Method for simultaneously producing needle coke raw material and pitch-coated material and device therefor

Abstract

The present application relates to the technical field of petroleum processing, in particular to a method for simultaneously preparing needle coke raw material and coating pitch, a device for simultaneously preparing needle coke raw material and coating pitch, needle coke and lithium ion battery negative electrode material.The method comprises the following steps: (1) performing first distillation cutting on catalytic diesel oil to obtain monocyclic aromatic hydrocarbon-rich component, bicyclic aromatic hydrocarbon-rich component and tricyclic aromatic hydrocarbon-rich component; (2) performing thermal polycondensation reaction on the bicyclic aromatic hydrocarbon-rich component to obtain cracking gas and thermal polycondensation product; (3) performing second distillation cutting on the thermal polycondensation product to obtain cracking light oil I, cracking light oil II, circulating oil and polycondensation heavy component; (4) performing vacuum distillation cutting on the polycondensation heavy component to obtain polycondensation wax oil and polycondensation pitch as needle coke raw material and coating pitch respectively.The method enriches the preparation process of carbon materials and widens the resource utilization of catalytic diesel oil.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of petroleum processing, in particular to a method for simultaneously preparing needle coke raw material and coated pitch, an apparatus for simultaneously preparing needle coke raw material and coated pitch, a needle coke and a lithium ion battery negative electrode material. BACKGROUND

[0002] Catalytic cracking diesel is a diesel fraction produced by catalytic cracking unit, which has high aromatic content and low cetane number, and is a relatively poor diesel component. At present, refining enterprises mainly convert catalytic cracking diesel into light aromatic hydrocarbons or high-octane gasoline through hydrogenation saturation and catalytic cracking. Domestic and foreign scholars have carried out a large amount 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, which convert poor LCO into high-octane catalytic cracking gasoline or light aromatic hydrocarbons (BTX).

[0003] With the rapid development of new energy vehicles and energy storage industry, the demand for lithium ion batteries and their negative materials has also increased rapidly. By 2025, the demand for lithium battery negative materials in China will reach 1,456,000 tons. The negative material is mainly composed of aggregate needle coke and binder coated pitch. Needle coke is a carbon material with silver-gray appearance and needle-shaped texture on the surface. It has high crystallinity, small thermal expansion coefficient, good orientation, good electrical conductivity and thermal conductivity, etc. It is a 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 bulk density, high mechanical strength, low nitrogen content, low gas expansion rate during graphitization, good adsorption performance for binders and easy molding. Although the raw materials of coal-based needle coke and oil-based needle coke are different, the existing needle coke preparation or production related technologies are all based on three to six ring polycyclic aromatic hydrocarbons as raw materials, which are prepared through heat polycondensation, mesophase culture and needle coke solidification.

[0004] In the past two years, affected by the strong market demand for needle coke, the number of new enterprises producing needle coke has increased significantly. From 2018 to 2021, the production capacity increased from 510,000 tons to 2,100,000 tons in just four years. At present, the main problem faced by the needle coke industry is that the sulfur and nitrogen content of needle coke raw materials is relatively high, and there is a shortage of low-sulfur and low-nitrogen content needle coke raw materials. 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 pitch is a high-softening-point pitch produced from ethylene tar. The main problem in 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, resulting in long-term high product prices.

[0005] The common point of needle coke raw materials, coated pitch and catalytic diesel is that their components are all polycyclic aromatic hydrocarbons. If a process can be developed to convert the di- and tri-ring aromatic hydrocarbons in catalytic diesel into tri- to hexa-ring aromatic hydrocarbons and hexa-ring aromatic hydrocarbons, and then into the relatively scarce carbon materials in the market, a new path for high-value conversion can be provided, effectively alleviating the problem of excess catalytic diesel in refineries. SUMMARY

[0006] The purpose of the present application is to overcome the above technical problems, provide a method for simultaneously preparing needle coke raw materials and coated pitch, a device for simultaneously preparing needle coke raw materials and coated pitch, 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 pitch, not only enriching the preparation process of carbon materials, but also opening up the resource utilization of catalytic diesel.

[0007] To achieve the above-mentioned purpose, the first aspect of the present application provides a method for simultaneously preparing needle coke raw materials and coated pitch, which comprises the following steps:

[0008] (1) The catalytic diesel is subjected to first distillation cutting to obtain a mono-ring aromatic hydrocarbon-rich component, a di-ring aromatic hydrocarbon-rich component, and a tri-ring aromatic hydrocarbon-rich component;

[0009] (2) The di-ring aromatic hydrocarbon-rich component is subjected to a thermal polycondensation reaction to obtain a cracking gas and a thermal polycondensation product;

[0010] (3) The thermal polycondensation product is subjected to second distillation cutting to obtain a cracking light oil I, a cracking light oil II, a circulating oil, and a polycondensation heavy component;

[0011] (4) The polycondensation heavy component is subjected to vacuum distillation cutting to obtain a polycondensation wax oil and a polycondensation pitch, which are used as needle coke raw materials and coated pitch, respectively.

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

[0013] Preferably, the method further comprises: returning at least part of the cycle oil to the thermal polycondensation reaction, preferably returning the cycle oil to the thermal polycondensation reaction.

