High flash point jet fuel and method of producing high flash point jet fuel

Abstract

This invention relates to the field of aviation fuel, and discloses a high flash point jet fuel and its production method. The method includes: mixing feedstock oil with hydrogen and then feeding the mixture into a hydrorefining reactor containing a hydrorefining catalyst for a hydrorefining reaction to obtain a refined effluent; wherein the feedstock oil is straight-run diesel oil with a density of 820-840 kg / m³ at 20°C. 3 The sulfur content is ≤1.0 wt%. The refined effluent is introduced into a hydrocracking reactor containing a hydrocracking catalyst for hydrocracking. The resulting cracked effluent is fractionated to obtain naphtha fraction, kerosene fraction, diesel fraction I, and diesel fraction II. Diesel fraction I undergoes gas-liquid separation to obtain light components that can be recycled for further fractionation and heavy components that are discharged from the unit as high flash point jet fuel products. This method enables the stable production of high flash point jet fuel with a flash point greater than 60°C at low cost and improves the quality of the high flash point jet fuel product.

Description

Technical Field

[0001] This invention relates to the field of aviation fuel, and more specifically to high flash point jet fuel and a method for producing high flash point jet fuel. Background Technology

[0002] High flash point jet fuel is a special type of jet fuel with a high flash point value. Compared with ordinary jet fuel, it effectively increases the flash point while maintaining other properties. Generally, jet fuel refers to RP-3 type fuel, mainly used in various civil and military jet aircraft. However, for carrier-based aircraft on naval vessels, the special operational environment dictates that their fuel is inevitably affected by many adverse factors such as high temperature, high humidity, high salinity, and the turbulence of the ship. For example, the fuel must not deteriorate under high temperature conditions and must not spontaneously combust, especially under the turbulence of the ship, it must have good fuel safety. Therefore, carrier-based aircraft fuel has higher requirements than ordinary aviation kerosene. To adapt to the complex operating environment of carrier-based aircraft, the fuel is required to have a high flash point (generally not lower than 60℃), good combustibility, stability, and low-temperature performance. Therefore, high flash point jet fuel is mainly used as carrier-based aircraft fuel, and the current standard is GJB560A-97. Existing jet fuel production technologies mainly include hydrorefining technology and hydrocracking technology for straight-run jet fuel fractions.

[0003] US4172815A discloses a single-stage circulating hydrocracking method for simultaneously producing jet fuel and diesel. The process flow is as follows: after hydrocracking, the heavy feedstock is fractionated to obtain jet fuel fraction, diesel fraction, and tail oil. All or part of the jet fuel fraction is mixed with the tail oil and returned to the hydrocracking reactor. A significant drawback of this process is that while further hydrocracking of the jet fuel improves its quality, it significantly reduces yield, increases hydrogen consumption, and raises investment costs.

[0004] CN1272524A discloses a combined process flow of medium-pressure hydrocracking and deep hydrotreating of kerosene. This process involves aromatic saturation of kerosene fractions with high aromatic content obtained from medium-pressure hydrocracking under conditions of low pressure, high hydrogen purity, and low reaction temperature, using a catalyst containing reduced Pt or Ni metals. This process can effectively process kerosene fractions with high aromatic content to obtain qualified jet fuel; however, this method requires significant investment in equipment and facilities and is more complex to operate.

[0005] Meanwhile, existing technologies for improving the flash point of jet fuel generally suffer from drawbacks such as cumbersome production processes, stringent control of reaction conditions, large quality fluctuations, and significant impacts on the quality of upstream and downstream products, resulting in poor production stability and high costs. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of high cost and low flash point of the product in the existing high flash point jet fuel production methods.

[0007] To achieve the above objectives, a first aspect of the present invention provides a method for producing high flash point jet fuel, the method comprising:

[0008] (1) The feedstock oil is mixed with hydrogen and then enters a hydrorefining reactor containing a hydrorefining catalyst to carry out a hydrorefining reaction and obtain a refined effluent.

[0009] The feedstock oil is straight-run diesel oil, and the density of the straight-run diesel oil at 20°C is 820-840 kg / m³. 3 Sulfur content ≤ 1.0 wt%;

[0010] (2) The refined effluent is introduced into a hydrocracking reactor containing a hydrocracking catalyst to carry out a hydrocracking reaction to obtain a cracked effluent;

[0011] (3) The cracking effluent is fractionated to obtain naphtha fraction, kerosene fraction, diesel fraction I and diesel fraction II;

[0012] (4) The diesel fraction I is subjected to gas-liquid separation to obtain a light component that can be recycled back to step (3) for the fractionation and a heavy component that is discharged from the device as a high flash point jet fuel product.

