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CN-119490870-B - High flash point jet fuel and method for producing high flash point jet fuel

CN119490870BCN 119490870 BCN119490870 BCN 119490870BCN-119490870-B

Abstract

The invention relates to the field of aviation fuel, and discloses a high-flash-point jet fuel and a production method thereof. The method comprises the steps of mixing raw oil and hydrogen, then, entering a hydrofining reactor containing a hydrofining catalyst for hydrofining reaction to obtain refined effluent, wherein the raw oil is straight-run diesel oil, the density of 20 ℃ is 820-840kg/m 3 , the sulfur content is less than 1.0wt%, introducing the refined effluent into the hydrocracking reactor containing a hydrocracking catalyst for hydrocracking reaction, fractionating the obtained cracked effluent to obtain naphtha fraction, kerosene fraction, diesel fraction I and diesel fraction II, and carrying out gas-liquid separation on the diesel fraction I to respectively obtain light components capable of being recycled for fractionation and heavy components serving as a high flash point jet fuel product outlet device. The method can realize stable production of the high-flash-point jet fuel with low cost, the flash point is more than 60 ℃, and the quality of the high-flash-point jet fuel product is improved.

Inventors

  • SONG YICHANG
  • CAO HUI
  • LIU JINSONG
  • A Yuyan
  • ZHANG CHUNLEI
  • TANG MING
  • LIU HONGLEI

Assignees

  • 中国石油化工股份有限公司

Dates

Publication Date
20260505
Application Date
20230821

Claims (17)

