A poly-alpha-olefin synthetic oil catalyst and its preparation method and application

Abstract

The present invention discloses a poly-alpha-olefin synthetic oil catalyst and a preparation method and application thereof. The catalyst is formed by loading AlCl3 on an acidic molecular sieve as a carrier, wherein the acidic molecular sieve is selected from any one of HY, H-USY, Hβ, HZSM-22, HZSM-5, and HZSM-11. The catalyst is used for the catalytic synthesis of poly-alpha-olefins, and has the advantages of high activity, small catalyst usage, low equipment corrosion, low product viscosity, etc.

Description

Technical Field

[0001] The invention belongs to the field of catalyst preparation, and specifically relates to a poly-alpha-olefin synthetic oil catalyst and a preparation method and application thereof. Background Art

[0002] In recent years, as the speed of lubricant upgrading has become faster and faster, the market demand for high-end lubricant products has driven the rapid growth of demand for polyalphaolefin (PAO) base oil. Compared with mineral oil, PAO base oil has better antioxidant stability and viscosity-temperature performance, high viscosity index, low pour point, good sensitivity to additives, and can be mixed with mineral oil in any proportion. Due to its excellent physical and chemical properties, PAO has been widely used in aerospace, military industry, high-end automobiles and other fields.

[0003] The catalysts used to synthesize PAO mainly include AlCl3, BF3, metallocene and ionic liquid catalysts. Since AlCl3 catalyst is cheap and the reaction conditions are mild, it is still the mainstream PAO catalyst. Patent US 8115040B2 discloses a method for synthesizing PAO using AlCl3 as a catalyst. A small amount of HCl is added as a promoter in the process. The product has a pour point of less than -50°C and a viscosity index of at least 134. Chevron's patent US 8178739B2 discloses a method for synthesizing PAO using AlCl3 as a catalyst. The patent adjusts the oligomerization step to produce a base oil with a kinematic viscosity of 20-90. Patent CN 104250564A uses a mixture of AlCl3 and TiCl4 as a catalyst, which can be used in the industrial production of coal wax cracking olefins to synthesize polyalphaolefin lubricant base oil. Patents CN 101977879A and CN105925340A disclose a method for preparing oligomeric poly-alpha-olefins, comprising oligomerizing low molecular weight PAO oligomers under oligomerization conditions in the presence of a Lewis acid catalyst such as promoted AlCl3 or BF3. The low molecular weight PAO oligomers used as feed or feed component of the method are light olefinic byproduct fractions, which contain dimers and light fractions derived from a metallocene-catalyzed PAO oligomerization process, characterized in that the molecular weight is 150 to 600 and the terminal olefin (vinylidene) content is at least 25%. Patents US 12261388 and US 12538746 use AlCl3 as a catalyst to obtain a series of base oil products with a viscosity index of up to 145 and a pour point of -54°C. AlCl3 is also used in ionic liquid catalyst systems. Patent US 8222471B2 uses olefins with boiling points below 82°C to obtain a kinematic viscosity greater than 1100 mm at 40°C. 2 / s lubricating oil base oil; Patent US 12763866 uses AlCl3 and 1-butylpyridinium chloride to prepare an ionic liquid catalyst, and prepares a lubricating oil synthetic oil with a viscosity index not less than 134 but a pour point not higher than -28°C by alkylating oligoolefins.

[0004] According to a large number of disclosed patents or reports, due to the strong acidity of AlCl3 and its large particle size, the existing technology still has problems such as large catalyst usage, difficult recovery, severe equipment corrosion, and low catalyst utilization. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a poly-alpha-olefin synthetic oil catalyst and its preparation method and application. The catalyst uses a large-pore molecular sieve as a carrier. When it is used to synthesize poly-alpha-olefin synthetic oil, it has the advantages of high activity, small catalyst usage, low equipment corrosion, and low product viscosity.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] A poly-alpha-olefin synthetic oil catalyst is prepared by loading AlCl3 on an acidic molecular sieve as a carrier; specifically, AlCl3 is dissolved in water to prepare a saturated solution, excess AlCl3 is filtered out, and then the acidic molecular sieve is added to the obtained AlCl3 saturated solution, and stirred at 80°C for 24 hours, and then the treated molecular sieve is collected by filtration, washed with deionized water, and dried at 120°C for 24 hours to obtain the catalyst.

[0008] Furthermore, the content of AlCl3 in the catalyst is 0.01wt%~10wt%, preferably 0.1wt%~5wt%.

[0009] Furthermore, the acidic molecules are selected from any one of HY, H-USY, Hβ, HZSM-22, HZSM-5, and HZSM-11.

[0010] The catalyst can be used for catalytic synthesis of polyalpha-olefins. The specific application method is to sequentially add the polyalpha-olefin synthesis oil catalyst and reaction raw materials into an inert solvent, stir and react at 30-150° C. for 0.1-10 hours, and collect the obtained polyalpha-olefins.

[0011] Furthermore, the inert solvent is hexane, cyclohexane, methylcyclohexane or 1,2-dichloroethane.