[0014] The second aspect of the present application provides a device for simultaneously preparing needle coke raw material and coating pitch, 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] The first distillation cutting unit is used for first distillation cutting of catalytic diesel to obtain mono-cyclic aromatic hydrocarbon-rich component, di-cyclic aromatic hydrocarbon-rich component and tri-cyclic aromatic hydrocarbon-rich component; the thermal polycondensation reaction unit is used for thermal polycondensation reaction of the di-cyclic aromatic hydrocarbon-rich component to obtain cracking gas and thermal polycondensation product; the second distillation cutting unit is used for second distillation cutting of the thermal polycondensation product to obtain cracking light oil I, cracking light oil II, cycle oil and polycondensation heavy component; and the vacuum distillation cutting unit is used for vacuum distillation cutting of the polycondensation heavy component to obtain polycondensation wax oil and polycondensation pitch as needle coke raw material and coating pitch, respectively.

[0016] The third aspect of the present application provides needle coke, which is obtained by calcination and graphitization of the needle coke raw material prepared by the method of the first aspect.

[0017] The fourth aspect of the present application provides a lithium ion battery negative electrode material, which comprises the coating pitch prepared by the method of the first aspect and / or the needle coke provided by the third aspect.

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

[0019] (1) The method provided by the present application uses catalytic diesel as raw material, and uses the technical means of first distillation cutting, thermal polycondensation reaction, second distillation cutting and vacuum distillation in sequence to simultaneously prepare two kinds of carbon materials, namely needle coke raw material and coating pitch. This method not only enriches the preparation process of carbon materials, but also widens the resource utilization of catalytic diesel and improves the added value of products.

[0020] (2) The method provided by the application, in particular, by adjusting the temperature of the first distillation cut (i.e., the distillation range of the diaromatic hydrocarbon-rich component) and the process conditions of the thermal polycondensation reaction, and recycling at least part of the cycle oil, thereby regulating the distribution of various components in the thermal polycondensation product, regulating the yield of the polycondensation wax oil and the polycondensation pitch, and realizing controllable polycondensation of the aromatic hydrocarbons in the catalytic diesel oil;

[0021] (3) The needle coke raw material prepared by the method provided by the application 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%, a true density (before calcination) of ≥1.35g / cm 3 , a true density (before calcination) of ≥2.12g / cm 3 , a thermal expansion coefficient (25-600℃) of ≤1.3×10 -6 / ℃, and a polarized light microstructure in the form of needle-shaped texture; at the same time, the needle coke is used in lithium ion batteries, which can effectively improve the electrochemical performance of the lithium ion batteries;

[0022] (4) The polycondensation pitch prepared by the method provided by the application is used as a coating pitch, and the coating pitch has a softening point of ≥150℃, a toluene insoluble content of ≥1wt%, a carbon residue of ≥50wt%, an ash content of ≤0.01wt%, and a sulfur content of ≤0.5wt%, which meets the group standard “Pitch for Lithium Ion Battery Negative Material” of the China Petroleum and Chemical Industry Association, and can be used in lithium ion battery negative materials. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a device for simultaneously preparing needle coke raw material and coating pitch provided by the application.

[0024] MARKS

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

[0026] 1, catalytic diesel oil; 2, monocyclic aromatic hydrocarbon-rich component; 3, diaromatic hydrocarbon-rich component; 4, triaromatic hydrocarbon-rich component; 5, cracking gas; 6, thermal polycondensation product; 7, cracking light oil I; 8, cracking light oil II; 9, cycle oil; 10, polycondensation heavy component; 11, polycondensation wax oil (needle coke raw material); 12, polycondensation pitch (coating pitch). DETAILED DESCRIPTION

[0027] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not critical to the invention. Any numeric range recited is intended to include all values from the lower value to the upper value, inclusive of both values, and to sub-ranges falling within the specified range. In this context, individual points within a range should not be dismissed as inherently excluded from the range merely because they are enumerated in the disclosure.

[0028] In the present invention, "first" and "second" do not indicate the order or limit the respective materials or steps, but are used to distinguish or indicate that they are not the same material or step, unless otherwise specified. 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] The first aspect of the present invention provides a method for simultaneously preparing needle coke raw material and coating pitch, comprising the following steps:

[0030] (1) performing first distillation cut on catalytic diesel to obtain monocyclic aromatic hydrocarbon-rich component, bicyclic aromatic hydrocarbon-rich component, and tricyclic aromatic hydrocarbon-rich component;

[0031] (2) performing thermal polycondensation reaction on the bicyclic aromatic hydrocarbon-rich component to obtain cracking gas and thermal polycondensation product;

[0032] (3) performing second distillation cut on the thermal polycondensation product to obtain cracking light oil I, cracking light oil II, cycle oil, and polycondensation heavy component;

[0033] (4) performing vacuum distillation cut on the polycondensation heavy component to obtain polycondensation wax oil and polycondensation pitch as needle coke raw material and coating pitch, respectively.

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

[0035] In a specific embodiment of the present invention, the monocyclic aromatic hydrocarbon content in the catalytic diesel is 20 wt%, the bicyclic aromatic hydrocarbon content is 50 wt%, the tricyclic aromatic hydrocarbon content is 10 wt%, and the saturated hydrocarbon content is 20 wt%.

[0036] In some embodiments of the present application, preferably, the property parameters of the catalytic diesel also satisfy: the sulfur content is 1 mg / kg-1 wt%; the nitrogen content is 1 mg / kg-1 wt%; and the oxygen content is 1 mg / kg-1 wt%.

