CN110540875A

CN110540875A - Process for producing high density jet fuel and clean diesel

Info

Publication number: CN110540875A
Application number: CN201810525427.1A
Authority: CN
Inventors: 任亮; 田鹏程; 梁家林; 许双辰; 毛以朝; 胡志海
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petrochemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petrochemical Corp
Priority date: 2018-05-28
Filing date: 2018-05-28
Publication date: 2019-12-06
Anticipated expiration: 2038-05-28
Also published as: CN110540875B

Abstract

The present disclosure relates to a method of producing high density jet fuel and clean diesel, the method comprising: (1) aromatic extraction is carried out on the poor-quality diesel raw material to obtain extract oil and raffinate oil; (2) enabling the extract oil to enter a hydrocracking reaction zone for hydrocracking reaction; (3) allowing the raffinate oil to enter a hydrofining reaction zone to perform a first hydrofining reaction; the hydrocracking reaction is carried out in the presence of the hydrocracking catalyst; the hydrocracking catalyst comprises a carrier based on the dry weight of the hydrocracking catalyst; the carrier comprises a phosphorus-containing Y-type molecular sieve and a heat-resistant inorganic oxide. The method takes the poor diesel oil rich in aromatic hydrocarbon as a raw material, adopts a special hydrocracking catalyst to carry out hydrocracking reaction, and can produce high-quality high-density jet fuel and clean diesel oil products.

Description

Process for producing high density jet fuel and clean diesel

Technical Field

The present disclosure relates to a method of producing high density jet fuel and clean diesel.

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. Compared with the common jet fuel, the jet fuel can improve the calorific value of the fuel in unit volume, can effectively increase the energy carried by the fuel tank when the volume of the fuel tank is fixed, and is an important guarantee for the high-speed and long-range flight of the aerospace craft.

Volumetric heating value is the energy characteristic of jet fuel, and refers to the net heat released per unit volume of fuel when it is completely combusted, and is numerically equal to the product of the fuel's gravimetric heating value and its density. The volume heat value has significance on the range of the aircraft, and the larger the value is, the higher the stored chemical energy is, so that the effective range of the aircraft can be increased. Increasing fuel density is the most effective way to increase its volumetric heating value, for example: compared with the fuel with the density of 780kg/m3 (the volume calorific value is about 33X 103MJ/m3), the fuel with the density of 845kg/m3 (the volume calorific value is about 36X 103MJ/m3) can enable the aircraft to carry about 9 percent of energy under the condition of the same oil carrying volume.

CN200980141907.7 discloses a high-energy fraction fuel composition and a preparation method thereof. The jet fuel composition comprises (1) less than 22 vol% aromatic compounds; (2) at least 72 vol% cycloalkane; (3) less than 28 vol% normal and iso-paraffins; (4) a heat of combustion value of at least 128000 Btu/gal; (5) smoke point above 19mm (measured according to ASTM D1322).

CN201110222378.2 discloses a production method for producing high-density jet fuel by using coal as raw material, which comprises: liquefied light oil and liquefied distillate oil from the direct coal liquefaction process enter an expanded bed hydrotreating reactor with forced internal circulation to contact with hydrogen and a hydrotreating catalyst, and the effluent of the reactor is separated and fractionated; the light distillate oil and the medium distillate oil are mixed and enter a deep hydrogenation refining fixed bed reactor to be in contact reaction with hydrogen and a hydrogenation refining catalyst, and the product is separated and fractionated to obtain the high-density jet fuel.

CN201210394711.2 discloses a method for improving the quality of heavy diesel oil, which comprises the steps of subjecting heavy diesel oil with a boiling range of 220-410 ℃ to aromatic extraction to obtain raffinate oil containing saturated hydrocarbon and extract oil containing polycyclic aromatic hydrocarbon, subjecting the raffinate oil to hydrorefining, subjecting a hydrorefined liquid product to fractionation, using a fraction below 180 ℃ as a gasoline blending component, subjecting a fraction above 180 ℃ to clean diesel oil, subjecting the extract oil containing polycyclic aromatic hydrocarbon to hydro-upgrading, mixing a product of the upgrading reaction with the heavy diesel oil, and then subjecting the mixture to aromatic extraction. The method can improve the quality of heavy diesel oil and produce low-sulfur and high-cetane diesel oil meeting the diesel oil standard.

US4875992 discloses a process for producing high gravity aviation kerosene from a fused ring aromatic hydrocarbon and a hydrogenated aromatic hydrocarbon feedstock. The raw material in the method is oil rich in bicyclic aromatic hydrocarbon and bicyclic hydrogenated aromatic hydrocarbon, and the oil comprises catalytic cycle oil, fuel oil, coal-based oil and the like. The raw material firstly enters a first section to carry out desulfurization and denitrification reaction, and the product enters a second section to carry out selective hydrogenation saturation bicyclic aromatic hydrocarbon and bicyclic hydrogenation aromatic hydrocarbon to generate naphthenic hydrocarbon and generate low molecular hydrocarbon as little as possible. The specific gravity index (API) of the obtained large-specific gravity aviation kerosene is between 25 and 35 degrees, and the content of aromatic hydrocarbon is less than 50 percent. The method requires that the range of the fraction of the raw material is 350F-700 degrees, and the raw material contains 85-100% of bicyclic aromatic hydrocarbon and bicyclic hydrogenated aromatic hydrocarbon, so that the method is harsh on the raw material.

Disclosure of Invention

It is an object of the present disclosure to provide a method for producing high quality, high density jet fuel and clean diesel.

To achieve the above objects, the present disclosure provides a method of producing high density jet fuel and clean diesel, the method comprising:

(1) Aromatic extraction is carried out on the poor-quality diesel raw material to obtain extract oil and raffinate oil;

(2) Enabling the extract oil obtained in the step (1) to enter a hydrocracking reaction zone for hydrocracking reaction, and separating the obtained product to obtain naphtha, high-density jet fuel and unconverted diesel oil;

(3) Enabling the raffinate oil obtained in the step (1) to enter a hydrofining reaction zone for carrying out a first hydrofining reaction, and carrying out product separation on an obtained product to obtain clean diesel oil;

The hydrocracking reaction zone is filled with a hydrocracking catalyst, and the hydrocracking reaction is carried out in the presence of the hydrocracking catalyst; the hydrocracking catalyst comprises 45-90 wt% of a carrier, 1-40 wt% of a first metal component and 1-15 wt% of a second metal component, wherein the carrier is calculated by the weight of the hydrocracking catalyst on a dry basis, and the first metal component is calculated by the weight of a metal oxide; the carrier comprises a phosphorus-containing Y-type molecular sieve and a heat-resistant inorganic oxide, wherein the weight ratio of the phosphorus-containing Y-type molecular sieve to the heat-resistant inorganic oxide is (0.03-20): 1; the first metal component is a metal selected from group VIB; the second metal component is a metal selected from group VIII; calculated by oxide, the phosphorus content of the phosphorus-containing Y-type molecular sieve is 0.3-5 wt%, the pore volume is 0.2-0.95 mL/g, and the ratio of pyridine infrared B acid to pyridine infrared L acid is 2-10.

