Search

CN-118620647-B - Method for producing needle coke of negative electrode material

CN118620647BCN 118620647 BCN118620647 BCN 118620647BCN-118620647-B

Abstract

The invention discloses a production method of needle coke of a negative electrode material, which comprises the following steps of introducing a raw material A into a coke tower J after being heated by a heating furnace, stopping introducing the raw material A into the coke tower J after a period of time, introducing a raw material B into the coke tower J after being heated by the heating furnace after a period of time, stopping introducing the raw material B into the coke tower J after a period of time, and finally introducing a raw material C into the coke tower J after being heated by the heating furnace after a period of time, stopping introducing the raw material C into the coke tower J, wherein the PDQI value of the raw material A is 5-40, preferably 7-30, the PDQI value of the raw material B is lower than that of the raw material A by 1-20, preferably 2-10, and further preferably 3-7. The method can produce the needle coke with high specific capacity of the first discharge cathode material.

Inventors

  • WU YUN
  • CHU RENQING
  • GUO DAN
  • GOU LIANZHONG
  • 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. The method for producing the needle coke of the cathode material is characterized in that the coking process of any coke tower J comprises the steps of firstly introducing a raw material A into the coke tower J after being heated by a heating furnace, stopping introducing the raw material A into the coke tower J after a period of time, then introducing a raw material B into the coke tower J after being heated by the heating furnace, stopping introducing the raw material B into the coke tower J after a period of time, and finally introducing a raw material C into the coke tower J after being heated by the heating furnace, and stopping introducing the raw material C into the coke tower J after a period of time; Wherein, the PDQI value of the raw material A is 5-40, and the PDQI value of the raw material B is 1-20 lower than that of the raw material A; the sulfur content of the raw material C is 0-1.0%, the distillation temperature of 5% is 250-380 ℃, and the distillation temperature of 95% is 350-520 ℃; Wherein, the raw material A is hydrogenation raw material, the raw material B is non-hydrogenation raw material, and the raw material C is coked wax oil; The outlet temperature of the raw material A heating furnace is 450-580 ℃, and 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 the raw material A in the heating furnace tube is 1min-100min, and the residence time of the raw material B in the heating furnace tube is 1min-90min less than the residence time of the raw material A in the heating furnace tube.
  2. 2. The method of claim 1, wherein feedstock A has a PDQI value of 7 to 30 and feedstock B has a PDQI value 2 to 10 lower than feedstock A; The sulfur content of the raw material C is 0-0.5%, the distillation temperature of 5% is 280-360 ℃, and the distillation temperature of 95% is 350-460 ℃.
  3. 3. The method of claim 1, wherein feedstock B has a PDQI value 3 to 7 lower than feedstock A.
  4. 4. The method of claim 1, wherein the sulfur content of the raw material A is not more than 1.0%, the 5% distillation temperature is 350-430 ℃, and the 95% distillation temperature is 450-550 ℃.
  5. 5. The process according to claim 4, wherein the sulfur content of the raw material A is 0 to 0.5%, the 5% distillation temperature is 360 to 400℃and the 95% distillation temperature is 480 to 530 ℃.
  6. 6. The process according to claim 1, wherein the feedstock B has a solids content of 0 to 500. Mu.g/g, a sulfur content of 0 to 1.0%, a 5% distillation temperature of 340 to 400℃and a 95% distillation temperature of 440 to 540 ℃.
  7. 7. The process according to claim 6, wherein the feedstock B has a solids content of 0-200. Mu.g/g, a sulfur content of 0-0.5%, a 5% distillation temperature of 350-380 ℃ and a 95% distillation temperature of 460-500 ℃.
  8. 8. The method according to claim 6, wherein the solid content of the raw material B is 0-100. Mu.g/g.
  9. 9. The method according to claim 1, wherein the raw material A is obtained by hydrotreating a fresh raw material selected from at least one of a coal-based raw material and a petroleum-based raw material.
  10. 10. The method according to claim 9, wherein the fresh raw material is at least one selected from coal tar, coal tar pitch, petroleum heavy oil, ethylene tar, catalytic cracking slurry oil or thermal cracking residual oil, and the solid content of the fresh raw material is 0-500 mug/g, and the sulfur mass content is more than 0.3%.
  11. 11. The method of claim 10, wherein the fresh raw material has a solid content of 0-200 μg/g and a sulfur mass content of 0.5% -5.0%.
  12. 12. The method of claim 10, wherein the fresh raw material has a solid content of 0-100 μg/g and a sulfur mass content of 0.5% -3.0%.
  13. 13. The method of claim 10, wherein the fresh raw material contains 1.5% -2.5% of sulfur by mass.
  14. 14. The method according to claim 1, wherein the raw material B is a low-sulfur raw material, and the mass content of sulfur is 0-1.0%.
  15. 15. The method according to claim 14, wherein the raw material B is a low-sulfur raw material, and the mass content of sulfur is 0-0.5%.
  16. 16. The method according to claim 14 or 15, wherein the low sulfur feedstock is at least one selected from the group consisting of coal-based feedstock and petroleum-based feedstock.
  17. 17. The method of claim 16, wherein the low sulfur feedstock 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.
  18. 18. The method of claim 1 wherein the total introduction time of feedstock A, feedstock B, feedstock C into a single coke drum is T, and T ranges from 24 hours to 72 hours.
  19. 19. The method of claim 18, wherein T ranges from 36 to 56 hours.
  20. 20. The method according to claim 1, wherein the outlet temperature of the heating furnace for the raw material A is 460-550 ℃, and the outlet temperature of the heating furnace for the raw material B is 10-50 ℃ lower than the outlet temperature of the heating furnace for the raw material A.

Description

Method for producing needle coke of 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, and main indexes of needle coke products are low thermal expansion coefficient and ordered structure. 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 aim of the needle coke is to achieve higher first discharge specific capacity of the needle coke product, the needle coke preparation process in the prior art is mostly designed for the purpose of producing graphite electrode needle coke, and if the needle coke is to be produced as the cathode material, the first discharge specific capacity is further required to be improved and optimized. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a production method of needle coke as a cathode material. The method can produce the needle coke with high specific capacity of the first discharge cathode material. The method for producing the needle coke of the cathode material comprises the following steps of introducing a raw material A into a coke tower J after being heated by a heating furnace, stopping introducing the raw material A into the coke tower J after a period of time, introducing a raw material B