CN117946745A - Method for processing heavy oil - Google Patents

Abstract

The present invention relates to the technical field of inferior heavy oil processing, and discloses a method for processing heavy oil. The method comprises: performing atmospheric distillation on a heavy oil raw material to obtain atmospheric distillate oil and atmospheric residue; performing extraction separation on the atmospheric residue by countercurrent contact with a solvent to obtain a light component and a heavy component; the temperature of the extraction separation is higher than the critical temperature of the solvent, and the pressure of the extraction separation is higher than the critical pressure of the solvent; performing vacuum distillation on the light component, and obtaining a vacuum component I with a residual carbon value of less than 0.45w% as a hydrogenation raw material; a vacuum component II with a residual carbon value of 0.45-2.0w% as a lubricating oil raw material; and a vacuum component III with a residual carbon value of more than 2.0w% as a catalytic cracking raw material. The method can obtain a light component with a lower residual carbon value and a higher yield, and the components obtained by graded utilization can be used as high-quality hydrogenation raw materials, lubricating oil raw materials and catalytic cracking raw materials, and the heavy component is used as an additive for hard asphalt, with excellent economic benefits.

Description

Method for processing heavy oil

Technical Field

The invention relates to the technical field of inferior heavy oil processing, and in particular to a method for processing heavy oil.

Background technique

Since the 21st century, conventional oil resources have been decreasing in the world, and the heavy and inferior quality of oil resources have intensified. With the improvement of crude oil extraction technology and the continuous increase in heavy oil production, environmental protection regulations have become increasingly stringent, and the demand for light oil products has continued to increase. The efficient conversion and comprehensive utilization of heavy oil has attracted the attention of major oil companies in the world. Heavy oil accounts for a large proportion of oil resources, and its total equivalent reserves far exceed conventional crude oil and natural gas. In recent years, the global production and processing of heavy oil has continued to grow. Continuous, efficient and economical use of heavy oil resources and reducing crude oil costs can effectively improve the economy of refineries.

Heavy oil has the characteristics of high density, high carbon residue value, high content of colloid and asphaltene, and high metal content. It is difficult to lighten it and it is difficult to process it using conventional petroleum resource processing technology. There are two difficulties in the process of lightening heavy oil: (1) The residual carbon value of residual oil is high, which is prone to condensation and coking; (2) The presence of a large amount of metals and asphaltene such as nickel and vanadium is easy to cause coking, metal aggregation, and a reduction in the number of active centers, which ultimately leads to catalyst deactivation. It is difficult to process it directly using a conventional fixed-bed residual oil hydrogenation unit, and the unit operation cycle is short. The economic benefits of processing through technical routes such as viscosity reduction and coking processes are low. The processing of heavy oil (especially inferior heavy oil) is somewhat difficult. The degree of coking tendency of the vacuum furnace is closely related to the oil temperature and its residence time in the furnace tube of the heating furnace. For a given heavy and inferior oil, a higher furnace outlet temperature is required when vacuum deep drawing is used. In order to reduce the thermal cracking reaction of the residual oil and reduce the risk of coking in the furnace tube, the branch temperature of the vacuum line of some vacuum devices is mostly below 385°C, making deep drawing difficult. When the oil temperature exceeds a certain limit, thermal cracking is likely to occur to produce free carbon, leading to coking of the furnace tubes. At the same time, it makes it difficult for the decompression system of the device to achieve long-term stable operation, and the wax oil fraction is not clearly cut and the yield is low. The needle penetration of the residual oil obtained after distillation may meet the needle penetration requirements of heavy traffic road petroleum asphalt products, but due to its small elongation, low flash point, large loss after TFOT, and the needle penetration ratio does not meet the product quality requirements, it is difficult to ship as a high-grade asphalt product. The overall economic benefits are low, and a single oil processing route and product structure will no longer be suitable for new market demands. Therefore, for heavy crude oil, research is carried out on processing methods that directly post-process atmospheric residue oil, avoid high-temperature cracking, and obtain high-value utilization. Bright oil is a type of high-viscosity base oil produced by distillation or separation of heavy oil as raw material. It has high added value and is widely used in daily life. It has broad market prospects. In the production of lubricating oil, C3 is often used as a solvent to separate residual oil to obtain bright oil raw materials that meet the requirements. However, it was found in the study that for atmospheric residual oil with high viscosity and high carbon residue, even if C3 is used as a solvent for extraction, the obtained light deasphalted oil cannot be directly used because its viscosity and flash point values are difficult to meet the requirements of bright oil raw materials.