[0013] The high flash point jet fuel product has an initial boiling point of 175-195℃ and a final boiling point of 245-260℃; its flash point is greater than 60℃.

[0014] The second aspect of the present invention provides a high flash point jet fuel prepared by the method described in the first aspect, wherein the high flash point jet fuel has an initial boiling point of 175-195°C, a final boiling point of 245-260°C, and a flash point greater than 60°C.

[0015] Through the above technical solution, the present invention has the following advantages:

[0016] (1) The method for producing high flash point jet fuel provided by the present invention can increase the flash point of the high flash point jet fuel to over 60°C based on RP-3 jet fuel, which significantly improves the safety and reliability of jet engines and can meet the special requirements of shipborne aircraft applications.

[0017] (2) The method for producing high flash point jet fuel provided by the present invention not only improves the quality of high flash point jet fuel products, but also does not require special technical modifications to the existing production process, requires no additional investment, only requires precise control of the operating conditions of each process stage, and the operating pressure and temperature are relatively mild; the entire preparation process has strong raw material adaptability, excellent production flexibility, and simple preparation process, which can achieve low-cost mass production.

[0018] (3) The method for producing high flash point jet fuel provided by the present invention, in a preferred case, produces high flash point jet fuel with low sulfur content, thereby reducing environmental pollution.

[0019] In summary, the method for producing high flash point jet fuel provided by this invention uses straight-run diesel oil (raw material) that meets specific performance parameter requirements as the main feedstock. By combining a suitable process flow and catalyst system, and controlling the reaction process and depth, a significant portion of the straight-run diesel oil components are converted into a high flash point jet fuel product with a flash point greater than 60°C. This method enables stable, low-cost production of high flash point jet fuel and improves the quality of the high flash point jet fuel product. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the process flow of a preferred embodiment of the method of the present invention.

[0021] Explanation of reference numerals in the attached figures

[0022] 1. Raw material oil 2. Hydrogen 3. Heating furnace

[0023] 4. Hydrorefining reactor; 5. Hydrocracking reactor; 6. Intermediate-temperature high-pressure separator.

[0024] 7. Medium-temperature low-pressure separator; 8. Cold high-pressure separator; 9. Cold low-pressure separator.

[0025] 10. Hydrogen sulfide stripping tower; 11. First tower top reflux tank; 12. Dry gas.

[0026] 13. Second Part: Light Naphtha Fraction 14. Product Fractionating Column 15. Naphtha Fraction

[0027] 16. Kerosene fraction 17. Diesel fraction I 18. Diesel fraction II

[0028] 19. Second reflux tank at the top of the tower; 20. First section of heavy naphtha fraction.

[0029] 21. Part Two: Heavy Naphtha Fraction

[0030] 22. Aviation kerosene stripping tower 23. Aviation kerosene products 24. Low-pour-point diesel stripping tower

[0031] 25. High flash point jet fuel products 26. Circulating hydrogen desulfurization tower

[0032] 27. First part: Light naphtha fraction 28. Light components Detailed Implementation

[0033] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0034] As previously stated, a first aspect of the present invention provides a method for producing high flash point jet fuel, the method comprising:

[0035] (1) The feedstock oil is mixed with hydrogen and then enters a hydrorefining reactor containing a hydrorefining catalyst to carry out a hydrorefining reaction and obtain a refined effluent.

[0036] The feedstock oil is straight-run diesel oil, and the density of the straight-run diesel oil at 20°C is 820-840 kg / m³. 3 Sulfur content ≤ 1.0 wt%;

[0037] (2) The refined effluent is introduced into a hydrocracking reactor containing a hydrocracking catalyst to carry out a hydrocracking reaction to obtain a cracked effluent;

[0038] (3) The cracking effluent is fractionated to obtain naphtha fraction, kerosene fraction, diesel fraction I and diesel fraction II;

[0039] (4) The diesel fraction I is subjected to gas-liquid separation to obtain a light component that can be recycled back to step (3) for the fractionation and a heavy component that is discharged from the device as a high flash point jet fuel product.

[0040] The high flash point jet fuel product has an initial boiling point of 175-195℃ and a final boiling point of 245-260℃; its flash point is greater than 60℃.

