Method for preparing a bulk hydrogenation refining catalyst containing rare earth

Abstract

The invention discloses a method for preparing a bulk phase hydrogenation refining catalyst containing rare earth, comprising: (1) subjecting a first precipitant, a sodium molybdate solution and a Ni and Si solution to a gelling reaction, adding an anionic surfactant during the reaction, and subjecting the first slurry to a first aging; (2) adding a Ni and Al solution, a sodium tungstate solution, a second precipitant and the first slurry to water and an oily liquid for a second gelling reaction, lowering the pH value in steps during the reaction, adding a portion of the rare earth solution divided according to the number of times the pH value is lowered, and subjecting the second aging to a second slurry; (3) subjecting the second slurry to aging, solid-liquid separation, obtaining a molded product, and desalting to obtain a catalyst. The method of the invention has low cost and a clean process, the pore volume and pore diameter of the catalyst are large, the hydrogenation metal and the rare earth metal in the catalyst have better synergistic effects, the hydrogen storage capacity is increased, the carbon deposition of the catalyst is reduced, and the catalyst has better activity stability when treating inferior distillate oil raw materials.

Description

Technical Field

[0001] The present invention relates to a hydrorefining catalyst and a preparation method thereof, in particular to a bulk phase hydrorefining catalyst containing rare earth and a preparation method thereof. The hydrorefining catalyst is used in processes such as hydrodesulfurization and denitrogenation of distillate oil. Background Art

[0002] In order to improve the competitiveness of catalysts in the market and meet the increasingly stringent environmental regulations, it is urgent to use relatively low-priced raw materials to prepare catalysts and use nitrogen-free raw materials in the catalyst preparation process to solve the problem of "ammonia nitrogen" and NO from the source. X pollution problem and reduce the cost of catalyst preparation.

[0003] Bulk hydrogenation catalysts are currently the catalysts with the highest hydrogenation activity centers. Bulk catalysts prepared by existing methods have smaller pore volumes and pore sizes, resulting in reactions on the catalyst surface that is inaccessible to reactant molecules. At the same time, the smaller pore volume and specific surface area cause the high content of active metals in the bulk catalyst to accumulate excessively on the catalyst surface, reducing the generation of active phases, lowering the activity of the catalyst, and also affecting the utilization rate of the active metals in the catalyst, thereby increasing the cost of using the catalyst.

[0004] The existing co-precipitation method mostly uses ammonia water as a precipitant and nitrogen-containing soluble salts as raw materials. The distribution of hydrogenation active metals and the interaction between different hydrogenation active metals are improved by changing the precipitation method and gelation conditions. However, it does not solve the problem that the bulk catalyst has a small pore volume and specific surface area, the pore size of the catalyst is small (the pore size distribution is mainly concentrated below 8nm), the metal oxide particles in the catalyst are large, and the introduced rare earth and other additives cannot play a good synergistic role with the active metals. Especially when using cheaper sodium-containing raw materials, the introduction of a large amount of sodium ions makes it difficult to remove the sodium ions in the catalyst. Even if the number of washings is increased (the increase in the number of washings will reduce the crushing strength of the catalyst), only the sodium ions on the surface of the catalyst can be removed. A large amount of sodium ions still exist in the precipitated material. The residual sodium ions lead to poor adhesion of the material. The sodium ions that have not been removed are not conducive to the formation of the catalyst pore structure. The gelled material is loose and difficult to shape, and the catalyst has many small pores.

[0005] CN106179474B discloses a high-activity bulk hydroprocessing catalyst and a preparation method thereof. A two-step method of positive addition and parallel flow is adopted to prepare a precipitate containing W, Ni and Mo, and a microporous and mesoporous composite molecular sieve is added. The catalyst has a high surface active metal content, a more uniform active metal dispersion, good coordination between active metals, and a high active metal utilization rate. At the same time, the catalyst has a reasonable pore structure, high mechanical strength, and high hydrodesulfurization and hydrodenitrogenation activity. The catalyst prepared by this method contains a molecular sieve, and a strong acidity can improve the ultra-deep desulfurization activity of the catalyst, but a cracking reaction occurs, which reduces the yield of the diesel product.

[0006] CN102451706A discloses a method for preparing a hydrogenation catalyst composition, which uses a sodium aluminate solution, a mixed solution containing Ni and W component salts and CO2 gas for parallel flow reaction to generate a precipitate. CN110038581A discloses a method for preparing a hydrogenation refining catalyst. The hydrogenation refining catalyst is prepared by two-step precipitation, using sodium tungstate alkaline solution and sodium molybdate alkaline solution as precipitants for precipitation, respectively. Both methods use a large amount of sodium ion-containing salt as raw material for precipitation reaction, but the precipitate generated by this method contains a certain amount of sodium ions, the metal oxide particles are relatively large, and the residual sodium ions lead to poor adhesion of the material. The residual sodium ions also make the pore volume and specific surface area of ​​the catalyst small.

[0007] CN106513006A discloses a method for preparing a bulk phase hydrorefining catalyst, which comprises: pre-dispersing a Ni-containing compound with deionized water under an ultrasonic environment, then adding a Mo-containing compound to form a Ni-Mo fine grain structure, then adding a W-containing compound and a complexing agent for hydrothermal reaction, and then kneading and extruding the obtained active component powder with aluminum hydroxide dry glue, drying and calcining to obtain a catalyst. The catalyst prepared by the method of the present invention has uniform dispersion between different active phase grains, W source is embedded in the Ni-Mo skeleton structure, Ni-W active phase is easily wrapped by Ni-Mo active phase at the microscopic level, and is not an oxide core-shell structure at the macroscopic level, the pore volume is small, the effective active phase is not much, the metal oxide particles are large, and the removal efficiency of complex sulfur-containing compounds with high nitrogen content is limited. Summary of the invention

[0008] In view of the shortcomings of the prior art, the present invention provides a method for preparing a bulk phase hydrogenation refining catalyst containing rare earth. The method of the present invention has low preparation cost, clean and pollution-free preparation process, large pore volume and pore diameter of the catalyst, better synergistic effect of hydrogenation active metal and rare earth metal in the catalyst, improved hydrogen storage capacity, reduced carbon deposition of the catalyst, and better activity stability when treating inferior distillate oil raw materials.

[0009] The method for preparing the bulk phase hydrogenation refining catalyst containing rare earth of the present invention comprises the following contents:

[0010] (1) preparing a first slurry: subjecting a first precipitant, a sodium molybdate solution and a solution containing Ni and Si to a first gelling reaction, adding an anionic surfactant having a carbon number of C9 to C26 during the reaction, and subjecting the mixture to a first aging step after the reaction to obtain a first slurry;

[0011] (2) preparing the second slurry: adding the Ni and Al-containing solution, the sodium tungstate solution, the second precipitant and the first slurry to a mixture of water and an oily liquid in parallel to carry out a second gelling reaction. During the gelling reaction, the pH value is lowered in batches. When the pH value is lowered and becomes constant each time, a portion of the rare earth solution is added according to the number of times the pH value is lowered. After the reaction, the second aging is carried out to generate the second slurry.

[0012] (3) Preparing a molded product: aging the second slurry, separating the solid from the liquid after aging, and drying and molding the solid phase to obtain a molded product;

[0013] (4) The formed product is desalted, washed, dried and calcined to obtain a bulk hydrogenation refining catalyst.

[0014] In the method of the present invention, in the solution containing Ni and Si in step (1), the weight concentration of Ni calculated as NiO is 5-120 g / L, preferably 10-110 g / L, and the weight concentration of Si calculated as SiO2 is 2-80 g / L, preferably 4-70 g / L. When preparing the solution containing Ni and Si, the nickel source generally used may be one or more of nickel sulfate, nickel nitrate, and nickel chloride, and the silicon source may be one or more of water glass, silica sol, and the like.

[0015] Furthermore, in the sodium molybdate solution in step (1), the weight concentration of Mo in terms of MoO3 is 5 to 110 g / L, preferably 10 to 100 g / L.

[0016] Furthermore, the first precipitant described in step (1) can be an aqueous solution of an alkaline compound that does not contain nitrogen, preferably sodium hydroxide. The weight concentration of the first precipitant is 5% to 30%. Those skilled in the art can determine the amount of the first precipitant according to actual needs.

[0017] In the method of the present invention, the anionic surfactant with carbon number of C9-C26 described in step (1) is selected from one or more of sulfonate type, carboxylate type, sulfate ester type, sulfate ester type, phosphate ester type, and phosphate ester type anionic surfactants, and is further selected from one or more of sodium lignin sulfonate, sodium alkyl glyceryl ether sulfonate, sodium dioctyl succinate sulfonate, sodium alkyl benzene sulfonate with carbon number of C10-C16, sodium oleic acid ethylene glycol diester sulfonate, sodium dibutylnaphthalene sulfonate, sodium dodecyl glyceryl ether carboxylate, sodium α-olefin sulfonate with carbon number of C14-C18, sodium lauryl alcohol polyoxyethylene ether sulfate, sodium monoglyceride disulfate, etc. The molar ratio of the added amount of the anionic surfactant to the Mo in the sodium molybdate solution in step (1) is 0.2:1-2.0:1, preferably 0.3:1-1.8:1.

