A process for the production of rocket propellant

Abstract

The application discloses a production method of rocket jet fuel, and through processing and treatment, rocket kerosene products are obtained, and a new process technology is provided for high-value utilization of poor diesel oil materials such as catalytic diesel oil; meanwhile, the application adopts two reactors to match the hydrogenation and cracking reaction process, so that the processing depth and product properties can be flexibly regulated and controlled, and the rocket jet fuel with low freezing point (the freezing point can be lower than -70 DEG C) and the density in the range of 0.830-0.836 g / cm 3 .

Description

Technical Field

[0001] The invention belongs to the technical field of oil processing, and in particular relates to a method for producing rocket jet fuel. Background Art

[0002] Rocket engines are used to eject a working fluid (a medium) to generate a reaction force that propels an aircraft forward. They carry their own propellant and do not rely on external working fluids to generate thrust. They can fly in and out of the dense atmosphere, and are the vehicles that enable space flight. Rockets are divided into sounding rockets and launch vehicles based on their purpose, and both types require rocket fuel as a power source. my country's aerospace industry has entered the commercialization process in many areas. In recent years, with the country's vigorous promotion of military-civilian integration and the industrial upgrading and transformation of "Internet + Space", against the backdrop of a new round of global industrial revolution, China's aerospace sector has made breakthrough progress in the development of commercial space. Taking all of these factors into consideration, the current use of rocket fuel is gradually increasing.

[0003] To meet the rapid growth of my country's satellite launch sector, the country will further develop high-thrust, highly reliable, low-cost, and pollution-free launch vehicles. Compared to previous rocket engines that used liquid fuels such as liquid hydrogen, hydrazine fuel, alcohol, hydrogen peroxide / kerosene, and liquid oxygen / methane, the new generation of rocket engines primarily uses liquid oxygen / kerosene fuel. Its advantages include: 1) high safety, as kerosene can be used as a room-temperature propellant, thus providing excellent safety; 2) high economic efficiency, as the low price of kerosene can significantly reduce rocket launch costs; 3) high environmental friendliness, as it is non-toxic and pollution-free compared to conventional fuels, making it environmentally friendly and green; and 4) high feasibility, as the development of liquid oxygen / kerosene engines is relatively easy. Therefore, the research and development of rocket kerosene fuel has attracted widespread attention.

[0004] The freezing point is the lowest temperature at which crystals disappear after the fuel crystallizes. The freezing point is a key indicator of aviation fuel's low-temperature performance. It determines whether the fuel can be pumped and filtered smoothly within the aircraft's fuel system at low temperatures. This means it must not clog filters due to hydrocarbon crystals or frozen water, hindering delivery. The GJB jet fuel standard requires rocket fuel to have a freezing point of ≤-60°C. This is more stringent than my country's current No. 3 jet fuel due to its more demanding operating conditions. Therefore, developing rocket fuel with a low freezing point is of great practical significance.

[0005] On the other hand, as my country's automotive diesel standards become increasingly stringent, inferior diesel with a high aromatic content is difficult to process directly as a blending component of automotive diesel. The high-value comprehensive utilization of inferior diesel has become a research and development hotspot. Therefore, the use of inferior diesel for processing and producing qualified rocket fuel has practical significance and broad application prospects.

[0006] CN 105441124 A discloses a method for producing jet fuel, comprising using a catalytically cracked diesel feedstock having an aromatics content of more than 40% and sequentially subjecting it to hydrorefining and hydrocracking to produce high-density jet fuel that meets the GJB1603 No. 6 jet fuel standard, while also producing high-quality diesel. This method also uses catalytically cracked diesel as a raw material to produce jet fuel products, and the process flow is simple and easy to implement, but it is not suitable for producing rocket jet fuel.

[0007] CN108191599 A discloses a four-membered ring fuel molecule and a method for photochemically preparing the four-membered ring fuel molecule. The high-tension four-membered ring fuel molecule of the invention exhibits the excellent properties of high density, high calorific value, and low freezing point. However, the method uses reagents such as substituted cycloalkenones, resulting in high production costs and limited widespread adoption.

[0008] CN105441127B discloses a method for producing jet fuel, comprising the following steps: first fractionating catalytically cracked diesel, contacting the light fraction with hydrogen and a hydrotreating catalyst, and obtaining a jet fuel with a total cycloalkanes yield of 75-90%. This method has a simple process flow and can produce high-density jet fuel. However, because the raw material fractionation does not focus on the enrichment of monocyclic and bicyclic hydrocarbons and lacks product optimization, the resulting jet fuel has a high density and is difficult to meet the standard requirements for rocket kerosene in my country.

[0009] CN105419865B uses catalytic diesel to produce high-density jet fuel using a hydrocracking process. This method can use catalytically cracked diesel as a feedstock to produce jet fuel that complies with GJB 16036 at a high yield. However, the process requires mixing at least a portion of the diesel with the feedstock oil, or mixing at least a portion of the diesel with a liquid feed of the hydrocracking catalyst, resulting in a complex distillation range and a low throughput.

