Preparation method of residual oil hydrodenitrification catalyst

Abstract

The preparation method comprises the following steps: S1, uniformly mixing aluminum hydroxide dry glue powder, silica sol and an extrusion aid, then adding deionized water and nitric acid for mixing and kneading, and after caragana microphylla is formed, drying and roasting to obtain an aluminum oxide-silicon oxide composite carrier; s2, putting the carrier into a modification solution, and performing modification treatment in a high-pressure reaction kettle to obtain a modified aluminum oxide-silicon oxide composite carrier; and S3, preparing a precursor containing metals Mo, Co and Re into an impregnation liquid, adding L-asparaginic acid into the impregnation liquid, impregnating the modified alumina-silicon oxide composite carrier in the impregnation liquid, drying, and roasting to obtain the catalyst. The catalyst prepared by the method has high hydrodenitrogenation performance and metal capacity and long service life.

Description

Technical Field

[0001] The present invention relates to the technical field of residual oil hydrogenation, and in particular to a method for preparing a residual oil hydrodenitrogenation catalyst. Background Art

[0002] Residue oil is the distillation product of crude oil. Therefore, most of the impurities in crude oil (such as sulfur, nitrogen, metals, and carbon residue) are concentrated in the residue oil. These impurities have a negative impact on subsequent processing of the residue oil. They can corrode refining equipment, degrade or permanently poison catalysts, and reduce oil quality. Combustion of the residue oil can also emit SOx and NOx, polluting the environment and endangering health.

[0003] Patent CN201910308417.7 discloses a residual oil hydrodenitrogenation catalyst and its preparation method. The catalyst includes a modified alumina-based support, molybdenum, and nickel metal components. The modified alumina-based support contains tungsten and cobalt metal components. The modified alumina-based support includes a main body modified alumina and rod-shaped modified alumina. The main body modified alumina is a modified alumina having micron-sized pores, wherein at least a portion of the rod-shaped modified alumina is distributed on the outer surface of the main body modified alumina and in the micron-sized pores with a pore diameter D of 3-7 μm. The catalyst has high hydrodenitrogenation and hydrodecarbonization capabilities, but its stability needs to be further improved to reduce the cost of the overall catalyst.

[0004] Patent CN201310110163.0 discloses a low-quality heavy distillate oil hydrodenitrogenation catalyst, its preparation method, and application. The catalyst preparation method comprises: surface acid-treating alumina and HY molecular sieve respectively, then mechanically compounding the acid-treated alumina and acid-treated HY molecular sieve as a carrier, loading the catalyst active components by impregnation with an impregnation solution containing catalytic active components, and then drying to obtain a heavy distillate oil hydrodenitrogenation catalyst. The catalyst comprises: a content of 5-20% of the acid-treated HY molecular sieve in the carrier; active components include Mo and / or W, and Co and / or Ni; the impregnation solution further contains a complexing agent; the catalyst contains 10-30% Mo and / or W oxides, and 1-10% Co and / or Ni oxides. The catalyst prepared by this method has the characteristics of reasonable acid distribution, high number of active metal stacking layers, and sufficient metal sulfidation. It has high hydrodenitrogenation activity for inferior heavy distillate oil and also has high hydrodesulfurization performance. However, in the residue oil hydrotreatment process, denitrogenation is usually a subsequent reaction of demetallization. Therefore, when the denitrogenation reaction occurs, it often leads to a significant increase in the amount of metal entering the subsequent hydrodenitrogenation catalyst bed. Therefore, the metal capacity of the catalyst in this patent needs to be improved. Summary of the Invention

[0005] The stability of the existing residual oil hydrodenitrogenation catalyst needs to be improved, and the metal tolerance is poor, the present application provides a preparation method of residual oil hydrodenitrogenation catalyst.

[0006] In order to solve the above technical problems, the present application provides the following technical scheme: A preparation method of residual oil hydrodenitrogenation catalyst, comprising the following steps: S1: the aluminum hydroxide dry gel powder, silica sol and extrusion aid are mixed uniformly, then deionized water and nitric acid are added and kneaded, and then the mixture is formed into a shape, dried and calcined to obtain an alumina-silica composite carrier; S2: the carrier is placed in a modified solution and modified in a high-pressure reactor to obtain a modified alumina-silica composite carrier; S3: a precursor containing Mo, Co and Re is prepared into an impregnation solution, L-aspartic acid is added to the impregnation solution, the modified alumina-silica composite carrier is impregnated in the impregnation solution, and then dried and calcined to obtain a catalyst.

