A method and system for producing high viscosity index lubricating oil base stocks

Abstract

The application discloses a method and system for producing high-viscosity-index lubricating oil base oil, which comprises the following steps: raw materials are introduced into an adsorption-isomerization reaction zone to react, and a stream a is obtained after the reaction; the stream a is introduced into a hydrofining reaction zone to perform a hydrogenation reaction; after the hydrogenation reaction effluent is separated, light high-aromatic special oil base oil and heavy high-aromatic special oil base oil are obtained; when the refractive index of the stream a is 0.1% to 5% higher than that of the raw materials, the raw materials are stopped from being introduced into the adsorption-isomerization reaction zone, hydrogen is introduced into the adsorption-isomerization reaction zone, and an isomerization and condensation reduction reaction is performed under the action of a catalyst and the hydrogen; and after the isomerization and condensation reduction reaction product is separated, light high-viscosity-index lubricating oil base oil and heavy high-viscosity-index lubricating oil base oil are obtained. The application can improve the viscosity index of the isomerization and condensation reduction product-lubricating oil base oil.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of petrochemical industry, and particularly relates to a production method of lubricating oil base oil. BACKGROUND

[0002] With the continuous upgrading of the standard of lubricating oil base oil, people's requirements for the use and environmental performance of lubricating oil base oil are gradually increasing. The traditional production of lubricating oil base oil adopts the "old three sets" process, i.e. solvent refining-solvent dewaxing-clay supplemental refining (normal order), or solvent dewaxing-solvent refining-clay supplemental refining (reverse order). Some refineries will also carry out hydrogenation supplemental refining on the lubricating oil base oil. Although solvent refining and solvent dewaxing can remove a large amount of non-ideal components such as aromatics and n-alkanes respectively, so as to improve the viscosity-temperature performance and low-temperature flow performance of the oil product, the performance of the lubricating oil base oil produced by the process is still poor, and there are problems such as low viscosity index, low liquid yield, high pour point and aromatic hydrocarbon content, high energy consumption, and environmental pollution. At the same time, due to the overall deterioration of global crude oil, the amount of crude oil suitable for producing high-quality lubricating oil base oil is decreasing year by year.

[0003] In recent years, the technology of producing lubricating oil base oil by full hydrogen method (usually referring to the method of producing lubricating oil base oil by adopting hydrocracking process or the combined process of hydroprocessing-isomerization dewaxing-hydrofining) has developed rapidly, and has the advantages of good product performance, strong raw material adaptability, high liquid yield, high economic value of by-products, small pollution, and low energy consumption. However, the isomerization dewaxing link of the method has the problem that when wide boiling range or full boiling range feed is used, it is difficult to balance the viscosity-temperature performance and low-temperature flowability of light components and heavy components. Usually, in order to reduce the pour point of heavy components, light components are excessively isomerized, causing excessive loss of viscosity index of light lubricating oil base oil, so that it is difficult to produce API III base oil.

[0004] CN111378499A discloses a combined method for producing high-quality lubricating oil base oil and environmentally friendly aromatic oil: API I lubricating oil base oil with low content of condensed ring aromatics produced by the "old three sets" process is subjected to solvent extraction to reduce the content of aromatics in the raffinate, and then subjected to hydrofining and hydro-upgrading to improve color and stability, and to improve viscosity-temperature performance and low-temperature flowability, so as to reach the standard of API III lubricating oil base oil; at the same time, the aromatics are enriched in the extract oil, so that the content of condensed ring aromatics in the extract oil is <3.0%, and the content of aromatics is >20%, which can be used as excellent rubber filling oil. SUMMARY

[0005] The inventors have found in the course of research that long-chain isomeric alkanes and long-side-chain monocyclic naphthenes are ideal components of lubricating oil base oils, but in addition to synthetic lubricating oil base oils such as Fischer-Tropsch synthesis oil (F-T oil), ester lubricating oil, poly-alpha-olefin, etc., feedstocks for producing lubricating oil base oils from natural petroleum processing products, such as hydrocracking tail oil, hydroprocessing wax oil, hydrofining wax oil, and hydrofining wax paste, etc., generally contain, in addition to long-chain isomeric alkanes, long-side-chain monocyclic naphthenes, and long-chain monocyclic aromatic hydrocarbons, a certain amount of non-ideal components such as di- and polynaphthenes and aromatic hydrocarbons, and isomerization and condensation processes cannot convert these non-ideal components into high-viscosity-index components, which severely restricts the improvement of the viscosity index of lubricating oil base oils. Based on the above findings, the inventors propose that if the non-ideal components in the feedstock can be separated in advance for hydrofining without isomerization and condensation treatment, and the hydrofining is used to produce high-aromatic special oil base oil, and only the high-isomeric alkane and monocyclic naphthene components are subjected to isomerization and condensation treatment, API Ⅲ and Ⅲ + lubricating oil base oils can be produced, which not only greatly improves product quality and processing scheme flexibility, but also reduces hydrogen consumption and enriches product categories.

[0006] In view of the problems and deficiencies in the prior art, the main purpose of the present application is to provide a method and system for producing high-viscosity-index lubricating oil base oil, which first separates the non-ideal components such as di- and polynaphthenes and part of aromatic hydrocarbons with low viscosity index from the lubricating oil base oil feedstock through a selective adsorption process, and then only the pretreated feedstock rich in long-chain isomeric alkanes, long-side-chain monocyclic naphthenes, and long-chain monocyclic aromatic hydrocarbons is subjected to isomerization and condensation reaction to generate high-viscosity-index lubricating oil base oil products, and the high-naphthene and aromatic components are subjected to hydrofining to produce high-aromatic special oil base oil.

