A highly selective hydrodesulfurization catalyst and its preparation method and application

Abstract

The present invention provides a highly selective hydrodesulfurization catalyst, which is composed of a complex formed by a metal central atom or central ion and an organic ligand through a coordination bond. The general formula of the highly selective hydrodesulfurization catalyst is: MoCoO3(RCOO) b , wherein RCOO represents the organic ligand, R represents a hydrocarbon group in the organic ligand, COO represents a coordinating group in the organic ligand, and b represents the molar ratio of the organic ligand to the metal molybdenum and cobalt. R is a C3-C19 hydrocarbon group, preferably a C5-C11 normal alkyl group, a C5-C11 isoalkyl group, a C5-C12 cycloalkyl group, a C6-C12 aryl group, or a combination thereof; and b is a positive number of 1-2. This catalyst and its composition, when used in the hydrogenation reaction of hydrocarbon-containing feedstocks, exhibit high oil-phase dispersibility, hydrogenation activity, and target product selectivity.

Description

Technical Field

[0001] The present invention relates to the field of petrochemical industry, and in particular to a high-selectivity hydrodesulfurization catalyst, a preparation method and application thereof. Background Art

[0002] With the continuous upgrading of petroleum products and increasingly stringent environmental regulations, sulfur, a key chemical element in petroleum, has become a major concern for refineries in oil processing. Furthermore, as major impurities in high-end carbon raw materials, sulfur and nitrogen significantly impact product quality during their production, making their removal essential for producing high-quality carbon materials. For example, needle coke raw materials must strictly adhere to a sulfur content of less than 0.5wt%.

[0003] Currently, the primary desulfurization process for sulfur-containing feedstocks is hydrodesulfurization using supported catalysts. These catalytic hydrogenation reactions are heterogeneous, requiring seven steps: diffusion of feedstock molecules onto the catalyst surface, diffusion into the catalyst pores, adsorption onto the catalyst active sites, surface-catalytic reaction between feedstock molecules and the catalyst active sites, desorption of reaction products from the catalyst active sites, diffusion of reaction products from the catalyst pores, and diffusion of reaction products from the catalyst surface into the liquid phase. The diffusion step significantly impacts the probability and efficiency of supported hydrogenation reactions. Furthermore, due to steric hindrance, some sulfur-containing compounds, such as dimethyldibenzothiophene, are difficult to contact with the active metal. Furthermore, this hydrodesulfurization process requires a complex process of first hydrogenating aromatic rings for saturation, followed by hydrodesulfurization. This results in low hydrodesulfurization activity and a loss of aromatic carbon content due to excessive aromatic saturation. Certain carbon material production processes also impose strict limits on the aromatic content of the feedstock. For example, needle coke production generally requires an aromatic content of 30%-50%.

[0004] Patent 202111162088.3 describes a method for producing needle coke feedstock from catalytic slurry. This method involves filtering and vacuum distilling the catalytic slurry and subjecting the product to a hydrogenation reaction. The hydrogenation catalyst employed is a supported catalyst, with molybdenum and nickel as active components and γ-Al2O3 as the carrier. After hydrodesulfurization, the catalyst enters an aromatization unit to ensure sufficient aromatics content. The catalyst uses alumina and ZSM 5 molecular sieves as carriers, with iron and zinc oxides as active components. Although the final product can meet the raw material requirements for needle coke production, the process is complex and the product yield is low.

[0005] Patent ZL201610970275.7 discloses a method and apparatus for preparing needle coke feedstock. Catalytic slurry and coker slurry are hydrotreated in a fixed-bed reactor. The catalyst's active components are at least two of nickel, tungsten, cobalt, and molybdenum, and the carrier is one of alumina and a molecular sieve. The resulting product has low sulfur and nitrogen contents and a high aromatics content, but a high coke yield. The yield of raw materials suitable for needle coke production in the final product is below 25%, and hydrogen consumption is high, resulting in high energy consumption.

[0006] Patent 201910914676.4 describes a slurry bed hydroprocessing method for removing sulfur and nitrogen from crude oil, retaining the desired components, and producing needle coke feedstock. The catalyst employed is an oil-insoluble metal sulfide selected from nickel, molybdenum, iron, cobalt, and tungsten, preferably molybdenum sulfide and iron sulfide. This method ultimately reduces the sulfur content to 0.45%, meeting the requirements for needle coke production. However, the use of oil-insoluble metal sulfides presents challenges with raw material mixing and low solid-liquid contact efficiency during the reaction. Summary of the Invention

[0007] The purpose of the present invention is to provide a highly selective hydrodesulfurization catalyst, a preparation method and application thereof, so as to solve the problems of low oil phase dispersibility, stability, hydrodesulfurization activity and target product selectivity of existing supported catalysts.

