Method for simultaneously preparing needle coke raw material and coating asphalt, obtained product, needle coke prepared therefrom and device

Abstract

The present invention relates to a method for simultaneously preparing a needle coke raw material and coating asphalt, a needle coke raw material and coating asphalt prepared by the method, needle coke prepared from the needle coke raw material, a lithium ion battery negative electrode material comprising the needle coke and / or the coating asphalt, and a device. The method comprises: (1) carrying out primary distillation cutting on catalytic diesel oil to obtain a bicyclic aromatic hydrocarbon enrichment component; (2) carrying out thermal polycondensation reaction on the bicyclic aromatic hydrocarbon enrichment component to obtain a thermal polycondensation product; (3) carrying out secondary distillation cutting on the thermal polycondensation product to obtain circulating oil and a polycondensation heavy component, wherein at least part of the circulating oil returns to step (2) for the thermal polycondensation reaction; and (4) carrying out reduced pressure distillation cutting on the polycondensation heavy component to obtain polycondensation wax oil serving as the needle coke raw material and polycondensation asphalt serving as the coating asphalt. The present invention improves the product yield, enriches the preparation process of a carbon material, and develops the reclamation of the catalytic diesel oil.

Description

Method for simultaneously preparing needle coke raw material and coated asphalt, obtained product, needle coke prepared therefrom, and device Technical Field

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

[0002] Catalytically cracked diesel, a diesel fraction produced in a catalytic cracking unit, has a high aromatics content and a low cetane number, making it a relatively low-quality diesel component. Currently, refining and petrochemical companies primarily convert catalytically cracked diesel into light aromatics or high-octane gasoline through hydrogenation and catalytic cracking. Domestic and international scholars have conducted extensive basic research and industrialized applications on this technology. CN201210410162.3, CN201310516588.1, CN201310517650.9, CN201310517666.X, and CN201310010219.5 disclose a series of processes or methods for the catalytic conversion and upgrading of catalytically cracked light diesel, converting low-quality LCO into high-octane catalytically cracked gasoline or light aromatics (BTX).

[0003] The rapid development of the new energy vehicle and energy storage industries has driven the rapid growth of lithium-ion batteries and their negative electrode materials. By 2025, my country's demand for lithium battery negative electrode materials is expected to reach 1.456 million tons. These negative electrode materials primarily consist of aggregate needle coke and binder-coated asphalt. Needle coke is a silver-gray carbon material with a needle-like surface texture. It boasts high crystallinity, a low thermal expansion coefficient, good orientation, and excellent electrical and thermal conductivity. It is a raw material for the production of 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, a high bulk density, high mechanical strength, a low nitrogen content, and a low gas expansion rate during graphitization, enabling rapid graphitization. It also has good binder adsorption properties 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, mesophase cultivation, and coke pulling and solidification.

[0004] In the past two years, driven by strong demand for needle coke, the number of new needle coke companies has increased significantly. From 2018 to 2021, production capacity increased from 510,000 tons to 2.1 million tons in just four years. Currently, the main challenge facing the needle coke industry is the high sulfur and nitrogen content of needle coke raw materials, and the insufficient supply of low-sulfur and low-nitrogen needle coke raw materials. This has resulted in a significant increase in needle coke production capacity without an improvement in overall quality, and high-quality needle coke still needs to be imported. Coated asphalt is a high-softening point asphalt produced from ethylene tar. Its composition is mainly composed of polycyclic aromatic hydrocarbons with six or more rings and a berth structure. The main problem in this industry is the lack of large-scale enterprises. Domestic production capacity cannot meet the growing demand for lithium battery negative electrode materials, and product prices have remained high for a long time.

[0005] Needle coke feedstock, coated pitch, and other carbon materials (feedstocks) share a common characteristic: they are all composed of polycyclic aromatic hydrocarbons. Developing a process to convert the two- and three-ring aromatics in catalytic diesel into three-, six-, and six-ring aromatics, and then into carbon materials in short supply, could provide a new high-value conversion pathway and effectively alleviate the problem of excess catalytic diesel in refineries.

[0006] Summary of the Invention

[0007] The purpose of the present invention is to solve the above-mentioned technical problems and to provide a method for simultaneously preparing needle coke raw material and coated asphalt, needle coke raw material and coated asphalt prepared by the method, needle coke prepared from the needle coke raw material, and a lithium-ion battery negative electrode material comprising the needle coke and / or the coated asphalt. The present invention also provides a device for simultaneously preparing needle coke raw material and coated asphalt. The technical solution of the present invention can improve the yield of needle coke raw material and coated asphalt and achieve controlled polycondensation of catalytic diesel aromatics. The method uses catalytic diesel as raw material to simultaneously prepare needle coke raw material and coated asphalt, which not only enriches the preparation process of carbon materials, but also opens up the resource utilization of catalytic diesel.

[0008] 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 pitch, the method comprising the following steps:

[0009] (1) performing a first distillation cut on the catalytic diesel to obtain a dicyclic aromatic hydrocarbon-rich component;

[0010] (2) subjecting the dicyclic aromatic hydrocarbon-enriched component to a thermal polycondensation reaction to obtain a thermal polycondensation product;

[0011] (3) subjecting the thermal polycondensation product to a second distillation cut to obtain circulating oil and polycondensation heavy components, wherein at least a portion of the circulating oil is returned to step (2) for the thermal polycondensation reaction;

[0012] (4) The polycondensed heavy components are subjected to vacuum distillation cutting to obtain polycondensed wax oil as a needle coke raw material and polycondensed asphalt as a coating asphalt.

[0013] The second aspect of the present invention provides needle coke raw material and coated pitch prepared by the method provided by the first aspect.

