Silicon capture catalyst and preparation method thereof

Abstract

A silicon capture catalyst comprising alumina and an active component, wherein the content of a Group VIB metal oxide is 2-20%, the content of a Group VIII metal oxide is 1-10%, and the specific surface area is ≮300m 2 / g, the surface hydroxyl content is ≮800µmol / g, and after the silicon-capturing catalyst is sulfurized, when analyzed by TEM, the number of stacking layers of the VIB group metal sulfide is 1-3 layers, and the chip length of the VIB group metal sulfide is 5-10nm. The precursor of aluminum oxide is evenly mixed with a metal salt or oxide and an extrusion aid, and then a peptizing agent and water are added to form a catalyst. During the preparation process of the silicon-capturing agent, the active metal salt or oxide is formed into a particle form wrapped by the aluminum oxide precursor, which blocks the contact between some aluminum oxide particles, thereby greatly increasing the specific surface area of ​​the catalyst, and more aluminum oxide surface is exposed to the outside, which can effectively increase the surface hydroxyl content of the catalyst, thereby improving the silicon-holding capacity of the silicon-capturing catalyst.

Description

Technical Field

[0001] The present invention relates to the technical field of oil hydrogenation, and in particular to a silicon-capturing catalyst and a preparation method thereof. Background Art

[0002] Currently, my country still has a large number of delayed coking units processing heavy, low-quality oil. Defoamers are used during this process, resulting in a certain amount of silicon in products such as coker dry gas, coker naphtha, and coker diesel. This silicon poisons the catalysts used in subsequent coking product processing, leading to permanent catalyst deactivation. Therefore, the hydroprocessing of coker dry gas, coker naphtha, and coker diesel requires the installation of silicon-capturing catalysts.

[0003] CN201911212127.9 discloses a coker gasoline hydrogenation catalyst grading and hydrotreating method, comprising: sequentially arranging a replaceable zone and a main reaction zone in series along the direction of material flow, wherein the replaceable zone is sequentially loaded with a diolefin saturation catalyst in the first reactor and a silicon scavenger in the second reactor along the direction of material flow, wherein the second reactor is a parallel dual reactor capable of online switching; and the main reaction zone is sequentially loaded with an arsenic removal agent and a gasoline hydrogenation catalyst along the direction of material flow. The method disclosed in the present invention can improve the impurity removal rate and extend the operating cycle of a gasoline hydrogenation unit, and is particularly suitable for gasoline hydrogenation units whose feedstock is coker gasoline or has a high coker gasoline content.

[0004] CN201911020775.4 discloses an oil product silicon scavenger and its preparation method. The oil product silicon scavenger includes a carrier and a hydrogenation active component, wherein the hydrogenation active component is a Group VIII metal sulfide, a Group VIB metal oxide, and a Group VIII metal oxide; based on the total weight of the silicon scavenger, the Group VIII metal sulfide is 0.1wt%-12.2wt%, the Group VIB metal oxide is 0.5wt%-17.2wt%, the Group VIII metal oxide is 0.1wt%-9.0wt%, and the carrier is 61.6%-90.3%. The preparation method includes the following: (1) impregnating the silicon scavenger carrier with an impregnation solution containing a Group VIII metal, then drying the material, and sulfurizing the dried material; (2) impregnating the material after sulfurization in step (1) with an impregnation solution containing Group VIB and Group VIII metals, and then drying and roasting under an inert atmosphere to obtain the oil product silicon scavenger. The active components in the silicon scavenger of the present invention have higher activity and better silicon-containing capacity, and are suitable for silicon scavenging treatment of silicon-containing oil products such as coking dry gas, coking naphtha, and coking diesel.

