on the central metal ^-7 ～1×10 ^-3 mol/L。

According to a preferred embodiment of the present invention, the main catalyst is added to the polymerization system in a concentration of the central metalOne step is preferably 1X 10 ^-6 ～5×10 ^-4 mol/L。

According to a preferred embodiment of the present invention, the cocatalyst and the main catalyst may be pre-mixed and then added into the reactor, or may be added directly into the reactor to form the catalytic active sites in situ.

According to a preferred embodiment of the present invention, the polymerization reactor is selected from one or more of a microchannel reactor, a tubular reactor, a tank reactor, a tower reactor, a packed reactor, a bubble reactor, a falling film reactor, a hypergravity reactor, an applied sound field reactor, an applied electric field reactor and an applied magnetic field reactor.

The reactors may be multiple reactors combined in series and/or parallel.

According to a preferred embodiment of the present invention, the reaction medium is selected from one or more of aromatic hydrocarbon, halogenated aromatic hydrocarbon, aliphatic hydrocarbon, halogenated aliphatic hydrocarbon, cycloaliphatic hydrocarbon or olefin.

According to a preferred embodiment of the invention, C is chosen as the reaction medium ₆ ～C ₁₈ Aromatic hydrocarbons, halogenated C ₆ ～C ₁₈ Aromatic hydrocarbon, C ₁ ～C ₁₈ Aliphatic hydrocarbons, halogenated C ₁ ～C ₁₈ Aliphatic hydrocarbons, C ₅ ～C ₁₈ Cycloaliphatic hydrocarbon, C ₅ ～C ₁₈ Linear alpha-olefins, C ₅ ～C ₁₈ One or more of cycloolefins.

According to a preferred embodiment of the present invention, the reaction medium may be one or more selected from benzene, toluene, xylene, chlorobenzene, ethylbenzene, chlorotoluene, cumene, pentane, isopentane, n-hexane, cyclohexane, methylcyclohexane, n-heptane, n-octane, n-nonane, chloromethane, chloroethane, 1-hexene, 1-octene, and cyclohexene.

According to a preferred embodiment of the present invention, the reaction medium is further selected from one or more of n-hexane, cyclohexane, methylcyclohexane, n-heptane, toluene, xylene.

According to a preferred embodiment of the invention, the polymerization temperature is between 100 and 200 ℃.

According to a preferred embodiment of the present invention, the polymerization temperature is further preferably 100 to 160 ℃.

According to a preferred embodiment of the present invention, the polymerization pressure is 0.05 to 1MPa.

According to a preferred embodiment of the present invention, the polymerization pressure is further preferably 0.1 to 1MPa.

In the preparation method of the polyolefin synthetic oil provided by the invention, the viscosity of the oil product is very sensitive to the change of the reaction temperature and the reaction pressure, and the viscosity of the oil product can be flexibly adjusted through different temperature and pressure combinations.

According to a preferred embodiment of the present invention, the resulting polymerization product is quenched, the catalyst residue is removed by adsorption, and the solvent and unreacted monomers are distilled off to obtain a polyolefin synthetic oil. According to the method provided by the invention, a series of low-viscosity synthetic oil base oil products can be produced by adopting different catalysts and/or different polymerization process conditions.

In a preferred embodiment of the present invention, the method for preparing the polyolefin synthetic oil comprises the steps of:

a) Heating and baking the polymerization reaction kettle, vacuumizing and drying, and replacing with high-purity nitrogen for many times to remove water/oxygen impurities in the reaction system;

b) Adjusting the temperature of the reaction kettle to the set reaction temperature of more than 100 ℃, adding a certain amount of reaction medium and comonomer, and starting stirring;

c) Sequentially adding a cocatalyst and a main catalyst, opening an ethylene pressure regulating valve, rapidly introducing ethylene and ensuring that the reaction pressure is below 1MPa, and starting to react;

d) And adding acidified ethanol to terminate the reaction after the reaction is finished, adding a certain amount of activated clay into the obtained product to adsorb and remove catalyst residues, then performing pressure filtration to obtain filtrate, and performing reduced pressure distillation on the filtrate to remove the solvent and unreacted monomers to obtain the polyolefin synthetic oil.

Compared with the prior art, the invention has the following advantages:

the method has the advantages of rich raw material sources, low production cost, high catalyst activity, strong regulation and control capability on the chain structure of the product, adjustable viscosity of the polymerization product, high viscosity index and narrow molecular weight distribution.

