Production method of negative electrode material needle-shaped coke

Abstract

This invention discloses a method for producing needle coke, a negative electrode material. The method includes a coking process in any coking tower J as follows: First, raw material A is heated in a furnace and then introduced into coking tower J. After a period of time, the introduction of raw material A into coking tower J is stopped. Then, raw material B, heated in a furnace, is introduced into coking tower J. After a period of time, the introduction of raw material B is stopped. Finally, raw material C, heated in a furnace, is introduced into coking tower J. After a period of time, the introduction of raw material C is stopped. The PDQI value of raw material A is 5-40, preferably 7-30, and the PDQI value of raw material B is 1-20 lower than that of raw material A, preferably 2-10 lower, and more preferably 3-7 lower. This method can produce needle coke, 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 in the production of HP and UHP graphite electrodes. The main performance indicators for needle coke products were low coefficient of thermal expansion 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 is to achieve a high initial discharge specific capacity for needle coke products. Most existing needle coke preparation processes are designed for the production of graphite electrode needle coke. To produce anode material needle coke, further improvement and optimization are needed in terms of initial discharge specific capacity. Summary of the Invention

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

[0010] A method for producing needle coke, a negative electrode material, comprising the following coking process in any coking tower J: First, raw material A is heated in a furnace and then introduced into coking tower J. After a period of time, the introduction of raw material A into coking tower J is stopped. Then, raw material B, heated in a furnace, is introduced into coking tower J. After a period of time, the introduction of raw material B into coking tower J is stopped. Finally, raw material C, heated in a furnace, is introduced into coking tower J. After a period of time, the introduction of raw material C into coking tower J is stopped.

[0011] Among them, the PDQI value of raw material A is 5-40, preferably 7-30, and the PDQI value of raw material B is 1-20 lower than that of raw material A, preferably 2-10 lower, and even more preferably 3-7 lower.

[0012] 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 working frequency was 80MHz, the scan width was 2kHz, and the 1H spectrum was obtained. The cumulative intensity of different types of hydrogen content was obtained by integrating the peaks at different shifts in the spectrum). PDQI = Hnβ / Ht × w(H)% × 10, where Hnβ is the peak area in the 1H spectrum with shifts 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 obtained by elemental analysis according to standard SH / T0656.

[0013] The sulfur content of the raw material C is 0-1.0%, preferably 0-0.5%; the 5% distillation point temperature is 250℃-380℃, preferably 280℃-360℃; and the 95% distillation point temperature is 350℃-520℃, preferably 350℃-460℃.

[0014] In the method of the present invention, the sulfur content of the raw material A 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℃.

[0015] In the method of the present invention, the solid content of raw material B is 0-500 μg / g, preferably 0-200 μg / g, more preferably 0-100 μg / g; the sulfur content is 0-1.0%, preferably 0-0.5%; the 5% distillation point temperature is 340℃-400℃, preferably 350℃-380℃, and the 95% distillation temperature is 440℃-540℃, preferably 460℃-500℃.

[0016] In the method of the present invention, the raw material C is one or more of catalytic cracking recycle oil, ethylene tar, and coking wax oil, preferably coking wax oil.

[0017] In the method of this invention, the raw material A is generally obtained by hydrogenating fresh raw material. The fresh raw material 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. The solid content of the fresh raw material is 0-500 μg / g, preferably 0-200 μg / g, more preferably 0-100 μg / g, and the sulfur content is greater than 0.3%, preferably 0.5%-5.0%, further preferably 0.5%-3.0%, particularly preferably 1.5%-2.5%. The hydrogenation treatment can be carried out using conventional technology.

[0018] In the method of this invention, raw material B is a low-sulfur raw material, with a sulfur content generally of 0-1.0%, preferably 0-0.5%. The low-sulfur raw material is selected from at least one of coal-based and petroleum-based raw materials, preferably from at least one of coal tar, coal tar pitch, heavy petroleum oil, ethylene tar, catalytic cracking slurry oil, or thermal cracking residue oil; the solid content of the fresh raw material is 0-500 μg / g, preferably 0-200 μg / g, more preferably 0-100 μg / g. The low-sulfur raw material is generally untreated by hydrogenation.

[0019] In the method of the present invention, the total introduction time of raw materials A, B and C into a single coke tower is T, where T ranges from 24 to 72 hours, preferably from 36 to 56 hours.

