Preparation method of hexadecahydropyrene

Abstract

The invention provides a preparation method of hexadecahydropyrene. The preparation method comprises the following steps: carrying out hydrofining reaction under the catalysis of a first hydrofining catalyst; product oil containing the first hydrogenation product is subjected to a hydrocracking reaction and a finishing reaction under catalysis of a hydrocracking catalyst and a second hydrorefining catalyst; fractionating the product oil containing the second hydrogenation product to obtain a fraction rich in hexadecahydropyrene; carrying out primary cooling crystallization on the fraction rich in hexadecahydropyrene to obtain a first mixed system containing a crude product, and carrying out primary solid-liquid separation on the first mixed system to obtain the crude product; dissolving the crude product with a solvent to obtain a solution containing the crude product, carrying out secondary cooling crystallization on the solution containing the crude product to obtain a second mixed system containing hexadecahydropyrene, and carrying out secondary solid-liquid separation on the second mixed system to obtain hexadecahydropyrene, the problems of low yield and purity of hexadecahydropyrene prepared in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of coal liquefaction oil processing, and in particular to a method for preparing hexadecahydropyrene. Background Art

[0002] Hexadecahydropyrene is the product of the complete saturation of the polycyclic aromatic hydrocarbon pyrene. It can be used as a hydrogen storage material and in the pharmaceutical field to prepare anti-inflammatory pharmaceutical products. The main method for producing high-purity hexadecahydropyrene is to use a synthetic route using pyrene as a raw material. Pyrene is a polycyclic aromatic hydrocarbon with a four-ring structure. Hexadecahydropyrene can be produced by fully hydrogenating it. However, during the implementation of this technical route, partially hydrogenated pyrenes such as hexahydropyrene and decahydropyrene are converted into hexadecahydropyrene. This reaction is costly and the possibility of large-scale production is low.

[0003] In the prior art, hexadecahydropyrene can be obtained by fractionating and cutting the liquefied products obtained by coal tar hydrorefining and hydrocracking. Although this process overcomes the shortcomings of the synthesis method, the process route uses hydrocarbon oil raw materials obtained by coal tar fractionation as the starting raw material, which contains 0.5% to 10% pyrene compounds. The content of pyrene compounds is low, and it is still difficult to obtain high-yield and high-purity hexadecahydropyrene. Summary of the Invention

[0004] The main purpose of the present invention is to provide a method for preparing hexadecahydropyrene to solve the problem of low yield and purity of hexadecahydropyrene prepared in the prior art.

[0005] In order to achieve the above object, according to one aspect of the present invention, a method for preparing hexahydropyrene comprises the following steps:

[0006] Step S1, performing a hydrofining reaction under the catalysis of a first hydrofining catalyst to obtain a product oil containing a first hydrogenated product;

[0007] Step S2, subjecting the product oil containing the first hydrogenation product to a hydrocracking reaction and a supplementary refining reaction under the catalysis of a hydrocracking catalyst and a second hydrorefining catalyst to obtain a product oil containing a second hydrogenation product;

[0008] Step S3, fractionating the product oil containing the second hydrogenation product to obtain a fraction rich in hexadecahydropyrene; the fraction rich in hexadecahydropyrene is selected from the distillate oil with a distillation range of 280° C. to 340° C. in the fractionation;

[0009] Step S4, performing a first cooling crystallization on the hexadecahydropyrene-rich fraction to obtain a first mixed system containing a crude product, and performing a first solid-liquid separation on the first mixed system to obtain a crude product; the temperature of the first cooling crystallization is -10 to 10°C;

[0010] Step S5: dissolving the crude product with a solvent to obtain a solution containing the crude product, cooling and crystallizing the solution containing the crude product for a second time to obtain a second mixed system containing hexahydropyrene, and performing a second solid-liquid separation on the second mixed system to obtain hexahydropyrene; the solvent is selected from one or more of methyl tert-butyl ether, N,N-dimethylformamide, anhydrous ethanol, isopropanol, acetone, acetonitrile, ethyl acetate, n-heptane, n-hexane, ethylene glycol dimethyl ether, and diethyl ether; and the dissolution temperature is 30° C. to 80° C.

[0011] Furthermore, the coal direct liquefaction product oil is selected from the distillate oil with a distillation range of 250°C to 450°C in the coal direct liquefaction oil.

[0012] Furthermore, the fraction rich in hexahydropyrene is selected from the distillate oil with a distillation range of 285° C. to 320° C. in the fractional distillation.

[0013] Furthermore, the coal direct liquefaction oil is selected from one of medium-temperature solvent oil and high-temperature solvent oil, or a combination of the two in any proportion.

[0014] Preferably, in terms of weight percentage, the content of paraffins in the medium-temperature solvent oil is 5% to 15%, the content of cycloalkanes is 20% to 40%, the content of monocyclic aromatic hydrocarbons is 40% to 60%, the content of bicyclic aromatic hydrocarbons is 10% to 20%, and the content of three-ring or higher aromatic hydrocarbons is 0.4% to 25%; in terms of weight percentage, the content of paraffins in the high-temperature solvent oil is 0% to 10%, the content of cycloalkanes is 3% to 20%, the content of monocyclic aromatic hydrocarbons is 30% to 50%, the content of bicyclic aromatic hydrocarbons is 15% to 35%, and the content of three-ring or higher aromatic hydrocarbons is 5% to 25%;

[0015] More preferably, the coal direct liquefaction oil is selected from a combination of medium-temperature solvent oil and high-temperature solvent oil in a mass ratio of 1:1 to 1:9.

[0016] More preferably, the coal direct liquefaction oil is selected from a combination of medium-temperature solvent oil and high-temperature solvent oil in a mass ratio of 1:3 to 1:8.

[0017] Furthermore, in the coal direct liquefaction product oil, the content of paraffins is 1% to 20%, the content of cycloalkanes is 1% to 30%, and the content of aromatics is 50% to 98%, calculated by weight percentage.

[0018] Furthermore, the first hydrorefining catalyst is selected from a supported catalyst that supports oxides of one or more active metals selected from molybdenum, nickel and tungsten, the second hydrorefining catalyst is selected from a supported catalyst that supports oxides of one or more active metals selected from molybdenum, nickel and tungsten, and the hydrocracking catalyst is selected from a supported catalyst that supports oxides of two active metals selected from nickel and tungsten; the carrier of the first hydrorefining catalyst, the carrier of the second hydrorefining catalyst and the carrier of the hydrocracking catalyst are independently selected from one or more of amorphous silicon, amorphous aluminum, amorphous silicon-aluminum compounds and porous molecular sieves.

[0019] Preferably, the first hydrorefining catalyst is selected from supported catalysts loaded with oxides of two active metals, molybdenum and nickel, and the second hydrorefining catalyst is selected from supported catalysts loaded with oxides of two metals, molybdenum and nickel.

[0020] Preferably, based on the total weight of the hydrocracking catalyst and the second hydrorefining catalyst being 100%, the weight of the second hydrorefining catalyst is 10% to 40%.

[0021] Preferably, the weight percentage content of the active metal in the first hydrorefining catalyst is 0.1% to 50%, more preferably 2% to 30%, calculated as oxide.

[0022] Preferably, the weight percentage content of the active metal in the second hydrorefining catalyst is 0.1% to 50%, more preferably 2% to 30%, calculated as oxide.

[0023] Preferably, the weight percentage of the active metal in the hydrocracking catalyst is 0.5% to 40%, more preferably 3% to 25%, calculated as oxide.

