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CN-117778043-B - Comprehensive utilization method and utilization system for catalytic slurry oil

CN117778043BCN 117778043 BCN117778043 BCN 117778043BCN-117778043-B

Abstract

The invention discloses a comprehensive utilization method and a utilization system of catalytic slurry oil, wherein the utilization method firstly carries out hydrogenation reaction on the catalytic slurry oil, the separated hydrogenated tail oil enters into a cracking reaction, a cracking reaction product is contacted with an extractant for treatment, the separated extract phase is recovered with the extractant to obtain aromatic-rich oil, the heavy fraction obtained by separating the aromatic-rich oil enters into a coking reaction zone, and oil gas and needle coke products are obtained after the reaction. The catalytic slurry oil comprehensive utilization system adopting the method is also provided. The method and the system can improve the mechanical strength of the obtained needle coke photo, effectively improve the microstructure of the needle coke and obtain high-quality needle coke.

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 comprehensively utilizing catalytic slurry oil, comprising the following steps: (1) In the presence of hydrogen, the catalytic slurry oil enters a hydrogenation reaction zone to contact a hydrogenation catalyst for hydrogenation reaction, and the reaction effluent is separated to obtain gas, naphtha and hydrogenated tail oil; (2) The hydrogenated tail oil obtained in the step (1) enters a cracking reaction zone for cracking reaction, wherein the reaction condition of the cracking reaction zone 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; (3) The cracking reaction product obtained in the step (2) enters an extraction unit, contacts with an extractant for treatment, and is separated to obtain an extraction phase and a raffinate phase; (4) The extract phase obtained in the step (3) enters an extractant recovery unit, and the regenerated extractant and aromatic-rich oil are obtained after separation; (5) And (3) separating the aromatic-rich oil obtained in the step (4) to obtain a light fraction and a heavy fraction, and allowing the heavy fraction to enter a coking reaction zone to react to obtain oil gas and needle coke products.
  2. 2. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the catalytic slurry oil in the step (1) is subjected to purification treatment firstly, and the purification treatment adopts one or more of filtration, centrifugal sedimentation, electrostatic adsorption and flocculation sedimentation methods, and the ash content of the purified catalytic slurry oil is not more than 0.01wt%.
  3. 3. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the catalytic slurry oil in the step (1) is subjected to purification treatment, and the purification treatment adopts filtration.
  4. 4. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the reaction condition of the hydrogenation reaction zone in the step (1) is that the reaction temperature is 300-450 ℃, the reaction pressure is 2-25 MPa, the volume ratio of hydrogen to oil is 100-2500, and the liquid hourly space velocity is 0.1h -1 ～2.0h -1 .
  5. 5. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the reaction condition of the hydrogenation reaction zone in the step (1) is that the reaction temperature is 340-385 ℃, the reaction pressure is 4-8 MPa, the hydrogen-oil volume ratio is 500-1800, and the liquid hourly space velocity is 0.6h -1 ～1.2h -1 .
  6. 6. The method for comprehensively utilizing catalytic slurry oil according to claim 1, wherein the sulfur content of the hydrogenated tail oil in the step (1) is not higher than 0.4wt%.
  7. 7. The method for comprehensively utilizing catalytic slurry oil according to claim 1, wherein the sulfur content of the hydrogenated tail oil in the step (1) is not higher than 0.35wt%.
  8. 8. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the reaction condition of the cracking reaction zone in the step (2) 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.
  9. 9. The method for comprehensively utilizing catalytic slurry oil according to claim 1, wherein carrier gas is introduced in the cracking reaction process, and the carrier gas is one or more of steam, nitrogen and inert gas.
  10. 10. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein carrier gas is introduced in the cracking reaction process, and the carrier gas is water vapor.
  11. 11. The method for comprehensively utilizing the catalytic slurry oil according to claim 9 or 10, wherein the mass ratio of the hydrogenated tail oil to the carrier gas is 100:0.1-100:20.
  12. 12. The method for comprehensively utilizing the catalytic slurry oil according to claim 9 or 10, wherein the mass ratio of the hydrogenated tail oil to the carrier gas is 100:1-100:8.
  13. 13. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the extractant in the step (3) is selected from one or more of furfural, N-methyl formamide, N-methyl pyrrolidone and dimethyl sulfoxide.
  14. 14. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the extracting agent in the step (3) is furfural.
  15. 15. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the mass ratio of the extractant to the cracking reaction product is 1:1-5:1.
  16. 16. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the mass ratio of the extractant to the cracking reaction product is 1.5:1-2.5:1.
  17. 17. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the light fraction obtained after the separation of the aromatic-rich oil in the step (5) is discharged out of the device or enters a hydrogenation reaction zone to be treated together with the catalytic slurry oil.
  18. 18. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the light fraction obtained after the separation of the aromatic-rich oil in the step (5) enters a hydrogenation reaction zone to be treated together with the catalytic slurry oil.
  19. 19. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the 5% distillation temperature of the heavy fraction in the step (5) is 300-400 ℃.
  20. 20. The method for comprehensively utilizing the catalytic slurry oil according to claim 1, wherein the 5% distillation temperature of the heavy fraction in the step (5) is 350-380 ℃.

