Method for producing low-carbon alkane through hydro-conversion of reforming raffinate oil

Abstract

The invention discloses a method for producing low-carbon alkane through hydro-conversion of reformed raffinate oil. The method comprises the following steps: (1) mixing the reformed raffinate oil with hydrogen, and feeding the mixture into a hydrofining reaction zone for hydrofining reaction; (2) the reaction effluent obtained in the step (1) enters a hydro-conversion reaction zone for hydro-conversion reaction, and low-carbon alkane is obtained; the hydro-conversion reaction zone is sequentially filled with a first hydro-conversion catalyst and a second hydro-conversion catalyst in the material flowing direction, the first hydro-conversion catalyst comprises a macroporous twelve-membered ring molecular sieve loaded with group VIII metal and macroporous alumina loaded with group VIII metal and group VIB metal, and the second hydro-conversion catalyst comprises a macroporous twelve-membered ring molecular sieve loaded with group VIB metal and macroporous alumina loaded with group VIII metal and group VIB metal. The second hydro-conversion catalyst comprises a small-hole eight-membered ring molecular sieve loaded with group VIII metal and macroporous alumina loaded with group VIII metal and group VIB metal. The reformed raffinate oil processed by the method can be converted into low-carbon alkane such as C2, C3 and the like, so that the yield of low-carbon olefin prepared by steam cracking is improved.

Description

Technical Field

[0001] This invention relates to the field of comprehensive utilization of reforming residue oil, specifically to a method for hydroconverting reforming residue oil to produce low-carbon alkanes as feedstock for steam cracking to produce low-carbon olefins. Background Technology

[0002] Aromatic hydrocarbon extraction is a crucial process technology in the petroleum refining industry for producing BTX (benzene, toluene, xylene). It primarily separates aromatic and non-aromatic components based on the different solubilities of hydrocarbon molecules in solvents. The raffinate obtained after aromatic hydrocarbon extraction from catalytic reforming product oil has a low octane number, making it unsuitable for use as a blending component in automotive gasoline. However, due to its low sulfur content, low aromatic hydrocarbon content, and easily adaptable process, it is frequently used in the preparation of solvent oils.

[0003] From the perspective of hydrocarbon molecular composition, reforming raffinate is rich in alkanes and can be used as a feedstock for steam cracking to produce low-carbon olefins such as ethylene and propylene. Currently, there is little research on raffinate as a feedstock for steam cracking.

[0004] CN201710984489.4 discloses a method for producing ethylene using aromatic raffinate as feedstock. The method includes: the aromatic raffinate entering a hydrogenation reactor; the effluent from the hydrogenation reaction being passed into a stabilizer for gas-liquid separation; and the bottom material from the stabilizer being passed into an ethylene cracking unit. A crossover line is installed to isolate the hydrogenation reactor from the stabilizer and ethylene cracking unit, allowing the aromatic raffinate to be directly introduced into the stabilizer. A leak-proof pipeline is installed, with one end connected to the crossover line and the other end connected to the outlet pipeline of the bottom circulation pump of the stabilizer. While this method solves the problem of substandard product quality caused during the initial startup of the hydrogenation unit, effectively addresses the issue of product defects or shortened unit operating cycles caused by internal leakage in the crossover line valves, and slows down the coking rate in the cracking furnace tubes, extending the coking cycle, the yield of low-carbon olefins from the cracking process is relatively low due to the high proportion of isomeric and cyclic hydrocarbons in the raffinate. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for hydroconverting reforming raffinate to produce low-carbon alkanes as feedstock for steam cracking to produce low-carbon olefins. By using this method to process reforming raffinate, it can be converted into low-carbon alkanes such as C2 and C3, thereby improving the yield of low-carbon olefins produced by steam cracking.

[0006] The first aspect of this invention provides a method for producing low-carbon alkanes by hydroconversion of reforming raffinate, the method comprising:

[0007] (1) After the reforming residue oil is mixed with hydrogen, it enters the hydrorefining reaction zone for hydrorefining reaction;

[0008] (2) The reaction effluent obtained in step (1) enters the hydrogenation conversion reaction zone for hydrogenation conversion reaction to obtain low carbon alkanes;

[0009] The hydroconversion reaction zone is sequentially filled with a first hydroconversion catalyst and a second hydroconversion catalyst along the material flow direction. The first hydroconversion catalyst includes a macroporous twelve-membered ring molecular sieve loaded with Group VIII metals and macroporous alumina loaded with Group VIII and Group VIB metals. The second hydroconversion catalyst includes a microporous eight-membered ring molecular sieve loaded with Group VIII metals and macroporous alumina loaded with Group VIII and Group VIB metals.

[0010] In the method of this invention, the material first reacts with a first hydroconversion catalyst, and then reacts with a second hydroconversion catalyst. The first and second hydroconversion catalysts can be graded and packed in one or more catalyst beds along the material flow direction.

[0011] In this invention, the hydrorefining reaction zone is filled with a hydrorefining catalyst, which generally comprises a hydrorefining active metal component and a support. The hydrorefining active metal is molybdenum and nickel, and the support is alumina. Generally, based on the weight of the catalyst, the content of the hydrorefining active metal (calculated as oxide) is 18.0% to 22.0%. The hydrorefining catalyst can be the FH-40A catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd. Furthermore, after the hydrorefining reaction, the olefin content in the reformate feedstock is reduced to below 0.5%.

[0012] In the method of the present invention, the volume ratio of the first hydroconversion catalyst to the second hydroconversion catalyst is 1:1 to 1:8, preferably 1:3 to 1:6.

[0013] In the method of this invention, in the first hydroconversion catalyst, Group VIII and Group VIB metals exist in the catalyst in oxide form. In the second hydroconversion catalyst, Group VIII and Group VIB metals exist in the catalyst in oxide form.

[0014] In the method of the present invention, preferably, in the first hydroconversion catalyst, the macroporous twelve-membered ring molecular sieve loaded with a group VIII metal is loaded onto the macroporous twelve-membered ring molecular sieve using a solution containing a group VIII metal amine complex as an impregnation liquid.

[0015] In the method of the present invention, preferably, in the second hydrogenation conversion catalyst, the small-pore eight-membered ring molecular sieve loaded with a group VIII metal is loaded onto the small-pore eight-membered ring molecular sieve using a solution containing a group VIII metal amine complex as an impregnation liquid.

