A method for preparing a hydrodecarbon residue catalyst

Abstract

The application discloses a preparation method of a hydroresid catalyst, and comprises the following contents: (1) preparing a boron-modified alumina carrier A; (2) immersing the boron-modified alumina carrier A into a propylene oxide solution, treating the carrier in a sealed pressure-resistant container at 60-100 DEG C for 1-4 hours, then increasing the temperature to 110-180 DEG C and treating the carrier for 2-6 hours, and then drying the carrier after the treatment to obtain an alumina carrier B; (3) ultrasonic treating the alumina carrier B immersed in a boric acid solution, drying the carrier after the treatment, preparing an alumina carrier C, and then loading a hydrogenation active component to obtain the hydroresid catalyst. The hydroresid catalyst has suitable B acid and L acid, the surface particle morphology is worm, the pore is open, and the catalyst is beneficial to the diffusion of reactant molecules to the inside of the catalyst. The catalyst has high hydrodesulfurization, hydrodenitrogenation and hydroresid activity when being used in a heavy oil and residual oil hydroprocessing process.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of catalyst preparation, and particularly relates to a preparation method of a hydro-decarbon residue catalyst. BACKGROUND

[0002] The heavy oil hydro-decarbon residue reaction is an important reaction in the residue oil hydrogenation process, and the conversion rate of carbon residue is an important index of the residue oil hydrogenation process. The raw material with high carbon residue value will greatly affect the operation stability and product distribution of the heavy oil catalytic cracking unit (RFCC unit). Reducing the carbon residue value of the oil generated by the residue oil hydrogenation unit will help improve the economic benefits of the residue oil hydrogenation and catalytic cracking combined unit. The carbon residue value is closely related to the content of five-ring and more than five-ring condensed ring aromatic hydrocarbons in the heavy oil. Generally, the precursors of carbon residue are mainly composed of large condensed ring aromatic hydrocarbons in asphaltene and resin. The essence of the residue oil hydro-decarbon residue is to treat the precursors of carbon residue, reduce the carbon residue precursor compounds, and its reaction is similar to the lightening reaction of the residue oil.

[0003] CN103785397A discloses a hydro-decarbon residue catalyst and a preparation method thereof. The preparation method of the catalyst comprises the following steps: (1) after the neutralization reaction of the acidic aluminum salt aqueous solution and the alkali metal aluminate aqueous solution, the slurry pH value is adjusted to 8.5-9.7 by passing the alkaline precipitant or the alkali metal aluminate aqueous solution, and the slurry is aged at 150-220℃ for 0.1-2 hours; (2) after the aging of the material in step (1), the material is filtered, washed, dried, and then 10-40wt% aluminum ammonium carbonate is added for molding; (3) the molded material is loaded with active components, dried, and calcined to obtain the hydro-decarbon residue catalyst. The catalyst has a high content of 6-10nm pores and a certain amount of 100nm and above pores, but the catalyst surface pores are not wide, which is not conducive to the entry of the reactant molecules into the catalyst interior.

[0004] CN106622261A discloses a hydro-decarbon residue catalyst, a preparation method and application thereof. The catalyst contains an active metal component and a modified hydrogenation catalyst carrier. The modified hydrogenation catalyst carrier is prepared by repeatedly immersing and drying the hydrothermally treated carrier in sequence, and calcining the last obtained dried product, wherein the immersion liquid used in each immersion process contains the same or different acid additive compounds, the number of repetitions n≥2, and when n≥3, the temperature of each immersion and drying is 20-150℃ higher than that of the adjacent previous immersion and drying, and the time of each immersion and drying is 1-10 hours longer than that of the adjacent previous immersion and drying. The method can obtain the modified hydrogenation catalyst carrier with the acid additive in a layered distribution, but the catalyst surface pores are not wide enough. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a preparation method of a hydroresid catalyst, which has suitable B acid and L acid, surface particle morphology is worm, and pore is open, which is beneficial to the diffusion of reactant molecules to the inside of the catalyst. The catalyst is used in the hydroprocessing process of heavy oil and residual oil, and has high hydrodesulfurization, denitrification and hydroresid activity.

