Method and device for preparing carbon material by processing catalytic diesel oil

Abstract

The invention relates to the technical field of petroleum processing, in particular to a method for preparing a carbon material by processing catalytic diesel oil, a device for preparing the carbon material by processing catalytic diesel oil and a lithium ion battery negative electrode material. The method comprises the following steps: (1) contacting catalytic diesel oil with a solvent, and extracting to obtain extract oil enriched with di-tricyclic aromatic hydrocarbon and raffinate oil enriched with saturated hydrocarbon and monocyclic aromatic hydrocarbon; (2) carrying out solvent recovery on the extract oil to obtain an enriched di-tricyclic aromatic hydrocarbon component; (3) carrying out condensation polymerization on the enriched di-tricyclic aromatic hydrocarbon component to obtain a condensation polymerization product; (4) carrying out distillation treatment on the polycondensation product to respectively obtain cracked light oil, naphthalene oil, circulating oil, polycondensation wax oil and polycondensation asphalt; wherein the polycondensed wax oil and the polycondensed asphalt are independently used as carbon materials. According to the method, the polycondensed wax oil and the polycondensed asphalt with high polycondensation yield are obtained, and the quality of the polycondensed wax oil and the polycondensed asphalt is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of petroleum processing technology, specifically to a method for preparing carbon materials from catalytic diesel, an apparatus for preparing carbon materials from catalytic diesel, and a lithium-ion battery anode material. Background Technology

[0002] Catalytic cracking diesel, or simply catalytic diesel, is a diesel fraction produced by a catalytic cracking unit. Catalytic diesel has high sulfur and nitrogen content, high aromatic content, and low cetane number, making it a relatively low-quality diesel component.

[0003] Currently, catalytic diesel is converted into light aromatics / high-octane gasoline through hydrogenation saturation and catalytic cracking. Domestic and international scholars have conducted extensive basic research and industrial practice on this technical route. CN201210410162.3, CN201310516588.1, CN201310517650.9, CN201310517666.X, and CN201310010219.5 all disclose a series of processes or methods for the catalytic conversion and upgrading of catalytic cracked light diesel, converting inferior catalytic diesel into high-octane catalytic cracked gasoline or light aromatics.

[0004] Needle coke is a silvery-gray carbon material with a needle-like texture on its surface. It boasts advantages such as high crystallinity, low coefficient of thermal expansion, good orientation, and excellent electrical and thermal conductivity, making it a raw material for preparing high-power graphite electrodes, high-performance lithium-ion battery anodes, and other high-end carbon material products. Needle coke can be divided into oil-based needle coke and coal-based needle coke. Although the raw material sources for coal-based and oil-based needle coke differ, existing needle coke preparation or production technologies all use polycyclic aromatic hydrocarbons (PAHs) with predominantly tri- to hexacyclic rings as raw materials, and are prepared through processes such as thermal polycondensation, mesophase cultivation, and coke pulling and solidification.

[0005] Catalytic diesel contains abundant bicyclic and tricyclic aromatic hydrocarbons. If its aromatic components can be effectively utilized to produce high-end carbon materials such as needle coke and coated asphalt, the economic added value of catalytic diesel can be increased.

[0006] In summary, although there is a lot of academic research and industrial practice on the upgrading and utilization of catalytic diesel in China, it is all aimed at producing clean diesel, low-sulfur marine fuel, increasing the production of light aromatics or high-octane gasoline, while the technology for preparing carbon materials using catalytic diesel as raw material is still lacking. Summary of the Invention

[0007] The purpose of this invention is to overcome the above-mentioned technical problems and provide a method for preparing carbon materials from catalytic diesel, an apparatus for preparing carbon materials from catalytic diesel, and a lithium-ion battery anode material. This method uses catalytic diesel as raw material and employs the technical means of "extraction-solvent recovery-condensation reaction-distillation treatment" to prepare condensation wax oil and condensation pitch as carbon materials, respectively. At the same time, this method enriches the preparation route of carbon materials and provides a new path for the increasingly surplus catalytic diesel.

[0008] To achieve the above objectives, a first aspect of the present invention provides a method for preparing carbon materials from catalytic diesel fuel, the method comprising the following steps:

[0009] (1) Catalytic diesel oil is contacted with a solvent and extracted to obtain extract oil enriched with di-tricyclic aromatic hydrocarbons and raffinate oil enriched with saturated hydrocarbons and monocyclic aromatic hydrocarbons.

[0010] (2) The extracted oil is subjected to solvent recovery to obtain a di-tricyclic aromatic hydrocarbon component;

[0011] (3) The enriched di-tricyclic aromatic hydrocarbon component is subjected to a polycondensation reaction to obtain a polycondensation product;

[0012] (4) The polycondensation product is distilled to obtain cracked light oil, naphthalene oil, recycled oil, polycondensed wax oil and polycondensed pitch, respectively.

[0013] In this process, the polycondensed wax oil and polycondensed pitch each serve independently as carbon materials.

[0014] Preferably, the solvent is selected from at least one of sulfolane, furfural, dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), N-methylpyrrolidone (NMP), and isopropanol.

[0015] Preferably, the circulating oil is divided into a portion of the circulating oil and a remaining portion of the circulating oil, which are returned to the polycondensation reaction and discharged, respectively.

[0016] A second aspect of the present invention provides an apparatus for processing catalytic diesel to prepare carbon materials, the apparatus comprising: an extraction unit, a solvent recovery unit, a polycondensation unit and a distillation unit connected in sequence;

[0017] The extraction unit is used to contact and extract catalytic diesel oil with solvent to obtain extract oil enriched with di- and tricyclic aromatics, and raffinate oil enriched with saturated hydrocarbons and monocyclic aromatics; the solvent recovery unit is used to recover the solvent from the extract oil to obtain di- and tricyclic aromatic components and recycled solvent; the polycondensation unit is used to carry out polycondensation reaction on the di- and tricyclic aromatic components to obtain polycondensation products and cracked gas; the distillation treatment unit is used to distill the polycondensation products to obtain cracked light oil, naphthalene oil, recycled oil, polycondensed wax oil, and polycondensed asphalt, respectively.