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

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

[0039] In the present application, unless otherwise specified, the carbon and hydrogen element content parameters are determined according to the "Determination of Carbon, Hydrogen and Nitrogen in Petroleum Products and Lubricants by Elemental Analyzer (SH / T 0656-2017)"; the oxygen content parameter is determined according to the "Determination of Total Oxygen Content in Gasoline, Diesel and Methanol Fuels by Reductive Cracking (SH / T 0986-2019)"; the nitrogen content parameter is determined according to the "Determination of Nitrogen Content in Petroleum and Petroleum Products by Boats Sampling Chemiluminescence (SH / T 0704-2010)"; and the sulfur content parameter is determined according to the "Determination of Sulfur Content in Petroleum and Petroleum Products by Energy Dispersive X-ray Fluorescence (GB / T 17040-2008)".

[0040] In the present application, the type of the catalytic diesel has a wide selection range as long as it satisfies the above limitations. 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 application, the catalytic cracking middle distillate oil is the middle distillate oil produced by a 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 raw material catalytic cracking unit; the catalytic cracking refined diesel refers to the refined catalytic diesel with low sulfur and low nitrogen obtained by hydrotreating and hydrofining of the catalytic cracking middle distillate oil.

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

[0043] In the present application, the first distillation cut is aimed to obtain a specific fraction, i.e. a diaromatics-enriched component. Preferably, in step (1), the distillation range of the diaromatics-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 within the range between any two of the cited values, preferably 230-340°C, more preferably 250-330°C. The distillation range meeting the above range is advantageous to obtain the diaromatics-enriched component with high content of diaromatics.

[0044] In the present application, the diaromatics-enriched component contains a small amount of saturated hydrocarbons, monoaromatics and triaromatics in addition to diaromatics.

[0045] In some embodiments of the present application, preferably, in step (1), the content of diaromatics in the diaromatics-enriched component is ≥ 70wt%, for example, 70wt%, 75wt%, 80wt%, 85wt%, 90wt%, 95wt%, 99wt%, 99.9wt%, and any value within the range between any two of the cited values, preferably ≥ 80wt%, more preferably 85-99.9wt%.

[0046] In some embodiments of the present application, further preferably, in step (1), the content of saturated hydrocarbons in the diaromatics-enriched component is ≤ 10wt%, the content of monoaromatics is ≤ 10wt%, and the content of triaromatics is ≤ 2wt%.

[0047] In the present application, the thermal polycondensation reaction is aimed to polycondense diaromatics and triaromatics in the diaromatics-enriched component. Preferably, in step (2), the conditions of the thermal polycondensation reaction include: 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 within the range between any two of the cited values, preferably 410-460°C; time of 0.1-5h, for example, 0.1h, 0.5h, 1h, 2h, 3h, 5h, and any value within the range between any two of the cited values, preferably 0.5-3h.

[0048] In some embodiments of the present application, preferably, the method further comprises: heating the diaromatics-enriched component to 400-480°C, preferably 410-460°C, before the thermal polycondensation reaction. In the present application, the mode of heating has a wide range of choices as long as the temperature of the thermal polycondensation reaction is reached, which includes but is not limited to tube furnace heating, heat exchanger heating, tube furnace heating, etc.

[0049] In some embodiments of the present application, preferably, the toluene insoluble content of the thermal polycondensation product is ≤ 3 wt%. When the toluene insoluble content of the thermal polycondensation product is > 3 wt%, coking is easy to occur.

[0050] In some embodiments of the present application, preferably, the total aromatic hydrocarbon content of the thermal polycondensation product is ≥ 75 wt%, preferably 75-99.9 wt%. In the present application, the total aromatic hydrocarbon in the thermal polycondensation product includes a small amount of saturated hydrocarbons, monocyclic aromatic hydrocarbons and bicyclic aromatic hydrocarbons, as well as tri- to hexacyclic aromatic hydrocarbons and aromatic hydrocarbons with more than six rings.

[0051] In the present application, the second distillation cut is intended to refine the thermal polycondensation product to obtain a polycondensation heavy component rich in tri- to hexacyclic aromatic hydrocarbons and aromatic hydrocarbons with more than six rings.

[0052] In some embodiments of the present application, 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 formed by any two of the above values, preferably 200-210°C. In the present application, 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 application, 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 formed by any two of the above values, preferably 210-230°C. In the present application, the cracked light oil II is rich in bicyclic aromatic hydrocarbons, for example, selected from naphthalene, methylnaphthalene and ethylnaphthalene, and can be used as a naphthalene oil product.

[0054] In some embodiments of the present application, 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 formed by any two of the above values, preferably 210-230°C. In the present application, the cracked light oil II is rich in bicyclic aromatic hydrocarbons, for example, selected from naphthalene, methylnaphthalene and ethylnaphthalene, and can be used as a naphthalene oil product.

[0055] In some embodiments of the present application, preferably, the initial boiling point of the polycondensation heavy component is 330-350°C, for example, 330°C, 335°C, 340°C, 345°C, 350°C, and any value in the range formed by any two of the above values, preferably 345-350°C, more preferably 350°C.

[0056] In a preferred embodiment of the present application, the final boiling 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 cracked light oil II is 230-350°C; and the initial boiling point of the polycondensation heavy component is 350°C.