Detailed Description

The following examples are provided to further illustrate the preparation method and the technical scheme of the polyolefin synthetic oil of the present invention, but the scope of the present invention should not be limited thereby. All changes and modifications that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

The analysis method applied in this embodiment is as follows:

the kinematic viscosity of the polyolefin synthetic oil is measured according to a GB265 petroleum product kinematic viscosity measuring method and a dynamic viscometer algorithm;

the viscosity index is calculated according to a GB2541 petroleum product viscosity index calculation table;

pour point was measured according to GB3535 petroleum products pour point determination.

Example 1

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. Then the temperature of the reaction kettle is adjusted to 140 ℃ through jacket cooling water circulation, 160mL of methylcyclohexane is added as a reaction medium, and 40mL of Fischer-Tropsch coal produced olefin is added as a comonomer. The content of alpha-olefin in the coal-made olefin is 69.6 percent, the content of alkane is 30 percent, the content of oxygen-containing compound is less than 0.4 percent, and 97 percent of the alpha-olefin is C5-C9 olefin. The main catalyst used is as follows,

the adopted cocatalysts are triisobutylaluminum and tri (p-n-octylphenyl) methyltetrakis (pentafluorophenyl) borate, the dosage of the main catalyst is set to be 20 mu mol, and according to the set dosage, the [ Al ]: [ Ti ] =200 molar ratio add a certain amount of triisobutylaluminum, then add the above-mentioned main catalyst and tris (p-n-octylphenyl) methyltetrakis (pentafluorophenyl) borate and stir reaction, wherein [ B ]: [ Ti ] =1.2. And opening an ethylene pressure regulating valve, rapidly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

After the reaction is finished, 1mL of acidified ethanol is added to terminate the reaction, 2-5wt% of activated clay is added to the obtained product to adsorb and remove catalyst residues, then, pressure filtration is carried out to obtain filtrate, the filtrate is subjected to reduced pressure distillation to remove the solvent and unreacted monomers to obtain the polyolefin synthetic oil, and the polymerization result is shown in Table 1.

Example 2

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. Then the temperature of the reaction kettle is adjusted to 120 ℃ through jacket cooling water circulation, 160mL of methylcyclohexane is added as a reaction medium, and 40mL of Fischer-Tropsch coal prepared olefin is added as a comonomer. The composition of the coal-to-olefin and the main catalyst and the cocatalyst used are the same as those in example 1.

The amount of the main catalyst used was set to 20. Mu. Mol, and according to the set amount, [ Al ]: [ Ti ] =200 a molar ratio of triisobutylaluminum added, then the main catalyst and tris (p-n-octylphenyl) methyltetrakis (pentafluorophenyl) borate are added, and a reaction is stirred, wherein [ B ]: [ Ti ] =1.2. And opening an ethylene pressure regulating valve, rapidly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

After the reaction is finished, 1mL of acidified ethanol is added to terminate the reaction, 2-5wt% of activated clay is added to the obtained product to adsorb and remove catalyst residues, then pressure filtration is carried out to obtain filtrate, the filtrate is subjected to reduced pressure distillation to remove the solvent and unreacted monomers to obtain the polyolefin synthetic oil, and the polymerization result is shown in Table 1.

Example 3

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. Then the temperature of the reaction kettle is adjusted to 100 ℃ by jacket cooling water circulation, 160mL of methylcyclohexane is added as a reaction medium, and 40mL of Fischer-Tropsch coal derived olefin is added as a comonomer. The composition of the coal-to-olefin and the main catalyst and the cocatalyst used are the same as those in example 1.

The amount of the main catalyst used was set to 20. Mu. Mol, and according to the set amount, [ Al ]: [ Ti ] =200 molar ratio add a certain amount of triisobutylaluminum, then add the above-mentioned main catalyst and tris (p-n-octylphenyl) methyltetrakis (pentafluorophenyl) borate and stir reaction, wherein [ B ]: [ Ti ] =1.2. And opening an ethylene pressure regulating valve, rapidly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 4

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to be above 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. Then the temperature of the reaction kettle is adjusted to 120 ℃ through jacket cooling water circulation, 180mL of methylcyclohexane is added as a reaction medium, and 20mL of Fischer-Tropsch coal prepared olefin is added as a comonomer. The composition of the coal-to-olefin and the main catalyst and the cocatalyst used are the same as those in example 1.

