A method for producing lubricating oil base oil from heavy raw materials and the resulting lubricating oil base oil

Abstract

This invention provides a method for producing lubricating oil base oil from heavy feedstock and the resulting lubricating oil base oil. The method includes: cutting the heavy feedstock to obtain a light component, a middle fraction, and a bottom wax; wherein the boiling point ranges of the light component, the middle fraction, and the bottom wax are 170-300℃, 300-500℃, and >500℃, respectively; subjecting the bottom wax to a first isomerization reaction under the catalysis of a first isomerization catalyst to obtain a first isomerization product; subjecting the first isomerization product and the middle fraction to a second isomerization reaction under the catalysis of a second isomerization catalyst to obtain a second isomerization product; subjecting the second isomerization product to hydrorefining; and then fractionating the obtained refined product to obtain the lubricating oil base oil. The lubricating oil base oil produced by this method has high yield, low pour point, low cloud point, and high viscosity index, making it a high-quality lubricating oil base oil.

Description

Technical Field

[0001] This invention relates to a method for producing lubricating oil base oil from heavy raw materials and the resulting lubricating oil base oil, belonging to the field of lubricating oil base oil production technology. Background Technology

[0002] Lubricating oil base oils are a specialty product of oil refining and a key source of profit for refineries. With increasingly stringent market demands for high-quality and long-life lubricating oils, the demand for Group II and III base oils produced using hydroisomerization technology is increasing year by year. Deep isomerization catalysts for alkanes are crucial to hydroisomerization technology. The active metal typically uses precious metals such as Pt, Rh, and Pd, which perform dehydrogenation and hydrogenation on alkanes or alkenes. The support is mainly composed of one-dimensional straight-pore molecular sieves such as SAPO-11, SAPO-31, SAPO-41, ZSM-22, ZSM-23, ZSM-48, and IZM-2. These sieves provide acidity and play a role in pore confinement and shape selection during the isomerization reaction. Their pore confinement and acidic characteristics determine the conversion ability of different feedstock molecules and the differences in product structure. Among them, ZSM-48 molecular sieve has a relatively large one-dimensional circular pore size and suitable acidity, making it suitable for removing single-branched / double-branched isomers formed by the isomerization of long-chain n-alkanes. It is applicable to the hydroisomerization of heavy feedstocks such as Fischer-Tropsch synthetic oil, hydrocracking tail oil, and high-wax VGO to produce base oil. Therefore, the preparation of lubricating oil isomerization dewaxing catalysts using ZSM-48 molecular sieve with suitable silica-alumina ratio and grain size as a carrier has high application value.

[0003] The following will introduce some prior art related to this invention and briefly explain its defects or shortcomings relative to this invention.

[0004] US 7704379B2 utilizes hydrotreated SASOLTM PARAFLINTTMC80F-T synthetic wax obtained from Moore and Munger, Inc. (Shelton, Conn.) without further processing as a feedstock. The C80 wax primarily contains straight-chain alkanes and small amounts of olefins and oxygenators. SASOLTM contains three grades of FT synthetic wax: PARAFLINTTMH1 (+371°C full-range FT synthetic wax), PARAFLINTTMC80, and C105 (371-593°C and +593°C fractions). This technology employs bifunctional catalytic hydroisomerization of the FT synthetic wax and waxy raffinate, with a dual-bed reactor configuration. The first reactor is loaded with a Pt / Beta catalyst, and the second with a Pt / ZSM-48 catalyst, exhibiting high selectivity for wax isomerization and minimizing gas generation during hydrodecondensation of the lubricating oil. The drawback of this technology, or its limitation compared to this invention, is that for heavier Fischer-Tropsch wax feedstocks, two dewaxing catalysts are required, increasing gas generation and reducing lubricating oil yield.

[0005] US 6051129A describes a catalyst prepared by combining EU-1 molecular sieve with ZSM-48 or SSZ-32. This catalyst is then used to catalyze the dewaxing of bright oil / refined lubricating oil with hydrogen, thereby reducing the haze point of the bright oil / refined lubricating oil. The drawbacks of this technology, or its shortcomings relative to the present invention, include the requirement to use two molecular sieves in combination to prepare the catalyst.

[0006] Existing technologies such as US 8263517B2 provide a process for producing naphtha, diesel, and lubricating oil base oils under acidic conditions. This reduces processing costs under high sulfur and nitrogen (S) conditions and increases flexibility in feedstock selection. Acidic feedstocks undergo dewaxing without desulfurization and denitrification, or are dewaxed under acidic conditions after separation under high pressure. Under acidic conditions, the feedstock undergoes preliminary dewaxing and selective hydrocracking dewaxing, separating diesel and bottom fractions. The bottom fraction is further hydrocracking and dewaxing to form diesel and lubricating oil base oils. Fractional distillation and separation improve diesel yield. Various combinations of hydrotreatment, catalytic dewaxing, hydrocracking, and hydrorefining are used to produce fuel oil products and lubricating oil base oil products. Using deionized water, 56% hexamethylammonium chloride, fumed silica, 45% sodium aluminate, and 50% sodium hydroxide as raw materials, and 0.15% ZSM-48 as seed crystals, a ZSM-48 molecular sieve with a SiO2 / Al2O3 ratio of 70-110 was prepared at 160°C for 48 hours at a rotation speed of 250 r / min. Then, 0.6 wt% Pt was loaded onto the ZSM-48 molecular sieve to form a dewaxing catalyst. The drawback of this technique, or its limitation compared to the present invention, is that the use of seed crystals in the ZSM-48 molecular sieve preparation process results in a relatively high loading of precious metals.

[0007] CN 115678602A provides a method for processing Fischer-Tropsch wax, comprising the following steps: subjecting Fischer-Tropsch wax to isomerization cracking to obtain product A; subjecting product A to a first separation to obtain fraction A1 with a boiling range <150℃, fraction A2 with a boiling range of 150-350℃, fraction A3 with a boiling range of 350-580℃, and fraction A4 with a boiling range >580℃; subjecting fraction A3 to isomerization dewaxing to obtain product B; subjecting product B to a second separation to obtain fraction B1 with a boiling range <150℃, fraction B2 with a boiling range of 150-350℃, and base oil B3; subjecting fraction A4 to deoiling treatment to obtain microcrystalline wax; and mixing fractions A2 and B2 to obtain diesel fuel. This technical solution not only yields high-grade API III+ base oil products, but also high-performance microcrystalline wax and diesel, thus achieving efficient utilization of Fischer-Tropsch wax. However, the drawbacks of this technology, or its shortcomings compared to the present invention, include multiple fractionation, high energy consumption, and a complex and difficult-to-control process.

[0008] CN 115678610A provides a method for preparing lubricating oil base oil from Fischer-Tropsch wax. The method includes: cutting the Fischer-Tropsch wax to obtain a first fraction, a second fraction, and bottom wax; performing isomerization reactions on the first and second fractions using a first activated isomerization catalyst and a second activated isomerization catalyst, respectively, to obtain a first isomer oil and a second isomer oil; performing refining reactions on the first and second isomer oils using a first activated refining catalyst and a second activated refining catalyst, respectively, to obtain a first base oil product and a second base oil product; the preparation method of the first and second activated isomerization catalysts includes: performing a reduction reaction on the first and second isomerization catalysts to obtain a reduced first isomer catalyst and a reduced second isomer catalyst; and performing a primary activation and stabilization reaction on the reduced first and second isomer catalysts to obtain a first activated isomer catalyst and a second activated isomer catalyst. The drawback of this technology, or its disadvantage compared to the present invention, is that it requires the use of two isomers and two refining agents, and the process is relatively complex.

[0009] CN 111484873A discloses a method for preparing lubricating oil base oil, comprising: (1) reacting Fischer-Tropsch wax with catalyst A, and fractionating the material i obtained after the reaction to obtain light component, medium component and heavy component respectively, wherein the fractionation point of light component and medium component is 320-420℃, and the fractionation point of medium component and heavy component is 500-580℃; (2) reacting medium component with catalyst B to obtain material ii; and reacting heavy component with catalyst C to obtain material iii; (3) reacting material ii and material iii with catalyst A, and fractionating the material iv obtained after the reaction, wherein both catalyst B and catalyst C contain molecular sieves, and the pore size of the molecular sieve in catalyst C is larger than the pore size of the molecular sieve in catalyst B. Although this method yields high yields of lubricating oil base oil, its drawbacks or shortcomings relative to the present invention include the following: after the medium and heavy components undergo isomerization reactions on different isomer catalysts, the products are mixed and then refined, followed by fractionation to obtain lubricating oil base oil and other components, resulting in high energy consumption and reduced efficiency.

