阅读说明：本技术 一种体相加氢催化剂及其制备方法 (Bulk phase hydrogenation catalyst and preparation method thereof ) 是由 姚运海 刘丽 杨成敏 段为宇 李扬 郭蓉 周勇 孙进 郑步梅 丁莉 于 2019-10-25 设计创作，主要内容包括：本发明公开了一种体相加氢催化剂及其制备方法,催化剂包括第VIB族金属硫化物、第VIII族金属氧化物、Al-2O-3和助剂；第VIB族金属硫化物分布在催化剂体相和表相,表相第VIB族金属硫化物的重量含量与体相第VIB族金属硫化物的重量含量的比为3:1～7.5:1。制备方法如下：(1)配制含第VIB族金属和铝源的混合溶液A,和沉淀剂并流成胶,生成浆液Ⅰ；(2)将浆液Ⅰ和助剂前驱物混合均匀,经成型得到前体I；(3)将前体I干燥和焙烧后,硫化处理,得到前体Ⅱ；(4)用含第VIII族金属的浸渍液浸渍前体Ⅱ,在惰性气氛下干燥和焙烧,得到体相加氢催化剂。本发明催化剂具有较高的硫化度及高的II类活性中心数,特别适用于柴油加氢精制过程。(The invention discloses a bulk phase hydrogenation catalyst and a preparation method thereof, wherein the catalyst comprises VIB group metal sulfide, VIII group metal oxide and Al 2 O 3 And an auxiliary agent; the VIB group metal sulfide is distributed in a catalyst bulk phase and a surface phase, and the ratio of the weight content of the VIB group metal sulfide in the surface phase to the weight content of the VIB group metal sulfide in the bulk phase is 3: 1-7.5: 1. The preparation method comprises the following steps: (1) preparing a mixed solution A containing a VIB group metal and an aluminum source, and co-flowing the mixed solution A and a precipitatorGluing to generate a slurry I; (2) uniformly mixing the slurry I and the auxiliary agent precursor, and forming to obtain a precursor I; (3) drying and roasting the precursor I, and then carrying out vulcanization treatment to obtain a precursor II; (4) and (3) impregnating the precursor II with an impregnating solution containing VIII group metal, drying and roasting in an inert atmosphere to obtain the bulk phase hydrogenation catalyst. The catalyst of the present invention has high sulfurization degree and high II-type active center number, and is especially suitable for diesel oil hydrorefining process.)

1. The bulk phase hydrogenation catalyst is characterized by comprising a VIB group metal sulfide, a VIII group metal oxide and Al₂O₃And an auxiliary agent, wherein the auxiliary agent is one or more of B, P, F, Mg, Zr or Si; based on the weight of the bulk phase hydrofining catalyst, the content of VIB group metal sulfide is 40-70%, the content of VIII group metal oxide is 3-25%, the content of auxiliary agent is 3-15% calculated by oxide, and Al is₂O₃24% -54%; the VIB group metal sulfide is distributed in a catalyst bulk phase and a surface phase, and the weight ratio of the VIB group metal sulfide in the surface phase to the VIB group metal sulfide in the bulk phase is 3: 1-7.5: 1.

2. The catalyst of claim 1, wherein: the VIB group metal is Mo and/or W, and the VIII group metal is Co and/or Ni.

3. The catalyst of claim 1, wherein: the catalyst is subjected to vulcanization and then is analyzed by XPS energy spectrum, wherein the molar ratio of the +4 valence VIB metal content to the total VIB metal content is 65-100%, and the molar ratio of the VIII metal-VIB metal-S species content to the VIII metal is 60-100%.

4. A method for preparing a bulk hydrogenation catalyst according to any one of claims 1 to 3, characterized by comprising: (1) preparing a mixed solution A containing a VIB group metal and an aluminum source, and carrying out parallel flow gelling reaction on the mixed solution A and a precipitator to generate slurry I containing the VIB group metal and aluminum precipitates; (2) pulping and uniformly mixing the slurry I obtained in the step (1) and an auxiliary agent precursor, filtering, washing, drying and forming to obtain a catalyst precursor I; (3) drying and roasting the catalyst precursor I obtained in the step (2), and then carrying out vulcanization treatment to obtain a catalyst precursor II containing a VIB group metal sulfide; (4) and (3) impregnating the catalyst precursor II obtained in the step (3) with an impregnating solution containing VIII group metals, and then drying and roasting the impregnated catalyst precursor II in an inert atmosphere to obtain the bulk phase hydrogenation catalyst.

