Method and device for simultaneously preparing needle coke raw material and coated asphalt

Abstract

The invention relates to the technical field of petroleum processing, in particular to a method for simultaneously preparing a needle coke raw material and coated asphalt, a device for simultaneously preparing the needle coke raw material and the coated asphalt, needle coke and a lithium ion battery negative electrode material. The method comprises the following steps: (1) carrying out first distillation cutting on catalytic diesel oil to obtain a monocyclic aromatic hydrocarbon enriched component, a bicyclic aromatic hydrocarbon enriched component and a tricyclic aromatic hydrocarbon enriched component; (2) performing thermal polycondensation reaction on the bicyclic aromatic hydrocarbon enriched component to obtain pyrolysis gas and a thermal polycondensation product; (3) carrying out second distillation cutting on the thermal polycondensation product to obtain cracked light oil I, cracked light oil II, circulating oil and polycondensation heavy components; and (4) carrying out reduced pressure distillation cutting on the polycondensation heavy component to obtain polycondensation wax oil and polycondensation asphalt which are respectively used as a needle coke raw material and coated asphalt. According to the method, on one hand, the preparation process of the carbon material is enriched, and on the other hand, the resource utilization of the catalytic diesel oil is widened.

Description

Technical Field

[0001] The present invention relates to the technical field of petroleum processing, and in particular to a method for simultaneously preparing a needle coke raw material and a coated asphalt, a device for simultaneously preparing a needle coke raw material and a coated asphalt, a needle coke, and a negative electrode material for a lithium ion battery. Background Art

[0002] Catalytic cracking diesel is a diesel fraction produced by a catalytic cracking unit. It has a high aromatic content and a low cetane number, and is a relatively inferior diesel component. At present, refining companies mainly convert catalytic cracking diesel into light aromatics or high-octane gasoline through hydrogenation, saturation and catalytic cracking. Domestic and foreign scholars have carried out a lot of basic research and industrial practice on this technical route. CN201210410162.3, CN201310516588.1, CN201310517650.9, CN201310517666.X and CN201310010219.5 disclose a series of processes or methods for catalytic conversion and upgrading of catalytic cracking light diesel, and technologies for converting inferior LCO into high-octane catalytic cracking gasoline or light aromatics (BTX).

[0003] With the rapid development of new energy vehicles and energy storage industries, lithium-ion batteries and their negative materials have developed rapidly. By 2025, the demand for negative electrode materials for lithium batteries in my country will reach 1.456 million tons. The negative electrode materials are mainly composed of aggregate needle coke and binder-coated asphalt. Needle coke is a carbon material with a silver-gray appearance and needle-like texture on the surface. It has the advantages of high crystallinity, small thermal expansion coefficient, good orientation, good electrical and thermal conductivity, etc. It is the raw material for preparing high-end carbon material products such as high-power graphite electrodes and high-performance lithium battery negative electrodes. Needle coke can be divided into oil-based needle coke and coal-based needle coke. Oil-based needle coke has fewer pores, high volume density, high mechanical strength, low nitrogen content, low gas expansion rate during graphitization, and can be quickly graphitized; it has good adsorption performance for binders and is easy to form. Although the raw materials of coal-based needle coke and oil-based needle coke come from different sources, the existing needle coke preparation or production-related technologies all use polycyclic aromatic hydrocarbons with three to six rings as raw materials, and are prepared through processes such as thermal polycondensation, intermediate phase cultivation, and coke pulling and solidification.

[0004] In the past two years, affected by the strong market demand for needle coke, the number of new needle coke companies has increased significantly. From 2018 to 2021, in just four years, the production capacity has increased from 510,000 tons to 2.1 million tons. At present, the main problem facing the needle coke industry is that the sulfur and nitrogen content of needle coke raw materials is relatively high, and the supply of low-sulfur and low-nitrogen needle coke raw materials is insufficient. This has led to a significant increase in needle coke production capacity, but the overall quality has not improved, and high-quality needle coke still needs to be imported. Coated asphalt is a high-softening point asphalt produced from ethylene tar as raw material. Its composition is polycyclic aromatic hydrocarbons with a berth structure of more than six rings. The main problem of the industry is that there are few large-scale enterprises, and domestic production capacity cannot meet the growing demand for lithium battery negative electrode materials. Product prices have been running at a high level for a long time.

[0005] The common point between needle coke raw materials, coated asphalt and other carbon materials (raw materials) and catalytic diesel is that their components are all polycyclic aromatic hydrocarbons. If a certain process can be developed to convert the two- and three-ring aromatic hydrocarbons in catalytic diesel into three- to six-ring aromatic hydrocarbons and six-ring or higher aromatic hydrocarbons, and then into carbon materials that are in short supply in the market, it will provide a new high-value conversion path and effectively alleviate the problem of excess catalytic diesel in refineries. Summary of the invention

[0006] The purpose of the present invention is to overcome the above-mentioned technical problems and to provide a method for simultaneously preparing needle coke raw materials and coated asphalt, a device for simultaneously preparing needle coke raw materials and coated asphalt, a needle coke, and a lithium-ion battery negative electrode material. The method uses catalytic diesel as raw material to simultaneously prepare needle coke raw materials and coated asphalt, which not only enriches the preparation process of carbon materials, but also opens up the resource utilization of catalytic diesel.

[0007] In order to achieve the above object, the first aspect of the present invention provides a method for simultaneously preparing needle coke raw material and coated asphalt, the method comprising the following steps:

[0008] (1) subjecting catalytic diesel to a first distillation cut to obtain a single-ring aromatics-enriched component, a two-ring aromatics-enriched component, and a three-ring aromatics-enriched component;

[0009] (2) subjecting the dicyclic aromatic hydrocarbon-enriched component to a thermal polycondensation reaction to obtain a cracking gas and a thermal polycondensation product;

[0010] (3) subjecting the thermal polycondensation product to a second distillation cut to obtain cracked light oil I, cracked light oil II, circulating oil and polycondensation heavy components;

[0011] (4) The polycondensed heavy components are subjected to vacuum distillation and cutting, and the obtained polycondensed wax oil and polycondensed asphalt are used as needle coke raw material and coated asphalt respectively.

[0012] Preferably, the total aromatic content in the catalytic diesel is ≥70wt%, preferably 70-99.9wt%; the dicyclic aromatic content is ≥40wt%, preferably 50-90wt%; and the tricyclic aromatic content is ≥1wt%, preferably 1-20wt%.