[0041] During the research process, the inventors of this invention discovered that straight-run diesel oil meeting specific performance parameter requirements is first mixed with hydrogen as feedstock, and then subjected to hydrorefining and hydrocracking reactions in sequence. The resulting cracking effluent is then fractionated to obtain naphtha fraction, kerosene fraction, diesel fraction I, and diesel fraction II. Diesel fraction I is then subjected to gas-liquid separation to obtain light components that can be recycled back to step (3) for further fractionation and heavy components that can be used as high flash point jet fuel products. The properties of these components meet the main indicators of GJB560A-97 high flash point jet fuel. This method enables the production of high flash point jet fuel products without requiring constant shutdown, while still ensuring the quality of other upstream and downstream products. The naphtha fraction can be used as reforming or cracking feedstock, the kerosene fraction can be used to produce jet fuel (RP-3 jet fuel), and diesel fraction II meets the requirements of Beijing Standard VI diesel.

[0042] According to some embodiments of the present invention, preferably, in step (1), the initial boiling point of the straight-run diesel oil is 187-213°C and the final boiling point is 322-349°C.

[0043] According to some embodiments of the present invention, preferably, the density of the straight-run diesel oil at 20°C is 822-830 kg / m³. 3 The sulfur content is 0.4-0.85 wt%.

[0044] According to some embodiments of the present invention, preferably, the nitrogen content of the straight-run diesel oil is ≤150 mg / kg, and more preferably 0-120 mg / kg.

[0045] According to some embodiments of the present invention, preferably, the carbon residue of the straight-run diesel oil is less than 0.1 wt%.

[0046] Using straight-run diesel that meets the above-mentioned specific parameter requirements is beneficial for obtaining high-flash-point jet fuel products with higher flash point and better quality.

[0047] According to some embodiments of the present invention, preferably, in step (1), the hydrorefining catalyst comprises a support and an active component supported on the support; the support is alumina; the active component is selected from at least two of Co, Mo, Ni and W, preferably Mo and Ni;

[0048] Preferably, based on the total weight of the hydrorefining catalyst, the content of Mo is 22-25 wt% and the content of Ni is 3.6-4.2 wt% (calculated as oxides); the content of the support is 68-72 wt%.

[0049] The above-described preferred embodiments are beneficial for removing impurities such as sulfur, nitrogen, oxygen, and metals, as well as for hydrogenation saturation of unsaturated hydrocarbons.

[0050] According to some embodiments of the present invention, preferably, in step (1), the reaction conditions of the hydrorefining reaction include: a reaction temperature of 300-400°C, a reaction pressure of 6-10 MPa, a hydrogen-to-oil volume ratio of (500-1000):1, and a volume hourly space velocity of 2-5 h⁻¹. -1 .

[0051] According to some embodiments of the present invention, preferably, before carrying out the hydrorefining reaction, step (1) further includes: preheating the raw material oil and hydrogen to 350-400°C respectively before mixing.

[0052] According to some embodiments of the present invention, preferably, in step (2), the reaction conditions of the hydrocracking reaction include: a reaction temperature of 300-400°C, a reaction pressure of 5-10 MPa, a hydrogen-to-oil volume ratio of (500-1000):1, and a volume hourly space velocity of 1-4 h⁻¹. -1 .

[0053] According to some embodiments of the present invention, preferably, in step (2), the hydrocracking catalyst comprises a support and an active component supported on the support; the support is alumina; the active component is selected from at least two of Co, Mo, Ni and W, preferably Ni and W;

[0054] Preferably, based on the total weight of the hydrocracking catalyst, the content of W is 22-25 wt% and the content of Ni is 6.0-7.5 wt% (calculated as oxides); the content of the support is 70-74 wt%.

[0055] The above-described preferred embodiments are beneficial for breaking down the chains of macromolecular hydrocarbons to generate small molecule hydrocarbons.

[0056] According to some embodiments of the present invention, preferably, in step (3), the fractionation is carried out in a fractionation tower. Before the fractionation, the method further includes: setting a high-pressure separator and a low-pressure separator between the hydrocracking reactor and the fractionation tower according to the flow direction of the reaction stream, so as to separate the cracking effluent into gas and liquid, and then introducing the obtained liquid phase product into a hydrogen sulfide stripping tower to remove hydrogen sulfide therein.

[0057] According to some embodiments of the present invention, preferably, in step (3), the top temperature of the distillation column is 110-125°C and the bottom temperature is 260-270°C.

[0058] According to some embodiments of the present invention, preferably, in step (3), the extraction temperature of the kerosene fraction is 150-158°C; and the extraction temperature of the diesel fraction I is 180-185°C.

[0059] According to some embodiments of the present invention, preferably, in step (3), the extraction rate of the kerosene fraction is 5-20 t / h.