[0018] In the method of the present invention, the conditions of the first gelling reaction in step (1) are as follows: the reaction temperature is 30-90°C, preferably 40-85°C, the pH value is controlled to be 7.0-11.0, preferably 7.2-10.0, and the gelling time is 0.2-2.5 hours, preferably 0.3-2.0 hours.

[0019] In the method of the present invention, the first aging conditions in step (1) are as follows: the aging temperature is 60-90°C, preferably 65-85°C, the pH value during aging is controlled to be 7.0-11.0, preferably 7.2-10.5, and the aging time is 0.3-2.5 hours, preferably 0.5-2.0 hours.

[0020] In the method of the present invention, in step (1), the weight of the introduced Ni accounts for 30% to 80%, preferably 35% to 78%, of the total Ni weight in the hydrotreating catalyst obtained in step (4), and the remaining Ni is introduced in step (2).

[0021] In the method of the present invention, in the Ni and Al solution of step (2), the weight concentration of Ni calculated as NiO is 5 to 110 g / L, preferably 10 to 100 g / L, and the weight concentration of Al calculated as Al2O3 is 2 to 95 g / L, preferably 5 to 85 g / L.

[0022] In the method of the present invention, in the sodium tungstate solution of step (2), the weight concentration of W calculated as WO3 is 4-140 g / L, preferably 6-120 g / L; in step (2), when preparing the Ni and Al-containing solution, the nickel source generally used can be one or more of nickel sulfate, nickel nitrate, and nickel chloride, and the aluminum source can be one or more of aluminum nitrate, aluminum sulfate, aluminum chloride, and aluminum acetate.

[0023] In the method of the present invention, the rare earth is one or more of lanthanum, cerium, praseodymium and rubidium. When preparing a solution containing rare earth ions, it is generally selected from soluble salts of rare earth, such as nitrates and / or chlorides.

[0024] In the method of the present invention, the mass concentration of the solution containing rare earth ions in step (2) is 1-45 g / L, preferably 2-40 g / L, calculated as rare earth oxide. The solution is divided equally by volume according to the number of times the pH value is adjusted downward for later use.

[0025] In the method of the present invention, the total mass ratio of Mo in the first slurry as MoO3, Ni as NiO, and Si as SiO2 to the total mass ratio of W in the second slurry as WO3, Ni as NiO, Al as Al2O3, and rare earth as oxide is 2:8-9:1, preferably 2.5:7.5-8.8:1.2.

[0026] In the method of the present invention, the second precipitant in step (2) is an alkaline precipitant, preferably an aqueous solution of sodium carbonate and / or sodium bicarbonate, and the concentration of the second precipitant is 5 wt% to 40 wt%. The amount of the second precipitant can be determined by those skilled in the art according to actual needs.

[0027] In the method of the present invention, the volume ratio of the water added in step (2) to the volume ratio of the first slurry in step (1) is 0.1:1 to 3:1.

[0028] In the method of the present invention, the oily liquid in step (2) is unsaturated higher fatty acid glyceride (vegetable oil), preferably one or more of peanut oil, rapeseed oil, cottonseed oil, sunflower oil, soybean oil, corn oil, tea oil, and olive oil. The volume ratio of the oily liquid to water is 1:60 to 1:4, preferably 1:40 to 1:6.

[0029] In the method of the present invention, the conditions of the second gelling reaction in step (2) are as follows: the reaction temperature is 30-90°C, preferably 40-85°C, the pH value is initially controlled to be 10.0-14.0, preferably 10.5-13.5, the final pH value is 7.0-8.5, preferably 7.2-8.3, and the gelling reaction time is 0.5-6.0 hours, preferably 0.6-5.0 hours. The pH value is adjusted downward from the initial value to the final pH value in batches, and the stepwise downward adjustment method is to adjust the pH value to the desired value at that time, and keep the pH value of the reaction slurry constant until the next downward adjustment begins, and the number of downward adjustments is 2-10 times, preferably 2-8 times. Preferably, the pH value is kept constant for 0.1-1.2 hours after each downward adjustment. The amplitude of each downward adjustment can be the same or different, and preferably the amplitude of the pH reduction in the current downward adjustment is equal to or less than the amplitude of the pH reduction in the previous downward adjustment. The time used for each downward adjustment process is from the start of the current downward adjustment to the start of the next downward adjustment, and further, is the sum of the time used for each pH value downward adjustment and the time when the pH value is constant. The time used for each downward adjustment process can be the same or different, and preferably the same time.

[0030] In the method of the present invention, the second aging conditions in step (2) are as follows: aging temperature is 40 to 90° C., aging time is 1 to 5 hours, and pH value is 7.0 to 11.0. The aging is generally carried out under stirring conditions.

[0031] The aging conditions in step (2) are preferably carried out as follows: the first step is normal pressure aging: the aging temperature is 30-90°C, preferably 40-80°C, the aging time is 1-6 hours, preferably 1.2-5 hours, and the pH value is 6.5-10.0, preferably 7.0-9.0; the second step is high pressure aging: the temperature is 100-195°C, preferably 100-190°C, the time is 0.1-3.5 hours, preferably 0.3-2.8 hours, the pressure is not less than 10 MPa, preferably 10-15 MPa, and the pH value is 10.0-13.0, preferably 10.0-12.5.

[0032] In the method of the present invention, the solid-liquid separation in step (3) is generally carried out by filtration, centrifugation or the like.

[0033] In the method of the present invention, the drying temperature in step (3) is 50 to 140° C., and the drying time is 0.5 to 24 hours.

[0034] In the method of the present invention, the molding process described in step (3) is well known in the field of catalyst preparation. During the extrusion molding process, an extrusion aid and a peptizing agent are generally added. The extrusion aid can be one or more of sesbania powder, carbon black, graphite powder or cellulose, etc. The peptizing agent is generally an acid solution containing one or more of hydrochloric acid, sulfuric acid, acetic acid, etc. The amount of the extrusion aid accounts for 1wt% to 10wt% of the total material dry basis. The catalyst of the present invention can be prepared into the shape of flakes, spheres, cylindrical strips and special-shaped strips (three-leaf clover, four-leaf clover) as needed.

[0035] In the method of the present invention, the desalination treatment process described in step (4) is: first curing is performed, and then washing can be performed to remove the salt precipitated on the surface of the molded object. The curing conditions are a temperature of 5 to 100° C., preferably a temperature of 10 to 90° C., and a time of 10 to 100 hours, preferably 24 to 90 hours.

[0036] In the method of the present invention, the desalination treatment described in step (4) is preferably carried out in the following manner: in the first stage, the temperature is 60 to 90° C., and the curing time is 5 to 60 hours, preferably 8 to 55 hours, so that the hydrated sodium ions are precipitated and vacancies are retained; in the second stage, the temperature is 10 to 30° C., and the time is 1 to 48 hours, preferably 2 to 42 hours, so that the vacancies are retained and shrunk, so that the pore volume of the catalyst is increased and the catalyst has good mechanical strength, and then the precipitated salt is washed away. The washing process can use a solvent with good solubility for sodium salts, such as water and ethanol.

[0037] In the method of the present invention, the washing, drying and roasting in step (4) can be carried out under conventional conditions in the art. The drying conditions are as follows: drying at 40-150°C for 1-48 hours, preferably drying at 50-120°C for 4-36 hours. The roasting conditions are as follows: roasting at 350-650°C for 1-24 hours, preferably roasting at 400-600°C for 2-12 hours. Washing is generally carried out with deionized water or ethanol solution until neutral.

[0038] The present invention also provides a bulk phase hydrorefining catalyst containing rare earth, which comprises core-shell structure composite amorphous oxide particles, wherein the core phase is an amorphous composite oxide containing molybdenum, nickel and silicon, and the shell phase is an amorphous composite oxide containing tungsten, nickel, rare earth and aluminum; the catalyst of the present invention can be in the form of flakes, spheres, cylindrical bars and shaped bars (three-leaf clover, four-leaf clover) as needed, preferably cylindrical bars and shaped bars (three-leaf clover, four-leaf clover). The average particle size of the catalyst particles is 8-13nm. Preferably, the particle size distribution of the catalyst particles is as follows: the number of particles with a particle size less than 7nm accounts for 2%-15% of the total number of particles, the number of particles with a particle size of 7nm-13nm accounts for 66%-88% of the total number of particles, and the number of particles with a particle size greater than 13nm accounts for 3%-21% of the total number of particles.

[0039] In the above catalyst, based on the mass of the core-shell structured composite oxide particles, the core phase accounts for 20% to 90%, preferably 25% to 88%, and the shell phase accounts for 10% to 80%, preferably 12% to 75%.

[0040] In the above catalyst, the molar ratio of molybdenum to nickel atoms in the core phase is 1:28~12:1, preferably 1:22~10:1, and the silicon content, calculated as SiO2, accounts for 2%~38% of the mass of the hydrorefining catalyst, preferably 4%~36%.

[0041] In the above catalyst, the molar ratio of tungsten to nickel atoms in the shell phase is 1:22~8:1, preferably 1:20~5:1, the aluminum content is 3%~28% of the mass of the hydrorefining catalyst calculated as Al2O3, preferably 5%~25%, and the rare earth content is 2%~12% of the mass of the hydrorefining catalyst calculated as oxide, preferably 3%~10%.