[0020] In the method of the present invention, the outlet temperature of the heating furnace for raw material A is 450℃-580℃, preferably 460℃-550℃; the outlet temperature of the heating furnace for raw material B is 5-80℃ lower than that of the heating furnace for raw material A, preferably 10-50℃ lower.

[0021] In the method of the present invention, the residence time of raw material A in the furnace tube of the heating furnace is 1 min to 100 min, preferably 5 min to 30 min, and the residence time of raw material B in the furnace tube of the heating furnace is 1 min to 90 min less than the residence time of raw material A in the furnace tube of the heating furnace, preferably 2 min to 20 min less, and more preferably 5 min to 10 min less.

[0022] In the method of the present invention, the introduction time of raw material A in the coke tower accounts for 20%-60% of the total introduction time T, preferably 30%-50%; the introduction time of raw material B accounts for 30%-80% of the total introduction time T, preferably 30%-50%; and the introduction time of raw material C accounts for 10%-50% of the total introduction time T, preferably 10%-40%.

[0023] In the method of the present invention, the mass ratio of raw material A, raw material B, and raw material C to the charge of a single coke tower is 1:0.5-2.0:0.2-1.5.

[0024] In the method of the present invention, the coking tower can be set as one or more, preferably two or more, specifically two, three, four coking towers, etc., and the multiple coking towers can be used interchangeably.

[0025] In the method of the present invention, the heating furnace can be set as one or more, preferably two or more, specifically two, three, four heating furnaces, etc. The multiple heating furnaces can heat different raw materials respectively, for example, they can be used to heat material A and material B respectively.

[0026] In the method of this invention, after stopping the introduction of raw material C into the coke tower J, 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; after coke removal, the coke tower can repeat the above process.

[0027] 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-quality needle coke products. 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 through a coking furnace into the coke tower for coking, aiming 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; therefore, its ability to improve the strength of needle coke products is limited. This invention achieves significant improvement in the coking feedstock before it enters the coke tower by segmenting the feedstock into hydrogenated and non-hydrogenated feedstocks and by setting the furnace outlet temperature and residence time in the furnace tubes differently according to the different thermal reaction performance. Then, the anode material application performance of the needle coke product is further improved by the coking wax oil pulling treatment. Attached Figure Description

[0028] 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 device, 3 is hydrotreated product pipeline, 4 is fractionation tower, 5 is hydrotreated gas product pipeline, 6 is light diesel oil or lower distillate, 7 is hydrotreated distillate, 8 is non-hydrotreated distillate, 9 is coking furnace I, 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 wax oil, 17 is coking furnace II, and 18 is feed pipeline to furnace II. Detailed Implementation

[0029] The production method of needle coke for negative electrode materials includes the following:

[0030] (1) Fresh feedstock enters the hydrofraction tower after passing through the hydrotreatment unit, at least separating the hydrotreated distillate oil;

[0031] (2) The hydrogenated distillate oil is heated by the heater I and then enters the coking tower A for coking reaction. The oil and gas generated by the coking 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.

[0032] (3) After the hydrogenated distillate oil finishes feeding coke tower A, non-hydrogenated distillate oil is heated by heater II and then fed into coke tower A again.

[0033] (4) The non-hydrogenated heavy distillate oil in step (3) is finished feeding the coke tower A. The coking wax oil fraction in step (2) is heated by heater II or heater III and then fed into coke tower A again.

[0034] (5) After the coking wax oil finishes feeding the coke tower A, small blowing, large blowing, and coke removal operations are performed on coke tower A, and needle coke products are discharged from the bottom of the tower.

[0035] (6) Repeat steps (2), (3), (4), and (5) of coke tower A for coke tower B.

[0036] 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.

[0037] 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;

[0038] In the above method, the hydrotreating device described in step (1) can be any hydrotreating technology applicable to 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 various other 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 -1Within the range, the total hydrogen-to-oil volume ratio is 100-5000, preferably 300-3000.

[0039] In the above method, the total coking time of the hydrogenated distillate oil, non-hydrogenated distillate oil and coking wax oil for a single coking tower is T, with T ranging from 24 to 72 hours, preferably 36 to 56 hours.

[0040] In the above method, the PDQI value of the hydrotreated distillate oil in step (1) is >7.0; 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℃.

