CN113528182B

CN113528182B - Method for producing heavy aviation kerosene from heavy raw materials

Info

Publication number: CN113528182B
Application number: CN202010314143.5A
Authority: CN
Inventors: 毛以朝; 龙湘云; 杨清河; 张润强; 赵阳; 赵广乐
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2020-04-20
Filing date: 2020-04-20
Publication date: 2022-11-15
Anticipated expiration: 2040-04-20
Also published as: CN113528182A

Abstract

The invention relates to the field of aviation kerosene production, and discloses a method for producing heavy aviation kerosene from heavy raw materials, which comprises the following steps: (1) Carrying out a first contact reaction on hydrogen and heavy raw oil and a hydrofining catalyst to obtain a hydrotreating effluent; (2) Carrying out a second contact reaction on the hydrotreating effluent obtained in the step (1) and a hydrocracking catalyst to obtain a hydrocracking effluent; 3) Performing a third contact reaction on the hydrocracking effluent obtained in the step (2) and a post-refining catalyst to obtain a post-refining effluent; (4) Fractionating the post-refining effluent obtained in the step (3) to obtain an aviation kerosene fraction, wherein the distillation range of the aviation kerosene fraction is 170-240 ℃, and the density of the heavy raw oil is 0.92-1.05g/cm ³ And the fraction above 350 ℃ in the distillation range accounts for more than 10 percent by weight. The method provided by the invention has simple process flow, and can obtain high-quality large-specific gravity aviation kerosene.

Description

Method for producing heavy aviation kerosene by heavy raw materials

Technical Field

The invention relates to the field of aviation kerosene production, in particular to a method for producing heavy aviation kerosene by using heavy raw materials.

Background

The high-density jet fuel is also called large specific gravity aviation kerosene, and is a jet fuel with high density and high volume heat value. RJ-4, RJ-5, JP-5,JP-9, JP-10 and other series of high-density synthetic jet fuel with density over 0.935g/cm ³ . Compared with common 3# jet fuel (the density is generally 0.77-0.81 g/cm) ³ ) Compared with the prior art, the fuel has the advantages of improving the heat value of the fuel in unit volume, providing 5-9% of endurance mileage, improving the flight speed, reducing the flight time and having wide application prospect. The domestic standard GJB1603-93 (Large specific gravity jet fuel specification) specifies the fuel standard suitable for high-speed turbine engines, and the main index requires that the density reaches 0.835g/cm ³ The weight heat value reaches or exceeds 42.9MJ/kg, the flash point is not lower than 60, the aromatic hydrocarbon content is not more than 10 and the like. In order to meet the domestic requirements, the Qilu petrochemical research institute uses naphthenic base kerosene fraction as raw material, and carries out the test of producing the aviation kerosene with large specific gravity by high-pressure hydrofining, and the density can be obtained to be 0.835g/cm ³ The product can obtain higher endurance mileage relative to common 3# aviation kerosene in flight test. Then, the preparation research of the large-specific gravity aviation kerosene in China makes a series of progress.

CN102304387B discloses a production method of coal-based high-density jet fuel, which comprises the following steps: the coal-to-liquid light oil and the liquefied distillate oil from the direct coal liquefaction process enter an expansion bed hydrotreating reactor with forced internal circulation to contact with hydrogen and a hydrotreating catalyst, and the outlet material flow of the expansion bed hydrotreating reactor is separated and fractionated to obtain light distillate oil, medium distillate oil and heavy distillate oil; mixing light distillate oil and medium distillate oil, then entering a deep hydrogenation refining fixed bed reactor, contacting and reacting with hydrogen and a hydrogenation refining catalyst, and separating and fractionating the material flow at the outlet of the deep hydrogenation refining fixed bed reactor to obtain high-density jet fuel; wherein, a liquid collecting cup is arranged above the inside of the hydrotreating reactor, and the collected liquid is conveyed by a pipeline, is pressurized by a forced circulation pump and then is sent to the bottom of the hydrotreating reactor.

CN105733670A discloses a method for producing large-specific gravity aviation kerosene by hydrogenation of catalytic recycle oil, which comprises the steps of mixing the catalytic recycle oil with hydrogen, then introducing the mixture into a hydrotreating reaction zone, and sequentially contacting with a hydrogenation protective agent, a hydrofining catalyst and a hydrogenation modified catalyst A for hydrogenation reaction; the hydrotreating effluent enters a hydro-upgrading reaction zone, and a hydro-upgrading catalyst B containing amorphous silica-alumina and modified Y zeolite is used in the hydro-upgrading reaction zone to carry out hydro-upgrading reaction in the presence of hydrogen; and the obtained hydrogenation modified effluent enters a hydrogenation complementary refining reaction zone to carry out hydrogenation complementary refining reaction, and the hydrogenation complementary refining product is separated to obtain the aviation kerosene with large specific gravity. The application takes the catalytic recycle oil as the raw material to produce the aviation kerosene with large specific gravity, which has large density, high volume heat value, low aromatic hydrocarbon content and good low-temperature performance to the maximum extent, and can widen the raw material sources of aviation kerosene products with large specific gravity.

CN105419865A discloses a method for producing jet fuel, comprising the steps of: (1) Hydrogen and raw oil are in contact reaction with a hydrofining catalyst; optional step (2): separating a gas phase material flow from the effluent obtained in the step (1) to obtain a liquid phase material flow; and (3): contacting the liquid phase material flow obtained in the step (2) and hydrogen or effluent obtained in the step (1) with a hydrocracking catalyst for reaction; and (4): separating jet fuel and diesel oil from the effluent obtained in step (3); and (5): sending at least part of diesel oil obtained in the step (4) into the step (1) to be mixed with raw oil, or sending at least part of diesel oil obtained in the step (4) into the step (3) to be mixed with the liquid phase material flow or the effluent obtained in the step (1); wherein the aromatic hydrocarbon content of the raw oil is more than 40 weight percent; the contact reaction conditions of the step (1) enable the saturation rate of bicyclic aromatics in raw oil to be 70-90%, and the contact reaction conditions of the step (3) enable the saturation rate of total aromatics in liquid feeding of the step (3) to be 75-95%.

