Coal tar hydrogenation catalyst as well as preparation method and application thereof

Abstract

The invention discloses a coal tar hydrogenation catalyst as well as a preparation method and application thereof. The catalyst comprises a carrier and an active metal component, wherein the carrier is a gallium modified silicon-aluminum carrier; in the gallium modified silicon-aluminum carrier, based on the mass of the gallium modified silicon-aluminum carrier, the mass content of gallium oxide is 2.0%-5.0%, the mass content of silicon dioxide is 20.0%-60.0%, and the mass content of aluminum oxide is 35.0%-78.0%; the active metal component comprises Mo and a group VIII metal element; the Mo comprises + 5 valence Mo; the group VIII metal element exists in the catalyst in the form of metal phosphide. The catalyst has high hydrogenation activity, appropriate cracking activity and good stability, and effectively improves the quality and yield of coal tar hydrogenation product oil.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of coal tar hydrogenation catalyst preparation, and particularly relates to a coal tar hydrogenation catalyst and a preparation method and application thereof. BACKGROUND

[0002] Coal tar is a liquid produced in the pyrolysis process of coal. According to different dry distillation temperatures and processes, it can be divided into low-temperature coal tar (450-650℃), medium-temperature coal tar (650-900℃) and high-temperature coal tar (900-1000℃). At present, the extraction capacity of high-value-added products from coal tar is limited, and most of them are still used as crude fuel for direct use, which not only has poor economic efficiency, but also seriously pollutes the environment. Producing clean fuel oil from coal tar through hydrogenation process has good economic, social and environmental benefits.

[0003] Compared with petroleum heavy distillates, coal tar feedstock contains oxygen, a large amount of unsaturated hydrocarbons such as olefins and polycyclic aromatic hydrocarbons, and sulfur and nitrogen compounds. It has the characteristics of high acidity, high gum content, and poor product stability (light stability, storage stability, oxidation stability), etc. Therefore, it is of great significance to develop a coal tar hydrogenation catalyst with strong water resistance, good hydrogenation and impurity removal performance, and good cracking performance.

[0004] CN108686702A discloses a boiling bed coal tar hydroprocessing-hydrocracking composite catalyst and a preparation method thereof. The catalyst is prepared from MoO3, WO3, NiO, alumina, silica molecular sieve and additives according to mass percentage. In the preparation process, the acidified silica-containing raw material is reacted with alkaline gas to form microsphere gel, and the catalyst carrier is obtained after drying and calcination. Then, the active metal components are loaded on the carrier to obtain the catalyst. In this preparation method, the molecular sieve is directly mixed with the raw material, and the metals and alkaline nitrogen in the coal tar are deposited on the molecular sieve, which causes the catalyst to be quickly deactivated, and cannot achieve the purpose of both hydroprocessing and hydrocracking. Moreover, the preparation process of the catalyst is relatively complex.

[0005] CN101885984A discloses a combined process for producing clean fuel oil from coal tar hydrogenation and a catalyst thereof. The active components of the hydro-upgrading catalyst in this patent are one or more of the group VIII and group VIB metal oxides NiO, MoO3, CoO and WO3, and the carrier is acid-modified kaolin. Since acid-modified kaolin is used as the carrier, its pore volume is small and its acidity is high. Therefore, for coal tar feedstock with high gum and asphaltene content, the gum and asphaltene cannot enter the pores of the catalyst, and a large amount of coke is formed on the surface of the catalyst, which causes the catalyst to be easily deactivated and the operation cycle to be short. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides a coal tar hydrogenation catalyst, a preparation method and application thereof. The coal tar hydrogenation catalyst has high hydrogenation activity, appropriate cracking activity and good stability, and effectively improves the quality and yield of the coal tar hydrogenation product oil.

[0007] The present application provides a coal tar hydrogenation catalyst in the first aspect. The catalyst comprises a carrier and an active metal component.

[0008] According to the present application, the carrier is a gallium-modified silicon-aluminum carrier. In the gallium-modified silicon-aluminum carrier, the mass content of gallium oxide is 2.0% to 5.0%, the mass content of silicon dioxide is 20.0% to 60.0%, and the mass content of aluminum oxide is 35.0% to 78.0%, based on the mass of the gallium-modified silicon-aluminum carrier.

[0009] According to the present application, the mass content of the carrier is 74% to 83%, the content of the Group VIII metal in the form of oxide is 2% to 6%, and the content of molybdenum in the form of oxide is 15% to 20%, based on the mass of the catalyst.

[0010] According to the present application, the catalyst has the following properties: the specific surface area is 150 to 200 m 2 / g, the pore volume is 0.5 to 0.8 mL / g, the mechanical strength is 110 to 190 N / cm, the total acid amount is 0.2 to 0.5 mmol / g, and the ratio of the B acid amount to the L acid amount is 0.35 to 0.65.

[0011] According to the present application, the catalyst has the following pore size distribution: the ratio of the pore volume of the pores with a pore diameter <10 nm to the total pore volume is 5% to 10%, the ratio of the pore volume of the pores with a pore diameter of 10 to 50 nm to the total pore volume is 65% to 80%, and the ratio of the pore volume of the pores with a pore diameter >50 nm to the total pore volume is 10% to 30%.

[0012] According to the present application, the active metal component comprises Mo and Group VIII metal elements; the Mo comprises +5 valence Mo; and the Group VIII metal elements exist in the catalyst in the form of metal phosphides.

[0013] According to the present application, in the catalyst, the Mo further comprises +4 valence Mo and +6 valence Mo.

[0014] According to the present application, in the catalyst, the +5 valence Mo accounts for more than 50% of the total Mo in atoms, preferably 55% to 80%. As a non-limiting example, the +5 valence Mo accounts for any one of 65%, 68%, 70%, 72%, 75%, and 78% of the total Mo in atoms.

[0015] According to the present application, in the catalyst, the sum of +4 valence Mo and +6 valence Mo accounts for 20% to 45% of total Mo in atom. Further preferably, in the catalyst, +4 valence Mo accounts for 10% to 43% of total Mo in atom; +6 valence Mo accounts for 2% to 10% of total Mo in atom. As non-limiting examples, +4 valence Mo accounts for any one of 15%, 20%, 22%, 25%, 32%, 35%, 38%, 40% of total Mo in atom; +6 valence Mo accounts for any one of 4%, 6%, 8%, 9% of total Mo in atom.

