Process for the preparation of a hydrogenation catalyst and use thereof

Abstract

The application discloses a preparation method of a hydrogenation catalyst and application of the hydrogenation catalyst. The preparation method comprises the following steps: step 1, co-precipitating an aluminum precursor and a modified metal salt by using an alkaline precipitant, wherein the alkaline precipitant is one or more of potassium carbonate, potassium hydroxide and potassium bicarbonate; step 2, aging a system obtained in step 1, filtering, and directly drying a filter cake obtained in the step 2 to obtain a modified alumina dry gel; and step 3, preparing a carrier from the modified alumina dry gel, and then loading an active component to obtain the hydrogenation catalyst. The hydrogenation catalyst has high catalytic activity and high desulfurization selectivity.

Description

TECHNICAL FIELD

[0001] The present application relates to a preparation method of a hydrogenation catalyst suitable for high selective hydrodesulfurization of catalytically cracked gasoline. BACKGROUND

[0002] The desulfurization activity and selectivity of the high selective hydrodesulfurization catalyst of catalytically cracked gasoline are closely related to the stacking number and the size of the MoS2 active phase, and the modification of the carrier by introducing rare earth elements and alkali elements and other additives can effectively control the stacking number and the size of the MoS2 active phase, which is beneficial to improve the metal sulfuration degree. CN102049269B discloses a selective hydrogenation catalyst for gasoline and a preparation method thereof. First, aluminum sulfate and sodium metaaluminate are used to form alumina gel, and titanium oxide and / or zirconium oxide are introduced during the beating process to obtain modified alumina dry gel powder. A proper amount of carbon and silicon oxide is added during kneading to obtain an alumina carrier. Then, the additives potassium and phosphorus are loaded by impregnation method, and the modified carrier is obtained after drying and calcination. Finally, the active metals Co and Mo are loaded by impregnation method. The method enhances the coordination between the carrier and the additives by introducing potassium and phosphorus additives, prevents the loss of alkali metal, inhibits the olefin saturation activity, and maintains high hydrodesulfurization activity, selectivity and stability. However, the preparation process is complicated, and the modification of the carrier by introducing additives by impregnation method has problems such as easy accumulation of modified additives on the surface of the carrier, difficult entry into the pores, and easy loss during use. Although the loss of potassium is prevented by introducing carbon and the additive phosphorus to play a coordinating role, carbon must be calcined at 400-550 degrees under anaerobic conditions to prevent the occurrence of phenomena such as catalyst ignition and bar explosion.

[0003] CN103657668A discloses a selective nickel-based hydrogenation catalyst and a preparation method thereof. The alumina carrier is prepared by spraying the aluminum hydroxide powder with a complex solution of alkali metal Li and / or K. The alumina hydroxide powder is fully contacted with the compound containing alkali metal Li and / or K by kneading, which can avoid the introduction of excessive water into the alumina hydroxide powder, reduce the acidity of the carrier, improve the electronic affinity of the carrier, and improve the thermal stability, diene hydrogenation selectivity and resistance to impurities such as sulfur and arsenic of the catalyst. Although the solution spraying method simplifies the catalyst preparation process, it still has problems such as easy accumulation of modified additives on the surface of the carrier, difficult entry into the pores, and easy loss during use. At the same time, it is easy to spray unevenly, and the kneading process can also affect the combination state of the alumina and the modified additives.

[0004] CN105268449B discloses a hydrogenation catalyst and its application in hydrodeoxygenation. The alumina support containing one or more auxiliary metal components selected from Groups IA, IIA, and IVB can be prepared via two routes: 1. Calcinated alumina is mixed with at least one boehmite and / or pseudo-boehmite and water to obtain a mixture, which is then heated, shaped, dried, and calcined before the auxiliary metal component is introduced by impregnation. 2. Based on route 1, the auxiliary metal is introduced during the mixing process, avoiding the subsequent impregnation step. This method, by adding improved auxiliary agents to alumina and boehmite, but requiring heat treatment to maintain the alumina crystal phase and high specific surface area and pore volume, effectively alleviates the problems of conventional impregnation methods, such as the accumulation of modified auxiliary agents on the support surface, difficulty in entering pores, and easy loss during use. However, problems still exist, such as metal auxiliary agent agglomeration on the crystal nucleus surface, weak metal-support interaction, and easy loss. Furthermore, the catalyst preparation process is relatively cumbersome.

