A method for preparing a hydrorefining catalyst

Abstract

The present invention provides a preparation method of a hydrorefining catalyst, comprising the following contents: (1) a first precipitant and a solution containing Ni, Mo and Si are subjected to a gelling reaction, and after the reaction, the first slurry is obtained by aging; (2) water, random polyether polyoxyethylene-polyoxypropylene copolymer and unsaturated higher fatty acid glyceride are added to the reactor, and then a solution containing Ni and Al, a sodium tungstate solution, a second precipitant and the first slurry obtained in step (1) are added to the reactor in parallel to carry out a gelling reaction, and after the reaction, the second slurry is generated by aging; (3) the second slurry is aged, the solid-liquid separation is carried out, and the solid phase is dried and formed to obtain a molded product; (4) the molded product is subjected to a desalting treatment, washing, drying and roasting to obtain a hydrorefining catalyst. The hydrorefining catalyst has a high hydrodesulfurization and denitrification performance, can avoid excessive cracking of diesel fractions, has good raw material adaptability, and can process inferior distillate oil raw materials.

Description

Technical Field

[0001] The present invention relates to a method for preparing a hydrorefining catalyst, in particular to a method for preparing a bulk hydrorefining catalyst. 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 use of impregnation and kneading methods to prepare catalysts results in high catalyst preparation costs and large wastewater treatment costs because relatively low-priced sodium metal salt raw materials cannot be used. The coprecipitation method can use relatively low-priced sodium raw materials to prepare catalysts, which greatly reduces the catalyst preparation costs and wastewater treatment costs. However, the introduction of a large number of sodium ions makes it difficult to remove sodium ions from 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 number of sodium ions still exist in the precipitated material. The residual sodium ions lead to poor adhesion of the material. The sodium ions that are not removed are not conducive to the formation of the catalyst pore structure, resulting in a small pore volume and pore size of the catalyst.

[0005] 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 problems of small pore volume and specific surface area of ​​bulk catalysts, small pore size of catalysts (pore size distribution is mainly concentrated below 8nm), large metal oxide particles in catalysts, and "ammonia nitrogen" and NO in catalyst preparation. X There are many problems such as pollution and high cost. Especially when using cheaper sodium-containing raw materials, the gel-forming materials are loose and difficult to shape, and the catalyst has many small pores.

[0006] 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.

[0007] CN102451706A discloses a method for preparing a hydrogenation catalyst composition, which comprises using a sodium aluminate solution, a mixed solution containing Ni and W component salts, and CO 2 The gas reacts in parallel to generate a precipitate. CN110038581A discloses a method for preparing a hydrorefining catalyst. The hydrorefining catalyst is prepared by two-step precipitation, using sodium tungstate alkaline solution and sodium molybdate alkaline solution as precipitants. 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.

[0008] 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

[0009] In view of the shortcomings of the prior art, the present invention provides a method for preparing a hydrorefining catalyst. The hydrorefining catalyst prepared by the method has low preparation cost, clean and pollution-free preparation process, large pore volume and pore diameter of the catalyst, high hydrodesulfurization and hydrodenitrogenation reaction performance, can avoid excessive cracking of diesel fractions, has good raw material adaptability, and can process inferior distillate oil raw materials.

[0010] The preparation method of the hydrotreating catalyst of the present invention comprises the following contents:

[0011] (1) subjecting a first precipitant and a solution containing Ni, Mo and Si to a first gelling reaction, followed by a first aging step to obtain a first slurry containing Ni, Si and Mo;

[0012] (2) adding water, random polyether polyoxyethylene-polyoxypropylene copolymer and unsaturated higher fatty acid glyceride into the reactor, and then adding Ni, Al-containing solution, sodium tungstate solution, second precipitant and the first slurry obtained in step (1) into the reactor in parallel to carry out a second gelling reaction, and after the reaction, subjecting the reaction to a second aging, to generate a second slurry;

[0013] (3) aging the second slurry, separating the solid from the liquid after aging, and drying and molding the solid phase to obtain a molded product;

[0014] (4) The formed product is desalted, washed, dried and calcined to obtain a hydrogenation refining catalyst.

[0015] In the method of the present invention, in the solution containing Ni, Mo and Si in step (1), the weight concentration of Ni in terms of NiO is 5 to 120 g / L, preferably 10 to 110 g / L, and the weight concentration of Mo in terms of MoO 3 The weight concentration is 5-120 g / L, preferably 10-110 g / L, Si is in the form of SiO 2 The weight concentration is 2-80 g / L, preferably 4-70 g / L; when preparing a solution containing Ni and Si, the nickel source used can be one or more of nickel sulfate, nickel nitrate, and nickel chloride, the molybdenum source can be ammonium molybdate, and the silicon source can be one or more of water glass, silica sol, etc.

[0016] In the method of the present invention, the first precipitant described in step (1) can be an aqueous solution of an alkaline compound that does not contain nitrogen, preferably ammonia water. The weight concentration of the first precipitant is 5% to 15%. 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 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.

[0018] 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.

[0019] In the method of the present invention, 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), preferably 32% to 78%. In step (2), the weight of the introduced Ni accounts for 20% to 70% of the total Ni weight in the hydrotreating catalyst obtained in step (4), preferably 22% to 68%.

[0020] In the method of the present invention, in the Ni and Al solution described in step (2), the weight concentration of Ni in terms of NiO is 5 to 110 g / L, preferably 10 to 100 g / L, and the weight concentration of Al in terms of Al is 10 to 20 g / L. 2 O 3 The weight concentration is 2 to 95 g / L, preferably 5 to 85 g / L.

[0021] In the method of the present invention, in the sodium tungstate solution of step (2), W is WO 3 The weight concentration is 4-140 g / L, preferably 6-120 g / L; in step (2), when preparing the Ni and Al 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.

[0022] In the method of the present invention, the random polyether polyoxyethylene-polyoxypropylene copolymer described in step (2) is selected from at least one of isomeric tridecanol random polyether TPE-1000, propylene glycol random polyether PPE-1500, glycerol random polyether GPE-3000, butanol random polyether BPE-1000, butanol random polyether BPE-1500, butanol random polyether BPE-2500, lauric acid random polyether LPE-1200, and dodecanol random polyether CPE-1500. The molar ratio of the random polyether polyoxyethylene-polyoxypropylene copolymer to W in the sodium tungstate solution is 0.2-2.0, preferably 0.3-1.5.

[0023] In the method of the present invention, the second precipitant in step (2) is one or more of sodium carbonate, sodium bicarbonate, and sodium hydroxide, preferably sodium carbonate and / or sodium hydroxide. The weight concentration of the second precipitant is 5% to 40%. The amount of the second precipitant can be determined by those skilled in the art according to actual needs.

