A process for producing a low cloud point lubricating oil base stock

Abstract

The application discloses a production method of low-cloud-point lubricating oil base oil, which comprises the following steps: sulfidizing a noble metal hydrogenation isomerization catalyst with a chlorine content of less than 0.05 wt%, and then reacting with a high-wax-content raw material to prepare VHVI 10 base oil with a pour point of ≯-18 DEG C and a cloud point of ≯-5 DEG C or VHVI 6 base oil with a pour point of ≯-18 DEG C and a cloud point of ≯-10 DEG C. The production method of the noble metal hydrogenation isomerization catalyst with a chlorine content of less than 0.05 wt% comprises the following steps: immersing a carrier in a Group VIII metal salt impregnation solution, performing calcination and reduction, and then performing water washing and drying to obtain the catalyst. In the preparation process, the metal precursor is first decomposed into noble metal atoms, the noble metal atoms are broken away from anions in the precursor, and the noble metal atoms are combined with the carrier closely; then the catalyst is soaked in deionized water, and in the soaking process, the anions of the residual noble metal precursor on the catalyst are more easily dissolved in water, so that the chlorine content on the catalyst is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lubricating oil base oil production, and particularly relates to a production method of low-turbidity lubricating oil base oil. BACKGROUND

[0002] China is a big country in the world in terms of lubricating oil production and consumption. In 2020, the apparent consumption of lubricating oil reached more than 10 million tons, the output was only 7.8 million tons, and most of them were I and II base oils. The output of high-quality III and III + base oils is low. Studies have shown that energy loss caused by poor lubrication accounts for 1.5% of GDP, and the use of high-efficiency lubricating oil can effectively reduce frictional energy consumption by more than 20%. The quality of base oil determines the performance and cost of lubricating oil, and the production and use of high-quality base oil have become an inevitable trend for the upgrading of the lubricating oil industry. Hydroisomerization technology uses the shape-selective effect of molecular sieve pores to convert n-alkanes into isomeric alkanes, improving the low-temperature fluidity of the oil product. It has the advantages of high base oil yield, large reduction in pour point, and high viscosity index. It is currently the main technical means for producing API II / III high-quality base oil.

[0003] Hydroisomerization dewaxing catalyst is a bifunctional catalyst. The shape-selective effect of molecular sieve pores and the acidic characteristics determine the conversion ability of different raw material molecules and the difference in product structure. Active metals play a dehydrogenation / hydrogenation role, affecting the activity and stability of the catalyst. With the deterioration and heavyization of the raw materials for producing lubricating oil base oil, F-T synthetic oil / wax, foots oil, and propane deasphalted oil have become important raw materials for producing II and III base oils. The preparation method of noble metal hydroisomerization catalyst is roughly as follows: mixing molecular sieves and binders into extruded strips, loading noble metals on the formed carrier by using an equal-volume impregnation method, calcining in air to obtain a hydroisomerization catalyst, and reducing the noble metals on the catalyst to metal elements by hydrogen or a substance containing a reducing agent in a solution. The active metal is usually loaded by using a metal salt containing chlorine. The existing technical means usually uses water washing or alkali washing to reduce the chlorine content on the catalyst, but it cannot reduce the residual halogen on the surface of the catalyst to below 0.05wt%, and the alkali washing or water washing affects the stability of the catalyst to a certain extent.

[0004] Patent CN104588010A discloses a preparation method of low carbon alkane dehydrogenation catalyst, including the following contents: (1) preparation of Sn and alkali metal additive containing alumina carrier, wherein Sn and alkali metal additive are introduced in the gelation process, the amount of introduced Sn accounts for 10-90% of the total amount of Sn metal in the final catalyst, preferably 40-80%; (2) loading active metal Pt on the Sn and alkali metal additive containing alumina prepared in step (1) as carrier, and then introducing Sn again or co-impregnating Sn and dehydrogenation active component on the carrier; (3) water vapor dechlorination of the catalyst obtained in step (2). The dechlorination method of the present application is treated at 300-800℃ for 1-20h, and the dechlorination atmosphere is 10v%-30v% water vapor containing air. The technical solution does not indicate the chlorine content on the catalyst after water vapor dechlorination.