[0005] The silicon-capturing catalyst of the above-mentioned invention patent is prepared by impregnating active metal into alumina or modified alumina carrier. The alumina or modified alumina carrier needs to be calcined at high temperature, resulting in loss of specific surface area and reducing the silicon holding capacity of the silicon-capturing catalyst. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the present invention starts from the silicon capture mechanism of the silicon capture catalyst and prepares a silicon capture catalyst with high silicon holding capacity and low cost by increasing the specific surface area and surface hydroxyl content of the silicon capture catalyst.

[0007] In the context of this specification, FTIR (infrared spectroscopy) was used to analyze the hydroxyl content of the catalyst. The FTIR test conditions included: the catalyst was ground, pressed into a Φ13 mm self-supporting piece, and placed on the in-situ cell sample holder. The experiment used a Nicolet 6700 Fourier transform infrared spectrometer with 32 scans and a resolution of 4 cm. -1 , 4000~650cm -1 The measurement was performed using an MCT / A detector. All infrared experimental results were normalized according to the catalyst mass. The specific surface area of ​​the silicon trap was analyzed using N2-adsorption / desorption. The N2-adsorption / desorption test conditions were as follows: the catalyst was placed in a sample tube, and the ASAP 2420 nitrogen physical adsorption instrument from MICROMERITICS, USA, was used to perform N2 adsorption and desorption tests at 77K. TEM (high-resolution transmission electron microscopy) was used to analyze the morphological characteristics of the active metal after sulfidation. The TEM test conditions included: the electron gun type was LaB6, the acceleration voltage was 200kV, the point resolution was 0.23nm, the line resolution was 0.14nm, the sample was placed on the sample stage for testing, and the number and length of the lamellae on at least 20 TEM images were counted. Then, the average length of the VIB group metal sulfide lamellae ( ) and the average number of stacked layers ( The TEM analysis was performed on the hydrogenation catalyst after sulfidation (referred to as the sulfided hydrogenation catalyst). The sulfidation conditions included sulfidation at 320°C with 30 mL / min of H2S for 2 hours.

[0008]

[0009] In formulas (1) and (2), Platelets m length; The length is The total number of lamellae; Platelets m The number of stacking layers; The number of layers is The number of platelets; k is the total number of stripes in the statistical area.

[0010] In order to achieve the above technical objectives, the technical solutions of the present invention are as follows:

[0011] The technical purpose of the first aspect of the present invention is to provide a silicon capture catalyst, comprising alumina and an active component, wherein the active component is a Group VIB metal oxide and a Group VIII metal oxide, and based on the total weight of the catalyst, the Group VIB metal oxide is 2-20%, preferably 3-13%, and the Group VIII metal oxide is 1-10%, preferably 2-5%; the specific surface area of ​​the silicon capture agent is ≮300m 2 / g, preferably 350-450m 2 / g; the surface hydroxyl content is ≮800µmol / g, preferably 1200-1800µmol / g, and most preferably 1200-1500µmol / g; after the silicon capture catalyst is sulfurized, when TEM analysis is performed, the number of stacking layers of the VIB Group metal sulfide is 1-3 layers, and the wafer length of the VIB Group metal sulfide is 5-10nm.

[0012] Furthermore, the vulcanization is dry vulcanization or wet vulcanization. The vulcanizing agent for dry vulcanization is hydrogen sulfide, and the vulcanizing agent for wet vulcanization is one or two selected from 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° C., and the vulcanization time is 4-12 hours.

[0013] Furthermore, the Group VIB metal oxide is molybdenum oxide and / or tungsten oxide, and the Group VIII metal oxide is nickel oxide and / or cobalt oxide.

[0014] The technical purpose of the second aspect of the present invention is to provide a method for preparing the above-mentioned silicon capture catalyst, comprising the following steps:

[0015] (1) An aluminum oxide precursor is uniformly mixed with a Group VIB metal salt or / and a Group VIB metal oxide, a Group VIII metal salt or / and a Group VIII metal oxide, and an extrusion aid to obtain a catalyst precursor; wherein the particle size of the aluminum oxide precursor is 1-500 nm, preferably 5-200 nm; the particle size of the Group VIB metal salt or / and the Group VIB metal oxide, the Group VIII metal salt or / and the Group VIII metal oxide is 1-100 μm, preferably 5-80 μm.

