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CN-117778041-B - Production method and production system of mesophase carbon microsphere

CN117778041BCN 117778041 BCN117778041 BCN 117778041BCN-117778041-B

Abstract

The invention discloses a production method and a production system of mesophase carbon microspheres, wherein the production method comprises the steps of carrying out hydrogenation reaction on purified catalytic slurry oil, separating the reaction to obtain light fraction, middle fraction and tail oil, dividing the middle fraction into two parts, carrying out cracking reaction on the first part, carrying out circulating treatment on cracked products, carrying out first heat treatment on the second part, crushing the first heat treated products to obtain solid-phase first material flow, carrying out second heat treatment on the first solvent and silicone oil, centrifuging, washing and drying the obtained reaction products to obtain the mesophase carbon microspheres. The production system comprises a purification unit, a hydrogenation reaction unit, a gas-liquid separation unit, a fractionation unit, a cracking reaction unit, a first heat treatment unit and a second heat treatment unit. The method and the system provide the optimized direction for preparing the intermediate phase carbon microsphere raw material, and obtain the high-quality intermediate phase asphalt raw material and intermediate phase carbon microsphere products.

Inventors

  • SONG YONGYI
  • JIAO DEWEI
  • CHU RENQING
  • GUO DAN
  • WU YUN

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
20220920

Claims (20)