5. The method of claim 4, wherein: in the mixed solution A in the step (1), the weight concentration of the VIB group metal calculated by oxide is 10-100 g/L, and the aluminum source is Al₂O₃The weight concentration is 2-60 g/L.

6. The method of claim 4, wherein: the precipitator in the step (1) is one or more of sodium carbonate, sodium bicarbonate, ammonia water, sodium hydroxide, potassium carbonate or potassium bicarbonate; the concentration of the precipitant is 0.5-3.0 mol/L.

7. The method of claim 4, wherein: in the step (1), the temperature of the parallel-flow gelatinizing reaction is 30-90 ℃, the pH value during parallel-flow gelatinizing is controlled to be 6.0-11.0, and the gelatinizing time is 0.2-4.0 hours.

8. The method of claim 4, wherein: in the step (2), the auxiliary agent precursor is one or more of boric acid, phosphoric acid, ammonium hydrofluoric acid, magnesium nitrate, water glass or zirconium nitrate, and the concentration of the auxiliary agent aqueous solution is 1.0-3.0 mol/L; and after the auxiliary agent and the slurry I are uniformly mixed, controlling the pH value to be 7.0-9.0.

9. The method of claim 4, wherein: the drying conditions in the step (3) are as follows: drying at 90-200 ℃ for 3-6 hours; the roasting conditions are as follows: the roasting temperature is 400-800 ℃, and the roasting time is 3-6 hours.

10. The method of claim 4, wherein: the vulcanization treatment in the step (3) is carried out under the following conditions: the vulcanization pressure is 3.2-6.4 MPa, the vulcanization temperature is 250-400 ℃, and the vulcanization time is 4-12 hours.

11. The method of claim 4, wherein: the second step of (4)The mass concentration of the group metal impregnation liquid is 0.1-1.0 g/mL, and an equal-volume impregnation mode is adopted; the first mentionedThe group metals are preferably Ni and/or Co.

12. The method of claim 4, wherein: the inert atmosphere in the step (4) is N₂And an inert gas; the drying temperature is 20-90 ℃, and the drying time is 4-16 hours; the roasting temperature is 200-500 ℃, and the roasting time is 2-5 hours.

13. Use of a bulk hydrogenation catalyst according to any one of claims 1 to 4 in a distillate hydrotreating process.

Technical Field

The invention relates to the technical field of oil product hydrogenation, in particular to a bulk phase hydrogenation catalyst and a preparation method thereof.

Background

In recent years, the bulk phase hydrofining catalyst has attracted more and more attention because of its high hydrodesulfurization and hydrodenitrogenation activity, and is mainly prepared by a precipitation method.

CN 106179379B discloses a preparation method of a hydrotreating catalyst, which is prepared by respectively coprecipitating Ni and Al and coprecipitating W and Al, and then mixing them and carrying out hydrothermal treatment. The active metal tungsten and nickel in the surface phase of the catalyst have high active site density, can be well matched with active metal molybdenum, and has high hydrogenation active metal utilization rate.

CN 106179480B discloses a hydrofining catalyst composition and a preparation method thereof. The catalyst composition is a bulk-phase hydrofining catalyst, and comprises a hydrogenation active metal component W, Ni, Mo, an SAPO-11 molecular sieve and alumina, wherein the surface-phase active metal content of the catalyst composition is high, and the active site density is high.