CN103789034A discloses a method for producing large-specific gravity aviation kerosene by hydrogenation of medium-low temperature coal tar, which comprises the following steps: (1) Fractionating the medium-low temperature coal tar to obtain light fraction and heavy fraction, wherein the cutting point is 480-510 ℃; (2) Mixing the light fraction obtained in the step (1) with hydrogen, then feeding the mixture into a hydrotreating reaction zone, and sequentially contacting with a hydrogenation protective agent and a hydrofining catalyst to carry out hydrogenation reaction; (3) Carrying out gas-liquid separation on the hydrofining effluent obtained in the step (2), and enabling a liquid-phase product obtained by separation to enter a fractionating tower; (4) The kerosene fraction with the temperature of 140-290 ℃ obtained by fractionation in the step (3) enters a hydrogenation modification reaction zone, and hydrogenation modification reaction is carried out in the hydrogenation modification reaction zone in the presence of hydrogen by using a hydrogenation modification catalyst containing amorphous silica-alumina and modified Y zeolite; (5) And (4) enabling the hydrogenation modified effluent obtained in the step (4) to enter a hydrogenation complementary refining reaction zone, contacting with a hydrogenation complementary refining catalyst in the presence of hydrogen to perform hydrogenation complementary refining reaction, and separating a hydrogenation complementary refining product to obtain a large-specific-gravity aviation kerosene component.

The research of the prior art mainly focuses on the production of the large-specific gravity aviation kerosene by adopting coal diesel oil fraction. The coal-diesel oil fractions mainly comprise secondary processing fractions such as catalytic diesel oil and coal tar. However, as aviation kerosene is special in use, the requirements on the quality of aviation kerosene are stricter than those of other finished oils in the world in order to ensure flight safety. China consistently attaches importance to flight safety and aviation kerosene quality, and establishes aviation kerosene production management methods, wherein clear requirements are provided for the doping proportion of secondary fractions in a production aviation kerosene hydrogenation device and the pressure grade of the device.

Disclosure of Invention

The invention aims to overcome the defect of high proportion of secondary processing heavy inferior distillate of the existing method for producing the aviation kerosene with large specific gravity, and provides a method for producing the aviation kerosene with heavy raw materials.

In order to achieve the above object, the present invention provides a method for producing heavy aviation kerosene from a heavy feedstock, the method comprising the steps of:

(1) Carrying out a first contact reaction on hydrogen and heavy raw oil and a hydrofining catalyst to obtain a hydrotreating effluent;

(2) Carrying out a second contact reaction on the hydrotreating effluent obtained in the step (1) and a hydrocracking catalyst to obtain a hydrocracking effluent;

(3) Carrying out a third contact reaction on the hydrocracking effluent obtained in the step (2) and a post-refining catalyst to obtain a post-refining effluent;

(4) Fractionating the post-refining effluent obtained in the step (3) to obtain an aviation kerosene fraction, wherein the distillation range of the aviation kerosene fraction is 170-240 ℃;

wherein the density of the heavy raw oil is 0.92-1.05g/cm ³ And the fraction above 350 ℃ in the distillation range accounts for more than 10 wt%.

The method according to the invention has the following advantages.

(1) The method can reduce the proportion of secondary processing heavy inferior distillate in the prior art, and is favorable for directly meeting the requirements of the prior laws and regulations;

(2) According to the method, the heavy inferior raw material is subjected to hydrocracking reaction to produce more branched alkane in the aviation kerosene component, so that the aviation kerosene component has a higher smoke point while the freezing point is ensured, the combustion performance and the low-temperature performance of the product are ensured, and the product quality is ensured;

(3) The heavy inferior raw material adopted by the method has higher density, and the process is combined to be more beneficial to obtaining the aviation kerosene with large specific gravity which meets the requirement;

(4) Other fractions obtained after hydrotreating by the method of the invention, such as naphtha, diesel oil and tail oil, can be used as high-quality clean fuel or chemical raw oil, and have higher economic value.

Drawings

FIG. 1 is an XRD spectrum of a phosphorus-containing high-silicon molecular sieve Y-1 and a phosphorus-containing high-silicon molecular sieve Y-2.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In the present invention, the dry weight of a substance means the weight of a solid product obtained by calcining the substance at 600 ℃ for 3 hours.

In the present invention, "about" used in defining the position of the diffraction angle of the diffraction peak means that the diffraction angle position may be deviated by ± 0.5 °.

The invention provides a method for producing heavy aviation kerosene from heavy raw materials, which comprises the following steps:

wherein the density of the heavy raw oil is 0.92-1.05g/cm ³ And the fraction above 350 ℃ in the distillation range accounts for more than 10 percent by weight.

The heavy raw oil adopted in the method provided by the invention has higher density and larger fraction ratio of the distillation range above 350 ℃. Whereas the conventional raw materials used in the prior art are generally coal diesel oil fractions (> 350 ℃ C. Is less than 10%).

The heavy feed oil is within the range usable in the present invention as long as it satisfies the above requirements. Preferably, the heavy feed oil contains a naphthenic wax oil fraction. The inventors of the present invention have found that the use of a naphthenic wax oil fraction is more beneficial in increasing the density of the jet fuel fraction.

The heavy raw oil of the present invention optionally contains other fractions selected from one or more of catalytic cracking cycle oil, coal tar, coal liquefaction oil, naphthenic diesel, heavy oil boiling bed diesel fraction, slurry bed diesel fraction and suspension bed diesel fraction. The catalytic cracking cycle oil, coal tar, coal liquefaction oil, naphthenic diesel oil, heavy oil boiling bed diesel oil fraction, slurry bed diesel oil fraction and suspension bed diesel oil fraction have conventional indications in the field, and the invention is not described herein.

According to a preferred embodiment of the present invention, the content of the naphthenic wax oil fraction in the heavy feedstock oil is not less than 30 wt%, preferably not less than 50 wt%, more preferably 50 to 100 wt%. By adopting the preferred embodiment, the large-specific gravity aviation kerosene meeting the quality requirement can be produced, the proportion of secondary processing heavy and poor fractions in the prior art can be further reduced, and the requirements of the existing regulations can be directly met.

According to the present invention, preferably, the density of the heavy raw oil is 0.93-0.97g/cm ³ . The heavy raw oil with the optimized density is more beneficial to improving the density of the aviation kerosene fraction.

According to the present invention, it is preferable that the fraction having a temperature of more than 370 ℃ accounts for 30 wt% or more of the distillation range of the heavy feedstock oil.

In the present invention, the heavy feed oil further contains sulfur and/or nitrogen, and the sulfur and nitrogen content in the heavy feed oil is not particularly limited.

According to the method provided by the present invention, preferably, the method further comprises: removing mechanical impurities in the heavy raw oil, and then carrying out the step (1). The method for removing the mechanical impurities in the present invention is not particularly limited, and examples thereof include filtration.

