Heavy oil hydrodemetallization catalyst for upflow reactor and its preparation method

Abstract

The present invention discloses a heavy oil hydrodemetallization catalyst for an up-flow reactor and a preparation method thereof. The catalyst is composed of a spherical alumina support and active metal components supported on the support, and the average pore diameter gradually increases and the active metal loading gradually decreases from the center of the sphere to the outer surface along the radial direction of the sphere. In the present invention, pseudoboehmite PB-1, pseudoboehmite PB-2 and a forming auxiliary are respectively added at different feeding rates, and a solution of active metal components with a decreasing concentration is continuously sprayed on the surface of the obtained support mixture to prepare the catalyst. The catalyst has the characteristics of good hydrodemetallization performance and high stability, and is particularly suitable for the up-flow heavy oil hydrotreatment process.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalyst preparation, and particularly relates to a heavy oil hydrodemetallization catalyst for an up-flow reactor and a preparation method thereof. Background Art

[0002] In recent years, with the heavy quality of crude oil resources, the growth of the consumption demand for fuel oil and chemical products, and the increasingly strict environmental protection regulations, the use of hydrogenation technology to convert heavy oil including residue oil into high-quality fuel oil and chemical products helps to improve the utilization rate of crude oil, reduce environmental pollution, increase the yield of light oil, and improve product quality.

[0003] The hydrotreating process of heavy oil such as residue oil generally includes fixed bed, ebullated bed, and slurry bed hydrogenation processes. Compared with other heavy oil hydrogenation technologies, fixed bed hydrogenation has become the preferred technology for residue oil hydrogenation at present due to its relatively mature technology, low investment and operating costs, and safe and simple operation. In the fixed bed heavy oil hydrotreating technology, in order to extend the operation cycle of the unit, an up-flow reactor (Up-Flow Reactor, UFR) can be arranged at the front. In the up-flow reactor, the raw oil and gas mixture flow upward from the bottom of the reactor through the catalyst bed layer, making the entire catalyst bed layer present a slightly expanded state, with a small pressure drop. At the same time, it can effectively reduce the metal content of the feed entering the subsequent reactor, protect the downstream fixed bed reactor, and better exert the performance of the overall catalyst.

[0004] Heavy oil such as residue oil contains a large amount of impurities such as metals (Fe, Ni, V, etc.), sulfur, and nitrogen, and has a high carbon residue content. These impurities mainly exist in macromolecular compounds such as resins and asphaltenes. This part of the material has a complex structure, large molecular size, difficult diffusion, and the metal will deposit on the catalyst surface and in the pores after being removed. Therefore, in order to improve the metal accommodation capacity of the hydrodemetallization catalyst and extend the service life of the catalyst, it is necessary not only to improve the pore structure and pore distribution of the catalyst, but also to optimize the distribution of the active metal components on the carrier. The egg yolk-type distribution catalyst with the active component located in the central position can transfer the part causing pore blockage from the pore mouth to the inside of the pore, thereby improving the ability of the catalyst to accommodate deposited metals.

[0005] Chinese Patent CN 1665907A discloses an up-flow hydrogenation catalyst, the carrier of which is composed of alumina, the pore volume is 0.6 - 1.1 mL / g, and the specific surface area is 110 - 190 m 2 / g, the pores with a diameter greater than 1000 Å are less than 35% and the peak pore diameter by nitrogen desorption method is 80 - 140 Å. The shape of the catalyst is spherical or oval, and the particle size is about 0.1 inches. The average pore diameter of this catalyst is relatively small. Compared with the catalyst prepared by the method of US 5472928, it has higher hydrodesulfurization activity and lower hydrodemetallization activity. During the heavy oil hydrogenation process, the heavy raw material first contacts with the catalyst prepared by the method of US 5472928 under hydrodemetallization conditions, and then the product contacts with this catalyst for hydrodesulfurization. This catalyst is suitable as a hydrodesulfurization catalyst, but it needs a pre-stage hydrodemetallization catalyst to extend its service life. Therefore, it is not suitable for being used alone in an up-flow reactor.