[0018] In this process, the polycondensed wax oil and polycondensed pitch each serve independently as carbon materials.

[0019] The third aspect of the present invention provides a lithium-ion battery anode material, wherein the lithium-ion battery anode material is selected from needle coke obtained by sequentially calcining and graphitizing the needle coke raw material provided in the first aspect as a condensation wax oil, and / or the condensation pitch provided in the first aspect as a coating pitch.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] (1) The method provided by the present invention uses catalytic diesel as raw material. First, it is extracted with a specific solvent to obtain extract oil enriched with di-tricyclic aromatic hydrocarbons. Then, solvent recovery, polycondensation reaction and distillation are carried out in sequence. This not only yields polycondensation wax oil and polycondensation pitch with high polycondensation yield, but also effectively improves the quality of polycondensation wax oil and polycondensation pitch. This method simultaneously prepares two carbon materials, polycondensation wax oil and polycondensation pitch, which enriches the preparation process of carbon materials and broadens the resource utilization of catalytic diesel, thereby increasing the added value of the products. In addition, this method also simultaneously obtains cracked light oil as gasoline and naphthalene oil as a product for separating and purifying naphthalene-based chemicals, thereby increasing the economic added value of the products.

[0022] (2) The method provided by the present invention, in particular, optimizes the type of solvent, the conditions of the polycondensation reaction and the recycling of recycled oil, thereby controlling the distribution of each component in the polycondensation product, thereby controlling the yield of polycondensation wax oil and polycondensation asphalt, and realizing the controllable polycondensation of catalytic diesel aromatics.

[0023] (3) The polycondensed wax oil obtained by the method provided in this invention is used as a raw material for needle coke production, which meets the requirements of GB / T37308-2019 Oil-based Needle Coke. It can be used as a negative electrode material for lithium-ion batteries and can effectively improve the electrochemical performance of lithium-ion batteries. At the same time, the polycondensed pitch obtained by the method provided in this invention is used as a coating pitch, which meets the requirements of the China Petroleum and Chemical Industry Federation group standard "Pitch for Negative Electrode Materials of Lithium-ion Batteries". It can be used as a negative electrode material for lithium-ion batteries and can effectively improve the electrochemical performance of lithium-ion batteries. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of an apparatus for preparing carbon materials from catalytic diesel fuel, provided by the present invention.

[0025] Explanation of reference numerals in the attached figures

[0026] 1. Extraction unit; 2. Solvent recovery unit; 3. Polycondensation unit; 4. Atmospheric distillation section; 5. Vacuum distillation section; 6. Catalytic diesel oil; 7. Solvent; 8. Raffinate oil; 9. Extracted oil; 10. Circulating solvent; 11. Enrichment of di- and tricyclic aromatic hydrocarbon components; 12. Cracking gas; 13. Polycondensation products; 14. Cracking light oil; 15. Naphthalene oil; 16. Circulating oil; 16-i. Partial circulating oil; 16-ii. Remaining portion of circulating oil; 17. Heavy fraction; 18. Polycondensed wax oil; 19. Polycondensed bitumen. Detailed Implementation

[0027] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0028] The first aspect of this invention provides a method for preparing carbon materials from catalytic diesel fuel, the method comprising the following steps:

[0029] (1) Catalytic diesel oil is contacted with a solvent and extracted to obtain extract oil enriched with di-tricyclic aromatic hydrocarbons and raffinate oil enriched with saturated hydrocarbons and monocyclic aromatic hydrocarbons.

[0030] (2) The extracted oil is subjected to solvent recovery to obtain a di-tricyclic aromatic hydrocarbon component;

[0031] (3) The enriched di-tricyclic aromatic hydrocarbon component is subjected to a polycondensation reaction to obtain a polycondensation product;

[0032] (4) The polycondensation product is distilled to obtain cracked light oil, naphthalene oil, recycled oil, polycondensed wax oil and polycondensed pitch, respectively.

[0033] In this process, the polycondensed wax oil and polycondensed pitch each serve independently as carbon materials.

[0034] In this invention, unless otherwise specified, the extracted oil enriched with di- and tricyclic aromatic hydrocarbons refers to the extracted oil that is simultaneously enriched with di- and tricyclic aromatic hydrocarbons; similarly, the content of di- and tricyclic aromatic hydrocarbons refers to the sum of the contents of di- and tricyclic aromatic hydrocarbons.

[0035] In some embodiments of the present invention, preferably, in step (1), the extraction conditions are as follows: temperature is 30-120℃, for example, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 100℃, 120℃, and any value within the range of any two values, preferably 40-80℃; pressure is 0.1-1MPa, for example, 0.1MPa, 0.15MPa, 0.2MPa, 0.25MPa, 0.3MPa, 0.5MPa, 1MPa, and any value within the range of any two values, preferably 0.1-0.3MPa; time is 0.5-2h, for example, 0.5h, 0.6h, 0.8h, 1h, 1.2h, 1.5h, 2h, and any value within the range of any two values, preferably 0.6-1.2h.

[0036] In this invention, all pressure parameters refer to gauge pressure.

[0037] In this invention, the extracted oil enriched with di- and tricyclic aromatic hydrocarbons mainly contains solvents, dicyclic aromatic hydrocarbons and tricyclic aromatic hydrocarbons, as well as small amounts of saturated hydrocarbons and monocyclic aromatic hydrocarbons; the raffinate oil enriched with saturated hydrocarbons and monocyclic aromatic hydrocarbons mainly contains saturated hydrocarbons and monocyclic aromatic hydrocarbons, as well as small amounts of dicyclic aromatic hydrocarbons and tricyclic aromatic hydrocarbons.

[0038] In some embodiments of the present invention, preferably, the mass ratio of the catalytic diesel oil to the solvent is 1:1-5, for example, 1:1, 1:2, 1:3, 1:4, 1:5, and any value within the range of any two values, preferably 1:1-3.

