A production method of a negative electrode material needle coke

Abstract

This invention discloses a method for producing needle coke as a negative electrode material. The method includes a coking stage and a coking pulling stage. The coking stage is a stage of heat treatment of raw materials to form a broad-area mesophase. The coking pulling stage is a stage of airflow coking of the broad-area mesophase to achieve microscopic ordering. In the coking stage, two raw materials are used, denoted as raw material 1 and raw material 2. Raw material 1 and raw material 2 are fed into the coking tower in the same coking cycle in sequence. The feed temperature of raw material 1 is higher than that of raw material 2, preferably 5-80°C higher, and more preferably 10-50°C higher. The feed temperature is the temperature of raw material 1 or raw material 2 before entering the coking tower after being heated in a furnace. The PDQI value of raw material 1 is higher than that of raw material 2, preferably 1-10 higher, and more preferably 2-6 higher. The PDQI value is the hydrogen supply index. This invention discloses a method for producing needle coke as a negative electrode material, which can produce needle coke as a negative electrode material with high initial discharge specific capacity.

Description

Technical Field

[0001] This invention relates to a method for producing needle coke, a negative electrode material, and more specifically to a method for producing needle coke, a negative electrode material, using petroleum-based or coal-based raw materials. Background Technology

[0002] Needle coke is an excellent carbon product, exhibiting a distinct streamlined texture. Due to its good electrical conductivity, orientation, and thermal conductivity, it has become a primary raw material for manufacturing ultra-high power graphite electrodes for steelmaking. Using ultra-high power electrodes in steelmaking can shorten smelting time by about two-thirds and reduce power consumption by about 50%, resulting in significant economic benefits. In recent years, with the rapid development of new energy vehicles, the demand for power batteries has increased substantially. Lithium-ion battery anode materials are divided into carbon materials and non-carbon materials, with artificial graphite being the main carbon material. Artificial graphite anode materials produced from needle coke are widely used in high-end graphite anode material products due to their excellent graphitization degree and initial discharge specific capacity.

[0003] CN202011305509.9 discloses a method and process system for producing needle coke from heavy oil, comprising: a fractional cutting process, using heavy oil as raw material to cut it into light distillate oil, heavy distillate oil and tailings; a hydrogenation process, wherein the heavy distillate oil is hydrogenated to obtain hydrogenated heavy distillate; a mixing process, wherein the hydrogenated heavy distillate is mixed with the light distillate oil to obtain a mixed oil; and a delayed coking process, wherein the mixed oil is subjected to delayed coking to obtain needle coke.

[0004] US4894144 discloses a method for simultaneously preparing needle coke and high-sulfur petroleum coke. It employs a hydrotreating process to pretreat straight-run heavy oil, and the hydrotreated residue is divided into two parts, which are then coked separately and subsequently calcined to obtain needle coke and high-sulfur petroleum coke.

[0005] US5286371 also discloses a hydrotreating process for straight-run residue, with a hydrotreating reaction temperature of 379-480℃ and a reaction pressure of 6.8MPa-34.4MPa. The treated heavy residue is mixed with catalytic cracking clarified oil and fed into a solvent deasphalting unit. The stream after deasphalting is used as feedstock for needle coke.

[0006] US4178229 discloses a method for producing high-quality petroleum coke from straight-run vacuum residue, which first converts vacuum residue into distillate oil and bitumen, and then further cracks the bitumen and hydrogen donor to produce feedstock for high-quality coke.

[0007] CN202010439340.X discloses a method for preparing needle coke for ultra-high power electrodes from heavy oil. The method uses heavy oil as raw material and employs a size exclusion separation method with polystyrene as the separation column packing to separate components with a relative molecular mass distribution of 400-1000. Acidic and basic components are removed by ion exchange chromatography to obtain a neutral raw material. The treated raw material undergoes a two-stage continuous carbonization process to prepare needle coke.

[0008] Prior to 2017, needle coke was mainly used as aggregate for producing HP and UHP graphite electrodes. The main indicators pursued by needle coke products were low thermal expansion coefficient and ordered structure. In recent years, with the rapid development of the electric vehicle industry, needle coke has been widely used in the lithium-ion battery anode material industry. The goal pursued by needle coke products is a high first discharge specific capacity. Most of the needle coke preparation processes in the existing technology are designed for the purpose of producing graphite electrode needle coke. If needle coke is to be used for anode material production, further improvement and optimization are needed in terms of first discharge specific capacity. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention discloses a method for producing needle coke, a negative electrode material, which can produce needle coke with high initial discharge specific capacity.

