Upflowing residue hydrotreating catalyst and method for preparing the same

Abstract

The application discloses an upflow type residual oil hydrogenation catalyst and a preparation method thereof. The catalyst is spherical, active metals loaded on the catalyst are in yolk type distribution, the active metal loadings decrease step by step along the radial direction of the sphere from the sphere center to the outside, at the same time, the average pore diameter of the catalyst increases step by step along the radial direction of the sphere from the sphere center to the outside surface, and the surface layer of the catalyst contains a macropore structure with a size of more than 100 nm. The catalyst obtained by the application has the characteristics of high impurity removal activity and high stability, and is particularly suitable for an upflow type residual oil catalytic hydrogenation treatment process.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to an upflow residue hydrogenation catalyst and its preparation method. Background Technology

[0002] As crude oil becomes increasingly heavy and of lower quality, and environmental regulations become more stringent, the use of hydrotreating technology to process residual oil can not only convert heavy oil into light oil products and improve crude oil utilization, but also reduce environmental pollution and meet environmental regulations. Therefore, residual oil hydrotreating technology has become the preferred technology for refining and chemical enterprises to process heavy oil.

[0003] Residue hydrotreating technologies generally include fixed-bed, moving-bed, fluidized-bed, and slurry-bed processes. Among these, fixed-bed residue hydrotreating technology has the highest maturity and is the most widely used. In fixed-bed residue hydrotreating technology, an upflow reactor (UFR) can be installed before the fixed-bed reactor to extend the unit's operating cycle. In the upflow reactor, the mixture of feedstock and hydrogen flows upward from the bottom of the reactor through the catalyst bed, causing the entire catalyst bed to be in a slightly expanded state. Therefore, the pressure drop in the reactor is small, and it can effectively remove impurities such as metals (mainly Ni and V), sulfur, and nitrogen from the feedstock, protecting the downstream fixed-bed catalyst and fully utilizing the overall catalyst performance, thereby extending the unit's operating cycle. It is generally believed that spherical catalysts with smaller particle sizes are more suitable for upflow residue hydrotreating.

[0004] Most metallic impurities in residual oil are found in macromolecular compounds such as asphaltenes and gums. These compounds have complex structures and large molecular sizes, making diffusion difficult within the catalyst channels. Therefore, residual oil hydrotreating is a typical internal diffusion-controlled process. Furthermore, coke and removed metals will deposit on the catalyst surface and within the channels. To prevent deposited metals and coke from clogging the catalyst pores and causing rapid catalyst deactivation, upflow residual oil hydrotreating catalysts require excellent pore structures. The catalyst surface should have large pores to facilitate the diffusion and mass transfer of macromolecular compounds such as asphaltenes, while the interior should have a mesoporous structure to provide sufficient active surface area, thereby improving catalyst reactivity and extending catalyst lifespan. In addition, a yolk-shaped distribution of active components within the catalyst facilitates the transfer of chemical reactions such as demetallization to the interior, minimizing the deposition of impurity metals at the catalyst pores and further extending catalyst lifespan.

[0005] Patent CN 1665907A discloses an upflow hydrogenation catalyst whose support is composed of alumina with a pore volume of 0.6~1.1 mL / g and a specific surface area of ​​110~190 m². 2The catalyst has a pore size of approximately 0.1 inches (about 2.5 mm), with less than 35% having a diameter greater than 1000 angstroms and a peak pore size of 80–140 angstroms for nitrogen desorption. The catalyst is spherical or elliptical in shape. The average pore size is small, and compared to the catalyst prepared in US Patent 5472928, this catalyst exhibits higher hydrodesulfurization activity and lower hydrodemetallization activity. In heavy oil hydrotreating, the heavy feedstock is first contacted with the catalyst prepared according to US 5472928 under hydrodemetallization conditions, and then the product is contacted with this catalyst for hydrodesulfurization. While suitable as a hydrodesulfurization catalyst, it requires prior gradation with a hydrodemetallization catalyst to extend its lifespan; therefore, it is not suitable for use alone in an upflow reactor.