[0016] (2) adding the peptizing agent and water evenly to the catalyst precursor of step (1), mixing evenly, and then extruding to obtain the silicon capture catalyst.

[0017] Furthermore, the uniform mixing in step (1) is to mix the raw materials by any solid material mixing means available in the prior art to achieve a degree of sufficient mixing recognized by those skilled in the art.

[0018] Furthermore, the precursor of the aluminum oxide in step (1) is selected from one or more of pseudo-boehmite, boehmite, gibbsite, nordstromite and diaspore.

[0019] Furthermore, the Group VIB metal salt in step (1) is selected from at least one of phosphates and ammonium salts.

[0020] Furthermore, the Group VIII metal salt in step (1) is selected from one or more of nitrates, carbonates, phosphates, sulfates, basic carbonates and acetates.

[0021] Furthermore, the Group VIB metal is molybdenum and / or tungsten, and the Group VIII metal is nickel and / or cobalt.

[0022] Furthermore, the extrusion aid in step (1) is well known to those skilled in the art. As a more specific embodiment, the extrusion aid is selected from at least one of starch, polyethylene glycol and sesbania powder.

[0023] Furthermore, the aluminum oxide precursor is calculated as aluminum oxide, and the amount of the extrusion aid added is 2-8 wt %, preferably 3-5 wt %, of the aluminum oxide.

[0024] Furthermore, the peptizing agent in step (2) is well known to those skilled in the art. As a more specific embodiment, the peptizing agent is selected from at least one of nitric acid, phosphoric acid and acetic acid.

[0025] Furthermore, the aluminum oxide precursor is calculated as aluminum oxide, and the amount of the peptizing agent added is 1-8 wt %, preferably 2-5 wt % of the aluminum oxide; the amount of water added is 50-150 wt %, preferably 80-120 wt % of the aluminum oxide.

[0026] Furthermore, step (2) further includes drying and optional calcination after extrusion molding, and the drying or calcination treatment conditions are: temperature 90-700°C, preferably 200-600°C, and time 1-10 hours, preferably 3-6 hours.

[0027] The third aspect of the present invention provides a method for using the silicon-capturing catalyst in the hydroprocessing of silicon-containing oils. The silicon-capturing catalyst requires vulcanization prior to use, with either dry or wet vulcanization being the preferred method. The dry vulcanizing agent is hydrogen sulfide, while the wet vulcanizing agent is one or two of carbon disulfide, dimethyl disulfide, methyl sulfide, and n-butyl sulfide. The vulcanization pressure is 2.0-6.4 MPa, the temperature is 250-400°C, and the time is 4-12 hours.

[0028] Compared with the prior art, the catalyst of the present invention has the following advantages:

[0029] (1) The silicon-capturing catalyst of the present invention adopts a preparation method of mixing and kneading a solid alumina precursor with a solid active metal salt or / and oxide. The inventors have conducted multiple experiments and characterization results, which show that when an alumina precursor with smaller particles and an active metal salt or oxide with relatively larger particles are used, when the materials are mixed and processed in the order of the present invention, a particle form in which the active metal salt or oxide is wrapped by the alumina precursor is formed, which blocks the contact between some alumina particles, thereby greatly increasing the specific surface area of ​​the catalyst. In addition, more alumina surface is exposed to the outside, which can effectively increase the surface hydroxyl content of the catalyst, thereby improving the silicon-holding capacity of the silicon-capturing catalyst.

[0030] (2) In addition, the preparation process of the present invention is simple, which greatly reduces the preparation cost of the catalyst and improves the competitiveness of the catalyst.

