A production method of high-strength, high-specific-capacity negative electrode material acicular coke

Abstract

This invention discloses a method for producing needle coke, a high-strength, high-specific-capacity negative electrode material. The method includes at least the following steps: introducing four different materials, denoted as material A, material B, material C, and material D, into a coke tower in a sequential manner. Material A has the following properties: PDQI value ≥7, sulfur content ≤1.0%, preferably 0-0.5%, 5% distillation point temperature 350℃-430℃, preferably 360℃-400℃, and 95% distillation temperature 450℃-550℃, preferably 480℃-530℃. Material B has the following properties: PDQI value 3-6, 5% distillation point temperature 340℃-400℃, preferably 350℃-380℃, 95% distillation temperature 440℃-540℃, preferably 460℃-500℃, and sulfur content ≤1.0%, preferably 0-0.5%. The method described above can produce needle coke, a high-strength, high-specific-capacity anode material.

Description

Technical Field

[0001] This invention relates to a method for producing needle coke, a high-strength, high-specific-capacity anode material, specifically a method for producing needle coke, a high-strength, high-specific-capacity anode 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 in the production of 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 initial discharge specific capacity. Most of the needle coke preparation processes in the existing technology are designed for the purpose of producing needle coke for graphite electrodes. If needle coke is to be used to produce anode material needle coke, further improvement and optimization are needed in terms of initial discharge specific capacity, while further improvement of the strength coefficient of needle coke products is also needed. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a method for producing needle coke, a high-strength, high-specific-capacity anode material.

[0010] A method for producing needle coke, a high-strength, high-specific-capacity negative electrode material, comprising at least the following steps: introducing four different materials, denoted as material A, material B, material C, and material D, into a coke tower in a sequential manner. Material A has the following properties: PDQI value ≥7, sulfur content ≤1.0%, preferably 0-0.5%, 5% distillation point temperature 350℃-430℃, preferably 360℃-400℃, and 95% distillation temperature 450℃-550℃, preferably 480℃-530℃. Material B has the following properties: PDQI value 3-6, 5% distillation point temperature 340℃-400℃, preferably 350℃-380℃, and 95% distillation temperature 450℃-550℃, preferably 480℃-530℃. The properties of material C are as follows: PDQI value 1-3, 5% distillation point temperature 300℃-380℃, preferably 340℃-360℃, 95% distillation point temperature 400℃-520℃, preferably 410℃-460℃, sulfur content ≤1.0%, preferably ≤0-0.5%; The properties of material D are as follows: PDQI value 1-3, 5% distillation point temperature 250℃-350℃, preferably 250℃-300℃, 95% distillation point temperature 350℃-450℃, preferably 350℃-400℃, sulfur content ≤1.5%, preferably 0-1.0%.

[0011] In the method of the present invention, the solid content of materials A, B, C and D is 0-500 μg / g, preferably 0-200 μg / g, and more preferably 0-100 μg / g.

[0012] In the method of this invention, the total time for introducing four different materials is denoted as T, which ranges from 24 to 72 hours, preferably 36 to 56 hours. The time for introducing material A accounts for 10% to 50% of the total time, preferably 30% to 50%; the time for introducing material B accounts for 15% to 50% of the total time, preferably 15% to 40%; the time for introducing material C accounts for 10% to 40% of the total time, preferably 15% to 35%; and the time for introducing material D accounts for 5% to 30% of the total time, preferably 5% to 15%.

[0013] In the method of the present invention, the operating conditions for introducing material A 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.

[0014] In the method of the present invention, the operating conditions for introducing material B 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 this invention, the outlet temperature of the heating furnace of the coking unit introduced by material B is 5-80°C lower than the outlet temperature of the heating furnace of the coking unit introduced by material A, preferably 10-50°C lower.

[0016] In the method of the present invention, the operating conditions for introducing material C 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 0.3-0.6MPa.

[0017] The operating conditions for introducing material D in the method of the present invention are as follows: the outlet temperature of the heating furnace is 450℃-550℃, preferably 480℃-530℃, and the pressure of the coke tower is 0.1-0.6MPa, preferably 0.1-0.3MPa.