[0057] In some embodiments of the present application, preferably, the temperature of the reduced pressure distillation cut is 500-540℃, for example, 500℃, 520℃, 530℃, 540℃, and any value in the range between any two of the values, preferably 520-540℃. The temperature meeting the above range is more conducive to obtaining the polycondensation wax oil rich in tri- to hexacyclic aromatic hydrocarbons and the polycondensation pitch rich in hexacyclic aromatic hydrocarbons.

[0058] In some embodiments of the present application, preferably, in step (4), the distillation range of the polycondensation wax oil is 350-540℃, preferably 350-520℃. The distillation range meeting the above range is more conducive to regulating the quality of the polycondensation wax oil and obtaining the polycondensation wax oil high in tri- to hexacyclic aromatic hydrocarbons, low in sulfur and nitrogen.

[0059] In some embodiments of the present application, preferably, the tri- to hexacyclic aromatic hydrocarbon content 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 application, preferably, in step (4), the initial boiling point of the polycondensation pitch is 500-540℃, for example, 500℃, 520℃, 530℃, 540℃, and any value in the range between any two of the values, preferably 520-540℃. The initial boiling point meeting the above range is more conducive to regulating the quality of the polycondensation pitch, i.e., obtaining the coating pitch high in hexacyclic aromatic hydrocarbons, high in softening point, high in carbon residue, low in sulfur and ash.

[0061] In some embodiments of the present application, preferably, the softening point of the polycondensation pitch is ≥150℃, the toluene insoluble 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 application, preferably, the method further comprises: returning at least part of the cycle oil to the thermal polycondensation reaction, preferably returning the cycle oil to the thermal polycondensation reaction. In this way, the yield of the needle coke raw material and the coating pitch can be effectively improved.

[0063] The second aspect of the present application provides a device structure for simultaneously preparing a needle coke raw material and a coating pitch, as shown in Figure 1 The device structure comprises a thermal polycondensation reaction device, a reduced pressure distillation device, a cycle oil return device, and a needle coke raw material and coating pitch collection device. Figure 1It can be known that the device comprises a first distillation cutting unit I, a thermal polycondensation reaction unit II, a second distillation cutting unit III and a vacuum distillation cutting unit IV connected in sequence; wherein the first distillation cutting unit I is used for carrying out first distillation cutting on the catalytic diesel oil 1 to obtain a single-ring aromatic hydrocarbon-rich component 2, a double-ring aromatic hydrocarbon-rich component 3 and a triple-ring aromatic hydrocarbon-rich component 4; the thermal polycondensation reaction unit II is used for carrying out thermal polycondensation reaction on the double-ring aromatic hydrocarbon-rich component 3 to obtain a cracking gas 5 and a thermal polycondensation product 6; the second distillation cutting unit III is used for carrying out second distillation cutting on the thermal polycondensation product 6 to obtain a cracking light oil I 7, a cracking light oil II 8, a cycle oil 9 and a polycondensation heavy component 10; and the vacuum distillation cutting unit IV is used for carrying out vacuum distillation cutting on the polycondensation heavy component 10 to obtain a polycondensation wax oil 11 and a polycondensation pitch 12 as the needle coke raw material and the coating pitch respectively.

[0064] In the present application, without special circumstances, the first distillation cutting unit can be selected from a distillation column, i.e. the single-ring aromatic hydrocarbon-rich component is extracted from the top of the column, the double-ring aromatic hydrocarbon-rich component is extracted from the side line of the column, and the triple-ring aromatic hydrocarbon-rich component is extracted from the bottom of the column; the thermal polycondensation reaction unit is selected from various types of reactors, the cracking gas is extracted from the top of the column, and the thermal polycondensation product is obtained from the bottom of the column; the second distillation cutting unit can be selected from a distillation column, i.e. the cracking light oil I is extracted from the top of the column, the cracking light oil II and the cycle oil are extracted from the side line of the column respectively, and the polycondensation heavy component is extracted from the bottom of the column; and the vacuum distillation cutting unit is selected from various types of reactors, the polycondensation wax oil is extracted from the top of the column, and the polycondensation pitch is obtained from the bottom of the column.

[0065] According to the present application, preferably, as shown in Figure 1 The second distillation cutting unit III is connected to the thermal polycondensation reaction unit II, and is used for returning at least part of the cycle oil and carrying out the thermal polycondensation reaction, preferably returning the cycle oil 9 and carrying out the thermal polycondensation reaction.

[0066] According to the present application, preferably, as shown in Figure 1 The device further comprises a heating unit V connected between the first distillation cutting unit I and the thermal polycondensation unit II, and is used for heating the double-ring aromatic hydrocarbon-rich component 3 before entering the thermal polycondensation unit II.

[0067] In a preferred embodiment of the present application, as shown in Figure 1 A device for simultaneously preparing needle coke raw material and coating pitch comprises 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 connected in sequence, and the second distillation cutting unit III is connected to the heating unit V.

[0068] In the present application, without special circumstances, the heating unit includes but is not limited to a heater, a heat exchanger and the like.

[0069] The third aspect of the present application provides a needle coke, which is obtained by sequentially subjecting the needle coke raw material prepared by the method of the first aspect to calcination and graphitization treatment.