[0016] According to the present application, in the catalyst, +5 valence Mo is preferably molybdenum pentachloride; +4 valence Mo is preferably molybdenum disulfide; +6 valence Mo is preferably molybdenum oxide.

[0017] According to the present application, the Group VIII metal element is selected from one or more of Fe, Co, Ni, preferably at least one of Co, Ni, more preferably Ni.

[0018] The second aspect of the present application provides a preparation method of the above catalyst, comprising:

[0019] (1) mixing a molybdenum source, a sulfur source and water to obtain a first impregnation solution, and impregnating the first impregnation solution on a carrier to obtain a catalyst intermediate I after drying;

[0020] (2) contacting and reacting the catalyst intermediate I of step (1) with chlorine to obtain a catalyst intermediate II;

[0021] (3) impregnating a second impregnation solution containing a nickel source and a phosphorus source on the catalyst intermediate II of step (2), and performing maintenance, drying and calcination to obtain the catalyst.

[0022] According to the present application, in step (1), the preparation method of the carrier comprises:

[0023] (11) mixing an acidic aluminum salt aqueous solution, a silicon source and an organic acid to obtain material AI;

[0024] (12) performing a precipitation reaction of material AI with a gallium-containing solution and an alkaline aluminum salt aqueous solution in parallel flow to obtain material AII;

[0025] (13) performing hydrothermal treatment of material AII with a non-ionic surfactant to obtain a gallium-modified silicon-aluminum material;

[0026] (14) mixing and kneading the gallium-modified silicon-aluminum material obtained in step (13), a cementing agent, a extrusion aid and water into a shape, drying and calcining to obtain a catalyst carrier.

[0027] According to the application, in the preparation method of the carrier, the acidic aluminum salt in step (11) is at least one of aluminum sulfate, aluminum chloride or aluminum nitrate, and the concentration of the acidic aluminum salt solution is 20-100 g / 100 mL of Al2O3; the silicon source is one or more of water-soluble silicate, water glass or silica sol, and the concentration of the silicon source is 30-70 g / 100 mL of SiO2, and the weight ratio of the silicon source (calculated as SiO2) to the acidic aluminum source (calculated as Al2O3) is 1:1-7:1.

[0028] According to the application, in the preparation method of the carrier, the organic acid in step (11) is one or more of maleic acid, fumaric acid, adipic acid, tartaric acid, citric acid, oxalic acid, acetic acid, salicylic acid or malic acid. The mass concentration of the organic acid is 7%-16%. The amount of the added organic acid is such that the pH value of the material AI is 2-4, preferably 3-4.

[0029] According to the application, in the preparation method of the carrier, the gallium-containing solution in step (12) is a gallium nitrate solution, and the concentration of the gallium-containing solution is 0.5-2.5 mol / L. The basic aluminum salt is at least one of sodium aluminate or potassium aluminate. The concentration of the basic aluminum salt solution is 20-100 g / 100 mL of Al2O3. The ratio of the flow rates of the gallium-containing solution, the material AI and the basic aluminum salt solution is 1:3-7:1-3. The reaction temperature in step (12) is 60-90°C, the reaction time is 60-180 minutes, and the pH value is 8.0-9.7. The reaction is preferably carried out under stirring, and the stirring rate is 100-500 rad / min, preferably 150-450 rad / min.

[0030] According to the application, in the preparation method of the carrier, the non-ionic surfactant in step (13) is selected from one or more of polyethylene glycol, alkyl alcohol amide or polyether. The alkyl alcohol amide is one or more of lauryl diethanolamine or coconut oil fatty acid diethanolamide. The polyether is one or more of AEO-6 or AEO-9. The molecular weight of the polyethylene glycol is 200-1000, preferably 200-700. The amount of the added non-ionic surfactant is 0.1%-5% of the mass of the material AII obtained in step (12) in terms of aluminum oxide, preferably 0.5%-3%. The concentration of the non-ionic surfactant is 30-70 g / 100 mL.

[0031] According to the application, in the preparation method of the carrier, the sealing hydrothermal treatment in step (13) is carried out at a temperature of 80-130°C for 3-18 hours, wherein the temperature rising rate is 8-15°C / min. Preferably, the hydrothermal treatment is carried out in two stages, the first stage is carried out at a temperature of 80-110°C for 1-9 hours, and the second stage is carried out at a temperature of 100-130°C for 1-9 hours, wherein the temperature of the second stage is at least 15°C higher than that of the first stage, preferably at least 20°C higher. After the reaction, washing and drying can be carried out. The drying is carried out at a temperature of 100-170°C for 1-7 hours.

[0032] According to the application, in the preparation method of the carrier, the preparation process of the catalyst carrier in step (14) is that the extrusion aid, the peptizing agent and the like are added to the gallium-modified silicon-aluminum material to form a plastic body, and then the plastic body is formed by a conventional forming method, such as extrusion, tabletting and the like, preferably extrusion. The addition amount of the extrusion aid is 1.0wt%-4.0wt% of the gallium-modified silicon-aluminum material; the addition amount of the peptizing agent is 1.0wt%-5.0wt% of the gallium-modified silicon-aluminum material; and the addition amount of water is 80.0wt%-100.0wt% of the gallium-modified silicon-aluminum material. The extrusion aid is pearl millet powder, and the peptizing agent is nitric acid.

[0033] According to the application, in the preparation method of the carrier, the drying temperature in step (14) is 120-160°C, the drying time is 2-6 hours, the calcination temperature is 550-800°C, and the calcination time is 4-6 hours.

[0034] According to the application, in the preparation method of the catalyst, the molybdenum source in step (1) is selected from at least one of ammonium dimolybdate, ammonium tetramolybdate dihydrate, and ammonium heptamolybdate tetrahydrate; the sulfur source is selected from at least one of thiocarbamide, ammonium sulfide, thioacetamide, and sodium thiosulfate; and the mass ratio of the molybdenum source to the sulfur source is 3-5:2-4. In the first impregnation solution, the mass content of the molybdenum source is 25wt%-45wt%.