[0039] In some embodiments of the present invention, preferably, the raffinate oil is used as a feedstock for catalytic cracking.

[0040] In this invention, a wide range of solvents can be selected. Preferably, the solvent is selected from at least one of sulfolane, furfural, dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), N-methylpyrrolidone (NMP), and isopropanol; more preferably, the solvent is selected from at least one of sulfolane, furfural, dimethyl sulfoxide, and isopropanol.

[0041] In some embodiments of the present invention, preferably, the catalytic diesel oil has the following characteristics: sulfur content of 0.1-4 wt%; nitrogen content of 1-1000 mg / kg; oxygen content of 1-1000 mg / kg; total aromatic hydrocarbon content of ≥70 wt%, preferably 75-99.9 wt%; and total saturated hydrocarbon content of ≤30 wt%, preferably 15-20 wt%.

[0042] In this invention, unless otherwise specified, the total aromatic hydrocarbon content refers to the sum of the contents of monocyclic aromatic hydrocarbons, dicyclic aromatic hydrocarbons, and tricyclic aromatic hydrocarbons; the total saturated hydrocarbon content refers to the sum of the contents of cycloalkanes and alkanes.

[0043] In some embodiments of the present invention, more preferably, the catalytic diesel oil contains ≥55wt% di-tricyclic aromatic hydrocarbons, for example, 55wt%, 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, and any value within a range of any two values, preferably 60-80wt%.

[0044] In this invention, unless otherwise specified, the hydrocarbon composition in catalytic diesel is determined according to the standard "Determination of Hydrocarbons in Saturated Hydrocarbon Fractions of Gas Oil (Mass Spectrometry) (SH / T 0659-1998)".

[0045] In this invention, unless otherwise specified, the hydrocarbon composition in the distillate oil is determined in accordance with the "Determination of Hydrocarbon Composition in Intermediate Phase Distillate (Mass Spectrometry) (SH / T 0606-2019)".

[0046] In this invention, unless otherwise specified, the carbon and hydrogen content parameters are determined according to the "Determination of Carbon, Hydrogen and Nitrogen in Petroleum Products and Lubricants - Elemental Analyzer Method (SH / T 0656-2017)"; the oxygen content parameter is determined according to the "Determination of Total Oxygen Content in Gasoline, Diesel and Methanol Fuels - Reduction Cracking Method (SH / T0986-2019)"; the nitrogen content parameter is determined according to the "Determination of Nitrogen Content in Petroleum and Petroleum Products - Submerged Chemiluminescence Method (SH / T 0704-2010)"; and the sulfur content parameter is determined according to the "Determination of Sulfur Content in Petroleum and Petroleum Products - Energy Dispersive X-ray Fluorescence (GB / T 17040-2008)".

[0047] In this invention, the type of catalytic diesel fuel can be selected from a wide range, as long as it meets the above-mentioned limitations. Preferably, the catalytic diesel fuel is selected from at least one of catalytic cracking middle distillate oil, catalytic cracking light cycle oil, catalytic cracking heavy cycle oil, catalytic cracking refined diesel fuel, and ethylene tar diesel fuel fraction.

[0048] In this invention, the catalytic cracking middle distillate oil is the middle distillate oil produced by a catalytic cracking unit. The catalytic cracking unit can be a residue oil catalytic cracking unit, a wax oil catalytic cracking unit, a heavy oil catalytic cracking unit, or a mixed feedstock catalytic cracking unit. The catalytic cracking refined diesel refers to the refined catalytic diesel obtained by hydrotreating and hydrorefining the catalytic cracking middle distillate oil to obtain low-sulfur and low-nitrogen refined diesel.

[0049] In one specific embodiment of the present invention, preferably, the catalytic cracking middle distillate is selected from at least one of residue catalytic cracking distillate, wax oil catalytic cracking distillate, and heavy oil catalytic cracking distillate.

[0050] In this invention, the enriched di- and tricyclic aromatic hydrocarbon component contains, in addition to di- and tricyclic aromatic hydrocarbons, small amounts of saturated hydrocarbons and monocyclic aromatic hydrocarbons. Preferably, in step (2), the enriched di- and tricyclic aromatic hydrocarbon component has a total aromatic hydrocarbon content ≥95wt% and a total saturated hydrocarbon content ≤5wt%. More preferably, the enriched di- and tricyclic aromatic hydrocarbon component has a di- and tricyclic aromatic hydrocarbon content ≥80wt%, for example, 80wt%, 85wt%, 86wt%, 87wt%, 88wt%, 90wt%, and any value within the range of any two values, preferably 85-90wt%; and a monocyclic aromatic hydrocarbon content ≤15wt%, 1wt%, 3wt%, 5wt%, 8wt%, 10wt%, 15wt%, and any value within the range of any two values, preferably 3-10wt%.

[0051] In this invention, the solvent recovery aims to remove solvent from the extracted oil. Preferably, the conditions for solvent recovery are: temperature of 130-220°C, for example, 130°C, 140°C, 150°C, 160°C, 190°C, 200°C, 220°C, or any value within the range of any two values, preferably 150-200°C; pressure of 10-200 kPa, for example, 10 kPa, 20 kPa, 50 kPa, 80 kPa, 100 kPa, 150 kPa, 200 kPa, or any value within the range of any two values, preferably 10-100 kPa; and time of 0.2-1 h, for example, 0.2 h, 0.3 h, 0.5 h, 0.6 h, 0.8 h, 1 h, or any value within the range of any two values, preferably 0.3-0.8 h.

[0052] In some embodiments of the present invention, preferably, the method further includes: returning the recycled solvent obtained from the solvent recovery and mixing it into the solvent.

[0053] In this invention, the polycondensation reaction is intended to polycondense the di-tricyclic aromatic hydrocarbons in the enriched di-tricyclic aromatic hydrocarbon component. Preferably, in step (3), the conditions for the polycondensation reaction are: a reaction temperature of 400-520℃, for example, 400℃, 410℃, 420℃, 430℃, 440℃, 450℃, 460℃, 470℃, 480℃, 500℃, 520℃, and any value within the range of any two values, preferably 430-480℃; and a reaction time of 0.1-4h, for example, 0.1h, 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, and any value within the range of any two values, preferably 1-3.5h.