[0060] According to some embodiments of the present invention, preferably, the method further includes: performing gas-liquid separation on the kerosene fraction to obtain a gas phase that can be recycled back to step (3) for the fractionation and a liquid phase that is used as a jet fuel product exit device.

[0061] According to some embodiments of the present invention, preferably, the gas-liquid separation is carried out in a jet fuel stripping tower, and the conditions for the gas-liquid separation include: the bottom temperature of the jet fuel stripping tower is 170-200°C.

[0062] According to some embodiments of the present invention, preferably, the distillation range of the liquid phase in the jet fuel product outlet device is 160-233°C.

[0063] According to some embodiments of the present invention, preferably, the density of the liquid phase at 20°C in the jet fuel product outlet device is 792-797 kg / m³. 3 .

[0064] According to some embodiments of the present invention, preferably, the freezing point of the liquid phase in the jet fuel product outlet device is less than -60°C.

[0065] According to some embodiments of the present invention, preferably, the flash point of the liquid phase in the jet fuel product outlet device is 43-50°C.

[0066] According to some embodiments of the present invention, preferably, the smoke point of the liquid phase in the jet fuel product outlet device is 21-23 mm.

[0067] According to some embodiments of the present invention, preferably, in step (4), the gas-liquid separation is carried out in a low-pour-point diesel stripping tower, and the conditions for gas-liquid separation include: the bottom temperature of the low-pour-point diesel stripping tower is 200-225°C; the extraction rate of the high flash point jet fuel product is 10-18 t / h; and the return temperature is 210-230°C. Adopting the above preferred embodiments is beneficial for obtaining high flash point jet fuel products of even better quality.

[0068] The second aspect of the present invention provides a high flash point jet fuel prepared by the method described in the first aspect, wherein the high flash point jet fuel has an initial boiling point of 175-195°C, a final boiling point of 245-260°C, and a flash point greater than 60°C.

[0069] According to some embodiments of the present invention, preferably, the flash point of the high flash point jet fuel is 61-75°C.

[0070] According to some embodiments of the present invention, preferably, the total sulfur content of the high flash point jet fuel is ≤0.005wt%.

[0071] According to some embodiments of the present invention, preferably, the smoke point of the high flash point jet fuel is greater than 20 mm, more preferably 20.5-22.5 mm.

[0072] According to some embodiments of the present invention, preferably, the high flash point jet fuel has a density of 804-810 kg / m³ at 20°C. 3 .

[0073] According to some embodiments of the present invention, preferably, the freezing point of the high flash point jet fuel is ≯-47°C.

[0074] According to some embodiments of the present invention, the high flash point jet fuel product can be ensured to have good oxidation stability, lubricity, and safety by adding appropriate amounts of aviation kerosene antioxidants, aviation kerosene antistatic agents, and aviation kerosene antiwear agents.

[0075] The method provided by the present invention will be further described in detail below with reference to the accompanying drawings.

[0076] like Figure 1 As shown, in a preferred embodiment of the method of the present invention, the feedstock oil (straight-run diesel) 1 is first heated by a heat exchanger, and the hydrogen gas 2 is heated by a heater 3. Then, the heated feedstock oil 1 and the heated hydrogen gas 2 are mixed and introduced into a hydrorefining reactor 4 containing a hydrorefining catalyst to carry out a hydrorefining reaction and obtain a refined effluent.

[0077] The refined effluent is fed into a hydrocracking reactor 5 containing a hydrocracking catalyst for hydrocracking reaction to obtain a cracked effluent.

[0078] The cracking effluent is heat-exchanged with the feed oil 1 in a heat exchanger and then sent to a medium-temperature high-pressure separator 6 for hot high-pressure gas-liquid separation to obtain gas phase product I and liquid phase product I; the liquid phase product I is sent to a medium-temperature low-pressure separator 7 for hot low-pressure gas-liquid separation to obtain gas phase product II and liquid phase product II; the gas phase product I is sent to a cold high-pressure separator 8 for gas-liquid separation to obtain gas phase product III and liquid phase product III.

[0079] The gaseous product III is sent to the circulating hydrogen desulfurization tower 26 to remove hydrogen sulfide, and then recycled.