  1. 1. A method for producing mesophase carbon microbeads, said method comprising the following: (1) In the presence of hydrogen, the catalytic slurry oil enters a hydrogenation unit to be contacted with a hydrogenation catalyst for hydrogenation reaction, a gas phase material flow and a liquid phase material flow are obtained after the hydrogenation reaction effluent is separated, and a light fraction, a middle fraction and tail oil are obtained after the liquid phase material flow is separated, wherein the 5% distillation temperature of the middle fraction is 360-430 ℃ and the 95% distillation temperature is 440-500 ℃; (2) The middle distillate obtained in the step (1) is further divided into a first stream and a second stream, wherein the first stream enters a cracking unit for cracking reaction, and a cracked reaction product is recycled and treated together with the liquid-phase stream obtained in the step (1), and the operation condition of the cracking unit is controlled as follows, the reaction pressure is 0.1-5 MPa, the reaction temperature is 380-520 ℃, and the residence time is 0.01-30 h; (3) The second stream obtained in the step (2) enters a first heat treatment unit, and is subjected to first heat treatment in the presence of inert atmosphere, and a solid-phase first stream is obtained after the first heat treatment product is crushed; (4) And (3) feeding the solid-phase first material flow, the first solvent and the silicone oil obtained in the step (3) into a second heat treatment unit, uniformly mixing, performing second heat treatment, cooling, and separating, washing and drying to obtain the mesophase carbon microsphere.
  2. 2. The method of producing mesophase carbon microbeads according to claim 1, wherein the catalytic slurry ash content in step (1) is not more than 0.08wt%.
  3. 3. The method of producing mesophase carbon microbeads according to claim 1, wherein the catalytic slurry ash content in step (1) is not more than 0.05wt%.
  4. 4. The method for producing the mesophase carbon microbeads according to claim 1, wherein the catalytic slurry oil is subjected to impurity removal and solid removal treatment, and one or more of filtration, centrifugal sedimentation, flocculation sedimentation and reduced pressure distillation are adopted.
  5. 5. The method for producing the mesophase carbon microbeads according to claim 1, wherein the catalytic slurry oil is subjected to impurity removal and solid removal treatment, and filtration is adopted.
  6. 6. The method for producing the mesophase carbon microsphere according to claim 1, wherein the operation condition of the hydrogenation unit in the step (1) is as follows, the reaction pressure is 2-20 MPa, the reaction temperature is 300-480 ℃, the hydrogen-oil volume ratio is 100-2500, and the liquid hourly space velocity is 0.1h -1 ～2.0h -1 .
  7. 7. The method for producing the mesophase carbon microsphere according to claim 1, wherein the operation condition of the hydrogenation unit in the step (1) is that the reaction pressure is 4-8 MPa, the reaction temperature is 330-390 ℃, the hydrogen-oil volume ratio is 500-1800, and the liquid hourly space velocity is 0.7h -1 ～1.2h -1 .
  8. 8. The method for producing mesophase carbon microbeads as claimed in claim 1, wherein the middle distillate in the step (1) has a 5% distillation temperature of 385 ℃ to 410 ℃ and a 95% distillation temperature of 455 ℃ to 475 ℃.
  9. 9. The method for producing mesophase carbon microbeads according to claim 1, wherein the light fraction obtained in the step (1) is fed into a condensation unit to react, or directly fed as a product outlet device, or partially fed into a condensation unit to react, and partially fed as a product outlet device.
  10. 10. The method for producing the mesophase carbon microbeads as claimed in claim 9, wherein the reaction conditions of the condensation unit are controlled to be that the reaction temperature is 350-550 ℃, the reaction pressure is 0.1-5 MPa, and the residence time is 0.01-50 h.
  11. 11. The method for producing the mesophase carbon microbeads according to claim 9, wherein the reaction conditions of the condensation unit are controlled to be 400-460 ℃, the reaction pressure is 0.8-3.0 MPa, and the residence time is 0.3-24 h.
  12. 12. The method for producing the mesophase carbon microbeads according to claim 9, wherein the reaction product obtained by the condensation reaction is separated to obtain top oil and bottom oil, the 5% distillation temperature of the bottom oil is controlled to be 300-420 ℃, the top oil is directly discharged out of the device or is mixed with catalytic slurry oil as a diluent to perform impurity removal and solid removal treatment, and the bottom oil is recycled to be separated together with the liquid phase stream obtained in the step (1).
  13. 13. The method for producing mesophase carbon microbeads according to claim 12, wherein the 5% distillation temperature of the base oil is controlled to be 330 ℃ to 370 ℃.
  14. 14. The method for producing mesophase carbon microbeads according to claim 9, wherein a condensation catalyst is added during the condensation reaction, the condensation reaction is carried out under the action of the condensation catalyst, the condensation catalyst comprises a carrier and an active component, wherein the carrier is one or more of kaolin, montmorillonite, alumina and siliceous alumina, the active component is at least one of oxides of metals of IVB group and/or VIB group, and the content of the active component is 0.1wt% to 50wt% based on the weight of the catalyst.
  15. 15. The method for producing mesophase carbon microbeads according to claim 14, wherein the carrier is alumina, and the content of the active component is 5wt% to 25wt% based on the weight of the catalyst.
  16. 16. The method for producing mesophase carbon microbeads, as claimed in claim 1, wherein the tail oil discharging apparatus in the step (1) is used as a raw material for producing low sulfur petroleum coke.
  17. 17. The method for producing the mesophase carbon microbeads as in claim 1, wherein the operation conditions of the cracking unit in the step (2) are controlled such that the reaction pressure is 0.2MPa to 1.0MPa, the reaction temperature is 420 ℃ to 490 ℃ and the residence time is 0.1h to 3h.
  18. 18. The method for producing the mesophase carbon microsphere is characterized in that carrier gas is introduced in the cracking reaction process, the carrier gas is one or more of water vapor, nitrogen and inert gas, and the mass ratio of the middle distillate to the carrier gas is 100:0.1-100:20.
  19. 19. The method for producing the mesophase carbon microsphere is characterized in that carrier gas is introduced in the cracking reaction process, the carrier gas is water vapor, and the mass ratio of the intermediate fraction to the carrier gas is 100:1-100:8.
  20. 20. The method for producing mesophase carbon microbeads as in claim 1, wherein the mass ratio of the second stream to the first stream in step (2) is 1:9-8:2.