[0024] In the method of the present invention, the water added in step (2) is deionized water, and the volume ratio of the added water to the volume of the first slurry obtained in step (1) is 0.1:1 to 3:1.

[0025] In the method of the present invention, the unsaturated higher fatty acid glyceride (vegetable oil) in step (2) is preferably 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, preferably 1:40 to 1:6.

[0026] 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. Preferably, the pH value can be adjusted from the initial value to the final pH value by a stepwise downward adjustment method, and the stepwise downward adjustment method is to adjust the pH value to the desired value of the 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, it is preferably 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 it is preferred that 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, it 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. The above operation process can make the catalyst composite oxide particle size more uniform.

[0027] 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.

[0028] In the method of the present invention, the aging conditions described 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.

[0029] The mild conditions in the aging process of step (2) are more conducive to the formation of uniform particle size. During the aging process in a closed environment, the phase structure of the material has formed a regular body in the first step of aging. In a closed environment, under the action of high temperature and pressure, the microscopic morphology of the material changes, and the material phase changes from a regular body to an irregular body formed by irregular flakes. This structural change causes the sodium ions in the phase to transfer to the surface of the phase, which is more conducive to the next step of desalination treatment. It is also conducive to increasing the specific surface area of ​​the bulk catalyst and improving the pore structure, so that more active metals are exposed on the catalyst surface, and more hydrogenation active centers are generated on the catalyst surface.

[0030] The solid-liquid separation in step (3) is generally carried out by filtration, centrifugation or the like.

[0031] The drying temperature in step (3) is 50 to 140° C., and the drying time is 0.5 to 24 hours.

[0032] 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.

[0033] The desalination process described in step (4) is: first curing, and 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., preferably a temperature of 10 to 90° C., and a time of 10 to 100 hours, preferably 24 to 90 hours.

[0034] 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, to promote the retention and shrinkage of vacancies, 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.

[0035] 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.

[0036] The bulk hydrorefining catalyst prepared by the method of the present invention is a composite amorphous oxide particle with a 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 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 required, 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.

[0037] In the catalyst of the present invention, 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%.

[0038] In the catalyst of the present invention, the molar ratio of molybdenum to nickel atoms in the core phase is 1:28 to 12:1, preferably 1:22 to 10:1, and the content of silicon is expressed as SiO 2 It accounts for 2% to 38% of the mass of the hydrotreating catalyst, preferably 4% to 36%.

[0039] In the catalyst of the present invention, the molar ratio of tungsten to nickel atoms in the shell phase is 1:22-8:1, preferably 1:20-5:1, and the content of aluminum is expressed as Al 2 O 3 It accounts for 5% to 36% of the mass of the hydrotreating catalyst, preferably 7% to 34%.

[0040] In the catalyst of the present invention, 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.

[0041] The Na in the catalyst of the present invention 2 The O content is less than 0.12%, preferably less than 0.1%.

[0042] In the catalyst of the present invention, the properties of the hydrotreating catalyst are as follows: the specific surface area is 180~700m2 / g, pore volume is 0.30~0.90mL / g. The pore size distribution of the bulk hydrorefining catalyst of the present invention is as follows: the pore volume occupied by pores with a diameter of less than 4nm accounts for 1%~10% of the total pore volume, the pore volume occupied by pores with a diameter of 4~10nm accounts for 12%~40% of the total pore volume, the pore volume occupied by pores with a diameter of 10~15nm accounts for 22%~56% of the total pore volume, and the pore volume of pores with a diameter of more than 15nm accounts for 18%~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 4nm accounts for 2%~8% of the total pore volume, the pore volume occupied by pores with a diameter of 4~10nm accounts for 14%~36% of the total pore volume, the pore volume occupied by pores with a diameter of 10~15nm accounts for 24%~54% of the total pore volume, and the pore volume of pores with a diameter of more than 15nm accounts for 20%~42% of the total pore volume.

[0043] The hydrofining catalyst of the present invention is used in diesel hydrofining reaction.

[0044] 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 .

[0045] Compared with the prior art, the present invention has the following advantages:

[0046] 1. In the method of the present invention, step (1) uses soluble ammonia salt and ammonia water as raw materials and precipitants respectively to prepare the inner core part (nickel, molybdenum, silicon composite oxide) of the core-shell structure composite amorphous oxide particles, and then uses soluble sodium salt as raw material and precipitant as the outer shell part (nickel, tungsten, aluminum composite oxide) of the core-shell structure composite amorphous oxide particles. That is, firstly, an aged slurry of molybdenum, nickel and silicon prepared by using soluble ammonia salt and ammonia water is added into a reactor containing water and unsaturated higher fatty acid glyceride in parallel with a nickel-aluminum mixed solution, a sodium tungstate solution and a precipitant for a second gelation, so that tungsten and nickel are uniformly and orderly precipitated on the molybdenum-nickel crystals, thereby forming tungsten-nickel-coated molybdenum-nickel nanoparticles with uniform particle size and good dispersion; at the same time, the sodium content in the composite oxide of the inner core part and the outer shell part is quite different. After the sodium removal treatment, the pore volume of the inner core part and the outer shell part of the core-shell structure composite amorphous oxide particles is quite different (the larger pore volume of the outer shell is conducive to the removal of sulfur and nitrogen in macromolecular compounds), and finally the core-shell structure composite amorphous oxide particles with stepped pore volume are formed. The hydrorefining catalyst prepared in this way is suitable for the hydrorefining reaction of heavy distillate oil (such as diesel), especially conducive to deep hydrodesulfurization and denitrogenation, and can also avoid reducing the diesel yield.

[0047] 2. The desalting process of the method of the present invention solves the problem that the catalyst pore volume is small and difficult to form when using clean raw materials to prepare bulk catalysts. Specifically, during the forming process, the sodium salt is first retained in the material, and then the formed material is desalted to remove the precipitated sodium salt. In this process, due to the occupation of the sodium salt during the forming process, the vacancies after sodium removal are more conducive to the formation of the catalyst pore structure, the pore distribution moves toward the macropore direction, the pore volume and pore size of the catalyst increase, and the diffusion performance of the catalyst is improved. In the second gelling reaction, the addition of organic additives such as random polyether polyoxyethylene-polyoxypropylene copolymers effectively improves the efficiency of removing sodium ions in the shell phase, and also prevents the sodium ions in the shell phase from entering the core phase, which can make it easier to remove the sodium salt in the outer shell of the composite oxide particles, and further increase the gap in pore volume between the inner core and the outer shell.

