A method for producing a lubricating oil base oil by a combination process

Abstract

The application provides a method for producing lubricating oil base oil through a combined process, which comprises the following steps: carrying out a hydrocracking reaction on raw oil, feeding the obtained hydrocracking tail oil into an adsorption-isomerization reaction zone, and treating the hydrocracking tail oil by contacting the hydrocracking tail oil with a catalyst to obtain a first stream; feeding the first stream into a hydrofinishing reaction zone to carry out a reaction, recycling the reaction effluent of the hydrofinishing reaction zone to the adsorption-isomerization reaction zone for treatment; when the refractive index (20 DEG C) of the first stream is 0.1-3% higher than the refractive index (20 DEG C) of the feed of the adsorption-isomerization reaction zone, stopping feeding the adsorption-isomerization reaction zone, and feeding hydrogen into the adsorption-isomerization reaction zone, so that an isomerization and condensation reduction reaction occurs under the action of the catalyst and the hydrogen; feeding the isomerization and condensation reduction reaction product into a separation system, and separating the isomerization and condensation reduction reaction product to obtain gas, light lubricating oil base oil and heavy lubricating oil base oil.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical technology and relates to a method for producing lubricating oil base oil, particularly a method for producing lubricating oil base oil using a combined process. Background Technology

[0002] Due to the global decline in crude oil quality, the quantity of paraffinic crude oil suitable for producing high viscosity index lubricating oil base oils using traditional processes has gradually decreased. Therefore, the hydrotreating process for producing lubricating oil base oils has developed rapidly. The hydrotreating process refers to the combined process of hydrotreating or hydrocracking followed by hydrodewaxing or isomerization dewaxing and hydrorefining to produce lubricating oil base oils. The advantages of this process include high feedstock flexibility, high base oil yield, and high-value byproducts.

[0003] Isomerization dewaxing is a technique that uses isomerization reactions to convert straight-chain alkanes with high pour points in oils into isoalkanes, thereby lowering the product's pour point while maintaining a high yield of lubricating oil base oils. Compared to solvent dewaxing and catalytic dewaxing, isomerization dewaxing results in higher base oil yields, lower pour points, and higher viscosity indices, making it an excellent blending component for modern high-performance internal combustion engine oils.

[0004] US 6,676,827 discloses a method for producing low-pour-point lubricating oil base oil through isomerization dewaxing. It employs a two-stage hydrocracking-isomerization dewaxing process, with each stage having its own hydrogen recirculation system. This is currently the most common process for producing lubricating oil base oils using hydrocracking. Due to the two-stage process, the process flow is complex, involves numerous pieces of equipment, and has high operating costs.

[0005] US Patent 4,283,272 discloses a method for producing lubricating oil base oil using a single-stage process of hydrocracking-hydrodewaxing-refining. This technology adds an adsorption unit after the hydrocracking unit to remove hydrogen sulfide and ammonia from the hydrocracking products. The resulting stream then directly enters the hydrodewaxing and refining unit, thus achieving lubricating oil base oil production with only a single hydrogen circulation system. However, the hydrocracking products are not distilled and separated; lubricating oil components and light products all enter the hydrodewaxing and refining unit together, significantly reducing their reaction efficiency and increasing energy consumption and operating costs. Furthermore, the addition of an adsorption unit to achieve single-stage lubricating oil production increases equipment investment and complicates the process. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a simple and flexible method for producing lubricating oil base oil. First, the feedstock is subjected to hydrocracking. Then, through a selective adsorption process, unconverted long-chain n-alkanes or lightly isomerized long-chain isoalkanes that affect the product's cloud point and pour point are adsorbed from the hydrocracking tail oil. This is followed by an isomerization and pour point depressant reaction, ultimately producing a high viscosity index lubricating oil base oil product.

[0007] This invention provides a method for producing lubricating oil base oil using a combined process, comprising the following steps:

[0008] (1) The feedstock oil and hydrogen are mixed and enter the hydrocracking reaction zone, where they come into contact with the hydrocracking catalyst to carry out the hydrocracking reaction;

[0009] (2) The hydrocracking effluent obtained in step (1) enters the separation system. The separated gas phase is returned to the hydrocracking reaction zone as recycled hydrogen, and the liquid phase product enters the fractionation system.

[0010] (3) The hydrocracking tail oil obtained after fractionation in step (2) enters the adsorption-isomerization reaction zone and is processed by contacting the catalyst packed in the adsorption-isomerization reaction zone to obtain the first feed stream.

[0011] (4) The first feed stream obtained in step (3) enters the hydrogenation supplementation and refining reaction zone for reaction, and the reaction effluent from the hydrogenation supplementation and refining reaction zone is recycled back to the adsorption-isomerization reaction zone for treatment.

[0012] (5) When the refractive index (20°C) of the first feed stream is 0.1-3% higher than the refractive index (20°C) of the feed in the adsorption-isomerization reaction zone, the feed to the adsorption-isomerization reaction zone is stopped, and hydrogen is introduced into the adsorption-isomerization reaction zone. Under the action of the catalyst and hydrogen, the isomerization dewaxing reaction occurs. The isomerization dewaxing reaction products enter the separation system and are separated to obtain gas, light lubricating oil base oil and heavy lubricating oil base oil. Among them, the gas is returned to the hydrocracking reaction zone as circulating hydrogen.