  1. 1. A method of producing a high flash point jet fuel, the method comprising: (1) Raw oil and hydrogen are mixed and then enter a hydrofining reactor containing a hydrofining catalyst for hydrofining reaction to obtain a refined effluent; wherein the raw oil is straight-run diesel oil, the density of the straight-run diesel oil at 20 ℃ is 820-840 kg/m 3 , the sulfur content is no more than 1.0wt%, the initial distillation point is 187-213 ℃, and the final distillation point is 322-349 ℃; The hydrofining catalyst comprises a carrier and an active component loaded on the carrier, wherein the carrier is alumina, the active component is Mo and Ni, the total weight of the hydrofining catalyst is taken as a reference, the content of Mo is 22-25wt%, the content of Ni is 3.6-4.2wt%, the content of the carrier is 68-72wt%, and the sum of the contents of the components is 100wt%; (2) Introducing the refined effluent into a hydrocracking reactor containing a hydrocracking catalyst to carry out a hydrocracking reaction to obtain a cracked effluent; The hydrocracking catalyst comprises a carrier and an active component loaded on the carrier, wherein the carrier is alumina, the active component is Ni and W, the total weight of the hydrocracking catalyst is taken as a reference, the content of W is 22-25wt%, the content of Ni is 6.0-7.5wt%, the content of the carrier is 70-74wt%, and the sum of the contents of the components is 100wt%; (3) Fractionating the cracked effluent to obtain naphtha fraction, kerosene fraction, diesel fraction I and diesel fraction II; (4) Subjecting the diesel fraction I to gas-liquid separation in a low-freezing diesel stripper to obtain a light fraction which can be recycled back to step (3) for said fractionation and a heavy fraction which is taken as a high flash point jet fuel product outlet means; The gas-liquid separation condition comprises that the bottom temperature of the low-freezing diesel stripping tower is 200-225 ℃, the extraction amount of the jet fuel product with the high flash point is 10-18t/h, the return tower temperature is 210-230 ℃, the initial distillation point of the jet fuel product with the high flash point is 175-195 ℃, the final distillation point is 245-260 ℃, and the flash point is more than 60 ℃.
  2. 2. The process of claim 1, wherein in step (1), the straight run diesel has a20 ℃ density of 822-830 kg/m 3 , a sulfur content of 0.4-0.85 wt%, a nitrogen content of no more than 150 mg/kg, and a char residue value of less than 0.1 wt%.
  3. 3. The method of claim 2, wherein the straight run diesel has a nitrogen content of 0-120 mg/kg.
  4. 4. The process according to any one of claims 1 to 3, wherein in the step (1), the reaction conditions of the hydrofining reaction include a reaction temperature of 300 to 400 ℃, a reaction pressure of 6 to 10MPa, a hydrogen-oil volume ratio of (500 to 1000): 1, and a volume space velocity of 2 to 5h -1 .
  5. 5. The method according to any one of claims 1 to 3, wherein in step (1), before the hydrofinishing reaction is performed, step (1) further comprises preheating the raw oil and hydrogen gas to 350 to 400 ℃ respectively, followed by the mixing.
  6. 6. A process according to any one of claims 1 to 3, wherein in step (2), the reaction conditions of the hydrocracking reaction comprise a reaction temperature of 300 to 400 ℃, a reaction pressure of 5 to 10MPa, a hydrogen-to-oil volume ratio of (500 to 1000): 1 and a volume space velocity of 1 to 4 h -1 .
  7. 7. The process according to any one of claims 1 to 3, wherein in step (3) the fractionation is carried out in a fractionation column, the process further comprising, in terms of the direction of flow of the reactant stream, providing a high pressure separator and a low pressure separator between the hydrocracking reactor and the fractionation column to gas-liquid separate the cracked effluent, and then introducing the resulting liquid phase product into a hydrogen sulfide stripping column to remove hydrogen sulfide therefrom.
  8. 8. The process of claim 7 wherein the fractionation column has a top temperature of 110-125 ℃ and a bottom temperature of 260-270 ℃.
  9. 9. A process according to any one of claims 1 to 3, wherein in step (3) the kerosene fraction is withdrawn at a temperature of 150 to 158 ℃ and the diesel fraction I is withdrawn at a temperature of 180 to 185 ℃.
  10. 10. A process according to any one of claims 1 to 3, wherein in step (3) the kerosene fraction is withdrawn in an amount of 5 to 20 t/h.
  11. 11. The process of any one of claims 1-3, wherein the process further comprises subjecting the kerosene fraction to gas-liquid separation to obtain a gas phase capable of being recycled back to step (3) for said fractionation and a liquid phase exiting the apparatus as a aviation kerosene product.
  12. 12. The process according to claim 11, wherein the kerosene fraction is subjected to gas-liquid separation in a aviation stripper having a bottom temperature of 170-200 ℃.
  13. 13. The method of claim 11, wherein the liquid phase exiting the apparatus as a aviation kerosene product has a distillation range of 160-233 ℃, a 20 ℃ density of 792-797 kg/m 3 , a freezing point of less than-60 ℃, a flash point of 43-50 ℃, and a smoke point of 21-23 mm.
  14. 14. A high flash point jet fuel produced by the method of any one of claims 1-13, wherein the high flash point jet fuel has an initial boiling point of 175-195 ℃ and a final boiling point of 245-260 ℃ and a flash point of 61 ℃ or greater.
  15. 15. The high flash point jet fuel of claim 14, wherein the high flash point jet fuel has a flash point of 61-75 ℃ and a total sulfur content of no more than 0.005wt%.
  16. 16. The high flash point jet fuel of claim 14, wherein the high flash point jet fuel has a smoke point greater than 20 mm, a 20 ℃ density of 804-810 kg/m 3 , and a freeze point no more than-47 ℃.
  17. 17. The high flash point jet fuel of claim 16, wherein the high flash point jet fuel has a smoke point of 20.5-22.5 mm.