[0008] In order to achieve the above object, the first aspect of the present invention provides a highly selective hydrodesulfurization catalyst, wherein the highly selective hydrodesulfurization catalyst is composed of a complex formed by a metal central atom or central ion and an organic ligand through a coordination bond, and the general formula of the highly selective hydrodesulfurization catalyst is:

[0009] MoCoO3(RCOO) b ,

[0010] Wherein RCOO represents the organic ligand, R represents the hydrocarbon group in the organic ligand, COO represents the coordinating group in the organic ligand, and b represents the molar ratio of the organic ligand to the metal molybdenum and cobalt, wherein: R is a C3-C19 hydrocarbon group, preferably a C5-C11 normal alkyl group, a C5-C11 isomeric alkyl group, a C5-C12 cycloalkyl group, a C6-C12 aromatic group or a combination thereof; and b is a positive number of 1-2.

[0011] Optionally, the infrared spectrum of the highly selective hydrodesulfurization catalyst is in the range of 700-1000 cm -1 、1350-1450cm -1 and 1500-1610cm -1 There is a characteristic peak at the position; wherein the infrared spectrum of the highly selective hydrodesulfurization catalyst is at 1350-1450cm -1Position and at 1500-1610cm -1 The distance between the peaks of the characteristic peaks at the position is 145 cm -1 above.

[0012] Optionally, at least part of the highly selective hydrodesulfurization catalyst has the structure of formula (1) and formula (2):

[0013]

[0014] Optionally, the highly selective hydrodesulfurization catalyst is a solid catalyst.

[0015] A second aspect of the present invention provides a method for producing a highly selective hydrodesulfurization catalyst, comprising: mixing a metal molybdenum source and / or a metal cobalt source, an organic carboxylic acid, and an organic solvent for a complexing reaction to obtain a complexing reaction product; and removing the solvent from the complexing reaction product under reduced pressure to obtain a highly selective hydrodesulfurization catalyst. The reaction conditions of the complexing reaction include a reaction temperature of 120-160° C. and a reaction time of 1-8 hours; the M metal source includes a cobalt-containing compound and / or a molybdenum-containing compound; and the organic carboxylic acid is selected from organic carboxylic acids having C4-C20 carbon atoms.

[0016] Optionally, the metal molybdenum source is selected from one or more of molybdenum oxide, ammonium molybdate, phosphomolybdic acid, molybdic acid, molybdenum chloride and hexacarbonyl molybdenum; the metal cobalt source is selected from one or more of cobalt oxide, cobalt hydroxide, cobalt carbonate, cobalt nitrate, cobalt sulfate, cobalt sulfide, cobalt acetylacetonate, cobalt cyclohexane and cobalt oxalate and various cobalt-containing complexes; the organic carboxylic acid is selected from C4-C20 organic carboxylic acids, preferably one or more of C4-C20 normal or isomeric alkyl carboxylic acids, C6-C20 cycloalkane carboxylic acids containing saturated carbon rings and C7-C20 aromatic carboxylic acids containing aromatic rings; the organic solvent is selected from one or more of aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohol solvents, ether solvents, ester solvents and ketone solvents; preferably one or more of xylene, gasoline, diesel and slurry oil.

[0017] Optionally, the weight ratio of the total weight of the metal molybdenum source and the metal cobalt source to the organic carboxylic acid is 1:(0.1-5), preferably 1:(0.5-2); the weight ratio of the total weight of the metal molybdenum source, the metal cobalt source and the organic carboxylic acid to the organic solvent is 1:(1-100), preferably 1:(2-10).

[0018] A third aspect of the present invention provides a method for a hydrodesulfurization reaction, comprising: mixing a feed oil with the highly selective hydrodesulfurization catalyst described in the first aspect of the present disclosure to obtain a feed oil; allowing the feed oil to enter a slurry bed hydrogenation reactor and contact it with hydrogen for a hydrodesulfurization treatment to obtain a hydrogenated product; and then separating a vacuum distillate oil from the hydrogenated product.

[0019] Optionally, the feed oil includes an organic solvent; the content of the organic solvent is 1-90 weight % based on the weight of the feed oil; the organic solvent is selected from one or more of aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohol solvents, ether solvents, ester solvents and ketone solvents, preferably one or more of xylene, gasoline, diesel and slurry oil.

[0020] Optionally, the hydrodesulfurization treatment conditions include: based on the weight of the feed oil, the amount of the highly selective hydrodesulfurization catalyst or its combination (in metal terms) is 50-10000 μg / g, preferably 100-5000 μg / g; the temperature is 350-450°C, preferably 380-420°C; the initial hydrogen pressure is 2-25 MPa, preferably 3-15 MPa; the liquid hourly space velocity is 0.01-10 h -1 , preferably 0.2-2h -1 .

[0021] Through the above-mentioned technical solution, the highly selective hydrodesulfurization catalyst employed in the present invention can increase the desulfurization rate and selectivity of the target product in the product, thereby meeting the raw material requirements for producing high-quality needle coke. Furthermore, the use of the disclosed catalyst can improve the yield of distillate oil at 350-500°C, ensuring that the raw oil can be significantly utilized while maintaining low hydrogen consumption, thereby reducing the energy consumption of the device.

