Petroleum coke and preparation method thereof

Abstract

The invention relates to the technical field of isotropic carbon materials, in particular to petroleum coke and a preparation method thereof. The method comprises the following steps: (1) carrying out solid removal on inferior aromatic hydrocarbon-rich oil, and then carrying out separation treatment to obtain light components and heavy components; wherein the separation mode is selected from distillation and / or extraction, the cutting temperature of distillation is 450-550 DEG C, and an extraction solvent for extraction is n-alkane; (2) contacting the heavy component, hydrogen and a hydrogenation catalyst, and carrying out hydrogenation reaction to obtain hydrogen-rich gas and hydrogenated oil; and (3) carrying out delayed coking on the hydrogenated oil and optional auxiliary oil to obtain petroleum coke. According to the preparation method of the petroleum coke, provided by the invention, the inferior aromatic hydrocarbon-rich oil is taken as a raw material, and the petroleum coke capable of being used for preparing isotropic graphite is prepared by utilizing heavy components in the inferior aromatic hydrocarbon-rich oil, so that the problem of the outlet of the inferior aromatic hydrocarbon-rich oil is solved, the added value of heavy fractions in the inferior aromatic hydrocarbon-rich oil is remarkably improved, and the preparation method is suitable for industrial popularization.

Description

Technical Field

[0001] The invention relates to the technical field of isotropic carbon materials, and in particular to petroleum coke and a preparation method thereof. Background Art

[0002] Isotropic graphite refers to a graphite material with an isotropic structure in which graphite microcrystals are arranged in an irregular orientation. The physical and chemical properties of isotropic graphite do not change with the change of its spatial direction, that is, the thermal properties (such as thermal expansion coefficient, etc.), mechanical properties, and electrical properties (such as resistivity, etc.) of isotropic graphite in all directions are roughly the same. Due to its excellent performance, it is widely used in the semiconductor industry, photovoltaic industry, nuclear energy, EDM and other fields.

[0003] The raw materials for preparing isotropic graphite are as follows: sulfur content <0.5wt%, ash content <0.3wt%, volatile content ≤8wt%, true density ≥2.10g / cm 3 , tap density (0.5-1mm) ≥ 0.88g / cm 3 Isotropic carbon materials, for example, petroleum coke.

[0004] CN101823707A discloses a process for producing isostatic graphite, which uses petroleum coke or asphalt coke as raw material, pulverizes it into 5-20 μm by air flow, and then undergoes primary kneading, sheet rolling, extrusion molding, rapid carbonization, crushing, screening, secondary kneading, sheet rolling, crushing, screening, preforming, isostatic molding, roasting, impregnation, graphitization and other processes to obtain fine-grained isostatically pressed isotropic graphite material.

[0005] At present, petroleum coke for preparing isotropic graphite is generally produced from light components with a boiling point of ≤500°C in aromatic-rich oils such as catalytic cracking oil slurry and ethylene tar. This method has the following main defects:

[0006] 1) The deterioration of petroleum raw materials has led to the increasingly poor properties of aromatic-rich oil, and inferior aromatic-rich oil is difficult to be used to produce petroleum coke that can be used to prepare isotropic graphite; 2) The existing preparation methods cannot efficiently utilize heavy components such as gums and asphaltene in inferior aromatic-rich oil, resulting in poor comprehensive utilization performance of inferior aromatic-rich oil.

[0007] CN114479906A discloses a method for preparing high-quality petroleum coke, which comprises: (1) mixing a feedstock oil containing a high aromatic component with a light mixed liquid phase component rich in tricyclic and tetracyclic aromatics, and heating the mixed feed in a coke-generating heating unit before entering a coke tower to generate oil gas and a wide-range intermediate phase; (2) the coke tower enters a coke-pulling stage to react and generate oil gas and needle coke, and in the coke-pulling stage of the coke tower, the light mixed liquid phase component rich in tricyclic and tetracyclic aromatics heated by the coke-pulling heating unit is separately introduced into the coke tower. However, this method only produces high-quality needle coke and cannot be used to prepare isotropic graphite.

[0008] Therefore, it is urgent to provide a method for preparing petroleum coke that can be used to prepare isotropic graphite by utilizing the heavy components in inferior aromatic-rich oil. Summary of the invention

[0009] The purpose of the present invention is to solve the problem in the prior art that inferior aromatic-rich oil has poor comprehensive utilization performance and is difficult to be used to produce petroleum coke that can be used to prepare isotropic graphite, and to provide a petroleum coke and a preparation method thereof.

