Search

CN-117778040-B - Method and system for producing needle coke raw material by catalytic slurry oil and method and system for producing needle coke

CN117778040BCN 117778040 BCN117778040 BCN 117778040BCN-117778040-B

Abstract

The invention discloses a method and a system for producing needle coke raw materials by catalytic slurry oil and a method and a system for producing needle coke. The method comprises the steps of purifying catalytic slurry oil, then carrying out hydrogenation reaction, and fractionating an obtained liquid product to obtain light oil, middle distillate oil and tail oil, wherein the middle distillate oil enters a cracking reaction unit to carry out cracking reaction, the obtained cracking product and the tail oil are mixed to serve as a first raw material for producing needle coke and sent to a coking unit, and coked heavy oil separated from coked oil and gas is returned to the coking unit as a second raw material for producing needle coke. The system comprises a purifying unit, a hydrogenation reaction unit, a gas-liquid separation unit, a fractionation unit, a cracking reaction unit and a coking unit. The method and the system provided by the invention provide the optimized direction of the needle coke raw material, and obtain the high-quality needle coke raw material and the needle coke product.

Inventors

  • GUO DAN
  • CHU RENQING
  • SONG YONGYI
  • GU CHENGYU
  • Qin Wangjian

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 needle coke feedstock from catalytic slurry oil, the method comprising: (1) After the catalytic slurry oil is purified, the catalytic slurry oil and hydrogen enter a hydrogenation reaction unit together, hydrogenation reaction is carried out under the action of a hydrogenation catalyst, and a gaseous product and a liquid product are obtained after the reaction effluent is separated; (2) Fractionating the liquid product obtained in the step (1) by a first fractionating unit to obtain light oil, middle distillate oil and tail oil, wherein the 5% distillation temperature of the middle distillate oil is 340-430 ℃ and the 95% distillation temperature is 440-530 ℃; (3) And (3) sending the middle distillate oil obtained in the step (2) to a cracking reaction unit for cracking reaction, mixing the obtained cracking product with the tail oil obtained in the step (2) to be used as a first raw material for producing needle coke, wherein the reaction condition of the cracking reaction unit is that the reaction temperature is 380-520 ℃, the reaction pressure is 0.1-5 MPa, and the residence time is 0.01-30 h.
  2. 2. The method for producing needle coke raw material by catalytic slurry oil according to claim 1, wherein the ash content of the catalytic slurry oil in the step (1) is higher than 0.01wt%, the sulfur content is higher than 0.4wt%, and the aromatic carbon ratio is not less than 60mol%.
  3. 3. The method for producing needle coke raw materials by using the catalytic slurry oil according to claim 1, wherein the sulfur content of the catalytic slurry oil in the step (1) is higher than 0.8wt% and the aromatic carbon ratio is 65-90 mol%.
  4. 4. The method for producing needle coke raw material by catalytic slurry oil according to claim 1, wherein the purification treatment in the step (1) adopts one or more of filtration, centrifugal sedimentation, flocculation sedimentation and reduced pressure distillation.
  5. 5. The method for producing needle coke raw material by catalytic slurry oil according to claim 1, wherein the purification treatment in the step (1) is filtration.
  6. 6. The method for producing needle coke raw material by catalytic slurry oil according to claim 1, wherein ash content is not more than 0.01wt% after the catalytic slurry oil is subjected to purification treatment.
  7. 7. The method for producing needle coke raw material by catalytic slurry oil according to claim 1, wherein ash content is not more than 0.005wt% after the catalytic slurry oil is subjected to purification treatment.
  8. 8. The method for producing needle coke raw materials by using catalytic slurry oil according to claim 1, wherein the hydrogenation reaction condition in the step (1) is that the reaction temperature is 300-480 ℃, the reaction pressure is 2-20 MPa, the hydrogen-oil volume ratio is 100-2500, and the liquid hourly space velocity is 0.1h -1 ～2.0h -1 .
  9. 9. The method for producing needle coke raw materials by using catalytic slurry oil according to claim 1, wherein the hydrogenation reaction condition in the step (1) is that the reaction temperature is 330-390 ℃, the reaction pressure is 4-8 MPa, the hydrogen-oil volume ratio is 500-1800, and the liquid hourly space velocity is 0.7h -1 ～1.2h -1 .
  10. 10. The method for producing needle coke raw material by catalytic slurry according to claim 1, wherein the liquid product in the step (1) means a liquid fraction after removing naphtha fraction.
  11. 11. The method for producing needle coke raw materials by using catalytic slurry oil according to claim 1, wherein the light oil obtained in the step (2) is directly taken as a product outlet device, or enters a condensation reaction unit for reaction, or is partly taken as a product outlet device, and the rest enters the condensation reaction unit for reaction.
  12. 12. The method for producing needle coke raw materials by using catalytic slurry oil according to claim 11, wherein the condensation reaction condition is that the reaction temperature is 350-550 ℃, the reaction pressure is 0.1-5 MPa, and the residence time is 0.01-50 h.
  13. 13. The method for producing needle coke raw materials by using catalytic slurry oil according to claim 11, wherein the condensation reaction condition is that the reaction temperature is 400-460 ℃, the reaction pressure is 0.8-3.0 MPa, and the residence time is 0.3-24 h.
  14. 14. The method for producing needle coke raw materials by using catalytic slurry oil according to claim 11, wherein the top oil and the bottom oil are obtained after the reaction products obtained by the condensation reaction are separated, and the 5% distillation temperature of the bottom oil is 300-420 ℃.
  15. 15. The method for producing needle coke raw materials by using catalytic slurry oil according to claim 11, wherein the top oil and the bottom oil are obtained after the reaction products obtained by the condensation reaction are separated, and the 5% distillation temperature of the bottom oil is 330-370 ℃.
  16. 16. The process for producing needle coke raw materials by catalytic slurry oil according to claim 14 or 15, wherein the top oil is directly discharged from the device or mixed with the catalytic slurry oil in the step (1) as a diluent for purification treatment, and the bottom oil is recycled and treated together with the liquid product obtained in the step (1).
  17. 17. The method for producing needle coke raw materials by catalytic slurry oil according to claim 11, wherein a condensation catalyst is added in the condensation reaction process, 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.
  18. 18. The method for producing needle coke raw materials by catalytic slurry oil according to claim 11, wherein a condensation catalyst is added in the condensation reaction process, 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 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 5-25 wt% based on the weight of the catalyst.
  19. 19. The method for producing needle coke raw material by catalytic slurry oil according to claim 1, wherein the 5% distillation temperature of middle distillate in the step (2) is 355 ℃ to 410 ℃ and the 95% distillation temperature is 460 ℃ to 505 ℃.
  20. 20. The method for producing needle coke raw materials by using catalytic slurry oil according to claim 1, wherein the reaction condition of the cracking reaction unit is that the reaction temperature is 420-490 ℃, the reaction pressure is 0.2-1.0 MPa, and the residence time is 0.1-3 h.