[0010] US Patent No. 4,875,992 discloses a method for producing aviation kerosene from condensed-ring aromatics and hydroaromatics. The feedstock is an oil rich in dicyclic aromatics and dicyclic hydroaromatics, including light catalytic cycle oil, fuel oil, or coal-based oil. The feedstock is first desulfurized and denitrogenated, then hydrogenated to produce cycloalkanes with an aromatics content of less than 50%. This method requires the feedstock to contain 85%-100% dicyclic aromatics and dicyclic hydroaromatics, placing stringent requirements on the feedstock. Furthermore, the product's high aromatics content makes it difficult to use as rocket kerosene. Summary of the Invention

[0011] Compared to general jet fuel (such as aviation jet fuel), rocket fuel has more stringent requirements for product properties, such as freezing point and density. Currently, low-quality diesel fuel, such as catalytically cracked diesel, contains high levels of aromatics, and the distribution of aromatics varies significantly across different distillation ranges. Based on the understanding of the distribution patterns of aromatics and cycloalkanes of different carbon numbers before and after hydrogenation of low-quality diesel feedstock, and the significant variation in paraffin content in different catalytically cracked diesel fuels, ranging from 5 to 20 wt%, this in turn affects the freezing point of the produced rocket fuel. Existing technologies for producing low-freezing-point rocket fuel from low-quality diesel fuel present technical obstacles.

[0012] In order to solve the above technical problems, the present invention provides a method for producing rocket jet fuel, which can produce rocket jet fuel with low freezing point (freezing point can be lower than -70℃) and density between 0.830-0.836g / cm 3 range of rocket jet fuel.

[0013] The present invention provides a method for producing rocket jet fuel, which specifically comprises the following steps:

[0014] S1, fractionating low-quality diesel crude oil and collecting its light components to obtain a component I rich in monocyclic and bicyclic hydrocarbons;

[0015] The final distillation point of the fractionation is 230-270°C;

[0016] The content of monocyclic and bicyclic aromatic hydrocarbons in the component I is 70-85 wt%;

[0017] The component I rich in monocyclic and bicyclic hydrocarbons includes monocyclic cycloalkanes, monocyclic aromatic hydrocarbons, bicyclic alkanes and bicyclic aromatic hydrocarbons;

[0018] S2. contacting the component I rich in monocyclic and bicyclic hydrocarbons with a hydrorefining catalyst under hydrorefining reaction conditions and performing a hydrorefining treatment to obtain a hydrorefining product stream;

[0019] S3, directly entering the hydrorefined product stream obtained in step S2 into a hydrocracking reactor without separation, contacting it with a hydrocracking catalyst and performing a hydrocracking treatment to obtain a hydrocracking product stream;

[0020] S4, separating low-freezing-point rocket fuel from the hydrocracked product stream obtained in step S3;

[0021] The total content of aromatics in the inferior diesel feedstock is 70-95 wt%, preferably 75-95 wt%.

[0022] The present application is to collect the light component by fractionating the inferior diesel oil raw material and strictly controlling the end point of fractionation at 230-270℃, so as to obtain the component rich in monocyclic and bicyclic hydrocarbons, which is beneficial to further reduce the freezing point of the rocket kerosene fuel. The fractionation method can be atmospheric or vacuum distillation, or the method recognized in the industry.

[0023] According to an embodiment of the present application, the inferior diesel oil raw material is catalytic cracking diesel oil, or a mixture of catalytic cracking diesel oil and one or more of catalytic cracking heavy cycle oil, coal tar, and coal liquefied oil. The total content of aromatic hydrocarbons in the inferior diesel oil raw material is 70-95wt%, preferably 75-95wt%, based on the total amount of the mixed oil. When the inferior diesel oil raw material is a mixture of catalytic cracking diesel oil and one or more of catalytic cracking heavy cycle oil, coal tar, and coal liquefied oil, the mixing ratio of catalytic cracking diesel oil is 50-100wt%.

[0024] According to an embodiment of the present application, the content of monocyclic and bicyclic aromatic hydrocarbons in the component I is 70-85wt%, preferably 75-80wt%. The content of tricyclic hydrocarbons in the raw material component I is less than 5wt%, preferably not more than 2wt%.

[0025] The monocyclic and bicyclic component I includes monocyclic naphthenes, monocyclic aromatic hydrocarbons, bicyclic alkanes, and bicyclic aromatic hydrocarbons.

[0026] According to an embodiment of the present application, the content of naphthenes in the hydrogenation refining product stream is 65-80wt%.

[0027] According to an embodiment of the present application, the content of naphthenes in the hydrogenation cracking product stream is 70-95wt%.

[0028] According to an embodiment of the present application, the total content of naphthenes in the low-freezing-point rocket kerosene fuel is 75-95wt%, and the freezing point is lower than -70℃.

[0029] According to an embodiment of the present application, the hydrogenation refining catalyst includes at least two metal components, an alumina carrier, and at least two organic compounds of different types selected from organic alcohols, organic carboxylic acids, and organic amines, and the hydrogenation refining catalyst contains at least two CO2 release spectrum peaks in the temperature programmed oxidation process.