[0005] Patent CN110639512A discloses a kind of palladium catalyst for production of hydrogen peroxide by anthraquinone method and its preparation method, including the following steps: (1) noble metal Pd is loaded on carrier, and the loading amount is 0.1-1.0% of the weight of carrier;(2) carrier aging is washed with water to remove oil and chlorine;(3) after water washing, the carrier is dried and calcined, and active metal is loaded. The water washing is because hydrochloric acid is used in the carrier forming process, resulting in chlorine residue on the carrier.

[0006] The technical solutions of the above documents can only control the chlorine content on the catalyst to be <0.15wt%, and research shows that during industrial application, the chlorine content on the catalyst can only be controlled to be <0.15wt%, which cannot ensure the safe operation of the device;And after water vapor treatment, the catalyst changes in acidity while reducing chlorine content, affecting the activity stability of the catalyst, and when processing high-wax raw materials, the turbidity point of the produced heavy base oil cannot meet the QSY 44-2009 《General Lubricating Oil Base Oil》standard;And the dechlorination process in the above documents is carried out at high temperature, and the whole operation process is relatively complex. SUMMARY

[0007] To solve the above technical problems, the purpose of the present application is to provide a production method of low turbidity point lubricating oil base oil.

[0008] To achieve the above purpose, the present application provides a production method of low turbidity point lubricating oil base oil, which comprises the following steps: sulfidizing a noble metal hydroisomerization catalyst with chlorine content <0.05wt%, and then reacting with high-wax raw materials to prepare VHVI 10 base oil with pour point ≯-18℃ and turbidity point ≯-5℃, or VHVI 6 base oil with pour point ≯-18℃ and turbidity point ≯-10℃, wherein the preparation method of the noble metal hydroisomerization catalyst with chlorine content <0.05wt% comprises the following steps: impregnating the carrier in a Group VIII metal salt impregnation solution, calcining and reducing, and then washing with water and drying to obtain the catalyst.

[0009] The production method of the low-haze lubricating oil base oil, the sulfurization process uses sulfurizing oil including a sulfurizing agent and carrying oil to perform sulfurization, the sulfurizing agent is one or more of CS2, dimethyl disulfide (DMDS) and di-tert-butyl high sulfide (SZ-54), and the carrying oil is hydrogenated kerosene or base oil after hydrogenation isomerization; the mass fraction of sulfur in the carrying oil is 0.003-0.3 wt%, and preferably 0.01-0.1 wt%.

[0010] The production method of the low-haze lubricating oil base oil, the water washing is soaking in deionized water at normal pressure and at 20-30 DEG C for 2-8 min, and preferably 3-5 min, and then removing the deionized water.

[0011] The production method of the low-haze lubricating oil base oil, the water washing process uses deionized water in an amount of 1-4 times the mass of the catalyst, and preferably 1-2 times, and the water washing is performed 2-3 times.

[0012] The production method of the low-haze lubricating oil base oil, the baking temperature is 300-400 DEG C, and preferably 330-360 DEG C; and the drying condition after the water washing is drying at 90-120 DEG C for 2-10 h, and preferably 100-120 DEG C for 3-6 h.

[0013] The production method of the low-haze lubricating oil base oil, the reduction process uses reducing gas including hydrogen and / or carbon monoxide to perform reduction, and the reducing gas can also be diluted with inert gas before reduction.

[0014] The production method of the low-haze lubricating oil base oil, the group VIII metal salt is one or more of H2PtCl6.6H2O, PdCl2, Pt(NH3)4Cl2.H2O and Pd(NH3)4Cl2.H2O.

[0015] The production method of the low-haze lubricating oil base oil, characterized in that, the carrier contains 50-80 wt% of molecular sieve based on 100% of the mass of the carrier, and the molecular sieve is microporous, micro-mesoporous ten-membered ring molecular sieve.

[0016] The production method of the low-haze lubricating oil base oil, the molecular sieve is one or more of SAPO-11, SAPO-31, ZSM-5, ZSM-22, ZSM-23 and ZSM-48.

[0017] The production method of the low-haze lubricating oil base oil, the high-wax-containing raw material is one or more of waxy distillate oil, foots oil, propane deasphalted oil, F-T synthetic oil and hydrocracking tail oil.

