A catalyst for hydrodemetallization of residual oil and a method for preparing the same

Abstract

The application discloses a catalyst for residual oil hydrodemetallization and a preparation method thereof. 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 comprises alumina and activated carbon; wherein, in the catalyst, the ratio of the content of the carbon distributed on the surface of the catalyst to the content of the alumina in the carrier component is 0.16-0.50, and the ratio of the content of the activated carbon to the content of the alumina in the carrier component is 0.10-0.30. The residual oil hydrodemetallization catalyst provided by the application has excellent channel smoothness, concentrated pore distribution and suitable specific surface area. When the catalyst is used for residual oil hydrodemetallization reaction, the activity and stability of the reaction can be obviously improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a residue hydrodemetallization catalyst, in particular to a catalyst for residue hydrodemetallization and a preparation method thereof. BACKGROUND

[0002] With the increasing trend of heavy and poor quality of crude oil worldwide, efficient processing and utilization of heavy and residue oil becomes very important. Most of the residue hydrodemetallization catalysts are supported hydrodemetallization catalysts, and the active metal components are generally supported on the surface of the carrier. Under the action of the catalyst, various metal compounds react with H2S to form metal sulfides, and the generated metal sulfides are then deposited on the catalyst, thereby being removed. Therefore, the pore properties of the catalyst will not only affect the distribution of the active metal on the surface of the catalyst, but also affect the deposition of other impurities after the reaction.

[0003] CN108745392A discloses a bimodal pore distribution hydrodemetallization catalyst and a preparation method thereof. The hydrodemetallization catalyst contains a hydrodemetallization active metal component selected from at least one metal component of Group VIB and at least one metal component of Group VIII. The specific preparation method includes mixing the precursor of alumina with the extrusion aid, adding a metal salt solution containing the hydrodemetallization active metal component, kneading, molding and drying, and then performing hydrothermal treatment, drying and calcination. CN102861588A discloses a residue hydrodemetallization catalyst and a preparation method thereof. The catalyst uses alumina as the carrier and M0O3 and NiO as the active components. The content of the active components M0O3 and NiO is 1.0-15.0% and 0.5-6.0% by weight of the catalyst, respectively. The pore volume of the catalyst is 0.90-1.20 mL / g, the specific surface area is 190.0-250.0 m 2 / g, the pores with a diameter of 10-20 nm account for 80-90% of the total pore volume, and the crushing strength is 110-150 N / cm. The preparation method of the catalyst includes the following steps: (1) weighing a certain amount of pseudo-boehmite dry gel powder and mixing the extrusion aid uniformly, and then adding an aqueous solution containing a peptizing agent and a chemical pore expander; (2) mixing the material obtained in step (1) uniformly and extruding into strips; (3) drying and calcining the material obtained in step (2) to obtain an alumina carrier; and (4) loading the active metal components Mo and Ni by impregnation. CN105983417A discloses a preparation method of a residue hydrodemetallization catalyst, which includes the following steps: mixing one or more selected from aluminum trihydrate, boehmite, pseudo-boehmite and amorphous aluminum hydroxide with a peptizing agent, an extrusion aid and an organic solution uniformly, and then molding, drying and calcining to obtain a carrier; impregnating the obtained carrier with a solution containing nickel and molybdenum, and drying and calcining to obtain the final catalyst.

[0004] Since there are more macromolecules in heavy oil feedstock, the residue hydrodemetallization catalyst should have a smooth pore structure; in addition, in order to make the active metal component fully play its role in hydrogenation, the active metal should be well dispersed in the interior and surface of the catalyst to prevent its accumulation in the external pores and orifice of the catalyst. Therefore, the alumina carrier and the hydrodemetallization catalyst prepared by the above method still need to be further improved in activity and stability. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a catalyst for residue hydrodemetallization and a preparation method thereof. The residue hydrodemetallization catalyst provided by the present application has excellent smoothness of pore channel, and has a relatively concentrated pore distribution and a suitable specific surface area. When the catalyst of the present application is used for residue hydrodemetallization reaction, the activity and stability of the reaction can be significantly improved.

[0006] The present application provides a catalyst for residue hydrodemetallization, which 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 comprises alumina and activated carbon; wherein the ratio of the content of carbon distributed on the surface of the catalyst to the content of alumina in the carrier component is 0.16-0.50, preferably 0.25-0.50, and the ratio of the content of activated carbon to the content of alumina in the carrier component is 0.10-0.30.