[0016] In the method of the present invention, the molar ratio X of the group VIII metal atoms in the bulk phase to the group VIII metal atoms on the surface of the first hydroconversion catalyst is 1.5 to 4.0, preferably 2.0 to 3.0, and more preferably 2.5 to 3.0. The molar ratio X of the group VIII metal atoms in the bulk phase to the group VIII metal atoms on the surface of the second hydroconversion catalyst is 1.5 to 4.0, preferably 2.0 to 3.0, and more preferably 2.5 to 3.0.

[0017] Furthermore, the overall mass of Group VIII metal oxides in the catalyst was determined by X-ray fluorescence spectroscopy, and the mass of Group VIII metal oxides on the catalyst surface was determined by X-ray photoelectron spectroscopy.

[0018] In the method of this invention, the specific surface area of ​​the first hydroconversion catalyst is 300–500 m². 2 / g, with a pore volume of 0.35–0.55 mL / g. The specific surface area of ​​the second hydroconversion catalyst is 250–450 m² / g. 2 / g, with a pore volume of 0.30~0.50mL / g.

[0019] In the method of the present invention, the initial boiling point of the reformate raffinate is 40-70°C and the final boiling point is 110-160°C; the mass content of C5-C8 isoalkanes in the reformate raffinate is 50%-80%, and the mass content of olefins is 1%-8%.

[0020] In the method of this invention, the hydrorefining reaction conditions are as follows: reaction pressure 1.0–6.0 MPa, reaction temperature 100–250 °C, hydrogen-to-oil volume ratio 200:1–800:1, and liquid hourly space velocity 0.5–4.0 h⁻¹. -1 .

[0021] In the method of this invention, the hydroconversion reaction conditions are as follows: reaction pressure is 1.0–6.0 MPa, reaction temperature is 380–500 °C, hydrogen-to-oil volume ratio is 200:1–800:1, and liquid hourly space velocity is 0.5–4.0 h⁻¹. -1 .

[0022] In the method of this invention, the first hydroconversion catalyst, based on the weight of the catalyst, contains 1.0%–6.0% of Group VIII metals (calculated as oxides), 5.0%–25.0% of Group VIB metals (calculated as oxides), 20.0%–65.0% of macroporous alumina, and 15.0%–70.0% of macroporous twelve-membered ring molecular sieve. Further, the macroporous alumina has the following properties: pore volume of 0.7–1.0 mL / g, and specific surface area of ​​200–500 m². 2 / g.

[0023] The preparation method of the first hydrogenation conversion catalyst in the method of the present invention includes the following steps:

[0024] (1) A metal amine complex solution containing a group VIII metal salt was mixed with a macroporous twelve-membered ring molecular sieve, impregnated in a sealed environment, dried and calcined to obtain a macroporous twelve-membered ring molecular sieve loaded with a group VIII metal.

[0025] (2) Macroporous alumina was impregnated with an aqueous solution containing Group VIB metal salt and Group VIII metal salt, dried and calcined to obtain macroporous alumina loaded with Group VIII metal and Group VIB metal.

[0026] (3) Mix macroporous twelve-membered ring molecular sieve loaded with Group VIII metal and macroporous alumina loaded with Group VIII metal and Group VIB metal, shape, dry and calcine to obtain the first hydrogenation conversion catalyst.

[0027] Further, the preparation process of the solution containing the Group VIII metal amine complex in step (1) is as follows: dissolve the Group VIII metal salt in deionized water, stir evenly, and then add inorganic ammonium and / or organic amine dropwise to the solution until the pH value of the solution is 7-8. Further, the Group VIII metal in the Group VIII metal salt is preferably cobalt and / or nickel; the Group VIII metal salt is preferably a nitrate; the inorganic ammonium is selected from one or more of ammonia water (preferably, the mass concentration of ammonia water is 20%-30%) and ammonium chloride; the organic amine is selected from one or more of ethylamine, isopropylamine, and diethylamine. Further, the content of the Group VIII metal in the solution containing the Group VIII metal amine complex, calculated as oxide, is 1-15 g / 100 mL.

[0028] Further, the closed impregnation process in step (1) is as follows: the macroporous twelve-membered ring molecular sieve is placed in a metal amine complex solution, placed in a closed reaction vessel, and then heated to 100-120℃ under autogenous pressure for stirring and impregnation for 2-4 hours at a stirring speed of 100-400 rpm. Further, the macroporous twelve-membered ring molecular sieve is in the hydrogen form, selected from one or more of Y, β, MOR, and MCM-22 molecular sieves, preferably β molecular sieve, wherein the pore volume of the β molecular sieve is 0.30-0.45 cm³. 3 / g, specific surface area of ​​500-700m² 2 / g, the silicon-aluminum molar ratio SiO2:Al2O3 is 40–120. Furthermore, the solid-liquid volume ratio of the macroporous twelve-membered ring molecular sieve and the metal amine complex solution is 1:2–1:5.

[0029] Further, after impregnation in step (1), macroporous twelve-membered ring molecular sieve loaded with Group VIII metal is obtained by conventional filtration, drying and calcination. For example, the drying temperature is 100-150℃ and the drying time is 1-12h; the calcination temperature is 450-550℃ and the calcination time is 3-6h.

[0030] Further, in the aqueous solution containing Group VIB and Group VIII metal salts described in step (2), the Group VIB metal salt is one or more of tungsten salts (such as ammonium metatungstate) or molybdenum salts (such as ammonium molybdate), and the Group VIII metal salt is one or more of nickel salts (such as nickel nitrate) or cobalt salts (such as cobalt nitrate). Further, the content of the Group VIB metal in the solution, calculated as oxides, is 10–50 g / 100 mL, and the content of the Group VIII metal, calculated as oxides, is 1–10 g / 100 mL.

[0031] Furthermore, the impregnation in step (2) is supersaturated impregnation, and the solid-liquid volume ratio of macroporous alumina to the aqueous solution containing Group VIB metals and Group VIII metals is 1:2 to 1:5.

[0032] Further, after impregnation in step (2), macroporous alumina loaded with Group VIII and Group VIB metals is obtained by conventional filtration, drying and calcination. For example, the drying temperature is 100-150℃ and the drying time is 1-12h; the calcination temperature is 450-550℃ and the calcination time is 3-6h.

[0033] Further, in step (3), the molding can be carried out using conventional methods in the art, such as extrusion molding. Molding aids can be added during the molding process, such as at least one of extrusion aids and pectinic acids, preferably pectinic acids; the extrusion aid can be guar gum powder; the pectinic acid can be at least one of citric acid, acetic acid, and nitric acid, preferably at least one of citric acid and nitric acid. Further, the amount of pectinic acid added is less than 2% of the sum of the mass of the macroporous twelve-membered ring molecular sieve loaded with Group VIII metals and the macroporous alumina loaded with Group VIII metals and Group VIB metals, and the amount of extrusion aid added is less than 3% of the sum of the mass of the macroporous twelve-membered ring molecular sieve loaded with Group VIII metals and the macroporous alumina loaded with Group VIII metals and Group VIB metals.