The conditions of the first contact are selected within a wide range, based on the possibility of a hydrorefining reaction, the conditions of the second contact are selected within a wide range, based on the possibility of a hydrocracking reaction, and the conditions of the third contact are selected within a wide range, based on the possibility of a refining reaction. Preferably, the conditions of the first contact reaction, the second contact reaction and the third contact reaction each independently comprise: the reaction pressure is 2.0-20.0MPa, the reaction temperature is 280-480 ℃, the volume ratio of hydrogen to oil is 500-5000 ^-1 (ii) a Further preferably, the reaction pressure is 8.0-17.0MPa, the reaction temperature is 350-450 ℃, the volume ratio of hydrogen to oil is 700-1500 ^-1 。

According to the method provided by the present invention, preferably, the conditions of the second contacting include: reaction(s) ofThe pressure is 6.0-17.0MPa, the reaction temperature is 350-450 ℃, the volume ratio of hydrogen to oil is 1-1500 ^-1 (ii) a Further preferably, the conditions of the second contacting include: the reaction pressure is 10.0-17.0MPa, the reaction temperature is 380-410 ℃, the volume ratio of hydrogen to oil is 800-1, and the volume space velocity is 0.5-4h ^-1 。

According to the process of the present invention, the ratio between the hydrocracking catalyst and the hydrofinishing catalyst may be selected according to specific reaction conditions. Preferably, the volume ratio of the hydrocracking catalyst to the hydrofinishing catalyst is 0.2 to 3. More preferably, the volume ratio of the hydrocracking catalyst to the hydrofinishing catalyst is from 0.5 to 1.5.

According to the method of the invention, the hydrofining catalyst can be a catalyst with catalytic activities of aromatic saturation, hydrodesulfurization and hydrodenitrogenation, and can be a noble metal catalyst or a non-noble metal catalyst. Preferably, the hydrofinishing catalyst is a non-noble metal catalyst.

Specifically, the hydrofining catalyst may contain a carrier and a group VIB metal component and a group VIII metal component supported on the carrier. The group VIB metal component may be present in an amount of from 5 to 50 wt.%, preferably from 7 to 35 wt.%, based on the total amount of hydrofinishing catalyst and calculated as oxide; the content of the group VIII metal component may be 1 to 10% by weight, preferably 1.5 to 7% by weight. Preferably, the hydrofining catalyst may further contain at least one auxiliary agent, and the auxiliary agent may be at least one of phosphorus, fluorine and boron. The content of the promoter may be 1 to 10% by weight based on the total amount of the hydrorefining catalyst and calculated as an element.

In the hydrofining catalyst, the VIB group metal is preferably Mo and/or W, and the VIII group metal is preferably Co and/or Ni.

The carrier of the hydrorefining catalyst is preferably at least one of alumina, silica and silica-alumina.

In the hydrofinishing catalyst, the group VIB metal component and the group VIII metal component may both be present in the form of oxides.

The hydrorefining catalyst may be an industrial catalyst (commercially available) or may be prepared by itself, and the present invention is not particularly limited thereto.

In the present invention, the method for producing the hydrotreating catalyst is not particularly limited as long as the hydrotreating reaction can be carried out, and the hydrotreating catalyst can be produced by, for example, an impregnation method. The impregnation method can be co-impregnation or step-by-step impregnation. The specific operation is well known to those skilled in the art, and the present invention is not described herein.

According to the process of the present invention, the hydrocracking catalyst may be a non-noble metal catalyst. Specifically, the hydrocracking catalyst may contain a carrier, and a group VIB metal component and a group VIII metal component supported on the carrier. Preferably, the group VIII metal component is present in an amount of from 1 to 15 wt.%, preferably from 1.5 to 6 wt.%, based on the total amount of hydrocracking catalyst and calculated as oxide; the group VIB metal component is present in an amount of from 1 to 40 wt.%, preferably from 10 to 40 wt.%.

The selection of the group VIB metal and the group VIII metal components may be as described above, and are not described herein again.

According to a preferred embodiment of the present invention, the carrier of the hydrocracking catalyst contains a phosphorus-containing molecular sieve. More preferably, the molecular sieve contains 86.5 to 99.8 wt.%, preferably 90 to 99.8 wt.%, silicon, 0.1 to 13.5 wt.%, preferably 0.1 to 9.0 wt.%, aluminum, and 0.01 to 6 wt.%, preferably 0.01 to 2.5 wt.%, phosphorus, calculated as oxides and based on the dry weight of the molecular sieve. The adoption of the preferred phosphorus-containing high-silicon molecular sieve is more beneficial to improving the density of the obtained aviation kerosene fraction.

According to the invention, the phosphorus-containing molecular sieve preferably has a pore volume of 0.20-0.50mL/g, preferably 0.30-0.45mL/g, and a specific surface area of 250-670m ² A/g, preferably from 260 to 600m ² (ii) in terms of/g. The pore volume and specific surface area of the molecular sieve can be determined by the static low temperature adsorption volumetric method.

According to the present invention, preferably, the phosphorus-containing molecular sieve has an XRD pattern with at least three diffraction peaks, wherein the first intense peak has a diffraction angle position in the range of about 5.9-6.9 °, preferably in the range of about 6.1-6.8 °; the diffraction angle position of the second intense peak is in the range of about 10.0-11.0, preferably in the range of about 10.2-10.7; and the diffraction angle position of the third intensity peak is about 15.6 to 16.7 deg., preferably about 15.8 to 16.5 deg.. The phosphorus-containing molecular sieve with different structural characteristics from the conventional silicon-aluminum material is more favorable for preparing the high-specific-gravity aviation kerosene with higher density and meeting the requirements on smoke point and freezing point.

In the invention, the diffraction angle position refers to a 2 theta angle value of the highest peak value of a diffraction peak in an XRD spectrogram.

In the present application, the ordinal numbers "first", "second" and "third" etc. in the expressions first, second and third intensity peaks etc. represent the relative order of intensity of the said diffraction peaks, determined by peak height, wherein the first intensity peak represents the diffraction peak with the highest peak height in the XRD spectrum, the second intensity peak represents the diffraction peak with the second highest peak height in the XRD spectrum, the third intensity peak represents the diffraction peak with the third highest peak height in the XRD spectrum, and so on.

It is well known to those skilled in the art that in the structural analysis of a substance by X-ray diffraction (XRD), the D value (interplanar distance) can be generally calculated from the wavelength and diffraction angle, and the primary phase identification is performed based on the features of the strongest three diffraction peaks, i.e., the first, second and third intensity peaks in the present application. The concept of the three strong peaks can be found in the literature, "research methods of heterogeneous catalysts", edited by Yi Yuan Gen, beijing: chemical industry publishers, 1988, pages 140-170.

According to a preferred embodiment of the present invention, the XRD spectrum of the phosphorous containing molecular sieve is I ₁ /I _23.5-24.5° From 3.0 to 11.0, for example from 4.0 to 10.5 or from 4.6 to 10.1; I.C. A ₂ /I _23.5-24.5° From 2.5 to 8.0, for example from 2.9 to 7.0 or from 3.0 to 6.4; i is ₃ /I _23.5-24.5° Is 1.0 to 4.5, for example 1.5 to 4.0 or 2.1 to 3.8, where I ₁ Is the peak height of the first strong peak, I ₂ Is the peak height of the second strong peak, I ₃ Is the peak height of the third strong peak, I _23.5-24.5° At diffraction angle positions of about 23.5-24.5 DEGPeak height of the peak.

