Residue hydrodemetallization catalyst and method for making same

Abstract

The application discloses a residual oil hydrodemetallization catalyst and a preparation method thereof. The preparation method of the catalyst comprises the following steps: dissolving aluminum nitrate, urea and a template agent in water to obtain solution X; transferring the solution X into a crystallization kettle to perform first crystallization, and taking the lower slurry to obtain material Y; dissolving the material Y, aluminum nitrate, urea and the template agent in water to obtain solution Z; transferring the solution Z into the crystallization kettle to perform second crystallization, and performing calcination to obtain carrier A; sealing and heat-treating the carrier A after being immersed in an ammonium bicarbonate aqueous solution, and performing drying to obtain carrier B; performing kneading and molding of the carrier B and a first active metal component source, and performing calcination to obtain carrier C; sealing and treating the carrier C after being immersed in the ammonium bicarbonate aqueous solution, and performing drying to obtain carrier D; and immersing the carrier D in a second active metal component containing water-soluble polymer J, and performing calcination to obtain the catalyst. The catalyst is applied to a residual oil hydrodemetallization reaction, and the reaction activity and stability are obviously improved.

Description

Technical Field

[0001] This invention relates to a catalyst for the hydrodemetallization of residual oil, and more specifically to a catalyst for the hydrodemetallization of residual oil and its preparation method. Background Technology

[0002] As is well known, most traditional residue hydrotreating catalysts are supported hydrotreating catalysts, with the active metal components typically supported on the surface of the support. Generally, under the action of the catalyst, various metal compounds react with H2S to form metal sulfides, which are then deposited on the catalyst and removed. Therefore, the specific surface area of ​​the catalyst not only affects the distribution of active metals during active metal support but also influences the deposition of metal impurities after the reaction.

[0003] CN111001424A discloses a phosphorus-containing residue hydrotreating catalyst and its preparation method. The catalyst has mesopores that are concentratedly distributed and uniform in size, with a pore size ranging from 10 to 30 nm. A strongly acidic support is uniformly distributed on the surface of the mesopore channels. The total pore volume of the catalyst support is 0.6–1.2 mL / g, and the specific surface area is 180–350 m² / g. 2 / g, the pore volume of mesopores accounts for 60-95% of the total pore volume of the catalyst support. CN101880049B discloses a method for preparing graded mesoporous alumina nanorods. Under the combined action of small biomolecules such as sucrose and macromolecules such as polyols, aluminum nitrate is used as a precursor, and ammonium carbonate or ammonium bicarbonate is used as a precipitant to synthesize graded mesoporous alumina nanorods with high specific surface area and large pore volume via hydrothermal crystallization. The smaller mesopores of the alumina obtained by this method are concentrated around 3 nm, while the larger mesopores can be controlled between 10 and 30 nm. The aspect ratio of the nanorods is less than 50, and the specific surface area is as high as 500 nm. 2 CN103785400A discloses a method for preparing a highly active residue oil hydrodemetallization catalyst. The method involves impregnating an alumina support with a polyol and / or monosaccharide aqueous solution, followed by hydrothermal carbonization in a sealed container after impregnation. Then, active metal components Mo and Ni are loaded onto the support. Finally, the alumina loaded with active components is calcined under a nitrogen atmosphere and then calcined under an air atmosphere to obtain the residue oil hydrodemetallization catalyst.

[0004] The alumina support prepared by the above method has a narrow pore size distribution range, which limits its role in the diffusion of macromolecules in the residue oil feedstock. Furthermore, during the impregnation of the active metal, it is impossible to avoid the accumulation of the active metal in and around the pores of the support. Therefore, the activity and stability of the alumina support and the hydrodemetallization catalyst prepared by the above method still need to be further improved. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a residue oil hydrodemetallization catalyst and its preparation method. The residue oil hydrodemetallization catalyst provided by this invention has a larger pore volume and pore size, and a more regular and unobstructed pore structure. When applied to the residue oil hydrodemetallization reaction, its reactivity and stability are significantly improved.

