Preparation method and application of heavy residual oil hydrogenation protectant

Abstract

The present invention aims to provide a method for preparing and applying a hydrotreating protectant for heavy residue oil, belonging to the field of catalyst preparation. The method includes the following steps: preparing an alumina sol and adding spherical carbon particles to the alumina sol; mixing the materials evenly and then forming droplets; drying and calcining the formed material to obtain an alumina support with spherical pores; hydrothermally treating the alumina support with spherical pores in an organic ammonium solution; drying and calcining the treated material to obtain another alumina support; impregnating the alumina support with an impregnation solution containing an active metal component; and drying and calcining the impregnated support to obtain the hydrotreating protectant. The hydrotreating protectant prepared by this method has large surface pores with good permeability and high internal pores that can accommodate metal impurities. This catalyst is suitable for the field of heavy residue oil hydrotreating.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation, specifically relating to a method for preparing and applying a heavy residue oil hydroprotectant. Background Technology

[0002] Deep processing of heavy oil, including residue oil, not only improves its utilization rate and alleviates energy supply shortages, but also reduces environmental pollution and achieves cleaner energy use. Compared to distillate oils, heavy oils, such as residue oil, have higher levels of metallic atoms such as nickel (Ni), vanadium (V), iron (Fe), and calcium (Ca); and iron in some heavy oils with high naphthenic acid content can concentrate in the form of iron naphthenate. Metallic impurities such as Ni, V, Fe, and Ca can easily cause scaling and blockage of the catalyst bed during residue oil hydrogenation, leading to forced shutdowns due to excessive pressure drop. One effective way to solve this problem is to load a hydrogenation-active protective agent (i.e., a hydrogenation protective agent) onto the top of the hydrogenation catalyst.

[0003] CN106622307A discloses a hydrogenation protective agent, its preparation method, and its application. The protective agent uses a carrier that has undergone hydrothermal treatment, which is repeatedly impregnated and dried sequentially, and the final dried product is calcined. The acidic auxiliary agent in the carrier prepared by this method is distributed in layers; however, the pore size of the carrier surface is small, making it prone to scaling and clogging during hydrogenation reactions.

[0004] CN111821990A discloses a support, catalyst, and preparation method for a residue oil hydrotreating protective agent. The catalyst comprises an alumina support and a hydrotreating active component. The support is a modified alumina-based support containing a modifying element and a first hydrotreating active metal component. The modified alumina-based support comprises a main modified alumina and rod-shaped modified alumina. The main modified alumina is alumina with micron-sized pores, wherein at least some rod-shaped modified alumina is distributed on the outer surface of the main modified alumina and in micron-sized pores with a pore diameter D of 5-10 μm. The modifying element is vanadium, and the first hydrotreating active metal component is molybdenum. The catalyst prepared by this method has large and open surface pores, but the rod-shaped alumina grains grown on the surface are prone to detachment. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for preparing a hydroprotectant for heavy residue oil and its application. The hydroprotectant prepared by this method has large surface pores with good permeability and high internal capacity for metal impurities. This catalyst is suitable for the field of heavy residue oil hydrotreating.

[0006] The present invention adopts the following technical solution:

[0007] A method for preparing a hydroprotectant for heavy residue oil includes the following steps:

[0008] The first step is to prepare aluminum sol and add spherical carbon particles to the aluminum sol. After the materials are mixed evenly, drop balls are formed. The formed products are dried and calcined to obtain an alumina carrier with spherical pores.

[0009] The second step involves placing the alumina support with spherical pores in an organic ammonium solution for hydrothermal treatment. After treatment, the material is dried and calcined to obtain the alumina support.

[0010] The third step involves impregnating the alumina carrier with an impregnation solution containing active metal components. The impregnated carrier is then dried and calcined to obtain a hydrogenation protective agent.

