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CN-118620641-B - Production method for improving strength of needle coke particles

CN118620641BCN 118620641 BCN118620641 BCN 118620641BCN-118620641-B

Abstract

The invention discloses a production method for improving the strength of needle coke particles, which comprises the following steps of (1) obtaining hydrogenated distillate oil from a high-sulfur raw material A through hydrotreatment, (2) introducing the hydrogenated distillate oil into a coke tower to charge coke after heating by a heating furnace, (3) continuously switching the coke charging process of step (2) into a low-sulfur raw material B for a period of time to continuously charge the coke tower, (4) carrying out a wax oil charging process after the coke charging of the low-sulfur raw material B is finished, and (5) carrying out a wax oil charging and coking end decoking process, wherein the sulfur content of the high-sulfur raw material A is higher than 1.0%, preferably higher than 0.8, more preferably 0.5-0.8%, and the sulfur content of the low-sulfur raw material B is lower than 0.5, preferably lower than 0.4, further preferably lower than 0.3%. The needle coke prepared by the method has the advantages of high particle strength, low thermal expansion coefficient and the like.

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 method of producing an enhanced needle coke particle strength, the method comprising the steps of: (1) The high-sulfur raw material A is hydrotreated to obtain hydrogenated distillate; (2) Heating the hydrogenated distillate oil by a heating furnace, and introducing the heated distillate oil into a coke tower for coke charging; (3) The coke charging process in the step (2) is switched to the low-sulfur raw material B to continuously charge the coke tower after a period of time; (4) After the low-sulfur raw material B is subjected to coke charging, carrying out wax oil coke charging; (5) Wax oil is filled with coke and is formed to carry out a decoking process; wherein the sulfur content of the high-sulfur raw material A is higher than 0.8 percent, and the sulfur content of the low-sulfur raw material B is lower than 0.5 percent; the low sulfur feedstock B is selected from fresh feedstock obtained without hydrotreating; The outlet temperature of the heating furnace in the step (2) is 400-580 ℃; the outlet temperature of the heating furnace in the step (3) is 5-50 ℃ lower than that of the heating furnace in the step (2).
  2. 2. The method of claim 1, wherein the low sulfur feedstock B has a sulfur content of less than 0.4%.
  3. 3. The method of claim 1, wherein the low sulfur feedstock B has a sulfur content of less than 0.3%.
  4. 4. The method according to claim 1, wherein the high sulfur feedstock A is at least one selected from the group consisting of a coal-based feedstock and a petroleum-based feedstock having a high sulfur content.
  5. 5. The method according to claim 4, wherein the high sulfur feedstock A 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.
  6. 6. The method according to claim 1, wherein the low sulfur feedstock B is at least one selected from the group consisting of a coal-based feedstock and a petroleum-based feedstock having a low sulfur content.
  7. 7. The method according to claim 6, wherein the low sulfur feedstock B 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.
  8. 8. The method according to claim 1, wherein the high sulfur feedstock A has the following properties, i.e., a solids content of 0-500. Mu.g/g.
  9. 9. The method according to claim 8, wherein the high sulfur feedstock A has the following properties, i.e., a solids content of 0-200. Mu.g/g.
  10. 10. The method according to claim 8, wherein the high sulfur feedstock A has the following properties, i.e., a solids content of 0-50. Mu.g/g.
  11. 11. The method according to claim 1, wherein the 5% distillation temperature of the high sulfur feedstock A is 360-430 ℃ and the 95% distillation temperature is 460-550 ℃.
  12. 12. The method according to claim 11, wherein the 5% distillation temperature of the high sulfur feedstock A is 380 ℃ to 430 ℃ and the 95% distillation temperature is 490 ℃ to 520 ℃.
  13. 13. The method according to claim 1, wherein the low sulfur feedstock B has the properties of a 5% distillation temperature of 350-430 ℃, a 95% distillation temperature of 430-520 ℃ and a solids content of 0-200 μg/g.
  14. 14. The method according to claim 13, wherein the low sulfur feedstock B has the properties of a 5% distillation temperature of 360-400 ℃, a 95% distillation temperature of 450-500 ℃ and a solid content of 0-100 μg/g.
  15. 15. A process according to claim 1, wherein the high sulfur feedstock A has a sulfur content of 0.1 to 1.5 wt.% higher than the low sulfur feedstock B.
  16. 16. The method of claim 15, wherein the sulfur content of the high sulfur feedstock A is 0.2 to 1.0wt% higher than the sulfur content of the low sulfur feedstock B.
  17. 17. The process of claim 1, wherein the hydrogenated fraction oil obtained in step (1) has a 5% distillation temperature of 350 to 450℃and a 95% distillation temperature of 450 to 550 ℃.
  18. 18. The method according to claim 17, wherein the hydrogenated distillate in step (1) has a 5% distillation temperature of 370-410℃and a 95% distillation temperature of 480-500 ℃.
  19. 19. The method of claim 1, wherein the furnace outlet temperature in step (2) is from 450 ℃ to 550 ℃.
  20. 20. The method of claim 19, wherein the furnace outlet temperature in step (2) is 480 ℃ to 520 ℃.