[0010] Therefore, providing a novel method for producing lubricating oil base oil from heavy raw materials and the resulting lubricating oil base oil has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0011] In order to solve the problems of low yield, high pour point and high cloud point in the production of lubricating oil base oil in the existing technology, one object of the present invention is to provide a method for producing lubricating oil base oil from heavy raw materials.

[0012] Another object of the present invention is to provide a lubricating oil base oil, which is obtained by the method of producing lubricating oil base oil from the heavy raw materials described above.

[0013] To achieve the above objectives, in one aspect, the present invention provides a method for producing lubricating oil base oil from heavy raw materials, wherein the method includes:

[0014] Step 1: The heavy raw material is cut to obtain light components, middle fractions and bottom wax; the boiling point ranges of the light components, middle fractions and bottom wax are 170-300℃, 300-500℃ and >500℃, respectively.

[0015] Step 2: Under the catalysis of the first isomer catalyst, the bottom wax of the tower undergoes the first isomerization reaction to obtain the first isomerization reaction product;

[0016] Step 3: Under the catalysis of the second isomer catalyst, the product of the first isomerization reaction and the middle fraction undergo a second isomerization reaction to obtain the product of the second isomerization reaction;

[0017] Step 4: Hydrogenate the product of the second isomerization reaction, and then fractionate the refined product to obtain the lubricating oil base oil.

[0018] As a specific embodiment of the method described above in this invention, the heavy feedstock includes one or a combination of several of the following: Fischer-Tropsch synthetic oil, hydrocracking tail oil, high-wax VGO, and Fischer-Tropsch wax.

[0019] In this invention, the cutting points for heavy feedstock are 300℃ and 500℃. Fractions with a boiling point range of 170-300℃ are considered light components, fractions with a boiling point range greater than 300℃ and less than or equal to 500℃ are considered middle fractions, and fractions with a boiling point range greater than 500℃ are considered bottom wax. If the bottom wax and middle fractions in the heavy feedstock are not cut and undergo isomerization together, at lower reaction temperatures, the isomerization reaction of the bottom wax (heavy component) is insufficient, resulting in poor pour point reduction. At higher reaction temperatures, the bottom wax undergoes sufficient isomerization, but the middle fraction may overreact due to side reactions, such as cracking, leading to a decrease in base oil yield and failing to achieve the desired effect. Therefore, the method for producing lubricating oil base oil from heavy feedstock provided by this invention first performs a first isomerization reaction on the bottom wax, and then mixes the products of the first isomerization reaction with the middle fraction to undergo a second isomerization reaction, thereby ensuring that the bottom wax reaches the required degree of isomerization reaction while preventing overreaction in the middle fraction.

[0020] In this invention, when the heavy raw material is Fischer-Tropsch synthetic oil, Fischer-Tropsch wax, or high-wax VGO, it needs to be hydrorefined before cutting these heavy raw materials. However, this invention does not make specific requirements on the operation steps and process parameters of hydrorefining, as long as it can ensure that these heavy raw materials can undergo olefin saturation and deoxygenation reactions to remove olefins and oxygen-containing compounds and avoid the generation of water in subsequent isomerization reactions.

[0021] In one specific embodiment of the method described above in this invention, the volume ratio of the first isomeric catalyst to the second isomeric catalyst is 1-2:1.

[0022] In one specific embodiment of the method described above, the volume hourly space velocity (VHSV) of the first isomerization reaction is 0.2-1.0 h⁻¹. -1 The hydrogen-to-oil ratio is 300:1-1000:1, the reaction temperature is 300-400℃, and the pressure is 3-16MPa.

[0023] In one specific embodiment of the method described above, the volume hourly space velocity (VHSV) of the first isomerization reaction is 0.5-1.0 h⁻¹. -1 The hydrogen-to-oil ratio is 500:1-800:1, and the reaction temperature is 310-350℃.

[0024] In one specific embodiment of the method described above, the volume hourly space velocity (VHSV) of the second isomerization reaction is 1.0-2.0 h⁻¹. -1 The hydrogen-to-oil ratio is 300:1-1000:1, the reaction temperature is 300-400℃, and the pressure is 3-16MPa.

[0025] In one specific embodiment of the method described above, the volume hourly space velocity (VHSV) of the second isomerization reaction is 1.5-1.8 h⁻¹. -1 The hydrogen-to-oil ratio is 500:1-800:1, and the reaction temperature is 310-350℃.

[0026] In one specific embodiment of the method described above in this invention, the first isomerization reaction and the second isomerization reaction are both carried out in an isomerization reactor, and the hydrorefining is carried out in a hydrorefining reactor. Both the isomerization reactor and the hydrorefining reactor are conventional equipment.

[0027] In one specific embodiment of the method described above in this invention, the first isomeric catalyst and the second isomeric catalyst may be the same or different. When the first isomeric catalyst and the second isomeric catalyst are different, they may be isomeric catalysts with different SiO2 to Al2O3 molar ratios in the ZSM-48 molecular sieve support and / or different loadings of active components.

[0028] In a specific embodiment of the method described above in this invention, the support for the first isomeric catalyst and the second isomeric catalyst is a ZSM-48 molecular sieve support, the active component is a noble metal, and the loading of the active component is 0.1-1.0 wt%, preferably 0.1-0.5 wt%, based on the total weight of the support as 100%.

[0029] The ZSM-48 molecular sieve support comprises ZSM-48 molecular sieve, wherein the molar ratio of SiO2 to Al2O3 in the ZSM-48 molecular sieve is 50-400, preferably 100-200; the grain length of the ZSM-48 molecular sieve is 0.1-0.5 μm, the grain diameter is 50-100 nm, and the axial-to-diameter ratio is less than 20, preferably 2-10. In this invention, the axial-to-diameter ratio is the ratio of the molecular sieve grain length to the cross-sectional width.

[0030] As a specific embodiment of the method described above in this invention, the precious metal includes platinum and / or palladium, etc.

[0031] As a specific embodiment of the method described above in this invention, the preparation method of the first isomeric catalyst and the second isomeric catalyst includes:

[0032] Step (1): Dissolve the noble metal salt in a mixture of water, alcohol and ligand and mix thoroughly to obtain a noble metal precursor solution;

[0033] Step (2): The particles of ZSM-48 molecular sieve support are impregnated in a noble metal precursor solution, and then the impregnated product is dried and calcined to obtain the first isomer catalyst and the second isomer catalyst.

[0034] As a specific embodiment of the method described above in this invention, the noble metal salt includes one or a combination of several of the following: chloroplatinic acid hexahydrate, palladium chloride, platinum dichloride, and ammonium hexachloroplatinate.

[0035] In one specific embodiment of the method described above, the ligand comprises one or more of sorbic acid, salicylic acid, nicotinamide, lactic acid, citric acid, and hyaluronic acid, and the molar ratio of the ligand to the noble metal atom is 6-18:1. During the preparation of the isomeric catalyst, the ligand complexes with the noble metal atom and is loaded onto the support, which is beneficial for the dispersion of the noble metal atom. The presence of the ligand can also, to a certain extent, prevent the noble metal from agglomerating and forming large particles.

[0036] As a specific embodiment of the method described above in this invention, the alcohol includes one or a combination of several of ethanol, propanol, isopropanol, glycerol, etc., preferably glycerol, and the mass ratio of water to alcohol is 50-1:1, preferably 20-10:1.

[0037] As a specific embodiment of the method described above in this invention, in step (1), the mixing is carried out at 30-60°C for 2-6 hours.

[0038] As a specific embodiment of the method described above in this invention, in step (2), the calcination is carried out in an air atmosphere at 400-600°C for 4-14 hours, preferably at 400-500°C for 6-14 hours.

[0039] In the preparation method of the heterogeneous catalyst provided by the present invention, extrusion, drying, and baking are all conventional operations. The operation steps of extrusion, drying, and baking, as well as the process parameters involved, can be reasonably adjusted according to the actual on-site operation needs.

[0040] As a specific embodiment of the method described above in this invention, the preparation method of the ZSM-48 molecular sieve support includes:

[0041] Mix ZSM-48 molecular sieve, alumina, titanium dioxide, acid solution, binder, and deionized water evenly.

[0042] The resulting mixture is then extruded, dried, and calcined to obtain the ZSM-48 molecular sieve support.

[0043] The mass ratio of ZSM-48 molecular sieve, alumina, titanium dioxide, acid solution, binder, and deionized water is 1:0.3-9:0.01-0.5:0.01-0.6:0.3-1:0.2-1, preferably 1:0.5-2:0.02-0.05:0.02-0.5:0.5-0.8:0.5-0.8.

[0044] In one specific embodiment of the method described above, the adhesive comprises guar gum powder and / or methylcellulose, preferably guar gum powder; the acid solution comprises nitric acid or phosphoric acid solution with a concentration of 5-15 wt%, preferably nitric acid. The alumina is a common alumina such as boehmite.

