Residue oil hydrodemetallization catalyst and preparation method thereof

Abstract

The present invention discloses a residual oil hydrodemetallization catalyst and a preparation method thereof. The method comprises: neutralizing an acidic aluminum salt solution and an alkaline aluminum salt solution to obtain a slurry; performing a primary aging reaction, adding a water-soluble polymer J1 after the reaction, performing a secondary aging reaction, and drying to obtain a dried product I; drying and crushing a biomass feedstock into a powder, which is then mixed with a polymer, a potassium-containing inorganic substance, and the dried product I in proportion, kneaded, formed, and heat-treated to obtain a dried product II; spraying a first impregnation solution onto the dried product II in an unsaturated impregnation manner, drying, and performing a first calcination to obtain a calcined body, which is then impregnated with an aqueous carbohydrate solution, dried, and carbonized to obtain an intermediate; and spraying a second impregnation solution onto the intermediate in a saturated impregnation manner, drying, and performing a second calcination to obtain a catalyst. When the catalyst of the present invention is used in a residual oil hydrodemetallization reaction, the catalytic activity and stability are significantly improved.

Description

Technical Field

[0001] The present invention relates to a hydrodemetallization catalyst, in particular to a hydrodemetallization catalyst suitable for heavy oil, especially residual oil hydrotreating process, and a preparation method and application thereof. Background Art

[0002] As we all know, residue hydrodemetallization is one of the key chemical reactions occurring during residue hydrotreating. Over the action of a catalyst, various metal compounds react with H2S to form metal sulfides, which are then deposited on the catalyst for removal. The presence of active metals on the catalyst support plays a crucial role in the catalyst's activity and stability.

[0003] CN1289640A discloses a method for preparing a supported hydrodemetallization catalyst. The method uses a macroporous alumina carrier and sprays an ammonia solution or an aqueous solution of an active metal onto the carrier in a spray drum. The method omits the normal temperature drying process of the carrier after impregnation. The sprayed carrier is directly placed in a roasting furnace at a temperature of 300-450°C for roasting, and then gradually heated to 460-550°C and kept constant at this temperature under air conditions for 1-5 hours.

[0004] 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, then subjecting the support to hydrothermal carbonization in a sealed container. Active metal components Mo and Ni are then loaded onto the support. Finally, the active component-loaded alumina is calcined under a nitrogen atmosphere and then again under an air atmosphere to produce the residue oil hydrodemetallization catalyst. CN102441399A discloses a method for preparing a hydrodemetallization catalyst. A Group VIB metal compound and / or a Group VIII metal compound is prepared into an ammonia solution or aqueous solution, then impregnated with the alumina support. The final catalyst is then dried and calcined.

[0005] The activity and stability of the hydrodemetallization catalyst prepared by the above method still need to be further improved. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention provides a residual oil hydrodemetallization catalyst and a preparation method thereof. The catalyst has high activity and activity stability when used in residual oil hydrodemetallization reaction.

[0007] The first aspect of the present invention provides a residue hydrodemetallization catalyst, comprising a carbon film-coated intermediate and a second active component supported on the intermediate, the second active component comprising molybdenum and a Group VIII metal; the intermediate comprising carbon, alumina, potassium oxide and a first active component, the first active component comprising molybdenum and a Group VIII metal; wherein, in the catalyst, the ratio of tetrahedral molybdenum to octahedral molybdenum content, calculated as Mo atoms, is 0.18 to 0.72, and the thickness of the carbon film is 0.1 μm to 400 μm, preferably 1 μm to 180 μm, and more preferably 25 μm to 70 μm.

[0008] In the present invention, the carbon film has macropores, and the pore volume of the carbon film layer is 0.9 to 2.0 cm 3 / g, preferably 1.0 to 1.8 cm 3 / g, more preferably 1.0 to 1.4 cm 3 / g. The average pore diameter is 40 to 70 nm, preferably 50 to 60 nm.

[0009] In the present invention, the intermediate comprises carbon, aluminum oxide, potassium oxide and a first active component, wherein the first component comprises molybdenum and a Group VIII metal, wherein the Group VIII metal is preferably nickel.

[0010] In the present invention, the Group VIII metal in the second active component is preferably nickel.

[0011] In the present invention, the catalyst further comprises an auxiliary component, which is selected from at least one of fluorine, phosphorus, silicon or boron, preferably phosphorus. The content of the auxiliary component in terms of oxide is 1.0% to 4.0% based on the mass of the catalyst.

[0012] In the present invention, the intermediate has a carbon content of 5.0% to 7.0%, an aluminum oxide content of 76.0% to 82.0%, a potassium oxide content of 5.0% to 6.0%, and the remainder is the first active metal, based on the mass of the intermediate.

[0013] In the present invention, the content of MoO3 in the catalyst is 5.0% to 15.0%, and the content of Group VIII metal oxide is 1.0% to 5.0%, based on the mass of the catalyst.