[0035] According to the application, in the preparation method of the catalyst, the impregnation in step (1) can be carried out by spraying, and the impregnation can be carried out by saturation or supersaturation. The drying is carried out at a temperature of 100-140°C for 4-8 hours.

[0036] According to the application, in the preparation method of the catalyst, in step (2), the purity of the chlorine gas is 96% or more by volume fraction. The flow rate of the chlorine gas is 2.7-6.8mL / (min·g of the catalyst intermediate I); and / or, the reaction is carried out at a temperature of 300-400°C for 40-90min.

[0037] According to the present application, in the preparation method of the catalyst, the nickel source in step (3) is a soluble salt, such as at least one of nitrate, monohydrogen phosphate, dihydrogen phosphate; and the phosphorus source is at least one of ammonium phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate and phytic acid. In the second impregnation solution, the molar ratio of the nickel source (calculated as metal element) to the phosphorus source (calculated as phosphorus element) is 0.3-3:1. In the second impregnation solution, the mass content of the nickel source is 40wt%-68wt%.

[0038] According to the present application, in the preparation method of the catalyst, the impregnation in step (3) can be carried out by spraying impregnation, and the impregnation can be carried out by saturated impregnation or supersaturated impregnation.

[0039] According to the present application, in the preparation method of the catalyst, the aging in step (3) is to place the impregnated sample in a closed condition at 10-30℃ for 6-12h, and the pressure during the aging is not particularly limited and can be autogenous pressure; and / or, the drying condition is to dry at 100-160℃ for 1-8h. The calcination condition is to calcine at 480-550℃ for 4-8h. The drying atmosphere is an oxygen-containing atmosphere. The calcination atmosphere is selected from any one of nitrogen atmosphere, inert gas atmosphere, hydrogen / nitrogen atmosphere and hydrogen / inert gas atmosphere, wherein the hydrogen volume fraction in the hydrogen / nitrogen atmosphere and the hydrogen / inert gas atmosphere is 5%-50%.

[0040] The third aspect of the present application provides the use of the above-mentioned catalyst or the catalyst prepared by the above-mentioned preparation method in the hydroprocessing of coal tar.

[0041] According to the present application, the application condition is that the reaction temperature is 300-420℃, the reaction pressure is 5-20MPa, the liquid hourly space velocity is 0.1-1.5h -1 , and the hydrogen / oil volume ratio is 100:1-1200:1. The reaction pressure is the total pressure.

[0042] According to the present application, the catalyst needs to be sulfided before use. The sulfidation process is to contact the catalyst with a sulfidation solution and hydrogen for sulfidation. The sulfidation solution comprises a solvent and a sulfur-containing solute, and the mass content of the sulfur-containing solute in the sulfidation solution is 4.0%-15.0%. The sulfur-containing solute has a solubility of more than 10wt% in the solvent at room temperature, and can react with hydrogen to produce H2S at high temperature. The sulfur-containing solute is preferably at least one of carbon disulfide (CS2), dimethyl sulfide (DMS), dimethyl disulfide (DMDS) and SZ-54. The solvent is hydrodesirable diesel oil with a nitrogen content of not more than 100μg / g. The purity of the hydrogen is not less than 90v%.

[0043] According to the application, the conditions of the sulfidation adopt conventional sulfidation conditions. Preferably, the sulfidation conditions are as follows: the sulfidation process comprises low-temperature sulfidation and high-temperature sulfidation. The low-temperature sulfidation stage: temperature rising to 150-260 DEG C, constant temperature for 6-10 hours; the high-temperature sulfidation stage: temperature rising to 260-390 DEG C, constant temperature for 5-8 hours. Among them, the temperature rising rate of the temperature rising to the low-temperature sulfidation stage is 8-12.0 DEG C / h, the temperature rising rate of the temperature rising to the high-temperature sulfidation stage is 5-12.0 DEG C / h, the flow rate of the sulfidation liquid is 15-30 mL / (h.g catalyst), the hydrogen pressure is 13.0-18.0 MPa, and the hydrogen flow rate is 80-130 mL / (min.g catalyst).

[0044] Compared with the prior art, the application has the following advantages:

[0045] 1. In the catalyst of the application, the carrier is a gallium-modified silicon-aluminum carrier; in the gallium-modified silicon-aluminum carrier, the mass content of gallium oxide is 2.0%-5.0%, the mass content of silicon dioxide is 20.0%-60.0%, and the mass content of aluminum oxide is 35.0%-78.0%, based on the mass of the gallium-modified silicon-aluminum carrier; the active metal component comprises Mo and a group VIII metal element; the Mo comprises +5 valence Mo; and the group VIII metal element exists in the catalyst in the form of a metal phosphide.

[0046] In the catalyst of the application, the +5 valence Mo is more easily sulfidized to +4 valence MoS2 in the sulfidation process, which accelerates the rate of Mo forming MoS2, and leads to the more easy formation of Ni-Mo-S(II) and Brim active sites with MoS2 as the skeleton and the metal nickel on the outer surface in the catalyst. In the catalyst of the application, an appropriate amount of transition metal phosphide is also formed, which is a compound formed by the insertion of phosphorus atoms into the metal crystal lattice and has the characteristics of noble metals. Because the phosphorus atom is larger, the octahedral coordination structure is more easily formed around the phosphorus atom after the bonding of phosphorus and transition metal, so that the phosphorus atom is located at the center position, and thus it is different from the layered structure of sulfide, and the phosphide structure is closer to spherical, which exposes more active center sites in the catalytic reaction, so that the macromolecular reactants are more easily close to the active sites on the surface of the catalyst. The catalyst effectively improves the quality and yield of the coal tar hydrogenation product oil.