[0013] (6) Part of the heavy lubricating oil base oil obtained from the separation system in step (4) is discharged as a product, and the remaining part enters the hydrotreating and refining reaction zone to carry out the hydrotreating and refining reaction in the presence of hydrogen and hydrotreating catalyst.

[0014] Furthermore, as a specific implementation method, the feedstock oil is one or more of vacuum distillate oil and solvent-refined deasphalted oil.

[0015] Furthermore, as a specific implementation, the mass ratio (referred to as the circulation ratio) of the heavy lubricating oil base oil entering the hydrorefining reaction zone to the heavy lubricating oil base oil discharged as a product is 0.2:1 to 5:1, preferably 0.5:1 to 2:1.

[0016] Furthermore, as a specific implementation, only one hydrogen circulation system is set up in the hydrocracking reaction zone, and the hydrogen in the adsorption-isomerization dewaxing reaction zone is passed through in a single pass.

[0017] Furthermore, as a specific implementation method, the hydrocracking process in step (1) can be a single-stage hydrocracking process or a series hydrocracking process. A single-stage hydrocracking process refers to the use of a single type of catalyst (which may include a protective agent, etc.). A series process flow refers to the formation of two or more different reaction zones in sequence by different types of catalysts. Different types of catalysts can be loaded into one reactor to form a series reaction zone, or two or more series reactors can be used with different types of catalysts to form a series reaction zone. In the series hydrocracking process, the feedstock first passes through a conventional hydropretreatment catalyst bed, and then through a hydrocracking catalyst bed. The catalyst used in the hydrocracking reaction zone is a conventional hydrorefining catalyst and a hydrocracking catalyst, with its active metal being a Group VIB or Group VIII metal. Before use, the catalyst should be sulfided to ensure that the active metal for hydrorefining is in a sulfided state during the reaction. Common commercial catalysts in this field can be selected.

[0018] Furthermore, as a specific implementation method, the reaction conditions in the hydrocracking reaction zone are as follows: reaction temperature of 250–420°C, reaction pressure of 5–15.0 MPa, hydrogen-to-oil volume ratio of 300–1500, and volume hourly space velocity of 0.5–10.0 h⁻¹. -1 .

[0019] Furthermore, as a specific implementation, the separation system generally includes a gas-liquid separator and a fractionation tower. The cut-off temperatures of light and heavy lubricating oil base oils are generally controlled between 450 and 520°C. The vacuum distillation method used is a technique well-known to those skilled in the art. For example, the conditions for vacuum distillation are generally as follows: feed temperature to the vacuum distillation tower is 350°C to 410°C, with a more suitable feed temperature of 375°C to 400°C; top pressure of the vacuum distillation tower is 4 kPa to 10 kPa, with a more suitable top pressure of 5 kPa to 8 kPa; and top temperature of the vacuum distillation tower is 110°C to 180°C. The conditions for vacuum distillation can generally be adjusted within the above ranges to obtain the desired product.

[0020] Furthermore, as a specific embodiment, the catalyst packed in the adsorption-isomerization reaction zone comprises an embedded molecular sieve of TON structure molecular sieve and 5A type molecular sieve, an active metal component, and an inorganic refractory oxide; preferably, the TON structure molecular sieve is embedded on at least a portion of the surface of the 5A type molecular sieve with a predetermined surface coverage rate. A suitable surface coverage rate may be more than 0.5% or more than 1%, and less than 50% or less than 20%, but the present invention is not limited thereto.

[0021] Furthermore, as a specific embodiment, the specific surface area of ​​the embedded molecular sieve is 300 m². 2 / g~600m 2 / g, pore volume 0.15cm 3 / g~0.40cm 3 / g.

[0022] Furthermore, as a specific embodiment, the catalyst has a specific surface area of ​​200 m². 2 / g~550m 2 / g, pore volume 0.25 cm³ 3 / g~0.60 cm 3 / g.

[0023] Furthermore, as a specific embodiment, the weight ratio of the 5A type molecular sieve to the TON structure molecular sieve is 1:80-3:1, preferably 1:30-1:1.

[0024] Furthermore, as a specific embodiment, the content of TON structured molecular sieve is 10wt%-80wt%, preferably 20wt%-60wt%, and the content of 5A type molecular sieve is 1wt%-50wt%, preferably 2wt%-20wt%, relative to the total weight of the catalyst of 100wt%.

[0025] Furthermore, as a specific embodiment, based on the total weight of the catalyst (100wt%), the content of the embedded molecular sieve is 10wt%-90wt%, preferably 20wt%-70wt%, and the content of the active metal component (calculated as metal element) is 0.05wt%-5.0wt%, preferably 0.1wt%-1.0wt%.

[0026] Furthermore, as a specific embodiment, the inorganic refractory oxide is selected from one or more of alumina, titanium oxide, boron oxide, silicon oxide, zirconium oxide and magnesium oxide, with alumina being preferred.