[0010] In order to achieve the above object, the first aspect of the present invention provides a method for preparing petroleum coke, wherein the method comprises the following steps:

[0011] (1) After desolidifying the inferior aromatic-rich oil, separation treatment is performed to obtain light components and heavy components; wherein the separation method is selected from distillation and / or extraction, the cutting temperature of the distillation is 450-550° C., and the extraction solvent of the extraction is normal alkane;

[0012] (2) contacting the heavy component, hydrogen and a hydrogenation catalyst to carry out a hydrogenation reaction to obtain hydrogen-rich gas and hydrogenated oil;

[0013] (3) Delaying coking the hydrogenated oil and optional auxiliary oil to obtain petroleum coke.

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

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

[0016] 2) The method for preparing petroleum coke provided in the present invention broadens the source of petroleum coke for preparing isotropic graphite, and has a simple process, convenient operation, and is suitable for industrial promotion. DETAILED DESCRIPTION

[0017] 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.

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

[0019] (1) After desolidifying the inferior aromatic-rich oil, separation treatment is performed to obtain light components and heavy components; wherein the separation method is selected from distillation and / or extraction, the cutting temperature of the distillation is 450-550° C., and the extraction solvent of the extraction is normal alkane;

[0020] (2) contacting the heavy component, hydrogen and a hydrogenation catalyst to carry out a hydrogenation reaction to obtain hydrogen-rich gas and hydrogenated oil;

[0021] (3) Delaying coking the hydrogenated oil and optional auxiliary oil 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 in the oil refining process, and the distillation range of the heavy oil can be 330-720°C, including but not limited to catalytic cracking slurry from a catalytic cracking process, ethylene tar from an ethylene cracking process, lubricating oil extracted from a lubricating oil production process, and thermal cracking residue oil obtained in a thermal cracking production process.

[0024] In one embodiment of the present invention, based on the total mass of the inferior aromatic-rich oil, the inferior aromatic-rich oil comprises 10-20wt% of saturated hydrocarbons, 50-70wt% of aromatic hydrocarbons, 15-25wt% of colloids, and 1-10wt% of asphaltenes.

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

[0026] Among them, in the present invention, the ash content of the inferior aromatic-rich oil is relatively high because it contains some catalyst powder added during the oil refining process. Desolidification treatment of the inferior aromatic-rich oil can reduce the ash content, which can prevent the solid powder from affecting the subsequent hydroprocessing and delayed coking treatment.

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

[0028] In one embodiment of the present invention, the sedimentation operation comprises: firstly allowing the inferior aromatic-rich oil to 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 filtering operation includes filtering the inferior aromatic-rich oil at 160-200° C. In the present invention, the filtering can be performed using a filter screen, or a filter medium such as ceramic, metal, or polymer.

[0030] In one embodiment of the present invention, the distillation is carried out in a vacuum distillation tower, and the cutting temperature of the distillation is preferably 480-520° C. The present invention does not specifically limit the operating conditions of the vacuum distillation tower, and the desolidified inferior aromatic-rich oil can be cut according to conventional operations.

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

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

[0033] Among them, in the present invention, the light components separated from the inferior aromatic-rich oil after desolidification can be used as raw materials for producing anisotropic carbon materials such as needle coke, and the heavy components separated from the inferior aromatic-rich oil after desolidification can be used as raw materials for producing isotropic graphite after hydrogenation reaction and delayed coking treatment. The method provided in the present invention can make full use of each component in the inferior aromatic-rich oil, realize the comprehensive utilization of the inferior aromatic-rich oil, and comprehensively improve the added value of the inferior aromatic-rich oil.

[0034] In step (2),

[0035] In one embodiment of the present invention, the hydrogenation catalyst comprises a hydrogenation protectant and a hydrogenation finishing agent.

[0036] Among them, the hydrogenation protective agent and hydrogenation refining agent known in the art can be used in the present invention. In the present invention, the hydrogenation protective agent can intercept the particulate matter in the desolidified rich aromatics, effectively remove the impurities such as metals and residual carbon in the desolidified rich aromatics, so as to reduce the pressure drop of the catalyst bed, effectively reduce the coking on the top of the catalyst bed, and extend the operation cycle of the device. The hydrogenation refining agent is mainly used to remove impurities such as S and N in the desolidified rich aromatics.

