Silicon capturing agent, preparation method and application thereof

Abstract

The application discloses a silicon capturing agent, a preparation method and application thereof. The silicon capturing agent comprises an alumina carrier containing a microspherical cavity, pseudo-boehmite and an active component; the pseudo-boehmite is in-situ grown on the outer surface and the microspherical cavity of the silicon capturing agent; the active component is a group VIB metal sulfide and a group VIII metal sulfide, and the group VIB metal sulfide and the group VIII metal sulfide are loaded on the alumina carrier and the pseudo-boehmite; the particle morphology of the pseudo-boehmite is a velvet worm structure, and the size of the velvet worm particle is 80-350 nm; and the surface hydroxyl content of the silicon capturing agent is 1000-2000 mu mol / g. The silicon capturing agent has high silicon capacity, can effectively capture silicon in oil from processes such as delayed coking, prevents the silicon poisoning and deactivation of a main catalyst, and has high hydrogenation desulfurization, denitrification and olefin saturation activities.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of petroleum refining, and particularly relates to a silicon capturing agent, a preparation method thereof and a method for hydrogenation and silicon capturing using the same. BACKGROUND

[0002] The coking dry gas, coking naphtha, coking diesel and the like need to be filled with a silicon capturing catalyst in the hydrogenation treatment process, and the silicon capturing catalyst needs to have not only a strong silicon capturing capacity but also a certain hydrogenation activity. It is found that the silicon type in the coking product is mainly a compound of cyclic siloxane, and the silicon needs to be captured on the silicon capturing catalyst, and the silicon-oxygen ring of the cyclic siloxane needs to be opened, which requires the silicon capturing catalyst to have a high acidity.

[0003] CN201911020761.2 discloses a silicon capturing agent and a preparation method thereof. The silicon capturing agent of the present application comprises a carrier and a hydrogenation active component, the hydrogenation active component is a group VIB metal sulfide, a group VIB metal oxide and a group VIII metal oxide, and the group VIB metal sulfide is 0.3wt%-18.3wt%, the group VIB metal oxide is 0.1wt%-5.0wt%, and the group VIII metal oxide is 0.2wt%-12.0wt% based on the total weight of the silicon capturing agent. The preparation method of the silicon capturing agent of the present application comprises the following contents: (1) impregnating the catalyst carrier with an impregnation liquid containing group VIB metal, then drying, and then sulfidizing the dried material; (2) impregnating the material after sulfidizing in step (1) with an impregnation liquid containing group VIB and group VIII metals, then drying and calcining in an inert atmosphere to obtain the silicon capturing agent. The active component of the silicon capturing agent of the present application has a high sulfidation degree, and the silicon capturing agent has a high silicon capacity, and is suitable for desiliconization and silicon capturing of coking dry gas, coking naphtha, coking diesel and the like containing silicon.

[0004] CN200710012085.5 discloses a method for hydrofining a silicon-containing distillate oil, which comprises passing the silicon-containing distillate oil and hydrogen through at least two beds of hydrofining catalysts under hydrofining conditions, wherein the silicon-containing distillate oil is first passed through a bed of a hydrofining catalyst having a silicon capturing function, and then passed through a bed of a conventional hydrofining catalyst; wherein the hydrofining catalyst having the silicon capturing function has a relatively large pore volume and specific surface area and a relatively low metal content.

[0005] The silicon capturing catalyst of the above-mentioned patent is prepared by impregnating active metals into an alumina or modified alumina carrier. Although the alumina or modified alumina carrier has a large specific surface area, the alumina or modified alumina carrier is subjected to high-temperature calcination, which causes a loss of the specific surface area and reduces the silicon capacity of the silicon capturing catalyst. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application provides a silicon capturing agent, a preparation method and application thereof, the silicon capturing agent has high silicon capacity, can effectively capture silicon in oil from processes such as delayed coking, and prevent the silicon poisoning and deactivation of the main catalyst, and has high hydrogenation activity such as hydrodesulfurization, denitrification and olefin saturation.