[0047] 2、The catalyst is prepared by the following steps: first, impregnating the carrier with an impregnation solution containing a molybdenum source and a sulfur source to obtain an intermediate I, then, contacting the intermediate I with chlorine to obtain an intermediate II, and finally, impregnating the intermediate II with a nickel-phosphorus impregnation solution to obtain the catalyst; further, the carrier is prepared by a specific method, i.e., the carrier is prepared by modifying the carrier with an organic acid and Ga. The method is beneficial to the coal tar hydrogenation catalyst having suitable pore structure, acid amount and acid distribution. Through the comprehensive coordination of the steps, the catalyst carrier and the active metal jointly act to further improve the water resistance and hydrogenation performance of the catalyst, and the catalyst is suitable for the coal tar hydrogenation process.

[0048] 3、The addition of the organic acid in the preparation method of the Ga-modified silicon-aluminum carrier provided by the application increases the absolute value of the Zeta potential of the system, and increases the electrostatic repulsion between particles, which is beneficial to the slurry dispersibility and fluidity, and the acidified silica gel particles are adsorbed on the aluminum hydroxide colloid to provide crystal nuclei for the subsequent reaction, promote the increase of the grain size of the carrier precursor, and are beneficial to the formation of the carrier precursor with large pore volume and large pore size and coated with organic chains. The hydrogen bond formed between the non-ionic surfactant and the hydroxyl group of the aluminum hydroxide hydrosol can avoid the mutual adhesion and aggregation of the particles, so that the gel particles are arranged in an ordered crystal or colloidal particles with a crystal structure, and the free silicon species can ion exchange with the non-ionic surfactant to form a complex, and finally form a mesoporous material with a stable structure. Ga replaces part of the skeleton Al, and since Ga can enter the Si-O-Al skeleton structure like Al, the acidity can be adjusted while avoiding the adverse effect of the reduction of the skeleton Al on the crystallinity, and a silicon-aluminum material with controllable acidity is obtained, and the weak acid sites formed by the skeleton Ga and the gallium existing outside the skeleton can synergistically act with the strong B acid sites formed by Si-O-Al, and the catalyst is suitable for the coal tar hydrogenation, especially the ebullated bed coal tar hydrogenation process.

[0049] 4、The catalyst is applied to the coal tar hydrogenation process, has high hydrogenation activity, suitable cracking activity and good stability, and effectively improves the quality and yield of the coal tar hydrogenation product oil. DETAILED DESCRIPTION

[0050] The technical solutions and effects of the application are further illustrated by the following examples, but the following examples do not limit the method of the application.

[0051] In the application, the % is the mass fraction unless otherwise specified.

[0052] In the application, the specific surface area, pore volume and pore distribution are measured by an ASAP2420 full-automatic physical adsorption instrument of Micromeritics Instrument Corporation, USA.

[0053] In the present application, the operating conditions of XPS are: light source: Mg K Alpha, energy step: 0.05eV, scanning range: 220-240eV (molybdenum), 850-880eV (nickel), 280-300eV (carbon). When analyzing the valence state of molybdenum, the binding energy at 232-233eV is +6 valence molybdenum species, the binding energy at 230-232eV is +5 valence molybdenum species, and the binding energy at 228-230eV is +4 valence molybdenum species. By the peak area of the three peaks, the respective proportions of +6 valence, +5 valence and +4 valence molybdenum in total Mo can be calculated respectively.

[0054] In the present application, the catalyst composition is tested by spectrophotometry. The testing instrument is Lambda 365 ultraviolet spectrophotometer.

[0055] In the present application, the determination of total acid, L acid and B acid is carried out by infrared spectroscopy, and the instrument is Nicot Fourier infrared spectrometer-6700 of the United States.

[0056] In the present application, HDS is hydrogen desulfurization, HDO is hydrogen deoxidation, HDCCR is hydrogen de-residual carbon, and HDM is hydrogen de-metal.

[0057] Example 1

[0058] (1) Preparation of the carrier:

[0059] (11) An aluminum sulfate solution with a concentration of 50g / 100mL calculated by Al2O3 and a silica sol solution with a concentration of 60g / 100mL calculated by SiO2 are prepared. The weight ratio of the silica source (calculated by SiO2) to the acidic aluminum source (calculated by Al2O3) is 2.4:1. A mass concentration of 8% of citric acid is added, and the pH of the solution is adjusted to 3 to obtain the material AI.

[0060] (12) 2.0L of pure water is loaded into the reaction kettle, and heated to 60℃, the stirring rate is 200rad / min, the flow rates of the material AI and 60g / 100mL sodium metaaluminate solution and 2mol / L gallium nitrate solution are controlled to be 50mL / min, 20mL / min and 10ml / min respectively, and continuously added to the reaction kettle. The pH of the reaction is controlled to be 8 during the reaction, the reaction time is 180min, and the reaction temperature is 60℃.

[0061] (13) After the precipitation reaction is completed, the temperature is adjusted to 95℃, and the stirring speed is adjusted to 300 rad / min. A solution of 55 g / 100 mL polyethylene glycol (molecular weight 600) is added to the reactor at a rate of 2.4 wt% of the mass of the material AII based on the mass of the alumina. After sealing, the temperature is increased to 100℃ at a rate of 15℃ / min, and then held at 100℃ for 3 hours. The temperature is then increased to 120℃ at a rate of 10℃ / min, and then held at 120℃ for 6 hours. The slurry after the reaction is washed with hot water at 90℃ until neutral, and then dried at 120℃ for 3 hours to obtain a gallium-modified silicon-aluminum material.

[0062] (14) 448 g of the gallium-modified silicon-aluminum material is weighed, mixed with 12 g of sesbania powder, 9 g of nitric acid, and 378 g of water, and then kneaded and formed. After drying at 140℃ for 3 hours and calcination at 650℃ for 4 hours, a catalyst support A-1 is obtained.

[0063] Preparation of the catalyst:

[0064] 58.3 g of ammonium heptamolybdate tetrahydrate, 44.9 g of ammonium sulfide, and water are mixed to obtain a first impregnation solution. In the first impregnation solution, the mass content of the molybdenum source is 29 wt%. The first impregnation solution is impregnated on the support A-1. The impregnation is saturated impregnation. After drying at 100℃ for 6 h in an air atmosphere, a catalyst intermediate I is obtained.

