Petroleum coke and method for its production

Abstract

This invention relates to the field of isotropic carbon materials technology, specifically to a petroleum coke and its preparation method. (1) After desolidation of inferior aromatic oil, it is separated to obtain light and heavy components; wherein the separation method is selected from distillation and / or extraction, the cutting temperature of distillation is 450-550℃, and the extraction solvent of extraction is n-alkanes; (2) The heavy components, hydrogen and hydrogenation catalyst are contacted to carry out a hydrogenation reaction to obtain hydrogen-rich gas and hydrogenated oil; (3) The hydrogenated oil and optional auxiliary oil are subjected to delayed coking to obtain petroleum coke. The petroleum coke preparation method provided in this invention uses inferior aromatic oil as raw material and utilizes the heavy components in the inferior aromatic oil to prepare petroleum coke that can be used to prepare isotropic graphite, solving the problem of the outlet of inferior aromatic oil, significantly improving the added value of the heavy fraction in inferior aromatic oil, and is suitable for industrial promotion.

Description

Technical Field

[0001] This invention relates to the field of isotropic carbon materials technology, specifically to a petroleum coke and its preparation method. Background Technology

[0002] Isotropic graphite refers to graphite materials with disordered orientation of graphite crystallites and an isotropic structure. The physical and chemical properties of isotropic graphite do not change with its spatial orientation. That is, the thermal properties (such as the coefficient of thermal expansion), mechanical properties, and electrical properties (such as resistivity) of isotropic graphite are roughly the same in all directions. Due to its excellent properties, it is widely used in semiconductor industry, photovoltaic industry, nuclear energy, electrical discharge machining and other fields.

[0003] The raw materials for preparing isotropic graphite meet the following requirements: sulfur content <0.5wt%, ash content <0.3wt%, volatile matter content ≤8wt%, and true density ≥2.10g / cm³. 3 Tap density (0.5-1mm) ≥ 0.88 g / cm³ 3 Isotropic carbon materials, such as petroleum coke.

[0004] CN101823707A discloses a process for producing isostatic graphite, which uses petroleum coke or pitch coke as raw material, pulverizes it to 5-20μm through airflow, then performs a first kneading, rolling, extrusion molding, rapid carbonization, crushing, screening, a second kneading, rolling, crushing, screening, preforming, and isostatic pressing, calcination, impregnation, graphitization and other processes to obtain fine-particle isostatic graphite material.

[0005] Currently, petroleum coke suitable for preparing isotropic graphite is generally produced using light components with boiling points ≤500℃ from aromatic-rich oils such as catalytic cracking slurry oil and ethylene tar. This method has the following main drawbacks:

[0006] 1) The deterioration of petroleum feedstocks has led to increasingly poor properties of aromatic oils, making it difficult to use inferior aromatic oils to produce petroleum coke that can be used to prepare isotropic graphite; 2) Existing preparation methods cannot efficiently utilize heavy components such as gums and asphaltenes in inferior aromatic oils, resulting in poor comprehensive utilization performance of inferior aromatic oils.

[0007] CN114479906A discloses a method for preparing high-quality petroleum coke, which includes: (1) mixing feedstock containing high aromatic components with a light mixed liquid phase component rich in tricyclic and tetracyclic aromatics, and then heating the mixed feedstock through a coking heating unit before it enters a coking tower to generate oil gas and a broad-area mesophase; (2) the coking tower enters a gas flow coking stage to react and generate oil gas and needle coke, and during the gas flow coking stage of the coking tower, the light mixed liquid phase component rich in tricyclic and tetracyclic aromatics heated by the coking heating unit is separately introduced into the coking tower. However, this method produces high-quality needle coke, which cannot be used to prepare isotropic graphite.

[0008] Therefore, there is an urgent need to provide a method for preparing petroleum coke that can be used to prepare isotropic graphite from heavy components in low-quality aromatic oil. Summary of the Invention

[0009] The purpose of this invention is to solve the problem that the existing technology has poor comprehensive utilization performance of inferior aromatic oil and is difficult to use for producing petroleum coke that can be used to prepare isotropic graphite, and to provide a petroleum coke and its preparation method.