[0007] The silicon capturing agent of the present application comprises an alumina carrier containing microspherical cavities, pseudoboehmite and an active component; the pseudoboehmite is in-situ grown on the outer surface and the microspherical cavities of the silicon capturing agent; the active component is a Group VIB metal sulfide and a Group VIII metal sulfide, and the Group VIB metal sulfide and the Group VIII metal sulfide are supported on the alumina carrier and the pseudoboehmite; the particle morphology of the pseudoboehmite is a bryoid structure, and the bryoid particle size is preferably 80-350 nm; further, the surface hydroxyl content of the silicon capturing agent is 1000-2000 μmol / g, preferably 1200-1800 μmol / g.

[0008] Further, the Group VIB metal sulfide is 2wt%-20wt%, preferably 3wt%-13wt%, and the Group VIII metal sulfide is 1wt%-10wt%, preferably 2wt%-5wt%, based on the total weight of the catalyst.

[0009] Further, the Group VIB metal sulfide is molybdenum sulfide or / and tungsten sulfide, and the Group VIII metal sulfide is nickel sulfide or / and cobalt sulfide.

[0010] The preparation method of the silicon capturing agent of the present application comprises the following contents:

[0011] (1) introducing Group VIB metal salt and Group VIII metal salt into the alumina carrier containing microspherical cavities by impregnation method, sulfidizing to obtain a catalyst precursor;

[0012] (2) sealing and heat treating the catalyst precursor of step (1) by immersing in propylene oxide aqueous solution, and after treatment, the material is subjected to solid-liquid separation, and the solid material is dried to obtain the silicon capturing agent.

[0013] In the method of the present application, the alumina carrier containing microspherical cavities in step (1) is γ phase alumina; its shape can be the shape of conventional alumina carrier, such as spherical shape, its particle size is generally 2-8.0 mm, such as cylindrical bar, three-leaf clover, four-leaf clover and the like, its diameter is about 0.2-3.0 mm, and its length is about 3-8.0 mm. The diameter of the microspherical cavity is 1-10 microns, preferably 1-5 microns, and the content of the microspherical cavity can be controlled as needed, preferably the microspherical cavity pore volume accounts for 1%-30% of the total pore volume of the alumina carrier, more preferably 5%-20%.

[0014] In the method, the alumina carrier containing microspherical cavities in step (1) can be prepared by the following method: mixing microspherical activated carbon and pseudoboehmite, adding deionized water to the mixture and stirring, drying the mixture, and kneading, drying, and calcining the dried mixture to obtain the alumina carrier precursor. The microspherical activated carbon can be prepared by an existing method or purchased. The diameter of the microspherical activated carbon is 1-10 microns. The mass ratio of the microspherical activated carbon to the pseudoboehmite is 1:4-1:9. The amount of the deionized water added is such that the mass ratio of liquid to solid in the slurry is 5:1-10:1. The kneading and molding are performed by a conventional method in the art. An extrusion aid and a peptizing agent can be added during the molding process as needed. The extrusion aid is pearl millet powder, and the amount of the pearl millet powder added is 0.1wt%-0.5wt% of the weight of the alumina carrier. The peptizing agent is one or more of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, and oxalic acid, and the amount of the peptizing agent added is 0.5wt%-1.5wt% of the weight of the alumina carrier. The drying temperature is 100-160°C, and the drying time is 6-10 hours. The calcination temperature is 450-700°C, and the calcination time is 4-6 hours. The calcination is performed in an oxygen-containing atmosphere, preferably an air atmosphere.

[0015] In the method, the Group VIB metal salt in step (1) is a phosphate salt and / or an ammonium salt. The Group VIII metal salt is selected from one or more of a nitrate salt, a carbonate salt, a phosphate salt, a sulfate salt, a basic carbonate salt, and an acetate salt.

[0016] In the method, step (1) can further include necessary drying and calcination processes before sulfidation. The drying conditions are a drying temperature of 90-300°C and a drying time of 3-6 hours. The calcination conditions are a calcination temperature of 300-600°C and a drying time of 3-6 hours.