[0065] (2) The catalyst intermediate I is contacted with chlorine gas to obtain a catalyst intermediate II. The purity of the chlorine gas is 98 vol% as a volume fraction. The flow rate of the chlorine gas is 3.4 mL / (min·g of the catalyst intermediate I). The reaction conditions are as follows: the reaction temperature is 400℃, and the reaction time is 90 min.

[0066] (3) A second impregnation solution of a nickel source and a phosphorus source (37.5 g of nickel nitrate hexahydrate and 8.5 g of diammonium hydrogen phosphate are dissolved in water, and in the second impregnation solution, the mass content of the nickel source is 54 wt%) is impregnated on the catalyst intermediate II of step (2). The impregnation is saturated impregnation. After standing for 10 h at 25℃, drying at 110℃ for 6 h in an air atmosphere, and calcination at 510℃ for 6 h in a nitrogen atmosphere, the catalyst C1 is prepared.

[0067] The catalyst composition, catalyst properties, and pore distribution of the catalyst are shown in Table 1. The Group VIII metal element exists in the catalyst in the form of a metal phosphide. The Mo includes +5 valence Mo, +6 valence Mo, and +4 valence Mo. That is, the Mo exists in the form of molybdenum pentachloride, molybdenum disulfide, and molybdenum oxide. The +5 valence Mo accounts for 79.0% of the total Mo in terms of atoms, the +4 valence Mo accounts for 12.1% of the total Mo in terms of atoms, and the +6 valence Mo accounts for 8.9% of the total Mo in terms of atoms.

[0068] Example 2

[0069] (1) Preparation of the carrier:

[0070] (11) An aluminum sulfate solution with a concentration of 30 g / 100 mL calculated as Al2O3and a silica sol solution with a concentration of 60 g / 100 mL calculated as SiO2were prepared. The weight ratio of the silica source (calculated as SiO2) to the acidic aluminum source (calculated as Al2O3) was 4:1. A mass concentration of 10% citric acid was added, and the pH of the solution was adjusted to 4 to obtain material AI.

[0071] (12) The reactor was charged with 2.0 L of pure water, and heated to 80°C at a stirring rate of 250 rad / min. The flow rates of material AI and 80 g / 100 mL of sodium metaaluminate solution and 2.5 mol / L of gallium nitrate solution were controlled at 60 mL / min, 11 mL / min and 10 mL / min, respectively, and continuously added to the reactor. The pH of the reaction was controlled at 8.5 during the reaction, the reaction time was 90 min, and the reaction temperature was 80°C.

[0072] (13) After the completion of the precipitation reaction, the temperature was adjusted to 85°C, and the stirring rate was adjusted to 350 rad / min. According to the nonionic surfactant addition amount of 2.4 wt% of the mass of material AII calculated as aluminum oxide, a lauryl diethanolamine solution with a concentration of 60 g / 100 mL was passed into the reactor for hydrothermal treatment. After sealing, the temperature was increased to 90°C at a rate of 10°C / min, and then held at 90°C for 4 hours, and then increased to 130°C at a rate of 15°C / min and held at 130°C for 4 hours. The slurry after the reaction was washed with hot water at 90°C until it was neutral, and the drying conditions were 130°C for 4 hours to obtain a gallium-modified silica-aluminum material.

[0073] (14) 435 g of the gallium-modified silica-aluminum material was weighed, mixed with 12 g of sesbania powder, 11.2 g of nitric acid and 375 g of water, and then kneaded and shaped. After drying at 120°C for 4 hours and calcining at 620°C for 6 hours, a catalyst carrier B-1 was obtained.

[0074] Preparation of the catalyst:

[0075] A first impregnation solution was prepared by mixing 54.8 g of ammonium heptamolybdate tetrahydrate, 34.3 g of thiourea and water. In the first impregnation solution, the mass content of the molybdenum source was 36 wt%. The first impregnation solution was impregnated on the carrier B-1. The impregnation was saturated impregnation. After drying at 120°C for 4 h in an air atmosphere, a catalyst intermediate I was obtained.

[0076] (2) The catalyst intermediate I was contacted with chlorine gas to obtain catalyst intermediate II. The purity of the chlorine gas was 97% by volume. The flow rate of the chlorine gas was 4.8 mL / (min-g catalyst intermediate I). The reaction conditions were as follows: the reaction temperature was 400°C, and the reaction time was 65 min.

[0077] (3) The catalyst intermediate II of step (2) was impregnated with a second impregnation solution of a nickel source and a phosphorus source (34.6 g of nickel nitrate hexahydrate and 9.5 g of sodium phosphate dibasic were dissolved in water, wherein the mass content of the nickel source in the second impregnation solution was 49 wt%). The impregnation was a saturation impregnation. After being placed at 23°C for 12 h for aging, dried at 120°C in an air atmosphere for 5 h, and calcined at 495°C in a nitrogen atmosphere for 6 h, the catalyst C2 was prepared.

[0078] The catalyst composition, catalyst properties, and pore distribution of the catalyst are shown in Table 1. The Group VIII metal element exists in the catalyst in the form of a metal phosphide. The Mo includes +5 valence Mo, +6 valence Mo, and +4 valence Mo. That is, the Mo exists in the form of molybdenum pentachloride, molybdenum disulfide, and molybdenum oxide. The +5 valence Mo accounts for 77.3% of the total Mo by atoms, the +4 valence Mo accounts for 16.5% of the total Mo by atoms, and the +6 valence Mo accounts for 6.2% of the total Mo by atoms.

[0079] Example 3

[0080] (1) Preparation of the carrier:

[0081] (11) An aluminum sulfate solution with a concentration of 80 g / 100 mL calculated as Al2O3and a silica sol solution with a concentration of 40 g / 100 mL calculated as SiO2were prepared. The weight ratio of the silicon source (calculated as SiO2) to the acidic aluminum source (calculated as Al2O3) was 1:1. A mass concentration of 15% citric acid was added, and the pH of the solution was adjusted to 3 to obtain the material AI.