[0054] In this invention, condensation reaction parameters that meet the above range are more conducive to improving the condensation yield, that is, condensation yield = the sum of condensation wax oil yield and condensation bitumen yield.

[0055] In some embodiments of the present invention, preferably, the content of toluene-insoluble matter in the condensation product is ≤3wt%, for example, 3wt%, 2wt%, 1wt%, 0.5wt%, 0.1wt%, and any value within a range of any two values.

[0056] In this invention, the condensation product includes small amounts 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; when the content of toluene insoluble matter in the condensation product is >3 wt%, it is prone to coking.

[0057] In some embodiments of the present invention, preferably, in step (4), the distillation process includes: atmospheric distillation and vacuum distillation; wherein, the polycondensation product is subjected to atmospheric distillation to obtain the cracked light oil, naphthalene oil, circulating oil and heavy fraction; the heavy fraction is subjected to vacuum distillation to obtain the polycondensed wax oil and polycondensed pitch.

[0058] In some embodiments of the present invention, preferably, the conditions for atmospheric distillation are: a column top pressure of 0.01-0.1 MPa, for example, 0.01 MPa, 0.02 MPa, 0.03 MPa, 0.04 MPa, 0.05 MPa, 0.06 MPa, 0.08 MPa, 0.1 MPa, or any value within the range of any two values, preferably 0.01-0.06 MPa; and a column top temperature of 170-210°C, for example, 170°C, 180°C, 190°C, 200°C, 210°C, or any two values. The temperature of the bottom of the tower is 320-360℃; for example, 320℃, 330℃, 340℃, 350℃, 360℃, and any value within the range of any two values; the temperature of the naphthalene oil side stream extraction is 215-225℃; for example, 215℃, 218℃, 220℃, 222℃, 225℃, and any value within the range of any two values; the temperature of the circulating oil side stream extraction is 265-295℃; for example, 265℃, 275℃, 285℃, 295℃, and any value within the range of any two values.

[0059] In some embodiments of the present invention, preferably, the conditions for vacuum distillation are: top pressure ≤ 0.5 mmHg, for example, 0.5 mmHg, 0.3 mmHg, 0.2 mmHg, 0.1 mmHg, 0.05 mmHg, 0.01 mmHg, or any value within any range of two such values, preferably ≤ 0.2 mmHg; top temperature ≥ 200℃, preferably ≥ 220℃; bottom temperature 270-330℃, for example, 270℃, 280℃, 290℃, 300℃, 310℃, 330℃, or any value within any range of two such values, preferably 270-310℃. In the present invention, 1 mmHg = 133 Pa.

[0060] In some embodiments of the present invention, preferably, the final boiling point of the cracked light oil is 170-210℃; the boiling range of the naphthalene oil is 215-225℃; the boiling range of the circulating oil is 265-295℃; the initial boiling point of the heavy fraction is 320-360℃; the boiling range of the polycondensed wax oil is 330-520℃, preferably 350-520℃; and the initial boiling point of the polycondensed pitch is 500-540℃, preferably 520-540℃.

[0061] In some embodiments of the present invention, preferably, in step (4), the circulating oil is divided into a portion of the circulating oil and a remaining portion of the circulating oil, which are returned to the polycondensation reaction and discharged, respectively; more preferably, the mass ratio of the portion of the circulating oil to the remaining portion of the circulating oil is 10-100:90-0. This setting can effectively improve the yield of needle coke feedstock and coated pitch.

[0062] In some embodiments of the present invention, preferably, in step (4), the polycondensed wax oil and polycondensed pitch are used as needle coke raw materials and coated pitch, respectively.

[0063] In some embodiments of the present invention, preferably, the polycondensation wax oil contains ≥80 wt% tri-hexacyclic aromatic hydrocarbons, more preferably ≥85 wt%; ≤1 wt% sulfur, more preferably ≤0.3 wt%; and ≤0.6 wt% nitrogen, more preferably ≤600 mg / kg. In the present invention, 1 wt% = 10000 mg / kg.

[0064] In some embodiments of the present invention, preferably, the softening point of the condensed asphalt is ≥210℃, more preferably ≥215℃; the toluene-insoluble content is ≥5wt%, more preferably ≥9wt%; the residual carbon content is ≥70wt%, more preferably ≥75wt%; the ash content is ≤0.01wt%; and the sulfur content is ≤0.5wt%, more preferably ≤0.15wt%.

[0065] In some embodiments of the present invention, preferably, the cracked light oil is used as gasoline.

[0066] In some embodiments of the present invention, preferably, the naphthalene oil is used to separate and purify naphthalene-based chemicals, wherein the naphthalene-based chemicals are selected from at least one of naphthalene, methylnaphthalene, and dimethylnaphthalene.

[0067] A second aspect of the present invention provides a schematic diagram of an apparatus for processing catalytic diesel to prepare carbon materials, as shown in the figure. Figure 1 As shown, the device includes: an extraction unit 1, a solvent recovery unit 2, a polycondensation unit 3, and a distillation unit connected in sequence;

[0068] The extraction unit 1 is used to contact and extract catalytic diesel oil 6 and solvent 7 to obtain extracted oil 9 enriched with di- and tricyclic aromatics, and raffinate oil 8 enriched with saturated hydrocarbons and monocyclic aromatics; the solvent recovery unit 2 is used to recover the solvent from the extracted oil 9 to obtain di- and tricyclic aromatic component 11 enriched with di- and tricyclic aromatics and recycled solvent 10; the polycondensation unit 3 is used to perform a polycondensation reaction on the di- and tricyclic aromatic component 11 to obtain polycondensation product 13 and cracked gas 12; the distillation treatment unit is used to distill the polycondensation product 13 to obtain cracked light oil 14, naphthalene oil 15, recycled oil 16, polycondensed wax oil 18, and polycondensed bitumen 19, respectively.