[0007] Further, the preparation method of the modified solution is as follows: sodium acetate trihydrate and acetic acid are dissolved in deionized water to prepare a modified solution with a pH of 4-5, and the concentration of sodium acetate trihydrate and acetic acid in the modified solution is 0.2M.

[0008] Further, the modification process is as follows: the carrier is stirred uniformly in the modified solution, then placed in a high-pressure reactor lined with polytetrafluoroethylene, and then the high-pressure reactor is placed in an oven and treated at 80-100℃ for 4-6h, then cooled to room temperature and dried in the oven to obtain a modified alumina-silica composite carrier.

[0009] Further, the extrusion aid is amaranth powder, the mass ratio of the aluminum hydroxide dry gel powder, silica sol and extrusion aid is 5-8:2:0.1-0.3, the mass ratio of the total mass of the aluminum hydroxide dry gel powder and silica sol to deionized water is 1:1, and the amount of nitric acid is 0.5-2% of the volume of deionized water.

[0010] Further, the precursor containing Mo, Co and Re is molybdenum trioxide, cobalt nitrate hexahydrate and high-rhenium acid amine, and the molar ratio of Mo, Co and Re in the three compounds is 1-3:0.5:0.05-0.1, and the total content of Mo, Co and Re is 15-28wt% (mass fraction) based on the total weight of the catalyst.

[0011] Further, the concentration of L-aspartic acid in the impregnation solution is 1-4g / L, and the temperature is maintained at 60℃ during the impregnation process for 3-6h.

[0012] Furthermore, the catalyst was prepared by calcining at a high temperature of 500° C. for 4 h.

[0013] The catalyst for residual oil hydrodenitrogenation is prepared according to any one of the above preparation methods.

[0014] The present invention has the following beneficial effects: 1. The present invention provides a method for preparing a residue oil hydrodenitrogenation catalyst. During the preparation process of the catalyst, the alumina-silicon oxide composite carrier is modified to make the adsorbent have a higher specific surface area and void volume. At the same time, after 3000 hours of use, it can still show high denitrification stability and metal capacity performance, which can effectively extend the service life of the catalyst, reduce production costs, and improve economic benefits.

[0015] 2. The present invention provides a method for preparing a residue oil hydrodenitrogenation catalyst. By appropriately mixing molybdenum, cobalt and rhenium, the prepared catalyst exhibits relatively good metal-containing properties, which is more suitable for the grading process of the hydrodenitrogenation catalyst in the reactor during the residue oil hydrogenation process.

[0016] 3. The present invention provides a method for preparing a residue oil hydrodenitrogenation catalyst. During the preparation process of the catalyst, L-aspartic acid is added to the impregnation liquid to further improve the metal capacity of the catalyst, thereby preventing excessively high concentrations of metal components from clogging the active components of the catalyst after a long reaction time and affecting the hydrogenation effect.

[0017] 4. The present invention provides a method for preparing a residue oil hydrodenitrogenation catalyst. The catalyst preparation method is easy to control and the preparation method is simple. DETAILED DESCRIPTION

[0018] The following describes the technical solutions of the present invention in a clear and complete manner, with reference to specific examples. The reagents and equipment used in this invention are all known products or commercially available. The silica sol was purchased from Zhejiang Yuda Chemical Co., Ltd. and was alkaline (25% silica content). The catalyst was formed using a HYNJ-20 laboratory precision extruder produced by Jiangsu Huayu Machinery Factory, operating at 0.55 kW and 12 MPa. Chemical composition was analyzed using a Rigaku ZSX Primus II X-ray fluorescence spectrometer. The wavelengths and intensities of the X-ray fluorescence lines correspond to the type and concentration of the measured elements, allowing analysis of the elements and their content in the sample. Prior to analysis, the catalyst was ground until no noticeable particles remained. The catalyst and an appropriate amount of boric acid were then pressed into a pellet press to form a round cake for measurement. Finally, the Mo, Co, and Re content in the catalyst was determined.