[0013] Preferably, the method further comprises: returning at least a portion of the circulating oil and performing the thermal polycondensation reaction, preferably returning the circulating oil and performing the thermal polycondensation reaction.

[0014] The second aspect of the present invention provides a device for simultaneously preparing needle coke raw materials and coated asphalt, the device comprising a first distillation cutting unit, a thermal polycondensation reaction unit, a second distillation cutting unit and a vacuum distillation cutting unit connected in sequence;

[0015] Among them, the first distillation and cutting unit is used to perform the first distillation and cutting on the catalytic diesel to obtain a single-ring aromatics-rich component, a two-ring aromatics-rich component and a three-ring aromatics-rich component; the thermal polycondensation reaction unit is used to perform a thermal polycondensation reaction on the two-ring aromatics-rich component to obtain cracking gas and thermal polycondensation products; the second distillation and cutting unit is used to perform the second distillation and cutting on the thermal polycondensation product to obtain cracked light oil I, cracked light oil II, circulating oil and polycondensation heavy components; the vacuum distillation and cutting unit is used to perform vacuum distillation and cutting on the polycondensation heavy components, and the obtained polycondensation wax oil and polycondensation asphalt are used as needle coke raw material and coated asphalt respectively.

[0016] The third aspect of the present invention provides a needle coke, wherein the needle coke is obtained by sequentially calcining and graphitizing the needle coke raw material obtained by the method provided by the first aspect.

[0017] The fourth aspect of the present invention provides a negative electrode material for a lithium-ion battery, wherein the negative electrode material for a lithium-ion battery comprises the coated asphalt obtained by the method provided in the first aspect, and / or the needle coke provided in the third aspect.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] (1) The method provided by the present invention uses catalytic diesel as raw material, and sequentially adopts the technical means of first distillation cutting, thermal polycondensation reaction, second distillation cutting and vacuum distillation to simultaneously prepare two carbon materials, needle coke raw material and coated asphalt. On the one hand, this method enriches the preparation process of carbon materials, and on the other hand, it broadens the resource utilization of catalytic diesel and improves the added value of the product;

[0020] (2) The method provided by the present invention, in particular, by adjusting the temperature of the first distillation cut (i.e., the distillation range of the dicyclic aromatics-enriched component) and the process conditions of the thermal polycondensation reaction, and recycling at least part of the circulating oil, the distribution of the components in the thermal polycondensation product is regulated, thereby regulating the yield of the polycondensation wax oil and the polycondensation asphalt, and realizing the controllable polycondensation of catalytic diesel aromatics;

[0021] (3) The needle coke raw material prepared by the method provided by the present invention is used to produce needle coke, and the prepared needle coke has a sulfur content of ≤0.5wt%, a nitrogen content of ≤0.5wt%, an ash content of ≤0.1wt%, and a true density (before calcination) of ≥1.35g / cm 3 , true density (before calcination) ≥2.12g / cm 3 , thermal expansion coefficient (25-600℃) ≤1.3×10 -6 / ℃, its polarized microstructure shows a needle-like texture; at the same time, the needle coke can be used in lithium-ion batteries to effectively improve the electrochemical performance of lithium-ion batteries;

[0022] (4) The polycondensed asphalt prepared by the method provided by the present invention is used as coated asphalt, and the softening point of the coated asphalt is ≥150°C, the toluene insoluble matter content is ≥1wt%, the residual carbon is ≥50wt%, the ash content is ≤0.01wt%, and the sulfur content is ≤0.5wt%, which meets the group standard "Bitumen for Negative Electrode Materials for Lithium Ion Batteries" of the China Petroleum and Chemical Industry Federation and can be used for negative electrode materials for lithium ion batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The invention provides a device for simultaneously preparing needle coke raw materials and coated asphalt.

[0024] Description of Reference Numerals

[0025] I, the first distillation cutting unit; II, the thermal polycondensation unit; III, the second distillation cutting unit; IV, the vacuum distillation cutting unit; V, the heating unit;

[0026] 1. Catalytic diesel; 2. Monocyclic aromatic hydrocarbons enriched components; 3. Dicyclic aromatic hydrocarbons enriched components; 4. Tricyclic aromatic hydrocarbons enriched components; 5. Pyrolysis gas; 6. Thermal polycondensation products; 7. Cracking light oil I; 8. Cracking light oil II; 9. Cycle oil; 10. Polycondensation heavy components; 11. Polycondensation wax oil (needle coke raw material); 12. Polycondensation asphalt (coated asphalt). DETAILED DESCRIPTION

[0027] 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.

[0028] In the present invention, unless otherwise specified, "first" and "second" do not indicate a sequence or limit to each material or step, but are only used to distinguish or indicate that they are not the same material or step. For example, "first" and "second" in "first distillation cut" and "second distillation cut" are only used to indicate that they are not the same distillation cut.

[0029] A first aspect of the present invention provides a method for simultaneously preparing needle coke raw material and coated asphalt, the method comprising the following steps:

[0030] (1) subjecting catalytic diesel to a first distillation cut to obtain a single-ring aromatics-enriched component, a two-ring aromatics-enriched component, and a three-ring aromatics-enriched component;

[0031] (2) subjecting the dicyclic aromatic hydrocarbon-enriched component to a thermal polycondensation reaction to obtain a cracking gas and a thermal polycondensation product;

[0032] (3) subjecting the thermal polycondensation product to a second distillation cut to obtain cracked light oil I, cracked light oil II, circulating oil and polycondensation heavy components;

[0033] (4) The polycondensed heavy components are subjected to vacuum distillation and cutting, and the obtained polycondensed wax oil and polycondensed asphalt are used as needle coke raw material and coated asphalt respectively.

[0034] In some embodiments of the present invention, preferably, the total aromatic content in the catalytic diesel is ≥70wt%, preferably 70-99.9wt%; the dicyclic aromatic content is ≥40wt%, preferably 50-90wt%; the tricyclic aromatic content is ≥1wt%, preferably 1-20wt%. The preferred conditions are more conducive to improving the single-pass yield of polycondensation wax oil and polycondensation asphalt. In the present invention, unless otherwise specified, the total aromatic content in the catalytic diesel refers to the sum of the contents of monocyclic aromatics, dicyclic aromatics and tricyclic aromatics.