[0014] A third aspect of the present invention provides a needle coke, which is obtained by sequentially subjecting the needle coke raw material provided by the second aspect to calcination and graphitization.

[0015] A 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 needle coke provided by the third aspect and / or the coated asphalt provided by the second aspect.

[0016] A fifth aspect of the present invention provides an apparatus for simultaneously preparing needle coke raw material and coated asphalt, 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;

[0017] The first distillation cutting unit is used to perform a first distillation cutting on the catalytic diesel to obtain a dicyclic aromatic hydrocarbon-rich component; the thermal polycondensation reaction unit is used to perform a thermal polycondensation reaction on the dicyclic aromatic hydrocarbon-rich component to obtain a thermal polycondensation product; the second distillation cutting unit is used to perform a second distillation cutting on the thermal polycondensation product to obtain circulating oil and polycondensation heavy components; the vacuum distillation cutting unit is used to perform a vacuum distillation cutting on the polycondensation heavy components to obtain polycondensation wax oil and polycondensation asphalt as needle coke raw material and coating asphalt, respectively.

[0018] 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.

[0019] In one embodiment of the above-mentioned device of the present invention, the first distillation cutting unit is used to perform a first distillation cutting on the catalytic diesel to obtain a single-ring aromatic hydrocarbon-enriched component and / or a tricyclic aromatic hydrocarbon-enriched component; and / or

[0020] The thermal polycondensation reaction unit is used to perform a thermal polycondensation reaction on the dicyclic aromatic hydrocarbon-enriched component to obtain cracking gas; and / or

[0021] The second distillation cutting unit is used to perform a second distillation cutting on the thermal polycondensation product to obtain cracked light oil I and / or cracked light oil II; and / or

[0022] Returning all of the circulating oil and performing the thermal polycondensation reaction; and / or

[0023] The device further comprises: a heating unit connected to the first distillation cutting unit and the thermal polycondensation unit, and configured to heat the dicyclic aromatic hydrocarbon enriched component and then allow it to enter the thermal polycondensation unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic diagram of an apparatus for simultaneously preparing needle coke raw materials and coated asphalt provided by the present invention.

[0025] Among them, I, the first distillation cutting unit; II, the thermal condensation unit; III, the second distillation cutting unit; IV, the vacuum distillation cutting unit; V, the heating unit; 1, catalytic diesel; 2, the monocyclic aromatic hydrocarbon-enriched component; 3, the dicyclic aromatic hydrocarbon-enriched component; 4, the tricyclic aromatic hydrocarbon-enriched component; 5, the cracking gas; 6, the thermal condensation product; 7, the cracking light oil I; 8, the cracking light oil II; 9, the circulating oil; 10, the condensation heavy component; 11, the condensation wax oil (needle coke raw material); 12, the condensation asphalt (coated asphalt). DETAILED DESCRIPTION

[0026] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and 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 to be specifically disclosed herein.

[0027] In the present invention, unless otherwise specified, the terms "first" and "second" do not indicate a sequential order or limit the materials or steps. They are used only to distinguish or indicate that they are not the same material or step. For example, the terms "first" and "second" in "first distillation cut" and "second distillation cut" are used only to indicate that they are not the same distillation cut.

[0028] A first aspect of the present invention provides a method for simultaneously preparing needle coke raw material and coated pitch, the method comprising the following steps:

[0029] (1) performing a first distillation cut on the catalytic diesel to obtain a dicyclic aromatic hydrocarbon-rich component;

[0030] (2) subjecting the dicyclic aromatic hydrocarbon-enriched component to a thermal polycondensation reaction to obtain a thermal polycondensation product;

[0031] (3) subjecting the thermal polycondensation product to a second distillation cut to obtain circulating oil and polycondensation heavy components, wherein at least a portion of the circulating oil is returned to step (2) for the thermal polycondensation reaction;

[0032] (4) The polycondensed heavy components are subjected to vacuum distillation cutting to obtain polycondensed wax oil as a needle coke raw material and polycondensed asphalt as a coating asphalt.

[0033] In a specific embodiment of the present invention, in step (1), the catalytic diesel is subjected to a first distillation cut to obtain a single-ring aromatic hydrocarbon-enriched component and / or a tri-ring aromatic hydrocarbon-enriched component.

[0034] In a specific embodiment of the present invention, in step (2), the dicyclic aromatic hydrocarbon-enriched component is subjected to a thermal polycondensation reaction to obtain cracking gas.

[0035] In a specific embodiment of the present invention, in step (3), the thermal polycondensation product is subjected to a second distillation cut to obtain cracked light oil I and / or cracked light oil II.

[0036] Preferably, the catalytic diesel fuel has a total aromatic content of ≥70 wt%, preferably 70-99.9 wt%, based on the total weight of the catalytic diesel fuel; a dicyclic aromatic content of ≥40 wt%, preferably 50-90 wt%; and / or a tricyclic aromatic content of ≥1 wt%, preferably 1-20 wt%. In the present invention, unless otherwise specified, the total aromatic content in the catalytic diesel fuel refers to the sum of the contents of monocyclic aromatics, dicyclic aromatics, and tricyclic aromatics. The preferred conditions employed herein are more conducive to improving the single-pass yield of polycondensation wax oil and polycondensation asphalt.

[0037] Preferably, the method further comprises: returning the circulating oil obtained from all steps (3) to step (2) for the thermal polycondensation reaction. This arrangement can more effectively improve the yield of needle coke raw material and coated asphalt.

[0038] 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 based on the total weight of the catalytic diesel.

[0039] In some embodiments of the present invention, preferably, the physical properties of the catalytic diesel further satisfy the following: sulfur content of 0.01 wt%-1 wt%; nitrogen content of 0.01 wt%-1 wt%; and oxygen content of 0.01 wt%-1 wt%.