[0030] The water absorption of the above-mentioned alumina carrier is greater than 0.9mL / g, the average pore size is 6-18nm, and the specific surface area is greater than 260mL / g.

[0031] Preferably, the pore volume of the alumina support used in the hydrotreating catalyst is not more than 10%, preferably not more than 8%, of the pore volume of the support. Furthermore, the pore volume of the alumina support used in the hydrotreating catalyst is not more than 4%, preferably not more than 2%, of the pore volume of the alumina support used in the hydrotreating catalyst.

[0032] The specific surface area, pore volume and average pore diameter are measured after the catalyst is calcined at 400°C for 3 hours.

[0033] The hydrorefining catalyst is in the shape of a cylinder, a three-leaf clover, a four-leaf clover, a honeycomb or other shapes.

[0034] In the present invention, the pore distribution, pore diameter, and pore volume of the catalyst were determined using the BET method and mercury intrusion porosimetry (see "Analytical Methods in Petrochemical Engineering (RIPP Test Method)", edited by Yang Cuiding et al., Science Press, 1990). The pore volume of pores in the range of 2-100 nm was calculated based on the BET results, and the pore volume of pores in the range of 100-300 nm was calculated based on the mercury intrusion porosimetry results.

[0035] The hydrorefining catalyst of the present invention utilizes an alumina carrier containing phosphorus, calculated as P2O5, in an amount of 10-40% by weight, and preferably 20-30% by weight, of the total phosphorus content of the hydrorefining catalyst. The phosphorus in the alumina carrier is derived from pseudo-boehmite powder, an alumina precursor. Preferably, the sodium oxide content of the pseudo-boehmite powder does not exceed 0.08% by weight, and more preferably, does not exceed 0.05% by weight.

[0036] The organic alcohol is one or more of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, amyl alcohol, heptanol, ethylene glycol, glycerol, tetratetrol, polyethylene glycol, polyglycerol, pentaerythritol, xylitol, sorbitol or trimethylolethane;

[0037] The carboxylic acid is one or more of formic acid, acetic acid, propionic acid, citric acid, caprylic acid, adipic acid, malonic acid, succinic acid, maleic acid, valeric acid, caproic acid, capric acid, benzoic acid, phenylacetic acid, phthalic acid, terephthalic acid, valeric acid, caproic acid, capric acid, octadecanoic acid, and tartaric acid;

[0038] The organic amine is one or more of ethylenediamine, ethylenediaminetetraacetic acid, ethanolamine, triethanolamine, and cyclohexanediaminetetraacetic acid.

[0039] According to one embodiment of the present invention, in the hydrorefining catalyst, the metal component includes nickel and at least one Group VIB metal element, and the nickel oxide content is 1-15wt%, and the content of the Group VIB metal oxide is 12-50wt% based on the entire hydrorefining catalyst; and the molar ratio of nickel oxide to total metal oxides in the hydrorefining catalyst is 0.1-0.5, preferably 0.2-0.35.

[0040] According to one embodiment of the present invention, the hydrotreating catalyst comprises at least two different types of organic compounds selected from organic alcohols, organic carboxylic acids and organic amines, wherein the molar ratio of the organic alcohol to the VIB Group metal is 0.2-4, and the molar ratio of the organic carboxylic acid compound or the organic amine to the Group VIII metal element is 0.1-4.

[0041] Two or more different types of organic additives are introduced into the hydrorefining catalyst. These organics can release CO2 during the temperature-programmed oxidation process. The temperature of the first CO2 release peak is between 200-300°C, and the temperature of the second CO2 release peak is between 300-400°C. The peak height ratio ranges from 1:1 to 5:1. Furthermore, the peak height ratio is preferably between 1.5:1 and 3:1.

[0042] According to one embodiment of the present invention, during the preparation process of the hydrorefining catalyst, a phosphorus-containing metal solution is used when citing the active metal, and the content of phosphorus element introduced into the catalyst together with the active metal in the hydrorefining catalyst is 1-5wt%, preferably 2-4wt%, calculated as P2O5.

[0043] Another portion of phosphorus in the hydrorefining catalyst of the present invention comes from the alumina carrier, accounting for 10-40 wt% of the total phosphorus content of the catalyst, preferably 20-30 wt% of the total phosphorus content.

[0044] According to one embodiment of the present invention, during the preparation of the hydrorefining catalyst, a phosphorus-containing substance is added during the preparation of a solution containing active metals.

[0045] By introducing phosphorus-containing substances during the preparation of the hydrorefining catalyst, especially adding phosphorus-containing substances during the preparation of the solution containing active metals, the hydrogenation of aromatic rings during the hydrorefining process is facilitated.

[0046] According to one embodiment of the present invention, during the solution preparation process for the hydrorefining catalyst, the hydroxyl-containing organic alcohol compound, the organic acid or organic amine, and the precursor containing the Group VIB metal element and nickel oxide are first added to an aqueous solution of the phosphorus-containing substance. The solution is then stirred at 40-100°C for 1-8 hours until all the solution is dissolved. The order of adding the organic substance, the phosphorus-containing substance, and the metal precursor can also be reversed.

