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CN-118620645-B - Production method of needle coke as negative electrode material

CN118620645BCN 118620645 BCN118620645 BCN 118620645BCN-118620645-B

Abstract

The invention discloses a production method of needle coke of a cathode material, which comprises a coke charging stage and a coke pulling Jiao Jieduan, wherein the coke charging stage is a wide area intermediate phase stage formed by heat treatment of raw materials, the coke pulling stage is a micro ordering stage realized by carrying out airflow coke pulling on the wide area intermediate phase, two raw materials are respectively marked as a raw material 1 and a raw material 2 in the coke charging stage, the raw material 1 and the raw material 2 enter a coke tower in sequence in the same coke charging period, the feeding temperature of the raw material 1 is higher than the feeding temperature of the raw material 2, preferably by 5-80 ℃ and further preferably by 10-50 ℃, the feeding temperature is the temperature before the raw material 1 or the raw material 2 enters the coke tower after being heated by a heating furnace, the PDQI value of the raw material 1 is higher than the PDQI value of the raw material 2, preferably by 1-10 and further preferably by 2-6, and the PDQI value is hydrogen supply index. The invention discloses a production method of cathode material needle coke, which can produce the cathode material needle coke with high initial discharge specific capacity.

Inventors

  • CHU RENQING
  • HOU SHUANDI
  • GUO DAN
  • WU YUN
  • ZHANG YUANYUAN

Assignees

  • 中国石油化工股份有限公司
  • 中石化（大连）石油化工研究院有限公司

Dates

Publication Date
20260505
Application Date
20230308

Claims (20)