[0019] Example 1 S1: Aluminum hydroxide dry rubber powder, alkaline silica sol and sesbania powder were mixed in a mass ratio of 5:2:0.1, and then deionized water of the same mass as the total mass of aluminum hydroxide dry rubber powder and silica sol was added and mixed, and then 65% (mass percentage) of nitric acid was added dropwise, and the final volume of nitric acid added was 0.5% of the volume of deionized water. The mixture was kneaded twice with an extruder, and after the caragana was formed, it was dried at 110°C for 5h, and then heated to 500°C in a muffle furnace at a rate of 1.5°C / min, and calcined for 4h to obtain an alumina-silica composite carrier; S2: Sodium acetate trihydrate and acetic acid are dissolved in deionized water and mixed to prepare a modified solution with a pH of 4. The concentrations of sodium acetate trihydrate and acetic acid in the modified solution are both 0.2 M. The solution is set aside after preparation.

[0020] The alumina-silica composite carrier is placed in the modified solution and stirred evenly, then placed in a high-pressure reactor lined with polytetrafluoroethylene, and the high-pressure reactor is placed in an oven and treated at 100°C for 6 hours. After the treatment is completed, it is cooled to room temperature and then dried completely in an oven at 100°C to obtain a modified alumina-silica composite carrier.

[0021] S3: Molybdenum trioxide, cobalt nitrate hexahydrate and ammonium perrhenate were weighed in a molar ratio of 3:0.5:0.08 of metal Mo, Co and Re, dissolved in a solution of L-aspartic acid with a solubility of 1 g / L to prepare an impregnation solution, and the modified alumina-silica composite support was placed in the impregnation solution. The impregnation was performed with equal volume, and the temperature was maintained at 60°C during the impregnation process for 6 hours.

[0022] After impregnation, the catalyst was dried at 110°C for 4 hours and then calcined in a muffle furnace at 500°C for 4 hours to obtain catalyst HDN-1. The total content of Mo, Co and Re in terms of oxides was 25.45 wt% based on the total weight of the catalyst.

[0023] Example 2 S1: Aluminum hydroxide dry rubber powder, alkaline silica sol and sesbania powder were mixed in a mass ratio of 8:2:0.1, and then deionized water of the same mass as the total mass of aluminum hydroxide dry rubber powder and silica sol was added and mixed, and then 65% (mass percentage) of nitric acid was added dropwise, and the final volume of nitric acid added was 0.5% of the volume of deionized water. The mixture was kneaded twice with an extruder, and after the caragana was formed, it was dried at 110°C for 5h, and then heated to 500°C in a muffle furnace at a rate of 1.5°C / min, and calcined for 4h to obtain an alumina-silica composite carrier; S2: Sodium acetate trihydrate and acetic acid are dissolved in deionized water and mixed to prepare a modified solution with a pH of 4. The concentrations of sodium acetate trihydrate and acetic acid in the modified solution are both 0.2 M. The solution is set aside after preparation.

[0024] The alumina-silica composite carrier is placed in the modified solution and stirred evenly, then placed in a high-pressure reactor lined with polytetrafluoroethylene, and the high-pressure reactor is placed in an oven and treated at 100°C for 6 hours. After the treatment is completed, it is cooled to room temperature and then dried completely in an oven at 100°C to obtain a modified alumina-silica composite carrier.

[0025] S3: Molybdenum trioxide, cobalt nitrate hexahydrate and ammonium perrhenate were weighed in a molar ratio of 1:0.5:0.05 of metal Mo, Co and Re, dissolved in a solution of L-aspartic acid with a solubility of 1 g / L to prepare an impregnation solution, and the modified alumina-silica composite support was placed in the impregnation solution. The impregnation was performed with equal volume. The temperature was maintained at 60°C during the impregnation process, and the solution was sealed and impregnated for 6 hours.

[0026] After impregnation, the catalyst was dried at 110°C for 4 hours and then calcined in a muffle furnace at 500°C for 4 hours to obtain catalyst HDN-2. The total content of Mo, Co and Re in terms of oxides was 15.77 wt% based on the total weight of the catalyst.

[0027] Example 3 S1: Aluminum hydroxide dry rubber powder, alkaline silica sol and sesbania powder were mixed in a mass ratio of 5:2:0.3, and then deionized water of the same mass as the total mass of aluminum hydroxide dry rubber powder and silica sol was added and mixed, and then 65% (mass percentage) nitric acid was added dropwise, and the final volume of nitric acid added was 2% of the volume of deionized water. The mixture was kneaded twice with an extruder, and after the caragana was formed, it was dried at 110°C for 5h, and then heated to 500°C in a muffle furnace at a rate of 1.5°C / min, and calcined for 4h to obtain an alumina-silica composite carrier; S2: Sodium acetate trihydrate and acetic acid are dissolved in deionized water and mixed to prepare a modified solution with a pH of 5. The concentrations of sodium acetate trihydrate and acetic acid in the modified solution are both 0.2 M. The solution is set aside after preparation.