[0047] The phosphorus-containing substances include, but are not limited to, one or more of phosphoric acid, hypophosphorous acid, ammonium phosphate, and ammonium dihydrogen phosphate.

[0048] According to one embodiment of the present invention, the alumina carrier is prepared by extrusion molding using pseudo-boehmite as a precursor.

[0049] In the present invention, examples of the VIB Group metal elements include, but are not limited to, one or more of chromium, molybdenum, and tungsten. The above-mentioned metal active components can be obtained in the catalyst by adding their precursors to the impregnation solution. Mo precursors include, but are not limited to, one or more of ammonium heptamolybdate, ammonium molybdate, ammonium phosphomolybdate, and molybdenum oxide; Ni precursors include, but are not limited to, one or more of nickel nitrate, basic nickel carbonate, nickel acetate, and nickel oxide; and tungsten precursors include, but are not limited to, one or more of ammonium metatungstate, ethylammonium metatungstate, and tungsten oxide.

[0050] According to the method of the present invention, the prepared hydrorefining catalyst has high aromatic saturation activity. Under hydrogenation process conditions, the aromatics in the low-quality diesel feedstock can be effectively hydrogenated and saturated to produce cycloalkanes. According to the method of the present invention, the hydrorefining reaction conditions are such that the cycloalkanes content in the hydrorefined product obtained in step S2 is 65-80wt%. Preferably, the hydrorefining reaction conditions are such that the total aromatic saturation rate in the hydrogenated product obtained in step S2 is 70-98wt%, preferably 80-96wt%. The total aromatic saturation rate is calculated using the following formula:

[0051] Total aromatic saturation rate = [(mass of aromatics in the feed oil - mass of aromatics in the obtained hydrogenation product) / mass of aromatics in the feed oil] × 100%.

[0052] According to one embodiment of the present invention, the hydrofining reaction conditions may include: a temperature of 280-410°C, preferably 300-380°C; a hydrogen partial pressure of 4-16 MPa, preferably 6-15 MPa; a liquid hourly space velocity of 0.1-3 h -1 , preferably 0.3-1.5h -1 ; Hydrogen to oil volume ratio is 100-1500Nm 3 / m 3 , preferably 300-1400Nm 3 / m 3 .

[0053] According to one embodiment of the present invention, the hydrocracking reaction conditions may include: a temperature of 290-410°C, preferably 320-390°C; a hydrogen partial pressure of 4-16 MPa, preferably 6-15 MPa; a liquid hourly space velocity of 0.1-3 h -1 , preferably 0.3-1.5h -1; Hydrogen to oil volume ratio is 100-1500Nm 3 / m 3 , preferably 300-1200Nm 3 / m 3 The hydrocracking reaction temperature is about 20°C higher than the hydrofining reaction temperature.

[0054] According to one embodiment of the present invention, the hydrocracking catalyst comprises a supported catalyst containing a Group VIB metal component and a Group VIII metal component, or an unsupported catalyst containing a Group VIB metal component and a Group VIII metal component; based on the total amount of the hydrocracking catalyst and calculated as oxide, the content of the Group VIII metal component is 1-10 wt%, preferably 2-6 wt%; and the content of the Group VIB metal component is 5-40 wt%, preferably 10-35 wt%.

[0055] According to one embodiment of the present invention, the carrier of the hydrocracking catalyst is one or more of silica, alumina, silica-alumina or zeolite molecular sieve; the zeolite molecular sieve is one or more of mordenite, L-type zeolite, ZSM-5 zeolite, Y-type zeolite or β-zeolite.

[0056] In the hydrocracking catalyst, the Group VIB metal is Mo and / or W, and the Group VIII metal is Co and / or Ni.

[0057] According to the method of the present invention, the prepared hydrocracking catalyst has high cracking activity for high-freezing-point hydrocarbon molecules. Under hydrogenation process conditions, the freezing point of rocket fuel can be significantly reduced. While meeting the requirements of GJB 9269 jet fuel, the freezing point is below -70°C.

[0058] The method of the present invention can produce high-density jet fuel that meets the GJB 9269 jet fuel standard, and the weight calorific value of the high-density jet fuel reaches or exceeds 42.9 MJ / kg.

[0059] Under the hydrocracking process conditions, the content of cycloalkanes in the obtained hydrocracking liquid product is 70-95wt%, preferably 75-90wt%;

[0060] The total content of cycloalkanes in the rocket fuel obtained during the fractionation process of the hydrocracking product stream is 75-95wt%, preferably 77-93wt%.

[0061] At present, the aromatic content in inferior diesel, such as catalytic cracking diesel, is relatively high, and there are obvious differences in the distribution patterns of aromatics within different distillation ranges. Based on the understanding of the distribution patterns of aromatics and cycloalkanes with different carbon numbers before and after hydrogenation of inferior diesel raw materials, and the large difference in the content of paraffins in different catalytic cracking diesels, ranging from 5 to 20wt%, which in turn affects the freezing point of the produced rocket fuel, there are technical obstacles to preparing low-freezing-point rocket jet fuel based on the above-mentioned inferior diesel. The technical solution of the present invention can solve the above technical problems and realize the preparation of low-freezing-point rocket jet fuel (freezing point below -70°C) using inferior diesel as raw material.