[0069] In this process, the polycondensed wax oil 18 and the polycondensed pitch 19 each independently serve as carbon materials.

[0070] In this invention, unless otherwise specified, the extraction unit can be selected from an extraction tower, that is, the raffinate oil enriched with saturated hydrocarbons and monocyclic aromatics is collected from the top of the tower, and the extracted oil enriched with di- and tricyclic aromatics is collected from the bottom of the tower; the solvent recovery unit can be selected from a solvent recovery tower, that is, the recycled solvent is collected from the top of the tower, and the di- and tricyclic aromatic components are collected from the bottom of the tower; the polycondensation unit is selected from a controlled polycondensation reactor, the cracked gas is collected from the top of the tower, and the polycondensation product is collected from the bottom of the tower.

[0071] According to the present invention, such as Figure 1 As shown, preferably, the distillation unit includes: an atmospheric distillation section 4 and a vacuum distillation section 5 connected in series; the atmospheric distillation section 4 is used to distill the polycondensation product 13 under atmospheric pressure to obtain the cracked light oil 14, naphthalene oil 15, recycled oil 16 and heavy fraction 17; the vacuum distillation section 5 is used to distill the heavy fraction 17 under vacuum to obtain the polycondensed wax oil 18 and polycondensed pitch 19.

[0072] In this invention, unless otherwise specified, the atmospheric distillation section is selected from an atmospheric distillation column, from which cracked light oil is collected at the top, naphthalene oil and circulating oil are collected from the side streams, and heavy fraction is collected from the bottom; the vacuum distillation section is selected from a vacuum distillation column, from which polycondensed wax oil is collected at the top and polycondensed pitch is collected from the bottom.

[0073] According to the present invention, such as Figure 1 As shown, preferably, the circulating oil outlet of the atmospheric distillation section 4 is connected to the polycondensation unit 3, for returning a portion of the circulating oil 16-i and carrying out the polycondensation reaction.

[0074] According to the present invention, such as Figure 1 As shown, preferably, the circulating solvent outlet of the solvent recovery unit 2 is connected to the extraction unit 1, for returning the circulating solvent 10 and performing the extraction.

[0075] The third aspect of the present invention provides a lithium-ion battery anode material, wherein the lithium-ion battery anode material is selected from needle coke obtained by sequentially calcining and graphitizing the needle coke raw material provided in the first aspect as a condensation wax oil, and / or the condensation pitch provided in the first aspect as a coating pitch.

[0076] In some embodiments of the present invention, preferably, the calcination conditions include: a temperature of 1300-1450℃, more preferably 1350-1400℃; and a time of 10-20h, more preferably 12-14h.

[0077] In some embodiments of the present invention, preferably, the conditions for the graphitization treatment include: a temperature of 2700-3000℃, preferably 2800-2900℃; and a time of 2-5h, preferably 3-4h.

[0078] In some embodiments of the present invention, preferably, the physical properties of the needle coke satisfy the following: sulfur content ≤ 0.5 wt%, preferably ≤ 0.191 wt%; nitrogen content ≤ 0.5 wt%, preferably ≤ 730 mg / kg; true density (before calcination) ≥ 1.35 g / cm³. 3 Preferred concentration: ≥1.37 g / cm³ 3 True density (after calcination) ≥ 2.12 g / cm³ 3 Preferred concentration: ≥2.14 g / cm³ 3 The coefficient of thermal expansion (25-600℃) ≤ 1.3 × 10⁻⁶ -6 / ℃, preferably ≤1.05×10 -6 / ℃, its polarized microstructure is a wide-area streamline type.

[0079] According to a particularly preferred embodiment of the present invention, a method for preparing carbon materials from catalytic diesel fuel includes the following steps:

[0080] (1) Catalytic diesel oil is contacted with a solvent and extracted to obtain extract oil enriched with di-tricyclic aromatic hydrocarbons and raffinate oil enriched with saturated hydrocarbons and monocyclic aromatic hydrocarbons.

[0081] (2) The extracted oil is subjected to solvent recovery to obtain a di-tricyclic aromatic hydrocarbon component;

[0082] (3) The enriched di-tricyclic aromatic hydrocarbon component is subjected to a polycondensation reaction to obtain a polycondensation product;

[0083] (4) The polycondensation product is distilled to obtain cracked light oil, naphthalene oil, recycled oil, polycondensed wax oil and polycondensed pitch, respectively.

[0084] In this embodiment, the polycondensed wax oil and polycondensed pitch each independently serve as carbon materials;

[0085] The catalytic diesel oil contains 0.1-4 wt% sulfur, 1-1000 mg / kg nitrogen, 1-1000 mg / kg oxygen, ≥70 wt% total aromatics (preferably 75-99.9 wt%), and ≤30 wt% total saturated hydrocarbons (preferably 15-20 wt%). The solvent is selected from at least one of sulfolane, furfural, dimethyl sulfoxide, and isopropanol.

[0086] The conditions for the polycondensation reaction are as follows: the reaction temperature is 400-520℃, preferably 430-480℃; the reaction time is 0.1-4h, preferably 1-3.5h.

[0087] The present invention will be described in detail below through embodiments.

[0088] The hydrocarbon composition in the feedstock was determined according to the standard "Determination of Hydrocarbons in Saturated Hydrocarbon Fractions of Gas Oil (Mass Spectrometry) (SH / T0659-1998)";

[0089] The hydrocarbon composition in the distillate oil was determined according to the standard "Determination of Hydrocarbon Composition in Intermediate Phase Distillate (Mass Spectrometry) (SH / T0606-2019)";

[0090] The carbon and hydrogen content parameters were determined according to the "Determination of Carbon, Hydrogen and Nitrogen in Petroleum Products and Lubricants by Elemental Analyzer Method (SH / T 0656-2017)";

[0091] The oxygen content parameter was determined according to the standard "Determination of Total Oxygen Content in Gasoline, Diesel and Methanol Fuels - Reduction Cracking Method (SH / T0986-2019)";

[0092] Nitrogen content parameters were determined according to the standard "Determination of Nitrogen Content in Petroleum and Petroleum Products - Carbohydrate Injection Chemiluminescence Method (SH / T0704-2010)";

[0093] The sulfur content parameter was determined in accordance with the standard "Determination of Sulfur Content in Petroleum and Petroleum Products - Energy Dispersive X-ray Fluorescence (GB / T 17040-2008)".