According to a more preferred embodiment of the present invention, the phosphorus-containing molecular sieve has an XRD pattern with at least five diffraction peaks, wherein the fourth intensity peak has a diffraction angle position between about 20.4 ° and 21.6 °, preferably between about 20.8 ° and 21.4 °; the diffraction angle position of the fifth intensity peak is between about 11.8 and 12.8, preferably between about 12.1 and 12.6; more preferably, in the XRD spectrum of the phosphorus-containing molecular sieve, I ₄ /I _23.5-24.5° From 1.0 to 4.0, for example from 1.1 to 3.0 or from 1.2 to 2.3; i is ₅ /I _23.5-24.5° Is 1.0 to 2.0, for example 1.0 to 1.6 or 1.0 to 1.2, where I ₄ Is the peak height of the fourth strong peak, I ₅ Is the peak height of the fifth strong peak, I _23.5-24.5° Peak height is the peak at diffraction angle position of about 23.5-24.5 °. The concept of the fourth strong peak and the fifth strong peak can be understood according to the description of the three strong peaks, and will not be described herein again.

In the present invention, the crystal structure of the molecular sieve is determined using an X-ray diffractometer model D5005 from Siemens, germany, according to the method of the industry standard SH/T0339-92.

The hydrocracking catalyst containing the phosphorus-containing molecular sieve shows higher hydrocracking activity.

The invention has wider selection range of the preparation method of the phosphorus-containing molecular sieve, and preferably, the preparation method of the phosphorus-containing molecular sieve comprises the following steps:

(a) Carrying out hydrothermal treatment on a phosphorus-containing molecular sieve raw material; the temperature of the hydrothermal treatment is 350-700 ℃;

(b) First contacting the molecular sieve material obtained in step (a) with a first acid solution; the temperature of the first contact is 40-95 ℃, and the addition amount of the first acid solution ensures that the pH value of the first contact product is 2.3-4.0, preferably 2.5-4.0;

(c) Second contacting the first solid product obtained in step (b) with a second acid solution; the temperature of the second contact is 40-95 ℃, and the second acid solution is added in an amount to ensure that the pH value of the second contact product is 0.8-2.0, and preferably 1.0-2.0.

According to the present invention, the phosphorus content of the phosphorus-containing molecular sieve feedstock is preferably in the range of from 0.1 to 15 wt.%, preferably 0.1 to 6 wt.%, for example 1.37 wt.%, calculated as oxides and based on the dry weight of the phosphorus-containing molecular sieve feedstock; the sodium content is from 0.5 to 4.5% by weight, preferably from 0.5 to 3.0% by weight, for example 1.44% by weight; the silicon content is 70 to 85 wt.%, preferably 70 to 80 wt.%, for example 76.7 wt.%; the aluminum content is 16.0 to 21.0 wt.%, preferably 18.0 to 21.0 wt.%, for example 20.5 wt.%.

In the present invention, the phosphorus-containing molecular sieve raw material refers to a phosphorus-containing molecular sieve, and the phosphorus-containing molecular sieve raw material may have a faujasite molecular sieve structure, and is preferably a phosphorus-containing Y-type molecular sieve. The Y-type molecular sieve can be selected from NaY, HNaY (hydrogen Y-type molecular sieve), REY (rare earth Y-type molecular sieve), USY (ultra stable Y-type molecular sieve) and the like. The cation sites of the phosphorus-containing Y-type molecular sieve can be occupied by one or more of sodium ions, ammonium ions and hydrogen ions; alternatively, all or part of the sodium, ammonium and hydrogen ions may be replaced by other ions by conventional ion exchange before or after the molecular sieve is introduced with phosphorus. The phosphorus-containing molecular sieve raw material can be a commercial product, and can also be prepared by any conventional technology.

Preferably, step (a) comprises: carrying out hydrothermal treatment on a phosphorus-containing molecular sieve raw material at the temperature of 350-700 ℃, under the pressure of 0.1-8.0MPa and in the presence of water vapor for about 0.5-10h to obtain a molecular sieve material subjected to hydrothermal treatment. More preferably, the temperature of the hydrothermal treatment is 400-650 ℃, e.g. 560 ℃. Preferably, the pressure of the hydrothermal treatment is 0.5 to 5MPa, for example 0.8MPa. Preferably, the hydrothermal treatment is carried out for a period of time of 1 to 7 hours, for example 3 hours.

According to the present invention, preferably, the step (b) comprises: adding water to the hydrothermally treated molecular sieve material obtained in step a) to form a first slurry, heating the first slurry to 40-95 ℃, preferably 50-85 ℃, for example about 80 ℃, then maintaining the temperature and adding a first acid solution to the first slurry in an amount such that the pH of the resulting acidified first slurry is 2.3-4.0, preferably 2.5-4.0, more preferably 2.5-3.5, for example about 2.8, then reacting at constant temperature for 0.5-20h, preferably 1-10h, for example 4h, and collecting a first solid product.

According to the present invention, preferably, step (c) comprises: adding water to said first solid product obtained in step (b) to form a second slurry, heating the second slurry to a temperature of 40-95 ℃, preferably 50-85 ℃, e.g. about 80 ℃, then maintaining the temperature and adding a second acid solution to the second slurry in an amount such that the pH of the resulting acidified second slurry is 0.8-2.0, preferably 1.0-2.0, more preferably 1.0-1.8, e.g. 1.4, and then reacting at constant temperature for 0.5-20h, preferably 1-10h, e.g. 3h, and collecting the second solid product.

The meaning of said water addition beating in step (b) and step (c) according to the present invention is well known to the person skilled in the art. In a preferred embodiment, in step (b), the ratio of the weight of water in the first slurry obtained after pulping to the weight of the phosphorus-containing molecular sieve feedstock on a dry basis may be from 14 to 5, for example 10; and/or in step (b), the ratio of the weight of water in the second slurry to the weight of phosphorus-containing molecular sieve feedstock on a dry basis may be from 0.5.

The amount of the first acid solution added can vary widely depending on the nature of the phosphorus-containing molecular sieve feedstock and the hydrothermal treatment conditions of step (a). It will be appreciated by those skilled in the art that the first acid solution is desirably added in an amount such that the pH of the first slurry after addition of the acid satisfies the above-mentioned suitable range. The rate of addition of the first acid solution is not particularly limited and may vary over a wide range.

In a preferred embodiment, the addition of the first acid solution in step (b) may be performed several times (e.g. 1-5 times), and each time the acid is added, the reaction may be performed at constant temperature for a period of time and then the next acid addition may be continued until the pH of the first slurry after the acid addition reaches the desired range.