[0042] In the above catalyst, the mass of NiO in the core phase accounts for 30% to 80% of the total mass of NiO in the hydrorefining catalyst, and the mass of NiO in the shell phase accounts for 20% to 70% of the total mass of NiO in the hydrorefining catalyst.

[0043] The Na2O content in the above catalyst is less than 0.12%, preferably less than 0.1%.

[0044] Among the above catalysts, the properties of the hydrotreating catalyst are as follows: the specific surface area is 180~700m 2 / g, and the pore volume is 0.30~0.90mL / g.

[0045] The pore size distribution of the above catalyst is as follows: the pore volume occupied by pores with a diameter of less than 4 nm accounts for 1% to 10% of the total pore volume, the pore volume occupied by pores with a diameter of 4 to 10 nm accounts for 12% to 40% of the total pore volume, the pore volume occupied by pores with a diameter of 10 to 15 nm accounts for 22% to 56% of the total pore volume, and the pore volume occupied by pores with a diameter of more than 15 nm accounts for 18% to 45% of the total pore volume; the preferred pore size distribution is as follows: the pore volume occupied by pores with a diameter of less than 4 nm accounts for 2% to 8% of the total pore volume, the pore volume occupied by pores with a diameter of 4 to 10 nm accounts for 14% to 36% of the total pore volume, the pore volume occupied by pores with a diameter of 10 to 15 nm accounts for 24% to 54% of the total pore volume, and the pore volume occupied by pores with a diameter of more than 15 nm accounts for 20% to 42% of the total pore volume.

[0046] The invention discloses an application of the rare earth-containing bulk hydrofining catalyst in diesel hydrofining reaction.

[0047] Furthermore, the conditions of the diesel hydrofining reaction are as follows: reaction temperature is 330-400°C, reaction pressure is 2.5-12MPa, hydrogen-oil volume ratio is 250:1-1200:1, liquid hourly volume space velocity is 0.3-5.0h -1 .

[0048] Compared with the prior art, the present invention has the following advantages:

[0049] 1. The method of the present invention adds a specific anionic surfactant in the first gelation reaction, which is conducive to the uniform dispersion of the active metal in the core of the composite oxide particles and the regular shape of the core phase part, resulting in a reduced average particle size of the oxide particles and uniform size. Afterwards, the nickel-aluminum mixed solution, sodium tungstate solution and precipitant are added to the existing water and oily liquid for the second gelation. The pH value decreases and the gelation method is adopted to control the growth of the core-shell composite oxide particles, so that tungsten and nickel are uniformly and orderly precipitated on the molybdenum-nickel grains, thereby forming tungsten-nickel coated molybdenum-nickel nanoparticles with uniform particle size and good dispersion. During the second gelation reaction, rare earth metals are added in batches when the pH value decreases and becomes constant. The composite formed by the rare earth metal and the hydrogenation active metal step by step has a higher hydrogen storage capacity, and the increase in the catalyst's absorption and dehydrogenation capacity is conducive to preventing the catalyst from carbon deposition, so that the catalyst has good activity stability. The core-shell composite oxide particles are smaller in size, which is also more conducive to the further function of the rare earth metal.

[0050] 2. The method of the present invention adopts a clean method to prepare a low-cost catalyst. Since soluble sodium salt is used as the raw material, the precipitate after gelation contains a large amount of sodium ions. The presence of a large amount of sodium ions causes the catalyst to have a small pore volume and is not easy to form. The inventor first retains the sodium salt in the material during the forming process, and then desalts the formed material to remove the precipitated sodium salt. In this process, due to the occupying effect of the sodium salt during the forming process, the vacancies after sodium removal are more conducive to the formation of the catalyst pore structure, and the pore distribution moves toward the macropore direction, which solves the problem that the catalyst has a small pore volume and is not easy to form when the prior art uses clean raw materials to prepare bulk catalysts. The catalyst preparation process reduces the number of washing times in the conventional catalyst preparation process and reduces the amount of water. The catalyst of the present invention has a core-shell composite oxide structure, which is more conducive to the desalination of the material.

[0051] 3. The hydrorefining catalyst of the present invention improves the distribution state of active metals at the nano level, that is, it is mainly composed of composite oxide particles containing molybdenum, nickel and silicon coated with composite oxides containing tungsten, nickel, rare earth and aluminum. This coating structure is different from the structure at the macro level (such as millimeter level). The catalytic material structure is controlled at the micro level, so that the overall performance of the catalyst can be improved, the hydrodesulfurization performance of the catalyst is improved, and a certain amount of acidic centers are formed at the junction of the core-shell structure of the catalyst, so that the catalyst can eliminate steric hindrance while performing hydrodesulfurization reaction, while reducing the occurrence of side reactions such as excessive cracking. When the distillate oil raw materials containing sulfur and nitrogen (especially the distillate oil raw materials containing sulfur and nitrogen that are difficult to remove) are in contact with the hydrorefining catalyst of the present invention, the desulfurization and denitrification activities are significantly improved. At the same time, the cracking reaction of the diesel fraction is reduced, and the reduction of the diesel yield is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is the TEM image of catalyst B obtained in Example 2. DETAILED DESCRIPTION

[0053] In the present invention, the specific surface area and pore volume are measured by low temperature liquid nitrogen adsorption method, and the mechanical strength is measured by lateral pressure method. The specific surface area, pore volume and pore size distribution are measured by ASAP-2405 BET nitrogen adsorption instrument; the crushing strength of the catalyst is measured by ZQJ-2 intelligent particle strength testing machine.

[0054] In the present invention, in the core-shell composite oxide particles, the metal content in the composite oxide in the core and the shell and the thickness of the shell are measured by TEM transmission electron microscope (Japan JSM-2100). Among them, the method for determining the metal content in the composite oxide in the core and the shell is as follows: the core-shell composite oxide particles are uniformly mixed with liquid epoxy resin, and then an appropriate amount of curing agent is added, and the mixture is heated and cured after being stirred evenly to form solid particles. The solid particles are cut into thin slices with a thickness of 5-20nm by an ultrathin slicer, and the obtained slices are placed in a transmission electron microscope for observation to find a core-shell structure (cross section) with a clear interface. The diameter of the electron beam is adjusted by a condenser so that its diameter basically covers the outline of the entire core-shell structure, and the energy spectrum EDS spectrum is collected to record the intensity of the main energy peak, which corresponds to the actual content of each element in the known feed and the energy peak intensity of each element. The electron beam diameter is adjusted so that it is smaller than or close to the core or shell size, and the metal content in the composite oxide in the core and the shell at this time is calculated according to the energy peak intensity corresponding to the element, compared with the peak intensity under full coverage and the corresponding actual value. In the core-shell structure, the shell thickness is identified and measured from the transmission electron microscope image, and the ratio of the shell thickness to the total core-shell thickness is the average value obtained by measuring 40 to 100 core-shell particles.

[0055] In the present invention, wt% refers to mass fraction, and v% refers to volume fraction.

[0056] Example 1

[0057] Add nickel chloride and water glass to a dissolving tank 1 filled with deionized water to prepare a solution containing Ni and Si. The weight concentration of Ni in the Ni and Si solutions is 28 g / L as NiO, and the weight concentration of SiO2 is 30 g / L. Add nickel chloride and aluminum chloride solutions to a dissolving tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the Ni and Al solutions is 24 g / L as NiO, and the weight concentration of Al in Al2O3 is 28 g / L. Among them, the mass ratio of Ni in the Ni and Si solution used in the reaction of this embodiment to Ni in the Ni and Al solution used is 14:12. Prepare a rare earth ion (lanthanum) solution C (the mass concentration of lanthanum in oxide is 14 g / L), and divide it into 6 equal parts by volume. A solution containing Ni and Si is placed in a reaction tank 1, and a sodium hydroxide solution (weight concentration of 12%), a sodium molybdate solution (weight concentration of Mo calculated as MoO3 is 36 g / L) and a sodium lignin sulfonate solution are dripped into the reaction tank 1 in parallel to carry out a first gelling reaction. The molar ratio of the sodium lignin sulfonate to the Mo in the sodium molybdate solution is 1.0, and the gelling temperature is maintained at 62°C. At the end of the reaction, the pH value is controlled at 7.8, and the gelling time is controlled at 1.2 hours. After the reaction is completed, aging is carried out at a temperature of 78°C, an aging pH value is controlled at 7.5, and aging is carried out for 1.8 hours to obtain a first slurry. First, 800 mL of deionized water and 60 mL of rapeseed oil were added to the reaction tank 2, and then a 10 wt% sodium carbonate solution, the first slurry, a solution containing Ni and Al, and a sodium tungstate solution (the weight concentration of W in terms of WO3 is 40 g / L) were added to the reaction tank 2 for a second gelling reaction. The gelling temperature was maintained at 60°C, and the pH value was initially controlled to be 13.0. The pH value was adjusted down 6 times to adjust the final pH value to 7.6 at the end. The pH value was adjusted down to 0.9 each time. After each adjustment to the adjusted value, the pH value of the reaction slurry was kept constant for 10 minutes. At the beginning of the constant, an equal portion of the rare earth ion solution was added dropwise, and the dropping time was the same as the constant time. After the second gelling reaction was completed, aging began, the aging temperature was 78°C, the pH value was controlled at 8.0, and the aging time was 2.5 hours to obtain the second slurry. The aged slurry was filtered, the filter cake was dried at 100°C for 7 hours, rolled, and extruded into a clover shape. The formed strips were cured at 70°C for 50 hours, then the temperature was lowered to 20°C and the curing continued for 30 hours. The strips were washed with deionized water at room temperature until neutral. The wet strips were then dried at 100°C for 12.0 hours, and the dried material was calcined at 500°C for 4 hours to obtain catalyst A. The catalyst composition and main properties are shown in Table 1.