[0034] Further, in step (3), after molding, the catalyst is dried and calcined to obtain the catalyst. The drying temperature is 100℃~150℃, and the drying time is 2~4h; the calcination temperature is 400℃~600℃, and the calcination time is 3~5h.

[0035] In the method of this invention, the second hydroconversion catalyst, based on the weight of the catalyst, contains 1.0%–6.0% of Group VIII metals (calculated as oxides), 5.0%–25.0% of Group VIB metals (calculated as oxides), 20.0%–65.0% of macroporous alumina, and 15.0%–70.0% of small-pore eight-membered ring molecular sieve. Further, the macroporous alumina has the following properties: pore volume of 0.7–1.0 mL / g, and specific surface area of ​​200–500 m². 2 / g.

[0036] The preparation method of the second hydrogenation conversion catalyst in this invention includes the following steps:

[0037] (1) A metal amine complex solution containing a Group VIII metal salt is mixed with a small-pore eight-membered ring molecular sieve, impregnated in a sealed environment, dried and calcined to obtain a small-pore eight-membered ring molecular sieve loaded with a Group VIII metal.

[0038] (2) Macroporous alumina was impregnated with an aqueous solution containing Group VIB metal salt and Group VIII metal salt, dried and calcined to obtain macroporous alumina loaded with Group VIII metal and Group VIB metal.

[0039] (3) Mix the small-pore eight-membered ring molecular sieve loaded with Group VIII metal and the macroporous alumina loaded with Group VIII metal and Group VIB metal, shape, dry and calcine to obtain the second hydrogenation conversion catalyst.

[0040] Further, the preparation process of the solution containing the Group VIII metal amine complex in step (1) is as follows: dissolve the Group VIII metal salt in deionized water, stir evenly, and then add inorganic ammonium and / or organic amine dropwise to the solution until the pH value of the solution is 7-8. Further, the Group VIII metal in the Group VIII metal salt is preferably cobalt and / or nickel; the Group VIII metal salt is preferably a nitrate; the inorganic ammonium is selected from one or more of ammonia water (preferably, the mass concentration of ammonia water is 20%-30%) and ammonium chloride; the organic amine is selected from one or more of ethylamine, isopropylamine, and diethylamine. Further, the content of the Group VIII metal in the solution containing the Group VIII metal amine complex, calculated as oxide, is 1-15 g / 100 mL.

[0041] Further, the closed impregnation process in step (1) is as follows: the small-pore eight-membered ring molecular sieve is placed in a metal amine complex solution, placed in a closed reaction vessel, and then heated to 100-120℃ under autogenous pressure for stirring and impregnation for 2-4 hours at a stirring speed of 100-400 rpm. Further, the small-pore eight-membered ring molecular sieve is in the hydrogen form and is selected from one or more of SAPO-34, SSZ-13, SAPO-18, and SAPO-35 molecular sieves, preferably SAPO-34 molecular sieve, wherein the pore volume of the SAPO-34 molecular sieve is 0.22-0.32 cm³. 3 / g, specific surface area of ​​550-750m² 2 / g, the silicon-aluminum molar ratio SiO2:Al2O3 is 0.1–1.2. Furthermore, the solid-liquid volume ratio of the small-pore eight-membered ring molecular sieve and the metal amine complex solution is 1:2–1:5.

[0042] Further, after impregnation in step (1), the small-pore eight-membered ring molecular sieve loaded with Group VIII metal is obtained by conventional filtration, drying and calcination. For example, the drying temperature is 100-150℃ and the drying time is 1-12h; the calcination temperature is 450-550℃ and the calcination time is 3-6h.

[0043] Further, in the aqueous solution containing Group VIB and Group VIII metal salts described in step (2), the Group VIB metal salt is one or more of tungsten salts (such as ammonium metatungstate) or molybdenum salts (such as ammonium molybdate), and the Group VIII metal salt is one or more of nickel salts (such as nickel nitrate) or cobalt salts (such as cobalt nitrate). Further, the content of the Group VIB metal in the solution, calculated as oxides, is 10–50 g / 100 mL, and the content of the Group VIII metal, calculated as oxides, is 1–10 g / 100 mL.

[0044] Furthermore, the impregnation in step (2) is supersaturated impregnation, and the solid-liquid volume ratio of macroporous alumina to the aqueous solution containing Group VIB metals and Group VIII metals is 1:2 to 1:5.

[0045] Further, after impregnation in step (2), macroporous alumina loaded with Group VIII and Group VIB metals is obtained by conventional filtration, drying and calcination. For example, the drying temperature is 100-150℃ and the drying time is 1-12h; the calcination temperature is 450-550℃ and the calcination time is 3-6h.

[0046] Further, in step (3), the molding can be carried out using conventional methods in the art, such as extrusion molding. Molding aids can be added during the molding process, such as at least one of extrusion aids and pectinic acids, preferably pectinic acids; the extrusion aid can be guar gum powder; the pectinic acid can be at least one of citric acid, acetic acid, and nitric acid, preferably at least one of citric acid and nitric acid. Further, the amount of pectinic acid added is less than 2% of the sum of the mass of the small-pore eight-membered ring molecular sieve loaded with Group VIII metals and the macroporous alumina loaded with Group VIII and Group VIB metals, and the amount of extrusion aid added is less than 3% of the sum of the mass of the small-pore eight-membered ring molecular sieve loaded with Group VIII metals and the macroporous alumina loaded with Group VIII and Group VIB metals.

[0047] Further, in step (3), after molding, the catalyst is dried and calcined to obtain the catalyst. The drying temperature is 100℃~150℃, and the drying time is 2~4h; the calcination temperature is 400℃~600℃, and the calcination time is 3~5h.