[0045] In one specific embodiment of the method described above in this invention, the obtained mixture is extruded, dried, and calcined at 400-500°C for 6-14 hours to obtain a ZSM-48 molecular sieve carrier.

[0046] As a specific embodiment of the method described above in this invention, the method for preparing the ZSM-48 molecular sieve includes:

[0047] First, an aluminum source, a silicon source, an alkali source, a crystallization inducer, a template agent, deionized water, a pore-forming agent, and a charge balancing agent are mixed evenly to obtain a gel solution. Then, the gel solution is pre-crystallized at 70-90℃ for 2-6 hours, crystallized at 120-140℃ for 2-6 hours, and crystallized at 140-170℃ for 10-48 hours. The crystallized product is then washed, dried, and calcined to obtain a molecular sieve precursor. The molecular sieve precursor is then mixed with an ammonium salt at 70-80℃ for 4-6 hours, followed by washing, drying, and calcination to obtain the final product.

[0048] Among them, the aluminum source is calculated as Al2O3, and the aluminum source is calculated as OH. - The molar ratio of the alkali source, template agent, H2O and silicon source (calculated as SiO2) is 0.0025-0.02:0.006-0.38:0.11-1.5:10-50:1, preferably 0.005-0.01:0.015-0.25:0.2-1:20-40:1;

[0049] The molar ratio of the pore-forming agent to the silicon source (calculated as SiO2) is 0.01-0.2:1, preferably 0.01-0.1:1;

[0050] The molar ratio of crystallization inducer (calculated as M2O) to silicon source (calculated as SiO2) is 0.002-0.2:1, preferably 0.005-0.03:1, wherein M is one or more alkali metals;

[0051] The molar ratio of the charge balancing agent to H2O is 0.1-1:1, preferably 0.2-0.5:1.

[0052] As a specific embodiment of the method described above in this invention, in the preparation method of ZSM-48 molecular sieve, the amount of the pore-forming agent is less than 5 wt% of the total weight of the gel solution.

[0053] As a specific embodiment of the method described above in this invention, in the preparation method of ZSM-48 molecular sieve, the amount of crystallization inducing agent calculated as M2O is within 5 wt% of the total weight of the gel solution.

[0054] As a specific embodiment of the method described above in this invention, the aluminum source includes one or a combination of several of aluminum sulfate, sodium aluminate, and aluminum nitrate, preferably aluminum sulfate;

[0055] The silicon source includes one or a combination of several of silica sol, fumed silica, and tetraethyl orthosilicate, preferably silica sol;

[0056] The alkali source includes NaOH and / or KOH, etc.

[0057] In one specific embodiment of the method described above in this invention, the template agent includes a first template agent and a second template agent, and the molar ratio of the first template agent and the second template agent is 1-400:1.

[0058] The first template agent includes one or a combination of several of cyclohexylamine, dodecylamine, 1,6-hexanediamine, 1,8-octanediamine and benzylamine, preferably 1,6-hexanediamine. The second template agent includes one or a combination of several of hexamethylammonium chloride, hexamethyldiammonium bromide, ammonium oxalate, ammonium acetate and benzyltriethylammonium bromide, preferably hexamethylammonium chloride.

[0059] As a specific embodiment of the method described above in this invention, the ammonium salt includes one or a combination of several of ammonium chloride, ammonium nitrate and ammonium sulfate, preferably ammonium chloride.

[0060] As a specific embodiment of the method described above in this invention, the crystallization inducing agent includes one or a combination of several of sodium chloride, potassium chloride, sodium sulfate, and potassium sulfate, preferably potassium chloride;

[0061] The pore-forming agent includes one or more of P123, Triton-100, polyhexamethylene biguanide, ammonium chloride, polyvinyl alcohol, etc., preferably P123;

[0062] The charge balancing agent includes one or a combination of several of glycerol, ethylene glycol, isopropanol, propanol, and 2-butanol, preferably isopropanol.

[0063] In one specific embodiment of the method described above in this invention, the relative molecular weight of P123 is 4000-8000.

[0064] As a specific embodiment of the method described above in this invention, an aluminum source, a silicon source, an alkali source, a crystallization inducer, a template agent, deionized water, a pore-forming agent, and a charge balancing agent are first mixed uniformly at 40-60°C to obtain a gel solution.

[0065] In one specific embodiment of the method described above in this invention, the crystallized product is washed, dried, and calcined at 500-600°C for 6-30 hours to obtain a molecular sieve precursor.

[0066] In a specific embodiment of the method described above in this invention, the molecular sieve precursor is mixed with ammonium salt at 70-80°C for 4-6 hours, followed by washing, drying, and calcination at 500-600°C for 6-40 hours, preferably 6-30 hours, to obtain the ZSM-48 molecular sieve.

[0067] In the preparation method of ZSM-48 molecular sieve provided by the present invention, washing and drying are conventional operations. The washing and drying operation steps and the process parameters involved can be reasonably adjusted according to the actual on-site operation needs.

[0068] In one specific embodiment of the method described above, in step four, the hydrorefining temperature is 200-300°C, and the volume hourly space velocity (VHSV) is 0.5-2.0 h⁻¹. -1 The pressure is 3-16 MPa, and the hydrogen-to-oil volume ratio is 300-1000:1.

[0069] This invention does not impose specific requirements on the cutting point of fractionation in step four. The cutting point can be reasonably adjusted according to the properties of the heavy raw material and the properties of the target lubricating oil base oil.

[0070] On the other hand, the present invention also provides a lubricating oil base oil, wherein the lubricating oil base oil is obtained by the method for producing lubricating oil base oil from the heavy raw materials described above.

[0071] As a specific embodiment of the lubricating oil base oil described above in this invention, the lubricating oil base oil has a pour point ≤ -16℃, a cloud point ≤ -10℃, a turbid point ≤ -1℃, and a viscosity index greater than 130.

[0072] Compared with the prior art, the beneficial technical effects achieved by the present invention include:

[0073] 1) In the preparation of ZSM-48 molecular sieve, the present invention uses a crystallization inducer, which can induce more crystal nuclei to form rapidly, greatly shorten the crystallization time, reduce the crystal size, that is, form more small-crystal molecular sieves, so that the crystal length is only 0.1-0.5μm. When the isomeric catalyst (whose support contains the above-mentioned ZSM-48 molecular sieve) is used to catalyze the production of lubricating oil base oil from heavy feedstock, it is beneficial for the product to diffuse out from the pores, thereby reducing the occurrence of cracking reaction;

[0074] 2) In the preparation of ZSM-48 molecular sieve, this invention uses alcohols as charge balancing agents. Alcohols are soluble in water, and their molecular size is between that of water molecules and structure-directing agents (i.e., template agents, including the first and second template agents). They can enter the pores and replace some water molecules to support / fill the pores during the molecular sieve synthesis process. The hydroxyl groups in alcohols form hydrogen bonds with the inorganic anionic framework of the molecular sieve, maintaining the charge balance within the pores. This allows more water molecules in the crystallization system to act as solvents (equivalent to an increase in the aqueous phase), enhancing fluidity and making the crystals more uniformly dispersed in the solvent, thus facilitating the formation of small-crystal molecular sieves. Furthermore, alcohols as charge balancing agents do not change the pH of the system, thereby avoiding the formation of impurity crystals. The added charge balancing agent also promotes the uniform distribution of acidic sites in the molecular sieve. When using heterogeneous catalysts (whose support contains the aforementioned ZSM-48 molecular sieve) to catalyze the production of lubricating oil base oil from heavy feedstocks, the reaction efficiency can be improved.

[0075] 3) The present invention uses a pore-forming agent in the preparation of ZSM-48 molecular sieve. Mesopores and micropores can be directly formed during the synthesis of molecular sieve. When the isomeric catalyst (whose support contains the above-mentioned ZSM-48 molecular sieve) is used to catalyze the production of lubricating oil base oil from heavy feedstock, it is beneficial for the diffusion of reactants and products in the pores, thereby improving the diffusion efficiency of reactants and products, improving the reaction efficiency and isomerization conversion rate, reducing the cracking rate, and reducing the amount of molecular sieve used in the catalyst.

[0076] 4) In the preparation of ZSM-48 molecular sieve, the gel solution is pre-crystallized at 70-90℃ for 2-6 hours, crystallized at 120-140℃ for 2-6 hours, and crystallized at 140-170℃ for 10-48 hours. The first stage of crystallization forms the primary structure, and the second stage of crystallization forms more crystal nuclei, which is conducive to the rapid growth of small crystals under the crystallization temperature of the third stage. The small crystal molecular sieve has a short pore length, which is conducive to the rapid diffusion of reaction products from the pores and reduces secondary cracking reactions.

[0077] 5) The preparation method of the present invention can directly synthesize short-axis ZSM-molecular sieves, shortening the pore length. When using the heterogeneous catalyst (whose support contains the above-mentioned ZSM-48 molecular sieve) to catalyze the production of lubricating oil base oil from heavy feedstocks, the reaction efficiency can be significantly improved.