[0014] In the present invention, based on the total mass of MoO3 in the catalyst, the content of MoO3 in the first active component is 35.0% to 65.0%, and the content of MoO3 in the second active component is 35.0% to 65.0%.

[0015] In the present invention, based on the total mass of Group VIII metal oxides in the catalyst, the content of Group VIII metal oxides in the second active component is 35.0% to 65.0%.

[0016] In the present invention, the specific surface area of ​​the catalyst is 180 to 230 m 2 / g, the pore volume is 0.7~1.2mL / g, and the pore diameter is 15~26nm.

[0017] In the present invention, preferably, the specific surface area of ​​the catalyst is 190 to 210 m 2 / g, the pore volume is 0.8~1.0mL / g, and the pore diameter is 15~24nm.

[0018] The second aspect of the present invention provides a method for preparing the above-mentioned residue hydrodemetallization catalyst, comprising the following steps:

[0019] (1) neutralizing an acidic aluminum salt solution with an alkaline aluminum salt solution to obtain a slurry;

[0020] (2) subjecting the slurry obtained in step (1) to primary aging; after the primary aging, adding a water-soluble polymer J1, subjecting the slurry to secondary aging, and drying to obtain a dried product I;

[0021] (3) kneading, shaping, and heat-treating the biomass raw material, the polymer, the potassium-containing inorganic substance, and the dried product I obtained in step (2) to obtain a dried product II;

[0022] (4) spraying a first impregnation solution containing a first active component onto the dried product II obtained in step (3) in an unsaturated impregnation manner, drying and first calcining to obtain a calcined body;

[0023] (5) soaking the calcined product obtained in step (4) in a carbohydrate aqueous solution, drying, and then carbonizing to obtain an intermediate;

[0024] (6) Spraying a second impregnation solution containing a second active component onto the intermediate obtained in step (5) in a saturated impregnation manner, followed by drying and a second calcination to obtain the catalyst.

[0025] In step (1) of the present invention, the acidic aluminum salt solution and the alkaline aluminum salt solution are added to the reactor in a parallel flow.

[0026] In step (1) of the present invention, the acidic aluminum salt solution is one or more of aluminum sulfate solution, aluminum nitrate solution, or aluminum chloride solution; the concentration of the acidic aluminum salt solution is 5 g / 100 mL to 25 g / 100 mL as calculated on the basis of Al2O3. The alkaline aluminum salt solution is one or more of sodium metaaluminate solution and potassium metaaluminate solution; the concentration of the alkaline aluminum salt solution is 8 g / 100 mL to 52 g / 100 mL as calculated on the basis of Al2O3.

[0027] In step (1) of the present invention, the neutralization reaction temperature is 75 to 120° C., the time is 30 to 150 minutes, and the pH value of the slurry is controlled to be 6.0 to 10.0 during the neutralization reaction. The pH value of the slurry is adjusted by controlling the addition rate of the acidic aluminum salt solution and the alkaline aluminum salt solution or by additionally adding an acid-base regulator during the neutralization reaction.

[0028] In step (2) of the present invention, the temperature of the primary aging is 90 to 240° C., the time is 50 to 240 minutes, and the pH value is 8.5 to 12.0.

[0029] In step (2) of the present invention, the water-soluble polymer J1 is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methyl cellulose, preferably polyethylene glycol; the viscosity (20°C) of the water-soluble polymer J1 is 10 to 1000 mPa·s, and the viscosity (20°C) of the slurry after adding the water-soluble polymer J1 is 120 to 660 mPa·s.

[0030] In step (2) of the present invention, after the primary aging is completed, preferably, the slurry is concentrated first and then subjected to secondary aging, wherein the volume of the concentrated slurry is 40% to 70% of the original volume.

[0031] In step (2) of the present invention, the secondary aging temperature is 120-260° C., the time is 45-190 minutes, and the secondary aging temperature is 30-60° C. higher than the primary aging temperature.

[0032] In step (2) of the present invention, the drying temperature after secondary aging is 120-180°C and the drying time is 2-10 hours. Filtering and washing can be performed according to conventional methods before drying. The dry matter I obtained after drying has a dry matter content of 45 wt% to 70 wt%.

[0033] In step (3) of the present invention, the biomass raw material is selected from one or more of wood, fruit shells, starch, bamboo, or other biomass raw materials. The biomass raw material is dried and crushed into powder before use. The drying conditions are: drying at 100-350°C for 2-10 hours. The particle size of the powder is 100-450 mesh, preferably 200-400 mesh.

[0034] In step (3) of the present invention, the polymer is one or more of cellulose and resin, preferably one or more of hydroxypropyl cellulose, methyl cellulose, and phenolic resin; and the potassium-containing inorganic substance is one or more of potassium carbonate, potassium hydroxide, and potassium oxide.