[0082] (12) The reaction kettle was charged with 2.0 L of pure water and heated to 80°C at a stirring rate of 200 rad / min. The flow rates of the material AI and 75 g / 100 mL of a sodium metaaluminate solution and 2 mol / L of a gallium nitrate solution were controlled to be 30 mL / min, 15 mL / min, and 10 mL / min, respectively, and were continuously added to the reaction kettle. The pH of the reaction was controlled to be 9 during the reaction, the reaction time was 120 min, and the reaction temperature was 80°C.

[0083] (13) After the precipitation reaction is completed, the temperature is adjusted to 95℃, and the stirring speed is adjusted to 400 rad / min. A solution of 45 g / 100 mL AEO-9 is added to the reactor at a rate of 2.6 wt% of the mass of the material AII based on the mass of the alumina. After sealing, the temperature is increased to 100℃ at a rate of 15℃ / min, and then held at 100℃ for 8 hours. The temperature is then increased to 130℃ at a rate of 10℃ / min, and then held at 130℃ for 8 hours. The slurry after the reaction is washed with hot water at 90℃ until neutral, and then dried at 120℃ for 4 hours to obtain a gallium-modified silicon-aluminum material.

[0084] (14) 446 g of the gallium-modified silicon-aluminum material is mixed with 15 g of sesbania powder, 9 g of nitric acid, and 363 g of water, and then kneaded and formed. After drying at 120℃ for 5 hours and calcining at 750℃ for 5 hours, a catalyst carrier C-1 is obtained.

[0085] Preparation of the catalyst:

[0086] A first impregnation solution is prepared by mixing 56.9 g of ammonium heptamolybdate tetrahydrate, 48.8 g of sodium thiosulfate, and water. In the first impregnation solution, the mass content of the molybdenum source is 41 wt%. The first impregnation solution is impregnated on the carrier C-1. The impregnation is saturated impregnation. After drying at 130℃ for 5 h in an air atmosphere, a catalyst intermediate I is obtained.

[0087] (2) The catalyst intermediate I is contacted with chlorine gas to obtain a catalyst intermediate II. The purity of the chlorine gas is 98 vol%. The flow rate of the chlorine gas is 5.3 mL / (min·g of the catalyst intermediate I). The reaction conditions are as follows: the reaction temperature is 350℃, and the reaction time is 60 min.

[0088] (3) A second impregnation solution of a nickel source and a phosphorus source (43.8 g of nickel nitrate hexahydrate and 7.9 g of diammonium hydrogen phosphate are dissolved in water, and in the second impregnation solution, the mass content of the nickel source is 63 wt%) is impregnated on the catalyst intermediate II of step (2). The impregnation is saturated impregnation. After standing for 12 h at 23℃, drying at 120℃ for 6 h in an air atmosphere, and calcining at 500℃ for 7 h in a nitrogen atmosphere, the catalyst C3 is prepared.

[0089] The catalyst composition, catalyst properties, and pore distribution of the catalyst are shown in Table 1. The Group VIII metal element exists in the catalyst in the form of a metal phosphide. The Mo includes +5 valence Mo, +6 valence Mo, and +4 valence Mo. That is, the Mo exists in the form of molybdenum pentachloride, molybdenum disulfide, and molybdenum oxide. The +5 valence Mo accounts for 77.8% of the total Mo in terms of atoms, the +4 valence Mo accounts for 16.1% of the total Mo in terms of atoms, and the +6 valence Mo accounts for 6.1% of the total Mo in terms of atoms.

[0090] Example 4

[0091] (1) Preparation of the carrier:

[0092] (11) An aluminum sulfate solution with a concentration of 65 g / 100 mL calculated as Al2O3and a silica sol solution with a concentration of 70 g / 100 mL calculated as SiO2were prepared. The weight ratio of the silica source (calculated as SiO2) to the acidic aluminum source (calculated as Al2O3) was 2:1. A mass concentration of 15% citric acid was added, and the pH of the solution was adjusted to 3 to obtain material AI.

[0093] (12) The reactor was charged with 2.0 L of pure water, and heated to 70°C at a stirring rate of 300 rad / min. The flow rates of material AI and 90 g / 100 mL sodium metaaluminate solution and 1.0 mol / L gallium nitrate solution were controlled at 60 mL / min, 25 mL / min and 10 ml / min, respectively, and continuously added to the reactor. The pH of the reaction was controlled at 9 during the reaction, the reaction time was 150 min, and the reaction temperature was 70°C.

[0094] (13) After the completion of the precipitation reaction, the temperature was adjusted to 95°C, and the stirring rate was adjusted to 350 rad / min. A non-ionic surfactant was added in an amount of 2.5 wt% of the mass of material AII calculated as aluminum oxide, and a 60 g / 100 mL polyethylene glycol (molecular weight 400) solution was introduced into the reactor for hydrothermal treatment. After sealing, the temperature was increased to 100°C at a rate of 12°C / min, and then held at 100°C for 4 hours, and then increased to 130°C at a rate of 15°C / min and held at 130°C for 8 hours. The slurry after the reaction was washed with hot water at 90°C until neutral, and dried at 140°C for 5 hours to obtain a gallium-modified silica-aluminum material.

[0095] (14) 435 g of the gallium-modified silica-aluminum material was weighed, mixed with 12 g of sesbania powder, 11 g of nitric acid and 375 g of water, and then kneaded and shaped. After drying at 130°C for 5 hours and calcining at 750°C for 8 hours, a catalyst carrier D-1 was obtained.

[0096] Preparation of the catalyst:

[0097] A first impregnation solution was prepared by mixing 60.5 g of ammonium heptamolybdate tetrahydrate, 45.4 g of thiourea and water. In the first impregnation solution, the mass content of the molybdenum source was 40 wt%. The first impregnation solution was impregnated on the carrier D-1. The impregnation was saturated impregnation. After drying at 130°C for 5 h in an air atmosphere, a catalyst intermediate I was obtained.

[0098] (2) The catalyst intermediate I was contacted with chlorine gas to obtain catalyst intermediate II. The purity of the chlorine gas was 99% by volume. The flow rate of the chlorine gas was 3.9 mL / (min.g catalyst intermediate I). The reaction conditions were as follows: the reaction temperature was 300°C, and the reaction time was 80 min.