[0010] To achieve the above objectives, a first aspect of the present invention provides a method for preparing petroleum coke, wherein the method includes the following steps:

[0011] (1) After desolidation of inferior aromatic oil, it is separated to obtain light components and heavy components; wherein, the separation method is selected from distillation and / or extraction, the cutting temperature of distillation is 450-550℃, and the extraction solvent of extraction is n-alkanes;

[0012] (2) The heavy components, hydrogen and hydrogenation catalyst are brought into contact to carry out a hydrogenation reaction to obtain hydrogen-rich gas and hydrogenated oil.

[0013] (3) The hydrogenated oil and optional auxiliary oil are subjected to delayed coking to obtain petroleum coke.

[0014] The beneficial technical effects achieved by the present invention through the above technical solution are as follows:

[0015] 1) The method for preparing petroleum coke provided in this invention uses inferior aromatic oil as raw material and utilizes the heavy components in the inferior aromatic oil to prepare petroleum coke that can be used to prepare isotropic graphite, thus solving the problem of the outlet of inferior aromatic oil and significantly improving the added value of the heavy fraction in the inferior aromatic oil.

[0016] 2) The method for preparing petroleum coke provided in this invention broadens the sources of petroleum coke for preparing isotropic graphite, and the process is simple, easy to operate, and suitable for industrial promotion. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein 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 the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] A first aspect of the present invention provides a method for preparing petroleum coke, wherein the method includes the following steps:

[0019] (1) After desolidation of inferior aromatic oil, it is separated to obtain light components and heavy components; wherein, the separation method is selected from distillation and / or extraction, the cutting temperature of distillation is 450-550℃, and the extraction solvent of extraction is n-alkanes;

[0020] (2) The heavy components, hydrogen and hydrogenation catalyst are brought into contact to carry out a hydrogenation reaction to obtain hydrogen-rich gas and hydrogenated oil.

[0021] (3) The hydrogenated oil and optional auxiliary oil are subjected to delayed coking to obtain petroleum coke.

[0022] In step (1):

[0023] In one embodiment of the present invention, the inferior aromatic-rich oil is a heavy oil rich in aromatics generated during the oil refining process. The distillation range of the heavy oil can be 330-720°C, including but not limited to catalytic cracking slurry oil from catalytic cracking process, ethylene tar from ethylene cracking process, lubricating oil extract oil obtained during lubricating oil production process, and thermal cracking residue oil obtained during thermal cracking production process.

[0024] In one embodiment of the present invention, the inferior aromatic oil comprises, by weight, 10-20 wt% saturated hydrocarbons, 50-70 wt% aromatics, 15-25 wt% gums, and 1-10 wt% asphaltenes.

[0025] In one embodiment of the present invention, the inferior aromatic oil contains 0.005-0.4 wt% ash, 0.3-1.5 wt% sulfur, 0.1-0.5 wt% nitrogen, and 10-800 μg / g total metals.

[0026] In this invention, the inferior aromatic oil contains catalyst powder added during the refining process, resulting in a relatively high ash content. Desolidification treatment of the inferior aromatic oil can reduce the ash content and prevent solid powder from affecting subsequent hydrotreating and delayed coking processes.

[0027] In one embodiment of the invention, the deconsolidation method is selected from sedimentation and / or filtration, preferably sedimentation.

[0028] In one embodiment of the present invention, the sedimentation operation includes: first, letting the inferior aromatic oil stand at 100-120°C for 36-60 hours, and then separating the upper clear liquid.

[0029] In one embodiment of the present invention, the filtration operation includes filtering the inferior aromatic oil at 160-200°C. In this invention, filtration can be performed using a filter screen, or using filter media such as ceramics, metals, or polymers.

[0030] In one embodiment of the present invention, the distillation is carried out in a vacuum distillation column, and the cutting temperature of the distillation is preferably 480-520°C. The present invention does not impose special limitations on the operating conditions of the vacuum distillation column; conventional operations can be used to cut the deconsolidated, low-quality aromatic oil.

[0031] In one embodiment of the present invention, the solvent n-alkane is selected from one or more of n-butane, n-pentane, n-hexane, n-heptane, n-octane, and n-decane, preferably n-butane and / or n-pentane.