[0058] Example 2

[0059] Add nickel chloride and water glass to a dissolving tank 1 filled with deionized water to prepare a solution containing Ni and Si. The weight concentration of Ni in the Ni and Si solution is 36 g / L as NiO, and the weight concentration of SiO2 is 40 g / L. Add nickel chloride and aluminum chloride solutions to a dissolving tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the Ni and Al solution is 20 g / L as NiO, and the weight concentration of Al in Al2O3 is 18 g / L. Among them, the mass ratio of Ni in the Ni and Si solution used in the reaction of this embodiment to Ni in the Ni and Al solution used is 9:5. Prepare a solution containing rare earth ions (lanthanum and cerium) (the mass concentration of lanthanum and cerium in oxides is 14 g / L, of which the total weight of rare earth metal oxides is the basis, La2O3 accounts for 39.1%, and CeO2 accounts for 60.9%), and divide it into 7 equal parts by volume. The solution containing Ni and Si is put into reaction tank 1, and sodium hydroxide solution (weight concentration of 12%), sodium molybdate solution (weight concentration of Mo calculated as MoO3 is 34g / L) and sodium oleyl glycol diester sulfonate are dripped into reaction tank 1 in parallel to carry out the first gelation reaction. The molar ratio of sodium oleyl glycol diester sulfonate to Mo in mixed solution A is 0.9, and the gelation temperature is maintained at 55°C. At the end of the reaction, the pH value is controlled at 8.0, and the gelation time is controlled at 1.6 hours. After the reaction is completed, aging is carried out at an aging temperature of 80°C and an aging pH value of 7.9 for 1.2 hours to obtain a first slurry. First, 800 mL of deionized water and 60 mL of corn oil were added to the reaction tank 2, and then a 13 wt% sodium carbonate solution, the first slurry, a solution containing Ni and Al, and a sodium tungstate solution (the weight concentration of W in terms of WO3 is 36 g / L) were added to the reaction tank 2 for the second gelation reaction. The gelation temperature was maintained at 55 ° C, and the pH value was initially controlled to be 13.0. The pH value was adjusted down 7 times to adjust the final pH value to 8.1 at the end. The pH value was adjusted down to 0.7 each time. After each adjustment to the adjusted value, it was kept constant. The adjusted pH value of the reaction slurry was kept constant for 15 minutes. At the beginning of the constant, one portion of the rare earth ion solution was added dropwise. The dropping time was the same as the constant time. After the second gelation reaction was completed, aging began. The aging temperature was 78 ° C, the pH value was controlled at 8.0, and the aging time was 3.2 hours to obtain the second slurry. The aged slurry was filtered, and the filter cake was dried for the first time, dried at 100 ° C for 8 hours, rolled, and extruded into a clover shape. The formed strips were cured at 72°C for 45 hours, then the temperature was lowered to 22°C and the curing continued for 28 hours. The strips were washed with deionized water at room temperature until neutral. The wet strips were then dried at 80°C for 12.0 hours, and the dried material was calcined at 550°C for 5 hours to obtain catalyst B. The catalyst composition and main properties are shown in Table 1.

[0060] Example 3

[0061] Nickel chloride and water glass are added to a dissolution tank 1 filled with deionized water to prepare a solution containing Ni and Si. The weight concentration of Ni in the Ni and Si solution is 20 g / L as NiO, and the weight concentration of SiO2 is 24 g / L. Nickel chloride and aluminum chloride solutions are added to a dissolution tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the Ni and Al solution is 28 g / L as NiO, and the weight concentration of Al in Al2O3 is 34 g / L. Among them, the mass ratio of Ni in the Ni and Si solution used in the reaction of this embodiment to Ni in the Ni and Al solution used is 5:7. A solution containing rare earth ions (lanthanum, cerium, praseodymium) is prepared (the mass concentration of lanthanum, cerium, and praseodymium in terms of oxide is 14 g / L, based on the total weight of rare earth metal oxides, La2O3 accounts for 45.3%, CeO2 accounts for 30.2%, and Pr2O5 accounts for 14.5%), and is divided into 6 equal parts by volume. The solution containing Ni and Si is placed in a reaction tank 1, and a sodium hydroxide solution (weight concentration of 14%), a sodium molybdate solution (the weight concentration of Mo in terms of MoO3 is 32 g / L) and a sodium lauryl alcohol polyoxyethylene ether sulfate solution are dripped into the reaction tank 1 in parallel to carry out a first gelling reaction, the molar ratio of sodium lauryl alcohol polyoxyethylene ether sulfate to Mo in the sodium molybdate solution is 1.2, the gelling temperature is maintained at 65°C, the pH value is controlled at 7.9 at the end of the reaction, and the gelling time is controlled at 1.1 hours. After the reaction is completed, aging is carried out, the aging temperature is 82°C, the aging pH value is controlled at 7.7, and the aging is carried out for 1.8 hours to obtain a first slurry. First, 900 mL of deionized water and 100 mL of peanut oil were added to the reaction tank 2, and then a 13 wt% sodium carbonate solution, the first slurry, a solution containing Ni and Al, and a sodium tungstate solution (the weight concentration of W in terms of WO3 is 48 g / L) were added to the reaction tank 2 for a second gelation reaction. The gelation temperature was maintained at 75 °C, and the pH value was initially controlled to be 12.6. The pH value was lowered 6 times to adjust the final pH value to 7.8 at the end. The pH value was lowered by 0.8 each time, and the pH value was lowered to the adjusted value each time. After that, the pH value of the adjusted reaction slurry is kept constant for 12 minutes. At the beginning of the constant process, an equal portion of the rare earth ion solution is added dropwise, and the dropping time is the same as the constant time. After the second gelation reaction is completed, aging begins, the aging temperature is 85°C, and the aging pH value is controlled at 8.0. After aging for 2.8 hours, the precipitate slurry continues to be aged under high pressure, the pressure is 12.9MPa, the aging temperature is 180°C, the aging time is 1.4 hours, and the aging pH value is 12.0 to obtain the second slurry. The aged slurry is filtered, the filter cake is dried at 120°C for 8 hours, rolled, and extruded into a clover shape. The formed strips are cured for 72 hours at a temperature of 40°C. Wash with deionized water at room temperature until neutral. The wet strips are then dried at 80°C for 13.0 hours, and the dried material is roasted at 520°C for 5 hours to obtain catalyst C.The composition and main properties of the catalyst are shown in Table 1.

[0062] Example 4

[0063] Nickel chloride and water glass were added to a dissolving tank 1 filled with deionized water to prepare a solution containing Ni and Si, wherein the weight concentration of Ni in the Ni and Si solution was 28 g / L as NiO, and the weight concentration of SiO2 was 26 g / L. Nickel chloride and aluminum chloride solutions were added to a dissolving tank 2 filled with deionized water to prepare a solution containing Ni and Al, wherein the weight concentration of Ni in the Ni and Al solution was 16 g / L as NiO, and the weight concentration of Al in the Al2O3 was 32 g / L. Among them, the mass ratio of Ni in the Ni and Si solution used in the reaction of this embodiment to Ni in the Ni and Al solution used is 14:8 to prepare a solution containing rare earth ions (lanthanum, cerium, praseodymium, and rubidium) (the mass concentration of lanthanum, cerium, praseodymium, and rubidium in terms of oxides is 12 g / L, based on the total weight of rare earth metal oxides, La2O3 accounts for 38.5%, CeO2 accounts for 30.5%, Pr2O5 accounts for 19.1%, and Nd2O3 accounts for 11.9%), and divide it into 5 equal parts by volume. The solution containing Ni and Si is placed in reaction tank 1, and sodium hydroxide solution (weight concentration of 14%) and sodium molybdate solution (weight concentration of Mo calculated as MoO3 is 42 g / L) are dropped into reaction tank 1 to carry out the first gelation reaction. The gelation temperature is maintained at 68°C, the pH value is controlled at 8.2 at the end of the reaction, and the gelation time is controlled at 1.2 hours. After the reaction is completed, aging is carried out at 83°C, the aging pH value is controlled at 8.2, and the aging is carried out for 1.6 hours to obtain the first slurry. First, 900 mL of deionized water and 80 mL of sunflower oil were added to the reaction tank 2, and then the sodium carbonate solution with a concentration of 10 wt%, the first slurry, the solution containing Ni and Al, the sodium tungstate solution (the weight concentration of W calculated as WO3 is 44 g / L) and the sodium diisooctyl sulfosuccinate solution were dripped into the reaction tank 1 in parallel to carry out the first gelation reaction. The molar ratio of sodium diisooctyl sulfosuccinate to Mo in the sodium molybdate solution was 0.8 and they were added to the reaction tank 2 in parallel to carry out the second gelation reaction. The gelation temperature was maintained at 53 ° C, and the pH value was initially controlled to be 12.8. The pH value was lowered 5 times to the lowest value at the end. The final pH value is adjusted to 7.8, and the pH value is adjusted downward each time to 1.0. After each adjustment to the adjusted value, it starts to be constant. The adjusted pH value of the reaction slurry is constant for 14 minutes. During the constant process, one portion of the rare earth ion solution is added dropwise, and the dropping time is the same as the constant time. After the second gelation reaction is completed, aging begins, the aging temperature is 77°C, the aging pH value is controlled at 7.9, and the aging is 2.6 hours. Then the precipitate slurry continues to be aged under high pressure, the pressure is 13.5MPa, the aging temperature is 176°C, the aging time is 1.4 hours, and the aging pH value is 11.8. The second slurry is obtained. The aged slurry is filtered, the filter cake is dried at 85°C for 10 hours, rolled, and extruded into a clover shape. After the formed strips are cured at a temperature of 75°C for 42 hours, the temperature is reduced to 25°C, and the curing is continued for 33 hours. Wash with deionized water at room temperature until neutral.The wet strips were then dried at 120°C for 8.0 hours, and the dried material was calcined at 540°C for 5 hours to obtain catalyst D. The catalyst composition and main properties are shown in Table 1.