[0007] In order to achieve the above-mentioned purpose of the application, the present application provides a method for producing high-viscosity-index lubricating oil base oil, comprising the following steps:

[0008] (1) The feedstock enters the reactor a in the adsorption-isomerization reaction zone, and reacts in the presence of a catalyst to obtain a stream a;

[0009] (2) The stream a obtained in step (1) enters the hydrofining reaction zone under contact conditions, and a hydrogenation reaction occurs in the presence of hydrogen and a hydrofining catalyst, and the hydrogenation reaction effluent is separated to obtain light high-aromatic special oil base oil and heavy high-aromatic special oil base oil;

[0010] (3) when the refractive index (20℃) of the stream a is 0.1% to 5% higher than the refractive index (20℃) of the raw material, the raw material is stopped from entering the reactor a, and hydrogen is introduced into the reactor a, and isomerization and condensation reduction reaction occurs under the action of the catalyst and hydrogen, and the isomerization and condensation reduction reaction product is separated to obtain light lubricating oil base oil with high viscosity index and heavy lubricating oil base oil with high viscosity index;

[0011] (4) when the raw material is stopped from entering the reactor a, the raw material is switched to enter the reactor b in the adsorption-isomerization reaction zone, and reaction is carried out in the presence of the catalyst, and stream b is obtained after the reaction; the reactor a and the reactor b are connected in parallel and switched for use;

[0012] (5) under the contact condition, the stream b obtained in step (4) enters the hydrofining reaction zone, and hydrofining reaction occurs under the action of hydrogen and the hydrofining catalyst, and the hydrofining reaction effluent is separated to obtain light high-aromatic special oil base oil and heavy high-aromatic special oil base oil;

[0013] (6) when the refractive index (20℃) of the stream b is 0.1% to 5% higher than the refractive index (20℃) of the raw material, the raw material is stopped from entering the reactor b, and hydrogen is introduced into the reactor b, and isomerization and condensation reduction reaction occurs under the action of the catalyst and hydrogen, and the isomerization and condensation reduction reaction product is separated to obtain light lubricating oil base oil with high viscosity index and heavy lubricating oil base oil with high viscosity index;

[0014] (7) the raw material is introduced into the reactor a in the adsorption-isomerization reaction zone again, and steps (1) to (6) are repeated.

[0015] Further, in the above method for producing high-viscosity-index lubricating oil base oil, the raw material in step (1) can be selected from one or more of hydrocracking tail oil, hydrocracked gas oil, hydrocracked bright stock, hydrocracked wax paste and hydrocracked foots oil.

[0016] Further, in the above method for producing high-viscosity-index lubricating oil base oil, the catalyst comprises mosaic molecular sieve of TON structure molecular sieve and 5A type molecular sieve, active metal component and inorganic refractory oxide; preferably, the TON structure molecular sieve is mosaic on at least part of the surface of the 5A type molecular sieve with a predetermined surface coverage, and the suitable surface coverage can be 0.5% or more or 1% or more, and 50% or less or 20% or less, but the application is not limited thereto.

[0017] According to one embodiment of the application, the specific surface area of the mosaic molecular sieve is 300m 2 / g to 600m 2 / g, and the pore volume is 0.15cm 3 / g to 0.40cm 3 / g.

[0018] According to one embodiment of the present application, the specific surface area of the catalyst is 200 m 2 / g to 550 m 2 / g, and the pore volume is 0.25 cm 3 / g to 0.60 cm 3 / g.

[0019] According to one embodiment of the present application, the weight ratio of the 5A type molecular sieve to the TON structure molecular sieve is 1:80 to 3:1, preferably 1:30 to 1:1.

[0020] According to one embodiment of the present application, the content of the TON structure molecular sieve is 10wt% to 80wt%, preferably 20wt% to 60wt%, and the content of the 5A type molecular sieve is 1wt% to 50wt%, preferably 2wt% to 20wt%, relative to the total weight of the catalyst being 100wt%.

[0021] According to one embodiment of the present application, the content of the embedded molecular sieve is 10wt% to 90wt%, preferably 20wt% to 70wt%, and the content of the active metal component is 0.05wt% to 5.0wt%, preferably 0.1wt% to 1.0wt%, relative to the total weight of the catalyst being 100wt%.

[0022] According to one embodiment of the present application, the inorganic refractory oxide is selected from one or more of alumina, titania, boria, silica, zirconia and magnesia, preferably alumina.

[0023] According to one embodiment of the present application, the active metal component is selected from at least one of the Group VIII noble metals of the Periodic Table, preferably at least one of Pt and Pd, in particular Pt.

[0024] According to one embodiment of the present application, the TON structure molecular sieve is selected from one or more of ZSM-22, Theta-1, ISI-1, KZ-2 and NU-10, preferably ZSM-22.

[0025] According to one embodiment of the present application, the 5A type molecular sieve is selected from 5A molecular sieve.

[0026] According to one embodiment of the present application, the catalyst is prepared by kneading the embedded molecular sieve with the inorganic refractory oxide, the extrusion aid, the binder, further forming the carrier by extrusion molding, and then loading the active metal to obtain the catalyst.

[0027] According to one embodiment of the present application, the extrusion aid, the binder can adopt the reagent commonly used in the prior art, and the general extrusion aid can be any one of pearl millet powder and starch, and the binder is an aqueous inorganic acid solution, which can be nitric acid solution and the like.

[0028] According to one embodiment of the present application, the preparation method of the mosaic molecular sieve comprises the following steps:

[0029] (a) contacting a silicon source, an aluminum source, and an alkali source in the presence of a template agent, a TON structure molecular sieve, and water to obtain a gel mixture, and

[0030] (b) hydrothermally crystallizing the gel mixture, and then washing, drying, and calcining to obtain a first mosaic molecular sieve.

[0031] According to one embodiment of the present application, the preparation method further comprises the following step:

[0032] (c) calcium exchanging the first mosaic molecular sieve, and then washing, drying, and calcining to obtain a second mosaic molecular sieve.

[0033] According to one embodiment of the present application, in step (a), the silicon source is at least one selected from water glass, sodium silicate, methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, and butyl orthosilicate.

[0034] According to one embodiment of the present application, in step (a), the alkali source is at least one selected from alkali metal hydroxides, and preferably sodium hydroxide.

