A high viscosity white oil and a method for making the same

Abstract

This invention provides a method for preparing high-viscosity white oil, comprising the following steps: mixing distilled dewaxed oil from a reduced-density 4mm distillation line, dewaxed oil from a reduced-density 4mm distillation line, and hydrocracking tail oil, and performing a hydrocracking reaction to obtain a first oil product; subjecting the first oil product to a first atmospheric distillation to obtain a first bottom fraction; subjecting the first bottom fraction to an isomerization dewaxing reaction and a hydrorefining reaction to obtain a second oil product; subjecting the second oil product to a second atmospheric distillation to obtain a second bottom fraction; subjecting the second bottom fraction to isomerization dewaxing and vacuum distillation to obtain a third top fraction, a third side fraction, and No. 100 industrial white oil (II), respectively. This invention specifically adjusts the depth of hydrocracking, isomerization, and supplementary refining reactions to overcome changes in sulfur content, aromatics, and polycyclic aromatic hydrocarbons caused by variations in the properties of the raw materials, thereby improving the performance of the obtained white oil and pioneering an innovative production method for high-viscosity white oil.

Description

Technical Field

[0001] This invention relates to the technical field of lubricant production, and in particular to a high-viscosity white oil and its preparation method. Background Technology

[0002] Lubricating oil is a liquid lubricant used in various types of machinery to reduce friction and protect the machinery and machined parts. Its main functions include lubrication, cooling, rust prevention, cleaning, sealing, and buffering. Lubricating oil accounts for 85% of all lubricating materials and comes in a wide variety of types and grades. Lubricating oil generally consists of two parts: base oil and additives. Base oil is the main component of lubricating oil, determining its basic properties, while additives compensate for and improve the shortcomings of the base oil, imparting certain new properties, and are an important component of lubricating oil.

[0003] Base oils are mainly divided into three categories: mineral oil, synthetic oil, and vegetable oil. Mineral oils are the most widely used because they are colorless, odorless, tasteless, chemically inert, and have excellent light and heat stability.

[0004] Mineral oil is generally derived from the lubricating oil components of crude oil. It is a special mineral oil product obtained by deep refining to remove impurities such as aromatics, sulfur and nitrogen. Its components are generally cycloalkanes and alkanes with a relative molecular mass of 300 to 400, and it belongs to the lubricating oil fraction.

[0005] Currently, the lubricating oils used in my country are mainly based on the SH / T 0006-2017 standard, which classifies them into two types: Industrial White Oil (I) and Industrial White Oil (II). Each type of Industrial White Oil includes 12 grades: No. 5, No. 7, No. 10, No. 15, No. 22, No. 32, No. 46, No. 68, No. 100, No. 150, No. 220, and No. 320. These oils are mainly used in the processing of chemical fibers and aluminum materials, as well as in rubber plasticizing. They are also suitable for use as lubricating oils in textile machinery, precision instruments, and compressor sealing oils.

[0006] Industrial white oil (II) has superior performance compared to industrial white oil (I), and the higher the viscosity of industrial white oil, the higher its price and profit. High-viscosity white oil has a wide range of applications, including high-speed equipment and high-pressure applications, thus its demand is increasing.

[0007] Currently, the main production processes for industrial white oil are the "old three-step" process and the full hydrogenation process. The "old three-step" process involves refining with ketones, benzene, furfural, and clay, primarily producing lower viscosity grades of industrial white oil (I). The full hydrogenation process, however, can produce higher viscosity grades of industrial white oil (II). The full hydrogenation process generally produces industrial white oil (II) grades below 68, and the high-viscosity white oils required by some high-end resin processing and pharmaceutical industries still need to be imported. Summary of the Invention

[0008] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a high-viscosity white oil and its preparation method, so as to solve the problem of insufficient high-viscosity industrial white oil produced in the prior art.

[0009] To achieve the above and other related objectives, the present invention is obtained through the following technical solution.

[0010] A first aspect of the present invention is to provide a method for preparing high-viscosity white oil, the method comprising the following steps:

[0011] (1) Mix the distilled dewaxed oil and the waxed oil to obtain mixture one. Mix mixture one and hydrocracking tail oil to obtain mixture two. Perform hydrocracking reaction on mixture two to obtain the first oil product.

[0012] (2) The first oil product obtained in step (1) is subjected to atmospheric distillation to obtain the first top component, the first side stream component and the first bottom component respectively;

[0013] (3) The first bottom component obtained in step (2) is mixed with hydrocracking tail oil, and then isomerization dewaxing reaction and hydrorefining reaction are carried out to obtain the second oil product; the volume ratio of the first bottom component to the hydrocracking tail oil is 1:0-0.8.

[0014] (4) The second oil obtained in step (3) is subjected to a second atmospheric pressure fractionation to obtain the second top component, the second side stream component and the second bottom component respectively;

[0015] (5) The second bottom component obtained in step (4) is subjected to isomerization dewaxing and vacuum fractionation to obtain the third top component, the third side stream component and the third bottom component, respectively. The third bottom component is high viscosity white oil.

[0016] A second aspect of the present invention is to provide a high-viscosity white oil prepared by the method described above.

[0017] As described above, the high-viscosity white oil and its preparation method and system of the present invention have the following beneficial effects:

[0018] (1) The present invention selects high viscosity raw material components, namely reduced 4 line wax oil and reduced 4 line dewaxed oil, and at the same time, appropriate hydrocracking tail oil is added to reduce the unfavorable characteristics of high sulfur and high nitrogen of reduced 4 line raw material, reduce the sulfur content and aromatic content of white oil, and the white oil obtained therefrom has more stable viscosity, flash point and pour point.

[0019] (2) This invention specifically adjusts the depth of hydrocracking reaction, isomerization reaction and supplementary refining reaction to overcome the changes in sulfur content, aromatic hydrocarbons and polycyclic aromatic hydrocarbons caused by changes in the properties of raw materials, improve the performance of the white oil produced, and explore and innovate the production method of high viscosity white oil, which not only improves the overall economic benefits of the equipment, but also provides reliable domestic high viscosity industrial white oil for the downstream market.

[0020] (3) The present invention is based on a vacuum fractionation process of multiple side-cut components, which makes it easier to adjust the index characteristics of the reduced-viscosity product more flexibly and accurately; the high-viscosity white oil product obtained is of stable and excellent quality and can be sold to the market, which not only improves economic benefits, but also enhances the differentiated competitiveness of domestic high-end oil products.

[0021] (4) The high viscosity white oil obtained by this invention helps to increase economic benefits. The original product was sold as a Group II base oil or a blending component of No. 68 and below industrial white oil, with a selling price of about RMB 6,200 per ton (excluding tax). When the product is No. 100 industrial white oil (II), the average selling price during the same period is RMB 8,230 per ton (excluding tax), which increases the marginal profit by RMB 2,030 per ton compared with the original product structure. Attached Figure Description

[0022] Figure 1 The diagram shows a process flow chart for a high-viscosity white oil preparation system.

[0023] Figure label:

[0024] 1. Hydrocracking reactor; 2. Hydrocracking atmospheric fractionation tower; 3. Isomerization dewaxing reactor; 4. Post-hydrocracking refining reactor; 5. Isomerization dewaxing atmospheric fractionation tower; 6. Isomerization dewaxing vacuum fractionation tower; 7. Heavy stripping tower. Detailed Implementation

[0025] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to embodiments. Those skilled in the art can easily understand other advantages and effects of this invention from the content disclosed in this specification.