[0041] In the above method, the outlet temperature of the heating furnace I in step (2) is 450℃-580℃, preferably 460℃-550℃.

[0042] In the above method, the residence time of the hydrotreated distillate oil in the furnace tube of the heating furnace I in step (2) is 1 min to 100 min, preferably 5 min to 30 min.

[0043] In the above method, during the feeding process of the hydrotreated distillate oil to coke tower A in step (2), the pressure of the coke tower is 0.1-2.0 MPa, preferably 0.5-1.0 MPa.

[0044] In the above method, the charging time of the hydrotreated distillate oil to the coke tower A in step (2) accounts for 20%-60% of the total charging time T, preferably 30%-50%.

[0045] In the above method, the PDQI value of the coking wax oil in step (2) is 3-6; the sulfur content is 0-1.0%, preferably 0-0.5%; the 5% distillation point temperature is 250℃-380℃, preferably 280℃-360℃; and the 95% distillation temperature is 350℃-520℃, preferably 350℃-460℃.

[0046] In the above method, the solid content of the non-hydrogenated distillate oil in step (3) is 0-500 μg / g, preferably 0-200 μg / g, more preferably 0-100 μg / g; the PDQI value is 3-6; the sulfur content is 0-1.0%, preferably 0-0.5%; the 5% distillation point temperature is 340℃-400℃, preferably 350℃-380℃; and the 95% distillation temperature is 440℃-540℃, preferably 460℃-500℃.

[0047] In the above method, the outlet temperature of the heating furnace II in step (3) is 440℃-550℃, preferably 450℃-530℃.

[0048] In the above method, the outlet temperature of the heating furnace II in step (3) is 5-80°C lower than the outlet temperature of the heating furnace in step (2), preferably 10-50°C.

[0049] In the above method, during the feeding process of the non-hydrogenated distillate oil to coke tower A in step (3), the pressure of the coke tower is 0.1-2.0 MPa, preferably 0.5-1.0 MPa.

[0050] In the above method, the non-hydrogenated distillate oil in step (3) accounts for 30%-80% of the total charge T, preferably 30-50%.

[0051] In the above method, during the feeding process of coking wax oil to coke tower A in step (4), the outlet temperature of heating furnace II is 450℃-550℃, preferably 480℃-530℃; and the coke tower pressure is 0.1-1.0MPa, preferably 0.2-0.6MPa.

[0052] In the above method, the charging time of the coking wax oil in step (4) to the coke tower A accounts for 10%-50% of the total charging time T, preferably 10-40%.

[0053] In the above method, the mass ratio of hydrogenated distillate oil, non-hydrogenated distillate oil, and coking wax oil to the single coke tower charge is 1:0.5-2.0:0.2-1.5.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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 "Petroleum Coke Test Method", the true density was determined according to the international standard GB / T32158, and the sulfur content was determined according to GB / T24256.

[0061] 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.

[0062] 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 heating furnace 9 via pipeline 7. The oil and gas generated by coking enter the coking fractionation tower 12 via pipeline 11 from the top of the coke tower, separating coking gas, coking gasoline, coking diesel and coking wax oil fractions. Among them, the coking gas, coking gasoline and coking diesel fractions exit the unit via pipelines 13, 14 and 15, respectively. The coking wax oil 16 and non-hydrogenated distillate oil 8 enter coke 10 via coking heating furnace 17, respectively. The produced needle coke exits the unit from the bottom of the coke tower.

[0063] Example 1

[0064] 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.

[0065] The fresh feedstock, after passing through a hydrogenation unit, yields a hydrogenated distillate oil with the following properties: PDQI value 8.5, sulfur content 0.3%, 5% distillation point temperature 362℃, 95% distillation point temperature 483℃, and solid content 80 μg / g. The hydrogenated distillate oil is heated in furnace I before entering coke tower coke A. The outlet temperature of furnace I is 485℃, the residence time of the hydrogenated distillate oil in the furnace tubes of furnace I is 6 minutes, and the coke tower pressure is 0.65 MPa. The non-hydrogenated distillate oil has the following properties: PDQI value 5.0, sulfur content 0.25%, 5% distillation point temperature 352℃, 95% distillation point temperature 468℃, and solid content 53 μg / g. The non-hydrogenated distillate oil is heated in furnace II before entering coke tower coke A. The outlet temperature of furnace II is 470℃, and the coke tower pressure is 0.65 MPa. The properties of the coking wax oil separated from the coking fractionation tower are as follows: PDQI value 2.8, sulfur content 0.26%, 5% distillation point temperature 310℃, 95% distillation point temperature 430℃, and solid content 40μg / g. The coking wax oil is heated in heater II before entering coke tower A. The outlet temperature of heater II is 510℃, and the pressure of the coke tower is 0.30MPa. The total charging time T for coking tower A alone, including hydrotreated distillate oil, non-hydrotreated distillate oil, and coking wax oil, is 36h. The charging time for hydrotreated distillate oil accounts for 25% of the total time, for non-hydrotreated distillate oil 60%, and for coking wax oil 15%.