[0064] Example 5

[0065] The same method as Example 1 was used, except that the rare earth ion solution was added into the deionized water in reaction tank 2 at one time during the second gel formation reaction to prepare catalyst E.

[0066] Comparative Example 1

[0067] The reference agent F having the same catalyst composition as that of Example 1 was prepared, and the specific process was as follows:

[0068] According to the catalyst composition of Example 1, nickel chloride, aluminum chloride and water glass are dissolved in deionized water to prepare a mixed solution, wherein the weight concentration of Ni in terms of NiO is 52g / L, the weight concentration of Al in terms of Al2O3 is 36g / L, and the weight concentration of SiO2 is 36g / L. 500mL of deionized water is added to a reaction tank, and a 10wt% NaOH solution, a sodium molybdate solution (the weight concentration of Mo in terms of MoO3 is 36g / L), a sodium tungstate solution (the weight concentration of W in terms of WO3 is 40g / L) and a mixed solution are added to the reaction tank in parallel to form a gel, and the gelling temperature is maintained at 62°C, the pH value is controlled at 7.8 at the end, and the gelling time is controlled at 1.2 hours to generate a nickel- and tungsten-containing precipitate slurry. Then, aging is performed, the aging time is 2.0 hours, the aging temperature is 78°C, the pH value is controlled at 7.5 during aging, and the reaction slurry is filtered after the aging is completed, and the filter cake is dried at 100°C for 7 hours, rolled, and extruded into strips. The molded product was washed with deionized water at room temperature, but no molded product was obtained after washing. The powder was dried at 100°C for 12 hours and calcined at 500°C for 4 hours to obtain catalyst F. The composition and main properties of the catalyst are shown in Table 1.

[0069] Comparative Example 2

[0070] According to the method disclosed in CN102049295A, a reference agent G having a catalyst composition similar to that of Example 1 was prepared. The specific process is as follows:

[0071] After adding 1000mL of deionized water into the dissolving tank, nickel chloride, ammonium metatungstate and aluminum chloride solution are added in sequence, and mixed solution is prepared after uniform stirring. Among them, the weight concentration of Ni in terms of NiO is 52g / L, the weight concentration of W in terms of WO3 is 40g / L, and the weight concentration of Al in terms of Al2O3 is 54g / L. Take 160g of ammonium bicarbonate to prepare an aqueous solution with a molar concentration of 2.5mol / L. Then the mixed solution, ammonium bicarbonate aqueous solution and precipitant 10% ammonia water are added to the reaction tank filled with deionized water at the same time and flow to form gel. The gel pH value is 7.8 and the gel temperature is 62°C. After the gel is completed, add the slurry containing SAPO-11 molecular sieve and age for 2 hours at an aging temperature of 78°C. The pH value is controlled at 7.5 during aging. After aging, the filter cake was filtered, 600 mL of deionized water and 36 g of molybdenum trioxide were added, slurried and stirred evenly, and filtered. The filter cake was dried at 100°C for 7 hours, then extruded into strips, washed with deionized water until neutral, and the wet strips were dried at 100°C for 12 hours and calcined at 500°C for 4 hours to obtain the final catalyst G. The composition and main properties are shown in Table 1.

[0072] The SAPO-11 molecular sieve used in the comparative example is the one used in CN102049295A, which can be synthesized by conventional methods, such as hydrothermal crystallization method, and has the following properties: SiO2 / Al2O3 molar ratio of 0.85, infrared acid content of 0.9 mmol / g, pore volume of 0.24 mL / g, specific surface area of ​​250 m 2 / g, particle size is 450nm and crystallinity is 85%.

[0073] Comparative Example 3

[0074] Reference agent H was prepared according to the preparation method of Example 1 (no grease was added to the gelling tank during the second step of gelling) and the catalyst composition.

[0075] Add nickel chloride and water glass to a dissolving tank 1 filled with deionized water to prepare a solution containing Ni and Si. The weight concentration of Ni in the Ni and Si solutions is 28 g / L as NiO, and the weight concentration of SiO2 is 30 g / L. Add nickel chloride and aluminum chloride solutions to a dissolving tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the Ni and Al solutions is 24 g / L as NiO, and the weight concentration of Al in Al2O3 is 28 g / L. Among them, the mass ratio of Ni in the Ni and Si solution used in the reaction of this embodiment to Ni in the Ni and Al solution used is 14:12. Prepare a rare earth ion (lanthanum) solution C (the mass concentration of lanthanum in oxide is 14 g / L), and divide it into 6 equal parts by volume. A solution containing Ni and Si is placed in a reaction tank 1, and a sodium hydroxide solution (weight concentration of 12%), a sodium molybdate solution (weight concentration of Mo calculated as MoO3 is 36 g / L) and a sodium lignin sulfonate solution are dripped into the reaction tank 1 in parallel to carry out a first gelling reaction. The molar ratio of the sodium lignin sulfonate to the Mo in the sodium molybdate solution is 1.0, and the gelling temperature is maintained at 62°C. At the end of the reaction, the pH value is controlled at 7.8, and the gelling time is controlled at 1.2 hours. After the reaction is completed, aging is carried out at a temperature of 78°C, an aging pH value is controlled at 7.5, and aging is carried out for 1.8 hours to obtain a first slurry. First, 800 mL of deionized water was added to the reaction tank 2, and then a 10 wt% sodium carbonate solution, the first slurry, a solution containing Ni and Al, and a sodium tungstate solution (the weight concentration of W in terms of WO3 was 40 g / L) were added to the reaction tank 2 for the second gelation reaction. The gelation temperature was maintained at 60°C, and the pH value was initially controlled to be 13.0. The pH value was adjusted down 6 times to adjust the final pH value to 7.6 at the end. The pH value was adjusted down to 0.9 each time. After each adjustment to the adjusted value, it was kept constant. The adjusted pH value of the reaction slurry was kept constant for 10 minutes. At the beginning of the constant, an equal portion of the rare earth ion solution was added dropwise. The dropping time was the same as the constant time. After the second gelation reaction was completed, aging began. The aging temperature was 78°C, the pH value was controlled at 8.0, and the aging time was 2.5 hours to obtain the second slurry. The aged slurry was filtered, the filter cake was dried at 100°C for 7 hours, rolled, and extruded into a clover shape. The formed strips were cured at 70°C for 50 hours, then the temperature was lowered to 20°C and cured for another 30 hours. The strips were washed with deionized water at room temperature until neutral. The wet strips were then dried at 100°C for 12.0 hours, and the dried material was calcined at 500°C for 4 hours to obtain Catalyst H. The composition and main properties of the catalyst are shown in Table 1.

[0076] Comparative Example 4

[0077] Reference agent I was prepared according to the preparation method of Example 1 (no silicon was added when preparing mixed solution A).