[0027] Furthermore, as a specific embodiment, the active metal component is selected from at least one of the noble metals in Group VIII of the periodic table, preferably from at least one of Pt and Pd, especially Pt.

[0028] Furthermore, as a specific embodiment, the TON structure molecule is selected from one or more of ZSM-22, Theta-1, ISI-1, KZ-2 and NU-10, with ZSM-22 being preferred.

[0029] Furthermore, as a specific embodiment, the 5A type molecular sieve is derived from 5A molecular sieve.

[0030] Furthermore, as a specific embodiment, the catalyst is prepared by mixing an embedded molecular sieve with an inorganic refractory oxide, an extrusion aid, and a binder, then extruding it into a support to obtain a carrier, and finally loading an active metal to obtain the catalyst.

[0031] According to one embodiment of the present invention, the extrusion aid and binder can be reagents commonly used in the art. The general extrusion aid can be either guar gum powder or starch, and the binder is an aqueous solution of inorganic acid, such as nitric acid.

[0032] Furthermore, as a specific embodiment, the catalyst used in the hydrogenation supplementary refining reaction zone is a conventional reducing hydrogenation refining catalyst, whose active metal is one or both of Pt and Pd, or the active metal is a reduced nickel catalyst. In noble metal catalysts, the active metal content is generally 0.05%–1% by weight, while in reduced nickel catalysts, the active metal content is 30%–80% by weight of oxides. The catalyst support is generally Al2O3 or Al2O3-SiO2, and may contain promoters such as P, Ti, B, and Zr. Before use, the catalyst undergoes conventional reduction to ensure that the hydrogenation active metal is in a reduced state during the reaction. Common commercial catalysts in this field can be selected, or prepared according to common methods in this field.

[0033] Furthermore, as a specific implementation, the adsorption-isomerization reaction zone is equipped with at least one reactor, preferably two reactors, and more preferably two reactors connected in parallel for switching use. That is, when one reactor switches from the adsorption reaction to the isomerization decondensation reaction process, the feed is switched to the other reactor to ensure continuous operation of the entire device. The reactor can be one or more of the existing fixed-bed hydrogenation reactors, fluidized-bed hydrogenation reactors, and slurry-bed hydrogenation reactors, with a fixed-bed hydrogenation reactor being preferred.

[0034] Furthermore, as a specific implementation, the operating conditions for the adsorption reaction in the adsorption-isomerization reaction zone in step (3) are as follows: reaction temperature is 40℃~250℃, preferably 60℃~200℃; reaction pressure is 0.01MPa~0.5MPa, preferably 0.08~0.1MPa; and volume hourly space velocity is 0.05h⁻¹. -1 ~5.0h -1 Preferably 0.1h -1 ~2.0h -1 .

[0035] Furthermore, as a specific implementation, when the refractive index (20°C) of the first feed stream is 0.3 to 2.0% higher than the refractive index (20°C) of the feed, feeding into the adsorption-isomerization reaction zone is stopped.

[0036] Furthermore, as a specific embodiment, the operating conditions for the isomerization-decondensation reaction in the adsorption-isomerization reaction zone are as follows: reaction temperature of 200–420°C, preferably 270–380°C; reaction pressure of 1.0–20.0 MPa, preferably 3.0–15.0 MPa; and volume hourly space velocity of 0.1–10.0 h⁻¹. -1 Preferably, it is 0.5 to 3.0 h. -1 The hydrogen-to-oil volume ratio is 100:1 to 1500:1, preferably 100:1 to 400:1.

[0037] Furthermore, as a specific embodiment, the operating conditions of the hydrogenation supplementary refining reaction zone are as follows: reaction temperature of 200℃~320℃, preferably 220℃~280℃; reaction pressure of 8.0MPa~18.0MPa, preferably 10.0~15.0MPa; and volume hourly space velocity of 0.4 h⁻¹. -1 ~6.0h -1 0.8 h is preferred -1 ~1.5h -1 The hydrogen-to-oil volume ratio is 400:1 to 1500:1, preferably 600:1 to 800:1.

[0038] Furthermore, as a specific implementation method, hydrotreating the heavy lubricating oil base oil improves the product quality. The reaction effluent from the hydrotreating process is then subjected to adsorption-isomerization treatment, which helps lower the pour point of the heavy lubricating oil base oil while maintaining a high viscosity index. The method of this invention yields both light and heavy lubricating oil base oils with low pour points and high viscosity indexes.

[0039] Compared with the prior art, the method of the present invention can produce light and heavy high viscosity index lubricating oil base oils with qualified pour points. The specific technical effects are reflected in the following aspects.