[0010] A method for producing needle coke for anode materials, the method comprising a coking stage and a coking pulling stage, wherein the coking stage is a stage of heat treatment of raw materials to form a broad-area mesophase, and the coking pulling stage is a stage of airflow coking of the broad-area mesophase to achieve microscopic ordering, wherein the coking stage uses two raw materials, referred to as raw material 1 and raw material 2, which are fed into the coking tower in the same coking cycle in sequence, wherein the feed temperature of raw material 1 is higher than that of raw material 2, preferably 5-80°C higher, and more preferably 10-50°C higher; the feed temperature is the temperature of raw material 1 or raw material 2 before entering the coking tower after being heated in a heating furnace, wherein the PDQI value of raw material 1 is higher than that of raw material 2, preferably 1-10 higher, and more preferably 2-6, wherein the PDQI value is the hydrogen supply index.

[0011] In the method of the present invention, the properties of the raw material 1 are as follows: PDQI value of 5-40, preferably 7-30; sulfur content ≤1.0wt%, preferably 0-0.5wt%; 5% distillation point temperature of 350℃-430℃, preferably 360℃-400℃; 95% distillation point temperature of 450℃-550℃, preferably 480℃-530℃.

[0012] In the method of the present invention, the properties of the raw material 2 are as follows: PDQI value of 3-6, 5% distillation point temperature of 340℃-400℃, preferably 350℃-380℃, 95% distillation temperature of 440℃-540℃, preferably 460℃-500℃, and sulfur content ≤1.0wt%, preferably 0-0.5wt%.

[0013] In the method of the present invention, the total time used for the coking stage of raw material 1 and raw material 2 and the coking stage is T, where T ranges from 24 to 72 hours, preferably 36 to 56 hours. The coking time of raw material 1 accounts for 30% to 60% of the total time, preferably 30% to 50%. The coking time of raw material 2 accounts for 30% to 80% of the total time, preferably 30% to 50%. The time used for the coking stage accounts for 10% to 50% of the total time, preferably 10% to 40%.

[0014] In the method of the present invention, the coking operation conditions for raw material 1 are as follows: the furnace outlet temperature of the heating furnace is 450℃-580℃, preferably 460℃-550℃; the coke tower pressure is 0.1-2.0MPa, preferably 0.5-1.0MPa; the coking operation conditions for raw material 2 are as follows: the furnace outlet temperature of the heating furnace is 440℃-550℃, preferably 450℃-530℃; the coke tower pressure is 0.1-2.0MPa, preferably 0.5-1.0MPa.

[0015] In the method of the present invention, the outlet temperature of the heating furnace of the coking unit introduced by raw material 2 is 5-80°C lower than the outlet temperature of the heating furnace of the coking unit introduced by raw material 1, preferably 10-50°C.

[0016] In the method of the present invention, raw material 1 and raw material 2 are selected from at least one of coal-based raw materials and petroleum-based raw materials, preferably selected from at least one of coal tar, coal tar pitch, heavy petroleum oil, ethylene tar, catalytic cracking slurry oil or thermal cracking residue oil.

[0017] In the method of the present invention, the raw material 1 can be obtained by hydrogenating fresh raw materials; the raw material 2 is generally a low-sulfur, low-nitrogen raw material that has not been hydrogenated.

[0018] A specific method for producing needle coke, a negative electrode material, includes the following steps:

[0019] (5) Fresh feedstock enters the hydrotreating tower after passing through the hydrotreating unit, at least separating material 1 - hydrotreated distillate oil;

[0020] (6) The material 1 in step (1) is heated in the heating furnace and then enters the coking tower for coking. The oil and gas generated by the reaction are discharged from the top of the coking tower and enter the coking fractionation tower to separate at least the coking wax oil fraction.

[0021] (7) In step (2), material 1 is switched to material 2 to continue feeding the coke tower;

[0022] (8) In step (3), material 2 is switched to coking wax oil fraction in step (2) to pull coke from the coke tower. After the coking of coke tower by coking wax oil is completed, small blowing, large blowing, and coke removal operations are performed on the coke tower. The needle coke product exits the device from the bottom of the tower.

[0023] In the above method, the fresh raw material in step (1) is selected from at least one of coal-based raw materials and petroleum-based raw materials, preferably selected from at least one of coal tar, coal tar pitch, heavy petroleum oil, ethylene tar, catalytic cracking slurry oil or thermal cracking residue oil.

[0024] In the above method, the solid content of the fresh raw material in step (1) is 0-500 μg / g, preferably 0-200 μg / g, and more preferably 0-100 μg / g;