[0032] In one embodiment of the present invention, the extraction operating conditions include: the mass ratio of the deconsolidated aromatic oil to the solvent is 1:2-10, preferably 1:4-6; the extraction temperature is 90-160℃, preferably 110-140℃; and the extraction pressure is 2-5MPa, preferably 3-4.5MPa.

[0033] In this invention, the light components separated from the deconsolidated inferior aromatic oil can be used as raw materials for producing anisotropic carbon materials such as needle coke, while the heavy components separated from the deconsolidated inferior aromatic oil can be used as raw materials for producing isotropic graphite after hydrogenation and delayed coking. The method provided in this invention can fully utilize each component in the inferior aromatic oil, achieving comprehensive utilization of the inferior aromatic oil and comprehensively enhancing its added value.

[0034] In step (2),

[0035] In one embodiment of the present invention, the hydrogenation catalyst includes a hydrogenation protectant and a hydrogenation refiner.

[0036] In this invention, both hydrogenation protectants and hydrogenation refining agents known in the art can be used. In this invention, the hydrogenation protectant can intercept particulate matter in the desolidified aromatic hydrocarbons, effectively removing impurities such as metals and residual carbon, thereby reducing the catalyst bed pressure drop, effectively reducing coking at the top of the catalyst bed, and extending the operating cycle of the unit. The hydrogenation refining agent is mainly used to remove impurities such as S and N from the desolidified aromatic hydrocarbons.

[0037] In one embodiment of the present invention, the hydrogenation protectant is selected from one or more of RG-20B, RG-30B, and RG-40B, preferably RG-30B; the hydrogenation refining agent is selected from one or more of RMS-10, RMS-20, and RMS-30, preferably RMS-30.

[0038] In one embodiment of the present invention, the hydrogenation treatment is carried out in a fixed-bed reactor, which is sequentially filled with a hydrogenation protectant and a hydrogenation refining agent, wherein the volume ratio of the hydrogenation protectant to the hydrogenation refining agent is 5-25:75-95, preferably 10-15:85-90.

[0039] In one embodiment of the present invention, the operating conditions for the hydrogenation treatment include: a hydrogenation reaction temperature of 280-445°C, preferably 300-350°C; a hydrogen partial pressure of 2-10 MPa, preferably 3-6 MPa; and a volume hourly space velocity of 0.2-2 h⁻¹. -1 Preferably 0.6-1.2h -1 The hydrogen-to-oil volume ratio is 200-1000 Nm. 3 / m 3 Preferably 600-800 Nm 3 / m 3 .

[0040] In this invention, volume hourly space velocity (VHSV) refers to the volume of heavy components passing through a unit volume of catalyst per unit time, and hydrogen-to-oil volume ratio refers to the volume ratio of hydrogen to heavy components.

[0041] In one embodiment of the present invention, after the hydrogenation reaction is completed, the hydrogenation product is subjected to gas-liquid separation to obtain hydrogen-rich gas and hydrogenated oil; wherein, the operating conditions for gas-liquid separation include: separation temperature of 200-250℃ and separation pressure of 3-5MPa.

[0042] In this invention, the liquid product separated from the hydrogenation product is hydrogenated oil, and the gaseous product separated is hydrogen-rich gas, comprising various C1-C4 hydrocarbons and hydrogen. To reduce hydrogen consumption, preferably, the hydrogen-rich gas is added to the hydrogen and recycled back into the hydrogenation process.

[0043] In step (3),

[0044] In one embodiment of the present invention, the auxiliary oil is selected from one or more of atmospheric residue, vacuum residue, thermal cracking residue, and furfural extract oil, preferably vacuum residue.

[0045] In this invention, atmospheric residue, vacuum residue, thermal cracking residue, and furfural extract oil have well-known meanings. The hydrogenated oil can be subjected to delayed coking alone, or it can be subjected to delayed coking after mixing with auxiliary oil. The inventors of this invention have discovered that delaying coking after mixing hydrogenated oil and auxiliary oil can further reduce the ash content in petroleum coke.