Optionally, the preparation step of the phosphorus-containing Y-type molecular sieve comprises:

a. Carrying out hydro-thermal treatment on a phosphorus-containing molecular sieve raw material for 0.5-10h at the temperature of 350-700 ℃ and the pressure of 0.1-2MPa in the presence of water vapor to obtain a hydro-thermally treated molecular sieve material; calculated by oxide and based on the dry weight of the phosphorus-containing molecular sieve raw material, the phosphorus content of the phosphorus-containing molecular sieve raw material is 0.1-15 wt%, and the sodium content is 0.5-4.5 wt%;

b. b, adding water into the molecular sieve material subjected to the hydrothermal treatment obtained in the step a for pulping to obtain molecular sieve slurry, heating the molecular sieve slurry to 40-95 ℃, keeping the temperature, and continuously adding an acid solution into the molecular sieve slurry, wherein the ratio of the weight of acid in the acid solution to the dry weight of the phosphorus-containing molecular sieve raw material is (0.01-0.6): 1, taking 1L of the molecular sieve slurry as a reference, taking H + as the reference, adding the acid solution at a speed of 0.05-10 mol/H, reacting at constant temperature for 0.5-20H after the acid is added, and collecting a solid product.

Optionally, in the step a, the phosphorus-containing molecular sieve is a phosphorus-containing Y-type molecular sieve, the unit cell constant of the phosphorus-containing Y-type molecular sieve is 2.425-2.47 nm, the specific surface area is 250-750 m2/g, and the pore volume is 0.2-0.95 ml/g;

The water content of the phosphorus-containing molecular sieve raw material is 10-40 wt%;

The phosphorus-containing molecular sieve raw material is granular, the content of the phosphorus-containing molecular sieve raw material with the granularity range of 1 mm-500 mm is 10-100 wt% of the total weight of the phosphorus-containing molecular sieve raw material, and the granularity is calculated by the diameter of a circumscribed circle of the granules.

optionally, in the step b, the ratio of the weight of water in the molecular sieve slurry obtained after pulping to the dry basis weight of the phosphorus-containing molecular sieve raw material is (14-5): 1;

the acid concentration of the acid solution is 0.01-15.0 mol/L, and the acid is at least one selected from phosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, citric acid, tartaric acid, formic acid and acetic acid.

Optionally, the heat-resistant inorganic oxide is at least one selected from the group consisting of alumina, zirconia, magnesia, thoria, beryllia, boria, and cadmium oxide; the first metal component is molybdenum and/or tungsten; the second metal component is at least one selected from iron, nickel and cobalt.

Optionally, in the step (1), the poor diesel raw material has a total aromatic content of 30-90 wt%, a paraffin content of 5-50 wt%, and a naphthene content of 5-55 wt%.

alternatively, in step (1), the aromatic extraction conditions comprise: the temperature is 20-100 ℃, the pressure is 0.05-0.5 MPa, the weight ratio of an extraction solvent to the poor-quality diesel raw material is (0.5-2.0): 1, and the extraction solvent is at least one selected from furfural, dimethyl sulfoxide, N-dimethylformamide and ionic liquid.

Optionally, in the step (1), the aromatic hydrocarbon content of the extract oil is 95-99.9 wt%; the raffinate oil has a saturated hydrocarbon content of 60-98 wt%.

Optionally, the method further comprises: in the step (2), according to the flow direction of a reactant flow, a second hydrofining catalyst is filled upstream of the hydrocracking catalyst in the hydrocracking reaction zone, the extract oil enters the hydrocracking reaction zone to firstly carry out a second hydrofining reaction in the presence of the second hydrofining catalyst and then carry out the hydrocracking reaction, and the volume ratio of the second hydrofining catalyst to the hydrocracking catalyst is (0.3-3): 1.

optionally, the method further comprises: in the step (2), according to the flow direction of a reactant flow, a hydrogenation protective agent is further filled at the upstream of the second hydrofining catalyst in the hydrocracking reaction zone, and the volume ratio of the hydrogenation protective agent to the second hydrofining catalyst is (5-30): 100.

Optionally, the method further comprises: in the step (2), according to the flow direction of a reactant flow, a third hydrofining catalyst is filled in the hydrocracking reaction zone downstream of the hydrocracking catalyst, the extract oil enters the hydrocracking reaction zone to undergo the hydrocracking reaction, then a third hydrofining reaction is performed in the presence of the third hydrofining catalyst, and then the obtained product is subjected to product separation, wherein the volume ratio of the third hydrofining catalyst to the hydrocracking catalyst is 1: (1-10).

Optionally, in the step (2), the reaction conditions of the hydrocracking reaction zone based on the volume of the extract oil comprise: the hydrogen partial pressure is 10.0-16.0 MPa, preferably 10.0-14.0 MPa; the reaction temperature is 300-450 ℃, and preferably 350-400 ℃; the volume ratio of the hydrogen to the oil is 400-2500, preferably 600-1600; the liquid hourly space velocity is 0.2-5.0 h < -1 >, and preferably 0.5-1.5 h < -1 >.

Optionally, in the step (2), the density of the high-density jet fuel is not lower than 0.830g/cm3, the weight calorific value is not lower than 42.9MJ/kg, the total aromatic hydrocarbon content is 0.5-10 wt%, the naphthenic hydrocarbon content is 80-95 wt%, and the paraffin hydrocarbon content is 0.5-10 wt%.

Optionally, the method further comprises: in the step (2), the unconverted diesel oil is returned to enter the hydrocracking reaction zone.

Alternatively, in step (3), the reaction conditions of the hydrofining reaction zone based on the volume of the raffinate oil comprise: the hydrogen partial pressure is 3.0-8.0 MPa, preferably 3.0-6.4 MPa; the reaction temperature is 300-450 ℃, and preferably 340-430 ℃; the volume ratio of the hydrogen to the oil is 300-1000, preferably 300-600; the liquid hourly space velocity is 0.5-10.0 h < -1 >, and preferably 1.0-4.0 h < -1 >.

Optionally, in the step (3), the clean diesel oil has a total aromatic hydrocarbon content of 0.5-10 wt%, a naphthenic hydrocarbon content of 9.5-40 wt%, a paraffin hydrocarbon content of 50-90 wt% and a cetane number of not less than 60.

By adopting the technical scheme, the inferior diesel oil rich in aromatic hydrocarbon is taken as a raw material, and a special hydrocracking catalyst is adopted for carrying out hydrocracking reaction, so that high-quality high-density jet fuel and clean diesel oil products can be produced. Compared with the prior art, the beneficial effects of the present disclosure are mainly embodied in the following aspects:

(1) The method disclosed by the invention can be used for producing high-density jet fuel which meets the specifications of large-specific gravity jet fuel (standard number GJB1603-1993) and kerosene for liquid rocket engines (standard number GJB5425-2005(K)), the density of the high-density jet fuel is more than 0.830g/cm3, and the heat value of the weight of the high-density jet fuel exceeds 42.9 MJ/kg;

(2) The high density jet fuel product produced by the process of the present disclosure is rich in naphthenes; the cycloparaffin has good high-temperature thermal stability, more importantly, has high mass density and volume heat value, can effectively increase the loading capacity, reduce the fuel consumption, meet the requirements of modern large-thrust vector engines on high navigational speed, large load and long navigational range under the condition of certain volume of an engine fuel tank, can also reduce the occupied volume of the engine fuel tank under the condition of keeping the performance of the airplane, improve the maneuverability and the penetration resistance of the airplane, and has good military application prospect;

(3) The high-density jet fuel product produced by the method disclosed by the invention has very low sulfur content and nitrogen content, reduces the environmental pollution and is a clean green product;

(4) The clean diesel produced by the method disclosed by the invention has high paraffin content and cetane number, the paraffin content is over 50 percent, and the sulfur content is less than 10 mu g/g, so that the clean diesel can be used as high-quality national V diesel or ethylene cracking material.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

fig. 1 is a schematic flow diagram of a method provided by the present disclosure.

