Process for the hydrogenation of naphthalene

Abstract

The present application relates to naphthalene hydrogenation technical field, specifically to a kind of naphthalene hydrogenation method.The method includes the following steps: (1) naphthalene-containing solution is optionally mixed with part of purified hydrofining product, to obtain hydrofining raw material;(2) under the condition of hydrofining catalyst, hydrofining raw material is carried out hydrofining treatment, to obtain hydrofining product;Optionally (3) hydrofining product is purified to obtain purified hydrofining product, at least part of purified hydrofining product is carried out hydrocracking treatment;Wherein, the temperature of the hydrofining product is higher than the feed temperature of hydrofining raw material by 20-80 ℃, and the feed temperature of hydrofining raw material is 210-290 ℃.By controlling the feed temperature difference of hydrofining product and hydrofining raw material, the present application can directly use hydrofining product as high-quality solvent oil blending component, combined with subsequent hydrocracking treatment, to maximize the production of benzene (B), toluene (T) and xylene (X), and improve its added value.

Description

Technical Field

[0001] This invention relates to the field of naphthalene hydrogenation technology, and more specifically to a method for naphthalene hydrogenation. Background Technology

[0002] Naphthalene is an important organic chemical raw material, widely used in synthetic fibers, synthetic resins, plasticizers, rubber antioxidants, dye intermediates, and medical and sanitary materials. In some fine chemical industries, it is used to produce chemical products such as phthalic anhydride, naphthol, naphthylamine, dispersants, water-reducing agents, dispersants, 2,6-dialkylnaphthalene, 2,6-naphthalenedicarboxylic acid, polyethylene naphthalate (PEN), and H-acid.

[0003] Naphthalene is classified into tar naphthalene and petroleum naphthalene based on its source, collectively known as industrial naphthalene. Tar naphthalene originates from coal tar and was discovered in 1819 and separated from pyrolyzed coal tar in 1821; it is a relatively pure solid and is commonly referred to as tar naphthalene. Petroleum naphthalene can also be obtained in petroleum refining processes using fractions from catalytic cracking and reforming as raw materials, followed by hydrorefining, catalytic dealkylation, and dehydrogenation; this is commonly referred to as petroleum naphthalene. Currently, tar naphthalene accounts for approximately 97% of the global market, while petroleum naphthalene accounts for approximately 3%.

[0004] Industrial naphthalene is a very important product in the primary processing of coal tar, accounting for about 10% of coal tar production. It has a large market demand and high value. Internationally, industrial naphthalene is mainly produced as tar naphthalene.

[0005] Impurities in industrial naphthalene mainly include tetrahydronaphthalene, thiazoindene, and xylenol, which have boiling points close to naphthalene. Using industrial naphthalene as raw material to manufacture higher-purity refined naphthalene through crystallization, acid washing, distillation, and sublimation methods presents environmental pollution and other problems.

[0006] CN103285886A uses NiMo or NiW metal sulfide catalysts in a fixed-bed reactor at a reaction pressure of 4-10 MPa, a reaction temperature of 160-320℃, and a liquid hourly space velocity of 1-10 h⁻¹. -1 Under certain conditions, naphthalene is hydrogenated in one step to synthesize decahydronaphthalene, with a conversion rate of over 99% and a selectivity of over 99%.

[0007] CN107670661B discloses a catalyst for the production of decahydronaphthalene by hydrodesulfurization of industrial naphthalene, its preparation method and application, which solves the technical problems of existing one-step hydrogenation catalysts not being able to completely achieve desulfurization and the high energy consumption and high investment of two-step processes.

[0008] CN104744203B discloses a method for hydrogenating industrial naphthalene to produce decahydronaphthalene. The method involves dissolving industrial naphthalene in a dissolving tower and then injecting it into a hydrogenation refining tower for reaction. This removes benzothiophene and quinoline from the industrial naphthalene and initially hydrogenates it to produce tetrahydronaphthalene. The hydrogenated product then enters an alkaline washing tower, which operates at room temperature. After alkaline washing, the product is mixed with hydrogen and enters a deep hydrogenation tower. The deep hydrogenated product then enters a distillation tower for atmospheric pressure distillation. The distilled product contains solvent that is recycled to redissolve industrial naphthalene, ethylbenzene, propylbenzene, and decahydronaphthalene as the final product, along with tetrahydronaphthalene. The tetrahydronaphthalene is then mixed with the alkaline washed product and subjected to deep hydrogenation again, with ethylbenzene, propylbenzene, and decahydronaphthalene remaining as the final product. Summary of the Invention

[0009] A comprehensive analysis of the above technologies reveals that while existing technologies have increased the added value of naphthalene to some extent, the product's added value still needs further improvement. Based on technologies such as naphthalene hydrorefining and / or hydrocracking, optimization and innovation can be implemented to directly use hydrorefined products as high-quality solvent oil blending components, or to maximize the production of benzene (B), toluene (T), and xylene (X), thereby increasing their added value.

[0010] The purpose of this invention is to overcome the problems of single processed products and low added value in the existing technology, and to provide a method for hydrogenating naphthalene, which has the characteristics of diverse processed products and high added value.

[0011] To achieve the above objectives, the present invention provides a method for hydrogenating naphthalene, the method comprising the following steps: (1) optionally mixing a naphthalene-containing solution with a portion of a purified hydrogenation product to obtain a hydrogenation feedstock; (2) subjecting the hydrogenation feedstock to hydrogenation purification under hydrogenation catalytic conditions to obtain a hydrogenation product; optionally (3) purifying the hydrogenation product to obtain a purified hydrogenation product, wherein at least a portion of the purified hydrogenation product is subjected to hydrocracking treatment; wherein the temperature of the hydrogenation product is 20-80°C higher than the feed temperature of the hydrogenation feedstock, and the feed temperature of the hydrogenation feedstock is 210-290°C.

[0012] Through the above technical solution, the present invention has the following advantages:

[0013] This invention, by controlling the temperature difference between the feed of hydrorefined products and hydrorefined feedstocks, enables the direct use of hydrorefined products as high-quality solvent oil blending components. Combined with subsequent hydrocracking treatment, it can maximize the production of benzene (B), toluene (T), and xylene (X), thereby increasing their added value. Attached Figure Description

[0014] Figure 1 These are TEM images of the catalyst used for hydrorefining after sulfidation, where (a) is a TEM image of the A2 sulfidation catalyst in Example 1, and (b) is a TEM image of the A4 sulfidation catalyst in Example 4.

[0015] Figure 2 This is the XRD pattern of the HZSM-5 / HMOR composite molecular sieve in Example 1;

[0016] Figure 3 This is the TPR diagram of catalyst B1 in Example 1;

[0017] Figure 4 This is the XRD pattern of HZSM-5 molecular sieve in Example 12;

[0018] Figure 5 This is the XRD pattern of the HMOR molecular sieve in Example 16;

[0019] Figure 6 This is a process flow diagram for the hydrogenation of naphthalene. Detailed Implementation

[0020] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0021] This invention provides a method for hydrogenating naphthalene, comprising the following steps: (1) optionally mixing a naphthalene-containing solution with a portion of purified hydrogenation product to obtain a hydrogenation feedstock; (2) subjecting the hydrogenation feedstock to hydrogenation purification under hydrogenation catalytic conditions to obtain a hydrogenation product; optionally (3) purifying the hydrogenation product to obtain a purified hydrogenation product, wherein at least a portion of the purified hydrogenation product is subjected to hydrocracking treatment; wherein the temperature of the hydrogenation product is 20-80°C higher than the feed temperature of the hydrogenation feedstock, and the feed temperature of the hydrogenation feedstock is 210-290°C.