[0025] In the above method, the hydrotreating device in step (1) can be any hydrotreating technology suitable for this invention, such as fixed-bed residue hydrotreating technology, suspended-bed residue hydrotreating technology, fluidized-bed residue hydrotreating technology, moving-bed residue hydrotreating technology, etc. Taking the currently mature fixed-bed hydrotreating technology as an example, the hydrotreating catalyst used refers to a single catalyst or a combination catalyst with functions such as hydrodemetallization, hydrodesulfurization, hydrodenitrogenation, and hydrocracking. These catalysts generally use porous refractory inorganic oxides such as alumina as a support, oxides of Group VIB and / or Group VIII metals such as W, Mo, Co, Ni, etc. as active components, and selectively add other various additives such as P, Si, F, B, etc. For example, the CEN, FZC, ZTN, and ZTS series residue hydrotreating catalysts produced by the Catalyst Branch of China Petroleum & Chemical Corporation, and the ZTN and ZTS series catalysts produced by the First Fertilizer Plant of Qilu Petrochemical Company belong to this type of catalyst. Currently, in fixed-bed hydrotreating technology, multiple catalysts are often used in combination, including a protective agent, a hydrodemetallization catalyst, a hydrodesulfurization catalyst, and a hydrodenitrogenation catalyst. The loading sequence is generally such that the feedstock oil comes into contact with the protective agent, hydrodemetallization catalyst, hydrodesulfurization catalyst, and hydrodenitrogenation catalyst in sequence. Of course, there are also techniques that mix and load these catalysts. Hydrotreating typically involves multiple reactors to increase processing capacity. Operation is usually carried out at an absolute pressure of 1 MPa-35 MPa, preferably 2 MPa-6 MPa, and a reaction temperature of 250℃-500℃, preferably 250℃-350℃. The liquid hourly space velocity (LHSV) and hydrogen partial pressure (HBP) are selected based on the characteristics of the feedstock, the required conversion rate, and the degree of refining. The LHSV is typically around 0.1 h⁻¹. -1 -5.0h -1 Ideally, it should be 0.15h. -1 -2.0h -1 Within the range, the total hydrogen-to-oil volume ratio is 100-5000, preferably 300-3000.

[0026] In the above method, the PDQI value of material 1 in step (1) is ≥7, the sulfur content is ≤1.0%, preferably 0-0.5%, the 5% distillation point temperature is 350℃-430℃, preferably 360℃-400℃, and the 95% distillation temperature is 450℃-550℃, preferably 480℃-530℃.

[0027] In the above method, the operating conditions for introducing material 1 into the coking unit in step (2) are as follows: the furnace outlet temperature of the heating furnace is 450℃-580℃, preferably 460℃-550℃; the coke tower pressure is 0.1-2.0MPa, preferably 0.5-1.0MPa.

[0028] In the above method, the coking wax oil fraction described in step 2 has a PDQI value of 1-3, a 5% distillation point temperature of 250℃-380℃, preferably 280℃-360℃, a 95% distillation point temperature of 350℃-520℃, preferably 350℃-460℃, and a sulfur content of ≤1.0%, preferably ≤0.5%.

[0029] In the above method, the PDQI value of material 2 in step (3) is 3-6, the 5% distillation point temperature is 340℃-400℃, preferably 350℃-380℃, the 95% distillation temperature is 440℃-540℃, preferably 460℃-500℃, and the sulfur content is ≤1.0%, preferably 0-0.5%.

[0030] In the above method, the operating conditions for introducing material 2 into the coking unit in step (3) are as follows: the outlet temperature of the heating furnace is 440℃-550℃, preferably 450℃-530℃; the pressure of the coke tower is 0.1-2.0MPa, preferably 0.5-1.0MPa.

[0031] In the above method, the outlet temperature of the heating furnace of the coking unit introduced by material 2 in step (3) is 5-80°C lower than the outlet temperature of the heating furnace of the coking unit introduced by material 1 in step (2), preferably 10-50°C.

[0032] In the above method, the operating conditions for introducing the coking wax oil into the coking unit in step (4) are as follows: the outlet temperature of the heating furnace is 450℃-550℃, preferably 480℃-530℃, and the pressure of the coke tower is 0.1-1.0MPa, preferably 0.2-0.6MPa.

[0033] In the above method, the total time used for the coking stages of material 1 and material 2, and the coking stage, is T, where T ranges from 24 to 72 hours, preferably 36 to 56 hours. The coking time of material 1 accounts for 30% to 60% of the total time, preferably 30% to 50%. The coking time of material 2 accounts for 30% to 80% of the total time, preferably 30% to 50%. The coking stage accounts for 10% to 50% of the total time, preferably 10% to 40%.

[0034] In the above method, the solid content of material 1, material 2, and coking wax oil is 0-500 μg / g, preferably 0-200 μg / g, and more preferably 0-100 μg / g.

[0035] In the above method, the mass ratio of material 1, material 2, and coking wax oil introduced into the coke tower within one operating cycle is 1:0.5-2.0:0.2-1.5.