[0099] (3) The catalyst intermediate II prepared in step (2) was impregnated with a second impregnation solution of a nickel source and a phosphorus source (47.2 g of nickel nitrate hexahydrate and 14.3 g of diammonium hydrogen phosphate were dissolved in water, and the mass content of the nickel source in the second impregnation solution was 67% by weight). The impregnation was saturated impregnation. After being placed at 23°C for 12 h for aging, dried at 120°C in an air atmosphere for 6 h, and calcined at 500°C in a nitrogen atmosphere for 7 h, the catalyst C4 was prepared.

[0100] The catalyst composition, catalyst properties, and pore distribution of the catalyst are shown in Table 1. The Group VIII metal element exists in the catalyst in the form of a metal phosphide. The Mo includes +5 valence Mo, +6 valence Mo, and +4 valence Mo. That is, the Mo exists in the form of molybdenum pentachloride, molybdenum disulfide, and molybdenum oxide. The +5 valence Mo accounts for 79.0% of the total Mo by atoms, the +4 valence Mo accounts for 15.3% of the total Mo by atoms, and the +6 valence Mo accounts for 5.7% of the total Mo by atoms.

[0101] Comparative Example 1

[0102] Compared with Example 1, the difference lies in that no organic acid is added to adjust the pH value in step (11) of the carrier preparation method; the other steps are the same as those in Example 1.

[0103] The comparative hydrogenation catalyst DCA-1 was prepared. The catalyst composition, catalyst properties, and pore distribution of the catalyst are shown in Table 1.

[0104] Comparative Example 2

[0105] Compared with Example 1, the difference lies in that no non-ionic surfactant is added in step (13), and only the material AII is subjected to hydrothermal treatment; the other steps are the same as those in Example 1.

[0106] The comparative hydrogenation catalyst DCA-2 was prepared. The catalyst composition, catalyst properties, and pore distribution of the catalyst are shown in Table 1.

[0107] Comparative Example 3

[0108] Compared with Example 1, the difference lies in that no gallium nitrate solution is added in step (12) of the carrier preparation method. The other steps are the same as those in Example 1.

[0109] The comparative hydrogenation catalyst DCA-3 was prepared. The catalyst composition, catalyst properties, and pore distribution of the catalyst are shown in Table 1.

[0110] Comparative Example 4

[0111] The active metals of the catalyst in this example include molybdenum oxide and nickel phosphide.

[0112] Comparative Example 4

[0113] Comparative hydrogenation catalyst DCA-4 was prepared. The catalyst composition, catalyst properties and pore distribution of the catalyst are shown in Table 1. The Mo is +6 valence Mo and +4 valence Mo, and does not contain +5 valence Mo. That is, the Mo exists in the form of molybdenum disulfide and molybdenum oxide. The +4 valence Mo accounts for 14.4% of the total Mo in terms of atoms, and the +6 valence Mo accounts for 85.6% of the total Mo in terms of atoms.

[0114] Comparative Example 5

[0115] The active metals of the catalyst in this example include molybdenum oxide and nickel oxide. Compared with Example 1, the air is used instead of chlorine in step (2) of Example 1, that is, the catalyst intermediate I is reacted with air. No phosphorus source is added in the second impregnation solution in step (3). The other steps are the same as those in Example 1.

[0116] Comparative hydrogenation catalyst DCA-5 was prepared. The catalyst composition, catalyst properties and pore distribution of the catalyst are shown in Table 2. The Mo is +6 valence Mo and +4 valence Mo, and does not contain +5 valence Mo. That is, the Mo exists in the form of molybdenum disulfide and molybdenum oxide. The +4 valence Mo accounts for 14.2% of the total Mo in terms of atoms, and the +6 valence Mo accounts for 85.8% of the total Mo in terms of atoms.

[0117] Application Example

[0118] The catalysts obtained in the examples and comparative examples were respectively subjected to activity evaluation experiments using the raw oil in Table 2. The properties of the raw oil and the reaction conditions are shown in Table 2. The oil sample was sampled and analyzed after running for 1000 hours, and the evaluation results are shown in Table 3. The sulfidation conditions are as follows: the sulfidation liquid is hydrogenated diesel oil containing 10.0% by mass of DMDS, the flow rate of the sulfidation liquid is 25.0 mL / (h·g catalyst), the hydrogen pressure is 14.0 MPa, the hydrogen flow rate is 120.0 mL / (min·g catalyst), the low-temperature sulfidation stage starts from 25°C, the temperature increasing rate is 9.0°C / h, and after the temperature is increased to 230°C, the temperature is kept constant for 8.0 h; the high-temperature sulfidation stage starts from 230°C, the temperature increasing rate is 10.0°C / h, and after the temperature is increased to 380°C, the temperature is kept constant for 6.0 h, and the sulfidation is completed.

[0119] Table 1 Catalyst composition and properties of examples and comparative examples

[0120]

[0121]

[0122] Table 2 Raw oil properties and reaction conditions

[0123] Item Property Feed oil property Density (20°C) / kg m -3 ]] 1104.5 S / wt% 0.23 Fe + Ca / pg g -1 ]] 258.4 CCR / wt% 15.2 O / wt% 7.6 Reaction condition Reaction temperature / °C 368 Reaction pressure / MPa 14.5 Liquid hourly space velocity / h -1 ]] 0.46 Hydrogen / oil volume ratio 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 650

[0124] Table 3 Activity evaluation results of each example catalyst

[0125]

[0126] The specific embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including that each technical feature is combined in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A coal tar hydroprocessing catalyst comprising a support and an active metal component; the support is a gallium-modified silica-alumina support; the gallium-modified silica-alumina support has a gallium oxide content of 2.0% to 5.0% by mass, a silicon dioxide content of 20.0% to 60.0% by mass, and an alumina content of 35.0% to 78.0% by mass, based on the mass of the gallium-modified silica-alumina support; the active metal component comprises Mo and a Group VIII metal element; the Mo comprises +5 valence Mo; the Group VIII metal element is present in the catalyst in the form of a metal phosphide. Preferably, the catalyst has a pore size distribution in which the ratio of the pore volume of pores having a pore diameter < 10 nm to the total pore volume is 5% to 10%, the ratio of the pore volume of pores having a pore diameter of 10 to 50 nm to the total pore volume is 65% to 80%, and the ratio of the pore volume of pores having a pore diameter > 50 nm to the total pore volume is 10% to 30%. Preferably, the catalyst has the following properties: specific surface area of 150-200 m 2 / g, pore volume of 0.5-0.8 mL / g, total acid amount of 0.2-0.5 mmol / g, ratio of B acid amount / L acid amount of 0.35-0.