[0006] US Patent 4,448,896 discloses an alumina carrier with unobstructed pores and its preparation method. It uses boehmite as a raw material and carbon black powder as a pore-expanding agent, obtaining the alumina carrier through mixing, extrusion, drying, and calcination. Its drawback is that adding a small amount of carbon black powder easily forms "ink bottle" shaped pores, making it difficult to form unobstructed pores; adding too much carbon black powder significantly reduces the carrier's strength.

[0007] Patent CN 104646005A discloses a catalyst with an open "trumpet-shaped" pore structure and its preparation method. The catalyst support pores gradually increase in size from the center of the particle to the outer surface, with an average pore diameter of 19.0~30.0 nm. This method can alleviate the pore blockage problem of the catalyst to some extent, but the lack of large pores on the catalyst surface limits the improvement on the catalyst diffusion performance, and large molecular reactants such as asphaltene still have difficulty penetrating to the center of the catalyst particles.

[0008] European Patent EP 0204314 discloses a hydrotreating catalyst with a non-uniform distribution of active metal components. This patent employs a stepwise, multiple-impregnation method to load the active metal components. First, the support is immersed in solution A containing a portion of the active metal components, then removed, washed, dried, and calcined. Next, it is immersed in solution B containing other active metal components, removed, washed, dried, and calcined again to obtain a catalyst with a higher concentration of internal metal components than on the outer surface. This method requires multiple steps of impregnation, washing, drying, and calcination, making the catalyst preparation process overly complex and increasing production costs.

[0009] Patent CN 115888690A discloses a heavy oil hydrodemetallization catalyst for upflow reactors and its preparation method. The catalyst consists of a spherical alumina support and an active metal component loaded on the support. The average pore diameter gradually increases from the center to the outer surface of the sphere, while the active metal loading gradually decreases. The catalyst surface still contains a certain amount of active metal and lacks large pores, so demetallization and other chemical reactions still occur on the catalyst surface. This has limited effectiveness in reducing the deposition of impurity metals at the catalyst pore openings. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides a catalyst for residue hydrotreating with directionally tunable catalyst pore structure and active metal, and its preparation method. This catalyst features high impurity removal activity and high stability, and is particularly suitable for upflow residue catalytic hydrotreating processes.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] An upflow residue hydrotreating catalyst is spherical, on which the active metals are distributed in an egg yolk pattern. The loading of active metals decreases in a stepwise manner from the center to the outside of the sphere along the radial direction of the sphere. At the same time, the average pore diameter of the catalyst increases in a stepwise manner from the center to the outer surface of the sphere along the radial direction of the sphere, and the surface layer of the catalyst contains macroporous structures with a diameter of more than 100 nm.

[0013] Furthermore, based on mercury porosimetry, the catalyst has a pore volume of 0.4–1.4 mL / g and a specific surface area of ​​60–200 m² / g. 2 / g; The active metal content from the center of the sphere to 30-50% of the radius of the sphere is 2-9 wt%, and the average pore diameter is 10-25 nm; The active metal content from 30-50% of the radius of the sphere to 50-80% of the radius of the sphere is 0.1-3 wt%, and the average pore diameter is 20-40 nm; The area from 50-80% of the radius of the sphere to the outer surface of the sphere contains no active metal, and the average pore diameter is 40-60 nm, with pores larger than 100 nm accounting for 20%-60% of the total pore volume.

[0014] Furthermore, the active metal is at least one group VIB metal, and the content of the active metal in the catalyst is 2 to 12 wt% in the form of metal oxide.

[0015] The preparation method of the upflow residue hydrotreating catalyst includes the following steps:

[0016] (1) Mix PB-1 of boehmite with active metal precursor and molding auxiliary material evenly as powder A, mix PB-2 of boehmite with active metal precursor and molding auxiliary material evenly as powder B, and mix PB-2 of boehmite with template agent and molding auxiliary material evenly as powder C.

[0017] (2) Powder A is fed into the sugar coating machine and sprayed with adhesive solvent to form balls. When the average wet ball size reaches an appropriate size, the feeding of powder A is stopped. Then powder B is fed into the sugar coating machine and sprayed with adhesive solvent to form balls. When the average wet ball size reaches an appropriate size, the feeding of powder B is stopped. Then powder C is fed into the sugar coating machine and sprayed with adhesive solvent to form balls. When the average wet ball size reaches an appropriate size, the ball forming is completed.