[0036] The ideal components of needle coke feedstock are tricyclic and tetracyclic short-chain aromatics. To meet downstream application requirements, low sulfur and nitrogen content is generally required. For feedstocks with high sulfur and nitrogen content, hydrorefining is necessary. However, the hydrorefining process inevitably involves ring-opening reactions of aromatics, leading to a significant reduction in the aromatic carbon content of the feedstock and the degradation of the ideal tricyclic and tetracyclic aromatics, resulting in poor performance of the produced needle coke. To address this issue, a common approach is to directly mix a portion of non-hydrogenated feedstock with the hydrotreated feedstock and then pass them together into the coking tower via a coking furnace to reduce the degradation of the coking feedstock. However, this blending method does not fully consider the differences in temperature requirements for the thermal reaction processes of the hydrotreated and non-hydrogenated feedstocks, severely impacting the performance of needle coke as a negative electrode material. This invention, by feeding hydrotreated and non-hydrogenated feedstocks in stages and differentiating the furnace outlet temperature according to their different thermal reaction performance, can significantly improve the negative electrode material performance of needle coke products. Attached Figure Description

[0037] Figure 1 This is a flowchart of a combined process for preparing needle coke according to the present invention, wherein 1 is fresh raw material, 2 is hydrotreating unit, 3 is hydrotreated product pipeline, 4 is fractionation tower, 5 is hydrotreated gas product pipeline, 6 is light diesel oil and below fractionation pipeline, 7 is hydrotreated distillate oil, 8 is non-hydrotreated distillate oil, 9 is coking furnace, 10 is coke tower, 11 is coking product pipeline, 12 is coking fractionation tower, 13 is coking gas, 14 is coking gasoline, 15 is coking diesel, and 16 is coking wax oil. Detailed Implementation

[0038] The specific embodiments of the present invention will be described in detail below. However, it should be noted that the scope of protection of the present invention is not limited to these specific embodiments, but is determined by the claims in the appendix.

[0039] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0040] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0041] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this specification are based on weight, unless being based on weight would not be in accordance with the common understanding of those skilled in the art.

[0042] In the context of this specification, any two or more embodiments of the present invention can be arbitrarily combined, and the resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0043] According to one embodiment of the present invention, there is no particular limitation on the type of separation tower. Any separation device that can separate the material fed to the separation tower into multiple components according to predetermined requirements can be used. Specifically, distillation towers, flash distillation towers, evaporation towers, or fractionation towers can be used, with fractionation towers being preferred.

[0044] In the context of this invention, including in the examples and comparative examples, the discharge specific capacity was determined according to GB / T24533-2019, the volatile matter was determined according to the petrochemical standard SH / T0313 "Test Method for Petroleum Coke", the true density was determined according to the international standard GB / T32158, and the sulfur content was determined according to GB / T24256. The PDQI is the hydrogen supply index. Hydrogen nuclear magnetic resonance (1H-NMR) analysis was performed using a superconducting nuclear magnetic resonance spectrometer, with deuterated chloroform as the solvent and tetramethylsilane as the internal standard. The operating frequency was 80 MHz, and the scan width was 2 kHz, yielding the 1H spectrum. The cumulative intensity of different types of hydrogen content was obtained by integrating the peaks at different shifts in the spectrum. PDQ I = Hnβ / Ht × w(H)% × 10 where Hnβ is the peak area in the 1H spectrum with a shift between 1.5 and 2.0 ppm; Ht is the sum of the peak areas in the 1H spectrum; and w(H)% is the percentage of hydrogen content determined by elemental analysis according to standard SH / T0656.

[0045] The present invention will be further described in detail below through embodiments and comparative examples, but the present invention is not limited to the following embodiments.

[0046] like Figure 1 As shown: Fresh feedstock 1 passes through hydrogenation unit 2, and the hydrogenation product enters hydrogenation fractionation tower 4 via pipeline 3, separating gas, light diesel oil and lower fractions, and hydrogenated distillate oil. The gas and light diesel oil and lower fractions exit the unit via pipelines 5 and 6, respectively. The hydrogenated distillate oil enters coke 10 via a four-way valve after passing through heater 9 via pipeline 7. The non-hydrogenated distillate oil enters coke 10 via a four-way valve after passing through heater 9 via pipeline 8. The oil and gas generated from coking enter the coking fractionation tower 12 from the top of the coke tower via pipeline 11, separating coking gas, coking gasoline, coking diesel, and coking wax oil fractions. The coking gas, coking gasoline, and coking diesel fractions exit the unit via pipelines 13, 14, and 15, respectively. The coking wax oil enters coke 10 via a four-way valve after passing through heater 9 via pipeline 16. The produced needle coke exits the unit from the bottom of the coke tower.

[0047] Example 1

[0048] Table 1 shows the property analysis of the catalytic slurry oil provided by a refinery. The catalyst used in the hydrotreating unit is the CEN, FZC, ZTN, and ZTS series of residue hydrotreating catalysts produced by the Catalyst Division of China Petroleum & Chemical Corporation (Sinopec). Specifically, it includes protective agents, demetallization catalysts, desulfurization catalysts, and denitrification catalysts. The loading sequence is generally to allow the feedstock oil to contact the protective agent, hydrodemetallization catalyst, hydrodesulfurization catalyst, and hydronitrification catalyst in sequence. Of course, there are also techniques that mix and load these catalysts. The catalyst loading techniques described above are well-known to those skilled in the art. The hydrotreating process conditions are shown in Table 2.