[0078] In summary, the isocatalyst used in this invention has suitable pore size and acidity, which is conducive to the production of more dibranched or multibranched isomers in the isomerization reaction of long-chain alkanes. The small crystal size and small axis-to-diameter ratio are conducive to the rapid diffusion of dibranched or multibranched isomer products from the pores, reducing the occurrence of cracking reactions.

[0079] 6) In the method for producing lubricating oil base oil from heavy feedstock provided by the present invention, the bottom wax of the tower undergoes a first isomerization reaction under the catalysis of a first isomerization catalyst to obtain a first isomerization reaction product; then, under the catalysis of a second isomerization catalyst, the first isomerization reaction product and the middle fraction undergo a second isomerization reaction to obtain a second isomerization reaction product; wherein, both the first and second isomerization reactions use isomerization catalysts supported by ZSM-48 molecular sieves (i.e., ZSM-48 molecular sieve catalysts with the same topology), following the same reaction sequence, which can reduce gas generation, resulting in high yield, low pour point, low cloud point, and high viscosity index of the lubricating oil base oil product; furthermore, the bottom wax, which is heavier in the distillate, undergoes two isomerization reactions, which can deepen the degree of isomerization reaction and reduce the cloud point of the obtained lubricating oil base oil; in addition, the present invention can flexibly adjust the reaction conditions and control the reaction depth according to different feedstocks and target products. Attached Figure Description

[0080] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0081] Figure 1 A flowchart illustrating a method for producing lubricating oil base oil from Fischer-Tropsch wax, as provided in an embodiment of the present invention.

[0082] Figure 2 The image shows the XRD pattern of the ZSM-48 molecular sieve provided in Example 1 of this invention.

[0083] Figure 3 This is a SEM image of the ZSM-48 molecular sieve provided in Example 1 of the present invention.

[0084] Figure 4 The XRD pattern of ZSM-48 molecular sieve provided for Comparative Example 2.

[0085] Figure 5 SEM image of ZSM-48 molecular sieve provided for Comparative Example 2.

[0086] Figure 6 The XRD pattern of the ZSM-48 molecular sieve provided for Comparative Example 3.

[0087] Figure 7 SEM image of ZSM-48 molecular sieve provided for Comparative Example 3.

[0088] Figure 8 The XRD pattern of the ZSM-48 molecular sieve provided for Comparative Example 5.

[0089] Figure 9 The XRD pattern of the ZSM-48 molecular sieve provided for Comparative Example 6.

[0090] Explanation of main icon numbers:

[0091] 1. First distillation tower;

[0092] 2. First heterogeneous reactor;

[0093] 3. Second heterogeneous reactor;

[0094] 4. First hydrorefining reactor;

[0095] 5. Second fractionation tower;

[0096] 6. Second hydrogenation refining reactor. Detailed Implementation

[0097] It should be noted that the term "comprising" and any variations thereof in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0098] The "range" disclosed in this invention is given in the form of a lower limit and an upper limit. It can be one or more lower limits and one or more upper limits, respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower and upper limits define the boundaries of the particular range. All ranges defined in this way are composable, meaning that any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for specific parameters, it is also expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if the listed minimum range values ​​are 1 and 2, and the listed maximum range values ​​are 3, 4, and 5, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.

[0099] In this invention, unless otherwise specified, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this invention, and "0-5" is simply a shortened representation of these numerical combinations.

[0100] In this invention, unless otherwise specified, all embodiments and preferred embodiments mentioned in this invention can be combined with each other to form new technical solutions.

[0101] In this invention, unless otherwise specified, all technical features and preferred features mentioned in this invention can be combined with each other to form new technical solutions.

[0102] In this invention, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0103] In this invention, unless otherwise specified, "first" and "second" do not indicate a sequence or limit the specific materials or steps; they are merely used to distinguish that these are not the same step or material. For example, "first" and "second" in "first isomer reaction" and "second isomer reaction" are only used to indicate that these are not the same isomer reaction.

[0104] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying tables, drawings, and embodiments. The embodiments described below are some, but not all, embodiments of this invention, and are only used to illustrate the invention, and should not be considered as limiting the scope of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0105] Examples and Comparative Examples of Heterogeneous Catalysts

[0106] Example 1

[0107] This embodiment provides an isomeric catalyst, which is prepared by a method including the following specific steps:

[0108] Preparation of ZSM-48 molecular sieve:

[0109] Step 1): Mix 0.32g aluminum nitrate, 18g tetraethyl orthosilicate, 1g KOH, 2.58g KCl, 0.2g ammonium oxalate, 16g 1,6-hexanediamine, 62.3g deionized water, 5.1g Triton X-100, and 100g isopropanol at 45°C until homogeneous to obtain a gel solution.

[0110] Among them, the aluminum source is calculated as Al2O3, and the aluminum source is calculated as OH. - The molar ratio of the alkali source, template agent, H2O and silicon source (calculated as SiO2) is 0.01:0.2:1.5:40:1;

[0111] The molar ratio of the pore-forming agent to the silicon source (based on SiO2) is 0.2:1;

[0112] The molar ratio of crystallization inducer (calculated as K2O) to silicon source (calculated as SiO2) is 0.2:1;

[0113] The molar ratio of charge balancing agent to H2O is 0.48:1;

[0114] The molar ratio of the first template agent to the second template agent is 85:1;

[0115] Step 2): The gel solution was pre-crystallized at 80℃ for 4 hours, crystallized at 130℃ for 4 hours, and crystallized at 160℃ for 20 hours in sequence to obtain the crystallized product;

[0116] Step 3): The crystallized product is washed, dried, and calcined at 550℃ for 20 hours to obtain the molecular sieve precursor;

[0117] Step 4): The molecular sieve precursor was mixed with ammonium chloride at 75°C for 4 hours, then washed, dried and calcined at 530°C for 24 hours to obtain ZSM-48 molecular sieve;

[0118] Preparation of ZSM-48 molecular sieve support:

[0119] 10g of the ZSM-48 molecular sieve prepared above, 50g of boehmite, 2g of titanium dioxide, 3g of nitric acid solution (5wt%), 5g of guar gum powder, and 8g of deionized water were mixed evenly. The mass ratio of each component was: ZSM-48 molecular sieve: alumina: titanium dioxide: acid solution: binder: deionized water = 1:5:0.2:0.3:0.5:0.8. The resulting mixture was then extruded, dried, and calcined at 450℃ for 8 hours to obtain the ZSM-48 molecular sieve carrier.

[0120] Preparation of isomeric catalysts:

[0121] Dissolve 0.27 g of platinum dichloride in a mixture of 90 g of water, 10 g of isopropanol and 1.64 g of lactic acid, and mix at 30 °C for 2 hours to obtain a noble metal precursor solution.

[0122] 100g of ZSM-48 molecular sieve support particles were impregnated in a noble metal precursor solution for 2 hours, then dried at 100℃ for 2 hours, and finally calcined at 450℃ in air for 4 hours to obtain an isomer catalyst with a Pt loading of 0.20wt%, denoted as catalyst A1.

[0123] Example 2

[0124] This embodiment provides an isomeric catalyst, which is prepared by a method including the following specific steps:

[0125] Preparation of ZSM-48 molecular sieve:

[0126] Step 1): Mix 0.12g aluminum nitrate, 18g silica sol (40wt% solid content), 1.86g NaOH, 0.43g potassium sulfate, 0.1g benzyltriethylammonium bromide, 10g benzylamine, 100g deionized water, 7.2g P123, and 46g 2-butanol at 50°C until homogeneous to obtain a gel solution.

[0127] Among them, the aluminum source is calculated as Al2O3, and the aluminum source is calculated as OH. - The molar ratio of the alkali source, template agent, H2O and silicon source (calculated as SiO2) is 0.0026:0.38:0.76:50:1.

[0128] The molar ratio of the pore-forming agent to the silicon source (calculated as SiO2) is 0.01:1;

[0129] The molar ratio of crystallization inducer (calculated as K2O) to silicon source (calculated as SiO2) is 0.02:1;

[0130] The molar ratio of charge balancing agent to H2O is 0.1:1;

[0131] The molar ratio of the first template agent to the second template agent is 254:1;

[0132] Step 2): The gel solution was pre-crystallized at 85℃ for 5 hours, crystallized at 135℃ for 5 hours, and crystallized at 160℃ for 30 hours in sequence to obtain the crystallized product;

[0133] Step 3): The crystallized product is washed, dried, and calcined at 530℃ for 12 hours to obtain the molecular sieve precursor;

[0134] Step 4): The molecular sieve precursor was mixed with ammonium chloride at 70°C for 4 hours, then washed, dried and calcined at 560°C for 28 hours to obtain ZSM-48 molecular sieve;

[0135] Preparation of ZSM-48 molecular sieve support:

[0136] 100g of the ZSM-48 molecular sieve prepared above, 50g of boehmite, 5g of titanium dioxide, 8g of nitric acid solution (5wt%), 40g of guar gum powder, and 30g of deionized water were mixed evenly. The mass ratio of each component was: ZSM-48 molecular sieve: alumina: titanium dioxide: acid solution: binder: deionized water = 1:0.5:0.05:0.08:0.4:0.3. The resulting mixture was then extruded, dried, and calcined at 480℃ for 10 hours to obtain the ZSM-48 molecular sieve carrier.