The amount of the main catalyst used was set to 20. Mu. Mol, and according to the set amount, [ Al ]: [ Ti ] =200 molar ratio add a certain amount of triisobutylaluminum, then add the above-mentioned main catalyst and tris (p-n-octylphenyl) methyltetrakis (pentafluorophenyl) borate and stir reaction, wherein [ B ]: [ Ti ] =1.2. Opening an ethylene pressure regulating valve, quickly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 5

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to be above 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The reactor temperature was then adjusted to 120 ℃ by circulation of jacketed cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst and cocatalyst used were the same as in example 1.

Example 6

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The temperature of the reactor was then adjusted to 100 ℃ by circulation of jacket cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalysts used are as follows.

The adopted cocatalyst is modified methylaluminoxane MMAO-7, the dosage of the main catalyst is set to be 20 mu mol, and according to the set dosage, the [ Al ]: the MMAO-7 is added into the molar ratio of [ Zr ] =500, and the main catalyst is added and stirred for reaction. And opening an ethylene pressure regulating valve, rapidly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 7

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The temperature of the reactor was then adjusted to 115 ℃ by circulation of jacket cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst and the cocatalyst used were the same as in example 6.

The adopted cocatalyst is modified methylaluminoxane MMAO-7, the dosage of the main catalyst is set to be 20 mu mol, and according to the set dosage, the [ Al ]: the MMAO-7 is added into the molar ratio of [ Zr ] =500, and the main catalyst is added and stirred for reaction. Opening an ethylene pressure regulating valve, quickly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 8

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to be above 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The reactor temperature was then adjusted to 130 ℃ by circulation of jacketed cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst and the cocatalyst used were the same as in example 6.

The adopted cocatalyst is modified methylaluminoxane MMAO-7, the dosage of the main catalyst is set to be 20 mu mol, and according to the set dosage, the catalyst is prepared by the following steps of [ Al ]: the MMAO-7 is added into the molar ratio of [ Zr ] =500, and the main catalyst is added and stirred for reaction. And opening an ethylene pressure regulating valve, rapidly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 9

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The reactor temperature was then adjusted to 140 ℃ by circulation of jacketed cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst and the cocatalyst used were the same as in example 6.

Example 10

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. Then the temperature of the reaction kettle is adjusted to 100 ℃ through jacket cooling water circulation, 180mL of methylcyclohexane is added as a reaction medium, and 20mL of coal olefin is added as a comonomer. The composition of the coal-to-olefin is the same as that of example 1, and the main catalyst and the cocatalyst are the same as those of example 6.

The adopted cocatalyst is modified methylaluminoxane MMAO-7, the dosage of the main catalyst is set to be 20 mu mol, and according to the set dosage, the [ Al ]: adding MMAO-7 into the molar ratio of [ Zr ] =500, adding the main catalyst, and stirring for reaction. And opening an ethylene pressure regulating valve, rapidly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 11

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to be above 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. Then the temperature of the reaction kettle is adjusted to 100 ℃ by jacket cooling water circulation, 160mL of methylcyclohexane is added as a reaction medium, and 40mL of coal-made olefin is added as a comonomer. The composition of the coal-to-olefin is the same as that in example 1, and the main catalyst and the cocatalyst used in the same manner as in example 6.

Example 12

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The temperature of the reactor was then adjusted to 100 ℃ by circulation of jacket cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst used is as follows,

the adopted cocatalyst is modified methylaluminoxane MMAO-7, the dosage of the main catalyst is set to be 20 mu mol, and according to the set dosage, the catalyst is prepared by the following steps of [ Al ]: the MMAO-7 is added into the molar ratio of [ Zr ] =500, and the main catalyst is added and stirred for reaction. Opening an ethylene pressure regulating valve, quickly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 13

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The temperature of the reactor was then adjusted to 115 ℃ by circulation of jacket cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst and the cocatalyst used were the same as in example 12.

The adopted cocatalyst is modified methylaluminoxane MMAO-7, the dosage of the main catalyst is set to be 20 mu mol, and according to the set dosage, the catalyst is prepared by the following steps of [ Al ]: adding MMAO-7 into the molar ratio of [ Zr ] =500, adding the main catalyst, and stirring for reaction. And opening an ethylene pressure regulating valve, rapidly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 14

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The reactor temperature was then adjusted to 130 ℃ by circulation of jacketed cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst and the cocatalyst are the same as those used in example 12.

Example 15

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to be above 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The reactor temperature was then adjusted to 140 ℃ by circulation of jacketed cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst and the cocatalyst used were the same as in example 12.