According to the present invention, in a preferred embodiment, the second acid solution may be added in a manner of: based on 1L of the second slurry, taking H as reference ⁺ In accordance with a rate of 0.05 to 15mol/h, preferably 0.05 to 10mol/h, more preferably 2 to 8mol/h, for example 5mol/hThe second acid solution is added to the second slurry. According to the invention, the slow acid adding speed is adopted in the step (c), so that the dealumination process can be more moderate, and the performance of the molecular sieve can be improved.

In a preferred embodiment, the addition of the second acid solution in step (c) may be performed several times (e.g. 1-5 times), and each time the acid is added, the reaction may be performed at constant temperature for a period of time and then the next addition of acid is continued until the pH of the second slurry after the addition of acid reaches the desired range.

The acid concentration of the first acid solution and the second acid solution may each independently be in the range of from 0.1 to 15.0mol/L, preferably from 0.1 to 5.0mol/L, for example 2.0mol/L. The acid in the first acid solution and the second acid solution may each independently be a conventional inorganic acid and/or organic acid, and for example, may be at least one selected from phosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, citric acid, tartaric acid, formic acid, and acetic acid, and preferably sulfuric acid and/or nitric acid. The second acid solution may be the same as or different from the first acid solution in terms of kind and concentration, and is preferably the same acid solution.

According to the present invention, in a preferred embodiment, the method may further comprise: and collecting the second solid product, and then washing and drying to obtain the phosphorus-containing molecular sieve. The washing and drying are conventional steps for preparing the molecular sieve, and the present invention is not particularly limited. For example, the drying conditions may be: the temperature is 50 to 350 ℃, preferably 70 to 200 ℃, for example 180 ℃; the time is from 1 to 24h, preferably from 2 to 6h, for example 3h.

According to a preferred embodiment of the present invention, the carrier of the hydrocracking catalyst further contains a refractory inorganic oxide. The heat-resistant inorganic oxide is a porous material with the highest use temperature not lower than 600 ℃. Specific examples of the heat-resistant inorganic oxide may include, but are not limited to, one or two or more of alumina, silica, titania, magnesia, zirconia, thoria, and beryllia. Preferably, the heat-resistant inorganic oxide is at least one of alumina, silica, titania, zirconia, and magnesia.

The invention has a wide selection range of the ratio of the phosphorus-containing molecular sieve to the heat-resistant inorganic oxide in the carrier, preferably, the weight ratio of the phosphorus-containing molecular sieve to the heat-resistant inorganic oxide is about 0.03 to 1, more preferably 0.1 to 1.

The preparation method of the hydrocracking catalyst has a wide selection range, and preferably, the preparation method of the hydrocracking catalyst comprises the following steps:

(I) Mixing the phosphorus-containing molecular sieve and a heat-resistant inorganic oxide to prepare a carrier;

(II) introducing a group VIB metal component and a group VIII metal component onto the carrier by an impregnation method. As described above, the impregnation method may be a co-impregnation method or a step-impregnation method. The specific operation of the impregnation method is well known to those skilled in the art, and the detailed description of the present invention is omitted here.

The preparation method of the carrier is well known to those skilled in the art, and the present invention is not particularly limited. For example, the method may include: and mixing the phosphorus-containing molecular sieve with a heat-resistant inorganic oxide, and then molding and drying to obtain the carrier. The molding method can adopt various conventional methods, such as tabletting molding, rolling ball molding or extrusion molding.

According to the present invention, post-refining after the hydrocracking reaction can further reduce the content of olefins and mercaptan sulfur in the hydrocracking effluent.

The amount of the post-refining catalyst is selected from a wide range, and preferably is based on the amount of the post-refining catalyst which can reduce the content of the olefin and the mercaptan sulfur in the hydrocracking effluent to the expected content. Further preferably, the volume ratio of the hydrocracking catalyst to the post-refining catalyst is 3 to 20, preferably 5 to 10. The type of the post-refining catalyst is the same as the above-mentioned hydrorefining catalyst, and is not described in detail here. The post-purification catalyst may be the same as or different from the hydropurification catalyst.

According to a preferred embodiment of the present invention, in the step (1), a hydrogenation protecting agent is further provided upstream of the hydrorefining catalyst with respect to the flow direction of the heavy feedstock oil. By adopting the preferred embodiment, coking precursors such as olefin and/or colloid in the raw oil can be prevented from coking on the hydrofining catalyst to cause coking and inactivation of the hydrofining catalyst, and simultaneously, metal in the raw oil can be prevented from causing poisoning of the hydrofining catalyst. The dosage of the hydrogenation protective agent can be selected according to the composition of the raw oil. Preferably, the hydrogenation protector is 5-80 vol%, such as 5-30 vol% of the total amount of the hydrofinishing catalyst.

The hydrogenation protective agent can be various catalysts capable of realizing the functions. Specifically, the hydrogenation protective agent comprises a carrier, and a VIB metal component and a VIII metal component which are loaded on the carrier, wherein the content of the VIB metal component can be 5.5-10 wt% and the content of the VIII metal component can be 1-5 wt% based on the total amount of the hydrogenation protective agent and calculated by oxides. Preferably, the group VIB metal is Mo and/or W; the group VIII metal component is Co and/or Ni. Further preferably, the group VIB metal is Mo and the group VIII metal is Ni. Preferably, the support is selected from at least one of alumina, silica and silica-alumina, more preferably alumina.

In the present invention, the aviation kerosene fraction having the distillation range described above may be obtained from the entire post-purification effluent obtained in step (3). The fractionation is not particularly limited. According to a particular embodiment of the invention, the process further comprises separating the post-refining effluent obtained in said step (3) and then carrying out said fractionation.

The specific operation steps of the separation and fractionation are not particularly limited, and a person skilled in the art can perform the separation and fractionation by various methods conventionally used in the art, for example, in the invention, the post-refining effluent can be introduced into a high-pressure separator to obtain a hydrogen-rich gas and a liquid effluent, the hydrogen-rich gas can be recycled after the conventional operation, and the separated liquid effluent enters a fractionating tower to be fractionated, so that the target product can be obtained.

According to the method provided by the invention, in addition to obtaining the aviation kerosene, other additional products can be obtained, for example, the step (4) can be used for fractionating the post-refining effluent obtained in the step (3) to obtain naphtha fraction, the aviation kerosene fraction, diesel oil fraction and tail oil fraction.

The distillation range of each additional product can be selected by one skilled in the art by the particular use of the fraction. The distillation range of the naphtha fraction, diesel fraction and tail oil fraction may be selected conventionally in the art and will not be described in detail herein.

Preferably, the aviation kerosene fraction has a distillation range of 180-215 ℃. The aviation kerosene in the preferred distillation range not only meets the requirements of smoke point and freezing point, but also has larger density. It should be noted that the distillation range of 180-215 ℃ does not mean that the initial boiling point is 180 ℃ and the final boiling point is 215 ℃, but means that the initial boiling point is not lower than 180 ℃ and the final boiling point is not higher than 215 ℃.