Description of the reference numerals

1 poor diesel raw material 2 extraction unit

3 raffinate oil 4 hydrofining reaction zone

5 clean diesel oil 6 hydrocracking reaction zone

7 product separation and fractionation system 8 naphtha

9 high density jet fuel 10 unconverted diesel

11 oil extraction

Detailed Description

The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

The present disclosure provides a method of producing high density jet fuel and clean diesel, the method comprising:

The hydrocracking reaction zone is filled with a hydrocracking catalyst, and the hydrocracking reaction is carried out in the presence of the hydrocracking catalyst; the hydrocracking catalyst comprises 45-90 wt% of a carrier, 1-40 wt% of a first metal component and 1-15 wt% of a second metal component, wherein the carrier is calculated by the weight of the hydrocracking catalyst on a dry basis, and the first metal component is calculated by the weight of a metal oxide; the carrier comprises a phosphorus-containing Y-type molecular sieve and a heat-resistant inorganic oxide, wherein the weight ratio of the phosphorus-containing Y-type molecular sieve to the heat-resistant inorganic oxide is (0.03-20): 1; the first metal component is a metal selected from group VIB; the second metal component is a metal selected from group VIII.

the inventor of the present disclosure finds through research that the poor quality diesel oil raw material is composed of alkane, cyclane and aromatic hydrocarbon, if the aromatic hydrocarbon in the poor quality diesel oil raw material is subjected to hydrogenation saturation and selective ring opening, a large amount of aviation kerosene fraction rich in cyclane can be produced, and the aviation kerosene fraction not only meets the property requirements of high density jet fuel on the family composition, but also meets other property requirements of heat value, sulfur content, smoke point and the like. After the alkane and the cycloalkane are subjected to hydrodesulfurization, clean diesel oil meeting the national V standard can be produced; the produced clean diesel oil has high paraffin content and may be used as ethylene cracking material.

In the hydrocracking catalyst adopted by the method, the phosphorus-containing Y-type molecular sieve as a carrier component has special performance, so that the hydrocracking catalyst has higher hydrocracking activity and ring opening selectivity, the naphthenic rings of tetrahydronaphthalene, tetrahydrophenanthrene and decahydrophenanthrene can be opened, and monocyclic naphthenic hydrocarbon is reserved, so that the density is reduced, and the hydrogen content is increased. Calculated by oxide, the phosphorus content of the phosphorus-containing Y-type molecular sieve is 0.3-5 wt%, the pore volume is 0.2-0.95 mL/g, and the ratio of pyridine infrared B acid to pyridine infrared L acid is 2-10.

The phosphorus-containing Y-type molecular sieve has a higher ratio of the B acid content to the L acid content. Particularly, the phosphorus-containing Y-type molecular sieve not only reserves high ratio of framework aluminum to non-framework aluminum, but also reserves certain non-framework aluminum at a position of-4 to-6 ppm or at a position of 3 to 7ppm at the position of the non-framework aluminum. Specifically, in an Al27-NMR structural spectrum of the molecular sieve, the peak height ratio of framework aluminum to non-framework aluminum of 60 +/-1 ppm and-1 +/-1 ppm, namely I60ppm/I-1ppm, can be 5-40; and the chemical shift position of 0ppm of non-framework aluminum has two obvious characteristic peaks: -1 + -1ppm, and-5.5 + -2 ppm or 3-7 ppm, the ratio of the peak heights of the two, i.e., I-1ppm/I + -6ppm, may be 0.4-2, preferably 0.8-2, wherein I + -6ppm is the greater of the peak heights of-5.5 + -2 ppm and 3-7 ppm.

the phosphorus-containing Y-type molecular sieve is prepared by carrying out special hydrothermal treatment and acid washing treatment on a phosphorus-containing molecular sieve raw material. Specifically, the preparation step of the phosphorus-containing Y-type molecular sieve may include:

In the step a, the phosphorus-containing molecular sieve raw material refers to a phosphorus-containing molecular sieve. By adopting the phosphorus-containing molecular sieve as a raw material, the phosphorus-aluminum species outside the molecular sieve framework can improve the framework stability of the molecular sieve, thereby further improving the performance of the molecular sieve. The structure of the phosphorus-containing molecular sieve raw material can be an octahedral zeolite molecular sieve structure, preferably a phosphorus-containing Y-type molecular sieve, the unit cell constant of the phosphorus-containing molecular sieve raw material can be 2.425-2.47 nm, the specific surface area can be 250-750 m2/g, and the pore volume can be 0.2-0.95 ml/g. Further, the specific selection of the Y-type molecular sieve may be widely varied as long as the phosphorus-containing molecular sieve raw material satisfies the above conditions, and for example, the Y-type molecular sieve may 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 position of the phosphorus-containing Y-type molecular sieve can be occupied by one or more of sodium ions, ammonium ions and hydrogen ions; alternatively, the sodium, ammonium, and hydrogen ions may be replaced by other ions, either before or after the molecular sieve is introduced with phosphorus, by conventional ion exchange. The phosphorus-containing molecular sieve raw material can be a commercial product, and can also be prepared by any prior art, for example, a method for preparing USY disclosed in a patent ZL00123139.1, a method for preparing PUSY disclosed in a patent ZL200410071122.6 and the like can be adopted, and the details of the disclosure are not repeated.

In the step a, the water content of the phosphorus-containing molecular sieve raw material is preferably 10-40 wt%. The phosphorus-containing molecular sieve raw material with the water content can be obtained by adding water into the molecular sieve, pulping, filtering and drying. The phosphorus-containing molecular sieve raw material is preferably granular, and the content of the phosphorus-containing molecular sieve raw material with the granularity range of 1 mm-500 mm can be 10-100 wt%, preferably 30-100 wt% of the total weight of the phosphorus-containing molecular sieve raw material. Further, the content of the phosphorus-containing molecular sieve raw material with the granularity range of 5 mm-100 mm is 30-100 wt% of the total weight of the phosphorus-containing molecular sieve raw material. Wherein the particle size is in terms of the diameter of the circumscribed circle of particles. The adoption of the phosphorus-containing molecular sieve raw material with the granularity range for hydrothermal treatment can obviously improve the mass transfer effect of the hydrothermal treatment, reduce the material loss and improve the stability of operation. The particle size control method of the molecular sieve raw material can be conventional in the field, such as a sieving method, an extrusion strip method, a rolling ball method and the like.

Wherein, the meaning of the water adding and pulping in the step b is well known to those skilled in the art, and the ratio of the weight of the water in the molecular sieve slurry obtained after pulping to the dry weight of the phosphorus-containing molecular sieve raw material can be (14-5): 1.