[0006] The first aspect of this invention provides a method for preparing a hydrodemetallization catalyst for residue oil, comprising the following steps:

[0007] (1) Dissolve aluminum nitrate, urea and template agent in water to obtain solution X;

[0008] (2) Perform the first crystallization on the solution X obtained in step (1), and take the lower layer of slurry to obtain material Y;

[0009] (3) Dissolve the material Y, aluminum nitrate, urea and template agent obtained in step (2) in water to obtain solution Z;

[0010] (4) The solution Z obtained in step (3) is subjected to a second crystallization, dried and calcined to obtain alumina carrier A;

[0011] (5) The carrier A obtained in step (4) is immersed in an ammonium bicarbonate aqueous solution, then sealed and heat-treated, and dried to obtain carrier B;

[0012] (6) Mix, shape, dry and calcine the carrier B obtained in step (5) and the first active metal component source to obtain carrier C;

[0013] (7) The carrier C obtained in step (6) is immersed in an ammonium bicarbonate aqueous solution, sealed and dried to obtain carrier D;

[0014] (8) The carrier D obtained in step (7) is impregnated with the second active metal component containing water-soluble polymer J, dried and calcined to obtain the residue oil hydrodemetallization catalyst.

[0015] In this invention, deionized water is preferably used. All crystallization processes are carried out in a crystallization reactor.

[0016] In step (1) of this invention, aluminum nitrate, urea and template agent are dissolved in deionized water in the order of dissolving and mixing to obtain solution X.

[0017] In step (1) of this invention, the molar ratio of Al(NO3)3 to the template agent is 160 to 240.

[0018] In step (1) of this invention, the molar ratio of urea to Al(NO3)3 is 7–14. Within this range, the OH- produced by the decomposition of urea... - Quantity and Al 3+With the hydrolysis rate just right, alumina can grow uniformly on the template agent surface.

[0019] In step (1) of the present invention, the template agent is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methylcellulose, preferably polyethylene glycol; the viscosity of the template agent (20°C) is 10 to 1000 mPa·s, and the viscosity of solution X (20°C) after adding the template agent and stirring evenly is 120 to 660 mPa·s.

[0020] In step (2) of this invention, the conditions for the first crystallization are as follows: the crystallization temperature is 90-140℃ and the crystallization time is 5-30h.

[0021] In step (3) of this invention, materials Y, aluminum nitrate, urea and template agent are dissolved in deionized water in the order of dissolving and mixing to obtain solution Z.

[0022] In step (3) of this invention, the ratio of Al(NO3)3, template agent and urea is the same as in step (1).

[0023] In step (3) of the present invention, the amount of material Y added accounts for 10% to 40% of the total mass of material Y and urea used for the second crystallization.

[0024] In step (4) of this invention, the conditions for the second crystallization are as follows: the crystallization temperature is 100-200℃, and the crystallization time is 25-35h. The temperature of the second crystallization is 60-100℃ higher than the temperature of the first crystallization.

[0025] In step (4) of this invention, filtration and washing can be performed according to conventional and known methods before drying. Washing can be done with deionized water until the pH of the filtrate is close to neutral. The dry basis content of the dried product obtained after drying is 50wt% to 80wt%.

[0026] In step (4) of this invention, the drying temperature is 120-200℃ and the drying time is 2-12h.

[0027] In step (4) of this invention, the calcination temperature is 500-750℃, the calcination time is 2-6h, and the calcination atmosphere is air.

[0028] In step (5) of this invention, the mass percentage concentration of the ammonium bicarbonate aqueous solution ranges from 10% to 20%. The sealing heat treatment temperature is 80 to 140°C, preferably 85 to 130°C, and the treatment time is 6 to 12 hours. The drying temperature is 120 to 180°C, and the drying time is 2 to 10 hours.

[0029] In step (6) of this invention, the first active metal component source is a soluble compound of molybdenum and a soluble compound containing a Group VIII metal. The Group VIII metal is preferably nickel.

[0030] In step (6) of the present invention, the soluble compound of metallic molybdenum is at least one of molybdenum oxide and ammonium molybdate, and the soluble compound of group VIII metal (preferably Ni) is at least one of basic nickel carbonate and nickel nitrate.

[0031] In step (6) of the present invention, the amount of MoO3 introduced into the catalyst by the first active metal component is 45% to 70% of the total MoO3 loading in the catalyst, and the amount of Group VIII metal oxide introduced into the catalyst by the first active metal component is 45% to 70% of the total Group VIII metal oxide loading in the catalyst.

[0032] In step (6) of the present invention, conventional molding aids, such as adhesives, extrusion aids, etc., can be added as needed during the molding process. The adhesive is one or more of nitric acid, sulfuric acid, and oxalic acid, preferably nitric acid; the extrusion aid is one or more of guar gum powder, cellulose, and resin, preferably guar gum powder.