[0040] In the present invention, unless otherwise specified, the hydrocarbon composition in catalytic diesel is determined according to the "Determination of Hydrocarbons in Saturated Hydrocarbon Fractions of Gas Oil (Mass Spectrometry) (SH / T 0659-1998)".

[0041] In the present invention, unless otherwise specified, the hydrocarbon composition in the distillate oil is determined in accordance with the “Determination of Hydrocarbon Composition of Mesophase Fraction (Mass Spectrometry) (SH / T 0606-2019)”.

[0042] In the present invention, unless otherwise specified, the carbon and hydrogen content parameters are determined in accordance with the "Petroleum Products and Lubricants - Determination of Carbon, Hydrogen and Nitrogen - Elemental Analyzer Method (SH / T 0656-2017)"; the oxygen content parameters are determined in accordance with the "Gasoline, Diesel and Methanol Fuels - Determination of Total Oxygen Content - Reduction Cracking Method (SH / T 0986-2019)"; the nitrogen content parameters are determined in accordance with the "Petroleum and Petroleum Products - Determination of Nitrogen Content - Boat Injection Chemiluminescence Method (SH / T 0704-2010)"; and the sulfur content parameters are determined in accordance with the "Petroleum and Petroleum Products - Determination of Sulfur Content - Energy Dispersive X-ray Fluorescence (GB / T 17040-2008)".

[0043] In the present invention, the type of catalytic diesel can be selected from a wide range, as long as it meets the above limitations. Preferably, the catalytic diesel is selected from at least one of catalytically cracked middle distillates, catalytically cracked light cycle oil, catalytically cracked heavy cycle oil, and catalytically cracked refined diesel.

[0044] In the present invention, the catalytically cracked middle distillate oil is a 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, or a mixed feed catalytic cracking unit. The catalytically cracked refined diesel oil is a low-sulfur and low-nitrogen refined catalytic diesel oil obtained by hydrotreating and hydrofining the catalytically cracked middle distillate oil.

[0045] In a specific embodiment of the present invention, preferably, the catalytic cracking middle distillate is selected from at least one of residual catalytic cracking distillate, wax oil catalytic cracking distillate and heavy oil catalytic cracking distillate.

[0046] The catalytic cracking light cycle oil is a product of the catalytic cracking process, and its boiling point range is, for example, generally 180°C to 350°C.

[0047] The catalytic cracking heavy cycle oil is a product of the catalytic cracking process, and its boiling point range is, for example, generally between 250°C and 400°C.

[0048] In the present invention, the first distillation cut is intended to obtain a specific fraction, i.e., a dicyclic aromatic hydrocarbon-rich fraction. Preferably, in step (1), the distillation range of the dicyclic aromatic hydrocarbon-rich fraction 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 a range consisting of any two values, preferably 230-340°C, more preferably 250-330°C. A distillation range that meets the above range is conducive to obtaining the dicyclic aromatic hydrocarbon-rich fraction with a high content of dicyclic aromatic hydrocarbons.

[0049] In some embodiments of the present invention, the dicyclic aromatic hydrocarbon-enriched component optionally contains, in addition to dicyclic aromatic hydrocarbons, a small amount of saturated hydrocarbons, monocyclic aromatic hydrocarbons, and / or tricyclic aromatic hydrocarbons. In some embodiments of the present invention, further preferably, in step (1), the dicyclic aromatic hydrocarbon-enriched component has a saturated hydrocarbon content of ≤10 wt%, a monocyclic aromatic hydrocarbon content of ≤10 wt%, and a tricyclic aromatic hydrocarbon content of ≤2 wt%.

[0050] 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 ≥70 wt%, for example, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, 95 wt%, 99 wt%, 99.9 wt%, and any value in the range consisting of any two values, preferably ≥80 wt%, more preferably 85-99.9 wt%.

[0051] In the present invention, the thermal polycondensation reaction is intended to polycondense the dicyclic aromatic hydrocarbons and optional tricyclic aromatic hydrocarbons in the dicyclic aromatic hydrocarbon-rich component. Preferably, in step (2), the thermal polycondensation reaction is carried out at ≥420°C, and preferably the thermal polycondensation reaction conditions include: a temperature of 420-480°C, for example, 420°C, 430°C, 440°C, 450°C, 460°C, 480°C, and any value in a range consisting of any two values, preferably 420-460°C; and a time of 0.1-5h, for example, 0.1h, 0.5h, 1h, 2h, 3h, 5h, and any value in a range consisting of any two values, preferably 0.5-3h.

[0052] In some embodiments of the present invention, the method preferably further comprises: heating the bicyclic aromatic hydrocarbon-enriched component to 420-480°C, preferably 430-460°C, prior to the thermal polycondensation reaction. In the present invention, a wide range of heating methods are available, as long as the temperature is reached for the thermal polycondensation reaction. The heating methods include, but are not limited to, heating in a tubular furnace, heating in a heat exchanger, or heating in a tubular furnace.

[0053] In some embodiments of the present invention, preferably, the toluene insoluble matter content in the thermal polycondensation product is ≤3 wt%, preferably ≤2.8 wt%. When the toluene insoluble matter content in the thermal polycondensation product is greater than 3 wt%, coking is likely to occur.

[0054] In some embodiments of the present invention, the total aromatic content of the thermal polycondensation product is preferably ≥ 75 wt %, preferably 75-99.9 wt %. Here, the total aromatic content of the thermal polycondensation product refers to all aromatics in the thermal polycondensation product. The total aromatic content refers to the content of all aromatics based on the total weight of the thermal polycondensation product.