[0035] According to one embodiment of the present application, in step (a), the aluminum source is at least one selected from sodium metaaluminate, aluminum isopropoxide, aluminum sulfate, aluminum hydroxide, aluminum oxide, and pseudo-boehmite.

[0036] According to one embodiment of the present application, in step (a), the template agent is at least one selected from polyethylene oxide triblock copolymer (P123) and dimethyloctadecyl [3-(trimethoxysilyl)propyl] ammonium chloride (TPOAC).

[0037] According to one embodiment of the present application, in step (a), the TON structure molecular sieve is one or more selected from ZSM-22, Theta-1, ISI-1, KZ-2, and NU-10, and preferably ZSM-22.

[0038] According to one embodiment of the present application, in step (a), the operation conditions of the contacting include that the temperature is 15-30°C and the time is 1-4h under the presence of stirring.

[0039] According to one embodiment of the present application, in step (a), the molar ratio of the alkali source (calculated as oxide), the silicon source (calculated as SiO2), the aluminum source (calculated as Al2O3), the template agent and water is (0.5-2.5):1:(0.4-0.7):(0.001-0.08):(30-200), and the amount of the TON structure molecular sieve is 0.3-8 times, preferably 1-7 times, of the amount of the silicon source added.

[0040] According to one embodiment of the present application, in step (b), the hydrothermal crystallization temperature is 60-120°C, and the crystallization time is 2-16h.

[0041] According to one embodiment of the present application, in step (b), the drying temperature is 80-200°C, and the drying time is 2-24h.

[0042] According to one embodiment of the present application, in step (b), the calcination temperature is 400-600°C, and the calcination time is 2-12h.

[0043] According to one embodiment of the present application, in step (c), the operation conditions of the calcium exchange include: the exchange temperature is 60-100°C, the exchange time is 1-12h, and the calcium ion concentration in the calcium exchange solution is 0.1-2.5mol / L.

[0044] According to one embodiment of the present application, in step (c), the drying temperature is 80-150°C, and the drying time is 2-12h.

[0045] According to one embodiment of the present application, in step (c), the calcination temperature is 300-500°C, and the calcination time is 2-8h.

[0046] Further, in the above method for producing high-viscosity-index lubricating oil base oil, the reactor a and the reactor b in the adsorption-isomerization reaction zone are connected in parallel and used alternately. The reactor can be one or more of the existing fixed bed hydrogenation reactor, fluidized bed hydrogenation reactor, and slurry bed hydrogenation reactor, and preferably is a fixed bed hydrogenation reactor.

[0047] Further, in the above method for producing lubricating oil base oil, the operation conditions of the adsorption reaction in the adsorption-isomerization reaction zone in step (1) and step (4) are as follows: the temperature is 40-250°C, preferably 60-200°C, the pressure is 0.01-0.5MPa, preferably 0.08-0.1MPa, the volume space velocity is 0.05-5.0h -1 , -1 , preferably 0.1-2.0h -1 , -1 .

[0048] Further, in the production method of the above lubricating oil base oil, the operating conditions of the hydrofining reaction zone are as follows: the reaction temperature is 200-400°C, preferably 220-380°C, the hydrogen partial pressure is 1.0-20.0 MPa, preferably 4.5-15.0 MPa, the volume space velocity is 0.1-10.0 h -1 -1, preferably 0.5-1.0 h -1 , and the hydrogen / oil volume ratio is 100:1-1500:1, preferably 200:1-800:1.

[0049] Further, in the above production method of high-viscosity-index lubricating oil base oil, the hydrofining catalyst can be a hydrofining catalyst available in the art, such as a commercially available product, or can be self-made according to the production method available in the art. Specifically, the hydrofining catalysts FTX-3, FF-36 / 66, FHDS-2 / 3, FMTA-2 / 20, FHDA-1, 10, and FHJ-2 developed by Dalian Petrochemical Research Institute of China Petroleum & Chemical Corporation can be used.

[0050] Further, in the above production method of high-viscosity-index lubricating oil base oil, the hydrofining reaction zone is provided with one or more reactors, and the reactor can be at least one selected from the group consisting of a fixed bed reactor, a fluidized bed reactor, a boiling bed reactor, and a slurry bed reactor, and preferably a fixed bed reactor.

[0051] Further, in the above production method of high-viscosity-index lubricating oil base oil, when the refractive index (20°C) of the stream a in step (3) is 0.5-2.5% higher than that (20°C) of the raw material, the raw material is switched from the reactor a in the adsorption-isomerization reaction zone to the reactor b.

[0052] Further, in the above production method of high-viscosity-index lubricating oil base oil, the operating conditions of the isomerization and pour point depression reaction in the adsorption-isomerization reaction zone in steps (3) and (6) are as follows: the reaction temperature is 200-420°C, preferably 270-380°C, the hydrogen partial pressure is 1.0-20.0 MPa, preferably 3.0-15.0 MPa, the volume space velocity is 0.1 h -1 -10.0 h -1 , preferably 0.5 h -1 -3.0 h -1 , and the hydrogen / oil volume ratio is 100:1-1500:1, preferably 100:1-400:1.

[0053] Further, in the method for producing high viscosity index lubricating oil base oil, when the refractive index (20℃) of the stream b in step (6) is 0.5-2.5% higher than the refractive index (20℃) of the raw material, the raw material is switched from the reactor b in the adsorption-isomerization reaction zone to the reactor a.

[0054] Further, in the method for producing high viscosity index lubricating oil base oil, the separation in step (2) and step (5) generally comprises gas-liquid separation and fractionation, and the hydrogenation reaction effluent is first introduced into a gas-liquid separation zone for gas-liquid separation, and after the separation, a gas phase stream and a liquid phase stream are obtained, the gas phase stream can be recycled as the recycle hydrogen after a purification treatment; the liquid phase stream is further introduced into a fractionation column for separation, and after the separation, a light high-aromatic special oil base oil and a heavy high-aromatic special oil base oil can be obtained according to actual needs.