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 It is the infrared spectrum of the product obtained in Example 1 of the present invention.

[0025] Figure 2 It is the infrared spectrum of the product obtained in Example 2 of the present invention. DETAILED DESCRIPTION

[0026] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0027] The first aspect of the present invention provides a highly selective hydrodesulfurization catalyst, which is composed of a complex formed by a metal central atom or central ion and an organic ligand bonded by a coordination bond. The general formula of the highly selective hydrodesulfurization catalyst is:

[0028] MoCoO3(RCOO) b ,

[0029] Wherein RCOO represents the organic ligand, R represents the hydrocarbon group in the organic ligand, COO represents the coordinating group in the organic ligand, and b represents the molar ratio of the organic ligand to the metal molybdenum and cobalt, wherein: R is a C3-C19 hydrocarbon group, preferably a C5-C11 normal alkyl group, a C5-C11 isomeric alkyl group, a C5-C12 cycloalkyl group, a C6-C12 aromatic group, or a combination thereof; b is a positive number of 1-2, preferably 1.2-1.8.

[0030] Through the above-mentioned technical solution, the highly selective hydrodesulfurization catalyst employed in the present invention can increase the desulfurization rate and selectivity of the target product in the product, thereby meeting the raw material requirements for producing high-quality needle coke. Furthermore, the use of the disclosed catalyst can improve the yield of distillate oil at 350-500°C, ensuring that the raw oil can be significantly utilized while maintaining low hydrogen consumption, thereby reducing the energy consumption of the device.

[0031] The infrared spectrum of the highly selective hydrodesulfurization catalyst is between 700 and 1000 cm -1 、1350-1450cm -1 and 1500-1610cm -1 There is a characteristic peak at the position; wherein the infrared spectrum of the highly selective hydrodesulfurization catalyst is at 1350-1450cm -1 Position and at 1500-1610cm -1 The distance between the peaks of the characteristic peaks at the position is 145 cm -1 above.

[0032] In the present application, the term "C3-C19 hydrocarbon group" refers to a hydrocarbon group having 3 to 19 carbon atoms, which may be saturated or unsaturated, and may be a straight chain, branched chain or a hydrocarbon group having a carbon ring, including but not limited to C3-C19 normal alkyl groups, C3-C19 isomeric alkyl groups, C5-C19 cycloalkyl groups and C6-C19 aromatic groups.

[0033] In the present application, the term "C5-C11 normal alkyl" refers to a straight-chain alkyl group having 5 to 11 carbon atoms, such as n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, and n-undecyl.

[0034] In the present application, the term "C5-C11 isomeric alkyl" refers to a branched alkyl group having 5 to 11 carbon atoms, such as isopentyl, isohexyl, isoheptyl, isooctyl, isononyl, isodecyl, and isoundecyl.

[0035] In the present application, the term "C5-C12 cycloalkyl group" refers to a saturated hydrocarbon group containing a saturated carbocyclic ring having 5 to 12 carbon atoms, such as cyclopentyl, cyclohexyl, methylcyclohexyl, decahydronaphthyl, methyldecahydronaphthyl, ethyldecahydronaphthyl, and the like.

[0036] In the present application, the term "C6-C12 aryl group" refers to a group containing an aromatic ring having 6 to 12 carbon atoms, for example, phenyl, naphthyl, anthracenyl, p-tolyl, benzyl, methylnaphthyl and the like.

[0037] According to the present application, the C3-C19 hydrocarbon group, C5-C11 normal alkyl group, C5-C11 isomeric alkyl group, C5-C12 cycloalkyl group and C6-C12 aryl group may be optionally substituted, for example, may be unsubstituted, or may be substituted by one or more groups selected from halo, nitro, sulfonic acid, etc.

[0038] According to the present application, the highly selective hydrodesulfurization catalyst is composed solely of a complex and does not contain any solid support component. However, as needed, the highly selective hydrodesulfurization catalyst of the present application may also be present and used in the form of a composition formed with a liquid component capable of dispersing the catalyst, such as an organic solvent.

[0039] In a specific embodiment of the present disclosure, the highly selective hydrodesulfurization catalyst composition is composed of a highly selective hydrodesulfurization catalyst and an organic solvent; based on the weight of the highly selective hydrodesulfurization catalyst composition, the content of the highly selective hydrodesulfurization catalyst is 50-95%, preferably 80-95%; the total content of the organic solvent is 5-50%, preferably 5-20%.

[0040] The organic solvent is selected from aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohol solvents, ether solvents, ester solvents, ketone solvents or combinations thereof, preferably xylene, gasoline, diesel, slurry oil, or combinations thereof.