[0055] In some embodiments of the present invention, the thermal polycondensation product includes a small amount of saturated hydrocarbons, monocyclic aromatic hydrocarbons, dicyclic aromatic hydrocarbons, and three to six-ring aromatic hydrocarbons and aromatic hydrocarbons with six or more rings.

[0056] In the present invention, the second distillation cut is intended to purify the thermal polycondensation product to obtain polycondensation heavy components rich in, for example, three- to six-ring aromatic hydrocarbons and aromatic hydrocarbons with six or more rings.

[0057] In some embodiments of the present invention, the final boiling point of the cracked light oil I is preferably 200-220° C., for example, 200° C., 205° C., 210° C., 220° C., and any value in a range consisting of any two values, preferably 200-210° C. In the present invention, for example, the cracked light oil I is rich in saturated hydrocarbons and monocyclic aromatic hydrocarbons and can be used as a gasoline product.

[0058] In some embodiments of the present invention, the distillation range of the cracked light oil II is preferably 200-250° C., for example, 200° C., 210° C., 220° C., 230° C., 250° C., and any value in a range consisting of any two values, preferably 210-230° C. In the present invention, the cracked light oil II is rich in, for example, dicyclic aromatic hydrocarbons, for example, naked ring aromatic hydrocarbons selected from naphthalene, methylnaphthalene, and ethylnaphthalene, and can be used as a naphthalene oil product.

[0059] In some embodiments of the present invention, preferably, the distillation range of the cycle 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.

[0060] 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.

[0061] 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 polycondensed heavy component is 350°C.

[0062] In some embodiments of the present invention, preferably, the vacuum distillation cutting temperature 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 that meets the above range is more conducive to obtaining condensation wax oil rich in three- to six-ring aromatic hydrocarbons and condensation asphalt rich in six- or more-ring aromatic hydrocarbons. The vacuum distillation cutting temperature is the temperature converted to normal pressure. For example, the vacuum distillation cutting temperature of 500-540°C can correspond to a gas phase operating pressure of 0.2 mmHg-1.5 mmHg and a liquid phase temperature of 243-320°C for the vacuum distillation.

[0063] 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 meeting the above range is more conducive to regulating the quality of the polycondensation wax oil, and obtaining the polycondensation wax oil with high three- to six-ring aromatics, low sulfur, and low nitrogen.

[0064] In some embodiments of the present invention, preferably, the content of three- to six-ring aromatic hydrocarbons 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.

[0065] 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 a range consisting of any two values, preferably 520-540°C. An initial distillation point that meets the above range is more conducive to regulating the quality of the polycondensation asphalt, that is, obtaining a coated asphalt with high six-ring aromatics, high softening point, high carbon residue, low sulfur and low ash.

[0066] In some embodiments of the present invention, preferably, the condensation asphalt has a softening point ≥150°C, a toluene insoluble matter content ≥1wt%, a carbon residue ≥50wt%, an ash content ≤0.01wt%, and a sulfur content ≤0.5wt%.

[0067] According to a particularly preferred embodiment of the present invention, the present invention provides a method for simultaneously preparing needle coke raw material and coated pitch, the method comprising the following steps:

[0068] (1) performing a first distillation cut on the catalytic diesel to obtain a monocyclic aromatic hydrocarbon-enriched component, a dicyclic aromatic hydrocarbon-enriched component, and a tricyclic aromatic hydrocarbon-enriched component;

[0069] (2) subjecting the dicyclic aromatic hydrocarbon-enriched component to a thermal polycondensation reaction at a temperature of ≥420° C. to obtain a cracking gas and a thermal polycondensation product;

[0070] (3) subjecting the thermal polycondensation product to a second distillation cut to obtain cracked light oil I, cracked light oil II, cycle oil, and polycondensation heavy components, wherein at least a portion of the cycle oil is returned to step (2);

[0071] (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 coating asphalt respectively.

[0072] According to a particularly preferred embodiment of the present invention, a method for simultaneously preparing needle coke raw material and coated pitch is provided, the method comprising the following steps:

[0073] (1) performing a first distillation cut on the catalytic diesel to obtain a monocyclic aromatic hydrocarbon-enriched component, a dicyclic aromatic hydrocarbon-enriched component, and a tricyclic aromatic hydrocarbon-enriched component;

[0074] (2) heating the dicyclic aromatic hydrocarbon-enriched component and performing a thermal polycondensation reaction to obtain a cracked gas and a thermal polycondensation product;

[0075] (3) subjecting the thermal polycondensation product to a second distillation cut to obtain cracked light oil I, cracked light oil II, cycle oil, and polycondensation heavy components, wherein at least a portion of the cycle oil is returned to step (2);

[0076] (4) subjecting the polycondensed heavy components to vacuum distillation and cutting, and the obtained polycondensed wax oil and polycondensed asphalt are used as needle coke raw material and coating asphalt respectively;

[0077] 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 reactions are each independently selected from 420-460° C.; and

[0078] 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 polycondensed heavy component is 345-350°C.

[0079] The second aspect of the present invention provides needle coke raw material and coated pitch prepared by the method provided by the first aspect,

[0080] Preferably, the needle coke raw material contains 20-35% by weight, preferably 23-31% by weight of mono- and di-ring aromatics and 65-80% by weight, preferably 69-77% by weight of tri- to hexa-ring aromatics, wherein the sulfur content is ≤0.3% by weight, preferably ≤0.2% by weight, and the nitrogen content is ≤700 mg / kg, preferably ≤600 mg / kg.

[0081] Preferably, 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%.

[0082] A third aspect of the present invention provides a needle coke, which is obtained by sequentially subjecting the needle coke raw material provided by the second aspect to calcination and graphitization.