[0018] (3) The obtained wet bulbs are cured, dried and calcined to obtain the catalyst.

[0019] Furthermore, the pseudoboehmite PB-1 and PB-2 mentioned in step (1) can be commercially available products or products prepared by any method in the prior art, such as aluminum sulfate method, carbonization method, aluminum alkoxide hydrolysis method, hydrothermal method, etc.

[0020] Furthermore, the pseudoboehmite PB-1 described in step (1) has a pore volume of 0.8~1.2 mL / g and a specific surface area of ​​200~350 m². 2 / g, with a grain size d(120) of 8~20 nm; the pseudoboehmite PB-2 has a pore volume of 1.0~1.5 mL / g and a specific surface area of ​​80~200 m² / g. 2 / g, grain size d(120)≥25 nm.

[0021] Further, the active metal precursor mentioned in step (1) is at least one group VIB metal oxide, and its amount in powder A is 30-60% of the dry basis mass of boehmite PB-1, and its amount in powder B is 3-15% of the dry basis mass of boehmite PB-2.

[0022] Further, the molding auxiliary material mentioned in step (1) is selected from one or more of guar gum powder, starch, methylcellulose, polyacrylamide, and polycarboxylic acid, and its addition amount is 0.3~5% of the dry basis mass of the corresponding boehmite.

[0023] Further, the template agent mentioned in step (1) is one or more of the following high molecular polymer powders: polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyurethane, etc., and its addition amount is 5 to 30% of the dry basis mass of pseudoboehmite PB-2.

[0024] Further, the adhesive solvent mentioned in step (2) is a variety of adhesive solvents commonly used in the art. It can be aluminum sol and / or silica sol, or it can be an inorganic acid and / or organic acid solution. The mass concentration of the inorganic acid and / or organic acid is 2-20%. The inorganic acid can be one or more of nitric acid, phosphoric acid, hydrochloric acid, and sulfuric acid, preferably nitric acid. The organic acid can be one or more of oxalic acid, acetic acid, and citric acid.

[0025] Furthermore, the temperature for health preservation in step (3) is 10~40℃ and the time is 6~48 h.

[0026] Furthermore, the drying temperature in step (3) is 50~150 ℃ and the time is 1-24 h.

[0027] Furthermore, the roasting temperature in step (3) is 450~750 ℃ ​​and the time is 1~6 h.

[0028] This invention combines pseudoboehmite raw materials with different grain sizes and different contents of active metal components and template agents, which can flexibly control the pore diameter inside and on the surface of the catalyst and the distribution of active metal components on the catalyst. Ultimately, the pore diameter of the catalyst continuously increases from the center of the sphere to the outer surface, forming an open, stepped pore structure, which improves the diffusion performance of the catalyst. At the same time, the active components are located inside the catalyst in an egg yolk-like distribution, which is conducive to transferring chemical reactions such as demetallization to the inside of the catalyst, so that the removed impurity metals are deposited inside the catalyst, minimizing the deposition of impurity metals at the catalyst pore openings, thereby improving the impurity removal activity and stability of the catalyst.

[0029] The significant advantages of this invention are:

[0030] The catalyst provided by this invention exhibits a stepped pore structure, with the active metal components distributed in an egg yolk-like and stepped pattern. The macroporous structure of the catalyst surface layer facilitates the diffusion and mass transfer of large molecular compounds, reducing surface-level reactions and preventing the removal of metals and carbon deposits from clogging the pore openings. The larger mesoporous structure and lower active metal content of the middle layer effectively promote the reaction process, allowing metals and carbon deposits to settle inside the catalyst. Simultaneously, it facilitates the further diffusion of smaller compound molecules after metal removal into the inner layer. The smaller mesoporous structure of the inner layer provides a larger specific surface area and a higher active metal content, offering sufficient space for the reaction. Furthermore, the product molecules can rapidly diffuse outwards due to the macroporous structure of the outer layer. Therefore, the catalyst prepared by this invention exhibits excellent performance and is particularly suitable for upflow residue hydrotreating processes.

[0031] The catalyst preparation method provided by this invention is simple, the process is concise, and the pore structure and active metal content of each layer can be flexibly adjusted and easily controlled, making it easy to apply in industry. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the radial distribution of the catalyst pore size provided by the present invention.