CN 106179382B discloses a bulk phase hydrogenationA preparation method of the physical catalyst. The catalyst comprises a hydrogenation active metal component W, Ni, Mo and alumina, and is prepared by preparing nickel and aluminum precipitate slurry I by an acid precipitation method; preparing slurry II of tungsten and aluminum precipitates by a cocurrent flow precipitation method, mixing the slurry II of tungsten and aluminum precipitates, aging, carrying out hydrothermal treatment by using water vapor, adding urea, and then mixing with MoO₃Pulping, mixing, soaking in solution containing organic compound, and molding to obtain the final product. However, in the above bulk phase catalyst preparation process, nickel aluminate spinel which is difficult to be sulfided is easily generated, resulting in a reduction in the sulfidation degree of the active metal of the catalyst and a reduction in the number of active sites of the catalyst, and at the same time, W and Mo in the active metal are more difficult to be sulfided than Ni, resulting in the sulfidation of Ni in the active metal first and the sulfidation of W and Mo later, resulting in a reduction in the number of W-Ni-S phases and Mo-Ni-S phases which are highly active, resulting in a reduction in the activity of the catalyst.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a bulk phase hydrogenation catalyst and a preparation method thereof. The catalyst of the present invention has high sulfurization degree and high II type activity center number, and may be used in fraction oil hydrogenating treatment, especially diesel oil hydrogenating and refining process.

The bulk phase hydrogenation catalyst comprises VIB group metal sulfide, VIII group metal oxide and Al₂O₃And an auxiliary agent, wherein the VIB group metal is preferably Mo and/or W, the VIII group metal is preferably Co and/or Ni, and the auxiliary agent is one or more of B, P, F, Mg, Zr or Si; based on the weight of the bulk phase hydrofining catalyst, the content of VIB group metal sulfide is 40-70%, preferably 50-65%, the content of VIII group metal oxide is 3-25%, preferably 3-15%, the content of the auxiliary agent is 3-15%, preferably 3-10%, calculated by oxide, and Al₂O₃From 24% to 54%, preferably from 25% to 42%; the group VIB metal sulfide is distributed in a bulk phase and a surface phase of the catalyst, the weight ratio of the group VIB metal sulfide in the surface phase to the group VIB metal sulfide in the bulk phase is 3: 1-7.5: 1, and the group VIII metal oxide is distributed in the surface phase of the catalyst; the bulk group VIB metal sulfide is characterized by SEM and TEM electron microscopy, and the surface-phase group VIB metal sulfideThe material and group VIII metal oxide were analyzed by XPS spectroscopy.

The catalyst is subjected to vulcanization and then is analyzed by XPS energy spectrum, wherein the molar ratio of the +4 valence VIB metal content to the total VIB metal content is 65-100%, and the molar ratio of the VIII metal-VIB metal-S (such as Co-Mo-S, Ni-Mo-S, Co-W-S and Ni-W-S) species content to the VIII metal is 60-100%. The "group VIII metal-group VIB metal-S" species is the species in which the group VIII metal and the group VIB metal interact.

The preparation method of the bulk phase hydrogenation catalyst comprises the following steps:

(1) preparing a mixed solution A containing a VIB group metal and an aluminum source, and carrying out parallel flow gelling reaction on the mixed solution A and a precipitator to generate slurry I containing the VIB group metal and aluminum precipitates;

(2) pulping and uniformly mixing the slurry I obtained in the step (1) and an auxiliary agent precursor, filtering, washing, drying and forming to obtain a catalyst precursor I;

(3) drying and roasting the catalyst precursor I obtained in the step (2), and then carrying out vulcanization treatment to obtain a catalyst precursor II containing a VIB group metal sulfide;

(4) and (3) impregnating the catalyst precursor II obtained in the step (3) with an impregnating solution containing VIII group metals, and then drying and roasting the impregnated catalyst precursor II in an inert atmosphere to obtain the bulk phase hydrogenation catalyst.

In the method, in the mixed solution A in the step (1), the weight concentration of the VIB group metal calculated by oxide is 10-100 g/L, preferably 20-90 g/L, and Al is Al₂O₃The weight concentration is 2-60 g/L, preferably 8-40 g/L. When preparing the mixed solution A, one or more of phosphate or ammonium salt of VIB group metal is generally adopted; the aluminum source can be one or more of aluminum nitrate, aluminum sulfate, aluminum chloride, aluminum acetate and the like.