[0035] In step (3) of the present invention, the mass ratio of the total mass of the biomass raw material, polymer, and potassium-containing inorganic matter to the dry matter I is 1:5-15.

[0036] In step (3) of the present invention, during the molding process, conventional molding aids, such as one or more of sesbania powder, cellulose, and resin, may be added as needed.

[0037] In step (3) of the present invention, the heat treatment conditions are: treatment at 100-400°C for 0.5-3.0h, wherein the heating rate used to heat the material to the required temperature is 20-120°C / h.

[0038] In step (4) of the present invention, in the unsaturated impregnation, the amount of the first impregnation liquid used accounts for 10% to 40% of the saturated water absorption of the dried product II.

[0039] In step (4) of the present invention, the first 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 contents of MoO3 and the Group VIII metal oxide in the first impregnation solution are 30.0-60.0 g / 100 ml and 5.0-30.0 g / 100 ml, respectively. The amount of MoO3 introduced into the catalyst by the first impregnation solution is 35%-65% of the total MoO3 loading in the catalyst; and the amount of the Group VIII metal oxide introduced into the catalyst by the first impregnation solution is 35%-65% of the total Group VIII metal oxide loading in the catalyst.

[0040] In step (4) of the present invention, at least one auxiliary agent containing fluorine, phosphorus, silicon or boron may be introduced into the first impregnation solution, and the amount of the auxiliary agent added in terms of oxide is 18% to 28% of the total mass of molybdenum oxide in the first impregnation solution, preferably 20% to 25%.

[0041] In step (4) of the present invention, the first impregnation liquid preferably further contains a water-soluble polymer J2. The water-soluble polymer J2 is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide, and methylcellulose. The viscosity of the water-soluble polymer J2 (at 20°C) is 10 to 1000 mPa·s. After the addition of the water-soluble polymer J2, the viscosity of the slurry (at 20°C) is 150 to 800 mPa·s.

[0042] In step (4) of the present invention, the impregnation adopts a spraying method, and the spraying time is 15 to 35 minutes.

[0043] In step (4) of the present invention, the drying temperature is 20 to 200° C., and the drying time is 2 to 12 hours.

[0044] In step (4) of the present invention, the first calcination is performed by programmed temperature increase. The heating rate is 1°C / min to 3°C / min, the first calcination temperature is 500 to 750°C, the calcination time is 2 to 6 hours, and the calcination atmosphere is an inert atmosphere (such as nitrogen) or water vapor, preferably water vapor.

[0045] In step (5) of the present invention, the carbohydrate solution is preferably an aqueous solution of starch and / or monosaccharides, wherein the mass percentage of starch and / or monosaccharides in the solution is 10.0% to 40.0%. The monosaccharides include one or more of glucose, ribose, fructose, maltose, etc. Ammonium bicarbonate is added to the carbohydrate solution as a pore-expanding agent, wherein the mass percentage of ammonium bicarbonate in the solution is 5.0% to 25.0%. The soaking is performed for 30 seconds to 240 seconds, preferably 40 seconds to 120 seconds.

[0046] In step (5) of the present invention, the carbonization conditions are: pre-oxidation in air at a temperature of 150 to 280°C, preferably 170 to 260°C, for 2 to 18 hours, preferably 2 to 12 hours; then carbonization in a nitrogen atmosphere at a temperature of 400 to 650°C, preferably 450 to 600°C, for 1 to 8 hours, and a carbon film is formed on the surface of the calcined body after carbonization.

[0047] In step (6) of the present invention, preferably, the second impregnation solution comprises 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 amount of MoO3 introduced into the catalyst by the second impregnation solution is 35% to 65% of the total MoO3 loading in the catalyst; and the amount of Group VIII metal oxide introduced into the catalyst by the second impregnation solution is 35% to 65% of the total Group VIII metal oxide loading in the catalyst.

[0048] In step (6) of the present invention, the second impregnation liquid further contains a water-soluble polymer J3. The water-soluble polymer J3 is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide, and methylcellulose. The viscosity of the water-soluble polymer J3 (at 20°C) is 10 to 1000 mPa·s. After the addition of the water-soluble polymer J3, the viscosity of the slurry (at 20°C) is 150 to 800 mPa·s.

[0049] In step (6) of the present invention, the impregnation adopts a spraying method, and the spraying time is 15 to 35 minutes.

[0050] In step (6) of the present invention, the drying temperature is 120 to 200° C., and the drying time is 2 to 12 hours.