[0094] The content of toluene insoluble matter was determined in accordance with the "Determination of Toluene Insoluble Matter Content in Coking Products (GB / T2292-2018)".

[0095] The yield is calculated as follows: Yield = Component mass / Raw material mass × 100%, where the components include: cracked gas, cracked light oil, naphthalene oil, recycled oil, polycondensed wax oil and polycondensed pitch.

[0096] The calculation method for polycondensation yield is as follows: Polycondensation yield = Polycondensation wax oil yield + Polycondensation pitch yield; Polycondensation wax oil yield = (mass of polycondensation wax oil / mass of raw materials) × 100%, Polycondensation pitch yield = (mass of polycondensation pitch / mass of raw materials) × 100%.

[0097] Example 1

[0098] (1) YS catalytic diesel (see Table 1 for each component and its content) and solvent (furfural and dimethyl sulfoxide in a mass ratio of 95:5) were contacted and extracted at a mass ratio of 100:200. The temperature was 60℃, the residence time was 1h, and the pressure was 0.2MPa to obtain extracted oil and raffinate (see Table 2 for each component and its content).

[0099] (2) The above-extracted oil was subjected to solvent recovery at a temperature of 200℃, a pressure of 10kPa, and a time of 0.5h to obtain a di-tricyclic aromatic hydrocarbon enriched component.

[0100] (3) The above-enriched di-tricyclic aromatic hydrocarbon components were subjected to a polycondensation reaction at a temperature of 440°C for 3 hours to obtain polycondensation product S1 and cracked gas; the content of toluene-insoluble matter in the above polycondensation product S1 was 2.5 wt%.

[0101] (4) The above polycondensation product S1 was subjected to atmospheric distillation with a top pressure of 0.01 MPa, a top temperature of 180°C, a side stream extraction temperature of naphthalene oil of 220°C, a side stream extraction temperature of circulating oil of 280°C, and a bottom temperature of 340°C to obtain cracked light oil, naphthalene oil, circulating oil and heavy fraction.

[0102] 88.9 wt% of the recycled oil is returned and subjected to the above-mentioned polycondensation reaction, while the remainder is discharged.

[0103] The above heavy fraction was subjected to vacuum distillation at a top pressure of 26 Pa and a top temperature of 200 °C and a bottom temperature of 276 °C. The resulting polycondensed wax oil and polycondensed pitch were used as needle coke feedstock P1 and coated pitch Q1, respectively.

[0104] The product distributions of the aforementioned cracked gas, cracked light oil, naphthalene oil, circulating oil, condensed wax oil, and condensed pitch are listed in Table 3; the physical properties of needle coke feedstock P1 and coated pitch Q1 are listed in Table 4.

[0105] Example 2

[0106] The method is the same as in Example 1, except that...

[0107] In step (1), the solvent was replaced with furfural, and the other conditions remained the same, resulting in extracted oil and raffinate oil (see Table 2 for each component and its content).

[0108] In step (2), the remaining conditions are the same, and a di-tricyclic aromatic hydrocarbon component is obtained;

[0109] In step (3), the other conditions are the same, and the content of toluene-insoluble matter in the polycondensation product S2 is 2.1 wt%.

[0110] In step (4), the other conditions remain the same, and needle coke raw material P2 and coated pitch Q2 are obtained;

[0111] The product distributions of the aforementioned cracked gas, cracked light oil, naphthalene oil, circulating oil, condensed wax oil, and condensed pitch are listed in Table 3; the physical properties of needle coke feedstock P2 and coated pitch Q2 are listed in Table 4.

[0112] Example 3

[0113] The method is the same as in Example 1, except that...

[0114] In step (1), the mass ratio of YS catalytic diesel and solvent is replaced with 100:100, and the other conditions are the same, to obtain extracted oil and raffinate oil (see Table 2 for each component and its content).

[0115] In step (2), the remaining conditions are the same, and a di-tricyclic aromatic hydrocarbon component is obtained;

[0116] In step (3), the other conditions are the same, and the content of toluene-insoluble matter in polycondensation product S3 is 1.9 wt%.

[0117] In step (4), the other conditions remain the same, and needle coke raw material P3 and coated pitch Q3 are obtained;

[0118] The product distributions of the aforementioned cracked gas, cracked light oil, naphthalene oil, circulating oil, condensed wax oil, and condensed pitch are listed in Table 3; the physical properties of needle coke feedstock P3 and coated pitch Q3 are listed in Table 4.

[0119] Example 4

[0120] The method is the same as in Example 1, except that...

[0121] In step (3), the temperature of the polycondensation reaction was replaced with 420℃, and the other conditions remained the same, resulting in a toluene-insoluble content of 0.9wt% in the polycondensation product S4.

[0122] In step (4), the other conditions remain the same, and needle coke raw material P4 and coated pitch Q4 are obtained;

[0123] 78.9 wt% of the recycled oil is returned and subjected to the above-mentioned polycondensation reaction, while the remainder is discharged.

[0124] The product distributions of the aforementioned cracked gas, cracked light oil, naphthalene oil, circulating oil, condensed wax oil, and condensed pitch are listed in Table 3; the physical properties of needle coke feedstock P4 and coated pitch Q4 are listed in Table 4.

[0125] Example 5

[0126] The method is the same as in Example 1, except that...

[0127] In step (4), the operating temperature of atmospheric distillation is changed, that is, the top temperature of the column is 170℃, the side stream extraction temperature of naphthalene oil is 215℃, the side stream extraction temperature of circulating oil is 280℃, and the other conditions are the same. The resulting polycondensed wax oil and polycondensed pitch are used as needle coke raw material P5 and coated pitch Q5, respectively.