[0011] Furthermore, the preparation method of the aluminum sol described in the first step is well known in the art. It generally involves mixing boehmite with a certain volume of distilled water until homogeneous, and then adding a certain amount of acid solution for acidification while stirring. The boehmite is preferably boehmite with a pore size greater than 15 nm, and more preferably prepared by the aluminum sulfate-sodium aluminate method. The acid solution is one or a mixture of several of nitric acid, acetic acid, formic acid, and oxalic acid solutions, preferably a nitric acid solution. The solid content in the sol is 15%-35%.

[0012] Furthermore, the spherical carbon particles mentioned in the first step can be commercially available or prepared by existing methods. The spherical carbon particles have a diameter of 1-8 μm, preferably 1-5 μm, and the mass ratio of spherical carbon particles to aluminum sol is 0.5%-1.0%.

[0013] Furthermore, the droplet forming technology described in the first step is well known in the art and is generally performed in an oil-ammonia column apparatus. The oil phase in the oil-ammonia column apparatus is one or more of diethyl ether, toluene, machine oil, petroleum ether, and mineral oil, while the aqueous phase is an ammonia solution. The oil phase height is 10-30 cm, and the aqueous phase height is 5-35 cm.

[0014] Furthermore, the drying temperature in the first step is 120-180℃, and the drying time is 1-8 hours; the calcination temperature is 450-600℃, and the calcination time is 4-8 hours, and the calcination is carried out in an oxygen atmosphere.

[0015] Furthermore, the organic ammonium solution mentioned in the second step includes one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrapropylammonium hydroxide, preferably tetraethylammonium hydroxide.

[0016] Furthermore, the hydrothermal treatment in the second step is a sealed hydrothermal treatment performed in a sealed device, preferably an autoclave. The hydrothermal treatment is carried out in two steps: a primary hydrothermal treatment and a secondary hydrothermal treatment. In the primary hydrothermal treatment, the organic ammonium solution has a mass concentration of 0.8%-2.0%, the solution volume is sufficient to completely submerge the solid material, the hydrothermal treatment temperature is 80-120℃, and the treatment time is 1-4 hours. In the secondary hydrothermal treatment, the organic ammonium solution has a mass concentration of 3.5%-12.5%, the solution volume is sufficient to completely submerge the solid material, the hydrothermal treatment temperature is 140-180℃, and the treatment time is 4-10 hours. The types of organic ammonium used in the primary and secondary hydrothermal treatments can be the same or different, but are preferably the same.

[0017] Furthermore, in the second step, the drying temperature is 100-160℃ and the drying time is 2-8 hours, and the calcination temperature is 650-850℃ and the calcination time is 4-6 hours.

[0018] Furthermore, the impregnation solution containing active metal components mentioned in the second step is a molybdenum-nickel-phosphorus solution, in which the molybdenum content, calculated as oxide, is 5.5-9.5 g / 100 mL, and the nickel content, calculated as oxide, is 1.3-4.0 g / 100 mL. During impregnation, supersaturated impregnation or equal-volume impregnation is used, preferably equal-volume impregnation.

[0019] Furthermore, in the third step, the drying temperature is 100-160℃ and the drying time is 2-8 hours, and the calcination temperature is 450-550℃ and the calcination time is 4-6 hours.

[0020] The application conditions of the heavy residue oil hydrotreating protectant of the present invention in the hydrotreating of heavy and residual oils are generally as follows: reaction temperature 320-420℃, hydrogen-to-oil volume ratio 450-1000, and liquid hourly space velocity 0.5-2.5 h⁻¹. -1 Operating pressure: 10.5-14.5 MPa.