[0051] In step (6) of the present invention, the second calcination is performed by programmed temperature increase. The heating rate is 1°C / min to 3°C / min, the second calcination temperature is 350°C to 450°C, the calcination time is 2 to 6 hours, and the calcination atmosphere is an inert atmosphere (such as nitrogen) or water vapor, preferably water vapor.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1. For hydrogenation catalysts, the reduction temperature of tetrahedral Mo species is higher than that of octahedral Mo species. The presence of tetrahedral Mo has an adverse effect on weakening the interaction between the support and the metal, thereby affecting the activity and stability of the catalyst. After extensive research, the inventors found that first, the support was optimized, and the slurry obtained after the neutralization reaction was aged in two stages. A water-soluble polymer was added before the second aging, and the second aging was performed at a higher temperature. This resulted in a porous material with a suitable specific surface area and a good pore size distribution, namely, dried material I; then the biomass raw material was dried and crushed into powder, which was then mixed and kneaded with the polymer, potassium-containing inorganic material, and dried material I in proportion, and then heat-treated to obtain dried material II; the first impregnation liquid was sprayed onto dried material I in an unsaturated impregnation manner. 1, dried and first calcined to obtain a catalyst calcined body; the obtained catalyst calcined body is then soaked with a carbohydrate aqueous solution, carbonized after drying, and a carbon film is formed on the surface of the catalyst calcined body to obtain a catalyst intermediate; finally, the remaining active metal is loaded on the intermediate in a saturated impregnation manner, and then a second calcination is performed to make the ratio of tetrahedral platinum and octahedral platinum species in the catalyst suitable, preferably, a water-soluble polymer is also added to the two impregnation solutions, on the one hand, the dispersion degree of the active metal can be promoted, and on the other hand, the acidity of the catalyst can be properly adjusted. The carbon film formed on the surface of the calcined body not only regulates the pore structure of the final obtained catalyst, but also provides a suitable reaction channel for the diffusion of heavy oil or residual oil macromolecules, while improving the catalyst metal capacity, it prevents the macromolecular compound in the residual oil from being blocked in the catalyst orifice violent reaction in the early stage of the reaction and causing the catalyst coking and deactivation, on the other hand, the presence of the carbon film complements the two impregnations of the active metal, so that the active metal is both concentrated and distributed inside the carbon film, and is widely distributed on the carbon film, effectively regulating the presence position and distribution mode of the active metal, and improving the utilization rate of the active metal. The method of the present invention achieves significant improvement in the activity and stability of the residue oil hydrodemetallization catalyst finally prepared through comprehensive coordination of various steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1This is the Raman spectrum of the catalyst surface obtained in Example 1;

[0055] Figure 2 This is the Raman spectrum of the catalyst surface obtained in Example 2;

[0056] Figure 3 is the Raman spectrum of the catalyst surface obtained in Comparative Example 1;

[0057] Figure 4 This is the Raman spectrum of the catalyst surface obtained in Comparative Example 2. DETAILED DESCRIPTION

[0058] In the present invention, the Raman spectroscopic characterization of the catalyst was performed using a DXR Microscope type DXR micro Raman spectrometer from Thermo Scientific. -1 The peak near it is the peak of tetrahedral molybdenum, at 960 cm -1 The nearby peak is the peak of octahedral molybdenum. The contents of tetrahedral molybdenum and octahedral molybdenum are calculated based on the area under the same baseline.

[0059] In the present invention, the ASAP-2420 physical adsorption instrument produced by Michael Company is used to characterize the pore structure (SVD) and specific surface area of ​​the catalyst.

[0060] The technical solutions and effects of the present invention are further described below with reference to the following embodiments, but are not limited to the following embodiments.

[0061] Example 1

[0062] 1.5L of aluminum sulfate aqueous solution (the concentration of Al2O3 is 10.0g / 100mL, the initial temperature is 75℃) is introduced from the top into a reactor equipped with 5L of purified water, a stirrer and a heating jacket, and 1L of sodium metaaluminate aqueous solution (the concentration of Al2O3 is 28.0g / 100mL, the initial temperature is 110℃) is introduced from the bottom of the reactor into the reactor, and the neutralization reaction temperature is controlled at 105℃; aluminum sulfate solution and sodium metaaluminate solution are added continuously, and the pH value is controlled at 8.5. The reaction is continued for 60 minutes. minutes; after the co-current flow is completed, primary aging is performed at an aging temperature of 140° C., an aging time of 120 minutes, and an aging pH value of 9.3; after the primary aging is completed, the slurry volume is concentrated to 5 L, 100 g of polyvinyl alcohol (viscosity of 30 mPa·s) is added, and the slurry viscosity (20° C.) after the addition of polyvinyl alcohol is 260 mPa·s, the temperature is raised to 170° C., secondary aging is performed at an aging time of 120 minutes, and the product is washed and dried at 120° C. for 6 hours to obtain a dry product I with a dry basis of 50 wt%;

[0063] The coconut shell raw material was dried at 120° C. for 6 hours and then crushed into 200-mesh coconut shell powder; 1000 g of the coconut shell powder, hydroxypropyl cellulose, potassium hydroxide, and dried product I were weighed and kneaded in a mass ratio of 0.5:0.5:0.5:8.5, and then formed; the temperature was increased to 300° C. at a heating rate of 30° C. / h, and the formed product was heat-treated at 300° C. for 1 hour to obtain dried product II;