[0031] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0032] The following non-limiting examples may enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0033] The present invention uses FTIR (infrared spectroscopy) to analyze the hydroxyl content of the catalyst. The FTIR test conditions include: after the catalyst is ground, pressed into a Φ13mm self-supporting sheet, and placed on the in-situ cell sample holder. The experiment uses a Nicolet 6700 Fourier transform infrared spectrometer with 32 scans and a resolution of 4cm. -1 , 4000~650cm -1 All infrared experimental results were normalized according to the catalyst mass.

[0034] The present invention uses N2-adsorption / desorption to analyze the specific surface area of ​​the silicon capture agent. The N2-adsorption / desorption test conditions are as follows: the catalyst is loaded into a sample tube, and the ASAP 2420 nitrogen physical adsorption instrument from MICROMERITICS, USA, is used to perform N2 adsorption and desorption tests at a temperature of 77K.

[0035] The present invention uses TEM (high-resolution transmission electron microscopy) to analyze the morphological characteristics of active metals after sulfidation. The TEM test conditions include: the electron gun type is LaB6, the acceleration voltage is 200kV, the point resolution is 0.23nm, and the line resolution is 0.14nm. The sample is placed on the sample stage for testing, and the number and length of the lamellae on at least 20 TEM images are counted. Then, the average length of the VIB group metal sulfide lamellae is calculated according to the following calculation formulas (1) and (2), respectively ( ) and the average number of stacked layers ( The TEM analysis was performed on the hydrogenation catalyst after sulfidation (referred to as the sulfided hydrogenation catalyst). The sulfidation conditions included sulfidation at 320°C with 30 mL / min of H2S for 2 hours.

[0036]

[0037] In formulas (1) and (2), Platelets m length; The length is The total number of lamellae; Platelets m The number of stacking layers; The number of layers is The number of platelets; k is the total number of stripes in the statistical area.

[0038] Example 1

[0039] (1) Grinding molybdenum oxide and nickel oxide to a particle size of 10-20 μm, and uniformly mixing with pseudo-boehmite and sesbania powder with a particle size of 5-10 nm, wherein the pseudo-boehmite is calculated as aluminum oxide, and the weight ratio of each component is m (molybdenum oxide): m (nickel oxide): m (aluminum oxide): m (sesbania powder) = 9.3:2.6:88.1:3, to obtain a catalyst precursor;

[0040] (2) Nitric acid and water are uniformly added to the catalyst precursor of step (1), wherein the amount of nitric acid added is 3% of the alumina and the amount of water added is 90% of the alumina. After mixing evenly, the mixture is extruded and then treated at 400°C for 3 hours to obtain a silicon capture catalyst FS-1.

[0041] The weight percentages of the components in the silicon capture catalyst FS-1 are: MoO3 is 9.3%, NiO is 2.6%, and the rest is alumina.

[0042] Example 2

[0043] (1) Grinding ammonium heptamolybdate and basic cobalt carbonate to a particle size of 10-20 μm, and uniformly mixing with pseudo-boehmite and sesbania powder having a particle size of 5-10 nm, wherein the active metal is calculated as oxide and the pseudo-boehmite is calculated as aluminum oxide, wherein the weight ratio of each component is m (molybdenum oxide): m (cobalt oxide): m (aluminum oxide): m (sesbania powder) = 8.9:3.1:88:4, to obtain a catalyst precursor;

[0044] (2) Phosphoric acid and water are uniformly added to the catalyst precursor of step (1), wherein the amount of phosphoric acid added is 5% of the alumina and the amount of water added is 95% of the alumina. After mixing evenly, the mixture is extruded and then treated at 500°C for 3 hours to obtain the silicon capture catalyst FS-2.

[0045] The weight percentages of the components in the silicon capture catalyst FS-2 are: MoO3 is 8.9%, CoO is 3.1%, and the rest is alumina.