[0006] US Patent US 4448896 uses the method of adding a pore-expanding agent to increase the pore volume of the alumina support and obtain unobstructed pores. This patent uses a pseudo-boehmite as the raw material, adds carbon black powder as the pore-expanding agent, and obtains the alumina support through kneading, extrusion, drying, and calcination. However, adding a small amount of carbon black powder is likely to form "ink bottle"-type pores and it is difficult to form effective through pores.

[0007] European Patent EP 0204314 provides a hydrotreating catalyst with an uneven distribution of active metal components. This catalyst uses a step-by-step and multiple impregnation method to load the active metal components, that is, first immerse the support in solution A containing part of the active metal components, take it out, wash, dry, and calcine it, then immerse it in solution B containing other active metal components, and take it out and wash, dry, and calcine it to obtain the catalyst. Through step-by-step washing and calcination, the metal component concentration inside the catalyst is higher than that on the outer surface. Compared with the catalyst with a uniform distribution, the service life of this catalyst with an uneven distribution of metal components is extended, thus ensuring a longer operation cycle of the device. However, due to this method using multiple, step-by-step impregnation, washing, and calcination, the preparation process of the catalyst is complex and the cost is increased. Summary of the Invention

[0008] The purpose of the present invention is to provide a spherical heavy oil hydrodemetallization catalyst with pore diameter directional modulation and controllable distribution of active metals and its preparation method. Its average pore diameter gradually increases from the center of the sphere to the outer surface along the radial direction of the catalyst sphere, and the active metal loading gradually decreases from the center of the sphere to the outer surface along the radial direction. It has the characteristics of good hydrodemetallization performance and high stability, and is particularly suitable for the up-flow heavy oil hydrotreating process.

[0009] To achieve the above purpose, the present invention adopts the following technical solutions:

[0010] A heavy oil hydrodemetallization catalyst for an upflow reactor, which is composed of a spherical alumina support and active metal components supported on the support, and the average pore diameter gradually increases and the active metal loading gradually decreases from the center of the sphere to the outer surface along the radial direction of the sphere.

[0011] Measured by mercury intrusion porosimetry, the pore volume of the catalyst is 0.5 - 0.9 mL / g, the average pore diameter is 15 - 30 nm, and the specific surface area is 80 - 200 m 2 / g; the average pore diameter at the center of the sphere is 10 - 20 nm, the average pore diameter at 60% to 80% of the sphere diameter is 13 - 25 nm, the average pore diameter at 80% to 90% of the sphere diameter is 16 - 30 nm, and the average pore diameter of the part from 90% of the sphere diameter to the outer surface of the sphere is 25 - 40 nm;

[0012] The active metal components are at least one metal of Group VIB and at least one metal of Group VIII; calculated in the form of metal oxides, the contents of the metal component oxides of Group VIB and Group VIII at the center of the catalyst sphere are 6 - 12 wt% and 1 - 3 wt% respectively, the contents of the metal component oxides of Group VIB and Group VIII at 40% to 60% of the sphere diameter are 5 - 10 wt% and 1 - 2.5 wt% respectively, the contents of the metal component oxides of Group VIB and Group VIII at 60% to 80% of the sphere diameter are 4 - 8 wt% and 0.6 - 2 wt% respectively, the contents of the metal component oxides of Group VIB and Group VIII at 80% to 90% of the sphere diameter are 2 - 6 wt% and 0.3 - 1.5 wt% respectively, and the contents of the metal component oxides of Group VIB and Group VIII of the part from 90% of the sphere diameter to the outer surface of the sphere are 1 - 3 wt% and 0.1 - 1 wt% respectively.

[0013] The heavy oil hydrodemetallization catalyst is prepared by separately adding pseudo-boehmite PB-1, pseudo-boehmite PB-2 and a forming auxiliary material into a mixer at different feeding rates for mixing, then transporting the obtained support mixture to a sugar coating machine, and continuously spraying a solution of active metal components with decreasing concentration into the sugar coating machine for rolling into balls, and then drying and calcining.

[0014] Furthermore, the pseudo-boehmite PB-1 and PB-2 used can be prepared by any method, such as precipitation method, alcohol-aluminum hydrolysis method, hydrothermal method, etc., and the weight percentages of the two are 20 - 80:80 - 20.