Description

Method and system for producing needle coke raw material by catalytic slurry oil and method and system for producing needle coke Technical Field The invention belongs to the technical field of needle coke preparation, and particularly relates to a method and a system for preparing oil system needle coke by catalytic slurry oil. Background The catalytic slurry oil is rich in aromatic hydrocarbon, is a high-quality raw material for producing needle coke, but the ash content and the sulfur content in the catalytic slurry oil are high, 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 needle coke. At present, the catalytic slurry oil is generally required to be de-solidified to lower the ash content in the catalytic slurry oil to below 0.01wt%, the main methods comprise filtration, flocculation precipitation, centrifugation-static method, electric adsorption separation, centrifugation separation, reduced pressure distillation and the like, and the desulfurization mainly adopts a hydrotreating method to lower the sulfur content in the catalytic slurry oil to below 0.5 wt%. CN1872963a discloses a pretreatment method of raw material for producing needle coke, the non-ideal components in raw material oil are removed by reduced pressure distillation, the rest ideal components are contacted with hydrogen and hydrogenation catalyst, and hydrogenation reaction flow is separated to obtain raw material for producing needle coke. The method can remove the light and heavy non-ideal components in the raw oil by combining the two processes, more reasonably utilizes hydrogen, saves investment, furthest reserves ideal components, and ensures that the treated raw oil meets the requirements of producing needle coke raw materials. CN103789028A discloses a pretreatment method for producing needle coke raw materials by catalytic slurry oil, which comprises the following steps of filtering the catalytic slurry oil, carrying out mild hydrotreatment, removing 20% -50% (based on weight content) of hydrogenated oil to a reduced pressure distillation device, wherein the operation conditions are that the pressure is 5 mmHg-100 mmHg, the temperature is 300-450 ℃, and the obtained hydrogenated light distillate oil is mixed with the rest hydrogenated oil to be used as the raw materials for producing needle coke. The method is suitable for producing needle coke raw materials from catalytic slurry oil rich in aromatic hydrocarbon. CN103013567a discloses a method for producing needle coke raw material from catalytic cracking slurry oil, said invention is characterized by that it is equipped with protection zone and hydrogenation reaction zone, the catalytic cracking slurry oil firstly is fed into the protection zone, and adsorbed to remove most of catalytic cracking catalyst powder, then mixed with hydrogen gas, fed into heating furnace, heated and fed into hydrogenation reaction zone to make hydrogenation treatment reaction. The invention sets a protection zone in front of the hydrogenation reaction zone, which can filter out most of catalytic cracking catalyst powder carried in the catalytic cracking slurry oil, thus achieving the purpose of protecting the hydrogenation main catalyst and realizing long-period operation. In addition, the sulfur in the catalytic cracking slurry oil is mostly removed by the catalytic cracking slurry oil hydrofinishing, and qualified needle coke raw materials are produced. In summary, the existing pretreatment method of needle coke raw materials generally comprises the steps of removing catalyst powder through filtration, adsorption, reduced pressure distillation and the like, and then removing part of sulfur through hydrotreating, wherein the ash content and the sulfur content of the obtained refined slurry oil can meet the requirements of producing needle coke, and the refined slurry oil is directly used as the raw material for producing needle coke. Disclosure of Invention In the research process, the applicant finds that in the hydrotreating process of the catalytic slurry oil, while desulfurization is realized, part of aromatic rings of aromatic hydrocarbon are saturated through hydrogenation reaction, and further converted into aromatic hydrocarbon with a large number of alkyl side chains and/or cycloalkyl side chains, and the part of aromatic hydrocarbon with side chains is subjected to side chain breaking reaction in the subsequent needle coke production process to generate a large number of small molecular hydrocarbon compounds. On the one hand, the newly generated small molecular hydrocarbon compounds continuously escape to cause disturbance to the reaction system and are unfavorable for the formation of wide area mesophases, on the other hand, part of small molecular hydrocarbon compounds such as monocyclic aromatic hydrocarbon and/or bicyclic aromatic hydrocarbon ca