[0028] The alumina-silica composite carrier is placed in the modified solution and stirred evenly, then placed in a high-pressure reactor lined with polytetrafluoroethylene, and the high-pressure reactor is placed in an oven and treated at 100°C for 4 hours. After the treatment is completed, it is cooled to room temperature and then dried completely in an oven at 100°C to obtain a modified alumina-silica composite carrier.

[0029] S3: Molybdenum trioxide, cobalt nitrate hexahydrate and ammonium perrhenate were weighed in a molar ratio of 3:0.5:0.05 of metal Mo, Co and Re, dissolved in a solution of L-aspartic acid with a solubility of 1 g / L to prepare an impregnation solution, and the modified alumina-silica composite support was placed in the impregnation solution. The impregnation was performed in an equal volume manner. The temperature was maintained at 60°C during the impregnation process, and the solution was sealed and impregnated for 6 hours.

[0030] After impregnation, the catalyst was dried at 110°C for 4 hours and then calcined in a muffle furnace at 500°C for 4 hours to obtain catalyst HDN-3. The total content of Mo, Co and Re in terms of oxides was 20.81 wt% based on the total weight of the catalyst.

[0031] Example 4 S1: Aluminum hydroxide dry rubber powder, alkaline silica sol and sesbania powder were mixed in a mass ratio of 8:2:0.1, and then deionized water of the same mass as the total mass of aluminum hydroxide dry rubber powder and silica sol was added and mixed, and then 65% (mass percentage) of nitric acid was added dropwise, and the final volume of nitric acid added was 0.5% of the volume of deionized water. The mixture was kneaded twice with an extruder, and after the caragana was formed, it was dried at 110°C for 5h, and then heated to 500°C in a muffle furnace at a rate of 1.5°C / min, and calcined for 4h to obtain an alumina-silica composite carrier; S2: Sodium acetate trihydrate and acetic acid are dissolved in deionized water and mixed to prepare a modified solution with a pH of 4. The concentrations of sodium acetate trihydrate and acetic acid in the modified solution are both 0.2 M. The solution is set aside after preparation.

[0032] The alumina-silica composite carrier is placed in the modified solution and stirred evenly, then placed in a high-pressure reactor lined with polytetrafluoroethylene, the high-pressure reactor is placed in an oven and treated at 80°C for 6 hours, cooled to room temperature after the treatment, and then completely dried in an oven at 100°C to obtain a modified alumina-silica composite carrier.

[0033] S3: Molybdenum trioxide, cobalt nitrate hexahydrate and ammonium perrhenate are weighed in a molar ratio of 1:0.5:0.1 of metal Mo, Co and Re, dissolved in a solution of L-aspartic acid with a solubility of 3 g / L to prepare an impregnation solution, and the modified alumina-silica composite support is placed in the impregnation solution. The impregnation is performed in an equal volume manner. The temperature is maintained at 60°C during the impregnation process, and the solution is sealed and impregnated for 3 hours.

[0034] After impregnation, the catalyst was dried at 110°C for 4 hours and then calcined in a muffle furnace at 500°C for 4 hours to obtain catalyst HDN-4. The total content of Mo, Co and Re in terms of oxides was 18.93 wt% based on the total weight of the catalyst.

[0035] Example 5 S1: Aluminum hydroxide dry rubber powder, alkaline silica sol and sesbania powder were mixed in a mass ratio of 5:2:0.1, and then deionized water of the same mass as the total mass of aluminum hydroxide dry rubber powder and silica sol was added and mixed, and then 65% (mass percentage) of nitric acid was added dropwise, and the final volume of nitric acid added was 0.5% of the volume of deionized water. The mixture was kneaded twice with an extruder, and after the caragana was formed, it was dried at 110°C for 5h, and then heated to 500°C in a muffle furnace at a rate of 1.5°C / min, and calcined for 4h to obtain an alumina-silica composite carrier; S2: Sodium acetate trihydrate and acetic acid are dissolved in deionized water and mixed to prepare a modified solution with a pH of 4. The concentrations of sodium acetate trihydrate and acetic acid in the modified solution are both 0.2 M. The solution is set aside after preparation.