[0078] Add nickel chloride and aluminum chloride solutions to dissolution tank 1 filled with deionized water to prepare solution A containing Ni and Al. The weight concentration of Ni in solution A is 28 g / L as NiO, and the weight concentration of Al in solution A is 30 g / L as Al2O3. Add nickel chloride and aluminum chloride solutions to dissolution tank 2 filled with deionized water to prepare solution B containing Ni and Al. The weight concentration of Ni in solution B containing Ni and Al is 24 g / L as NiO, and the weight concentration of Al in solution B containing Ni and Al is 28 g / L. Among them, the mass ratio of Ni in solution A containing Ni and Al used in the reaction of this embodiment to Ni in solution B containing Ni and Al used is 14:12. Prepare solution C containing rare earth ions (lanthanum) (the mass concentration of lanthanum in oxide is 14 g / L), and divide it into 6 equal parts by volume. The solution A containing Ni and Al is placed in a reaction tank 1, and a sodium hydroxide solution (weight concentration of 12%), a sodium molybdate solution (weight concentration of Mo calculated as MoO3 is 36 g / L) and a sodium lignin sulfonate solution are dripped into the reaction tank 1 in parallel to carry out a first gelling reaction. The molar ratio of the sodium lignin sulfonate to the Mo in the sodium molybdate solution is 1.0, and the gelling temperature is maintained at 62°C. At the end of the reaction, the pH value is controlled at 7.8, and the gelling time is controlled at 1.2 hours. After the reaction is completed, aging is carried out at a temperature of 78°C, an aging pH value is controlled at 7.5, and aging is carried out for 1.8 hours to obtain a first slurry. First, 800 mL of deionized water and 60 mL of rapeseed oil were added to the reaction tank 2, and then a sodium carbonate solution with a concentration of 10 wt%, the first slurry, a solution B containing Ni and Al, and a sodium tungstate solution (the weight concentration of W in terms of WO3 is 40 g / L) were added to the reaction tank 2 for a second gelling reaction. The gelling temperature was maintained at 60 ° C, and the pH value was initially controlled to be 13.0. The pH value was adjusted down 6 times to adjust the final pH value to 7.6 at the end. The pH value was adjusted down to 0.9 each time. After each adjustment to the adjusted value, it was kept constant. The adjusted pH value of the reaction slurry was kept constant for 10 minutes. At the beginning of the constant, one portion of the rare earth ion solution was added dropwise, and the dropping time was the same as the constant time. After the second gelling reaction was completed, aging began, the aging temperature was 78 ° C, the pH value was controlled at 8.0, and the aging time was 2.5 hours to obtain the second slurry. The aged slurry was filtered, the filter cake was dried at 100 ° C for 7 hours, rolled, and extruded into a clover shape. The formed strips were cured at 70°C for 50 hours, then the temperature was lowered to 20°C and the curing continued for 30 hours. The strips were washed with deionized water at room temperature until neutral. The wet strips were then dried at 100°C for 12.0 hours, and the dried material was calcined at 500°C for 4 hours to obtain Catalyst I. The composition and main properties of the catalyst are shown in Table 1.

[0079] Comparative Example 5

[0080] Catalyst J was prepared according to the method of Example 1 and the component content ratio of Catalyst A in Table 1. The formed strips were not subjected to desalination treatment.

[0081] Add nickel chloride and water glass to a dissolving tank 1 filled with deionized water to prepare a solution containing Ni and Si. The weight concentration of Ni in the Ni and Si solutions is 28 g / L as NiO, and the weight concentration of SiO2 is 30 g / L. Add nickel chloride and aluminum chloride solutions to a dissolving tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the Ni and Al solutions is 24 g / L as NiO, and the weight concentration of Al in Al2O3 is 28 g / L. Among them, the mass ratio of Ni in the Ni and Si solution used in the reaction of this embodiment to Ni in the Ni and Al solution used is 14:12. Prepare a rare earth ion (lanthanum) solution C (the mass concentration of lanthanum in oxide is 14 g / L), and divide it into 6 equal parts by volume. A solution containing Ni and Si is placed in a reaction tank 1, and a sodium hydroxide solution (weight concentration of 12%), a sodium molybdate solution (weight concentration of Mo calculated as MoO3 is 36 g / L) and a sodium lignin sulfonate solution are dripped into the reaction tank 1 in parallel to carry out a first gelling reaction. The molar ratio of the sodium lignin sulfonate to the Mo in the sodium molybdate solution is 1.0, and the gelling temperature is maintained at 62°C. At the end of the reaction, the pH value is controlled at 7.8, and the gelling time is controlled at 1.2 hours. After the reaction is completed, aging is carried out at a temperature of 78°C, an aging pH value is controlled at 7.5, and aging is carried out for 1.8 hours to obtain a first slurry. First, 800 mL of deionized water and 60 mL of rapeseed oil were added to the reaction tank 2, and then a 10 wt% sodium carbonate solution, the first slurry, a solution containing Ni and Al, and a sodium tungstate solution (the weight concentration of W in terms of WO3 is 40 g / L) were added to the reaction tank 2 for a second gelling reaction. The gelling temperature was maintained at 60°C, and the pH value was initially controlled to be 13.0. The pH value was adjusted down 6 times to adjust the final pH value to 7.6 at the end. The pH value was adjusted down to 0.9 each time. After each adjustment to the adjusted value, the pH value of the reaction slurry was kept constant for 10 minutes. At the beginning of the constant, an equal portion of the rare earth ion solution was added dropwise, and the dropping time was the same as the constant time. After the second gelling reaction was completed, aging began, the aging temperature was 78°C, the pH value was controlled at 8.0, and the aging time was 2.5 hours to obtain the second slurry. The aged slurry was filtered, the filter cake was dried at 100°C for 7 hours, rolled, and extruded into a clover shape. After washing with deionized water at room temperature, no molding was obtained. The powder was calcined at 500°C for 4 hours to obtain catalyst J. The catalyst composition and main properties are shown in Table 1.

[0082] Comparative Example 6

[0083] According to the preparation method disclosed in CN106513006A, a reference agent K having a composition similar to that of the catalyst in Example 1 of the present invention was prepared. The specific process is as follows:

[0084] Nickel carbonate and 300 ml of deionized water were uniformly mixed and added to a 1L high-pressure ultrasonic reactor. The ultrasonic frequency was set to 60 KHz, and the mixture was heated to 80°C. After being kept at this temperature for 1 hour, the ultrasonic frequency was reduced to 20 KHz, the system temperature was increased to 120°C, ammonium molybdate and 3 g of polyvinyl pyrrolidone were added, and then 10 ml of 25 wt% ammonia water was added dropwise to the system. After being kept at this temperature for 2 hours, the ultrasound was turned off, stirring was turned on, and the speed was 300 rpm. Ammonium metatungstate was added, and then citric acid was added until the pH of the system was 4.2. After being kept at this temperature for 2 hours, the heating was turned off, and the slurry was collected after the system was cooled to room temperature. The slurry was spray dried, and the inlet temperature and outlet temperature were controlled at about 200°C and 100°C, respectively. The obtained dry powder was roasted at 330°C in a muffle furnace for 3 hours to obtain the active component powder. The active component powder was mixed with aluminum hydroxide dry gel, and then a 10% dilute nitric acid aqueous solution was added for kneading and extrusion to obtain a strip. The strip was dried at 110°C for 10 hours and calcined in a muffle furnace at 400°C for 5 hours to obtain a reference agent K. The catalyst composition and main properties are shown in Table 1.

[0085] Comparative Example 7

[0086] According to the preparation method disclosed in CN1951558A, reference agent L was prepared as follows:

[0087] Add deionized water to the dissolving tank, add nickel chloride, ammonium metatungstate and aluminum chloride to dissolve, prepare acidic working solution A, the weight concentration of Ni in solution A is 74.8g / L in terms of NiO, the weight concentration of W in terms of WO3 is 48.6g / L, the weight concentration of Al in terms of Al2O3 is 44g / L, and the pH value of solution A is 1.8. Add 350mL of deionized water to the reaction tank, and the temperature rises to 62°C. Under stirring, add solution A and 10wt% ammonia water to the reaction tank in parallel to form gel, the gelling temperature is 62°C, the gelling time is 1 hour, and the pH value of the slurry during the gelling process is 8.5. After the gelling is completed, age for 2 hours, the aging temperature is 75°C, and the pH value is controlled at 7.6 during aging. Then filter, add 600mL of deionized water and 32.6g of molybdenum trioxide to the filter cake, beat and stir evenly, filter, dry the filter cake at 120°C for 8 hours, roll, and extrude into a cylindrical shape. The wet strips were washed with deionized water at room temperature until neutral. The wet strips were then dried at 80°C for 10 hours and calcined at 500°C for 4 hours to obtain catalyst L. The catalyst composition and main properties are shown in Table 1.

[0088] Example 6

[0089] This example is an activity evaluation experiment of the catalyst of the present invention, and is compared with the catalyst of the comparative example. From the physicochemical properties of the catalyst in Table 1, it can be seen that when the raw materials contain more sodium raw materials during the preparation process, the catalysts A, B, C, E of the present invention and the comparative catalysts G, H, I, K, L (the comparative catalysts F and J are washed into powders without activity evaluation) are used respectively during washing. A comparative evaluation test is carried out on a 200mL small hydrogenation device, and mixed diesel (the weight ratio of straight-run diesel, coking diesel, and catalytic diesel is 28:20:52) is used as the test raw material. The process conditions for the evaluation of catalyst activity are: hydrogen partial pressure of 6.4MPa, reaction temperature of 365°C, liquid hourly volume space velocity of 2.0h -1 , the volume ratio of hydrogen to oil is 500:1, and the main properties of the raw materials are shown in Table 4. The results of catalyst activity evaluation are shown in Table 5. The types of sulfides in the hydrorefined oil were detected by gas chromatography-atomic emission spectrometry detector (GC-AED), and the results are shown in Table 6. The results of catalyst activity life evaluation are shown in Table 7.

[0090] It can be seen from Table 1 that when the catalyst of the present invention uses a relatively high sodium-containing raw material in the preparation process, the catalyst has good crushing strength after desalting and washing after molding, while without desalting, the molded catalyst strips become powder after washing.