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

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

[0072] In some embodiments of the present application, preferably, the needle coke has a sulfur content of ≤0.5wt%, a nitrogen content of ≤0.5wt%, an ash content of ≤0.1wt%, a true density (before calcination) of ≥1.35g / cm 3 , a true density (after calcination) of ≥2.12g / cm 3 , a thermal expansion coefficient (25-600°C) of ≤1.3×10 -6 / °C, and a polarized light microscopic structure showing needle-like texture.

[0073] The fourth aspect of the present application provides a lithium ion battery negative electrode material, which is selected from the coated pitch prepared by the method of the first aspect and / or the needle coke of the third aspect.

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

[0075] (1) subjecting catalytic diesel to first distillation cutting to obtain monocyclic aromatic hydrocarbon-rich component, di-cyclic aromatic hydrocarbon-rich component and tri-cyclic aromatic hydrocarbon-rich component;

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

[0077] (3) subjecting the thermal polycondensation product to second distillation cutting to obtain cracking light oil I, cracking light oil II, cycle oil and polycondensation heavy component;

[0078] (4) subjecting the polycondensation heavy component to vacuum distillation cutting to obtain polycondensation wax oil and polycondensation pitch as needle coke raw material and coated pitch, respectively;

[0079] wherein the distillation range of the di-cyclic aromatic hydrocarbon-rich component is selected from 250-330°C; and the temperature of the heating and thermal polycondensation reaction is independently selected from 410-460°C.

[0080] The cutting temperature of the cracked light oil I and the cracked light oil II is 200-210℃; the cutting temperature of the cracked light oil II and the cycle oil is 230-350℃; the initial boiling point of the polycondensation heavy component is 345-350℃.

[0081] The application will be described in detail below by way of examples.

[0082] The hydrocarbon composition in the raw oil is determined according to the Hydrocarbon Determination Method for Saturated Hydrocarbon Fractions in Gas Oil (Mass Spectrometry) (SH / T0659-1998);

[0083] The hydrocarbon composition in the distillate oil is determined according to the Hydrocarbon Composition Determination Method for Intermediate Distillate (Mass Spectrometry) (SH / T0606-2019);

[0084] The carbon and hydrogen element content parameters are determined according to the Elemental Analysis Instrument Method for 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 by Reductive Pyrolysis (SH / T0986-2019);

[0086] The nitrogen content parameters are determined according to the Determination of Nitrogen Content in Petroleum and Petroleum Products by Boats Sampling Chemical Luminescence Method (SH / T0704-2010);

[0087] The sulfur content parameters are determined according to the Determination of Sulfur Content in Petroleum and Petroleum Products by Energy Dispersive X-ray Fluorescence (GB / T 17040-2008).

[0088] The toluene insoluble content is determined according to the Determination of Toluene Insoluble Content in Coking Products (GB / T2292-2018).

[0089] The calculation method of the polycondensation yield is: polycondensation yield = polycondensation wax oil yield + polycondensation pitch yield; polycondensation wax oil yield = (polycondensation wax oil mass / raw material mass) x 100%, and polycondensation pitch yield = (polycondensation pitch mass / raw material mass) x 100%.

[0090] Example 1

[0091] (1) The YS catalytic diesel oil (see Table 1 for each component and content) is used as a raw material for first distillation cutting to obtain a dicyclic aromatic hydrocarbon rich component (see Table 2 for each component and content) with a distillation range of 250-330℃ as a distillate oil;

[0092] (2) The distillate oil is heated to 440°C for thermal polycondensation (temperature: 440°C, time: 4 hours) to obtain a cracked gas and a thermal polycondensation product S1, wherein the toluene insoluble content in the thermal polycondensation product S1 is 2.76 wt%;

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

[0094] wherein the end boiling 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 boiling point of the polycondensation heavy component is 350°C;

[0095] wherein the cycle oil is returned and mixed with the di-cyclic aromatic hydrocarbon-rich component, and is sequentially subjected to heating and thermal polycondensation;

[0096] (4) The polycondensation heavy component is subjected to a vacuum distillation cut, wherein the cut temperature of polycondensation wax oil and polycondensation pitch is 520°C, to obtain polycondensation wax oil and polycondensation pitch as needle coke raw material P1 and coating pitch Q1, respectively;

[0097] wherein the product distribution of the cracked gas, the cracked light oil I, the cracked light oil II, the cycle oil, the polycondensation wax oil and the polycondensation pitch is shown in Table 3, and the physical property parameters of the needle coke raw material P1 and the coating pitch Q1 are shown in Table 4.

[0098] Example 2

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

[0100] In step (2), the distillate oil is heated to 460°C for thermal polycondensation (temperature: 460°C, time: 2 hours) to obtain a cracked gas and a thermal polycondensation product S2, wherein the toluene insoluble content 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 cut, wherein the cut temperature of cracked light oil I and cracked light oil II is 210°C, the cut temperature of cracked light oil II and cycle oil is 230°C, and the cut temperature of cycle oil and polycondensation heavy component is 350°C, to obtain cracked light oil I, cracked light oil II, cycle oil and polycondensation heavy component;

[0102] wherein the end point of the cracking light oil I is 210°C, the distillation range of the cracking light oil II is 210-230°C, the distillation range of the cycle oil is 230-350°C, and the initial point of the polycondensation heavy component is 350°C;

[0103] wherein the cycle oil is returned and mixed into the diaromatics-rich component, and sequentially heated and subjected to thermal polycondensation;

[0104] In step (4), the polycondensation heavy component is subjected to vacuum distillation cutting, wherein the cutting temperature of the polycondensation wax oil and the polycondensation pitch is 520°C, and the obtained polycondensation wax oil and polycondensation pitch are used as the needle coke raw material P2 and the coating pitch Q2, respectively;

[0105] wherein the product distribution of the cracking gas, the cracking light oil I, the cracking light oil II, the cycle oil, the polycondensation wax oil and the polycondensation pitch is listed in Table 3, and the physical property parameters of the needle coke raw material P2 and the coating pitch Q2 are listed in Table 4.