[0048] In the method of the present invention, the X values ​​in the first hydroconversion catalyst and the second hydroconversion catalyst can be the same or different.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] This invention improves the quality of the feedstock for steam cracking to produce low-carbon olefins by setting up a hydrorefining reaction zone to hydrogenate and saturate the unsaturated hydrocarbon components in the reforming raffinate, which then enters the hydroconversion zone to convert them into C2, C3, and other low-carbon alkanes. The raffinate contains a high content of C5-C8 alkanes, and since alkanes have weak adsorption capacity during the hydroconversion reaction, this improves the distance between the acidic centers and metal active sites of the catalyst. Through research, the inventors discovered that the hydroconversion reaction zone employs a first hydroconversion catalyst (containing a macroporous twelve-membered ring molecular sieve catalyst) and a second hydroconversion catalyst (containing a small-pore eight-membered ring molecular sieve catalyst) arranged in an upper and lower cascade configuration. First, the high acid strength of the macroporous twelve-membered ring molecular sieve initiates the first-step cracking reaction of the refined raffinate. Then, the pore confinement effect of the small-pore eight-membered ring molecular sieve is utilized to improve the selectivity of low-carbon products. This fully leverages the cracking performance of the twelve-membered ring molecular sieve and the pore confinement performance of the eight-membered ring molecular sieve, which is beneficial for improving the activity and selectivity of the catalyst, thereby achieving deep conversion of raffinate into low-carbon alkanes such as C2 and C3.

[0051] In the preparation of the hydroconversion catalyst in this invention, a metal amine complex solution prepared with a Group VIII metal, which has a stronger dehydrogenation capacity, is used to impregnate the molecular sieve under self-generated pressure. The basic groups of the metal amine complex selectively adsorb and bind to the acidic sites within the molecular sieve pores, effectively shortening the distance between the metal active sites and the acidic sites of the molecular sieve. This accelerates the rate of the cracking reaction after dehydrogenation of the raffinate molecules and increases the conversion depth of the cracking reaction. Impregnation of macroporous alumina with a mixed aqueous solution of a Group VIB metal and a Group VIII metal salt allows for the selective adsorption of the more active bimetallic sites in the macroporous alumina. This enables the small molecule olefins generated from the cracking of the raffinate to diffuse out of the molecular sieve pores and quickly become saturated, thus improving the catalyst activity. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the process flow of the embodiments and comparative examples of the present invention;

[0053] Explanation of key figure labels:

[0054] 1-Reformed raffinate oil, 2-Hydrogen, 3-Hydrorefining reaction zone, 4-Hydrorefining catalyst, 5-Hydrorefining product, 6-Hydroconversion reaction zone, 7-First hydroconversion catalyst, 8-Second hydroconversion catalyst, 9-Hydroconversion product, 10-Separator, 11-Hydrogen-rich gas stream, 12-Liquid stream. Detailed Implementation

[0055] The following examples and comparative examples further illustrate the role and effect of the technical solution of the present invention, but the following examples do not constitute a limitation on the scope of protection of the present invention.

[0056] In this invention, the mass of the bulk group VIII metal oxide catalyst was obtained by X-ray fluorescence spectroscopy (XRF) analysis using a ZSX100e X-ray fluorescence spectrometer with Kα spectral line, LiF1 crystal, Rh target material, SC scintillation detector, timing of 20 s, and vacuum atmosphere.

[0057] In this invention, the mass of the Group VIII metal oxide on the catalyst surface was determined by X-ray photoelectron spectroscopy (XPS). The elemental composition and state of the catalyst surface (3 nm–10 nm) were measured using a Thermofisher Multilab 2000 electron spectrometer. The excitation source was Mg Kα, and the cathode voltage and current were 13 kV and 20 mA, respectively. The electron binding energy was calibrated using C1s (284.6 eV).

[0058] In this invention, unless otherwise specified, all percentages (%) in the embodiments and comparative examples refer to mass fractions.

[0059] In this invention, the first hydrogenation conversion catalyst is represented by CAT-A followed by a number, such as CAT-A-1, CAT-A-2, CAT-A-3, etc., and the second hydrogenation conversion catalyst is represented by CAT-B followed by a number, such as CAT-B-1, CAT-B-2, CAT-B-3, etc.

[0060] The β-zeolite involved in the embodiments and comparative examples of this invention is a commercially available product with a pore volume of 0.39 cm³. 3 / g, specific surface area is 641m² 2 / g, the silicon-aluminum molar ratio SiO2:Al2O3 is 72, and the SAPO-34 molecular sieve is a commercially available product with a pore volume of 0.28 cm³. 3 / g, specific surface area is 607m² 2 / g, the silicon-to-aluminum molar ratio SiO2:Al2O3 is 0.4. The macroporous alumina is a commercially available product with a pore volume of 1.0 cm³. 3 / g, specific surface area is 400m² 2 / g.

[0061] In this invention, the calculation methods for raffinate conversion rate, product selectivity, and yield are as follows:

[0062] Conversion rate = (mass of C5-C8 hydrocarbons in feedstock - mass of C5-C8 hydrocarbons in product) / (mass of C5-C8 hydrocarbons in feedstock) × 100%;

[0063] C2+C3 selectivity = (mass of C2 and C3 in the product / total mass of the product) × 100%;

[0064] C2+C3 yield = (C2+C3 yield) / conversion rate × 100%;

[0065] C5, C6, C7, C8, C2, and C3 refer to pentane, hexane, heptane, octane, ethane, and propane, respectively.

[0066] In this invention, the olefin content of the reformate after hydrorefining is 0.35%.

[0067] Example

[0068] (1) Dissolve 40g of nickel nitrate (NiO mass fraction of 25%) in deionized water, stir evenly, add ammonia water (mass concentration of 20%), adjust the pH of the solution to 7.0, and then make up to 1000mL to obtain a nickel amine complex solution with a nickel content (calculated as oxide) of 3.0g / 100mL. Mix 100g of β molecular sieve and 100g of SAPO-34 molecular sieve with 200mL of the above nickel amine complex solution, respectively, and put them into reaction vessels. After sealing, stir at 150rpm, heat to 100℃, keep at the temperature for 3h, then quench and cool, filter, dry at 120℃ for 6h, and calcine at 550℃ for 4h. The materials obtained are denoted as NA-1 and NB-1, respectively.

[0069] (2) Take 400g of macroporous alumina, soak it in 800ml of an aqueous solution with a nickel content (calculated as oxide) of 2.0g / 100mL and a tungsten content (calculated as oxide) of 20.0g / 100mL for 2h, filter it, dry it at 120℃ for 6h, and calcine it at 550℃ for 4h. The resulting material is denoted as NW-1.

[0070] (3) Take 100g NA-1 and 100g N-B-1 and mix them with 200g NW-1 respectively. Then put them into a rolling mill for grinding. Add 120g dilute nitric acid solution (HNO3 mass fraction of 4%) to each, grind into paste, extrude into strips, dry the extruded strips at 120℃ for 6h, and then calcine at 550℃ for 4h to obtain catalysts CAT-A-1 and CAT-B-1 respectively. Their properties are shown in Table 1.