[0026] This application includes an extended section and a description of its effects, including but not limited to subsequent data analysis and mechanism explanations.

[0027] The first aspect of this invention is to provide a method for preparing high-viscosity white oil, the method comprising the following steps:

[0028] (1) Mix the distilled dewaxed oil and the waxed oil to obtain mixture one. Mix mixture one and hydrocracking tail oil to obtain mixture two. Perform hydrocracking reaction on mixture two to obtain the first oil product.

[0029] (2) The first oil product obtained in step (1) is subjected to atmospheric pressure fractionation to obtain the first top component, the first side stream component and the first bottom component respectively;

[0030] (3) The first bottom component obtained in step (2) is mixed with hydrocracking tail oil, and then isomerization dewaxing reaction and hydrorefining reaction are carried out to obtain the second oil product; the volume ratio of the first bottom component to the hydrocracking tail oil is 1:0-0.8.

[0031] (4) The second oil obtained in step (3) is subjected to a second atmospheric pressure fractionation to obtain the second top component, the second side stream component and the second bottom component;

[0032] (5) The second bottom component obtained in step (4) is subjected to isomerization dewaxing and vacuum fractionation to obtain the third top component, the third side stream component and the third bottom component, respectively. The third bottom component is high viscosity white oil.

[0033] The third bottom component of the present invention is a bottom-reducing lubricating oil, which is also a high-viscosity white oil.

[0034] This invention improves the viscosity of the white oil by screening high-viscosity raw material components, specifically dewaxing oil and wax oil from the fourth-line dewaxing line. However, the high sulfur and nitrogen content of the dewaxing oil and wax oil can easily lead to deterioration and color changes in the white oil, reducing its quality. To mitigate the impact of high sulfur and nitrogen on the white oil's performance, appropriate hydrocracking tail oil is blended in. This process differs from conventional desulfurization and denitrification processes, making it easier to reduce the influence of the high sulfur and nitrogen content of the dewaxing oil and wax oil on the white oil's performance. Furthermore, targeted hydrocracking, isomerization, and supplementary refining reactions are performed to adjust the depth of the reaction. Combined with vacuum fractionation of multiple side-stream components, the white oil produced by this method has lower sulfur and aromatic content, and more stable viscosity, flash point, and pour point.

[0035] During the experiment, the inventors found that simply combining reduced-grade wax oil and added tail oil could not achieve continuous and stable production of No. 100 industrial white oil.

[0036] This invention was used in a lubricating oil hydrotreating unit of an oil refinery to conduct pilot production of No. 100 industrial white oil, using a mixture of reduced-pressure four-layer wax oil and cracked tailings oil as raw material. The ratio of reduced-pressure four-layer wax oil to cracked tailings oil was 1:0.3-1.5. The properties of the raw materials, process flow, and parameter ranges are basically the same as described below.

[0037] In the pilot production using the mixture as raw material, through extreme operations in units such as reaction and fractionation, the nitrogen content of the material entering the isomerization and dewaxing process exceeded the standard, resulting in a reduced viscosity (40℃) of the lubricating oil product between 88.5 and 105 mm. 2 Fluctuations between / s cannot perfectly match 90.0~110mm2 The quality requirement is 8t / s; and a production rate below 8t / h is prone to problems such as equipment coking, failing to meet industrial safety production requirements. Therefore, it was concluded that using only reduced-grade wax oil + cracked tail oil as raw material is not suitable as a raw material for No. 100 industrial white oil. Starting from improving viscosity, the introduction of reduced-grade dewaxing oil was successful.

[0038] In some embodiments of the present invention, the dewaxing oil of the reduced-temperature dewaxing line is the oil produced by the ketone-benzene dewaxing unit of the lubricating oil product line in a general petroleum processing enterprise after cooling dewaxing, and its source is relatively wide.

[0039] In some embodiments of the present invention, the reduced-pressure fourth-line wax oil is the fourth-line product of the vacuum distillation tower in the first process of atmospheric and vacuum distillation in general petroleum processing enterprises, i.e., it is called distilled reduced-pressure fourth-line wax oil. The sulfur content of the distilled reduced-pressure fourth-line wax oil is ≤0.5%. The distilled reduced-pressure fourth-line wax oil can be obtained from general crude oil after atmospheric and vacuum distillation, and its source is relatively wide.

[0040] In some embodiments of the present invention, the hydrocracking tail oil is the end-product oil of a hydrocracking unit in a general petroleum processing enterprise. The sulfur content of the hydrocracking tail oil is ≤0.5%.

[0041] In some embodiments of the present invention, the mass ratio of reduced 4-line dewaxing oil to reduced 4-line wax oil in step (1) is 2-4:1. Specifically, it can be 2-3:1 or 3-4:1; typically, but not limitingly, it is 2:1, 3:1, or 4:1.

[0042] In some embodiments of the present invention, the mass ratio of mixture one and hydrocracking tail oil in step (1) is 0.9-1.5:1. Specifically, it can be 0.9-1.1:1, 1.1-1.3:1, or 1.3-1.5:1; typically, but not limitingly, it is, for example, 0.9:1, 1.1:1, 1.3:1, or 1.5:1.

[0043] In some embodiments of the present invention, the nitrogen content of mixture one in step (1) is <1500 mg / kg; and the nitrogen content of mixture two is <700 mg / kg.

[0044] In some embodiments of the present invention, the kinematic viscosity of mixture two in step (1) is 5.9-7.5 mm at 100°C. 2 / s, specifically, can be 5.9-6.5mm. 2 / s, 6.5-7mm 2 / s, 7-7.5mm 2 / s; typical but not limiting, for example, 5.9mm 2 / s, 6.5mm 2 / s, 7mm 2 / s, 7.5mm 2 / s.

[0045] In some embodiments of the present invention, the distillation range of mixture two in step (1) is 330-550°C, and the distillation range width is ≥160°C; specifically, it can be 330-400°C or 400-550°C, typically but not limitingly, for example, 330°C, 400°C, or 550°C. The initial boiling point of mixture one should not be lower than 330°C, and the final boiling point should not exceed 550°C. The distillation range width is the temperature difference between the final boiling point and the initial boiling point of the actual raw material.

[0046] In some embodiments of the present invention, the wax content of mixture two in step (1) is 30-40 wt%, specifically, it can be 30-35 wt%, 35-40 wt%, typically but not limitingly, for example 30 wt%, 35%, 40%.

[0047] In some embodiments of the present invention, the moisture content of mixture two in step (1) is ≤0.03wt%.

[0048] In some embodiments of the present invention, the pour point of mixture two in step (1) is 36-50°C; specifically, it can be 36-40°C, 40-45°C, or 45-50°C; typically but not limitingly, it is, for example, 36°C, 40°C, 45°C, or 50°C.

[0049] In some embodiments of the present invention, in step (1), mixture two is filtered to remove solid particles and impurities.

[0050] In some specific embodiments of the present invention, the particle size of the solid particles and impurities is greater than 25 μm.

[0051] In some embodiments of the present invention, the concentration of hydrogen sulfide in the circulating hydrogen introduced into the hydrocracking reaction in step (1) is ≤1500ppm.

[0052] In some embodiments of the present invention, the temperature of the hydrocracking reaction in step (1) is 369-378°C; specifically, it can be 369-374°C, 374°C-378°C, typically but not limitingly, for example, 369°C, 374°C, 378°C.