[0106] Example 3

[0107] According to the method of Example 1, except that the distillation range of the diaromatics-rich component in step (1) is changed, i.e.,

[0108] (1) YS catalytic diesel oil is used as the raw material to perform first distillation cutting, and a diaromatics-rich component with a distillation range of 250-300°C is obtained as the distillate (see Table 2 for the components and their contents);

[0109] (2) The distillate is heated to 440°C to perform thermal polycondensation (the temperature is 440°C, and the time is 4h), and a cracking gas and a thermal polycondensation product S3 are obtained, wherein the toluene insoluble content in the thermal polycondensation product S3 is 1.75wt%;

[0110] (3) The thermal polycondensation product S3 is subjected to second distillation cutting, wherein the cutting temperature of the cracking light oil I and the cracking light oil II is 210°C, the cutting temperature of the cracking light oil II and the cycle oil is 230°C, and the cutting temperature of the cycle oil and the polycondensation heavy component is 350°C, and the cracking light oil I, the cracking light oil II, the cycle oil and the polycondensation heavy component are obtained;

[0111] wherein the end point of the cracking light oil I is 210°C, the distillation range of the cracking light oil II is 210-230°C, the distillation range of the cycle oil is 230-350°C, and the initial point of the polycondensation heavy component is 350°C;

[0112] wherein the cycle oil is returned and mixed into the diaromatics-rich component, and sequentially heated and subjected to thermal polycondensation;

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

[0114] The yields of the cracking gas, the cracking light oil I, the cracking light oil II, the cycle oil, the polycondensation wax oil and the polycondensation pitch are listed in Table 3, and the physical parameters of the needle coke raw material P3 and the coating pitch Q3 are listed in Table 4.

[0115] Example 4

[0116] According to the method of Example 1, except that the conditions of heating and thermal polycondensation reaction in step (2) are changed, i.e., the heating temperature is 400°C, and the heating time is 4h.

[0117] (1) The YS catalytic diesel oil is used as the raw material to perform first distillation cutting, and a diaromatic hydrocarbon-rich component (same as Example 1) with a distillation range of 250-330°C is obtained as the distillate oil;

[0118] (2) The distillate oil is heated to 400°C to perform thermal polycondensation reaction (the temperature is 400°C, and the time is 4h), and a cracking gas and a thermal polycondensation product S4 are obtained, wherein the toluene insoluble content in the thermal polycondensation product S4 is 0.2wt%;

[0119] (3) The thermal polycondensation product S4 is subjected to second distillation cutting, wherein the cutting temperature of the cracking light oil I and the cracking light oil II is 210°C, the cutting temperature of the cracking light oil II and the cycle oil is 230°C, and the cutting temperature of the cycle oil and the polycondensation heavy component is 350°C, and the cracking light oil I, the cracking light oil II, the cycle oil and the polycondensation heavy component are obtained.

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

[0121] The cycle oil is returned and mixed into the diaromatic hydrocarbon-rich component, and heating and thermal polycondensation reaction are sequentially performed.

[0122] (4) The polycondensation heavy component is subjected to vacuum distillation cutting, wherein the cutting temperature of the polycondensation wax oil and the polycondensation pitch is 520°C, and the obtained polycondensation wax oil and polycondensation pitch are respectively used as the needle coke raw material P3 and the coating pitch Q3.

[0123] The yields of the cracking gas, the cracking light oil I, the cracking light oil II, the cycle oil, the polycondensation wax oil and the polycondensation pitch are listed in Table 3, and the physical parameters of the needle coke raw material P3 and the coating pitch Q3 are listed in Table 4.

[0124] Example 5

[0125] The method of Example 1 was followed except that the distillation range of the cycle oil in step (3) was changed, i.e., the distillation range of the cycle oil was 250-330°C.

[0126] In step (3), the above thermal polycondensation product S1 was subjected to a second distillation cut, in which the cut temperature of the cracking light oil I and the cracking light oil II was 210°C, the cut temperature of the cracking light oil II and the cycle oil was 250°C, and the cut temperature of the cycle oil and the polycondensation heavy component was 330°C, to obtain the cracking light oil I, the cracking light oil II, the cycle oil, and the polycondensation heavy component.

[0127] In which the final boiling point of the cracking light oil I was 210°C, the distillation range of the cracking light oil II was 210-250°C, the distillation range of the cycle oil was 250-330°C, and the initial boiling point of the polycondensation heavy component was 330°C.

[0128] In which the above cycle oil was returned and mixed into the di-cyclic aromatic hydrocarbon-rich component, and was sequentially subjected to heating and thermal polycondensation reaction.

[0129] In step (4), the remaining conditions were the same, and the polycondensation wax oil and the polycondensation pitch obtained were used as the needle coke raw material P5 and the coating pitch Q5, respectively.