[0049] Fresh feedstock is processed through a hydrogenation unit to obtain coking feedstock 1. The properties of feedstock 1 are as follows: PDQI value 8.2, sulfur content 0.38%, 5% distillation point temperature 362℃, 95% distillation point temperature 482℃, solid content 40μg / g. Feedstock 1 is introduced into the coking unit at the heater outlet temperature of 463℃, and the coke tower pressure is 0.7MPa. The properties of coking feedstock 2 are as follows: PDQI value 5.4, sulfur content 0.4%, 5% distillation point temperature 362℃, 95% distillation point temperature… The coking unit's heating furnace outlet temperature for material 2 was 453℃, with a solid content of 38 μg / g. The coke tower pressure was 0.65 MPa. The properties of the coking wax oil separated from the coking fractionation tower were as follows: PDQI value 2.5, sulfur content 0.32%, 5% distillation point temperature 302℃, 95% distillation point temperature 453℃, solid content 40 μg / g, and the coking unit heating furnace outlet temperature for the coking wax oil was 505℃. The coke tower pressure was 0.40 MPa. The total time (T) for the coking and pulling stages of materials 1 and 2 was 38 h. Among them, the coking time of material 1 accounted for 35% of the total time, the coking time of material 2 accounted for 40% of the total time, and the coking time of the pulling stage accounted for 25% of the total time. The mass ratio of material 1, material 2, and coking wax oil to the single coke tower was 1:0.9:0.6. The properties of the obtained needle coke product are shown in Table 3.

[0050] Comparative Example 1

[0051] The process of feeding material 2 into the coke tower was cancelled, and material 1 replaced material 2 to complete the coking stage of material 2 in Example 1. All other conditions were exactly the same as in Example 1. The properties of the obtained needle coke product are shown in Table 3.

[0052] Table 1 Properties of Catalytic Oil Slurry from a Refinery

[0053] Analysis Project Fresh ingredients <![CDATA[Density g / cm 3 > 1.0325 Ash content % 0.01 C%(w) 90.64 H%(w) 7.56 S%(w) 1.68 N% (w) 0.12 Four components % (w) Saturated portion 27.53 Aromatic components 66.56 gelatinous 5.26 Asphalt 0.65

[0054] Table 2 Hydrogenation Process Conditions

[0055] project Operating conditions raw material Fresh ingredients Hydrogen partial pressure, MPa 5.0 Reaction temperature, °C 310 <![CDATA[Space velocity, h -1 > 1.0 Hydrogen-to-oil ratio 900

[0056] Table 3 Properties of needle coke produced in the examples and comparative examples

[0057] project Example 1 Comparative Example 1 Specific capacity, mAh / g 354.2 345.2 Volatile matter, w% 5.68 8.65 Ash content, w% 0.02 0.02 Sulfur content, w% 0.41 0.40 <![CDATA[True density, g / cm 3 > 1.44 1.41

[0058] Example 2

[0059] Table 4 shows the property analysis of the catalytic slurry oil provided by a refinery. The catalyst used in the hydrotreating unit is the CEN, FZC, ZTN, and ZTS series of residue hydrotreating catalysts produced by the Catalyst Division of China Petroleum & Chemical Corporation (Sinopec). Specifically, it includes protective agents, demetallization catalysts, desulfurization catalysts, and denitrification catalysts. The loading sequence is generally to allow the feedstock oil to contact the protective agent, hydrodemetallization catalyst, hydrodesulfurization catalyst, and hydronitrification catalyst in sequence. Of course, there are also techniques that mix and load these catalysts. The catalyst loading techniques described above are well-known to those skilled in the art. The hydrotreating process conditions are shown in Table 5.

[0060] Fresh feedstock is hydrogenated to obtain coking feedstock 1, with the following properties: PDQI value 9.5, sulfur content 0.26%, 5% distillation point temperature 384℃, 95% distillation point temperature 496℃, and solid content 33μg / g. Feedstock 1 is introduced into the coking unit at the heater outlet temperature of 487℃ and the coke tower pressure is 0.9MPa. Coking feedstock 2 has the following properties: PDQI value 4.2, sulfur content 0.36%, 5% distillation point temperature 372℃, and 95% distillation point temperature... The temperature of material 2 at 483℃ and the solid content at 25μg / g were as follows: the outlet temperature of the heating furnace of the coking unit was 472℃, and the pressure of the coke tower was 0.6MPa. The properties of the coking wax oil separated from the coking fractionation tower were as follows: PDQI value 2.2, sulfur content 0.25%, 5% distillation point temperature 286℃, 95% distillation point temperature 441℃, solid content 20μg / g, the outlet temperature of the coking wax oil at the heating furnace of the coking unit was 495℃, and the pressure of the coke tower was 0.50MPa. The total time T used for the coking and coking stages of materials 1 and 2 was 52h, of which the coking time of material 1 accounted for 45% of the total time, the coking time of material 2 accounted for 40% of the total time, and the coking time of the coking stage accounted for 15% of the total time. The mass ratio of material 1, material 2, and coking wax oil to the single coke tower was 1:0.6:0.6. The properties of the obtained needle coke product are shown in Table 6.