In the step b, the molecular sieve slurry is preferably heated to 50-85 ℃, and then the acid solution is continuously added into the molecular sieve slurry while maintaining the temperature until the weight of the acid in the acid solution reaches a set amount. The most important of the preparation steps of the phosphorus-containing Y-type molecular sieve is that a continuous acid adding mode is adopted, acid adding and acid washing reaction are carried out simultaneously, the acid adding speed is low, the dealumination process is more moderate, and the improvement of the performance of the molecular sieve is facilitated.

wherein, the acid solution can be continuously added into the molecular sieve slurry at one time, namely, the whole acid solution is continuously added according to a specific acid adding speed, and then the reaction is carried out at constant temperature. In particular, the acid solution may also be added in multiple portions in order to increase the utilization of the material and reduce the waste output. For example, the acid solution can be added to the molecular sieve slurry at a specific acid addition rate of 2-10 times, and after each acid addition, the reaction can be carried out at constant temperature for a period of time to continue the next acid addition until the set amount of the acid solution is added. When the acid solution is added in multiple portions, the ratio of the weight of acid in the acid solution to the dry weight of the phosphorus-containing molecular sieve starting material is preferably (0.01-0.3): 1. the acid concentration of the acid solution can be 0.01-15.0 mol/L, and the pH value can be 0.01-3. The acid may be a conventional inorganic acid and/or organic or 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.

Wherein, the preparation step of the phosphorus-containing Y-type molecular sieve can also comprise the following steps: in step b, adding an ammonium salt into the molecular sieve slurry during the adding of the acid solution, wherein the ammonium salt can be at least one selected from ammonium nitrate, ammonium chloride and ammonium sulfate, and the weight ratio of the ammonium salt to the dry weight of the phosphorus-containing molecular sieve raw material can be (0.1-2.0): 1. the ammonium salt may be added to the molecular sieve slurry independently of the acid solution, or an aqueous solution containing the ammonium salt and the acid may be prepared in a desired amount and added to the molecular sieve slurry.

wherein, the preparation step of the phosphorus-containing Y-type molecular sieve can also comprise the following steps: and collecting the solid product, and then washing and drying to obtain the phosphorus-containing Y-type molecular sieve. The washing and drying are conventional steps for preparing the molecular sieve, and the disclosure is not particularly limited. For example, the drying may be performed by using an oven, a mesh belt, a converter, or the like, and the drying conditions may be: the temperature is 50-350 ℃, and preferably 70-200 ℃; the time is 1-24 h, preferably 2-6 h.

According to the present disclosure, the heat-resistant inorganic oxide can increase the strength of the catalyst and improve and adjust physicochemical properties of the catalyst, such as improving the pore structure of the catalyst. The heat-resistant inorganic oxide may be an inorganic oxide commonly used for hydrogenation catalyst supports, such as alumina, silica, amorphous silica-alumina compounds, zirconia, magnesia, thoria, beryllia, boria, cadmium oxide, and the like. In a preferred embodiment of the present disclosure, the heat-resistant inorganic oxide is preferably alumina, which may include gibbsite such as gibbsite (gibbsite), bayerite nordstrandite (bayerite) and diaspore such as boehmite (boehmite, diasporite, pseudoboehmite). In other embodiments, the refractory inorganic oxide is of another species or combination.

according to the present disclosure, preferably, the first metal component is molybdenum and/or tungsten; the second metal component is at least one selected from iron, nickel and cobalt.

According to the present disclosure, the hydrocracking catalyst may be prepared by a conventional method, for example, the hydrocracking catalyst may be prepared by a method including: the impregnation liquid containing the metal precursor is contacted with the carrier for impregnation, and then the material obtained after the impregnation is dried. The contact impregnation method of the impregnation liquid and the carrier can adopt any one of the methods known in the art, for example, the method disclosed in patent CN200810241082.3, which comprises loading a group VIB metal component, a group VIII metal component and an organic additive onto a catalyst carrier, wherein the process of loading the group VIB metal component, the group VIII metal component and the organic additive onto the catalyst carrier is any one of the following methods:

Mode 1: contacting the catalyst carrier with a first solution, then contacting with a second solution, or contacting the catalyst carrier with a second solution, then contacting with the first solution, wherein the first solution contains a compound of a group VIB metal component and a compound of a group VIII metal component, the second solution contains a compound of a group VIB metal component but does not contain a compound of a group VIII metal component, and the first solution and/or the second solution contain the organic additive;

Mode 2: contacting the catalyst carrier with a third solution and then with a fourth solution, or contacting the catalyst carrier with a fourth solution and then with a third solution, wherein the third solution contains a compound of a group VIB metal component, the fourth solution contains a compound of a group VIII metal component and an organic auxiliary agent but does not contain the compound of the group VIB metal component, and the third solution contains or does not contain the compound of the group VIII metal component and the organic additive,

wherein, after each contact, the catalyst support after the contact is heated.

methods for preparing such carriers are well known to those skilled in the art and may include, for example: mixing the phosphorus-containing Y-type molecular sieve, the heat-resistant inorganic oxide, the solvent and the optional auxiliary agent, 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. The solvent is a common solvent in the catalyst forming process. When the extrusion molding method is employed, an appropriate amount of an auxiliary is preferably added to facilitate molding.

Alternatively, the preparation method of the carrier may include: mixing the phosphorus-containing Y-type molecular sieve, the heat-resistant inorganic oxide, the peptizing agent and the optional lubricant, and then molding, drying and roasting to obtain the carrier. The peptizing agent can be an acid-containing solution or an alkali-containing solution, the acid is at least one of organic acid or inorganic acid familiar to the technical field, such as at least one of phosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, tungstic and/or molybdic heteropoly acid, citric acid, tartaric acid, formic acid and acetic acid, and ammonium, iron, cobalt, nickel, aluminum and other cations can be added into the acid-containing solution to keep the acid; the alkali-containing solution comprises at least one of ammonia, organic amine, and urea.

The shape of the carrier is not particularly limited, and may be spherical, strip-like, hollow strip-like, spherical, block-like, etc., and the strip-like carrier may be cloverleaf-like, clover-like, and their modifications.

In an alternative embodiment, the support may be prepared as disclosed in patent CN107029779A, in particular: (1) mixing a phosphorus-containing Y-type molecular sieve with a heat-resistant inorganic oxide, a peptizing agent, a lubricant and water to obtain a mixture, wherein the dosage of each component enables the weight ratio of the mass of the peptizing agent in the mixture to the weight of powder to be 0.28 x 10 < -4 > to 4.8 x 10 < -4 > mol/g, the weight ratio of the weight of water to the mass of the peptizing agent to be 2.0 x 103 to 30 x 103g/mol, the weight of the powder is the sum of the weight of the phosphorus-containing Y-type molecular sieve and the heat-resistant inorganic oxide, and the mass of the peptizing agent refers to the mole number of H protons metered in the peptizing agent; the lubricant is one or two of sesbania powder and graphite; (2) and (2) kneading, molding, drying and roasting the mixture obtained in the step (1) to obtain the carrier.

the metal precursors may include a first metal precursor and a second metal precursor. Wherein the first metal precursor is a soluble compound containing the first metal, and comprises at least one of an inorganic acid of the first metal, an inorganic salt of the first metal and a first metal organic compound; the inorganic salt may be at least one selected from the group consisting of nitrate, carbonate, hydroxycarbonate, hypophosphite, phosphate, sulfate and chloride; the organic substituent in the first metal organic compound is at least one selected from hydroxyl, carboxyl, amino, ketone, ether and alkyl. For example, when the first metal is molybdenum, the first metal precursor may be at least one selected from the group consisting of molybdic acid, paramolybdic acid, molybdate, paramolybdate, and the like; when the first metal component is tungsten, the first metal precursor may be at least one selected from tungstic acid, metatungstic acid, ethyl metatungstic acid, tungstate, metatungstate, and ethyl metatungstate. The second metal precursor is a soluble compound containing the second metal and comprises at least one of inorganic acid of the second metal, inorganic salt of the second metal and organic compound of the second metal; the inorganic salt may be at least one selected from the group consisting of nitrate, carbonate, hydroxycarbonate, hypophosphite, phosphate, sulfate and chloride; the organic substituent in the second metal organic compound is at least one selected from hydroxyl, carboxyl, amino, ketone, ether and alkyl.