[0021] The beneficial effects of this invention are as follows:

[0022] The alumina support used in the heavy residue oil hydrotreating protectant of this invention contains hexagonal plate-shaped alumina particles, which cover the surface of the alumina support and accumulate in micron-sized spherical pores. The interwoven accumulation of these plate-shaped particles forms channels of 100-600 μm. The large pores on the catalyst surface prepared using this alumina support facilitate the diffusion of large molecular reactants into the support, while the open pores on the surface enhance the catalyst's resistance to impurity deposition and clogging. The channels formed by the accumulation of plate-shaped particles in the micron-sized spherical pores of the catalyst bulk phase provide reaction sites for large molecular reactants and have a high capacity to accommodate metallic impurities. During support preparation, two hydrothermal treatments are employed to make the size of the hexagonal plate-shaped alumina particles grown on the alumina support surface and in the micron-sized spherical pores more uniform, resulting in higher surface coverage and micron-sized spherical pore filling. The micron-sized spherical pores are highly filled with hexagonal plate-shaped alumina particles, which support each other, providing large pore channels while giving the catalyst high strength. Attached Figure Description

[0023] Figure 1 is a scanning electron microscope image of the surface of the alumina support A1 prepared in Example 1.

[0024] Figure 2 is a scanning electron microscope image of the cross-section of the alumina support A1 prepared in Example 1.

[0025] Figure 3 is a scanning electron microscope image of the cross-section of the alumina support prepared in Comparative Example 1. Detailed Implementation

[0026] The technical solutions and effects of the present invention will be further illustrated below with reference to the embodiments, but the invention is not limited to the following embodiments.

[0027] The microstructure of the sample was characterized using scanning electron microscopy. The specific operation was as follows: accelerating voltage 8KV, accelerating current 10µA, working distance 8mm.

[0028] Carbon particle preparation:

[0029] The preparation method of the carbon particles used in this invention is referenced in the literature: Preparation of starch-based porous carbon materials and their methylene blue adsorption properties [J]. Journal of Dalian University of Technology, 2020, 39(6): 434-438. The carbon particles prepared are spherical with a particle size of 1-5 μm.

[0030] Example 1

[0031] (1) Weigh 150 g of boehmite (prepared by aluminum sulfate-sodium aluminate method, with a pore size of 15.5 nm), add 400 g of distilled water, stir evenly, add 23.5 ml of concentrated nitric acid to acidify into a sol; weigh 100 g of the above aluminum sol, add 0.8 g of carbon particles prepared by the above method, and then stir the mixture evenly; drop the mixed sol into an oil-ammonia column device to form drop balls, age the formed material for 3 hours, then dry at 150°C for 4 hours, and calcine at 500°C in an oxygen atmosphere for 6 hours to obtain an alumina carrier with spherical pores.

[0032] (2) Take an appropriate amount of the alumina support prepared in step (1) and add it to the polytetrafluoroethylene liner of the autoclave. Add a 1.45wt% tetraethylammonium hydroxide solution to completely submerge the alumina support. After sealing the autoclave, perform a first hydrothermal treatment at 95℃ for 3 hours. After treatment, the material undergoes liquid-solid separation. Add a 6.5wt% tetraethylammonium hydroxide solution again. After sealing the autoclave, perform a second hydrothermal treatment at 160℃ for 6 hours. After treatment, dry the material at 140℃ for 6 hours and calcine at 750℃ for 5 hours to obtain the alumina support. The scanning electron microscope image of the support surface is shown below. Figure 1 Cross-sectional scanning electron microscope image is shown below. Figure 2 .

[0033] (3) Weigh an appropriate amount of the alumina support from step (2) and place it in a spray-dip boiling pot. Impregnate the support with an equal volume of molybdenum-nickel-phosphorus impregnation solution with a molybdenum oxide concentration of 6.2 g / 100 mL and a nickel oxide concentration of 1.5 g / 100 mL. After impregnation, dry the material at 120 °C for 4 hours and calcine at 450 °C for 5 hours to obtain the hydrogenation protection agent Cat-1. The properties of the catalyst are shown in Table 1.

[0034] Example 2

[0035] Same as Example 1, except that the amount of carbon particles added in step (1) is 0.7 g. In step (2), the concentration of the organic ammonium solution in the first hydrothermal treatment is 1.15 wt%, the hydrothermal treatment temperature is 105 °C, and the treatment time is 2 hours. In the second hydrothermal treatment, the concentration of the organic ammonium solution is 9 wt%, the hydrothermal treatment temperature is 150 °C, and the treatment time is 7 hours, thus obtaining the hydrogenation protective agent Cat-2. The catalyst properties are shown in Table 1.