[0015] Furthermore, the pore volume of the pseudo-boehmite PB-1 is 0.7 - 1.1 mL / g, the specific surface area is 150 - 250 m 2 / g, and the crystal size d(120) is 5 - 15 nm; the pore volume of the pseudo-boehmite PB-2 is 0.6 - 1.0 mL / g, the specific surface area is 60 - 150 m 2 / g, the crystal size d(120) is 30 - 50 nm.

[0016] Furthermore, the shaping adjuvant is one or several of sesbania powder, methyl cellulose, hydroxymethyl cellulose, polyvinyl alcohol, and polyacrylamide, and the addition amount thereof accounts for 0.5 - 5.0 wt% of the weight of the carrier mixture.

[0017] Furthermore, during mixing, pseudoboehmite PB - 1 is continuously added to the mixer at an initial feeding rate of 20 - 40% of its total amount per hour and at a rate of decreasing its total amount by 2 - 8% per hour, while pseudoboehmite PB - 2 is continuously added to the mixer at an initial feeding rate of 0.1 - 10% of its total amount per hour and at a rate of increasing its total amount by 2 - 8% per hour, and the shaping adjuvant is continuously added at a constant rate of 10 - 20% of its total amount per hour.

[0018] Furthermore, the active metal component solution with decreasing concentration is formed by continuously diluting a solution containing an active metal component with a dilute acid solution.

[0019] Furthermore, the solution containing an active metal component is a phosphoric acid solution containing a Group VI B metal salt and a Group VIII metal salt, wherein the content of the Group VI B metal is 3 - 10 wt%, the content of the Group VIII metal is 0.5 - 3 wt%, and the content of phosphoric acid is 1 - 5 wt%; the dilute acid solution is a mixed acid solution containing citric acid and nitric acid, wherein the content of citric acid is 1 - 5 wt% and the content of nitric acid is 1 - 5 wt%.

[0020] Furthermore, the drying temperature is 20 - 120 °C and the time is 1 - 24 hours; the calcination temperature is 450 - 750 °C and the time is 1 - 6 hours.

[0021] The present invention controls the pore diameter inside and on the surface of the catalyst sphere in a targeted manner by combining carrier raw materials with different grain sizes and modulating the packing state of particles, and finally makes the pore diameter of the spherical catalyst continuously increase from the center to the outer surface of the sphere, forming an open "horn - shaped" pore structure, thereby improving the diffusion performance. At the same time, the present invention controls the addition concentration of the active metal during the sphere - forming process to achieve a controllable distribution of the active metal component on the carrier, and finally makes the active metal loading on the spherical catalyst continuously decrease from the center to the outer surface of the sphere, thereby improving the reaction performance of the catalyst.

[0022] Compared with the existing catalyst preparation methods, the advantages of the method of the present invention are that the pore diameter of the catalyst continuously increases from the center of the sphere to the outer surface, presenting an open "trumpet-shaped" pore structure with a relatively large surface pore opening and unobstructed pores. At the same time, the content of the active metal component of the catalyst continuously decreases from the center of the sphere to the outer surface, which is beneficial to optimizing the hydrodemetallization activity on the catalyst surface, reducing the metal deposition at the pore openings of the catalyst, and enabling the catalyst to have high hydrodemetallization activity and stability. Detailed implementation mode

[0023] A heavy oil hydrodemetallization catalyst for an upflow reactor is prepared by continuously adding pseudoboehmite PB-1 into a mixer at an initial feeding rate of 20-40% of its total amount per hour and at a rate of decreasing its total amount by 2-8% per hour, while continuously adding pseudoboehmite PB-2 into the mixer at an initial feeding rate of 0.1-10% of its total amount per hour and at a rate of increasing its total amount by 2-8% per hour, and continuously adding a shaping auxiliary material into the mixer at a constant rate of 10-20% of its total amount per hour for mixing. Then, the obtained carrier mixture is transported to a sugar coating machine, and a solution containing 3-10 wt% of Group VI B metal, 0.5-3% of Group VIII metal, and 1-5 wt% of phosphoric acid is continuously sprayed into the sugar coating machine by a high-efficiency sprayer for rolling into balls. At the same time, a dilute acid solution (containing 1-5 wt% of citric acid and 1-5 wt% of nitric acid) is continuously diluted with a constant rate of 10-20% of its total amount per hour to the phosphoric acid solution containing the active metal component in the sprayer (the total amount of the dilute acid solution is 20-60% of the total mass of the pseudoboehmite). Then, it is dried at 20-120 °C for 1-24 hours and calcined at 450-750 °C for 1-6 hours.