[0137] Preparation of isomeric catalysts:

[0138] 0.69 g of ammonium hexachloroplatinate was dissolved in a mixture of 95 g of water, 5 g of glycerol and 2.2 g of salicylic acid, and mixed at 30 °C for 2 hours to obtain a noble metal precursor solution.

[0139] 100g of ZSM-48 molecular sieve support particles were impregnated in a noble metal precursor solution for 2 hours, then dried at 100℃ for 2 hours, and finally calcined at 450℃ in air for 4 hours to obtain an isomer catalyst with a Pt loading of 0.30wt%, denoted as catalyst A2.

[0140] Comparative Example 1

[0141] This comparative example provides an isomer catalyst, denoted as catalyst A11, which differs from Example 1 only in that Triathon X-100 and isopropanol were not used in the preparation of ZSM-48 molecular sieve.

[0142] Comparative Example 2

[0143] This comparative example provides an isomer catalyst, denoted as catalyst A12, which differs from Example 1 only in that KCl was not used in the preparation of ZSM-48 molecular sieve.

[0144] Comparative Example 3

[0145] This comparative example provides an isomeric catalyst, denoted as catalyst A13, which differs from Example 1 only in that isopropanol was not used in the preparation of ZSM-48 molecular sieve.

[0146] Comparative Example 4

[0147] This comparative example provides an isomer catalyst, denoted as catalyst A14, which differs from Example 1 only in that: in step 2), the gel solution is crystallized at 160°C for 28 hours.

[0148] Comparative Example 5

[0149] This comparative example provides an isomeric catalyst, which is prepared by a method including the following specific steps:

[0150] Preparation of ZSM-48 molecular sieve:

[0151] Step 1): Mix 0.32g aluminum nitrate, 18g tetraethyl orthosilicate, 1g KOH, 2.58g KCl, 0.2g ammonium oxalate, 16g 1,6-hexanediamine, 62.3g deionized water, 5.1g Triton X-100, and 314.2g bis(cyclopentadiene)cobalt at 45°C to obtain a gel solution.

[0152] Among them, the aluminum source is calculated as Al2O3, and the aluminum source is calculated as OH. - The molar ratio of the alkali source, template agent, H2O and silicon source (calculated as SiO2) is 0.01:0.2:1.5:40:1;

[0153] The molar ratio of the pore-forming agent to the silicon source (based on SiO2) is 0.2:1;

[0154] The molar ratio of crystallization inducer (calculated as K2O) to silicon source (calculated as SiO2) is 0.2:1;

[0155] The molar ratio of charge balancing agent to H2O is 0.48:1;

[0156] The molar ratio of the first template agent to the second template agent is 85:1;

[0157] Step 2): The gel solution was pre-crystallized at 80℃ for 4 hours, crystallized at 130℃ for 4 hours, and crystallized at 160℃ for 20 hours in sequence to obtain the crystallized product;

[0158] Step 3): The crystallized product is washed, dried, and calcined at 550℃ for 20 hours to obtain the molecular sieve precursor;

[0159] Step 4): The molecular sieve precursor is mixed with ammonium chloride at 75°C for 4 hours, then washed, dried and calcined at 530°C for 24 hours to obtain ZSM-48 molecular sieve, which also contains ZSM-5 impurity crystals and amorphous silicon-aluminum.

[0160] Preparation of ZSM-48 molecular sieve support:

[0161] 10g of the ZSM-48 molecular sieve prepared above, 50g of boehmite, 2g of titanium dioxide, 3g of nitric acid solution (5wt%), 5g of guar gum powder, and 8g of deionized water were mixed evenly. The mass ratio of each component was: ZSM-48 molecular sieve: alumina: titanium dioxide: acid solution: binder: deionized water = 1:5:0.2:0.3:0.5:0.8. The resulting mixture was then extruded, dried, and calcined at 450℃ for 8 hours to obtain the ZSM-48 molecular sieve carrier.

[0162] Preparation of isomeric catalysts:

[0163] Dissolve 0.27 g of platinum dichloride in a mixture of 90 g of water, 10 g of isopropanol and 1.64 g of lactic acid, and mix at 30 °C for 2 hours to obtain a noble metal precursor solution.

[0164] 100g of ZSM-48 molecular sieve support particles were impregnated in a noble metal precursor solution for 2 hours, then dried at 100℃ for 2 hours, and finally calcined at 450℃ in air for 4 hours to obtain an isomer catalyst with a Pt loading of 0.20wt%, denoted as catalyst A15.

[0165] Comparative Example 6

[0166] This comparative example provides an isomeric catalyst, which is prepared by a method including the following specific steps:

[0167] Preparation of ZSM-48 molecular sieve:

[0168] Step 1): Mix 0.32g aluminum nitrate, 18g tetraethyl orthosilicate, 1g KOH, 2.58g KCl, 0.2g ammonium oxalate, 16g 1,6-hexanediamine, 62.3g deionized water, 5.1g Triton X-100, and 193.1g 1,6-hexanediamine at 45℃ until homogeneous to obtain a gel solution;

[0169] Among them, the aluminum source is calculated as Al2O3, and the aluminum source is calculated as OH. - The molar ratio of the alkali source, template agent, H2O and silicon source (calculated as SiO2) is 0.01:0.2:1.5:40:1;

[0170] The molar ratio of the pore-forming agent to the silicon source (based on SiO2) is 0.2:1;

[0171] The molar ratio of crystallization inducer (calculated as K2O) to silicon source (calculated as SiO2) is 0.2:1;

[0172] The molar ratio of charge balancing agent to H2O is 0.48:1;

[0173] The molar ratio of the first template agent to the second template agent is 85:1;

[0174] Step 2): The gel solution was pre-crystallized at 80℃ for 4 hours, crystallized at 130℃ for 4 hours, and crystallized at 160℃ for 20 hours in sequence to obtain the crystallized product;

[0175] Step 3): The crystallized product is washed, dried, and calcined at 550℃ for 20 hours to obtain the molecular sieve precursor;

[0176] Step 4): The molecular sieve precursor is mixed with ammonium chloride at 75°C for 4 hours, then washed, dried and calcined at 530°C for 24 hours to obtain ZSM-48 molecular sieve, which also contains ZSM-5 impurity crystals and amorphous silicon-aluminum.

[0177] Preparation of ZSM-48 molecular sieve support:

[0178] 10g of the ZSM-48 molecular sieve prepared above, 50g of boehmite, 2g of titanium dioxide, 3g of nitric acid solution (5wt%), 5g of guar gum powder, and 8g of deionized water were mixed evenly. The mass ratio of each component was: ZSM-48 molecular sieve: alumina: titanium dioxide: acid solution: binder: deionized water = 1:5:0.2:0.3:0.5:0.8. The resulting mixture was then extruded, dried, and calcined at 450℃ for 8 hours to obtain the ZSM-48 molecular sieve carrier.

[0179] Preparation of isomeric catalysts:

[0180] Dissolve 0.27 g of platinum dichloride in a mixture of 90 g of water, 10 g of isopropanol and 1.64 g of lactic acid, and mix at 30 °C for 2 hours to obtain a noble metal precursor solution.

[0181] 100g of ZSM-48 molecular sieve support particles were impregnated in a noble metal precursor solution for 2 hours, then dried at 100℃ for 2 hours, and finally calcined at 450℃ in air for 4 hours to obtain an isomer catalyst with a Pt loading of 0.20wt%, denoted as catalyst A16.

[0182] The total BET specific surface area, microporous specific surface area, and mesoporous specific surface area data of the ZSM-48 molecular sieves provided in Examples 1-2 and Comparative Examples 1-6 of this invention are shown in Table 1 below.

[0183] Table 1

[0184]

[0185] As can be seen from Table 1 above, the ZSM-48 molecular sieves provided in Examples 1-2 and Comparative Examples 1-4 of the present invention all have micropores and mesopores. However, the total BET specific surface area and mesopore specific surface area of ​​the ZSM-48 molecular sieves prepared in the comparative examples are significantly lower than those of the ZSM-48 molecular sieves provided in the examples of the present invention.