[0091] It can be seen from the evaluation results that compared with the comparative example catalyst, the catalyst of the present invention shows high hydrodesulfurization activity when removing difficult-to-treat 4,6-DMDBT macromolecular sulfides, and has excellent ultra-deep hydrodesulfurization activity. At the same time, the diesel product has a good yield. After the catalyst has been running for 2000 hours, the sulfur content of the refined oil after the catalytic treatment of the present invention is still less than 10μg / g, indicating that the catalyst has good stability. The hydrorefining catalyst of the present invention has a large pore volume and specific surface area, and the pore distribution is mainly concentrated above 10nm. The catalyst of the present invention is used for processing light distillate oil, especially for processing inferior diesel fractions, and has excellent ultra-deep hydrodesulfurization and denitrification performance. At the same time, by comparing the evaluation results of Table 5 and Table 7, after long-term operation, the catalyst of the present invention still has a high hydrodesulfurization performance and hydrogenation saturation performance, indicating that the catalyst has good stability.

[0092] Table 1 Composition and properties of catalysts prepared in Examples and Comparative Examples

[0093] Catalyst No. A B C D E NiO,wt% 26 28 24 22 26 <![CDATA[WO3,wt%]]> 20 18 24 22 20 <![CDATA[MoO3,wt%]]> 18 17 16 21 18 <![CDATA[SiO2,wt%]]> 15 20 12 13 15 <![CDATA[Al2O3,wt%]]> 14 9 17 16 14 Rare earth as oxide, wt% 7 7 7 6 7 <![CDATA[Na2O,%]]> 0.076 0.074 0.080 0.069 0.078 <![CDATA[Specific surface area, m 2 / g]]> 299 294 309 304 297 Pore ​​volume, mL / g 0.418 0.407 0.434 0.422 0.413 Pore ​​distribution <4nm 4.47 4.62 3.92 4.33 4.76 4nm~10nm 22.46 23.87 21.56 22.12 22.74 10nm~15nm 41.83 40.96 42.71 42.94 41.43 >15nm 31.24 30.55 31.81 30.61 31.07 Mechanical strength, N / mm 19.7 19.8 19.0 19.5 19.3

[0094] Table 1 (Continued) Composition and properties of catalysts prepared in Examples and Comparative Examples

[0095] Catalyst No. F G H I J K L NiO,wt% 26 26 26 26 26 26 37.4 <![CDATA[WO3,wt%]]> 20 20 20 20 20 20 24.3 <![CDATA[MoO3,wt%]]> 18 18 18 18 18 18 16.3 <![CDATA[SiO2,wt%]]> 18 4 15 - 15 - - <![CDATA[Al2O3,wt%]]> 18 28 14 30 14 36 22 <![CDATA[P2O5,wt%]]> - 4 - - - - - Rare earth as oxide, wt% - - 7 7 7 - - <![CDATA[Na2O,%]]> 0.42 0.14 0.108 0.073 0.482 0.13 0.13 <![CDATA[Specific surface area, m 2 / g]]> 142 199 268 294 240 283 174 Pore ​​volume, mL / g 0.232 0.252 0.374 0.413 0.348 0.385 0.301 Pore ​​distribution <4nm 62.81 22.82 12.03 4.42 16.17 38.21 46.87 4nm~10nm 30.52 71.44 33.67 23.05 43.11 48.61 40.72 10nm~15nm 4.37 4.50 36.12 42.91 27.34 7.28 8.26 >15nm 2.30 1.24 18.18 29.62 13.38 5.90 4.15 Mechanical strength, N / mm - 17.6 18.8 19.0 - 13.5 19.1

[0096] Table 2 The composition of the composite oxides in the core and shell of the catalysts obtained in each example (based on the mass of the catalyst)

[0097] Catalyst No. A B C D E Composite oxide composition in the core NiO,wt% 14 18 10 14 14 <![CDATA[MoO3,wt%]]> 18 17 16 21 18 <![CDATA[SiO2,wt%]]> 15 20 12 13 15 <![CDATA[WO3,wt%]]> - - - - - <![CDATA[Al2O3,wt%]]> - - - - - Rare earth oxides, wt% - - - - - Composite oxide composition in shell NiO,wt% 12 10 14 8 12 <![CDATA[WO3,wt%]]> 20 18 24 22 20 <![CDATA[Al2O3,wt%]]> 14 9 17 16 14 <![CDATA[MoO3,wt%]]> - - - - - <![CDATA[SiO2,wt%]]> - - - - - Rare earth oxides, wt% 7 7 7 6 7

[0098] Table 2 (Continued) Composite oxide composition in the core and shell of the catalyst obtained in each example (based on the catalyst mass)

[0099] Catalyst No. H I J Composite oxide composition in the core NiO,wt% 19 14 14 <![CDATA[MoO3,wt%]]> 14 18 18 <![CDATA[SiO2,wt%]]> 10 - 15 <![CDATA[WO3,wt%]]> 8 - - <![CDATA[Al2O3,wt%]]> 4 15 - Rare earth oxides, wt% 2 Composite oxide composition in shell NiO,wt% 7 12 12 <![CDATA[WO3,wt%]]> 12 20 20 <![CDATA[Al2O3,wt%]]> 10 14 14 <![CDATA[MoO3,wt%]]> 4 - - <![CDATA[SiO2,wt%]]> 5 - - Rare earth oxides, wt% 5

[0100] Table 3 Average particle size and particle size distribution of the catalyst core-shell composite oxide particles obtained in each example

[0101] Catalyst No. A B C D E F G Average particle size of core-shell composite oxide particles, nm 9.0 9.4 9.6 9.1 9.1 33.6 23.8 Particle size distribution of core-shell composite oxide particles, % Particle size less than 7nm 5.34 5.01 5.12 5.23 5.31 3.32 4.05 Particle size is 7nm-13nm 84.63 83.54 83.18 84.03 84.20 21.22 28.19 Particle size greater than 13nm 10.03 11.45 11.70 10.74 10.49 77.46 67.76

[0102] Table 3 (Continued) Average particle size and particle size distribution of the catalyst core-shell composite oxide particles obtained in each example

[0103] Catalyst No. H I J K L Average particle size of core-shell composite oxide particles, nm 30.3 9.5 12.3 24.4 19.4 Particle size distribution of core-shell composite oxide particles, % Particle size less than 7nm 2.74 5.44 6.97 8.93 8.42 Particle size is 7nm-13nm 24.07 83.32 76.46 28.46 33.62 Particle size greater than 13nm 73.19 11.24 16.57 62.61 57.96

[0104] Table 4 Main properties of crude oil

[0105] project Analyze the results <![CDATA[Density (20 °C), g / cm 3 > 0.8897 Distillation range, ℃ 175-379 S, µg / g 13100 N, µg / g 922

[0106] Table 5 Evaluation results of initial catalyst activity (150 hours)

[0107] Catalyst No. A B C E G H I <![CDATA[Generated oil density (20 °C), g / cm 3 > 0.8636 0.8638 0.8634 0.8639 0.8656 0.8712 0.8652 S, µg / g 8.3 8.8 7.8 9.8 38.2 144.9 32.2 N, µg / g 3.8 4.0 3.6 4.4 16.4 70.3 12.7 Diesel yield, % 99.1 99.3 99.1 99.1 86.6 98.6 99.1

[0108] Table 5 Evaluation results of initial catalyst activity (150 hours)

[0109] Catalyst No. K L <![CDATA[Generated oil density (20 °C), g / cm 3 > 0.8732 0.8707 S, µg / g 236.8 118.8 N, µg / g 112.8 62. 2 Diesel yield, % 98.3 98.9

[0110] Table 6 Initial activity evaluation (150 hours) Content of different sulfides in hydrorefined oil

[0111] Catalyst No. A B C E G H I Sulfur content in hydrorefined oil, µg / g 8.3 8.8 7.8 9.8 38.2 144.9 32.2 <![CDATA[C1-DBT,µg / g]]> 0 0 0 3.2 11.2 3.2 4- MDBT, µg / g 1.9 2.1 1.8 2.3 8.1 31.3 7.0 6-MDBT, µg / g 2.1 2.2 2.0 2.5 9.6 31.3 7.9 4,6-DMDBT, µg / g 4.3 4.5 4.0 5.0 17.3 71.1 14.1

[0112] Table 6 (Continued) Initial activity evaluation (150 hours) Content of different sulfides in hydrorefined oil

[0113] Catalyst No. K L Sulfur content in hydrorefined oil, µg / g 236.8 118.8 <![CDATA[C1-DBT,µg / g]]> 22.1 9.1 4- MDBT, µg / g 52.2 25.4 6-MDBT, µg / g 60.2 26.3 4,6-DMDBT, µg / g 102.3 58.0

[0114] Table 7 Activity evaluation results of catalysts after 2000 hours of operation

[0115] Catalyst No. A B G H I L <![CDATA[Generated oil density (20 °C), g / cm 3 > 0.8637 0.8639 0.8671 0.8745 0.8663 0.8733 S, µg / g 8.4 9.0 67.2 173.2 58.1 152.3 N, µg / g 3.8 4.1 25.4 78.4 18.4 67. 5 Diesel yield, % 99.0 99.1 84.7 98.5 99.0 98.7

[0116] Table 8 Activity evaluation (2000 hours) Content of different sulfides in hydrorefined oil