Description

Production method for improving strength of needle coke particles Technical Field The invention belongs to the field of needle coke production, relates to a production method for improving the particle strength of needle coke, and in particular relates to a method for producing high-particle-strength needle coke by adopting petroleum or coal raw materials. Background The needle coke is a solid carbon material with metallic luster, has obvious needle texture structure when observed under a polarizing microscope, and is widely used in the fields of high-performance graphite electrode materials, lithium ion batteries, electrochemical capacitors and the like due to the characteristics of high mechanical strength, high true density, low thermal expansion coefficient and the like. US5286371 discloses a straight-run residuum hydrotreating process, wherein the hydrogenation reaction temperature is 379-480 ℃, the reaction pressure is 6.8-34.4 MPa, 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. 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. 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. CN202011165491.7 discloses a method for preparing needle coke, wherein the mixed feed of raw oil containing high aromatic hydrocarbon component and light distillate oil is heated by a heating unit, and the heated material enters a coke tower to react to produce oil gas and needle coke. US4894144 discloses a method for simultaneously preparing needle coke and high-sulfur petroleum coke, which adopts a hydrotreating process to pretreat straight-run heavy oil, and the hydrogenated residual oil is divided into two parts, and is subjected to coking and then satin firing to prepare the needle coke and the high-sulfur petroleum coke. Needle coke particle strength is one of the important indicators of needle coke performance. In the prior art, few reports on how to improve the particle strength of needle coke are provided, and the particle strength of the needle coke obtained by the existing preparation method still needs to be further improved. Disclosure of Invention Aiming at the defects of the prior art, the invention discloses a production method for improving the particle strength of needle coke, and the needle coke prepared by the method has the advantages of high particle strength, low thermal expansion coefficient and the like. A method of producing an enhanced needle coke particle strength, the method comprising the steps of: (1) The high-sulfur raw material A is hydrotreated to obtain hydrogenated distillate; (2) Heating the hydrogenated distillate oil by a heating furnace, and introducing the heated distillate oil into a coke tower for coke charging; (3) The coke charging process in the step (2) is switched to the low-sulfur raw material B to continuously charge the coke tower after a period of time; (4) After the low-sulfur raw material B is subjected to coke charging, carrying out wax oil coke charging; (5) Wax oil is filled with coke and is formed to carry out a decoking process; wherein the sulfur content of the high sulfur raw material A is higher than 1.0%, preferably higher than 0.8%, more preferably 0.5-0.8%, and the sulfur content of the low sulfur raw material B is lower than 0.5%, preferably lower than 0.4%, more preferably lower than 0.3%. In the above process, the low sulfur feedstock B may be selected from the feedstock obtained after hydrotreating, or may be selected from the fresh feedstock obtained without hydrotreating, preferably the latter. In the above method, the high sulfur feedstock a is at least one selected from a coal-based feedstock and a petroleum-based feedstock having a high sulfur conte