[0005] CN 112619632 A discloses a modified alumina support and its preparation method. First, pseudoboehmite is prepared by co-currently adding an aluminum source and a precipitant to an aqueous solution of one or more precursors (boron, phosphorus, or fluorine) for a precipitation reaction. Second, the pseudoboehmite is added to an aqueous solution containing one or more precursors (magnesium oxide, calcium oxide, or zirconium oxide) and urea for hydrothermal treatment to obtain modified pseudoboehmite. Then, the modified pseudoboehmite is mixed uniformly with a binder and an extrusion aid, extruded into strips, dried, and calcined to obtain an alumina support. Finally, a metal containing Group VIII is loaded onto the alumina support and subjected to sulfidation treatment to obtain the modified alumina support. The method involves four steps: introducing acidic regulating agents through precipitation reaction, introducing metal additives through hydrothermal treatment, kneading and extruding the carrier into strips, and loading the metal to prepare the modified alumina carrier. The preparation process is quite complicated. Although adding metal additives to the pseudoboehmite base and performing hydrothermal treatment can maintain the alumina crystal phase and characteristics such as high specific surface area and pore volume, the metal additives are easy to deposit on the surface of the crystal nuclei and have difficulty entering the pores, resulting in problems such as weak interaction between the metal and the carrier and easy loss during use.

[0006] CN 102989453 B discloses a pre-hydrogenation catalyst for C2 and its preparation method. First, KAlO2 or NaAlO2, ZrCl4, and TiCl4 solutions are mixed under stirring conditions, then neutralized with an alkaline solution to generate a coprecipitate of aluminum zirconium titanium hydroxide. The K2 hydroxide is then filtered and washed away. + Na + and Cl -After ionization, a pore-expanding agent is added, and the mixture is kneaded, shaped, dried, and calcined to obtain a support. The support is then immersed in a solution containing palladium and silver, filtered, washed, dried, and calcined to obtain a catalyst. Although this method introduces K or Na through co-precipitation, and K and Na can change the surface acidity of the catalyst, the co-precipitated product is washed down to less than 0.5% during filtration. Due to the low content, its ability to regulate the acidity of the catalyst is limited, and its effect on modulating the interaction between the metal and the support is not significant. At the same time, in order to ensure the content of K or Na, repeated washing easily leads to the generation of a lot of waste liquid, which is not conducive to environmentally friendly production.

[0007] Therefore, the commonly used method for modifying catalyst supports is the loading method. However, this method is cumbersome and easily leads to the accumulation of modified additives on the support surface, making it difficult for them to enter the catalyst channels and affecting their ability to regulate the metal active phase. Furthermore, these additives are prone to loss during use, making it difficult to maintain catalyst stability over a long period. In the process of synthesizing supports from boehmite using the co-precipitation method, potassium carbonate is sometimes used as a co-precipitant. However, in order to control the metal cation K in the precipitant… + The high K content necessitates multiple washings, resulting in a large amount of waste liquid, which is detrimental to environmental protection. It also leads to excessively low K content, resulting in an insignificant effect on the modulation of the interaction force between the metal and the carrier. Summary of the Invention

[0008] The main objective of this invention is to provide a method for preparing a hydrogenation catalyst and its application, so as to overcome the defects of existing hydrogenation catalysts such as poor stability, poor control effect of modifying agents, and large amount of waste liquid.

[0009] To achieve the above objectives, the present invention provides a method for preparing a hydrogenation catalyst, comprising the following steps:

[0010] Step 1: Co-precipitate aluminum precursor and modified metal salt using an alkaline precipitant, wherein the alkaline precipitant is one or more of potassium carbonate, potassium hydroxide, and potassium bicarbonate.

[0011] Step 2: Aging and filtering the system obtained in Step 1, and then drying the resulting filter cake to obtain modified alumina dry gel.

[0012] Step 3: Prepare the modified alumina dry gel as a support, and then load the active component to obtain the hydrogenation catalyst.

[0013] In the preparation method of the hydrogenation catalyst of the present invention, the filtrate obtained by filtration in step 2 is recycled for the co-precipitation process in step 1.

[0014] The method for preparing the hydrogenation catalyst according to the present invention, wherein step 1 includes:

[0015] Step 1a: Mix the solution of aluminum precursor and part of the solution of alkaline precipitant, and control the pH value of the system between 7.0 and 9.0 by controlling the mixing rate;

[0016] Step 1b: Add the remaining alkaline precipitant solution and the modified metal salt solution to the system of step 1a. By controlling the addition rate, the pH value of the system is controlled at 7.0 to 9.0.

[0017] In step 2, the filtrate obtained from filtration is recycled for the preparation of solutions for aluminum precursors and alkaline precipitants.

[0018] The method for preparing the hydrogenation catalyst according to the present invention, wherein the amount of alkaline precipitant added, including a portion and the remainder, is such that the mass content of K, calculated as potassium oxide, in the obtained hydrogenation catalyst is 2% to 4%.