[0033] In step (6) of the present invention, the amount of adhesive solvent added accounts for 0.5% to 6.0% of the carrier B, and the amount of extrusion aid added accounts for 0.1% to 5.5% of the carrier B.

[0034] In step (6) of this invention, the drying temperature is 20-200℃ and the drying time is 2-12h.

[0035] In step (6) of the present invention, the calcination temperature is 500-750℃, the calcination time is 2-6h, and the calcination atmosphere is air.

[0036] In step (7) of this invention, the mass percentage concentration of the ammonium bicarbonate aqueous solution ranges from 20% to 30%. The sealing treatment temperature is 10–60°C, preferably 20–50°C, and the treatment time is 6–12 hours. The heat treatment temperature in step (7) is 70–95°C lower than the heat treatment temperature in step (5). The drying temperature is 10–40°C, the drying time is 2–10 hours, and the drying method is static drying.

[0037] In step (7) of this invention, the mass concentration of the ammonium bicarbonate aqueous solution is 8 to 15 percentage points higher than that of the ammonium bicarbonate aqueous solution in step (5).

[0038] In step (8) of this invention, the saturated immersion method is used for impregnation, and the standing time after impregnation is 4 to 14 hours.

[0039] In step (8) of this invention, when the carrier D is impregnated with the second active metal component containing the water-soluble polymer J, an impregnation solution containing the second active metal component of the water-soluble polymer J is used. The impregnation solution is an impregnation solution containing Mo and a Group VIII metal (preferably Ni), wherein the active metal component molybdenum is derived from one or both of molybdenum oxide and ammonium heptamolybdate, and the nickel is derived from one or both of basic nickel carbonate and nickel nitrate. The content of MoO3 and Group VIII metal oxide in the impregnation solution containing the second active metal component is 10.0–80.0 g / 100 mL and 2.0–40.0 g / 100 mL, respectively.

[0040] In step (8) of the present invention, the amount of MoO3 introduced into the catalyst by the second active metal component is 30% to 55% of the total MoO3 loading in the catalyst, and the amount of Group VIII metal oxide introduced into the catalyst by the second active metal component is 30% to 55% of the total Group VIII metal oxide loading in the catalyst.

[0041] In step (8) of this invention, the water-soluble polymer J is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide, and methylcellulose, preferably polyethylene glycol. The viscosity (20°C) of the water-soluble polymer J is 10–1000 mPa·s, and the viscosity (20°C) of the impregnation solution after adding the water-soluble polymer J is 150–800 mPa·s.

[0042] In step (8) of the present invention, at least one additive containing fluorine, phosphorus, silicon or boron may be introduced into the impregnation solution of the second active metal component. The amount of additive (calculated as oxide) added is 2% to 20% of the total mass of molybdenum oxide in the impregnation solution containing the second active metal component, preferably 2% to 15%.

[0043] In step (8) of this invention, the drying temperature is 120-200℃ and the drying time is 2-12h.

[0044] In step (8) of this invention, the calcination temperature is 350-500℃, the calcination time is 2-6h, and the calcination atmosphere is a mixture of an inert atmosphere and other atmospheres, with a volume ratio of 0.5-5:1 between the inert atmosphere and other atmospheres. The inert atmosphere is mainly one or two of nitrogen and helium, and the other atmosphere is one or more of water vapor and air.

[0045] The second aspect of the present invention provides a residue hydrodemetallization catalyst prepared by the above preparation method, comprising a support component, an active metal component, and carbon distributed on the catalyst surface, wherein the active metal component comprises molybdenum and a Group VIII metal, and the support component is alumina; wherein the mass ratio of carbon distributed on the catalyst surface to alumina in the catalyst is 0.20 to 0.40.

[0046] In this invention, the active metal component includes a first active metal component distributed inside the alumina and a second active metal component distributed on the surface of the alumina.

[0047] In this invention, the active metal component includes molybdenum and a Group VIII metal, wherein the Group VIII metal is preferably nickel.

[0048] In this invention, the first active metal component includes molybdenum and a Group VIII metal, wherein the Group VIII metal is preferably nickel.

[0049] In this invention, the second active metal component includes molybdenum and a Group VIII metal, wherein the Group VIII metal is preferably nickel.

[0050] In this invention, based on the mass of the catalyst, the content of MoO3 is 2.0% to 20.0%, and the content of Group VIII metal oxides is 1.0% to 6.0%.

[0051] In this invention, based on the total MoO3 mass in the catalyst, the content of MoO3 in the first active component is 45% to 70%, and the content of MoO3 in the second active component is 30% to 55%.