[0033] Figure 2 This is a schematic diagram of the radial distribution of active metal content in the catalyst provided by the present invention. Detailed Implementation

[0034] An upflow residue hydrotreating catalyst, the preparation method of which includes the following steps:

[0035] (1) Mix PB-1 of boehmite with active metal precursor and molding auxiliary material evenly as powder A, mix PB-2 of boehmite with active metal precursor and molding auxiliary material evenly as powder B, and mix PB-2 of boehmite with template agent and molding auxiliary material evenly as powder C.

[0036] (2) Powder A is fed into the sugar coating machine and sprayed with adhesive solvent to form balls. When the average wet ball size reaches an appropriate size, the feeding of powder A is stopped. Then powder B is fed into the sugar coating machine and sprayed with adhesive solvent to form balls. When the average wet ball size reaches an appropriate size, the feeding of powder B is stopped. Then powder C is fed into the sugar coating machine and sprayed with adhesive solvent to form balls. When the average wet ball size reaches an appropriate size, the ball forming is completed.

[0037] (3) After the obtained wet bulbs are cured at 10~40℃ for 6~48 h, they are dried at 50~150℃ for 1~24 h, and then calcined at 450~750℃ for 1~6 h to obtain the catalyst.

[0038] In step (1), the active metal precursor is at least one group VIB metal oxide, and its amount in powder A is 30-60% of the dry weight of boehmite PB-1, and its amount in powder B is 3-15% of the dry weight of boehmite PB-2. The molding auxiliary material is selected from one or more of guar gum powder, starch, methylcellulose, polyacrylamide, and polycarboxylic acids, and its amount added is 0.3-5% of the corresponding dry weight of boehmite. The template agent is one or more of high molecular weight polymer powders such as polyethylene, polypropylene, polyvinyl chloride, polystyrene, and polyurethane, and its amount added is 5-30% of the dry weight of boehmite PB-2.

[0039] To make the content of this invention easier to understand, the technical solution of this invention will be further described below with reference to specific embodiments, but this invention is not limited thereto.

[0040] Example 1

[0041] (1) Weigh 1000 g of pseudoboehmite PB-1 (pore volume of 1.0 mL / g, specific surface area of ​​220 m²) 2 / g, crystal size d(120) is 15 nm) and 520 g of molybdenum trioxide and 25 g of guar gum powder were mixed evenly to obtain powder A1; 1000 g of pseudoboehmite PB-2 (pore volume is 1.2 mL / g, specific surface area is 120 m²) was weighed. 2 / g, crystal size d(120) is 40 nm) and 40 g molybdenum trioxide, 25 g guar gum powder, are mixed evenly to obtain powder B1; 1000 g boehmite PB-2, 25 g guar gum powder and 70 g polyethylene powder are weighed and mixed evenly to obtain powder C1.

[0042] (2) Add 20 g of citric acid and 35 g of nitric acid to 1000 g of water and stir to mix evenly to obtain peptide solvent P1.

[0043] (3) Powder A1 is fed into the sugar coating machine and sprayed with adhesive solvent P1 to roll into balls. When the average wet ball size reaches 1.5 mm, the feeding of powder A1 is stopped. Then powder B1 is fed into the sugar coating machine and the adhesive solvent P1 is sprayed to continue to form balls. When the average wet ball size reaches 3.0 mm, the feeding of powder B1 is stopped. Then powder C1 is fed into the sugar coating machine and the adhesive solvent P1 is sprayed to continue to form balls. When the average wet ball size reaches 4.0 mm, the ball forming is completed.

[0044] (4) The wet bulb was cured at room temperature for 24 h, then dried at 80 ℃ for 6 h, and finally calcined at 650 ℃ for 4 h to obtain catalyst D1.

[0045] Example 2

[0046] (1) Weigh 1000 g of pseudoboehmite PB-1 (pore volume of 1.0 mL / g, specific surface area of ​​220 m²) 2 / g, crystal size d(120) is 15 nm) and 430 g of molybdenum trioxide and 25 g of guar gum powder were mixed evenly to obtain powder A2; 1000 g of pseudoboehmite PB-2 (pore volume is 1.2 mL / g, specific surface area is 120 m²) was weighed. 2 / g, crystal size d(120) is 40 nm) and 50 g molybdenum trioxide and 25 g guar gum powder are mixed evenly to obtain powder B2; 1000 g boehmite PB-2, 25 g guar gum powder and 80 g polyethylene powder are weighed and mixed evenly to obtain powder C2.