[0055] Further, in the method for producing high viscosity index lubricating oil base oil, the separation in step (4) and step (6) generally comprises gas-liquid separation and fractionation, and the isomerization and condensation reaction product is first introduced into a gas-liquid separation zone for gas-liquid separation, and after the separation, a gas phase stream and a liquid phase stream are obtained, the gas phase stream can be recycled as the recycle hydrogen after a purification treatment; the liquid phase stream is further introduced into a fractionation column for separation, and after the separation, a high viscosity index light lubricating oil base oil and a high viscosity index heavy lubricating oil base oil can be obtained according to actual needs.

[0056] The second aspect of the present application provides a system for producing high viscosity index lubricating oil base oil, comprising:

[0057] an adsorption-isomerization reaction zone, which comprises a reactor a and a reactor b arranged in parallel, and the raw material is first introduced into the reactor a in the adsorption-isomerization reaction zone, and is treated by contacting with the adsorbent, and after the treatment, a stream a is obtained;

[0058] a hydrofining reaction zone, in which the stream a is introduced into the hydrofining reaction zone 6, and is subjected to a hydrogenation reaction under the action of hydrogen and a hydrofining catalyst;

[0059] a first separation unit, which comprises a first gas-liquid separator and a first fractionation column, and is used for receiving the reaction product from the hydrofining reaction zone, and after the gas-liquid separation, a first gas phase stream and a first liquid phase stream are obtained, and the first liquid phase stream is introduced into the first fractionation column for separation, and after the separation, a light high-aromatic special oil base oil and a heavy high-aromatic special oil base oil are obtained;

[0060] when the refractive index (20℃) of the stream a is 0.1-5% higher than the refractive index (20℃) of the raw material, the raw material is stopped from being introduced into the reactor a in the adsorption-isomerization reaction zone, and hydrogen is introduced into the reactor a, and the isomerization and condensation reaction occurs under the action of the adsorbent and the hydrogen;

[0061] a second separation unit comprising a second gas-liquid separator and a second fractionating column, which is used to receive the isomerization dewaxing reaction product from the reactor a, and after gas-liquid separation, a second gas phase stream and a second liquid phase stream are obtained, and the second liquid phase stream enters the second fractionating column to separate light lubricating oil base oil and heavy lubricating oil base oil;

[0062] When the raw material into the reactor a in the adsorption-isomerization reaction zone is stopped, the raw material is switched into the reactor b in the adsorption-isomerization reaction zone at the same time, and the reactor a and the reactor b are switched.

[0063] Further, in the above system for producing high viscosity index lubricating oil base oil, the reactor a and the reactor b in the adsorption-isomerization reaction zone are connected in parallel and switched, the reactor a and the reactor b are the same, and the same adsorbent is filled in the reactor. The reactor can adopt one or more of the existing fixed bed hydrogenation reactor, fluidized bed hydrogenation reactor, and slurry bed hydrogenation reactor, and preferably adopts the fixed bed hydrogenation reactor.

[0064] Further, in the above system for producing high viscosity index lubricating oil base oil, the first gas phase stream and the second gas phase stream separated by the first gas-liquid separator and the second gas-liquid separator are purified and then communicated with the adsorption-isomerization reaction zone through a pipeline to be recycled as the circulating hydrogen.

[0065] Compared with the prior art, the method and system for producing high viscosity index lubricating oil base oil provided by the application have the following advantages:

[0066] 1. The inventors of the application found in the research process that long-chain isomeric alkanes and long-side-chain monocyclic naphthenes are ideal components for high viscosity index lubricating oil base oil. In addition to synthetic products such as Fischer-Tropsch synthesis oil (F-T oil) and polyesters, feedstocks for producing lubricating oil base oil from natural petroleum products, such as hydrocracking tail oil, hydroprocessed wax oil, hydrorefined wax oil, and hydrorefined wax paste, generally contain long-chain isomeric alkanes, long-side-chain monocyclic naphthenes, and long-chain monocyclic aromatic hydrocarbons, as well as a certain amount of non-ideal components such as di- and polynaphthenes and aromatic hydrocarbons. These non-ideal components cannot be converted into high viscosity index components during isomerization dewaxing and condensation, and their presence seriously restricts the improvement of the viscosity index of the isomerization dewaxing product-lubricating oil base oil. The inventors proposed that if the non-ideal components in the feedstock can be removed in advance, without subsequent isomerization dewaxing treatment, the viscosity index of the isomerization dewaxing product-lubricating oil base oil can be improved, and the hydrogen consumption of the isomerization dewaxing process can be greatly reduced, thereby reducing the operation and production costs of the device. The present application is completed based on the above findings.

[0067] 2. The production method of the lubricating oil base oil provided by the present application, which uses the catalyst with the selective adsorption ability to long-chain isomeric alkanes, long-side-chain monocyclic naphthenes and long-chain monocyclic aromatics and the ability to selectively isomerize alkanes in the presence of hydrogen and under suitable reaction conditions, simplifies the production process of the high-viscosity-index lubricating oil base oil, reduces the device investment, lowers the hydrogen consumption in the process, and enriches the product types.

[0068] 3. The catalyst provided by the present application, in which the mosaic molecular sieve is composed of 5A molecular sieve and TON structure molecular sieve by the way of mutual mosaic, the 5A molecular sieve has good adsorption function and can enrich alkanes, the TON structure molecular sieve has specific pore structure and suitable acidity and is beneficial to the selective isomerization of alkanes, and the molecular sieve composition provided by the present application has the above specific functions and still maintains good adsorption performance after loading active metals. After the isomerization reaction and regeneration, the molecular sieve still maintains good stability.