[0022] This invention, by controlling the temperature difference between the feed of hydrorefined products and hydrorefined feedstocks, enables the direct use of hydrorefined products as high-quality solvent oil blending components. Combined with subsequent hydrocracking treatment, it can maximize the production of benzene (B), toluene (T), and xylene (X), thereby increasing their added value.

[0023] According to a preferred embodiment of the present invention, the temperature of the hydrorefined product is higher than the temperature of the hydrorefined raw material as long as it is within the aforementioned range, such as 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C and 75°C, preferably 35-75°C, more preferably 45-75°C.

[0024] According to a preferred embodiment of the present invention, the temperature for hydrogenating the product is 290-350°C, for example, 295°C, 305°C, 310°C, 315°C, 320°C, 325°C, 340°C, and 345°C, preferably 300-335°C. By adopting the aforementioned preferred embodiment, the added value of naphthalene can be further increased.

[0025] According to a preferred embodiment of the present invention, the purpose of the present invention can be achieved as long as the feed temperature of the hydrorefining raw material is within the aforementioned range, such as 220°C, 230°C, 240°C, 250°C, 260°C, 270°C and 280°C, preferably 235-260°C.

[0026] According to a preferred embodiment of the present invention, at least two layers of the hydrorefining catalyst are sequentially packed along the material flow direction, and the pore size of each layer of hydrorefining catalyst decreases sequentially, preferably with the pore size of adjacent packed catalysts decreasing by 2-5 nm, for example, 3 nm and 4 nm. By adopting the aforementioned preferred scheme, the added value of naphthalene can be further improved.

[0027] To further enhance the added value of naphthalene, according to a preferred embodiment of the present invention, the concentration of naphthalene in the naphthalene-containing solution is 10-70 wt%, for example, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 60 wt%, and 65 wt%, preferably 12-55 wt%.

[0028] In this invention, the naphthalene-containing solution also includes 0.01-1 wt% of impurities, preferably including at least one of tetrahydronaphthalene, thiazoindene, and xylenol.

[0029] In this invention, the naphthalene-containing solution is an industrial naphthalene solution.

[0030] In this invention, as long as the purpose of this invention can be achieved, the type of solvent in the naphthalene-containing solution can be a conventional choice in the art. According to a preferred embodiment of this invention, the solvent in the naphthalene-containing solution is a benzene-based solvent, preferably selected from one or more of methyl ethylbenzene, propylbenzene, tetramethylbenzene, and diethylbenzene.

[0031] According to a preferred embodiment of the present invention, in the hydrorefining feedstock, the volume ratio of the purified hydrorefined product to the naphthalene-containing solution is 0-0.5, for example, 0.05, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, and 0.45, preferably 0.1-0.5. By adopting the aforementioned preferred embodiment, low-quality naphthalene can be further fully utilized, thereby increasing its added value.

[0032] According to a preferred embodiment of the present invention, the sulfur content in the purified hydrogenated product is ≤1ppm, preferably ≤0.85ppm.

[0033] According to a preferred embodiment of the present invention, the nitrogen content in the purified hydrogenated product is ≤1ppm, preferably ≤0.8ppm.

[0034] According to a preferred embodiment of the present invention, the conditions for the hydrorefining treatment include: a feed temperature of 210-290°C, preferably 235-260°C;

[0035] In this invention, as long as the purpose of this invention can be achieved, the pressure of the hydrorefining treatment can be a conventional choice in the art. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the pressure of the hydrorefining treatment is 2.0-8.0 MPa, preferably 2.2-6.0 MPa.

[0036] In this invention, the hydrogen-to-oil volume ratio of the hydrorefining process can be selected within a wide range. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the hydrogen-to-oil volume ratio of the hydrorefining process is 400-3000, preferably 600-2000.

[0037] In this invention, as long as the objective of the invention can be achieved, the volume hourly space velocity (VHSV) of the naphthalene-containing solution undergoing hydrorefining can be a conventional choice in the art. According to a preferred embodiment of the invention, the VHSV of the naphthalene-containing solution undergoing hydrorefining is 0.2-3 h⁻¹. -1 Preferably 0.6-1.2h -1 .

[0038] According to a preferred embodiment of the present invention, the conditions for the hydrocracking treatment include: a feed temperature of 260-500°C, preferably 260-480°C.

[0039] In this invention, as long as the purpose of this invention can be achieved, the pressure of the hydrocracking treatment can be a conventional choice in the art. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the pressure of the hydrocracking treatment is 2.0-8.0 MPa, preferably 3.0-6.5 MPa.

[0040] In this invention, the hydrogen-to-oil volume ratio of the hydrocracking treatment has a wide selectable range. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the hydrogen-to-oil volume ratio of the hydrocracking treatment is 400-3000, preferably 600-2000.

[0041] In this invention, as long as the objective of the invention can be achieved, the volume hourly space velocity (VHSV) of the naphthalene-containing solution subjected to hydrocracking can be a conventional choice in the art. According to a preferred embodiment of the invention, the VHSV of the naphthalene-containing solution subjected to hydrocracking is 0.2-3 h⁻¹. -1 Preferably 0.6-1.2h -1 .

[0042] According to a preferred embodiment of the present invention, the unreacted hydrogen gas after hydrorefining is recycled back into the hydrorefining process.

[0043] According to a preferred embodiment of the present invention, the unreacted hydrogen gas after hydrocracking is recycled back into the hydrocracking process.

[0044] According to a preferred embodiment of the present invention, the heavy aromatics separated from the hydrocracking products in step (3) are recycled back into the hydrorefining feedstock.

[0045] According to a preferred embodiment of the present invention, the hydrocracking treatment is carried out in the presence of a hydrocracking catalyst, wherein the TPR hydrogen atmosphere reduction temperature of the hydrocracking catalyst is below 400°C, for example, 395°C, 385°C, 375°C, 360°C, 355°C, 345°C, 335°C, 325°C, 315°C, and 300°C, preferably 350-390°C. By adopting the aforementioned preferred embodiment, the added value of naphthalene can be further increased.

[0046] In this invention, no special requirements are made for the hydrocracking catalyst. According to a preferred embodiment of the invention, the hydrocracking catalyst includes an active component, an auxiliary component, and a molecular sieve support.

[0047] According to a preferred embodiment of the present invention, the active component comprises a Group VIII metal element and optionally a lanthanide metal element, and the auxiliary component comprises a Group IVB metal element. By adopting the aforementioned preferred embodiment, the added value of naphthalene can be further increased.

[0048] According to a preferred embodiment of the present invention, the dispersion of Group VIII metal elements in the hydrocracking catalyst is not less than 8%, for example, 9%, 10%, 11%, 12%, 13%, 14%, 16%, 17%, 18%, 19%, and 20%, preferably 8-15%. By adopting the aforementioned preferred embodiment, the added value of naphthalene can be further increased.

[0049] According to a preferred embodiment of the present invention, the ratio of the weak acid content to the strong acid content of the molecular sieve support is 2-6, for example, 3, 3.5, 4, 4.5 and 5.5, preferably 2.5-5. By adopting the aforementioned preferred embodiment, the added value of naphthalene can be further improved.