[0007] In the present application, the active metal component comprises molybdenum and a group VIII metal, and the group VIII metal is preferably nickel.

[0008] In the present application, the content of MoO3 is 6.0%-25.0% and the content of group VIII metal oxide is 2.0%-5.0% based on the mass of the catalyst.

[0009] In the present application, the specific surface area of the catalyst is 170-210m 2 / g, and the pore volume is 0.70-1.00mL / g.

[0010] In the present application, preferably, the specific surface area of the catalyst is 175-190m 2 / g, and the pore volume is 0.85-0.95mL / g.

[0011] In the present application, the pore distribution of the catalyst is as follows: the pore volume of the pores with a pore diameter of <30nm accounts for 22%-30% of the total pore volume, the pore volume of the pores with a pore diameter of 30-100nm accounts for 35%-45% of the total pore volume, and the pore volume of the pores with a pore diameter of 100-300nm accounts for 34%-37% of the total pore volume.

[0012] In the present application, the strength of the catalyst is 10.0-18.0 N / mm.

[0013] In the present application, the catalyst further comprises an auxiliary component selected from at least one of fluorine, phosphorus, silicon or boron, preferably phosphorus. The content of the auxiliary component in terms of oxide is 2.0%-6.0% based on the mass of the catalyst.

[0014] The present application provides a preparation method of the catalyst for residual oil hydrodemetallization.

[0015] (1) dissolving aluminum nitrate, urea and a template agent in water to obtain solution X;

[0016] (2) crystallizing the solution X obtained in step (1), drying and calcining to obtain an alumina carrier A;

[0017] (3) sealing and heat-treating the carrier A obtained in step (2) after being immersed in an ammonium bicarbonate aqueous solution, and drying to obtain a carrier B;

[0018] (4) immersing and loading the active carbon with a first active metal component, standing, drying to obtain a dispersion medium containing the first active metal component;

[0019] (5) kneading and molding the carrier B and the dispersion medium obtained in step (4), drying and calcining to obtain a carrier C;

[0020] (6) sealing and treating the carrier C obtained in step (5) after being immersed in an ammonium bicarbonate aqueous solution, and drying to obtain a carrier D;

[0021] (7) immersing and loading the carrier D obtained in step (6) with a second active metal component containing a water-soluble high polymer J, drying and calcining to obtain the catalyst for residual oil hydrodemetallization.

[0022] In the present application, the water used is preferably deionized water. The crystallization is carried out in a crystallization kettle.

[0023] In step (1) of the present application, the aluminum nitrate, urea and template agent are sequentially dissolved in deionized water to obtain solution X.

[0024] In step (1) of the present application, the molar ratio of Al(NO3)3 to the template agent is 160-240, preferably 180-220.

[0025] In step (1) of the present application, the molar ratio of urea to Al(NO3)3 is 7-14. Within this range, the OH - generated by the decomposition of urea and the hydrolysis rate of Al 3+ are just right, and the alumina can grow uniformly on the surface of the template agent.

[0026] In step (1) of the present application, the template agent is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methyl cellulose, preferably polyethylene glycol; the viscosity of the template agent (20℃) is 10-1000 mPa·s, and the viscosity of solution X (20℃) is 120-660 mPa·s after the template agent is added and stirred uniformly.

[0027] In step (2) of the present application, the crystallization temperature is 80-200℃, and the crystallization time is 25-35 h.

[0028] In step (2) of the present application, filtration and washing can be performed according to conventional known methods before drying. Washing can be performed using deionized water until the pH of the filtrate is close to neutral. After drying, the dry basis content of the obtained dried product is 50wt%-80wt%.

[0029] In step (2) of the present application, the drying temperature is 120-200℃, and the drying time is 2-12 h.

[0030] In step (2) of the present application, the calcination temperature is 500-750℃, the calcination time is 2-6 h, and the calcination atmosphere is air.

[0031] In step (3) of the present application, the mass percentage concentration of the ammonium bicarbonate aqueous solution is in the range of 10%-20%. The sealing heat treatment temperature is 80-140℃, preferably 90-140℃, and the treatment time is 6-12 h. The drying temperature is 120-180℃, and the drying time is 2-10 h.

[0032] In step (4) of the present application, impregnation is performed using a saturation impregnation method, and the standing time after impregnation is 4-12 h.

[0033] In step (4) of the present application, the drying temperature is 20-200℃, and the drying time is 2-12 h.