Description

Production method and production system of mesophase carbon microsphere Technical Field The invention belongs to the field of carbon materials, and relates to a production method and a production system of mesophase carbon microspheres. Background The Japanese scholars in 1973 separated anisotropic pellets from the pitch matrix during the heat treatment of pitch for the first time and called mesophase carbon microspheres. The mesocarbon microbeads have good chemical stability, high bulk density, easy graphitization, good thermal stability, excellent electric conduction and thermal conduction and the like, are high-quality precursors for preparing high-performance carbon materials, and are of great interest to carbon workers, and are currently applied to developing high-density high-strength C/C composite materials, high-performance liquid chromatographic column materials, high-specific-surface-area active carbon materials, lithium ion battery anode materials and the like. CN1308113a discloses a copolycondensation preparation method of mesophase carbon microsphere, which uses medium-temperature coal tar pitch and secondary petroleum heavy oil with low quinoline insoluble matter as raw materials, and makes mixed heating copolycondensation reaction to obtain pitch product containing mesophase carbon microsphere, then adopts mixed liquor of coal tar and light fraction of petroleum to make hot melting and filtering, and uses organic solvent of toluene to make extraction so as to obtain the invented mesophase carbon microsphere. The method uses organic solvents such as toluene with high toxicity and the like as an extraction liquid, has high environmental hazard, and has low yield of only 20-30%. CN101920956A discloses a method for efficiently preparing asphalt-based mesophase carbon microspheres, which takes medium-temperature coal asphalt and high-temperature coal asphalt as raw materials and rosin as an additive, and comprises the specific processes of preparing the raw materials and the additive, preparing the asphalt-based carbon microspheres through raw material preparation, polymerization reaction, pyrolysis reaction, separation of pyrolysis products and drying, wherein the raw materials are one or two of the medium-temperature coal asphalt and the high-temperature coal asphalt, and the additive is one or two of rosin and disproportionated rosin. The catalytic slurry oil is rich in aromatic hydrocarbon and is a high-quality raw material for producing the intermediate-phase carbon microsphere, but ash and sulfur contained in the catalytic slurry oil are high in content, and generally, the catalytic slurry oil needs to be subjected to solid removal and desulfurization treatment, and the purified slurry oil can be used as the raw material for producing the intermediate-phase carbon microsphere. At present, the process for preparing the intermediate phase carbon microsphere by taking catalytic slurry oil as a raw material generally has the problems of low yield, difficult separation, requirement for using a large amount of toxic organic solvents, over-wide sphere diameter distribution of the obtained intermediate phase carbon microsphere product and the like. Disclosure of Invention In the research process, the applicant finds that, while the catalytic slurry oil is subjected to hydrodesulfurization treatment, part of aromatic rings of aromatic hydrocarbon in the slurry oil are saturated through hydrogenation reaction and are further converted into aromatic hydrocarbon with a large number of alkyl side chains and/or cycloalkyl side chains, and the aromatic hydrocarbon with the side chains is subjected to side chain breaking reaction in the subsequent production process of the mesophase carbon microsphere to generate a large number of micromolecular hydrocarbon compounds. On one hand, the newly generated micromolecular hydrocarbon compounds continuously escape to cause disturbance to the reaction system and are unfavorable for the formation of a wide area mesophase, on the other hand, part of micromolecular hydrocarbon compounds such as monocyclic aromatic hydrocarbon cannot escape from the reaction system, and condensation reaction inevitably occurs when the micromolecular hydrocarbon compounds stay in the system, and in the reaction period, the micromolecular hydrocarbon compounds cannot form enough molecules and are solidified into coke without forming the wide area mesophase, so that the hydrotreated catalytic slurry oil is unfavorable for the formation of the wide area mesophase, and the yield of mesophase pitch is lower. Aiming at the defects in the prior art, the invention mainly aims to provide a production method and a production system of mesophase carbon microspheres. The production method and the production system of the invention provide the optimization direction of the raw materials by deep analysis of the molecular reaction performance of the raw materials and the correlation analysis between th