[0053] In some embodiments of the present invention, the pressure of the hydrocracking reaction in step (1) is 14-16 MPa; specifically, it can be 14-14.5 MPa, 14.5-15.5 MPa, 15.5-16 MPa, typically but not limitingly, for example, 14 MPa, 14.5 MPa, 15.5 MPa, 16 MPa.

[0054] In some embodiments of the present invention, the hydrocracking reaction in step (1) is carried out in a hydrocracking reactor.

[0055] This invention utilizes hydrocracking under high temperature and high pressure conditions to achieve desulfurization, denitrification, saturation of olefins and aromatics, and hydrocracking. All of these reactions are exothermic. In the desulfurization and denitrification reactions, sulfur and nitrogen are released from sulfur- or nitrogen-containing hydrocarbon rings through aromatic ring saturation and cracking, generating H₂S and NH₃. The hydrocracking reaction largely preserves the hydrocarbon rings. Unsaturated bonds in olefins and aromatics are significantly saturated. Aromatic rings undergo hydrogenation saturation to form cycloalkanes, which then break open, thereby reducing the sulfur, nitrogen, and aromatic content in the resulting white oil.

[0056] In some embodiments of the present invention, the first atmospheric distillation in step (2) is carried out in a hydrocracking distillation tower.

[0057] In some embodiments of the present invention, the top temperature of the first atmospheric distillation in step (2) is 112-122°C, specifically, it can be 112-115°C, 115-119°C, or 119-122°C, typically but not limitingly, for example, 112°C, 115°C, 119°C, or 122°C.

[0058] In some embodiments of the present invention, the feed temperature for the first atmospheric distillation in step (2) is 306-310°C; specifically, it can be 306-307°C, 307-308°C, 308-309°C, or 309°C-310°C, typically but not limitingly, for example, 306°C, 307°C, 308°C, 309°C, or 310°C.

[0059] In some embodiments of the present invention, the bottom temperature of the first atmospheric distillation in step (2) is 295-302°C; specifically, it can be 295-297°C, 297-299°C, or 299-302°C; typically, but not limitingly, it is, for example, 295°C, 297°C, 299°C, or 302°C.

[0060] In some embodiments of the present invention, the first atmospheric distillation side stream extraction temperature in step (2) is 168-182°C; specifically, it can be 168-170°C, 170-178°C, or 178-182°C; typically, but not limitingly, it is, for example, 168°C, 170°C, 178°C, or 182°C.

[0061] In some embodiments of the present invention, the nitrogen content of the first bottom component in step (2) is <2.2 mg / kg. Here, the nitrogen content in the first bottom component refers to the maximum permissible amount of nitrogen in subsequent feeds; in actual production, the lower the better.

[0062] In some embodiments of the present invention, the sulfur content of the first bottom component in step (2) is <50 mg / kg. Here, the sulfur content in the first bottom component refers to the maximum permissible amount of sulfur in subsequent feed, and in actual production, the lower the better.

[0063] In some embodiments of the present invention, the first bottom component in step (2) is hydrocracked naphtha. The hydrocracked naphtha is a light component oil obtained from the top of the first atmospheric fractionation tower after hydrocracking, typically composed mainly of C5 and C6 components. After being obtained from the top of the hydrocracked atmospheric fractionation tower, a portion of the hydrocracked naphtha is cooled and sent out of the hydrocracked atmospheric fractionation tower as a conventional naphtha product, while the other portion is returned as reflux to the top of the hydrocracked atmospheric fractionation tower to control the tower top temperature.

[0064] In some embodiments of the present invention, the first sidestream component in step (2) is hydrocracking kerosene. The hydrocracking kerosene is a kerosene component extracted from the sidestream of the hydrocracking atmospheric distillation tower after hydrocracking reaction, and generally consists of C11 to C19 compounds. In this preparation method, the aforementioned hydrocracking kerosene can be extracted from the hydrocracking atmospheric distillation tower, and the hydrocracking kerosene exits the tower as a kerosene product.

[0065] In some embodiments of the present invention, the first top component is obtained at the top of an atmospheric distillation column, the first side stream component is obtained at the side stream of an atmospheric distillation column, and the first bottom component is obtained at the bottom of an atmospheric distillation column.

[0066] In some embodiments of the present invention, the isomerization dewaxing reaction in step (3) is carried out in an isomerization dewaxing reactor.

[0067] In some embodiments of the present invention, the temperature of the isomerization dewaxing reaction in step (3) is 334-340°C; specifically, it can be 334-335°C, 335-337°C, 337-338°C, or 338-340°C; typically, but not limitingly, it is, for example, 334°C, 335°C, 337°C, 338°C, or 340°C.

[0068] In some embodiments of the present invention, the 13.5-14.5 MPa in step (3) can specifically be 13.5-13.8 MPa, 13.8-14.2 MPa, or 14.2-14.5 MPa; typically, but not limitingly, it can be, for example, 13.5 MPa, 13.8 MPa, 14.2 MPa, or 14.5 MPa.

[0069] In some embodiments of the present invention, the isomerization dewaxing reaction in step (3) uses a conventional catalyst.

[0070] In some embodiments of the present invention, the volume hourly space velocity (VHSV) of the isomerization dewaxing reaction in step (3) is 0.5-1.5 / h.

[0071] In some embodiments of the present invention, the hydrogen-to-oil ratio of the isomerization dewaxing reaction in step (3) is 500-2000 v / v.

[0072] The isomerization dewaxing reaction of the present invention selects long-chain alkyl hydrocarbons and isomerizes them into isoalkanes to lower the pour point of the target product while retaining the viscosity index of the original alkane.

[0073] In some embodiments of the present invention, the post-hydrogenation refining reaction in step (3) is carried out in a post-hydrogenation refining reactor.

[0074] In some embodiments of the present invention, the reaction temperature of the hydrogenation purification reaction in step (3) is ≤250℃; specifically, it can be 236-239℃.

[0075] In some embodiments of the present invention, the reaction pressure of the hydrogenation purification reaction in step (3) is 13.5-14.5 MPa; specifically, it can be 13.5-13.8 MPa, 13.8-14.2 MPa, or 14.2-14.5 MPa; typically, but not limitingly, it is, for example, 13.5 MPa, 13.8 MPa, 14.2 MPa, or 14.5 MPa.

[0076] In some embodiments of the present invention, the volume hourly space velocity (VHSV) of the hydrorefining in step (3) is 0.6-2 / h.

[0077] In some embodiments of the present invention, the hydrogen-to-oil volume ratio of the hydrorefining reaction in step (3) is 400-1000:1.

[0078] In some embodiments of the present invention, the catalyst used in the hydrorefining reaction in step (3) is a conventional catalyst.

[0079] In some embodiments of the present invention, the second atmospheric distillation in step (4) is carried out in an isomer dewaxing atmospheric distillation column;

[0080] In some embodiments of the present invention, the top temperature of the second atmospheric distillation in step (4) is 114-126°C; specifically, it can be 114-116°C, 116-120°C, or 120-126°C; typically, but not limitingly, it is, for example, 114°C, 116°C, 120°C, or 126°C.

[0081] In some embodiments of the present invention, the feed temperature for the second atmospheric distillation in step (4) is 307-312°C; specifically, it can be 307-308°C, 308-311°C, or 311-312°C; typically, but not limitingly, it is, for example, 307°C, 308°C, 311°C, or 312°C.