[0012] Furthermore, the reaction raw material is at least one of 1-octene, 1-decene and 1-dodecene.

[0013] The present invention adopts acidic molecular sieve loaded with AlCl3 to prepare catalyst for the first time. The prepared catalyst has the following advantages compared with the prior art:

[0014] (1) The Lewis acidity and Brons acidity of molecular sieves are used to adjust the strong acidity of AlCl3, so as to control the temperature in the process of catalytic α-olefin polymerization;

[0015] (2) Reduce the amount of aluminum chloride used, improve the utilization rate of AlCl3, and achieve the purpose of reducing acidity and slowing down equipment corrosion;

[0016] (3) Using the confinement effect of molecular sieves to control product distribution, PAO products with low molecular weight, low pour point, low viscosity and narrow distribution are obtained;

[0017] (4) The catalyst can be recycled to achieve the purpose of recycling. DETAILED DESCRIPTION

[0018] In order to make the contents of the present invention easier to understand, the technical solution of the present invention is further described below in conjunction with specific implementation methods, but the present invention is not limited thereto.

[0019] Embodiment 1:

[0020] Take 2g AlCl3, add it into water to make a saturated solution, and then remove the excess AlCl3 by suction filtration. Then add 1g HY molecular sieve to the saturated AlCl3 solution, stir at 80℃ for 24 hours and then filter. The obtained molecular sieve is washed with deionized water and dried in a vacuum oven at 120℃ for 24 hours to remove water to obtain AlCl3 / HY molecular sieve catalyst.

[0021] Embodiment 2:

[0022] The HY molecular sieve used was replaced with an equal mass of HZSM-5 molecular sieve, and the remaining operations were the same as in Example 1 to obtain an AlCl3 / HZSM-5 molecular sieve catalyst.

[0023] Embodiment 3:

[0024] The amount of AlCl3 in Example 1 was changed to 1g, and the remaining operations were the same as in Example 1.

[0025] Embodiment 4:

[0026] The amount of AlCl3 in Example 2 was changed to 1g, and the remaining operations were the same as in Example 2.

[0027] Embodiment 5:

[0028] The amount of AlCl3 in Example 1 was changed to 3g, and the remaining operations were the same as in Example 1.

[0029] Embodiment 6:

[0030] The amount of AlCl3 in Example 2 was changed to 3g, and the remaining operations were the same as in Example 2.

[0031] Comparative Example 1:

[0032] The HY molecular sieve used was replaced with an equal mass of MCM-41 mesoporous material, and the remaining operations were the same as in Example 1 to obtain an AlCl3 / MCM-41 catalyst.

[0033] Comparative Example 2:

[0034] The HY molecular sieve used was replaced with an equal mass of SBA-15 molecular sieve, and the remaining operations were the same as in Example 1 to obtain an AlCl3 / SBA-15 molecular sieve catalyst.

[0035] Comparative Example 3: 2 g of AlCl3 was used.

[0036] Comparative Example 4: 5 g of AlCl3 was used.

[0037] Application Example 1: Synthesis of poly-α-olefins

[0038] The synthesis experiment of α-olefins was carried out in a three-necked flask, and the operation was as follows:

[0039] 1) Take out the three-necked flask and rotor that have been dried in advance and weigh them, and connect the three-necked flask to a thermocouple, a condenser, and a turn-over stopper respectively; weigh the required raw materials, solvents, and catalysts in a glove box; turn on the vacuum pump, turn the double-row tube to the vacuum position, and evacuate the three-necked flask to room temperature; turn on the nitrogen, slowly adjust the double-row tube to the nitrogen position, and be sure to prevent backflow; switch the vacuum-nitrogen environment three times, and finally keep the device in a nitrogen environment, and turn off the vacuum pump; turn on the stirring, turn on the condensing water, turn on the heater and set the reaction temperature to 70°C, and inject 40ml of cyclohexane into the turn-over stopper with a syringe; after heating to 50°C, quickly remove the sealing stopper, pour in 3g of the catalyst obtained in Example 1, and then after heating to 70°C, inject 80ml of 1-decene with a syringe, turn the three-way valve above the condenser to the three-way, adjust the nitrogen to a small amount, react for 2 hours, and weigh the syringe and the weighing bottle.

[0040] 2) Add NaOH solution to the reaction product and wash it until it is neutral, then let it stand in a separatory funnel to separate the liquids, collect the oil phase and continue to wash it three times with ultrapure water, add 1g of anhydrous sodium sulfate and let it stand for several hours, then vacuum filter to remove the sodium sulfate solid, and then perform vacuum distillation on the obtained oil at 180°C until no droplets appear on the wall of the condenser tube. Weigh the obtained product, test the viscosity and pour point, and calculate the yield.

[0041] Application Example 2:

[0042] The catalyst used in step 1) is replaced with an equal mass of the catalyst obtained in Example 2, and the other operations are the same as those in Application Example 1.