[0050] According to a preferred embodiment of the present invention, the weak acid content of the molecular sieve support is 0.5-1.2 mmol·g. -1 Preferably, it is 0.6-1.1 mmol·g -1 By adopting the aforementioned preferred scheme, the added value of naphthalene can be further increased.

[0051] According to a preferred embodiment of the present invention, the strong acid content of the molecular sieve support is 0.08-0.5 mmol·g. -1 Preferably, it is 0.1-0.5 mmol·g -1 By adopting the aforementioned preferred scheme, the added value of naphthalene can be further increased.

[0052] According to a preferred embodiment of the present invention, the particle size of the molecular sieve support is 50-1000 nm, preferably 100-500 nm.

[0053] According to a preferred embodiment of the present invention, the pore size of the molecular sieve support is 3-10 nm, preferably 3-8 nm.

[0054] According to a preferred embodiment of the present invention, the specific surface area of ​​the molecular sieve support is 250-450 m². 2 ·g -1 Preferably 250-400m 2 ·g -1 .

[0055] According to a preferred embodiment of the present invention, the SiO2 / Al2O3 molar ratio of the molecular sieve support is 10-200, preferably 15-60.

[0056] According to a preferred embodiment of the present invention, the molecular sieve carrier comprises at least one of HZSM-5 molecular sieve, HMOR molecular sieve, and Beta molecular sieve.

[0057] To further enhance the added value of naphthalene, the molecular sieve support is an HZSM-5 / HMOR composite molecular sieve; preferably, the mass content of HZSM-5 molecular sieve in the HZSM-5 / HMOR composite molecular sieve is 55%-95%, for example, 60%, 70%, 80%, 85% and 90%, and more preferably 75%-92%. By adopting the aforementioned preferred embodiment, the added value of naphthalene can be further enhanced.

[0058] In this invention, no special requirements are made regarding the preparation method of the HZSM-5 / HMOR composite molecular sieve. The following is an exemplary preparation method, comprising: slowly adding an aluminum source (e.g., sodium aluminate aqueous solution) and a template agent (e.g., tetrapropylammonium hydroxide aqueous solution) to a silicon source aqueous solution (e.g., water glass) in a certain proportion under dynamic mixing conditions; adjusting the pH of the solution to a suitable value with acetic acid; and finally adding the MOR molecular sieve. Under certain crystallization conditions, such as 150℃ and 60h, the ZSM-5 / MOR composite molecular sieve is synthesized. After crystallization, the sieve is separated, washed, and dried to obtain zeolite powder. Each gram of zeolite powder is subjected to ion exchange with 10 ml of an ammonium salt aqueous solution (e.g., 0.8 mol / L NH4NO3 solution) in a water bath at a certain temperature (e.g., 80℃) to convert it to the ammonia form. The powder is then dried and calcined at a certain temperature (e.g., 550℃) for a certain time (e.g., 5h) to form the HZSM-5 / HMOR composite molecular sieve, which is then shaped.

[0059] According to a preferred embodiment of the present invention, the content of Group VIII metal elements in the hydrocracking catalyst, calculated as oxides, is 50-260 g / L, preferably 50-150 g / L, based on the total mass of the catalyst. By adopting the aforementioned preferred embodiment, the added value of naphthalene can be further increased.

[0060] According to a preferred embodiment of the present invention, the content of lanthanide metal elements in the hydrocracking catalyst, calculated as oxides, is 0.1-100 g / L, preferably 0.1-50 g / L, based on the total mass of the catalyst. By adopting the aforementioned preferred embodiment, the added value of naphthalene can be further increased.

[0061] To further enhance the added value of naphthalene, according to a preferred embodiment of the present invention, the content of Group IVB metal elements in the hydrocracking catalyst, calculated as oxides, is 0.1-100 g / L, preferably 0.1-50 g / L, based on the total mass of the catalyst.

[0062] In this invention, there are no special requirements for the type of Group VIII metal element in the hydrocracking catalyst. According to a preferred embodiment of the present invention, the Group VIII metal element in the hydrocracking catalyst is selected from at least one of Fe, Co, Ni, Pt and Pd, preferably Ni and / or Pt.

[0063] In this invention, there are no special requirements for the type of lanthanide metal element in the hydrocracking catalyst. According to a preferred embodiment of the invention, the lanthanide metal element in the hydrocracking catalyst is La and / or Ce.

[0064] In this invention, there are no special requirements for the type of Group IVB metal element in the hydrocracking catalyst. According to a preferred embodiment of the invention, the Group IVB metal element in the hydrocracking catalyst is selected from Zr and / or Ti, preferably Zr.

[0065] In this invention, as long as a hydrocracking catalyst with the aforementioned characteristics of this invention can be prepared, there are no special requirements for the preparation method of the hydrocracking catalyst. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the preparation method of the hydrocracking catalyst in this invention includes: mixing the active component source, the auxiliary component source and the surfactant source uniformly, loading the mixture on a molecular sieve support, first drying, and first calcination.

[0066] In the preparation method of the hydrocracking catalyst of the present invention, 1,2-cyclohexanediaminetetraacetic acid is used as an exemplary surfactant.

[0067] The conditions for the first drying described in this invention have a wide range of options. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the conditions for the first drying include: a drying temperature of 50-130°C, preferably 60-120°C, and a drying time determined according to the drying temperature, for example, a drying time of 3-46 hours, preferably 6-36 hours.

[0068] The conditions for the first roasting described in this invention have a wide range of options. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the conditions for the first roasting include: a roasting temperature of 150-520℃, preferably 280-500℃, and a roasting time determined according to the roasting temperature, for example, a roasting time of 2-24h, preferably 3-12h.

[0069] According to a preferred embodiment of the present invention, the hydrorefining catalyst is a sulfide-type catalyst, which includes a support and a sulfide formed by the sulfidation of an oxide supported on the support, wherein the sulfide is a sulfide of the active element and has a tower-shaped structure. By adopting the aforementioned preferred embodiment, the added value of naphthalene can be further improved.

[0070] According to a preferred embodiment of the present invention, the number of stacking layers of the tower structure is 3-10 layers, preferably 3-5 layers.

[0071] According to a preferred embodiment of the present invention, the stacking length of the tower structure is 3-12 nm, preferably 3-6 nm.

[0072] According to a preferred embodiment of the present invention, the stacking layer spacing of the tower structure is 0.2-2 nm.

[0073] According to a preferred embodiment of the present invention, the total content of active elements in the hydrorefining catalyst, calculated as oxides, is not less than 30 g / L, preferably 50-700 g / L, and more preferably 60-650 g / L, based on the total mass of the sulfidation catalyst before sulfidation.

[0074] In this invention, the sulfidation catalyst is a metal oxide catalyst before sulfidation.

[0075] In this invention, as long as the purpose of this invention can be achieved, the support in the hydrorefining catalyst can be a conventional choice in the art. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the support in the hydrorefining catalyst is selected from at least one of Al2O3, TiO2, and SiO2.

[0076] According to a preferred embodiment of the present invention, the active element comprises a Group VIB metal and / or a Group VIII metal, and a lanthanide metal and / or a Group VA element, preferably comprising Group VIB metal, Group VIII metal, lanthanide metal, and / or Group VA element, wherein, based on oxides, the mass ratio of the Group VIB metal to the Group VIII metal is 0.1-15, preferably 0.8-9. By adopting the aforementioned preferred embodiment, the added value of naphthalene can be further increased.