[0061] Table 4 Properties of Catalytic Oil Slurry from a Refinery

[0062] Analysis Project Catalytic slurry <![CDATA[Density g / cm 3 > 1.0251 Ash content % 0.01 C%(w) 90.08 H%(w) 7.98 S%(w) 1.69 N% (w) 0.25 Four components % (w) Saturated portion 17.62 Aromatic components 77.84 gelatinous 4.21 Asphalt 0.33

[0063] Table 5 Hydrogenation Process Conditions

[0064]

[0065]

[0066] Table 6 Properties of needle coke in the examples

[0067] project Example 2 Specific capacity, mAh / g 354.6 Volatile matter, w% 6.25 Ash content, w% 0.02 Sulfur content, w% 0.35 <![CDATA[True density, g / cm 3 > 1.43

[0068] Example 3

[0069] Table 7 shows the property analysis of the catalytic slurry oil provided by a refinery. The catalyst used in the hydrotreating unit is the CEN, FZC, ZTN, and ZTS series of residue hydrotreating catalysts produced by the Catalyst Division of China Petroleum & Chemical Corporation (Sinopec). Specifically, it includes protective agents, demetallization catalysts, desulfurization catalysts, and denitrification catalysts. The loading sequence is generally to allow the feedstock oil to contact the protective agent, hydrodemetallization catalyst, hydrodesulfurization catalyst, and hydronitrification catalyst in sequence. Of course, there are also techniques that mix and load these catalysts. The above catalyst loading techniques are well-known to those skilled in the art. The hydrotreating process conditions are shown in Table 8.

[0070] Fresh feedstock is hydrogenated to obtain coking feedstock 1, with the following properties: PDQI value 8.6, sulfur content 0.25%, 5% distillation point temperature 398℃, 95% distillation point temperature 516℃, and solid content 30μg / g. Feedstock 1 is introduced into the coking unit heater at an outlet temperature of 530℃, and the coke tower pressure is 0.6MPa. Coking feedstock 2 has the following properties: PDQI value 3.0, sulfur content 0.25%, 5% distillation point temperature 374℃, and 95% distillation point temperature... The temperature of material 2 was 496℃, the solid content was 36μg / g, the outlet temperature of the heating furnace of the coking unit was 510℃, and the pressure of the coke tower was 0.6MPa. The properties of the coking wax oil separated from the coking fractionation tower are as follows: PDQI value 1.4, sulfur content 0.26%, 5% distillation point temperature 320℃, 95% distillation point temperature 450℃, solid content 24μg / g, the outlet temperature of the coking wax oil introduced into the heating furnace of the coking unit was 520℃, and the pressure of the coke tower was 0.30MPa. The total time T used for the coking and coke pulling stages of material 1 and material 2 was 46h, of which the coking time of material 1 accounted for 40% of the total time, the coking time of material 2 accounted for 30% of the total time, and the coking time of the coke pulling stage accounted for 30% of the total time. The mass ratio of material 1, material 2, and coking wax oil to the single coke tower was 1:0.7:0.3. The properties of the obtained needle coke product are shown in Table 9.

[0071] Table 7 Properties of Catalytic Slurry Oil from a Refinery

[0072] Analysis Project Catalytic slurry <![CDATA[Density g / cm 3 > 1.0665 Ash content % 0.01 C%(w) 90.32 H%(w) 6.85 S%(w) 2.54 N% (w) 0.27 Four components % (w) Saturated portion 5.65 Aromatic components 86.90 gelatinous 6.86 Asphalt 0.59

[0073] Table 8 Hydrogenation Process Conditions

[0074] project Operating conditions raw material Fresh ingredients Hydrogen partial pressure, MPa 6.5 Reaction temperature, °C 310 <![CDATA[Space velocity, h -1 > 1.0 Hydrogen-to-oil ratio 1000

[0075] Table 9 Properties of needle coke in the examples

[0076] project Example 3 Specific capacity, mAh / g 354.0 Volatile matter, w% 6.59 Ash content, w% 0.01 Sulfur content, w% 0.28 <![CDATA[True density, g / cm 3 > 1.44

Claims

1. A method for producing needle coke, a negative electrode material, characterized in that: The method includes a coking stage and a coking pulling stage. The coking stage is a stage of heat treatment of raw materials to form a broad-area mesophase. The coking pulling stage is a stage of airflow coking of the broad-area mesophase to achieve microscopic ordering. In the coking stage, two raw materials are used, referred to as raw material 1 and raw material 2. In the same coking cycle, raw material 1 and raw material 2 are fed into the coking tower in sequence. The feed temperature of raw material 1 is higher than that of raw material 2. The feed temperature is the temperature of raw material 1 or raw material 2 before entering the coking tower after being heated in the heater. The PDQI value of raw material 1 is higher than that of raw material 2. The PDQI value is the hydrogen supply index. The coking operation conditions for raw material 1 are: furnace outlet temperature of 450℃-580℃; coke tower pressure of 0.1-2.0MPa; the coking operation conditions for raw material 2 are: furnace outlet temperature of 440℃-550℃; coke tower pressure of 0.1-2.0MPa. The outlet temperature of the heater in the coking unit where raw material 2 is introduced is 5-80℃ lower than the outlet temperature of the heater in the coking unit where raw material 1 is introduced; Raw material 1 is obtained by hydrogenating fresh raw materials; raw material 2 is a low-sulfur, low-nitrogen raw material that has not undergone hydrogenation treatment.