[0040] 1. In the lubricating oil base oil production method provided by this invention, non-ideal components are separated by pre-adsorption treatment of hydrocracking tail oil. This ensures that only feedstocks rich in ideal components such as long-chain isoalkanes, long-side-chain monocyclic cycloalkanes, and long-chain monocyclic aromatics undergo isomerization and pour point depressing reactions, thereby generating high viscosity index lubricating oil base oil products. This significantly reduces the participation of non-ideal components in the hydrogenation reaction, thus reducing the isomerization and pour point depressing processing load, decreasing hydrogen consumption, and improving the economic efficiency of the equipment. Furthermore, the applicant discovered during the research process that adding 5A type molecular sieves to the currently used hydroisomerization dewaxing catalyst has a selective adsorption effect on the feedstock of lubricating oil base oil under the condition of no hydrogen presence. This can separate low viscosity index non-ideal components such as bicyclic or higher-ring cycloalkanes and some aromatics from the feedstock, thereby reducing the content of low viscosity index components in the lubricating oil base oil product from the feedstock perspective and increasing the viscosity index of the lubricating oil base oil product.

[0041] 2. The catalyst embedded with a molecular sieve composition provided by this invention is composed of a 5A-type molecular sieve and a TON-structured molecular sieve interlocked. The 5A-type molecular sieve possesses excellent adsorption capabilities and can enrich alkanes, while the TON-structured molecular sieve has a specific pore structure and suitable acidity, which is beneficial for the selective isomerization of alkanes. The molecular sieve composition provided by this invention combines both of these specific functions and maintains good adsorption performance even after loading with an active metal. The catalyst prepared using the molecular sieve composition provided by this invention maintains good stability even after isomerization and regeneration.

[0042] 3. In the lubricating oil base oil production method provided by the present invention, the molecular sieve composition has the ability to selectively adsorb long-chain isomeric alkanes, long-side-chain monocyclic cycloalkanes and long-chain monocyclic aromatics, as well as the ability to selectively isomerize alkanes in the presence of hydrogen and under suitable reaction conditions. This simplifies the production process of high viscosity index lubricating oil base oil, reduces equipment investment, and lowers process hydrogen consumption.

[0043] 4. In the lubricating oil base oil production method provided by the present invention, the adsorption separation efficiency is characterized by the change in the refractive index of the raw material before and after adsorption treatment. This parameter is simple and convenient to measure and can intuitively reflect the separation effect of ideal components such as long-chain isoalkanes, long-side-chain monocyclic cycloalkanes and long-chain monocyclic aromatics in the raw material. Attached Figure Description

[0044] Figure 1 This is a schematic flowchart of the method for producing lubricating oil base oil using the combined process of the present invention. Detailed Implementation

[0045] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The following embodiments will further illustrate the method provided by the present invention, but do not limit the scope of the invention.

[0046] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0047] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “up,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0048] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0049] In this document, all numeric values ​​of parameters (e.g., quantity or condition) should be understood to be modified by the term “about” in all cases, regardless of whether “about” actually appears before the numeric value.

[0050] In the context of this specification, unless explicitly stated otherwise, both the silicon-aluminum material and the catalyst undergo calcination treatment, sometimes referred to as "calcination form," prior to measurement. The conditions for this calcination treatment include: calcination at 600°C in an air atmosphere for a calcination time of 3 hours or more.

[0051] In the context of this specification, long side-chain hydrocarbons specifically refer to one or more of long side-chain isoalkanes, long side-chain monocyclic cycloalkanes, and long side-chain monocyclic aromatics, excluding other hydrocarbons with long side chains. Furthermore, according to the present invention, a long side chain refers to a straight-chain alkyl group of C8-22 (preferably C10-18) as the side chain.

[0052] In the context of this specification, a mechanical mixture refers to a mixture of two or more materials obtained by mechanical mixing. Here, mechanical mixing includes simple mixing, grinding, pulping, etc.

[0053] In the context of this specification, an embedded molecular sieve refers to a composite crystal in which one or more molecular sieve crystals are embedded on or within their surface, exhibiting structural characteristics of two or more molecular sieves. Compared to mechanical mixtures, the different molecular sieves are more tightly bound in an embedded structure, truly forming an integrated composite structure at the molecular level.

[0054] In the context of this specification, the refractive index was characterized using a Mettler R5 refractometer, the long-chain hydrocarbon content was characterized using an Agilent GC 7890, the XRD patterns of the samples were characterized using a D / max-2500 fully automated rotating target X-ray diffractometer, the specific surface area, pore volume, and average pore size of the embedded molecular sieves and the specific surface area, pore volume, and average pore size of the catalyst were characterized using an ASAP 2405 physical adsorption instrument via N2 adsorption-desorption, and the calcium content of the calcium-type molecular sieves was characterized using X-ray fluorescence diffraction.

[0055] In the context of this specification, the content of TON structured molecular sieves in the embedded molecular sieves is quantitatively analyzed by XRD determination.

[0056] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this specification are based on weight, pressure is gauge pressure, and weight or content is on a dry basis.

[0057] In this embodiment of the invention, the hydrocracking reaction zone adopts a conventional single-stage series hydrocracking process, including a hydrocracking pretreatment reaction zone and a hydrocracking reaction zone. The gas obtained after separation is used as recycled hydrogen for hydrocracking.