[0018] Advantages of the present application:

[0019] In the preparation of the catalyst used in the present application, the metal precursor is first reduced, and the noble metal atoms are broken from the anions in the precursor and tightly combined with the carrier. Then the catalyst is soaked in deionized water, and the anions of the noble metal precursor remaining on the catalyst are more easily dissolved in water during the soaking process, thereby reducing the chlorine content on the catalyst to <0.05wt%, reducing the corrosion of the device by chlorine. At the same time, the catalyst treatment temperature is relatively low during the calcination and dechlorination processes of the catalyst, and both processes are carried out at atmospheric pressure, which is simple to operate. After sulfuration with low-sulfur oil during use, S is distributed between noble metal atoms, preventing noble metal particles from aggregating, which is more conducive to the stability of the catalyst. The catalyst dechlorination process is operated at room temperature, which can avoid metal aggregation of the catalyst and improve the stability of the catalyst. The catalyst dechlorination process does not require the use of ammonia water and other solvents with irritating gas temperature, which is simple and safe to operate and has low energy consumption. The sulfur content of the sulfuration oil used in the sulfuration process is very low, compared with ordinary sulfuration, the amount of sulfuration agent is saved, and it is relatively friendly to the environment. DETAILED DESCRIPTION

[0020] The present application will be described in detail below by examples. It is necessary to point out here that the following examples are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application according to the above content of the present application.

[0021] The properties of all raw materials in the present application are shown in Table 1:

[0022] Table 1

[0023] Wax distillate 1 Wax distillate 2 Wax distillate 3 Density, g / cm 3 ]]> 0.8596 0.8734 0.8586 Sulfur, pg / g 1.74 1.65 5.02 Nitrogen, pg / g ＜1.1 ＜1.1 1.676 100 °C viscosity, mm 2 / s]] 9.698 9.288 4.657 Viscosity index 153 140 128 Pour point, °C 59 42 4 Distillation range, °C 280～580 240～570 210～505 Saturated hydrocarbon content, wt% 96.06 96.69 98.96

[0024] The following examples and comparative examples use waxy distillate oil 1, waxy distillate oil 2 and waxy distillate oil 3 for hydrogenation isomerization reaction.

[0025] Example 1

[0026] 1. SAPO-11 molecular sieve and pseudoboehmite were mixed for 30 minutes, wherein the SAPO-11 molecular sieve accounted for 50wt% of the mixed system (dry basis), 5wt% of concentrated nitric acid and deionized water were added to the mixed system, and the mixture was continuously mixed for 40 minutes and then extruded into a strip. The carrier was prepared by calcination at 500℃ in an air atmosphere.

[0027] 2. Dissolve 1.3 g of H2PtCl6.6H2O in deionized water to obtain a platinum chloride impregnation solution. Impregnate 100 g of the support in the platinum chloride impregnation solution by vacuum isovolume impregnation. After impregnation for 6 h, obtain a catalyst wet strip. Calcine the catalyst wet strip at 300°C for 12 h to obtain the catalyst.

[0028] 3. After calcination, heat the catalyst in a hydrogen atmosphere at a heating rate of 25°C / h from room temperature to 150°C and keep the temperature for 3 h, then heat the catalyst at a heating rate of 30°C / h from 150°C to 300°C and keep the temperature for 6 h, then reduce the temperature to room temperature to obtain the reduced catalyst.

[0029] 4. Take 70 g of the reduced catalyst and soak in 100 ml of deionized water at 20°C for 3 min, then separate the catalyst and deionized water by using a funnel with filter paper.

[0030] 5. Take the separated catalyst and repeat step 4 twice. Dry the separated catalyst at 120°C for 4 h to obtain the final catalyst.

[0031] 6. Pack the prepared catalyst into a fixed bed reactor, introduce hydrogen, and heat the reactor to 200°C at a heating rate of 20°C / h under a pressure of 12 MPa. Introduce sulfurized oil (containing CS2 1 g and hydrogenated kerosene 5000 g) after 8 h of sulfurization. Introduce kerosene for flushing after the temperature of the reactor is increased to 385°C. Introduce the waxy distillate oil 1.

[0032] Example 2

[0033] 1. Mix ZSM-22 molecular sieve with pseudoboehmite for 30 min, wherein the ZSM-22 molecular sieve accounts for 65 wt% (dry basis) of the mixed system. Add 8 wt% nitric acid and deionized water to the mixed system, continue to mix for 30 min, and then extrude into strips. Calcine the support at 500°C in an air atmosphere.