[0024] Preferably, the specific surface area of the first hydrorefining catalyst is 100cm2 / g to 1000cm2 / g, the pore volume is 0.1mL / g to 20mL / g, and the average pore diameter is 0.5nm to 20nm; the specific surface area of the second hydrorefining catalyst is 100cm2 / g to 1000cm2 / g, the pore volume is 0.1mL / g to 20mL / g, and the average pore diameter is 0.5nm to 20nm; the specific surface area of the hydrocracking catalyst is 100cm2 / g to 1000cm2 / g, the pore volume is 0.1mL / g to 20mL / g, and the average pore diameter is 0.5nm to 20nm.

[0025] Preferably, the first hydrorefining catalyst has a specific surface area of 100 cm2 / g to 300 cm2 / g, a pore volume of 0.25 mL / g to 1.5 mL / g, and an average pore diameter of 4 nm to 15 nm.

[0026] Preferably, the specific surface area of the second hydrorefining catalyst is 100 cm2 / g to 300 cm2 / g, the pore volume is 0.25 mL / g to 1.5 mL / g, and the average pore diameter is 4 nm to 15 nm.

[0027] Preferably, the specific surface area of the hydrocracking catalyst is 140 cm2 / g to 300 cm2 / g, the pore volume is 0.2 mL / g to 1.5 mL / g, and the average pore diameter is 2 nm to 15 nm.

[0028] Furthermore, the process conditions for the hydrorefining reaction include: a hydrogen partial pressure of 3MPa to 20MPa, a reaction temperature of 300°C to 450°C, a liquid hourly volume space velocity of 0.3h-1 to 2.2h-1, and a hydrogen-to-oil volume ratio of 100:1 to 2000:1; the process conditions for the hydrocracking reaction and the supplementary refining reaction include: a hydrogen partial pressure of 3MPa to 20MPa, a reaction temperature of 300°C to 400°C, a liquid hourly volume space velocity of 0.3h-1 to 2.0h-1, and a hydrogen-to-oil volume ratio of 100:1 to 2000:1.

[0029] Preferably, in the process conditions of the hydrorefining reaction, the hydrogen partial pressure is 10MPa~17MPa, the reaction temperature is 320℃~400℃, the liquid hourly volume space velocity is 0.7h-1~1.5h-1, and the hydrogen-oil volume ratio is 500:1~1500:1; in the process conditions of the hydrocracking reaction and the supplementary refining reaction, the hydrogen partial pressure is 13MPa~16MPa, the reaction temperature is 300℃~370℃, the liquid hourly volume space velocity is 0.7h-1~1.2h-1, and the hydrogen-oil volume ratio is 500:1~1000:1.

[0030] Furthermore, the hydrorefining reaction, the hydrocracking reaction and the supplementary refining reaction are all carried out in the catalytic bed respectively; the catalytic bed in the hydrorefining reaction is filled with the first hydrorefining catalyst and one or more of the first diluent, the first protective agent and the first proppant; the catalytic bed in the hydrocracking reaction and the supplementary refining reaction is filled with the second hydrorefining catalyst and one or more of the second diluent, the second protective agent and the second proppant.

[0031] Preferably, the first diluent and the second diluent are independently selected from one or more of Φ1 inert porcelain balls, Φ3 inert porcelain balls and Φ6 inert porcelain balls; the first protective agent and the second protective agent are independently selected from the commercially available product RGC; the first proppant and the second proppant are independently selected from one or more of Φ1 inert porcelain balls, Φ3 inert porcelain balls and Φ6 inert porcelain balls.

[0032] Furthermore, the temperature of the first cooling crystallization is -5 to 5°C, and the time of the first cooling crystallization is 10 hours to 48 hours.

[0033] Preferably, the first solid-liquid separation is performed by negative pressure filtration.

[0034] Furthermore, the mass volume ratio of the crude product to the solvent is 1:0.2 to 1:10, expressed in g / ml; and in the second cooling crystallization, the cooling temperature is 0°C to 20°C.

[0035] Preferably, the mass volume ratio of the crude product to the solvent is 1:1 to 1:5, expressed in g / ml, the dissolution temperature is 40°C to 65°C, and the dissolution time is 10h to 40h; in the second cooling crystallization, the cooling temperature is 0°C to 10°C.

[0036] Preferably, the second solid-liquid separation is performed by negative pressure filtration.

[0037] Furthermore, after the second solid-liquid separation, the solid matter of the second solid-liquid separation is eluted with an eluent, and the solid matter after elution is washed and the eluent is removed to obtain hexahydropyrene; the eluent is selected from one or more of methyl tert-butyl ether, N,N-dimethylformamide, anhydrous ethanol, isopropanol, acetone, acetonitrile, ethyl acetate, n-heptane, n-hexane, ethylene glycol dimethyl ether, and ether; the temperature of the eluent is 0°C to 15°C, and the mass volume ratio of the solid matter to the eluent is 10:1 to 1:1, and the unit is g / ml.

[0038] Preferably, the temperature of the eluent is 0° C. to 12° C., and the mass volume ratio of the solid matter to the eluent is 6:1 to 1:1, and the unit is g / ml.

[0039] Preferably, negative pressure filtration is used to remove the eluent.

[0040] By applying the technical solution of the present invention, the coal direct liquefaction oil is rich in aromatic hydrocarbons, especially polycyclic aromatic hydrocarbons with two or more rings. In addition, due to the influence of the coal direct liquefaction process, the aromatic hydrocarbon structure composition in the coal direct liquefaction oil is very different from that of coal tar. The content of polycyclic aromatic hydrocarbons in the coal direct liquefaction oil is relatively high, among which the content of pyrene can be as high as more than 10%. The side chain alkanes in the polycyclic aromatic hydrocarbons are relatively short, mostly methyl and ethyl groups. The aromatic hydrocarbons can be saturated to form cycloalkanes through a hydrorefining reaction, and the side chain alkanes of the polycyclic aromatic hydrocarbons can be disconnected through a hydrocracking reaction to ultimately produce hexahydropyrene. In addition, using the coal direct liquefaction product oil as a raw material, a hydrorefining catalyst and a hydrocracking catalyst are used to adjust the hydrocarbon structure therein. Through a hydrorefining reaction, a hydrocracking reaction and a supplementary refining reaction, the content of hexahydropyrene in the hydrogenated product is effectively increased, and hexahydropyrene with high yield and high purity is subsequently obtained through fractionation, solid-liquid separation and recrystallization.

[0041] The method of the present invention utilizes the structural characteristics of direct coal liquefaction product oil, which is rich in aromatic hydrocarbons, especially polycyclic aromatic hydrocarbons, and the short chain length of side chain alkanes in polycyclic aromatic hydrocarbons. Through a hydrogenation process, the structure of polycyclic aromatic hydrocarbons is regulated to obtain hexahydropyrene. The product has a high yield and high purity, and the raw material source and synthesis process of hexahydropyrene are broadened. It solves the problem of low content of target raw material pyrene compounds, great difficulty in product purification and low purity when using coal tar as raw material in the prior art. In addition, the presence of polycyclic aromatic hydrocarbons in direct coal liquefaction oil not only reduces the quality of direct coal liquefaction oil for use as fuel oil or other specialty oils, but also affects its environmental friendliness. By adopting the method of the present invention, aromatic hydrocarbons with lower value are enriched and separated, and at the same time, are converted into hexadecahydropyrene with higher value. This not only improves the quality of coal direct liquefaction oil as fuel oil, but also opens up a new raw material route for the production of hexadecahydropyrene. At the same time, the liquid product after fractional distillation to remove the hexadecahydropyrene-rich fraction can still be used to prepare cycloalkyl oils for other special purposes, thereby increasing the economic added value of the coal direct liquefaction process and having far-reaching significance for effectively utilizing coal resources, giving full play to my country's resource advantages and protecting the environment. DETAILED DESCRIPTION

[0042] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0043] As described in the background art, the prior art has the problem of low yield and purity of the prepared hexadecahydropyrene. To solve the above problem, according to one aspect of the present invention, a method for preparing hexadecahydropyrene is provided, comprising the following steps:

[0044] Step S1, performing a hydrofining reaction under the catalysis of a first hydrofining catalyst to obtain a product oil containing a first hydrogenated product;

[0045] Step S2, subjecting the product oil containing the first hydrogenation product to a hydrocracking reaction and a supplementary refining reaction under the catalysis of a hydrocracking catalyst and a second hydrorefining catalyst to obtain a product oil containing a second hydrogenation product;

[0046] Step S3, fractionating the product oil containing the second hydrogenation product to obtain a fraction rich in hexadecahydropyrene; the fraction rich in hexadecahydropyrene is selected from the distillate oil with a distillation range of 280° C. to 340° C. in the fractionation;

[0047] Step S4, performing a first cooling crystallization on the hexadecahydropyrene-rich fraction to obtain a first mixed system containing a crude product, and performing a first solid-liquid separation on the first mixed system to obtain a crude product; the temperature of the first cooling crystallization is -10 to 10°C;

[0048] Step S5: dissolving the crude product with a solvent to obtain a solution containing the crude product, cooling and crystallizing the solution containing the crude product for a second time to obtain a second mixed system containing hexahydropyrene, and performing a second solid-liquid separation on the second mixed system to obtain hexahydropyrene; the solvent is selected from one or more of methyl tert-butyl ether, N,N-dimethylformamide, anhydrous ethanol, isopropanol, acetone, acetonitrile, ethyl acetate, n-heptane, n-hexane, ethylene glycol dimethyl ether, and diethyl ether; and the dissolution temperature is 30° C. to 80° C.

[0049] Based on the preparation method of hexahydropyrene of the present invention, the technical scheme of the present invention is applied, the coal direct liquefaction oil is rich in aromatic hydrocarbons, especially the content of polycyclic aromatic hydrocarbons with two or more rings is large, and due to the influence of the coal direct liquefaction process, the aromatic hydrocarbon structure composition in the coal direct liquefaction oil is very different from that of coal tar, the content of polycyclic aromatic hydrocarbons in the coal direct liquefaction oil is high, among which the content of pyrene can be as high as more than 10%, and the side chain alkane in the polycyclic aromatic hydrocarbons is short, mostly methyl and ethyl. Aromatic hydrocarbons can be saturated to produce cycloalkanes, and the side chain alkanes of polycyclic aromatic hydrocarbons can be disconnected through hydrocracking reactions to ultimately produce hexadecahydropyrene. In addition, using coal direct liquefaction product oil as raw material, a hydrorefining catalyst and a hydrocracking catalyst are used to adjust the hydrocarbon structure therein. Through hydrorefining reactions, hydrocracking reactions and supplementary refining reactions, the content of hexadecahydropyrene in the hydrogenated product is effectively increased, and subsequently high-yield and high-purity hexadecahydropyrene is obtained through distillation, solid-liquid separation and recrystallization.

[0050] The method of the present invention utilizes the structural characteristics of direct coal liquefaction product oil, which is rich in aromatic hydrocarbons, especially polycyclic aromatic hydrocarbons, and the short chain length of side chain alkanes in polycyclic aromatic hydrocarbons. Through a hydrogenation process, the structure of polycyclic aromatic hydrocarbons is regulated to obtain hexahydropyrene. The product has a high yield and high purity, and the raw material source and synthesis process of hexahydropyrene are broadened. It solves the problem of low content of target raw material pyrene compounds, great difficulty in product purification and low purity when using coal tar as raw material in the prior art. In addition, the presence of polycyclic aromatic hydrocarbons in direct coal liquefaction oil not only reduces the quality of direct coal liquefaction oil for use as fuel oil or other specialty oils, but also affects its environmental friendliness. By adopting the method of the present invention, aromatic hydrocarbons with lower value are enriched and separated, and at the same time, are converted into hexadecahydropyrene with higher value. This not only improves the quality of coal direct liquefaction oil as fuel oil, but also opens up a new raw material route for the production of hexadecahydropyrene. At the same time, the liquid product after fractional distillation to remove the hexadecahydropyrene-rich fraction can still be used to prepare cycloalkyl oils for other special purposes, thereby increasing the economic added value of the coal direct liquefaction process and having far-reaching significance for effectively utilizing coal resources, giving full play to my country's resource advantages and protecting the environment.

[0051] In some embodiments, the coal direct liquefaction product oil is selected from the distillate oil with a distillation range of 250° C. to 450° C. in the coal direct liquefaction oil.

[0052] Based on the technical solution of the embodiment of the present invention, compared with using coal direct liquefaction oil as raw material, using heavy distillate oil with a distillation range of 250°C to 450°C in coal direct liquefaction oil (i.e., coal direct liquefaction product oil) as raw material has a higher content of pyrene polycyclic aromatic hydrocarbons, which is beneficial to improving the production efficiency of hexadecahydropyrene and obtaining hexadecahydropyrene with higher purity and content.

[0053] In some embodiments, the hexadecahydropyrene-rich fraction is selected from the distillate oil with a boiling point range of 285° C. to 320° C. in the fractional distillation.

[0054] Based on the technical solution of the embodiment of the present invention, with the distillation range of 285°C to 320°C as the target, the distillate oil within this range is intercepted, which can effectively reduce the amount of components with too low or too high boiling points mixed in, so that hexahydropyrene can be effectively enriched and separated, thereby obtaining a crude hexahydropyrene product with higher purity and content, improving the efficiency of subsequent purification steps, reducing production costs, and improving economic benefits.

[0055] In one embodiment, the coal direct liquefaction oil is selected from one of medium-temperature solvent oil and high-temperature solvent oil or a combination of the two in any proportion. The medium-temperature solvent oil and the high-temperature solvent oil are produced in the coal direct liquefaction process. The distillation range of the medium-temperature solvent oil is mainly between 220 and 350° C., and the distillation range of the high-temperature solvent oil is mainly within a temperature range greater than 350° C. It is rich in aromatics and can be used alone or in combination to prepare hexahydropyrene and cycloalkane oils for other special purposes. Preferably, in terms of weight percentage, the content of paraffins in the medium-temperature solvent oil is 5% to 15%, the content of cycloalkanes is 20% to 40%, the content of monocyclic aromatics is 40% to 60%, the content of bicyclic aromatics is 10% to 20%, and the content of three-ring or higher aromatics is 10%. The content is 0.4% to 25%; in terms of weight percentage, the content of chain alkanes in the high-temperature solvent oil is 0% to 10%, the content of cycloalkanes is 3% to 20%, the content of monocyclic aromatic hydrocarbons is 30% to 50%, the content of bicyclic aromatic hydrocarbons is 15% to 35%, and the content of three-ring or higher aromatic hydrocarbons is 5% to 25%; more preferably, the coal direct liquefaction oil is selected from a combination of medium-temperature solvent oil and high-temperature solvent oil in a mass ratio of 1:1 to 1:9. The combination of medium-temperature solvent oil and high-temperature solvent oil in the above ratio is conducive to obtaining hexahydropyrene with a higher yield and purity, and at the same time has a higher hydrogenation efficiency; further preferably, the coal direct liquefaction oil is selected from a combination of medium-temperature solvent oil and high-temperature solvent oil in a mass ratio of 1:3 to 1:8.

[0056] In some embodiments, in the coal direct liquefaction product oil, the content of paraffins is 1% to 20%, the content of cycloalkanes is 1% to 30%, and the content of aromatics is 50% to 98%, calculated by weight percentage.