[0036] Example 3

[0037] Same as Example 1, except that the amount of carbon particles added in step (1) is 0.6 g. In step (2), during the first hydrothermal treatment, tetraethylammonium hydroxide is replaced with tetrapropylammonium hydroxide, the solution concentration is 1.75 wt%, the hydrothermal treatment temperature is 85 °C, and the treatment time is 4 hours. During the second hydrothermal treatment, tetraethylammonium hydroxide is replaced with tetrapropylammonium hydroxide, the solution concentration is 4 wt%, the hydrothermal treatment temperature is 170 °C, and the treatment time is 5 hours, thus obtaining the hydrogenation protective agent Cat-3. The catalyst properties are shown in Table 1.

[0038] Example 4

[0039] Same as Example 1, except that the amount of carbon particles added in step (1) is 0.9 g. In step (2), during the first hydrothermal treatment, the concentration of the organic ammonium solution is 0.85 wt%, the hydrothermal treatment temperature is 115 °C, and the treatment time is 1.5 hours. During the second hydrothermal treatment, the concentration of the organic ammonium solution is 12 wt%, the hydrothermal treatment temperature is 140 °C, and the treatment time is 9 hours, thus obtaining the hydrogenation protective agent Cat-4. The catalyst properties are shown in Table 1.

[0040] Comparative Example 1

[0041] Same as Example 1, except that tetraethylammonium hydroxide in step (2) was replaced with ammonia of the same concentration to prepare the comparative hydrogenation protectant Cat-5. The catalyst properties are shown in Table 1, and the corresponding scanning electron microscope images of the alumina support cross-section are shown in Table 1. Figure 3 .

[0042] Comparative Example 2

[0043] Same as Example 1, except that step (2) tetraethylammonium hydroxide was replaced with sodium hydroxide of the same concentration to prepare comparative hydrogenation protectant Cat-6. Catalyst properties are shown in Table 1.

[0044] Comparative Example 3

[0045] Same as Example 1, except that the hydrothermal treatment was not performed using a high-pressure autoclave, but instead under atmospheric pressure reflux in a condenser reflux apparatus to obtain the comparative hydrogenation protectant Cat-7. The catalyst properties are shown in Table 1.

[0046] Table 1 Properties of Hydrogenation Protectants

[0047]

[0048] As can be seen from Table 1, the catalyst prepared by the method of the present invention has a large number of macropores of 100-600 nm on its surface and in its micron-sized spherical pores.

[0049] from Figure 1 and Figure 2It can be seen that the alumina support used to prepare the catalyst of the present invention has open pores on its surface, which is conducive to the diffusion of macromolecular reactants and improves the anti-clogging ability of the catalyst surface; at the same time, the catalyst bulk phase contains a lot of macroporous regions with strong metal impurity tolerance.

[0050] Example 5

[0051] The hydrogenation protective catalysts Cat-1 to Cat-7 prepared in the above examples and comparative examples were respectively loaded into fixed-bed hydrogenation reactors for reaction activity evaluation. The feedstock oil contained Ni 53.5 mg / kg, V 92.2 mg / kg, Fe 13.8 mg / kg, and Ca 16.6 mg / kg. The operating conditions were as follows: reaction temperature 385℃, hydrogen-to-oil volume ratio 850, and liquid hourly space velocity 1.0 h⁻¹. -1 The hydrogen partial pressure was 14.5 MPa, and the impurity removal properties were obtained after 1200 hours of continuous operation. See Table 2 for the results.

[0052] Table 2 Evaluation results of the catalyst

[0053]

[0054] As can be seen from the results in Table 2, the hydrogenation protection catalyst prepared by the method of the present invention has high activity for removing Ca, Fe, Ni and V, and at the same time, the catalyst has good activity stability.