[0082] In some embodiments of the present invention, the extraction temperature of the second atmospheric distillation side stream in step (4) is ≥158°C; specifically, it can be 168-205°C.

[0083] In some embodiments of the present invention, the bottom temperature of the second atmospheric distillation in step (4) is 298-305°C; specifically, it can be 298-300°C, 300-302°C, or 302-305°C; typically, but not limitingly, it is, for example, 298°C, 300°C, 302°C, or 305°C.

[0084] In some embodiments of the present invention, the second top component in step (4) is isomerized dewaxed naphtha, generally C5 and C6. After being drawn from the top of the isomerized dewaxed atmospheric fractionation column, the second top component is split into two streams: one stream is sent out of the isomerized dewaxed atmospheric fractionation column as a conventional naphtha product, and the other stream is returned to the top of the isomerized dewaxed atmospheric fractionation column as reflux to control the top temperature.

[0085] In some embodiments of the present invention, the second side stream component in step (4) is isomerized dewaxed kerosene. The isomerized dewaxed kerosene, as a conventional kerosene component, is generally composed of C11 to C19. In this preparation method, the second side stream component can be extracted from the isomerized dewaxed atmospheric distillation tower, and after extraction, the light components are stripped in a reboiler before being discharged as a conventional kerosene product.

[0086] In some embodiments of the present invention, the vacuum fractionation in step (5) is carried out in a heterogeneous dewaxing vacuum fractionation tower. The heterogeneous dewaxing vacuum fractionation tower is a side-stream packed tower; the heterogeneous dewaxing vacuum fractionation tower consists of a first packed bed, a second packed bed, a third packed bed, a fourth packed bed, a fifth packed bed, a sixth packed bed, and a seventh packed bed from bottom to top. Stripping steam is fed from the bottom of the tower, and the material is fed between the first and second packed beds. Under vacuum conditions, the gas and liquid phases are fully contacted on each packing bed, the light components rise layer by layer, and the heavy components descend layer by layer, achieving fine separation of the product.

[0087] In some embodiments of the present invention, the pressure at the top of the reduced pressure distillation column in step (5) is -101 to -90 kPa; specifically, it can be -101 to -98 kPa, -98 to -94 kPa, or -94 to -90 kPa; typically, but not limitingly, it is, for example, -101 kPa, -98 kPa, -94 kPa, or -90 kPa.

[0088] In some embodiments of the present invention, the temperature at the top of the vacuum distillation column in step (5) is 94-98°C; specifically, it can be 94-95°C, 95-96°C, or 96-98°C; typically, but not limitingly, it is, for example, 94°C, 95°C, 96°C, or 98°C.

[0089] In some embodiments of the present invention, the discharge rate of the third top component in step (5) is 0 to 2 t / h; specifically, it can be 0 to 0.8 t / h, 0.8 to 1.2 t / h, or 1.2 to 2 t / h; typically, but not limitingly, it is, for example, 0.8 t / h, 1.2 t / h, or 2 t / h.

[0090] In some embodiments of the present invention, the feed temperature for vacuum fractionation in step (5) is 328-345°C; specifically, it can be 328-335.5°C, 335.5-340.5°C, or 340.5-345°C; typically, but not limitingly, it is, for example, 328°C, 335.5°C, 340.5°C, or 345°C.

[0091] In some embodiments of the present invention, when the second bottom component undergoes vacuum fractionation in step (5), the third top component is obtained at the top of the vacuum fractionation column. The third side stream component includes light lubricating oil, medium lubricating oil, and heavy lubricating oil. Specifically, the light lubricating oil is obtained from side stream one of the vacuum fractionation column, the medium lubricating oil from side stream two, and the heavy lubricating oil from side stream three. The third bottom component is vacuum-finished lubricating oil, which is obtained at the bottom of the vacuum fractionation column. Side stream one of the vacuum fractionation column is located between the fifth and sixth packed beds within the vacuum fractionation column; side stream two is located between the fourth and fifth packed beds within the vacuum fractionation column; and side stream three is located between the second and third packed beds within the vacuum fractionation column.

[0092] In some embodiments of the present invention, the third top component in step (5) is a light component, specifically, the light component is vacuum distillation diesel. After being drawn from the top of the vacuum distillation column, the light component is split into two streams: one stream is sent out as diesel product, and the other stream is returned to the top of the vacuum distillation column as reflux to control the top temperature.

[0093] In some specific embodiments of the present invention, the output rate of the light component in step (5) is 0 to 2 t / h, specifically, it can be 0 to 0.8 t / h, 0.8 to 1.2 t / h, or 1.2 to 2 t / h; typically but not limitingly, it is, for example, 0.8 t / h, 1.2 t / h, or 2 t / h.

[0094] In some embodiments of the present invention, the third side component in step (5) is a light lubricating oil, a medium lubricating oil, and a heavy lubricating oil.

[0095] In some specific embodiments of the present invention, the light lubricating oil is obtained from a side stream of a vacuum distillation tower. The extraction temperature of the side stream of the vacuum distillation tower is >190°C, specifically, it can be 191-200°C. The light lubricating oil is the product medium extracted from the side stream between the fifth and sixth packed beds in the vacuum distillation tower. After being stripped by steam in the side stream packed tower, the light components are returned to the vacuum distillation tower, and the bottom components exit the vacuum distillation tower as lubricating oil products. The kinematic viscosity of the light lubricating oil at 40°C is 9 mmHg. 2 / s-11mm 2 / s.

[0096] In some specific embodiments of the present invention, the medium-quality lubricating oil is obtained from the second side stream of the vacuum distillation tower. The extraction temperature of the second side stream is >230°C, specifically, it can be 245-260°C. The medium-quality lubricating oil is the product medium extracted from the second side stream between the fourth and fifth packed beds in the vacuum distillation tower. After steam stripping in the side stream packed tower, the light components are returned to the vacuum distillation tower, and the bottom components exit the vacuum distillation tower as lubricating oil products. The kinematic viscosity of the medium-quality lubricating oil at 40°C is ≥12 mmHg. 2 / s and <25mm 2 / s.

[0097] In some specific embodiments of the present invention, the heavy lubricating oil is obtained from side stream three of a vacuum distillation tower; the extraction temperature of side stream three of the vacuum distillation tower is >280°C, specifically, it can be 288-300°C. The heavy lubricating oil is the product medium extracted from side stream three between the second and third packed beds in the vacuum distillation tower. The kinematic viscosity of the heavy lubricating oil at 40°C is ≥38 mmHg. 2 / s and <56mm 2 / s.

[0098] In some specific embodiments of the present invention, when the second bottom component is subjected to vacuum fractionation in step (5), there is no limit to the temperature of the bottom of the vacuum fractionation column.

[0099] In some specific embodiments of the present invention, the third bottom component in step (5) is the product medium drawn from the bottom of the vacuum fractionation tower, which, after being cooled by air cooling, exits the vacuum fractionation tower as a lubricating oil product (i.e., the target product). The kinematic viscosity of the aforementioned vacuum fractionation lubricating oil at 40°C is ≥90 mmHg. 2 / s and ≤110mm 2 / s.

[0100] In some embodiments of the present invention, step (6) is further included, wherein the heavy lubricating oil is divided into a first part of heavy lubricating oil, a second part of heavy lubricating oil and a third part of heavy lubricating oil, and then processed.