[0069] 4. The production method of the lubricating oil base oil provided by the present application, in which the non-ideal components are separated out by the preliminary adsorption treatment of the raw materials, so that the isomerization and condensation reaction is only performed on the raw materials rich in ideal components such as long-chain isomeric alkanes, long-side-chain monocyclic naphthenes and long-chain monocyclic aromatics, thereby realizing the generation of high-viscosity-index lubricating oil base oil products, greatly reducing the participation of non-ideal components in the hydrogenation reaction, lowering the isomerization and condensation processing load, reducing the hydrogen consumption in the process, and improving the economic efficiency of the device. Moreover, the applicant finds in the research process that the addition of 5A molecular sieve to the currently used hydrogenation isomerization dewaxing catalyst has selective adsorption effect on the raw materials of the lubricating oil base oil in the absence of hydrogen, which can separate out the non-ideal components such as two-ring or more ring naphthenes and part of aromatics with low viscosity index in the raw materials, thereby reducing the content of low-viscosity-index components in the lubricating oil base oil products from the raw material aspect and improving the viscosity index of the lubricating oil base oil products. BRIEF DESCRIPTION OF DRAWINGS

[0070] Figure 1 The method and system for producing high-viscosity-index lubricating oil base oil provided by the present application. DETAILED DESCRIPTION

[0071] The present application will be further described in combination with the drawings and specific embodiments. The following embodiments will further illustrate the method provided by the present application, but do not limit the scope of the present application.

[0072] Unless specifically stated otherwise, the term "comprising" or variations such as "comprise" or "comprises" throughout this specification is not intended to exclude any element or component from the description, nor to impose any limitations on the scope of the present disclosure.

[0073] In this document, relational terms such as "first," "second," and the like can be used solely to distinguish one entity or action from another entity or action, without necessarily implying any actual relationship or order between such entities or actions. In this document, the terms "comprises," "comprising," "includes," "including," or the like means "including, but not limited to."

[0074] In this document, the terms "first," "second," etc. are used merely as labels, and are not intended to impose numerical or other order unless specifically stated otherwise.

[0075] In this document, all numerical values of parameters (e.g., of quantities or conditions) are to be interpreted in a "about" sense, unless expressly identified otherwise.

[0076] In the context of the present specification, unless explicitly stated otherwise, both the silicon-aluminum material and the catalyst are subjected to a calcination treatment, sometimes referred to as "calcined form", prior to measurement. Here, the conditions of the calcination treatment include a calcination temperature of 600°C in an air atmosphere for 3 hours or more.

[0077] In the context of the present specification, long-side-chain hydrocarbons refer specifically to one or more of long-side-chain isomeric alkanes, long-side-chain monocyclic naphthenes, and long-side-chain monocyclic aromatics, excluding other hydrocarbons with long-side-chains. In addition, according to the present disclosure, by long-side-chain is meant a C8-22 (preferably C10-18) straight-chain alkyl group as the side chain.

[0078] In the context of the present specification, a mechanical mixture refers to a mixture of two or more materials obtained by mechanical mixing. Here, the mechanical mixing includes simple mixing, grinding, pulping, and the like.

[0079] In the context of the present specification, the mosaic molecular sieve refers to one or more molecular sieve crystals having the surface or interior inlaid with another one or more molecular sieves, and is a composite crystal having two or more molecular sieve structural characteristics. Compared with the mechanical mixture, the combination of different molecular sieves in the mosaic structure is more compact, and a truly integrated composite structure at the molecular level is formed.

[0080] In the context of the present specification, the refractive index is represented by a Mettler refractometer R5, the long-chain hydrocarbon content is represented by an Agilent gas chromatograph 7890, the XRD pattern of the sample is represented by a D / max-2500 full-automatic rotating target X-ray diffractometer, the specific surface area, pore volume and average pore diameter of the mosaic molecular sieve and the specific surface area, pore volume and average pore diameter of the molecular sieve composition are tested and represented by an ASAP 2405 physical adsorption instrument through the N2 adsorption-desorption method, and the calcium content of the calcium-type molecular sieve is represented by X-ray fluorescence diffraction.

[0081] In the context of the present specification, the content quantitative analysis of the TON structure molecular sieve in the mosaic molecular sieve is determined by XRD.

[0082] In the context of the present specification, all percentages, parts, ratios, etc. mentioned are by weight, the pressure is the gauge pressure, and the weight or content is on a dry basis.

[0083] In the context of the present specification, any two or more embodiments of the present application can be combined arbitrarily, and the technical solutions formed thereby belong to the part of the original disclosure of the present specification and also fall within the protection scope of the present application.

[0084] As Figure 1As shown, the method for producing high viscosity index lubricating oil base oil provided by the present application specifically includes the following steps: raw material 1 enters the reactor a2 in the adsorption-isomerization reaction zone, is treated by contacting with the catalyst, and a treated stream a4 is obtained; the stream a4 enters the hydrogenation refining reaction zone 6, and is subjected to hydrogenation reaction under the action of hydrogen 22 and the hydrogenation refining catalyst; the reaction product 7 enters the first separation unit, which includes the first gas-liquid separator 8 and the first fractionating column 9; the reaction product 7 of the hydrogenation refining reaction zone is subjected to gas-liquid separation through the first gas-liquid separator 8, and a first gas phase stream 10 and a first liquid phase stream 11 are obtained; the first liquid phase stream 11 enters the first fractionating column 9, and is separated to obtain a light high-aryl special oil base oil 12 and a heavy high-aryl special oil base oil 13; when the refractive index (20℃) of the stream a4 is 0.1% to 5% higher than the refractive index (20℃) of the raw material 1, the raw material 1 stops entering the reactor a2 in the adsorption-isomerization reaction zone, and hydrogen 22 is introduced into the reactor a2 at the same time, so that isomerization and condensation reduction reaction occurs under the action of the adsorbent and hydrogen; the isomerization and condensation reduction reaction product 14 enters the second separation unit, which includes the second gas-liquid separator 15 and the second fractionating column 16; the isomerization and condensation reduction reaction product 14 enters the second gas-liquid separator 15, and is separated to obtain a second gas phase stream 17 and a second liquid phase stream 18; the second liquid phase stream 18 enters the second fractionating column 16, and is separated to obtain a high viscosity index light lubricating oil base oil 19 and a heavy lubricating oil base oil 20. When the raw material 1 stops entering the reactor a2 in the adsorption-isomerization reaction zone, the raw material 1 is switched to enter the reactor b3 in the adsorption-isomerization reaction zone at the same time, is treated by contacting with the catalyst, and a treated stream b5 is obtained; the obtained stream b5 enters the hydrogenation refining reaction zone 6, and is subjected to hydrogenation reaction under the action of hydrogen 22 and the hydrogenation refining catalyst; the reaction product 7 enters the first gas-liquid separator 8, and is subjected to gas-liquid separation to obtain a first gas phase stream 10 and a first liquid phase stream 11; the first liquid phase stream 11 enters the first fractionating column 9, and is separated to obtain a light high-aryl special oil base oil 12 and a heavy high-aryl special oil base oil 13; when the refractive index (20℃) of the stream b5 is 0.1% to 5% higher than the refractive index (20℃) of the raw material 1, the raw material 1 stops entering the reactor b3 in the adsorption-isomerization reaction zone, and hydrogen 22 is introduced into the reactor b3 at the same time, so that isomerization and condensation reduction reaction occurs under the action of the catalyst and hydrogen; the isomerization and condensation reduction reaction product 21 enters the second gas-liquid separator 15, and is separated to obtain a second gas phase stream 17 and a second liquid phase stream 18; the second liquid phase stream 18 enters the second fractionating column 16, and is separated to obtain a high viscosity index light lubricating oil base oil 19 and a heavy lubricating oil base oil 20.