Description

Comprehensive utilization method and utilization system for catalytic slurry oil Technical Field The invention belongs to the technical field of catalytic slurry oil treatment, and particularly relates to a method and a system for preparing oil needle coke from catalytic slurry oil. Background The catalytic slurry oil contains a large amount of aromatic hydrocarbon and is a high-quality raw material for producing oil needle coke. Along with the gradual increase of the sulfur content of crude oil, the sulfur content of catalytic slurry oil also increases, low-sulfur catalytic slurry oil resources are in shortage, and the catalytic slurry oil with the sulfur content of more than 0.5 weight percent becomes a main raw material source for producing needle coke. Aiming at the problem of high sulfur content of the existing catalytic slurry oil, a hydrotreating process is generally adopted to remove part of sulfur, so that the sulfur content of the catalytic slurry oil is reduced to below 0.5wt percent, even below 0.4wt percent. CN110511785A discloses a method for preparing needle coke raw material by catalyzing oil slurry, which comprises the specific steps of adding low molecular weight normal alkane into the oil slurry, carrying out deasphalting to obtain upper liquid, extracting and de-solidifying the upper liquid to obtain aromatic-rich oil, and carrying out hydrodesulfurization treatment on the aromatic-rich oil to obtain the needle coke raw material. CN106147835A discloses a combined method for separating catalytic slurry oil and preparing oil needle coke, using C3-C5 light hydrocarbon fraction as extraction solvent to make subcritical or supercritical extraction on catalytic cracking slurry oil, making the obtained extracted oil phase into extraction component by supercritical recovery solvent, using extraction component as preparation raw material of intermediate phase asphalt, making intermediate phase asphalt by thermal polycondensation reaction, and making intermediate phase asphalt undergo the process of delayed coking reaction so as to obtain the invented high-quality oil needle coke. When the sulfur content of the catalytic cracking slurry oil is higher, the extracted light component can be subjected to hydrodesulfurization treatment, the hydrogenated oil is fractionated to collect hydrogenated tail oil, and the hydrogenated tail oil is used as a raw material for preparing mesophase pitch, so that needle coke is prepared. In the method, aromatic hydrocarbon is enriched by adopting an extraction method, and impurity sulfur is removed by utilizing a hydrotreating process, so that the obtained low-sulfur catalytic slurry oil is directly used as a raw material for producing needle coke. Disclosure of Invention The applicant finds that after the catalytic slurry oil is subjected to hydrotreatment, the molecular structure of aromatic hydrocarbon rich in the catalytic slurry oil can be changed, the aromatic hydrocarbon with a short side chain can be converted into aromatic hydrocarbon with a large number of alkyl side chains or cycloalkyl side chains, and the hydrogenated slurry oil is used in the needle coke production process, and the molecular reaction states are greatly different, so that the structure among the obtained needle coke product slices is loose, and the mechanical property of the product is influenced. Aiming at the defects existing in the prior art, the invention provides a comprehensive utilization method and a utilization system of catalytic slurry oil, which can improve the mechanical strength of needle coke, effectively improve the microstructure of the needle coke, improve the density between sheets and obtain high-quality needle coke, and can also produce naphtha products as byproducts. The first aspect of the invention provides a comprehensive utilization method of catalytic slurry oil, which comprises the following steps: (1) In the presence of hydrogen, the catalytic slurry oil enters a hydrogenation reaction zone to contact a hydrogenation catalyst for hydrogenation reaction, and the reaction effluent is separated to obtain gas, naphtha and hydrogenated tail oil; (2) The hydrogenated tail oil obtained in the step (1) enters a cracking reaction zone for cracking reaction; (3) The cracking reaction product obtained in the step (2) enters an extraction unit, contacts with an extractant for treatment, and is separated to obtain an extraction phase and a raffinate phase; (4) The extract phase obtained in the step (3) enters an extractant recovery unit, and the regenerated extractant and aromatic-rich oil are obtained after separation; (5) And (3) separating the aromatic-rich oil obtained in the step (4) to obtain a light fraction and a heavy fraction, and allowing the heavy fraction to enter a coking reaction zone to react to obtain oil gas and needle coke products. In the method for comprehensively utilizing the catalytic slurry oil, the catalytic slurry oil in the step (1) is prefera