[0066] The properties of the needle coke product obtained by using hydrogenated distillate oil, non-hydrogenated distillate oil, and coking wax oil in a single coke tower with a mass ratio of 1:1:0.5 are shown in Table 3.

[0067] Comparative Example 1

[0068] The same raw materials as in Example 1 were used, but the process of feeding non-hydrogenated distillate oil into the coke tower was cancelled. Hydrogenated distillate oil replaced non-hydrogenated distillate oil to complete the coking stage 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.

[0069] Example 1-1 (set as an example)

[0070] The same raw materials as in Example 1 were used, but the residence time of the hydrotreated distillate oil in the furnace tube of furnace I was set to 40s according to conventional coking conditions. All other conditions were exactly the same as in Example 1. The properties of the obtained needle coke product are shown in Table 3.

[0071] Table 1 Properties of Catalytic Slurry Oil from a Refinery

[0072]

[0073]

[0074] Table 2 Hydrogenation Process Conditions

[0075] 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

[0076] Table 3 Properties of needle coke produced in the examples and comparative examples

[0077] project Example 1 Comparative Example 1 Example 1-1 Specific capacity, mAh / g 356.2 344.3 352.1 Volatile matter, w% 5.98 8.95 10.41 Ash content, w% 0.02 0.02 0.02 Sulfur content, w% 0.36 0.42 0.36 <![CDATA[True density, g / cm 3 > 1.45 1.40 1.44

[0078] Example 2

[0079] 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.

[0080] The fresh feedstock, after passing through a hydrogenation unit, yields a hydrogenated distillate oil with the following properties: PDQI value 9.2, sulfur content 0.20%, 5% distillation point temperature 386℃, 95% distillation point temperature 498℃, and solid content 85 μg / g. The hydrogenated distillate oil is heated in furnace I before entering coke tower coke A. The outlet temperature of furnace I is 505℃, the residence time of the hydrogenated distillate oil in the furnace tubes of furnace I is 10 min, and the coke tower pressure is 1.0 MPa. The non-hydrogenated distillate oil has the following properties: PDQI value 4.2, sulfur content 0.41%, 5% distillation point temperature 365℃, 95% distillation point temperature 482℃, and solid content 25 μg / g. The non-hydrogenated distillate oil is heated in furnace II before entering coke tower coke A. The outlet temperature of furnace II is 490℃, and the coke tower pressure is 0.90 MPa. The properties of the coking wax oil separated from the coking fractionation tower are as follows: PDQI value 2.2, sulfur content 0.25%, 5% distillation point temperature 286℃, 95% distillation point temperature 441℃, and solid content 32μg / g. The coking wax oil is heated in heater II before entering coke tower A. The outlet temperature of heater II is 465℃, and the coke tower pressure is 0.40MPa. The total charging time T for coking tower A alone, consisting of hydrotreated distillate oil, non-hydrotreated distillate oil, and coking wax oil, is 42h. Hydrotreated distillate oil accounts for 40% of the total charging time, non-hydrotreated distillate oil accounts for 35%, and coking wax oil accounts for 25%. The mass ratio of hydrotreated distillate oil, non-hydrotreated distillate oil, and coking wax oil to the single coking tower is 1:0.6:0.3. The properties of the obtained needle coke product are shown in Table 6.