[0037] In one embodiment of the present invention, the hydrogenation protective agent 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 hydroprocessing is carried out in a fixed bed reactor, and the fixed bed reactor is sequentially filled with a hydrogenation protective agent and a hydrogenation refining agent, and the filling volume ratio of the hydrogenation protective agent 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 of the hydroprocessing include: the hydrogenation reaction temperature is 280-445°C, preferably 300-350°C; the hydrogen partial pressure is 2-10MPa, preferably 3-6MPa; the volume space velocity is 0.2-2h -1 , preferably 0.6-1.2h -1 ; Hydrogen oil volume ratio is 200-1000Nm 3 / m 3 , preferably 600-800Nm 3 / m 3 .

[0040] In the present invention, volume space velocity 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 the gas-liquid separation include: a separation temperature of 200-250°C and a separation pressure of 3-5MPa.

[0042] Among them, in the present invention, the liquid phase product separated from the hydrogenation product is hydrogenated oil, and the gas phase product separated is hydrogen-rich gas, including various hydrocarbons of C1-C4 and hydrogen and other components. In order to reduce hydrogen consumption, preferably, the hydrogen-rich gas is added to the hydrogen and returned to the hydrogenation process for recycling.

[0043] In step (3),

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

[0045] Among them, atmospheric residue, vacuum residue, thermal cracking residue, and furfural extracted oil have well-known meanings. In the present invention, the hydrogenated oil can be subjected to delayed coking alone, or the hydrogenated oil and auxiliary oil can be mixed and then subjected to delayed coking. The inventor of the present invention has found through research that the ash content in petroleum coke can be further reduced by mixing the hydrogenated oil and auxiliary oil and then subjected to delayed coking.

[0046] In one embodiment of the present invention, the hydrogenated oil and the 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°C, preferably 460-520°C; the temperature of the top of the coke tower is 400-460°C, preferably 410-440°C; the pressure at the top of the coke tower is 0.3-1MPa, preferably 0.5-0.8MPa; the circulation ratio is 0.4-1.5, preferably 0.6-1.

[0048] Among them, in the present invention, after delayed coking treatment, coking dry gas, coking gasoline, coking diesel, coking gas oil and petroleum coke can be obtained. The obtained petroleum coke is an isotropic carbon material and 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 unit. As is common knowledge in the technical field, a delayed coking unit at least includes a heating furnace, two coke towers and a fractionation tower.

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

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

[0052] The petroleum coke in the present invention has a high true density and a tap density, as well as good particle homogeneity, and is a raw material for producing isotropic graphite. The present invention utilizes the recombinant fraction in the inferior aromatic-rich oil as a raw material to produce the petroleum coke that can be used for preparing isotropic graphite, which can significantly increase the added value of the inferior aromatic-rich oil.

[0053] The present invention will be described in detail below through examples. The hydrogenation protective agent uses the RG-30B catalyst developed by the Institute of Petroleum Science and Technology, and the hydrogenation refining agent uses the RMS-30 catalyst developed by the Institute of Petroleum Science and Technology. The hydrogenation protective agent and the hydrogenation refining agent are both produced by the Changling Catalyst Plant of Sinopec Catalyst Branch.

[0054] Example 1

[0055] (1) placing catalytic cracking slurry I in a raw material buffer tank, standing at 110° C. for 48 hours, performing a desolidification treatment, and separating an upper clear liquid; introducing the separated upper clear liquid into a vacuum distillation tower for vacuum distillation to obtain a light component with a boiling point of less than 510° C. and a heavy component with a boiling point of ≥510° C.;

[0056] (2) The heavy component is pressurized by a booster pump and mixed with hydrogen, and then heated to 350°C in a heating furnace and enters a fixed bed hydrogenation reactor, where it is contacted with the RG-30B catalyst and the RMS-30 catalyst in sequence to undergo a hydrogenation reaction to obtain a hydrogenated product; wherein the loading volume ratio of the RG-30B catalyst and the 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 Nm 3 / m 3 , volume space velocity is 1h -1 ;