[0041] The infrared spectrum of the highly selective hydrodesulfurization catalyst composition is in the range of 700-1000 cm -1 、1350-1450cm -1 and 1500-1610cm -1 There are characteristic peaks at the position. Among them, at 700-1000cm -1 、1350-1450cm -1and 1500-1610cm -1 The characteristic peak at the position is the characteristic peak of the coordination compound, 1700-1750cm -1 The characteristic peak at the position is the characteristic peak of the organic ligand compound.

[0042] The highly selective hydrodesulfurization catalyst composition may further comprise other components for improving oil solubility, storage stability and antioxidant properties, such as organic substances with reducing functions such as formic acid, oxalic acid, formaldehyde, ethylenediamine, oleylamine, etc. The content of the other components may be 0-80%, preferably 0-50%, based on the weight of the composition.

[0043] In certain preferred embodiments, at least part of the highly selective hydrodesulfurization catalyst has the structure of formula (1) and formula (2):

[0044]

[0045] The highly selective hydrodesulfurization catalyst described in the present application is a solid catalyst. Compared with liquid catalysts or semi-solid colloidal catalysts, solid catalysts are more convenient to store and transport and are less likely to be deactivated by oxidation.

[0046] A second aspect of the present disclosure provides a method for producing a highly selective hydrodesulfurization catalyst, the method comprising: mixing a metal molybdenum source and / or a metal cobalt source, an organic carboxylic acid, and an organic solvent for a complexing reaction to obtain a complexing reaction product; removing the solvent from the complexing reaction product to obtain a highly selective hydrodesulfurization catalyst; reaction conditions for the complexing reaction include: a reaction temperature of 120-160° C., preferably 130-150° C.; a reaction time of 1-8 hours, preferably 2-6 hours; and the organic carboxylic acid is selected from C4-C20 organic carboxylic acids.

[0047] The metal molybdenum source is selected from one or more of molybdenum oxide, ammonium molybdate, phosphomolybdic acid, molybdic acid, molybdenum chloride and hexacarbonyl molybdenum; the metal cobalt source is selected from one or more of cobalt oxide, cobalt hydroxide, cobalt carbonate, cobalt nitrate, cobalt sulfate, cobalt sulfide, cobalt acetylacetonate, cobalt naphthenate and cobalt oxalate and various cobalt-containing complexes.

[0048] The organic carboxylic acid is selected from C4-C20 organic carboxylic acids, preferably one or more of C4-C20 normal or isomeric alkyl carboxylic acids, C6-C20 cycloalkane carboxylic acids containing saturated carbon rings, and C7-C20 aromatic carboxylic acids containing aromatic rings, more preferably one or more of C6-C12 normal or isomeric alkyl carboxylic acids, C6-C13 cycloalkane carboxylic acids containing saturated carbon rings, and C7-C13 aromatic carboxylic acids containing aromatic rings, further preferably one or more of succinic acid, hexanoic acid, adipic acid, heptanoic acid, octanoic acid, nonanoic acid, ethylhexanoic acid, oleic acid, petroleum acid, salicylic acid, benzoic acid, and phenylacetic acid.

[0049] The organic solvent is selected from one or more of aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohol solvents, ether solvents, ester solvents and ketone solvents; preferably one or more of xylene, gasoline, diesel and slurry oil.

[0050] Wherein, the weight ratio of the total weight of the metal molybdenum source and the metal cobalt source to the organic carboxylic acid is 1:(0.1-5), preferably 1:(0.5-2); the weight ratio of the total weight of the metal molybdenum source, the metal cobalt source and the organic carboxylic acid to the organic solvent is 1:(1-100), preferably 1:(2-10). The reaction steps for preparing a highly selective hydrodesulfurization catalyst disclosed in the present invention do not have strict requirements on the reaction pressure and reaction atmosphere. For example, the reaction pressure can be normal pressure, and the reaction atmosphere can be air, nitrogen or an inert atmosphere. According to the present application, the reaction can be carried out in the absence of water or in the presence of water (for example, 0-10 times the weight of water relative to the weight of the organic ligand compound). The method for removing the solvent disclosed in the present invention is a conventional choice in the art. The present application does not meet special requirements. For example, the solvent can be removed by vacuum distillation.

[0051] In one embodiment, a method for preparing a highly selective hydrodesulfurization catalyst comprises:

[0052] A source of metallic molybdenum and cobalt, an organic carboxylic acid, and an organic solvent are added to a reactor. The reaction liquid is heated while being stirred with a magnetic stirrer until the organic solvent is refluxed (120-160°C). The generated water is separated using a water separator, and the complex reaction is carried out for 1-8 hours to obtain a complex reaction product. The weight ratio of the metallic molybdenum and cobalt sources to the organic carboxylic acid is 1:(0.1-5), preferably 1:(0.5-2); and the weight ratio of the total weight of the metallic molybdenum and cobalt sources and the organic carboxylic acid to the organic solvent is 1:(1-100), preferably 1:(2-10). After the reaction is completed, the mixture is filtered and separated while hot. The solvent in the filtrate is then evaporated using a rotary evaporator at a speed of 50-160 rpm and a temperature of 80-150°C. The evaporated product is poured into an evaporating dish and dried in a vacuum drying oven for 2 hours to obtain the highly selective hydrodesulfurization catalyst.