[0130] In which the product distribution of the cracking gas, the cracking light oil I, the cracking light oil II (naphthalene oil), the cycle oil, the polycondensation wax oil, and the polycondensation pitch is listed in Table 3; the physical property parameters of the needle coke raw material P5 and the coating pitch Q5 are both listed in Table 4.

[0131] Example 6

[0132] The method of Example 1 was followed except that in step (3), the above cycle oil was not recycled but was discarded; i.e., the distillation range of the cycle oil was 250-330°C.

[0133] In step (2), the remaining conditions were the same, and the thermal polycondensation product S6 was obtained.

[0134] In step (3), the remaining conditions were the same, and the cracking light oil I, the cracking light oil II, the cycle oil, and the polycondensation heavy component were obtained.

[0135] In step (4), the remaining conditions were the same, and the polycondensation wax oil and the polycondensation pitch obtained were used as the needle coke raw material P6 and the coating pitch Q6, respectively.

[0136] In which the product distribution of the cracking gas, the cracking light oil I, the cracking light oil II (naphthalene oil), the cycle oil, the polycondensation wax oil, and the polycondensation pitch is listed in Table 3; the physical property parameters of the needle coke raw material P6 and the coating pitch Q6 are both listed in Table 4.

[0137] Comparative Example 1

[0138] The method of Example 1 was followed except that in step (3), the above cycle oil was not recycled but was discarded; i.e., the distillation range of the cycle oil was 250-330°C.

[0139] In step (1), the YS catalytic diesel was replaced by MY ethene tar (elemental composition is shown in Table 1), and other conditions were the same, to obtain a diaromatics-rich component (each component and its content are shown in Table 2) with a distillation range of 250-330°C as distillate oil;

[0140] In step (2), other conditions were the same, to obtain a cracking gas and a thermal polycondensation product DS1.

[0141] In step (3), other conditions were the same, to obtain a cracking light oil I, a cracking light oil II, a cycle oil and a polycondensation heavy component.

[0142] In step (4), other conditions were the same, to obtain a polycondensation wax oil and a polycondensation pitch as a needle coke raw material DP1 and a coating pitch DQ1, respectively.

[0143] In which, the product distribution of the cracking gas, the cracking light oil I, the cracking light oil II (naphthalene oil), the cycle oil, the polycondensation wax oil and the polycondensation pitch is shown in Table 3; the physical property parameters of the needle coke raw material DP1 and the coating pitch DQ1 are shown in Table 4.

[0144] Table 1

[0145] Oil No. YS catalytic diesel MY ethylene tar Hydrocarbon composition, wt% Paraffins 8.8 - Total naphthenes 4.5 - Total saturates 13.3 - Monocyclic aromatics 23.9 - Bicyclic aromatics 55.3 - Tricyclic aromatics 7.5 - Total aromatics 86.7 - Gelation 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 content in the thermal polycondensation product, wt%;

[0152] #-product distribution of each component of the cracking gas, the cracking light oil I, the cracking light oil II, the polycondensation wax oil, the polycondensation pitch and the cycle oil, and the sum of the component distribution is 100wt%;

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

[0154] Table 4

[0155]

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

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

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

[0159] Test Example

[0160] The needle coke raw materials (P1-P6 and DP1) prepared from Examples 1-6 and Comparative Example 1 are successively calcined (temperature is 1400℃, time is 12h), and graphitized (temperature is 2800℃, time is 3h), to obtain the physical property parameters of the needle coke (W1-W6), which are listed in Table 5.

[0161] Table 5

[0162]

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

[0164] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application, and all fall within the protection scope of the present application.

Claims

1. A method for simultaneously preparing needle coke feedstock and coated bitumen, characterized in that, The method includes the following steps: (1) The catalytic diesel is subjected to first distillation to obtain monocyclic aromatic hydrocarbon enriched components, dicyclic aromatic hydrocarbon enriched components and tricyclic aromatic hydrocarbon enriched components; (2) The dicyclic aromatic hydrocarbon enriched component is subjected to thermal polycondensation reaction to obtain cracked gas and thermal polycondensation product; (3) The thermal polycondensation product is subjected to a second distillation to obtain cracked light oil I, cracked light oil II, recycled oil and polycondensation heavy components; (4) The polycondensed heavy components are cut by vacuum distillation, and the resulting polycondensed wax oil and polycondensed pitch are used as needle coke raw materials and coated pitch, respectively.

2. The method according to claim 1, wherein, In step (1), The catalytic diesel fuel contains ≥70 wt% total aromatics; ≥40 wt% dicyclic aromatics; and ≥1 wt% tricyclic aromatics. And / or, the catalytic diesel oil 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 oil.

3. The method according to claim 2, wherein, In step (1), The catalytic diesel contains 70-99.9 wt% total aromatics, 50-90 wt% bicyclic aromatics, and 1-20 wt% tricyclic aromatics.

4. The method according to claim 1, wherein, In step (1), The distillation range of the dicyclic aromatic hydrocarbon enrichment component is selected from 220-390℃; And / or, the dicyclic aromatic hydrocarbon content in the enriched component is ≥70 wt%; And / or, the saturated hydrocarbon content in the dicyclic aromatic hydrocarbon enrichment component is ≤10wt%, the monocyclic aromatic hydrocarbon content is ≤10wt%, and the tricyclic aromatic hydrocarbon content is ≤2wt%.