[0036] The alumina-silica composite carrier is placed in the modified solution and stirred evenly, then placed in a high-pressure reactor lined with polytetrafluoroethylene, the high-pressure reactor is placed in an oven and treated at 80°C for 6 hours, cooled to room temperature after the treatment, and then completely dried in an oven at 100°C to obtain a modified alumina-silica composite carrier.

[0037] S3: Molybdenum trioxide, cobalt nitrate hexahydrate and ammonium perrhenate were weighed in a molar ratio of 3:0.5:0.1 of metal Mo, Co and Re, dissolved in a solution of L-aspartic acid with a solubility of 1 g / L to prepare an impregnation solution, and the modified alumina-silica composite support was placed in the impregnation solution. The impregnation was performed in an equal volume manner. The temperature was maintained at 60°C during the impregnation process, and the solution was sealed and impregnated for 6 hours.

[0038] After impregnation, the catalyst was dried at 110° C. for 4 h and then calcined in a muffle furnace at 500° C. for 4 h to obtain the catalyst HDN-5. The total content of Mo, Co and Re in terms of oxides was 28.19% based on the total weight of the catalyst.

[0039] Example 6 S1: Aluminum hydroxide dry rubber powder, alkaline silica sol and sesbania powder were mixed in a mass ratio of 5:2:0.1, and then deionized water of the same mass as the total mass of aluminum hydroxide dry rubber powder and silica sol was added and mixed, and then 65% (mass percentage) of nitric acid was added dropwise, and the final volume of nitric acid added was 0.5% of the volume of deionized water. The mixture was kneaded twice with an extruder, and after the caragana was formed, it was dried at 110°C for 5h, and then heated to 500°C in a muffle furnace at a rate of 1.5°C / min, and calcined for 4h to obtain an alumina-silica composite carrier; S2: Molybdenum trioxide, cobalt nitrate hexahydrate and ammonium perrhenate were weighed in a molar ratio of 3:0.5:0.1 of metal Mo, Co and Re, dissolved in a solution containing L-aspartic acid with a solubility of 1 g / L to prepare an impregnation solution, and the modified alumina-silica composite support was placed in the impregnation solution. The impregnation was performed with equal volume, and the temperature was maintained at 60°C during the impregnation process for 6 hours.

[0040] After impregnation, the catalyst was dried at 110°C for 4 hours and then calcined in a muffle furnace at 500°C for 4 hours to obtain catalyst HDN-6. The total content of Mo, Co and Re in terms of oxides was 27.83 wt% based on the total weight of the catalyst.

[0041] Example 7 S1: Aluminum hydroxide dry rubber powder, alkaline silica sol and sesbania powder were mixed in a mass ratio of 5:2:0.1, and then deionized water of the same mass as the total mass of aluminum hydroxide dry rubber powder and silica sol was added and mixed, and then 65% (mass percentage) of nitric acid was added dropwise, and the final volume of nitric acid added was 0.5% of the volume of deionized water. The mixture was kneaded twice with an extruder, and after the caragana was formed, it was dried at 110°C for 5h, and then heated to 500°C in a muffle furnace at a rate of 1.5°C / min, and calcined for 4h to obtain an alumina-silica composite carrier; S2: Acetic acid is dissolved in deionized water and mixed to prepare a modified solution with a pH of 4. The concentration of acetic acid in the modified solution is 0.2 M. The modified solution is set aside after preparation.

[0042] The alumina-silica composite carrier is placed in the modified solution and stirred evenly, then placed in a high-pressure reactor lined with polytetrafluoroethylene, and the high-pressure reactor is placed in an oven and treated at 100°C for 6 hours. After the treatment is completed, it is cooled to room temperature and then dried completely in an oven at 100°C to obtain a modified alumina-silica composite carrier.

[0043] S3: Molybdenum trioxide, cobalt nitrate hexahydrate and ammonium perrhenate were weighed in a molar ratio of 3:0.5:0.05 of metal Mo, Co and Re, dissolved in a solution of L-aspartic acid with a solubility of 1 g / L to prepare an impregnation solution, and the modified alumina-silica composite support was placed in the impregnation solution. The impregnation was performed with equal volume, and the temperature was maintained at 60°C during the impregnation process for 6 hours.