[0058] like Figure 1As shown, the process flow for producing lubricating oil base oil using the combined process of this invention is as follows: Feedstock oil 1 enters the hydrocracking pretreatment reaction zone 3, where it reacts with hydrogen and the hydrocracking catalyst. The resulting hydrocracking pretreatment effluent 4 enters the hydrocracking reaction zone 5, where it undergoes hydrocracking reaction with hydrogen and the hydrocracking catalyst. The hydrocracking reaction effluent 6 enters the separation system 7 for separation. The resulting gas 8, after treatment, is used as recycled hydrogen and pressurized by the recycled hydrogen compressor before returning to the hydrocracking pretreatment reaction zone 3 and the hydrocracking catalyst. The hydrocracking reaction zone 5 is used, and the separated liquid product 9 enters the fractionation tower 10. After fractionation, gasoline 11, diesel 12, and hydrocracking tail oil 13 are obtained. The hydrocracking tail oil 13 and the reaction effluent 23 from the hydrorefining reaction zone are mixed and fed into reactor 14a in the adsorption-isomerization reaction zone (the adsorption-isomerization reaction zone is equipped with two reactors, reactor 14a and reactor 14b, which are switched. When one reactor completes the adsorption reaction and switches to the isomerization dewaxing reaction, the feed is switched to the other reactor to ensure continuous operation of the unit). The reactor reacts with the catalyst in the reactor, and the resulting first feed stream 24 enters the hydrorefining reaction zone 22 for processing. When the refractive index of the first feed stream 24 is higher than that of the feed by 0.1%-3%, the feed to reactor 14a in the adsorption-isomerization reaction zone is stopped, and the feed is switched to reactor 14b. Hydrogen is then introduced into reactor 14a in the adsorption-isomerization reaction zone to carry out the isomerization dewaxing reaction. The reaction products enter the gas-liquid separation system. After separation in unit 15, gas 16 is used as circulating hydrogen and compressed by the circulating hydrogen compressor before returning to the hydrocracking pretreatment reaction zone 3 and the hydrocracking reaction zone 5. Liquid product 17 enters the fractionation tower 18, and after fractionation, light lubricating oil base oil 19 and heavy lubricating oil base oil are obtained. A portion 20 of the heavy lubricating oil base oil is discharged as a product, and the remaining portion 21 of the heavy lubricating oil base oil is mixed with fresh hydrogen 2 and continues to enter the hydrorefining reaction zone 22. The hydrorefining effluent 23 is returned to the adsorption-isomerization reaction zone for further recycling.

[0059] The properties of the feedstock oils used in the embodiments and comparative examples of the present invention are shown in Table 1. In the first-stage tandem hydrocracking process, a commercially available catalyst, such as FF-26 hydrocracking pretreatment catalyst developed and produced by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd., can be selected for the hydrocracking reaction zone. A commercially available catalyst, such as FC-14 commercial hydrocracking catalyst developed and produced by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd., can be selected for the hydrocracking supplementary refining catalyst, based on its properties.

[0060] Table 1 Properties of Crude Oil

[0061]

[0062] In this invention, the catalyst used in the adsorption-isomerization reaction zone is prepared by the following method, and the properties of the obtained catalyst are shown in Table 2.

[0063] Example 1

[0064] Preparation of catalyst CAT-1:

[0065] 128g sodium hydroxide, 208g tetraethyl orthosilicate, 82g sodium aluminate, 14.88g dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (TPOAC), and 1800g water were mixed evenly and placed into a crystallization vessel. Then, 300g of ZSM-22 molecular sieve was added and stirred. The vessel was sealed, and the temperature was raised to 110℃ for hydrothermal crystallization for 6 hours. After crystallization, the crystallized product was washed, dried at 110℃ for 6 hours, and then calcined at 500℃ for 5 hours to obtain the first embedded molecular sieve Z2. Molecular sieve Z2 was then subjected to ion exchange in a 1.8mol / L CaCl2 solution at 90℃ for 4 hours, filtered and washed, dried at 100℃ for 4 hours, and then calcined at 400℃ for 3 hours to obtain the second embedded molecular sieve GZ-1, with a specific surface area of ​​452 m². 2 / g, pore volume is 0.25mL / g, and the mass fraction of TON structured molecular sieve is 85%.

[0066] 210g of the eutectic molecular sieve GZ-1 prepared above was thoroughly mixed with 90g of pseudoboehmite (dry basis) and 20g of guar gum powder. 9ml of concentrated nitric acid (65% by mass) and an appropriate amount of water were added, and the mixture was thoroughly kneaded and then extruded into strips. The shaped support was dried at 100℃ for 4h and calcined at 550℃ for 4h to obtain support ES-1. Then, noble metal Pt was impregnated using a saturated impregnation method, with a Pt loading of 0.50wt% of the support. After drying at 100℃ for 6h and calcining at 500℃ for 3h, the catalyst of this invention, designated CAT-1, was obtained.