[0048] 3. The hydrofining 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 oxide containing tungsten, nickel and aluminum. This coating structure is different from the structure at the macro level (such as millimeter level). The shell phase has a large pore volume. The structure of the catalytic material is controlled at the micro level, so that the overall performance of the catalyst is improved, the hydrodesulfurization performance of the catalyst is improved, and a certain amount of acid 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, and reduce the occurrence of side reactions such as excessive cracking, so that when the sulfur and nitrogen-containing distillate oil raw materials (especially the distillate oil raw materials containing sulfur and nitrogen that are difficult to remove) contact with the hydrofining catalyst of the present invention, the desulfurization and denitrification activities are significantly improved, and at the same time, the cracking reaction of the diesel fraction is reduced, and the diesel yield is avoided. In addition, the catalyst of the present invention can reduce the content of active metals while ensuring the desulfurization and denitrification activities, thereby reducing the preparation cost of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is the TEM image of catalyst B obtained in Example 2. DETAILED DESCRIPTION

[0050] 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.

[0051] 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. In the present invention, wt% is the mass fraction and v% is the volume fraction.

[0052] Example 1

[0053] Nickel chloride, ammonium molybdate and water glass are added to a dissolving tank 1 filled with deionized water to prepare a solution containing Ni, Mo and Si. The weight concentration of Ni in the Ni, Mo and Si solution is 28 g / L in terms of NiO and 28 g / L in terms of MoO. 3 The weight concentration is 36g / L, SiO 2 The weight concentration is 36g / L. The nickel chloride and aluminum chloride solutions are added to the dissolution tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the solution containing Ni and Al is 24g / L in terms of NiO and 24g / L in terms of Al. 2 O 3The weight concentration is 36g / L. Among them, the mass ratio of Ni in the solution containing Ni, Mo, and Si used in the reaction of this embodiment to Ni in the solution containing Ni and Al used is 14:12. The solution containing Ni, Mo, and Si is placed in a reaction tank 1, and an ammonia solution (weight concentration of 12%) is dripped into the reaction tank 1 for the first gelation reaction. The gelation temperature is maintained at 62°C. At the end of the reaction, the pH value is controlled at 7.8, and the gelation time is controlled at 1.2 hours. After the reaction is completed, aging is carried out, the aging temperature is 78°C, the aging pH value is controlled at 7.5, and the aging is 1.8 hours to obtain the first slurry. First, 800mL of deionized water, 60mL of rapeseed oil and isotridecyl alcohol random polyether TPE-1000, the molar ratio of isotridecyl alcohol random polyether TPE-1000 to W in the sodium tungstate solution is 1.0. Add to the reaction tank 2, and then add 10wt% sodium carbonate solution, the first slurry, the solution containing Ni and Al and the sodium tungstate solution (W in WO 3 The weight concentration of the measured solution is 40g / L) and then added to the reaction tank 2 for the second gelling reaction. The gelling temperature is maintained at 60℃, and the pH value is initially controlled to be 13.0. The pH value is adjusted down 6 times to adjust the final pH value to 7.6 at the end. The pH value is adjusted down to 0.9 each time. After each adjustment to the adjusted value, the adjusted pH value of the reaction slurry is kept constant for 10 minutes. After the second gelling reaction, aging begins. The aging temperature is 78℃, the pH value is controlled at 8.0, and the aging time is 2.5 hours to obtain the second slurry. The aged slurry is filtered, the filter cake is dried at 100℃ for 7 hours, rolled, and extruded into a clover shape. After the formed strips are cured at a temperature of 70℃ for 50 hours, the temperature is reduced to 20℃, and the curing is continued for 30 hours. Wash with deionized water at room temperature until neutral. The wet strips are then dried at 100℃ for 12.0 hours, and the dried material is calcined at 500℃ for 4 hours to obtain catalyst A. The composition and main properties of the catalyst are shown in Table 1.

[0054] Example 2

[0055] Nickel chloride, ammonium molybdate and water glass are added to a dissolving tank 1 filled with deionized water to obtain a solution containing Ni, Mo and Si. The concentration of Ni in the solution is 24 g / L in terms of NiO and the concentration of Mo in the solution is 24 g / L in terms of MoO. 3 The weight concentration is 28g / L, SiO 2 The weight concentration is 32g / L. The nickel chloride and aluminum chloride solutions are added to the dissolution tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the solution containing Ni and Al is 36g / L in terms of NiO and 36g / L in terms of Al. 2 O 3The weight concentration is 40g / L. Among them, the mass ratio of Ni in the solution containing Ni, Mo, and Si used in the reaction of this embodiment to Ni in the solution containing Ni and Al used is 12:18. The solution containing Ni, Mo, and Si is placed in reaction tank 1, and an ammonia solution (weight concentration of 12%) is dripped into reaction tank 1 for the first gelation reaction. The gelation temperature is maintained at 65°C. At the end of the reaction, the pH value is controlled at 8.0, and the gelation time is controlled at 1.1 hours. After the reaction is completed, aging is carried out, the aging temperature is 80°C, the aging pH value is controlled at 8.5, and the aging is 1.4 hours to obtain the first slurry. First, 700mL of deionized water, 75mL of corn oil and propylene glycol random polyether PPE-1500 are added to reaction tank 2, and the molar ratio of propylene glycol random polyether PPE-1500 to W in mixed solution B is 0.8. Then, a sodium carbonate solution with a concentration of 11wt%, a first slurry, a solution containing Ni and Al, and a sodium tungstate solution (W is WO 3 The weight concentration of the measured solution is 40g / L) and then added to the reaction tank 2 for the second gelling reaction. The gelling temperature is maintained at 75℃, and the initial pH value is controlled to be 12.2. The pH value is adjusted down 6 times to adjust the final pH value to 8.0 at the end. The pH value is adjusted down to 0.7 each time. After each adjustment to the adjusted value, the pH value of the adjusted reaction slurry is kept constant for 9 minutes. After the second gelling reaction, aging begins. The aging temperature is 80℃, the pH value is controlled at 8.0, and the aging time is 3.4 hours to obtain the second slurry. The aged slurry is filtered, and the filter cake is dried for the first time, dried at 100℃ for 8 hours, rolled, and extruded into a clover shape. After the formed strips are cured at a temperature of 70℃ for 45 hours, the temperature is reduced to 15℃, and the curing is continued for 38 hours. Wash with deionized water at room temperature until neutral. The wet strips are then dried at 90℃ for 12 hours, and the dried material is roasted at 530℃ for 6 hours to obtain catalyst B. The composition and main properties of the catalyst are shown in Table 1.