[0057] Based on the technical solution of the embodiment of the present invention, coal direct liquefaction oil is a liquid fuel obtained by catalytic liquefaction of coal under high temperature and high pressure, and mainly includes the following hydrocarbons: paraffins, cycloalkanes and aromatics. By maintaining the content of aromatics in the coal direct liquefaction product oil at the above-mentioned relatively high content (50% to 98%) and adjusting the ratio of paraffins and cycloalkanes, it is beneficial to effectively convert aromatics into hexahydropyrene during the subsequent hydrorefining and cracking process, thereby obtaining hexahydropyrene of higher purity and content while improving production efficiency; the above-mentioned amount of paraffins and cycloalkanes can be used as diluents to help regulate the viscosity and reaction rate of the reaction medium, which is beneficial to avoid excessive reaction or local overheating, and can also provide additional by-products. For example, other fractions except hexahydropyrene can be used as special oil products such as industrial white oil, transformer oil, rubber filler oil, etc., thereby increasing the economic benefits of the entire process.

[0058] In some embodiments, the first hydrorefining catalyst is selected from a supported catalyst that supports oxides of one or more active metals selected from molybdenum, nickel, and tungsten, the second hydrorefining catalyst is selected from a supported catalyst that supports oxides of one or more active metals selected from molybdenum, nickel, and tungsten, and the hydrocracking catalyst is selected from a supported catalyst that supports oxides of two active metals selected from nickel and tungsten; the carrier of the first hydrorefining catalyst, the carrier of the second hydrorefining catalyst, and the carrier of the hydrocracking catalyst are independently selected from one or more of amorphous silicon, amorphous aluminum, an amorphous silicon-aluminum compound, and a porous molecular sieve.

[0059] In one embodiment, the first hydrorefining catalyst is selected from a supported catalyst loaded with oxides of two active metals, molybdenum and nickel, and the second hydrorefining catalyst is selected from a supported catalyst loaded with oxides of two active metals, molybdenum and nickel, so as to obtain a higher hydrogenation reaction efficiency. Specifically, the first hydrorefining catalyst and the second hydrorefining catalyst can be independently selected from one or a combination of any proportion of the commercial product RNC-2 catalyst produced by the Petrochemical Research Institute and the commercial product FFT-1 catalyst produced by the Fushun Petrochemical Research Institute; and the hydrocracking catalyst can be selected from one or a combination of any proportion of the commercial product RCC series catalysts produced by the Petrochemical Research Institute, the commercial product THDW-5 produced by CNOOC Tianjin Chemical Research and Design Institute Co., Ltd., and the commercial product 9 catalyst produced by China National Offshore Oil Corporation.

[0060] In order to obtain hexahydropyrene with higher yield and purity, in one embodiment, based on the total weight of the hydrocracking catalyst and the second hydrorefining catalyst being 100%, the weight of the second hydrorefining catalyst is 10% to 40%.

[0061] In one embodiment, the weight percentage content of the active metal in the first hydrorefining catalyst is 0.1% to 50%, more preferably 2% to 30%, calculated as oxide.

[0062] In one embodiment, the weight percentage of active metals in the second hydrorefining catalyst is 0.1% to 50%, more preferably 2% to 30%, calculated as oxides.

[0063] In one embodiment, the weight percentage of active metals in the hydrocracking catalyst is 0.5% to 40%, more preferably 3% to 25%, calculated as oxides.

[0064] In one embodiment, the specific surface area of the first hydrofining catalyst is 100 cm 2 / g~1000cm 2 / g, pore volume is 0.1mL / g~20mL / g, average pore diameter is 0.5nm~20nm; the specific surface area of the second hydrorefining catalyst is 100cm 2 / g~1000cm 2 / g, pore volume is 0.1mL / g~20mL / g, average pore diameter is 0.5nm~20nm; specific surface area of hydrocracking catalyst is 100cm 2 / g~1000cm 2 / g, the pore volume is 0.1mL / g~20mL / g, and the average pore diameter is 0.5nm~20nm.

[0065] In one embodiment, the specific surface area of the first hydrofining catalyst is 100 cm 2 / g~300cm 2 / g, the pore volume is 0.25mL / g~1.5mL / g, and the average pore diameter is 4nm~15nm.

[0066] In one embodiment, the specific surface area of the second hydrofining catalyst is 100 cm 2 / g~300cm 2 / g, the pore volume is 0.25mL / g~1.5mL / g, and the average pore diameter is 4nm~15nm.

[0067] In one embodiment, the specific surface area of the hydrocracking catalyst is 140 cm 2 / g~300cm 2 / g, the pore volume is 0.2mL / g~1.5mL / g, and the average pore diameter is 2nm~15nm.

[0068] In some embodiments, the process conditions of the hydrofining reaction include: hydrogen partial pressure of 3MPa to 20MPa, reaction temperature of 300℃ to 450℃, liquid hourly volume space velocity of 0.3h-1 ~2.2h -1 The hydrogen-oil volume ratio is 100:1 to 2000:1; the process conditions for the hydrocracking reaction and the supplementary refining reaction include: a hydrogen partial pressure of 3MPa to 20MPa, a reaction temperature of 300℃ to 400℃, a liquid hourly volume space velocity of 0.3h -1 ~2.0h -1 The volume ratio of hydrogen to oil is 100:1 to 2000:1.

[0069] In one embodiment, the process conditions of the hydrofining reaction are as follows: the hydrogen partial pressure is 10 MPa to 17 MPa, the reaction temperature is 320°C to 400°C, the liquid hourly space velocity is 0.7 h -1 ~1.5h -1 The hydrogen-to-oil volume ratio is 500:1 to 1500:1. The process conditions for the hydrocracking reaction and the supplementary refining reaction are as follows: the hydrogen partial pressure is 13MPa to 16MPa, the reaction temperature is 300℃ to 370℃, and the liquid hourly volume space velocity is 0.7h -1 ~1.2h -1 The volume ratio of hydrogen to oil is 500:1 to 1000:1, which is beneficial to the saturation of aromatics to generate cycloalkanes and the disconnection of side chain alkanes of polycyclic aromatic hydrocarbons, thereby improving the yield and purity of hexahydropyrene.

[0070] In some embodiments, the hydrorefining reaction, the hydrocracking reaction, and the supplementary refining reaction are all carried out in catalytic beds, respectively; the catalytic bed in the hydrorefining reaction is filled with a first hydrorefining catalyst and one or more of a first diluent, a first protective agent, and a first proppant; the catalytic bed in the hydrocracking reaction and the supplementary refining reaction is filled with a hydrocracking catalyst and a second hydrorefining catalyst and one or more of a second diluent, a second protective agent, and a second proppant. Specifically, the hydrorefining reaction, the hydrocracking reaction, and the supplementary refining reaction can all use a single catalyst bed or multiple catalyst beds; for example, when the hydrorefining reaction uses a single bed, the same type of catalyst can be used, or two or more types of catalysts can be used to form two or more different reaction zones; when multiple beds are used, each bed can use the same type of catalyst, or two or more types of catalysts can be used to form two or more different reaction zones, and each reaction zone can be realized in the same reactor or in two or more reactors in series.

[0071] In one embodiment, the content of the first hydrogenation catalyst in the catalyst bed in the hydrorefining reaction is 30%-70%, preferably 40%-55%, and the content of the second hydrogenation catalyst in the catalyst bed in the hydrocracking reaction and the supplementary refining reaction is 25%-60%, preferably 40%-55%, in order to obtain a higher hydrogenation reaction efficiency.

[0072] In one embodiment, the first diluent and the second diluent are independently selected from one or more of Φ1 inert porcelain balls, Φ3 inert porcelain balls and Φ6 inert porcelain balls; the first protective agent and the second protective agent are independently selected from the commercially available product RGC; the first proppant and the second proppant are independently selected from one or more of Φ1 inert porcelain balls, Φ3 inert porcelain balls and Φ6 inert porcelain balls.

[0073] In some embodiments, in order to obtain a higher yield of crystalline product and higher production efficiency, the temperature of the first cooling crystallization is -5 to 5°C, and the time of the first cooling crystallization is 10 hours to 48 hours.