[0064] The dried product II (the amount of the first impregnation solution is 20% of the saturated water absorption capacity of the support) is sprayed with a first impregnation solution (the content of MoO3 is 58.8g / 100ml, the content of NiO is 11.5g / 100ml, and the amount of P (calculated as oxide) in the auxiliary phosphoric acid is 23.2% of the total mass of molybdenum oxide in the impregnation solution), and polyacrylamide (viscosity is 950mPa·s) is added to the first impregnation solution, and the viscosity after addition is 600mPa·s, wherein the amount of MoO3 introduced into the catalyst by the first impregnation solution is 40% of the total MoO3 loading in the catalyst; the amount of NiO introduced into the catalyst by the first impregnation solution is 40% of the total NiO loading in the catalyst, the spraying time is controlled within 30min, and then the product is allowed to stand and dry for 2h at room temperature of 25°C, and then the obtained sample is dried at 120°C for 6h and calcined at 700°C for 5h, wherein the heating rate of the calcination process is 3°C / min, to obtain a calcined body;

[0065] The calcined body obtained above was immersed in an aqueous solution containing 6.0% by mass of ammonium bicarbonate and 12.0% by mass of starch for 40 seconds, then taken out and pre-oxidized in air at 180°C for 3 hours. It was then carbonized at 600°C for 6 hours in a nitrogen atmosphere to form a 28 μm thick carbon film on the surface of the calcined body to obtain an intermediate; the aluminum oxide content was 77.2%, and the sum of the carbon and potassium oxide contents was 12.7%.

[0066] 200 g of the intermediate was weighed and impregnated a second time with the second impregnation solution by saturation impregnation. Polyacrylamide (viscosity of 950 mPa·s) was added to the second impregnation solution, resulting in a viscosity of 400 mPa·s. The amount of MoO3 introduced into the catalyst by the second impregnation solution accounted for 60% of the total MoO3 loading on the catalyst, and the amount of NiO introduced into the catalyst by the second impregnation solution accounted for 60% of the total NiO loading on the catalyst. The spraying time was controlled within 30 minutes. The catalyst was then dried at 120°C for 6 hours and calcined at 350°C for 3 hours at a heating rate of 3°C / min to produce hydrodemetallization catalyst CAT-1. The physicochemical properties of the catalyst are shown in Table 1.

[0067] Example 2

[0068] The same method as in Example 1 was used, except that the initial temperature of the sodium metaaluminate aqueous solution added was 100°C, 110 g of polyvinyl alcohol (viscosity 30 mPa·s) was added after primary aging, and the slurry viscosity (20°C) after the addition of polyvinyl alcohol was 280 mPa·s. The resulting calcined catalyst was immersed in an aqueous solution containing 9.0% by mass of ammonium bicarbonate and 18.0% by mass of starch for 50 seconds, then removed. The catalyst was pre-oxidized in air at 200°C for 4 hours and carbonized at 550°C for 5 hours under a nitrogen atmosphere, forming a 44 μm thick carbon film on the surface of the calcined catalyst, yielding an intermediate having an aluminum oxide content of 77.0% and a combined carbon and potassium oxide content of 12.9%. The first calcination step was followed by heating the catalyst to 650°C at a rate of 3°C / min for 4 hours. The second calcination step was followed by heating the catalyst to 400°C at a rate of 3°C / min for 4 hours, yielding the hydrodemetallization catalyst CAT-2. The physicochemical properties of the catalyst are shown in Table 1.

[0069] Example 3

[0070] The present invention is the same as Example 1, except that the coconut shell raw material is dried at 120° C. for 6 h and then ground into 200-mesh coconut shell powder; 1000 g of coconut shell powder, hydroxypropyl cellulose, potassium hydroxide, and dried product I are weighed in a mass ratio of 0.4:0.4:0.4:8.8, kneaded, and formed; the resulting catalyst calcined body is soaked in an aqueous solution of 15% by mass of ammonium bicarbonate and 24% by mass of glucose for 85 seconds, taken out, pre-oxidized in air at 220° C. for 5 hours, and carbonized at 500° C. under a nitrogen atmosphere for 4 hours to form a 57 μm thick carbon film on the surface of the calcined body to obtain an intermediate; wherein the aluminum oxide content is 77.8%, and the sum of the carbon and potassium oxide contents is 12.1%. In the first calcination step, the temperature was raised to 600°C at a rate of 3°C / min for 3 h. In the second calcination step, the temperature was raised to 450°C at a rate of 3°C / min for 5 h to produce the hydrodemetallization catalyst CAT-3. The physicochemical properties of the catalyst are shown in Table 1.