The impregnation liquid can also contain organic additives; the concentration of the organic additive may be 2-300 g/L. The organic additive is an oxygen-containing organic compound and/or a nitrogen-containing organic compound. Specifically, the oxygen-containing organic compound may be at least one selected from the group consisting of ethylene glycol, glycerol, polyethylene glycol (molecular weight may be 200 to 1500), diethylene glycol, butanediol, acetic acid, maleic acid, oxalic acid, nitrilotriacetic acid, 1, 2-cyclohexanediaminetetraacetic acid, citric acid, tartaric acid, and malic acid; the nitrogen-containing organic compound may be at least one selected from the group consisting of ethylenediamine, diethylenetriamine, cyclohexanediaminetetraacetic acid, glycine, nitrilotriacetic acid, ethylenediaminetetraacetic acid and ammonium ethylenediaminetetraacetate.

The contacting temperature in the preparation of the hydrocracking catalyst is not particularly limited, and may be various temperatures that the impregnation solution can reach. The time for the impregnation is also not particularly limited as long as the catalyst carrier can be supported with the desired amount of the metal active component precursor. In general, the higher the impregnation temperature, the higher the concentration of the impregnation solution, and the shorter the time required to achieve the same impregnation amount (i.e., the weight difference between the catalyst support after impregnation and the catalyst support before impregnation); and vice versa. When the desired amount and conditions of impregnation are determined, one skilled in the art can readily select an appropriate impregnation time based on the teachings of the present disclosure. The present disclosure does not specifically require an impregnation method, which may be either a saturated impregnation or a supersaturated impregnation. The impregnation may be carried out under a sealed condition or in an open environment according to a conventional method in the art, and the loss of the aqueous solvent may or may not be replenished during the impregnation. Various gases, such as air, nitrogen, water vapor, etc., may be introduced during the impregnation process, or any new components may not be introduced.

In the preparation of the hydrocracking catalyst, the drying conditions are not particularly limited, and may be various drying conditions commonly used in the art, for example, may be: the temperature is 80-350 ℃, preferably 100-300 ℃ and the time is 0.5-24 hours, preferably 1-12 hours.

In the preparation of the hydrocracking catalyst, a step of drying the contacted material and then calcining the dried material, which is a conventional step for preparing the catalyst, may be further included, and the disclosure is not particularly limited. The conditions for the calcination may be, for example: the temperature is 350-600 ℃, and preferably 400-550 ℃; the time is 0.2 to 12 hours, preferably 1 to 10 hours.

according to the disclosure, in the step (1), the poor diesel raw material may be at least one of catalytic cracking light diesel oil (LCO), straight-run diesel oil and coker diesel oil; the catalyst also can contain catalytic cracking heavy cycle oil, coal tar, coal liquefaction oil or mixed oil of the above types and other oil products rich in aromatic hydrocarbon or naphthenic hydrocarbon, and the distillation range of the catalyst can be 180-370 ℃. Specifically, the total aromatic hydrocarbon content of the poor diesel raw material can be 30-90 wt%, the paraffin hydrocarbon content can be 5-50 wt%, and the naphthene hydrocarbon content can be 5-55 wt%. The density of the poor diesel raw material can be generally 0.80-0.95 g/cm3, and preferably 0.86-0.95 g/cm 3.

In accordance with the present disclosure, in step (1), the aromatic extraction is a process well known to those skilled in the art, and the steps mainly comprise: the poor diesel raw material and the extraction solvent are in reverse contact in an extraction tower, raffinate oil containing saturated hydrocarbons such as alkane, cyclane and the like flows out from the top of the extraction tower, extract oil containing aromatic hydrocarbons and the solvent flow out from the bottom of the extraction tower, and the extract oil is obtained after the solvent is separated by distillation. The aromatic extraction conditions may include: the temperature is 20-100 ℃, the pressure is 0.05-0.5 MPa, and the weight ratio of the extraction solvent to the poor diesel raw material is (0.5-2.0): 1; the extraction solvent may be of conventional kind well known to those skilled in the art, for example selected from furfural, dimethyl sulfoxide, N-dimethylformamide, ionic liquids and the like, wherein the cation of the ionic liquid may be imidazoles, BF4, pyridines and the like; the anion can be sulfonate, sulfate, nitrate, alkyl sulfonate, and the like.

According to the present disclosure, in the step (1), the aromatic hydrocarbon content of the extract oil obtained by aromatic hydrocarbon extraction may be 95 to 99.9 wt%; the raffinate oil may contain saturated hydrocarbons in an amount of 60 to 98 wt%.

According to the present disclosure, the method may further comprise: in the step (2), according to the flow direction of a reactant flow, a second hydrofining catalyst is loaded upstream of the hydrocracking catalyst in the hydrocracking reaction zone, the extract oil enters the hydrocracking reaction zone to perform a second hydrofining reaction in the presence of the second hydrofining catalyst, and then the hydrocracking reaction is performed, wherein the volume ratio of the second hydrofining catalyst to the hydrocracking catalyst may be (0.3-3): 1. therefore, the extract oil enters a hydrocracking reaction zone and is subjected to hydrodesulfurization, hydrodenitrogenation, aromatic saturation and other reactions under the catalysis of a second hydrofining catalyst with hydrodenitrogenation performance and aromatic saturation performance, so that the organic nitrogen content in the extract oil can be reduced to 20 mu g/g, and the aromatic hydrogenation saturation is naphthenic hydrocarbon or monocyclic aromatic hydrocarbon, so that a more appropriate feed is provided for the hydrocracking catalyst. The second hydrotreating catalyst is not particularly limited in kind in the present disclosure, and may be selected by those skilled in the art according to various hydrotreating catalysts conventionally used in the art. The second hydrofining catalyst may be the same as or different from the first hydrofining catalyst loaded in the hydrofining reaction zone.

Further, in order to prevent coking of the second hydrofining catalyst due to coking precursors such as olefins and gums in the diesel fuel feedstock, the method may further comprise: in the step (2), according to the flow direction of the reactant flow, a hydrogenation protective agent is further filled in the hydrocracking reaction zone at the upstream of the second hydrofining catalyst to protect the second hydrofining catalyst and avoid rapid coking of a catalyst bed. The volume ratio of the hydrogenation protective agent to the second hydrofining catalyst can be (5-30): 100. the type of the hydrogenation protective agent may be conventional in the art and may, for example, consist of 1.0 to 5.0 wt% nickel oxide, 5.5 to 10.0 wt% molybdenum oxide and the balance of an alumina support having a bimodal distribution.

in accordance with the present disclosure, to further reduce the olefin and mercaptan sulfur content in the reaction product, the process may further comprise: in the step (2), according to the flow direction of a reactant stream, a third hydrofining catalyst is loaded downstream of the hydrocracking catalyst in the hydrocracking reaction zone, the extract oil is allowed to enter the hydrocracking reaction zone to undergo the hydrocracking reaction, then a third hydrofining reaction is performed in the presence of the third hydrofining catalyst, and then the obtained product is subjected to product separation, wherein the volume ratio of the third hydrofining catalyst to the hydrocracking catalyst may be 1: (1-10). The third hydrofinishing catalyst may be the same as the first hydrofinishing catalyst.