  1. 1. A production method of needle coke of a cathode material is characterized by comprising a coke charging stage and a drawing Jiao Jieduan, wherein the coke charging stage is a wide area mesophase stage formed by raw material heat treatment, the drawing stage is a micro ordering stage realized by carrying out airflow coke drawing on the wide area mesophase, wherein the two raw materials are respectively marked as a raw material 1 and a raw material 2 in the coke charging stage, the raw material 1 and the raw material 2 enter a coke tower in the same coke charging period in sequence, the feeding temperature of the raw material 1 is higher than the feeding temperature of the raw material 2, the feeding temperature is the temperature before the raw material 1 or the raw material 2 enters the coke tower after being heated by a heating furnace, the PDQI value of the raw material 1 is higher than the PDQI value of the raw material 2, and the PDQI value is a hydrogen supply index; The coke charging operation condition of the raw material 1 is that the outlet temperature of a heating furnace is 450-580 ℃, the pressure of a coke tower is 0.1-2.0MPa, the coke charging operation condition of the raw material 2 is that the outlet temperature of the heating furnace is 440-550 ℃, and the pressure of the coke tower is 0.1-2.0MPa; The outlet temperature of the heating furnace of the raw material 2 introduced into the coking device is 5-80 ℃ lower than that of the heating furnace of the raw material 1 introduced into the coking device; The raw material 1 is obtained by hydrotreating a fresh raw material, and the raw material 2 is a low-sulfur and low-nitrogen raw material which is not hydrotreated.
  2. 2. The method according to claim 1, wherein the feed temperature of feed 1 is 5-80 ℃ higher than the feed temperature of feed 2, and the PDQI value of feed 1 is 1-10 higher than the PDQI value of feed 2.
  3. 3. The method according to claim 1, wherein the feed temperature of feed 1 is 10-50deg.C higher than the feed temperature of feed 2, and the PDQI value of feed 1 is 2-6 higher than the PDQI value of feed 2.
  4. 4. The method according to claim 1, wherein the feedstock 1 has a property of PDQI to 40, a sulfur content of not more than 1.0wt%, a 5% distillation temperature of 350 to 430 ℃ and a 95% distillation temperature of 450 to 550 ℃.
  5. 5. The method according to claim 4, wherein the feedstock 1 has a property of PDQI having a value of 7 to 30 and a sulfur content of 0 to 0.5wt%, a 5% distillation temperature of 360 to 400 ℃ and a 95% distillation temperature of 480 to 530 ℃.
  6. 6. The method according to claim 1, wherein the feedstock 2 has a property of PDQI% distillation temperature of 340-400 ℃ and 95% distillation temperature of 440-540 ℃ and sulfur content of not more than 1.0wt%.
  7. 7. The method according to claim 6, wherein the feedstock 2 has a 5% distillation temperature of 350 to 380 ℃, a 95% distillation temperature of 460 to 500 ℃ and a sulfur content of 0 to 0.5wt%.
  8. 8. The method of claim 1, wherein the total time for the raw material 1 and the raw material 2 in the coke charging stage is T, the range of T is 24-72h, the coke charging time of the raw material 1 is 30-60% of the total time, the coke charging time of the raw material 2 is 30-80% of the total time, and the time for the coke charging stage is 10-50% of the total time.
  9. 9. The method of claim 8, wherein the total time for the raw material 1 and the raw material 2 in the coke charging stage is T, the range of T is 36-56h, the coke charging time of the raw material 1 is 30-50% of the total time, the coke charging time of the raw material 2 is 30-50% of the total time, and the time for the coke charging stage is 10-40% of the total time.
  10. 10. The method according to claim 1, wherein the charging operation condition of the raw material 1 is that the outlet temperature of the heating furnace is 460-550 ℃, the pressure of the coke tower is 0.5-1.0MPa, the outlet temperature of the heating furnace is 450-530 ℃ and the pressure of the coke tower is 0.5-1.0MPa.
  11. 11. The method of claim 1 wherein the temperature at the outlet of the furnace from which feedstock 2 is introduced into the coker is 10-50 ℃ lower than the temperature at the outlet of the furnace from which feedstock 1 is introduced into the coker.
  12. 12. The method according to claim 1, wherein the fresh raw material or the raw material 2 is at least one selected from the group consisting of a coal-based raw material and a petroleum-based raw material.
  13. 13. The method of claim 12, wherein the fresh feedstock, feedstock 2, is at least one selected from the group consisting of coal tar, coal tar pitch, petroleum heavy oil, ethylene tar, catalytic cracking slurry oil and thermal cracking residuum.
  14. 14. The method according to claim 1, comprising the following steps: (1) The fresh raw material enters a hydrogenation fractionating tower after passing through a hydrogenation treatment device, and at least raw material 1-hydrogenation distillate is separated; (2) Heating the raw material 1 in the step (1) by a heating furnace, charging the raw material into a coke tower for coke charging, discharging oil gas generated by the reaction from the top of the coke tower, and charging the oil gas into a coking fractionating tower to at least separate coking wax oil fraction; (3) Switching the raw material 1 in the step (2) into the raw material 2 to continuously charge the coke in the coke tower; (4) And (3) switching the raw material 2 in the step (2) into the coker wax oil fraction for carrying out coke pulling on the coker, wherein the coker wax oil fraction is used for carrying out small blowing, large blowing and decoking operations on the coker after the coke pulling is finished, and the needle coke product is discharged from the bottom of the tower.
  15. 15. The method according to claim 14, wherein the fresh raw material in the step (1) is at least one selected from the group consisting of a coal-based raw material and a petroleum-based raw material.
  16. 16. The method according to claim 15, wherein the fresh raw material in the step (1) is at least one selected from the group consisting of coal tar, coal tar pitch, petroleum heavy oil, ethylene tar, catalytic cracking slurry oil and thermal cracking residual oil.
  17. 17. The method of claim 14, wherein the fresh feed in step (1) has a solids content of 0-500. Mu.g/g.
  18. 18. The method of claim 17, wherein the fresh feed in step (1) has a solids content of 0-200. Mu.g/g.
  19. 19. The method of claim 17, wherein the fresh feed in step (1) has a solids content of 0-100. Mu.g/g.
  20. 20. The process of claim 14 wherein feedstock 1 in step (1) has a PDQI value of no less than 7, a sulfur content of no more than 1.0%, a 5% distillation temperature of from 350 ℃ to 430 ℃ and a 95% distillation temperature of from 450 ℃ to 550 ℃.