[0035] In a specific embodiment of the present invention, the catalytic diesel contains 20 wt% of monocyclic aromatic hydrocarbons, 50 wt% of dicyclic aromatic hydrocarbons, 10 wt% of tricyclic aromatic hydrocarbons, and 20 wt% of saturated hydrocarbons.

[0036] In some embodiments of the present invention, preferably, the physical property parameters of the catalytic diesel also meet the following requirements: sulfur content is 1 mg / kg-1 wt%; nitrogen content is 1 mg / kg-1 wt%; oxygen content is 1 mg / kg-1 wt%.

[0037] In the present invention, unless otherwise specified, the hydrocarbon composition in catalytic diesel is determined according to the "Determination of Hydrocarbons in Saturated Hydrocarbon Fraction in Gas Oil (Mass Spectrometry) (SH / T 0659-1998)".

[0038] In the present invention, unless otherwise specified, the hydrocarbon composition in the distillate oil is determined according to the "Determination of Hydrocarbon Composition of Mesophase Fraction (Mass Spectrometry) (SH / T 0606-2019)".

[0039] In the present invention, unless otherwise specified, the carbon and hydrogen content parameters are determined according to the "Determination of Carbon, Hydrogen and Nitrogen in Petroleum Products and Lubricants - Elemental Analyzer Method (SH / T 0656-2017)"; the oxygen content parameters are determined according to the "Determination of Total Oxygen Content in Gasoline, Diesel and Methanol Fuels - Reduction Cracking Method (SH / T0986-2019)"; the nitrogen content parameters are determined according to the "Determination of Nitrogen Content in Petroleum and Petroleum Products - Boat Injection Chemiluminescence Method (SH / T 0704-2010)"; the sulfur content parameters are determined according to the "Determination of Sulfur Content in Petroleum and Petroleum Products - Energy Dispersive X-ray Fluorescence (GB / T 17040-2008)".

[0040] In the present invention, the type of catalytic diesel has a wide selection range, as long as it meets the above definition. Preferably, the catalytic diesel is selected from at least one of catalytic cracking middle distillate oil, catalytic cracking light cycle oil, catalytic cracking heavy cycle oil and catalytic cracking refined diesel.

[0041] In the present invention, the catalytic cracking middle distillate oil is the middle distillate oil produced by the catalytic cracking unit, wherein the catalytic cracking unit can be a residual oil catalytic cracking unit, a wax oil catalytic cracking unit, a heavy oil catalytic cracking unit and a mixed feedstock catalytic cracking unit; the catalytic cracking refined diesel refers to the catalytic cracking middle distillate oil that is hydrotreated and hydrorefined to obtain a low-sulfur, low-nitrogen refined catalytic diesel.

[0042] In a specific embodiment of the present invention, preferably, the catalytic cracking intermediate distillate is selected from at least one of residual catalytic cracking distillate, wax oil catalytic cracking distillate and heavy oil catalytic cracking distillate.

[0043] In the present invention, the first distillation cut is intended to obtain a specific fraction, that is, a dicyclic aromatic hydrocarbon-enriched component. Preferably, in step (1), the distillation range of the dicyclic aromatic hydrocarbon-enriched component is selected from 220-390°C, for example, 220°C, 230°C, 250°C, 270°C, 280°C, 290°C, 300°C, 320°C, 330°C, 340°C, 390°C, and any value in the range consisting of any two values, preferably 230-340°C, more preferably 250-330°C. The distillation range meeting the above range is conducive to obtaining the dicyclic aromatic hydrocarbon-enriched component with a high content of dicyclic aromatic hydrocarbons.

[0044] In the present invention, the dicyclic aromatic hydrocarbon-enriched component contains, in addition to dicyclic aromatic hydrocarbons, a small amount of saturated hydrocarbons, monocyclic aromatic hydrocarbons and tricyclic aromatic hydrocarbons.

[0045] In some embodiments of the present invention, preferably, in step (1), the content of dicyclic aromatic hydrocarbons in the dicyclic aromatic hydrocarbon-enriched component is ≥70wt%, for example, 70wt%, 75wt%, 80wt%, 85wt%, 90wt%, 95wt%, 99wt%, 99.9wt%, and any value in the range consisting of any two values, preferably ≥80wt%, more preferably 85-99.9wt%.

[0046] In some embodiments of the present invention, it is further preferred that in step (1), the content of saturated hydrocarbons in the dicyclic aromatic hydrocarbon-enriched component is ≤10 wt%, the content of monocyclic aromatic hydrocarbons is ≤10 wt%; and the content of tricyclic aromatic hydrocarbons is ≤2 wt%.

[0047] In the present invention, the thermal polycondensation reaction is intended to polycondense the dicyclic aromatics and tricyclic aromatics in the dicyclic aromatics-enriched component. Preferably, in step (2), the conditions of the thermal polycondensation reaction include: a temperature of 400-480°C, for example, 400°C, 410°C, 420°C, 430°C, 440°C, 450°C, 460°C, 480°C, and any value in the range of any two values, preferably 410-460°C; a time of 0.1-5h, for example, 0.1h, 0.5h, 1h, 2h, 3h, 5h, and any value in the range of any two values, preferably 0.5-3h.

[0048] In some embodiments of the present invention, preferably, the method further comprises: before the thermal polycondensation reaction, heating the dicyclic aromatic hydrocarbon-enriched component to 400-480° C., preferably 410-460° C. In the present invention, the heating method has a wide range of selection, as long as it is heated to the temperature of the thermal polycondensation reaction, and the heating method includes but is not limited to heating in a tubular heating furnace, heating in a heat exchanger, heating in a tubular furnace, etc.

[0049] In some embodiments of the present invention, preferably, the content of toluene insoluble matter in the thermal polycondensation product is ≤3 wt %. When the content of toluene insoluble matter in the thermal polycondensation product is greater than 3 wt %, coking is likely to occur.

[0050] In some embodiments of the present invention, preferably, the total aromatic content in the thermal polycondensation product is ≥75wt%, preferably 75-99.9wt%. In the present invention, the total aromatics in the thermal polycondensation product include a small amount of saturated hydrocarbons, monocyclic aromatic hydrocarbons and dicyclic aromatic hydrocarbons, as well as tricyclic to hexacyclic aromatic hydrocarbons and aromatic hydrocarbons with six or more rings.

[0051] In the present invention, the second distillation cut is intended to purify the thermal polycondensation product to obtain a polycondensation heavy component rich in three- to six-ring aromatic hydrocarbons and aromatic hydrocarbons with six or more rings.