[0062] According to the method of the present invention, jet fuel can be separated from the effluent obtained in step S4 using various recognized methods. In one embodiment, the effluent obtained in step S4 can be separated in a high-pressure separator and then in a low-pressure separator. The gaseous stream separated in the high-pressure separator is a hydrogen-rich gas, which can be used as circulating hydrogen after purification and pressurization. The liquid stream from the low-pressure separator is fed into a fractionation unit to ultimately produce a jet fuel fraction rich in low-freezing-point components such as cycloalkanes.

[0063] The GJB 9629 rocket kerosene standard requires a distillation range of 188-270°C. Therefore, according to the method of the present invention, the distillation range of the rocket fuel is 188-270°C. Preferably, the final distillation point of the fractionation in step S4 is 220-260°C. The distillation range of the jet fuel is determined using the method specified in ASTM D-86.

[0064] The method of the present invention is used to produce jet fuel, and the obtained jet fuel is rocket fuel, and its density is 0.830-0.836g / cm 3 within the range.

[0065] The method according to the present invention has the following advantages:

[0066] (1) The method of the present invention can be used to produce rocket kerosene that meets the requirements of GJB9629 "Liquid Rocket Engine Kerosene Specifications" by utilizing inferior diesel such as catalytic diesel, and the density thereof reaches 0.830-0.836 g / cm 3 The weight calorific value reaches or exceeds 42.9MJ / kg, and the yield can reach 35-70% by weight;

[0067] (2) According to the method of the present invention, the freezing point of the rocket fuel produced can be lower than -70°C, which is lower than the standard requirement of no more than -60°C, and can provide technical guarantee for the smooth operation of rocket engines under extreme working conditions.

[0068] (3) The raw oil used in the present application is diesel oil fraction with wide sources and poor cleanliness, and the rocket kerosene product is obtained by processing and treatment, which provides a new process technology for high value utilization of catalytic diesel and other poor diesel raw materials, and the present application adopts two reactors to match the hydrogenation and cracking reaction process, so that the processing depth and product properties can be flexibly regulated. BRIEF DESCRIPTION OF DRAWINGS

[0069] Figure 1 A production method of a low-freezing-point rocket kerosene

[0070] BRIEF DESCRIPTION OF DRAWINGS

[0071] 1, hydrogen supplement; 2, raw oil;

[0072] 3, fractionating column; 4, reactor;

[0073] 5, cold hydrogen; 6, high-pressure separator;

[0074] 7, circulating hydrogen purification unit; 8, circulating hydrogen compression unit;

[0075] 9, low-pressure separator; 10, gas product;

[0076] 11, fractionating column; 12, naphtha;

[0077] 13, rocket kerosene; 14, diesel product;

[0078] 15, liquid stream; 16, gas stream;

[0079] 17, liquid stream 18, liquid stream;

[0080] 19, hydrocracking reactor; 20, liquid stream. DETAILED DESCRIPTION

[0081] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, and together with the following detailed description, serve to explain the present application, but do not constitute a limitation of the present application.

[0082] Figure 1 A preferred embodiment of the method according to the present application is shown. The following detailed description of the embodiment is given in conjunction with the drawings. Figure 1 The embodiment is described in detail. As Figure 1As shown, the poor quality diesel feedstock 2 is mixed with hydrogen and fed into a fractionating column 3 for heating. The separated component rich in single ring and double ring hydrocarbons is fed into a hydrofining reactor 4 for reaction with a hydrofining catalyst. The hydrofining reactor effluent is directly fed into a hydrocracking reactor 19 for reaction with a hydrocracking catalyst without separation. The hydrocracking reactor effluent 20 is fed into a high pressure separator 6 for gas-liquid separation to obtain a gas phase stream 16 and a liquid phase stream 17. The gas phase stream 16 is hydrogen-rich gas which is fed into a recycle hydrogen purification unit 7 for removal of impurities (such as sulfur compounds and / or nitrogen compounds) and then compressed by a recycle hydrogen compression unit 8 for use as recycle hydrogen. Make-up hydrogen 1 is mixed with the recycle hydrogen output from the recycle hydrogen compression unit 8. The liquid phase stream 17 is further separated in a low pressure separator 9 to obtain a gas product 10 which can be discharged and a liquid product 15. The liquid product 15 is fractionated in a fractionating column 11 to obtain rocket fuel 13, diesel product 14 and a small amount of light naphtha 12.

[0083] The application will be described in detail below with reference to the examples, but the scope of the application is not limited by the examples.

[0084] Examples 1-3 are used to illustrate the method of the application.