In the present invention, the hydrofining catalyst, the hydrocracking catalyst, the post-refining catalyst and the optional hydrogenation protecting agent may be filled in different reaction zones of the same reactor, or may be located in different reactors, and may be selected according to specific apparatuses, and are not particularly limited. In the present invention, "optionally" means optionally, and may be understood as containing or not containing.

The present invention will be described in detail below by way of examples.

In the following examples and comparative examples, the hydrogenation protecting agent in the hydrogenation protecting reaction zone was RG series protecting catalyst RG-10 developed by the institute of petrochemical engineering science, and the hydrofining catalyst in the hydrofining reaction zone and the post-refining catalyst in the post-refining reaction zone were RN-32V developed by the institute of petrochemical engineering science.

In the following preparation examples, the pore volume and the specific surface area of the molecular sieve were determined by the static cryogenic adsorption capacity method using an ASAP 2400 model automatic adsorption apparatus from micromeritics instruments USA (according to the method of the national Standard GB/T5816-1995): vacuumizing and degassing a molecular sieve to be detected for 4h at 250 ℃ and 1.33Pa, and contacting the molecular sieve with nitrogen serving as an adsorbate at-196 ℃, so that static adsorption reaches adsorption balance; the amount of nitrogen adsorbed by the adsorbent is calculated according to the difference between the nitrogen gas inflow and the amount of nitrogen remained in the gas phase after adsorption, then the pore size distribution is calculated by using a BJH formula, and the specific surface area and the pore volume are calculated by using a BET formula.

The crystal structure of the molecular sieve was determined using an X-ray diffractometer model D5005 from Siemens Germany, according to the method of the industry Standard SH/T0339-92. The experimental conditions were: cu target, k alpha radiation, a solid detector, tube voltage of 40kV, tube current of 40mA, step scanning, step of 0.02 degrees, prefabrication time of 2s and scanning range of 5-70 degrees. The diffraction angle position refers to the 2 theta angle value of the highest value of the diffraction peak.

The silicon content, aluminum content, phosphorus content and sodium content of the molecular sieve are measured by a 3271E type X-ray fluorescence spectrometer of Nippon science and electronics industries, and the measuring method comprises the following steps: tabletting and forming a powder sample, carrying out rhodium target, detecting the spectral line intensity of each element by a scintillation counter and a proportional counter under the laser voltage of 50kV and the laser current of 50mA, and carrying out quantitative and semi-quantitative analysis on the element content by an external standard method.

Preparation of hydrocracking catalyst example 1

(1) Preparation of phosphorus-containing high-silicon molecular sieve

Taking phosphorus-containing molecular sieve raw material (USY molecular sieve produced by Chang Ling division of Chinese petrochemical catalyst, unit cell constant is 2.456nm, and specific surface area is 672m ² Per g, pore volume of 0.357mL/g, na ₂ O content 1.44 wt%, P ₂ O ₅ 1.37 wt.% of SiO ₂ The content was 76.7% by weight and Al ₂ O ₃ 20.5 percent by weight) of the molecular sieve powder is put into a hydrothermal kettle, 100 percent of water vapor is introduced, hydrothermal treatment is carried out for 3 hours at 560 ℃ and 0.8MPa, and then the molecular sieve material after the hydrothermal treatment is taken out.

Taking 50g (dry basis) of the molecular sieve material subjected to the hydrothermal treatment, adding 500mL of deionized water, stirring and pulping to obtain first slurry. Heating the mixture to 80 ℃, adding 2.0mol/L sulfuric acid solution, stopping adding the acid when the pH value of the first slurry after adding the acid is detected to be 2.8, then reacting for 4 hours at constant temperature, and filtering to obtain 40g of a first solid product.

Adding 4 to the first solid productAnd (5) stirring and pulping 00mL of deionized water to obtain second slurry. Heating to 80 deg.C, taking 1L second slurry as reference, and taking H as reference ⁺ Adding 2mol/L sulfuric acid solution into the second slurry at the speed of 5mol/h, stopping adding acid when the pH value of the acid-added second slurry is detected to be 1.4, then reacting for 3h at constant temperature, filtering and collecting a second solid product.

Drying the obtained solid product at 180 ℃ for 3h to obtain the phosphorus-containing high-silicon molecular sieve Y-1, wherein an XRD spectrogram of the phosphorus-containing high-silicon molecular sieve Y-1 is shown in figure 1. The XRD diffraction peak positions of the obtained molecular sieve are shown in Table 1, the diffraction peak heights are shown in Table 2, and other properties are shown in Table 3.

(2) Preparation of the catalyst

Mixing 80g of molecular sieve Y-1 in a dry basis and 28.8g of pseudo-boehmite (trade name PB90, 70 wt% of dry basis) in a dry basis, extruding into trilobe strips with the circumscribed circle diameter of 1.6 mm, drying at 120 ℃ for 3h, and roasting at 600 ℃ for 3h to obtain the carrier CS-1.

After the temperature is reduced to room temperature, 100g of CS-1 carrier is taken and dipped in 70mL of aqueous solution containing 34.65g of ammonium metatungstate (Sichuan tribute cemented carbide factory, with the content of tungsten oxide of 82 wt%) and 24.37g of nickel nitrate (Beijing New photochemical reagent factory, with the content of nickel oxide of 27.85 wt%), dried at 120 ℃ for 3h, and roasted at 480 ℃ for 4h, thus obtaining the hydrocracking catalyst C-1. Composition of C-1 of the catalyst: 74 percent of carrier, calculated by oxide, 5 percent of VIII group metal, 21 percent of VIB group metal, 80 percent of phosphorus-containing molecular sieve and 20 percent of heat-resistant inorganic oxide.

Preparation example 2 of hydrocracking catalyst

The preparation process is carried out according to preparation example 1 of the hydrocracking catalyst, except that in the preparation process of the phosphorus-containing high-silicon molecular sieve, when a second acid solution is added, the second acid solution is added at a speed of 15mol/h, so as to prepare the phosphorus-containing high-silicon molecular sieve Y-2, and an XRD spectrogram of the phosphorus-containing high-silicon molecular sieve is shown in figure 1. The XRD diffraction peak positions of the obtained molecular sieve are shown in Table 1, the diffraction peak heights are shown in Table 2, and other properties are shown in Table 3. To prepare the hydrocracking catalyst C-2.