[0056] Example 3

[0057] Nickel chloride, ammonium molybdate and water glass are added to a dissolving tank 1 filled with deionized water to prepare a solution containing Ni, Mo and Si. The weight concentration of Ni in the Ni, Mo and Si solution is 28 g / L in terms of NiO and 28 g / L in terms of MoO. 3 The weight concentration is 32g / L, SiO 2 The weight concentration is 40g / L. The nickel chloride and aluminum chloride solutions are added to the dissolution tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the solution containing Ni and Al is 20g / L in terms of NiO and 20g / L in terms of Al. 2 O 3The weight concentration is 36g / L. Among them, the mass ratio of Ni in the solution containing Ni, Mo, and Si used in the reaction of this embodiment to Ni in the solution containing Ni and Al used is 14:10. The solution containing Ni, Mo, and Si is placed in reaction tank 1, and an ammonia solution (weight concentration of 13%) is dripped into reaction tank 1 for the first gelation reaction. The gelation temperature is maintained at 55°C. At the end of the reaction, the pH value is controlled at 8.6, and the gelation time is controlled at 0.9 hours. After the reaction is completed, aging is carried out, the aging temperature is 78°C, the aging pH value is controlled at 8.0, and the aging is 1.3 hours to obtain the first slurry. First, 1000mL of deionized water, 80mL of peanut oil and butanol random polyether BPE-1000 are added to reaction tank 2. The molar ratio of butanol random polyether BPE-1000 to W in mixed solution B is 1.1. Then, a 15wt% sodium carbonate solution, a first slurry, a solution containing Ni and Al, and a sodium tungstate solution (W is WO 3 The weight concentration of the measured solution is 44g / L) and then added to the reaction tank 2 for the second gelling reaction. The gelling temperature is maintained at 70℃, and the initial pH value is controlled to be 13.0. The pH value is adjusted down 5 times to adjust the final pH value to 8.0 at the end. The pH value is adjusted down to 1.0 each time. After each adjustment to the adjusted value, the adjusted pH value of the reaction slurry is kept constant for 14 minutes. After the second gelling reaction, aging begins. The aging temperature is 77℃, 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 175℃, the aging time is 1.6 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℃ for 8 hours, rolled, and extruded into a clover shape. The formed strips are cured for 75 hours at a temperature of 80℃. Wash 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 520°C for 5 hours to obtain Catalyst C. The composition and main properties of the catalyst are shown in Table 1.

[0058] Example 4

[0059] Nickel chloride, ammonium molybdate and water glass are added to a dissolving tank 1 filled with deionized water to prepare a solution containing Ni, Mo and Si. The weight concentration of Ni in the solution is 16 g / L in terms of NiO and Mo in terms of MoO 3 The weight concentration is 36g / L, SiO 2 The weight concentration is 44g / L. The nickel chloride and aluminum chloride solutions are added to the dissolution tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the solution containing Ni and Al is 24g / L in terms of NiO and 24g / L in terms of Al. 2 O 3The weight concentration is 32g / L. Among them, the mass ratio of Ni in the solution containing Ni, Mo, and Si used in the reaction of this embodiment to Ni in the solution containing Ni and Al used is 8:12. The solution containing Ni, Mo, and Si is placed in a reaction tank 1, and an ammonia solution (weight concentration of 14%) is dripped into the reaction tank 1 for the first gelation reaction. The gelation temperature is maintained at 52°C. The pH value is controlled at 8.0 at the end of the reaction, and the gelation time is controlled at 1.3 hours. After the reaction is completed, aging is carried out, the aging temperature is 79°C, the aging pH value is controlled at 8.3, and the aging is 1.8 hours to obtain the first slurry. First, 800mL of deionized water, 70mL of sunflower oil and glycerol random polyether GPE-3000 are added to the reaction tank 2, and the molar ratio of glycerol random polyether GPE-3000 to W in the mixed solution B is 0.9. Add to the reaction tank 2, and then add the 13wt% sodium carbonate solution, the first slurry, the solution containing Ni and Al and the sodium tungstate solution (W in WO 3 The weight concentration of the measured product is 48g / L) and then added to the reaction tank 2 for the second gelling reaction. The gelling temperature is maintained at 58°C, and the initial pH value is controlled to be 11.8. The pH value is adjusted down 5 times to adjust the final pH value to 7.3 at the end. The pH value is adjusted down to 0.9 each time. After each adjustment to the adjusted value, the adjusted pH value of the reaction slurry is kept constant for 15 minutes. After the second gelling reaction, aging begins. The aging temperature is 79°C, and the aging pH value is controlled at 7.6. The aging is 2.6 hours. Then the precipitate slurry is further aged under high pressure. The pressure is 13.8MPa, the aging temperature is 180°C, the aging time is 1.2 hours, and the aging pH value is 11.5. The second slurry is obtained. The aged slurry is filtered, the filter cake is dried at 80°C for 12 hours, rolled, and extruded into a clover shape. After the formed strips are cured at a temperature of 70°C for 44 hours, the temperature is reduced to 23°C, and the curing is continued for 32 hours. The wet strips were washed 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 4 hours to obtain catalyst D. The catalyst composition and main properties are shown in Table 1.

[0060] Comparative Example 1

[0061] The reference agent E having the same catalyst composition as that of Example 1 was prepared, and the specific process was as follows:

[0062] According to the catalyst composition of Example 1, nickel chloride, aluminum chloride and water glass were dissolved in deionized water to prepare a mixed solution, wherein the weight concentration of Ni in terms of NiO was 52 g / L, and the weight concentration of Al in terms of Al 2 O 3 The weight concentration is 36g / L, SiO 2The weight concentration is 36g / L. 500mL of deionized water is added to the reaction tank, and a 10wt% NaOH solution, a sodium molybdate solution (Mo in the form of MoO 3 The weight concentration is 36g / L), sodium tungstate solution (W is WO 3 The weight concentration of the calculated product is 40g / L) and the mixed solution are added to the reaction tank in parallel for gelation. The gelation temperature is maintained at 62°C. At the end, the pH value is controlled at 7.8 and the gelation time is controlled at 1.2 hours to generate a slurry containing nickel and tungsten precipitates. Then the aging is carried out. The aging time is 2.0 hours and the aging temperature is 78°C. The pH value is controlled at 7.5 during aging. After the aging, the reaction slurry is filtered, the filter cake is dried at 100°C for 7 hours, rolled, and extruded into strips. The molded product is washed with deionized water at room temperature, and no molded product is obtained after washing. The powder is dried at 100°C for 12 hours and calcined at 500°C for 4 hours to obtain catalyst E. The composition and main properties of the catalyst are shown in Table 1.