[0046] In one embodiment of the present invention, the hydrogenated oil and auxiliary oil are subjected to delayed coking treatment; wherein the mass ratio of the hydrogenated oil to the auxiliary oil is 5-15:1, preferably 8-12:1.

[0047] In one embodiment of the present invention, the operating conditions of the delayed coking treatment include: the outlet temperature of the heating furnace is 440-550℃, preferably 460-520℃; the temperature at the top of the coke tower is 400-460℃, preferably 410-440℃; the pressure at the top of the coke tower is 0.3-1MPa, preferably 0.5-0.8MPa; and the circulation ratio is 0.4-1.5, preferably 0.6-1.

[0048] In this invention, delayed coking treatment yields coking dry gas, coking gasoline, coking diesel, coking gas oil, and petroleum coke. The resulting petroleum coke is an isotropic carbon material that can be used to produce isotropic graphite.

[0049] In one embodiment of the present invention, the delayed coking process is carried out in a delayed coking apparatus. As is common knowledge in the art, a delayed coking apparatus includes at least a heating furnace, two coke towers and a fractionation tower.

[0050] A second aspect of the present invention provides a petroleum coke prepared using the preparation method described in the first aspect of the present invention.

[0051] In one embodiment of the present invention, the petroleum coke contains less than 0.5 wt% sulfur, less than 0.3 wt% ash, less than 8 wt% volatile matter, and has a true density of ≥2.1 g / cm³. 3 Tap density (0.5-1mm) ≥ 0.88 g / cm³ 3 Particle homogeneity ≥ 0.8.

[0052] The petroleum coke in this invention has high true density and tap density, as well as good particle isotropy, making it a suitable raw material for producing isotropic graphite. This invention utilizes the heavy fractions in low-quality aromatic oil as raw materials to produce petroleum coke suitable for preparing isotropic graphite, significantly increasing the added value of low-quality aromatic oil.

[0053] The present invention will be described in detail below through examples. The hydrogenation protectant uses the RG-30B catalyst developed by the Research Institute of Petroleum Processing and Refining (RIPP), and the hydrogenation refining agent uses the RMS-30 catalyst developed by RIPP. Both the hydrogenation protectant and the hydrogenation refining agent are produced by Changling Catalyst Plant of Sinopec Catalyst Branch.

[0054] Example 1

[0055] (1) Place the catalytic cracking slurry I in the feed buffer tank and let it stand at 110℃ for 48h to carry out desolidification treatment and separate the upper clear liquid; introduce the separated upper clear liquid into the vacuum distillation tower for vacuum distillation to obtain light components with boiling point <510℃ and heavy components with boiling point ≥510℃.

[0056] (2) The above-mentioned heavy components are pressurized by a booster pump and mixed with hydrogen. After being heated to 350°C in a heater, the mixture enters a fixed-bed hydrogenation reactor and is sequentially contacted with RG-30B catalyst and RMS-30 catalyst to carry out a hydrogenation reaction, yielding hydrogenated products. The loading volume ratio of RG-30B catalyst to RMS-30 catalyst is 10:90, the hydrogenation reaction temperature is 320°C, the hydrogen partial pressure is 4.5 MPa, and the hydrogen oil volume is 650 Nm³. 3 / m 3 The volumetric space velocity is 1 h. -1 ;

[0057] The hydrogenation products were then introduced into a high-pressure separator and subjected to gas-liquid separation at 220°C and 4 MPa to obtain hydrogen-rich gas and hydrogenated oil. The hydrogen-rich gas was then added to the hydrogen and returned to the fixed-bed hydrogenation reactor for recycling.

[0058] (3) The above-mentioned hydrogenated oil is introduced into a delayed coking unit for thermal cracking reaction to obtain coking dry gas, coking gasoline, coking diesel, coking gas oil and petroleum coke.

[0059] The operating conditions of the delayed coking unit include a furnace outlet temperature of 470-500℃, a coke tower top temperature of 420℃, a coke tower top pressure of 0.7MPa, and a circulation ratio of 0.8. The yields of coking dry gas, coking gasoline, coking diesel, coking gas oil, and petroleum coke are 20.12%, 9.21%, 17.74%, 5.41%, and 47.52%, respectively.