According to the present disclosure, in the step (2), the reaction conditions of the hydrocracking reaction zone may include, based on the volume of the extract oil: the hydrogen partial pressure is 10.0-16.0 MPa, preferably 10.0-14.0 MPa; the reaction temperature is 300-450 ℃, and preferably 350-400 ℃; the volume ratio of the hydrogen to the oil is 400-2500, preferably 600-1600; the liquid hourly space velocity is 0.2-5.0 h < -1 >, and preferably 0.5-1.5 h < -1 >.

according to the disclosure, in the step (2), the fraction obtained by separation at 150-300 ℃ is a high-density jet fuel, and has the advantages of high density and high volumetric heat value, and specifically, the properties of the fraction can be as follows: the density is not lower than 0.830g/cm3, the weight heat value is not lower than 42.9MJ/kg, the total aromatic hydrocarbon content is 0.5-10 wt%, the naphthenic hydrocarbon content is 80-95 wt%, and the paraffin hydrocarbon content is 0.5-10 wt%; further, the density can be 0.835-0.860 g/cm3, and the heat value by weight is 43.0-45.5 MJ/kg.

The operation of isolating the product obtained in step (2) is well known to those skilled in the art in light of the present disclosure and will not be described in detail herein. In addition, the method may further include: in the step (2), the unconverted diesel oil is returned to enter the hydrocracking reaction zone.

According to the disclosure, in the step (3), the raffinate oil enters the hydrorefining reaction zone to perform the first hydrorefining reaction, i.e., deep desulfurization and denitrification are performed, so that the clean diesel oil standard can be met. The hydrofining reaction zone is filled with a first hydrofining catalyst with high desulfurization activity. The type of the first hydrofinishing catalyst is not particularly limited in the present disclosure, and those skilled in the art can select the first hydrofinishing catalyst according to various types of hydrofinishing catalysts conventionally used in the art. In order to make the quality of the clean diesel oil product disclosed by the disclosure more excellent, the method disclosed by the disclosure preferably selects the first hydrofining catalyst, and the composition based on the dry weight of the catalyst is as follows: 1 to 10 wt% of nickel oxide, 10 to 50 wt% of the sum of molybdenum oxide and tungsten oxide, 1 to 10 wt% of fluorine, 0.5 to 8 wt% of phosphorus oxide, and the balance of a mixture containing silicon oxide and aluminum oxide. Based on the mixture containing the silicon oxide and the aluminum oxide, the content of the silicon oxide is 2-45 wt%, and the content of the aluminum oxide is 55-98 wt%. The examples of the present disclosure illustratively use RS-2100 as the first hydrofinishing catalyst and those skilled in the art should not be construed as limiting the invention.

According to the present disclosure, in step (3), the reaction conditions of the hydrofinishing reaction zone may include, based on the volume of the raffinate oil: the hydrogen partial pressure is 3.0-8.0 MPa, preferably 3.0-6.4 MPa; the reaction temperature is 300-450 ℃, and preferably 340-430 ℃; the volume ratio of the hydrogen to the oil is 300-1000, preferably 300-600; the liquid hourly space velocity is 0.5-10.0 h < -1 >, and preferably 1.0-4.0 h < -1 >.

According to the disclosure, in the step (3), the fraction obtained by separation at 250-350 ℃ is the clean diesel, the total aromatic hydrocarbon content can be 0.5-10 wt%, the naphthenic hydrocarbon content can be 9.5-40 wt%, the paraffin hydrocarbon content can be 50-90 wt%, and the cetane number can be not less than 60.

The process flow of the method provided by the present disclosure is briefly described below with reference to fig. 1, and those skilled in the art will appreciate that many devices, such as pumps, heat exchangers, compressors, etc., are omitted from fig. 1, and the present disclosure is not limited thereto.

The poor diesel raw material 1 enters an extraction unit 2 for aromatic extraction, and extract oil 11 and raffinate oil 3 are obtained by separation. The extract oil 11 enters a hydrocracking reaction zone 6 for hydrocracking reaction, the reaction product enters a product separation and fractionation system 7, naphtha 8, high-density jet fuel 9 and unconverted diesel 10 are obtained through separation, and the unconverted diesel 10 circularly enters the hydrocracking reaction zone 6. The raffinate oil 3 enters a hydrofining reaction zone 4 to carry out a first hydrofining reaction, and clean diesel oil 5 is obtained.

The following examples further illustrate the methods provided by the present disclosure, but are not intended to limit the disclosure thereto.

In the examples and comparative examples of the present disclosure, the high density jet fuel fraction yield is defined as the weight percentage of the high density jet fuel fraction to the poor quality diesel feedstock cut from the whole fraction product by the fractionation tower.

The hydrofinishing catalyst used in the examples is sold under the trade designation RN-32V, RS-2000. The hydroprotectant is sold under the trade name RG-30A, RG-30B. The hydrocracking catalyst described in comparative example 1 was sold under the trade designation RT-5 and was prepared by conventional methods well known to those skilled in the art. The catalysts are all produced by Changjingtie division of petrochemical Co.

The pore volume and the specific surface area of the molecular sieve are measured by a static low-temperature adsorption capacity method (by adopting a national standard GB/T5816-1995 method) by adopting an ASAP 2400 model automatic adsorption instrument of American micromeritics instruments, and the specific method comprises the following steps: vacuumizing and degassing at 250 deg.C and 1.33Pa for 4 hr, contacting with nitrogen as adsorbate at-196 deg.C, and statically reaching adsorption balance; and calculating the nitrogen adsorption amount of the adsorbent according to the difference between the nitrogen gas inflow and the nitrogen gas remaining in the gas phase after adsorption, calculating the pore size distribution by using a BJH (British Ribose) formula, and calculating the specific surface area and the pore volume by using a BET (BET) formula.

The unit cell constant is determined by an X-ray diffractometer model D5005 of Siemens Germany, and is in accordance with the method of industry standard SH/T0339-92. The experimental conditions are as follows: cu target, Ka radiation, solid detector, tube voltage 40kV, tube current 40mA, step scanning, step width of 0.02 degrees, prefabrication time of 2s and scanning range of 5-70 degrees.

The phosphorus content and the sodium content of the molecular sieve are measured by a 3271E type X-ray fluorescence spectrometer of Japan science and Motor industry Co., Ltd, 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.