[0081] Table 4 Properties of Catalytic Slurry Oil from a Refinery

[0082] Analysis Project Catalytic slurry <![CDATA[Density g / cm 3 > 1.0368 Solid content μg / g 98 C%(w) 89.96 H%(w) 8.56 S%(w) 1.26 N% (w) 0.22 Four components % (w) Saturated portion 15.62 Aromatic components 80.47 gelatinous 3.65 Asphalt 0.26

[0083] Table 5 Hydrogenation Process Conditions

[0084] 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

[0085] Table 6. Properties of needle coke in the examples

[0086]

[0087]

[0088] Example 3

[0089] 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.

[0090] The properties of the hydrotreated distillate oil obtained from the fresh feedstock after passing through the hydrotreating unit are as follows: PDQI value 7.2, sulfur content 0.41%, 5% distillation point temperature 393℃, 95% distillation point temperature 520℃, and solid content 56μg / g. The hydrotreated distillate oil is heated in furnace I and then enters the coke tower (coke A). The outlet temperature of furnace I is 525℃, the residence time of the hydrotreated distillate oil in the furnace tubes of furnace I is 20 min, and the coke tower pressure is 0.8 MPa. The properties of the non-hydrotreated distillate oil are as follows: PDQI value 3.5, sulfur content 0.26%, 5% distillation point temperature 359℃, 95% distillation point temperature 492℃, and solid content 36μg / g. The non-hydrotreated distillate oil is heated in furnace II and then enters the coke tower (coke A). The outlet temperature of furnace II is 510℃, and the coke tower pressure is 0.60 MPa. 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℃, and solid content 29μg / g. The coking wax oil is heated in heater II before entering coke tower A. The outlet temperature of heater II is 520℃, and the pressure of the coke tower is 0.20MPa. The total charging time T for coking tower A (hydrogenated distillate oil, non-hydrogenated distillate oil, and coking wax oil) is 50h. Hydrogenated distillate oil accounts for 45% of the total charging time, non-hydrogenated distillate oil accounts for 30%, and coking wax oil accounts for 25%. The mass ratio of hydrogenated distillate oil, non-hydrogenated distillate oil, and coking wax oil to the single coking tower is 1:0.7:0.3. The properties of the obtained needle coke product are shown in Table 9.

[0091] Table 7 Properties of Catalytic Slurry Oil from a Refinery

[0092]

[0093]

[0094] Table 8 Hydrogenation Process Conditions

[0095] project Operating conditions raw material Fresh ingredients Hydrogen partial pressure, MPa 7.0 Reaction temperature, °C 330 <![CDATA[Space velocity, h -1 > 1.0 Hydrogen-to-oil ratio 1000

[0096] Table 9 Properties of needle coke in the examples

[0097] project Example 3 Specific capacity, mAh / g 356.3 Volatile matter, w% 5.12 Ash content, w% 0.01 Sulfur content, w% 0.39 <![CDATA[True density, g / cm 3 > 1.45

Claims

1. A method for producing needle coke as a negative electrode material, characterized in that: The method includes the following coking process of any coke tower J: First, raw material A is heated in a heater and then introduced into coke tower J. After a period of time, the introduction of raw material A into coke tower J is stopped. Then, raw material B, which has been heated in a heater, is introduced into coke tower J. After a period of time, the introduction of raw material B into coke tower J is stopped. Finally, raw material C, which has been heated in a heater, is introduced into coke tower J. After a period of time, the introduction of raw material C into coke tower J is stopped. Among them, the PDQI value of raw material A is 5-40, and the PDQI value of raw material B is 1-20 lower than that of raw material A; The raw material has a sulfur content of 0-1.0% by mass; the 5% distillation temperature is 250℃-380℃, and the 95% distillation temperature is 350℃-520℃. Among them, raw material A is a hydrogenated raw material, raw material B is a non-hydrogenated raw material, and raw material C is coking wax oil; The outlet temperature of the raw material A heating furnace is 450℃-580℃; the outlet temperature of the raw material B heating furnace is 5-80℃ lower than that of the raw material A heating furnace. The residence time of raw material A in the furnace tube is 1 min to 100 min, and the residence time of raw material B in the furnace tube is 1 min to 90 min less than that of raw material A.

2. The method according to claim 1, characterized in that: The PDQI value of raw material A is 7-30, and the PDQI value of raw material B is 2-10 lower than that of raw material A; The raw material has a sulfur content of 0-0.5% by mass; the 5% distillation temperature is 280℃-360℃, and the 95% distillation temperature is 350℃-460℃.