In the method, the precipitant in the step (1) is one or more of sodium carbonate, sodium bicarbonate, ammonia water, sodium hydroxide, potassium carbonate and potassium bicarbonate, and the concentration of the precipitant is 0.5-3.0 mol/L.

In the method, the temperature of the parallel-flow gelling reaction in the step (1) is 30-90 ℃, and preferably 40-80 ℃. And controlling the pH value to be 6.0-11.0, preferably 7.0-9.0, and controlling the gelling time to be 0.2-4.0 hours, preferably 0.5-3.0 hours when the gel is formed in a parallel flow mode.

In the method, the precursor of the auxiliary agent in the step (2) is one or more of boric acid, phosphoric acid, ammonium hydrofluoric acid, magnesium nitrate, water glass or zirconium nitrate, and the concentration of the aqueous solution of the auxiliary agent is 1.0-3.0 mol/L; and after the auxiliary agent and the slurry I are uniformly mixed, controlling the pH value to be 7.0-9.0.

In the method of the present invention, the washing, drying and shaping in step (2) may be carried out by a method conventional in the art. The washing is generally carried out by washing with deionized water or a solution containing decomposable salts (such as ammonium acetate, ammonium chloride, ammonium nitrate, etc.) until the solution is neutral. The drying conditions were as follows: drying the mixture for 3 to 6 hours at a temperature of between 90 and 200 ℃. In the forming process, conventional forming aids, such as one or more of peptizers, extrusion aids, and the like, can be added as required. The peptizing agent is one or more of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, oxalic acid and the like, the extrusion aid is a substance which is beneficial to extrusion forming, such as one or more of sesbania powder, carbon black, graphite powder, citric acid and the like, and the amount of the extrusion aid accounts for 1-10 wt% of the total dry basis of the materials.

In the method of the present invention, the drying conditions in step (3) are: the drying temperature is 90-200 ℃, the drying time is 3-6 hours, and the roasting conditions are as follows: the roasting temperature is 400-800 ℃, and the roasting time is 3-6 hours.

In the method of the present invention, the vulcanization treatment in step (3) is well known to those skilled in the art, and usually adopts dry vulcanization or wet vulcanization, wherein the dry vulcanization agent is hydrogen sulfide, and the wet vulcanization agent is one or two of carbon disulfide, dimethyl disulfide, methyl sulfide, and n-butyl sulfide; the vulcanization pressure is 3.2-6.4 MPa, the vulcanization temperature is 250-400 ℃, and the vulcanization time is 4-12 h.

In the method of the present invention, the second step of step (4)The preparation method of the dipping solution of the group metal is well known to those skilled in the art, for example, nitrate, acetate, sulfate solution and the like are generally adopted, the mass concentration of the dipping solution is 0.1 g/mL-1.0 g/mL, an equal-volume dipping mode can be adopted, and the second step isThe group metals are preferably Ni and/or Co.

In the method of the invention, the inert atmosphere in the step (4) is N₂And an inert gas; the drying temperature is 20-90 ℃, and the drying time is 4-16 hours; the roasting temperature is 200-500 ℃, and the roasting time is 2-5 hours.

The application of the bulk phase hydrogenation catalyst in the distillate oil hydrotreating process is disclosed, wherein the distillate oil is preferably gasoline, kerosene, diesel oil or wax oil.

The hydrogenation catalyst of the invention needs to be vulcanized before application, and the general vulcanization conditions are as follows: adopting dry vulcanization or wet vulcanization, wherein the dry vulcanization agent is hydrogen sulfide, and the wet vulcanization agent is one or more of carbon disulfide, dimethyl disulfide, methyl sulfide and n-butyl sulfide; the vulcanization pressure is 3.2-6.4 MPa, the vulcanization temperature is 250-400 ℃, and the vulcanization time is 4-12 hours.