[0071] Example 4

[0072] The present invention is the same as Example 1, except that the coconut shell raw material is dried at 120° C. for 6 hours and then crushed into 200-mesh coconut shell powder; 1000 g of coconut shell powder, hydroxypropyl cellulose, potassium hydroxide, and dried material I are weighed in a mass ratio of 0.3:0.3:0.3:9.1, kneaded, and formed; the resulting catalyst calcined body is immersed in an aqueous solution of 24% by mass of ammonium bicarbonate and 36% by mass of glucose for 105 seconds, removed, pre-oxidized in air at 240° C. for 6 hours, and carbonized at 450° C. under a nitrogen atmosphere for 3 hours to form a 66 μm thick carbon film on the surface of the calcined body to obtain an intermediate; wherein the aluminum oxide content is 78.3%, and the sum of the carbon and potassium oxide contents is 11.6%. In the first calcination step, the temperature was raised to 550°C at a rate of 3°C / min for 2 h. In the second calcination step, the temperature was raised to 400°C at a rate of 3°C / min for 6 h to produce the hydrodemetallization catalyst CAT-4. The physicochemical properties of the catalyst are shown in Table 1.

[0073] Example 5

[0074] The same method as in Example 1 was used, except that the amount of MoO3 introduced into the catalyst by the first impregnation solution was 45% of the total MoO3 loading in the catalyst; the amount of Group VIII metal oxide introduced into the catalyst by the first impregnation solution was 45% of the total Group VIII metal oxide loading in the catalyst; and the spraying time was controlled within 30 minutes. The resulting calcined catalyst was immersed in an aqueous solution containing 9.0% by mass of ammonium bicarbonate and 18.0% by mass of starch for 120 seconds, then removed. The catalyst was pre-oxidized in air at 220°C for 5 hours and carbonized at 500°C for 4 hours under a nitrogen atmosphere, forming a 49 μm thick carbon film on the surface of the calcined catalyst to obtain an intermediate having an aluminum oxide content of 77.5% and a combined carbon and potassium oxide content of 10.3%. In the second calcination step, the temperature was raised to 400°C at a rate of 3°C / min and calcined for 3 hours to produce hydrodemetallation catalyst CAT-5. The physicochemical properties of the catalyst are shown in Table 1.

[0075] Example 6

[0076] The same method as in Example 1 was used, except that after the co-current flow was completed, the primary aging temperature was 160°C, the aging time was 140 minutes, and the aging pH was 9.5. After the primary aging, the slurry was concentrated to a volume of 5 L, and 100 g of polyvinyl alcohol (viscosity 30 mPa·s) was added. After the addition of polyvinyl alcohol, the slurry viscosity (at 20°C) was 240 mPa·s. The temperature was then raised to 200°C, and a secondary aging was performed for 140 minutes. A 28 μm thick carbon film was formed on the surface of the calcined product, yielding an intermediate having an aluminum oxide content of 77.2% and a combined carbon and potassium oxide content of 12.7%. Finally, the hydrodemetallization catalyst CAT-6 was obtained. The physicochemical properties of the catalyst are shown in Table 1.

[0077] Comparative Example 1

[0078] Dried material I (same as in Example 1), 2.7 wt% acetic acid, and 2.5 wt% sesbania powder were mixed and shaped, dried at 150°C for 5 hours, and calcined at 860°C for 4 hours to prepare an alumina support. This support was then directly impregnated with a saturated impregnation solution containing the active metals Mo, Ni, and P, dried at 150°C for 5 hours, and then calcined at 600°C for 3 hours to produce the hydrodemetallation catalyst dCAT-1. The physicochemical properties of this catalyst are shown in Table 1.

[0079] Comparative Example 2

[0080] The hydrodemetallization catalyst dCAT-2 was prepared in the same manner as in Example 1, except that industrial-grade pseudo-boehmite was directly used for aging, and the calcined product was not soaked in any carbohydrate aqueous solution. The physicochemical properties of the catalyst are shown in Table 1.

[0081] Comparative Example 3

[0082] The same method as in Example 1 was used, except that the active metal solution was directly mixed with coconut shell powder, hydroxypropyl cellulose, potassium hydroxide, and dried product I (in the same proportions as in Example 1) to produce a hydrodemetallation catalyst dCAT-3. The physicochemical properties of the catalyst are shown in Table 1.

[0083] Table 1 Physicochemical properties of hydrogenation catalysts

[0084]

[0085] Evaluation test

[0086] Activity stability tests were conducted on Examples 1 to 6 and Comparative Examples 1 to 3 in a 200 ml fixed-bed hydrogenation test apparatus. The properties of the feed oil are shown in Table 2, the test conditions are shown in Table 3, and the test results are shown in Table 4.