[0024] Among them, the weight percentages of the used pseudoboehmite PB-1 and PB-2 are 20-80:80-20. The pore volume of the pseudoboehmite PB-1 is 0.7-1.1 mL / g, the specific surface area is 150-250 m 2 / g, and the crystal size d(120) is 5-15 nm; the pore volume of the pseudoboehmite PB-2 is 0.6-1.0 mL / g, the specific surface area is 60-150 m 2 / g, and the crystal size d(120) is 30-50 nm.

[0025] The used shaping auxiliary material is one or several of sesbania powder, methyl cellulose, hydroxymethyl cellulose, polyvinyl alcohol, and polyacrylamide, and its addition amount accounts for 0.5-5.0 wt% of the weight of the carrier mixture.

[0026] Measured by the mercury intrusion method, the pore volume of the obtained catalyst is 0.5-0.9 mL / g, the average pore diameter is 15-30 nm, and the specific surface area is 80-200 m 2 / g; the average pore diameter at the center of the sphere is 10 - 20 nm, the average pore diameter at 60% to 80% of the sphere diameter is 13 - 25 nm, the average pore diameter at 80% to 90% of the sphere diameter is 16 - 30 nm, and the average pore diameter of the part from 90% of the sphere diameter to the outer surface of the sphere is 25 - 40 nm;

[0027] Calculated as metal oxides, the contents of metal component oxides of Group VIB and Group VIII at the center of the catalyst sphere are 6 - 12 wt% and 1 - 3 wt% respectively, the contents of metal component oxides of Group VIB and Group VIII at 40% to 60% of the sphere diameter are 5 - 10 wt% and 1 - 2.5 wt% respectively, the contents of metal component oxides of Group VIB and Group VIII at 60% to 80% of the sphere diameter are 4 - 8 wt% and 0.6 - 2 wt% respectively, the contents of metal component oxides of Group VIB and Group VIII at 80% to 90% of the sphere diameter are 2 - 6 wt% and 0.3 - 1.5 wt% respectively, and the contents of metal component oxides of Group VIB and Group VIII of the part from 90% of the sphere diameter to the outer surface of the sphere are 1 - 3 wt% and 0.1 - 1 wt% respectively.

[0028] To make the content of the present invention easier to understand, the technical solutions of the present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0029] Example 1

[0030] 1) Add 38.0 g of nickel basic carbonate, 96.8 g of molybdenum trioxide, and 31.4 g of phosphoric acid to 950 g of water, heat to 95 °C, stir until the solids are completely dissolved, then cool to room temperature, add 25 g of citric acid and 25 g of nitric acid to obtain solution A1, and place it in a spray can for later use;

[0031] 2) Add 25 g of citric acid and 25 g of nitric acid to 1030 g of water, stir and mix evenly to obtain dilute acid solution B1;

[0032] 3) Weigh 1260 g of pseudo-boehmite PB-1 (pore volume is 0.9 mL / g, specific surface area is 180 m 2 / g, crystal size d(120) is 10 nm), add it to the mixer at an initial feeding rate of 390 g / h and continuously reduce the rate by 60 g per hour. At the same time, weigh 1140 g of pseudo-boehmite PB-2 (pore volume is 0.8 mL / g, specific surface area is 100 m 2 / g, crystal size d(120) is 40 nm), add it to the mixer at an initial feeding rate of 10 g / h and continuously increase the rate by 60 g per hour, and continuously add 60 g of sesbania powder to the mixer at a feeding rate of 10 g / h;

[0033] 4) While being mixed, the mixed materials in the mixer are continuously conveyed to the sugar coating machine at a rate of 410 g / h for rolling into balls. During the ball forming process, while rolling, solution A1 in the spray tank is continuously and evenly sprayed onto the surface of the materials in the pot at a rate of 370 g / h, causing the spherical balls to form and grow. And simultaneously with the start of spraying, dilute acid solution B1 is uniformly added to the spray tank at a rate of 180 g / h to dilute solution A1; after the ball growth is completed, it is left for curing for 24 h, then dried at 60 °C for 12 h, and then heated to 580 °C at a rate of 2 °C / min and kept at a constant temperature for roasting for 3 h, and spherical catalyst Cat-A with a diameter of 3.0 - 3.5 mm is screened out.