[0101] In some embodiments of the present invention, the mass ratio of the first part of heavy lubricating oil, the second part of heavy lubricating oil, and the third part of heavy lubricating oil in step (6) is 1:2 to 3:1.5 to 2.5. Specifically, it can be 1:2 to 2.5:2 to 2.5, 1:2.5-3:1.5-2; typically, but not limitingly, it is, for example, 1:2.8:2.37.

[0102] In some embodiments of the present invention, the first portion of the heavy lubricating oil in step (6) is returned to step (5) as a hot reflux. In some specific embodiments of the present invention, the hot reflux flow rate in step (6) is <8 t / h; specifically, it can be 4.5 t / h to 6.2 t / h. The first portion of the heavy lubricating oil is returned to the vacuum fractionation tower via the second and third packed beds, and the return position of the first portion of the heavy lubricating oil is lower than the extraction position of the heavy lubricating oil from the vacuum fractionation tower. Returning the first portion of the heavy lubricating oil as a hot reflux to the vacuum fractionation tower facilitates the control of the heat balance inside the vacuum fractionation tower.

[0103] In some embodiments of the present invention, the second portion of the heavy lubricating oil in step (6) is returned to step (5) as cold reflux. The second portion of the heavy lubricating oil is returned to the vacuum fractionation tower via the third and fourth packed beds. The return of the second portion of the heavy lubricating oil as cold reflux to the vacuum fractionation tower facilitates its coordination with the first portion of the heavy lubricating oil, adjusts the heat balance in the vacuum fractionation tower, and thereby improves the performance of the high-viscosity white oil produced.

[0104] In some specific embodiments of the present invention, the second part of the heavy lubricating oil in step (6) is cooled by a heat exchanger.

[0105] In some specific embodiments of the present invention, the cold return flow rate in step (6) is >10t / h; specifically, it can be 10.5t / h to 15t / h.

[0106] In some specific embodiments of the present invention, the cooled temperature is 215-232°C; specifically, it can be 215-217°C, 217-223°C, or 223-232°C; typically, but not limitingly, it is 215°C, 217°C, 223°C, or 232°C.

[0107] In some embodiments of the present invention, the third portion of the heavy lubricating oil in step (6) is stripped. The stripping is performed using a side-stream packed tower. Under the action of steam stripping, the light components in the third portion of the heavy lubricating oil further volatilize and return from the top of the stripping tower to a vacuum distillation tower.

[0108] In some embodiments of the present invention, the light component I in step (6) is obtained at the top of the heavy stripping tower, and the light component I can generally be regarded as diesel oil.

[0109] The heavy lubricating oil and the bottom-reducing lubricating oil are relatively close in height within the packed tower. Therefore, during the third-stage stripping of the heavy lubricating oil, the light components inside evaporate, and the light components of the high-viscosity white oil near the heavy lubricating oil evaporate along with the light components. This reduces the components with relatively small molecular weight, high volatility, and good fluidity in the high-viscosity white oil, thereby slightly adjusting the viscosity of the high-viscosity white oil at the bottom of the tower, increasing the viscosity of the high-viscosity white oil, and thus improving the performance of the extracted high-viscosity white oil.

[0110] In some embodiments of the present invention, the light component I in step (6) is returned to the vacuum distillation tower between the third and fourth packed beds of the vacuum distillation tower, and the return position of the light component I is higher than the return position of the second part of the heavy lubricating oil as cold reflux.

[0111] In some embodiments of the present invention, in step (6), the temperature at which the light component is returned to the vacuum distillation tower is ≥255°C, preferably 280°C~290°C.

[0112] In some specific embodiments of the present invention, the steam rate for stripping is 0 to 0.2 t / h. Specifically, it can be 0-0.1 t / h, 0.1 to 0.2 t / h, 0.2 to 0.4 t / h, or 0.4 to 0.5 t / h, typically but not limitingly, for example, 0.1 t / h, 0.2 t / h, 0.4 t / h, or 0.5 t / h.

[0113] In some specific embodiments of the present invention, the stripping temperature is 160-175°C; specifically, it can be 160-165°C, 165-170°C, or 170-175°C; typically, but not limitingly, it is, for example, 160°C, 165°C, 170°C, or 175°C.

[0114] In some specific embodiments of the present invention, the steam pressure of the stripping is ≥0.8 MPa. Specifically, it can be 1.0 MPa.

[0115] A second aspect of the present invention is to provide a high-viscosity white oil prepared by the above-described preparation method.

[0116] The present invention provides a high-viscosity white oil preparation system, comprising a hydrocracking reactor 1, a hydrocracking atmospheric distillation tower 2, an isomerization dewaxing reactor 3, a post-hydrocracking refining reactor 4, an isomerization dewaxing atmospheric distillation tower 5, an isomerization dewaxing vacuum distillation tower 6, and a heavy stripping tower 7, which are connected in sequence by pipelines.

[0117] In some specific embodiments of the present invention, the hydrocracking reactor 1, the hydrocracking atmospheric distillation tower 2, the isomerization dewaxing reactor 3, the post-hydrocracking refining reactor 4, the isomerization dewaxing atmospheric distillation tower 5, the isomerization dewaxing vacuum distillation tower 6, and the heavy stripping tower 7 are all reaction devices conventionally used in the art.

[0118] In some specific embodiments of the present invention, the bottom of the hydrocracking reactor 1 is connected to the hydrocracking atmospheric distillation tower 2 via a pipeline. After the bottom product of the hydrocracking reactor 1 undergoes three-phase separation of water, gas, and oil, the oil phase medium is transported to the hydrocracking atmospheric distillation tower 2 via a pipeline.

[0119] In some specific embodiments of the present invention, the bottom of the hydrocracking atmospheric distillation column 2 is connected to the isomerization dewaxing reactor 3 via a pipeline. The bottom product of the hydrocracking atmospheric distillation column 2 is transported to the isomerization dewaxing reactor 3 via pipelines and other dynamic and static equipment.

[0120] In some specific embodiments of the present invention, the bottom of the heterogeneous dewaxing reactor 3 is connected to the top of the hydrogenation refining reactor 4 via a pipeline.

[0121] In some specific embodiments of the present invention, the bottom of the hydrorefining reactor 4 is connected to the isomerization dewaxing atmospheric distillation tower 5 via a pipeline. After the bottom product of the hydrorefining reactor 4 undergoes three-phase separation of water, gas, and oil, the oil phase medium is transported to the isomerization dewaxing atmospheric distillation tower 5 via a pipeline.

[0122] In some specific embodiments of the present invention, the bottom of the heterogeneous dewaxing atmospheric distillation column 5 is connected to the heterogeneous dewaxing vacuum distillation column 6 via a pipeline. The bottom product of the heterogeneous dewaxing atmospheric distillation column 5 is transported to the heterogeneous dewaxing vacuum distillation column 6 via pipelines and other dynamic and static equipment.

[0123] In some embodiments of the present invention, the heterogeneous dewaxing and vacuum distillation tower 6 consists of, from bottom to top, a first packed bed, a second packed bed, a third packed bed, a fourth packed bed, a fifth packed bed, a sixth packed bed, and a seventh packed bed.

[0124] The present invention will be further illustrated by the following examples, but these examples do not limit the scope of the invention.

[0125] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. All reagents or instruments whose manufacturers are not specified are conventional products that can be purchased commercially. In addition to the specific methods, equipment, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, equipment, and materials similar to or equivalent to those described, used, and materials in the embodiments of this invention may be used to implement this invention.