[0071] Example 2

[0072] (1) Dissolve 400g of nickel nitrate (NiO mass fraction of 25%) in deionized water, stir evenly, add isopropylamine, adjust the pH of the solution to 8.0, and then make up to 1000mL to obtain a nickel amine complex solution with a nickel content (calculated as oxide) of 10g / 100mL. Mix 100g of β molecular sieve and 100g of SAPO-34 molecular sieve with 200mL of the above nickel amine complex solution, respectively, and put them into reaction vessels. After sealing, stir at 300rpm, heat to 110℃, keep at the temperature for 3h, then quench and cool, filter, dry at 120℃ for 6h, and calcine at 550℃ for 4h to obtain materials, which are respectively NA-2 and NB-2;

[0073] (2) Take 400g of macroporous alumina and soak it in 800mL of an aqueous solution with a nickel content (calculated as oxide) of 5.0g / 100mL and a tungsten content (calculated as oxide) of 50.0g / 100mL for 2h. After filtration, drying at 120℃ for 6h and calcining at 550℃ for 4h, material II is obtained, which is denoted as NW-2.

[0074] (3) Take 100g NA-2 and 100g N-B-2 and mix them with 50g NW-2 respectively, and put them into a rolling mill for grinding. Add 60g dilute nitric acid solution (HNO3 mass fraction of 4%) to each, grind into paste, extrude into strips, dry the extruded strips at 120℃ for 6h, and then calcine at 550℃ for 4h to obtain catalysts CAT-A-2 and CAT-B-2 respectively. Their properties are shown in Table 1.

[0075] Comparative Example 1

[0076] 100g of β-molecular sieve and 100g of SAPO-34 molecular sieve were mixed with 200g of macroporous alumina, respectively. The mixtures were then impregnated for 4 hours in 600mL of an aqueous solution containing 5.0g / 100mL nickel (based on oxides) and 20.0g / 100mL tungsten (based on oxides). After filtration, drying at 120℃ for 6 hours, and calcination at 550℃ for 4 hours, the resulting materials were designated DNW-A-1 and DNW-B-1, respectively. DNW-A-1 and DNW-B-1 were then separately placed in a mill and milled. 120g of dilute nitric acid solution (4% HNO3 by mass) was added to each, and the mixture was milled into pastes. The pastes were then extruded, dried at 120℃ for 6 hours, and then calcined at 550℃ for 4 hours to obtain comparative catalysts DCAT-A-1 and DCAT-B-1, respectively. Their properties are shown in Table 2.

[0077] Comparative Example 2

[0078] (1) Dissolve 600g of nickel nitrate (NiO mass fraction of 25%) in deionized water, stir evenly, add isopropylamine, adjust the pH of the solution to 8.0, and then make up to 1000mL to obtain a nickel amine complex solution with a nickel content (calculated as oxide) of 15g / 100mL. Mix 100g of β molecular sieve and 100g of SAPO-34 molecular sieve with 200mL of the above nickel amine complex solution, respectively, and put them into reaction vessels. After sealing, stir at 300rpm, heat to 110℃, keep at the temperature for 3h, then quench and cool down. After filtration, drying at 120℃ for 6h and calcining at 550℃ for 4h, the materials obtained are recorded as DN-A-2 and DN-B-2, respectively.

[0079] (2) Take 200g of macroporous alumina, soak it in 400mL of aqueous solution with tungsten content (calculated as oxide) of 50.0g / 100mL for 2h, filter it, dry it at 120℃ for 6h, and calcine it at 550℃ for 4h to obtain material II, which is denoted as DW-2;

[0080] (3) Take 100g of DN-A-2 and 100g of DN-B-2 and mix them with 50g of DW-2 respectively. Then put them into a rolling mill for grinding. Add 60g of dilute nitric acid solution (HNO3 mass fraction of 4%) to each, grind into paste, extrude into strips, dry the extruded strips at 120℃ for 6h, and then calcine at 550℃ for 4h to obtain comparative catalysts DCAT-A-2 and DCAT-B-2 respectively. Their properties are shown in Table 1.

[0081] Comparative Example 3

[0082] (1) Dissolve 40g of nickel nitrate (NiO mass fraction of 25%) in deionized water and make up to 1000mL to obtain a nickel salt aqueous solution with a nickel content (calculated as oxide) of 3.0g / 100mL. Mix 100g of β molecular sieve and 100g of SAPO-34 with 200mL of the above nickel salt solution respectively, and put them into reaction vessels. After sealing, stir at 150rpm, heat to 100℃, keep at the temperature for 3h, then quench and cool down. After filtration, drying at 120℃ for 6h and calcining at 550℃ for 4h, the materials obtained are recorded as DN-A-3 and DN-B-3 respectively.

[0083] (2) Take 400g of macroporous alumina, soak it in 800ml of an aqueous solution with a nickel content (calculated as oxide) of 2.0g / 100mL and a tungsten content (calculated as oxide) of 20.0g / 100mL for 2h, filter it, dry it at 120℃ for 6h, and calcine it at 550℃ for 4h. The resulting material is DNW-3.

[0084] (3) Take 100g of DN-A-3 and DN-B-3 and mix them with 200g of DNW-3 respectively. Then put them into a rolling mill for grinding. Add 120g of dilute nitric acid solution (HNO3 mass fraction of 4%) to each, grind into paste, extrude into strips, dry the extruded strips at 120℃ for 6h, and then calcine at 550℃ for 4h to obtain comparative catalysts DCAT-A-3 and DCAT-B-3 respectively. Their properties are shown in Table 1.

[0085] Example 3

[0086] (1) Dissolve 240g of cobalt nitrate (CoO mass fraction of 25%) in deionized water, stir evenly, add ammonia water (mass fraction of 20%), adjust the pH of the solution to 7.5, and then make up to 1000mL to obtain a cobalt amine complex solution with a cobalt content (calculated as oxide) of 8g / 100mL. Mix 100g of β molecular sieve and 100g of SAPO-34 with 200mL of the above cobalt amine complex solution, respectively, and put them into reaction vessels. After sealing, stir at 250rpm, heat to 120℃, keep at the temperature for 4h, then quench and cool, filter, dry at 120℃ for 6h, and calcine at 550℃ for 4h to obtain materials, which are respectively named CA-3 and CB-3;

[0087] (2) Take 400g of macroporous alumina, soak it in 800mL of an aqueous solution with a cobalt content (calculated as oxide) of 6g / 100mL and a molybdenum content (calculated as oxide) of 30g / 100mL for 2h, filter it, dry it at 120℃ for 6h, and calcine it at 550℃ for 4h. The resulting material is CM-3.