[0034] Example 2

[0035] 1) Add 44.8 g of nickel basic carbonate, 114.0 g of molybdenum trioxide, and 37.0 g of phosphoric acid to 1060 g of water, heat to 95 °C, stir until the solids are completely dissolved, then cool to room temperature, add 30 g of citric acid and 25 g of nitric acid to obtain solution A2, and load it into the spray tank for standby;

[0036] 2) Add 25 g of citric acid and 25 g of nitric acid to 1030 g of water, stir and mix evenly to obtain dilute acid solution B2;

[0037] 3) Weigh 1380 g of pseudo-boehmite PB-1 (pore volume is 0.9 mL / g, specific surface area is 180 m 2 / g, crystal size d(120) is 10 nm), and add it to the mixer at an initial feeding rate of 410 g / h and a continuous decreasing rate of 60 g / h per hour. At the same time, weigh 1170 g of pseudo-boehmite PB-2 (pore volume is 0.8 mL / g, specific surface area is 100 m 2 / g, crystal size d(120) is 40 nm), and add it to the mixer at an initial feeding rate of 15 g / h and a continuous increasing rate of 60 g / h per hour, and continuously add 66 g of talc powder to the mixer at a feeding rate of 11 g / h;

[0038] 4) While being mixed, the mixed materials in the mixer are continuously conveyed to the sugar coating machine at a rate of 436 g / h for rolling into balls. During the ball forming process, while rolling, solution A2 in the spray tank is continuously and evenly sprayed onto the surface of the materials in the pot at a rate of 395 g / h, causing the spherical balls to form and grow. And simultaneously with the start of spraying, dilute acid solution B2 is uniformly added to the spray tank at a rate of 180 g / h to dilute solution A2; after the ball growth is completed, it is left for curing for 24 h, then dried at 60 °C for 12 h, and then heated to 600 °C at a rate of 2 °C / min and kept at a constant temperature for roasting for 3 h, and spherical catalyst Cat-B with a diameter of 3.0 - 3.5 mm is screened out.

[0039] Example 3

[0040] 1) Add 40.0 g of nickel hydroxycarbonate, 101.6 g of molybdenum trioxide, and 33.0 g of phosphoric acid to 1050 g of water, heat to 95 °C, stir until the solids are completely dissolved, then cool to room temperature, add 30 g of citric acid and 25 g of nitric acid to obtain solution A3, and place it in a spray can for later use;

[0041] 2) Add 25 g of citric acid and 25 g of nitric acid to 1030 g of water, stir and mix evenly to obtain dilute acid solution B3;

[0042] 3) Weigh 1320 g of pseudoboehmite PB-1 (pore volume 0.9 mL / g, specific surface area 180 m 2 / g, crystal size d(120) 10 nm), and add it to the mixer at an initial feeding rate of 400 g / h, continuously reducing at a rate of 60 g per hour. At the same time, weigh 1200 g of pseudoboehmite PB-2 (pore volume 0.8 mL / g, specific surface area 100 m 2 / g, crystal size d(120) 40 nm), and add it to the mixer at an initial feeding rate of 20 g / h, continuously increasing at a rate of 60 g per hour. And continuously add 60 g of talc powder to the mixer at a feeding rate of 10 g / h;

[0043] 4) The mixed materials in the mixer are continuously transported to a sugar coating machine at a rate of 430 g / h while being mixed for rolling into balls. During the ball forming process, while rolling, continuously and evenly spray solution A3 in the spray can onto the surface of the materials in the pot at a rate of 390 g / h, so that the spherical balls are formed and grow. And at the same time as starting to spray, evenly add dilute acid solution B3 to the spray can at a rate of 180 g / h to dilute solution A3; After the ball growth is completed, let it cure for 24 h, then dry at 60 °C for 12 h, then heat up to 600 °C at a rate of 2 °C / min, and keep it at a constant temperature for calcination for 3 h, and screen out spherical catalyst Cat-C with a diameter of 3.0 - 3.5 mm.