[0034] In step (4) of the present application, when the activated carbon is impregnated with the first active metal component, an impregnation solution containing the first active metal component is used. The impregnation solution is an impregnation solution containing Mo and a Group VIII metal (preferably Ni), wherein the active metal component Mo 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 first active metal component is 2-30 g / 100 mL and 2-50 g / 100 mL, respectively.

[0035] The amount of MoO3 introduced into the catalyst by the first active metal component in step (4) is 45% to 60% 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 60% of the total Group VIII metal oxide loading in the catalyst.

[0036] In step (5), the ratio of the total mass of the activated carbon in the dispersion medium obtained in step (4) to other solid materials is in the range of 0.15 to 0.35.

[0037] In step (5), conventional molding aids such as one or more of a peptizing agent, an extrusion aid, etc. can be added as needed during the molding process. The peptizing agent is one or more of nitric acid, sulfuric acid, oxalic acid, and preferably nitric acid. The extrusion aid is one or more of sesbania powder, cellulose, and resin, and preferably sesbania powder.

[0038] In step (5), the mass of the peptizing agent added is 0.5% to 4.0% of the carrier B, and the mass of the extrusion aid added is 0.1% to 5.0% of the carrier B.

[0039] In step (5), the drying temperature is 20 to 200°C, and the drying time is 2 to 12 hours.

[0040] In step (5), the calcination temperature is 500 to 750°C, the calcination time is 2 to 6 hours, and the calcination atmosphere is air.

[0041] In step (6), the mass percentage concentration of the ammonium bicarbonate aqueous solution is in the range of 20% to 30%. The sealing treatment temperature is 10 to 60°C, preferably 20 to 50°C, and the treatment time is 6 to 12 hours. The heat treatment temperature in step (6) is 60 to 90°C lower than the heat treatment temperature in step (3). The drying temperature is 10 to 40°C, the drying time is 2 to 10 hours, and the drying method is static drying.

[0042] In step (6), the mass concentration of the ammonium bicarbonate aqueous solution is 8 to 15 percentage points higher than the mass concentration of the ammonium bicarbonate aqueous solution in step (3).

[0043] In step (7), the impregnation is performed by a saturation impregnation method, and the standing time after impregnation is 4 to 14 hours.

[0044] In step (7) of the present application, the impregnation solution of the second active metal component containing the water-soluble polymer J is used when the support D in step (6) is impregnated with the second active metal component containing the water-soluble polymer J. The impregnation solution is an impregnation solution of Mo and Group VIII metal (preferably Ni), wherein the active metal component Mo is derived from one or both of molybdenum oxide and ammonium heptamolybdate, and the active metal component Ni 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 of the second active metal component containing the water-soluble polymer J is 10.0-70.0 g / 100 mL and 2.0-60.0 g / 100 mL, respectively.

[0045] In step (7) of the present application, the amount of MoO3 introduced into the catalyst by the second active metal component is 40%-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 40%-55% of the total Group VIII metal oxide loading in the catalyst.

[0046] In step (7) of the present application, the water-soluble polymer J is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methyl cellulose, and is preferably polyethylene glycol. The viscosity of the water-soluble polymer J (20℃) is 10-1000 mPa·s, and the viscosity of the impregnation solution after the addition of the water-soluble polymer J (20℃) is 150-800 mPa·s.

[0047] In step (7) of the present application, at least one additive containing fluorine, phosphorus, silicon or boron can also be introduced into the impregnation solution of the second active metal component containing the water-soluble polymer J. The additive (calculated as oxide) is added in an amount of 6%-18% of the total mass of molybdenum oxide in the impregnation solution of the second active metal component, and is preferably added in an amount of 8%-15%.

[0048] In step (7) of the present application, the drying temperature is 120-200℃, and the drying time is 2-12 h.

[0049] In step (7) of the present application, the calcination temperature is 350-500℃, the calcination time is 2-6 h, the calcination atmosphere is a mixed atmosphere of an inert atmosphere and another atmosphere, and the volume ratio of the inert atmosphere to the other atmosphere is 0.5-5:1. 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.

[0050] In step (7) of the present application, the ratio of the carbon content on the surface of the catalyst to the content of alumina in the support component is 0.16-0.50, and the ratio of the active carbon content to the content of alumina in the support component is 0.10-0.30.