2. The method according to claim 1, characterized in that: The feed temperature of raw material 1 is 5-80℃ higher than that of raw material 2; the PDQI value of raw material 1 is 1-10 higher than that of raw material 2.

3. The method according to claim 1, characterized in that: The feed temperature of raw material 1 is 10-50°C higher than that of raw material 2; the PDQI value of raw material 1 is 2-6 higher than that of raw material 2.

4. The method according to claim 1, characterized in that: The properties of the raw material 1 are as follows: PDQI value 5-40, sulfur content ≤1.0wt%, 5% distillation temperature 350℃-430℃, 95% distillation temperature 450℃-550℃.

5. The method according to claim 4, characterized in that: The properties of raw material 1 are as follows: PDQI value 7-30, sulfur content 0-0.5wt%, 5% distillation temperature 360℃-400℃, and 95% distillation temperature 480℃-530℃.

6. The method according to claim 1, characterized in that: The properties of the raw material 2 are as follows: PDQI value is 3-6, 5% distillation temperature is 340℃-400℃, 95% distillation temperature is 440℃-540℃, and sulfur content is ≤1.0wt%.

7. The method according to claim 6, characterized in that: The properties of the raw material 2 are as follows: 5% distillation temperature is 350℃-380℃, 95% distillation temperature is 460℃-500℃, and sulfur content is 0-0.5wt%.

8. The method according to claim 1, characterized in that: The total time used for the coking stages of raw material 1 and raw material 2, and the coking stage is T, which ranges from 24 to 72 hours. The coking time of raw material 1 accounts for 30% to 60% of the total time, the coking time of raw material 2 accounts for 30% to 80% of the total time, and the time used for the coking stage accounts for 10% to 50% of the total time.

9. The method according to claim 8, characterized in that: The total time used for the coking stages of raw material 1 and raw material 2, and the coking stage is T, which ranges from 36 to 56 hours. The coking time of raw material 1 accounts for 30% to 50% of the total time, the coking time of raw material 2 accounts for 30% to 50% of the total time, and the time used for the coking stage accounts for 10% to 40% of the total time.

10. The method according to claim 1, characterized in that: The coking operation conditions for raw material 1 are: furnace outlet temperature of 460℃-550℃; coke tower pressure of 0.5-1.0MPa; the coking operation conditions for raw material 2 are: furnace outlet temperature of 450℃-530℃; coke tower pressure of 0.5-1.0MPa.

11. The method according to claim 1, characterized in that: The outlet temperature of the heating furnace of the coking unit introduced from raw material 2 is 10-50℃ lower than that of the heating furnace of the coking unit introduced from raw material 1.

12. The method according to claim 1, characterized in that: The fresh raw material and raw material 2 are selected from at least one of coal-based raw materials and petroleum-based raw materials.

13. The method according to claim 12, characterized in that: The fresh raw material, raw material 2, is selected from at least one of coal tar, coal tar pitch, heavy petroleum oil, ethylene tar, catalytic cracking slurry oil, or thermal cracking residue oil.

14. The method according to claim 1, characterized in that: Includes the following: (1) Fresh feedstock passes through a hydrotreating unit and then enters a hydrofractionation tower to separate at least feedstock 1-hydrotreated distillate oil; (2) In step (1), the raw material 1 is heated in a heating furnace and then enters the coking tower for coking. The oil and gas generated by the reaction are discharged from the top of the coking tower and enter the coking fractionation tower to separate at least the coking wax oil fraction. (3) In step (2), raw material 1 is switched to raw material 2 to continue coking the coke tower; (4) In step (3), raw material 2 is switched to coking wax oil fraction in step (2) to pull coke from the coke tower. After the coking wax oil fraction pulls coke from the coke tower, small blowing, large blowing and coke removal operations are performed on the coke tower. The needle coke product exits the device from the bottom of the tower.

15. The method according to claim 14, characterized in that: The fresh raw material mentioned in step (1) is selected from at least one of coal-based raw materials and petroleum-based raw materials.

16. The method according to claim 15, characterized in that: The fresh raw material mentioned in step (1) is selected from at least one of coal tar, coal tar pitch, petroleum heavy oil, ethylene tar, catalytic cracking slurry oil or thermal cracking residue oil.

17. The method according to claim 14, characterized in that: The solid content of the fresh raw materials mentioned in step (1) is 0-500µg / g.

18. The method according to claim 17, characterized in that: The solid content of the fresh raw materials mentioned in step (1) is 0-200µg / g.