[0186] The XRD and SEM images of the ZSM-48 molecular sieve provided in Example 1 of this invention are as follows: Figure 2 and Figure 3 As shown, the XRD and SEM images of the ZSM-48 molecular sieve provided in Comparative Example 2 are as follows: Figure 4 and Figure 5 As shown, the XRD and SEM images of the ZSM-48 molecular sieve provided in Comparative Example 3 are as follows: Figure 6 and Figure 7 As shown, the XRD pattern of the ZSM-48 molecular sieve provided in Comparative Example 5 is as follows. Figure 8 As shown, the XRD pattern of the ZSM-48 molecular sieve provided in Comparative Example 6 is as follows. Figure 9 As shown.

[0187] from Figure 2 As can be seen from the above, the ZSM-48 molecular sieve prepared in Example 1 of this invention is a pure-phase ZSM-48 molecular sieve with no impurity crystals formed; from Figure 3 As can be seen from Table 1, the ZSM-48 molecular sieve prepared in Example 1 of this invention has a grain length of 100-500 nm, a grain diameter of 50-100 nm, and an axis-to-diameter ratio of approximately 2-10, indicating that it is a short-axis ZSM-molecular sieve. (Comparison) Figure 3 , Figure 5 and Figure 7 As can be seen from the experimental data in Table 1, the ZSM-48 molecular sieve provided in the comparative example has a larger crystal size compared to the ZSM-48 molecular sieve provided in Example 1 of this invention.

[0188] contrast Figure 2 , Figure 8 and Figure 9 It is evident that the ZSM-48 molecular sieve prepared in Example 1 of this invention is a pure-phase ZSM-48 molecular sieve without the formation of impurity crystals. In contrast, Comparative Examples 5 and 6, which prepared ZSM-48 molecular sieves by adding non-alcoholic charge-balancing agents such as organometallic complexes (bis(cyclopentadiene)cobalt) and organic amines (1,6-hexanediamine), respectively, can affect the pH value or structural orientation of the system, easily leading to the formation of impurity crystals or amorphous structures. Furthermore, as shown in Table 1 above, compared to the ZSM-48 molecular sieve provided in Example 1, the ZSM-48 molecular sieves provided in Comparative Examples 5 and 6 have larger grain sizes and axial diameter ratios.

[0189] In summary, comparing the ZSM-48 molecular sieves provided in Example 1 and Comparative Examples 5-6, it can be seen that, compared with the bis(cyclopentadiene)cobalt and 1,6-hexanediamine charge balancing agents used in Comparative Examples 5 and 6, Example 1 of the present invention uses isopropanol, an alcohol-based charge balancing agent, to obtain a pure phase molecular sieve, and the molecular sieve has smaller crystal size and axial diameter ratio.

[0190] The acidity data of the isomeric catalysts provided in Examples 1-2 and Comparative Examples 1-6 of this invention are shown in Table 2 below.

[0191] Table 2

[0192]

[0193]

[0194] As can be seen from Table 2, the contents of weak Brønsted acid (200°C) and moderately strong Brønsted acid (350°C) in the isomeric catalysts provided in the embodiments of the present invention are significantly higher than those in the isomeric catalysts provided in the comparative examples. When these isomeric catalysts are used to produce lubricating oil base oil from heavy feedstocks, the reaction efficiency can be significantly improved. For the isomeric catalysts provided in Comparative Examples 5 and 6, since the ZSM-48 molecular sieve used therein contains ZSM-5 heterocrystals and amorphous silica-alumina, the contents of weak Brønsted acid (200°C) and moderately strong Brønsted acid (350°C) in these isomeric catalysts are lower than those in the isomeric catalyst provided in Example 1.

[0195] Method Examples and Comparative Examples

[0196] Example 1-1

[0197] This embodiment provides a method for producing lubricating oil base oil from Fischer-Tropsch wax, the flowchart of which is shown below. Figure 1 As stated, from Figure 1 As can be seen from the above, the method includes the following specific steps:

[0198] Step 1: The Fischer-Tropsch wax is hydrotreated in the first hydrorefining reactor 4 to carry out olefin saturation and deoxygenation reactions, thereby removing olefins and oxygen-containing compounds from the Fischer-Tropsch wax and avoiding the formation of water in the subsequent isomerization reaction. The hydrotreated Fischer-Tropsch wax is then cut in the first fractionation column 1 to obtain light fraction, middle fraction and bottom wax. The boiling point ranges of the light fraction, middle fraction and bottom wax are 170-300℃, 300-500℃ and >500℃, respectively.

[0199] The property parameters of the Fischer-Tropsch wax raw material are shown in Table 3 below.

[0200] Table 3

[0201]

[0202]

[0203] Step 2: The bottom wax is fed into the first isomer reactor 2, which is filled with catalyst A1. Under the catalytic action of catalyst A1, the bottom wax undergoes the first isomerization reaction to obtain the first isomerization product.

[0204] Step 3: The product of the first isomerization reaction and the middle fraction are fed together into the second isomerization reactor 3, which is packed with catalyst A1, to carry out the second isomerization reaction and obtain the product of the second isomerization reaction.

[0205] The volume ratio of catalyst A1 packed in the second isomer reactor 3 to catalyst A1 packed in the first isomer reactor 2 is 1:1.

[0206] The volume hourly space velocity (VHSV) of the first isomerization reaction is 0.2 h⁻¹. -1 The hydrogen-to-oil ratio is 300:1, the reaction temperature is 380℃, and the pressure is 5MPa.

[0207] The volume hourly space velocity (VHSV) for the second isomerization reaction is 2.0 h⁻¹. -1 The hydrogen-to-oil ratio is 1000:1, the reaction temperature is 300℃, and the pressure is 5MPa.

[0208] Step 4: The product of the second isomerization reaction is fed into the second hydrorefining reactor 6 for hydrorefining, and then the refined product is fractionated and cut in the second fractionation tower 5 to obtain the lubricating oil base oil.

[0209] The hydrorefining temperature is 200°C, and the volume hourly space velocity (VHSV) is 1.0 h⁻¹. -1 The pressure is 5 MPa, and the hydrogen-to-oil volume ratio is 1000:1.

[0210] In this embodiment, the yield of the lubricating oil base oil is 62%, the pour point is not greater than -17℃, the pour point is not less than -12℃, the cloud point is not less than -2℃, and the viscosity index is 136.

[0211] Example 2-1

[0212] This embodiment provides a method for producing lubricating oil base oil from Fischer-Tropsch wax, wherein the method includes the following specific steps:

[0213] Step 1: Fischer-Tropsch wax is hydrotreated in the first hydrorefining reactor to remove olefins and oxygen-containing compounds through olefin saturation and deoxygenation reactions, thus preventing the formation of water in subsequent isomerization reactions. The hydrotreated Fischer-Tropsch wax (properties shown in Table 3) is then fractionated in the first fractionation column to obtain light fraction, middle fraction, and bottom wax. The boiling point ranges of the light fraction, middle fraction, and bottom wax are 170-300℃, 300-500℃, and >500℃, respectively.

[0214] Step 2: The bottom wax is fed into the first isomerization reactor containing catalyst A2. Under the catalytic action of catalyst A2, the bottom wax undergoes the first isomerization reaction to obtain the first isomerization product.

[0215] Step 3: The product of the first isomerization reaction and the middle fraction are fed together into a second isomerization reactor packed with catalyst A2 to carry out a second isomerization reaction, and the product of the second isomerization reaction is obtained.

[0216] The volume ratio of catalyst A2 loaded in the second isomer reactor to that loaded in the first isomer reactor is 1:2.

[0217] The volume hourly space velocity (VHSV) of the first isomerization reaction is 1.0 h⁻¹. -1 The hydrogen-to-oil ratio is 1000:1, the reaction temperature is 300℃, and the pressure is 8MPa.

[0218] The volume hourly space velocity (VHSV) for the second isomerization reaction is 1.0 h⁻¹. -1 The hydrogen-to-oil ratio is 300:1, the reaction temperature is 370℃, and the pressure is 8MPa.

[0219] Step 4: The product of the second isomerization reaction is fed into the second hydrorefining reactor for hydrorefining, and then the refined product is fractionated in the second distillation tower to obtain the lubricating oil base oil.

[0220] The hydrorefining temperature is 300°C, and the volume hourly space velocity (VHSV) is 2.0 h⁻¹. -1 The pressure is 8 MPa, and the hydrogen-to-oil volume ratio is 800:1.

[0221] In this embodiment, the yield of the lubricating oil base oil is 56%, the pour point is not greater than -19℃, the pour point is not less than -12℃, the cloud point is not less than -2℃, and the viscosity index is 142.