[0018] In the method of the present invention, the order of operations can be sequential or intermittent. The order of operations refers to one operating cycle of a certain coke, where the operating cycle refers to the period from the introduction of raw materials to the removal of coke. The next cycle can repeat the process of introducing four different materials sequentially.

[0019] In the method of the present invention, the mass ratio of materials A, B, C and D introduced in one operating cycle is 1:0.5-1.5:0.5-4.0:0.1-0.6.

[0020] In the method of this invention, material A can be obtained by hydrogenating fresh raw materials; material B is generally a low-sulfur, low-nitrogen raw material that has not been hydrogenated; material C can be coking heavy distillate oil; and material D can be coking light distillate oil.

[0021] In the method of the present invention, the coking tower can be set as one or more, and operated alternately. Specifically, it can be set as N coking towers, where N is an integer greater than or equal to 1.

[0022] To facilitate understanding of the technical solution of the present invention, the process and advantages of the present invention will be specifically explained using the example of setting up a coke tower.

[0023] A method for producing high-strength, high-specific-capacity needle coke includes the following steps:

[0024] (7) Fresh raw materials are fed into a hydrofraction tower after passing through a hydrotreatment unit, at least material A is separated out;

[0025] (8) Material A is heated in a heating furnace and then fed into the coking tower. 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 material C (coking heavy distillate oil) and material D (coking light distillate oil).

[0026] (9) In step (2), material A is switched to material B to continue feeding the coke tower;

[0027] (10) In step (3), material B is switched to material C, coking heavy distillate oil, in step (2) to continue feeding the coke tower;

[0028] (11) In step (4), the coking heavy distillate oil is switched to material D coking light distillate oil in step (2) to continue feeding the coke tower;

[0029] (12) After the coking light distillate oil finishes feeding the coke tower, small blowing, large blowing, and coke removal operations are performed on the coke tower, and the needle coke product exits the device from the bottom of the tower.

[0030] 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, petroleum heavy oil, ethylene tar, catalytic cracking slurry oil or thermal cracking residue oil.

[0031] 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 to allow the feedstock to contact the protective agent, hydrodemetallization catalyst, hydrodesulfurization catalyst, and hydrodenitrogenation catalyst sequentially. 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 generally between 0.1 h⁻¹ and 5.0 h⁻¹, preferably 0.15 h⁻¹. -1 Within the range of -2.0h-1, the total hydrogen-to-oil volume ratio is 100-5000, preferably 300-3000.

[0032] In the above method, the PDQI value of material A 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℃.

[0033] In the above method, the operating conditions for introducing material A 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.

[0034] In the above method, the PDQI value of material C in step (2) is 1-3, the 5% distillation point temperature is 300℃-380℃, preferably 340℃-360℃, the 95% distillation point temperature is 400℃-520℃, preferably 410℃-460℃, and the sulfur content is ≤1.0%, preferably ≤0.5%.

[0035] In the above method, the PDQI value of material D in step (2) is 1-3, the 5% distillation point temperature is 250℃-350℃, preferably 250℃-300℃, the 95% distillation point temperature is 350℃-450℃, preferably 350℃-400℃, and the sulfur content is ≤1.5%, preferably 0-1.0%.

[0036] In the above method, the PDQI value of material B 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%.

[0037] In the above method, the operating conditions for introducing material B 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.

[0038] In the above method, the outlet temperature of the heating furnace of the coking unit introduced by material B in step (3) is 5-80°C lower than the outlet temperature of the heating furnace of the coking unit introduced by material A in step (2), preferably 10-50°C.

[0039] In the above method, the operating conditions for introducing material C 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 0.3-0.6MPa.

[0040] In the above method, the operating conditions for introducing material D 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 0.1-0.6MPa, preferably 0.1-0.3MPa.

[0041] In the above method, the solid content of materials A, B, C, and D is 0-500 μg / g, preferably 0-200 μg / g, and more preferably 0-100 μg / g.

[0042] In the above method, the total time for feeding the coke tower with the four different materials is T, which ranges from 24 to 72 hours, preferably 36 to 56 hours. The time for introducing material A accounts for 10% to 50% of the total time, preferably 30% to 50%; the time for introducing material B accounts for 15% to 50% of the total time, preferably 15% to 40%; the time for introducing material C accounts for 10% to 40% of the total time, preferably 15% to 35%; and the time for introducing material D accounts for 5% to 30% of the total time, preferably 5% to 15%.