[0046] Example 3

[0047] (1) Grinding molybdenum oxide, basic nickel carbonate, and basic cobalt carbonate to a particle size of 20-30 μm, and uniformly mixing with pseudo-boehmite and sesbania powder having a particle size of 50-80 nm, wherein the active metal is calculated as oxide and the pseudo-boehmite is calculated as aluminum oxide, wherein the weight ratio of each component is m(molybdenum oxide):m(nickel oxide):m(cobalt oxide):m(aluminum oxide):m(sesbania powder) = 9.3:1.2:2.1:87.4:4, to obtain a catalyst precursor;

[0048] (2) Nitric acid and water are uniformly added to the catalyst precursor of step (1), wherein the amount of nitric acid added is 3.5% of the alumina and the amount of water added is 95% of the alumina. After mixing evenly, the mixture is extruded and then treated at 400°C for 3 hours to obtain a silicon capture catalyst FS-3.

[0049] The weight percentages of the components in the silicon capture catalyst FS-3 are: MoO3 is 9.3%, NiO is 1.2%, CoO is 2.1%, and the rest is alumina.

[0050] Example 4

[0051] (1) Grind ammonium tungstate and nickel sulfide to a particle size of 20-30 μm, and mix them evenly with boehmite and sesbania powder with a particle size of 5-10 nm. The active metal is calculated as oxide, and the boehmite is calculated as aluminum oxide. The weight ratio of each component is m (molybdenum oxide): m (nickel oxide): m (aluminum oxide): m (sesbania powder) = 12.1:3.6:84.3:4, to obtain a catalyst precursor.

[0052] (2) Phosphoric acid and water are uniformly added to the catalyst precursor of step (1), wherein the amount of phosphoric acid added is 4.5% of the alumina and the amount of water added is 95% of the alumina. After mixing evenly, the mixture is extruded and then treated at 400°C for 3 hours to obtain the silicon capture catalyst FS-4.

[0053] The weight percentages of the components in the silicon capture catalyst FS-4 are: WO3 is 12.1%, NiO is 3.6%, and the rest is alumina.

[0054] Example 5

[0055] (1) Grind ammonium tungstate and basic cobalt carbonate to a particle size of 10-30 μm, and mix them evenly with boehmite and sesbania powder with a particle size of 5-10 nm. The active metal is calculated as oxide, and the boehmite is calculated as aluminum oxide. The weight ratio of each component is m (molybdenum oxide): m (cobalt oxide): m (aluminum oxide): m (sesbania powder) = 10.7:2.8:86.5:4, to obtain a catalyst precursor.

[0056] (2) Phosphoric acid and water are uniformly added to the catalyst precursor of step (1), wherein the amount of phosphoric acid added is 3.5% of the alumina and the amount of water added is 95% of the alumina. After mixing evenly, the mixture is extruded and then treated at 430°C for 3 hours to obtain the silicon capture catalyst FS-5.

[0057] The weight percentages of the components in the silicon capture catalyst FS-5 are: WO3 is 10.7%, CoO is 2.8%, and the rest is alumina.

[0058] Example 6

[0059] (1) Grinding tungsten oxide, nickel oxide, and basic cobalt carbonate to a particle size of 50-100 μm, and uniformly mixing with pseudo-boehmite and sesbania powder with a particle size of 5-10 nm, wherein the active metal is calculated as oxide and the pseudo-boehmite is calculated as alumina, wherein the weight ratio of each component is m(tungsten oxide):m(nickel oxide):m(cobalt oxide):m(alumina):m(sesbania powder) = 12.3:2.1:2.6:83:4, to obtain a catalyst precursor;

[0060] (2) Phosphoric acid and water are uniformly added to the catalyst precursor of step (1), wherein the amount of phosphoric acid added is 3.5% of the alumina and the amount of water added is 95% of the alumina. After mixing evenly, the mixture is extruded and then treated at 480°C for 3 hours to obtain the silicon capture catalyst FS-6.