[0044] Comparative Example 1

[0045] 1) Add 38.0 g of nickel hydroxycarbonate, 96.8 g of molybdenum trioxide, and 31.4 g of phosphoric acid to 2000 g of water, heat to 95 °C, stir until the solids are completely dissolved, then cool to room temperature, add 50 g of citric acid and 50 g of nitric acid to obtain solution CA-1, and place it in a spray can for later use;

[0046] 2) Weigh 2400 g of pseudoboehmite PB-1 (pore volume 0.9 mL / g, specific surface area 200 m 2( / g, the crystal size d(120) is 10 nm), and it is continuously fed into a sugar coating machine at a feeding rate of 400 g / h for rolling into balls. During the ball forming process, while rolling, a solution CA-1 is continuously sprayed onto the materials in the pot at a rate of 370 g / h using a sprayer, causing the spherical balls to form and grow. After the ball growth is completed, it is left to cure for 24 h, then dried at 60 °C for 12 h, and then heated to 600 °C at a rate of 2 °C / min and calcined at a constant temperature for 3 h. Spherical catalysts CC-1 with a diameter of 3.0 - 3.5 mm are screened out.

[0047] Comparative Example 2

[0048] 1) Add 38.0 g of nickel basic carbonate, 96.8 g of molybdenum trioxide, and 31.4 g of phosphoric acid to 950 g of water, heat to 95 °C, stir until the solids are completely dissolved, then cool to room temperature, and add 25 g of citric acid and 25 g of nitric acid to obtain solution CA-2;

[0049] 2) Add 25 g of citric acid and 25 g of nitric acid to 1030 g of water, stir and mix evenly to obtain a dilute acid solution CB-1, and load it into a spray tank for standby;

[0050] 3) Weigh 1200 g of pseudo-boehmite PB-1 (pore volume is 0.9 mL / g, specific surface area is 180 m 2 / g, the crystal size d(120) is 10 nm), and add it to a mixer at an initial feeding rate of 20 g / h and a continuous increasing rate of 60 g / h per hour. At the same time, weigh 1200 g of pseudo-boehmite PB-2 (pore volume is 0.8 mL / g, specific surface area is 100 m 2 / g, the crystal size d(120) is 40 nm), and add it to the mixer at an initial feeding rate of 380 g / h and a continuous decreasing rate of 60 g / h per hour. And continuously add 60 g of talc powder to the mixer at a feeding rate of 10 g / h;

[0051] 4) The mixed materials in the mixer are continuously fed into a sugar coating machine at a rate of 410 g / h for rolling into balls while being mixed. During the ball forming process, while rolling, the solution CB-1 in the spray tank is continuously and evenly sprayed onto the surface of the materials in the pot at a rate of 360 g / h, causing the spherical balls to form and grow. And at the same time when spraying starts, a metal solution CA-2 is evenly added to the spray tank at a rate of 190 g / h. After the ball growth is completed, it is left to cure for 24 h, then dried at 60 °C for 12 h, and then heated to 580 °C at a rate of 2 °C / min and calcined at a constant temperature for 3 h. Spherical catalysts CC-2 with a diameter of 3.0 - 3.5 mm are screened out.

[0052] The physical and chemical properties of the catalysts obtained in the examples and comparative examples are listed in Table 1.

[0053] The method for determining the average pore diameter of the catalyst from the center of the sphere to different parts of the outer surface is as follows: During the sphere-forming process, when the spherical carrier grows to a certain particle size, a sample is taken out for drying and calcination. The pore volume, specific surface area, and average pore diameter of the sample are measured by mercury intrusion porosimetry. Based on the relationship that the total pore volume and surface area of the sample equal the sum of each part, the average pore diameter from the center of the sphere to different parts of the outer surface is calculated (According to the Washburn equation, a mercury contact angle of 130° and a mercury interfacial tension of 480 dyne / cm are selected to calculate the pore diameter).