[0077] In this invention, there are no special requirements for the type of Group VIB metal element in the active element. According to a preferred embodiment of the invention, the Group VIB metal element in the active element is selected from Mo and / or W.

[0078] In this invention, there are no special requirements for the type of Group VIII metal element in the active element. According to a preferred embodiment of this invention, the Group VIII metal element in the active element is selected from at least one of Ni, Co, Fe, Pt and Pd.

[0079] In this invention, there are no special requirements for the type of lanthanide metal element in the active element. According to a preferred embodiment of the invention, the lanthanide metal element in the active element is selected from La and / or Ce.

[0080] In this invention, there are no special requirements for the type of Group VA element in the active element. According to a preferred embodiment of this invention, the Group VA element in the active element is selected from P and / or Sb, preferably P.

[0081] In this invention, there are no special requirements for the preparation method of the hydrorefining catalyst. For example, it can be impregnation, co-precipitation, ion exchange, or supercritical fluid drying. This invention provides a method for preparing a hydrorefining catalyst that enables the active component elements to be distributed in a tower-like manner on the surface of the support after sulfidation, achieving a better hydrorefining effect. The preparation method includes: mixing an active element source, a support, a chelating surfactant, and a water-soluble additive to obtain a mixture, impregnation, curing, second drying, second calcination, and sulfidation.

[0082] The impregnation solution (mixture) of this invention has a high metal concentration, weak interaction between the active component and the carrier, and low viscosity. After subsequent curing, drying, calcination, and sulfidation, the active metal of the catalyst has a tower-shaped structure, with active sites such as edges, corners, and sides fully exposed. It has good hydrogenation activity of polycyclic aromatic hydrocarbons, high desulfurization and denitrification rates, and can be used under relatively mild conditions with a long service life.

[0083] According to a preferred embodiment of the present invention, the chelating surfactant is selected from at least one of 1,2-cyclohexanediaminetetraacetic acid, citric acid, tartaric acid, and ethylenediaminetetraacetic acid, preferably a combination of 1,2-cyclohexanediaminetetraacetic acid and / or ethylenediaminetetraacetic acid and citric acid, more preferably the mass ratio of 1,2-cyclohexanediaminetetraacetic acid and / or ethylenediaminetetraacetic acid and citric acid in the composition is 1-3:2-1.

[0084] According to a preferred embodiment of the present invention, the water-soluble additive is selected from one or more of ethanol, ethylene glycol, and acetone.

[0085] According to a preferred embodiment of the present invention, the chelated surfactant content in the mixture is 0.01-10% by mass, preferably 1.5-7.5%.

[0086] According to a preferred embodiment of the present invention, the water-soluble additive in the mixture has a mass content of 0.1-20%, preferably 5-12.5%.

[0087] According to a preferred embodiment of the present invention, the conditions for health preservation include: a health preservation temperature of 0-60℃, preferably 20-40℃, and a health preservation time determined according to the health preservation temperature, for example, the health preservation time can be 2-96 hours, preferably 6-48 hours.

[0088] The second drying conditions described in this invention have a wide range of options and are illustrative, but do not limit the scope of this invention. According to a preferred embodiment of this invention, the second drying conditions include: a drying temperature of 50-130°C, preferably 60-120°C, and a drying time determined according to the drying temperature, for example, a drying time of 3-46 hours, preferably 6-36 hours.

[0089] The conditions for the second roasting described in this invention have a wide range of options. This is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the conditions for the second roasting include: a roasting temperature of 150-520℃, preferably 280-500℃, and a roasting time determined according to the roasting temperature, for example, a roasting time of 2-24h, preferably 3-12h.

[0090] In this invention, the vulcanization conditions are vulcanization performed by programmed temperature increase, including: initial temperature of 25-150℃, heating rate of 5-15℃ / min, step temperature interval of 50-80℃, step temperature holding time of 4-10h, final temperature of 320-360℃, and final temperature treatment time of 12-35h.

[0091] In this invention, the temperature is achieved by heating with devices such as heaters and heat exchangers to meet the requirements of this invention.

[0092] The present invention will be described in detail below through embodiments. The following embodiments include:

[0093] The structural characteristics of the catalyst and the size of the metal nanoparticles were measured using a G2F30 transmission electron microscope (TEM) from FEI Corporation, USA.

[0094] The elemental composition of the catalyst was determined using a Rigaku ZSX-100e 4580 X-ray fluorescence spectrometer.

[0095] Nitrogen and sulfur tests were performed on an Antek 900 sulfur-nitrogen analyzer. The nitrogen content test method referenced standard SH / T0657-2007 (chemiluminescence method), and the sulfur content test method referenced standard SH / T0689-2000 (ultraviolet fluorescence method).

[0096] XRD patterns were obtained using a Bruker D8 Advance X-ray diffractometer (Germany) for phase analysis of the catalyst samples. Specific parameters were: operating voltage 30kV, current 30mA, and scanning range 0°-80°.

[0097] The H2-TPR spectrum was measured using an AutoChem 2920 dynamic adsorption analyzer from Micron Instruments, Inc., USA. The specific parameters were: reducing gas was a 10% H2-Ar mixture, sample mass was 50 mg, gas flow rate was 50 ml / min, and the temperature was increased from room temperature to 800℃ at a rate of 10℃ / min.

[0098] NH3-TPD data were obtained using an Altamira AMI-3300 chemisorption analyzer from Micron Instruments, Inc., USA.

[0099] The pore structure parameters of the molecular sieve support were measured using a Micrometrics Tristar 3000 surface area analyzer at a test temperature of -196℃. Before the test, the sample was vacuum activated at 300℃ for 6 hours.

[0100] In this invention, the method for testing the dispersion of the active component Ni is as follows.

[0101] R = [Ni] / [Ni] 总 *100%=(2 / 3×V0×N) A / 22400) / (WP N A / M)*100%

[0102] In the formula:

[0103] R-----Dispersion degree of Ni;

[0104] [Ni] ----- Number of nickel atoms on the surface;

[0105] [Ni] 总 -----Total number of nickel atoms;

[0106] V0 ----- The titration amount of hydrogen, expressed in mL;

[0107] N A -----Avogadro's constant (6.02) × 10 23 mol -1 ;

[0108] W-----Sample mass, g;

[0109] P-----Mass fraction of nickel in the sample;

[0110] M ----- Atomic weight of nickel: 58.7 g·mol -1 .

[0111] The naphthalene conversion rate and tetrahydronaphthalene selectivity in the product are calculated using the following formula:

[0112]

[0113] In the following examples, the evaluation method for hydrogenation of aromatic cracked distillate oil includes:

[0114] Raw material for naphthalene hydrogenation refining: industrial naphthalene dissolved in tetramethylbenzene, sulfur content = 500 ppm, nitrogen content = 40 ppm.

[0115] Evaluation criteria:

[0116] Hydrorefining: The feed temperature (i.e., the temperature of the hydrorefining feed stream) is in the range of 220-260℃, and the volume hourly space velocity (VHSV) of the naphthalene-containing solution is 0.8 h⁻¹. -1Pressure 6.0 MPa, H2 / Oil(v / v) = 1200;

[0117] Hydrocracking: Feed temperature 400℃, liquid hourly space velocity 0.8h -1 Pressure 4.0 MPa, H2 / Oil(v / v) = 600.

[0118] In the following embodiments, unless otherwise specified, "%" refers to mass percentage, all pressures are gauge pressures, and all raw materials are commercially available products.