[0043] In the above method, the mass ratio of materials A, B, C, and D introduced within one operating cycle is 1:0.5-1.5:0.5-4.0:0.1-0.6.

[0044] 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.

[0045] Through experiments, the inventors discovered that the strength of needle coke is closely related to the medium and operating conditions during the coking process. Especially in the later stages of coking, when the main product of needle coke has solidified, the coking medium continues to react and form coke, resulting in very low-strength petroleum coke. This invention uses coking light wax oil and heavy wax oil to carry out the coking process of needle coke. The main function of heavy wax oil coking is to raise the temperature and solidify the system, while the main function of light wax oil coking is to further provide heat to the solidified needle coke product to increase its strength, while significantly reducing the generation of low-strength needle coke by the coking medium. Attached Figure Description

[0046] Figure 1This is a flow chart 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, 16 is coking heavy wax oil, and 17 is coking light wax oil. Detailed Implementation

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] In the context of this invention, including in the examples and comparative examples, the particle strength coefficient was determined according to T / ZGTS002-2019, the discharge specific capacity was determined according to GB / T24533-2019, the volatile matter was determined according to the petrochemical standard SH / T0313 "Petroleum Coke Test Method", the true density was determined according to the international standard GB / T32158, the sulfur content was determined according to GB / T24256, and 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 1H spectra. The cumulative intensity of different types of hydrogen content was obtained by integrating the peaks at different shifts in the spectra. 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 / T 0656.

[0054] 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.

[0055] 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 heavy wax oil and coking light wax oil enter coke 10 via a four-way valve after passing through heater 9 via pipelines 16 and 17, respectively. The produced needle coke exits the unit from the bottom of the coke tower.

[0056] Example 1

[0057] 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.

[0058] Fresh feedstock is processed through a hydrotreating unit to obtain feedstock A – hydrotreated distillate oil. Feedstock A has the following properties: PDQI value 8.6, sulfur content 0.36%, 5% distillation point temperature 365℃, 95% distillation point temperature 485℃, and solid content 48 μg / g. Feedstock A is introduced into the coking unit at the heater outlet temperature of 465℃ and the coke tower pressure is 0.75 MPa. Feedstock B has the following properties: PDQI value 5.8, sulfur content 0.41%, 5% distillation point temperature 360℃, 95% distillation point temperature 470℃, and solid content 50 μg / g. Feedstock B is introduced into the coking unit at the heater outlet temperature of 455℃ and the coke tower pressure is 0.75 MPa. Pa; The properties of material C separated from the coking unit are as follows: PDQI value 2.6, sulfur content 0.30%, 5% distillation point temperature 345℃, 95% distillation point temperature 420℃, solid content 41μg / g, material C is introduced into the coking unit heater outlet temperature 495℃, coke tower pressure 0.70MPa; The properties of material D separated from the coking unit are as follows: PDQI value 2.1, sulfur content 0.12%, 5% distillation point temperature 260℃, 95% distillation point temperature 380℃, solid content 43μg / g, material D is introduced into the coking unit heater outlet temperature 485℃, coke tower pressure 0.20MPa. The total time T for introducing four materials A, B, C, and D was 44 hours. The time for introducing material A accounted for 40% of the total time, the time for introducing material B accounted for 30% of the total time, the time for introducing material C accounted for 20% of the total time, and the time for introducing material D accounted for 10% of the total time. The mass ratio of materials A, B, C, and D to the charge of a single coke tower was 1:0.8:0.5:0.2. The properties of the obtained needle coke product are shown in Table 3.

[0059] Comparative Example 1

[0060] The process of feeding material D into the coke tower was cancelled, and material C replaced material D to complete the coking stage of material D 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.

[0061] Comparative Example 2

[0062] The process of feeding material C into the coke tower was cancelled, and material D replaced material C to complete the coking stage of material C 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.

[0063] Comparative Example 3

[0064] The process of feeding material B into the coke tower was cancelled, and all other conditions were exactly the same as in Example 1. The properties of the obtained needle coke product are shown in Table 3.