[0061] The weight percentages of the components in the silicon capture catalyst FS-6 are: WO3 is 12.3%, NiO is 2.1%, CoO is 2.6%, and the rest is alumina.

[0062] Example 7

[0063] (1) Grinding ammonium molybdate, ammonium tungstate, and basic nickel carbonate to a particle size of 10-20 μm, and uniformly mixing with pseudo-boehmite and sesbania powder having a particle size of 5-10 nm, wherein the active metal is calculated as oxide and the pseudo-boehmite is calculated as aluminum oxide, wherein the weight ratio of each component is m(molybdenum oxide):m(tungsten oxide):m(nickel oxide):m(aluminum oxide):m(sesbania powder) = 6.1:5.9:2.3:85.7:4, to obtain a catalyst precursor;

[0064] (2) Phosphoric acid and water are uniformly added to the catalyst precursor of step (1), wherein the amount of phosphoric acid added is 3.5% of the alumina and the amount of water added is 115% of the alumina. After mixing evenly, the mixture is extruded and then treated at 380°C for 3 hours to obtain the silicon capture catalyst FS-7.

[0065] The weight percentages of the components in the silicon capture catalyst FS-7 are: MoO3 is 6.1%, WO3 is 5.9%, NiO is 2.3%, and the rest is alumina.

[0066] Comparative Example 1

[0067] (1) dissolving ammonium heptamolybdate and nickel nitrate in water to form a metal salt solution, and then uniformly mixing the solution with pseudo-boehmite and sesbania powder having a particle size of 5-10 nm, wherein the active metal is calculated as oxide and the pseudo-boehmite is calculated as aluminum oxide, and the weight ratio of the components is m (molybdenum oxide): m (nickel oxide): m (aluminum oxide): m (sesbania powder) = 9.3:2.6:88.1:3, to obtain a catalyst precursor;

[0068] The operation process of step (2) is the same as that of Example 1 to obtain a comparative silicon capture catalyst DC-1.

[0069] The weight percentages of the components in the comparative silicon capture catalyst DC-1 are as follows: MoO3 is 9.3%, NiO is 2.6%, and the rest is alumina.

[0070] Comparative Example 2

[0071] (1) Pseudoboehmite, nitric acid, starch, and deionized water were uniformly mixed, wherein the mass ratio of pseudoboehmite: nitric acid: starch: deionized water was 100:3.5:3:90, and then kneaded and extruded into strips, and then dried at 80°C for 10 hours and calcined at 650°C for 3 hours to obtain an alumina carrier.

[0072] (2) The ammonium heptamolybdate and nickel nitrate solution were impregnated into the alumina carrier prepared in step (1), and then dried at 90°C for 3 hours and calcined at 450°C for 3 hours to obtain the silicon capture catalyst DC-2.

[0073] The weight percentages of the components in the comparative silicon capture catalyst DC-2 are as follows: MoO3 is 9.3%, NiO is 2.6%, and the rest is alumina.

[0074] Comparative Example 3

[0075] (1) Pseudoboehmite, phosphoric acid, sesbania powder, and deionized water were uniformly mixed, wherein the mass ratio of pseudoboehmite: phosphoric acid: sesbania powder: deionized water was 100:4.5:4.5:95, and then kneaded and extruded into strips, and then dried at 80°C for 10 hours and calcined at 550°C for 3 hours to obtain an alumina carrier.

[0076] (2) The ammonium heptamolybdate and cobalt nitrate solution was impregnated into the alumina carrier prepared in step (1), and then dried at 90°C for 3 hours and calcined at 450°C for 3 hours to obtain the silicon capture catalyst DC-3.

[0077] The weight percentages of the components in the comparative silicon capture catalyst DC-3 are as follows: MoO3 is 8.9%, CoO is 3.1%, and the rest is alumina.