[0067] Example 2

[0068] Preparation of catalyst CAT-2

[0069] 64g sodium hydroxide, 208g tetraethyl orthosilicate, 98.4g sodium aluminate, 24.8g dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (TPOAC), and 2700g water were mixed evenly and placed into a crystallization vessel. Then, 240g of ZSM-22 molecular sieve was added and stirred. The vessel was sealed, and the temperature was raised to 100℃ for hydrothermal crystallization for 7 hours. After crystallization, the product was washed, dried at 100℃ for 6 hours, and then calcined at 450℃ for 8 hours to obtain the first embedded molecular sieve Z6. Then, molecular sieve Z6 was subjected to ion exchange in a 1.5 mol / L CaCl2 solution at 80℃ for 4 h, filtered and washed, dried at 100℃ for 5 h, and then calcined at 350℃ for 6 h to obtain the second embedded molecular sieve GZ-2, which has a specific surface area of ​​498 m2 / g, a pore volume of 0.23 mL / g, and a TON structure molecular sieve mass fraction of 82%.

[0070] The preparation process of the catalyst CAT-2 of the present invention is the same as that in Example 1, except that the embedded molecular sieve used is GZ-2 and the Pt loading is 0.48 wt% of the support, thus preparing the catalyst CAT-2 of the present invention.

[0071] Example 3

[0072] Preparation of catalyst CAT-3

[0073] 80g sodium hydroxide, 184g sodium silicate, 65.6g sodium aluminate, 4.96g dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (TPOAC), and 540g water were mixed evenly and placed into a crystallization vessel. Then, 42g of ZSM-22 molecular sieve was added and stirred. The vessel was sealed, and the temperature was raised to 120℃ for hydrothermal crystallization for 5 hours. After crystallization, the product was washed, dried at 120℃ for 5 hours, and then calcined at 500℃ for 4 hours to obtain the first embedded molecular sieve Z3. Then, molecular sieve Z3 was subjected to ion exchange in a 1.2 mol / L CaCl2 solution at 70℃ for 6 h, filtered and washed, dried at 100℃ for 4 h, and then calcined at 450℃ for 3 h to obtain the second embedded molecular sieve GZ-3, which has a specific surface area of ​​573 m2 / g, a pore volume of 0.19 mL / g, and a TON structure molecular sieve mass fraction of 47%.

[0074] The preparation process of catalyst 3 of the present invention is the same as that in Example 1, except that the embedded molecular sieve used is GZ-3, the Pt loading is 0.31 wt% of the support, and the catalyst CAT-3 of the present invention is prepared.

[0075] Table 2 Physicochemical properties of catalysts

[0076]

[0077] Example 4

[0078] Using the raw materials listed in Table 1, Figure 1 The process flow described above uses catalyst CAT-1 in the adsorption-isomerization reaction zone. The process conditions are shown in Table 3.

[0079] Example 5 - Implementation 6

[0080] Using the raw materials listed in Table 1, Figure 1 The process flow described above uses catalysts CAT-2 and CAT-3 in the adsorption-isomerization reaction zone, respectively. The process conditions are shown in Table 3.

[0081] Comparative Example 1

[0082] Take 134g of ZSM-22 molecular sieve (silicon-to-aluminum ratio 90), 200g of 5A molecular sieve, 150g of aluminum hydroxide (SB produced by Condean GmbH, Germany) and 30g of guar gum powder and mix them evenly. Then add water and concentrated nitric acid (mass concentration of 66.5wt%) and knead thoroughly to make a paste-like plastic material. Extrude cylindrical strips with a diameter of 1.5mm on an extruder. Dry the cylindrical strips at 100℃ for 12 hours and then calcine them at 550℃ in air for 4 hours to obtain the catalyst support of the present invention.

[0083] The precious metal Pt was loaded onto 300 g of support using a saturated impregnation method, then dried at 110 °C for 7 hours and calcined at 500 °C for 3 hours in air atmosphere to obtain the catalyst of this invention containing 0.49 wt% Pt, designated as C-D1.

[0084] Comparative Example 2

[0085] 40g sodium hydroxide, 208g tetraethyl orthosilicate, 285.6g aluminum isopropoxide, 5.75g polyethylene oxide triblock copolymer (P123), and 1440g water were mixed evenly and placed into a crystallization vessel. Then, 60g Hβ molecular sieve was added and stirred. The vessel was sealed, and the temperature was raised to 90℃ for hydrothermal crystallization for 10 hours. After crystallization, the crystallized product was washed, dried at 110℃ for 6 hours, and then calcined at 450℃ for 8 hours to obtain the first mosaic molecular sieve. The molecular sieve was then subjected to ion exchange in a 1.8mol / L CaCl2 solution at 90℃ for 4 hours, filtered and washed, dried at 100℃ for 4 hours, and then calcined at 400℃ for 3 hours to obtain the second mosaic molecular sieve D.

[0086] The preparation process of the comparative catalyst C-D2 in this invention is the same as that in Example 1, except that the embedded molecular sieve D is used and the Pt loading is 0.30 wt% of the support. The resulting catalyst is designated as C-D2.

[0087] Comparative Example 3 and Comparative Example 4

[0088] Using the raw materials listed in Table 1, Figure 1 The process flow described above uses catalysts C-D1 and C-D2 in the adsorption-isomerization reaction zone. The process conditions are shown in Table 3.

[0089] Table 3. Process conditions and results of the examples and comparative examples.