CN101050383A discloses a combined process for heavy oil processing, wherein vacuum residue is treated by butane deasphalting process to obtain two components, deasphalted oil and deoiled asphalt; deasphalted oil is mixed with one or two of other catalytic cracking raw materials, atmospheric residue and vacuum wax oil, as raw materials for catalytic cracking unit, and high value-added light hydrocarbons and gasoline and diesel are produced by catalytic cracking process; the remaining catalytic cracking oil slurry that is difficult to crack is used as raw material for oil slurry topping, i.e. vacuum fractionation process, and is separated into two components, light oil slurry and topping heavy oil slurry after vacuum fractionation process; light oil slurry is mixed with part of deoiled hard asphalt produced by solvent deasphalting unit, as raw material for visbreaking unit, and No. 7 commercial fuel oil is produced; topping heavy oil slurry and another part of deoiled hard asphalt produced by solvent deasphalting unit enter asphalt online blending unit, i.e. static mixer, and are fully mixed to produce high-grade road petroleum asphalt. When this method processes inferior and heavy crude oil, the vacuum distillation unit fluctuates greatly due to easy cracking, and the operation is unstable, and the energy consumption is high, and the equipment is easily corroded by high-temperature sulfur and high-temperature acid, which makes the start-up period of the device short and the operating cost high.

In addition, in the prior art, after the atmospheric residue is separated by solvent, the light deasphalted oil obtained directly enters the hydrogenation device or the catalytic unit. However, when this method is used to treat the atmospheric residue with high viscosity and high carbon residue, the solvent refined oil obtained is often difficult to be directly used as a raw material for bright oil production because the flash point does not meet the requirements.

How to efficiently convert and utilize low-quality residual oil is of great significance to improving the overall efficiency of the refinery. The existing technology for processing low-quality heavy oil is mainly a simple combination of several processing techniques, without targeted fine processing according to the characteristics of the components. In view of the characteristics of heavy oil with high density, high content of colloid and asphaltene, it is necessary to develop suitable processing technology and routes to reduce the production cost of the equipment and maximize the value of crude oil. To this end, refining enterprises must continuously enrich the process routes, learn from the strengths of existing processing technologies, focus on the research of combined processing technologies, and optimize the refinery's crude oil processing routes under the condition of low investment cost.

Summary of the invention

The purpose of the present invention is to overcome the problems that the existing heavy oil processing method is not suitable for processing high-viscosity and high-carbon residual heavy oil, the obtained light deasphalted oil is difficult to meet the requirements of directly being used as a raw material for the production of high-value-added product lubricating oil, and the hydrogenation unit has a short operating cycle.

In order to achieve the above object, the present invention provides a method for processing heavy oil, the method comprising:

(1) subjecting a heavy oil raw material to atmospheric distillation to obtain atmospheric distillate oil and atmospheric residue oil; the heavy oil raw material has a density at 20° C. greater than 0.92 g/cm ³ and a residual carbon value greater than 6 w %;

(2) contacting the atmospheric residue with a solvent in countercurrent flow to perform extraction separation to obtain a light component and a heavy component; wherein the temperature of the extraction separation is higher than the critical temperature of the solvent, and the pressure of the extraction separation is higher than the critical pressure of the solvent; and the heavy component is used as an additive for hard asphalt;

(3) subjecting the light component to vacuum distillation to obtain vacuum component I, vacuum component II and vacuum component III; wherein the vacuum component I has a residual carbon value of less than 0.45w%, and is used as a hydrogenation raw material; the vacuum component II has a residual carbon value of 0.45-2.0w%, and is used as a lubricating oil raw material; and the vacuum component III has a residual carbon value of greater than 2.0w%, and is used as a catalytic cracking raw material.