[0119] Example 1

[0120] 1. Preparation of hydrorefining catalyst

[0121] Take 1 L of Al2O3 support (pore size: 16 nm) and Al2O3-TiO2-SiO2 support (pore size: 11 nm, of which Al2O3 is 97%, TiO2 is 1.5% and SiO2 is 1.5%) and mix them with 0.85 L of a mixed solution containing nickel acetate, lanthanum nitrate, ammonium molybdate, 1,2-cyclohexanediaminetetraacetic acid, citric acid, phosphoric acid, ethylene glycol and acetone (containing 83 g NiO, 440 g MoO3, 5 g La2O3 and 10 g P2O5). The amount of 1,2-cyclohexanediaminetetraacetic acid is 5.5% of the mass of the mixed solution, the amount of citric acid is 2.5% of the mass of the mixed solution, the amount of ethylene glycol is 2.5% of the mass of the mixed solution, and the amount of acetone is 0.5% of the mass of the mixed solution. After impregnation, the catalysts were cured at 25°C for 24 hours, dried at 110°C for 6 hours, and calcined at 450°C for 4 hours to obtain catalysts A1 and A2, respectively.

[0122] One L of Al2O3-SiO2 support (pore size: 9 nm, of which Al2O3 is 95% and SiO2 is 5%) was mixed with 0.85 L of a mixed solution containing cobalt acetate, lanthanum nitrate, ammonium molybdate, 1,2-cyclohexanediaminetetraacetic acid, citric acid, phosphoric acid, ethylene glycol, and acetone (containing 83 g CoO, 440 g MoO3, 5 g La2O3, and 10 g P2O5). The amounts of 1,2-cyclohexanediaminetetraacetic acid, citric acid, ethylene glycol, and acetone were 5.5% and 2.5% of the total mass of the mixed solution, respectively. After impregnation, the mixture was cured at 25°C for 24 hours, dried at 110°C for 6 hours, and calcined at 450°C for 4 hours to obtain catalyst A3.

[0123] Catalysts A1 and A2 contain 83 g / L NiO, 440 g / L MoO3, 5 g / L La2O3, and 10 g / L P2O5, while catalyst A3 contains 83 g / L CoO, 440 g / L MoO3, 5 g / L La2O3, and 10 g / L P2O5.

[0124] 2. Preparation of hydrocracking catalyst

[0125] Sodium aluminate aqueous solution and tetrapropylammonium hydroxide aqueous solution were slowly added to water glass under stirring. The pH of the solution was adjusted to 11 with acetic acid. Finally, MOR (SiO2 / Al2O3 molecular ratio 25) was added to make the molar ratio of the mixed solution: n(Na2O):n(Al2O3):n(CH3COOH):n(SiO2):n(TPA) + The ratio of n(H₂O) to n(H₂O) is 2.5:1:0.8:25:2.5:375. ZSM-5 / MOR composite molecular sieves were synthesized under crystallization conditions of 150℃ for 60 hours. After crystallization, the sieve was filtered, washed, and dried at 120℃ to obtain zeolite powder. Each gram of zeolite powder was subjected to ion exchange three times in 10 ml of 0.8 mol / L NH₄NO₃ solution at 80℃ for 1 hour each time, converting it to the ammonia form. The powder was then dried at 120℃ for 8 hours and calcined at 550℃ for 5 hours to obtain HZSM-5 / HMOR composite molecular sieves. The sieves were then pressed into tablets, crushed, and sieved. 20-mesh HZSM-5 / HMOR composite molecular sieves were collected for later use.

[0126] Take the formed HZSM-5 / HMOR composite molecular sieve (SiO2 / Al2O3 molar ratio 25, weak acid 0.68 mmol·g) -1 0.22 mmol·g strong acid -1 Weak acid strength / strong acid strength ratio 3.09, pore size 6nm, specific surface area 288m² 2 ·g -1 The composite molecular sieve, containing 0.9 g HZSM-5 by mass, was mixed with a mixed solution of nickel acetate, nickel nitrate, basic nickel carbonate, cerium nitrate, zirconium nitrate, and 1,2-cyclohexanediaminetetraacetic acid (containing 108 g NiO, 8 g CeO2, 6 g ZrO2, and 48 g 1,2-cyclohexanediaminetetraacetic acid), wherein the amount of 1,2-cyclohexanediaminetetraacetic acid was 7.5% of the mass of the mixed solution. The mixture was dried at 110℃ for 6 hours and calcined at 450℃ for 4 hours to prepare catalyst B1. The TPR hydrogen atmosphere reduction temperature of catalyst B1 was measured to be 375℃. Figure 3 As shown.

[0127] The XRD pattern of the HZSM-5 / HMOR composite molecular sieve is shown below. Figure 2 The NH3-TPD data are shown in Table 3.

[0128] Catalyst B1 contains 108 g / L NiO, 8 g / L CeO2, and 6 g / L ZrO2.

[0129] 3. Hydrorefining catalyst loading

[0130] Catalysts A3, A2, and A1 are loaded into the adiabatic bed reactor (hydrogenation refining reactor, hereinafter the same) in a volume ratio of 2:6:2 from bottom to top.

[0131] 4. Hydrorefining catalyst sulfidation

[0132] After the airtightness is verified, sulfidation begins. The system pressure is 5.5 MPa, and the hydrogen volume hourly space velocity is 800 h⁻¹. -1 Hydrogen gas was introduced, and the temperature was increased from room temperature to 150°C at a rate of 30°C / h, with a volume hourly space velocity (VHSV) of 1 h⁻¹. -1 A sulfurizing agent containing 0.5 wt% sulfur was introduced, and the temperature was increased to 180°C at a rate of 5°C / h for 6 hours, held at this temperature for 5 hours, then increased to 230°C at a rate of 5°C / h for 10 hours, held at this temperature for 4 hours, then increased to 280°C at a rate of 10°C / h for 5 hours, held at this temperature for 4 hours, then increased to 320°C at a rate of 10°C / h for 4 hours, and held at this temperature for 2 hours. The sulfurization of the catalyst was then complete. The sulfurized A2 catalyst was tested using a G2F30 transmission electron microscope (TEM) from FEI Corporation, USA. Figure 1 (a) As can be seen from the figure, the active phase of the sulfidation catalyst has a tower-shaped structure with 3-5 stacked layers; the stacking layer spacing is 0.2-2 nm; and the stacking length is 3-6 nm.

[0133] 5. Hydrocracking catalyst loading and reduction

[0134] Take B1 and load it into an adiabatic bed reactor (hydrocracking reactor, the same below). Heat it from room temperature to 500℃ at a rate of 20℃ / h and keep it at that temperature for 3 hours. Use a hydrogen atmosphere with a hydrogen gas flow rate of 500ml / min.

[0135] 6. Catalyst Evaluation

[0136] like Figure 6 The process flow shown is as follows: A naphthalene-containing solution (industrial naphthalene dissolved in tetramethylbenzene, with a naphthalene content of 50 wt%) is mixed with fresh hydrogen and hydrorefining circulating hydrogen. After being heated by a heater and mixed with the purified product circulating liquid, the mixture enters the hydrorefining reactor. The temperature of the mixture entering the hydrorefining reactor is controlled at 235°C. The hydrorefining product enters the high-precision separator, the hydrogen enters the refining compressor for circulation, the liquid phase enters the refining product oil-water separator, the oil phase is dehydrated and then enters the low-precision separator and stripping tower. After H2S is removed from the oil phase by the stripping tower, the ratio of the purified product circulation volume to the naphthalene-containing solution feed volume is 0.2. The purified product is heated by the hydrocracking heater and then enters the hydrocracking reactor. The cracking product enters the hydrocracking high-precision separator, the hydrogen enters the hydrocracking compressor for circulation, and the liquid phase enters the distillation column after passing through three low-precision separators to obtain ethylene cracking feedstock, BTX, and heavy aromatics.