[0052] In this invention, based on the total mass of Group VIII metal oxides in the catalyst, the content of Group VIII metal oxides in the first active component is 45% to 70%, and the content of Group VIII metal oxides in the second active component is 30% to 55%.

[0053] In this invention, the catalyst has a specific surface area of ​​185–225 m². 2 / g, with a pore volume of 0.75~1.05mL / g.

[0054] In this invention, preferably, the catalyst has a specific surface area of ​​190–210 m². 2 / g, with a pore volume of 0.80~0.95mL / g.

[0055] In this invention, the pore distribution of the catalyst is as follows: pores with a diameter of <30nm account for 27% to 36% of the total pore volume, pores with a diameter of 30 to 100nm account for 31% to 37% of the total pore volume, and pores with a diameter of 100nm to 300nm account for 33% to 36% of the total pore volume.

[0056] In this invention, the strength of the catalyst is 8.0 to 18.0 N / mm.

[0057] In this invention, the catalyst further includes an auxiliary component, which is selected from at least one of fluorine, phosphorus, silicon, or boron, preferably phosphorus. Based on the mass of the catalyst, the content of the auxiliary component, calculated as oxides, is 1.0% to 8.0%.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] For hydrodemetallization catalysts, a good pore structure and a reasonable distribution of active metals on the catalyst are crucial for their catalytic performance. On the one hand, since heavy oil feedstocks contain many large molecules, the resulting catalyst should have a smooth pore structure. On the other hand, to ensure that the active metal components can fully exert their hydrogenation effect, the active metals should be well dispersed inside and on the surface of the catalyst to prevent them from accumulating at the pore openings and blocking molecular diffusion channels. Through extensive research, the inventors discovered that by introducing seed crystals (material Y) during the preparation of alumina supports using a homogeneous precipitation method, the pore structure of the resulting alumina support is more regular and unobstructed. Further heat treatment with ammonium bicarbonate aqueous solution further improves the pore unobstructedness. Then, by mixing and molding the mixture with nitric acid, guar gum powder, some active metals, and deionized water, followed by drying and calcination, a support with a large specific surface area and unobstructed pores can be obtained. Finally, the molded support is subjected to another heat treatment with ammonium bicarbonate aqueous solution to ensure that the solution fills the external pores and openings of the support, preventing the accumulation of active metal components around the openings during impregnation. Finally, the support is impregnated with an impregnation solution prepared from the remaining active metal using a saturated impregnation method. After drying and calcination, the hydrogenation demetallization catalyst is obtained. Furthermore, a water-soluble polymer is added to the impregnation solution, and the final calcination atmosphere is a mixed atmosphere. This process not only releases the pore structure on the catalyst surface, preventing pore blockage during impregnation, but also causes incomplete decomposition of the polymer, forming dotted carbon dots. This allows for appropriate adjustment of the catalyst's acidity, which helps to weaken the interaction between the active metal and the support, and promotes the dispersion of the active metal on the catalyst surface. Through the comprehensive coordination of each step, the catalyst prepared by this method exhibits significantly improved activity and stability. Detailed Implementation

[0060] In this invention, the pore structure (SVD) and specific surface area of ​​the catalyst are characterized using the Mack ASAP-2420 physical adsorption instrument.

[0061] In this invention, the ZQJ-III intelligent particle strength tester is used to test the crushability of catalyst particles.

[0062] In this invention, the carbon / alumina mass ratio on the catalyst surface was determined using a NETZSCH STA409PC-QMS403C thermogravimetric-mass spectrometer (TG-MS).

[0063] The technical solutions and effects of the present invention will be further illustrated below with reference to the embodiments, but the invention is not limited to the following embodiments.

[0064] Example 1

[0065] (1) Weigh out appropriate amounts of aluminum nitrate, urea and template agent polyethylene glycol (viscosity 500 mPa·s), wherein the molar ratio of Al(NO3)3 to polyethylene glycol is 180 and the molar ratio of urea to Al(NO3)3 is 9. Dissolve the above substances in a certain amount of deionized water in the order of aluminum nitrate, urea and polyethylene glycol. After mixing evenly by magnetic stirring for 5 hours, solution X (viscosity 350 mPa·s) is obtained.

[0066] (2) Transfer the obtained solution X to the crystallization kettle, then place the crystallization kettle in an oven at 100°C, react for 8 hours, and then take out the crystallization kettle and take out a certain mass of the lower layer slurry of the crystallization kettle as material Y.