[0006] The preparation method of the hydroresid catalyst of the present application comprises the following contents:

[0007] (1) preparing a boron-modified alumina carrier A;

[0008] (2) immersing the boron-modified alumina carrier A into a propylene oxide solution, treating it in a sealed pressure-resistant container at 60-100℃ for 1-4 hours, then increasing the temperature to 110-180℃ for 2-6 hours, and then drying the carrier after treatment to obtain an alumina carrier B;

[0009] (3) immersing the alumina carrier B into a boric acid solution for ultrasonic treatment, drying the carrier after treatment to obtain an alumina carrier C, and then loading a hydrogenation active component to obtain a hydroresid catalyst.

[0010] In the method of the present application, the preparation of the boron-modified alumina carrier A in step (1) is a method well known in the art, and the specific process is as follows: a parallel flow gelation reaction is carried out between an aluminum sulfate solution and a sodium metaaluminate solution, then aging, and filtering to obtain a filter cake, then mixing the filter cake with boric acid, and then filtering, washing, and drying to obtain boron-modified pseudo-boehmite; the boron-modified pseudo-boehmite is mixed, extruded, dried, and calcined to obtain the boron-modified alumina carrier A. The concentration of the aluminum sulfate solution is 8.3-9.5 g / 100 mL (calculated as Al2O3), the concentration of the sodium metaaluminate solution is 15.5-19.6 g / 100 mL (calculated as Al2O3), the dropwise addition speed of the aluminum sulfate solution is 0.8-1.4 L / h, the dropwise addition speed of the sodium metaaluminate solution is 1.0-1.6 L / h, the reaction pH value is 8.0-9.2, the aging temperature is 70-90℃, and the aging time is 0.5-2 h. The concentration of the boric acid solution is 10.5 wt%-15.5 wt%, the solution amount is enough to completely immerse the filter cake, and the stirring time is 0.5-2.5 hours; the drying temperature is 100-160℃, and the drying time is 1-10 hours; and the calcination temperature is 450-600℃, and the calcination time is 2-8 hours.

[0011] In the method of the present application, the concentration of the propylene oxide aqueous solution in step (2) is 2.5 wt%-12 wt%, preferably 4 wt%-8 wt%, and the mass ratio of the propylene oxide aqueous solution to the boron-modified alumina carrier A is 3:1-10:1, preferably 4:1-8:1.

[0012] In the method, the closed pressure-resistant container in step (2) is preferably an autoclave. The drying temperature in step (2) is 100-160 ℃, and the drying time is 2-8 hours.

[0013] In the method, the concentration of the boric acid solution in step (3) is 17wt%-28wt%, the solution is used in an amount to completely immerse the alumina carrier, the temperature during ultrasonic treatment is 45-65 ℃, the ultrasonic frequency is 25-50 KHz, the ultrasonic power is 50-125 W, and the ultrasonic time is 30-60 min. The drying temperature is 100-160 ℃, and the drying time is 6-10 hours.

[0014] In the method, the loading process in step (3) is carried out by impregnation, the active component impregnation solution is a solution containing Group VIB and Group VIII metals, the Group VIB metal is selected from one or more of W and Mo, and the Group VIII metal is selected from one or more of Co and Ni. The content of the Group VIB metal in the impregnation solution is 6.5-25.0 g / 100 mL in terms of metal oxide, and the content of the Group VIII metal is 1.5-8.5 g / 100 mL in terms of metal oxide.

[0015] In the method, the drying temperature in step (3) is 100-160 ℃, the drying time is 2-8 hours, the calcination temperature is 450-550 ℃, and the calcination time is 4-6 hours.

[0016] Compared with the prior art, the method has the following advantages:

[0017] (1) The method first adds boron when pseudo-boehmite forms a precipitate to prepare a boron-modified alumina carrier, and then the boron-modified alumina carrier is sealed and heat-treated in a propylene oxide solution. During low-temperature sealed heat treatment, propylene oxide is hydrolyzed to form an alcohol solution and make the solution weakly alkaline. During high-temperature sealed hydrothermal treatment, the surface grains of the alumina carrier grow into worm-like pseudo-boehmite under the alkaline and alcohol solution environment, the worm-like particles accumulate on the surface of the carrier to form a large number of 30-100 nm open channels, which is beneficial to the entry of macromolecular reactants into the interior of the catalyst and improves the catalytic activity and utilization rate in the interior of the catalyst. During hydrothermal treatment, the rehydration of the alumina grains makes the impregnated boron more easily embedded in the alumina grain phase, thereby improving the B acid content on the surface of the carrier. When the treated carrier is immersed in a boric acid solution for ultrasonic treatment, most of the boron species are adsorbed on the surface of the alumina grains, which improves the L acid content of the carrier without reducing the B acid content of the carrier.