[0083] In some embodiments of the present invention, preferably, the calcination conditions include: a temperature of 1300-1450° C., preferably 1350-1400° C.; and a calcination time of 10-20 h, preferably 12-14 h.

[0084] 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 hours, preferably 3-4 hours.

[0085] In some embodiments of the present invention, preferably, the sulfur content of the needle coke is ≤0.5wt%, the nitrogen content is ≤0.5wt%, 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.

[0086] A 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 needle coke provided by the third aspect and / or the coated asphalt provided by the second aspect.

[0087] A fifth aspect of the present invention provides an apparatus for simultaneously preparing needle coke raw material and coated asphalt.

[0088] FIG1 represents an embodiment of the present invention, and the structural schematic diagram shown in FIG1 is explained as follows: As shown in FIG1 , the device includes 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;

[0089] Among them, 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, cycle 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 to obtain a polycondensation wax oil 11 and a polycondensation asphalt 12 as a needle coke raw material and a coated asphalt, respectively, wherein the second distillation and cutting unit III is connected to the thermal polycondensation reaction unit II, and is used to return at least part of the cycle oil and perform the thermal polycondensation reaction.

[0090] 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-rich component is extracted from the top of the tower, a two-ring aromatic hydrocarbon-rich component is extracted from the side line of the tower, and a three-ring aromatic hydrocarbon-rich component is extracted from the bottom of the tower; the thermal polycondensation reaction unit can be 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 line respectively, and polycondensation heavy components are extracted from the bottom of the tower; the vacuum distillation cutting unit can be 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.

[0091] According to the present invention, preferably, as shown in FIG1 , all of the circulating oil 9 is returned and subjected to the thermal polycondensation reaction.

[0092] According to the present invention, preferably, as shown in FIG1 , the device further comprises: a heating unit V connected to the first distillation cutting unit I and the thermal polycondensation unit II, for heating the dicyclic aromatic hydrocarbon enriched component 3 and then feeding it into the thermal polycondensation unit II.

[0093] In a preferred embodiment of the present invention, as shown in Figure 1, a device for simultaneously preparing needle coke raw materials 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 connected in sequence, and the second distillation cutting unit III is connected to the heating unit V.

[0094] In the present invention, unless otherwise specified, the heating unit includes but is not limited to a heater, a heat exchanger, and the like.

[0095] Compared with the prior art, the present invention has the following advantages:

[0096] (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 increases the added value of the product;

[0097] (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 aromatic hydrocarbon-enriched component) and the process conditions of the thermal polycondensation reaction, and recycling at least part of the circulating oil, thereby regulating the distribution of the components in the thermal polycondensation product, thereby regulating the yield of the polycondensation wax oil and the polycondensation asphalt, and achieving controlled polycondensation of catalytic diesel aromatics;

[0098] (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%, and a true density (before calcination) of ≥1.35g / cm 3 , true density (after 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 use of this needle coke in lithium-ion batteries can effectively improve the electrochemical performance of lithium-ion batteries;

[0099] (4) The polycondensed asphalt prepared by the method provided by the present invention is used as the coated asphalt, and the coated asphalt has a softening point of ≥150°C, a toluene insoluble matter 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 "Asphalt for Negative Electrode Materials for Lithium-ion Batteries" of the China Petroleum and Chemical Industry Federation and can be used as negative electrode materials for lithium-ion batteries.

[0100] Example

[0101] The present invention will be described in detail below through examples.

[0102] The hydrocarbon composition of the feed oil is determined in accordance with the "Determination of Hydrocarbons in Saturated Hydrocarbon Fractions of Gas Oil (Mass Spectrometry) (SH / T 0659-1998)";

[0103] The hydrocarbon composition of distillate oil is determined according to the “Determination of Hydrocarbon Composition of Mesophase Fraction (Mass Spectrometry) (SH / T 0606-2019)”;

[0104] The carbon and hydrogen content parameters are determined in accordance with the "Determination of Carbon, Hydrogen and Nitrogen in Petroleum Products and Lubricants - Elemental Analyzer Method (SH / T 0656-2017)"

[0105] Oxygen content parameters are determined in accordance with the "Determination of total oxygen content in gasoline, diesel and methanol fuels - Reduction cracking method (SH / T 0986-2019)";

[0106] Nitrogen content parameters are determined in accordance with the "Determination of Nitrogen Content in Petroleum and Petroleum Products - Boat Injection Chemiluminescence Method (SH / T 0704-2010)"

[0107] The sulfur content parameters are determined in accordance with the "Petroleum and petroleum products - Determination of sulfur content - Energy dispersive X-ray fluorescence (GB / T 17040-2008)".

[0108] The toluene insoluble matter content is determined in accordance with the "Determination of Toluene Insoluble Matter Content of Coking Products (GB / T2292-2018)".

[0109] The ash content is determined in accordance with the “Determination of Ash Content of Petroleum Products (GB 508-1985)”.

[0110] 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%.

[0111] Example 1

[0112] (1) YS catalytic diesel (refer to Table 1 for each component and its content) was used as a raw material for the first distillation cutting to obtain a dicyclic aromatic hydrocarbon-rich component (refer to Table 2 for each component and its content) with a distillation range of 250-330° C. as a distillate oil;

[0113] (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 thermal polycondensation product S1 has a toluene insoluble matter content of 2.76 wt %;

[0114] (3) subjecting the thermal polycondensation product S1 to a second distillation cut, wherein the cut temperature for cracked light oil I and cracked light oil II is 210° C., the cut temperature for cracked light oil II and cycle oil is 230° C., and the cut temperature for 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;

[0115] The final 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 polycondensed heavy component is 350°C.