[0017] In the method, the sulfidation treatment in step (1) is dry sulfidation or wet sulfidation. The sulfidation agent for dry sulfidation is hydrogen sulfide. The sulfidation agent for wet sulfidation is selected from one or two of carbon disulfide, dimethyl disulfide, methyl sulfide, and n-butyl sulfide. The sulfidation pressure is 2.0-6.4 MPa, the sulfidation temperature is 250-400°C, and the sulfidation time is 4-12 hours.

[0018] In the method, the concentration of the propylene oxide aqueous solution in step (2) is 2.5wt%-12wt%, preferably 4wt%-8wt%. The mass ratio of the amount of the propylene oxide aqueous solution to the catalyst precursor is 3:1-10:1, preferably 4:1-8:1.

[0019] In the method of the present application, the sealing heat treatment in step (2) is carried out in a sealed pressure-resistant container, preferably an autoclave, and is a two-step sealing heat treatment, i.e. first sealing heat treatment at 60-100°C for 1-4 hours, and then sealing heat treatment at 110-180°C, preferably 120-160°C, for 2-6 hours, preferably 2-4 hours.

[0020] In the method of the present application, the drying temperature in step (2) is 100-160°C, and the drying time is 2-8 hours.

[0021] The application of the silicon-trapping agent in the oil desilication process, wherein the oil is generally obtained from a delayed coking process, and is generally one or more of coking dry gas, coking naphtha, coking diesel and other silicon-containing oils, with a silicon content of 1-2000 ppm.

[0022] Further, the oil desilication is carried out in a fixed bed reactor, and the above-mentioned silicon-trapping agent is loaded into the reactor to form a catalyst bed layer and is in contact with the oil for reaction. The reaction conditions are as follows: the reaction temperature is 260-350°C, the pressure is 2.0-8.0 MPa, and the hydrogen / oil ratio is 100:1-1000:1.

[0023] Compared with the prior art, the present application has the following advantages:

[0024] (1) In the silicon-trapping agent of the present application, the bryoid boehmite component is covered on the outer surface of the alumina carrier and in the spherical cavity, which provides abundant surface hydroxyl groups and reaction space for the silicon-trapping agent, thereby greatly improving its silicon capacity. At the same time, the silicon-containing compounds in the raw oil first react with the hydroxyl groups of the boehmite on the outer surface, and the unreacted silicon-containing compounds diffuse into the spherical cavity to continue the reaction with the boehmite in the spherical cavity, thereby performing secondary desilication and greatly reducing the escape of silicon.

[0025] (2) In the silicon-trapping agent of the present application, an alumina carrier containing micron-level spherical cavities is first prepared, and then an active metal is impregnated to prepare a catalyst precursor, and then the catalyst precursor is placed in a solution in a special hydrothermal environment, and is subjected to sealing heat treatment to obtain a catalyst with bryoid boehmite particles directionally grown on the outer surface of the carrier and in the micron-level spherical cavities. The boehmite will also grow on the active metal sulfide crystal sheet, and the generated boehmite can provide abundant surface hydroxyl groups to improve the silicon capacity of the silicon-trapping agent.

[0026] (3) The Group VIB metal sulfide and the Group VIII metal sulfide in the silicon capturing agent of the present application are supported on the alumina carrier, and the pseudo-boehmite is grown in situ on the surface of the alumina or / and the active component, which can increase the contact surface between the pseudo-boehmite and the Group VIII metal and the Group VIB metal, improve the synergistic effect of the hydrogenation performance and the silicon capturing performance of the silicon capturing agent, and also reduce the carbon deposition of the catalyst and prevent the carbon deposition from occupying the silicon capturing active sites.

[0027] (4) The catalyst of the present application is in a sulfided state, and does not need to be sulfided during use, thereby preventing the temperature runaway during sulfidation. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 SEM photo of the outer surface of the silicon capturing agent Cat-1 of Example 1.

[0029] Figure 2 SEM photo of the cross section of the silicon capturing agent Cat-1 of Example 1. DETAILED DESCRIPTION

[0030] The technical solutions and technical effects of the present application are further illustrated below in combination with examples, but are not limited to the following examples. In the present application, wt% represents mass fraction.