[0051] Compared with the prior art, the present application has the following beneficial effects:

[0052] Due to the presence of more macromolecules in the heavy oil raw material, the prepared hydrogen demetallization catalyst should have a smooth pore structure; in addition, in order to make the active metal component fully play its hydrogenation role, the active metal should be well dispersed inside and on the surface of the catalyst to prevent its accumulation in the external pores and orifices of the catalyst. The inventors have found through a large number of studies that the alumina carrier prepared by the uniform precipitation method has a large specific surface area and a regular pore structure, and after the sealed heat treatment of the alumina carrier after the ammonium bicarbonate aqueous solution, the pore properties are adjusted, and the most probable pore diameter is significantly increased. In order to further improve the pore permeability of the carrier, part of the active metal is impregnated on the activated carbon in a saturated impregnation manner, and the dispersion medium is obtained after the static placement and drying of the activated carbon. Then, the obtained dispersion medium is mixed and kneaded with alumina, nitric acid, sesbania powder and deionized water, and then formed, dried and calcined to obtain a carrier with more smooth pores and a suitable specific surface area. Then, the carrier after forming is again subjected to sealed treatment after the ammonium bicarbonate aqueous solution, so that the ammonium bicarbonate aqueous solution fills the external pores and orifices of the carrier, preventing the active metal component from accumulating around the orifices during the impregnation process. Finally, the remaining active metal is used to prepare an impregnating solution, and the carrier is impregnated with the impregnating solution in a saturated impregnation manner, and then dried and calcined to obtain the hydrogen demetallization catalyst. In addition, a water-soluble polymer is added to the impregnating solution during the second impregnation, and the final calcination atmosphere is a mixed gas atmosphere. This process not only makes the polymer not completely decomposed to form point-like distributed carbon points, but also appropriately adjusts the acidity of the catalyst, which is beneficial to weakening the interaction between the active metal and the carrier, promoting the dispersion degree of the active metal on the surface of the catalyst, and making the external orifices of the catalyst smooth again, which is beneficial to the diffusion of macromolecules during the reaction. Through the comprehensive coordination of each step, a macropore-mesoporous composite material is constructed, which not only makes the continuous distribution of macropores more extensive, but also enhances the connectivity of the pores. The catalyst prepared by this method not only has large pore volume and pore diameter, but also has high mechanical strength and suitable specific surface area. When the catalyst is used for residual oil hydrogen demetallization reaction, the hydrogenation reaction activity and stability can be significantly improved. DETAILED DESCRIPTION

[0053] In the present application, the pore structure (SVD) and specific surface area of the catalyst are characterized by using the ASAP-2420 physical adsorption instrument of the Micromeritics company.

[0054] In the present application, the crush resistance of the catalyst particles is detected by using the ZQJ-III intelligent particle strength tester.

[0055] In the present application, the carbon / alumina mass ratio on the surface of the catalyst is determined by using the STA409PC-QMS403C thermal gravimetric-mass spectrometry analyzer (TG-MS) of the NETZSCH company.

[0056] The technical solutions and effects of the present application are further illustrated below with examples, but are not limited to the following examples.

[0057] Example 1

[0058] (1) A certain amount of aluminum nitrate, urea and template agent polyethylene glycol (viscosity of 500 mPa·s) were weighed, wherein the molar ratio of Al(NO3)3 to polyethylene glycol was 180, and the molar ratio of urea to Al(NO3)3 was 9. The above substances were sequentially dissolved in a certain amount of deionized water, and then mixed uniformly by magnetic stirring for 5 h to obtain solution X (viscosity of 350 mPa·s);

[0059] (2) The obtained solution X was transferred to a crystallization kettle, and the crystallization kettle was placed in an oven at 190℃. After 34 h of reaction, the crystallization kettle was taken out and cooled. A mixed slurry containing white precipitate was obtained in the reaction kettle. The obtained white precipitate was filtered and washed several times until the pH value of the filtrate was close to 7. The white precipitate was placed in an oven for drying at a drying temperature of 140℃ for 8 h, and then calcined in a muffle furnace at a calcination temperature of 650℃ for 3 h to obtain an alumina carrier A;

[0060] (3) The obtained alumina carrier A was immersed in an ammonium bicarbonate aqueous solution and then sealed for heat treatment to obtain a carrier B, wherein the mass percentage concentration of the ammonium bicarbonate aqueous solution was in the range of 18%, the sealed heat treatment temperature was 90℃, the treatment time was 6 h, and the drying temperature was 140℃ for 4 h;