Through the above technical scheme, the method provided by the present invention processes heavy oil raw materials with high viscosity and high carbon residue, and through supercritical solvent separation, avoids the problem of easy cracking of components and low extraction rate at high temperature in the process of vacuum deep extraction of inferior heavy oil, and obtains light components with lower carbon residue value and higher yield than subcritical solvent separation. The light components obtained by extraction and separation of atmospheric residue oil are separated and graded by combining supercritical solvent separation and vacuum distillation, and high-quality hydrogenation raw materials, lubricating oil raw materials and catalytic cracking raw materials are respectively sent to each device, so that each device is converted under its own optimized process conditions, which improves the operation cycle of downstream devices and significantly improves the yield of light oil. The heavy components obtained by extraction and separation of atmospheric residue oil can be used as additives for hard asphalt to improve the rutting formed by insufficient high-temperature stability of asphalt concrete pavement, improve the high-temperature deformation resistance and fatigue resistance of asphalt concrete pavement, and have excellent economic benefits.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic flow diagram of a method for processing heavy oil according to an embodiment of the present invention.

Description of Reference Numerals

1. Heavy oil raw material 2. Atmospheric distillation unit 3. Gas

4. Atmospheric distillate oil 5. Atmospheric residue oil 6. Extraction separation unit

7. Light components 8. Vacuum distillation unit 9. Heavy components

10. Decompression component I 11. Decompression component II 12. Decompression component III

13. Hydroprocessing unit 14. Lubricating oil refining unit 15. Catalytic cracking unit

16. Blending tank 17. Hard asphalt 18. Hydrorefined oil

19. Bright oil 20. Catalytic cracking products

Detailed ways

The endpoints and any values of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

The present invention provides a method for processing heavy oil, the method comprising:

(1) subjecting a heavy oil raw material to atmospheric distillation to obtain atmospheric distillate oil and atmospheric residue oil; the heavy oil raw material has a density at 20° C. greater than 0.92 g/cm ³ and a residual carbon value greater than 6 w %;

(2) contacting the atmospheric residue with a solvent in countercurrent flow to perform extraction separation to obtain a light component and a heavy component; wherein the temperature of the extraction separation is higher than the critical temperature of the solvent, and the pressure of the extraction separation is higher than the critical pressure of the solvent; and the heavy component is used as an additive for hard asphalt;

(3) subjecting the light component to vacuum distillation to obtain vacuum component I, vacuum component II and vacuum component III; wherein the vacuum component I has a residual carbon value of less than 0.45w%, and is used as a hydrogenation raw material; the vacuum component II has a residual carbon value of 0.45-2.0w%, and is used as a lubricating oil raw material; and the vacuum component III has a residual carbon value of greater than 2.0w%, and is used as a catalytic cracking raw material.

According to some embodiments of the present invention, in step (1), the 20°C density of the heavy oil feedstock is greater than 0.92 g/ ^cm3 and the carbon residue value is greater than 6w%, and it is a low-quality heavy oil with high viscosity and high carbon residue. There is no particular limitation on the source of the heavy oil feedstock, which can be a low-quality heavy crude oil that meets the above requirements.

According to some embodiments of the present invention, preferably, in step (1), the heavy oil feedstock is distilled in an atmospheric distillation unit, the cut-off temperature of the atmospheric distillation is 350°C, and an atmospheric residue with a temperature greater than 350°C is obtained at the bottom of the atmospheric distillation tower (that is, the atmospheric residue is a fraction with a temperature greater than 350°C). Because under atmospheric pressure, the heavy oil feedstock has a significant decomposition phenomenon starting from 350°C, so usually, the fraction with a boiling point higher than 350°C is distilled under reduced pressure.

According to some embodiments of the present invention, preferably, in step (1), the atmospheric residue has a viscosity at 100°C greater than 280 mm2/s and a carbon residue value not less than 13w%; more preferably, the atmospheric residue has a viscosity at 100°C of 320-5500 ^mm2 /s and a carbon residue value of 15-18w%. The viscosity and carbon residue value of the atmospheric residue are also high.

According to some embodiments of the present invention, preferably, the atmospheric residue has a density at 20° C. greater than 0.95 g/cm ³ .

According to some embodiments of the present invention, preferably, in step (1), the atmospheric residue has a nickel content of 20-130 mg/kg; a vanadium content of 1-380 mg/kg; a nitrogen content of 0.4-1.1 w%; and a sulfur content of 0.3-3.5 w%.

According to some embodiments of the present invention, preferably, in step (1), the product of the atmospheric distillation also includes a gas component.

According to some embodiments of the present invention, preferably, in step (2), the conditions for the extraction separation include: a temperature of 110-175° C. and a pressure of 7.5-12 MPa.