[0034] 2. Dissolve 0.85 g of PdCl2 in 2 wt% HCl to obtain a palladium chloride impregnation solution. Impregnate 100 g of the support in the palladium chloride impregnation solution by vacuum isovolume impregnation. After impregnation for 4 h, obtain a catalyst wet strip. Calcine the catalyst wet strip at 340°C for 14 h to obtain the catalyst.

[0035] 3. After calcination, heat the catalyst in a hydrogen atmosphere at a heating rate of 40°C / h from room temperature to 150°C and keep the temperature for 4 h, then heat the catalyst at a heating rate of 25°C / h from 150°C to 320°C and keep the temperature for 6 h, then reduce the temperature to room temperature to obtain the reduced catalyst.

[0036] 4. Take 70 g of the reduced catalyst and soak in 200 ml of deionized water at 30 °C for 4 min. Then separate the catalyst from the deionized water using a funnel with filter paper.

[0037] 5. Take the separated catalyst and repeat step 4 twice. Dry the separated catalyst at 100 °C for 4 h to obtain the final catalyst.

[0038] 6. Pack the prepared catalyst into a fixed bed reactor, introduce hydrogen, and raise the temperature of the reactor to 200 °C at a rate of 25 °C / h under a pressure of 14 MPa. Introduce sulfurizing oil (containing CS 22.5 g, hydrogenated kerosene 2100 g) after 10 h of sulfurization. Introduce kerosene for flushing after sulfurization. Raise the temperature of the reactor to 375 °C, and introduce the waxy distillate oil 1.

[0039] Example 3

[0040] 1. Mix ZSM-23 molecular sieve with pseudoboehmite for 30 min, wherein the ZSM-23 molecular sieve accounts for 70 wt% of the mixed system (on a dry basis). Add 1 wt% nitric acid and deionized water to the mixed system, continue mixing for 30 min, and then extrude into strips. Sinter the strips at 550 °C under an air atmosphere to obtain the carrier.

[0041] 2. Dissolve 0.93 g of Pt(NH3)4Cl2-H2O in deionized water to obtain a platinum chloride impregnation solution. Use vacuum isometric impregnation to impregnate 100 g of the carrier in the platinum chloride impregnation solution for 4 h to obtain catalyst wet strips. Sinter the catalyst wet strips at 360 °C for 12 h to obtain the catalyst.

[0042] 3. Raise the temperature of the sintered catalyst from room temperature to 150 °C at a rate of 20 °C / h under a hydrogen atmosphere and maintain the temperature for 4 h. Then raise the temperature from 150 °C to 280 °C at a rate of 20 °C / h and maintain the temperature for 6 h. Then reduce the temperature to room temperature to obtain the reduced catalyst.

[0043] 4. Take 70 g of the reduced catalyst and soak in 280 ml of deionized water at 20 °C for 8 min. Then separate the catalyst from the deionized water using a funnel with filter paper.

[0044] 5. Take the separated catalyst and repeat step 4 three times. Dry the separated catalyst at 90 °C for 10 h to obtain the final catalyst.

[0045] 6. Pack the prepared catalyst into a fixed bed reactor, introduce hydrogen, and raise the temperature of the reactor to 200 °C at a rate of 25 °C / h under a pressure of 16 MPa. Introduce sulfurizing oil (containing DMDS 1 g, hydrogenated kerosene 1400 g) after 12 h of sulfurization. Introduce kerosene for flushing after sulfurization. Raise the temperature of the reactor to 375 °C, and introduce the waxy distillate oil 3.

[0046] Example 4

[0047] 1. ZSM-48 molecular sieve was mixed with pseudoboehmite for 30 minutes, wherein the ZSM-48 molecular sieve accounted for 80 wt% of the mixed system (dry basis), 10 wt% nitric acid and deionized water were added to the mixed system, and the mixed system was continuously mixed for 30 minutes and then extruded into strips, and the carrier was prepared by calcining at 550°C in an air atmosphere.

[0048] 2. 1.22 g of Pd(NH3)4Cl2-H2O was dissolved in deionized water to obtain a palladium chloride impregnation solution, 100 g of the carrier was impregnated in the palladium chloride impregnation solution by vacuum isometric impregnation method, and the catalyst wet strip was obtained after impregnation for 4 h, and the catalyst was prepared by calcining the catalyst wet strip at 400°C for 10 h.