[0080] After the liquid product III and the gaseous product II obtained from the medium-temperature low-pressure separator 7 are separated by the cold low-pressure separator 9, the liquid product IV at the bottom of the cold low-pressure separator 9 and the liquid product II are sent to the hydrogen sulfide stripping tower 10 to remove the hydrogen sulfide. The gaseous phase at the top of the tower is sent to the first top reflux tank 11 for three-phase separation of oil, gas and water phases to obtain water phase, dry gas 12 and light naphtha fraction. The light naphtha fraction is divided into a first part light naphtha fraction 27 and a second part light naphtha fraction 13. The first part light naphtha fraction 27 is returned to the hydrogen sulfide stripping tower 10, and the second part light naphtha fraction 13 is discharged from the device.

[0081] Preferably, the volumetric flow rate ratio of the first portion of light naphtha fraction to the second portion of light naphtha fraction is (4-5):1;

[0082] The bottom liquid phase of the hydrogen sulfide stripping tower 10 is sent to the product fractionation tower 14 for fractionation to obtain naphtha fraction 15, kerosene fraction 16, diesel fraction I 17, and diesel fraction II 18; wherein:

[0083] The naphtha fraction 15 is sent to the second top reflux tank 19 for gas-liquid separation to obtain light component 28 and heavy naphtha fraction. The heavy naphtha fraction is divided into a first heavy naphtha fraction 20 and a second heavy naphtha fraction 21. The first heavy naphtha fraction 20 is returned to the product fractionation tower 14, and the second heavy naphtha fraction 21 is discharged from the device.

[0084] Preferably, the volumetric flow rate ratio of the first portion of heavy naphtha fraction to the second portion of heavy naphtha fraction is (1-2):1;

[0085] The kerosene fraction 16 enters the aviation kerosene stripping tower 22 for gas-liquid separation. The light components at the top of the tower are returned to the product fractionation tower 14, and the liquid phase at the bottom of the tower is discharged from the device as aviation kerosene product 23.

[0086] The diesel fraction I17 enters the low-pour-point diesel stripping tower 24 for gas-liquid separation. The light components at the top of the tower are returned to the product fractionation tower 14, while the heavy components at the bottom of the tower are discharged from the device as high-flash-point jet fuel product 25.

[0087] The present invention will be described in detail below through embodiments.

[0088] In the following examples and comparative examples, unless otherwise specified, all raw materials used are commercially available products. The properties of the raw material oils used are shown in Table 1.

[0089] The hydrorefining catalyst used has the following composition: the support is alumina; the active components are MoO3 and NiO; based on the total weight of the hydrorefining catalyst, the content of MoO3 is 25wt%, the content of NiO is 4.2wt%, and the balance is the support.

[0090] The hydrocracking catalyst used has the following composition: the support is alumina; the active components are NiO and WO3; based on the total weight of the hydrorefining catalyst, the content of WO3 is 22wt%, the content of NiO is 6.0wt%, and the balance is the support.

[0091] Table 1: Properties of Feed Oil

[0092] Property parameters unit Test methods Raw material oil A Raw material oil B Machine miscellaneous / Visual inspection none none Density at 20℃ <![CDATA[kg / m 3 ]]> SH / T0604 827 824 Nitrogen content mg / kg SH / T 0657 106 74 Sulfur content wt% GB / T 17040 0.77 0.73 Chlorine content mg / kg Q / SH3155.S01.078 ＜0.5 ＜0.5 Initial boiling point ℃ GB / T 6536 198 190 Final boiling point ℃ GB / T 6536 334 330 Moisture / Visual inspection none none Carbon residue wt% GB / T17144 ＜0.1 ＜0.1 Total metal content μg / g Q / SH3155.S01.500 ＜1 ＜1 C7 insoluble matter μg / g Q / SH3155.SO1.130 ＜100 ＜100

[0093] Examples 1-6 illustrate the method provided by the present invention.

[0094] Example 1

[0095] Adopting such Figure 1 The process flow shown is as follows, wherein:

[0096] The straight-run diesel oil used is feedstock A; before the hydrorefining reaction, the feedstock oil and hydrogen are preheated to 350°C respectively before being mixed.

[0097] The reaction conditions for the hydrorefining reaction were: reaction temperature 355℃, reaction pressure 8.5MPa, hydrogen-to-oil volume ratio 700:1, and volume hourly space velocity (VHSV) 3h⁻¹. -1 ;

[0098] The reaction conditions for the hydrocracking reaction were: a reaction temperature of 371℃, a reaction pressure of 8.5 MPa, a hydrogen-to-oil volume ratio of 700:1, and a volume hourly space velocity of 2 h⁻¹. -1 ;

[0099] The top temperature of the distillation column is 120℃, and the bottom temperature is 268℃.