[0067] (3) Weigh material Y, measured amounts of aluminum nitrate, urea and template agent polyethylene glycol (viscosity 500 mPa·s), wherein the molar ratio of Al(NO3)3 to polyethylene glycol is 180 and the molar ratio of urea to Al(NO3)3 is 9, and dissolve them in a certain amount of deionized water. The mass of material Y accounts for 15% of the total mass of material Y and the urea used in the second crystallization. After being mixed evenly by magnetic stirring, solution Z is obtained.

[0068] (4) Transfer the solution Z obtained in step (3) to a crystallization vessel, place the crystallization vessel in an oven at 200°C, react for 35 hours, remove the crystallization vessel, and after cooling, obtain a mixed slurry containing a white precipitate in the reaction vessel; filter and wash the obtained white precipitate several times until the pH value of the filtrate is close to 7; place the white precipitate in an oven to dry at 130°C for 7 hours, and then calcine it in a muffle furnace at 550°C for 4 hours to prepare carrier A;

[0069] (5) The obtained alumina carrier A is immersed in ammonium bicarbonate aqueous solution and then sealed and heat treated to obtain carrier B. The mass percentage concentration of ammonium bicarbonate aqueous solution is 18%, the sealing heat treatment temperature is 120℃, the treatment time is 4h, the drying temperature is 150℃, and the drying time is 6h.

[0070] (6) The carrier B, nitric acid (68wt%), guar gum powder, the first active metal component source (ammonium molybdate and nickel nitrate), and deionized water were mixed, shaped, dried, and calcined to obtain the carrier C. The mass content of nitric acid (68wt%) added was 2.5% of the carrier B, and the mass content of guar gum powder added was 3.5% of the carrier B. During the shaping process, the content of deionized water added was adjusted in real time according to the material state. The drying temperature was 120℃, the drying time was 6h, the calcination temperature was 700℃, and the calcination time was 6h (the heating rate was 2.5℃ / min). The amount of MoO3 introduced into the catalyst by the first active metal component was 60% of the total MoO3 loading in the catalyst, and the amount of NiO was 60% of the total NiO loading in the catalyst.

[0071] (7) The obtained carrier C was immersed in an ammonium bicarbonate aqueous solution and then sealed and dried to obtain carrier D. The mass percentage concentration of the ammonium bicarbonate aqueous solution was 28%, the sealing temperature was 25℃, the treatment time was 7h, the drying temperature was 25℃, the drying time was 5h, and the drying method was static drying.

[0072] (8) The support D is impregnated by a saturated impregnation method with an impregnation solution containing the second active metal component (MoO3 content is 30.68 g / 100 mL, NiO content is 5.07 g / 100 mL, and the amount of P (calculated as oxide) added in the auxiliary phosphoric acid is 8.87% of the total mass of molybdenum oxide in the impregnation solution). The amount of MoO3 introduced into the catalyst by the second active metal component is 40% of the total MoO3 loading in the catalyst, and the amount of NiO is 40% of the total NiO loading in the catalyst. The impregnation solution contained water-soluble polymer J polyethylene glycol. After adding water-soluble polymer J polyethylene glycol, the viscosity of the impregnation solution (at 20℃) was 320 mPa·s. The impregnated sample was left to stand at room temperature (25℃) for 6 hours, then dried (at 120℃ for 6 hours), calcined at 500℃ for 4 hours (heating rate 2.0℃ / min) in a mixed atmosphere of nitrogen and air (nitrogen to air volume ratio 3:1) to obtain the residue oil hydrodemetallization catalyst. The prepared residue oil hydrodemetallization catalyst was named CAT-1. The physicochemical properties of this catalyst are shown in Table 1.

[0073] Example 2

[0074] The differences between this example and Example 1 are as follows: In step (1), the molar ratio of Al(NO3)3 to polyethylene glycol is 200, and the molar ratio of urea to Al(NO3)3 is 11; in step (3), material Y accounts for 20% of the total mass of material Y and urea used in secondary crystallization; in step (4), the obtained solution Z is transferred to a crystallization vessel, and then the crystallization vessel is placed in an oven at 160°C. After reacting for 30 hours, the crystallization vessel is removed, and the white precipitate is placed in an oven to dry at 140°C for 8 hours. Then, it is calcined in a muffle furnace at 650°C for 3 hours. The residue oil hydrodemetallization catalyst CAT-2 is obtained. The physicochemical properties of the catalyst are shown in Table 1.