Because the catalyst exists in an oxidation state before vulcanization, the VIB group metal is difficult to vulcanize the VIII group metal and is easy to vulcanize, the phenomenon that the VIII group metal in a vulcanization state is wrapped by the VIB group metal in a vulcanization state is easy to cause, the VIII group metal cannot fully play the auxiliary role of the VIII group metal, a II-type active center is not easy to generate, the activity of the catalyst is reduced, meanwhile, the VIII group metal and aluminum salt are jointly precipitated, a spinel phase which is difficult to vulcanize is easy to generate, the vulcanization degree of the active metal is reduced, and the activity of the catalyst is reduced. The inventor firstly precipitates the VIB group metal and aluminum salt together by means of fractional precipitation, vulcanization and impregnation of different active metals, then carries out presulfurization, and then impregnates the sulfideGroup metals of the group IIIThe group metal covers the surface of the VIB group metal in a vulcanized state and gives full play toThe group metal auxiliary agent acts to create the condition of interaction between the two, promote the generation of II active centers, further improve the activity of the catalyst and weaken the secondThe interaction between the group metal and the alumina inhibits the generation of spinel, improves the degree of metal sulfidation, and further improves the activity of the catalyst.

Detailed Description

The following examples further illustrate the present invention and the effects thereof, but are not intended to limit the present invention. The composition of the catalyst provided by the invention can be characterized by combining inductively coupled plasma ICP and XPS energy spectrums, and the total content of VIB group metals and the total content of the VIB group metals in the catalyst are firstly characterized by ICPAnd (3) quantitatively characterizing the content of metal elements with different valence states in the catalyst by an XPS spectrometer. The bulk phase metal species are characterized by adopting an SEM energy spectrum and a TEM electron microscope, a Quanta 200FEG type scanning electron microscope (FEI company) is adopted, the cross section of the catalyst is directly stuck on a sample table by using conductive adhesive, an ultrahigh vacuum mode is adopted for observation, the accelerating voltage is 20.0kV, and meanwhile, the metal composition in the bulk phase of the catalyst is investigated by combining an EDX technology. The TEM is characterized by adopting a JEM-2100 high-resolution transmission electron microscope produced by JEOL company of Japan, the type of the electron gun is LaB6, the accelerating voltage is 200 kV, the dot resolution is 0.23 nm, and the line resolution is 0.14 nm. The metal species of the watch phase were characterized by XPS spectroscopy. The catalyst provided by the invention has metal vulcanization degree of Mo⁴⁺Or W⁴⁺Content represents catalysisThe degree of metal sulfidation of the agent. Using 20mL/min H at 340 DEG C₂S sulfurizing for 2h, characterizing the metal valence state of the surface of the sample by an XPS PEAK spectrometer, respectively fitting and peak-splitting the energy spectrums of Mo3d, W4f, Co2p and Ni2p by adopting XPSPEAK version4.0, and calculating according to the peak area to obtain the metal sulfurization degree and the proportion of Co-Mo-S, Ni-Mo-S, Co-W-S, Ni-W-S.

Example 1

Dissolving ammonium metatungstate and aluminum chloride in deionized water to prepare a mixed solution A, wherein WO is contained in the mixed solution A₃Has a weight concentration of 80g/L and Al₂O₃The weight concentration of (B) is 50 g/L. Slowly adding sodium hydroxide with the concentration of 1.0mol/L into 1L of the solution A under stirring, keeping the gelling temperature at 70 ℃, controlling the pH value at 7-8 after finishing gelling, and controlling the gelling time at 60 minutes to generate a tungsten and aluminum-containing precipitate slurry I.

And (3) uniformly mixing 160mL of 1.0mol/L magnesium nitrate solution with the slurry I, then adjusting the pH value to 7-8 by using ammonia water, then washing the mixture for three times by using deionized water, filtering the mixture, and drying the filtered mixture for 5 hours at 120 ℃ to obtain mixed powder. Then 150g of mixed powder is uniformly mixed with 5g of nitric acid, 5g of starch and 60g of deionized water, then the mixture is kneaded, extruded into strips and molded, dried for 3 hours at 120 ℃, roasted for 3 hours at 500 ℃, and then the mixture is roasted for 3 hours by adopting the mixed powder containing 1.5 percent of H₂Sulfurizing S hydrogen at 340 deg.C under 5.0MPa for 8 hr, and adding N₂And cooling to room temperature in the atmosphere to obtain a catalyst precursor II.