[0222] Example 3-1

[0223] This embodiment provides a method for producing lubricating oil base oil from Fischer-Tropsch wax, wherein the method includes the following specific steps:

[0224] Step 1: Fischer-Tropsch wax is hydrotreated in the first hydrorefining reactor to remove olefins and oxygen-containing compounds through olefin saturation and deoxygenation reactions, thus preventing the formation of water in subsequent isomerization reactions. The hydrotreated Fischer-Tropsch wax (properties shown in Table 3) is then fractionated in the first fractionation column to obtain light fraction, middle fraction, and bottom wax. The boiling point ranges of the light fraction, middle fraction, and bottom wax are 170-300℃, 300-500℃, and >500℃, respectively.

[0225] Step 2: The bottom wax is fed into the first isomerization reactor containing catalyst A1. Under the catalytic action of catalyst A1, the bottom wax undergoes the first isomerization reaction to obtain the first isomerization product.

[0226] Step 3: The product of the first isomerization reaction and the middle fraction are fed together into a second isomerization reactor packed with catalyst A2 to carry out a second isomerization reaction, and the product of the second isomerization reaction is obtained.

[0227] The volume ratio of catalyst A2 packed in the second isomer reactor to catalyst A1 packed in the first isomer reactor is 1:2.

[0228] The volume hourly space velocity (VHSV) of the first isomerization reaction is 0.6 h⁻¹. -1 The hydrogen-to-oil ratio is 600:1, the reaction temperature is 320℃, and the pressure is 7MPa.

[0229] The volume hourly space velocity (VHSV) for the second isomerization reaction was 1.6 h⁻¹. -1 The hydrogen-to-oil ratio is 700:1, the reaction temperature is 350℃, and the pressure is 10MPa.

[0230] Step 4: The product of the second isomerization reaction is fed into the second hydrorefining reactor for hydrorefining, and then the refined product is fractionated in the second distillation tower to obtain the lubricating oil base oil.

[0231] The hydrorefining temperature is 250°C, and the volume hourly space velocity (VHSV) is 1.0 h⁻¹. -1 The pressure is 10 MPa, and the hydrogen-to-oil volume ratio is 800:1.

[0232] In this embodiment, the yield of the lubricating oil base oil is 60%, the pour point is not greater than -19℃, the pour point is not less than -12℃, the cloud point is not less than -2℃, and the viscosity index is 138.

[0233] Comparative Example 1-1

[0234] This comparative example provides a method for producing lubricating oil base oil from Fischer-Tropsch wax, which differs from Example 1-1 only in that:

[0235] Both the first and second isomer reactors are filled with catalyst A11.

[0236] In this comparative example, the yield of the lubricating oil base oil was 45%, the pour point was not greater than -15℃, the cloud point was not less than -8℃, the turbid point was not less than 0℃, and the viscosity index was 113.

[0237] Comparative Examples 1-2

[0238] This comparative example provides a method for producing lubricating oil base oil from Fischer-Tropsch wax, which differs from Example 1-1 only in that:

[0239] Both the first and second isomer reactors are filled with catalyst Al2.

[0240] In this comparative example, the yield of the lubricating oil base oil was 42%, the pour point was no greater than -15℃, the cloud point was no less than -8℃, the turbid point was no less than 0℃, and the viscosity index was 115.

[0241] Comparative Examples 1-3

[0242] This comparative example provides a method for producing lubricating oil base oil from Fischer-Tropsch wax, which differs from Example 1-1 only in that:

[0243] Both the first and second isomer reactors are filled with catalyst A13.

[0244] In this comparative example, the yield of the lubricating oil base oil was 46%, the pour point was no greater than -15℃, the cloud point was no less than -8℃, the turbid point was no less than 0℃, and the viscosity index was 115.

[0245] Comparative Examples 1-4

[0246] This comparative example provides a method for producing lubricating oil base oil from Fischer-Tropsch wax, which differs from Example 1-1 only in that:

[0247] Both the first and second isomer reactors are filled with catalyst A14.

[0248] In this comparative example, the yield of the lubricating oil base oil was 42%, the pour point was not greater than -15℃, the cloud point was not less than -8℃, the turbid point was not less than 0℃, and the viscosity index was 117.

[0249] Comparative Examples 1-5

[0250] This comparative example provides a method for producing lubricating oil base oil from Fischer-Tropsch wax, wherein the method includes the following specific steps:

[0251] Fischer-Tropsch wax is hydrotreated in the first hydrotreating reactor to carry out olefin saturation and deoxygenation reactions to remove olefins and oxygen-containing compounds from the Fischer-Tropsch wax, thus avoiding the generation of water in the subsequent isomerization reaction. The hydrotreated Fischer-Tropsch wax (properties as shown in Table 3) is then cut in the first fractionation column to obtain the middle fraction (450-500℃) and the bottom wax (520-570℃).

[0252] The middle distillate and bottom wax are intermittently fed into an isomerizing reactor packed with catalyst A1 for isomerization, wherein the volume hourly space velocity (VHSV) of the isomerization reaction is 1.0 h⁻¹. -1 The hydrogen-to-oil ratio is 1000:1, and the reaction temperature is 300℃;

[0253] The reaction products from the isomer reactor enter the second hydrorefining reactor, and after hydrorefining, they are fractionated in the second fractionation tower to obtain the lubricating oil base oil fraction.

[0254] The hydrorefining temperature is 200-300℃, and the volume hourly space velocity is 0.5-2.0 h⁻¹. -1 The pressure is 3-16 MPa, and the hydrogen-to-oil volume ratio is 300-1000:1.

[0255] In this comparative example, the yield of the lubricating oil base oil was 51%, the pour point was not greater than -15℃, the cloud point was not greater than -8℃, the turbid point was not greater than 0℃, and the viscosity index was 118.

[0256] Comparative Examples 1-6

[0257] This comparative example provides a method for producing lubricating oil base oil from Fischer-Tropsch wax, which differs from Example 1-1 only in that:

[0258] Both the first and second isomer reactors are filled with catalyst A15.

[0259] In this comparative example, the yield of the lubricating oil base oil was 40%, the pour point was no greater than -13℃, the cloud point was no less than -5℃, the turbid point was no less than 1℃, and the viscosity index was 112.

[0260] Comparative Examples 1-7

[0261] This comparative example provides a method for producing lubricating oil base oil from Fischer-Tropsch wax, which differs from Example 1-1 only in that:

[0262] Both the first and second isomer reactors are filled with catalyst A16.

[0263] In this comparative example, the yield of the lubricating oil base oil was 39%, the pour point was no greater than -13℃, the cloud point was no less than -6℃, the turbid point was no less than 2℃, and the viscosity index was 113.

[0264] To more intuitively compare the parameters of the lubricating oil base oils obtained in Examples 1-1 to 3-1 and Comparative Examples 1-1 to 1-7 of the present invention, the parameters of these lubricating oil base oils are listed in Table 4 below.

[0265] Table 4

[0266] Yield / % Pour point / °C Pour point / ℃ Cloud point / °C Viscosity Index Example 1-1 62 ≯-17 ≯-12 ≯-2 136 Example 2-1 56 ≯-19 ≯-12 ≯-2 142 Example 3-1 60 ≯-19 ≯-12 ≯-2 138 Comparative Example 1-1 45 ≯-15 ≯-8 ≯0 113 Comparative Examples 1-2 42 ≯-15 ≯-8 ≯0 115 Comparative Examples 1-3 46 ≯-15 ≯-8 ≯0 115 Comparative Examples 1-4 42 ≯-15 ≯-8 ≯0 117 Comparative Examples 1-5 51 ≯-15 ≯-8 ≯0 118 Comparative Examples 1-6 40 ≯-13 ≯-5 ≯1 112 Comparative Examples 1-7 39 ≯-13 ≯-6 ≯2 113

[0267] As can be seen from the data of the lubricating oil base oils provided in Examples 1-1, 2-1, and 3-1 shown in Table 4 above, in the embodiments of the present invention, the bottom wax of the tower undergoes a first isomerization reaction under the catalysis of the first isomerization catalyst to obtain the first isomerization reaction product; then, under the catalysis of the second isomerization catalyst, the first isomerization reaction product and the middle fraction undergo a second isomerization reaction to obtain the second isomerization reaction product; wherein, both the first and second isomerization reactions use isomerization catalysts supported by ZSM-48 molecular sieves (i.e., ZSM-48 molecular sieve catalysts with the same topology), following the same reaction rules, which can reduce gas generation, and the lubricating oil base oil product has a high yield, low pour point, low cloud point, and high viscosity index; and the bottom wax of the tower, which has a heavier fraction, undergoes two isomerization reactions, which can deepen the degree of isomerization reaction and reduce the cloud point of the obtained lubricating oil base oil;

[0268] Comparing the data of the lubricating oil base oils obtained in Examples 1-1, 2-1, and 3-1, as well as Comparative Examples 1-1 to 1-5, it can be seen that, under the same method, the use of a specific isomer catalyst in the embodiments of the present invention can obtain a higher yield of lubricating oil base oil products, and the obtained lubricating oil base oil products have low pour point, low cloud point, and high viscosity index. Under the same isomer catalyst, compared with the existing method for producing lubricating oil base oils from Fischer-Tropsch wax, the method provided in the embodiments of the present invention obtains a higher yield of lubricating oil base oil products, and the obtained lubricating oil base oil products have low pour point, low cloud point, and high viscosity index. That is, compared with the comparative examples, the embodiments of the present invention can obtain higher quality lubricating oil base oils.