3. The method according to claim 1, characterized in that: The PDQI value of raw material B is 3-7 lower than that of raw material A.

4. The method according to claim 1, characterized in that: The sulfur content of the raw material A is ≤1.0%; the 5% distillation temperature is 350℃-430℃, and the 95% distillation temperature is 450℃-550℃.

5. The method according to claim 4, characterized in that: The sulfur content of the raw material A is 0-0.5%; the 5% distillation temperature is 360℃-400℃, and the 95% distillation temperature is 480℃-530℃.

6. The method according to claim 1, characterized in that: The raw material B has a solid content of 0-500µg / g and a sulfur content of 0-1.0%; the 5% distillation temperature is 340℃-400℃, and the 95% distillation temperature is 440℃-540℃.

7. The method according to claim 6, characterized in that: The raw material B has a solid content of 0-200 µg / g and a sulfur content of 0-0.5%; the 5% distillation temperature is 350℃-380℃, and the 95% distillation temperature is 460℃-500℃.

8. The method according to claim 6, characterized in that: The solid content of raw material B is 0-100µg / g.

9. The method according to claim 1, characterized in that: Raw material A is obtained by hydrogenating fresh raw material, wherein the fresh raw material is selected from at least one of coal-based raw materials and petroleum-based raw materials.

10. The method according to claim 9, characterized in that: The fresh feedstock 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; the solid content of the fresh feedstock is 0-500 µg / g, and the sulfur content is greater than 0.3% by mass.

11. The method according to claim 10, characterized in that: The fresh raw materials have a solid content of 0-200 µg / g and a sulfur content of 0.5%-5.0% by mass.

12. The method according to claim 10, characterized in that: The fresh raw materials have a solid content of 0-100 µg / g and a sulfur content of 0.5%-3.0% by mass.

13. The method according to claim 10, characterized in that: The sulfur content of the fresh raw materials is 1.5%-2.5% by mass.

14. The method according to claim 1, characterized in that: Raw material B is a low-sulfur raw material with a sulfur content of 0-1.0% by mass.

15. The method according to claim 14, characterized in that: Raw material B is a low-sulfur raw material with a sulfur content of 0-0.5% by mass.

16. The method according to claim 14 or 15, characterized in that: The low-sulfur raw material is selected from at least one of coal-based and petroleum-based raw materials.

17. The method according to claim 16, characterized in that: The low-sulfur feedstock 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.

18. The method according to claim 1, characterized in that: The total introduction time of raw materials A, B, and C into a single coke tower is T, where T ranges from 24 to 72 hours.

19. The method according to claim 18, characterized in that: The T range is 36-56h.

20. The method according to claim 1, characterized in that: The outlet temperature of the furnace for raw material A is 460℃-550℃; the outlet temperature of the furnace for raw material B is 10-50℃ lower than that of the furnace for raw material A.

21. The method according to claim 1, characterized in that: The residence time of raw material A in the furnace tube is 5 min-30 min, and the residence time of raw material B in the furnace tube is 2 min-20 min less than that of raw material A.

22. The method according to claim 21, characterized in that: The residence time of raw material B in the furnace tubes is 5-10 minutes less than that of raw material A.

23. The method according to claim 1, characterized in that: In the coking tower, the introduction time of raw material A accounts for 20%-60% of the total introduction time T; the introduction time of raw material B accounts for 30%-80% of the total introduction time T; and the introduction time of raw material C accounts for 10%-50% of the total introduction time T.

24. The method according to claim 23, characterized in that: The introduction time of raw material A in the coke tower accounts for 30-50% of the total introduction time T; the introduction time of raw material B accounts for 30-50% of the total introduction time T; and the introduction time of raw material C accounts for 10-40% of the total introduction time T.

25. The method according to claim 1, characterized in that: The mass ratio of raw material A, raw material B, and raw material C to the charge of a single coke tower is 1:0.5-2.0:0.2-1.

5.

26. The method according to claim 1, characterized in that: The coke tower is configured as one or more.

27. The method according to claim 1, characterized in that: The coke towers are configured to be two or more.

28. The method according to claim 1, characterized in that: The heating furnace can be set to one or more.

29. The method according to claim 28, characterized in that: The heating furnace is set to have two or more units.

30. The method according to claim 1, characterized in that: After stopping the introduction of raw material C into coke tower J, 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.

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