[0060] The composition of catalytic cracking slurry I is shown in Table 1:

[0061] Table 1

[0062]

[0063]

[0064] The properties of petroleum coke are shown in Table 2:

[0065] Table 2

[0066]

[0067]

[0068] Note: Tapped density refers to the tapped density of petroleum coke with an average particle size of 0.5-1 mm. Particle homogeneity is tested using the ratio of thermal expansion coefficients.

[0069] As shown in Table 2, the petroleum coke prepared by the present invention using catalytic cracking slurry I is an isotropic carbon material. Its sulfur content, ash content, volatile matter, true density and tap density meet the requirements of raw materials that can be used to prepare isotropic graphite, and it can be used to prepare high-quality isotropic graphite.

[0070] Example 2

[0071] (1) The catalytic cracking slurry II was placed in the feed buffer tank and filtered at 180°C using a metal filter medium to remove the solid powder. The solidified catalytic cracking slurry II was extracted with n-butane at a mass ratio of 1:4.5 at 125°C and 4.2 MPa, and then the light and heavy components were separated.

[0072] (2) The above-mentioned heavy components are pressurized by a booster pump and mixed with hydrogen. After being heated to 360°C in a heater, the mixture enters a fixed-bed hydrogenation reactor and is sequentially contacted with RG-30B catalyst and RMS-30 catalyst for hydrogenation treatment to obtain hydrogenated products. The loading volume ratio of RG-30B catalyst to RMS-30 catalyst is 15:85, the hydrogenation reaction temperature is 330°C, the hydrogen partial pressure is 5.0 MPa, and the hydrogen oil volume is 750 Nm³. 3 / m 3 The volumetric space velocity is 0.8 h⁻¹. -1 ;

[0073] The hydrogenation products were then introduced into a high-pressure separator and subjected to gas-liquid separation at 220°C and 4 MPa to obtain hydrogen-rich gas and hydrogenated oil. The hydrogen-rich gas was then added to the hydrogen and returned to the fixed-bed hydrogenation reactor for recycling.

[0074] (3) The above-mentioned hydrogenated oil and vacuum residue are mixed in a mass ratio of 9:1 and then introduced into a delayed coking unit for thermal cracking reaction to obtain coking dry gas, coking gasoline, coking diesel, coking gas oil and petroleum coke.

[0075] The operating conditions of the delayed coking unit include a furnace outlet temperature of 465-505℃, a coke tower top temperature of 430℃, a coke tower top pressure of 0.6MPa, and a circulation ratio of 0.6. The yields of coking dry gas, coking gasoline, coking diesel, coking gas oil, and petroleum coke are 17.28%, 11.19%, 21.12%, 5.6%, and 44.81%, respectively.

[0076] The compositions of catalytic cracking slurry II and vacuum residue are shown in Table 3.

[0077] Table 3

[0078]

[0079]

[0080] The properties of petroleum coke are shown in Table 4:

[0081] Table 4

[0082] project Performance indicators S, wt% 0.28 Ash content, wt% 0.15 Volatile matter, wt% 6.8 <![CDATA[True density, g / cm 3 > 2.12 <![CDATA[Tap density (0.5 - 1 mm), g / cm 3 > 0.91 Particle homogeneity 0.85

[0083] Tap density refers to the tap density of petroleum coke with an average particle size of 0.5-1 mm. Particle homogeneity is tested using the ratio of thermal expansion coefficients.

[0084] As shown in Table 4, the petroleum coke prepared by the present invention using catalytic cracking slurry II and vacuum residue is an isotropic carbon material. Its sulfur content, ash content, volatile matter, true density and tap density meet the raw material requirements for the preparation of isotropic graphite, and it can be used to prepare high-quality isotropic graphite.

[0085] Comparative Example 1

[0086] Similar to Example 1, except that the catalytic cracking slurry I is directly introduced into a vacuum distillation tower for vacuum distillation to obtain light components with a boiling point <510℃ and heavy components with a boiling point ≥510℃; then the heavy components are introduced into a delayed coking unit for thermal cracking reaction.

[0087] The properties of the prepared petroleum coke were analyzed, and the results are shown in Table 5.