[0031] In the context of the present specification, the surface hydroxyl content of the catalyst is analyzed by FTIR (infrared spectroscopy), and the test conditions of the FTIR include: the catalyst is ground and then pressed into a self-supporting sheet with a diameter of 13 mm and placed on an in-situ cell sample holder; the experiment uses a Nicolet 6700 Fourier transform infrared spectrometer, the scanning number is 32 times, the resolution is 4 cm -1 , the measurement range is 4000-650 cm -1 , and the detector is MCT / A; all infrared experimental results are normalized according to the mass of the catalyst, and the hydroxyl content is calculated using the molar integral absorption coefficient Ao = 1.5 cm / μmol and the integral intensity of 3590-3830 cm -1 . The specific surface area of the silicon capturing agent is analyzed by N2-adsorption / desorption, and the test conditions of the N2-adsorption / desorption are as follows: the catalyst is loaded into a sample tube, and the N2 adsorption and desorption tests are performed at a temperature of 77 K using an ASAP 2420 nitrogen physical adsorption instrument of the American MICROMERITICS company. The microstructure of the catalyst is characterized by a scanning electron microscope, and the specific operation is as follows: the microstructure of the carrier is characterized by a JSM-7500F scanning electron microscope, the acceleration voltage is 5 KV, the acceleration current is 20 μA, and the working distance is 8 mm.

[0032] Preparation of microspherical activated carbon:

[0033] The micrometer spherical activated carbon used in the method of the application is prepared according to the method in the document: Preparation of micrometer spherical activated carbon by hydrothermal carbonization of carboxymethylcellulose-CO2 activation [J]. Forest Chemistry and Industry, 2015, 35(4): 21-27. The micrometer spherical activated carbon prepared has a diameter of 1-10 micrometers.

[0034] Example 1

[0035] (1) Preparation of an alumina carrier

[0036] 100 grams of the micrometer spherical activated carbon described above is weighed, 600 grams of pseudoboehmite is added, and the materials are mixed uniformly. Then, deionized water is added to make the liquid-to-solid mass ratio of the materials 8:1, and the mixed materials are mechanically stirred for 2 hours. After stirring, the mixed materials are subjected to liquid-to-solid separation, and the solid materials are dried at 130℃ for 6 hours. 4.5 grams of sesbania powder is added to the dried materials, and the mixture is mixed uniformly. Then, an appropriate amount of a 1.0% acetic acid solution is added to the mixed materials, and the materials are uniformly kneaded and formed into strips. The formed materials are dried at 130℃ for 8 hours, and then calcined at 700℃ in an oxygen atmosphere for 5 hours to obtain an alumina carrier S0.

[0037] (2) An impregnation solution containing ammonium heptamolybdate and nickel nitrate is used to impregnate the alumina carrier in an equal volume. After impregnation, the materials are dried at 110℃ for 3 hours and calcined at 400℃ for 3 hours. Then, the materials are subjected to sulfidation treatment using hydrogen containing 1.5% H2S, at a sulfidation temperature of 330℃, a sulfidation pressure of 3.2 MPa, and a sulfidation time of 5 hours. Then, the materials are cooled to room temperature in a N2 atmosphere to obtain a catalyst precursor.

[0038] (3) 100 grams of the catalyst precursor is weighed, and 550 grams of a propylene oxide aqueous solution with a mass concentration of 6.2% is added. The mixed materials are transferred into an autoclave, which is sealed and placed in an oven for sealed treatment at 70℃ for 2.8 hours, and then the temperature is increased to 135℃ for sealed treatment for 3 hours. After treatment, the materials are cooled, washed, filtered, and the solid materials are dried at 120℃ for 3 hours to obtain a silicon capture agent Cat-1. As can be seen from the SEM photo, the surface and the spherical cavity of the silicon capture agent have in-situ grown pectin-like pseudoboehmite.

[0039] The weight percentage of each component in the silicon capture agent Cat-1 is as follows: MoS2 is 9.3%, and NiS is 4.6%; the hydroxyl content is 1293 μmol / g.