[0074] In one embodiment, in order to obtain a higher yield and production efficiency of hexadecahydropyrene, the first solid-liquid separation adopts negative pressure filtration; preferably, in the first solid-liquid separation, the vacuum degree of negative pressure filtration is 100mbar~500mbar, the pore size of filter paper is 0.2μm~2μm, and the filtration time is 1min~10min; more preferably, in the first solid-liquid separation, the vacuum degree of negative pressure filtration is 100mba~300mbar, the pore size of filter paper is 0.2μm~1μm, and the filtration time is 2min~5min.

[0075] In some embodiments, the mass volume ratio of the crude product to the solvent is 1:0.2 to 1:10, expressed in g / ml; and in the second cooling crystallization, the cooling temperature is 0°C to 20°C.

[0076] In one embodiment, the mass volume ratio of the crude product to the solvent is 1:1 to 1:5, the unit is g / ml, the dissolution temperature is 40°C to 65°C, and the dissolution time is 10h to 40h; in the second cooling crystallization, the cooling temperature is 0°C to 10°C to obtain hexahydropyrene with higher yield and purity.

[0077] In one embodiment, the second solid-liquid separation adopts negative pressure filtration. In the second solid-liquid separation, the vacuum degree of negative pressure filtration is 100mba~500mbar, the pore size of filter paper is 0.2μm~2μm, and the filtration time is 1min~10min; preferably, the vacuum degree of negative pressure filtration is 100mba~300mbar, the pore size of filter paper is 0.2μm~1μm, and the filtration time is 2min~5min.

[0078] In some embodiments, after the second solid-liquid separation, the solid matter of the second solid-liquid separation is eluted with an eluent, and the eluted solid matter is washed and the eluent is removed to obtain hexahydropyrene; the eluent is selected from one or more of methyl tert-butyl ether, N,N-dimethylformamide, anhydrous ethanol, isopropanol, acetone, acetonitrile, ethyl acetate, n-heptane, n-hexane, ethylene glycol dimethyl ether, and ether; the temperature of the eluent is 0°C to 15°C, and the mass volume ratio of the solid matter to the eluent is 10:1 to 1:1, and the unit is g / ml.

[0079] In one embodiment, in order to obtain hexahydropyrene with higher yield and purity, the temperature of the eluent is 0° C. to 12° C., and the mass volume ratio of the solid matter to the eluent is 6:1 to 1:1, expressed in g / ml.

[0080] In one embodiment, negative pressure filtration is used to remove the eluent; preferably, during the eluent removal, the vacuum degree of the negative pressure filtration is 100mbar~500mbar, the pore size of the filter paper is 0.2μm~2μm, and the filtration time is 1min~10min; more preferably, during the eluent removal, the vacuum degree of the negative pressure filtration is 100mba~300mbar, the pore size of the filter paper is 0.2μm~1μm, and the filtration time is 2min~5min.

[0081] The present application is further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in this application.

[0082] Example 1

[0083] A method for preparing hexahydropyrene comprises the following steps:

[0084] Step 1: The coal direct liquefaction product oil is subjected to a hydrorefining reaction in a single catalytic bed under the catalysis of a first hydrorefining catalyst to obtain a product oil containing a first hydrogenation product. The coal direct liquefaction product oil is a full-fraction oil obtained by blending medium-temperature solvent oil and high-temperature solvent oil in a mass ratio of 1:1. The basic physical properties and hydrocarbon composition of the medium-temperature solvent oil and the high-temperature solvent are shown in Table 1; the catalytic bed is filled with a first hydrorefining catalyst, a first diluent, a first protective agent and a first proppant. The content of the first hydrogenation reaction catalyst in the catalytic bed is 50% by volume; the first hydrorefining catalyst is Cat1 (Cat1 is the RNC-2 catalyst, a commercial product produced by the Petrochemical Research Institute, RNC-2 The weight percentage content of the active metal in the catalyst as oxide, the specific surface area, the pore volume, and the average pore diameter are shown in Table 2, respectively; the first diluent used was Φ1 inert porcelain balls, Φ3 inert porcelain balls, and Φ6 inert porcelain balls; the first protective agent used was RGC-1, a commercial product developed and produced by the Petrochemical Research Institute; and the first proppant used was Φ1 inert porcelain balls, Φ3 inert porcelain balls, and Φ6 inert porcelain balls; the process conditions for the hydrorefining reaction, including hydrogen partial pressure, reaction temperature, liquid hourly volume space velocity, hydrogen-to-oil volume ratio, and the specific type of the first hydrorefining catalyst used are shown in Table 3.

[0085] Step 2: subjecting the product oil containing the first hydrogenation product to a hydrocracking reaction and a supplementary refining reaction in a single catalytic bed under the catalysis of a hydrocracking catalyst and a second hydrorefining catalyst to obtain a product oil containing a second hydrogenation product. The catalytic bed is filled with a hydrocracking catalyst, a second hydrorefining catalyst, a second diluent, a second protective agent, and a second proppant. The content of the second hydrorefining catalyst in the catalytic bed is 50% by volume, and the weight ratio of the hydrocracking catalyst to the second hydrorefining catalyst is 7:3. The second hydrorefining catalyst adopts Cat1, and the hydrocracking catalyst adopts Cat3 (Cat3 is a commercial product RCC-2 catalyst produced by the Petrochemical Research Institute. The weight percentage of active metals in RCC-2 is 100% by volume). The percentage content, specific surface area, pore volume and average pore diameter are shown in Table 2, respectively); the second diluent used was Φ1 inert porcelain balls, Φ3 inert porcelain balls and Φ6 inert porcelain balls; the second protective agent used was RGC-1, a commercial product developed and produced by the Petrochemical Research Institute; the second proppant used was Φ1 inert porcelain balls, Φ3 inert porcelain balls and Φ6 inert porcelain balls; the process conditions for the hydrocracking reaction and the supplementary refining reaction, hydrogen partial pressure, reaction temperature, liquid hourly volume space velocity, hydrogen-to-oil volume ratio, and the specific types of the hydrocracking catalyst and the second hydrorefining catalyst used are shown in Table 3.

[0086] Step 3: Distill and cut the product oil containing the second hydrogenation product, cut a fraction with a distillation range of 280° C. to 300° C., and obtain a fraction rich in hexahydropyrene.

[0087] Step 4: Cooling and crystallizing the hexahydropyrene-rich fraction at 5° C. for 48 hours to obtain a first mixed system containing a crude product, and filtering the first mixed system under negative pressure to obtain a crude product.

[0088] Step 5: Dissolve the crude product in methyl tert-butyl ether (MTBE) to obtain a solution containing the crude product, cool and crystallize the solution containing the crude product at 0°C to obtain a second mixed system containing hexahydropyrene, filter the second mixed system under vacuum, and elute the solid obtained by vacuum filtration with MTBE, then remove the eluent by vacuum filtration to obtain hexahydropyrene. The mass volume ratio of the crude product to the solvent is 1:5, the dissolution temperature is 45°C, and the dissolution time is 24 hours; the eluent temperature is 5°C, and the mass volume ratio of the solid to the eluent is 3:1, with the unit being g / ml.

[0089] In this example, the yield of the crude product was 8.3%, the yield of hexadecahydropyrene was 5.81%, and the purity was 99.74%, as shown in Table 3. The yield (%) of the crude product = mass of the crude product / mass of the product oil containing the second hydrogenation product * 100%. The purity of the final product, hexadecahydropyrene, was analyzed by gas chromatography combined with nuclear magnetic resonance. The yield (%) of hexadecahydropyrene = mass of hexadecahydropyrene / mass of the product oil containing the second hydrogenation product * 100%.