[0269] Comparing the data of the lubricating oil base oils obtained in Examples 1-1, 1-6, and 1-7, it can be seen that Comparative Examples 5 and 6 used bis(cyclopentadiene)cobalt and 1,6-hexanediamine as charge balancing agents to prepare ZSM-48 molecular sieves, respectively. In contrast, Example 1 of this invention used isopropanol, an alcohol-based charge balancing agent, to prepare ZSM-48 molecular sieves. Compared to the ZSM-48 molecular sieves obtained in Comparative Examples 5 and 6, the ZSM-48 molecular sieve obtained in Example 1 is a pure-phase molecular sieve with smaller crystal size and axial diameter ratio. Furthermore, the isomeric catalyst prepared from this ZSM-48 molecular sieve has a higher content of weak Brønsted acid (200°C) and moderately strong Brønsted acid (350°C). Therefore, when using this isomeric catalyst to produce lubricating oil base oils, a higher lubricating oil base oil product yield can be obtained, and the resulting lubricating oil base oil product has a low pour point and a high viscosity index.

[0270] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical features and technical inventions, and technical inventions in this invention can be freely combined and used.

Claims

1. A method for producing lubricating oil base oil from heavy raw materials, characterized in that, The method includes: Step 1: The heavy raw material is cut to obtain light components, middle fractions and bottom wax; the boiling point ranges of the light components, middle fractions and bottom wax are 170-300℃, 300-500℃ and >500℃, respectively. Step 2: Under the catalysis of the first isomer catalyst, the bottom wax of the tower undergoes the first isomerization reaction to obtain the first isomerization reaction product; Step 3: Under the catalysis of the second isomer catalyst, the product of the first isomerization reaction and the middle fraction undergo a second isomerization reaction to obtain the product of the second isomerization reaction; Wherein, the support for both the first isomeric catalyst and the second isomeric catalyst is a ZSM-48 molecular sieve support, wherein the ZSM-48 molecular sieve support contains ZSM-48 molecular sieve, and the ZSM-48 molecular sieve has a crystal length of 0.1-0.5 μm, a crystal diameter of 50-100 nm, and an axial diameter ratio of less than 20. The preparation method of the ZSM-48 molecular sieve includes: First, an aluminum source, a silicon source, an alkali source, a crystallization inducer, a template agent, deionized water, a pore-forming agent, and a charge balancing agent are mixed evenly to obtain a gel solution. Then, the gel solution is pre-crystallized at 70-90℃ for 2-6 hours, crystallized at 120-140℃ for 2-6 hours, and crystallized at 140-170℃ for 10-48 hours. The crystallized product is then washed, dried, and calcined to obtain a molecular sieve precursor. The molecular sieve precursor is then mixed with an ammonium salt and washed, dried, and calcined to obtain the final product. The charge balancing agent includes one or a combination of several of the following: glycerol, ethylene glycol, isopropanol, propanol, and 2-butanol; Step 4: Hydrogenate the product of the second isomerization reaction, and then fractionate the refined product to obtain the lubricating oil base oil.

2. The method according to claim 1, characterized in that, The heavy feedstock includes one or a combination of several of the following: Fischer-Tropsch synthetic oil, hydrocracking tail oil, high-wax VGO, and Fischer-Tropsch wax.

3. The method according to claim 1, characterized in that, The volume ratio of the first isocatalyst to the second isocatalyst is 1-2:

1.

4. The method according to claim 1 or 3, characterized in that, The volume space velocity of the first isomerization reaction is 0.2-1.0h -1 , the hydrogen oil ratio is 300:1-1000:1, the reaction temperature is 300-400℃, and the pressure is 3-16 MPa.

5. The method according to claim 1 or 3, characterized in that, The volume space velocity of the second isomerization reaction is 1.0-2.0h -1 , the hydrogen oil ratio is 300:1-1000:1, the reaction temperature is 300-400℃, and the pressure is 3-16 MPa.

6. The method according to claim 1 or 3, characterized in that, The first isocatalyst and the second isocatalyst may be the same or different.

7. The method according to claim 6, characterized in that, The active components of both the first and second isomeric catalysts are noble metals, and the loading of the active component is 0.1-1.0 wt% based on the total weight of the support (100%). The molar ratio of SiO2 to Al2O3 in ZSM-48 molecular sieve is 50-400.

8. The method according to claim 7, characterized in that, The preparation methods of the first isomeric catalyst and the second isomeric catalyst include: Step (1): Dissolve the noble metal salt in a mixture of water, alcohol and ligand and mix thoroughly to obtain a noble metal precursor solution; Step (2): The particles of ZSM-48 molecular sieve support are impregnated in a noble metal precursor solution, and then the impregnated product is dried and calcined to obtain the first isomeric catalyst and the second isomeric catalyst.

9. The method according to claim 8, characterized in that, The precious metal salt includes one or a combination of several of the following: chloroplatinic acid hexahydrate, palladium chloride, platinum dichloride, and ammonium hexachloroplatinate.

10. The method according to claim 8 or 9, characterized in that, The ligands include one or more of sorbic acid, salicylic acid, nicotinamide, lactic acid, citric acid, and hyaluronic acid, and the molar ratio of the ligand to the noble metal atom is 6-18:

1.

11. The method according to claim 8 or 9, characterized in that, The alcohols include one or a combination of several of ethanol, propanol, isopropanol, and glycerol, and the mass ratio of water to alcohols is 50-1:

1.

12. The method according to claim 8 or 9, characterized in that, In step (2), the calcination is carried out in an air atmosphere at 400-600℃ for 4-14 hours.

13. The method according to claim 7, characterized in that, The preparation method of the ZSM-48 molecular sieve support includes: Mix ZSM-48 molecular sieve, alumina, titanium dioxide, acid solution, binder, and deionized water evenly. The resulting mixture is then extruded, dried, and calcined to obtain the ZSM-48 molecular sieve support. The mass ratio of ZSM-48 molecular sieve, alumina, titanium dioxide, acid solution, binder, and deionized water is 1:0.3-9:0.01-0.5:0.01-0.6:0.3-1:0.2-1.

14. The method according to claim 13, characterized in that, The adhesive comprises guar gum powder and / or methylcellulose; the acid solution comprises a nitric acid or phosphoric acid solution with a concentration of 5-15 wt%.

15. The method according to any one of claims 1-3, 7-9, and 13-14, characterized in that, Aluminum source calculated as Al2O3, and OH - The molar ratio of the alkali source, template agent, H2O and silicon source (calculated as SiO2) is 0.0025-0.02:0.006-0.38:0.11-1.5:10-50:1; The molar ratio of the pore-forming agent to the silicon source (calculated as SiO2) is 0.01-0.2:1; The molar ratio of crystallization inducer (calculated as M2O) to silicon source (calculated as SiO2) is 0.002-0.2:1, where M is one or more alkali metals. The molar ratio of charge balancing agent to H2O is 0.1-1:1; And mix the molecular sieve precursor with the ammonium salt at 70-80℃ for 4-6 hours.

16. The method according to claim 15, characterized in that, The aluminum source includes one or a combination of aluminum sulfate, sodium aluminate, and aluminum nitrate. The silicon source includes one or a combination of several of silica sol, silica fume, and tetraethyl orthosilicate. The alkali source includes NaOH and / or KOH.

17. The method according to claim 15, characterized in that, The template agent includes a first template agent and a second template agent, and the molar ratio of the first template agent and the second template agent is 1-400:1; The first template agent includes one or a combination of several of cyclohexylamine, dodecylamine, 1,6-hexanediamine, 1,8-octanediamine and benzylamine, and the second template agent includes one or a combination of several of hexamethylammonium chloride, hexamethyldiammonium bromide, ammonium oxalate, ammonium acetate and benzyltriethylammonium bromide.

18. The method according to claim 15, characterized in that, The crystallization inducing agent includes one or a combination of several of sodium chloride, potassium chloride, sodium sulfate, and potassium sulfate; The pore-forming agent includes one or a combination of several of P123, Triton X-100, polyhexamethylene biguanide, ammonium chloride, and polyvinyl alcohol.

19. A lubricating oil base oil, characterized in that, The lubricating oil base oil is obtained by the method of producing lubricating oil base oil from heavy raw materials as described in any one of claims 1-18.

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