[0052] In some embodiments of the present invention, preferably, the final boiling point of the cracked light oil I is 200-220° C., for example, 200° C., 205° C., 210° C., 220° C., and any value in the range of any two values, preferably 200-210° C. In the present invention, the cracked light oil I is rich in saturated hydrocarbons and monocyclic aromatic hydrocarbons and can be used as a gasoline product.

[0053] In some embodiments of the present invention, preferably, the distillation range of the cracked light oil II is 200-250° C., for example, 200° C., 210° C., 220° C., 230° C., 250° C., and any value in the range consisting of any two values, preferably 210-230° C. In the present invention, the cracked light oil II is rich in dicyclic aromatic hydrocarbons, for example, selected from naked ring aromatic hydrocarbons such as naphthalene, methylnaphthalene and ethylnaphthalene, and can be used as a naphthalene oil product.

[0054] In some embodiments of the present invention, preferably, the distillation range of the circulating oil is 220-350°C, for example, 220°C, 230°C, 250°C, 280°C, 300°C, 320°C, 350°C, and any value in the range consisting of any two values, preferably 230-350°C.

[0055] In some embodiments of the present invention, preferably, the initial distillation point of the condensation heavy component is 330-350°C, for example, 330°C, 335°C, 340°C, 345°C, 350°C, and any value in the range of any two values, preferably 345-350°C, more preferably 350°C.

[0056] In a preferred embodiment of the present invention, the final distillation point of the cracked light oil I is 200-210°C; the distillation range of the cracked light oil II is 210-230°C; the distillation range of the cycle oil is 230-350°C; and the initial distillation point of the polycondensation heavy component is 350°C.

[0057] In some embodiments of the present invention, preferably, the temperature of the vacuum distillation cutting is 500-540° C., for example, 500° C., 520° C., 530° C., 540° C., and any value in the range of any two values, preferably 520-540° C. The temperature satisfying the above range is more conducive to obtaining polycondensation wax oil rich in three-six-ring aromatics and polycondensation asphalt rich in six-ring or more aromatics.

[0058] In some embodiments of the present invention, preferably, in step (4), the distillation range of the polycondensation wax oil is 350-540° C., preferably 350-520° C. The distillation range within the above range is more conducive to regulating the quality of the polycondensation wax oil and obtaining the polycondensation wax oil with high three-six ring aromatics, low sulfur and low nitrogen.

[0059] In some embodiments of the present invention, preferably, the content of three- to six-ring aromatics in the polycondensation wax oil is ≥50wt%, preferably ≥70wt%; the sulfur content is ≤1wt%, preferably ≤0.3wt%; and the nitrogen content is ≤0.6wt%, preferably ≤600mg / kg.

[0060] In some embodiments of the present invention, preferably, in step (4), the initial distillation point of the polycondensation asphalt is 500-540° C., for example, 500° C., 520° C., 530° C., 540° C., and any value in the range of any two values, preferably 520-540° C. The initial distillation point meeting the above range is more conducive to regulating the quality of the polycondensation asphalt, that is, obtaining a coated asphalt with high six-ring or more aromatics, high softening point, high residual carbon, low sulfur and low ash.

[0061] In some embodiments of the present invention, preferably, the softening point of the polycondensation asphalt is ≥150°C, the toluene insoluble matter content is ≥1wt%, the carbon residue is ≥50wt%, the ash content is ≤0.01wt%, and the sulfur content is ≤0.5wt%.

[0062] In some embodiments of the present invention, preferably, the method further comprises: returning at least part of the circulating oil and performing the thermal polycondensation reaction, preferably returning the circulating oil and performing the thermal polycondensation reaction. This arrangement can effectively improve the yield of needle coke raw material and coated asphalt.

[0063] The second aspect of the present invention provides a schematic diagram of a device for simultaneously preparing needle coke raw materials and coated asphalt. Figure 1 As shown by Figure 1It can be seen that the device includes a first distillation and cutting unit I, a thermal polycondensation reaction unit II, a second distillation and cutting unit III and a vacuum distillation and cutting unit IV which are connected in sequence; wherein the first distillation and cutting unit I is used to perform a first distillation and cutting on the catalytic diesel 1 to obtain a monocyclic aromatic hydrocarbon enriched component 2, a dicyclic aromatic hydrocarbon enriched component 3 and a tricyclic aromatic hydrocarbon enriched component 4; the thermal polycondensation reaction unit II is used to perform a thermal polycondensation reaction on the dicyclic aromatic hydrocarbon enriched component 3 to obtain a cracking gas 5 and a thermal polycondensation product 6; the second distillation and cutting unit III is used to perform a second distillation and cutting on the thermal polycondensation product 6 to obtain cracked light oil I 7, cracked light oil II 8, circulating oil 9 and a polycondensation heavy component 10; the vacuum distillation and cutting unit IV is used to perform a vacuum distillation and cutting on the polycondensation heavy component 10, and the obtained polycondensation wax oil 11 and polycondensation asphalt 12 are used as needle coke raw material and coated asphalt respectively.

[0064] In the present invention, unless otherwise specified, the first distillation cutting unit can be selected from a distillation tower, that is, a single-ring aromatic hydrocarbon-enriched component is extracted from the top of the tower, a dicyclic aromatic hydrocarbon-enriched component is extracted from the side line of the tower, and a tricyclic aromatic hydrocarbon-enriched component is extracted from the bottom of the tower; the thermal polycondensation reaction unit is selected from various types of reactors, cracking gas is extracted from the top of the tower, and a thermal polycondensation product is obtained in the bottom of the tower; the second distillation cutting unit can be selected from a distillation tower, that is, cracking light oil I is extracted from the top of the tower, cracking light oil II and circulating oil are extracted from the side lines of the tower, and polycondensation heavy components are extracted from the bottom of the tower; the vacuum distillation cutting unit is selected from various types of reactors, polycondensation wax oil is extracted from the top of the tower, and polycondensation asphalt is obtained in the bottom of the tower.

[0065] According to the present invention, preferably, Figure 1 As shown, the second distillation cutting unit III is connected to the thermal polycondensation reaction unit II, and is used to return at least part of the circulating oil and perform the thermal polycondensation reaction, preferably to return the circulating oil 9 and perform the thermal polycondensation reaction.