[0126] Example 1

[0127] The method for preparing high-viscosity white oil in this embodiment includes the following steps:

[0128] (1) Mix the dewaxed oil from the distillation of the fourth-distillation line and the waxed oil from the fourth-distillation line to obtain mixture one. Mix mixture one and hydrocracking tail oil are mixed to obtain mixture two. After heat exchange, mixture two is filtered to remove solid particles and impurities with a particle size >25μm. Then it is mixed with circulating hydrogen, heated and fed into the hydrocracking reactor for hydrocracking reaction to obtain the first oil product.

[0129] (2) The first oil product obtained in step (1) is fed into the hydrocracking atmospheric fractionation tower for the first atmospheric fractionation to separate the first top component, the first side stream component and the first bottom component; the first top component is hydrocracking naphtha; the first side stream component is hydrocracking kerosene;

[0130] (3) The first bottom component obtained in step (2) is mixed with hydrocracking tail oil at a volume ratio of 1:0.5 and then fed into the isomerization dewaxing reactor for isomerization dewaxing reaction to carry out long carbon chain isomerization reaction of the oil product and lower the pour point; then fed into the hydrorefining reactor for hydrorefining reaction, and under the low temperature and high pressure conditions of hydrorefining, the aromatics are saturated to a large extent to obtain the second oil product;

[0131] (4) Input the second oil product obtained in step (3) into the isomerization dewaxing atmospheric distillation tower for a second atmospheric distillation to obtain the second top component, the second side stream component and the second bottom component respectively;

[0132] (5) Input the second bottom component obtained in step (4) into the isomerization dewaxing vacuum fractionation column for vacuum fractionation to obtain the third top component, the third side stream component and the third bottom component respectively. The third bottom component is vacuum fractionation lubricating oil, and the vacuum fractionation lubricating oil is No. 100 industrial white oil (II).

[0133] The third top component is a light component, which is top-reduced diesel oil; the third side component includes light lubricating oil, medium lubricating oil, and heavy lubricating oil, with the light lubricating oil obtained from the first side; the medium lubricating oil obtained from the second side; and the heavy lubricating oil obtained from the third side.

[0134] (6) The heavy lubricating oil is divided into three parts: the first part, the second part, and the third part. The first part is returned to the vacuum distillation tower as hot reflux. The second part is returned to the vacuum distillation tower as cold reflux after being cooled by a heat exchanger. The third part is steam stripped in the stripping tower to obtain light component one, which is then returned to the vacuum distillation tower from the top of the stripping tower under the action of steam stripping.

[0135] In step (1), the mass ratio of the reduced-temperature dewaxing oil, the reduced-temperature wax oil, and the hydrocracking tail oil is 0.8:0.4:1; the total feed rate is 33 t / h, and the distillation rates of the reduced-temperature dewaxing oil, wax oil, and hydrocracking tail oil are 12 t / h, 6 t / h, and 15 t / h, respectively. The properties of the mixture are shown in Table 1; the hydrocracking reaction temperature is 376.51℃, the hydrocracking reaction pressure is 14.51 MPa; and the hydrogen sulfide concentration in the circulating hydrogen participating in the hydrocracking reaction is 360 ppm.

[0136] In step (2), the feed temperature of the hydrocracking atmospheric distillation tower is 308.4℃, the top temperature is 116.7℃, the bottom temperature is 297.9℃, and the extraction temperature of the side stream is 178.9℃; the nitrogen content of the bottom product of the distillation tower is controlled at <2.2mg / kg, and the sulfur content is controlled at <50mg / kg.

[0137] In step (3), the temperature of the isomerization dewaxing reaction is 336.4℃, the temperature of the hydrogenation purification reaction is 237.4℃, and the pressure of the isomerization dewaxing reaction and the hydrogenation purification reaction is 13.96MPa.

[0138] In step (4), the top temperature of the tower is 119.7℃, the feed temperature is 308.9℃, the extraction temperature of the side stream component is 168℃, and the bottom temperature of the tower is 300.3℃.

[0139] In step (5), the feed temperature of the vacuum fractionation is 334.2℃, the pressure at the top of the vacuum fractionation tower is -99.24KPa, the output rate of diesel oil from the top of the tower is 0.1t / h, the temperature at the top of the vacuum fractionation tower is 94.8℃, the extraction temperature of the first side stream is 194.8℃, the extraction temperature of the second side stream is 253.5℃, the extraction temperature of the third side stream, i.e., the heavy lubricating oil side stream, is 297.1℃, and there is no limit to the temperature at the bottom of the tower.

[0140] In step (6), the mass ratio of the first part of heavy lubricating oil, the second part of heavy lubricating oil, and the third part of heavy lubricating oil is 1:2.2:2.4; the heat return flow rate of the first part of heavy lubricating oil is 5.5t / h; the temperature of the second part of heavy lubricating oil after cooling is 218℃, and the cold return flow rate is 12.1t / h.

[0141] The third component of the heavy lubricating oil: The steam stripping steam flow rate is 0.2 t / h, the steam stripping temperature is 169℃, and the steam stripping steam pressure is 1.0 MPa. The temperature at which the first light component is returned to the vacuum distillation tower is 282.5℃, and the yield of the third component of the heavy lubricating oil is 13.2 t / h. The bottom stripping steam flow rate of the vacuum distillation tower is 0.55 t / h, the temperature is 255℃, and the pressure is 0.9 MPa.

[0142] The high-viscosity white oil in this embodiment was prepared using the method described above.

[0143] Example 2

[0144] The method for preparing high-viscosity white oil in this embodiment differs from that in Example 1 in that:

[0145] In step (1), the mass ratio of the reduced-temperature dewaxing oil, reduced-temperature wax oil, and hydrocracking tail oil is 1.08:0.36:1; the total feed rate is 35 t / h, and the distillation rates of the reduced-temperature dewaxing oil, wax oil, and hydrocracking tail oil are 13.36 t / h, 5.73 t / h, and 15.91 t / h, respectively. The properties of the mixture are shown in Table 1; the hydrocracking reaction temperature is 377.2℃, the hydrocracking reaction pressure is 14.53 MPa; and the hydrogen sulfide concentration in the circulating hydrogen participating in the hydrocracking reaction is 500 ppm.

[0146] In step (2), the feed temperature of the hydrocracking atmospheric distillation tower is 309.3℃, the top temperature is 121.6℃, the bottom temperature is 298.3℃, and the extraction temperature of the side stream is 181.2℃; the nitrogen content of the bottom product of the distillation tower is controlled at <2.2mg / kg, and the sulfur content is controlled at <50mg / kg.

[0147] In step (3), the temperature of the isomerization dewaxing reaction is 338.5℃, the temperature of the hydrogenation purification reaction is 238℃, and the pressure of the isomerization dewaxing reaction and the hydrogenation purification reaction is 14.03MPa.

[0148] In step (4), the top temperature of the tower is 124.7℃, the feed temperature is 310.6℃, the extraction temperature of the side stream component is 170.1℃, and the bottom temperature of the tower is 301.8℃.

[0149] In step (5), the feed temperature of the vacuum fractionation is 335.2℃, the pressure at the top of the vacuum fractionation tower is -100.7KPa, the output rate of diesel oil from the top of the tower is 0.12t / h, the temperature at the top of the vacuum fractionation tower is 96.4℃, the extraction temperature of the first side stream is 197℃, the extraction temperature of the second side stream is 256.2℃, the extraction temperature of the third side stream, i.e., the heavy lubricating oil side stream, is 299.5℃, and there is no limit to the temperature at the bottom of the tower.