[0085] In the following examples and comparative examples, the composition of the catalyst is calculated based on the amount of the raw materials. The pore distribution, pore size and pore volume of the catalyst and the support in the range of 2-100 nm are determined by low temperature nitrogen adsorption method (see Petroleum Chemical Industry Analysis Method (RIPP Test Method), Yang Cuiding et al., Science Press, published in 1990), and the pore distribution, pore size and pore volume in the range of 100-300 nm are determined by mercury intrusion method. The sulfur mass fraction in the product is analyzed by a sulfur and nitrogen analyzer (Thermo Fisher, model TN / TS3000), and the aromatic content is analyzed by near infrared spectroscopy.

[0086] In the following examples and comparative examples, the rocket fuel fraction yield is defined as the weight percentage of the rocket fuel fraction separated from the whole fraction product by the fractionating column to the feedstock oil.

[0087] Example 1

[0088] The hydrofining catalyst I used in this example is prepared by the following method.

[0089] A certain amount of MoO3, basic nickel carbonate, ethylene glycol and citric acid are added to an aqueous solution containing phosphoric acid respectively, and heated and stirred until completely dissolved to obtain an impregnation solution containing active metals. The impregnation solution is mixed with the support uniformly, and then dried at 120°C for 5h to obtain an oxidized catalyst with a particle size of 1.6mm.

[0090] The catalyst was prepared using a γ-alumina carrier with a water absorption rate of 1.02 mL / g and a specific surface area of ​​275 m 2 / g, an average pore diameter of 12.5nm, pore volume with a pore diameter of 2-6nm accounts for 6.0% of the total pore volume, and pore volume with a pore diameter of 2-4nm accounts for 2.0% of the total pore volume. The sodium oxide content in the carrier is 0.05%.

[0091] The prepared catalyst contained 28.0% MoO₃, 5.5% nickel oxide, and 6.0% P₂O₅, of which 30% was derived from the support. The molar ratio of ethylene glycol to Group VI metal Mo was 1:1, and the molar ratio of citric acid to nickel oxide was 0.8:1. Temperature-programmed oxidation testing of the catalyst revealed CO₂ emission peaks at 250°C and 335°C, respectively, with a peak height ratio of 2.6.

[0092] The prepared catalyst is numbered as catalyst I.

[0093] The hydrocracking catalyst was prepared by mixing 182.3 g of pseudo-boehmite (a product of the Changling Branch of Sinopec Corporation, 70 wt. % on a dry basis) with 35.6 g of USY zeolite (a product of the Changling Branch of Sinopec Corporation, 75 wt. % on a dry basis) and extruding the mixture into trilobal bars with a circumscribed circle diameter of 1.6 mm. The wet bars were dried at 120°C for 3 hours and then calcined at 450°C for 4 hours to obtain the carrier ZT1.

[0094] 100 g of the carrier DZ1 was impregnated with 56 ml of a mixed aqueous solution of ammonium metatungstate (422 g / L in terms of WO3), ammonium molybdate (24.3 g / L in terms of MoO3), and nickel nitrate (69.8 g / L in terms of NiO) for 1 hour, followed by drying at 120°C for 2 hours and calcination at 450°C for 3 hours to obtain the catalytic cracking catalyst. The composition of the catalytic cracking catalyst was determined by X-ray fluorescence spectrometry, revealing that the content of MoO3 was 0.62% by weight, the content of WO3 was 21.3% by weight, and the content of NiO was 3.3% by weight. The resulting hydrocracking catalyst was L.

[0095] Raw material B was used to obtain raw material B1 after optimized fractionation. The specific fractionation method was atmospheric distillation, and the final distillation point was controlled at 270°C. The monocyclic aromatic hydrocarbon content in B1 was 58.7%. The specific process conditions and product distribution are shown in Table 2.

[0096] Table 1

[0097]

[0098]

[0099] Example 2

[0100] The hydrotreating catalyst II used in this example was prepared by the following method.

[0101] A certain amount of MoO3, basic nickel carbonate, glycerol, and acetic acid were added to an aqueous solution containing phosphoric acid and heated with stirring until completely dissolved, yielding an impregnation solution containing the active metals. The impregnation solution was then mixed with the support and dried at 120°C for 5 hours to produce an oxidized catalyst with a particle size of 1.6 mm.

[0102] The catalyst was prepared using a γ-alumina carrier with a water absorption rate of 1.02 mL / g and a specific surface area of ​​275 m 2 / g, an average pore diameter of 12.5nm, pore volume with a pore diameter of 2-6nm accounts for 6% of the total pore volume, and pore volume with a pore diameter of 2-4nm accounts for 2% of the total pore volume. The sodium oxide content in the carrier is 0.05%.

[0103] The prepared catalyst contained 15.0% MoO₃, 3.8% nickel oxide, and 8.0% P₂O₅, of which 30% was derived from the support. The molar ratio of glycerol to Group VI metal was 2:1, and the molar ratio of acetic acid to nickel oxide was 1:1. Temperature-programmed oxidation testing of the catalyst revealed CO₂ emission peaks at 245°C and 325°C, respectively, with a peak height ratio of 3.5.

[0104] The prepared catalyst is numbered as catalyst II. The hydrocracking catalyst is the same as that in Example 1.