[0053] A third aspect of the present disclosure provides a method for a hydrodesulfurization reaction, comprising: mixing a feed oil and the highly selective hydrodesulfurization catalyst described in the first aspect of the present disclosure to obtain a feed oil; allowing the feed oil to enter a slurry bed hydrogenation reactor and contact it with hydrogen for a hydrodesulfurization treatment to obtain a hydrogenated product; and then separating a vacuum distillate oil from the hydrogenated product.

[0054] The feedstock oil may be various sulfur-containing compounds, such as sulfides, mercaptans, disulfides, thiophene, benzothiophene, dibenzothiophene, and the like, and the oil products may include crude oil, gasoline, diesel, wax oil, and residual oil. Preferably, the feedstock oil is at least one of heavy distillate oil, catalytic cracking slurry oil, catalytic cracking clarified oil, unhydrogenated vacuum distillate oil, thermal cracking residual oil, coker oil slurry, coal tar, and steam cracking residual oil; and the aromatics content of the feedstock oil is greater than 20% by weight. Among them, the catalytic cracking slurry is the heavy fraction in the catalytic cracking product, the initial boiling point of its distillation range can be any value between 150-230°C, for example, 162°C, and the final boiling point can be any value between 620-700°C, for example, 645°C. Its main component can be unhydrogenated vacuum distillate oil, the initial boiling point of the unhydrogenated vacuum distillate oil is any temperature between 290-310°C, for example, 300°C, and the final boiling point is any temperature between 490-510°C, for example, 500°C, for example, unhydrogenated distillate oil between 350-500°C. Other fractions may also be involved depending on the differences in raw materials and processing conditions.

[0055] The feed oil includes an organic solvent; the content of the organic solvent is 1-90% by weight based on the weight of the feed oil; the organic solvent is selected from one or more of aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohol solvents, ether solvents, ester solvents and ketone solvents, preferably one or more of xylene, gasoline, diesel and slurry oil.

[0056] The hydrodesulfurization treatment conditions include: based on the weight of the feed oil, the amount of the highly selective hydrodesulfurization catalyst or its combination (in metal terms) is 50-20,000 μg / g, preferably 100-10,000 μg / g; the temperature is 350-450°C, preferably 380-420°C; the initial hydrogen pressure is 2-25 MPa, preferably 3-15 MPa; the liquid hourly space velocity is 0.01-10 h -1 , preferably 0.2-2h -1 .

[0057] Optionally, the method further comprises: performing a first separation on the hydrogenation product to obtain a first separated product and a second separated product; the first separated product comprises naphtha, hydrogen, and light oil and gas; and the second separated product comprises heavy oil slurry and the oil-soluble hydrogenation catalyst. The first separation can be performed using a thermal high separation device. The first separated product can be the overhead effluent of the thermal high separation device. The second separated product can be the bottom effluent of the thermal high separation device.

[0058] Optionally, the method further comprises: returning the circulating tail oil and mixing it with the feed oil and the oil-soluble hydrogenation catalyst for reuse. The circulating tail oil contains residual catalyst and feed oil and can be used for further hydrogenation.

[0059] The present invention is further illustrated below by way of examples, but the present invention is not limited thereto.

[0060] In the following examples, unless otherwise specified, the raw materials used are commercially available products.

[0061] Example 1

[0062] Example 1 Preparation of Highly Selective Hydrodesulfurization Catalyst C1 is MoCoO3 (C7H 15 COO) 1.8 .

[0063] Weigh 38.8g (0.27mol) of isooctanoic acid and add it directly to a 500ml three-necked flask. Then, add 13.95g (0.15mol) of cobalt hydroxide and 300ml of xylene solvent to the flask. Weigh 26.0g (0.15mol) of tetrahydrate and ammonium molybdate and add them to the flask. Heat the reaction mixture while stirring with a magnetic stirrer until the xylene refluxes. Use a water separator to separate the generated water and react for 8 hours. The reaction product is a yellow-brown solution. After the reaction is completed, filter and separate the solution while hot. Then, use a rotary evaporator to evaporate the solvent. The speed is 120 rpm and the temperature is 80°C. Finally, pour the evaporated product into an evaporating dish and place it in a vacuum drying oven. Dry at 80°C for 2 hours. The product is a dark brown solid. Elemental analysis results are shown in Table 1.

[0064] Example 2

[0065] Example 2 Preparation of Highly Selective Hydrodesulfurization Catalyst C2 is MoCoO3 (C6H 13 COO) 1.5 .