[0018] (2) The surface of the alumina carrier is pseudo-boehmite, and the inside is γ-alumina grain. When the active component is impregnated and then calcined, the surface pseudo-boehmite is converted into γ-alumina, and the active metal component on the surface cooperates with the phase change process of the pseudo-boehmite, so as to adjust the action of the active metal component and the alumina carrier, reduce the formation of nickel-aluminum spinel phase, and improve the catalytic activity of the catalyst. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is an SEM image of the catalyst prepared in Example 1.

[0020] Figure 2 is an SEM image of the catalyst prepared in Comparative Example 2. EMBODIMENT

[0021] The technical solutions and technical effects of the present application will be further illustrated below in combination with examples, but are not limited to the following examples. In the present application, wt% represents mass fraction.

[0022] BET method: N2 physical adsorption-desorption is applied to characterize the pore structure of the carrier in the examples and comparative examples, and the specific operation is as follows: an ASAP-2420 type N2 physical adsorption-desorption instrument is used to characterize the pore structure of the sample. A small amount of sample is vacuum treated at 300℃ for 3-4 hours, and finally the product is placed in liquid nitrogen low temperature (-200℃) condition for nitrogen adsorption-desorption test. The specific surface area is obtained according to the BET equation, and the distribution rate of pore volume and pore diameter below 30nm is obtained according to the BJH model.

[0023] The scanning electron microscope is applied to characterize the microstructure of the alumina carrier, and the specific operation is as follows: a JSM-7500F scanning electron microscope is used to characterize the microstructure of the carrier, with an acceleration voltage of 5kV, an acceleration current of 20µA, and a working distance of 8mm. Example 1

[0024] (1) Prepare aluminum sulfate solution with a concentration of 8.8 g / 100 mL (calculated as Al2O3) and sodium metaaluminate solution with a concentration of 18.3 g / 100 mL (calculated as Al2O3). Add the aluminum sulfate and sodium metaaluminate solutions drop by drop into a reaction tank in a parallel flow gelation manner. The dropwise addition speed of the aluminum sulfate solution is 1 L / h, and the dropwise addition speed of the sodium metaaluminate solution is 1.2 L / h. Control the pH value of the reaction to be about 8.5. The formed precipitate is aged at 85°C for 1 h. The obtained precipitate is washed and filtered to obtain a filter cake. Take 1000 g of the filter cake, add 1200 mL of boric acid solution with a concentration of 13.5 wt%, and magnetically stir for 2 h, and then filter. The filter cake is dried at 120°C for 6 h to prepare boron-modified pseudoboehmite. Take 500 g of the pseudoboehmite, uniformly mix with 3 g of sesbania powder, then add an appropriate amount of acetic acid solution with a mass concentration of 0.5% to the mixture, uniformly knead, extrude into a strip, dry the formed material at 120°C for 5 h, and calcine at 550°C for 5 h to prepare boron-modified alumina carrier precursor A1.

[0025] (2) Take 100 g of the boron-modified alumina carrier precursor A1 prepared in step (1), add 610 g of propylene oxide aqueous solution with a concentration of 5.7 wt%, and transfer the mixture into an autoclave. After sealing, the autoclave is placed in an oven for sealed treatment at 85°C for 2 h, and then the temperature is increased to 145°C for sealed treatment for 3.5 h. After treatment, the material is cooled, washed, filtered, and the solid material is dried at 140°C for 6 h to prepare an alumina carrier B1.

[0026] (3) Immerse the alumina carrier B1 prepared in step (2) in a boric acid solution with a concentration of 21 wt%, and ultrasonically treat the carrier at 60°C for 40 min. The ultrasonic frequency is 35 kHz and the power is 100 W. After ultrasonic treatment, the carrier is filtered and dried at 140°C for 6 h to prepare a boron-modified alumina carrier C1.