[0150] In step (6), the mass ratio of the first part, the second part, and the third part of the heavy lubricating oil is 1:2.3:2.4; the heat return flow rate of the first part of the heavy lubricating oil is 5.8 t / h; the temperature of the second part of the heavy lubricating oil after cooling is 222℃, and the cold return flow rate is 13.34 t / h.

[0151] The third component of the heavy lubricating oil: The steam stripping steam flow rate is 0.16 t / h, the steam stripping temperature is 172℃, and the steam stripping steam pressure is 1.0 MPa. The light component I is returned to the vacuum distillation tower at a temperature of 285℃. The yield of the third component of the heavy lubricating oil is 13.92 t / h. The bottom stripping steam flow rate of the vacuum distillation tower is 0.55 t / h, the temperature is 254℃, and the pressure is 0.9 MPa.

[0152] Example 3

[0153] The method for preparing high-viscosity white oil in this embodiment differs from that in Example 1 in that:

[0154] In step (1), the mass ratio of the reduced-temperature dewaxing oil, reduced-temperature wax oil, and hydrocracking tail oil is 2:0.5:1; the total feed rate is 32 t / h, and the distillation rates of the reduced-temperature dewaxing oil, wax oil, and hydrocracking tail oil are 11.13 t / h, 6.96 t / h, and 13.91 t / h, respectively. The properties of the mixture are shown in Table 1; the hydrocracking reaction temperature is 375.8℃, the hydrocracking reaction pressure is 14.48 MPa; and the hydrogen sulfide concentration in the circulating hydrogen participating in the hydrocracking reaction is 600 ppm.

[0155] In step (2), the feed temperature of the hydrocracking atmospheric distillation tower is 307.2℃, the top temperature is 114.3℃, the bottom temperature is 297.3℃, and the extraction temperature of the side stream is 176.4℃; the nitrogen content of the bottom product of the distillation tower is controlled at <2.2mg / kg, and the sulfur content is controlled at <50mg / kg.

[0156] In step (3), the temperature of the isomerization dewaxing reaction is 335.4℃, the temperature of the hydrogenation purification reaction is 236.7℃, and the pressure of the isomerization dewaxing reaction and the hydrogenation purification reaction is 13.85MPa.

[0157] In step (4), the temperature at the top of the column is 114.6℃, the feed temperature is 307.5℃, the extraction temperature of the side stream component is 160.9℃, and the temperature at the bottom of the column is 299℃.

[0158] In step (5), the feed temperature of the vacuum fractionation is 333.7℃, the pressure at the top of the vacuum fractionation tower is -97.3KPa, the output rate of diesel oil from the top of the tower is 0.18t / h, the temperature at the top of the vacuum fractionation tower is 94℃, the extraction temperature of the first side stream is 191.8℃, the extraction temperature of the second side stream is 250.9℃, the extraction temperature of the third side stream, i.e., the heavy lubricating oil side stream, is 294.2℃, and there is no limit to the temperature at the bottom of the tower.

[0159] In step (6), the mass ratio of the first part of heavy lubricating oil, the second part of heavy lubricating oil, and the third part of heavy lubricating oil is 1:2.25:2.35; the heat return flow rate of the first part of heavy lubricating oil is 5.37 t / h; the temperature of the second part of heavy lubricating oil after cooling is 217℃, and the cold return flow rate is 12.08 t / h.

[0160] The third component of the heavy lubricating oil: The steam stripping steam flow rate is 0.12 t / h, the steam stripping temperature is 166℃, and the steam stripping steam pressure is 1.0 MPa. The temperature at which the first light component is returned to the vacuum distillation tower is 281℃. The yield of the third component of the heavy lubricating oil is 12.62 t / h. The bottom stripping steam flow rate of the vacuum distillation tower is 0.55 t / h, the temperature is 256℃, and the pressure is 0.9 MPa.

[0161] Table 1. Material properties of the mixture in step (1) of the high viscosity white oil in Examples 1-3.

[0162] index Example 1 Example 2 Example 3 Moisture (mixed), wt% ≤0.03 ≤0.03 ≤0.03 <![CDATA[Kinematic viscosity (100 °C), mm 2 / s]]> 6.647 6.542 6.647 Pour point (°C) 48 45 40 Initial boiling point, ℃ 331 335 340 50% recovery temperature, ℃ 407 405 412 Final boiling point, ℃ 532 530 535 Wax content, wt% 36.01 38.6 30.65 <![CDATA[Density (20 °C), kg / m 3 > 898.9 896.3 899.5 Sulfur content, wt% 0.28 0.26 0.23 Nitrogen content, mg / kg 698.95 632.53 616.99

[0163] Comparative Example

[0164] Comparative Example 1

[0165] The method for preparing the high-viscosity white oil in this comparative example differs from that in Example 1 in that:

[0166] In step (1), the reduced-strength wax oil and the cracked tail oil are mixed at a volume ratio of 1:1.5 and subjected to hydrocracking reaction to obtain the first oil product; the rest is exactly the same as in Example 1.

[0167] The high-viscosity white oil in this comparative example was prepared using the above-described method.

[0168] Comparative Example 2

[0169] The preparation method of the high viscosity white oil in this comparative example differs from that in Example 1 in that the mass ratio of the reduced-four dewaxing oil and the reduced-four wax oil is 1:3, while all other aspects are exactly the same as in Example 1.

[0170] Comparative Example 3

[0171] The preparation method of the high viscosity white oil in this comparative example differs from that in Example 1 in that the mass ratio of the reduced-four dewaxing oil and the reduced-four wax oil is 6:1, while all other aspects are exactly the same as in Example 1.

[0172] Comparative Example 4

[0173] The preparation method of the high-viscosity white oil in this comparative example differs from that in Example 1 in that the mass ratio of mixture one and hydrocracking tail oil is 3:1, while all other aspects are exactly the same as in Example 1.

[0174] Performance testing

[0175] The high-viscosity white oils prepared in Examples 1-3 and Comparative Examples 1-4 were tested for kinematic viscosity, flash point, pour point, color, copper strip corrosion level, sulfur content, aromatic hydrocarbon content, moisture and mechanical impurities. The test results are shown in Table 2.

[0176] Table 2 Performance data of high viscosity white oils from Examples 1-3 and Comparative Examples 1-4

[0177]

[0178] Based on Examples 1-3 and the data in Table 2, it can be seen that the high viscosity white oils prepared in Examples 1-3 have good properties and meet the standards of Industrial White Oil (II) in NB / SH / T0006-2017 "Industrial White Oil".

[0179] Based on Examples 1 and Comparative Examples 1-4, and the data in Table 2, it can be seen that the high viscosity white oil produced by adding different proportions of reduced-temperature dewaxing oil, reduced-temperature wax oil, and hydrocracking tail oil has different properties.

[0180] Based on the examples and the Group II base oil obtained by existing processes, the selling price of Group II base oil obtained by existing processes is RMB 6,200 / ton (excluding tax), while the average selling price of the high-viscosity white oil of this application during the same period is RMB 8,230 / ton (excluding tax). When the sales quantity is 300 tons, the sales revenue of the high-viscosity white oil is RMB 2,469,000, which is RMB 609,000 more than the Group II base oil or No. 68 and below industrial white oil obtained in the comparative example, and the marginal profit increases by RMB 2,030 / ton, significantly increasing economic benefits.