[0065] Table 1 Properties of Catalytic Slurry Oil from a Refinery

[0066] Analysis Project Fresh ingredients <![CDATA[Density g / cm 3 > 1.0456 Ash content % 0.01 C%(w) 90.92 H%(w) 7.26 S%(w) 1.56 N%(w) 0.26 Four components % (w) Saturated portion 10.65 Aromatic components 82.69 gelatinous 6.10 Asphalt 0.56

[0067] Table 2 Hydrogenation Process Conditions

[0068] project Operating conditions raw material Fresh ingredients Hydrogen partial pressure, MPa 5.5 Reaction temperature, °C 305 <![CDATA[Space velocity, h -1 > 0.9 Hydrogen-to-oil ratio 900

[0069] Table 3 Properties of needle coke produced in the examples and comparative examples

[0070] project Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Specific capacity, mAh / g 355.4 354.2 352.1 350.1 Volatile matter, w% 5.21 8.54 7.65 8.15 Ash content, w% 0.02 0.02 0.03 0.02 Sulfur content, w% 0.41 0.42 0.43 0.40 <![CDATA[True density, g / cm 3 > 1.45 1.40 1.41 1.39 Particle strength modulus, % 24.21 18.21 17.25 24.12

[0071] Example 2

[0072] 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 for mixing and loading these catalysts. The above catalyst loading techniques are well-known to those skilled in the art. The hydrotreating process conditions are shown in Table 5.

[0073] Fresh feedstock is processed through a hydrotreating unit to obtain feedstock A – hydrotreated distillate oil. Feedstock A has the following properties: PDQI value 9.3, sulfur content 0.21%, 5% distillation point temperature 380℃, 95% distillation point temperature 495℃, and solid content 32 μg / g. Feedstock A is introduced into the coking unit at the heater outlet temperature of 485℃ and the coke tower pressure is 0.9 MPa. Feedstock B has the following properties: PDQI value 4.2, sulfur content 0.32%, 5% distillation point temperature 370℃, 95% distillation point temperature 480℃, and solid content 21 μg / g. Feedstock B is introduced into the coking unit at the heater outlet temperature of 470℃ and the coke tower pressure is 0.8 MPa. Pa; The properties of material C separated from the coking unit are as follows: PDQI value 2.0, sulfur content 0.25%, 5% distillation point temperature 350℃, 95% distillation point temperature 440℃, solid content 33μg / g, material C is introduced into the coking unit heater outlet temperature 505℃, coke tower pressure 0.6MPa; The properties of material D separated from the coking unit are as follows: PDQI value 1.9, sulfur content 0.15%, 5% distillation point temperature 270℃, 95% distillation point temperature 390℃, solid content 25μg / g, material D is introduced into the coking unit heater outlet temperature 495℃, coke tower pressure 0.10MPa. The total time T for introducing four materials A, B, C, and D was 48 hours. The time for introducing material A accounted for 30% of the total time, the time for introducing material B accounted for 35% of the total time, the time for introducing material C accounted for 30% of the total time, and the time for introducing material D accounted for 5% of the total time. The mass ratio of materials A, B, C, and D to the charge of a single coke tower was 1:1:0.5:0.3. The properties of the obtained needle coke product are shown in Table 6.

[0074] Table 4 Properties of Catalytic Slurry Oil from a Refinery

[0075] Analysis Project Catalytic slurry <![CDATA[Density g / cm 3 > 1.0521 Ash content % 0.01 C%(w) 91.5 H%(w) 7.58 S%(w) 0.82 N%(w) 0.10 Four components % (w) Saturated portion 12.56 Aromatic components 83.99 gelatinous 3.2 Asphalt 0.25

[0076] Table 5 Hydrogenation Process Conditions

[0077] 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 1000

[0078] Table 6. Properties of needle coke in the examples

[0079] project Example 2 Specific capacity, mAh / g 355.9 Volatile matter, w% 5.18 Ash content, w% 0.02 Sulfur content, w% 0.39 <![CDATA[True density, g / cm 3 > 1.44 Particle strength coefficient, % 24.60

[0080] Example 3

[0081] 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.