[0063] Comparative Example 2

[0064] According to the method disclosed in CN102049295A, a reference agent F having a catalyst composition similar to that of Example 1 was prepared. The specific process is as follows:

[0065] After adding 1000mL of deionized water to the dissolving tank, nickel chloride, ammonium metatungstate, and aluminum chloride solution were added in sequence, and stirred evenly to form a mixed solution. The weight concentration of Ni in terms of NiO is 52g / L, and the weight concentration of W in terms of WO 3 The weight concentration is 40g / L, Al is expressed as Al 2 O 3 The weight concentration 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, the ammonium bicarbonate aqueous solution, and the precipitant 10% ammonia water are added to the reaction tank filled with deionized water to form a gel. The pH value of the gel is 7.8 and the gel temperature is 62°C. After the gel is completed, add the slurry containing SAPO-11 molecular sieve, age for 2 hours, the aging temperature is 78°C, and the pH value is controlled at 7.5 during aging. After aging, filter, add 600mL of deionized water and 36 grams of molybdenum trioxide to the filter cake, beat and stir evenly, filter, and the obtained filter cake is dried at 100°C for 7 hours, then extruded into strips, washed with deionized water until neutral, and the wet strips are dried at 100°C for 12 hours and calcined at 500°C for 4 hours to obtain the final catalyst F. The composition and main properties are shown in Table 1.

[0066] 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: SiO 2 / Al 2 O 3The molar ratio is 0.85, the infrared acid content is 0.9mmol / g, the pore volume is 0.24mL / g, and the specific surface area is 250m 2 / g, particle size is 450nm and crystallinity is 85%.

[0067] Comparative Example 3

[0068] Reference agent G 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.

[0069] Nickel chloride, ammonium molybdate and water glass are added to a dissolving tank 1 filled with deionized water to prepare a solution containing Ni, Mo and Si. The weight concentration of Ni in the Ni, Mo and Si solution is 28 g / L in terms of NiO and 28 g / L in terms of MoO. 3 The weight concentration is 36g / L, SiO 2 The weight concentration is 36g / L. The nickel chloride and aluminum chloride solutions are added to the dissolution tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the solution containing Ni and Al is 24g / L in terms of NiO and 24g / L in terms of Al. 2 O 3 The weight concentration is 36g / L. Among them, the mass ratio of Ni in the solution containing Ni, Mo, and Si used in the reaction of this embodiment to Ni in the solution containing Ni and Al used is 14:12. The solution containing Ni, Mo, and Si is placed in reaction tank 1, and an ammonia solution (weight concentration of 12%) is dripped into reaction tank 1 for the first gelation reaction. The gelation temperature is maintained at 62°C. At the end of the reaction, the pH value is controlled at 7.8, and the gelation time is controlled at 1.2 hours. After the reaction is completed, aging is carried out, the aging temperature is 78°C, the aging pH value is controlled at 7.5, and the aging is 1.8 hours to obtain the first slurry. First, 800mL of deionized water and isomeric tridecanol random polyether TPE-1000, the molar ratio of isomeric tridecanol random polyether TPE-1000 to W in the sodium tungstate solution is 1.0. Add to reaction tank 2, and then add a 10wt% sodium carbonate solution, the first slurry, a solution containing Ni and Al, and a sodium tungstate solution (W is WO 3The weight concentration of the measured solution is 40g / L) and then added to the reaction tank 2 for the second gelling reaction. The gelling temperature is maintained at 60℃, and the pH value is initially controlled to be 13.0. The pH value is adjusted to 7.6 at the end by 6 times. The pH value is adjusted to 0.9 each time. After each adjustment to the adjusted value, the pH value of the adjusted reaction slurry is kept constant for 10 minutes. After the second gelling reaction, aging begins. The aging temperature is 78℃, the pH value is controlled at 8.0, and the aging time is 2.5 hours to obtain the second slurry. The aged slurry is filtered, the filter cake is dried at 100℃ for 7 hours, rolled, and extruded into a clover shape. After the formed strips are cured at a temperature of 70℃ for 50 hours, the temperature is reduced to 20℃, and the curing is continued for 30 hours. Wash with deionized water at room temperature until neutral. The wet strips are then dried at 100℃ for 12.0 hours, and the dried material is calcined at 500℃ for 4 hours to obtain catalyst G. The composition and main properties of the catalyst are shown in Table 1.

[0070] Comparative Example 4

[0071] Reference agent H was prepared according to the preparation method of Example 1 (no silicon was added when preparing mixed solution A).

[0072] Add nickel chloride, ammonium molybdate and aluminum chloride solutions into a dissolving tank 1 filled with deionized water to prepare solutions containing Ni, Mo and Al. The weight concentration of Ni in the Ni, Mo and Al solutions is 28 g / L in terms of NiO and 28 g / L in terms of MoO 3 The weight concentration of Al is 36g / L. 2 O 3 The weight concentration is 36g / L. The nickel chloride and aluminum chloride solutions are added to the dissolution tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the solution containing Ni and Al is 24g / L in terms of NiO and 24g / L in terms of Al. 2 O 3The weight concentration is 36g / L. Among them, the mass ratio of Ni in the solution containing Ni, Mo, and Al used in the reaction of this embodiment to Ni in the solution containing Ni and Al used is 14:12. The solution containing Ni, Mo, and Al is placed in a reaction tank 1, and an ammonia solution (weight concentration of 12%) is dripped into the reaction tank 1 for the first gelation reaction. The gelation temperature is maintained at 62°C. At the end of the reaction, the pH value is controlled at 7.8, and the gelation time is controlled at 1.2 hours. After the reaction is completed, aging is carried out, the aging temperature is 78°C, the aging pH value is controlled at 7.5, and the aging is 1.8 hours to obtain the first slurry. First, 800mL of deionized water, 40mL of rapeseed oil and isotridecyl alcohol random polyether TPE-1000, the molar ratio of isotridecyl alcohol random polyether TPE-1000 to W in the sodium tungstate solution is 1.0. Add to the reaction tank 2, and then add 10wt% sodium carbonate solution, the first slurry, the solution containing Ni and Al and the sodium tungstate solution (W in WO 3 The weight concentration of the measured solution is 40g / L) and then added to the reaction tank 2 for the second gelling reaction. The gelling temperature is maintained at 60℃, and the pH value is initially controlled to be 13.0. The pH value is adjusted to 7.6 at the end by 6 times. The pH value is adjusted to 0.9 each time. After each adjustment to the adjusted value, the pH value of the adjusted reaction slurry is kept constant for 10 minutes. After the second gelling reaction, aging begins. The aging temperature is 78℃, the pH value is controlled at 8.0, and the aging time is 2.5 hours to obtain the second slurry. The aged slurry is filtered, the filter cake is dried at 100℃ for 7 hours, rolled, and extruded into a clover shape. After the formed strips are cured at a temperature of 70℃ for 50 hours, the temperature is reduced to 20℃, and the curing is continued for 30 hours. Wash with deionized water at room temperature until neutral. The wet strips are then dried at 100℃ for 12.0 hours, and the dried material is calcined at 500℃ for 4 hours to obtain catalyst H. The composition and main properties of the catalyst are shown in Table 1.