[0040] Example 2

[0041] Step (1) is the same as in Example 1;

[0042] (2) The impregnation solution containing ammonium heptamolybdate and cobalt nitrate was impregnated into the alumina carrier in equal volume. After impregnation, the carrier was dried at 120°C for 5 hours and calcined at 450°C for 4 hours. Then the carrier was sulfidized by using hydrogen containing 1.5% H2S at a temperature of 340°C, a pressure of 3.6 MPa and a time of 5 hours. After sulfidization, the carrier was cooled to room temperature in N2 atmosphere to obtain the catalyst precursor.

[0043] Step (3) was the same as in Example 1, except that the concentration of propylene oxide in step (3) was 5.5%, the solution amount was 630 g, and the hydrothermal treatment was first at 80°C for 2.5 hours and then at 145°C for 2.5 hours to obtain the silicon trapping agent Cat-2.

[0044] The weight percentage of each component in the silicon trapping agent Cat-2 was as follows: MoS2 was 9.6%, NiS was 3.1%, and the hydroxyl content was 1384 μmol / g.

[0045] Example 3

[0046] Step (1) was the same as in Example 1.

[0047] (2) The impregnation solution containing ammonium heptamolybdate, nickel nitrate and cobalt nitrate was impregnated into the alumina carrier in equal volume. After impregnation, the carrier was dried at 120°C for 4 hours and calcined at 500°C for 3 hours. Then the carrier was sulfidized by using hydrogen containing 1.5% H2S at a temperature of 360°C, a pressure of 4.2 MPa and a time of 6 hours. After sulfidization, the carrier was cooled to room temperature in N2 atmosphere to obtain the catalyst precursor.

[0048] Step (3) was the same as in Example 1, except that the concentration of propylene oxide in step (3) was 4.5%, the solution amount was 720 g, and the hydrothermal treatment was first at 60°C for 3.5 hours and then at 160°C for 2 hours to obtain the silicon trapping agent Cat-3.

[0049] The weight percentage of each component in the silicon trapping agent Cat-3 was as follows: MoS2 was 10.6%, NiS was 2.7%, CoS was 1.1%, and the hydroxyl content was 1496 μmol / g.

[0050] Example 4

[0051] Step (1) was the same as in Example 1.

[0052] (2) The impregnation solution containing ammonium metatungstate and nickel nitrate was impregnated into the alumina carrier in equal volume. After impregnation, the carrier was dried at 120°C for 4 hours and calcined at 500°C for 3 hours. Then the carrier was sulfidized by using hydrogen containing 2.5% H2S at a temperature of 360°C, a pressure of 4.2 MPa and a time of 4 hours. After sulfidization, the carrier was cooled to room temperature in N2 atmosphere to obtain the catalyst precursor.

[0053] Step (3) is the same as Example 1, except that the concentration of propylene oxide in step (3) is 7.6%, the solution is 430 g, and the hydrothermal treatment is first at 90°C for 1.5 hours, then at 120°C for 3 hours, to produce the silicon capturing agent Cat-4.

[0054] The weight percentage of each component in the silicon capturing agent Cat-4 is: WS2 is 11.5%, NiS is 3.6%, and the hydroxyl content is 1370 μmol / g.

[0055] Comparative Example 1

[0056] The same as Example 1, except that the propylene oxide aqueous solution is replaced by an ethylene oxide solution of the same concentration, to produce the silicon capturing agent DC-1; no pseu do-boehmite of the woolworm shape is obtained, and the hydroxyl content is 729 μmol / g.

[0057] Comparative Example 2

[0058] The same as Example 1, except that the concentration of propylene oxide is 1%, to produce the silicon capturing agent DC-2; no pseu do-boehmite of the woolworm shape is obtained, and the hydroxyl content is 1063 μmol / g.

[0059] Comparative Example 3

[0060] The same as Example 1, except that the hydrothermal treatment is one-step hydrothermal treatment at 60°C for 20 hours, to produce the silicon capturing agent DC-3; no pseu do-boehmite of the woolworm shape is obtained, and the hydroxyl content is 968 μmol / g.