The adopted cocatalyst is modified methylaluminoxane MMAO-7, the dosage of the main catalyst is set to be 20 mu mol, and according to the set dosage, the [ Al ]: adding MMAO-7 into the molar ratio of [ Zr ] =500, adding the main catalyst, and stirring for reaction. Opening an ethylene pressure regulating valve, quickly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 16

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. Then the temperature of the reaction kettle is adjusted to 100 ℃ by jacket cooling water circulation, 180mL of methylcyclohexane is added as a reaction medium, and 20mL of coal-made olefin is added as a comonomer. The composition of the coal-to-olefin was the same as in example 1, and the main catalyst and the cocatalyst used were the same as in example 12.

Example 17

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. Then the temperature of the reaction kettle is adjusted to 100 ℃ by jacket cooling water circulation, 160mL of methylcyclohexane is added as a reaction medium, and 40mL of coal-made olefin is added as a comonomer. The composition of the coal-to-olefin was the same as in example 1, and the main catalyst and the cocatalyst used were the same as in example 12.

Example 18

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The reactor temperature was then adjusted to 100 ℃ by circulation of jacketed cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst used is as follows,

the adopted cocatalysts are triisobutylaluminum and tri (p-n-octylphenyl) methyltetrakis (pentafluorophenyl) borate, the dosage of the main catalyst is set to be 20 mu mol, and according to the set dosage, the [ Al ]: adding a certain amount of triisobutylaluminum in a molar ratio of [ Zr ] =150, adding the main catalyst and tris (p-n-octylphenyl) methyltetrakis (pentafluorophenyl) borate, and stirring for reaction, wherein [ B ]: [ Zr ] =1.2. And opening an ethylene pressure regulating valve, rapidly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 19

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to be above 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The temperature of the reactor was then adjusted to 120 ℃ by circulation of jacket cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst and the cocatalyst are the same as those in example 18.

The amount of the main catalyst used was set to 20. Mu. Mol, and according to the set amount, [ Al ]: a certain amount of triisobutylaluminum was added in a molar ratio of [ Zr ] =150, and the main catalyst and tris (p-n-octylphenyl) methyltetrakis (pentafluorophenyl) borate were added thereto and stirred to react, wherein [ B ]: [ Zr ] =1.2. And opening an ethylene pressure regulating valve, rapidly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 20

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to more than 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The reactor temperature was then adjusted to 140 ℃ by circulation of jacketed cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst and the cocatalyst are the same as those in example 18.

The amount of the main catalyst used was set to 20. Mu. Mol, and according to the set amount, [ Al ]: adding a certain amount of triisobutylaluminum in a molar ratio of [ Zr ] =150, adding the main catalyst and tris (p-n-octylphenyl) methyltetrakis (pentafluorophenyl) borate, and stirring for reaction, wherein [ B ]: [ Zr ] =1.2. And opening an ethylene pressure regulating valve, rapidly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 21

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to be above 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. Then the temperature of the reaction kettle is adjusted to 100 ℃ through jacket cooling water circulation, 180mL of methylcyclohexane is added as a reaction medium, and 20mL of coal olefin is added as a comonomer. The composition of the coal-to-olefin was the same as in example 1, and the main catalyst and the cocatalyst used were the same as in example 18.

The amount of the main catalyst used was set to 20. Mu. Mol, and according to the set amount, [ Al ]: adding a certain amount of triisobutylaluminum in a molar ratio of [ Zr ] =150, adding the main catalyst and tris (p-n-octylphenyl) methyltetrakis (pentafluorophenyl) borate, and stirring for reaction, wherein [ B ]: [ Zr ] =1.2. Opening an ethylene pressure regulating valve, quickly introducing ethylene and ensuring that the reaction pressure is 0.5MPa and the polymerization reaction time is 60min.

Example 22

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to be above 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The reactor temperature was then adjusted to 100 ℃ by circulation of jacketed cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst used is as follows,

the adopted cocatalyst is methylaluminoxane MAO (10 wt% toluene solution), the dosage of the main catalyst is set to be 20 mu mol, and according to the set dosage, the [ Al ]: [ Ti ] =500 mol ratio, adding certain amount of MAO, adding the main catalyst and stirring to react. Opening an ethylene pressure regulating valve, quickly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

Example 23

The polymerization was carried out in a 500mL autoclave. Firstly, heating a reaction kettle to be above 100 ℃, vacuumizing and baking for 2 hours, and replacing with high-purity nitrogen for many times. The reactor temperature was then adjusted to 120 ℃ by circulation of jacketed cooling water, and 200mL of methylcyclohexane was added as the reaction medium. The main catalyst and the cocatalyst are the same as those in example 22.