[0090] Example 2

[0091] A method for preparing hexahydropyrene comprises the following steps:

[0092] Step 1 differs from Step 1 in Example 1 only in that the coal direct liquefaction product oil is a distillate oil with a distillation range of 250°C to 400°C from a whole distillate oil obtained by blending medium-temperature solvent oil and high-temperature solvent oil in a mass ratio of 1:9; the first hydrorefining catalyst is Cat2 (Cat2 is a commercial product FFT-1 catalyst produced by Fushun Petrochemical Research Institute. The weight percentage content of active metals in the FFT-1 catalyst as oxides, specific surface area, pore volume, and average pore diameter are shown in Table 2, respectively); the process conditions of the hydrorefining reaction, hydrogen partial pressure, reaction temperature, liquid hourly volume space velocity, hydrogen-to-oil volume ratio, and the specific type of the first hydrorefining catalyst used are shown in Table 3.

[0093] Step 2 differs from Step 1 in Example 1 only in that the second hydrorefining catalyst is Cat2; the process conditions for the hydrocracking reaction and the supplemental refining reaction, hydrogen partial pressure, reaction temperature, liquid hourly volume space velocity, hydrogen-to-oil volume ratio, and the specific types of the hydrocracking catalyst and the second hydrorefining catalyst used are shown in Table 3.

[0094] Step 3: Distill and cut the product oil containing the second hydrogenation product, cut a fraction with a distillation range of 300° C.-320° C., and obtain a fraction rich in hexahydropyrene.

[0095] Step 4: Cooling and crystallizing the hexahydropyrene-rich fraction at 0° C. for 40 hours to obtain a first mixed system containing a crude product, and filtering the first mixed system under negative pressure to obtain a crude product.

[0096] Step 5: Dissolve the crude product in N,N-dimethylformamide to obtain a solution containing the crude product, cool the solution containing the crude product at 5°C to crystallize, obtain a second mixed system containing hexahydropyrene, filter the second mixed system under vacuum, elute the solid obtained by vacuum filtration with methyl tert-butyl ether, and then remove the eluent by vacuum filtration to obtain hexahydropyrene. The mass volume ratio of the crude product to the solvent is 1:9, the dissolution temperature is 50°C, and the dissolution time is 30 hours; the eluent temperature is 10°C, and the mass volume ratio of the solid to the eluent is 5:1, with the unit being g / ml.

[0097] In this example, the yield of the crude product, the yield and purity of hexahydropyrene are shown in Table 3, respectively.

[0098] Example 3

[0099] A method for preparing hexahydropyrene comprises the following steps:

[0100] Step 1 differs from Step 1 in Example 1 only in that the coal direct liquefaction product oil uses a distillate oil with a distillation range of 280°C to 380°C from a whole distillate oil prepared by blending medium-temperature solvent oil and high-temperature solvent oil in a mass ratio of 1:5; the process conditions of the hydrorefining reaction, hydrogen partial pressure, reaction temperature, liquid hourly volume space velocity, hydrogen-to-oil volume ratio, and the specific type of the first hydrorefining catalyst used are shown in Table 3.

[0101] Step 2 differs from Step 1 in Example 1 only in that the hydrocracking catalyst is Cat 4 (Cat 4 is the commercial product THDW-5 catalyst produced by CNOOC Tianjin Chemical Research and Design Institute Co., Ltd.; the weight percentage content of active metals in the THDW-5 catalyst as oxides, specific surface area, pore volume, and average pore diameter are shown in Table 2). The process conditions for the hydrocracking reaction and the supplemental refining reaction, including hydrogen partial pressure, reaction temperature, liquid hourly volume space velocity, hydrogen-to-oil volume ratio, and the specific types of the hydrocracking catalyst and the second hydrorefining catalyst used are shown in Table 3.

[0102] Step 3: Distill and cut the product oil containing the second hydrogenation product, cut a fraction with a distillation range of 290° C. to 330° C., and obtain a fraction rich in hexahydropyrene.

[0103] Step 4: Cooling and crystallizing the hexahydropyrene-rich fraction at 2° C. for 48 hours to obtain a first mixed system containing a crude product, and filtering the first mixed system under negative pressure to obtain a crude product.

[0104] Step 5: Dissolve the crude product in n-hexane to obtain a solution containing the crude product, cool the solution containing the crude product at 5°C to crystallize, obtain a second mixed system containing hexahydropyrene, filter the second mixed system under vacuum, and use N,N-dimethylformamide as an eluent to elute the solid obtained by vacuum filtration, and then remove the eluent by vacuum filtration to obtain hexahydropyrene. The mass volume ratio of the crude product to the solvent is 1:9, the dissolution temperature is 60°C, and the dissolution time is 20 hours; the eluent temperature is 12°C, and the mass volume ratio of the solid to the eluent is 2:1, with the unit being g / ml.

[0105] In this example, the yield of the crude product, the yield and purity of hexahydropyrene are shown in Table 3, respectively.

[0106] Example 4

[0107] A method for preparing hexahydropyrene comprises the following steps:

[0108] Step 1 differs from Step 1 in Example 1 only in that the coal direct liquefaction product oil is a distillate oil with a distillation range of 300°C to 420°C from a whole distillate oil obtained by blending medium-temperature solvent oil and high-temperature solvent oil in a mass ratio of 1:3; the first hydrorefining catalyst is Cat2; and the process conditions of the hydrorefining reaction, hydrogen partial pressure, reaction temperature, liquid hourly volume space velocity, hydrogen-to-oil volume ratio, and the specific type of the first hydrorefining catalyst used are shown in Table 3.

[0109] Step 2 differs from Step 1 in Example 1 only in that the second hydrorefining catalyst is Cat 2; the hydrocracking catalyst is Cat 4; the process conditions for the hydrocracking reaction and the supplemental refining reaction, hydrogen partial pressure, reaction temperature, liquid hourly volume space velocity, hydrogen-to-oil volume ratio, and the specific types of the hydrocracking catalyst and the second hydrorefining catalyst used are shown in Table 3.

[0110] Step 3: Distill and cut the product oil containing the second hydrogenation product, cut a fraction with a distillation range of 295° C. to 325° C., and obtain a fraction rich in hexahydropyrene.

[0111] Step 4: Cooling and crystallizing the hexahydropyrene-rich fraction at 2° C. for 36 hours to obtain a first mixed system containing a crude product, and filtering the first mixed system under negative pressure to obtain a crude product.

[0112] Step 5: Dissolve the crude product in n-heptane to obtain a solution containing the crude product, cool the solution containing the crude product at 0°C to crystallize, obtain a second mixed system containing hexahydropyrene, filter the second mixed system under vacuum, and elute the solid obtained by vacuum filtration with methyl tert-butyl ether as an eluent, then remove the eluent by vacuum filtration to obtain hexahydropyrene. The mass volume ratio of the crude product to the solvent is 1:4, the dissolution temperature is 55°C, and the dissolution time is 20 hours; the eluent temperature is 5°C, and the mass volume ratio of the solid to the eluent is 10:1, with the unit being g / ml.

[0113] In this example, the yield of the crude product, the yield and purity of hexahydropyrene are shown in Table 3, respectively.

[0114] Example 5

[0115] A method for preparing hexahydropyrene comprises the following steps:

[0116] Step 1 differs from Step 1 in Example 1 only in that the coal direct liquefaction product oil uses a distillate oil with a distillation range of 275°C to 380°C from a whole distillate oil obtained by blending medium-temperature solvent oil and high-temperature solvent oil in a mass ratio of 1:7; the first hydrorefining catalyst is Cat2; and the process conditions of the hydrorefining reaction, hydrogen partial pressure, reaction temperature, liquid hourly volume space velocity, hydrogen-to-oil volume ratio, and the specific type of the first hydrorefining catalyst used are shown in Table 3.