[0019] The method for preparing the hydrogenation catalyst of the present invention includes an aluminum precursor that is a soluble aluminum salt and a modified metal salt that is at least one of zirconium salt, lanthanum salt, and copper salt. The amount of modified metal salt added is such that the mass content of the modified metal, calculated as modified metal oxide, in the obtained hydrogenation catalyst is 0.1%-5%.

[0020] The method for preparing the hydrogenation catalyst according to the present invention includes an aluminum precursor that is at least one of aluminum nitrate and aluminum sulfate; and a modified metal salt that is at least one of zirconium nitrate, lanthanum nitrate, copper nitrate, zirconium acetate, lanthanum acetate, and copper acetate.

[0021] In the preparation method of the hydrogenation catalyst of the present invention, in step 1a, the mixing temperature of the aluminum precursor solution and the solution of part of the alkaline precipitant is 20-80℃, and the mixing time is 30-50min.

[0022] In the preparation method of the hydrogenation catalyst of the present invention, the addition time of the solution of the remaining alkaline precipitant and the solution of the modified metal salt is 5-15 min, and the temperature of the system is controlled at 20-80℃.

[0023] The method for preparing the hydrogenation catalyst of the present invention includes an aging temperature of 60-100°C and an aging time of 60-180 min; and a filter cake drying temperature of 120-180°C and a drying time of 60-120 min.

[0024] The method for preparing the hydrogenation catalyst according to the present invention includes the following step: preparing the modified alumina dry adhesive into a carrier by mixing the modified alumina dry adhesive with a binder, a pore-expanding agent, and an extrusion aid, extruding the mixture into strips, and then drying and calcining it to obtain the carrier; the binder is one or more of silica sol, nitric acid, acetic acid, and malic acid; the pore-expanding agent is one or more of citric acid, yeast, methylcellulose, and hydroxypropyl methylcellulose; the extrusion aid is one or more of guar gum powder, starch, and citric acid; the dry weight ratio of the binder to the modified alumina dry adhesive is 0.02-0.05:1, the dry weight ratio of the pore-expanding agent to the modified alumina dry adhesive is 0.01-0.1:1, and the dry weight ratio of the extrusion aid to the modified alumina dry adhesive is 0.01-0.05:1.

[0025] The method for preparing the hydrogenation catalyst of the present invention, wherein the active component is at least one of a Group VIII element and a Group VIB element; and the active component in the hydrogenation catalyst has a mass content of 9%-20% based on metal oxides.

[0026] The method for preparing the hydrogenation catalyst according to the present invention, wherein the active component is Mo, and at least one of Co and Ni; wherein the content of Mo as MoO3 in the hydrogenation catalyst is 8.0% to 16.0%, and the content of Co and / or Ni as oxides is 1.0% to 4.0%.

[0027] To achieve the above objectives, the present invention also provides the application of the hydrogenation catalyst obtained by the above preparation method in the hydrodesulfurization of distillate oil.

[0028] The beneficial effects of this invention are:

[0029] (1) This invention uses potassium salt as an alkaline precipitant, and can also utilize K + As a precursor for modified metals, it achieves the dual purpose of precipitation and metal modification. In addition, after the system is aged and filtered, the resulting filter cake is directly dried without washing to obtain modified alumina dry gel. The potassium retained on the alumina can then modify the alumina in situ. Utilizing potassium's characteristics as an electronic aid to donate electrons and as an alkaline aid to regulate the acid and pore distribution of the support, the alumina has a concentrated pore structure (60-80% of the pores are 10-20 nm), while weakening the interaction between the support and the active component, which helps to improve the desulfurization selectivity of the catalyst. Moreover, it can avoid the generation of a large amount of waste liquid caused by washing.

[0030] (2) Further, the present invention first mixes the aluminum precursor with a portion of the alkaline precipitant to precipitate aluminum, and then adds the remaining alkaline precipitant and modified metal salt to precipitate the modified metal. By controlling the pH value of the precipitation system, it can not only ensure that the alumina grains are uniform, structurally complete, with few agglomerates and ideal pore structure, but also utilize the rich pore structure of alumina to achieve in-situ modification of alumina by the modified metal, promote the modified metal to enter the alumina pores, effectively modulate the interaction force between the modified metal and the carrier, avoid problems such as loss of modified metal during use, and at the same time increase the sulfidation degree of the active metal component and increase the number of MoS2 active centers, which helps to improve the desulfurization activity of the hydrogenation catalyst.

[0031] (3) Furthermore, the present invention filters the aging system and recycles the filtrate for the preparation of aluminum precursor solution and alkaline precipitant solution. This not only reduces the loss of aluminum and alkaline precipitant and achieves the environmentally friendly production goal of zero discharge of waste liquid containing metal ions, but also saves water resources. Detailed Implementation

[0032] The technical solution of the present invention will be described in detail below. The following embodiments are implemented under the premise of the technical solution of the present invention and a detailed implementation process is given. However, the protection scope of the present invention is not limited to the following embodiments. Structures or experimental methods that do not specify specific conditions in the following embodiments are generally performed under conventional conditions.