[0066] Weigh 25.87g (0.23mol) of n-hexanoic acid and add it directly to a 500ml three-necked flask. Then, add 13.95g (0.15mol) of cobalt hydroxide and 300ml of xylene solvent to the flask. Weigh 26.0g (0.15mol) of tetrahydrate and ammonium molybdate and add them to the flask. Heat the reaction mixture while stirring with a magnetic stirrer until the xylene refluxes. Use a water separator to separate the generated water. Allow to react for 5 hours. The reaction product is a yellow-brown solution. After the reaction is complete, filter and separate the solution while hot. Then, use a rotary evaporator to remove the solvent. The speed is 120 rpm and the temperature is 80°C. Finally, pour the evaporated product into an evaporating dish and place it in a vacuum drying oven. Dry at 80°C for 2 hours. The product is a dark brown solid. Elemental analysis results are shown in Table 1.

[0067] Example 3

[0068] The highly selective hydrodesulfurization catalyst C1 prepared in Example 1 was used as a catalyst, along with 1 g of dibenzothiophene and 9 g of decalin, in a 100 ml fully back-mixed autoclave to obtain a feed oil. The mixture was then exposed to hydrogen for hydrodesulfurization to produce a hydrogenated product. The experimental conditions included an initial hydrogen pressure of 7 MPa, a reaction temperature of 360°C, and a reaction time of 60 min. The concentration of the highly selective hydrodesulfurization catalyst (calculated as metal) was 2500 μg / g, based on the weight of the feed oil. The hydrodesulfurization results and properties of the hydrogenated product are shown in Table 2.

[0069] Example 4

[0070] 200 g of slurry oil A, containing 1.07% sulfur and 47.6% tri- and tetra-ring aromatics, was used as the feedstock. This feedstock was mixed with a highly selective hydrodesulfurization catalyst C1 in a 2-liter batch autoclave. The feedstock was then hydrodesulfurized by contact with hydrogen under hydrogenation reaction conditions. The resulting hydrogenated product was distilled and cut to yield a VGO fraction with a distillation range of 350-500°C. Operating pressures were set at 10 mmHg at 350°C and 0.3 mmHg at 500°C. The resulting VGO fraction was analyzed for sulfur content and hydrocarbon composition. The experimental results and hydrodesulfurization conditions are shown in Table 3.

[0071] Example 5

[0072] The hydrodesulfurization treatment method is the same as that of Example 4, except that the highly selective hydrodesulfurization catalyst is a combination of 50 wt% C1 and 50 wt% isooctanoic acid, and the hydrodesulfurization treatment temperature is 420°C. The experimental results and hydrodesulfurization treatment conditions are shown in Table 3.

[0073] Example 6

[0074] The hydrodesulfurization treatment method is the same as that of Example 4, except that the highly selective hydrodesulfurization catalyst is C2 and the reaction time is 150 min. The experimental results and hydrodesulfurization treatment conditions are shown in Table 3.

[0075] Comparative Example 1

[0076] Weigh 34.8g (0.3mol) of n-hexanoic acid and add it directly to a 500ml three-necked flask, then add 13.95g (0.15mol) of cobalt hydroxide, and use 300ml of toluene as the solvent in the flask. Weigh 26.0g (0.15mol) of tetrahydrate and ammonium molybdate and add them to the flask. Heat and stir the reaction liquid with a magnetic stirrer at the same time, heat until the toluene refluxes, and use a water separator to separate the generated water. React for 5h, and the reaction product is a blue liquid. After the reaction is completed, filter and separate while hot. Use a rotary evaporator to evaporate the solvent. The speed is 120 rpm and the temperature is 80°C. Finally, pour the rotary evaporated product into an evaporating dish and place it in a vacuum drying oven. Dry at 80°C for 2h. The product is a blue solid. The elemental analysis results are shown in Table 1. From the results, it can be seen that no bimetallic organometallic compound is formed in Comparative Example 1.

[0077] Comparative Example 2

[0078] The method for carrying out the hydrodesulfurization reaction of dibenzothiophene is the same as that of Example 3, except that oil-soluble single metal Mo is used as the catalyst; the results of the hydrodesulfurization treatment and the product properties of the hydrogenation product are shown in Table 2.

[0079] Comparative Example 3

[0080] The method for carrying out the hydrodesulfurization reaction of dibenzothiophene is the same as that of Example 3, except that a fixed-bed Mo-Co / Al2O3 supported catalyst is used as the catalyst; the results of the hydrodesulfurization treatment and the product properties of the hydrogenated product are shown in Table 2.

[0081] Comparative Example 4

[0082] The hydrodesulfurization treatment method is the same as that of Example 4, except that the slurry A is directly subjected to vacuum distillation, and the obtained VGO fraction is analyzed; the experimental results and hydrodesulfurization treatment conditions are shown in Table 3.

[0083] Test Case

[0084] Test Example 1

[0085] The metal content of the highly selective hydrodesulfurization catalysts of Example 1, Example 2 and Comparative Example 1 was determined using a SPECTROARCOS SOP plasma optical emission spectrometer and inductively coupled plasma optical emission spectrometry (ICP-OES). The measurement conditions were a closed optical chamber filled with argon, vertical observation, and a wavelength range of 130-770 nm.