[0073] Comparative Example 5

[0074] According to the method of Example 1, Catalyst I was prepared according to the component content ratio of Catalyst A in Table 1, and the formed strips were not subjected to desalination treatment.

[0075] Nickel chloride, ammonium molybdate and water glass are added to a dissolving tank 1 filled with deionized water to prepare a solution containing Ni, Mo and Si. The weight concentration of Ni in the Ni, Mo and Si solution is 28 g / L in terms of NiO and 28 g / L in terms of MoO. 3 The weight concentration is 36g / L, SiO 2 The weight concentration is 36g / L. The nickel chloride and aluminum chloride solutions are added to the dissolution tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the solution containing Ni and Al is 24g / L in terms of NiO and 24g / L in terms of Al.2 O 3 The weight concentration is 36g / L. Among them, the mass ratio of Ni in the solution containing Ni, Mo, and Si used in the reaction of this embodiment to Ni in the solution containing Ni and Al used is 14:12. The solution containing Ni, Mo, and Si is placed in a reaction tank 1, and an ammonia solution (weight concentration of 12%) is dripped into the reaction tank 1 for the first gelation reaction. The gelation temperature is maintained at 62°C. At the end of the reaction, the pH value is controlled at 7.8, and the gelation time is controlled at 1.2 hours. After the reaction is completed, aging is carried out, the aging temperature is 78°C, the aging pH value is controlled at 7.5, and the aging is 1.8 hours to obtain the first slurry. First, 800mL of deionized water, 40mL of rapeseed oil and isotridecyl alcohol random polyether TPE-1000, the molar ratio of isotridecyl alcohol random polyether TPE-1000 to W in the sodium tungstate solution is 1.0. Add to the reaction tank 2, and then add 10wt% sodium carbonate solution, the first slurry, the solution containing Ni and Al and the sodium tungstate solution (W in WO 3 The weight concentration of the calculated solution is 40g / L) and then added to the reaction tank 2 for the second gelling reaction. The gelling temperature is maintained at 60°C, and the initial pH value is controlled to be 13.0. The pH value is adjusted down 6 times to adjust the final pH value to 7.6 at the end. The pH value is adjusted down by 0.9 each time. After each adjustment to the adjusted value, the adjusted pH value of the reaction slurry is kept constant for 10 minutes. After the second gelling reaction, aging begins. The aging temperature is 78°C, the pH value is controlled at 8.0, and the aging time is 2.5 hours to obtain the second slurry. The aged slurry is filtered, and the filter cake is dried at 100°C for 7 hours, rolled, and extruded into strips. Wash with deionized water at room temperature, and no molded product is obtained after washing. The powder is calcined at 500°C for 4 hours to obtain catalyst I. The composition and main properties of the catalyst are shown in Table 1.

[0076] Comparative Example 6

[0077] According to the preparation method disclosed in CN106513006A, a reference agent J having a catalyst composition similar to that of Example 1 of the present invention was prepared. The specific process is as follows:

[0078] 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 polyvinyl pyrrolidone were added, and then 10 ml of 25wt% 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 J. The catalyst composition and main properties are shown in Table 1.

[0079] Comparative Example 7

[0080] According to the preparation method disclosed in CN1951558A, reference agent K was prepared as follows:

[0081] Add deionized water to the dissolving tank, add nickel chloride, ammonium metatungstate and aluminum chloride to dissolve, and prepare acidic working solution A. The weight concentration of Ni in solution A is 74.8 g / L in terms of NiO, and the weight concentration of W in terms of WO 3 The weight concentration is 48.6 g / L, Al is expressed as Al 2 O 3 The weight concentration of the solution is 44g / L, and the pH value of solution A is 1.8. 350mL of deionized water was added to the reaction tank, and the temperature was raised to 62°C. Under stirring, solution A and 10wt% ammonia water were added to the reaction tank in parallel to form gel. The gelling temperature was 62°C, the gelling time was 1 hour, and the pH value of the slurry during the gelling process was 8.5. After the gelling was completed, it was aged for 2 hours at a temperature of 75°C, and the pH value was 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 100°C for 7 hours, roll, and extrude into a cylindrical shape. Wash with deionized water at room temperature until neutral. Then the wet strips were dried at 100°C for 12 hours and calcined at 500°C for 4 hours to obtain catalyst K. The composition and main properties of the catalyst are shown in Table 1.

[0082] Comparative Example 8

[0083] The same method as Example 1 was used except that the random polyether polyoxyethylene-polyoxypropylene copolymer was not added in the second gelling process to prepare the reference agent L, which was specifically as follows:

[0084] Nickel chloride, ammonium molybdate and dilute water glass solution are added to a dissolving tank 1 filled with deionized water to prepare a solution containing Ni, Mo and Si. The weight concentration of Ni in the Ni, Mo and Si solution is 28 g / L in terms of NiO and 28 g / L in terms of MoO 3 The weight concentration is 36g / L, SiO 2 The weight concentration is 36g / L. The nickel chloride and aluminum chloride solutions are added to the dissolution tank 2 filled with deionized water to prepare a solution containing Ni and Al. The weight concentration of Ni in the solution containing Ni and Al is 24g / L in terms of NiO and 24g / L in terms of Al. 2 O 3 The weight concentration is 36g / L. Among them, the mass ratio of Ni in the solution containing Ni, Mo, and Si used in the reaction of this embodiment to Ni in the solution containing Ni and Al used is 14:12. The solution containing Ni, Mo, and Si is placed in a reaction tank 1, and an ammonia solution (weight concentration of 12%) is dripped into the reaction tank 1 for the first gelation reaction. The gelation temperature is maintained at 62°C. At the end of the reaction, the pH value is controlled at 7.8, and the gelation time is controlled at 1.2 hours. After the reaction is completed, aging is carried out, the aging temperature is 78°C, the aging pH value is controlled at 7.5, and the aging is 1.8 hours to obtain the first slurry. First, 800mL of deionized water, 60mL of rapeseed oil and isotridecyl alcohol random polyether TPE-1000, the molar ratio of isotridecyl alcohol random polyether TPE-1000 to W in the sodium tungstate solution is 1.0. Add to the reaction tank 2, and then add 10wt% sodium carbonate solution, the first slurry, the solution containing Ni and Al and the sodium tungstate solution (W in WO 3 The weight concentration of the calculated solution is 40g / L) and then added to the reaction tank 2 for the second gelling reaction. The gelling temperature is maintained at 60℃, and the pH value is initially controlled to 13.0. The pH value is adjusted to 7.6 at the end by 6 times. The pH value is adjusted to 0.9 each time. After each adjustment to the adjusted value, the pH value of the adjusted reaction slurry is kept constant for 10 minutes. After the second gelling reaction, aging begins. The aging temperature is 78℃, the pH value is controlled at 8.0, and the aging time is 2.5 hours to obtain the second slurry. The aged slurry is filtered, the filter cake is dried at 100℃ for 7 hours, rolled, and extruded into strips. After the formed strips are cured at a temperature of 70℃ for 50 hours, the temperature is reduced to 20℃, and the curing is continued for 30 hours. Wash with deionized water at room temperature until neutral. The wet strips are then dried at 100℃ for 12.0 hours, and the dried material is calcined at 500℃ for 4 hours to obtain catalyst L. The catalyst composition and main properties are shown in Table 1.