[0061] (4) The activated carbon was impregnated with a first active component metal component impregnating solution (MoO3 content of 25.36 g / 100 mL, NiO content of 4.64 g / 100 mL) in a saturated impregnation manner. After impregnation, the impregnated medium containing part of the active metal was formed after standing at room temperature (25℃) for 4 h and drying at 120℃ for 6 h. The amount of MoO3 introduced into the catalyst by the first active metal component was 50% of the total MoO3 loading in the catalyst, and the amount of NiO was 50% of the total NiO loading in the catalyst;

[0062] (5) The carrier B and nitric acid (68wt%), sesbania powder, dispersion medium and deionized water were mixed and kneaded, and then shaped, dried and calcined to obtain a carrier C. The mass content of the added nitric acid (68wt%) was 2.5% of the carrier B, the mass content of the added sesbania powder was 3.0% of the carrier B, the amount of the added activated carbon in the dispersion medium was 16% of the sum of the mass of the carrier B and the sesbania powder, the content of the added deionized water was adjusted in real time according to the state of the material during the shaping process, the drying temperature was 120℃, the drying time was 6 h, the calcination temperature was 750℃, and the calcination time was 5 h (the heating rate was 2.5℃ / min);

[0063] (6) The obtained carrier C is immersed in an aqueous ammonium bicarbonate solution, sealed, dried, and carrier D is obtained, wherein the mass percentage concentration of the aqueous ammonium bicarbonate solution is 28%, the sealing treatment temperature is 30°C, the treatment time is 6h, the drying temperature is 30°C, the drying time is 4h, and the drying method is static drying;

[0064] (7) The carrier D is impregnated with a saturated impregnation solution containing a second active component metal component (the content of MoO3 is 25.36g / 100mL, the content of NiO is 4.64g / 100mL, and the added amount of P (calculated as an oxide) in the additive phosphoric acid is 9.86% of the total mass of molybdenum oxide in the impregnation solution) to obtain the catalyst for residue hydrodemetallization, wherein the amount of MoO3 introduced into the catalyst by the second active metal component is 50% of the total MoO3 loading in the catalyst, and the amount of NiO is 50% of the total NiO loading in the catalyst; the impregnation solution contains a water-soluble high polymer J polyethylene glycol, and the viscosity of the impregnation solution after adding the water-soluble high polymer J polyethylene glycol is 300mPa·s (20°C); after the impregnated sample is left at room temperature (25°C) for 6h, it is dried (temperature is 120°C, drying time is 6h), calcined at a temperature of 450°C for 5h (heating rate is 2.0°C / min), and the calcination atmosphere is a mixed gas atmosphere of nitrogen and air (volume ratio of nitrogen to air is 3:1). The catalyst for residue hydrodemetallization is obtained. The above-prepared catalyst for residue hydrodemetallization is named CAT-1. The physicochemical properties of the catalyst are shown in Table 1.

[0065] Example 2

[0066] This example is different from Example 1 in that the molar ratio of Al(NO3)3 to polyethylene glycol in step (1) is 215, and the molar ratio of urea to Al(NO3)3 is 11; and the added amount of activated carbon in the dispersion medium in step (5) is 24% of the sum of the mass of carrier B and the mass of the sesbania powder. The catalyst for residue hydrodemetallization CAT-2 is prepared. The physicochemical properties of the catalyst are shown in Table 1.

[0067] Example 3

[0068] This example is different from Example 1 in that the mass percentage concentration of the first aqueous ammonium bicarbonate solution in step (3) is 15%, the sealing heat treatment temperature is 120°C, the treatment time is 6h, the drying temperature is 140°C, and the drying time is 6h; the mass percentage concentration of the second aqueous ammonium bicarbonate solution in step (6) is 25%, the sealing treatment temperature is 35°C, the treatment time is 6h, the drying temperature is 30°C, and the drying time is 8h. The catalyst for residue hydrodemetallization CAT-3 is prepared. The physicochemical properties of the catalyst are shown in Table 1.