[0066] According to the present invention, preferably, Figure 1 As shown, the device further comprises: a heating unit V connected to the first distillation cutting unit I and the thermal polycondensation unit II, and used for heating the dicyclic aromatic hydrocarbon enriched component 3 and then entering the thermal polycondensation unit II.

[0067] In a preferred embodiment of the present invention, Figure 1 As shown, a device for simultaneously preparing needle coke raw material and coated asphalt includes a first distillation cutting unit I, a heating unit V, a thermal polycondensation reaction unit II, a second distillation cutting unit III and a vacuum distillation cutting unit IV which are connected in sequence, and the second distillation cutting unit III is connected to the heating unit V.

[0068] In the present invention, unless otherwise specified, the heating unit includes but is not limited to a heater, a heat exchanger, and the like.

[0069] The third aspect of the present invention provides a needle coke, wherein the needle coke is obtained by sequentially calcining and graphitizing the needle coke raw material obtained by the method provided by the first aspect.

[0070] In some embodiments of the present invention, preferably, the calcination conditions include: temperature of 1300-1450° C., preferably 1350-1400° C.; time of 10-20 h, preferably 12-14 h.

[0071] In some embodiments of the present invention, preferably, the conditions of the graphitization treatment include: a temperature of 2700-3000° C., preferably 2800-2900° C.; and a time of 2-5 h, preferably 3-4 h.

[0072] In some embodiments of the present invention, preferably, the sulfur content of the needle coke is ≤0.5wt%, the nitrogen content is ≤0.5wt%, the ash content is ≤0.1wt%, and the true density (before calcination) is ≥1.35g / cm 3 , true density (after calcination) ≥2.12g / cm 3 , thermal expansion coefficient (25-600℃) ≤1.3×10 -6 / ℃, polarized light microstructure shows needle-like texture.

[0073] The fourth aspect of the present invention provides a negative electrode material for a lithium-ion battery, wherein the negative electrode material for a lithium-ion battery is selected from the coated asphalt obtained by the method provided in the first aspect, and / or the needle coke provided in the third aspect.

[0074] According to a particularly preferred embodiment of the present invention, a method for simultaneously preparing needle coke raw material and coated asphalt comprises the following steps:

[0075] (1) subjecting catalytic diesel to a first distillation cut to obtain a single-ring aromatics-enriched component, a two-ring aromatics-enriched component, and a three-ring aromatics-enriched component;

[0076] (2) subjecting the dicyclic aromatic hydrocarbon-enriched component to a thermal polycondensation reaction after heating to obtain a cracking gas and a thermal polycondensation product;

[0077] (3) subjecting the thermal polycondensation product to a second distillation cut to obtain cracked light oil I, cracked light oil II, circulating oil and polycondensation heavy components;

[0078] (4) subjecting the polycondensed heavy components to vacuum distillation cutting, and obtaining the polycondensed wax oil and polycondensed asphalt as needle coke raw material and coated asphalt, respectively;

[0079] Wherein, the distillation range of the dicyclic aromatic hydrocarbon-enriched component is selected from 250-330°C; the temperature of the heating and thermal polycondensation reaction is independently selected from 410-460°C;

[0080] The cutting temperatures of the cracked light oil I and cracked light oil II are 200-210°C; the cutting temperatures of the cracked light oil II and circulating oil are 230-350°C; and the initial boiling point of the polycondensation heavy component is 345-350°C.

[0081] The present invention will be described in detail below through examples.

[0082] The hydrocarbon composition in the feedstock oil is determined in accordance with the "Determination of Hydrocarbons in Saturated Hydrocarbon Fractions in Gas Oil (Mass Spectrometry) (SH / T0659-1998)";

[0083] The hydrocarbon composition in the distillate oil is determined according to the "Determination of Hydrocarbon Composition of Mesophase Fraction (Mass Spectrometry) (SH / T0606-2019)";

[0084] The carbon and hydrogen content parameters are determined in accordance with the "Elemental Analyzer Method for the Determination of Carbon, Hydrogen and Nitrogen in Petroleum Products and Lubricants (SH / T 0656-2017)";

[0085] The oxygen content parameters are determined according to the "Determination of total oxygen content in gasoline, diesel and methanol fuels - Reduction cracking method (SH / T0986-2019)";

[0086] The nitrogen content parameters are determined in accordance with the "Determination of Nitrogen Content in Petroleum and Petroleum Products - Boat Injection Chemiluminescence Method (SH / T0704-2010)";

[0087] The sulfur content parameters are determined in accordance with the "Determination of sulfur content of petroleum and petroleum products - Energy dispersive X-ray fluorescence (GB / T 17040-2008)".

[0088] The toluene insoluble matter content is determined in accordance with the "Determination of Toluene Insoluble Matter Content of Coking Products (GB / T2292-2018)".

[0089] Calculation method of polycondensation yield: polycondensation yield = polycondensation wax oil yield + polycondensation asphalt yield; polycondensation wax oil yield = (polycondensation wax oil mass / raw material mass) × 100%, polycondensation asphalt yield = (polycondensation asphalt mass / raw material mass) × 100%.

[0090] Example 1

[0091] (1) using YS catalytic diesel (each component and its content are shown in Table 1) as a raw material for the first distillation cutting to obtain a dicyclic aromatic hydrocarbon-enriched component with a distillation range of 250-330° C. (each component and its content are shown in Table 2) as a distillate oil;

[0092] (2) heating the distillate oil to 440° C. for a thermal polycondensation reaction (temperature: 440° C., time: 4 h) to obtain cracking gas and a thermal polycondensation product S1, wherein the content of toluene insoluble matter in the thermal polycondensation product S1 is 2.76 wt %;

[0093] (3) subjecting the thermal polycondensation product S1 to a second distillation cutting, wherein the cutting temperature of cracked light oil I and cracked light oil II is 210° C., the cutting temperature of cracked light oil II and cycle oil is 230° C., and the cutting temperature of cycle oil and polycondensation heavy components is 350° C., to obtain cracked light oil I, cracked light oil II, cycle oil and polycondensation heavy components;

[0094] The final distillation point of the cracked light oil I is 210°C, the distillation range of the cracked light oil II is 210-230°C, the distillation range of the cycle oil is 230-350°C, and the initial distillation point of the polycondensed heavy component is 350°C.