[0085] The properties of the raw oil used in the method embodiments of the present application are shown in Table 1. The isomerization dewaxing catalyst and the hydrofining catalyst involved in Examples 1-2 can be selected from commercially available catalysts or prepared according to the knowledge in the art. In the method of the present application, the adsorbent is prepared as shown below and the specific physical and chemical properties of the hydrofining catalyst are shown in Table 2, in which the hydrocracking tail oil 1 uses the hydrofining catalyst 1 and the hydrocracking tail oil 2 uses the hydrofining catalyst 2.

[0086] Table 1 Properties of raw oil

[0087]

[0088] Example 1

[0089] A crystallization kettle was charged with 128 g of sodium hydroxide, 208 g of tetraethyl orthosilicate, 82 g of sodium metaaluminate, 14.88 g of dimethyloctadecyl [3- (trimethoxysilyl) propyl] ammonium chloride (TPOAC), and 1800 g of water, and the mixture was stirred until uniform. Then, 300 g of ZSM-22 molecular sieve was added and stirred, and the reaction kettle was sealed, heated to 110°C, and subjected to hydrothermal crystallization for 6 h. After the crystallization was completed, the product obtained by the crystallization was washed, then dried at 110°C for 6 h, and then calcined at 500°C for 5 h, thereby obtaining a first eutectic molecular sieve Z1. Then, the molecular sieve Z1 was subjected to ion exchange in a 1.8 mol / L CaCl2 solution at 90°C for 4 h, suction filtered and washed, then dried at 100°C for 4 h, and then calcined at 400°C for 3 h, thereby obtaining a second eutectic molecular sieve GZ-1, which has a specific surface area of 452 m2 / g, a pore volume of 0.25 mL / g, and a TON type molecular sieve mass fraction of 85%.

[0090] The eutectic molecular sieve GZ-1 prepared above was mixed with 90 g of pseudoboehmite (dry basis) and 20 g of sesbania powder to obtain a mixture, and 9 ml of concentrated nitric acid (65% by mass) and an appropriate amount of water were added to the mixture and kneaded thoroughly. Then, the mixture was extruded into strips. The extruded carrier was dried at 100°C for 4 h and calcined at 550°C for 4 h to obtain a carrier ES-1. Then, the carrier ES-1 was impregnated with a noble metal Pt by a saturation impregnation method, and the Pt loading amount was 0.50 wt% of the carrier. After drying at 100°C for 6 h and calcining at 500°C for 3 h, a catalyst numbered E-1 was obtained.

[0091] Example 2

[0092] A mixture of 64 g of sodium hydroxide, 208 g of tetraethyl orthosilicate, 98.4 g of sodium metaaluminate, 24.8 g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (TPOAC) and 2700 g of water was uniformly mixed and loaded into a crystallization kettle, 240 g of ZSM-22 molecular sieve was added and stirred, then the reaction kettle was sealed, heated to 100°C and hydrothermally crystallized for 7 h. After crystallization, the crystallized product was washed, then dried at 100°C for 6 h, and then calcined at 450°C for 8 h, thereby obtaining a first eutectic molecular sieve Z2. Then the molecular sieve Z2 was ion exchanged in a 1.5 mol / L CaCl2 solution at 80°C for 4 h, suction filtered and washed, then dried at 100°C for 5 h, and then calcined at 350°C for 6 h, thereby obtaining a second eutectic 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 type molecular sieve mass fraction of 82%.

[0093] The catalyst E-2 was prepared according to the process of Example 1, except that the eutectic molecular sieve used was GZ-2 and the Pt loading was 0.48 wt% of the support, thereby obtaining a catalyst numbered E-2.

[0094] Example 3

[0095] Example 3 used the raw materials 1 listed in Table 1, wherein the adsorption-isomerization reaction zone used the catalyst E-1 and the hydrofining reaction unit used the FMTA-2 catalyst, and the process shown in the following flow chart was adopted to obtain the results shown in Table 2. Figure 1

[0096] Example 4

[0097] Example 4 used the raw materials 2 listed in Table 1, wherein the adsorption-isomerization reaction zone used the catalyst E-2 and the hydrofining reaction unit used the FMTA-2 catalyst, and the process shown in the following flow chart was adopted to obtain the results shown in Table 2. Figure 1

[0098] Example 5

[0099] Example 5 used the raw materials 1 listed in Table 1, wherein the adsorption-isomerization reaction zone used the catalyst E-1 and the hydrofining reaction unit used the FMDA-1 catalyst, and the process shown in the following flow chart was adopted to obtain the results shown in Table 2. Figure 1

[0100] Comparative Example 1

[0101] ​​​ZSM-22 molecular sieve (Si / Al ratio 90) 134 g, 5A molecular sieve 200 g and 150 g (as Al2O3) aluminum hydroxide (SB produced by Condean Company, Germany), 30 g of sesbania powder were mixed uniformly, then water and concentrated nitric acid (mass concentration 66.5 wt%) were added, and they were kneaded thoroughly to become a paste-like plastic material, which was extruded into cylindrical strips with a diameter of 1.5 mm on an extruder, the cylindrical strips were dried at 100 ℃ for 12 h, and then calcined at 550 ℃ for 4 h in an air atmosphere to obtain the catalyst carrier of the present application.