[0117] Step 2 differs from Step 1 in Example 1 only in that the second hydrorefining catalyst is Cat2; the process conditions for the hydrocracking reaction and the supplemental refining reaction, hydrogen partial pressure, reaction temperature, liquid hourly volume space velocity, hydrogen-to-oil volume ratio, and the specific types of the hydrocracking catalyst and the second hydrorefining catalyst used are shown in Table 3.

[0118] Step 3: Distill and cut the product oil containing the second hydrogenation product, cut a fraction with a distillation range of 280° C. to 310° C., and obtain a fraction rich in hexahydropyrene.

[0119] Step 4: Cooling and crystallizing the hexahydropyrene-rich fraction at 2° C. for 36 hours to obtain a first mixed system containing a crude product, and filtering the first mixed system under negative pressure to obtain a crude product.

[0120] Step 5: Dissolve the crude product in n-hexane to obtain a solution containing the crude product, cool the solution containing the crude product at 0°C and crystallize to obtain a second mixed system containing hexahydropyrene, filter the second mixed system under vacuum, and use N,N-dimethylformamide as an eluent to elute the solid obtained by vacuum filtration, and then remove the eluent by vacuum filtration to obtain hexahydropyrene. The mass volume ratio of the crude product to the solvent is 1:0.5, the dissolution temperature is 50°C, and the dissolution time is 20 hours; the eluent temperature is 5°C, and the mass volume ratio of the solid to the eluent is 6:1, with the unit being g / ml.

[0121] In this example, the yield of the crude product, the yield and purity of hexahydropyrene are shown in Table 3, respectively.

[0122] Example 6

[0123] The only difference from Example 1 is that the coal direct liquefaction product oil is a distillate oil with a distillation range of 250°C to 400°C from the whole distillate oil obtained by blending medium-temperature solvent oil and high-temperature solvent oil in a mass ratio of 1:1.

[0124] In this example, the yield of the crude product, the yield and purity of hexahydropyrene are shown in Table 3, respectively.

[0125] Comparative Example 1

[0126] A method for preparing hexadecahydropyrene, which differs from Example 1 only in that step 2 is not performed, and in step 3, the product oil containing the first hydrogenation product is directly distilled and cut.

[0127] Specifically, the yield of the crude product and the yield and purity of hexadecahydropyrene are shown in Table 3. Here, the yield (%) of the crude product = the mass of the crude product / the mass of the product oil containing the first hydrogenation product * 100%. The purity of the final product, hexadecahydropyrene, was determined by gas chromatography combined with nuclear magnetic resonance analysis. The yield (%) of hexadecahydropyrene = the mass of hexadecahydropyrene / the mass of the product oil containing the first hydrogenation product * 100%. As shown in Table 3, the yield of hexadecahydropyrene in Comparative Example 1 was only 0.8%, a significant decrease compared to Example 1.

[0128] Comparative Example 2

[0129] A method for preparing hexadecahydropyrene, which differs from that in Example 2 only in that, in step 2, the product oil containing the first hydrogenation product is subjected to a supplementary refining reaction in a single catalytic bed under the catalysis of a second hydrorefining catalyst, and the catalytic bed is filled with the second hydrorefining catalyst, a second diluent, a second protective agent, and a second proppant.

[0130] Specifically, the yield of the crude product and the yield and purity of hexadecahydropyrene are shown in Table 3. As shown in Table 3, the yield of hexadecahydropyrene in Comparative Example 2 is only 0.84%, which is significantly lower than that in Example 2.

[0131] Comparative Example 3

[0132] A method for preparing hexadecahydropyrene, which differs from that in Example 3 only in that, in step 4, the hexadecahydropyrene-rich fraction is cooled and crystallized at 25° C. for 48 hours.

[0133] Specifically, the yield of the crude product and the yield and purity of hexadecahydropyrene are shown in Table 3, respectively. It can be seen from Table 3 that the yield of hexadecahydropyrene in Comparative Example 3 is only 1.24% and the purity is only 60.5%. Compared with Example 3, the yield and purity of hexadecahydropyrene are significantly reduced.

[0134] Comparative Example 4

[0135] A method for preparing hexahydropyrene, which differs from that in Example 4 only in that, in step 5, the temperature at which the crude product is dissolved is 25°C.

[0136] Specifically, the yield of the crude product and the yield and purity of hexadecahydropyrene are shown in Table 3, respectively. It can be seen from Table 3 that the yield of hexadecahydropyrene in Comparative Example 3 is only 2.96%, and the purity is only 65.2%. Compared with Example 4, the yield and purity of hexadecahydropyrene are significantly reduced.

[0137] Table 1

[0138]

[0139] Table 2

[0140]

[0141] Note: “-” in the table means that the relevant components are not included.

[0142] Table 3

[0143]

[0144]

[0145] Note: “-” in the table means relevant process conditions were not adopted.

[0146] As shown in Table 3, the preparation methods of hexadecahydropyrene according to Examples 1 to 6 of the present invention use coal direct liquefaction product oil as raw material, and obtain hexadecahydropyrene with high yield and high purity through hydrorefining reaction, hydrocracking reaction and supplementary refining reaction, fractionation, solid-liquid separation, and recrystallization.

[0147] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for preparing hexahydropyrene, characterized in that: The steps include: Step S1, subjecting the coal direct liquefaction product oil to a hydrorefining reaction under the catalysis of a first hydrorefining catalyst to obtain a product oil containing a first hydrogenation product; the coal direct liquefaction product oil is selected from coal direct liquefaction oil or a distillate oil in the coal direct liquefaction oil with a distillation range of 250° C. to 450° C.; Step S2, subjecting the product oil containing the first hydrogenation product to a hydrocracking reaction and a supplementary refining reaction under the catalysis of a hydrocracking catalyst and a second hydrorefining catalyst to obtain a product oil containing a second hydrogenation product; Step S3, fractionating the product oil containing the second hydrogenation product to obtain a fraction rich in hexadecahydropyrene; the fraction rich in hexadecahydropyrene is selected from the distillate oil with a distillation range of 280° C. to 340° C. in the fractionation; Step S4, performing a first cooling crystallization on the hexadecahydropyrene-rich fraction to obtain a first mixed system containing a crude product, and performing a first solid-liquid separation on the first mixed system to obtain a crude product; the temperature of the first cooling crystallization is -10 to 10° C.; Step S5, dissolving the crude product with a solvent to obtain a solution containing the crude product, cooling and crystallizing the solution containing the crude product for a second time to obtain a second mixed system containing the hexahydropyrene, and performing a second solid-liquid separation on the second mixed system to obtain the hexahydropyrene; the solvent is selected from one or more of methyl tert-butyl ether, N,N-dimethylformamide, anhydrous ethanol, isopropanol, acetone, acetonitrile, ethyl acetate, n-heptane, n-hexane, ethylene glycol dimethyl ether, and diethyl ether; and the dissolution temperature is 30°C to 80°C.

2. The method for preparing hexahydropyrene according to claim 1, wherein The coal direct liquefaction product oil is selected from the distillate oil with a distillation range of 250° C. to 450° C. in the coal direct liquefaction oil; and / or The hexadecahydropyrene-rich fraction is selected from the distillate oil with the distillation range between 285° C. and 320° C. in the fractionation.