[0095] wherein the above-mentioned circulating oil is returned and mixed with the dicyclic aromatic hydrocarbon enriched component, and is heated and subjected to thermal polycondensation reaction in sequence;

[0096] (4) subjecting the polycondensed heavy components to vacuum distillation cutting, wherein the cutting temperature of the polycondensed wax oil and the polycondensed asphalt is 520° C., and the obtained polycondensed wax oil and polycondensed asphalt are used as needle coke raw material P1 and coated asphalt Q1, respectively;

[0097] The product distributions of the above-mentioned cracking gas, cracking light oil I, cracking light oil II, circulating oil, polycondensation wax oil and polycondensation asphalt are listed in Table 3; the physical properties of needle coke raw material P1 and coated asphalt Q1 are listed in Table 4.

[0098] Example 2

[0099] The method of Example 1 is followed, except that the conditions for heating and thermal polycondensation in step (2) are changed, that is,

[0100] In step (2), the distillate oil is heated to 460° C. for a thermal polycondensation reaction (temperature is 460° C., time is 2 h) to obtain cracking gas and a thermal polycondensation product S2, wherein the content of toluene insoluble matter in the thermal polycondensation product S2 is 2.57 wt %;

[0101] In step (3), the thermal polycondensation product S2 is subjected to a second distillation cutting, wherein the cutting temperature of cracked light oil I and cracked light oil II is 210° C., the cutting temperature of cracked light oil II and cycle oil is 230° C., and the cutting temperature of cycle oil and polycondensation heavy components is 350° C., to obtain cracked light oil I, cracked light oil II, cycle oil and polycondensation heavy components;

[0102] The final distillation point of the cracked light oil I is 210°C, the distillation range of the cracked light oil II is 210-230°C, the distillation range of the cycle oil is 230-350°C, and the initial distillation point of the polycondensed heavy component is 350°C.

[0103] wherein the above-mentioned circulating oil is returned and mixed with the dicyclic aromatic hydrocarbon enriched component, and is heated and subjected to thermal polycondensation reaction in sequence;

[0104] In step (4), the polycondensed heavy components are subjected to vacuum distillation cutting, wherein the cutting temperature of the polycondensed wax oil and the polycondensed asphalt is 520° C. The obtained polycondensed wax oil and polycondensed asphalt are used as needle coke raw material P2 and coated asphalt Q2, respectively;

[0105] The product distributions of the above-mentioned cracking gas, cracking light oil I, cracking light oil II, circulating oil, polycondensation wax oil and polycondensation asphalt are listed in Table 3; the physical properties of needle coke raw material P2 and coated asphalt Q2 are listed in Table 4.

[0106] Example 3

[0107] The method of Example 1 is followed, except that the distillation range of the dicyclic aromatic hydrocarbon enriched component in step (1) is changed, that is,

[0108] (1) Using YS catalytic diesel as a raw material, a first distillation cut is performed to obtain a dicyclic aromatic hydrocarbon-rich component with a distillation range of 250-300° C. as a distillate oil (the components and their contents are shown in Table 2);

[0109] (2) heating the distillate oil to 440° C. for a thermal polycondensation reaction (temperature: 440° C., time: 4 h) to obtain cracking gas and a thermal polycondensation product S3, wherein the content of toluene insoluble matter in the thermal polycondensation product S3 is 1.75 wt %;

[0110] (3) subjecting the thermal polycondensation product S3 to a second distillation cutting, wherein the cutting temperature of cracked light oil I and cracked light oil II is 210° C., the cutting temperature of cracked light oil II and cycle oil is 230° C., and the cutting temperature of cycle oil and polycondensation heavy components is 350° C., to obtain cracked light oil I, cracked light oil II, cycle oil and polycondensation heavy components;

[0111] The final distillation point of the cracked light oil I is 210°C, the distillation range of the cracked light oil II is 210-230°C, the distillation range of the cycle oil is 230-350°C, and the initial distillation point of the polycondensed heavy component is 350°C.

[0112] wherein the above-mentioned circulating oil is returned and mixed with the dicyclic aromatic hydrocarbon enriched component, and is heated and subjected to thermal polycondensation reaction in sequence;

[0113] (4) The polycondensed heavy components are subjected to vacuum distillation cutting, wherein the cutting temperature of the polycondensed wax oil and the polycondensed asphalt is 520°C, and the obtained polycondensed wax oil and polycondensed asphalt are used as needle coke raw material P3 and coated asphalt Q3, respectively.

[0114] Among them, the yields of the above-mentioned cracking gas, cracking light oil I, cracking light oil II, circulating oil, polycondensation wax oil and polycondensation asphalt are all listed in Table 3; the physical properties of needle coke raw material P3 and coated asphalt Q3 are all listed in Table 4.

[0115] Example 4

[0116] The method of Example 1 is followed, except that the conditions for heating and thermal polycondensation in step (2) are changed, that is,

[0117] (1) using YS catalytic diesel as a raw material to perform a first distillation cut to obtain a dicyclic aromatic hydrocarbon-enriched component with a distillation range of 250-330° C. (same as in Example 1) as a distillate oil;

[0118] (2) heating the distillate oil to 400° C. for a thermal polycondensation reaction (temperature: 400° C., time: 4 h) to obtain cracking gas and a thermal polycondensation product S4, wherein the content of toluene insoluble matter in the thermal polycondensation product S4 is 0.2 wt %;

[0119] (3) subjecting the thermal polycondensation product S4 to a second distillation cutting, wherein the cutting temperature of cracked light oil I and cracked light oil II is 210° C., the cutting temperature of cracked light oil II and cycle oil is 230° C., and the cutting temperature of cycle oil and polycondensation heavy components is 350° C., to obtain cracked light oil I, cracked light oil II, cycle oil and polycondensation heavy components;

[0120] The final distillation point of the cracked light oil I is 210°C, the distillation range of the cracked light oil II is 210-230°C, the distillation range of the cycle oil is 230-350°C, and the initial distillation point of the polycondensed heavy component is 350°C.

[0121] wherein the above-mentioned circulating oil is returned and mixed with the dicyclic aromatic hydrocarbon enriched component, and is heated and subjected to thermal polycondensation reaction in sequence;

[0122] (4) The polycondensed heavy components are subjected to vacuum distillation cutting, wherein the cutting temperature of the polycondensed wax oil and the polycondensed asphalt is 520°C, and the obtained polycondensed wax oil and polycondensed asphalt are used as needle coke raw material P4 and coated asphalt Q4, respectively.