[0054] 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 sphere-forming process, when the spherical carrier grows to a certain particle size, a sample is taken out for drying and calcination. The metal content of the sample is measured by inductively coupled plasma method (ICP). Based on the relationship that the total metal content of the sample equals the sum of each part, the average metal loading from the center of the sphere to different parts of the outer surface is calculated.

[0055] Table 1 Physicochemical properties of different catalysts

[0056]

[0057] From the results in Table 1, it can be seen that the catalysts prepared in the examples have an open "horn-shaped" pore structure, the pore diameter increases continuously from the center of the sphere to the outer surface, and at the same time, the content of the active metal component decreases continuously from the center of the sphere to the outer surface.

[0058] Application examples

[0059] Using a residue oil with a density (20 °C) of 1006 kg / m 3 , a nickel content of 35 ppm, a vanadium content of 109 ppm, a sulfur content of 4.65 wt%, and a heptane-insoluble content of 5.8 wt% as the raw material, the heavy oil hydrodemetallization performance of the catalysts obtained in the examples and comparative examples was evaluated. The catalyst filling volume was 100 mL. Before evaluation, the catalyst was sulfided by wet presulfidation. The process conditions used for evaluating each catalyst were the same (conditions: reaction temperature 380 °C, hydrogen partial pressure 16 MPa, liquid hourly space velocity 1.1 h -1 , and hydrogen-oil volume ratio 300). An inductively coupled plasma atomic emission spectrometer (ICP-AES) was used to measure the nickel and vanadium contents in the oil before and after hydrotreating (for the specific method, see GB / T 37160). The metal removal rate was calculated according to the following formula:

[0060] .

[0061] The evaluation results are listed in Table 2.

[0062] Table 2 Evaluation results of the demetallization activity and stability of different catalysts

[0063]

[0064] The results in Table 2 show that the hydrodemetallization activity and stability of the catalyst provided by the examples are superior to those of the catalyst obtained in the comparative example.

[0065] The above are only the preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims

1. A preparation method of a heavy oil hydrodemetallization catalyst for an up-flow reactor, characterized in that: The specific steps are as follows: 1) Add 44.8 g of nickel basic carbonate, 114.0 g of molybdenum trioxide, and 37.0 g of phosphoric acid into 1060 g of water, heat to 95 °C, stir until the solids are completely dissolved, then cool to room temperature, add 30 g of citric acid and 25 g of nitric acid to obtain solution A2, and put it into a spray tank for later use; 2) Add 25 g of citric acid and 25 g of nitric acid into 1030 g of water, stir and mix evenly to obtain dilute acid solution B2; 3) Weigh 1380 g of pseudoboehmite PB-1, and add it to the mixer at an initial feeding rate of 410 g / h and a decreasing rate of 60 g per hour. At the same time, weigh 1170 g of pseudoboehmite PB-2, and add it to the mixer at an initial feeding rate of 15 g / h and an increasing rate of 60 g per hour. And continuously add 66 g of sesbania powder to the mixer at a feeding rate of 11 g / h; 4) The mixed materials in the mixer are continuously transported to a sugar coating machine at a rate of 436 g / h while being mixed for rolling into balls. During the ball forming process, solution A2 in the spray tank is continuously and evenly sprayed onto the surface of the materials in the pot at a rate of 395 g / h while rolling, so that the spherical balls grow and form. And at the same time as starting to spray, dilute acid solution B2 is evenly added to the spray tank at a rate of 180 g / h to dilute solution A2; After the ball growth is completed, let it cure for 24 h, then dry at 60 °C for 12 h, and then heat up to 600 °C at a rate of 2 °C / min and keep it at a constant temperature for calcination for 3 h, and screen out spherical catalysts with a diameter of 3.0 - 3.5 mm; Among them, the pore volume of the pseudo-boehmite PB-1 used is 0.9 mL / g, the specific surface area is 180 m 2 / g, and the crystal size d(120) is 10 nm; The pore volume of the pseudo-boehmite PB-2 used is 0.8 mL / g, the specific surface area is 100 m 2 / g, and the crystal size d(120) is 40 nm.

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