3. The method for preparing hexahydropyrene according to claim 1 or 2, wherein The coal direct liquefaction oil is selected from one of medium-temperature solvent oil and high-temperature solvent oil, or a combination of the two in any proportion; Preferably, in terms of weight percentage, the content of paraffins in the medium-temperature solvent oil is 5% to 15%, the content of cycloalkanes is 20% to 40%, the content of monocyclic aromatic hydrocarbons is 40% to 60%, the content of bicyclic aromatic hydrocarbons is 10% to 20%, and the content of three-ring or higher aromatic hydrocarbons is 0.4% to 25%; in terms of weight percentage, the content of paraffins in the high-temperature solvent oil is 0% to 10%, the content of cycloalkanes is 3% to 20%, the content of monocyclic aromatic hydrocarbons is 30% to 50%, the content of bicyclic aromatic hydrocarbons is 15% to 35%, and the content of three-ring or higher aromatic hydrocarbons is 5% to 25%; More preferably, the coal direct liquefaction oil is selected from a combination of medium-temperature solvent oil and high-temperature solvent oil in a mass ratio of 1:1 to 1:9; More preferably, the coal direct liquefaction oil is selected from a combination of medium-temperature solvent oil and high-temperature solvent oil in a mass ratio of 1:3 to 1:

8.

4. The method for preparing hexahydropyrene according to claim 1 or 2, wherein Calculated by weight percentage, the content of paraffins in the direct coal liquefaction product oil is 1% to 20%, the content of cycloparaffins is 1% to 30%, and the content of aromatics is 50% to 98%.

5. The method for preparing hexahydropyrene according to claim 1 or 2, wherein The first hydrorefining catalyst is selected from a supported catalyst loaded with oxides of one or more active metals selected from molybdenum, nickel, and tungsten; the second hydrorefining catalyst is selected from a supported catalyst loaded with oxides of one or more active metals selected from molybdenum, nickel, and tungsten; and the hydrocracking catalyst is selected from a supported catalyst loaded with oxides of two active metals selected from nickel and tungsten; the support of the first hydrorefining catalyst, the support of the second hydrorefining catalyst, and the support of the hydrocracking catalyst are independently selected from one or more of amorphous silicon, amorphous aluminum, an amorphous silicon-aluminum compound, and a porous molecular sieve; Preferably, the first hydrorefining catalyst is selected from a supported catalyst loaded with oxides of two active metals, molybdenum and nickel, and the second hydrorefining catalyst is selected from a supported catalyst loaded with oxides of two active metals, molybdenum and nickel; Preferably, based on the total weight of the hydrocracking catalyst and the second hydrorefining catalyst being 100%, the weight of the second hydrorefining catalyst is 10% to 40%; Preferably, the weight percentage content of the active metal in the first hydrorefining catalyst is 0.1% to 50%, more preferably 2% to 30%, calculated as oxide; Preferably, the weight percentage content of the active metal in the second hydrorefining catalyst is 0.1% to 50%, more preferably 2% to 30%, calculated as oxide; Preferably, the weight percentage content of the active metal in the hydrocracking catalyst is 0.5% to 40%, more preferably 3% to 25%, calculated as oxide; Preferably, the specific surface area of the first hydrorefining catalyst is 100 cm 2 / g~1000cm 2 / g, pore volume of 0.1mL / g~20mL / g, average pore diameter of 0.5nm~20nm; the specific surface area of the second hydrorefining catalyst is 100cm 2 / g~1000cm 2 / g, pore volume of 0.1mL / g~20mL / g, average pore diameter of 0.5nm~20nm; the specific surface area of the hydrocracking catalyst is 100cm 2 / g~1000cm 2 / g, pore volume is 0.1mL / g~20mL / g, and average pore diameter is 0.5nm~20nm; Preferably, the specific surface area of the first hydrorefining catalyst is 100 cm 2 / g~300cm 2 / g, the pore volume is 0.25mL / g to 1.5mL / g, and the average pore diameter is 4nm to 15nm; Preferably, the specific surface area of the second hydrorefining catalyst is 100 cm 2 / g~300cm 2 / g, the pore volume is 0.25mL / g to 1.5mL / g, and the average pore diameter is 4nm to 15nm; Preferably, the specific surface area of the hydrocracking catalyst is 140 cm 2 / g~300cm 2 / g, the pore volume is 0.2mL / g to 1.5mL / g, and the average pore diameter is 2nm to 15nm.

6. The method for preparing hexahydropyrene according to claim 5, wherein The process conditions of the hydrofining reaction include: hydrogen partial pressure of 3MPa to 20MPa, reaction temperature of 300℃ to 450℃, liquid hourly volume space velocity of 0.3h -1 ~2.2h -1 , the hydrogen-oil volume ratio is 100:1 to 2000:1; the process conditions of the hydrocracking reaction and the supplementary refining reaction include: hydrogen partial pressure of 3MPa to 20MPa, reaction temperature of 300℃ to 400℃, liquid hourly volume space velocity of 0.3h -1 ~2.0h -1 , the volume ratio of hydrogen to oil is 100:1 to 2000:1; Preferably, in the process conditions of the hydrofining reaction, the hydrogen partial pressure is 10MPa to 17MPa, the reaction temperature is 320℃ to 400℃, the liquid hourly volume space velocity is 0.7h -1 ~1.5h -1 , the hydrogen-to-oil volume ratio is 500:1 to 1500:1; in the process conditions of the hydrocracking reaction and the supplementary refining reaction, the hydrogen partial pressure is 13MPa to 16MPa, the reaction temperature is 300℃ to 370℃, and the liquid hourly volume space velocity is 0.7h -1 ~1.2h -1 , the hydrogen-to-oil volume ratio is 500:1 to 1000:

1.

7. The method for preparing hexahydropyrene according to claim 1 or 2, wherein: The hydrorefining reaction, the hydrocracking reaction, and the supplementary refining reaction are all carried out in a catalyst bed, respectively; the catalyst bed in the hydrorefining reaction is filled with the first hydrorefining catalyst and one or more of a first diluent, a first protective agent, and a first proppant; the catalyst bed in the hydrocracking reaction and the supplementary refining reaction is filled with the hydrocracking catalyst and the second hydrorefining catalyst and one or more of a second diluent, a second protective agent, and a second proppant; Preferably, the first diluent and the second diluent are independently selected from one or more of Φ1 inert porcelain balls, Φ3 inert porcelain balls and Φ6 inert porcelain balls; the first protective agent and the second protective agent are independently selected from the commercially available product RGC; the first proppant and the second proppant are independently selected from one or more of Φ1 inert porcelain balls, Φ3 inert porcelain balls and Φ6 inert porcelain balls.

8. The method for preparing hexahydropyrene according to claim 1 or 2, wherein: The temperature of the first cooling crystallization is -5 to 5°C, and the time of the first cooling crystallization is 10h to 48h; Preferably, the first solid-liquid separation is performed by negative pressure filtration.

9. The method for preparing hexahydropyrene according to claim 1 or 2, wherein: The mass volume ratio of the crude product to the solvent is 1:0.2 to 1:10, expressed in g / ml; in the second cooling crystallization, the cooling temperature is 0°C to 20°C; Preferably, the mass volume ratio of the crude product to the solvent is 1:1 to 1:5, expressed in g / ml, the dissolution temperature is 40°C to 65°C, and the dissolution time is 10h to 40h; in the second cooling crystallization, the cooling temperature is 0°C to 10°C; Preferably, the second solid-liquid separation is performed by negative pressure filtration.

10. The method for preparing hexahydropyrene according to claim 9, wherein After the second solid-liquid separation, the solid obtained from the second solid-liquid separation is eluted with an eluent, and the solid after the elution is washed and the eluent is removed to obtain the hexadecahydropyrene; the eluent is selected from one or more of methyl tert-butyl ether, N,N-dimethylformamide, anhydrous ethanol, isopropanol, acetone, acetonitrile, ethyl acetate, n-heptane, n-hexane, ethylene glycol dimethyl ether, and diethyl ether; the temperature of the eluent is 0° C. to 15° C., and the mass volume ratio of the solid to the eluent is 10:1 to 1:1, and the unit is g / ml; Preferably, the temperature of the eluent is 0°C to 12°C, and the mass volume ratio of the solid matter to the eluent is 6:1 to 1:1, in units of g / ml; Preferably, negative pressure filtration is used to remove the eluent.

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