[0088] (3) Take 100g CA-3 and 100g C-B-3 and mix them with 150g CM-3 respectively, and put them into a rolling mill for grinding. Add 100g dilute nitric acid solution (HNO3 mass fraction of 4%) to each, grind into paste, extrude into strips, dry the extruded strips at 120℃ for 6h, and then calcine at 550℃ for 4h to obtain catalysts CAT-A-3 and CAT-B-3 respectively. Their properties are shown in Table 1.

[0089] Example 4

[0090] (1) Dissolve 160g of nickel nitrate (NiO mass fraction of 25%) in deionized water, stir evenly, add isopropylamine, adjust the pH of the solution to 7.0, and then make up to 1000mL to obtain a nickel amine complex solution with a nickel content (calculated as oxide) of 12g / 100mL. Mix 100g of β molecular sieve and 100g of SAPO-34 with 200mL of the above nickel amine complex solution, respectively, and put them into reaction vessels. After sealing, stir at 300rpm and heat to 110℃, keep at the temperature for 4h, then quench and cool down. After filtration, drying at 120℃ for 6h and calcining at 550℃ for 4h, the materials obtained are denoted as NA-4 and NB-4, respectively.

[0091] (2) Take 400g of macroporous alumina, soak it in 800mL of an aqueous solution with a nickel content (calculated as oxide) of 6g / 100mL and a molybdenum content (calculated as oxide) of 60g / 100mL for 2h, filter it, dry it at 120℃ for 6h, and calcine it at 550℃ for 4h. The resulting material is denoted as NM-4.

[0092] (3) Take 100g NA-4 and 100g N-B-4 and mix them with 125g NM-4 respectively, and put them into a rolling mill for grinding. Add 90g dilute nitric acid solution (HNO3 mass fraction of 4%) to each, grind into paste, extrude into strips, dry the extruded strips at 120℃ for 6h, and then calcine at 550℃ for 4h to obtain CAT-A-4 and CAT-B-4 respectively. Their properties are shown in Table 1.

[0093] Example 5

[0094] (1) Dissolve 180g of cobalt nitrate (CoO mass fraction of 25%) in deionized water, stir evenly, add isopropylamine, adjust the pH of the solution to 8.0, and then make up to 1000mL to obtain a cobalt amine complex solution with a cobalt content (calculated as oxide) of 8g / 100mL. Mix 100g of β molecular sieve and 100g of SAPO-34 with 200mL of the above cobalt amine complex solution, respectively, and put them into reaction vessels. After sealing, stir at 350rpm and heat to 120℃, keep at the temperature for 4h, then quench and cool down. After filtration, drying at 120℃ for 6h and calcining at 550℃ for 4h, the materials obtained are recorded as CA-5 and CB-5, respectively.

[0095] (2) Take 400g of macroporous alumina, soak it in 800mL of an aqueous solution with a cobalt content (calculated as oxide) of 4g / 100mL and a tungsten content (calculated as oxide) of 40.0g / 100mL for 2h, filter it, dry it at 120℃ for 6h, and calcine it at 550℃ for 4h. The resulting material is called CW-5.

[0096] (3) Take 100g CA-5 and 100g C-B-5 and mix them with 100g CW-5 respectively, and put them into a rolling mill for grinding. Add 80g dilute nitric acid solution (HNO3 mass fraction of 4%) to each, grind into paste, extrude into strips, dry the extruded strips at 120℃ for 6h, and then calcine at 550℃ for 4h to obtain catalysts CAT-A-5 and CAT-B-5 respectively. Their properties are shown in Table 1.

[0097] Example 6

[0098] (1) Dissolve 320g of nickel nitrate (NiO mass fraction of 25%) in deionized water, stir evenly, add ammonia water (mass fraction of 20%), adjust the pH of the solution to 7.0, and then make up to 1000mL to obtain a nickel amine complex solution with a nickel content (calculated as oxide) of 6.0g / 100mL. Mix 100g of β molecular sieve and 100g of SAPO-34 with 200mL of the above nickel amine complex solution, respectively, and put them into reaction vessels. After sealing, stir at 250rpm and heat to 120℃, keep at the temperature for 4h, then quench and cool down. After filtration, drying at 120℃ for 6h and calcining at 550℃ for 4h, the materials obtained are denoted as NA-6 and NB-6, respectively.

[0099] (2) Take 400g of macroporous alumina, soak it in 800ml of an aqueous solution with a nickel content (calculated as oxide) of 3.0g / 100mL and a tungsten content (calculated as oxide) of 20.0g / 100mL for 2h, filter it, dry it at 120℃ for 6h, and calcine it at 550℃ for 4h. The resulting material is called NW-6.

[0100] (3) Take 100g NA-6 and 100g N-B-6 and mix them with 75g NW-6 respectively. Then put them into a rolling mill for grinding. Add 56g dilute nitric acid solution (HNO3 mass fraction of 4%) to each, grind into paste, extrude into strips, dry the extruded strips at 120℃ for 6h, and then calcine at 550℃ for 4h to obtain catalysts CAT-A-6 and CAT-B-6 respectively. Their properties are shown in Table 1.

[0101] Table 1. Composition and properties of catalysts obtained in the examples and comparative examples.

[0102]

[0103] Example 7

[0104] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 3.0 MPa, hydrogen-to-oil volume ratio 400:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1 The purification reaction temperature was 180℃, and the volume hourly space velocity (VHSV) of the hydrogenation reaction was 1.5 h⁻¹. 1 The conversion reaction temperature is 440℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is filled with commercially available hydrorefining catalyst FH-40A, while the upper and lower (upper feed) sections of the hydroconversion reaction zone are filled with CAT-A-1 and CAT-B-1 respectively, at a volume ratio of 1:1. The feedstock oil used for evaluation is reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 3.

[0105] Example 8

[0106] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 3.0 MPa, hydrogen-to-oil volume ratio 400:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1 The purification reaction temperature was 180℃, and the volume hourly space velocity (VHSV) of the hydrogenation reaction was 1.5 h⁻¹. 1 The conversion reaction temperature is 440℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is loaded with commercially available hydrorefining catalyst FH-40A, while the upper and lower (upper feed) sections of the hydroconversion reaction zone are loaded with CAT-A-2 and CAT-B-2 respectively, at a volume ratio of 1:8. The feedstock oil used for evaluation is reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 3.