[0078] Comparative Example 4

[0079] (1) Grinding molybdenum oxide and nickel oxide to a particle size of 10-20 μm, and uniformly mixing with pseudo-boehmite and sesbania powder having a particle size of 800-900 nm, wherein the active metal is calculated as oxide and the pseudo-boehmite is calculated as aluminum oxide, wherein the weight ratio of each component is m(molybdenum oxide):m(nickel oxide):m(aluminum oxide):m(sesbania powder) = 9.3:2.6:88.1:3, to obtain a catalyst precursor;

[0080] The operation process of step (2) is the same as that of Example 1, and a comparative silicon capture catalyst DC-4 is obtained.

[0081] The weight percentages of the components in the comparative silicon capture catalyst DC-4 are as follows: MoO3 is 9.3%, NiO is 2.6%, and the rest is alumina.

[0082] Comparative Example 5

[0083] (1) Molybdenum oxide and nickel oxide were ground into particles with a particle size of 10-20 μm, and mixed evenly with pseudo-boehmite and sesbania powder with a particle size of 5-10 nm, nitric acid, and deionized water. The active metals were calculated as oxides, and the pseudo-boehmite was calculated as aluminum oxide. The weight ratio of each component was m(molybdenum oxide):m(nickel oxide):m(aluminum oxide):m(sesbania powder):m(nitric acid):m(water)=9.3:2.6:88.1:3:3:90. The mixture was extruded and then treated at 400°C for 3 hours to obtain a comparative silicon capture catalyst DC-5.

[0084] The weight percentages of the components in the comparative silicon capture catalyst DC-5 are as follows: MoO3 is 9.3%, NiO is 2.6%, and the rest is alumina.

[0085] The physicochemical properties of the catalysts FS-1 to FS-7 prepared in the above examples and the catalysts DC-1 to DC-5 prepared in the comparative examples were analyzed. The analysis results are shown in Table 1.

[0086] Table 1.

[0087]

[0088] Example 8

[0089] This example illustrates the silicon capture activity of the catalyst provided by the present invention for coker naphtha.

[0090] The raw oil used for evaluation is coking naphtha provided by a refinery of Sinopec, and its main properties are as follows: sulfur content is 4356μg / g, nitrogen content is 86μg / g, and silicon content is 305μg / g. A 200mL fixed bed hydrogenation device was used to evaluate the silicon capture capacity of silicon capture catalysts FS-1 to FS-7 and comparative examples DC-1 to DC-5. Among them, silicon capture catalysts FS-1 to FS-7 and comparative examples DC-1 to DC-5 were pre-sulfurized. The pre-sulfurization conditions are: using aviation kerosene containing 3wt% CS2 at an air velocity of 2.0h -1 The presulfidation was carried out at an operating pressure of 3.5 MPa, a hydrogen / oil volume ratio of 500:1, and an operating pressure of 3.5 MPa. The evaluation reaction conditions were: operating pressure 3.0 MPa, reaction temperature 260°C, hydrogen / oil volume ratio 200:1, and volume space velocity 3.0 h -1 After running for 240 hours, the silicon scavenger was unloaded and then calcined at 500℃ for 3 hours. The SiO2 content in the silicon scavenger was analyzed by XRF. The evaluation results are shown in Table 2.

[0091] Table 2.

[0092]

[0093] As can be seen from Table 2, the silicon-capturing catalyst of the present invention has a very high silicon-holding capacity.