Claims

1. A method for preparing a hydroprotectant for heavy residue oil, characterized in that: Includes the following steps: The first step is to prepare aluminum sol and add spherical carbon particles to the aluminum sol. After the materials are mixed evenly, drop balls are formed. The formed products are dried and calcined to obtain an alumina carrier with spherical pores. The second step involves placing the alumina support with spherical pores in an organic ammonium solution for hydrothermal treatment. After treatment, the material is dried and calcined to obtain the alumina support. The organic ammonium solution includes one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrapropylammonium hydroxide; The hydrothermal treatment is a sealed hydrothermal treatment carried out in a sealed device. The hydrothermal treatment is carried out in two steps, namely a primary hydrothermal treatment and a secondary hydrothermal treatment. In the primary hydrothermal treatment, the mass concentration of the organic ammonium solution is 0.8%-2.0%, the solution volume is sufficient to completely submerge the solid material, the hydrothermal treatment temperature is 80-120℃, and the treatment time is 1-4 hours. In the secondary hydrothermal treatment, the mass concentration of the organic ammonium solution is 3.5%-12.5%, the solution volume is sufficient to completely submerge the solid material, the hydrothermal treatment temperature is 140-180℃, and the treatment time is 4-10 hours. The types of organic ammonium in the primary and secondary hydrothermal treatments may be the same or different. The third step involves impregnating the alumina carrier with an impregnation solution containing active metal components. The impregnated carrier is then dried and calcined to obtain a hydrogenation protective agent. The impregnation solution containing active metal components is a molybdenum-nickel-phosphorus solution, in which the molybdenum content (calculated as oxide) is 5.5-9.5 g / 100 mL and the nickel content (calculated as oxide) is 1.3-4.0 g / 100 mL. Supersaturated impregnation or equal-volume impregnation is used during impregnation.

2. The method for preparing a heavy residue oil hydrotreating protectant according to claim 1, characterized in that: The preparation method of the aluminum sol in the first step is as follows: Boehmite is mixed evenly with distilled water, and then acidified by adding an acid solution under stirring; the possible pore size of the boehmite is greater than 15 nm; the acid solution includes one or a mixture of several of nitric acid, acetic acid, formic acid and oxalic acid solutions, and the solid content in the sol is 15%-35%.

3. The method for preparing a heavy residue oil hydrotreating protectant according to claim 1, characterized in that: The spherical carbon particles mentioned in the first step have a particle size of 1-8 μm, and the mass ratio of spherical carbon particles to aluminum sol is 0.5%-1.0%.

4. The method for preparing a heavy residue oil hydrotreating protectant according to claim 1, characterized in that: The droplet forming described in the first step is completed in an oil-ammonia column apparatus. The oil phase of the oil-ammonia column apparatus includes one or more of diethyl ether, toluene, machine oil, petroleum ether, and mineral oil, and the aqueous phase is an ammonia solution. The height of the oil phase is 10-30 cm and the height of the aqueous phase is 5-35 cm. The drying temperature in the first step is 120-180℃, and the drying time is 1-8 hours; the calcination temperature is 450-600℃, and the calcination time is 4-8 hours, and the calcination is carried out in an oxygen atmosphere.

5. The method for preparing a heavy residue oil hydrotreating protectant according to claim 1, characterized in that: The drying temperature in the second step is 100-160℃, and the drying time is 2-8 hours. The calcination temperature is 650-850℃, and the calcination time is 4-6 hours.

6. The method for preparing a heavy residue oil hydrotreating protectant according to claim 1, characterized in that: The drying temperature in the third step is 100-160℃, and the drying time is 2-8 hours. The calcination temperature is 450-550℃, and the calcination time is 4-6 hours.

7. A heavy residue oil hydrotreating protectant as described in claim 1, applied to the hydrotreating of heavy and residual oils, wherein the application conditions are: reaction temperature 320-420℃, hydrogen-to-oil volume ratio 450-1000, and liquid hourly space velocity 0.5-2.5 h⁻¹. -1 Operating pressure: 10.5-14.5 MPa.

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