[0086] The elemental composition of the highly selective hydrodesulfurization catalysts of Example 1, Example 2, and Comparative Example 1 was determined as follows: the C and H contents were determined using the SH0656 method on an Italian Cara Erba EA1110 elemental analyzer; the S content was determined using energy dispersive X-ray fluorescence spectrometry (GB17040) using an Oxford Lab-X3500 desktop XRF analyzer; and the O content was determined using the O-content method.

[0087] Table 1 Elemental analysis of highly selective hydrodesulfurization catalyst C1

[0088]

[0089]

[0090] Test Example 2

[0091] The infrared spectra of the highly selective hydrodesulfurization catalysts of Examples 1 and 2 were measured using a NICOLET IS50 spectrometer from Thermo Fisher Scientific. The measurement conditions were a scanning wavelength from 400 to 4000 cm -1 The number of scans is 16. ZnSe crystal and HgCdTe infrared detector are used together to measure the attenuated total reflectance (ATR) of the sample with a resolution of 4cm -1 .

[0092] Figure 1The highly selective hydrodesulfurization catalyst C1 prepared in Example 1 is MoCoO3 (C7H 15 COO) 1.8 Schematic diagram of infrared spectrum analysis. The analysis results are as follows: at 2800~3000cm -1 The stretching vibration absorption peak of CH is located at 1680 cm -1 and 1400cm -1 The symmetrical and asymmetrical stretching vibration peaks of -COO are located at 980cm -1 Mo=O stretching vibration peak, located at 780cm -1 The peak of Mo-O-Ni stretching vibration can be confirmed by infrared spectrum.

[0093] Figure 2 The highly selective hydrodesulfurization catalyst C2 prepared in Example 2 is MoCoO3 (C6H 13 COO) 1.5 Schematic diagram of infrared spectrum analysis. The analysis results are as follows: at 2800~3000cm -1 The stretching vibration absorption peak of CH is located at 1680 cm -1 and 1400cm -1 The symmetrical and asymmetrical stretching vibration peaks of -COO are located at 980cm -1 Mo=O stretching vibration peak, located at 780cm -1 The peak of Mo-O-Ni stretching vibration can be confirmed by infrared spectrum.

[0094] Test Example 3

[0095] The hydrocarbon compositions of the hydrogenated products obtained in Examples 3-6 and Comparative Examples 2-4 were analyzed using an Agilent 7890B-5977A gas chromatograph-mass spectrometer (GC-MS) equipped with a flame ionization detector (FID) and a capillary column (40 m × 0.25 mm × 0 μm). The GC conditions were: inlet temperature of 350°C, injection volume of 1 μL, split ratio of 30:1, helium carrier gas at a flow rate of 1.5 mL / min; the oven temperature program was 50°C for 2 min, then increased to 350°C at a rate of 40°C / min and held for 10 min; the transfer line temperature was 300°C. The mass spectrometry conditions were: bombardment voltage of 70 eV, ion source temperature of 250°C, quadrupole temperature of 150°C, scan range of 50-700°C, and solvent delay of 2 min.

[0096] Table 2 Reaction results of Example 3 and Comparative Examples 2 and 3

[0097]

[0098] Table 3 Results of Examples 4-6 and Comparative Example 4

[0099]

[0100] It can be seen from the data in the table that, by comparing the data in Examples 1-2 and Comparative Example 1, when the temperature of the preparation method of the highly selective hydrodesulfurization catalyst is 120-160°C, a bimetallic organometallic compound can be formed. By comparing the data in Example 3 and Comparative Examples 2-3, it can be seen that the highly selective hydrodesulfurization catalyst disclosed herein has a high dibenzothiophene conversion rate, and at the same time, the biphenyl yield in the product is high, and it has a high selective hydrodesulfurization activity. By comparing the data in Examples 4-6 and Comparative Example 4, it can be seen that the hydrogen desulfurization catalyst of the present application and its composition have a high desulfurization rate, and the content of three-ring and four-ring aromatics in the product is greatly increased, which can meet the raw material requirements for the production of high-quality needle coke. At the same time, its distillate oil yield at 350-500°C is relatively high, which can ensure that the raw material utilization rate of the raw oil can be greatly improved at a lower hydrogen consumption, and the energy consumption of the device will also be lower.