TABLE 1 XRD diffraction peak positions of molecular sieves

TABLE 2 XRD diffraction peak heights of molecular sieves

TABLE 3 other Properties of the molecular sieves

Preparation of hydrocracking catalyst example 3

20g of a phosphorus-containing ultrastable molecular sieve (produced by Changjing catalyst division, trade name USY-5, phosphorus pentoxide content of 1.2%, unit cell constant of 2.444nm, pore volume of 0.40mL/g, dry basis of 81 wt%) and 80g of pseudo-boehmite (produced by Changjing catalyst division, trade name PB90, dry basis of 70 wt%) were mixed, extruded into trilobal strips with a circumscribed circle diameter of 1.6 mm, dried at 120 ℃ and calcined at 600 ℃ for 3 hours to obtain the carrier CS-3. After the temperature is reduced to room temperature, 100g of CS-3 carrier is taken and dipped in 70mL of aqueous solution containing 34.65g of ammonium metatungstate (Sichuan tribute cemented carbide factory, tungsten oxide content is 82 wt%) and 24.37g of nickel nitrate (product of Beijing New photochemical reagent factory, nickel oxide content is 27.85 wt%), dried at 120 ℃ and roasted at 480 ℃ for 4h, thus obtaining the hydrocracking catalyst C-3.

Preparation example 4 of hydrocracking catalyst

An industrial catalyst RT-1 developed by a petrochemical engineering science research institute is adopted as a hydrocracking catalyst C-4.

Comparative example 1

Hydrogenation protective agent RG-10, hydrofining catalyst RN-32V, hydrocracking catalyst C-3 and post-refining catalyst RN-32V are sequentially filled in the hydrogenation reaction zone. Wherein, the filling volume ratio of the hydrocracking catalyst to the post-refining catalyst is 5, the filling volume ratio of the hydrocracking catalyst to the hydrofining catalyst is 0.92, and the hydrogenation protective agent accounts for 2.27 volume percent of the hydrofining catalyst. The middle east VGO raw material (properties are shown in Table 4) is mixed with hydrogen and enters a hydrogenation reaction zone, and specific reaction conditions and product properties are shown in Table 5.

Example 1

The procedure of example 1 was followed except that the middle east VGO feedstock was replaced with a soxhlet mix feedstock (properties see Table 4), and the specific reaction conditions and product properties are shown in Table 5.

Comparative example 2

The process of example 1 was followed except that the jet fuel cut distillation range was 145-250 ℃ and the specific reaction conditions and product properties are shown in Table 5.

Example 2

The procedure of example 1 was followed except that the hydrocracking catalyst C-3 was replaced with the hydrocracking catalyst C-1. Specific reaction conditions and product properties are shown in Table 5.

Example 3

The procedure of example 1 was followed except that the hydrocracking catalyst C-3 was replaced with a hydrocracking catalyst C-2. Specific reaction conditions and product properties are shown in Table 5.

Example 4

The procedure of example 1 was followed except that the hydrocracking catalyst C-3 was replaced with a hydrocracking catalyst C-4. Specific reaction conditions and product properties are shown in Table 5.

Example 5

The process of example 1 was followed except that the reaction feed was a blend of trunk mix and catalytic diesel (properties see table 4), the mass ratio of trunk mix and catalytic diesel was 50.

TABLE 4

TABLE 5

As can be seen from the results in Table 5, the large-specific gravity aviation kerosene which has the smoke point and the freezing point meeting the standards can be prepared by the production method provided by the invention. Comparative example 1 aviation kerosene obtained using a conventional density feed had a lower density. The aviation kerosene with a large specific gravity which meets the requirements could not be obtained by the cutting method of comparative example 2.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including various technical features being combined in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A process for producing heavy aviation kerosene from a heavy feedstock, the process comprising the steps of:

(4) Fractionating the post-refining effluent obtained in the step (3) to obtain aviation kerosene fraction, wherein the distillation range of the aviation kerosene fraction is 170-240 ℃;

wherein the density of the heavy raw oil is 0.93-0.97g/cm ³ And the fraction above 350 ℃ accounts for more than 10 weight percent in the distillation range;

the conditions of the first contact reaction, the second contact reaction and the third contact reaction each independently comprise: the reaction pressure is 2.0-20.0MPa, the reaction temperature is 280-480 ℃, the volume ratio of hydrogen to oil is 500-5000 ^-1 ；

The hydrofining catalyst comprises a carrier, and a VIB group metal component and a VIII group metal component which are loaded on the carrier; the hydrocracking catalyst contains a carrier, and a VIB group metal component and a VIII group metal component which are loaded on the carrier; the post-refining catalyst is the same as or different from the hydrofining catalyst.

2. The process according to claim 1, wherein the heavy raw oil contains naphthenic wax oil fraction and optionally other fractions selected from one or more of catalytically cracked cycle oil, coal tar, coal liquefaction oil, naphthenic diesel, heavy boiling bed diesel fraction, slurry bed diesel fraction and suspended bed diesel fraction.

3. The process according to claim 2, wherein the content of naphthenic wax oil fraction in the heavy raw oil is not less than 30 wt%.

4. A process according to claim 3, wherein the content of naphthenic wax oil fraction in the heavy feedstock oil is 50 wt% or more.

5. The process according to claim 4, wherein the content of naphthenic wax oil fraction in the heavy raw oil is 50-100 wt%.

6. The process according to claim 1, wherein the fraction having a temperature of 370 ℃ or higher in the distillation range of the heavy raw oil accounts for 30% by weight or more.

7. The method of claim 1, wherein the conditions of the second contacting comprise: the reaction pressure is 6.0-17.0MPa, the reaction temperature is 350-450 ℃, the volume ratio of hydrogen to oil is 1-1500 ^-1 。

8. The process of any one of claims 1 to 6, wherein the volume ratio of hydrocracking catalyst to hydrofinishing catalyst is from 0.2 to 3.

9. The process of claim 8 wherein the volume ratio of hydrocracking catalyst to hydrofinishing catalyst is from 0.5 to 1.5.

10. The process of any of claims 1-6, wherein the volume ratio of hydrocracking catalyst to post-refining catalyst is 3-20.

11. The process of claim 10, wherein the volume ratio of hydrocracking catalyst to post-refining catalyst is 5-10.

12. The process of claim 1, wherein the group VIII metal component is present in an amount of from 1 to 10 wt.% and the group VIB metal component is present in an amount of from 5 to 50 wt.%, based on the total amount of hydrofinishing catalyst and calculated as oxides.

13. The process of claim 1, wherein in the hydrofinishing catalyst, the group VIB metal is Mo and/or W; the group VIII metal component is Co and/or Ni.

14. The process of claim 1, wherein in the hydrofinishing catalyst, the support is selected from at least one of alumina, silica and silica-alumina.

15. The process of claim 1 wherein the group VIII metal component is present in an amount of from 1 to 15 wt.%, based on the total amount of hydrocracking catalyst and calculated as oxide; the content of the VIB group metal component is 1-40 wt%.