[0116] wherein the above-mentioned circulating oil is returned and mixed with the dicyclic aromatic hydrocarbon enriched component, and then heated and subjected to thermal polycondensation reaction in sequence;

[0117] (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;

[0118] The product distributions of the pyrolysis gas, cracked light oil I, cracked light oil II, cycle oil, polycondensed wax oil, and polycondensed pitch are listed in Table 3; the physical properties of the needle coke feedstock P1 and the coated pitch Q1 are listed in Table 4.

[0119] Example 2

[0120] The method of Example 1 is followed, except that the conditions of heating and thermal polycondensation in step (2) are changed, i.e.,

[0121] 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 toluene insoluble matter content in the thermal polycondensation product S2 is 2.57 wt %;

[0122] 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;

[0123] The final 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 polycondensed heavy component is 350°C.

[0124] wherein the above-mentioned circulating oil is returned and mixed with the dicyclic aromatic hydrocarbon enriched component, and then heated and subjected to thermal polycondensation reaction in sequence;

[0125] 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;

[0126] The product distributions of the pyrolysis gas, cracked light oil I, cracked light oil II, cycle oil, polycondensed wax oil, and polycondensed pitch are listed in Table 3; the physical properties of the needle coke feedstock P2 and the coated pitch Q2 are listed in Table 4.

[0127] Example 3

[0128] 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,

[0129] (1) YS catalytic diesel was used as a raw material for the first distillation cutting to obtain a dicyclic aromatic hydrocarbon-rich component with a distillation range of 250-300°C as a distillate oil (refer to Table 2 for each component and its content);

[0130] (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 thermal polycondensation product S3 has a toluene insoluble matter content of 1.75 wt %;

[0131] (3) subjecting the thermal polycondensation product S3 to a second distillation cut, wherein the cut temperature for cracked light oil I and cracked light oil II is 210° C., the cut temperature for cracked light oil II and cycle oil is 230° C., and the cut temperature for 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;

[0132] The final 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 polycondensed heavy component is 350°C.

[0133] wherein the above-mentioned circulating oil is returned and mixed with the dicyclic aromatic hydrocarbon enriched component, and then heated and subjected to thermal polycondensation reaction in sequence;

[0134] (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.

[0135] The yields of the pyrolysis gas, cracked light oil I, cracked light oil II, cycle oil, polycondensation wax oil, and polycondensation pitch are listed in Table 3; the physical properties of the needle coke feedstock P3 and the coated pitch Q3 are listed in Table 4.

[0136] Example 4

[0137] The method of Example 1 is followed, except that the distillation range of the circulating oil in step (3) is changed, i.e.,

[0138] 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;

[0139] The final boiling point of the cracked light oil I is 210°C, the distillation range of the cracked light oil II is 210-250°C, the distillation range of the cycle oil is 250-330°C, and the initial boiling point of the polycondensed heavy component is 330°C.

[0140] wherein the above-mentioned circulating oil is returned and mixed with the dicyclic aromatic hydrocarbon enriched component, and then heated and subjected to thermal polycondensation reaction in sequence;

[0141] In step (4), the remaining conditions are the same, and the obtained polycondensation wax oil and polycondensation pitch are used as needle coke raw material P4 and coating pitch Q4 respectively.

[0142] The product distributions of the pyrolysis gas, cracked light oil I, cracked light oil II (naphthalene oil), cycle oil, polycondensed wax oil, and polycondensed pitch are listed in Table 3; the physical properties of the needle coke feedstock P4 and the coated pitch Q4 are listed in Table 4.

[0143] Comparative Example 1

[0144] According to the method of Example 1, the difference is that

[0145] In step (1), YS catalytic diesel is replaced by MY ethylene tar (its composition is shown in Table 1), and other conditions are the same, to obtain a dicyclic aromatic hydrocarbon-rich component with a distillation range of 250-330° C. (each component and its content are shown in Table 2) as a distillate oil;

[0146] In step (2), the other conditions are the same, and cracking gas and thermal polycondensation product DS1 are obtained;

[0147] 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;

[0148] In step (4), the remaining conditions are the same, and the obtained polycondensation wax oil and polycondensation pitch are used as needle coke raw material DP1 and coated pitch DQ1, respectively.

[0149] The product distributions of the pyrolysis gas, cracked light oil I, cracked light oil II (naphthalene oil), cycle oil, polycondensed wax oil, and polycondensed pitch are listed in Table 3. The physical properties of the needle coke feedstock DP1 and the coated pitch DQ1 are listed in Table 4.

[0150] Comparative Example 2

[0151] The method of Example 1 is followed, except that step (1) is not performed; that is,

[0152] Directly carry out step (2) on the YS-catalyzed diesel;

[0153] In step (2), the other conditions are the same, and cracking gas and thermal condensation product DS2 are obtained;

[0154] 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;

[0155] In step (4), the remaining conditions are the same, and the obtained polycondensation wax oil and polycondensation pitch are used as needle coke raw material DP2 and coated pitch DQ2, respectively.

[0156] The product distributions of the pyrolysis gas, cracked light oil I, cracked light oil II (naphthalene oil), cycle oil, polycondensed wax oil, and polycondensed pitch are listed in Table 3. The physical properties of the needle coke feedstock DP2 and the coated pitch DQ2 are listed in Table 4.

[0157] Comparative Example 3

[0158] The method of Example 1 is followed, except that step (1) is not performed; that is,

[0159] The MM catalytic slurry is directly subjected to step (2);

[0160] In step (2), the other conditions are the same, and cracking gas, thermal polycondensation product DS3 and coke are obtained;

[0161] 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;

[0162] In step (4), the remaining conditions are the same, and the obtained polycondensation wax oil and polycondensation pitch are used as needle coke raw material DP3 and coated pitch DQ3 respectively.