According to some embodiments of the present invention, preferably, the extractive separation is carried out in an extraction tower, and the bottom temperature of the extraction tower is 110-165° C., and the top temperature of the extraction tower is 115-175° C.;

More preferably, the bottom temperature of the extraction tower is lower than the top temperature.

According to some embodiments of the present invention, preferably, in step (2), the volume ratio of the solvent to the atmospheric residue is 6-12:1.

According to some embodiments of the present invention, preferably, in step (2), the solvent is selected from at least one of C3-C4 alkanes, preferably propane and/or isobutane.

According to some embodiments of the present invention, preferably, in step (2), the distillation range of the light component is 345-737°C.

According to some embodiments of the present invention, preferably, in step (2), the yield of the light component is 15-60%.

According to some embodiments of the present invention, preferably, in step (2), the carbon residue value of the light component is 0.2-5.5w%; and the viscosity at 100°C is 15-80mm ² /s.

According to some embodiments of the present invention, the method uses supercritical solvent separation to avoid the problem of easy cracking of components at high temperatures and low extraction rate of inferior heavy oil during vacuum deep extraction, and can obtain light components with lower residual carbon value and higher yield than subcritical solvent separation.

According to some embodiments of the present invention, preferably, in step (2), the softening point of the heavy component is 65-125°C.

According to some embodiments of the present invention, preferably, the yield of the heavy component is 40-85%.

According to some embodiments of the present invention, preferably, the density of the heavy component at 20°C is 0.99-1.07 g/cm ³ ; the residual carbon value is 20-30w%. The heavy component can be used as an additive for hard asphalt to prepare hard asphalt.

According to some embodiments of the present invention, preferably, in step (3), the temperature of the reduced pressure distillation is 370-580°C.

According to some embodiments of the present invention, preferably, in step (3), the first cutting temperature of the decompression component I and the decompression component II is 370-460°C; the second cutting temperature of the decompression component II and the decompression component III is 420-580°C, and the first cutting temperature is lower than the second cutting temperature; the decompression component I is a fraction having a temperature lower than the first cutting temperature, the decompression component II is a fraction having a temperature between the first cutting temperature and the second cutting temperature, and the decompression component III is a fraction having a temperature higher than the second cutting temperature.

According to some embodiments of the present invention, preferably, in step (3), the viscosity of the vacuum component I at 100°C is 10-50 ^mm2 /s; the total content of nickel and vanadium is less than 5 mg/kg. The vacuum component I can be used as a hydrogenation feedstock for a hydrogenation reaction, preferably, the reaction conditions include: a hydrogen partial pressure of 10-17 MPa, and a temperature of 350-400°C.

According to some embodiments of the present invention, preferably, in step (3), the viscosity of the vacuum component II at 100°C is 25-150 ^mm2 /s; and/or the flash point of the vacuum component II is greater than 280°C, which can meet the raw material requirements for producing bright oil. The vacuum component II can be directly used as a lubricating oil raw material for solvent extraction-solvent dewaxing-adsorbent adsorption refining. Preferably, the reaction conditions include: the mass ratio of the extraction solvent to the deasphalted oil in the solvent extraction is 3.0-6:1; the extraction tower top temperature is 90-130°C, and the extraction tower bottom temperature is 50-70°C; the solvent dewaxing filtration temperature is -25 to -20°C; the adsorption refining conditions include: the contact temperature is 120-210°C, and the contact time is 25-50min.

According to some embodiments of the present invention, preferably, in step (3), the 100°C viscosity of the vacuum component III is 90-210 mm ² /s. The vacuum component III can be used as a catalytic cracking feedstock for catalytic cracking reaction. Preferably, the reaction conditions include: reaction temperature of 490-650°C, catalyst-oil mass ratio of 5-55:1, and mass space velocity of 4h ^-1 .

In the prior art, for atmospheric residue oil with high viscosity and high carbon residue value, even if C3 is used as solvent for extraction, the obtained light deasphalted oil cannot be directly used because its viscosity and flash point value are difficult to meet the requirements of bright oil raw materials. However, the inventors of the present invention found in the research process that by supercritical solvent separation, the problem of easy cracking of components and low extraction rate at high temperature in the process of vacuum deep extraction of inferior heavy oil is avoided, and light components with lower carbon residue value and higher yield than subcritical solvent separation are obtained. By combining supercritical solvent separation and vacuum distillation, the light components obtained by extraction and separation of atmospheric residue oil are separated and graded for utilization, and high-quality hydrogenation raw materials, lubricating oil raw materials and catalytic cracking raw materials are respectively sent to each device, so that each device is converted under its own optimized process conditions, the operation cycle of downstream devices is improved, and the yield of light oil is significantly improved. The heavy components obtained by extraction and separation of atmospheric residue oil are used as additives for hard asphalt. The production cost of improving the rutting resistance of asphalt concrete pavement by re-seeding heavy components is much lower than that of polymer-modified asphalt and anti-rutting, which has excellent economic benefits.