16. The process of claim 15 wherein the group VIII metal component is present in an amount of from 1.5 to 6 wt.%, based on the total amount of hydrocracking catalyst and as oxides; the content of the VIB group metal component is 10-40 wt%.

17. The process according to claim 1, wherein in the hydrocracking catalyst, the group VIB metal is Mo and/or W; the group VIII metal component is Co and/or Ni.

18. The process of claim 1, wherein the hydrocracking catalyst support comprises a phosphorus-containing molecular sieve.

19. The process of claim 18 wherein the molecular sieve contains 86.5 to 99.8 wt.% silicon, 0.1 to 13.5 wt.% aluminum, and 0.01 to 6 wt.% phosphorus, on an oxide basis and on a dry weight basis of the molecular sieve.

20. The process of claim 19 wherein the molecular sieve contains 90 to 99.8 wt.% silicon, 0.1 to 9.0 wt.% aluminum, and 0.01 to 2.5 wt.% phosphorus, calculated as oxides and based on the dry weight of the molecular sieve.

21. The process of claim 18, wherein the phosphorus-containing molecular sieve has a pore volume of 0.20 to 0.50mL/g and a specific surface area of 250 to 670m ² /g。

22. The process of claim 21, wherein the phosphorus-containing molecular sieve has a pore volume of 0.30 to 0.45mL/g and a specific surface area of 260 to 600m ² /g。

23. The process of claim 18, wherein the phosphorus-containing molecular sieve has an XRD pattern with at least three diffraction peaks, wherein the first intensity peak has a diffraction angle position in the range of 5.9-6.9 °; the diffraction angle position of the second intense peak is between 10.0 and 11.0 degrees; and the diffraction angle position of the third intensity peak is 15.6 to 16.7 deg.

24. The process of claim 23, wherein the phosphorus-containing molecular sieve has an XRD pattern with at least three diffraction peaks, wherein the first intensity peak has a diffraction angle position between 6.1 and 6.8 °; the diffraction angle position of the second strong peak is 10.2-10.7 degrees; and the diffraction angle position of the third intensity peak is 15.8 to 16.5 deg.

25. The method of claim 23, wherein the phosphorous containing molecular sieve has an XRD pattern of I ₁ /I _23.5-24.5° Is in the range of 3.0 to 11.0 ₂ /I _23.5-24.5° Is 2.5 to 8.0 ₃ /I _23.5-24.5° Is 1.0 to 4.5, wherein I ₁ Is the peak height of the first strong peak, I ₂ Is the peak height of the second strong peak, I ₃ Is the peak height of the third strong peak, I _23.5-24.5° The peak height of the peak at a diffraction angle position of 23.5 to 24.5 degrees.

26. The process of claim 18, wherein the phosphorus-containing molecular sieve has an XRD pattern with at least five diffraction peaks, wherein the fourth intensity peak has a diffraction angle position between 20.4-21.6 °; the diffraction angle position of the fifth intensity peak is 11.8-12.8 deg.

27. The process of claim 26, wherein the phosphorus-containing molecular sieve has an XRD pattern with at least five diffraction peaks, wherein the fourth intensity peak is at an angle of diffraction position between 20.8 and 21.4 °; the diffraction angle position of the fifth intensity peak is 12.1 to 12.6 deg.

28. The process of claim 26, wherein I is the XRD spectrum of the phosphorous containing molecular sieve ₄ /I _23.5-24.5° 1.0 to 4.0, and I ₅ /I _23.5-24.5° Is 1.0 to 2.0, wherein I ₄ Is the peak height of the fourth strong peak, I ₅ Is the peak height of the fifth strong peak, I _23.5-24.5° The peak height of the peak at a diffraction angle position of 23.5 to 24.5 degrees.

29. The method of any of claims 18-28, wherein the method of preparing the phosphorus-containing molecular sieve comprises:

(b) First contacting the first solid product obtained in step (a) with a first acid solution; the temperature of the first contact is 40-95 ℃, and the addition amount of the first acid solution ensures that the pH value of a first contact product is 2.3-4.0;

(c) Carrying out second contact on the molecular sieve material obtained in the step (b) and a second acid solution; the temperature of the second contact is 40-95 ℃, and the addition amount of the second acid solution enables the pH value of the second contact product to be 0.8-2.0.

30. The method of claim 29, wherein in step (b), the first acid solution is added in an amount such that the first contact product has a pH of 2.5 to 4.0.

31. The process of claim 29, wherein in step (c), the second acid solution is added in an amount such that the second contact product has a pH of 1.0 to 2.0.

32. The process of any one of claims 18 to 28, wherein the carrier of the hydrocracking catalyst further comprises a refractory inorganic oxide; the weight ratio of the phosphorus-containing molecular sieve to the heat-resistant inorganic oxide is 0.03.

33. The method of claim 32, wherein the refractory inorganic oxide is selected from at least one of alumina, silica, titania, zirconia, and magnesia.

34. The process of any of claims 1-6, wherein the post-refining catalyst comprises a support and a group VIB metal component and a group VIII metal component supported on the support.

35. The process of claim 34, wherein the group VIII metal component is present in an amount of from 1 to 10 wt.% and the group VIB metal component is present in an amount of from 5 to 50 wt.%, based on the total amount of post-refining catalyst and calculated as oxides.

36. The process according to claim 34, wherein in the post-refining catalyst the group VIB metal is Mo and/or W; the group VIII metal component is Co and/or Ni.

37. The method of claim 34, wherein in the post-refining catalyst, the support is selected from at least one of alumina, silica, and silica-alumina.

38. The process according to any one of claims 1 to 6, wherein in step (1), a hydrogenation protecting agent is further provided upstream of the hydrofinishing catalyst based on the flow direction of the heavy feedstock oil.

39. The process of claim 38, wherein the hydro-protectant is 5-80 vol% of the total amount of hydrofinishing catalyst.

40. The process of claim 39, wherein the hydro-protectant is 5-30 vol% of the total amount of hydrofinishing catalyst.

41. The method of claim 38, wherein the hydrogenation protective agent comprises a carrier and a group VIB metal component and a group VIII metal component which are loaded on the carrier, and the content of the group VIB metal component is 5.5-10 wt% and the content of the group VIII metal component is 1-5 wt% based on the total amount of the hydrogenation protective agent and calculated by oxides.

42. The process of claim 41, wherein in the hydro-protectant, the group VIB metal is Mo and/or W; the group VIII metal component is Co and/or Ni.

43. The method of claim 41, wherein in the hydroprotectant, the support is selected from at least one of alumina, silica and silica-alumina.

44. The process according to any one of claims 1 to 6, wherein step (4) fractionates the post-refining effluent obtained in step (3) to obtain a naphtha fraction, the jet fuel fraction, a diesel fraction and a tail oil fraction.

45. A process according to any one of claims 1 to 6 wherein the jet fuel fraction has a distillation range of from 180 to 215 ℃.