[0181] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing high-viscosity white oil, characterized in that, The preparation method includes the following steps: (1) Mix the distilled dewaxed oil and the waxed oil to obtain mixture one. Mix mixture one and hydrocracking tail oil to obtain mixture two. Perform hydrocracking reaction on mixture two to obtain the first oil product. (2) The first oil product obtained in step (1) is subjected to atmospheric pressure fractionation to obtain the first top component, the first side stream component and the first bottom component respectively; (3) The first bottom component obtained in step (2) is mixed with hydrocracking tail oil and then subjected to isomerization dewaxing reaction and hydrorefining reaction in sequence to obtain the second oil product; the volume ratio of the first bottom component to the hydrocracking tail oil is 1:0-0.

8. (4) The second oil obtained in step (3) is subjected to a second atmospheric pressure fractionation to obtain the second top component, the second side stream component and the second bottom component; (5) The second bottom component obtained in step (4) is subjected to isomerization dewaxing and vacuum fractionation to obtain the third top component, the third side stream component and the third bottom component, respectively. The third bottom component is high viscosity white oil.

2. The method for preparing high-viscosity white oil according to claim 1, characterized in that: Step (1) further includes one or more of the following features: A1) The mass ratio of the reduced-four dewaxing oil and the reduced-four wax oil is 2-4:1; A2) The mass ratio of the mixture I and the hydrocracking tail oil is 0.9-1.5:1; A3) The nitrogen content of mixture one is <1500 mg / kg; the nitrogen content of mixture two is <700 mg / kg; A4) The kinematic viscosity of the second mixture is 5.9–7.5 mm at 100°C. 2 / s; A5) The distillation range of the mixture 2 is 330-550℃, and the distillation range width is ≥160℃; A6) The wax content of the mixture 2 is 30-40 wt%; A7) The moisture content of the mixture 2 is ≤0.03wt%; A8) The pour point of the mixture 2 is 36-50℃; A9) The mixture 2 is filtered before the hydrocracking reaction; preferably, the filtration accuracy is greater than 25 μm; A10) The hydrogen sulfide concentration in the circulating hydrogen introduced into the hydrocracking reaction is ≤1500 ppm; The temperature of the hydrocracking reaction described in A11) is 369-378℃; The pressure of the hydrocracking reaction described in A12) is 14-16 MPa; The hydrocracking reaction described in A13) is carried out in a hydrocracking reactor.

3. The method for preparing high-viscosity white oil according to claim 1, characterized in that: Step (2) further includes one or more of the following features: B1) The first atmospheric distillation is carried out in a hydrocracking distillation tower; B2) The top temperature of the first atmospheric distillation column is 112-122℃; B3) The feed temperature for the first atmospheric distillation is 306-310℃; B4) The bottom temperature of the first atmospheric distillation is 295-302℃; B5) The first atmospheric distillation side stream extraction temperature is 168-182℃; B6) The nitrogen content of the first bottom component is <2.2 mg / kg; B7) The sulfur content of the first bottom component is <50 mg / kg; B8) The first bottom component of the tower is hydrocracked naphtha; B9) The first side-stream component is hydrocracking kerosene.

4. The method for preparing high-viscosity white oil according to claim 1, characterized in that: Step (3) also includes one or more of the following features: C1) The isomerization dewaxing reaction is carried out in an isomerization dewaxing reactor; The temperature for the isomerization dewaxing reaction described in C2) is 334-346℃; The pressure of the isomerization dewaxing reaction described in C3) is 13.5-14.5 MPa; The volume hourly space velocity (VHSV) for the isomerization dewaxing reaction described in C4) is 0.5-1.5 h. The hydrogen-to-oil ratio for the isomerization dewaxing reaction described in C5) is 500-2000 v / v; The post-hydrogenation refining reaction described in C6) is carried out in a post-hydrogenation refining reactor; The reaction temperature for the hydrogenation purification reaction described in C7) is ≤250℃; The reaction pressure of the hydrogenation purification reaction described in C8) is 13.5-14.5 MPa; The volume hourly space velocity (VHSV) for the hydrorefining process described in C9 is 0.6-2 / h. The hydrogen-to-oil volume ratio of the hydrorefining reaction described in C10 is 400-1000:1; C11) The second top component of the tower is isomerized dewaxed naphtha; C12) The second side-line component is isomerized dewaxed kerosene.

5. The method for preparing high-viscosity white oil according to claim 1, characterized in that: Step (4) also includes one or more of the following features: D1) The second atmospheric distillation is carried out in an isomerized dewaxing atmospheric distillation column; D2) The top temperature of the second atmospheric distillation column is 114-126℃; D3) The bottom temperature of the second atmospheric distillation column is 298-305℃; D4) The extraction temperature of the second atmospheric distillation side stream is ≥158℃; D5) The feed temperature for the second atmospheric distillation is 307-312℃.

6. The method for preparing high-viscosity white oil according to claim 1, characterized in that: Step (5) further includes one or more of the following features: E1) The third top component is a light component, preferably, the light component is top-reduced diesel oil; E2) The third side-line components are light lubricating oil, medium lubricating oil and heavy lubricating oil, respectively; E3) The vacuum fractionation described herein is carried out in a heterogeneous dewaxing vacuum fractionation tower; E4) The pressure at the top of the vacuum distillation column is -101 to -90 kPa; E5) The temperature at the top of the vacuum distillation column is 94-98℃; E6) The output rate of the third top component is 0-2 t / h; E7) The feed temperature for the vacuum fractionation is 328-345℃; E8) When the second bottom component is subjected to vacuum fractionation, the vacuum fractionation stripping steam temperature is >240℃, the flow rate is 0.5~1t / h, and the pressure is ≥0.8MPa.

7. The method for preparing high-viscosity white oil according to claim 6, characterized in that: Step (5) further includes the following features: the light lubricating oil is obtained from side stream one of the vacuum distillation tower, the medium lubricating oil is obtained from side stream two of the vacuum distillation tower, and the heavy lubricating oil is obtained from side stream three of the vacuum distillation tower; preferably, the extraction temperature of side stream one of the vacuum distillation tower is >190℃; the extraction temperature of side stream two of the vacuum distillation tower is >230℃; and the extraction temperature of side stream three of the vacuum distillation tower is >280℃.

8. The method for preparing high-viscosity white oil according to claim 7, characterized in that: The process also includes step (6), which involves dividing the heavy lubricating oil into a first part, a second part, and a third part, followed by further processing; the processing includes any one or more of the following: F1) The mass ratio of the first, second, and third portions of heavy lubricating oil is 1:2 to 3:1.5 to 2.5; F2) The first part of the heavy lubricating oil is returned as a hot reflux step (5); preferably, the hot reflux flow rate is <8t / h; F3) The second part of the heavy lubricating oil is returned as a cold reflux step (5); preferably, the cold reflux flow rate is >10t / h; more preferably, the temperature after cooling is 215-232℃.

9. The method for preparing high-viscosity white oil according to claim 8, characterized in that: The heavy lubricating oil is stripped in the third part; preferably, the stripping is carried out in a heavy lubricating oil stripping tower; and / or, the steam flow rate of the stripping is 0-0.2 t / h; and / or, the stripping temperature is 160-175℃; and / or, the stripping steam pressure is ≥0.8 MPa.

10. A high-viscosity white oil, characterized in that, It is prepared by the preparation method according to any one of claims 1-9.

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