[0090] Table 3. Process conditions and results of the examples and comparative examples.

[0091] Example number Example 4 Example 5 Example 6 Comparative Example 3 Comparative Example 4 Process conditions of the hydrocracking pretreatment reaction zone Reaction temperature / °C 380 350 320 380 350 Reaction pressure / MPa 6 10 15 6 10 Hydrogen-to-oil volume ratio 900 800 1000 900 800 <![CDATA[Space velocity per hour -1 > 2.0 1.0 0.5 2.0 1.0 Hydrocracking reaction zone process conditions Reaction temperature / °C 390 395 390 390 395 Reaction pressure / MPa 15 14 14 15 14 Hydrogen-to-oil volume ratio 400 900 1200 400 900 <![CDATA[Space velocity per hour -1 > 1.2 1.4 1.5 1.2 1.4 Refractive index of hydrocracking tail oil stream (20℃) 1.468 1.473 1.478 1.468 1.473 Adsorption-Isomerization Reaction Zone Adsorption Reaction Process Conditions Adsorption temperature / ℃ 180 140 80 180 140 Adsorption pressure / MPa 0.09 0.08 0.1 0.09 0.08 <![CDATA[Space velocity per hour -1 > 1.5 1.0 0.5 1.5 1.0 First material flow refractive index (20℃) 1.491 1.486 1.483 1.474 1.479 Adsorption-Isomerization Reaction Zone Isomerization Dewaxing Process Conditions Reaction temperature / °C 360 320 280 360 320 Reaction pressure / MPa 14 10 8 14 10 Hydrogen-to-oil volume ratio 200 300 400 200 300 <![CDATA[Space velocity per hour -1 > 1.0 2.0 3.0 1.0 2.0 Hydrogenation supplemental refining process conditions Reaction temperature / °C 240 260 280 240 260 Reaction pressure / MPa 14 12 10 14 12 Hydrogen-to-oil volume ratio 600 700 800 600 700 <![CDATA[Space velocity per hour -1 > 1.0 1.2 1.4 1.0 1.2 Properties of base oil products Light lubricating oil base oil Pour point / ℃ -24 -21 -18 -9 -6 Cloud point / °C -18 -14 -12 -3 0 <![CDATA[Viscosity (100 °C), mm / s 2 > 4.19 4.15 4.20 4.10 4.17 Viscosity Index 121 117 115 108 104 Heavy lubricating oil base oil Pour point / ℃ -21 -15 -12 -6 -3 Cloud point / °C -15 -10 -6 0 2 <![CDATA[Viscosity (100 °C), mm / s 2 > 6.08 6.03 6.10 5.96 6.07 Viscosity Index 125 122 121 110 107

Claims

1. A method for producing lubricating oil base oil using a combined process, comprising the following steps: (1) The feedstock oil and hydrogen are mixed and enter the hydrocracking reaction zone, where they come into contact with the hydrocracking catalyst to carry out the hydrocracking reaction; (2) The hydrocracking effluent obtained in step (1) enters the separation system. The separated gas phase is returned to the hydrocracking reaction zone as recycled hydrogen, and the liquid phase product enters the fractionation system. (3) The hydrocracking tail oil obtained after fractionation in step (2) enters the adsorption-isomerization reaction zone and is processed by contacting the catalyst packed in the adsorption-isomerization reaction zone to obtain the first feed stream; the operating conditions of the adsorption reaction in the adsorption-isomerization reaction zone are: reaction temperature of 40℃~250℃, reaction pressure of 0.01MPa~0.5MPa, and volume hourly space velocity of 0.05h. -1 ~5.0h -1 ; (4) The first feed stream obtained in step (3) enters the hydrogenation supplementation and refining reaction zone for reaction, and the reaction effluent from the hydrogenation supplementation and refining reaction zone is recycled back to the adsorption-isomerization reaction zone for treatment. (5) When the refractive index of the first feed stream at 20°C is 0.1-3% higher than that of the feed to the adsorption-isomerization reaction zone at 20°C, the feed to the adsorption-isomerization reaction zone is stopped, and hydrogen is introduced into the adsorption-isomerization reaction zone at the same time. Under the action of the catalyst and hydrogen, an isomerization dewaxing reaction occurs. The isomerization dewaxing reaction products enter the separation system and are separated to obtain gas, light lubricating oil base oil and heavy lubricating oil base oil. Among them, the gas is returned to the hydrocracking reaction zone as circulating hydrogen. The operating conditions of the isomerization dewaxing reaction in the adsorption-isomerization reaction zone are: reaction temperature of 200-420°C, reaction pressure of 1.0-20.0 MPa, and volume hourly space velocity of 0.1-10.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 100:1 to 1500:1; (6) Part of the heavy lubricating oil base oil obtained from the separation system in step (4) is discharged as a product, and the remaining part enters the hydrotreating and refining reaction zone to carry out the hydrotreating and refining reaction in the presence of hydrogen and hydrotreating catalyst. The catalyst packed in the adsorption-isomerization reaction zone comprises an embedded molecular sieve of TON structure molecular sieve and 5A type molecular sieve, an active metal component, and an inorganic refractory oxide; the active metal component is selected from at least one of the noble metals in Group VIII of the periodic table.

2. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The feedstock is one or more of vacuum distillate oil and solvent-refined deasphalted oil.

3. A method for producing lubricating oil base oil according to the combined process described in claim 1, characterized in that: The mass ratio of heavy lubricating oil base oil entering the hydrorefining reaction zone to the heavy lubricating oil base oil discharged as a product is 0.2:1 to 5:

1.

4. A method for producing lubricating oil base oil according to the combined process described in claim 1, characterized in that: The mass ratio of heavy lubricating oil base oil entering the hydrorefining reaction zone to the heavy lubricating oil base oil discharged as a product is 0.5:1 to 2:

1.

5. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: A hydrogen circulation system is set up in the hydrocracking reaction zone, and the hydrogen in the adsorption-isomerization dewaxing reaction zone is passed through in one go.

6. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The reaction conditions in the hydrocracking reaction zone are as follows: reaction temperature 250–420℃, reaction pressure 5–15.0 MPa, hydrogen-to-oil volume ratio 300–1500, and volume hourly space velocity 0.5–10.0 h⁻¹. -1 .

7. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The cutting point temperature of light lubricating oil base oil and heavy lubricating oil base oil is 450-520℃.

8. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: TON structured molecular sieves are embedded on at least a portion of the surface of the 5A type molecular sieve with a predetermined surface coverage, wherein the suitable surface coverage is more than 0.5% and less than 50%.

9. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: TON structured molecular sieves are embedded on at least a portion of the surface of 5A type molecular sieves with a predetermined surface coverage, wherein the suitable surface coverage is greater than 0.5% and less than 20%.

10. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: TON structured molecular sieves are embedded on at least a portion of the surface of 5A type molecular sieves with a predetermined surface coverage, wherein the suitable surface coverage is more than 1% and less than 50%.

11. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: TON structured molecular sieves are embedded on at least a portion of the surface of 5A type molecular sieves with a predetermined surface coverage, wherein the suitable surface coverage is more than 1% and less than 20%.

12. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The catalyst has a specific surface area of ​​200 m². 2 / g~550m 2 / g, pore volume 0.25 cm³ 3 / g~0.60 cm 3 / g.

13. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The weight ratio of 5A molecular sieve to TON structured molecular sieve is 1:80-3:

1.

14. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The weight ratio of 5A molecular sieve to TON structured molecular sieve is 1:30-1:

1.

15. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: Based on a total catalyst weight of 100wt%, the content of the embedded molecular sieve is 10wt%-90wt%, and the content of the active metal component, calculated as metal element, is 0.05wt%-5.0wt%.

16. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: Based on a total catalyst weight of 100wt%, the content of the embedded molecular sieve is 20wt%-70wt%, and the content of the active metal component, calculated as metal element, is 0.1wt%-1.0wt%.

17. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The inorganic refractory oxide is selected from one or more of alumina, titanium oxide, boron oxide, silicon oxide, zirconium oxide, and magnesium oxide.

18. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The inorganic refractory oxide is aluminum oxide.

19. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The active metal component is selected from at least one of Pt and Pd.

20. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The active metal component is Pt.

21. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: TON structural molecules were screened from one or more of ZSM-22, Theta-1, ISI-1, KZ-2, and NU-10.

22. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The TON structure molecular sieve is ZSM-22.

23. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: 5A type molecular sieve is derived from 5A molecular sieve.

24. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The adsorption-isomerization reaction zone shall be equipped with at least one reactor.

25. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The adsorption-isomerization reaction zone is equipped with two reactors connected in parallel and switched between each other. That is, when one reactor switches from the adsorption reaction to the isomerization decondensation reaction process, the feed is switched to the other reactor to ensure continuous operation of the entire unit.

26. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The operating conditions for the adsorption reaction in the adsorption-isomerization reaction zone in step (3) are: reaction temperature of 60℃~200℃, reaction pressure of 0.08~0.1MPa, and volume hourly space velocity of 0.1h. -1 ~2.0h -1 .

27. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The operating conditions for the isomerization-decondensation reaction in the adsorption-isomerization reaction zone are: reaction temperature 270–380℃, reaction pressure 3.0–15.0 MPa, and volume hourly space velocity 0.5–3.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 100:1 to 400:

1.

28. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The operating conditions for the hydrogenation supplementation purification reaction zone are: reaction temperature 200℃~320℃, reaction pressure 8.0MPa~18.0MPa, and volume hourly space velocity (VHSV) 0.4 h⁻¹. -1 ~6.0h -1 The hydrogen-to-oil volume ratio is 400:1 to 1500:

1.

29. A method for producing lubricating oil base oil according to the combined process of claim 1, characterized in that: The operating conditions for the hydrogenation supplemental purification reaction zone are: reaction temperature 220℃~280℃, reaction pressure 10.0~15.0MPa, and volume hourly space velocity (VHSV) 0.8 h⁻¹. -1 ~1.5h -1 The hydrogen-to-oil volume ratio is 600:1 to 800:1.

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