[0069] Example 4

[0070] The difference between this example and Example 1 is that in step (4), the activated carbon is impregnated with an impregnation solution containing the first active metal component (MoO3 content of 27.90 g / 100 mL, NiO content of 5.10 g / 100 mL) by saturated impregnation, and after impregnation, the sample is left to stand at room temperature (25 °C) for 6 h and dried at 120 °C for 8 h, to form a dispersion medium containing part of the active metals; the amount of MoO3 introduced into the catalyst by the first active metal component is 55% of the total MoO3 loading in the catalyst, and the amount of NiO is 55% of the total NiO loading in the catalyst; in step (5), the carrier B, nitric acid (68 wt%), sesbania powder, dispersion medium and deionized water are mixed and kneaded, shaped, dried and calcined to obtain carrier C, the drying temperature is 140 °C, the drying time is 6 h, the calcination temperature is 700 °C, and the calcination time is 4 h (the heating rate is 3.0 °C / min); in step (7), the carrier D is impregnated with an impregnation solution containing the second active metal component (MoO3 content of 22.82 g / 100 mL, NiO content of 4.18 g / 100 mL, and the amount of P (as an oxide) in the additive phosphoric acid is 8.87% of the total mass of molybdenum oxide in the impregnation solution) by saturated impregnation, wherein the amount of MoO3 introduced into the catalyst by the second active metal component is 45% of the total MoO3 loading in the catalyst, and the amount of NiO is 45% of the total NiO loading in the catalyst; the impregnation solution contains a water-soluble high polymer J polyvinyl alcohol, and the viscosity of the impregnation solution after adding the water-soluble high polymer J polyvinyl alcohol is 350 mPa·s (20 °C), the impregnated sample is left to stand at room temperature for 10 h, then dried (drying temperature of 160 °C, drying time of 7 h), calcined at a calcination temperature of 500 °C for 5 h (heating rate of 2.5 °C / min), and in a calcination atmosphere of a mixture of helium and air (volume ratio of nitrogen to air is 1:1), to obtain a residue oil hydrodemetallization catalyst CAT-4. The physicochemical properties of the catalyst are shown in Table 1.

[0071] Comparative Example 1

[0072] The difference compared with Example 1 is that in step (1), the molar ratio of Al (NO3) 3 to polyethylene glycol is 255, and the molar ratio of urea to Al (NO3) 3 is 6.5, and the above substances are dissolved in a certain amount of deionized water in the order of aluminum nitrate, urea and polyethylene glycol, and after magnetic stirring for 6 h, solution X is obtained; in step (2), the obtained solution X is transferred to a crystallization kettle, and the crystallization kettle is placed in an oven at 160 °C, and after 20 h, the crystallization kettle is taken out; a residue oil hydrodemetallization catalyst dCAT-1 is prepared. The physicochemical properties of the catalyst are shown in Table 1.

[0073] Comparative Example 2

[0074] Comparative Example 1 was different from Example 1 in that the mass percentage concentration of the second ammonium bicarbonate aqueous solution in step (6) was 32%, the sealing treatment temperature was 75°C, the treatment time was 7h, the drying temperature was 140°C, and the drying time was 8h. The catalyst dCAT-2 for residue hydrodemetallization was prepared. The physicochemical properties of the catalyst are shown in Table 1.

[0075] Comparative Example 2

[0076] Comparative Example 3 was different from Example 1 in that the activated carbon was not impregnated with the first active metal component in step (4), but the carrier D was impregnated with an impregnation solution containing the active metal component in step (7) in a saturated impregnation manner. The impregnation solution contained a water-soluble high polymer J, polyethylene glycol. The viscosity of the impregnation solution (20°C) was 400 mPa-s after the addition of the water-soluble high polymer J, polyethylene glycol. The impregnated sample was allowed to stand at room temperature for 7h, and then dried (drying temperature 150°C, drying time 7h). The calcination temperature was 650°C, the calcination time was 3h (the temperature rising rate was 3.0°C / min), and the calcination atmosphere was a mixed atmosphere of nitrogen and water vapor. The catalyst dCAT-3 for residue hydrodemetallization was prepared. The physicochemical properties of the catalyst are shown in Table 1.

[0077] Comparative Example 4

[0078] Comparative Example 4 was different from Example 1 in that the water-soluble high polymer J, polyethylene glycol, was not added to the impregnation solution containing the second active metal component in step (7), and the calcination atmosphere was air. The catalyst dCAT-4 for residue hydrodemetallization was prepared. The catalyst dCAT-4 did not contain carbon on the surface. The physicochemical properties of the catalyst are shown in Table 1.