[0027] (4) Take 50 g of the boron-modified alumina carrier C1 prepared in step (3), and immerse the alumina carrier in a molybdenum oxide impregnating solution with a concentration of 17.8 g / 100 mL and a nickel oxide impregnating solution with a concentration of 3.6 g / 100 mL in a saturated immersion manner. The impregnated material is dried at 120°C for 6 h and calcined at 500°C for 5 h to prepare a hydro-decoking catalyst Cat-1. The properties of the catalyst are shown in Table 1, and the scanning electron microscope image of the outer surface of the catalyst is shown in FIG. 1. Figure 1 . Example 2

[0028] The same as example 1, except that the concentration of boric acid solution in step (1) is 11.5wt%, the concentration of propylene oxide in step (2) is 6.8wt%, the solution amount is 530g, the hydrothermal treatment is first at 75°C for 2.5h, then at 130°C for 4.5h; the concentration of boric acid solution in step (3) is 24wt%, the temperature is 55°C, the ultrasonic frequency is 45kHz, the power is 80W, and the ultrasonic time is 50min, to produce the hydrogenation de-coking catalyst Cat-2, the catalyst properties are shown in Table 1. Example 3

[0029] The same as example 1, except that the concentration of boric acid solution in step (1) is 14.5wt%, the concentration of propylene oxide in step (2) is 7.5wt%, the solution amount is 450g, the hydrothermal treatment is first at 60°C for 3.5h, then at 160°C for 2.5h; the concentration of boric acid solution in step (3) is 18wt%, the temperature is 65°C, the ultrasonic frequency is 25kHz, the power is 120W, and the ultrasonic time is 30min, to produce the hydrogenation de-coking catalyst Cat-3, the catalyst properties are shown in Table 1. Example 4

[0030] The same as example 1, except that the concentration of boric acid solution in step (1) is 12.5wt%, the concentration of propylene oxide in step (2) is 4.5wt%, the solution amount is 760g, the hydrothermal treatment is first at 90°C for 1.5h, then at 125°C for 5.5h; the concentration of boric acid solution in step (3) is 26wt%, the temperature is 50°C, the ultrasonic frequency is 50kHz, the power is 60W, and the ultrasonic time is 60min, to produce the hydrogenation de-coking catalyst Cat-4, the catalyst properties are shown in Table 1.

[0031] Comparative Example 1

[0032] The same as example 1, except that the alumina carrier in step (1) is not boron-modified, but in step (3) the carrier is impregnated with the same amount of boron at one time, to produce the catalyst Cat-5, the catalyst properties are shown in Table 1.

[0033] Comparative Example 2

[0034] The same as example 1, except that the propylene oxide aqueous solution in step (2) is replaced by the same concentration of ethylene oxide solution, to produce the catalyst Cat-6, the catalyst properties are shown in Table 1, and the scanning electron microscope image of the outer surface of the catalyst is shown in Figure 2 .

[0035] Comparative Example 3

[0036] The same as example 1, except that the concentration of propylene oxide in step (2) is 2%, to produce the catalyst Cat-7, the catalyst properties are shown in Table 1.

[0037] Comparative Example 4

[0038] The same as Example 1, except that the hydrothermal treatment in step (2) is one-step hydrothermal treatment, the temperature of the hydrothermal treatment is 75℃, and the treatment time is 14 hours, to obtain a catalyst Cat-8. The properties of the catalyst are shown in Table 1.

[0039] Table 1 Properties of the catalysts for hydro-decarbon residue removal

[0040] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Catalyst Cat-1 Cat-2 Cat-3 Cat-4 Cat-5 Cat-6 Cat-7 Cat-8 Specific surface area, m 2 / g]] 253 267 271 259 256 221 235 242 Pore volume, mL / g 0.92 0.95 0.89 0.93 0.93 0.79 0.85 0.83 8-15 nm Pore Channel Content, % 75.3 74.8 73.6 76.5 75.1 50.8 52.7 53.1 Surface Worm-like Grain Size, nm 85-330 90-340 80-340 85-335 85-335 — — — Molybdenum Oxide Content, wt% 18.2 18.4 18.1 18.3 18.6 18.3 18.4 18.2 Nickel Oxide Content, wt% 3.7 3.8 3.7 3.9 3.8 3.9 3.8 3.7 Total Acid Amount 0.51 0.50 0.48 0.46 0.49 0.50 0.48 0.49 B Acid 0.14 0.15 0.14 0.12 0.05 0.15 0.12 0.14 L Acid 0.37 0.35 0.34 0.34 0.44 0.35 0.36 0.35