[0088] Table 5

[0089] petroleum coke Performance indicators S, wt% 0.72 Ash content, wt% 0.35 Volatile matter, wt% 7.2 <![CDATA[True density, g / cm 3 > 2.08 <![CDATA[Tap density (0.5 - 1 mm), g / cm 3 > 0.84 Particle homogeneity 0.60

[0090] Table 5 shows that the petroleum coke prepared in Comparative Example 1 has a sulfur content as high as 0.72 wt% and an ash content of 0.35 wt%, exceeding the requirements for raw materials used in the preparation of isotropic graphite, which stipulate a sulfur content of less than 0.5 wt% and an ash content of less than 0.3 wt%. Meanwhile, its true density is 2.08 g / cm³. 3 The tap density is 0.84 (0.5-1 mm), g / cm³. 3 This indicates that the microstructure of petroleum coke is too dense and cannot meet the requirements of isotropic graphite raw materials. The petroleum coke prepared in Comparative Example 1 cannot be used to produce isotropic graphite.

[0091] Test Example 1

[0092] The petroleum coke prepared in Examples 1-2 and Comparative Example 1 was used to prepare graphite under the same conditions, wherein the graphitization temperature was 2850℃ and the residence time was 2h. Then, the isotropic properties, bulk density and flexural strength of the graphite were tested, and the test results are shown in Table 6.

[0093] Table 6

[0094] same sex <![CDATA[Volume density, g / cm 3 > Flexural strength, MPa Example 1 0.88 1.90 98.1 Example 2 0.85 1.87 93.5 Comparative Example 1 0.60 1.62 62.4

[0095] As can be seen from Table 6, the graphite prepared using petroleum coke in Examples 1-2 is isotropic graphite with high bulk density and flexural strength, meeting application requirements. In contrast, the graphite prepared using petroleum coke in Comparative Example 1 has poor isotropy, higher density, and higher impurity content, failing to meet the relevant performance requirements of isotropic graphite.

[0096] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing petroleum coke that can be used to prepare isotropic graphite, characterized in that, The method includes the following steps: (1) After desolidation of inferior aromatic oil, it is separated to obtain light components and heavy components; The inferior aromatic oil, based on its total mass, comprises 10-20 wt% saturated hydrocarbons, 50-70 wt% aromatics, 15-25 wt% gums, and 1-10 wt% asphaltenes; and based on its total mass, the inferior aromatic oil contains 0.005-0.4 wt% ash, 0.3-1.5 wt% sulfur, 0.1-0.5 wt% nitrogen, and 10-800 µg / g of total metals. The separation process is selected from distillation and / or extraction, the distillation cutting temperature is 480-550℃, and the extraction solvent is n-alkanes. Wherein, the n-alkane is selected from one or more of n-butane, n-pentane, n-hexane, n-heptane, n-octane, and n-decane; the extraction operating conditions include: the mass ratio of the deconsolidated aromatic oil to the extraction solvent is 1:2-10, the extraction temperature is 90-160℃, and the extraction pressure is 2-5MPa. (2) The heavy components, hydrogen, and hydrogenation catalyst are contacted to carry out a hydrogenation reaction to obtain hydrogen-rich gas and hydrogenated oil; wherein the operating conditions of the hydrogenation reaction include: hydrogenation reaction temperature of 280-445℃, hydrogen partial pressure of 2-10MPa, and volume hourly space velocity of 0.2-2h. -1 And the hydrogen-to-oil volume ratio is 200-1000 Nm 3 / m 3 ; (3) The hydrogenated oil and optional auxiliary oil are subjected to delayed coking to obtain petroleum coke; wherein the operating conditions of the delayed coking treatment include: the outlet temperature of the heating furnace is 440-550℃, the temperature at the top of the coke tower is 400-460℃, the pressure at the top of the coke tower is 0.3-1MPa, and the circulation ratio is 0.4-1.

5. The petroleum coke contains less than 0.5 wt% sulfur, less than 0.3 wt% ash, less than 8 wt% volatile matter, and has a true density of ≥2.1 g / cm³. 3 Tap density (0.5-1mm) ≥ 0.88 g / cm³ 3 Particle homogeneity ≥ 0.

8.