[0044] After impregnation, the catalyst was dried at 110°C for 4 hours and then calcined in a muffle furnace at 500°C for 4 hours to obtain the catalyst HDN-7. The total content of Mo, Co and Re in terms of oxides was 26.21 wt% based on the total weight of the catalyst.

[0045] Example 8 S1: Aluminum hydroxide dry rubber powder, alkaline silica sol and sesbania powder were mixed in a mass ratio of 5:2:0.1, and then deionized water of the same mass as the total mass of aluminum hydroxide dry rubber powder and silica sol was added and mixed, and then 65% (mass percentage) of nitric acid was added dropwise, and the final volume of nitric acid added was 0.5% of the volume of deionized water. The mixture was kneaded twice with an extruder, and after the caragana was formed, it was dried at 110°C for 5h, and then heated to 500°C in a muffle furnace at a rate of 1.5°C / min, and calcined for 4h to obtain an alumina-silica composite carrier; S2: Sodium acetate trihydrate and acetic acid are dissolved in deionized water and mixed to prepare a modified solution with a pH of 4. The concentrations of sodium acetate trihydrate and acetic acid in the modified solution are both 0.2 M. The solution is set aside after preparation.

[0046] The alumina-silica composite carrier is placed in the modified solution and stirred evenly, then placed in a high-pressure reactor lined with polytetrafluoroethylene, and the high-pressure reactor is placed in an oven and treated at 100°C for 6 hours. After the treatment is completed, it is cooled to room temperature and then dried completely in an oven at 100°C to obtain a modified alumina-silica composite carrier.

[0047] S3: Molybdenum trioxide and cobalt nitrate hexahydrate are weighed in a molar ratio of 3:0.5 of metal Mo and Co, and dissolved in a solution of L-aspartic acid with a solubility of 1 g / L to prepare an impregnation solution. The modified alumina-silica composite support is placed in the impregnation solution and the impregnation is performed with equal volume. The temperature is maintained at 60°C during the impregnation process and the impregnation is carried out for 6 hours.

[0048] After impregnation, the catalyst was dried at 110° C. for 4 h and then calcined in a muffle furnace at 500° C. for 4 h to obtain the catalyst HDN-8. The total content of Mo and Co in terms of oxides was 23.42 wt % based on the total weight of the catalyst.

[0049] Determination of catalyst characterization The specific surface area and pore distribution of the samples were measured using mercury intrusion porosimetry (V9610 mercury intrusion porosimeter, manufactured by Micromeritics, Inc., USA). The samples were first dried at 110-120°C, followed by low-pressure and high-pressure analyses to obtain the specific surface area data of the catalyst.

[0050] Denitrification activity detection First, grind the catalyst to 40 mesh, put it into a quartz tube, and introduce a mixture of hydrogen sulfide and nitrogen at a flow rate of 50 ml min -1 The pre-sulfurized catalyst is protected by nitrogen.

[0051] Residue oil containing 55 ppm nickel, 125 ppm vanadium, and 3940 ppm nitrogen was added to an autoclave as feedstock, and the catalyst performance was evaluated in a fixed-bed reactor. Pyridine, a representative basic nitrogen-containing compound, was used to examine the catalyst's denitrification performance, while nickel and vanadium, representative metal compounds, were used to examine the catalyst's metal-tolerance properties. The reaction conditions were: a 100 ml catalyst loading, a hydrogen partial pressure of 10-14 MPa, a reaction temperature between 300-400°C, a hydrogen-to-oil volume ratio of 750, and sampling after 100 and 3000 hours of reaction. The nickel and vanadium contents in the oil before and after hydrotreatment were determined using an inductively coupled plasma atomic emission spectrometer (ICP-AES) (for specific methods, see RIPP124-90), and the demetallization rate (metal capacity) of the catalyst was then determined. The demetallization rate (metal capacity) is the ratio of the difference between the metal content before and after the reaction to the metal content before the reaction (displayed as %). A chemiluminescence analyzer (ANTEK, USA) was used to detect the nitrogen content. The denitrification rate is the ratio of the difference between the nitrogen content before and after the reaction to the nitrogen content before the reaction (displayed as %).

[0052] The specific surface area parameters and pore volume results of the catalysts prepared in specific Examples 1-8 are shown in Table 1 below.