[0163] The product distributions of the pyrolysis gas, cracked light oil I, cracked light oil II (naphthalene oil), cycle oil, polycondensed wax oil, polycondensed pitch, and coke are listed in Table 3. The physical properties of the needle coke feedstock DP3 and the coated pitch DQ3 are listed in Table 4.

[0164] Comparative Example 4

[0165] The method of Example 1 is followed, except that the conditions of heating and thermal polycondensation in step (2) are changed, i.e.,

[0166] (1) YS catalytic diesel is used as a raw material for the first distillation cutting to obtain a dicyclic aromatic hydrocarbon-rich component with a distillation range of 250-330° C. (same as in Example 1) as a distillate oil;

[0167] (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 thermal polycondensation product S4 has a toluene insoluble matter content of 0.2 wt %;

[0168] (3) subjecting the thermal polycondensation product S4 to a second distillation cut, wherein the cut temperature for cracked light oil I and cracked light oil II is 210° C., the cut temperature for cracked light oil II and cycle oil is 230° C., and the cut temperature for 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;

[0169] The final 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 polycondensed heavy component is 350°C.

[0170] wherein the above-mentioned circulating oil is returned and mixed with the dicyclic aromatic hydrocarbon enriched component, and then heated and subjected to thermal polycondensation reaction in sequence;

[0171] (4) The polycondensed heavy components are subjected to vacuum distillation cutting, wherein the cutting temperature of the polycondensed wax oil and the polycondensed pitch is 520°C, and the obtained polycondensed wax oil and polycondensed pitch are used as needle coke raw material DP4 and coated pitch DQ4 respectively.

[0172] The yields of the pyrolysis gas, cracked light oil I, cracked light oil II, cycle oil, polycondensation wax oil, and polycondensation pitch are listed in Table 3; the physical properties of the needle coke feedstock DP4 and the coated pitch DQ4 are listed in Table 4.

[0173] Comparative Example 5

[0174] The method of Example 1 is different in that, in step (3), the circulating oil is not reused but discarded; that is,

[0175] In step (1), the remaining conditions are the same, and a dicyclic aromatic hydrocarbon-enriched component is obtained as a distillate oil;

[0176] In step (2), the other conditions are the same to obtain a thermal polycondensation product S6;

[0177] 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;

[0178] In step (4), the other conditions are the same, and the obtained polycondensation wax oil and polycondensation pitch are used as needle coke raw material DP5 and coated pitch DQ5 respectively.

[0179] The product distributions of the pyrolysis gas, cracked light oil I, cracked light oil II (naphthalene oil), cycle oil, polycondensed wax oil, and polycondensed pitch are listed in Table 3. The physical properties of the needle coke feedstock DP5 and the coated pitch DQ5 are listed in Table 4.

[0180] Table 1 Components and contents of various raw materials

[0181] Table 2 Distillation range and hydrocarbon composition of dicyclic aromatic hydrocarbon enriched components

[0182] Table 3 Product distribution Note: # - Product distribution of cracked gas, cracked light oil I, cracked light oil II, polycondensed wax oil, polycondensed asphalt and cycle oil, and the sum of the distribution of each component is 100wt%; ** - 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 is ≠ 0wt%.

[0183] Table 4 Physical properties of needle coke raw materials and coated asphalt

[0184] As shown in Tables 1-4, compared to Comparative Example 1 (using MZ ethylene tar as the feedstock) and Comparative Examples 2-5, Example 1, using catalytic diesel as the feedstock, sequentially employs a first distillation cut followed by a thermal polycondensation reaction, a second distillation cut, and a vacuum distillation cut, yielding both a high polycondensation yield (58.2%) and high-quality needle coke feedstock and coated asphalt. Examples 2-4 also yielded high-quality needle coke feedstock and coated asphalt with high polycondensation yields.

[0185] Test Case

[0186] The needle coke raw materials (P1-P4 and DP1-DP5) prepared in Examples 1-4 and Comparative Examples 1-5 were sequentially calcined (temperature: 1400°C, time: 12 h) and graphitized (temperature: 2800°C, time: 3 h). The physical properties of the needle cokes obtained are listed in Table 5.

[0187] Table 5 Physical properties of needle coke products

[0188] The results in Table 5 show 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%, and a true density (before calcination) of ≥1.35g / cm 3 , true density (after 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.

[0189] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for simultaneously preparing needle coke raw material and coated asphalt, the method comprising the following steps: (1) performing a first distillation cutting on the catalytic diesel to obtain a dicyclic aromatic hydrocarbon-enriched component; (2) subjecting the dicyclic aromatic hydrocarbon-enriched component to a thermal polycondensation reaction to obtain a thermal polycondensation product; (3) subjecting the thermal polycondensation product to a second distillation cut to obtain circulating oil and polycondensation heavy components, wherein at least a portion of the circulating oil is returned to step (2) for the thermal polycondensation reaction; (4) The polycondensed heavy components are cut by vacuum distillation to obtain polycondensed wax oil as a raw material for needle coke and polycondensed asphalt as a coating asphalt.

2. The method according to claim 1, wherein: In step (1), the catalytic diesel is subjected to a first distillation cut to obtain a single-ring aromatics-enriched component and / or a tri-ring aromatics-enriched component, and / or In step (2), the dicyclic aromatic hydrocarbon-enriched component is subjected to a thermal polycondensation reaction to obtain cracking gas, and / or In step (3), the thermal polycondensation product is subjected to a second distillation cut to obtain cracked light oil I and / or cracked light oil II.