[0082] Fresh feedstock is processed through a hydrotreating unit to obtain feedstock A – hydrotreated distillate oil. Feedstock A has the following properties: PDQI value 8.8, sulfur content 0.42%, 5% distillation point temperature 395℃, 95% distillation point temperature 515℃, and solid content 32 μg / g. Feedstock A is introduced into the coking unit at the heater outlet temperature of 535℃ and the coke tower pressure is 0.6 MPa. Feedstock B has the following properties: PDQI value 3.1, sulfur content 0.36%, 5% distillation point temperature 375℃, 95% distillation point temperature 495℃, and solid content 36 μg / g. Feedstock B is introduced into the coking unit at the heater outlet temperature of 505℃ and the coke tower pressure is 0.6 MPa. Pa; The properties of material C separated from the coking unit are as follows: PDQI value 1.3, sulfur content 0.25%, 5% distillation point temperature 355℃, 95% distillation point temperature 455℃, solid content 26μg / g, material C is introduced into the coking unit heater outlet temperature 515℃, coke tower pressure 0.6MPa; The properties of material D separated from the coking unit are as follows: PDQI value 1.6, sulfur content 0.2%, 5% distillation point temperature 295℃, 95% distillation point temperature 395℃, solid content 20μg / g, material D is introduced into the coking unit heater outlet temperature 505℃, coke tower pressure 0.10MPa. The total time T for introducing four materials A, B, C, and D was 54 hours. The time for introducing material A accounted for 45% of the total time, the time for introducing material B accounted for 20% of the total time, the time for introducing material C accounted for 25% of the total time, and the time for introducing material D accounted for 10% of the total time. The mass ratio of materials A, B, C, and D to the charge of a single coke tower was 1:0.6:0.4:0.1. The properties of the obtained needle coke product are shown in Table 9.

[0083] Table 7 Properties of Catalytic Slurry Oil from a Refinery

[0084]

[0085]

[0086] Table 8 Hydrogenation Process Conditions

[0087] project Operating conditions raw material Fresh ingredients Hydrogen partial pressure, MPa 6.0 Reaction temperature, °C 295 <![CDATA[Space velocity, h -1 > 0.8 Hydrogen-to-oil ratio 800

[0088] Table 9 Properties of needle coke in the examples

[0089] project Example 3 Specific capacity, mAh / g 355.7 Volatile matter, w% 5.62 Ash content, w% 0.02 Sulfur content, w% 0.44 <![CDATA[True density, g / cm 3 > 1.45 Particle strength coefficient, % 24.52

Claims

1. A method for producing needle coke, a high-strength, high-specific-capacitance anode material, characterized in that: The method includes at least the following: introducing four different materials, denoted as material A, material B, material C, and material D, into a coke tower in a sequential order. Material A has the following properties: PDQI value ≥7, sulfur content ≤1.0%, 5% distillation temperature 350℃-430℃, and 95% distillation temperature 450℃-550℃. Material B has the following properties: PDQI value 3-6, 5% distillation temperature 340℃-400℃. Material C has the following properties: PDQI value 1-3, 5% distillation temperature 300℃-380℃, 95% distillation temperature 400℃-520℃, sulfur content ≤1.0%; Material D has the following properties: PDQI value 1-3, 5% distillation temperature 250℃-350℃, 95% distillation temperature 350℃-450℃, sulfur content ≤1.5%. The operating conditions for introducing material A are as follows: furnace outlet temperature is 450℃-580℃; coke tower pressure is 0.1-2.0MPa; The operating conditions for introducing material B are as follows: furnace outlet temperature is 440℃-550℃; coke tower pressure is 0.1-2.0MPa; The outlet temperature of the heating furnace of the coking unit introduced by material B is 5-80℃ lower than that of the heating furnace of the coking unit introduced by material A; Material A is obtained by hydrogenating fresh feedstock; Material B is a low-sulfur, low-nitrogen feedstock that has not undergone hydrogenation treatment; Material C is coking heavy distillate oil; and Material D is coking light distillate oil.

2. The method according to claim 1, characterized in that: The properties of material A are as follows: sulfur content 0-0.5%, 5% distillation temperature 360℃-400℃, 95% distillation temperature 480℃-530℃; the properties of material B are as follows: 5% distillation temperature 350℃-380℃, 95% distillation temperature 460℃-500℃, sulfur content 0-0.5%; the properties of material C are as follows: 5% distillation temperature 340℃-360℃, 95% distillation temperature 410℃-460℃, sulfur content 0-0.5%; the properties of material D are as follows: PDQI value 1-3, 5% distillation temperature 250℃-300℃, 95% distillation temperature 350℃-400℃, sulfur content 0-1.0%.