[0079] Table 1 Physicochemical properties of the catalysts for residue hydrodemetallization of the examples

[0080]

[0081]

[0082] Evaluation test

[0083] The activity stability tests of the catalysts CAT-1 to 4 and dCAT-1 to 4 for residue hydrodemetallization were carried out in a 200 mL fixed bed hydrogenation test device. The catalysts used were in the form of strips with a length of 2 to 3 mm. The reaction conditions were as follows: reaction temperature 380°C, hydrogen partial pressure 13.0 MPa, liquid hourly space velocity 1.0 h-1, and hydrogen to oil volume ratio 800. After the reaction for 1500h, the demetallization rates (Ni+V) of the catalysts were shown in Table 3, and the properties of the raw oil were shown in Table 2. 1

[0084] Table 2 Properties of the raw oil

[0085] ​

[0086]

[0087] Table 3 Catalyst test results of each example of residue hydrodemetallization

[0088]

[0089] As can be seen from Table 1, Table 2 and Table 3, the hydrodemetallization catalyst prepared according to the method of the present application has a more open pore structure, and at the same time has a suitable specific surface area, maintains a high reaction activity and stability during the reaction, and can well meet the process of heavy oil, especially residue hydrodemetallization.

Claims

1. A catalyst for hydrodemetallization of residual oil, characterized in that, The catalyst comprises a support component, an active metal component, and carbon distributed on the catalyst surface. The active metal component includes molybdenum and Group VIII metals, and the support component includes alumina and activated carbon. The ratio of carbon content on the catalyst surface to alumina content in the support component is 0.16–0.50, and the ratio of activated carbon content to alumina content in the support component is 0.10–0.

30. The specific surface area of ​​the catalyst is 170–210 m². 2 / g, with a pore volume of 0.70~1.00mL / g; the pore distribution of the catalyst is as follows: pores with a diameter <30nm account for 22%~30% of the total pore volume, pores with a diameter of 30~100nm account for 35%~45% of the total pore volume, and pores with a diameter of 100nm~300nm account for 34%~37% of the total pore volume; the strength of the catalyst is 10.0~18.0N / mm; The preparation method of the catalyst for hydrodemetallization of residue oil includes the following steps: (1) Dissolve aluminum nitrate, urea and template agent in water to obtain solution X; (2) Crystallize the solution X obtained in step (1), dry and calcine to obtain alumina carrier A; (3) The carrier A obtained in step (2) is immersed in an ammonium bicarbonate aqueous solution, then sealed and heat-treated, and dried to obtain carrier B; (4) Impregnate activated carbon with the first active metal component, let stand, and dry to obtain a dispersion medium containing the first active metal component; (5) Mix carrier B and the dispersion medium obtained in step (4), shape them, dry them, and calcine them to obtain carrier C; (6) The carrier C obtained in step (5) is immersed in an ammonium bicarbonate aqueous solution, sealed, and dried to obtain carrier D; (7) Impregnate the carrier D obtained in step (6) with the second active metal component containing water-soluble polymer J, dry and calcine to obtain the catalyst for hydrodemetallization of residue oil; In step (4), when the activated carbon is impregnated with the first active metal component, an impregnation solution containing the first active metal component is used, wherein the impregnation solution contains Mo and Group VIII metals. In step (7), when the carrier D is impregnated with the second active metal component containing water-soluble polymer J, an impregnation solution containing the second active metal component containing water-soluble polymer J is used. The impregnation solution is an impregnation solution containing Mo and Group VIII metals. In step (7), the water-soluble polymer J is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methylcellulose; the viscosity of the water-soluble polymer J at 20°C is 10~1000 mPa·s, and the viscosity of the impregnation solution at 20°C after adding the water-soluble polymer J is 150~800 mPa·s.

2. The catalyst according to claim 1, characterized in that, In the catalyst, the ratio of carbon content distributed on the catalyst surface to alumina content in the support component is 0.25~0.

50.

3. The catalyst according to claim 1, characterized in that, The Group VIII metal is nickel.

4. The catalyst according to claim 1, characterized in that, Based on catalyst mass, the content of MoO3 is 6.0%~25.0%, and the content of Group VIII metal oxides is 2.0%~5.0%.

5. The catalyst according to claim 1, characterized in that, The catalyst has a specific surface area of ​​175~190 m². 2 / g, with a pore volume of 0.85~0.95mL / g.

6. The catalyst according to claim 1, characterized in that, The catalyst includes an auxiliary component selected from at least one of fluorine, phosphorus, silicon, or boron; the content of the auxiliary component, calculated as oxide, is 2.0% to 6.0% based on the mass of the catalyst.