[0087] Table 2 Properties of crude oil

[0088] Raw oil properties Middle East residual oil S, wt% 2.58 Ni, μg / g 34.7 V, μg / g 61.8

[0089] Table 3 Test conditions

[0090] Reaction temperature, °C 390 Reaction pressure, MPa 16.0 <![CDATA[Liquid hourly space velocity, h -1 > 0.5 Hydrogen to oil ratio, V / V 800

[0091] Table 4 Test results of various hydrodemetallization catalysts

[0092]

[0093] As can be seen from Table 1 and Table 4, the hydrodemetallization catalyst prepared according to the method of the present invention has a high specific surface area and pore volume, and has high reaction activity and stability, and can well meet the requirements of the hydrodemetallization process of heavy oil, especially residual oil.

Claims

1. A residue hydrodemetallization catalyst comprising a carbon film-coated intermediate and a second active component supported on the intermediate, wherein the second active component comprises molybdenum and a Group VIII metal; the intermediate comprises carbon, alumina, potassium oxide, and a first active component, wherein the first active component comprises molybdenum and a Group VIII metal; wherein: In the catalyst, the ratio of tetrahedral molybdenum to octahedral molybdenum, calculated as Mo atoms, is 0.18-0.72, and the thickness of the carbon film is 0.1 μm-400 μm.

2. The catalyst according to claim 1, characterized in that The thickness of the carbon film is 1 μm to 180 μm.

3. The catalyst according to claim 1, characterized in that The thickness of the carbon film is 25 μm to 70 μm.

4. The catalyst according to claim 1, characterized in that The carbon film has macropores, and the pore volume of the carbon film layer is 0.9~2.0cm 3 / g; the average pore size is 40~70nm.

5. The catalyst according to claim 1, characterized in that The carbon film has macropores, and the pore volume of the carbon film layer is 1.0-1.8 cm 3 / g; the average pore size is 50~60nm.

6. The catalyst according to claim 1, characterized in that The pore volume of the carbon film layer is 1.0~1.4 cm 3 / g.

7. The catalyst according to claim 1, characterized in that In the first active component, the Group VIII metal is nickel.

8. The catalyst according to claim 1, characterized in that Based on the mass of the intermediate, the mass content of carbon is 5.0% to 7.0%, the mass content of aluminum oxide is 76.0% to 82.0%, the mass content of potassium oxide is 5.0% to 6.0%, and the remainder is the first active component.

9. The catalyst according to claim 1, characterized in that Based on the total mass of MoO3 in the catalyst, the content of MoO3 in the first active component is 35.0%~65.0%, and based on the total mass of Group VIII metal oxides in the catalyst, the content of Group VIII metal oxides in the second active component is 35.0%~65.0%.

10. The catalyst according to claim 1, characterized in that In the catalyst, based on the mass of the catalyst, the content of MoO3 is 5.0% to 15.0%, and the content of the Group VIII metal oxide is 1.0% to 5.0%.

11. The catalyst according to claim 1, characterized in that The specific surface area of ​​the catalyst is 180~230m 2 / g, the pore volume is 0.7~1.2mL / g, and the pore diameter is 15~26nm.

12. The catalyst according to claim 1, characterized in that The specific surface area of ​​the catalyst is 190~210m 2 / g, the pore volume is 0.8~1.0mL / g, and the pore diameter is 15~24nm.

13. The catalyst according to claim 1, characterized in that The catalyst includes an auxiliary component, which is selected from at least one of fluorine, phosphorus, silicon or boron. The content of the auxiliary component in terms of oxide is 1.0% to 4.0% based on the mass of the catalyst.

14. The catalyst according to claim 13, characterized in that The auxiliary component is phosphorus.

15. The method for preparing the residue hydrodemetallization catalyst according to any one of claims 1 to 14, comprising the following steps: (1) Acidic aluminum salt solution and alkaline aluminum salt solution are neutralized to obtain a slurry; (2) subjecting the slurry obtained in step (1) to primary aging; after the primary aging, adding a water-soluble polymer J, subjecting the slurry to secondary aging, and drying to obtain a dried product I; (3) kneading, shaping, and heat-treating the biomass raw material, the polymer, the potassium-containing inorganic substance, and the dried product I obtained in step (2) to obtain a dried product II; (4) spraying a first impregnation solution containing a first active component onto the dried product II obtained in step (3) in an unsaturated impregnation manner, drying and first calcining to obtain a calcined body; (5) soaking the calcined body obtained in step (4) in a carbohydrate aqueous solution, drying, and then carbonizing to obtain an intermediate; (6) Spraying a second impregnation solution containing a second active component onto the intermediate obtained in step (5) in a saturated impregnation manner, followed by drying and a second calcination to obtain the catalyst.

16. The preparation method according to claim 15, characterized in that In step (1), the acidic aluminum salt solution and the alkaline aluminum salt solution are subjected to a parallel neutralization reaction; the concentration of the acidic aluminum salt solution in terms of Al2O3 is 5 g / 100mL to 25 g / 100mL; the concentration of the alkaline aluminum salt solution in terms of Al2O3 is 8 g / 100mL to 52 g / 100mL.