[0057] Then, the hydrogenation product is introduced into a high-pressure separator, and gas-liquid separation is performed at 220°C and 4MPa to obtain hydrogen-rich gas and hydrogenated oil. The hydrogen-rich gas is added to hydrogen and returned to the fixed-bed hydrogenation reactor for recycling;

[0058] (3) introducing the hydrogenated oil 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] Among them, the operating conditions of the delayed coking unit include a heating furnace outlet temperature of 470-500°C, a coke tower top temperature of 420°C, 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] Wherein, 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: Tap density refers to the tap density of petroleum coke with an average particle size of 0.5-1mm. Particle homogeneity is tested using the thermal expansion coefficient ratio method.

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

[0070] Example 2

[0071] (1) placing catalytic cracking slurry II in a raw material buffer tank, filtering it with a metal filter medium at 180° C. to remove solid powder therein; extracting the desolidified catalytic cracking slurry II with n-butane at a mass ratio of 1:4.5 at 125° C. and 4.2 MPa, and then separating the light component and the heavy component;

[0072] (2) The heavy component is pressurized by a booster pump and mixed with hydrogen, heated to 360°C in a heating furnace, and then enters a fixed bed hydrogenation reactor, where it is contacted with the RG-30B catalyst and the RMS-30 catalyst in sequence for hydrogenation treatment to obtain a hydrogenated product; wherein the loading volume ratio of the RG-30B catalyst and the 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 Nm 3 / m 3 , volume space velocity is 0.8h -1 ;

[0073] Then, the hydrogenation product is introduced into a high-pressure separator, and gas-liquid separation is performed at 220°C and 4MPa to obtain hydrogen-rich gas and hydrogenated oil. The hydrogen-rich gas is added to hydrogen and returned to the fixed-bed hydrogenation reactor for recycling;

[0074] (3) mixing the hydrogenated oil and vacuum residue in a mass ratio of 9:1 and introducing the mixture 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] Among them, the operating conditions of the delayed coking unit include a heating furnace outlet temperature of 465-505°C, a coke tower top temperature of 430°C, 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] Wherein, 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, 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 0.5-1mm. Particle homogeneity is tested using the thermal expansion coefficient ratio method.

[0084] Among them, it can be seen from Table 4 that the petroleum coke prepared by using catalytic cracking oil slurry II and vacuum residue in the present invention is an isotropic carbon material, and its sulfur element, ash content, volatile matter, true density and tap density meet the requirements of raw materials that can be used to prepare isotropic graphite, and can be used to prepare high-quality isotropic graphite.

[0085] Comparative Example 1

[0086] The same as Example 1, except that the catalytic cracking slurry I is directly introduced into the vacuum distillation tower for vacuum distillation to obtain light components with a boiling point of less than 510°C and heavy components with a boiling point of ≥510°C; and then the heavy components are introduced into the 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, 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] As shown in Table 5, the sulfur content of the petroleum coke prepared in Comparative Example 1 is as high as 0.72wt%, and the ash content is 0.35wt%, which exceeds the requirements of the raw materials for preparing isotropic graphite that the sulfur content is less than 0.5wt% and the ash content is less than 0.3wt%. At the same time, the true density is 2.08g / cm 3 , tap density is 0.84 (0.5-1mm), g / cm 3 , indicating that the microstructure density of petroleum coke is low and cannot meet the index 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 cokes prepared in Examples 1-2 and Comparative Example 1 were respectively prepared into graphite under the same conditions, wherein the graphitization temperature was 2850°C and the residence time was 2h. Then the isotropy, bulk density and flexural strength of the graphite were tested. The test results are shown in Table 6.

[0093] Table 6

[0094] Homosexuality <![CDATA[Bulk 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] It can be seen from Table 6 that the graphite prepared using the petroleum coke in Examples 1-2 is isotropic graphite and has high bulk density and flexural strength, which can meet the application requirements. However, the graphite prepared using the petroleum coke in Comparative Example 1 has poor isotropy, high self-density and high impurity content, and does not meet the relevant performance requirements of isotropic graphite.