[0049] 3. The calcined catalyst was heated from room temperature to 150°C at a heating rate of 40°C / h in a carbon monoxide atmosphere and kept for 2 h, then heated from 150°C to 360°C at a heating rate of 40°C / h and kept for 4 h, and then cooled to room temperature to obtain the reduced catalyst.

[0050] 4. 70 g of the reduced catalyst was soaked in 250 ml of deionized water at 20°C for 5 min, and then the catalyst and deionized water were separated by a funnel with filter paper.

[0051] 5. The separated catalyst was taken out and step 4 was repeated twice, and the separated catalyst was dried at 120°C for 2 h to obtain the final catalyst.

[0052] 6. The prepared catalyst was loaded into a fixed bed reactor, hydrogen was introduced, the reactor was heated to 200°C at a heating rate of 20°C / h under a pressure of 15.5 MPa, and sulfided oil (containing 1.5 g of SZ-54 and 1500 g of hydrogenated kerosene) was introduced, after 10 h of sulfidation, kerosene was introduced for flushing, the reactor was heated to 365°C, and waxy distillate oil 2 was introduced.

[0053] Comparative Example 1

[0054] Steps 1 and 2 were the same as Example 1, but the calcined catalyst was first washed with water (steps 4 and 5), and then reduced (step 3). Finally, step 6 was performed.

[0055] Comparative Example 2

[0056] Steps 1 and 2 were the same as Example 2, but the calcined catalyst was first washed with water (steps 4 and 5), and then reduced (step 3). Finally, step 6 was performed.

[0057] Comparative Example 3

[0058] Step 1, Step 2 and Step 3 are the same as Example 4, but the calcined catalyst is first washed with water (Step 4 and Step 5) and then reduced (Step 3). Finally, Step 6 is performed.

[0059] Comparative Example 4

[0060] Step 1, Step 2 and Step 3 are the same as Example 4, but the calcined catalyst is first washed with water (Step 4 and Step 5) and then reduced (Step 3). Finally, Step 6 is performed.

[0061] Comparative Example 5

[0062] Step 1, Step 2 and Step 3 are the same as Example 4, and the reduced catalyst is obtained, then water vapor is introduced at 400℃, the amount of water vapor is 20ml / min, and the treatment time is 1h. The treated catalyst is dried at 100℃ in air atmosphere for 4h to obtain the final catalyst. Finally, Step 6 is performed.

[0063] Comparative Example 6

[0064] Step 1 and Step 2 are the same as Example 4, and the calcined catalyst is first treated with water vapor at 400℃, the amount of water vapor is 20ml / min, and the treatment time is 1h. The treated catalyst is then reduced (i.e. Step 3) to obtain the final catalyst. Finally, Step 6 is performed.

[0065] Comparative Example 7

[0066] Step 1, Step 2 and Step 3 are the same as Example 4, and Step 3 is:

[0067] The calcined catalyst is heated from room temperature to 150℃ at a heating rate of 30℃ / h and kept for 2h in carbon monoxide atmosphere, then heated from 150℃ to 360℃ at a heating rate of 30℃ / h, then water vapor is introduced, the molar ratio of water vapor to carbon monoxide is 8:1, and kept for 4h, then reduced to room temperature to obtain the final catalyst. Finally, Step 6 is performed.

[0068] Comparative Example 8

[0069] Step 1-5 are the same as Example 4, and Step 6 is:

[0070] The prepared catalyst is loaded into a fixed bed reactor, and hydrogen is introduced, the reactor is heated to 320℃ at a rate of 25℃ / h under a pressure of 15.5MPa, and then the reactor is heated to 365℃.

[0071] The hydrogen isomerization catalysts of the above examples and comparative examples are tested for chlorine content, and the test method is quantitative XRF method. The test results are shown in Table 2.

[0072] Table 2

[0073] Catalyst wet strip chlorine content / ppm Catalyst chlorine content / ppm Example 1 4210 350 Comparative Example 1 4210 1210 Example 2 4840 320 Comparative Example 2 4840 1300 Example 3 1930 310 Comparative Example 3 1930 1400 Example 4 4580 310 Comparative Example 4 4580 1280 Comparative Example 5 4580 360 Comparative Example 6 4580 1210 Comparative Example 7 4580 1180

[0074] From the data of Table 2, it can be seen that the chlorine content of the catalyst according to the technical solution is controlled below 0.05wt%, which is lower than that of the technical solution of washing first and then reducing, water vapor treatment and reducing at the same time; compared with the water vapor treatment solution after reduction, the dechlorination effect is equivalent, but the technical solution is simpler, easy to operate, short processing time and low energy consumption.