[0053] Table 1 It can be seen from the data in Table 1 above that the surface area and pore volume of the catalyst prepared after the final impregnation of the carrier that is not modified or modified during the carrier preparation process are relatively reduced.

[0054] The catalysts prepared in Examples 1-8 were tested for denitrification and metal storage effects. The specific test results are shown in Table 2.

[0055] Table 2 The above data show that the absence of rhenium, the active component, significantly impacts the catalyst's denitrification performance, but its metal-carrying capacity remains unaffected. Furthermore, catalysts prepared without modification or with altered modification conditions exhibit poor denitrification stability.

[0056] In order to detect the role of L-aspartic acid added during the preparation of the catalyst, the concentration of L-aspartic acid in the impregnation solution was set to three concentration gradients of 0, 0.5 g / L, and 10 g / L (due to the poor water solubility of L-aspartic acid at room temperature, the above concentration data were prepared at 60°C). The denitrification and metal tolerance effects were tested after 100 hours. The specific results are shown in Table 3 below.

[0057] Table 3 According to the test results in Table 3 above, L-aspartic acid has a significant effect on the metal content of the catalyst during the entire catalyst preparation process. In comparison, its effect on the denitrification effect is not particularly significant.

Claims

1. A method for preparing a residue hydrodenitrogenation catalyst, characterized in that: The steps include: S1: Aluminum hydroxide dry rubber powder, silica sol and extrusion aid are mixed evenly, and then deionized water and nitric acid are added and kneaded. After the caragana is formed, it is dried and calcined to obtain an alumina-silica composite carrier; S2: placing the support in a modification solution and performing a modification treatment in a high-pressure reactor to obtain a modified alumina-silica composite support; S3: Precursors containing metals Mo, Co and Re are prepared into an impregnation solution, L-aspartic acid is added to the impregnation solution, and the modified alumina-silicon oxide composite carrier is placed in the impregnation solution for impregnation, followed by drying and calcination to obtain a catalyst.

2. The method for preparing a residue hydrodenitrogenation catalyst according to claim 1, wherein The modified solution is prepared by dissolving sodium acetate trihydrate and acetic acid in deionized water and mixing them to prepare a modified solution with a pH of 4-5, wherein the concentrations of sodium acetate trihydrate and acetic acid in the modified solution are both 0.2 M / L.

3. The method for preparing the residue hydrodenitrogenation catalyst according to claim 2, wherein The modification process is as follows: placing the carrier in the modification solution and stirring it evenly, then placing it in a high-pressure reactor lined with polytetrafluoroethylene, placing the high-pressure reactor in an oven at 80-100° C. for 4-6 hours, cooling it to room temperature after the treatment is completed, and drying it in an oven to obtain a modified alumina-silicon oxide composite carrier.

4. The method for preparing a residue hydrodenitrogenation catalyst according to claim 1, wherein The extrusion aid is sesbania powder, the mass ratio of the aluminum hydroxide dry glue powder, silica sol and sesbania powder is 5-8:2:0.1-0.3, the mass ratio of the total mass of the aluminum hydroxide dry glue powder and silica sol to deionized water is 1:1, and the amount of nitric acid used is 0.5-2% of the volume of the deionized water.

5. The method for preparing a residue hydrodenitrogenation catalyst according to claim 1, wherein The calcination condition in step S1 is a high temperature calcination at 500° C. for 4-6 hours.

6. The method for preparing a residue hydrodenitrogenation catalyst according to claim 1, wherein: The precursor containing metals Mo, Co and Re is molybdenum trioxide, cobalt nitrate hexahydrate and ammonium perrhenate.

7. The method for preparing a residue hydrodenitrogenation catalyst according to claim 6, wherein: The molar ratio of metals Mo, Co and Re in the three compounds of molybdenum trioxide, cobalt nitrate hexahydrate and ammonium perrhenate is 1-3:0.5:0.05-0.

1.

8. The method for preparing a residue hydrodenitrogenation catalyst according to claim 1, wherein: The concentration of L-aspartic acid in the impregnation solution is 1-4 g / L, the temperature is maintained at 60° C. during the impregnation process, and the impregnation is carried out for 3-6 hours.

9. The method for preparing a residue hydrodenitrogenation catalyst according to claim 1, wherein: Calcination conditions: calcination at 500℃ for 4h to obtain the catalyst.

10. A residue hydrodenitrogenation catalyst prepared according to the preparation method according to any one of claims 1 to 9.

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