65. The Mo further comprises +4 valence Mo and +6 valence Mo; furthermore, the +5 valence Mo accounts for 50% or more of the total Mo by atoms, preferably 55% to 80%.

2. The catalyst of claim 1, wherein The Group VIII metal element is selected from one or more of Fe, Co, and Ni, preferably at least one of Co and Ni, more preferably Ni.

3. The catalyst of claim 2, wherein 4. A method for preparing the catalyst of any one of claims 1 to 3, comprising: (1) mixing a molybdenum source, a sulfur source, and water to obtain a first impregnation solution, and impregnating the support with the first impregnation solution to obtain a catalyst intermediate I after drying; (2) contacting the catalyst intermediate I of step (1) with chlorine to obtain a catalyst intermediate II; (3) impregnating the catalyst intermediate II of step (2) with a second impregnation solution containing a nickel source and a phosphorus source, and preparing the catalyst by aging, drying, and calcination. The method for preparing the support comprises:

5. The method of claim 4, wherein, (11) mixing an acidic aqueous aluminum salt solution, a silicon source, and an organic acid, and stirring to obtain a material AI; (12) performing a co-current precipitation reaction of the material AI with a gallium-containing solution and an alkaline aqueous aluminum salt solution to obtain a material AII; (13) performing a hydrothermal treatment of the material AII with a non-ionic surfactant to obtain a gallium-modified silica-alumina material; (14) mixing and kneading the gallium-modified silica-alumina material obtained in step (13), a binder, a extrusion aid, and water, shaping, drying, and calcining to obtain the catalyst support. In step (11), the organic acid is one or more of maleic acid, fumaric acid, adipic acid, tartaric acid, citric acid, oxalic acid, acetic acid, salicylic acid, and malic acid; 6. The method of claim 5, wherein, and / or, the mass concentration of the organic acid is 7% to 16%; and / or, the amount of the organic acid is such that the pH value of the material AI is 2 to 4, preferably 3 to 4. In step (12), the gallium-containing solution is a gallium nitrate solution, and the concentration of the gallium-containing solution is 0.5 to 2.5 mol / L; 7. The method of claim 5, wherein, and / or, the alkaline aluminum salt is at least one of sodium aluminate and potassium aluminate; and / or, the concentration of the alkaline aluminum salt solution, calculated as Al2O3, is 20 to 100 g / 100 mL; and / or, the ratio of the co-current flow rates of the gallium-containing solution, the material AI, and the alkaline aluminum salt solution is 1:3 to 7:1 to 3. ​ And / or, the reaction temperature is 60-90℃, the reaction time is 60-180 minutes, and the pH value is 8.0-9.7; the reaction is preferably carried out under stirring, and the stirring rate is 100-500 rad / min, preferably 150-450 rad / min.

8. The method of claim 5, wherein, In step (13), the nonionic surfactant is selected from one or more of polyethylene glycol, alkyl alcohol amide, and polyether; And / or, the alkyl alcohol amide is one or more of lauryl diethanolamide and coconut oil fatty acid diethanolamide; And / or, the polyether is one or more of AEO-6 and AEO-9; the molecular weight of the polyethylene glycol is 200-1000, preferably 200-700; And / or, the amount of the nonionic surfactant added is 0.1%-5% of the mass of the material AII obtained in step (12) based on alumina, preferably 0.5%-3%; And / or, the concentration of the nonionic surfactant is 30-70 g / 100 mL.

9. The method of claim 5, wherein, In step (13), the sealing hydrothermal treatment is carried out under the following conditions: the hydrothermal treatment temperature is 80-130℃, and the time is 3-18 hours, wherein the temperature rising rate is 8-15℃ / min; Preferably, the hydrothermal treatment is carried out in two stages, the first stage is carried out at 80-110℃ for 1-9 hours, and the second stage is carried out at 100-130℃ for 1-9 hours, wherein the temperature of the second stage is at least 15℃ higher than that of the first stage, preferably at least 20℃ higher.

10. The method of claim 4, wherein, In step (1), the molybdenum source is selected from at least one of ammonium dimolybdate, ammonium tetramolybdate dihydrate, and ammonium heptamolybdate tetrahydrate; And / or, the sulfur source is selected from at least one of thiocyanate, ammonium sulfide, thioacetamide, and sodium thiosulfate; And / or, the mass ratio of the molybdenum source to the sulfur source is 3-5:2-4; And / or, in the first impregnation solution, the mass content of the molybdenum source is 25wt%-45wt%.

11. The method of claim 4 wherein, In step (2), the purity of the chlorine gas is 96% or more by volume fraction; and the flow rate of the chlorine gas is 2.7-6.8 mL / (min·g of catalyst intermediate I); And / or, the reaction is carried out under the following conditions: the reaction temperature is 300-400℃, and the reaction time is 40-90 min.

12. The method of claim 4, wherein, In step (3), the nickel source is a soluble salt, such as at least one of nitrate, monohydrogen phosphate, and dihydrogen phosphate; And / or, the phosphorus source is selected from at least one of ammonium phosphate, sodium dihydrogen phosphate, sodium hydrogen phosphate, potassium dihydrogen phosphate, potassium hydrogen phosphate, and phytic acid; And / or, in the second impregnation solution, the molar ratio of the nickel source to the phosphorus source is 0.3-3:1, with the nickel source being calculated as a metal element and the phosphorus source being calculated as a phosphorus element; And / or, in the second impregnation solution, the mass content of the nickel source is 40wt%-68wt%.

13. Use of the catalyst of any one of claims 1-3 or prepared by the method of any one of claims 4-12 in the hydroprocessing of coal tar.

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