[0041] From the data in Table 1 and Figure 1 、 2 It can be seen that, compared with the catalysts of the comparative examples, the catalysts prepared by the method of the present application have a higher content of pores with a diameter of 8-15 nm, and the catalysts have a rich content of large pores on the surface and good pore opening. Example 5

[0042] The catalysts Cat-1, Cat-2, Cat-3, Cat-4 prepared by the method of the present application and the catalysts Cat-5, Cat-6, Cat-7, Cat-8 prepared by the method of the comparative examples are respectively loaded into a fixed-bed hydrogenation reactor, and the catalytic performance of the catalysts is evaluated, with a certain vacuum residue as the raw material (the content of sulfur in the raw material is 4.8wt%, the content of nitrogen is 0.42wt%, and the content of carbon residue is 17.6wt%). The reaction conditions are as follows: the reaction temperature is 380℃, the pressure is 14.0MPa, the liquid hourly space velocity is 0.5h -1 , the hydrogen / oil volume ratio is 750, and the content of each impurity in the generated oil is measured after 2000 hours of reaction, to calculate the removal rate of the impurities. The evaluation results are shown in Table 2.

[0043] Table 2 Evaluation results of the catalysts

[0044]

Claims

1. A process for the preparation of a hydrodecarbon residue catalyst, characterized in that The preparation method comprises the following steps: (1) preparing a boron-modified alumina carrier A; (2) immersing the boron-modified alumina carrier A into an aqueous propylene oxide solution, treating the carrier in a sealed pressure-resistant container at 60-100 DEG C for 1-4 hours, then raising the temperature to 110-180 DEG C and treating the carrier for 2-6 hours, and then drying the carrier after the treatment to obtain an alumina carrier B; (3) ultrasonic treating the alumina carrier B immersed in a boric acid solution, and then drying the carrier after the treatment to obtain an alumina carrier C, and then loading a hydrogenation active component to obtain a hydro-decoking catalyst; the preparation process of the boron-modified alumina carrier A in step (1) comprises the following steps: performing a parallel flow gelation reaction of an aluminum sulfate solution and a sodium metaaluminate solution, then aging, filtering to obtain a filter cake, mixing the filter cake with boric acid, then filtering, washing and drying to obtain boron-modified pseudo-boehmite; mixing, extruding, drying and calcining the boron-modified pseudo-boehmite to obtain the boron-modified alumina carrier A; the concentration of the aluminum sulfate solution is 8.3-9.5 g / 100 mL in terms of Al2O3, the concentration of the sodium metaaluminate solution is 15.5-19.6 g / 100 mL in terms of Al2O3, the reaction pH value is 8.0-9.2, the aging temperature is 70-90 DEG C, and the aging time is 0.5-2 h; the concentration of the boric acid solution is 10.5 wt%-15.5 wt%; the drying temperature is 100-160 DEG C, and the drying time is 1-10 hours; the calcination temperature is 450-600 DEG C, and the calcination time is 2-8 hours; the concentration of the aqueous propylene oxide solution in step (2) is 2.5 wt%-12 wt%; the mass ratio of the aqueous propylene oxide solution to the boron-modified alumina carrier A is 3:1-10:1; the loading process in step (3) adopts an impregnation method, the active component impregnation solution is a solution containing Group VIB and Group VIII metals, the Group VIB metal is selected from one or more of W and Mo, and the Group VIII metal is selected from one or more of Co and Ni.

2. The method of claim 1, wherein: The concentration of the aqueous propylene oxide solution in step (2) is 4 wt%-8 wt%.

3. The method of claim 1, wherein: The mass ratio of the aqueous propylene oxide solution to the boron-modified alumina carrier A is 4:1-8:

1.

4. The method of claim 1, wherein: The drying temperature in step (2) is 100-160 DEG C, and the drying time is 2-8 hours.

5. The method of claim 1, wherein: The concentration of the boric acid solution in step (3) is 17 wt%-28 wt%, and the solution amount is enough to immerse the alumina carrier completely.

6. The method of claim 1, wherein: The ultrasonic treatment temperature in step (3) is 45-65 DEG C, the ultrasonic frequency is 25-50 kHz, the ultrasonic power is 50-125 W, and the ultrasonic time is 30-60 min.

7. The method of claim 1, wherein: The drying temperature in step (3) is 100-160 DEG C, the drying time is 2-8 hours, the calcination temperature is 450-550 DEG C, and the calcination time is 4-6 hours.

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