[0047] (2) Add 30 g of citric acid and 35 g of nitric acid to 980 g of water and stir to mix evenly to obtain peptide solvent P2.

[0048] (3) Powder A2 is fed into the sugar coating machine and sprayed with adhesive solvent P2 to roll into balls. When the average wet ball size reaches 1.6 mm, the feeding of powder A2 is stopped. Then powder B2 is fed into the sugar coating machine and the adhesive solvent P2 is sprayed to continue to form balls. When the average wet ball size reaches 2.8 mm, the feeding of powder B2 is stopped. Then powder C2 is fed into the sugar coating machine and the adhesive solvent P2 is sprayed to continue to form balls. When the average wet ball size reaches 4.0 mm, the ball forming is completed.

[0049] (4) The wet bulb was cured at room temperature for 24 h, then dried at 80 ℃ for 6 h, and finally calcined at 650 ℃ for 4 h to obtain catalyst D2.

[0050] Example 3

[0051] (1) Weigh 1000 g of pseudoboehmite PB-1 (pore volume of 1.0 mL / g, specific surface area of ​​220 m²) 2 / g, crystal size d(120) is 15 nm) and 300 g of molybdenum trioxide and 25 g of guar gum powder are mixed evenly to obtain powder A3; 1000 g of pseudoboehmite PB-2 (pore volume is 1.2 mL / g, specific surface area is 120 m²) is weighed. 2 / g, crystal size d(120) is 40 nm) and 30 g molybdenum trioxide and 25 g guar gum powder are mixed evenly to obtain powder B3; 1000 g boehmite PB-2, 25 g guar gum powder and 90 g polyethylene powder are weighed and mixed evenly to obtain powder C3.

[0052] (2) Add 30 g of citric acid and 40 g of nitric acid to 980 g of water and stir to mix evenly to obtain peptide solvent P3.

[0053] (3) Powder A3 is fed into the sugar coating machine and sprayed with adhesive solvent P3 to roll into balls. When the average wet ball size reaches 1.8 mm, the feeding of powder A3 is stopped. Then powder B3 is fed into the sugar coating machine and the adhesive solvent P3 is sprayed to continue to form balls. When the average wet ball size reaches 3.2 mm, the feeding of powder B3 is stopped. Then powder C3 is fed into the sugar coating machine and the adhesive solvent P3 is sprayed to continue to form balls. When the average wet ball size reaches 4.0 mm, the ball forming is completed.

[0054] (4) The wet bulb was cured at room temperature for 24 h, then dried at 80 ℃ for 6 h, and finally calcined at 650 ℃ for 4 h to obtain catalyst D3.

[0055] Comparative Example 1

[0056] (1) Weigh 1000 g of pseudoboehmite PB-1 (pore volume of 1.0 mL / g, specific surface area of ​​220 m²)2 / g, crystal size d(120) is 15 nm) and 42 g molybdenum trioxide and 25 g guar powder were mixed evenly to obtain powder A4.

[0057] (2) Add 20 g of citric acid and 35 g of nitric acid to 1000 g of water and stir to mix evenly to obtain peptide solvent P1.

[0058] (3) Powder A4 is fed into the sugar coating machine and sprayed with adhesive solvent P1 to roll into balls. When the average particle size of the wet balls reaches 4.0 mm, the ball forming ends.

[0059] (4) The wet bulb was cured at room temperature for 24 h, then dried at 80 ℃ for 6 h, and finally calcined at 650 ℃ for 4 h to obtain catalyst DD-1.