The ratio of the B acid amount to the L acid amount of the molecular sieve is measured by a Bio-Rad IFS-3000 type infrared spectrometer. The specific method comprises the following steps: grinding a molecular sieve sample, pressing into a self-supporting sheet of about 10mg/cm2, placing the self-supporting sheet in an in-situ pool of an infrared spectrometer, performing surface purification treatment for 2 hours at 350 ℃ under a vacuum degree of 10-3Pa, introducing pyridine saturated steam after cooling to room temperature, performing adsorption equilibrium for 15 minutes, performing vacuum desorption for 30 minutes at 350 ℃, and measuring the adsorption pyridine vibration spectrum after cooling to room temperature. The scanning range is 1400cm-1-1700cm-1, and the B acid amount [ infrared absorption value per unit area and unit mass of the sample, which is defined as the ratio of infrared absorption value of 1540 + -5 cm-1 band to the weight and area of the sample piece, is expressed as: AB. (cm 2. g) -1 ]. The L acid amount [ infrared absorption value per unit area, unit mass of the sample, is defined as the ratio of infrared absorption value of 1450. + -.5 cm-1 band to the weight and area of the sample piece, and is expressed as: AL (cm2 g) -1], and the value of AB/AL is defined as the ratio of the amount of B acid to the amount of L acid of the zeolite molecular sieve.

The molecular sieve adopts a Varian UNITYINOVA300M nuclear magnetic resonance instrument to perform sample analysis, wherein the resonance frequency of Al MAS is 78.162MHzs, the rotor speed is 3000Hz, the repetition delay time is 0.5s, the sampling time is 0.020s, the pulse width is 1.6 mus, the spectrum width is 54.7kHz, the data is collected at 2000 points, the cumulative frequency is 800 times, and the test temperature is room temperature.

The hydrocracking catalyst C was prepared by the following method:

300g of PSRY molecular sieve (product name of PSRY, unit cell constant of 2.456nm, specific surface area of 620m2/g, pore volume of 0.39ml/g, Na2O content of 2.2 wt%, P2O5 content of 1.5 wt% and Al2O3 content of 18 wt%) which is produced by Zhongshimei catalyst Changling division company is taken, deionized water is added for pulping, the total amount of water is 1000ml, and the raw material of the phosphorus-containing molecular sieve with the water content of 35 wt% is obtained after filtering and drying for 2h at 70 ℃.

Crushing the phosphorus-containing molecular sieve raw material, sieving to 5-20 meshes (wherein 5 mm-100 mm particles account for 70 wt% of the total weight of the phosphorus-containing molecular sieve raw material), placing into a hydrothermal treatment device, introducing 100% of water vapor, heating to 580 ℃, controlling the pressure in the device to be 0.4MPa, performing hydrothermal treatment for 2 hours constantly, and taking out the molecular sieve material after the hydrothermal treatment.

according to the weight ratio of sulfuric acid to phosphorus-containing molecular sieve raw material (dry basis) of 0.02: 1 preparing 250ml of sulfuric acid aqueous solution, wherein the concentration of sulfuric acid in the aqueous solution is 0.2 mol/L.

taking 50g (dry basis) of the molecular sieve material subjected to the hydrothermal treatment, adding 500ml of deionized water, stirring and pulping to obtain molecular sieve slurry, and heating to 80 ℃. And (2) taking 1L of molecular sieve slurry as a reference, adding the prepared sulfuric acid aqueous solution into the molecular sieve slurry at a constant speed of 0.5mol/H in terms of H + for three times at a constant speed, reacting for 2 hours at a constant temperature after each time of adding acid, filtering, and taking a filter cake to continue to add acid for the next time in the same manner. After the last time of acid addition and reaction for 2 hours, collecting a solid product, and drying at 100 ℃ for 8 hours to obtain the phosphorus-containing molecular sieve Y, wherein the phosphorus content is 1.3 percent by weight, the pore volume is 0.38ml/g, the acid content of B/L is 3.5, the acid content of I60ppm/I-1ppm is 11.1, and the acid content of I-1ppm/I +/-6 ppm is 0.46.

583.3g of pseudo-boehmite powder PB90 (produced by Zhongpetrochemical catalyst ChangLing division, with a pore volume of 0.9ml/g and a water content of 28 wt.%), 98.8g Y molecular sieve (with a water content of 19 wt.%), and 18 g of sesbania powder are mixed uniformly, 580ml of aqueous solution containing 18ml of nitric acid (65-68 wt.% in Beijing chemical reagent factory) is added, extruded into trilobal strips with a circumscribed circle diameter of 1.6 mm, and the three-leaf strips are dried at 120 ℃ and calcined at 600 ℃ for 3 hours to obtain the carrier CS.

after the temperature is reduced to room temperature, 100g of CS carrier is taken and dipped in 80ml of aqueous solution containing 52 g of ammonium metatungstate (82 wt% of tungsten oxide in Sichuan tribute cemented carbide factory), 8.7 g of basic nickel carbonate (51 wt% of nickel oxide in Jiangsu Yixing brady chemical Co., Ltd.) and 10.5g of citric acid, and the carrier is baked for 10 hours at 120 ℃ to obtain the hydrocracking catalyst C, wherein the carrier comprises the following components: 84 wt% of heat-resistant oxide, 16 wt% of phosphorus-containing molecular sieve; the catalyst comprises the following components: 29 wt% of group VIB metal, 3 wt% of group VIII metal and 68 wt% of carrier.

Example 1

catalytic diesel oil A (properties are shown in Table 1) is used as a poor-quality diesel oil raw material, and aromatic extraction is firstly carried out on the catalytic diesel oil A according to the flow of a figure 1 to obtain extract oil (the aromatic content is 99.4 weight percent) and raffinate oil (the saturated hydrocarbon content is 61.2 weight percent). The extract oil enters a hydrocracking reaction zone to carry out second hydrofining reaction, hydrocracking reaction and third hydrofining reaction in sequence, reaction products enter a separation system and a fractionation system to cut gas, naphtha products, jet fuel products and unconverted diesel oil, and the unconverted diesel oil returns to enter the hydrocracking reaction zone. And (3) allowing the raffinate oil to enter a hydrofining reaction zone for carrying out a first hydrofining reaction, and separating and fractionating a reaction product to obtain a clean diesel oil product.

Hydrogenation protective agents RG-30A and RG-30B, a second hydrofining catalyst RN-32V, a hydrocracking catalyst C and a third hydrofining catalyst RN-32V are sequentially filled in the hydrocracking reaction zone according to the flowing direction of reactant flow. Wherein the volume ratio of the hydrogenation protective agent to the second hydrogenation refining catalyst to the hydrocracking catalyst to the third hydrogenation refining catalyst is 10: 60: 40: 10. the hydrofining reaction area is filled with a first hydrofining catalyst RS-2000. The process conditions are shown in Table 2, and the properties of the product of each fraction are shown in Table 3.

As can be seen from Table 3, the high-density jet fuel with the yield of 56.8 percent can be produced by taking the catalytic diesel oil A as the raw material, the density of the high-density jet fuel reaches 0.855g/cm3, the net heat value is 44.3MJ/kg, the smoke point is 23.0mm, and the freezing point is less than minus 60 ℃. The clean diesel oil product has sulfur content less than 10 microgram/g, paraffin content up to 55 wt% and cetane number up to 60, is a clean diesel oil component with high cetane number, and can also be used as ethylene raw material.

Comparative example 1

By adopting a conventional single-stage one-pass hydrocracking method, hydrogenation protective agents RG-30A and RG-30B, a second hydrofining catalyst RN-32V, a hydrocracking catalyst RT-5 and a third hydrofining catalyst RN-32V are sequentially filled (the volume ratio of the hydrogenation protective agent to the second hydrofining catalyst to the hydrocracking catalyst to the third hydrofining catalyst is 10: 60: 40: 10), so that the catalytic diesel oil A is directly subjected to a second hydrofining reaction, a hydrocracking reaction and a third hydrofining reaction without aromatic extraction, reaction products enter a separation system and a fractionation system for separation, the process conditions are shown in table 2, and the properties of each fraction product are shown in table 3.

it can be seen that the jet fuel of this comparative example has a low yield, and its density and net calorific value are both low, and cannot meet the requirements of the large specific gravity jet fuel specification, compared to example 1; the paraffin content of the diesel oil product is far lower than that of the diesel oil product in example 1, and in addition, the naphtha yield is high, so that more aviation kerosene fractions are subjected to secondary cracking reaction, and the selectivity of aviation kerosene fractions is reduced.