[0061] Comparative Example 4

[0062] The same as Example 1, except that the treatment process of step (3) is not performed, to produce the silicon capturing agent DC-4; no pseu do-boehmite of the woolworm shape is obtained, and the hydroxyl content is 791 μmol / g.

[0063] The silicon capturing agents Cat-1, Cat-2, Cat-3, Cat-4 prepared according to the present application and the silicon capturing agents DC-1, DC-2, DC-3, DC-4 prepared according to the comparative examples are respectively loaded into a fixed-bed hydrogenation reactor, and the silicon capturing activity is investigated. The evaluation raw oil used is coking naphtha raw material provided by a refinery of SINOPEC, and the main properties are as follows: silicon content is 141 μg / g, sulfur content is 1241 μg / g, and nitrogen content is 51 μg / g. The evaluation reaction conditions are: operating pressure is 4.0 MPa, reaction temperature is 320°C, hydrogen / oil volume ratio is 500:1, and volume space velocity is 4.5 h -1 After running for 20 hours, the desulfurization and denitrogenation rates of the silicon capturing agent are tested, after running for 300 hours, the silicon capturing agent is unloaded, then is calcined at 500°C for 3 hours in a nitrogen atmosphere, the SiO2 content in the silicon capturing agent is analyzed by XRF, and the evaluation results are shown in Table 1.

[0064] Table 1

[0065] Catalyst No. silicon content (as SiO2), %] Desulfurization rate, % Denitrogenation rate, % Cat-1 21.9 78 81 Cat-2 34.1 81 84 Cat-3 35.9 83 89 Cat-4 30.3 92 95 DC-1 8.1 82 79 DC-2 11.4 79 80 DC-3 13.1 83 81 DC-4 6.7 88 83

Claims

1. A silicon-scavenging agent, characterized in that: The active component includes an alumina support containing micron-sized spherical cavities, boehmite, and active components; the boehmite is grown in situ on the outer surface of the silica-trapping agent and in the micron-sized spherical cavities; the active components are Group VIB metal sulfides and Group VIII metal sulfides, which are loaded on the alumina support and the boehmite; the particle morphology of the boehmite is a velvety structure; the surface hydroxyl content of the silica-trapping agent is 1000-2000 µmol / g; based on the total weight of the silica-trapping agent, the Group VIB metal sulfides are 2wt%-20wt%, and the Group VIII metal sulfides are 1wt%-10%; the preparation method of the silica-trapping agent includes the following: (1) introducing the group VIB metal sulfides into the alumina support containing micron-sized spherical cavities by impregnation. Group VIB and Group VIII metal salts are sulfided to obtain catalyst precursors; (2) The catalyst precursors from step (1) are immersed in an aqueous solution of propylene oxide and sealed for heat treatment. After treatment, the material is separated into solid and liquid phases, and the solid phase material is dried to obtain a silicon scavenger; the concentration of the aqueous solution of propylene oxide in step (2) is 2.5wt%-12wt%, and the mass ratio of the amount of aqueous solution of propylene oxide to the mass of the catalyst precursor is 3:1-10:1; the sealing heat treatment in step (2) is carried out in a sealed pressure-resistant container. The sealing heat treatment is a two-step sealing heat treatment, that is, firstly, it is sealed for heat treatment at 60-100℃ for 1-4 hours, and then sealed for heat treatment at 110-180℃ for 2-6 hours; the drying temperature in step (2) is 120-160℃, and the drying time is 2-8 hours.

2. The silicon-collecting agent according to claim 1, characterized in that: The particle size of pseudoboehmite is 80-350 nm.

3. The silicon-collecting agent according to claim 1, characterized in that: The surface hydroxyl content of the silicon-catching agent is 1200-1800 µmol / g.

4. The silicon-collecting agent according to claim 1, characterized in that: Based on the total weight of the silicon-catching agent, Group VIB metal sulfides account for 3wt%-13wt%, and Group VIII metal sulfides account for 2wt%-5wt%.