[0085] Example 5

[0086] 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 of the present invention and the comparative catalysts F, G, H, J, K, L (the comparative catalysts E and I 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 catalyst activity evaluation 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.

[0087] 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.

[0088] 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. When the activity evaluation reaction space velocity is increased, the catalyst of the present invention still has excellent ultra-deep desulfurization activity by increasing the reaction temperature. Compared with the evaluation results of the comparative example catalyst, the catalyst of the present invention effectively reduces the influence of thermodynamic equilibrium on the high-temperature hydrogenation pathway and has good temperature adaptability. 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.

[0089] Table 1 Composition and properties of catalysts prepared in Examples and Comparative Examples

[0090] Catalyst No. A B C D NiO, wt% 26 30 24 20 <![CDATA[WO 3 ,wt%]]> 20 20 22 24 <![CDATA[MoO 3 ,wt%]]> 18 14 16 18 <![CDATA[SiO 2 ,wt%]]> 18 16 20 22 <![CDATA[Al 2 O 3 ,wt%]]> 18 20 18 16 <![CDATA[Na 2 O,%]]> 0.066 0.069 0.070 0.061 <![CDATA[Specific surface area, m 2 / g]]> 279 288 281 275 Pore ​​volume, mL / g 0.387 0.399 0.390 0.384 Pore ​​distribution <4nm 6.34 5.56 5.98 6.82 4nm~10nm 26.76 25.81 26.13 27.01 10nm~15nm 39.22 40.62 39.92 39.03 >15nm 27.68 28.01 27.97 27.14 Mechanical strength, N / mm 19.8 19.7 19.3 19.9

[0091] Table 1 (Continued) Composition and properties of catalysts prepared in Examples and Comparative Examples

[0092] Catalyst No. E F G H I J K L NiO, wt% 26 26 26 26 26 26 37.4 26 <![CDATA[WO 3 ,wt%]]> 20 20 20 20 20 20 24.3 20 <![CDATA[MoO 3 ,wt%]]> 18 18 18 18 18 18 16.3 18 <![CDATA[SiO 2 ,wt%]]> 18 4 18 - 18 - - 18 <![CDATA[Al 2 O 3 ,wt%]]> 18 28 18 36 18 36 22 18 <![CDATA[P 2 O 5 ,wt%]]> - 4 - - - - - <![CDATA[Na 2 O,%]]> 0.42 0.14 0.090 0.070 0.48 0.13 0.13 0.094 <![CDATA[Specific surface area, m 2 / g]]> 142 199 250 274 214 283 174 276 Pore ​​volume, mL / g 0.232 0.252 0.353 0.381 0.298 0.385 0.301 0.383 Pore ​​distribution <4nm 62.81 22.82 25.45 6.05 14.40 38.21 46.87 6.83 4nm~10nm 30.52 71.44 58.12 26.91 43.27 48.61 40.72 26.38 10nm~15nm 4.37 4.50 12.01 39.62 29.12 7.28 8.26 39.54 >15nm 2.30 1.24 4.42 27.42 13.21 5.90 4.15 27.25 Mechanical strength, N / mm - 17.6 18.1 18.8 - 13.5 19.1 19.8

[0093] 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)

[0094] Catalyst No. A B C D G H I L Composite oxide composition in the core NiO, wt% 14 12 14 8 17 14 14 14 <![CDATA[MoO 3 ,wt%]]> 18 14 16 18 11 18 18 18 <![CDATA[SiO 2 ,wt%]]> 18 16 20 22 10 - 18 18 <![CDATA[WO 3 ,wt%]]> - - - - 6 - - - <![CDATA[Al 2 O 3 ,wt%]]> - - - - 6 18 - - Composite oxide composition in shell NiO, wt% 12 18 10 12 9 12 12 12 <![CDATA[WO 3 ,wt%]]> 20 20 22 24 14 20 20 20 <![CDATA[Al 2 O 3 ,wt%]]> 18 20 18 16 12 18 18 18 <![CDATA[MoO 3 ,wt%]]> - - - - 7 - - - <![CDATA[SiO 2 ,wt%]]> - - - - 8 - - -

[0095] Table 3 Average particle size and particle size distribution of the catalyst core-shell composite oxide particles obtained in each example

[0096] Catalyst No. A B C D E F Average particle size of core-shell composite oxide particles, nm 10.4 10.2 10.7 10.9 33.6 23.8 Particle size distribution of core-shell composite oxide particles, % Particle size less than 7nm 7.11 7.25 6.93 6.58 3.32 4.05 Particle size is 7nm-13nm 77.98 78.31 77.46 77.12 21.22 28.19 Particle size greater than 13nm 14.91 14.44 15.61 16.30 75.46 67.76

[0097] Table 3 (Continued) Average particle size and particle size distribution of the catalyst core-shell composite oxide particles obtained in each example

[0098] Catalyst No. G H I J K L Average particle size of core-shell composite oxide particles, nm 30.8 10.7 11.1 24.4 19.4 11.4 Particle size distribution of core-shell composite oxide particles, % Particle size less than 7nm 2.63 7.01 6.43 8.93 8.42 6.03 Particle size is 7nm-13nm 24.31 77.28 76.93 28.46 33.62 76.38 Particle size greater than 13nm 73.06 15.71 16.64 62.61 57.96 17.59

[0099] Table 4 Main properties of crude oil

[0100] 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

[0101] Table 5 Catalyst evaluation process conditions and activity evaluation results

[0102] Catalyst No. A B C F G H J K L <![CDATA[Generated oil density (20 °C), g / cm 3 > 0.8634 0.8630 0.8632 0.8656 0.8718 0.8652 0.8772 0.8707 0.8643 S, µg / g 7.8 7.0 7.5 38.2 140.6 30.9 236.8 118.8 12.4 N, µg / g 3.6 3.3 3.5 16.4 71.4 11.4 112.8 62. 2 5.0 Diesel yield, % 99.1 99.2 99.0 86.6 98.7 99.0 98.3 98.9 99.0