42.2g of Ni (NO)₃)₂•6H₂Dissolving O into 50mL of deionized water, soaking the solution into a precursor II in equal volume, and then adding the solution into N₂Drying at 90 ℃ for 4h under the atmosphere, and roasting at 300 ℃ for 3h to obtain the catalyst C-1.

Example 2

Dissolving ammonium molybdate and aluminum sulfate in deionized water to prepare a mixed solution A, wherein MoO is contained in the mixed solution A₃Has a weight concentration of 80g/L and Al₂O₃The weight concentration of (B) is 50 g/L. Slowly adding sodium hydroxide with the concentration of 1.0mol/L into 1L of the solution A under stirring, keeping the gelling temperature at 80 ℃, controlling the pH value at 7-8 when the gelling is finished, controlling the gelling time at 90 minutes, and generating the productMolybdenum and aluminum precipitate slurry I.

And (3) uniformly mixing 100mL of 1.0mol/L zirconium nitrate solution with the slurry I, then adjusting the pH value to 7-8 by using ammonia water, then washing the mixture for three times by using deionized water, filtering the mixture, and drying the filtered mixture for 6 hours at 110 ℃ to obtain mixed powder. Then 150g of mixed powder is uniformly mixed with 10g of phosphoric acid, 5g of starch and 60g of deionized water, then the mixture is kneaded, extruded into strips and formed, dried for 3 hours at 120 ℃, roasted for 2 hours at 600 ℃, and then the mixture is roasted for 2 hours by adopting the mixture containing 1.5 percent of H₂Sulfurizing S hydrogen at 340 deg.C under 5.0MPa for 8 hr, and adding N₂And cooling to room temperature in the atmosphere to obtain a catalyst precursor II.

42.2g of Ni (NO)₃)₂•6H₂Dissolving O into 50mL of deionized water, soaking the solution into a precursor II in equal volume, and then adding the solution into N₂Drying at 90 ℃ for 4h under the atmosphere, and roasting at 350 ℃ for 3h to obtain the catalyst C-2.

Example 3

Dissolving ammonium molybdate and aluminum sulfate in deionized water to prepare a mixed solution A, wherein MoO is contained in the mixed solution A₃Has a weight concentration of 80g/L and Al₂O₃The weight concentration of (B) is 50 g/L. Slowly adding sodium hydroxide with the concentration of 1.0mol/L into 1L of the solution A under stirring, keeping the gelling temperature at 80 ℃, controlling the pH value at 7-8 after finishing gelling, and controlling the gelling time at 90 minutes to generate molybdenum-aluminum-containing precipitate slurry I.

And (3) uniformly mixing 160mL of 1.0mol/L zirconium nitrate solution with the slurry I, then adjusting the pH value to 7-8 with ammonia water, then washing with deionized water for three times, filtering, and drying at 110 ℃ for 6 hours to obtain mixed powder. Then 150g of the mixed powder is uniformly mixed with 10g of phosphoric acid, 5g of starch and 60g of deionized water, and then the mixture is kneaded, extruded into strips and formed, dried for 3h at 120 ℃ and roasted for 2h at 600 ℃. Then using 3wt% CS₂Carrying out vulcanization treatment on the aviation kerosene at the airspeed of 1.0h^-1Hydrogen-oil volume ratio of 500:1, under 5.0MPa operating pressure, sulfurizing for 8h, then adding N₂And cooling to room temperature in the atmosphere to obtain a catalyst precursor II.

32.2g of Co (NO)₃)₂•6H₂O is dissolved to 50mSoaking the precursor II in deionized water of L in the same volume, and then soaking the precursor II in N₂Drying at 90 ℃ for 4h under the atmosphere, and roasting at 350 ℃ for 3h to obtain the catalyst C-3.

Example 4

Dissolving ammonium metatungstate and aluminum chloride in deionized water to prepare a mixed solution A, wherein WO is contained in the mixed solution A₃Has a weight concentration of 80g/L and Al₂O₃The weight concentration of (B) is 50 g/L. Slowly adding sodium hydroxide with the concentration of 1.0mol/L into 1L of the solution A under stirring, keeping the gelling temperature at 70 ℃, controlling the pH value at 7-8 after finishing gelling, and controlling the gelling time at 60 minutes to generate a tungsten and aluminum-containing precipitate slurry I.