[0100] The extraction temperature of the kerosene fraction is 152℃; the extraction temperature of diesel fraction I is 183℃.

[0101] The extraction rate of kerosene fraction is 8 t / h; the conditions for gas-liquid separation of kerosene fraction in the jet kerosene stripping tower are: the bottom temperature of the jet kerosene stripping tower is 182℃.

[0102] The conditions for gas-liquid separation of diesel fraction I in the low-pour-point diesel stripping tower are as follows: the bottom temperature of the low-pour-point diesel stripping tower is 210℃; the extraction rate of high flash point jet fuel product is 14.5t / h; and the return temperature is 214℃.

[0103] The volumetric flow rate ratio of the first part of light naphtha fraction to the second part of light naphtha fraction is 4.9:1; the volumetric flow rate ratio of the first part of heavy naphtha fraction to the second part of heavy naphtha fraction is 1.5:1.

[0104] Example 2

[0105] The method is the same as in Example 1, except that:

[0106] The straight-run diesel oil used is feedstock B;

[0107] The reaction conditions for the hydrorefining reaction were: reaction temperature 355℃, reaction pressure 8.5MPa, hydrogen-to-oil volume ratio 700:1, and volume hourly space velocity (VHSV) 3h⁻¹. -1 ;

[0108] The reaction conditions for the hydrocracking reaction were: a reaction temperature of 371℃, a reaction pressure of 8.5 MPa, a hydrogen-to-oil volume ratio of 700:1, and a volume hourly space velocity of 2 h⁻¹. -1 ;

[0109] The top temperature of the distillation column is 122℃, and the bottom temperature is 265℃.

[0110] The extraction temperature of the kerosene fraction is 155℃, and the extraction temperature of diesel fraction I is 183℃.

[0111] The extraction rate of kerosene fraction is 10 t / h; the conditions for gas-liquid separation of kerosene fraction in the jet kerosene stripping tower are: the bottom temperature of the jet kerosene stripping tower is 184℃.

[0112] The conditions for gas-liquid separation of diesel fraction I in the low-pour-point diesel stripping tower are as follows: the bottom temperature of the low-pour-point diesel stripping tower is 210℃; the extraction rate of high flash point jet fuel product is 14.5t / h; the return temperature is 214℃; and all other conditions are the same.

[0113] Example 3

[0114] The method is the same as in Example 1, except that:

[0115] The reaction conditions for the hydrorefining reaction were: reaction temperature 355℃, reaction pressure 8.5MPa, hydrogen-to-oil volume ratio 700:1, and volume hourly space velocity (VHSV) 3h⁻¹. -1 ;

[0116] The reaction conditions for the hydrocracking reaction were: a reaction temperature of 371℃, a reaction pressure of 8.5 MPa, a hydrogen-to-oil volume ratio of 700:1, and a volume hourly space velocity of 2 h⁻¹. -1 ;

[0117] The top temperature of the distillation column is 124℃, and the bottom temperature is 265℃.

[0118] The extraction temperature of the kerosene fraction is 155℃, and the extraction temperature of diesel fraction I is 183℃.

[0119] The extraction rate of kerosene fraction is 10 t / h; the conditions for gas-liquid separation of kerosene fraction in the jet kerosene stripping tower are: the bottom temperature of the jet kerosene stripping tower is 184℃.

[0120] The conditions for gas-liquid separation of diesel fraction I in the low-pour-point diesel stripping tower are as follows: the bottom temperature of the low-pour-point diesel stripping tower is 210℃; the extraction rate of high flash point jet fuel product is 14.5t / h; the return temperature is 214℃; and all other conditions are the same.

[0121] Example 4

[0122] The method is the same as in Example 1, except that:

[0123] The reaction conditions for the hydrorefining reaction were: reaction temperature 355℃, reaction pressure 8.5MPa, hydrogen-to-oil volume ratio 700:1, and volume hourly space velocity (VHSV) 3h⁻¹. -1 ;

[0124] The reaction conditions for the hydrocracking reaction were: a reaction temperature of 371℃, a reaction pressure of 8.5 MPa, a hydrogen-to-oil volume ratio of 700:1, and a volume hourly space velocity of 2 h⁻¹. -1 ;

[0125] The top temperature of the distillation column is 120℃, and the bottom temperature is 268℃.

[0126] The extraction temperature of the kerosene fraction is 152℃, and the extraction temperature of diesel fraction I is 180℃.

[0127] The extraction rate of kerosene fraction is 8 t / h; the conditions for gas-liquid separation of kerosene fraction in the jet kerosene stripping tower are: the bottom temperature of the jet kerosene stripping tower is 180℃.