[0137] The feed temperature of the hydrorefining feedstock is 235℃, and the temperature of the hydrorefining product stream is 310℃.

[0138] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0139] Example 2

[0140] Same as Example 1, except that the ratio of purified product circulation volume to naphthalene-containing solution feed mass is 0.35, the feed temperature of the hydrorefining raw material stream is 250°C, and the temperature of the hydrorefining product stream is 310°C.

[0141] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0142] Example 3

[0143] Same as Example 1, except that the ratio of purified product circulation volume to naphthalene-containing solution feed mass is 0.5, the feed temperature of the hydrorefining raw material stream is 260°C, and the temperature of the hydrorefining product stream is 305°C.

[0144] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0145] Example 4

[0146] Same as Example 1, except that A2 is replaced with A4. Preparation of hydrogenation refining catalyst A4:

[0147] 1 L of Al2O3-SiO2 support (pore size: 11 nm, Al2O3 91%, SiO2 9%) was mixed with 0.75 L of a mixed solution of nickel acetate, ammonium metatungstate, lanthanum nitrate, ammonium molybdate, 1,2-cyclohexanediaminetetraacetic acid, urea, ethanol, and phosphoric acid (containing 40 g NiO, 60 g MoO3, 5 g La2O3, 165 g WO3, 129 g total of 1,2-cyclohexanediaminetetraacetic acid, urea, and ethanol, and 10 g P2O5). The amounts of 1,2-cyclohexanediaminetetraacetic acid, citric acid, ethylene glycol, and acetone were 5.5% and 2.5% of the total mass of the mixed solution, respectively. After impregnation, the mixture was cured at 25 °C for 24 hours, dried at 110 °C for 6 hours, and calcined at 450 °C for 4 hours to prepare catalyst A4. The sulfurized A4 catalyst was tested using a G2F30 transmission electron microscope (TEM) from FEI Corporation, USA. (See attached image.) Figure 1 (b) As can be seen from the figure, the active phase of the sulfidation catalyst has a tower-shaped structure with 3-5 stacked layers; the stacking layer spacing is 0.2-2 nm; and the stacking length is 3-6 nm.

[0148] The A4 catalyst contains 40 g / L NiO, 60 g / L MoO3, 165 g / L WO3, 5 g / L La2O3, and 10 g / L P2O5.

[0149] The feed temperature of the hydrorefining feedstock is 250℃, and the temperature of the hydrorefining product stream is 325℃.

[0150] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0151] Example 5

[0152] Same as Example 1, except that B1 is replaced with B2. The preparation of B2 is as follows:

[0153] (1) HZSM-5 / HMOR composite molecular sieve was prepared by adjusting the synthesis conditions. The SiO2 / Al2O3 molar ratio of the composite molecular sieve was 25, and the weak acid content was 0.945 mmol·g. -1 0.21 mmol·g strong acid -1 Weak acid strength / strong acid strength ratio 4.5, pore size 6nm, specific surface area 309m² 2 ·g -1 The mass content of HZSM-5 in the composite molecular sieve is 0.85.

[0154] (2) Preparation of B2: The active component and auxiliary component were loaded in the same manner as in Example 1 to obtain catalyst B2 containing 108 g / L NiO, 8 g / L CeO2, and 6 g / L ZrO2. The TPR hydrogen atmosphere reduction temperature of catalyst B2 was measured to be 382℃.

[0155] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0156] Example 6

[0157] According to Example 1, the difference is that the temperature of the hydrorefined product is 78°C higher than the temperature of the hydrorefined feedstock (i.e., the temperature of the hydrorefined product is 313°C). The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0158] Example 7

[0159] According to Example 1, the difference is that the feed temperature of the hydrorefining feedstock is 280°C. The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0160] Example 8

[0161] According to Example 1, the difference is that the temperature of the hydrorefined product is 360°C and the feed temperature of the hydrorefined feedstock is 285°C. The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0162] Example 9

[0163] According to Example 1, the difference is that the hydrorefining catalyst was loaded in the following manner: catalysts A3, A1, and A2 were loaded sequentially from bottom to top in proportion. The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking). The catalyst stability was worse than in Example 1.

[0164] Example 10

[0165] According to Example 1, the difference is that the concentration of naphthalene in the hydrorefining feedstock is 60 wt%. The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0166] Example 11

[0167] Following Example 1, except that the purified product was not recycled and evaluated, the catalyst evaluation results are shown in Table 1 (hydropurification) and Table 2 (hydrocracking). The catalyst stability was worse than in Example 1.

[0168] Example 12

[0169] Same as Example 1, except that B1 is replaced with B3, and the hydrocracking catalyst B3 is prepared as follows:

[0170] The formed HZSM-5 molecular sieve (SiO2 / Al2O3 molar ratio 25, weak acid 0.43 mmol·g-1, strong acid 0.61 mmol·g-1, weak acid concentration / strong acid concentration 0.7, pore size 5 nm, specific surface area 324 m²) was used. 2 ·g -1 The TPR hydrogen atmosphere reduction temperature of catalyst B3 was measured to be 386℃.

[0171] The XRD pattern of HZSM-5 molecular sieve is shown below. Figure 4 The NH3-TPD data are shown in Table 3.

[0172] Catalyst B3 contains 108 g / L NiO, 8 g / L CeO2, and 6 g / L ZrO2.

[0173] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0174] Example 13

[0175] Same as Example 1, except that the refining catalyst is A1.

[0176] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking). The catalyst stability is worse than that of Example 1.

[0177] Example 14

[0178] Same as Example 1, except that the refining catalyst is A2.

[0179] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking). The catalyst stability is worse than that of Example 1.

[0180] Example 15

[0181] Same as Example 1, except that the refining catalyst is A4.

[0182] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking). The catalyst stability is worse than that of Example 1.

[0183] Example 16

[0184] Same as Example 1, except that B1 is replaced with B4, and the hydrocracking catalyst B4 is prepared as follows:

[0185] Take the formed HMOR molecular sieve (SiO2 / Al2O3 molar ratio 25, weak acid 0.416 mmol·g) -1 0.256 mmol·g strong acid -1 Weak acid strength / strong acid strength ratio is 1.63, pore size is 7 nm, and specific surface area is 424 m². 2 ·g -1 1 L of a mixture was added to a solution of nickel acetate, nickel nitrate, basic nickel carbonate, cerium nitrate, zirconium nitrate, and 1,2-cyclohexanediaminetetraacetic acid (containing 108 g NiO, 8 g CeO2, 6 g ZrO2, and 48 g 1,2-cyclohexanediaminetetraacetic acid), wherein the amount of 1,2-cyclohexanediaminetetraacetic acid was 7.5% of the mass of the mixed solution. The mixture was dried at 110 °C for 6 hours and calcined at 450 °C for 4 hours to prepare catalyst B4. The TPR reduction temperature of catalyst B4 under hydrogen atmosphere was measured to be 397 °C.

[0186] The XRD pattern of HMOR molecular sieve is shown below. Figure 5 The NH3-TPD data are shown in Table 3.