7. The catalyst according to claim 6, characterized in that, The auxiliary agent component is phosphorus.

8. A method for preparing the catalyst for hydrodemetallization of residue oil according to any one of claims 1-7, comprising the following steps: (1) Dissolve aluminum nitrate, urea and template agent in water to obtain solution X; (2) Crystallize the solution X obtained in step (1), dry and calcine to obtain alumina carrier A; (3) The carrier A obtained in step (2) is immersed in an ammonium bicarbonate aqueous solution, then sealed and heat-treated, and dried to obtain carrier B; (4) Impregnate activated carbon with the first active metal component, let stand, and dry to obtain a dispersion medium containing the first active metal component; (5) Mix carrier B and the dispersion medium obtained in step (4), shape them, dry them, and calcine them to obtain carrier C; (6) The carrier C obtained in step (5) is immersed in an ammonium bicarbonate aqueous solution, sealed, and dried to obtain carrier D; (7) The carrier D obtained in step (6) is impregnated with the second active metal component containing water-soluble polymer J, dried and calcined to obtain the catalyst for hydrodemetallization of residue oil.

9. The preparation method according to claim 8, characterized in that, In step (1), the molar ratio of Al(NO3)3 to the template agent is 160~240; the molar ratio of urea to Al(NO3)3 is 7~14.

10. The preparation method according to claim 9, characterized in that, In step (1), the molar ratio of Al(NO3)3 to the template agent is 180~220.

11. The preparation method according to claim 8, characterized in that, In step (1), the template agent is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methylcellulose; the viscosity of the template agent at 20°C is 10~1000 mPa·s, and the viscosity of the solution at 20°C after adding the template agent and stirring evenly is 120~660 mPa·s.

12. The preparation method according to claim 11, characterized in that, In step (1), the template agent is polyethylene glycol.

13. The preparation method according to claim 8, characterized in that, In step (2), the crystallization temperature is 80~200℃ and the crystallization time is 25~35h.

14. The preparation method according to claim 8, characterized in that, In step (3), the mass percentage concentration of the ammonium bicarbonate aqueous solution ranges from 10% to 20%; and / or, In step (6), the mass percentage concentration of the ammonium bicarbonate aqueous solution ranges from 20% to 30%; and / or, The mass concentration of the ammonium bicarbonate aqueous solution in step (6) is 8 to 15 percentage points higher than that in step (3).

15. The preparation method according to claim 8, characterized in that, In step (3), the sealing heat treatment temperature is 80~140℃, and the treatment time is 6~12h; the drying temperature is 120~180℃, and the drying time is 2~10h; and / or, In step (6), the sealing treatment temperature is 10~60℃, and the treatment time is 6~12h; the drying temperature is 10~40℃, and the drying time is 2~10h; and / or, The processing temperature in step (6) is 60~90℃ lower than the heat treatment temperature in step (3).

16. The preparation method according to claim 8, characterized in that, In step (3), the sealing heat treatment temperature is 90~140℃; and / or, In step (6), the sealing treatment temperature is 20~50℃.

17. The preparation method according to claim 8, characterized in that, In step (4), when the activated carbon is impregnated with the first active metal component, an impregnation solution containing the first active metal component is used; the contents of MoO3 and Group VIII metal oxides in the impregnation solution are 2~30g / 100mL and 2~50g / 100mL, respectively; and / or, In step (7), when the carrier D is impregnated with the second active metal component containing water-soluble polymer J, the impregnation solution containing the second active metal component of water-soluble polymer J is used; the contents of MoO3 and Group VIII metal oxides in the impregnation solution are 10.0~70.0g / 100mL and 2.0~60.0g / 100mL, respectively.

18. The preparation method according to claim 8, characterized in that, In step (7), the water-soluble polymer J is polyethylene glycol.

19. The preparation method according to claim 8, characterized in that, In step (7), at least one additive containing fluorine, phosphorus, silicon or boron is introduced into the impregnation solution of the second active metal component. The amount of additive added is 6% to 18% of the total mass of molybdenum oxide in the impregnation solution of the second active metal component containing water-soluble polymer J.

20. The preparation method according to claim 19, characterized in that, The amount of additive added is 8% to 15% of the total mass of molybdenum oxide in the impregnation solution containing the second active metal component of water-soluble polymer J.

21. The preparation method according to claim 8, characterized in that, The mass ratio of activated carbon to other solid materials in the dispersion medium obtained in step (4) is in the range of 0.15 to 0.

35.

22. The preparation method according to claim 8, characterized in that, In step (7), 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; wherein, the inert atmosphere is one or two of nitrogen and helium, and the other atmosphere is one or more of water vapor and air.

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