17. The preparation method according to claim 15, characterized in that In step (1), the neutralization reaction temperature is 5-120° C., the time is 30-150 minutes, and the pH value of the slurry is controlled to be 6.0-10.0 during the neutralization reaction.

18. The preparation method according to claim 15, characterized in that In step (2), the primary aging temperature is 90-240° C., the time is 50-240 minutes, and the pH value is 8.5-12.

0.

19. The preparation method according to claim 15, characterized in that In step (2), the water-soluble polymer J1 is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methyl cellulose; the viscosity of the water-soluble polymer J1 is 10-1000 mPa·s, and the viscosity of the slurry at 20°C after adding the water-soluble polymer J1 is 120-660 mPa·s.

20. The preparation method according to claim 15, characterized in that In step (2), the water-soluble polymer J1 is polyethylene glycol.

21. The preparation method according to claim 15, characterized in that In step (2), the secondary aging temperature is 120-260°C, the time is 45-190 minutes, and the secondary aging temperature is 30-60°C higher than the primary aging temperature. After the secondary aging, the drying temperature is 120-180°C, the drying time is 2-10 hours, and the dry basis content of the dried product I obtained after drying is 45wt%-70wt%.

22. The preparation method according to claim 15, characterized in that In step (3), the biomass raw material is selected from one or more of wood, fruit shell, starch, bamboo or other biomass raw materials, and the particle size of the biomass raw material is 100-450 mesh; and / or, the polymer is one or more of cellulose and resin; the potassium-containing inorganic substance is one or more of potassium carbonate, potassium hydroxide and potassium oxide; and / or, in step (5), the carbohydrate aqueous solution is preferably an aqueous solution of starch and / or monosaccharide, and the mass percentage of starch and / or monosaccharide in the solution is 10.0%-40.0%; the monosaccharide includes one or more of glucose, ribose and fructose.

23. The preparation method according to claim 15, characterized in that In step (3), the particle size of the biomass raw material is 200-400 mesh; and / or the polymer is one or more of hydroxypropyl cellulose, methyl cellulose, and phenolic resin.

24. The preparation method according to claim 15, characterized in that In step (3), the mass ratio of the total mass of the biomass raw material, the polymer, and the potassium-containing inorganic matter to the dry material I is 1:5-15; and / or, in step (3), the heat treatment conditions are: treatment at 100-400°C for 0.5-3.0h, wherein the heating rate adopted for heating to the required temperature for heat treatment is 20-120°C / h.

25. The preparation method according to claim 15, characterized in that In step (4), in the unsaturated impregnation, the amount of the first impregnation liquid used accounts for 10% to 40% of the saturated water absorption of the dried product II.

26. The preparation method according to claim 15, characterized in that In step (4), the first impregnation solution is introduced with at least one auxiliary agent containing fluorine, phosphorus, silicon or boron, and the amount of the auxiliary agent added in terms of oxide is 18% to 28% of the total mass of molybdenum oxide in the first impregnation solution.

27. The preparation method according to claim 26, characterized in that The amount of the additive added, calculated as oxide, is 20% to 25% of the total mass of molybdenum oxide in the first impregnation solution.

28. The preparation method according to claim 15, characterized in that In step (4), the drying temperature is 20-200°C, the drying time is 2-12 hours, the first roasting temperature is 500-750°C, the roasting time is 2-6 hours, and the roasting atmosphere is an inert atmosphere or water vapor; and / or, in step (6), the drying temperature is 120-200°C, the drying time is 2-12 hours, the second roasting temperature is 350-450°C, the roasting time is 2-6 hours, and the roasting atmosphere is an inert atmosphere or water vapor.

29. The preparation method according to claim 15, characterized in that In step (4), the first roasting atmosphere is water vapor; and / or, in step (6), the second roasting atmosphere is water vapor.

30. The preparation method according to claim 15, characterized in that In step (5), ammonium bicarbonate is added to the carbohydrate aqueous solution as a pore-enlarging agent, the mass percentage of ammonium bicarbonate in the solution is 5.0% to 25.0%, and the soaking is for 30 seconds to 240 seconds.

31. The preparation method according to claim 30, characterized in that The soaking is performed for 40 to 120 seconds.

32. The preparation method according to claim 15, characterized in that In step (5), the carbonization conditions are: pre-oxidation in air at a temperature of 150-280°C for 2-18 hours; and then carbonization in a nitrogen atmosphere at a temperature of 400-650°C for 1-8 hours.

33. The preparation method according to claim 15, characterized in that In step (5), the carbonization conditions are: pre-oxidation in air at a temperature of 170-260°C for 2-12 hours; and then carbonization in a nitrogen atmosphere at a temperature of 450-600°C for 1-8 hours.

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