[0187] Catalyst B4 contains 108 g / L NiO, 8 g / L CeO2, and 6 g / L ZrO2.

[0188] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0189] Example 17

[0190] Same as Example 1, except that B1 is replaced with B5, and the hydrocracking catalyst B5 is prepared as follows:

[0191] Mordenite (SiO2 / Al2O3 molar ratio 25) and ZSM-5 (SiO2 / Al2O3 molar ratio 25) were mixed at a mass ratio of 1:1, ground uniformly to form a mechanical mixture, and then pressed into 20-mesh supports to load the active components, thus preparing hydrocracking catalyst B5. The TPR hydrogen atmosphere reduction temperature of catalyst B5 was measured to be 391℃.

[0192] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0193] Example 18

[0194] Same as Example 1, except that B1 is replaced with B6. Preparation of hydrocracking catalyst B6:

[0195] Take the formed HZSM-5 / HMOR composite molecular sieve (SiO2 / Al2O3 molar ratio 25, weak acid 0.64 mmol·g) -1 0.21 mmol·g strong acid -1 Weak acid strength / strong acid strength ratio 1.5, pore size 6nm, specific surface area 277m² 2 ·g -1 The composite molecular sieve, containing 0.98 g HZSM-5 by mass, was mixed with a mixed solution of nickel acetate, nickel nitrate, basic nickel carbonate, cerium nitrate, zirconium nitrate, and 1,2-cyclohexanediaminetetraacetic acid (containing 108 g NiO, 8 g CeO2, 6 g ZrO2, and 48 g 1,2-cyclohexanediaminetetraacetic acid), wherein the amount of 1,2-cyclohexanediaminetetraacetic acid was 7.5% of the mass of the mixed solution. The mixture was dried at 110 °C for 6 hours and calcined at 450 °C for 4 hours to prepare catalyst B6. The TPR hydrogen atmosphere reduction temperature of catalyst B6 was measured to be 382 °C.

[0196] Catalyst B2 contains 108 g / L NiO, 8 g / L CeO2, and 6 g / L ZrO2.

[0197] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0198] Example 19

[0199] Same as Example 1, except that A1 is replaced with A5, A2 is replaced with A6, and A3 is replaced with A7.

[0200] 1. Preparation of hydrorefining catalyst

[0201] Take 1L of support (pore size: 16nm, Al2O3 100%) and mix it with 0.75L of a mixed solution of nickel nitrate, ammonium molybdate, urea, citric acid, water and phosphoric acid (containing 83g NiO, 440g MoO3, 129g total amount of citric acid and urea, and 10g P2O5). After impregnation, dry at 110℃ for 6 hours and calcine at 480℃ for 4 hours to prepare catalyst A5.

[0202] One L of support (pore size: 11 nm, Al₂O₃ 95%, SiO₂ 5%) was mixed with 0.75 L of a mixed solution of nickel nitrate, ammonium molybdate, urea, citric acid, water, and phosphoric acid (containing 83 g NiO, 440 g MoO₃, 129 g total of citric acid and urea, and 10 g P₂O₅). After impregnation, the mixture was dried at 110 °C for 6 hours and calcined at 480 °C for 4 hours to prepare catalyst A6.

[0203] 1 L of a support (pore size: 9 nm, Al₂O₃ 95%, SiO₂ 5%) was mixed with 0.78 L of a mixed solution of cobalt nitrate, ammonium molybdate, urea, citric acid, water, and phosphoric acid (containing 83 g CoO, 440 g MoO₃, 129 g total of citric acid and urea, and 10 g P₂O₅). After impregnation, the mixture was dried at 110 °C for 6 hours and calcined at 480 °C for 4 hours to prepare catalyst A7.

[0204] 3. Hydrorefining catalyst loading

[0205] Catalysts with pore sizes of 9 nm (A7), 11 nm (A6), and 16 nm (A5) were sequentially loaded into the adiabatic bed reactor (hydrogenation refining reactor, hereinafter the same) from bottom to top in a volume ratio of 2:6:2.

[0206] 4. Hydrorefining catalyst sulfidation

[0207] After the airtightness is verified, sulfidation begins. The system pressure is 3.5 MPa, and the hydrogen volume hourly space velocity is 800 h⁻¹. -1 Hydrogen gas was introduced, and the temperature was increased from room temperature to 150°C at a rate of 30°C / h, with a volume hourly space velocity (VHSV) of 1 h⁻¹. -1 A vulcanizing agent containing 0.5 wt% sulfur is introduced, and the temperature is increased to 230℃ at 10℃ / h for 8 hours. After holding at this temperature for 4 hours, the temperature is increased to 280℃ at 20℃ / h for 2.5 hours. After holding at this temperature for 2 hours, the temperature is increased to 320℃ at 20℃ / h for 4 hours. After holding at this temperature for 2 hours, the catalytic vulcanization is complete.

[0208] After sulfidation, A5, A6, and A7 have a lamellar structure with an edge length of 10–30 nm, and the distribution of sulfides is extremely uneven, with agglomeration.

[0209] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0210] Example 20

[0211] Same as Example 1, except that: each layer of hydrorefining catalyst is A8;

[0212] Preparation of A8:

[0213] Solution A: Nickel nitrate (calculated as NiO) is 0.60 mol / L, and aluminum chloride (calculated as Al₂O₃) is 0.38 mol / L. Solution B: Sodium tungstate is 0.30 mol / L, and sodium molybdate is 0.75 mol / L. Solution C: Sodium aluminate is 0.10 mol / L (calculated as Al₂O₃). Divide Solution C into four equal portions. Heat Solution A to 70°C. Add Solution B and sodium hydroxide solution (pH = 13.8) to Solution A in parallel streams for co-precipitation. Control the reaction pH at 6.2–6.3, the reaction temperature at 70°C, and the reaction time at 60 min. The catalyst underwent aging treatment at 83℃. First, the pH was adjusted to 13.5 using sodium aluminate solution for 0.3 hours. Then, one part of solution C was added, and the pH was adjusted to 10.0 for 0.4 hours. Next, the pH was adjusted to 6.4 for 0.2 hours. This complete process of adding one part of solution C was repeated four times until all solution C was added. The amount of Al added during the aging process, calculated as Al2O3, accounted for 25.0% of the final catalyst Al2O3 composition, ultimately yielding slurry D. Slurry D was vacuum filtered to obtain a filter cake. The filter cake underwent a single conditioning process directly in a vacuum filter at 37℃ for 5.0 hours, resulting in a cake thickness of 22%. Deionized water at a mass ratio of 4:1 (to the catalyst preparation) was added to the top of the filter cake at 37℃. After 1 minute, vacuum filtration was performed until no filtrate dripped from the filter cake. The filter cake was further cured a second time at 65℃ for 1.2 hours, until the cake content was 28%. Deionized water (2:1 mass ratio to catalyst preparation) was added to the top layer of the filter cake at 65℃ for 2 minutes. Vacuum filtration was then performed until no filtrate dripped from the filter cake. Filter cake F was obtained after washing. Filter cake F was dried at 72℃ to a dry basis of 48%. It was then extruded, dried at 110℃ for 6 hours, and calcined at 510℃ for 4 hours to obtain the final catalyst A8. Its main properties are shown in Table 3.

[0214] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0215] Comparative Example 1

[0216] Same as Example 1, except that the temperature of the hydrorefined product is 96°C higher than the temperature of the hydrorefined feedstock, and the temperature of the hydrorefined product is 331°C.