[0107] Example 9

[0108] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 3.0 MPa, hydrogen-to-oil volume ratio 400:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1The purification reaction temperature was 180℃, and the volume hourly space velocity (VHSV) of the hydrogenation reaction was 1.5 h⁻¹. 1 The conversion reaction temperature is 440℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is filled with commercially available hydrorefining catalyst FH-40A, while the upper and lower (upper feed) sections of the hydroconversion reaction zone are filled with CAT-A-5 and CAT-B-5 respectively, at a volume ratio of 1:4. The feedstock oil used for evaluation is reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 3.

[0109] Example 10

[0110] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 3.0 MPa, hydrogen-to-oil volume ratio 400:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1 The purification reaction temperature was 180℃, and the volume hourly space velocity (VHSV) of the hydrogenation reaction was 1.5 h⁻¹. 1 The conversion reaction temperature is 440℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is filled with commercially available hydrorefining catalyst FH-40A, while the upper and lower (upper feed) sections of the hydroconversion reaction zone are filled with CAT-A-5 and CAT-B-5 respectively, at a volume ratio of 1:7. The feedstock oil used for evaluation is reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 3.

[0111] Example 11

[0112] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 2.0 MPa, hydrogen-to-oil volume ratio 200:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1 The purification reaction temperature was 180℃, and the volume hourly space velocity (VHSV) of the hydrogenation reaction was 2.0 h⁻¹. 1 The conversion reaction temperature is 440℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is loaded with commercially available hydrorefining catalyst FH-40A, while the upper and lower (upper feed) sections of the hydroconversion reaction zone are loaded with CAT-A-3 and CAT-B-3 respectively, at a volume ratio of 1:6. The feedstock oil used for evaluation is reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 3.

[0113] Example 12

[0114] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 3.0 MPa, hydrogen-to-oil volume ratio 600:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1 The purification reaction temperature was 180℃, and the hydrogenation reaction volume hourly space velocity was 3.5 h⁻¹.1 The conversion reaction temperature is 400℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is loaded with commercially available hydrorefining catalyst FH-40A, while the upper and lower (upper feed) sections of the hydroconversion reaction zone are loaded with CAT-A-4 and CAT-B-4 respectively, at a volume ratio of 1:3. The feedstock oil used for evaluation is reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 3.

[0115] Example 13

[0116] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 5.5 MPa, hydrogen-to-oil volume ratio 200:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1 The purification reaction temperature was 180℃, and the volume hourly space velocity (VHSV) of the hydrogenation reaction was 2.5 h⁻¹. 1 The conversion reaction temperature is 480℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is filled with commercially available hydrorefining catalyst FH-40A, while the upper and lower (upper feed) sections of the hydroconversion reaction zone are filled with CAT-A-6 and CAT-B-6 respectively, at a volume ratio of 1:4. The feedstock oil used for evaluation is reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 3.

[0117] Comparative Example 4

[0118] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 3.0 MPa, hydrogen-to-oil volume ratio 400:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1 The purification reaction temperature was 180℃, and the volume hourly space velocity (VHSV) of the hydrogenation reaction was 1.5 h⁻¹. 1 The conversion reaction temperature is 440℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is loaded with commercially available hydrorefining catalyst FH-40A, while the upper and lower (upper feed) sections of the hydroconversion reaction zone are loaded with DCAT-A-1 and DCAT-B-1 respectively, at a volume ratio of 1:1. The feedstock oil used for evaluation is reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 4.

[0119] Comparative Example 5

[0120] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 3.0 MPa, hydrogen-to-oil volume ratio 400:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1 The purification reaction temperature was 180℃, and the volume hourly space velocity (VHSV) of the hydrogenation reaction was 1.5 h⁻¹. 1The conversion reaction temperature is 440℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is loaded with commercially available hydrorefining catalyst FH-40A, while the upper and lower (upper feed) sections of the hydroconversion reaction zone are loaded with DCAT-A-2 and DCAT-B-2 respectively, at a volume ratio of 1:8. The feedstock oil used for evaluation is reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 4.

[0121] Comparative Example 6

[0122] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 3.0 MPa, hydrogen-to-oil volume ratio 400:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1 The purification reaction temperature was 180℃, and the volume hourly space velocity (VHSV) of the hydrogenation reaction was 1.5 h⁻¹. 1 The conversion reaction temperature is 440℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is loaded with commercially available hydrorefining catalyst FH-40A, while the upper and lower (upper feed) sections of the hydroconversion reaction zone are loaded with DCAT-A-3 and DCAT-B-3 respectively, at a volume ratio of 1:1. The feedstock oil used for evaluation is reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 4.

[0123] Comparative Example 7

[0124] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 3.0 MPa, hydrogen-to-oil volume ratio 400:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1 The purification reaction temperature was 180℃, and the volume hourly space velocity (VHSV) of the hydrogenation reaction was 1.5 h⁻¹. 1 The conversion reaction temperature is 440℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is filled with commercially available hydrorefining catalyst FH-40A, while the hydroconversion reaction zone is filled with CAT-A-1. The feedstock oil used for evaluation is reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 4.

[0125] Comparative Example 8

[0126] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 3.0 MPa, hydrogen-to-oil volume ratio 400:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1 The purification reaction temperature was 180℃, and the volume hourly space velocity (VHSV) of the hydrogenation reaction was 1.5 h⁻¹. 1The conversion reaction temperature is 440℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is filled with commercially available hydrorefining catalyst FH-40A, while the hydroconversion reaction zone is filled with CAT-B-1. The feedstock oil used for evaluation was reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 4.

[0127] Comparative Example 9

[0128] The evaluation was conducted on a fixed-bed hydrogenation test apparatus under the following conditions: reaction pressure 3.0 MPa, hydrogen-to-oil volume ratio 400:1, and purification reaction volume hourly space velocity (VHSV) 2.0 h⁻¹. 1 The purification reaction temperature was 180℃, and the volume hourly space velocity (VHSV) of the hydrogenation reaction was 1.5 h⁻¹. 1 The conversion reaction temperature is 440℃. The feedstock oil, after passing through the hydrorefining reaction zone, enters the hydroconversion reaction zone for hydroconversion. The hydrorefining zone is filled with commercially available hydrorefining catalyst FH-40A, while the upper and lower (upper feed) sections of the hydroconversion reaction zone are filled with CAT-A-5 and CAT-B-5 respectively, at a volume ratio of 4:1. The feedstock oil used for evaluation is reformate raffinate oil, and its properties are shown in Table 2. The evaluation results are shown in Table 4.