[0075] Example 3

[0076] The difference between this example and Example 1 is as follows: In step (5), the mass percentage concentration of the first ammonium bicarbonate aqueous solution is 16%, the sealing heat treatment temperature is 110℃, the treatment time is 7h, and the drying temperature is 130℃, the drying time is 5h; In step (7), the mass percentage concentration of the second ammonium bicarbonate aqueous solution is 26%, the sealing treatment temperature is 30℃, the treatment time is 7h, and the drying temperature is 30℃, the drying time is 8h; thus, the residue oil hydrodemetallization catalyst CAT-3 is obtained. The physicochemical properties of the catalyst are shown in Table 1.

[0077] Example 4

[0078] The difference between this example and Example 1 is as follows: In step (6), carrier B is mixed and shaped with nitric acid (68wt%), guar gum powder, the first active metal component source (ammonium molybdate and nickel nitrate), and deionized water. After drying and calcination, carrier C is obtained. The drying temperature is 140℃, the drying time is 8h, the calcination temperature is 750℃, and the calcination time is 5h (heating rate is 3.0℃ / min). The amount of MoO3 introduced into the catalyst by the first active metal component is 70% of the total MoO3 loading in the catalyst, and the amount of NiO is 70% of the total NiO loading in the catalyst. In step (8), the catalyst is impregnated with a second active metal component impregnation solution (MoO3 content is 23.01g / 100mL, NiO content is 3.80g / 100mL, and auxiliary agent content is 3.80g / 100mL) by saturation impregnation. The amount of phosphoric acid (calculated as oxide) added to the catalyst was 6.65% of the total mass of molybdenum oxide in the impregnation solution. The impregnation support D was impregnated, with the amount of MoO3 introduced into the catalyst by the second active metal component being 30% of the total MoO3 loading and the amount of NiO being 30% of the total NiO loading. The impregnation solution contained water-soluble polymer J polyvinyl alcohol. After adding water-soluble polymer J polyvinyl alcohol, the viscosity of the impregnation solution (20℃) was 400 mPa·s. After impregnation, the sample was allowed to stand at room temperature for 8 h, then dried (drying temperature 140℃, drying time 5 h), calcined at 500℃ for 4 h (heating rate 3.0℃ / min), and calcined in a mixed atmosphere of nitrogen and air (nitrogen to air volume ratio 1:1). This yielded the hydrogenation demetallization catalyst CAT-4. The physicochemical properties of the catalyst are shown in Table 1.

[0079] Comparative Example 1

[0080] Compared with Example 1, the difference is that in step (1), the molar ratio of Al(NO3)3 to polyethylene glycol is 260, and the molar ratio of urea to Al(NO3)3 is 6. The above substances are dissolved in a certain amount of deionized water in the order of aluminum nitrate, urea, and polyethylene glycol. After being magnetically stirred for 8 hours to mix evenly, solution X is obtained. In step (2), the obtained solution X is transferred to a crystallization vessel, and then the crystallization vessel is placed in an oven at 160°C. After reacting for 20 hours, the crystallization vessel is removed. The dCAT-1 catalyst for hydrogen demetallization of sludge oil is obtained. The physicochemical properties of the catalyst are shown in Table 1.

[0081] Comparative Example 2

[0082] Compared with Example 1, the difference is that in step (7), the mass percentage concentration of the second ammonium bicarbonate aqueous solution is 35%, the sealing treatment temperature is 80℃, the treatment time is 5h, the drying temperature is 140℃, and the drying time is 5h; thus, the residue oil hydrodemetallization catalyst dCAT-2 is obtained. The physicochemical properties of the catalyst are shown in Table 1.

[0083] Comparative Example 3

[0084] Compared with Example 1, the difference is that: no active metal is added during the mixing process in step (6), but in step (8), the carrier D is impregnated with an active metal component impregnation solution by saturation impregnation. The impregnation solution contains water-soluble polymer J polyethylene glycol. After adding water-soluble polymer J polyethylene glycol, the viscosity of the impregnation solution (at 20°C) is 400 mPa·s. The impregnated sample is left to stand at room temperature for 6 hours, then dried (drying temperature is 120°C, drying time is 6 hours), calcined at 650°C for 4 hours (heating rate is 3.0°C / min), and calcined in a mixed atmosphere of nitrogen and water vapor to obtain the residue oil hydrodemetallization catalyst dCAT-3. The physicochemical properties of this catalyst are shown in Table 1.