[0060] Comparative Example 2

[0061] (1) Weigh 1000 g of pseudoboehmite PB-1 (pore volume of 1.0 mL / g, specific surface area of ​​220 m²) 2 / g, crystal size d(120) is 15 nm) and 400 g of molybdenum trioxide and 25 g of guar gum powder are mixed evenly to obtain powder A5; 1000 g of pseudoboehmite PB-2 (pore volume is 1.2 mL / g, specific surface area is 120 m²) is weighed. 2 / g, crystal size d(120) is 40 nm) and 40 g molybdenum trioxide and 25 g guar gum powder, are mixed evenly to obtain powder B5; 1000 g boehmite PB-2, 12 g molybdenum trioxide, 25 g guar gum powder and 70 g polyethylene powder are weighed and mixed evenly to obtain powder C5.

[0062] (2) Add 20 g of citric acid and 35 g of nitric acid to 1000 g of water and stir to mix evenly to obtain peptide solvent P1.

[0063] (3) Powder A5 is fed into the sugar coating machine and sprayed with adhesive solvent P1 to roll into balls. When the average wet ball size reaches 1.5 mm, the feeding of powder A5 is stopped. Then powder B5 is fed into the sugar coating machine and the adhesive solvent P1 is sprayed to continue to form balls. When the average wet ball size reaches 3.0 mm, the feeding of powder B5 is stopped. Then powder C5 is fed into the sugar coating machine and the adhesive solvent P1 is sprayed to continue to form balls. When the average wet ball size reaches 4.0 mm, the ball forming is completed.

[0064] (4) The wet bulb was cured at room temperature for 24 h, then dried at 80 ℃ for 6 h, and finally calcined at 650 ℃ for 4 h to obtain catalyst DD-2.

[0065] 1. The physicochemical properties of the catalysts obtained in the examples and comparative examples are listed in Table 1.

[0066] The method for determining the average pore diameter of the catalyst from the center to the outer surface is as follows: During the spheroidization process, when the catalyst grows to a certain particle size, the sample is taken out for conditioning, drying and calcination. The pore volume, specific surface area and average pore diameter of the sample are determined by physical adsorption, mercury porosimetry and other analytical methods. The average pore diameter from the center to the outer surface is calculated based on the relationship that the total pore volume and surface area of ​​the sample are equal to the sum of the individual parts.

[0067] The method for determining the metal loading of the catalyst from the center of the sphere to different parts of the outer surface is as follows: During the spheroidization process, when the catalyst grows to a certain particle size, the sample is taken out for curing, drying and calcination. The metal content of the sample is determined by inductively coupled plasma (ICP). Based on the relationship that the total metal content of the sample is equal to the sum of the contents of each part, the average metal loading from the center of the sphere to different parts of the outer surface is calculated (the content of active metals refers to the mass fraction of the entire catalyst).

[0068] Table 1 Physicochemical properties of catalysts obtained in the examples and comparative examples

[0069]

[0070] As shown in Table 1, the catalyst prepared in the examples possesses an open, stepped-increase pore structure with larger pore volume and diameter, and a significant proportion of pores larger than 100 nm. The outer pore diameter is significantly larger than the inner pore diameter, and the pores are more open. Furthermore, the active metal component is distributed in an egg yolk pattern on the catalyst, and its content decreases in a stepwise manner from the center of the sphere outwards.

[0071] Application Examples

[0072] The catalysts obtained in the examples and comparative examples were evaluated on a 200 mL residue hydrotreating pilot unit. The feedstock residue oil had a sulfur content of 4.35 wt%, a nitrogen content of 2920 ppm, a nickel content of 32 ppm, and a vanadium content of 88 ppm. The catalyst loading volume was 100 mL. The catalyst was pre-sulfurized using a wet pre-sulfurization process before evaluation. The reaction conditions were: reaction temperature 385 °C. o C, hydrogen partial pressure 15 MPa, liquid hourly space velocity 1.0 h⁻¹ -1 The hydrogen-to-oil volume ratio was 700. The process conditions for evaluating each catalyst were identical.

[0073] The contents of nickel and vanadium in the oil before and after the reaction were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) (see GB / T 37160 for specific methods). The contents of sulfur in the oil before and after the reaction were determined by energy-dispersive X-ray fluorescence spectrometry (see GB / T17040 for specific methods). The demetallization rate and desulfurization rate of each catalyst were calculated according to the following formulas, and the evaluation results of each catalyst are shown in Table 2.

[0074] ,

[0075] .