3. The method according to claim 1, characterized in that: The solid content of materials A, B, C, and D is 0-500 µg / g.

4. The method according to claim 3, characterized in that: The solid content of materials A, B, C, and D is 0-200 µg / g.

5. The method according to claim 3, characterized in that: The solid content of materials A, B, C, and D is 0-100 µg / g.

6. The method according to claim 1, characterized in that: The total time for introducing four different materials is T, which ranges from 24 to 72 hours. The time for introducing material A accounts for 10% to 50% of the total time; the time for introducing material B accounts for 15% to 50% of the total time; the time for introducing material C accounts for 10% to 40% of the total time; and the time for introducing material D accounts for 5% to 30% of the total time.

7. The method according to claim 6, characterized in that: The total time for introducing four different materials is T, which ranges from 36 to 56 hours. The time for introducing material A accounts for 30% to 50% of the total time; the time for introducing material B accounts for 15% to 40% of the total time; the time for introducing material C accounts for 15% to 35% of the total time; and the time for introducing material D accounts for 5% to 15% of the total time.

8. The method according to claim 1, characterized in that: The operating conditions for introducing material A are as follows: the outlet temperature of the heating furnace is 460℃-550℃; the pressure of the coke tower is 0.5-1.0MPa.

9. The method according to claim 1, characterized in that: The operating conditions for introducing material B are as follows: the outlet temperature of the heating furnace is 450℃-530℃; the pressure of the coke tower is 0.5-1.0MPa.

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

11. The method according to claim 1, characterized in that: The operating conditions for introducing material C 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.

12. The method according to claim 11, characterized in that: The operating conditions for introducing material C are as follows: the outlet temperature of the heating furnace is 480℃-530℃, and the pressure of the coke tower is 0.3-0.6MPa.

13. The method according to claim 1, characterized in that: The operating conditions for introducing material D are as follows: the outlet temperature of the heating furnace is 450℃-550℃, and the pressure of the coke tower is 0.1-0.6MPa.

14. The method according to claim 13, characterized in that: The operating conditions for introducing material D are as follows: the outlet temperature of the heating furnace is 480℃-530℃, and the pressure of the coke tower is 0.1-0.3MPa.

15. The method according to claim 1, characterized in that: The order of precedence can be carried out sequentially or at intervals. The order of precedence refers to the process within one operating cycle of a certain coke. The operating cycle refers to the process from the introduction of raw materials to the removal of coke. The next cycle repeats the process of introducing four different materials sequentially.

16. The method according to claim 1, characterized in that: The mass ratio of materials A, B, C, and D introduced in one operating cycle is 1:0.5-1.5:0.5-4.0:0.1-0.

6.

17. The method according to claim 1, characterized in that: The coking towers are configured as one or more, operating alternately, specifically as N coking towers, where N is an integer greater than or equal to 1.

18. The method according to claim 1, characterized in that: The specific preparation method of needle coke, a high-strength, high-specific-capacitance anode material, includes the following: (1) Fresh raw materials are fed into a hydrotreating tower after passing through a hydrotreating unit, at least material A is separated; (2) Material A is heated in a heating furnace and then fed into the coking tower. 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 material C coking heavy distillate oil and material D coking light distillate oil. (3) In step (2), material A is switched to material B to continue feeding the coke tower; (4) In step (3), material B is switched to material C, coking heavy distillate oil, in step (2) to continue feeding the coke tower; (5) In step (4), the coking heavy distillate oil is switched to material D coking light distillate oil in step (2) to continue feeding the coke tower; (6) After the coking light distillate oil finishes feeding the coke tower, the coke tower is subjected to small blowing, large blowing and coke removal operations, and the needle coke product exits the device from the bottom of the tower.

19. The method according to claim 1 or 18, characterized in that: The mass ratio of materials A, B, C, and D introduced in one operating cycle is 1:0.5-1.5:0.5-4.0:0.1-0.6.

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