[0123] Among them, the yields of the above-mentioned cracking gas, cracking light oil I, cracking light oil II, circulating oil, polycondensation wax oil and polycondensation asphalt are all listed in Table 3; the physical properties of needle coke raw material P4 and coated asphalt Q4 are all listed in Table 4.

[0124] Example 5

[0125] The method of Example 1 is followed, except that the distillation range of the circulating oil in step (3) is changed, that is,

[0126] In step (3), the thermal polycondensation product S1 is subjected to a second distillation cutting, wherein the cutting temperature of cracked light oil I and cracked light oil II is 210° C., the cutting temperature of cracked light oil II and cycle oil is 250° C., and the cutting temperature of cycle oil and polycondensation heavy components is 330° C., to obtain cracked light oil I, cracked light oil II, cycle oil and polycondensation heavy components;

[0127] The final distillation point of the above cracked light oil I is 210°C, the distillation range of cracked light oil II is 210-250°C, the distillation range of cycle oil is 250-330°C, and the initial distillation point of the polycondensed heavy component is 330°C.

[0128] wherein the above-mentioned circulating oil is returned and mixed with the dicyclic aromatic hydrocarbon enriched component, and is heated and subjected to thermal polycondensation reaction in sequence;

[0129] In step (4), the other conditions are the same, and the obtained polycondensation wax oil and polycondensation asphalt are used as needle coke raw material P5 and coated asphalt Q5 respectively.

[0130] Among them, the product distribution of the above-mentioned cracking gas, cracking light oil I, cracking light oil II (naphthalene oil), cycle oil, condensation wax oil and condensation asphalt is listed in Table 3; the physical properties of needle coke raw material P5 and coated asphalt Q5 are listed in Table 4.

[0131] Example 6

[0132] The method of Example 1 is different in that in step (3), the circulating oil is not reused but dumped; that is,

[0133] In step (2), the other conditions are the same to obtain a thermal polycondensation product S6;

[0134] In step (3), the other conditions are the same, and cracked light oil I, cracked light oil II, circulating oil and polycondensation heavy components are obtained;

[0135] In step (4), the other conditions are the same, and the obtained polycondensation wax oil and polycondensation asphalt are used as needle coke raw material P6 and coated asphalt Q6 respectively.

[0136] Among them, the product distribution of the above-mentioned cracking gas, cracking light oil I, cracking light oil II (naphthalene oil), cycle oil, condensation wax oil and condensation asphalt is listed in Table 3; the physical properties of needle coke raw material P6 and coated asphalt Q6 are listed in Table 4.

[0137] Comparative Example 1

[0138] According to the method of Example 1, the difference is that

[0139] In step (1), YS catalytic diesel is replaced by MY ethylene tar (element composition is shown in Table 1), and other conditions are the same, and a dicyclic aromatic hydrocarbon-enriched component with a distillation range of 250-330° C. (each component and its content is shown in Table 2) is obtained as a distillate oil;

[0140] In step (2), the other conditions are the same, and cracking gas and thermal polycondensation product DS1 are obtained;

[0141] In step (3), the other conditions are the same, and cracked light oil I, cracked light oil II, circulating oil and polycondensation heavy components are obtained;

[0142] In step (4), the other conditions are the same, and the obtained polycondensation wax oil and polycondensation asphalt are used as needle coke raw material DP1 and coated asphalt DQ1 respectively.

[0143] The product distributions of the above-mentioned cracking gas, cracking light oil I, cracking light oil II (naphthalene oil), cycle oil, polycondensation wax oil and polycondensation asphalt are listed in Table 3; the physical properties of needle coke raw material DP1 and coated asphalt DQ1 are listed in Table 4.

[0144] Table 1

[0145] Oil product number YS catalytic diesel MY Ethylene Tar Hydrocarbon composition, wt% Alkanes 8.8 - Total cycloalkanes 4.5 - Total saturated hydrocarbons 13.3 - Monocyclic aromatic hydrocarbons 23.9 - Bicyclic aromatic hydrocarbons 55.3 - Tricyclic aromatic hydrocarbons 7.5 - Total aromatics 86.7 - Gel 0 - total 100 - C, wt% 90.10 92.03 H, wt% 9.30 7.07 S, wt% 0.136 0.054 N, mg / kg 853 92 O, mg / kg 654 230

[0146] Table 2

[0147]

[0148]

[0149] Table 3

[0150]

[0151] Note: *-Toluene insoluble matter content in the thermal polycondensation product, wt%;

[0152] #-Product distribution of cracked gas, cracked light oil I, cracked light oil II, polycondensed wax oil, polycondensed asphalt and circulating oil, and the sum of the distribution of each component is 100wt%;

[0153] **-When the circulating oil is reused, the product distribution of the circulating oil is 0wt%; when the circulating oil is not reused, the product distribution of the circulating oil is ≠0wt%.

[0154] Table 4

[0155]

[0156] It can be seen from the data in Tables 1-4 that compared with Comparative Example 1 which uses MZ ethylene tar as raw material, Example 1 uses catalytic diesel as raw material, and sequentially adopts the first distillation cutting - thermal polycondensation reaction - second distillation cutting - vacuum distillation cutting to obtain needle coke raw materials and coated asphalt with high polycondensation yield (≥30%) and high quality.

[0157] Compared with Example 4, Example 1 adopts the technical solution of the preferred conditions for the thermal polycondensation reaction, which not only has a higher polycondensation yield, but also obtains high-quality polycondensation wax oil and polycondensation asphalt.

[0158] Compared with Example 6, Example 1 adopts the technical solution of recycling the above-mentioned circulating oil, which not only has a higher polycondensation yield, but also obtains high-quality polycondensation wax oil and polycondensation asphalt.

[0159] Test Case

[0160] The needle coke raw materials (P1-P6 and DP1) prepared in Examples 1-6 and Comparative Example 1 were calcined (temperature: 1400°C, time: 12 h) and graphitized (temperature: 2800°C, time: 3 h) in sequence to obtain the physical properties of the needle cokes (W1-W6), which are listed in Table 5.

[0161] Table 5

[0162]

[0163] It can be seen from the results in Table 5 that the needle coke raw material prepared by the method provided by the present invention is used to produce needle coke, and the prepared needle coke has a sulfur content of ≤0.5wt%, a nitrogen content of ≤0.5wt%, an ash content of ≤0.1wt%, and a true density (before calcination) of ≥1.35g / cm 3 , true density (before calcination) ≥2.12g / cm 3 , thermal expansion coefficient (25-600℃) ≤1.3×10 -6 / ℃, its polarized microstructure shows a needle-like texture; it also has a high yield and meets the performance requirements of GB / T 37308-2019.