[0075] The properties of the 10cSt base oil of the above examples and comparative examples were analyzed, and the results are shown in Table 3.

[0076] Table 3

[0077]

[0078]

[0079] From the data of Table 2, it can be seen that the isomerization and pour point depression effect of the low-chlorine catalyst according to the technical solution can produce qualified VHVI10 and VHVI6 base oils compared with the technical solution of washing first and then reducing, water vapor treatment and reducing at the same time; the VHVI10 produced by the catalyst sulfided according to the technical solution can meet the index requirements, but the base oil produced by the catalyst without sulfidation cannot meet the requirements of pour point and cloud point, which shows that the low-chlorine catalyst according to the technical solution has better activity.

[0080] After 1000h of operation of Example 4 and Comparative Example 8, the properties of the VHVI10 base oil produced are shown in Table 4: the catalyst according to the technical solution can still maintain good stability, but the pour point and cloud point of the base oil produced by the catalyst without sulfidation have a serious rebound, which shows that the low-chlorine catalyst according to the technical solution has good stability.

[0081] Table 4

[0082] 100 °C viscosity, mm 2 / s]] Viscosity index Pour point, °C Cloud point, °C Example 4 10.05 130 -23 -6 Comparative Example 8 10.11 129 -8 11 VHVI 10 specification requirements 9.0-11.0 ≮120 ≯-18 ≯-5

[0083] Of course, the present application can have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application, but these corresponding changes and modifications should all belong to the protection scope of the claims of the present application.

Claims

1. A method for producing a low cloud point lubricating oil base oil, characterized in that, A noble metal hydroisomerization catalyst with a chlorine content of <0.05wt% is sulfided and then reacted with a high-wax raw material to prepare VHVI 10 base oil with a pour point of ≤18℃ and a cloud point of ≤5℃ or VHVI 6 base oil with a pour point of ≤18℃ and a cloud point of ≤10℃. The preparation method of the noble metal hydroisomerization catalyst with a chlorine content of <0.05wt% is as follows: the support is impregnated in a group III metal salt impregnation solution, calcined, reduced, washed with water, and dried to obtain the catalyst. The water washing process involves soaking the sample in deionized water at 20℃-30℃ for 2-8 minutes under normal pressure, followed by removing the deionized water. The group VIII metal salt is one or more of H2PtCl6·6H2O, PdCl2, Pt(NH3)4Cl2·H2O, and Pd(NH3)4Cl2·H2O; Based on the carrier mass of 100%, the carrier contains 50-80 wt% molecular sieve, wherein the molecular sieve is one or more of SAPO-11, SAPO-31, ZSM-5, ZSM-22, ZSM-23, and ZSM-48; The high-wax feedstock is one or more of the following: waxy distillate oil, wax under-wax oil, propane deasphalted oil, FT synthetic oil, and hydrocracking tail oil.

2. The method for producing low cloud point lubricating oil base oil according to claim 1, characterized in that, The water washing process involves soaking the sample in deionized water at 20℃-30℃ for 3-5 minutes under normal pressure, followed by removing the deionized water.

3. The method for producing low cloud point lubricating oil base oil according to claim 2, characterized in that, During the washing process, the amount of deionized water used is 1-4 times the mass of the catalyst, and the number of washing cycles is 2-3.

4. The method for producing low cloud point lubricating oil base oil according to claim 3, characterized in that, The amount of deionized water used in the water washing process is 1-2 times the mass of the catalyst.

5. The method for producing low cloud point lubricating oil base oil according to claim 1, characterized in that, The roasting temperature is 300-400℃; the drying conditions after washing are 90-120℃ for 2-10 hours.

6. The method for producing low cloud point lubricating oil base oil according to claim 1, characterized in that, The roasting temperature is 330-360℃; the drying conditions after washing are 100-120℃ for 3-6 hours.

7. The method for producing low cloud point lubricating oil base oil according to claim 1, characterized in that, The reduction process uses hydrogen gas for reduction, or the hydrogen gas is diluted with an inert gas before reduction.

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