Description

Production method of needle coke as negative electrode material Technical Field The invention relates to a production method of cathode material needle coke, in particular to a method for producing the cathode material needle coke by adopting petroleum or coal raw materials. Background Needle coke is an excellent carbon product, has obvious streamline texture structure when seen from the outside, and is a main raw material for manufacturing the ultra-high power graphite electrode for steelmaking due to good electric conductivity, orientation and heat conduction performance. The ultra-high power electrode is adopted for steelmaking, the smelting time can be shortened by about 2/3, the electricity consumption can be reduced by about 50%, and the economic benefit is obvious. With the rapid development of new energy automobiles in recent years, the requirements of power batteries are greatly increased, the negative electrode materials of lithium batteries are divided into carbon materials and non-carbon materials, the carbon materials mainly comprise artificial graphite materials, and the artificial graphite negative electrode materials produced by needle coke have excellent graphitization degree and first discharge specific capacity index, so that the negative electrode materials are widely applied to high-end graphite negative electrode material products. CN202011305509.9 discloses a method and a process system for producing needle coke by using heavy oil, wherein the method comprises a component cutting process, a hydrogenation process, a mixing process and a delayed coking process, wherein the heavy oil is used as a raw material and is cut into light distillate, heavy distillate and tailings, the heavy distillate is subjected to hydrogenation treatment to obtain hydrogenation heavy distillate, the hydrogenation heavy distillate is mixed with the light distillate to obtain mixed oil, and the mixed oil is subjected to delayed coking treatment to obtain the needle coke. US4894144 discloses a method for preparing needle coke and high sulfur petroleum coke simultaneously, which adopts a hydrotreating process to pretreat straight-run heavy oil, the hydrogenated residual oil is divided into two parts, and the two parts are respectively coked and then satin fired to prepare the needle coke and the high sulfur petroleum coke US5286371 also discloses a straight-run residuum hydrotreating process, wherein the hydrogenation reaction temperature is 379-480 ℃, the reaction pressure is 6.8MPa-34.4MPa, the treated heavy residuum and the catalytically cracked clear oil are mixed and enter a solvent deasphalting device, and the material flow after asphalt removal is used as the raw material of needle coke. US4178229 discloses a method for producing high quality petroleum coke from straight-run vacuum residuum by converting the vacuum residuum into distillate oil and asphalt, and further cracking the asphalt and hydrogen donor to produce raw materials of high quality coke. The invention discloses a method for preparing needle coke for ultra-high power electrode by using heavy oil, which comprises the steps of taking heavy oil as a raw material, adopting a size exclusion separation method, taking polystyrene as a packing of a separation column, separating out components with specific molecular volume with relative molecular mass distribution of 400-1000, respectively removing acidic components and alkaline components in the components by ion exchange chromatography to obtain neutral raw materials, and preparing the needle coke by two sections of continuous carbonization processes of the treated raw materials. Before 2017, needle coke is mainly used as graphite electrode aggregate to produce HP and UHP graphite electrodes, the main indexes pursued by needle coke products are low thermal expansion coefficients and ordered structures, along with the rapid development of the electric automobile industry in recent years, the needle coke is widely applied to the lithium ion battery cathode material industry, the pursued goal is that the needle coke products have higher first discharge specific capacity, the needle coke preparation process in the prior art is mostly designed for the purpose of producing graphite electrode needle coke, and the first discharge specific capacity needs to be further improved and optimized if the needle coke is required to be produced as the cathode material. Disclosure of Invention Aiming at the defects of the prior art, the invention discloses a production method of cathode material needle coke, which can produce the cathode material needle coke with high initial discharge specific capacity. The method comprises a charging stage and a pulling Jiao Jieduan, wherein the charging stage is a stage of forming a wide area intermediate phase by heat treatment of raw materials, the pulling stage is a stage of carrying out airflow pulling on the wide area intermediate phase to realize microscopic ordering, two r