[0103] Table 6 Content of different sulfides in hydrorefined oil

[0104] Catalyst No. A B C F G H J K L Sulfur content in hydrorefined oil, µg / g 7.8 7.0 7.5 38.2 140.6 30.9 236.8 118.8 12.4 <![CDATA[C 1 -DBT,µg / g]]> 0 0 0 3.2 10.2 2.0 22.1 9.1 0 4- MDBT, µg / g 1.8 1.6 1.8 8.1 30.1 6.2 52.2 25.4 2.7 6-MDBT, µg / g 2.6 2.3 2.4 9.6 31.2 8.7 60.2 26.3 3.6 4,6-DMDBT, µg / g 3.4 3.1 3.3 17.3 69.1 14.0 102.3 58.0 6.1

Claims

1. A method for preparing a hydrotreating catalyst, Features The method comprises the following contents: (1) subjecting a first precipitant and a solution containing Ni, Mo and Si to a first gelling reaction, and subjecting the first precipitant to a first aging process to obtain a first slurry containing Ni, Si and Mo; (2) adding water, a random polyether polyoxyethylene-polyoxypropylene copolymer and an unsaturated higher fatty acid glyceride into a reactor, and then subjecting a solution containing Ni and Al, a sodium tungstate solution, a second precipitant and the first slurry obtained in step (1) to a second gelling reaction in parallel in the reactor, and subjecting the second precipitant to a second aging process to generate a second slurry; (3) subjecting the second slurry to a aging process, and subjecting the solid-liquid separation process after the aging process to a drying and molding process to obtain a molded product; (4) subjecting the molded product to a desalting process, washing, drying and roasting to obtain a hydrogenation refining catalyst; the first precipitant described in step (1) is ammonia water; the second precipitant described in step (2) is one or more of sodium carbonate, sodium bicarbonate and sodium hydroxide.

2. The method according to claim 1, Features: In the solution containing Ni, Mo and Si in step (1), the weight concentration of Ni as NiO is 5-120 g / L, and the weight concentration of Mo as MoO 3 The weight concentration is 5~120g / L, Si is SiO 2 The weight concentration is 2~80g / L.

3. The method according to claim 1, Features: The weight concentration of the first precipitant in step (1) is 5% to 15%.

4. The method according to claim 1, Features: 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.

5. The method according to claim 1, Features: 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.

6. The method according to claim 1, Features: 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); in step (2), the weight of the introduced Ni accounts for 20% to 70% of the total Ni weight in the hydrotreating catalyst obtained in step (4).

7. The method according to claim 1, Features: In the Ni and Al solution described in step (2), the weight concentration of Ni in terms of NiO is 5-110 g / L, and the weight concentration of Al in terms of Al is 2 O 3 The weight concentration is 2~95g / L.

8. The method according to claim 1, Features: In the sodium tungstate solution of step (2), W is WO 3 The calculated weight concentration is 4~140g / L.

9. The method according to claim 1, Features: The random polyether polyoxyethylene-polyoxypropylene copolymer described in step (2) is selected from at least one of isomeric tridecanol random polyether TPE-1000, propylene glycol random polyether PPE-1500, propylene glycol random polyether GPE-3000, butanol random polyether BPE-1000, butanol random polyether BPE-1500, butanol random polyether BPE-2500, lauric acid random polyether LPE-1200, and dodecanol random polyether CPE-1500.

10. The method according to claim 1, Features: The molar ratio of the random polyether polyoxyethylene-polyoxypropylene copolymer to W in the sodium tungstate solution is 0.2-2.

0.

11. The method according to claim 1, Features: In step (2), the weight concentration of the second precipitant is 5% to 40%.

12. The method according to claim 1, Features: The water added in step (2) is deionized water, and the volume ratio of the added water to the volume of the first slurry obtained in step (1) is 0.1:1 to 3:

1.

13. The method according to claim 1, Features: 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 1:60~1:

4.

14. The method according to claim 1, Features: 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.

15. The method according to claim 14, Features: The pH value is adjusted downward from the initial value to the final pH value in stages. The pH value is adjusted downward to the desired value at that time, and the pH value of the reaction slurry is kept constant until the next downward adjustment. The number of downward adjustments is 2 to 10 times.

16. The method according to claim 1, Features: 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.

17. The method according to claim 1, Features: 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 not less than 10 MPa, and the pH value is 10.0-13.

0.

18. The method according to claim 1, Features: 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, a temperature of 10 to 90°C, and a time of 10 to 100 hours.

19. The method according to claim 1, Features: The desalination treatment in step (4) is carried out as follows: in the first stage, the temperature is 60 to 90° C., and the curing time is 5 to 60 hours, so that the hydrated sodium ions are precipitated and the vacancies are retained; in the second stage, the temperature is 10 to 30° C., and the time is 1 to 48 hours, so as to promote the retention and shrinkage of the vacancies, and then the precipitated salt is removed by washing.

20. A hydrotreating catalyst prepared by the method according to any one of claims 1 to 19, Features: The hydrorefining catalyst is a core-shell structured composite amorphous oxide particle, 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 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; Na 2 The O content is less than 0.07%.

21. The hydrotreating catalyst according to claim 20, Features: Based on the mass of the core-shell structured composite amorphous oxide particles, the core phase is 20% to 90%, and the shell phase is 10% to 80%; the molar ratio of molybdenum to nickel atoms in the core phase is 1:28 to 12:1, and the content of silicon is SiO 2 The molar ratio of tungsten to nickel atoms in the shell phase is 1:22~8:1, and the content of aluminum is expressed as Al 2 O 3 It accounts for 5% to 36% of the mass of the hydrotreating catalyst.

22. The hydrotreating catalyst according to claim 20, Features: The mass of NiO in the core phase accounts for 30% to 80% of the total mass of NiO in the hydrotreating catalyst, and the mass of NiO in the shell phase accounts for 20% to 70% of the total mass of NiO in the hydrotreating catalyst.

23. The hydrotreating catalyst according to claim 20, Features: The properties of the hydrotreating catalyst are as follows: Specific surface area is 180~700m 2 / g, the pore volume is 0.30~0.90mL / g; the pore size distribution is as follows: the pore volume occupied by pores with a diameter of less than 4nm accounts for 1%~10% of the total pore volume, the pore volume occupied by pores with a diameter of 4~10nm accounts for 12%~40% of the total pore volume, the pore volume occupied by pores with a diameter of 10~15nm accounts for 22%~56% of the total pore volume, and the pore volume occupied by pores with a diameter of more than 15nm accounts for 18%~45% of the total pore volume.

24. Use of a hydrotreating catalyst prepared by the method according to any one of claims 1 to 19 in a diesel hydrotreating reaction.

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