[0085] Comparative Example 4

[0086] Compared with Example 1, the difference is that in step (8), the impregnation solution containing the second active metal component does not contain water-soluble polymer J polyethylene glycol, and the calcination atmosphere is air. The residue oil hydrodemetallization catalyst dCAT-4 was obtained. The surface of catalyst dCAT-4 does not contain carbon. The physicochemical properties of this catalyst are shown in Table 1.

[0087] Comparative Example 5

[0088] Compared with Example 1, the difference lies in that the crystallization conditions were the same for both instances: crystallization at 150°C for 15 hours. The residue oil hydrodemetallization catalyst dCAT-5 was obtained. The physicochemical properties of this catalyst are shown in Table 1.

[0089] Table 1 Physicochemical properties of residue hydrodemetallization catalysts

[0090]

[0091] Table 1. Physicochemical properties of catalysts for hydrodemetallization of residue oil (continued)

[0092]

[0093]

[0094] Evaluation test

[0095] The activity and stability tests of residue oil hydrodemetallization catalysts CAT-1~4 and dCAT-1~5 were conducted in a 200mL fixed-bed hydrotreating experimental setup. All catalysts used were strip-shaped with a length of 2–3 mm. The reaction conditions were: reaction temperature 395℃, reaction pressure 15.7 MPa, and liquid hourly space velocity 1.0 h⁻¹. 1 With a hydrogen-to-oil volume ratio of 900, after 1500 hours of reaction, the demetallization rates (Ni+V) of each catalyst are shown in Table 3, and the properties of the feedstock oil are shown in Table 2.

[0096] Table 2 Properties of Crude Oil

[0097]

[0098]

[0099] Table 3. Test results of residue hydrodemetallization catalysts for each example.

[0100]

[0101] As can be seen from Tables 1, 2 and 3, the hydrodemetallization catalyst prepared according to the method of the present invention has a smooth pore structure and a large specific surface area. It exhibits high reactivity and stability during the reaction process and can well meet the requirements of hydrodemetallization process of heavy oil, especially residue oil.

Claims

1. A preparation method of a residue hydrodemetalization catalyst, comprising the following steps: (1) dissolving aluminum nitrate, urea and a template agent in water to obtain a solution X; (2) performing first crystallization on the solution X obtained in step (1) to obtain a slurry Y; (3) dissolving the slurry Y obtained in step (2), aluminum nitrate, urea and a template agent in water to obtain a solution Z; (4) performing second crystallization on the solution Z obtained in step (3), drying, and calcining to obtain an alumina carrier A; (5) sealing and heat-treating the carrier A obtained in step (4) after being immersed in an aqueous ammonium bicarbonate solution, and drying to obtain a carrier B; (6) mixing and kneading the carrier B obtained in step (5) and a first active metal component source, shaping, drying, and calcining to obtain a carrier C; (7) sealing and treating the carrier C obtained in step (6) after being immersed in an aqueous ammonium bicarbonate solution, and drying to obtain a carrier D; (8) impregnating the carrier D obtained in step (7) with a second active metal component containing a water-soluble polymer J, and drying and calcining to obtain the residue hydrodemetalization catalyst. In step (1), the molar ratio of Al(NO3)3 to the template agent is 160-240, and the molar ratio of urea to Al(NO3)3 is 7-14; in step (3), the molar ratio of Al(NO3)3 to the template agent is 160-240, and the molar ratio of urea to Al(NO3)3 is 7-14. The temperature of the first crystallization is 90-140℃, and the temperature of the second crystallization is 100-200℃, which is 60-100℃ higher than that of the first crystallization. In step (5), the mass percentage concentration of the aqueous ammonium bicarbonate solution is 10%-20%; in step (7), the mass percentage concentration of the aqueous ammonium bicarbonate solution is 20%-30%; and in step (7), the mass concentration of the aqueous ammonium bicarbonate solution is 8-15 percentage points higher than that in step (5). In step (5), the sealing and heat-treatment temperature is 80-140℃; in step (7), the sealing treatment temperature is 10-60℃; and the treatment temperature in step (7) is 70-95℃ lower than the heat-treatment temperature in step (5). In step (6), the first active metal component source is a soluble compound of metallic molybdenum and a soluble compound containing a Group VIII metal; in step (8), when the carrier D is impregnated with the second active metal component containing the water-soluble polymer J, a second active metal component containing the water-soluble polymer J is used, and the impregnation liquid contains Mo and a Group VIII metal; in step (8), the water-soluble polymer J is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methyl cellulose; the viscosity of the water-soluble polymer J at 20℃ is 10-1000 mPa·s, and the viscosity of the impregnation liquid after the water-soluble polymer J is added is 150-800 mPa·s.