[0105] The optimized raw material B1 was used to carry out hydrogenation reaction on raw material B. The specific process conditions and product distribution are shown in Table 2.

[0106] Example 3

[0107] The hydrotreating catalyst used in this example is the same as that in Example 1, namely, hydrogenation catalyst I. The hydrocracking catalyst is the same as that in Example 1.

[0108] The raw material B3 obtained after optimization was subjected to hydrogenation reaction. The raw material B was obtained by optimized fractionation of the raw material B. The specific fractionation method was atmospheric pressure fractionation, and the final distillation point was controlled at 230°C. The specific process conditions and product distribution are shown in Table 2.

[0109] Comparative Example 1

[0110] The hydrorefining catalyst I used in this example is the same as that used in Example 1, namely, hydrogenation catalyst I. The hydrocracking catalyst is the same as that used in Example 1. The separated feedstock B2 was used for the hydrogenation reaction. The specific fractionation method was atmospheric pressure fractionation, with the final distillation point controlled at 279°C. Specific process conditions and product distribution are shown in Table 2.

[0111] Comparative Example 2

[0112] The hydrorefining catalyst used in this example is the NiMo industrial catalyst RS-2100 developed by the China Petrochemical Research Institute, and the hydrocracking catalyst is the same as that in Example 1. The hydrogenation reaction was carried out using feedstock B1. The specific process conditions and product distribution are shown in Table 2.

[0113] Comparative Example 3

[0114] Other conditions were the same as those in Example 1, except that ethylene glycol and citric acid were not added during the preparation of the hydrorefining catalyst, and the resulting hydrogenation catalyst was Catalyst III.

[0115] Comparative Example 4

[0116] Other conditions were the same as those in Example 1, except that phosphoric acid was not added during the preparation of the active metal solution of the hydrorefining catalyst, and the resulting hydrogenation catalyst was Catalyst IV.

[0117] The results of Examples 1-3 demonstrate that the catalysts prepared using the method of the present invention exhibit high hydrogenation activity, can achieve ultra-deep hydrogenation saturation of aromatics in catalytic diesel feedstocks, and effectively reduce impurity content. Using the optimized feedstocks B1 and B3, the jet fuels prepared meet the technical requirements of GJB9629 jet fuel. However, in Comparative Example 1, the feedstock was not fractionated and optimized, so the properties of the resulting product did not meet the standard requirements. Due to the low hydrogenation activity of catalyst D1 in Comparative Example 2, the aromatics content of the hydrogenated product did not meet the standard. The hydrorefining catalysts in Comparative Examples 3 and 4 did not utilize the preferred catalyst preparation method, resulting in products with sulfur contents exceeding 10 μg / g and aromatics contents exceeding the required 5%.

[0118] Table 2

[0119]

[0120]

Claims

1. A method for producing rocket jet fuel, characterized in that: The specific steps include: S1, fractionating low-quality diesel crude oil and collecting its light components to obtain a component I rich in monocyclic and bicyclic hydrocarbons; The final distillation point of the fractionation is 230-270°C; The content of monocyclic and bicyclic aromatic hydrocarbons in the component I is 70-85 wt%; The component I rich in monocyclic and bicyclic hydrocarbons includes monocyclic cycloalkanes, monocyclic aromatic hydrocarbons, bicyclic alkanes and bicyclic aromatic hydrocarbons; S2. Contacting the monocyclic and bicyclic hydrocarbon-rich component I with a hydrorefining catalyst and performing a hydrorefining treatment under hydrorefining reaction conditions to obtain a hydrorefining product stream; the hydrorefining product stream has a cycloparaffin content of 65-80 wt %; S3, directly entering the hydrorefined product stream obtained in step S2 into a hydrocracking reactor without separation, contacting it with a hydrocracking catalyst and performing a hydrocracking treatment to obtain a hydrocracking product stream; The hydrocracking product stream has a cycloalkane content of 70-95 wt%; S4. Separating a low-freezing-point rocket fuel from the hydrocracked product stream obtained in step S3; wherein the low-freezing-point rocket fuel has a total cycloparaffin content of 75-95% by weight and a freezing point below -70°C; The total content of aromatics in the inferior diesel raw oil is 70-95wt%; The hydrorefining catalyst comprises: at least two active metals, an alumina carrier, and two different types of organic compounds selected from organic alcohols, organic carboxylic acids, and organic amines, wherein the organic amines are one or more of ethylenediamine, ethylenediaminetetraacetic acid, ethanolamine, triethanolamine, and cyclohexanediaminetetraacetic acid. The hydrorefining catalyst comprises two CO2 release spectrum peaks during a temperature-programmed oxidation process. The phosphorus content of the hydrorefining catalyst introduced into the catalyst together with the active metals is 1-5 wt% in terms of P2O5. Another portion of the phosphorus in the hydrorefining catalyst comes from the alumina carrier, accounting for 10-40 wt% of the total phosphorus content of the catalyst. The hydrorefining reaction conditions include: a temperature of 280-410°C; a hydrogen partial pressure of 4-16 MPa; and a liquid hourly volume space velocity of 0.1-3 h -1 ; Hydrogen to oil volume ratio is 100-1500Nm 3 / m 3 ; The hydrocracking catalyst is a supported catalyst containing a Group VIB metal component and a Group VIII metal component, or an unsupported catalyst containing a Group VIB metal component and a Group VIII metal component; based on the total amount of the hydrocracking catalyst and calculated as oxide, the content of the Group VIII metal component is 1-10 wt %; the content of the Group VIB metal component is 5-40 wt %; the hydrocracking reaction conditions include: a temperature of 290-410° C.; a hydrogen partial pressure of 4-16 MPa; a liquid hourly volume space velocity of 0.1-3 h -1 ; Hydrogen to oil volume ratio is 100-1500Nm 3 / m 3 ; The hydrocracking reaction temperature is 20°C higher than the hydrorefining reaction temperature.