[0101] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0102] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0103] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A highly selective hydrodesulfurization catalyst, wherein: The highly selective hydrodesulfurization catalyst is composed of a complex formed by a metal central atom or central ion and an organic ligand through coordination bonds. The general formula of the highly selective hydrodesulfurization catalyst is: MoCoO3(RCOO) b , Wherein RCOO represents the organic ligand, R represents the hydrocarbon group in the organic ligand, COO represents the coordinating group in the organic ligand, and b represents the molar ratio of the organic ligand to the metal molybdenum and cobalt, wherein: R is a C3-C19 hydrocarbon group; b is a positive number between 1 and 2; The infrared spectrum of the highly selective hydrodesulfurization catalyst is in the range of 700-1000 cm -1 、1350-1450cm -1 and 1500-1610cm -1 There is a characteristic peak at the position; wherein the infrared spectrum of the highly selective hydrodesulfurization catalyst is at 1350-1450cm -1 Position and at 1500-1610cm -1 The distance between the peaks of the characteristic peaks at the position is 145 cm -1 above; At least part of the highly selective hydrodesulfurization catalyst has the structure of formula (1) and formula (2): Formula (1) Formula (2).

2. The highly selective hydrodesulfurization catalyst according to claim 1, wherein The C3-C19 hydrocarbon group is a C5-C11 normal alkyl group, a C5-C11 isomeric alkyl group, a C5-C12 cycloalkyl group, a C6-C12 aryl group or a combination thereof.

3. The highly selective hydrodesulfurization catalyst according to claim 1, wherein The highly selective hydrodesulfurization catalyst is a solid catalyst.

4. A method for preparing the highly selective hydrodesulfurization catalyst according to any one of claims 1 to 3, wherein: The method includes: A metal molybdenum source and a metal cobalt source, an organic carboxylic acid, and an organic solvent are mixed to carry out a complexing reaction to obtain a complexing reaction product; and a highly selective hydrodesulfurization catalyst is obtained after removing the solvent from the complexing reaction product. The reaction conditions of the coordination reaction include: reaction temperature of 120-160°C, reaction time of 1-8h; The organic carboxylic acid is selected from C4-C20 organic carboxylic acids.

5. The method according to claim 4, wherein The metal molybdenum source is selected from one or more of molybdenum oxide, ammonium molybdate, phosphomolybdic acid, molybdic acid, molybdenum chloride and molybdenum hexacarbonyl; The metallic cobalt source is selected from one or more of cobalt oxide, cobalt hydroxide, cobalt carbonate, cobalt nitrate, cobalt sulfate, cobalt sulfide, cobalt acetylacetonate, cobalt naphthenate, cobalt oxalate, and various cobalt-containing complexes; The organic carboxylic acid is selected from C4-C20 organic carboxylic acids; The organic solvent is selected from one or more of aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohol solvents, ether solvents, ester solvents and ketone solvents.

6. The method according to claim 4, wherein: The organic carboxylic acid is one or more of a C4-C20 normal or isomeric alkyl carboxylic acid, a C6-C20 cycloalkane carboxylic acid containing a saturated carbon ring, and a C7-C20 aromatic carboxylic acid containing an aromatic ring; The organic solvent is one or more of xylene, gasoline, diesel and slurry oil.

7. The method according to claim 4, wherein: The weight ratio of the total weight of the metal molybdenum source and the metal cobalt source to the organic carboxylic acid is 1: (0.1-5); The weight ratio of the total weight of the metal molybdenum source, the metal cobalt source and the organic carboxylic acid to the organic solvent is 1:(1-100).

8. The method according to claim 4, wherein The weight ratio of the total weight of the metal molybdenum source and the metal cobalt source to the organic carboxylic acid is 1:(0.5-2); The weight ratio of the total weight of the metal molybdenum source, the metal cobalt source and the organic carboxylic acid to the organic solvent is 1:(2-10).

9. A method for hydrodesulfurization reaction, wherein: The method includes: The raw oil and the highly selective hydrodesulfurization catalyst according to any one of claims 1 to 3 are mixed to obtain feed oil, and the feed oil is brought into a slurry bed hydrogenation reactor to contact with hydrogen for hydrodesulfurization treatment to obtain a hydrogenated product; and then a vacuum distillate oil is separated from the hydrogenated product.

10. The method according to claim 9, wherein: The feed oil includes an organic solvent; Based on the weight of the feed oil, the content of the organic solvent is 1-90% by weight; The organic solvent is selected from one or more of aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohol solvents, ether solvents, ester solvents and ketone solvents.

11. The method according to claim 10, wherein: The organic solvent is one or more of xylene, gasoline, diesel and slurry oil.

12. The method according to claim 9, wherein The conditions of the hydrodesulfurization treatment include: based on the weight of the feed oil, the amount of the highly selective hydrodesulfurization catalyst is 50-10000 μg / g, the temperature is 350-450°C, the initial hydrogen pressure is 2-25 MPa, and the liquid hourly space velocity is 0.01-10 h -1 .

13. The method according to claim 12, wherein: The hydrodesulfurization treatment conditions include: based on the weight of the feed oil, the amount of the highly selective hydrodesulfurization catalyst is 100-5000 μg / g, the temperature is 380-420°C, the initial hydrogen pressure is 3-15 MPa, and the liquid hourly space velocity is 0.2-2h -1 .

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