[0102] 300 g of the carrier was loaded with noble metal Pt by saturated impregnation, then dried at 110 ℃ for 7 h, and calcined at 500 ℃ for 3 h in an air atmosphere to obtain the catalyst of the present application containing 0.49 wt% Pt, numbered C-D1.

[0103] Comparative Example 2

[0104] 40 g of sodium hydroxide, 208 g of tetraethyl orthosilicate, 285.6 g of aluminum isopropoxide, 5.75 g of polyoxyethylene tri-block copolymer (P123) and 1440 g of water were mixed uniformly and loaded into a crystallization kettle, then 60 g of Hβ molecular sieve was added and stirred, the reaction kettle was sealed, heated to 90 ℃ and hydrothermally crystallized for 10 h. After the crystallization was completed, the product obtained by crystallization was washed, then dried at 110 ℃ for 6 h, and then placed in a muffle furnace at 450 ℃ for 8 h to obtain the first inlaid molecular sieve. Then the molecular sieve was ion exchanged in a 1.8 mol / L CaCl2 solution at 90 ℃ for 4 h, suction filtered and washed, then dried at 100 ℃ for 4 h, and then placed in a muffle furnace at 400 ℃ for 3 h to obtain the second inlaid molecular sieve D.

[0105] The preparation process of the comparative catalyst C-D2 of the present application is the same as that of Example 1, except that the inlaid molecular sieve D is used, and the Pt loading is 0.30 wt% of the carrier. The prepared catalyst is numbered C-D2.

[0106] Comparative Example 3

[0107] Comparative Example 3 uses raw material 1 listed in Table 1, the adsorption-isomerization reaction zone uses catalyst C-D1, the hydrogenation refining reaction unit uses FMTA-2 catalyst, and the process shown in Table 1 is used, and the results are shown in Table 3. Figure 1

[0108] Comparative Example 4

[0109] Comparative Example 4 uses raw material 2 listed in Table 1, the adsorption-isomerization reaction zone uses catalyst C-D2, the hydrogenation refining reaction unit uses FMTA-2 catalyst, and the process shown in Table 1 is used, and the results are shown in Table 3. Figure 1

[0110] ​​Table 2 Process conditions and results for Examples 3-5

[0111]

[0112]

[0113] Table 3 Process conditions and results for Comparative Examples 1-2

[0114]

[0115]

Claims

1. A method for producing high viscosity index lubricating oil base oil, comprising the following steps: (1) The raw material enters reactor a in the adsorption-isomerization reaction zone and reacts in the presence of a catalyst to obtain feed stream a after the reaction; the raw material is selected from one or more of hydrocracking tail oil, hydrocracking wax oil, hydrocracking bright oil, hydrocracking wax paste, and hydrocracking wax off oil. (2) Under contact conditions, the feed stream a obtained in step (1) enters the hydrorefining reaction zone and undergoes a hydrorefining reaction in the presence of hydrogen and hydrorefining catalyst. The hydrorefining effluent is separated to obtain light high aromatic specialty oil base oil and heavy high aromatic specialty oil base oil. (3) When the refractive index of the material flow a at 20℃ is 0.1% to 5% higher than that of the raw material at 20℃, the raw material is stopped from entering reactor a, and hydrogen is introduced into reactor a. Under the action of catalyst and hydrogen, isomerization dewaxing reaction occurs. The isomerization dewaxing reaction products are separated to obtain light lubricating oil base oil with high viscosity index and heavy lubricating oil base oil with high viscosity index. (4) When the raw material is stopped from entering reactor a, the raw material is switched to reactor b in the adsorption-isomerization reaction zone, and the reaction is carried out in the presence of catalyst. After the reaction, the material stream b is obtained. Reactor a and reactor b are connected in parallel and used interchangeably. (5) Under contact conditions, the feed stream b obtained in step (4) enters the hydrorefining reaction zone and undergoes a hydrorefining reaction under the action of hydrogen and hydrorefining catalyst. The hydrorefining effluent is separated to obtain light high aromatic specialty oil base oil and heavy high aromatic specialty oil base oil. (6) When the refractive index of the material flow b at 20℃ is 0.1% to 5% higher than that of the raw material at 20℃, the raw material is stopped from entering reactor b, and hydrogen is introduced into reactor b. Under the action of catalyst and hydrogen, isomerization dewaxing reaction occurs. The isomerization dewaxing reaction products are separated to obtain light lubricating oil base oil with high viscosity index and heavy lubricating oil base oil with high viscosity index. (7) Reintroduce the raw material into reactor a in the adsorption-isomerization reaction zone and repeat steps (1) to (6). The catalyst 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. The operating conditions for the adsorption reaction in the adsorption-isomerization reaction zone in steps (1) and (4) are: temperature 40℃~250℃, pressure 0.01MPa~0.5MPa, and volume hourly space velocity 0.05h. -1 ~5.0h -1 .

2. The method for producing high viscosity index lubricating oil base oil according to 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 50%.

3. The method for producing high viscosity index lubricating oil base oil according to 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%.

4. The method for producing high viscosity index lubricating oil base oil according to 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%.

5. The method for producing high viscosity index lubricating oil base oil according to 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%.

6. The method for producing high viscosity index lubricating oil base oil according to 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.

7. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: The weight ratio of the 5A type molecular sieve to the TON structure molecular sieve is 1:80-3:

1.

8. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: The weight ratio of the 5A type molecular sieve to the TON structure molecular sieve is 1:30-1:

1.