[0096] 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

1. A method for preparing petroleum coke, characterized in that: The method comprises the following steps: (1) After desolidifying the inferior aromatic-rich oil, separation treatment is performed to obtain light components and heavy components; wherein the separation method is selected from distillation and / or extraction, the cutting temperature of the distillation is 450-550° C., and the extraction solvent of the extraction is normal alkane; (2) contacting the heavy component, hydrogen and a hydrogenation catalyst to carry out a hydrogenation reaction to obtain hydrogen-rich gas and hydrogenated oil; (3) Delaying coking of the hydrogenated oil and optional auxiliary oil to obtain petroleum coke.

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, and is selected from one or more of catalytic cracking slurry, ethylene tar, lubricating oil extraction oil, and thermal cracking residue oil; Preferably, based on the total mass of the inferior aromatic-rich oil, the inferior aromatic-rich oil comprises 10-20wt% of saturated hydrocarbons, 50-70wt% of aromatic hydrocarbons, 15-25wt% of colloids, and 1-10wt% of asphaltenes; Preferably, the ash content of the inferior aromatic-rich oil is 0.005-0.4wt%, the sulfur content is 0.3-1.5wt%, the nitrogen content is 0.1-0.5wt%, and the total content of metal elements is 10-800μg / g.

3. The preparation method according to claim 1 or 2, wherein The desolidification method is selected from sedimentation and / or filtration; Preferably, the sedimentation operation comprises separating the upper clear liquid after standing the inferior aromatic-rich oil at 100-120° C. for 36-60 hours; Preferably, the filtering operation comprises filtering the inferior aromatic-rich oil at 160-200°C.

4. The preparation method according to any one of claims 1 to 3, wherein The distillation is carried out in a vacuum distillation tower; preferably, the cutting temperature of the distillation is 480-520°C; Preferably, the normal alkane is selected from one or more of normal butane, normal pentane, normal hexane, normal heptane, normal octane and normal heptane, preferably normal butane and / or normal pentane; Preferably, the operating conditions of the extraction include: the mass ratio of the aromatic-rich oil after desolidification to the extraction solvent is 1:2-10, preferably 1:4-6; the extraction temperature is 90-160°C, preferably 110-140°C; the extraction pressure is 2-5MPa, preferably 3-4.5MPa.

5. The preparation method according to any one of claims 1 to 4, wherein: The hydrogenation catalyst comprises a hydrogenation protective agent and a hydrogenation refining agent; Preferably, the hydrogenation protective agent is selected from one or more of RG-20B, RG-30B, and RG-40B, preferably RG-30B; Preferably, the hydrogenation refining agent is selected from one or more of RMS-10, RMS-20, and RMS-30, preferably RMS-30; Preferably, the hydroprocessing is carried out in a fixed bed reactor, in which a hydrogenation protective agent and a hydrogenation refining agent are sequentially loaded, and the loading volume ratio of the hydrogenation protective agent to the hydrogenation refining agent is 5-25:75-95, preferably 10-15:85-90.

6. The preparation method according to any one of claims 1 to 5, wherein: The operating conditions of the hydrogenation reaction include: the hydrogenation reaction temperature is 280-445°C, preferably 300-350°C; the hydrogen partial pressure is 2-10MPa, preferably 3-6MPa; the volume space velocity is 0.2-2h -1 , preferably 0.6-1.2h -1 ; Hydrogen oil volume ratio is 200-1000Nm 3 / m 3 , preferably 600-800Nm 3 / m 3 .

7. The preparation method according to any one of claims 1 to 6, 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 the gas-liquid separation include: a separation temperature of 200-250°C and a separation pressure of 3-5MPa; Preferably, the hydrogen-rich gas is added to the hydrogen gas and returned to the hydrogenation reaction for cyclic use.

8. The preparation method according to any one of claims 1 to 7, wherein: The auxiliary oil is selected from one or more of atmospheric residue oil, vacuum residue oil, thermal cracking residue oil, and furfural extracted oil, preferably vacuum residue oil; Preferably, the hydrogenated oil and the 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.

9. The preparation method according to any one of claims 1 to 8, wherein: The operating conditions of the delayed coking treatment include: the outlet temperature of the heating furnace is 440-550°C, preferably 460-520°C; the temperature of the top of the coke tower is 400-460°C, preferably 410-440°C; the pressure at the top of the coke tower is 0.3-1MPa, preferably 0.5-0.8MPa; the circulation ratio is 0.4-1.5, preferably 0.6-1.

10. Petroleum coke prepared by the preparation method according to any one of claims 1 to 9.

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