[0164] 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 simultaneously preparing needle coke raw material and coated asphalt, characterized in that: The method comprises the following steps: (1) subjecting catalytic diesel to a first distillation cut to obtain a single-ring aromatics-enriched component, a two-ring aromatics-enriched component, and a three-ring aromatics-enriched component; (2) subjecting the dicyclic aromatic hydrocarbon-enriched component to a thermal polycondensation reaction to obtain a cracking gas and a thermal polycondensation product; (3) subjecting the thermal polycondensation product to a second distillation cut to obtain cracked light oil I, cracked light oil II, circulating oil and polycondensation heavy components; (4) The polycondensed heavy components are subjected to vacuum distillation and cutting, and the obtained polycondensed wax oil and polycondensed asphalt are used as needle coke raw material and coated asphalt respectively.

2. The method according to claim 1, wherein: In step (1), The total aromatic content of the catalytic diesel is ≥70wt%, preferably 70-99.9wt%; the dicyclic aromatic content is ≥40wt%, preferably 50-90wt%; the tricyclic aromatic content is ≥1wt%, preferably 1-20wt%; And / or, the catalytic diesel is selected from at least one of catalytic cracking middle distillate oil, catalytic cracking light cycle oil, catalytic cracking heavy cycle oil and catalytic cracking refined diesel.

3. The method according to claim 1 or 2, wherein: In step (1), The distillation range of the dicyclic aromatic hydrocarbon-enriched component is selected from 220-390°C, preferably 230-340°C, and more preferably 250-330°C; and / or, the content of dicyclic aromatic hydrocarbons in the dicyclic aromatic hydrocarbon-enriched component is ≥70 wt%, preferably ≥80 wt%, more preferably 85-99.9 wt%; And / or, the content of saturated hydrocarbons in the dicyclic aromatic hydrocarbon-enriched component is ≤10wt%, the content of monocyclic aromatic hydrocarbons is ≤10wt%; and the content of tricyclic aromatic hydrocarbons is ≤2wt%.

4. The method according to any one of claims 1 to 3, wherein: In step (2), The conditions of the thermal polycondensation reaction include: temperature of 400-480°C, preferably 410-460°C; time of 0.1-5h, preferably 0.5-3h; And / or, the content of toluene insoluble matter in the thermal polycondensation product is ≤3wt%; and / or, the total aromatic content in the thermal polycondensation product is ≥75wt%, preferably 75-99.9wt%; And / or, before the thermal polycondensation reaction, the bicyclic aromatic hydrocarbon-enriched component is heated to 400-480°C, preferably to 410-460°C.

5. The method according to any one of claims 1 to 4, wherein: In step (3), The cracked light oil I and the cracked light oil II are used as gasoline and naphthalene oil respectively; and / or, the final boiling point of the cracked light oil I is 200-220° C., preferably 200-210° C.; and / or, the distillation range of the cracked light oil II is 200-250° C., preferably 210-230° C.; and / or, the distillation range of the cycle oil is 220-350°C, preferably 230-350°C; And / or, the initial distillation point of the polycondensed heavy component is 330-350°C, preferably 345-350°C.

6. The method according to any one of claims 1 to 5, wherein: In step (4), The temperature of the vacuum distillation cutting is 500-540°C, preferably 520-540°C; And / or, the polycondensation wax oil has a tri- to hexa-ring aromatic content of ≥50wt%, preferably ≥70wt%; a sulfur content of ≤1wt%, preferably ≤0.3wt%; Nitrogen content ≤ 0.6 wt%, preferably ≤ 600 mg / kg; And / or, the softening point of the polycondensation asphalt is ≥150°C, the toluene insoluble matter content is ≥1wt%, the residual carbon is ≥50wt%, the ash content is ≤0.01wt%, and the sulfur content is ≤0.5wt%.

7. The method according to any one of claims 1 to 6, wherein: The method further comprises: returning at least a portion of the circulating oil and performing the thermal polycondensation reaction, preferably returning the circulating oil and performing the thermal polycondensation reaction.

8. A device for simultaneously preparing needle coke raw material and coated asphalt, characterized in that: The device comprises a first distillation cutting unit, a thermal polycondensation reaction unit, a second distillation cutting unit and a reduced pressure distillation cutting unit connected in sequence; Among them, the first distillation and cutting unit is used to perform the first distillation and cutting on the catalytic diesel to obtain a single-ring aromatics-rich component, a two-ring aromatics-rich component and a three-ring aromatics-rich component; the thermal polycondensation reaction unit is used to perform a thermal polycondensation reaction on the two-ring aromatics-rich component to obtain cracking gas and thermal polycondensation products; the second distillation and cutting unit is used to perform the second distillation and cutting on the thermal polycondensation product to obtain cracked light oil I, cracked light oil II, circulating oil and polycondensation heavy components; the vacuum distillation and cutting unit is used to perform vacuum distillation and cutting on the polycondensation heavy components, and the obtained polycondensation wax oil and polycondensation asphalt are used as needle coke raw material and coated asphalt respectively.

9. The device according to claim 8, wherein: The second distillation cutting unit is connected to the thermal polycondensation reaction unit, and is used to return at least part of the circulating oil and perform the thermal polycondensation reaction, preferably to return the circulating oil and perform the thermal polycondensation reaction; And / or, the device further comprises: a heating unit connected to the first distillation cutting unit and the thermal polycondensation unit, and used for heating the dicyclic aromatic hydrocarbon enriched component and then allowing it to enter the thermal polycondensation unit.

10. A needle coke, characterized in that: The needle coke is obtained by calcining and graphitizing the needle coke raw material prepared by the method according to any one of claims 1 to 7; Preferably, the sulfur content of the needle coke is ≤0.5wt%, the nitrogen content is ≤0.5wt%, the ash content is ≤0.1wt%, and the true density (before calcination) is ≥1.35g / cm 3 , true density (after calcination) ≥2.12g / cm 3 , thermal expansion coefficient (25-600℃) ≤1.3×10 -6 / ℃.

11. A negative electrode material for a lithium ion battery, characterized in that: The negative electrode material for the lithium-ion battery is selected from the coated asphalt prepared by the method described in any one of claims 1 to 7, and / or the needle coke described in claim 10.

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