According to a particularly preferred embodiment of the present invention, the method for processing heavy oil comprises:

(1) subjecting a heavy oil feedstock to atmospheric distillation to obtain atmospheric distillate oil and atmospheric residue oil; the heavy oil feedstock has a density at 20°C greater than 0.92 g/ ^cm3 and a carbon residue value greater than 6w%; the atmospheric residue oil has a viscosity at 100°C greater than 280 ^mm2 /s and a carbon residue value not less than 13w%;

(2) contacting the atmospheric residue with a solvent in countercurrent flow to perform extraction separation to obtain a light component and a heavy component; the heavy component is used as an additive for hard asphalt;

The extraction separation is carried out in an extraction tower, and the bottom temperature of the extraction tower is 110-165°C, and the top temperature of the extraction tower is 115-175°C; the bottom temperature of the extraction tower is lower than the top temperature; the pressure of the extraction separation is 7.5-12MPa; the volume ratio of the solvent to the atmospheric residue is 6-12:1; the solvent is selected from at least one of C3-C4 alkanes;

(3) subjecting the light component to vacuum distillation to obtain vacuum component I, vacuum component II and vacuum component III;

The temperature of the vacuum distillation is 370-580°C; the residual carbon value of the vacuum component I is less than 0.45w%, and it is used as a hydrogenation raw material; the residual carbon value of the vacuum component II is 0.45-2.0w%, and it is used as a lubricating oil raw material; the residual carbon value of the vacuum component III is greater than 2.0w%, and it is used as a catalytic cracking raw material.

The method for processing heavy oil provided by the present invention is further described in detail below in conjunction with the accompanying drawings.

The present invention illustratively provides a schematic flow chart of a method for processing heavy oil according to an embodiment, as shown in FIG1 , the method comprises:

(1) In an atmospheric distillation unit 2, a heavy oil feedstock 1 is subjected to atmospheric distillation to obtain a gas 3, an atmospheric distillate oil 4 and an atmospheric residue oil 5;

(2) In the extraction tower of the extraction and separation unit 6, the atmospheric residue 5 is countercurrently contacted with the solvent from the extraction and separation unit 6 to perform extraction and separation, thereby obtaining a light component 7 and a heavy component 9; the heavy component 9 is transported to the blending tank 16 as an additive for the hard asphalt 17 to prepare the hard asphalt 17;

(3) in a vacuum distillation unit 8, the light component 7 is subjected to vacuum distillation to obtain a vacuum component I 10, a vacuum component II 11, and a vacuum component III 12;

The reduced pressure component I10 is transported as a hydrogenation feedstock to a hydroprocessing unit 13 for a hydroprocessing reaction to obtain a hydrorefined oil 18;

The decompression component II 11 is transported as a lubricating oil raw material to a lubricating oil refining unit 14 for solvent refining reaction to obtain bright oil 19;

The vacuum component III 12 is transported as a catalytic cracking feedstock to a catalytic cracking unit 15 for catalytic cracking reaction to obtain a catalytic cracking product 20.

The raw materials and operating conditions of each step can be selected by referring to the above and will not be described in detail here.

The present invention will be described in detail below through examples.

In the following examples and comparative examples, unless otherwise specified, the raw materials used are commercially available.

The heavy oil raw materials used were from PetroChina Co., Ltd., wherein the density of heavy oil raw material A at 20°C was 0.921 g/cm ³ , and the residual carbon value was 7.0 w %; the density of heavy oil raw material B at 20°C was 0.924 g/cm ³ , and the residual carbon value was 6.7 w %.

Example 1

(1) subjecting a heavy oil raw material A to atmospheric distillation to obtain atmospheric distillate oil and atmospheric residue oil; wherein:

The cut-off temperature of atmospheric distillation is 350°C. Atmospheric residue is the fraction with a temperature greater than 350°C. Its properties are shown in Table 1.