[0217] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0218] Comparative Example 2

[0219] Same as Example 1, except that the inlet temperature of the hydrorefining feedstock is 200°C and the outlet temperature is 275°C.

[0220] The catalyst evaluation results are shown in Table 1 (hydrorefining) and Table 2 (hydrocracking).

[0221] Table 1

[0222]

[0223]

[0224] Table 2

[0225]

[0226]

[0227] Table 3

[0228]

[0229] The preferred 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 combinations of 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 hydrogenating naphthalene, characterized in that, The method includes the following steps: (1) The naphthalene-containing solution is optionally mixed with a portion of the purified hydrogenation product to obtain the hydrogenation raw material; (2) Under the conditions of hydrorefining catalyst, the hydrorefining feedstock is subjected to hydrorefining treatment to obtain the hydrorefined product; Optionally (3) the hydrorefined product is purified to obtain a purified hydrorefined product, and at least a portion of the purified hydrorefined product is subjected to hydrocracking. The temperature of the hydrorefined product is 20-80°C higher than the feed temperature of the hydrorefined feedstock, which is 210-290°C.

2. The method according to claim 1, wherein, The temperature of the hydrorefined product is 35-75°C higher than the temperature of the hydrorefined feedstock, preferably 45-75°C; more preferably, The temperature for hydrogenation refining the product is 290-350℃, preferably 300-335℃; and / or The feed temperature of the hydrorefining feedstock is 235-260℃.

3. The method according to claim 1 or 2, wherein, Along the material flow direction, the hydrorefining catalyst is sequentially packed in at least two layers, and the pore size of each layer of hydrorefining catalyst decreases sequentially, preferably with the pore size of adjacent packed catalysts decreasing by 2-5 nm.

4. The method according to any one of claims 1-3, wherein, The concentration of naphthalene in the naphthalene-containing solution is 10-70 wt%, preferably 12-55 wt%; and / or The naphthalene-containing solution also includes 0.01-1 wt% impurities, preferably including at least one of tetrahydronaphthalene, thiazoindene, and xylenol; and / or The naphthalene-containing solution is an industrial naphthalene solution; and / or The solvent in the naphthalene-containing solution is a benzene-based solvent, preferably selected from one or more of methyl ethylbenzene, propylbenzene, tetramethylbenzene, and diethylbenzene.

5. The method according to any one of claims 1-4, wherein, In the hydrogenation refining feedstock, the volume ratio of the purified hydrogenation refining product to the naphthalene-containing solution is 0-0.5, preferably 0.1-0.5; and / or The purified hydrogenated product contains sulfur at ≤1 ppm, preferably ≤0.85 ppm; and / or nitrogen at ≤1 ppm, preferably ≤0.8 ppm.

6. The method according to any one of claims 1-5, wherein, The conditions for the hydrorefining treatment include: a feed temperature of 210-290℃, preferably 235-260℃; and / or a pressure of 2.0-8.0 MPa, preferably 2.2-6.0 MPa; and / or a hydrogen-to-oil volume ratio of 400-3000, preferably 600-2000; and / or a volume hourly space velocity (VHSV) of the naphthalene-containing solution of 0.2-3 h⁻¹. -1 Preferably 0.6-1.2h -1 ; and / or The conditions for the hydrocracking treatment include: a feed temperature of 260-500℃, preferably 260-480℃; and / or a pressure of 2.0-8.0 MPa, preferably 3.0-6.5 MPa; and / or a hydrogen-to-oil volume ratio of 400-3000, preferably 600-2000; and / or a purified hydrorefined product volume hourly space velocity of 0.2-3 h⁻¹. -1 Preferably 0.6-1.2h -1 .

7. The method according to any one of claims 1-6, wherein, The method also includes: The unreacted hydrogen gas after hydrorefining is recycled back into the hydrorefining process; and / or The unreacted hydrogen after hydrocracking is recycled back into the hydrocracking process; and / or The heavy aromatics separated from the hydrocracking products in step (3) are recycled back into the hydrorefining feedstock.

8. The method according to any one of claims 1-7, wherein, The hydrocracking process is carried out in the presence of a hydrocracking catalyst, wherein the TPR hydrogen atmosphere reduction temperature of the hydrocracking catalyst is below 400°C, preferably 350-390°C. and / or The hydrocracking catalyst comprises an active component, an auxiliary component, and a molecular sieve support, wherein the active component contains a Group VIII metal element and optionally a lanthanide metal element, and the auxiliary component contains a Group IVB metal element; preferably, The dispersion of Group VIII metal elements in the hydrocracking catalyst is not less than 8%, preferably 8-15%; and / or The ratio of the weak acid content to the strong acid content of the molecular sieve support is 2-6, preferably 2.5-5; and / or The weak acid content of the molecular sieve support is 0.5-1.2 mmol·g. -1 Preferably, it is 0.6-1.1 mmol·g -1 ; and / or The molecular sieve support has a strong acid content of 0.08-0.5 mmol·g. -1 Preferably, it is 0.1-0.5 mmol·g -1 ; and / or The molecular sieve support has a particle size of 50-1000 nm, preferably 100-500 nm; and / or The molecular sieve support has a pore size of 3-10 nm, preferably 3-8 nm; and / or The specific surface area of ​​the molecular sieve support is 250-450 m². 2 ·g -1 Preferably 250-400m 2 ·g -1 ; and / or The SiO2 / Al2O3 molar ratio of the molecular sieve support is 10-200, preferably 15-60.

9. The method according to claim 8, wherein, The molecular sieve carrier comprises at least one of HZSM-5 molecular sieve, HMOR molecular sieve, and Beta molecular sieve, preferably an HZSM-5 / HMOR composite molecular sieve; more preferably, the mass content of HZSM-5 molecular sieve in the HZSM-5 / HMOR composite molecular sieve is 55%-95%, preferably 75%-92%; and / or The content of Group VIII metal elements in the hydrocracking catalyst, calculated as oxides, is 50-260 g / L, preferably 50-150 g / L, based on the total mass of the catalyst; and / or The content of lanthanide metal elements in the hydrocracking catalyst, calculated as oxides, is 0.1-100 g / L, preferably 0.1-50 g / L, based on the total mass of the catalyst; and / or The content of Group IVB metal elements in the hydrocracking catalyst, calculated as oxides, is 0.1-100 g / L, preferably 0.1-50 g / L, based on the total mass of the catalyst; and / or The Group VIII metallic element is selected from at least one of Fe, Co, Ni, Pt, and Pd, preferably Ni and / or Pt; and / or The lanthanide metal element is La and / or Ce; and / or The group IVB metal element is selected from Zr and / or Ti, preferably Zr.

10. The method according to any one of claims 1-9, wherein, The hydrorefining catalyst is a supported catalyst of the hydrorefining active component, which includes a support and a hydrorefining active component supported on the support in the form of a sulfide. Preferably, the sulfide is distributed in a tower-like shape on the catalyst surface; More preferably, The number of stacking layers of the tower type is 3-10, preferably 3-5; and / or the stacking length of the tower type is 3-12 nm, preferably 3-6 nm; and / or the stacking layer spacing of the tower type is 0.2-2 nm; and / or Based on the total mass of the hydrogenated active component supported catalyst before sulfidation, the total content of the hydrogenated active component in the hydrogenated active component supported catalyst, calculated as oxides, is not less than 30 g / L, preferably 50-700 g / L, and more preferably 60-650 g / L.

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