2. The production method according to claim 1, characterized in that The total content of aromatics in the inferior diesel raw oil is 75-95 wt%.

3. The production method according to claim 1, characterized in that The inferior diesel feedstock oil is catalytically cracked diesel, or a mixture of catalytically cracked diesel and one or more of catalytically cracked heavy cycle oil, coal tar, and coal liquefaction oil; when the inferior diesel feedstock oil is a mixture of catalytically cracked diesel and one or more of catalytically cracked heavy cycle oil, coal tar, and coal liquefaction oil, the blending ratio of catalytically cracked diesel is greater than or equal to 50% and less than 100wt%.

4. The production method according to claim 1, characterized in that The active metal includes nickel and at least one Group VIB metal element. Based on the entire hydrorefining catalyst, the nickel oxide content is 1-15wt%, and the Group VIB metal oxide content is 12-50wt%. The molar ratio of nickel oxide to total metal oxides in the hydrorefining catalyst is 0.1-0.

5.

5. The production method according to claim 4, characterized in that The molar ratio of nickel oxide to total metal oxides in the hydrorefining catalyst is 0.2-0.

35.

6. The production method according to claim 4, characterized in that The molar ratio of the organic alcohol to the VIB group metal is 0.2-4, and the molar ratio of the carboxylic acid compound or nitrogen-containing organic matter to nickel is 0.1-4.

7. The production method according to claim 1, characterized in that The alumina carrier has a water absorption rate greater than 0.9 mL / g, an average pore diameter of 6-18 nm, and a specific surface area greater than 260 mL / g.

8. The production method according to claim 1, characterized in that During the preparation of the hydrorefining catalyst, a phosphorus-containing metal solution is used when adding active metal.

9. The production method according to claim 1, characterized in that The phosphorus content of the hydrorefining catalyst introduced into the catalyst together with the active metal is 2-4 wt% in terms of P2O5; Another portion of phosphorus in the hydrotreating catalyst comes from the alumina support, accounting for 20-30 wt% of the total phosphorus content of the catalyst.

10. The production method according to claim 1, characterized in that The organic alcohol is one or more of methanol, ethanol, propanol, butanol, pentanol, heptanol, ethylene glycol, glycerol, tetratrol, polyethylene glycol, polyglycerol, pentaerythritol, xylitol, sorbitol or trimethylolethane; The carboxylic acid is one or more of formic acid, acetic acid, propionic acid, citric acid, caprylic acid, adipic acid, malonic acid, succinic acid, maleic acid, valeric acid, hexanoic acid, capric acid, benzoic acid, phenylacetic acid, phthalic acid, terephthalic acid, octadecanoic acid, and tartaric acid.

11. The production method according to claim 1, characterized in that The hydrofining reaction conditions include: temperature of 300-380°C; hydrogen partial pressure of 6-15 MPa; liquid hourly volume space velocity of 0.3-1.5 h -1 ; Hydrogen to oil volume ratio is 300-1400Nm 3 / m 3 .

12. The production method according to claim 1, characterized in that The hydrocracking reaction conditions include: temperature of 320-390°C; hydrogen partial pressure of 6-15 MPa; liquid hourly volume space velocity of 0.3-1.5 h -1 ; Hydrogen to oil volume ratio is 300-1200Nm 3 / m 3 .

13. The production method according to claim 1, characterized in that The hydrocracking catalyst is a supported catalyst containing a Group VIB metal component and a Group VIII metal component, or an unsupported catalyst containing a Group VIB metal component and a Group VIII metal component; based on the total amount of the hydrocracking catalyst and calculated as oxide, the content of the Group VIII metal component is 2-6 wt%; and the content of the Group VIB metal component is 10-35 wt%.

14. The production method according to claim 13, characterized in that The carrier of the hydrocracking catalyst is one or more of silicon oxide, aluminum oxide, silicon oxide-alumina or zeolite molecular sieve; the zeolite molecular sieve is one or more of mordenite, L-type zeolite, ZSM-5 zeolite, Y-type zeolite or beta zeolite.

15. The production method according to claim 13, characterized in that In the hydrocracking catalyst, the Group VIB metal is Mo and / or W, and the Group VIII metal is Co and / or Ni.

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