(2) The atmospheric residue oil is contacted with a solvent in a countercurrent manner in an extraction tower for extraction and separation to obtain light components and heavy components; wherein:

The volume ratio of solvent to atmospheric residue is 10:1; the solvent is propane (purity>99%); the bottom temperature of the extraction tower is 115°C, the top temperature of the extraction tower is 125°C; the pressure of extraction separation is 12MPa;

The distillation range of the light component is 347-718°C; the yield and properties of the light component are shown in Table 2; the yield and properties of the heavy component are shown in Table 3; the heavy component is used as an additive for hard asphalt, and the properties of the hard asphalt obtained by blending it with 90# asphalt are shown in Table 5;

(3) subjecting the light component to vacuum distillation to obtain vacuum component I, vacuum component II and vacuum component III; wherein:

The cut-off temperature of vacuum distillation, the distillation range and properties of each component are shown in Table 4; vacuum component I is used as a hydrogenation feedstock; vacuum component II is used as a lubricating oil feedstock; and vacuum component III is used as a catalytic cracking feedstock.

Comparative Example 1

Step (1) and step (2) were carried out according to the method of Example 1, except that in step (2), the extraction separation was carried out under subcritical conditions, the bottom temperature of the extraction tower was 75° C., and the top temperature of the extraction tower was 85° C.; the pressure of the extraction separation was 4 MPa; the rest was the same as in Example 1, and a light component and a heavy component were obtained; the yield and properties of the light component are shown in Table 2.

Comparative Example 2

The method of Example 1 is followed, except that step (3) is not performed.

Example 2

The method of Example 1 is different from that of Example 1:

In step (1), heavy oil feedstock A is replaced by heavy oil feedstock B, and the properties of the atmospheric residue obtained are shown in Table 1;

In step (2), the volume ratio of the solvent to the atmospheric residue is 7:1; the solvent is isobutane (purity> 99%); the bottom temperature of the extraction tower is 165° C., the top temperature of the extraction tower is 175° C.; the pressure of the extraction separation is 9.2 MPa;

The distillation range of the light component is 347-719°C; the yield and properties of the light component are shown in Table 2; the yield and properties of the heavy component are shown in Table 3, and the properties of the hard asphalt obtained by blending it with 90# asphalt are shown in Table 5;

In step (3), the cut-off temperature of the vacuum distillation, the distillation range and properties of each component are shown in Table 4;

The rest are the same as in Example 1.

Table 1 (Properties of atmospheric residue oil)

Table 2 (Light component properties)

Analysis Project Analytical method Example 1 Example 2 Comparative Example 1 Light component yield/% / 45.3 55.0 42.3 Residual carbon/w% GB/T 17144 1.07 3.03 1.35 Viscosity (80℃)/( ^mm2 /s) GB/T 11137 171.90 214.1 165.3 Viscosity (100℃)/( ^mm2 /s) GB/T 11137 56.43 79.72 54.5 Flash point/℃ GB/T 3536 257 264 245 C7 insoluble matter/(mg/kg) C7_INSOL_M ＜50 ＜50 ＜50 Ni+V content/(mg/kg) GB/T 37160 1.8 2.58 3.7

Table 3 (Heavy Component Properties)

Table 4 (Properties of components obtained by vacuum distillation)

Table 5 (Hard Asphalt Properties)

project Example 1 Example 2 Needle penetration (25℃, 100g, 5s)/(0.1mm) 35 31 Softening point (ring and ball method)/℃ 64 66 Brittle point/℃ -14 -12 PG rating PG76-22 PG82-16

It can be seen from the above results that the method provided by the present invention is used to process high-viscosity and high-carbon heavy oil raw materials, and a light component with a lower carbon residue value and a higher yield than that of subcritical solvent separation can be obtained, and the light component can be separated by vacuum distillation to achieve its graded utilization, especially to obtain a vacuum component II with a carbon residue value of 0.45-2.0w%, which can meet the requirements of directly being used as a raw material for the production of high-value-added product lubricating oil. The vacuum component I has a low carbon residue value and low metal content, and enters the hydrogenation unit, which can improve the operating cycle of the hydrogenation unit.

Comparing the methods of Example 1 and Comparative Example 1, it can be seen that the method provided by the present invention can obtain light components with lower carbon residue value and higher yield than that of subcritical solvent separation;

Comparing the methods of Example 1 and Comparative Example 2, it can be seen that the flash point of the light component is less than 280°C. If vacuum distillation is not performed, it is not suitable to be directly used as a raw material for producing bright oil.