Description

High flash point jet fuel and method for producing high flash point jet fuel Technical Field The invention relates to the field of aviation fuel, in particular to a high-flash-point jet fuel and a method for producing the high-flash-point jet fuel. Background High flash point jet fuels are a class of special jet fuels with high flash point values that effectively increase the flash point of the fuel while maintaining other properties as compared to ordinary jet fuels. Generally, the jet fuel is RP-3 type fuel, which is mainly applied to various civil aviation and military jet aircraft, but the particularity of the operational environment determines that the oil consumption of the jet fuel is inevitably influenced by various adverse factors such as high temperature, high humidity, high salt environment, unstable ship body swing and the like for naval warships, for example, the fuel is required to be not deteriorated and not spontaneous combustion under the high temperature condition, and particularly, the fuel is required to have good fuel safety under the condition of unstable ship body swing, so that the requirements for the naval warship fuel are higher than those of common aviation coal. In order to adapt to the complex environment of the operation of the carrier-based aircraft, the fuel is required to have higher flash point (generally not lower than 60 ℃), good combustibility, stability, low temperature property and the like. Thus, high flash point jet fuels are mainly used as carrier-based aircraft fuels, and the standard currently implemented is GJB560A-97. The existing jet fuel production technology mainly comprises a hydrofining technology and a hydrocracking technology of straight-run jet fuel fractions. US4172815A discloses a single-stage cyclic hydrocracking method for simultaneously producing jet fuel and diesel, which comprises the following steps of hydrocracking heavy raw oil, fractionating the product to obtain jet fuel fraction, diesel fraction and tail oil, mixing all or part of jet fuel fraction with the tail oil, and returning to a hydrocracking reactor. The obvious disadvantage of this process flow is that the jet fuel is hydrocracked again, while improving quality, its yield is reduced more, hydrogen consumption is increased, and investment is increased. CN1272524a discloses a combined process flow of medium pressure hydrocracking and kerosene deep hydrotreating. The process is that the kerosene distillate oil with higher aromatic hydrocarbon content obtained in the middle-pressure hydrocracking process is subjected to aromatic saturation under the conditions of lower pressure, higher hydrogen purity and lower reaction temperature, and the catalyst is a catalyst containing Pt or Ni reduced metal. The process can well process kerosene fraction with higher aromatic hydrocarbon content to obtain qualified jet fuel, but the method needs more equipment and device investment and is more complex to operate. Meanwhile, the technology for improving the flash point of jet fuel in the prior art has the defects of complicated production flow, severe reaction condition control, large quality fluctuation and larger influence on the quality of upstream and downstream products, and causes poor production stability and high cost. Disclosure of Invention The invention aims to solve the problems of high cost and low flash point of the product in the production method of the jet fuel with high flash point in the prior art. To achieve the above object, a first aspect of the present invention provides a method of producing a high flash point jet fuel, the method comprising: (1) Raw oil and hydrogen are mixed and then enter a hydrofining reactor containing a hydrofining catalyst for hydrofining reaction to obtain a refined effluent; Wherein the raw oil is straight-run diesel oil, the density of the straight-run diesel oil at 20 ℃ is 820-840kg/m 3, and the sulfur content is no more than 1.0wt%; (2) Introducing the refined effluent into a hydrocracking reactor containing a hydrocracking catalyst to carry out a hydrocracking reaction to obtain a cracked effluent; (3) Fractionating the cracked effluent to obtain naphtha fraction, kerosene fraction, diesel fraction I and diesel fraction II; (4) Subjecting the diesel fraction I to gas-liquid separation to obtain, respectively, a light fraction capable of being recycled back to step (3) for said fractionation and a heavy fraction as a high flash point jet fuel product exiting means; Wherein the jet fuel product with high flash point has initial boiling point of 175-195 deg.C, final boiling point of 245-260 deg.C, and flash point of above 60 deg.C. In a second aspect, the invention provides a high flash point jet fuel prepared by the method of the first aspect, wherein the jet fuel has a primary boiling point of 175-195 ℃ and a final boiling point of 245-260 ℃ and a flash point of greater than 60 ℃. Through the technical scheme, the invention has the following adva