9. The method for producing high viscosity index lubricating oil base oil according to 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%.

10. The method for producing high viscosity index lubricating oil base oil according to 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%.

11. The method for producing high viscosity index lubricating oil base oil according to 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.

12. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: The inorganic refractory oxide is selected from alumina.

13. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: The active metal component is selected from at least one of Pt and Pd.

14. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: The active metal component is Pt.

15. The method for producing high viscosity index lubricating oil base oil according to 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.

16. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: TON structural molecules were screened from ZSM-22.

17. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: 5A type molecular sieve is derived from 5A molecular sieve.

18. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: The preparation method of the embedded molecular sieve includes the following steps: (a) By contacting a silicon source, an aluminum source, and an alkali source in the presence of a template agent, a TON-structured molecular sieve, and water, a gel mixture is obtained. (b) The gel mixture is subjected to hydrothermal crystallization, followed by washing, drying, and calcination to obtain a first embedded molecular sieve.

19. The method for producing high viscosity index lubricating oil base oil according to claim 18, characterized in that: The preparation method further includes the following steps: (c) The first embedded molecular sieve is subjected to calcium exchange, and then washed, dried and calcined to obtain the second embedded molecular sieve.

20. The method for producing high viscosity index lubricating oil base oil according to claim 18, characterized in that: In step (a), the silicon source is selected from at least one of water glass, sodium silicate, methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, and butyl orthosilicate.

21. The method for producing high viscosity index lubricating oil base oil according to claim 18, characterized in that: In step (a), the alkali source is selected from at least one of alkali metal hydroxides.

22. The method for producing high viscosity index lubricating oil base oil according to claim 18, characterized in that: In step (a), the alkali source is selected from sodium hydroxide.

23. The method for producing high viscosity index lubricating oil base oil according to claim 18, characterized in that: In step (a), the aluminum source is selected from at least one of sodium aluminate, aluminum isopropoxide, aluminum sulfate, aluminum hydroxide, aluminum oxide, and boehmite.

24. The method for producing high viscosity index lubricating oil base oil according to claim 18, characterized in that: In step (a), the template agent is selected from at least one of polyethylene oxide triblock copolymer and dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride.

25. The method for producing high viscosity index lubricating oil base oil according to claim 18, characterized in that: In step (a), the contact operating conditions include: a temperature of 15°C-30°C and a time of 1h-4h in the presence of stirring.

26. The method for producing high viscosity index lubricating oil base oil according to claim 19, characterized in that: In step (c), the operating conditions for calcium exchange include: an exchange temperature of 60℃-100℃, an exchange time of 1h-12h, and a calcium ion concentration of 0.1mol / L-2.5mol / L in the calcium exchange solution.

27. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: The operating conditions for the adsorption reaction in the adsorption-isomerization reaction zone in steps (1) and (4) are: temperature 60℃~200℃, pressure 0.08~0.1MPa, and volume hourly space velocity 0.1h. -1 ~2.0h -1 .

28. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: The operating conditions of the hydrorefining reaction zone are as follows: reaction temperature 200–400℃, hydrogen partial pressure 1.0–20.0 MPa, and volume hourly space velocity 0.1–10.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 100:1 to 1500:

1.

29. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: The operating conditions of the hydrorefining reaction zone are as follows: reaction temperature 220–380℃, hydrogen partial pressure 4.5–15.0 MPa, and volume hourly space velocity 0.5–1.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 200:1 to 800:

1.

30. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: The operating conditions for the isomerization-decondensation reaction in the adsorption-isomerization reaction zone in steps (3) and (6) are as follows: reaction temperature 200–420 °C, hydrogen partial pressure 1.0–20.0 MPa, and volume hourly space velocity 0.1 h⁻¹. -1 ~10.0h -1 The hydrogen-to-oil volume ratio is 100:1 to 1500:

1.

31. The method for producing high viscosity index lubricating oil base oil according to claim 1, characterized in that: The operating conditions for the isomerization-decondensation reaction in the adsorption-isomerization reaction zone in steps (3) and (6) are as follows: reaction temperature 270–380 °C, hydrogen partial pressure 3.0–15.0 MPa, and volume hourly space velocity 0.5 h⁻¹. -1 ~3.0h -1 The hydrogen-to-oil volume ratio is 100:1 to 400:

1.

32. A system for implementing the method for producing high viscosity index lubricating oil base oil according to any one of claims 1-31, comprising: The adsorption-isomerization reaction zone includes reactors a and b connected in parallel and used interchangeably. The raw material first enters reactor a in the adsorption-isomerization reaction zone and is processed by contacting the adsorbent. After processing, the material stream a is obtained. In the hydrorefining reaction zone, feed stream a enters the hydrorefining reaction zone and undergoes a hydrogenation reaction under the action of hydrogen and a hydrorefining catalyst. The first separation unit includes a first gas-liquid separator and a first fractionation tower, which is used to receive the reaction products from the hydrorefining reaction zone. After gas-liquid separation, a first gas phase feed stream and a first liquid phase feed stream are obtained. The first liquid phase feed stream enters the first fractionation tower for separation to obtain light high aromatic specialty oil base oil and heavy high aromatic specialty oil base oil. When the refractive index of feed stream a at 20℃ is 0.1% to 5% higher than that of the raw material at 20℃, the raw material is stopped from entering reactor a in the adsorption-isomerization reaction zone, and hydrogen is introduced into reactor a at the same time. Under the action of adsorbent and hydrogen, isomerization decondensation reaction occurs. The second separation unit includes a second gas-liquid separator and a second fractionation tower, which is used to receive the isomerization decondensation reaction products from reactor a. After gas-liquid separation, a second gas phase stream and a second liquid phase stream are obtained. The second liquid phase stream enters the second fractionation tower for separation to obtain light lubricating oil base oil and heavy lubricating oil base oil. When the feed material stops entering reactor a in the adsorption-isomerization reaction zone, the feed material is simultaneously switched to reactor b in the adsorption-isomerization reaction zone, and reactor a and reactor b are switched.

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