[0043] Application Example 3:

[0044] The catalyst used in step 1) is replaced with an equal mass of the catalyst obtained in Example 3, and the other operations are the same as those in Application Example 1.

[0045] Application Example 4:

[0046] The catalyst used in step 1) is replaced with an equal mass of the catalyst obtained in Example 4, and the other operations are the same as those in Application Example 1.

[0047] Application Example 5:

[0048] The catalyst used in step 1) is replaced with an equal mass of the catalyst obtained in Example 5, and the other operations are the same as those in Application Example 1.

[0049] Application Example 6:

[0050] The catalyst used in step 1) is replaced with an equal mass of the catalyst obtained in Example 6, and the other operations are the same as those in Application Example 1.

[0051] Application Example 7:

[0052] After the experiment of Application Example 1 was completed, the catalyst was filtered and recovered under a nitrogen atmosphere, and dried in a vacuum oven at 50° C. overnight, and then the operation of Application Example 1 was repeated.

[0053] Application Example 8:

[0054] After the experiment of Application Example 7 was completed, the catalyst was filtered and recovered under a nitrogen atmosphere, and dried in a vacuum oven at 50° C. overnight, and then the operation of Application Example 1 was repeated.

[0055] Application Comparative Example 1:

[0056] The catalyst used in step 1) is replaced with the catalyst obtained in comparative example 1 of equal mass, and the other operations are the same as those in application example 1.

[0057] Application Comparative Example 2:

[0058] The catalyst used in step 1) is replaced with the catalyst obtained in comparative example 2 of equal mass, and the other operations are the same as those in application example 1.

[0059] Application Comparative Example 3:

[0060] The catalyst used in step 1) is replaced with the catalyst obtained in comparative example 3 of equal mass, and the other operations are the same as those in application example 1.

[0061] Application Comparative Example 4:

[0062] The catalyst used in step 1) is replaced with the catalyst obtained in comparative example 4 of equal mass, and the other operations are the same as those in application example 1.

[0063] Table 1 shows the measurement results of various application examples and application comparative examples.

[0064] Table 1

[0065]

[0066] As shown in Table 1, compared with the catalyst without molecular sieve loading (Comparative Examples 3 and 4), the viscosity of PAO synthesized by the catalyst loaded with non-acidic MCM-41 or SBA-15 mesoporous material (Comparative Examples 1 and 2) is not significantly reduced, and the pour point is equivalent to that of conventional aluminum chloride catalyst. Unlike MCM-41 or SBA-15 mesoporous material, the catalyst loaded with acidic HY and HZSM-15 molecular sieves (Example) has a confinement effect because the pore size of HY and HZSM-15 molecular sieves is less than 1nm, and can also use Lewis acidity and Browns acidity to synergistically catalyze PAO synthesis, so the viscosity of the synthesized PAO is significantly reduced, and the pour point is also significantly reduced, and it can improve the utilization rate of AlCl3, significantly reduce the amount of AlCl3, and reduce the corrosion of the strong acidity of AlCl3 to the device.

[0067] The carbon number distribution of the PAO product was further characterized by high temperature simulated distillation. The results are shown in Table 2.

[0068] Table 2

[0069]

[0070] It can be seen from Table 2 that the PAO synthesized using the catalysts supported by HY and HZSM-15 molecular sieves has a larger proportion of C30 and C40 components, while the PAO synthesized using the catalysts prepared by supporting non-acidic MCM-41 or SBA-15 mesoporous materials has a larger proportion of C50 and above carbon number components, which further proves that HY and HZSM-15 molecular sieves can obtain polymerization products with low carbon number distribution due to their confinement effect.

[0071] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A poly-alpha-olefin synthetic oil catalyst, characterized in that: The catalyst is composed of AlCl3 loaded on an acidic molecular sieve as a carrier; wherein the content of AlCl3 is 0.01wt%~10wt%; The acidic molecules are selected from any one of HY, H-USY, Hβ, HZSM-22, HZSM-5, and HZSM-11.

2. A method for preparing a poly-α-olefin synthetic oil catalyst as claimed in claim 1, characterized in that: AlCl3 is dissolved in water to prepare a saturated solution. After filtering to remove excess AlCl3, an acidic molecular sieve is added to the obtained AlCl3 saturated solution and stirred at 80°C for 24 hours. The treated molecular sieve is then collected by filtration, washed with deionized water, and dried at 120°C for 24 hours.

3. Use of the poly-α-olefin synthetic oil catalyst as claimed in claim 1 in a catalytic synthesis of poly-α-olefins, characterized in that: The poly-α-olefin synthetic oil catalyst and the reaction raw materials are sequentially added into an inert solvent, stirred and reacted at 30-150° C. for 0.1-10 hours, and the obtained poly-α-olefin is collected.

4. The use according to claim 3, characterized in that: The inert solvent is hexane, cyclohexane, methylcyclohexane or 1,2-dichloroethane.

5. The use according to claim 3, characterized in that: The reaction raw material is at least one of 1-octene, 1-decene and 1-dodecene.

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