[0128] The product distributions of the aforementioned cracked gas, cracked light oil, naphthalene oil, circulating oil, condensed wax oil, and condensed pitch are listed in Table 3; the physical properties of needle coke feedstock P5 and coated pitch Q5 are listed in Table 4.

[0129] Example 6

[0130] The method is the same as in Example 1, except that...

[0131] The aforementioned circulating oil is not reused; it is all discharged externally.

[0132] In step (3), the other conditions are the same, and the content of toluene-insoluble matter in polycondensation product S6 is 1.9 wt%.

[0133] In step (4), the other conditions remain the same, and the resulting polycondensed wax oil and polycondensed pitch are used as needle coke raw material P6 and coated pitch Q6, respectively.

[0134] The product distributions of the aforementioned cracked gas, cracked light oil, naphthalene oil, circulating oil, condensed wax oil, and condensed pitch are listed in Table 3; the physical properties of needle coke feedstock P6 and coated pitch Q6 are listed in Table 4.

[0135] Example 7

[0136] The method is the same as in Example 1, except that...

[0137] In step (1), YS catalytic diesel is replaced with MY ethylene tar diesel fraction (elemental composition is shown in Table 1), and the other conditions are the same, to obtain extract oil and raffinate oil (each component and its content are shown in Table 2).

[0138] In step (2), the remaining conditions are the same, and a di-tricyclic aromatic hydrocarbon component is obtained;

[0139] In step (3), the other conditions are the same, and the content of toluene-insoluble matter in the thermal polycondensation product S7 is 1.5 wt%.

[0140] In step (4), the other conditions remain the same, and the resulting polycondensed wax oil and polycondensed pitch are used as needle coke raw material P7 and coated pitch Q7, respectively.

[0141] 78.9 wt% of the recycled oil is returned and subjected to polycondensation reaction, while the remainder is discharged.

[0142] The product distributions of the aforementioned cracked gas, cracked light oil, naphthalene oil, circulating oil, condensed wax oil, and condensed pitch are listed in Table 3; the physical properties of needle coke feedstock P7 and coated pitch Q7 are listed in Table 4.

[0143] Comparative Example 1

[0144] The method is the same as in Example 1, except that...

[0145] There are no steps (1)-(2), that is,

[0146] YS catalytic diesel was directly subjected to step (3) under the same conditions to obtain polycondensation product DS1 and cracked gas. The content of toluene-insoluble matter in polycondensation product DS1 was 1.6 wt%.

[0147] In step (4), the other conditions are the same, and the obtained polycondensed wax oil and polycondensed pitch are used as needle coke raw material DP1 and coated pitch DQ1, respectively.

[0148] 90 wt% of the recycled oil is returned and subjected to the above-mentioned polycondensation reaction, while the remainder is discharged.

[0149] The product distributions of the aforementioned cracked gas, cracked light oil, naphthalene oil, circulating oil, condensed wax oil, and condensed pitch are listed in Table 3; the physical property parameters of needle coke feedstock DP1 and coated pitch DQ1 are listed in Table 4.

[0150] Table 1

[0151]

[0152]

[0153] Table 2

[0154]

[0155] Note: 1 - Mass ratio of solvent to catalytic diesel.

[0156] Table 3

[0157]

[0158]

[0159] Table 4

[0160]

[0161] As can be seen from the results in Tables 1-4, compared with Comparative Example 1, Examples 1-7, using the method provided by this invention, use catalytic diesel as raw material and employ extraction, solvent recovery, polycondensation reaction, and distillation techniques to obtain polycondensation wax oil with both high polycondensation yield and high total content of tri- and hexacyclic aromatic hydrocarbons, as well as high-quality polycondensation asphalt. At the same time, cracked light oil suitable for gasoline and naphthalene oil suitable for separating and purifying naphthalene-based chemicals are also obtained, fully realizing the economic added value of catalytic diesel.

[0162] Test case

[0163] The needle coke raw materials (P1-P7 and DP1) obtained in Examples 1-7 and Comparative Example 1 were sequentially calcined (at 1400℃ for 12h) and graphitized (at 2800℃ for 3h), and the physical properties of the needle coke obtained are listed in Table 5.

[0164] Table 5

[0165]

[0166] As can be seen from the results in Table 5, compared with Comparative Example 1, the needle coke raw materials prepared by the method provided by the present invention in Examples 1-7 are used to produce needle coke. The needle coke produced has better quality while meeting the performance requirements of GB / T37308-2019. That is, it has a lower coefficient of thermal expansion, lower sulfur content and nitrogen content, as well as higher true density (before calcination) and higher true density (after calcination).

[0167] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing carbon materials from catalytic diesel fuel, characterized in that, The method includes the following steps: (1) Catalytic diesel oil is contacted with a solvent and extracted to obtain extract oil enriched with di-tricyclic aromatic hydrocarbons and raffinate oil enriched with saturated hydrocarbons and monocyclic aromatic hydrocarbons. (2) The extracted oil is subjected to solvent recovery to obtain a di-tricyclic aromatic hydrocarbon component; (3) The enriched di-tricyclic aromatic hydrocarbon component is subjected to a polycondensation reaction to obtain a polycondensation product; (4) The polycondensation product is distilled to obtain cracked light oil, naphthalene oil, recycled oil, polycondensed wax oil and polycondensed pitch, respectively. In this process, the polycondensed wax oil and polycondensed pitch each serve independently as carbon materials.

2. The method according to claim 1, wherein, In step (1), The extraction conditions are as follows: temperature 30-120℃, preferably 40-80℃; pressure 0.1-1MPa, preferably 0.1-0.3MPa; time 0.5-2h, preferably 0.6-1.2h. Preferably, the mass ratio of the catalytic diesel oil to the solvent is 1:1-5, more preferably 1:1-3; Preferably, the raffinate is used as feedstock for catalytic cracking.