3. The method according to claim 1 or 2, wherein: The catalytic diesel has a total aromatic content of ≥70wt%, preferably 70-99.9wt%, based on the total weight of the catalytic diesel; a dicyclic aromatic content of ≥40wt%, preferably 50-90wt%; and / or, the tricyclic aromatic hydrocarbon content is ≥ 1 wt%, preferably 1-20 wt%; and / or The method further comprises: returning the circulating oil obtained in all steps (3) to step (2) for the thermal polycondensation reaction; and / or The physical properties of the catalytic diesel also meet the following requirements: sulfur content of 0.01wt%-1wt%; nitrogen content of 0.01wt%-1wt%; oxygen content of 0.01wt%-1wt%; 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.

4. The method according to any one of claims 1 to 3, wherein: The distillation range of the dicyclic aromatic hydrocarbon-enriched component is selected from 220-390° C., preferably 230-340° C., more preferably 250-330° C.; and / or The content of dicyclic aromatics in the dicyclic aromatics-enriched component is ≥70 wt %, preferably ≥80 wt %, and more preferably 85-99.9 wt %.

5. The method according to any one of claims 1 to 4, wherein: The method further comprises: before the thermal polycondensation reaction, heating the bicyclic aromatic hydrocarbon-enriched component to 420-480° C., preferably 430-460° C.; and / or In step (2), the conditions of the thermal polycondensation reaction include: temperature ≥ 420°C, preferably 420-480°C, more preferably 420-460°C; time 0.1-5h, preferably 0.5-3h; and / or The toluene insoluble matter content of the thermal polycondensation product is ≤3wt%, preferably ≤2.8wt%; and / or The total aromatic content of the thermal polycondensation product is ≥75 wt%, preferably 75-99.9 wt%.

6. The method according to any one of claims 1 to 5, wherein: The distillation range of the circulating oil is 220-350°C, preferably 230-350°C; and / or The initial boiling point of the polycondensed heavy component is 330-350°C, preferably 345-350°C, more preferably 350°C; and / or The vacuum distillation cutting temperature is 500-540°C, preferably 520-540°C, and the vacuum distillation cutting temperature is the temperature converted to normal pressure; and / or In step (4), the distillation range of the polycondensation wax oil is 350-540°C, preferably 350-520°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%; a nitrogen content of ≤0.6wt%, preferably ≤600mg / kg; and / or In step (4), the initial boiling point of the polycondensation asphalt is 500-540°C, preferably 520-540°C; and / or The polycondensation asphalt has a softening point of ≥150° C., a toluene insoluble matter content of ≥1wt%, a carbon residue of ≥50wt%, an ash content of ≤0.01wt%, and a sulfur content of ≤0.5wt%.

7. [Corrected 17.10.2024 in accordance with Rule 26] A method according to any one of claims 2 to 6, wherein: 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.

8. The method according to any one of claims 1 to 7, comprising the following steps: (1) performing a first distillation cutting on the catalytic diesel to obtain a single-ring aromatics-enriched component, a two-ring aromatics-enriched component, and a three-ring aromatics-enriched component; (2) heating the dicyclic aromatic hydrocarbon-enriched component and performing a thermal polycondensation reaction to obtain a cracked 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, cycle oil and polycondensation heavy components, wherein at least a portion of the cycle oil is returned to step (2); (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; 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 420-460°C; and 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.

9. Needle coke raw material and coated asphalt prepared according to the method according to any one of claims 1 to 9, Preferably, the needle coke raw material contains 20-35 wt%, preferably 23-31 wt% of mono- and di-ring aromatics and 65-80 wt%, preferably 69-77 wt% of tri- to hexa-ring aromatics, wherein the sulfur content is ≤0.3 wt%, preferably ≤0.2 wt%, and the nitrogen content is ≤700 mg / kg, preferably ≤600 mg / kg; Preferably, 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%.

10. A needle coke, which is obtained by sequentially calcining and graphitizing the needle coke raw material according to claim 9; Preferably, the calcination conditions include: The temperature is 1300-1450°C, preferably 1350-1400°C; the time is 10-20h, preferably 12-14h; 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. Preferably, the sulfur content of the needle coke is ≤0.5wt%, the nitrogen content is ≤0.5wt%, 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. 11 . A negative electrode material for a lithium ion battery, comprising the needle coke according to claim 9 and / or the coated asphalt according to claim 9 .

12. A device for preparing needle coke raw material 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; in, The first distillation cutting unit is used to perform a first distillation cutting on the catalytic diesel to obtain a dicyclic aromatic hydrocarbon-enriched component; the thermal polycondensation reaction unit is used to perform a thermal polycondensation reaction on the dicyclic aromatic hydrocarbon-enriched component to obtain a thermal polycondensation product; The second distillation cutting unit is used to perform a second distillation cutting on the thermal polycondensation product to obtain circulating oil and polycondensation heavy components; the vacuum distillation cutting unit is used to perform vacuum distillation cutting on the polycondensation heavy components to obtain polycondensation wax oil and polycondensation asphalt as needle coke raw material and coating asphalt, respectively. The second distillation cutting unit is connected to the thermal polycondensation reaction unit for returning at least part of the circulating oil and performing the thermal polycondensation reaction.

13. The device according to claim 12, wherein The first distillation cutting unit is used to perform a first distillation cutting on the catalytic diesel, and further obtain a single-ring aromatics-enriched component and / or a tri-ring aromatics-enriched component; and / or The thermal polycondensation reaction unit is used to perform a thermal polycondensation reaction on the dicyclic aromatic hydrocarbon-enriched component to obtain cracking gas; and / or The second distillation cutting unit is used to perform a second distillation cutting on the thermal polycondensation product to obtain cracked light oil I and / or cracked light oil II; and / or Returning all the circulating oil and performing 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.

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