[0117] Catalyst No. A B G H I L Sulfur content in hydrorefined oil, µg / g 8.4 9.0 67.2 173.2 58.1 152.3 <![CDATA[C1-DBT,µg / g]]> 0 0 7.1 18.1 10.2 18.3 4- MDBT, µg / g 2.0 2.1 16.6 39.4 12.1 36.2 6-MDBT, µg / g 2.1 2.3 14.2 38.4 14.5 32.3 4,6-DMDBT, µg / g 4.3 4.6 29.3 87.3 21.3 65.5

Claims

1. A method for preparing a bulk phase hydrogenation refining catalyst containing rare earth, characterized in that The method comprises the following contents: (1) preparing a first slurry: subjecting a first precipitant, a sodium molybdate solution and a solution containing Ni and Si to a first gelling reaction, adding an anionic surfactant having a carbon number of C9 to C26 during the reaction, and subjecting the solution to a first aging after the reaction to obtain a first slurry; (2) preparing a second slurry: adding a solution containing Ni and Al, a sodium tungstate solution, a second precipitant and the first slurry to a mixture of water and an oily liquid in parallel to conduct a second gelling reaction, lowering the pH value in batches during the gelling reaction, adding a portion of a rare earth solution divided by the number of times the pH value is lowered when the pH value remains constant after each lowering, and the number of times the pH value is lowered is 2 to 10, and subjecting the solution to a second aging after the reaction to obtain a second slurry; (3) preparing a molded product: subjecting the second slurry to aging, subjecting the solid-liquid separation after the aging to the solid phase drying and molding to obtain a molded product; (4) subjecting the molded product to a desalting treatment, washing, drying and roasting to obtain a bulk hydrogenation refining catalyst; the oily liquid described in step (2) is an unsaturated higher fatty acid glyceride.

2. The method according to claim 1, characterized in that: In the Ni and Si-containing solution described in step (1), the weight concentration of Ni as NiO is 5-120 g / L, and the weight concentration of Si as SiO2 is 2-80 g / L; in the sodium molybdate solution, the weight concentration of Mo as MoO3 is 5-110 g / L; and the first precipitant is an aqueous solution of an alkaline compound not containing nitrogen, and the weight concentration of the first precipitant is 5%-30%.

3. The method according to claim 1, characterized in that: The anionic surfactant with a carbon number of C9 to C26 described in step (1) is selected from one or more of sulfonate type, carboxylate type, sulfate ester type, sulfate ester type, phosphate ester type, and phosphate ester type anionic surfactants.

4. The method according to claim 1, characterized in that: The anionic surfactant with a carbon number of C9 to C26 described in step (1) is selected from one or more of sodium lignin sulfonate, sodium alkyl glyceryl ether sulfonate, sodium dioctyl succinate sulfonate, sodium alkyl benzene sulfonate with a carbon number of C10 to C16, sodium oleic acid ethylene glycol diester sulfonate, sodium dibutylnaphthalene sulfonate, sodium dodecyl glyceryl ether carboxylate, sodium α-olefin sulfonate with a carbon number of C14 to C18, sodium lauryl alcohol polyoxyethylene ether sulfate, and sodium monoglyceride disulfate.

5. The method according to claim 1, characterized in that: The molar ratio of the amount of the anionic surfactant having a carbon number of C9 to C26 to Mo in the sodium molybdate solution in step (1) is 0.2:1 to 2.0:

1.

6. The method according to claim 1, characterized in that: The conditions of the first gelling reaction in step (1) are: reaction temperature of 30-90° C., pH value of 7.0-11.0, and gelling time of 0.2-2.5 hours.

7. The method according to claim 1, characterized in that: The first aging conditions in step (1) are as follows: the aging temperature is 60-90° C., the pH value during aging is controlled at 7.0-11.0, and the aging time is 0.3-2.5 hours.

8. The method according to claim 1, characterized in that: In step (1), the weight of the introduced Ni accounts for 30% to 80% of the total Ni weight in the hydrotreating catalyst obtained in step (4), and the remaining Ni in the catalyst is introduced in step (2).

9. The method according to claim 1, characterized in that: In the Ni and Al solution of step (2), the weight concentration of Ni as NiO is 5-110 g / L, and the weight concentration of Al as Al2O3 is 2-95 g / L; in the sodium tungstate solution, the weight concentration of W as WO3 is 4-140 g / L; the second precipitant is an aqueous solution of sodium carbonate and / or sodium bicarbonate, and the concentration of the second precipitant is 5wt%-40wt%.

10. The method according to claim 1, characterized in that: The rare earth is one or more of lanthanum, cerium, praseodymium and rubidium. The mass concentration of the solution containing rare earth ions is 1-45 g / L in terms of rare earth oxide. The solution is divided into equal parts by volume according to the number of times the pH value is lowered.

11. The method according to claim 1, characterized in that: The volume ratio of the water added in step (2) to the first slurry obtained in step (1) is 0.1:1 to 3:

1.

12. The method according to claim 1, characterized in that: The unsaturated higher fatty acid glyceride described in step (2) is one or more of peanut oil, rapeseed oil, cottonseed oil, sunflower seed oil, soybean oil, corn oil, tea oil, and olive oil; the volume ratio of the unsaturated higher fatty acid glyceride to water is 1:60 to 1:

4.

13. The method according to claim 1, characterized in that: The conditions of the second gelling reaction in step (2) are as follows: the reaction temperature is 30-90° C., the initial pH value is controlled at 10.0-14.0, the final pH value is 7.0-8.5 at the end, and the gelling reaction time is 0.5-6.0 hours.

14. The method according to claim 13, characterized in that: During the second gelling reaction of step (2), the pH value is adjusted downward from the initial value to the final pH value in batches, and the pH value of the reaction slurry is kept constant until the next downward adjustment. After each downward adjustment, the pH value is kept constant for 0.1 to 1.2 hours.

15. The method according to claim 1, characterized in that: The second aging conditions described in step (2) are as follows: aging temperature is 40 to 90° C., aging time is 1 to 5 hours, and pH value is 7.0 to 11.

0.

16. The method according to claim 1, characterized in that: The second aging condition in step (2) is carried out as follows: the first step is normal pressure aging: the aging temperature is 30-90°C, the aging time is 1-6 hours, and the pH value is 6.5-10.0; the second step is high pressure aging: the temperature is 100-195°C, the time is 0.1-3.5 hours, the pressure is 10-15 MPa, and the pH value is 10.0-13.

0.

17. The method according to claim 1, characterized in that: The desalination process described in step (4) is: first curing, then washing to remove the salt precipitated on the surface of the molded product; the curing conditions are a temperature of 5 to 100° C. and a time of 10 to 100 hours.

18. The method according to claim 1, characterized in that: The desalination treatment in step (4) is carried out as follows: the first stage is carried out at a temperature of 60 to 90°C for curing for 5 to 60 hours; the second stage is carried out at a temperature of 10 to 30°C for 1 to 48 hours, and then the precipitated salt is removed by washing.

19. A bulk hydrogenation refining catalyst containing rare earth prepared by the method according to any one of claims 1 to 18, characterized in that: The catalyst comprises composite amorphous oxide particles of core-shell structure, wherein the core phase is an amorphous composite oxide containing molybdenum, nickel and silicon, and the shell phase is an amorphous composite oxide containing tungsten, nickel, rare earth and aluminum; the average particle size of the catalyst particles is 8-13 nm; the particle size distribution of the catalyst particles is as follows: the number of particles with a particle size less than 7 nm accounts for 2%-15% of the total number of particles, the number of particles with a particle size of 7 nm-13 nm accounts for 66%-88% of the total number of particles, and the number of particles with a particle size greater than 13 nm accounts for 3%-21% of the total number of particles; Based on the mass of the core-shell structured composite amorphous oxide particles, the core phase accounts for 20% to 90%, and the shell phase accounts for 10% to 80%; the atomic molar ratio of molybdenum to nickel in the core phase is 1:28 to 12:1, and the content of silicon is 2% to 38% of the mass of the hydrorefining catalyst calculated as SiO2; the atomic molar ratio of tungsten to nickel in the shell phase is 1:22 to 8:1, the content of aluminum is 3% to 28% of the mass of the hydrorefining catalyst calculated as Al2O3, and the content of rare earth is 2% to 12% of the mass of the hydrorefining catalyst calculated as oxide.

20. The catalyst according to claim 19, characterized in that: The Na2O content in the catalyst is less than 0.12%, and the specific surface area is 180~700m 2 / g, and the pore volume is 0.30~0.90mL / g.

21. The catalyst according to claim 19, characterized in that: The pore size distribution is as follows: the pore volume occupied by pores with a diameter of less than 4 nm accounts for 1%~10% of the total pore volume, the pore volume occupied by pores with a diameter of 4~10 nm accounts for 12%~40% of the total pore volume, the pore volume occupied by pores with a diameter of 10~15 nm accounts for 22%~56% of the total pore volume, and the pore volume occupied by pores with a diameter of more than 15 nm accounts for 18%~45% of the total pore volume.

22. Use of a bulk hydrotreating catalyst containing rare earth prepared by the method according to any one of claims 1 to 18 in a diesel hydrotreating reaction.

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