And (3) uniformly mixing 160mL of 1.0mol/L magnesium nitrate solution with the slurry I, then adjusting the pH value to 7-8 by using ammonia water, then washing the mixture for three times by using deionized water, filtering the mixture, and drying the filtered mixture for 5 hours at 120 ℃ to obtain mixed powder. Then 150g of mixed powder is uniformly mixed with 5g of nitric acid, 5g of starch and 60g of deionized water, then the mixture is kneaded, extruded into strips and molded, dried for 3 hours at 120 ℃, roasted for 3 hours at 500 ℃, and then the mixture is roasted for 3 hours by adopting the mixed powder containing 1.5 percent of H₂Sulfurizing S hydrogen at 340 deg.C under 5.0MPa for 8 hr, and adding N₂And cooling to room temperature in the atmosphere to obtain a catalyst precursor II.

15.6g of Ni (NO)₃)₂•6H₂O and 20.9g of Co (NO)₃)₂•6H₂Dissolving O into 50mL of deionized water, soaking the solution into a precursor II in equal volume, and then adding the solution into N₂Drying at 90 ℃ for 4h under the atmosphere, and roasting at 400 ℃ for 3h to obtain the catalyst C-4.

Example 5

Dissolving ammonium metatungstate, ammonium metatolybdate and aluminum sulfate in deionized water to prepare a mixed solution A, wherein WO is contained in the mixed solution A₃Has a weight concentration of 50g/L and MoO₃Has a weight concentration of 60g/L and Al₂O₃The weight concentration of (B) is 50 g/L. Slowly adding sodium hydroxide with the concentration of 1.0mol/L into 1L of the solution A under stirring, keeping the gelling temperature at 60 ℃, controlling the pH value at 7-8 after finishing gelling, and controlling the gelling time at 60 minutes to generate slurry I containing tungsten and aluminum precipitates.

And (3) uniformly mixing 160mL of 1.0mol/L magnesium nitrate solution with the slurry I, then adjusting the pH value to 7-8 by using ammonia water, then washing the mixture for three times by using deionized water, filtering the mixture, and drying the filtered mixture for 5 hours at 120 ℃ to obtain mixed powder. Then 150g of mixed powder is uniformly mixed with 5g of nitric acid, 5g of starch and 60g of deionized water, then the mixture is kneaded, extruded into strips and molded, dried for 3 hours at 120 ℃, roasted for 3 hours at 500 ℃, and then the mixture is roasted for 3 hours by adopting the mixed powder containing 1.5 percent of H₂Sulfurizing S hydrogen at 340 deg.C under 5.0MPa for 8 hr, and adding N₂And cooling to room temperature in the atmosphere to obtain a catalyst precursor II.

42.2g of Ni (NO)₃)₂•6H₂Dissolving O into 50mL of deionized water, soaking the solution into a precursor II in equal volume, and then adding the solution into N₂Drying at 90 ℃ for 4h under the atmosphere, and roasting at 400 ℃ for 3h to obtain the catalyst C-5.

Comparative example 1

Dissolving ammonium metatungstate, nickel nitrate and aluminum chloride in deionized water to prepare a mixed solution A, wherein WO is contained in the mixed solution A₃Has a weight concentration of 80g/L, a weight concentration of NiO of 8g/L and Al₂O₃The weight concentration of (B) is 50 g/L. Slowly adding sodium hydroxide with the concentration of 1.0mol/L into 1L of the solution A under stirring, keeping the gelling temperature at 70 ℃, controlling the pH value at 7-8 after finishing gelling, and controlling the gelling time at 60 minutes to generate a tungsten and aluminum-containing precipitate slurry I.

And (3) uniformly mixing 160mL of 1.0mol/L magnesium nitrate solution with the slurry I, then adjusting the pH value to 7-8 by using ammonia water, then washing the mixture for three times by using deionized water, filtering the mixture, and drying the filtered mixture for 5 hours at 120 ℃ to obtain mixed powder. And then, uniformly mixing 150g of the mixed powder with 5g of nitric acid, 5g of starch and 60g of deionized water, kneading, extruding into strips, forming, drying at 120 ℃ for 3h, and roasting at 500 ℃ for 3h to obtain the catalyst DC-1.