The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims (10)

1. A method for processing heavy oil, characterized in that the method comprises: (1) subjecting a heavy oil raw material to atmospheric distillation to obtain atmospheric distillate oil and atmospheric residue oil; the heavy oil raw material has a density at 20° C. greater than 0.92 g/cm ³ and a residual carbon value greater than 6 w %; (2) contacting the atmospheric residue with a solvent in countercurrent flow to perform extraction separation to obtain a light component and a heavy component; wherein the temperature of the extraction separation is higher than the critical temperature of the solvent, and the pressure of the extraction separation is higher than the critical pressure of the solvent; and the heavy component is used as an additive for hard asphalt; (3) subjecting the light component to vacuum distillation to obtain vacuum component I, vacuum component II and vacuum component III; wherein the vacuum component I has a residual carbon value of less than 0.45w%, and is used as a hydrogenation feedstock; the vacuum component II has a residual carbon value of 0.45-2.0w%, and is used as a lubricating oil feedstock; and the vacuum component III has a residual carbon value of greater than 2.0w%, and is used as a catalytic cracking feedstock. 2. The method according to claim 1, wherein, in step (1), the atmospheric residue is a fraction with a temperature greater than 350°C; and/or the product of the atmospheric distillation further comprises a gas component. 3. The method according to claim 1, wherein in step (1), the viscosity of the atmospheric residue at 100°C is greater than 280 ^mm2 /s and the carbon residue value is not less than 13w%; preferably, the viscosity of the atmospheric residue at 100°C is 320-5500 ^mm2 /s and the carbon residue value is 15-18w%; And/or, the atmospheric residue has a density at 20°C greater than 0.95 g/cm ³ . 4. The method according to any one of claims 1 to 3, wherein in step (1), the atmospheric residue has a nickel content of 20-130 mg/kg, a vanadium content of 1-380 mg/kg, a nitrogen content of 0.4-1.1 w% and a sulfur content of 0.3-3.5 w%. 5. The method according to any one of claims 1 to 3, wherein in step (2), the conditions for the extraction separation include: a temperature of 110-175° C. and a pressure of 7.5-12 MPa; Preferably, the extraction separation is carried out in an extraction tower, and the bottom temperature of the extraction tower is 110-165° C., and the top temperature of the extraction tower is 115-175° C.; More preferably, the bottom temperature of the extraction tower is lower than the top temperature. 6. The method according to any one of claims 1 to 3, wherein in step (2), the volume ratio of the solvent to the atmospheric residue is 6-12:1; And/or, the solvent is selected from at least one of C3-C4 alkanes, preferably propane and/or isobutane. 7. The method according to any one of claims 1 to 3, wherein in step (2), the distillation range of the light component is 345-737°C; the yield of the light component is 15-60%; And/or, the carbon residue value of the light component is 0.2-5.5w%; the viscosity at 100°C is ^15-80mm2 /s. 8. The method according to any one of claims 1 to 3, wherein in step (2), the softening point of the heavy component is 65-125°C; the yield of the heavy component is 40-85%; And/or, the density of the heavy component at 20° C. is 0.99-1.07 g/cm ³ ; and the carbon residue value is 20-30 w %. 9. The method according to any one of claims 1 to 3, wherein in step (3), the temperature of the reduced pressure distillation is 370-580°C; And/or, the first cutting temperature of the decompression component I and the decompression component II is 370-460° C.; the second cutting temperature of the decompression component II and the decompression component III is 420-580° C., and the first cutting temperature is lower than the second cutting temperature; The decompression component I is a fraction having a temperature lower than the first cutting temperature, the decompression component II is a fraction having a temperature between the first cutting temperature and the second cutting temperature, and the decompression component III is a fraction having a temperature higher than the second cutting temperature. 10. The method according to any one of claims 1 to 3, wherein in step (3), the viscosity of the reduced pressure component I at 100°C is 10-50 ^mm2 /s; the total content of nickel and vanadium is less than 5 mg/kg; and/or, the viscosity of the reduced pressure component II at 100°C is 25-150 mm ² /s; the flash point is greater than 280°C; And/or, the viscosity of the reduced pressure component III at 100° C. is 90-210 mm ² /s.