3. The method according to claim 1 or 2, wherein, In step (1), The solvent is selected from at least one of sulfolane, furfural, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and isopropanol, preferably selected from at least one of sulfolane, furfural, dimethyl sulfoxide and isopropanol; Preferably, the catalytic diesel oil has the following characteristics: sulfur content 0.1-4 wt%; nitrogen content 1-1000 mg / kg; oxygen content 1-1000 mg / kg; total aromatic hydrocarbon content ≥70 wt%, preferably 75-99.9 wt%; and total saturated hydrocarbon content ≤30 wt%, preferably 15-20 wt%. More preferably, the catalytic diesel oil contains ≥55wt% di-tricyclic aromatic hydrocarbons, and more preferably 60-80wt%. Preferably, 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, catalytic cracking refined diesel oil, and ethylene tar diesel fraction.

4. The method according to any one of claims 1-3, wherein, In step (2), The enriched di- and tricyclic aromatic hydrocarbon components contain a total aromatic hydrocarbon content of ≥95wt% and a total saturated hydrocarbon content of ≤5wt%. Preferably, in the enriched di- and tricyclic aromatic hydrocarbon components, the content of di- and tricyclic aromatic hydrocarbons is ≥80 wt%, preferably 85-90 wt%; and the content of monocyclic aromatic hydrocarbons is ≤15 wt%, preferably 3-10 wt%. Preferably, the solvent recovery conditions are: temperature of 130-220℃, preferably 150-200℃; pressure of 10-200kPa, preferably 10-100kPa; and time of 0.2-1h, preferably 0.3-0.8h. Preferably, the method further includes: returning the recycled solvent obtained from the solvent recovery and mixing it back into the solvent.

5. The method according to any one of claims 1-4, wherein, In step (3), The conditions for the polycondensation reaction are: a reaction temperature of 400-520℃, preferably 430-480℃; and a reaction time of 0.1-4h, preferably 1-3.5h. Preferably, the content of toluene-insoluble matter in the condensation product is ≤3 wt%.

6. The method according to any one of claims 1-5, wherein, In step (4), the distillation process includes: atmospheric distillation and vacuum distillation; The polycondensation product is subjected to atmospheric distillation to obtain cracked light oil, naphthalene oil, recycled oil and heavy fraction; the heavy fraction is subjected to vacuum distillation to obtain polycondensed wax oil and polycondensed pitch. Preferably, the atmospheric distillation conditions are as follows: top pressure of 0.01-0.1 MPa, preferably 0.01-0.06 MPa; top temperature of 170-210℃; bottom temperature of 320-360℃; naphthalene oil side stream extraction temperature of 215-225℃; and circulating oil side stream extraction temperature of 265-295℃. Preferably, the conditions for vacuum distillation are: top pressure ≤ 0.5 mmHg, more preferably ≤ 0.2 mmHg; top temperature ≥ 200℃, more preferably ≥ 220℃; bottom temperature 270-330℃, more preferably 270-310℃.

7. The method according to any one of claims 1-6, wherein, In step (4), The circulating oil is divided into a portion of the circulating oil and a remaining portion of the circulating oil, which are respectively returned to the polycondensation reaction and discharged. Preferably, the mass ratio of the partial circulating oil to the remaining circulating oil is 10-100:90-0.

8. The method according to any one of claims 1-7, wherein, In step (4), the polycondensed wax oil and polycondensed pitch are used as needle coke raw materials and coated pitch, respectively; Preferably, the polycondensation wax oil contains ≥80 wt% tri-hexacyclic aromatic hydrocarbons, more preferably ≥85 wt%; ≤1 wt% sulfur, more preferably ≤0.3 wt%; and ≤0.6 wt% nitrogen, more preferably ≤600 mg / kg. Preferably, the softening point of the coated asphalt is ≥210℃, more preferably ≥215℃; the toluene-insoluble content is ≥5wt%, more preferably ≥9wt%; the residual carbon content is ≥70wt%, more preferably ≥75wt%; the ash content is ≤0.01wt%; and the sulfur content is ≤0.5wt%, more preferably ≤0.15wt%. Preferably, the cracked light oil is used as gasoline; Preferably, the naphthalene oil is used to separate and purify naphthalene-based chemicals, which are selected from at least one of naphthalene, methylnaphthalene, and dimethylnaphthalene.

9. An apparatus for processing catalytic diesel to prepare carbon materials, characterized in that, The apparatus includes: an extraction unit, a solvent recovery unit, a polycondensation unit, and a distillation unit connected in sequence. The extraction unit is used to contact and extract catalytic diesel oil with solvent to obtain extract oil enriched with di- and tricyclic aromatics, and raffinate oil enriched with saturated hydrocarbons and monocyclic aromatics; the solvent recovery unit is used to recover the solvent from the extract oil to obtain di- and tricyclic aromatic components and recycled solvent; the polycondensation unit is used to carry out polycondensation reaction on the di- and tricyclic aromatic components to obtain polycondensation products and cracked gas; the distillation treatment unit is used to distill the polycondensation products to obtain cracked light oil, naphthalene oil, recycled oil, polycondensed wax oil, and polycondensed asphalt, respectively. In this process, the polycondensed wax oil and polycondensed pitch each serve independently as carbon materials.

10. The apparatus according to claim 9, wherein, The distillation unit includes an atmospheric distillation section and a vacuum distillation section connected in series. The atmospheric distillation section is used to distill the polycondensation product under atmospheric pressure to obtain the cracked light oil, naphthalene oil, recycled oil, and heavy fraction. The vacuum distillation section is used to distill the heavy fraction under vacuum to obtain the polycondensed wax oil and polycondensed asphalt. Preferably, the circulating oil outlet of the atmospheric distillation section is connected to the polycondensation unit, for returning a portion of the circulating oil and carrying out the polycondensation reaction; Preferably, the circulating solvent outlet of the solvent recovery unit is connected to the extraction unit for returning the circulating solvent and performing the extraction.

11. A lithium-ion battery anode material, characterized in that, The negative electrode material of the lithium-ion battery is selected from: needle coke obtained by calcining and graphitizing the polycondensed wax oil described in any one of claims 1-8 as needle coke raw material, and / or polycondensed pitch described in any one of claims 1-8 as coating pitch.

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