[0128] The conditions for gas-liquid separation of diesel fraction I in the low-pour-point diesel stripping tower are as follows: the bottom temperature of the low-pour-point diesel stripping tower is 207℃; the extraction rate of high flash point jet fuel product is 13.5t / h; the return temperature is 214℃; and all other conditions are the same.

[0129] Example 5

[0130] The method is the same as in Example 1, except that:

[0131] The reaction conditions for the hydrorefining reaction were: reaction temperature 355℃, reaction pressure 8.5MPa, hydrogen-to-oil volume ratio 700:1, and volume hourly space velocity (VHSV) 3h⁻¹. -1 ;

[0132] The reaction conditions for the hydrocracking reaction were: a reaction temperature of 371℃, a reaction pressure of 8.5 MPa, a hydrogen-to-oil volume ratio of 700:1, and a volume hourly space velocity of 2 h⁻¹. -1 ;

[0133] The top temperature of the distillation column is 122℃, and the bottom temperature is 265℃.

[0134] The extraction temperature of the kerosene fraction is 155℃, and the extraction temperature of diesel fraction I is 180℃.

[0135] The extraction rate of kerosene fraction is 10 t / h; the conditions for gas-liquid separation of kerosene fraction in the jet kerosene stripping tower are: the bottom temperature of the jet kerosene stripping tower is 180℃.

[0136] The conditions for gas-liquid separation of diesel fraction I in the low-pour-point diesel stripping tower are as follows: the bottom temperature of the low-pour-point diesel stripping tower is 207℃; the extraction rate of high flash point jet fuel product is 13t / h; the return temperature is 214℃; and all other conditions are the same.

[0137] Example 6

[0138] The method is the same as in Example 1, except that:

[0139] The reaction conditions for the hydrorefining reaction were: reaction temperature 355℃, reaction pressure 8.5MPa, hydrogen-to-oil volume ratio 700:1, and volume hourly space velocity (VHSV) 3h⁻¹. -1 ;

[0140] The reaction conditions for the hydrocracking reaction were: a reaction temperature of 371℃, a reaction pressure of 8.5 MPa, a hydrogen-to-oil volume ratio of 700:1, and a volume hourly space velocity of 2 h⁻¹. -1 ;

[0141] The top temperature of the distillation column is 118℃, and the bottom temperature is 265℃.

[0142] The extraction temperature of the kerosene fraction is 150℃, and the extraction temperature of diesel fraction I is 183℃.

[0143] The extraction rate of kerosene fraction is 7 t / h; the conditions for gas-liquid separation of kerosene fraction in the jet kerosene stripping tower are: the bottom temperature of the jet kerosene stripping tower is 178℃.

[0144] The conditions for gas-liquid separation of diesel fraction I in the low-pour-point diesel stripping tower are as follows: the bottom temperature of the low-pour-point diesel stripping tower is 210℃; the extraction rate of high flash point jet fuel product is 14.5t / h; the return temperature is 214℃; and all other conditions are the same.

[0145] The yield and properties of the products obtained in each embodiment are shown in Table 2.

[0146] Table 2

[0147]

[0148]

[0149] The results above show that the method provided by the present invention can achieve stable production of high flash point jet fuel at low cost, with a flash point greater than 60°C, and improves the quality of high flash point jet fuel products.

[0150] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for producing high flash point jet fuel, characterized in that, The method includes: (1) After the feedstock oil is mixed with hydrogen, it enters a hydrorefining reactor containing a hydrorefining catalyst to carry out a hydrorefining reaction and obtain a refined effluent; The feedstock oil is straight-run diesel oil, and the density of the straight-run diesel oil at 20°C is 820-840 kg / m³. 3 Sulfur content ≤ 1.0 wt%, initial boiling point 187-213℃, final boiling point 322-349℃; The hydrorefining catalyst comprises a support and an active component supported on the support; the support is alumina; the active component is Mo and Ni; based on the total weight of the hydrorefining catalyst, the content of Mo is 22-25 wt% and the content of Ni is 3.6-4.2 wt% (calculated as oxides); the content of the support is 68-72 wt%; and the sum of the contents of all components is 100 wt%. (2) The refined effluent is introduced into a hydrocracking reactor containing a hydrocracking catalyst to carry out a hydrocracking reaction, thereby obtaining a cracked effluent; The hydrocracking catalyst comprises a support and an active component supported on the support; the support is alumina; the active component is Ni and W; based on the total weight of the hydrocracking catalyst, the content of W is 22-25 wt% and the content of Ni is 6.0-7.5 wt% (calculated as oxides); the content of the support is 70-74 wt%; and the sum of the contents of all components is 100 wt%. (3) The cracking effluent is fractionated to obtain naphtha fraction, kerosene fraction, diesel fraction I and diesel fraction II; (4) The diesel fraction I is separated into gas and liquid in a low-pour-point diesel stripping tower to obtain a light component that can be recycled back to step (3) for the fractionation and a heavy component that is discharged from the device as a high flash point jet fuel product. The conditions for gas-liquid separation include: the bottom temperature of the low-pour-point diesel stripping tower is 200-225℃; the extraction rate of the high flash point jet fuel product is 10-18 t / h; the return temperature is 210-230℃; the initial boiling point of the high flash point jet fuel product is 175-195℃, the final boiling point is 245-260℃, and the flash point is greater than 60℃.