19. The method according to claim 17, characterized in that: The solid content of the fresh raw materials mentioned in step (1) is 0-100µg / g.

20. The method according to claim 14, characterized in that: The PDQI value of raw material 1 in step (1) is ≥7, the sulfur content is ≤1.0%, the 5% distillation temperature is 350℃-430℃, and the 95% distillation temperature is 450℃-550℃.

21. The method according to claim 20, characterized in that: The sulfur content of raw material 1 in step (1) is 0-0.5%, the 5% distillation temperature is 360℃-400℃, and the 95% distillation temperature is 480℃-530℃.

22. The method according to claim 14, characterized in that: The operating conditions for introducing raw material 1 into the coking unit in step (2) are as follows: the outlet temperature of the heating furnace is 450℃-580℃; the pressure of the coke tower is 0.1-2.0MPa.

23. The method according to claim 22, characterized in that: The operating conditions for introducing raw material 1 into the coking unit in step (2) are as follows: the outlet temperature of the heating furnace is 460℃-550℃; the pressure of the coke tower is 0.5-1.0MPa.

24. The method according to claim 14, characterized in that: The coking wax oil fraction described in step (2) has a PDQI value of 1-3, a 5% distillation temperature of 250℃-380℃, a 95% distillation temperature of 350℃-520℃, and a sulfur content of ≤1.0%.

25. The method according to claim 24, characterized in that: The coking wax oil fraction described in step (2) has a 5% distillation temperature of 280℃-360℃, a 95% distillation temperature of 350℃-460℃, and a sulfur content of ≤0.5%.

26. The method according to claim 14, characterized in that: The PDQI value of raw material 2 in step (3) is 3-6, the 5% distillation temperature is 340℃-400℃, the 95% distillation temperature is 440℃-540℃, and the sulfur content is ≯1.0%.

27. The method according to claim 26, characterized in that: The raw material 2 described in step (3) has a 5% distillation temperature of 350℃-380℃, a 95% distillation temperature of 460℃-500℃, and a sulfur content of 0-0.5%.

28. The method according to claim 14, characterized in that: The operating conditions for introducing raw material 2 into the coking unit in step (3) are as follows: the outlet temperature of the heating furnace is 440℃-550℃; the pressure of the coke tower is 0.1-2.0MPa.

29. The method according to claim 28, characterized in that: The operating conditions for introducing raw material 2 into the coking unit in step (3) are as follows: the outlet temperature of the heating furnace is 450℃-530℃; the pressure of the coke tower is 0.5-1.0MPa.

30. The method according to claim 14, characterized in that: In step (3), the outlet temperature of the heating furnace of the coking unit introduced by raw material 2 is 5-80°C lower than that of the outlet temperature of the heating furnace of the coking unit introduced by raw material 1 in step (2).

31. The method according to claim 30, characterized in that: In step (3), the outlet temperature of the heating furnace of the coking unit introduced by raw material 2 is 10-50°C lower than that of the outlet temperature of the heating furnace of the coking unit introduced by raw material 1 in step (2).

32. The method according to claim 14, characterized in that: The operating conditions for introducing the coking wax oil fraction into the coking unit in step (4) are as follows: the outlet temperature of the heating furnace is 450℃-550℃, and the pressure of the coke tower is 0.1-1.0MPa.

33. The method according to claim 32, characterized in that: The operating conditions for introducing the coking wax oil fraction into the coking unit in step (4) are as follows: the outlet temperature of the heating furnace is 480℃-530℃, and the pressure of the coke tower is 0.2-0.6MPa.

34. The method according to claim 14, characterized in that: The total time used for the coking stages of raw material 1 and raw material 2, and the coking stage is T, which ranges from 24 to 72 hours. The coking time of raw material 1 accounts for 30% to 60% of the total time, the coking time of raw material 2 accounts for 30% to 80% of the total time, and the time used for the coking stage accounts for 10% to 50% of the total time.

35. The method according to claim 34, characterized in that: The total time used for the coking stages of raw material 1 and raw material 2, and the coking stage is T, which ranges from 36 to 56 hours. The coking time of raw material 1 accounts for 30% to 50% of the total time, the coking time of raw material 2 accounts for 30% to 50% of the total time, and the time used for the coking stage accounts for 10% to 40% of the total time.

36. The method according to claim 14, characterized in that: The solid content of raw material 1, raw material 2, and coking wax oil fraction is 0-500µg / g.

37. The method according to claim 26, characterized in that: The solid content of raw material 1, raw material 2, and coking wax oil fraction is 0-200µg / g.

38. The method according to claim 36, characterized in that: The solid content of raw material 1, raw material 2, and coking wax oil fraction is 0-100µg / g.

39. The method according to claim 14, characterized in that: The mass ratio of feedstock 1, feedstock 2, and coking wax oil fraction introduced into the coke tower during one operating cycle is 1:0.5-2.0:0.2-1.5.

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