Comparative example 2

catalytic diesel A was treated according to the procedure of example 1, except that hydrocracking catalyst C was replaced by hydrocracking catalyst RT-5, the product properties being shown in Table 3.

It can be seen that the jet fuel of this comparative example has a greatly reduced yield and lower density and net heating value than example 1; the paraffin content of the diesel product is also lower than in example 1.

Example 2

Straight-run diesel B was treated according to the method of example 1, except that the volume ratio of the hydrocracking reaction zone hydrogenation protecting agent, the second hydrofinishing catalyst, the hydrocracking catalyst, the third hydrofinishing catalyst was 10: 70: 30: 10, the process conditions are shown in Table 2, and the product properties of the fractions are shown in Table 3.

Comparative example 3

Straight-run diesel B was processed according to the method of comparative example 1, and the product properties are shown in Table 3.

As can be seen from the data in table 3, the jet fuel produced in this comparative example 3 has a lower density and net calorific value and does not meet the specifications for high gravity jet fuels.

example 3

Coker diesel C was processed according to the method of example 1, with the process conditions shown in table 2 and the product properties of the fractions shown in table 3.

TABLE 1

Analysis item	Catalytic diesel fuel A	Straight-run diesel oil B	Coker diesel fuel C
				³Density (20 ℃ C.)/(g/cm 3)	0.950	0.8467	0.8662
Sulfur content/(μ g/g)	8900	5800	4900
				Nitrogen content/(μ g/g)	1090	62	2200
Group composition/%)
				Total paraffins	8.8	39.3	32.3
Total cycloalkanes	9.5	30.5	33.1
				Aromatic hydrocarbons with more than two rings	67.3	15.0	14.5
Total aromatic hydrocarbons	83.7	30.2	46.6
				Distillation Range (ASTMD-86)/. deg.C
IBP	200	226	188
				10％	225	258	232
50％	276	287	285
				90％	325	315	329
FBP	355	331	360

TABLE 2

TABLE 3

The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

it should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. a method of producing high density jet fuel and clean diesel, the method comprising:

2. The method of claim 1, wherein the step of preparing the phosphorus-containing Y-type molecular sieve comprises:

3. The method of claim 2, wherein in the step a, the phosphorus-containing molecular sieve raw material is a phosphorus-containing Y-type molecular sieve, the unit cell constant of the phosphorus-containing Y-type molecular sieve is 2.425-2.47 nm, the specific surface area is 250-750 m2/g, and the pore volume is 0.2-0.95 ml/g;

4. The method of claim 2, wherein in the step b, the ratio of the weight of water in the molecular sieve slurry obtained after beating to the dry weight of the phosphorus-containing molecular sieve raw material is (14-5): 1;

5. The method according to claim 1, wherein the heat-resistant inorganic oxide is at least one selected from the group consisting of alumina, zirconia, magnesia, thoria, beryllia, boria, and cadmium oxide; the first metal component is molybdenum and/or tungsten; the second metal component is at least one selected from iron, nickel and cobalt.

6. The method according to claim 1, wherein in the step (1), the poor quality diesel raw material has a total aromatic content of 30 to 90 wt%, a paraffin content of 5 to 50 wt%, and a naphthene content of 5 to 55 wt%.

7. the method of claim 1, wherein in step (1), the aromatic extraction conditions comprise: the temperature is 20-100 ℃, the pressure is 0.05-0.5 MPa, and the weight ratio of the extraction solvent to the poor diesel raw material is (0.5-2.0): 1, the extraction solvent is at least one selected from furfural, dimethyl sulfoxide, N-dimethylformamide and ionic liquid.

8. The process according to claim 1, wherein in step (1), the aromatic content of the extract oil is 95-99.9 wt%; the raffinate oil has a saturated hydrocarbon content of 60-98 wt%.

9. the method of claim 1, wherein the method further comprises: in the step (2), according to the flow direction of a reactant flow, a second hydrofining catalyst is filled upstream of the hydrocracking catalyst in the hydrocracking reaction zone, the extract oil enters the hydrocracking reaction zone to firstly carry out a second hydrofining reaction in the presence of the second hydrofining catalyst and then carry out the hydrocracking reaction, and the volume ratio of the second hydrofining catalyst to the hydrocracking catalyst is (0.3-3): 1.

10. the method of claim 9, wherein the method further comprises: in the step (2), according to the flow direction of a reactant flow, a hydrogenation protective agent is further filled at the upstream of the second hydrofining catalyst in the hydrocracking reaction zone, and the volume ratio of the hydrogenation protective agent to the second hydrofining catalyst is (5-30): 100.

11. The method of claim 1, wherein the method further comprises: in the step (2), according to the flow direction of a reactant flow, a third hydrofining catalyst is filled in the hydrocracking reaction zone downstream of the hydrocracking catalyst, the extract oil enters the hydrocracking reaction zone to undergo the hydrocracking reaction, then a third hydrofining reaction is performed in the presence of the third hydrofining catalyst, and then the obtained product is subjected to product separation, wherein the volume ratio of the third hydrofining catalyst to the hydrocracking catalyst is 1: (1-10).

12. The process according to claim 1, wherein in step (2), the reaction conditions of the hydrocracking reaction zone based on the volume of the extract oil comprise: the hydrogen partial pressure is 10.0-16.0 MPa, preferably 10.0-14.0 MPa; the reaction temperature is 300-450 ℃, and preferably 350-400 ℃; the volume ratio of the hydrogen to the oil is 400-2500, preferably 600-1600; the liquid hourly space velocity is 0.2-5.0 h < -1 >, and preferably 0.5-1.5 h < -1 >.

13. The method according to claim 1, wherein in the step (2), the high density jet fuel has a density of not less than 0.830g/cm3, a calorific value by weight of not less than 42.9MJ/kg, a total aromatic content of 0.5 to 10 wt%, a naphthenic content of 80 to 95 wt%, and a paraffinic content of 0.5 to 10 wt%.

14. The method of claim 1, wherein the method further comprises: in the step (2), the unconverted diesel oil is returned to enter the hydrocracking reaction zone.

15. The process of claim 1, wherein in step (3), the reaction conditions of the hydrofinishing reaction zone comprise, based on the volume of the raffinate oil: the hydrogen partial pressure is 3.0-8.0 MPa, preferably 3.0-6.4 MPa; the reaction temperature is 300-450 ℃, and preferably 340-430 ℃; the volume ratio of the hydrogen to the oil is 300-1000, preferably 300-600; the liquid hourly space velocity is 0.5-10.0 h < -1 >, and preferably 1.0-4.0 h < -1 >.

16. the method according to claim 1, wherein in the step (3), the clean diesel has a total aromatic content of 0.5 to 10 wt%, a naphthenic content of 9.5 to 40 wt%, a paraffinic content of 50 to 90 wt%, and a cetane number of not less than 60.