2. The method according to claim 1, wherein, In step (1), the density of the straight-run diesel oil at 20°C is 822-830 kg / m³. 3 Sulfur content is 0.4-0.85 wt%; nitrogen content is ≤150 mg / kg; residual carbon value is less than 0.1 wt%.

3. The method according to claim 2, wherein, The nitrogen content of the straight-run diesel oil is 0-120 mg / kg.

4. The method according to any one of claims 1-3, wherein, In step (1), the reaction conditions for the hydrorefining reaction include: a reaction temperature of 300-400℃, a reaction pressure of 6-10 MPa, a hydrogen-to-oil volume ratio of (500-1000):1, and a volume hourly space velocity of 2-5 h⁻¹. -1 .

5. The method according to any one of claims 1-3, wherein, In step (1), before the hydrorefining reaction is carried out, step (1) further includes: preheating the raw material oil and hydrogen to 350-400°C respectively before mixing.

6. The method according to any one of claims 1-3, wherein, In step (2), the reaction conditions for the hydrocracking reaction include: a reaction temperature of 300-400℃, a reaction pressure of 5-10 MPa, a hydrogen-to-oil volume ratio of (500-1000):1, and a volume hourly space velocity of 1-4 h⁻¹. -1 .

7. The method according to any one of claims 1-3, wherein, In step (3), the fractionation is carried out in a fractionation tower. Before the fractionation, the method further includes: setting a high-pressure separator and a low-pressure separator between the hydrocracking reactor and the fractionation tower according to the flow direction of the reaction stream, so as to separate the cracking effluent into gas and liquid, and then introducing the obtained liquid phase product into a hydrogen sulfide stripping tower to remove the hydrogen sulfide therein.

8. The method according to claim 7, wherein, The temperature at the top of the distillation column is 110-125℃, and the temperature at the bottom of the column is 260-270℃.

9. The method according to any one of claims 1-3, wherein, In step (3), the extraction temperature of the kerosene fraction is 150-158℃; the extraction temperature of the diesel fraction I is 180-185℃.

10. The method according to any one of claims 1-3, wherein, In step (3), the extraction rate of the kerosene fraction is 5-20 t / h.

11. The method according to any one of claims 1-3, wherein, The method further includes: performing gas-liquid separation on the kerosene fraction to obtain a gas phase that can be recycled back to step (3) for the fractionation and a liquid phase that is used as aviation kerosene product exit device.

12. The method according to claim 11, wherein, The kerosene fraction is subjected to gas-liquid separation in an aviation kerosene stripping tower, wherein the bottom temperature of the aviation kerosene stripping tower is 170-200℃.

13. The method according to claim 11, wherein, The liquid phase of the jet fuel product outlet has a distillation range of 160-233℃ and a density of 792-797 kg / m³ at 20℃. 3 Freezing point less than -60℃; flash point 43-50℃; smoke point 21-23 mm.

14. A high flash point jet fuel prepared by the method according to any one of claims 1-13, characterized in that, The high flash point jet fuel has an initial boiling point of 175-195℃ and a final boiling point of 245-260℃; its flash point is greater than or equal to 61℃.

15. The high flash point jet fuel according to claim 14, wherein, The high flash point jet fuel has a flash point of 61-75℃ and a total sulfur content of ≤0.005wt%.

16. The high flash point jet fuel according to claim 14, wherein, The high flash point jet fuel has a smoke point greater than 20 mm; its density at 20°C is 804-810 kg / m³. 3 Freezing point ≯ -47℃.

17. The high flash point jet fuel according to claim 16, wherein, The smoke point of the high flash point jet fuel is 20.5-22.5 mm.

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