5. The method according to claim 4, wherein, In step (1), The distillation range of the dicyclic aromatic hydrocarbon enrichment component is 230-340℃; And / or, the bicyclic aromatic hydrocarbon content in the enriched component is ≥80wt%.

6. The method according to claim 5, wherein, In step (1), The distillation range of the dicyclic aromatic hydrocarbon enrichment component is 250-330℃; And / or, the content of bicyclic aromatic hydrocarbons in the enriched component is 85-99.9 wt%.

7. The method according to claim 1, wherein, In step (2), The conditions for the thermal polycondensation reaction include: a temperature of 400-480℃ and a time of 0.1-5h; And / or, the toluene-insoluble content in the thermopolymerization product is ≤3 wt%; And / or, the total aromatic hydrocarbon content in the thermopolymerization product is ≥75 wt%; And / or, prior to the thermal polycondensation reaction, the dicyclic aromatic hydrocarbon enriched component is heated to 400-480°C.

8. The method according to claim 7, wherein, In step (2), The conditions for the thermal polycondensation reaction include: a temperature of 410-460℃ and a time of 0.5-3 hours; And / or, the total aromatic hydrocarbon content in the thermopolymerization product is 75-99.9 wt%; And / or, prior to the thermal polycondensation reaction, the dicyclic aromatic hydrocarbon enriched component is heated to 410-460°C.

9. The method according to claim 1, wherein, In step (3), The cracked light oil I and 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; And / or, the distillation range of the cracked light oil II is 200-250°C; And / or, the boiling range of the circulating oil is 220-350°C; And / or, the initial boiling point of the polycondensation component is 330-350°C.

10. The method according to claim 9, wherein, In step (3), The cracked light oil I and 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 200-210℃; And / or, the distillation range of the cracked light oil II is 210-230°C; And / or, the boiling range of the circulating oil is 230-350°C; And / or, the initial boiling point of the polycondensation component is 345-350°C.

11. The method according to any one of claims 1-10, wherein, In step (4), The temperature for vacuum distillation cutting is 500-540℃; And / or, the polycondensation wax oil contains ≥50 wt% tri-hexacyclic aromatic hydrocarbons; ≤1 wt% sulfur; and ≤0.6 wt% nitrogen. And / or, the softening point of the condensed bitumen is ≥150℃, the content of toluene-insoluble matter is ≥1wt%, the residual carbon is ≥50wt%, the ash content is ≤0.01wt%, and the sulfur content is ≤0.5wt%.

12. The method according to claim 11, wherein, In step (4), The temperature for vacuum distillation cutting is 520-540℃; And / or, the polycondensation wax oil contains ≥70wt% tri-hexacyclic aromatic hydrocarbons; ≤0.3wt% sulfur; and ≤600mg / kg nitrogen.

13. The method according to claim 1, wherein, The method further includes: returning at least a portion of the circulating oil and carrying out the thermal polycondensation reaction.

14. The method according to claim 13, wherein, The method further includes: returning the circulating oil and carrying out the thermal polycondensation reaction.

15. The method according to any one of claims 1-10, wherein, The method is carried out in an apparatus that simultaneously prepares needle coke feedstock and coated bitumen, the apparatus comprising a first distillation and cutting unit, a thermal polycondensation reaction unit, a second distillation and cutting unit, and a vacuum distillation and cutting unit connected in sequence. The first distillation cutting unit is used to perform a first distillation cutting on catalytic diesel oil to obtain monocyclic aromatic hydrocarbon enriched components, dicyclic aromatic hydrocarbon enriched components, and tricyclic aromatic hydrocarbon enriched components; the thermal polycondensation reaction unit is used to perform a thermal polycondensation reaction on the dicyclic aromatic hydrocarbon enriched components to obtain cracked gas and thermal polycondensation products; the second distillation cutting unit is used to perform a second distillation cutting on the thermal polycondensation products to obtain cracked light oil I, cracked light oil II, recycled oil, and polycondensed heavy components; the vacuum distillation cutting unit is used to perform vacuum distillation cutting on the polycondensed heavy components, and the obtained polycondensed wax oil and polycondensed asphalt are used as needle coke feedstock and coated asphalt, respectively.

16. The method according to claim 15, wherein, The second distillation and cutting unit is connected to the thermal polycondensation reaction unit and is used to return at least a portion of the circulating oil and carry out the thermal polycondensation reaction; And / or, the apparatus further includes: a heating unit connecting the first distillation cutting unit and the thermal polycondensation unit, for heating the bicyclic aromatic hydrocarbon enriched component before it enters the thermal polycondensation unit.

17. The method according to claim 16, wherein, The second distillation and cutting unit is connected to the thermal polycondensation reaction unit and is used to return the circulating oil and carry out the thermal polycondensation reaction.

18. The method according to any one of claims 1-10, wherein, The needle coke raw material is subjected to calcination and graphitization treatment in sequence to obtain needle coke; The needle coke has a sulfur content ≤0.5wt%, a nitrogen content ≤0.5wt%, an ash content ≤0.1wt%, and a true density before calcination ≥1.35g / cm³. 3 True density after calcination ≥ 2.12 g / cm³ 3 The coefficient of thermal expansion at 25-600℃ is ≤1.3×10⁻⁶. -6 / ℃.

19. The method according to claim 18, wherein, The coated asphalt and / or needle coke are used as negative electrode materials for lithium-ion batteries.

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