2. The preparation method according to claim 1, wherein, The inferior aromatic-rich oil is a heavy oil rich in aromatics generated during the oil refining process, selected from one or more of the following: catalytic cracking slurry oil, ethylene tar, lubricating oil extract, and thermal cracking residue oil.

3. The preparation method according to claim 1 or 2, wherein, The deconsolidation method is selected from sedimentation and / or filtration.

4. The preparation method according to claim 3, wherein, The sedimentation process includes separating the upper clear liquid after the inferior aromatic oil has been allowed to stand at 100-120°C for 36-60 hours.

5. The preparation method according to claim 3, wherein, The filtration operation includes filtering the inferior aromatic oil at 160-200°C.

6. The preparation method according to any one of claims 1-2 and 4-5, wherein, The distillation is carried out in a vacuum distillation column.

7. The preparation method according to claim 6, wherein, The n-alkane is n-butane and / or n-pentane.

8. The preparation method according to any one of claims 1-2, 4-5 and 7, wherein, The extraction operating conditions include: a mass ratio of the deconsolidated aromatic oil to the extraction solvent of 1:4-6, an extraction temperature of 110-140℃, and an extraction pressure of 3-4.5MPa.

9. The preparation method according to any one of claims 1-2, 4-5 and 7, wherein, The hydrogenation catalyst includes a hydrogenation protectant and a hydrogenation refiner.

10. The preparation method according to claim 9, wherein, The hydrogenation protectant is selected from one or more of RG-20B, RG-30B, and RG-40B.

11. The preparation method according to claim 9, wherein, The hydrogenated reagent is selected from one or more of RMS-10, RMS-20, and RMS-30.

12. The preparation method according to claim 10, wherein, The hydrogenation protectant is RG-30B.

13. The preparation method according to claim 11, wherein, The hydrogenated refining agent is RMS-30.

14. The preparation method according to claim 9, wherein, The hydrogenation reaction is carried out in a fixed-bed reactor, which is sequentially filled with a hydrogenation protectant and a hydrogenation refining agent, wherein the volume ratio of the hydrogenation protectant to the hydrogenation refining agent is 5-25:75-95.

15. The preparation method according to claim 14, wherein, The filling volume ratio of the hydrogenation protective agent to the hydrogenation refining agent is 10-15:85-90.

16. The preparation method according to any one of claims 1-2, 4-5, 7 and 10-15, wherein, The operating conditions for the hydrogenation reaction include: a hydrogenation reaction temperature of 300-350℃, a hydrogen partial pressure of 3-6 MPa, and a volume hourly space velocity of 0.6-1.2 h⁻¹. -1 And the hydrogen-to-oil volume ratio is 600-800 Nm 3 / m 3 .

17. The preparation method according to any one of claims 1-2, 4-5, 7 and 10-15, wherein, After the hydrogenation reaction is completed, the hydrogenation product is subjected to gas-liquid separation to obtain hydrogen-rich gas and hydrogenated oil; wherein the operating conditions for gas-liquid separation include: separation temperature of 200-250℃ and separation pressure of 3-5MPa.

18. The preparation method according to claim 17, wherein, The hydrogen-rich gas is added to the hydrogen gas and returned to the hydrogenation reaction for recycling.

19. The preparation method according to any one of claims 1-2, 4-5, 7, 10-15, and 18, wherein, The auxiliary oil is selected from one or more of atmospheric residue, vacuum residue, thermal cracking residue, and furfural extract.

20. The preparation method according to claim 19, wherein, The hydrogenated oil and auxiliary oil are subjected to delayed coking treatment; wherein the mass ratio of the hydrogenated oil to the auxiliary oil is 5-15:

1.

21. The preparation method according to claim 19, wherein, The auxiliary oil is vacuum residue.

22. The preparation method according to claim 20, wherein, The mass ratio of hydrogenated oil to auxiliary oil is 8-12:

1.

23. The preparation method according to any one of claims 1-2, 4-5, 7, 10-15, 18, and 20-22, wherein, The operating conditions for the delayed coking process include: a furnace outlet temperature of 460-520℃, a coke tower top temperature of 410-440℃, a coke tower top pressure of 0.5-0.8MPa, and a circulation ratio of 0.6-1.

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