The amount of the main catalyst used was set to 20. Mu. Mol, and according to the set amount, [ Al ]: [ Ti ] =500 mol ratio, adding certain amount of MAO, adding the main catalyst and stirring to react. And opening an ethylene pressure regulating valve, rapidly introducing ethylene and ensuring that the reaction pressure is 0.1MPa and the polymerization reaction time is 60min.

TABLE 1 summary of the results of the examples

As can be seen from the above examples and comparative examples, the preparation method of the polyolefin synthetic oil provided by the invention can prepare a series of low-viscosity polyolefin synthetic oil base oil products (mAPO, metallocene Apalene-Poly-Olefiins), and the key indexes of the products are close to those of PAO products with similar viscosity grades to Fumei, and the products have excellent performance.

Claims

1. A method for preparing polyolefin synthetic oil, comprising: premixing a cocatalyst and a main catalyst or respectively adding the cocatalyst and the main catalyst into a polymerization reactor containing a reaction medium, introducing low-carbon olefin as a main polymerization monomer, controlling the reaction temperature to be 100-140 ℃, and controlling the reaction pressure to be below 1MPa, and preparing low-viscosity polyolefin synthetic oil by homopolymerization of the low-carbon olefin or copolymerization of the low-carbon olefin and alpha-olefin prepared by an ethylene oligomerization method or alpha-olefin prepared by a Fischer-Tropsch method; the alpha-olefin content in the alpha-olefin or the crude product thereof prepared by the Fischer-Tropsch method is 10-90 percent, and the content of oxygen-containing compounds is not more than 5 percent; the raw material conditions enable the preparation method to fully utilize raw material resources and obviously reduce the production cost; wherein the low-carbon olefin is ethylene, propylene or butene-1;

the procatalyst is selected from the group consisting of metallocene CGC catalysts having a defined geometry and having the following general structural formula:

wherein the content of the first and second substances,

i) L is a hetero-atom coordinating group of O, P, S for substituting one Cp ring in a conventional bis Cp metal catalyst, L is connected with another Cp by a bridging group E, E is C, ge or Sn,nis an integer of more than or equal to 1;

ii）R ₁ and R ₂ Same or different, each independently selected from hydrogen, saturated or unsaturated C ₁ To C ₂₀ Hydrocarbyl, saturated or unsaturated C ₁ To C ₂₀ Halogenated hydrocarbon groups, saturated or unsaturated C ₁ To C ₂₀ Hydrocarbyloxy, saturated or unsaturated C ₃ To C ₂₀ Cycloalkyl radical, C ₆ To C ₂₀ Aryl radicals or C ₆ To C ₂₀ A heterocyclic aromatic hydrocarbon group; or, R ₁ 、R ₂ And E _n Together form a benzene ring, a heterocycle or other aromatic ring;

iii）R ₃ selected from hydrogen, saturated or unsaturated C ₁ To C ₂₀ Hydrocarbyl, saturated or unsaturated C ₁ To C ₂₀ Halogenated hydrocarbon group, saturated or unsaturated C ₁ To C ₂₀ Hydrocarbyloxy, saturated or unsaturated C ₃ To C ₂₀ Cycloalkyl radical, C ₆ To C ₂₀ Aryl radicals or C ₆ To C ₂₀ A heterocyclic aromatic hydrocarbon group;

iv）R ₄ 、R ₅ 、R ₆ and R ₇ Identical or different, each independently selected from hydrogen, halogen, saturated or unsaturated C ₁ To C ₁₀ Hydrocarbyl, saturated or unsaturated C ₁ To C ₁₀ Halogenated hydrocarbon groups, saturated or unsaturated C ₁ To C ₁₀ Hydrocarbyloxy, saturated or unsaturated C ₃ To C ₁₀ Cycloalkyl radical, C ₆ To C ₁₀ Aryl radicals or C ₆ To C ₁₀ A heterocyclic aromatic hydrocarbon group;

v) M is Zr or Hf;

vi）X ₁ and X ₂ Identical or different, each independently selected from hydrogen, saturated or unsaturated C ₁ To C ₂₀ A hydrocarbyl group;

and L, R ₁ And R ₂ 、R ₃ 、R ₄ 、R ₅ 、R ₆ And R ₇ M and X ₁ And X ₂ The bridged group in the metallocene CGC catalyst enables the metal active center of the metallocene CGC catalyst to be opened only in one direction, and the engaging angle of Cp-M-L in the metallocene CGC catalyst is smaller than the included angle of Cp-M-Cp of the metallocene bridged complex;

wherein the preparation method utilizes the sensitivity of the viscosity of the polymerization product to the change of reaction temperature and reaction pressure, and adjusts the viscosity through the combination of different catalysts, temperatures and pressures so as to prepare a series of low-viscosity polyolefin synthetic oil base oil products.