Comparative example 2

Dissolving ammonium metatungstate and aluminum chloride in deionized water to prepare a mixed solution A, wherein WO is contained in the mixed solution A₃Has a weight concentration of 80g/L and Al₂O₃The weight concentration of (B) is 50 g/L. Slowly adding sodium hydroxide with the concentration of 1.0mol/L under stirringAnd (3) adding the mixture into 1L of the solution A, keeping the gelling temperature at 70 ℃, controlling the pH value to be 7-8 after finishing gelling, and controlling the gelling time to be 60 minutes to generate precipitate slurry I containing tungsten and aluminum.

And (3) uniformly mixing 160mL of 1.0mol/L magnesium nitrate solution with the slurry I, then adjusting the pH value to 7-8 by using ammonia water, then washing the mixture for three times by using deionized water, filtering the mixture, and drying the filtered mixture for 5 hours at 120 ℃ to obtain mixed powder. And then, uniformly mixing 150g of the mixed powder with 5g of nitric acid, 5g of starch and 60g of deionized water, kneading, extruding into strips, forming, drying at 120 ℃ for 3h, and roasting at 500 ℃ for 3h to obtain a catalyst precursor II.

42.2g of Ni (NO)₃)₂•6H₂Dissolving O into 50mL of deionized water, soaking the solution into a precursor II in equal volume, and then adding the solution into N₂Drying at 90 ℃ for 4h under the atmosphere, and roasting at 300 ℃ for 3h to obtain the catalyst DC-2.

TABLE 1 catalyst active Metal content and distribution

The catalyst active metal content and distribution in table 1 illustrate that the catalysts of the present invention have a relatively high weight content of the active metal in the superficial phase compared to the weight content of the active metal in the bulk phase.

Example 6

This example demonstrates the performance of the catalyst provided by the present invention for hydrodesulfurization of diesel and hydrogenation saturation of polycyclic aromatic hydrocarbons.

The adopted evaluation raw oil is mixed diesel oil provided by a certain refinery of China Petroleum chemical.

The hydrogenation performance of the catalysts C-1 to C-5 and the comparative examples DC-1 to DC-2 was evaluated by using a 200mL fixed bed hydrogenation apparatus.

Presulfurizing conditions of the catalyst: using a catalyst containing 3wt% of CS₂The space velocity of the aviation kerosene is 2.0h^-1Presulfurizing the catalyst at an operating pressure of 6.0MPa with a hydrogen-oil volume ratio of 600: 1.

The prevulcanisation process is as follows: feeding pre-vulcanized oil at 120 ℃, feeding oil for 2h, vulcanizing at constant temperature for 2h, heating to 150 ℃ at 15 ℃/h, vulcanizing at constant temperature for 4h, heating to 230 ℃ at 6 ℃/h, vulcanizing at constant temperature for 10h, heating to 300 ℃ at 6 ℃/h, vulcanizing at constant temperature for 6h, heating to 340 ℃ at 10 ℃/h, vulcanizing at constant temperature for 6h, naturally cooling to 200 ℃, and finishing the pre-vulcanization.

The evaluation reaction conditions were: the operating pressure is 6.0MPa, the reaction temperature is 360 ℃, the hydrogen/oil volume ratio is 600:1, and the volume space velocity of the fresh raw material is 1.2h^-1The evaluation results are shown in Table 2.

TABLE 2 Properties and evaluation results of the catalyst after vulcanization

The evaluation results in Table 2 can show that the active metal of the catalyst of the invention has higher sulfuration degree, and the catalyst of the invention has the operating pressure of 6.0MPa, the reaction temperature of 360 ℃, the hydrogen/oil volume ratio of 600:1 and the fresh raw material volume space velocity of 1.2h when being used in the diesel oil hydrofining reaction^-1Under the process conditions, the high desulfurization and polycyclic aromatic hydrocarbon saturation performance is achieved.