5. The silicon-collecting agent according to claim 1, characterized in that: The group VIB metal sulfides are molybdenum sulfide and / or tungsten sulfide, and the group VIII metal sulfides are nickel sulfide and / or cobalt sulfide.

6. A method for preparing the silicon-scavenging agent according to any one of claims 1 to 5, characterized in that... The process includes the following: (1) introducing Group VIB and Group VIII metal salts into an alumina support containing micron-sized spherical cavities by impregnation, followed by sulfidation to obtain a catalyst precursor; (2) immersing the catalyst precursor from step (1) in an aqueous solution of propylene oxide for sealed heat treatment, followed by solid-liquid separation of the treated material, and drying of the solid material to obtain a silicon scavenger.

7. The method according to claim 6, characterized in that: The alumina carrier containing micron-sized spherical cavities in step (1) is γ-phase alumina; the diameter of the micron-sized spherical cavities is 1-10 microns, and the pore volume of the micron-sized spherical cavities accounts for 1%-30% of the total pore volume of the alumina carrier.

8. The method according to claim 6, characterized in that: The alumina carrier containing micron-sized spherical cavities described in step (1) is prepared as follows: micron-sized spherical activated carbon is mixed with boehmite, deionized water is added to the mixture and stirred to obtain a slurry, and the material is dried after stirring. The dried material is kneaded, dried, and calcined to obtain the alumina carrier precursor. The diameter of the micron-sized spherical activated carbon is 1-10 microns. The mass ratio of micron-sized spherical activated carbon to boehmite is 1:4-1:

9. The liquid-solid mass ratio in the slurry is 5:1-10:

1. The drying temperature is 100-160℃ and the drying time is 6-10 hours. The calcination temperature is 450-700℃ and the calcination time is 4-6 hours. The calcination is carried out in an oxygen-containing atmosphere.

9. The method according to claim 6, characterized in that: The Group VIB metal salt mentioned in step (1) is a phosphate and / or ammonium salt; the Group VIII metal salt is selected from one or more of nitrates, carbonates, phosphates, sulfates, basic carbonates and acetates.

10. The method according to claim 6, characterized in that: Step (1) includes a drying and roasting process before vulcanization. The drying conditions are: drying temperature 90-300℃, drying time 3-6 hours; the roasting conditions are: roasting temperature 300-600℃, drying time 3-6 hours.

11. The method according to claim 6, characterized in that: The vulcanization process in step (1) is either dry vulcanization or wet vulcanization; the vulcanizing agent for dry vulcanization is hydrogen sulfide, and the vulcanizing agent for wet vulcanization is selected from one or two of carbon disulfide, dimethyl disulfide, methyl sulfide and n-butyl sulfide; the vulcanization pressure is 2.0-6.4 MPa, the vulcanization temperature is 250-400℃, and the vulcanization time is 4-12 h.

12. The method according to claim 6, characterized in that: The concentration of the propylene oxide aqueous solution in step (2) is 2.5wt%-12wt%, and the mass ratio of the amount of propylene oxide aqueous solution to the mass ratio of the catalyst precursor is 3:1-10:

1.

13. The method according to claim 6, characterized in that: The sealing heat treatment described in step (2) is carried out in a sealed pressure-resistant container. The sealing heat treatment is a two-step sealing heat treatment, namely, firstly, sealing heat treatment at 60-100℃ for 1-4 hours, and then sealing heat treatment at 110-180℃ for 2-6 hours.

14. The method according to claim 6, characterized in that: The drying temperature in step (2) is 100-160℃ and the drying time is 2-8 hours.

15. The application of any one of the silica-collecting agents according to claims 1 to 5 in the desiliconization process of oil products, wherein the oil products are derived from one or more of coking naphtha and coking diesel oil produced by delayed coking processes, and have a silica content of 1-2000 ppm.

16. The application according to claim 15, characterized in that: The desilication of the oil is carried out in a fixed-bed reactor under the following conditions: reaction temperature of 260-350℃, pressure of 2.0-8.0MPa, and hydrogen-to-oil ratio of 100:1-1000:1.

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