2. The method according to claim 1, wherein the Fischer-Tropsch alpha-olefin is an alpha-olefin obtained by converting coal or natural gas through Fischer-Tropsch synthesis, or a crude product thereof.

3. The process according to claim 1, wherein the cocatalyst is an organoaluminum compound, an organoboron compound or a combination of both.

4. The production method according to claim 3, wherein the organoaluminum compound is one or more selected from the group consisting of: the alkyl aluminum, alkyl aluminum halide, alkoxy aluminum, alkyl aluminoxane or modified alkyl aluminoxane is specifically selected from trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tri-n-hexyl aluminum, tri-n-octyl aluminum, diethyl aluminum chloride, ethyl aluminum dichloride, ethyl aluminum sesquichloride, aluminum isopropoxide, methyl aluminoxane, ethyl aluminoxane, isobutyl aluminoxane, modified methyl aluminoxane and derivatives thereof.

5. The production method according to claim 3, wherein the organic compound isThe boron compound is selected from one or more of the following groups: boroxine, triethylborane, triphenylborane ammonia complex, naBH ₄ Tributyl borate, triisopropyl borate, tris (pentafluorophenyl) borane, trityltetrakis (pentafluorophenyl) borate, tris (p-n-octylphenyl) methyltetrakis (pentafluorophenyl) borate, dimethylphenylammonium tetrakis (pentafluorophenyl) borate, diethylphenylammonium tetrakis (pentafluorophenyl) borate, methyldiphenylammonium tetrakis (pentafluorophenyl) borate, ethyldiphenylammonium tetrakis (pentafluorophenyl) borate, methyldioctadecylammonium tetrakis (pentafluorophenyl) borate, trioctylammonium tetrakis (pentafluorophenyl) borate.

6. The process of claim 3 wherein the cocatalyst is selected from the group consisting of combinations of organoaluminum compounds and organoborides, wherein the organoaluminum compounds are alkylaluminoxanes, modified alkylaluminoxanes or alkylaluminums.

7. The process according to claim 3, wherein the concentration of the main catalyst in the polymerization reaction system is 1X 10 based on the central metal ^-7 ~1×10 ^-3 mol/L; the molar ratio of aluminum in the organoaluminum compound to a metal contained in the main catalyst is 20 to 5000; the molar ratio of boron in the organic boride to metal contained in the main catalyst is 1 to 5.

8. The method of claim 1, wherein the polymerization reactor is selected from one or more of the group consisting of: the polymerization reactor is a combination of multiple reactors in series and/or in parallel.

9. The method of claim 1, wherein the reaction medium is selected from one or more of the following group: aromatic hydrocarbons, halogenated aromatic hydrocarbons, aliphatic hydrocarbons, halogenated aliphatic hydrocarbons, cycloaliphatic hydrocarbons or olefins.

10. The process according to claim 9, wherein the reaction medium is methylcyclohexane.

11. The process according to claim 1, wherein the reaction temperature is from 100 ℃ to 140 ℃; the reaction pressure is 0.05 to 1MPa; the polymerization product is quenched and purified to obtain the polyolefin synthetic oil.

12. The production method according to claim 11, wherein the reaction pressure is 0.1 to 1MPa.

13. The process according to claim 11, wherein the reaction pressure is from 0.05 to 0.1MPa.

14. The production process according to claim 11, wherein the reaction temperature is 140 ℃ and the reaction pressure is 0.1MPa.

15. The production process according to claim 11, wherein the reaction temperature is 130 ℃ and the reaction pressure is 0.1MPa.

16. The production process according to claim 11, wherein the reaction temperature is 120 ℃ and the reaction pressure is 0.1MPa.

17. The production process according to claim 11, wherein the reaction temperature is 115 ℃ and the reaction pressure is 0.1MPa.

18. The production process according to claim 11, wherein the reaction temperature is 100 ℃ and the reaction pressure is 0.1MPa.

19. The production process according to any one of claims 11 to 18, wherein the reaction medium is methylcyclohexane.