2. The production method according to claim 1, characterized by, In step (3), the amount of the slurry Y added accounts for 10%-40% of the total mass of the urea used in the second crystallization.

3. The preparation method according to claim 1, characterized in that, In step (1), the template agent is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methyl cellulose; and / or, the viscosity of the template agent at 20℃ is 10-1000 mPa·s, and the viscosity of the solution X after the template agent is stirred uniformly is 120-660 mPa·s.

4. The production method according to claim 3, characterized by, In step (1), the template agent is polyethylene glycol.

5. The preparation method according to claim 1, characterized in that, The conditions of the first-time crystallization are as follows: the crystallization time is 5-30 h; and the conditions of the second-time crystallization are as follows: the crystallization time is 25-35 h.

6. The method of claim 1, wherein, In step (5), the sealing heat treatment temperature is 85-130℃, the treatment time is 6-12 h, the drying temperature is 120-180℃, and the drying time is 2-10 h; and / or, in step (7), the sealing treatment temperature is 20-50℃, the treatment time is 6-12 h, the drying temperature is 10-40℃, and the drying time is 2-10 h.

7. The preparation method according to claim 1, characterized in that, In step (6), in the first active metal component source, the Group VIII metal is nickel; and / or, in step (8), in the impregnation solution of the second active metal component containing the water-soluble polymer J, the contents of MoO3 and Group VIII metal oxide are 10.0-80.0 g / 100 mL and 2.0-40.0 g / 100 mL, respectively.

8. The method of claim 1, wherein, In step (8), the water-soluble polymer J is polyethylene glycol.

9. The method of claim 1, wherein, In step (8), the impregnation solution of the second active metal component is introduced with an additive containing at least one of fluorine, phosphorus, silicon or boron, and the additive is added in an amount of 2%-20% of the total mass of the molybdenum oxide in the impregnation solution of the second active metal component.

10. The method of claim 9, wherein, The additive is added in an amount of 2%-15% of the total mass of the molybdenum oxide in the impregnation solution of the second active metal component.

11. The method of claim 1, wherein, In step (8), the calcination temperature is 350-500℃, the calcination time is 2-6 h, and the calcination atmosphere is a mixed atmosphere of an inert atmosphere and other atmosphere; the inert atmosphere is mainly one or both of nitrogen and helium, and the other atmosphere is one or more of water vapor and air.

12. The residual hydrodemetallization catalyst produced by the process of any one of claims 1 to 11, characterized in that, The catalyst comprises a carrier component, an active metal component and carbon distributed on the surface of the catalyst, the active metal component comprises molybdenum and a Group VIII metal, and the carrier component is alumina; wherein, in the catalyst, the mass ratio of the carbon distributed on the surface of the catalyst to the alumina is 0.20-0.

40.

13. The catalyst according to claim 12, characterized in that, The content of MoO3 is 2.0%-20.0% and the content of Group VIII metal oxide is 1.0%-6.0% based on the mass of the catalyst.

14. The catalyst of claim 12, wherein the catalyst is characterized by, The specific surface area of the catalyst is 185 to 225 m 2 / g, and the pore volume is 0.75 to 1.05 mL / g.

15. The catalyst according to claim 14, characterized in that, The specific surface area of the catalyst is 190 to 210 m 2 / g, and the pore volume is 0.80 to 0.95 mL / g.

16. The catalyst of claim 12, wherein the catalyst is characterized by: The pore distribution of the catalyst is as follows: the pore volume of the pores with a pore diameter of <30 nm accounts for 27%-36% of the total pore volume, the pore volume of the pores with a pore diameter of 30-100 nm accounts for 31%-37% of the total pore volume, and the pore volume of the pores with a pore diameter of 100 nm-300 nm accounts for 33%-36% of the total pore volume; and / or, the strength of the catalyst is 8.0-18.0 N / mm.

17. The catalyst of claim 12, wherein the catalyst is characterized by: The catalyst comprises an additive component selected from at least one of fluorine, phosphorus, silicon or boron; and / or, the content of the additive component in terms of oxide is 1.0%-8.0% based on the mass of the catalyst.

18. The catalyst of claim 17, wherein, The additive component is phosphorus.

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