[0129] Table 2 Properties of Reforming Residue Oil Feedstock

[0130] Carbon number composition <![CDATA[C5~C8]]> <![CDATA[Density, g / cm 3 > 0.62 Distillation range, °C 45～130 Sulfur content, ppm 6.3 <![CDATA[Bromine number, gBr2 / 100g]]> 23.0 Composition, wt% n-Alkanes 24.6 Isoalkanes 64.5 Cycloalkanes 4.3 n-olefins 1.5 Isoolefins 4.6 Cycloolefins 0.4 Aromatics 0.1

[0131] Table 3 Evaluation results of the catalysts in the examples

[0132]

[0133] Table 4 Evaluation results of the comparative example catalysts

[0134] Test number Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Conversion rate, % 40.5 34.7 52.7 68.4 19.2 76.9 <![CDATA[Yield of C2 + C3, %]]> 21.6 19.6 31.9 28.4 13.4 52.6 <![CDATA[C2 + C3 selectivity, %]]> 53.3 56.5 60.5 41.5 69.8 68.4

[0135] As can be seen from the evaluation results in Tables 3 and 4, the method of the present invention has a higher reformate conversion rate, higher yield and selectivity of C2 and C3, significantly improves the quality of steam cracking feedstock, and is conducive to improving the yield of low-carbon olefins.

[0136] The specific embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for producing low-carbon alkanes by hydroconversion of reforming residue oil, the method comprising: (1) After the reforming residue oil is mixed with hydrogen, it enters the hydrorefining reaction zone for hydrorefining reaction; (2) The reaction effluent obtained in step (1) enters the hydrogenation conversion reaction zone for hydrogenation conversion reaction to obtain low carbon alkanes; The hydroconversion reaction zone is sequentially filled with a first hydroconversion catalyst and a second hydroconversion catalyst along the material flow direction. The first hydroconversion catalyst includes a macroporous twelve-membered ring molecular sieve loaded with Group VIII metals and macroporous alumina loaded with Group VIII and Group VIB metals. The second hydroconversion catalyst includes a microporous eight-membered ring molecular sieve loaded with Group VIII metals and macroporous alumina loaded with Group VIII and Group VIB metals.

2. The method according to claim 1, characterized in that: The macroporous twelve-membered ring molecular sieve loaded with Group VIII metals was loaded onto a macroporous ten-membered ring molecular sieve using a solution containing a Group VIII metal amine complex as the impregnation solution. And / or, the small-pore eight-membered ring molecular sieve loaded with Group VIII metals is loaded onto the small-pore eight-membered ring molecular sieve using a solution containing a Group VIII metal amine complex as the impregnation solution.

3. The method according to claim 1, characterized in that: The hydrorefining reaction zone is filled with a hydrorefining catalyst, which includes a hydrorefining active metal component and a support, wherein the hydrorefining active metal is molybdenum and nickel, and the support is alumina; Preferably, the content of hydrogenation active metal, calculated as oxide, is 18.0% to 22.0% based on the weight of the catalyst.

4. The method according to claim 1, characterized in that: The initial boiling point of the reformate raffinate is 40–70°C, and the final boiling point is 110–160°C. Preferably, the reformate raffinate contains 50%–80% C5–C8 isoalkanes and 1%–8% olefins by mass.

5. The method according to claim 1, characterized in that: The hydrorefining reaction conditions are as follows: reaction pressure 1.0–6.0 MPa, reaction temperature 100–250 °C, hydrogen-to-oil volume ratio 200:1–800:1, and liquid hourly space velocity 0.5–4.0 h⁻¹. -1 ; Preferably, the hydroconversion reaction conditions are as follows: reaction pressure of 1.0–6.0 MPa, reaction temperature of 380–500 °C, hydrogen-to-oil volume ratio of 200:1–800:1, and liquid hourly space velocity of 0.5–4.0 h⁻¹. -1 .

6. The method according to claim 1, characterized in that: In the first hydroconversion catalyst, the macroporous twelve-membered ring molecular sieve is of the hydrogen form and is selected from one or more of Y, β, MOR, and MCM-22 molecular sieves, preferably β molecular sieve; the group VIB metal is preferably molybdenum and / or tungsten, and the group VIII metal is preferably cobalt and / or nickel; And / or, in the second hydroconversion catalyst, the small-pore eight-membered ring molecule is screened from one or more of SAPO-34, SSZ-13, SAPO-18, and SAPO-35 molecular sieves, preferably SAPO-34 molecular sieve; the Group VIB metal is preferably molybdenum and / or tungsten, and the Group VIII metal is preferably cobalt and / or nickel.

7. The method according to claim 1, characterized in that: In the first hydroconversion catalyst, the molar ratio X of the bulk group VIII metal atoms to the surface group VIII metal atoms of the first hydroconversion catalyst is 1.5 to 4.0, preferably 2.0 to 3.0, and more preferably 2.5 to 3.0; And / or, the molar ratio X of the bulk group VIII metal atoms to the surface group VIII metal atoms of the second hydroconversion catalyst is 1.5 to 4.0, preferably 2.0 to 3.0, and more preferably 2.5 to 3.

0.

8. The method according to claim 1, characterized in that: In the first hydroconversion catalyst, based on the weight of the catalyst, the content of Group VIII metals as oxides is 1.0% to 6.0%, the content of Group VIB metals as oxides is 5.0% to 25.0%, the content of macroporous alumina is 20.0% to 65.0%, and the content of macroporous twelve-membered ring molecular sieve is 15.0% to 70.0%.

9. The method according to claim 1, characterized in that: In the second hydroconversion catalyst, based on the weight of the catalyst, the content of Group VIII metals as oxides is 1.0% to 6.0%, the content of Group VIB metals as oxides is 5.0% to 25.0%, the content of macroporous alumina is 20.0% to 65.0%, and the content of microporous eight-membered ring molecular sieve is 15.0% to 70.0%.

10. The method according to claim 1, characterized in that: The specific surface area of ​​the first hydroconversion catalyst is 300–500 m². 2 / g, with a pore volume of 0.35–0.55 mL / g; and / or, the specific surface area of ​​the second hydroconversion catalyst is 250–450 m² / g. 2 / g, with a pore volume of 0.30~0.50mL / g.

11. The method according to claim 1, characterized in that: In the first hydroconversion catalyst, the macroporous alumina has the following properties: pore volume of 0.7–1.0 mL / g and specific surface area of ​​200–500 m² / g. 2 / g; and / or, in the second hydroconversion catalyst, the macroporous alumina has the following properties: pore volume of 0.7–1.0 mL / g, specific surface area of ​​200–500 m² / g. 2 / g.

12. The method according to claim 1, characterized in that: The volume ratio of the first hydroconversion catalyst to the second hydroconversion catalyst is 1:1 to 1:8, preferably 1:3 to 1:6.

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