[0076] Table 2 Performance evaluation results of the catalysts obtained in the examples and comparative examples

[0077]

[0078] The results in Table 2 show that the catalysts prepared in the examples have higher impurity removal activity and better activity stability.

[0079] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.

Claims

1. An upflowing residual hydroprocessing catalyst characterized in that, The catalyst is spherical, the active metal loaded thereon is in yolk-like distribution on the catalyst, and the active metal loading decreases stepwise from the center to the outside of the sphere along the radial direction of the sphere, at the same time, the average pore diameter of the catalyst increases stepwise from the center to the outer surface of the sphere along the radial direction of the sphere, and the surface layer of the catalyst contains macroporous structure of 100 nm or more; the preparation method comprises the following steps: (1) uniformly mixing pseudo-boehmite PB-1, active metal precursor and molding auxiliary as powder A, uniformly mixing pseudo-boehmite PB-2, active metal precursor and molding auxiliary as powder B, and uniformly mixing pseudo-boehmite PB-2, template agent and molding auxiliary as powder C; (2) feeding powder A into a sugar-coating machine, spraying a glue solvent to form a ball, when the average particle size of the wet ball reaches an appropriate size, stopping feeding powder A; then feeding powder B into the sugar-coating machine, continuing to spray the glue solvent to form a ball, when the average particle size of the wet ball reaches an appropriate size, stopping feeding powder B; then feeding powder C into the sugar-coating machine, continuing to spray the glue solvent to form a ball, when the average particle size of the wet ball reaches an appropriate size, the ball forming is completed; (3) after the obtained wet ball is aged, dried and calcined, the catalyst is obtained.

2. The upflowing residual oil hydroprocessing catalyst according to claim 1, characterized in that, The catalyst has a pore volume of 0.4 to 1.4 mL / g and a specific surface area of 60 to 200 m 2 / g; an active metal content of 2 to 9 wt% from the sphere center to a distance of 30-50 % of the sphere radius, an average pore diameter of 10 to 25 nm; an active metal content of 0.1 to 3 wt% from a distance of 30-50 % of the sphere radius to a distance of 50-80 % of the sphere radius, an average pore diameter of 20 to 40 nm; no active metal from a distance of 50-80 % of the sphere radius to the outer surface of the sphere, an average pore diameter of 40 to 60 nm, and wherein the pores having a diameter of 100 nm or more account for 20 to 60 % of the total pore volume.

3. The upflowing residual oil hydroprocessing catalyst of claim 1, wherein, The active metal is at least one metal of group VIB, and the content of the active metal in the catalyst is 2-12 wt% in the form of metal oxide.

4. The upflowing residual oil hydroprocessing catalyst of claim 1, wherein, The pseudo-boehmite PB-1 has a pore volume of 0.8-1.2 mL / g, a specific surface area of 200-350 m 2 / g, and a crystal grain size d(120) of 8-20 nm; and the pseudo-boehmite PB-2 has a pore volume of 1.0-1.5 mL / g, a specific surface area of 80-200 m 2 / g, and a crystal grain size d(120) of ≥25 nm.

5. The upflowing residual oil hydroprocessing catalyst of claim 1, wherein, The amount of the active metal precursor in powder A in step (1) is 30-60 % of the dry basis mass of pseudo-boehmite PB-1, and the amount in powder B is 3-15 % of the dry basis mass of pseudo-boehmite PB-2.

6. The upflowing residual oil hydroprocessing catalyst according to claim 1, characterized in that, The molding auxiliary in step (1) is selected from one or more of sesbania gum, starch, methyl cellulose, polyacrylamide and polycarboxylic acid, and the addition amount is 0.3-5 % of the dry basis mass of pseudo-boehmite.

7. The upflowing residual oil hydroprocessing catalyst according to claim 1, characterized in that, The template agent in step (1) is one or more of polyethylene, polypropylene, polyvinyl chloride, polystyrene and polyurethane, and the addition amount is 5-30 % of the dry basis mass of pseudo-boehmite PB-2.

8. The upflowing residual oil hydroprocessing catalyst according to claim 1, characterized in that, The temperature for aging in step (3) is 10-40 ℃, and the time is 6-48 h; the temperature for drying is 50-150 ℃, and the time is 1-24 h; the temperature for calcining is 450-750 ℃, and the time is 1-6 h.

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