Claims

1. A silicon capture catalyst, characterized in that The catalyst comprises aluminum oxide and an active component, wherein the active component is a metal oxide of Group VIB and a metal oxide of Group VIII. Based on the total weight of the catalyst, the metal oxide of Group VIB accounts for 2-20%, and the metal oxide of Group VIII accounts for 1-10%. The specific surface area of ​​the silicon capture catalyst is ≮300m 2 / g, the surface hydroxyl content is ≮800µmol / g; after the silicon capture catalyst is sulfurized, when analyzed by TEM, the number of stacking layers of the VIB group metal sulfide is 1-3 layers, and the length of the crystal of the VIB group metal sulfide is 5-10nm; The silicon capture catalyst is prepared by the following method: (1) uniformly mixing an aluminum oxide precursor with a Group VIB metal salt or / and a Group VIB metal oxide, a Group VIII metal salt or / and a Group VIII metal oxide, and an extrusion aid to obtain a catalyst precursor; wherein the particle size of the aluminum oxide precursor is 1-500 nm; the particle size of the Group VIB metal salt or / and a Group VIB metal oxide, the Group VIII metal salt or / and a Group VIII metal oxide is 1-100 μm; (2) adding the peptizing agent and water evenly to the catalyst precursor of step (1), mixing evenly, extruding and molding, and drying to obtain the silicon capture catalyst.

2. The silicon-trapping catalyst according to claim 1, characterized in that The specific surface area of ​​the silicon capture catalyst is 350-450m 2 / g, and the surface hydroxyl content is 1200-1800µmol / g.

3. The silicon-trapping catalyst according to claim 2, characterized in that The surface hydroxyl content of the silicon capture catalyst is 1200-1500 μmol / g.

4. The silicon-trapping catalyst according to claim 1, characterized in that The Group VIB metal oxide is molybdenum oxide and / or tungsten oxide, and the Group VIII metal oxide is nickel oxide and / or cobalt oxide.

5. The method for preparing the silicon-trapping catalyst according to claim 1, comprising the following steps: (1) uniformly mixing an aluminum oxide precursor with a Group VIB metal salt or / and a Group VIB metal oxide, a Group VIII metal salt or / and a Group VIII metal oxide, and an extrusion aid to obtain a catalyst precursor; wherein the particle size of the aluminum oxide precursor is 1-500 nm; the particle size of the Group VIB metal salt or / and a Group VIB metal oxide, the Group VIII metal salt or / and a Group VIII metal oxide is 1-100 μm; (2) adding the peptizing agent and water evenly to the catalyst precursor of step (1), mixing evenly, extruding and molding, and drying to obtain the silicon capture catalyst.

6. The method for preparing a silicon-trapping catalyst according to claim 5, wherein: The particle size of the aluminum oxide precursor in step (1) is 5-200 nm, and the particle size of the Group VIB metal salt or / and Group VIB metal oxide, the Group VIII metal salt or / and Group VIII metal oxide is 5-80 μm.

7. The method for preparing a silicon-trapping catalyst according to claim 5, wherein: The precursor of aluminum oxide in step (1) is selected from one or more of pseudo-boehmite, boehmite, gibbsite, nordstromite and diaspore.

8. The method for preparing a silicon-trapping catalyst according to claim 5, wherein: The extrusion aid is selected from at least one of starch, polyethylene glycol and sesbania powder.

9. The method for preparing a silicon-trapping catalyst according to claim 5, wherein: The alumina precursor is calculated as alumina, and the amount of the extrusion aid added is 2-8 wt % of the alumina.

10. The method for preparing a silicon-trapping catalyst according to claim 5, wherein: The peptizing agent is selected from at least one of nitric acid, phosphoric acid and acetic acid.

11. The method for preparing a silicon-trapping catalyst according to claim 5, wherein: The aluminum oxide precursor is calculated as aluminum oxide, and the amount of the peptizing agent added is 1-8 wt % of the aluminum oxide.

12. The method for preparing a silicon-trapping catalyst according to claim 5, wherein: The aluminum oxide precursor is calculated based on aluminum oxide, and the amount of water added is 50-150 wt % of the aluminum oxide.

13. The method for preparing a silicon-trapping catalyst according to claim 5, wherein: The drying treatment conditions in step (2) are: temperature 90-700°C, time 1-10 hours.

14. The use of the silicon-trapping catalyst according to claim 1, characterized in that: It is used in the hydrotreating process of silicone oil products.

15. The use according to claim 14, characterized in that The silicon capture catalyst needs to be sulfurized before use.

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