[0033] This invention provides a method for preparing a hydrogenation catalyst, comprising the following steps:

[0034] Step 1: Co-precipitate aluminum precursor and modified metal salt using an alkaline precipitant, wherein the alkaline precipitant is one or more of potassium carbonate, potassium hydroxide, and potassium bicarbonate.

[0035] Step 2: Aging and filtering the system obtained in Step 1, and then drying the resulting filter cake to obtain modified alumina dry gel.

[0036] Step 3: Prepare the modified alumina dry gel as a support, and then load the active component to obtain the hydrogenation catalyst.

[0037] This invention uses potassium salts as alkaline precipitants. After aging, the system is filtered, and the resulting filter cake is directly dried without washing to obtain modified alumina dry gel. The potassium retained on the alumina can serve as a precursor for modified metals, enabling in-situ modification of the alumina. Utilizing potassium's electron-donating properties as an electronic aid and its ability to regulate the acid and pore distribution of the support as an alkaline aid, the alumina achieves a concentrated pore structure (60-80% of pores are 10-20 nm) while weakening the interaction between the support and the active components, thus improving the catalyst's desulfurization selectivity. Furthermore, it avoids the generation of large amounts of waste liquid caused by washing.

[0038] In one embodiment, step 1 includes:

[0039] Step 1a: Mix the solution of aluminum precursor and part of the solution of alkaline precipitant, and control the pH value of the system between 7.0 and 9.0 by controlling the mixing rate;

[0040] Step 1b: Add the remaining alkaline precipitant solution and the modified metal salt solution to the system of step 1a. By controlling the addition rate, the pH value of the system is controlled at 7.0 to 9.0.

[0041] In this invention, after mixing the solution of aluminum precursor and a partial solution of alkaline precipitant, the aluminum precursor begins to precipitate under the action of the alkaline precipitant. After the aluminum precipitation is complete, the remaining alkaline precipitant solution and the modified metal salt solution are added, and the modified metal begins to precipitate. After the modified metal precipitation is complete, the reaction system is aged, filtered, and the resulting filter cake is directly dried to obtain modified alumina dry gel.

[0042] This invention first mixes an aluminum precursor with a portion of an alkaline precipitant to precipitate aluminum, and then adds the remaining alkaline precipitant and a modified metal salt to precipitate a modified metal. By controlling the pH value of the precipitation system, it not only ensures that the alumina grains are uniform, structurally complete, with minimal agglomeration and ideal pore structure, but also utilizes the abundant pore structure of alumina to achieve in-situ modification of alumina by the modified metal, promoting the entry of the modified metal into the alumina channels, effectively modulating the interaction force between the modified metal and the support, avoiding problems such as loss of modified metal during use, and simultaneously increasing the sulfidation degree of the active metal component and the number of MoS2 active centers, which helps to improve the desulfurization activity of the hydrogenation catalyst.

[0043] The hydrogenation catalyst of this invention is particularly suitable for highly selective hydrodesulfurization of catalytic cracking gasoline.

[0044] In one embodiment, the aluminum precursor of the present invention is a soluble aluminum salt, more specifically, it can be a soluble inorganic aluminum salt, such as at least one of aluminum nitrate and aluminum sulfate.

[0045] In one embodiment, the alkaline precipitant of the present invention is one or more of potassium carbonate, potassium hydroxide, and potassium bicarbonate. The pH value of the solution of the alkaline precipitant of the present invention is 8-12, preferably 10-12. The pH value can be adjusted by adding inorganic bases such as ammonia, ammonium bicarbonate, or ammonium carbonate, or by adding organic bases such as carbamide or triethylamine. The sum of the amounts of the partial and residual alkaline precipitant used in the present invention is the total amount of alkaline precipitant added. The present invention does not particularly limit the ratio of the partial to the residual alkaline precipitant, as long as the pH value of the system can be controlled within the range of 7.0 to 9.0. The amount of the partial and residual alkaline precipitant added ensures that the mass content of K (calculated as potassium oxide) in the obtained hydrogenation catalyst is 2% to 4%.

[0046] In one embodiment, the modified metal salt of the present invention is at least one selected from zirconium salt, lanthanum salt, and copper salt, such as at least one selected from zirconium nitrate, lanthanum nitrate, copper nitrate, zirconium acetate, lanthanum acetate, and copper acetate. The amount of modified metal salt added is such that the mass content of the modified metal in the resulting hydrogenation catalyst, based on the modified metal oxide, is 0.1%-5%.

[0047] In one embodiment, in step 1a, after mixing the aluminum precursor solution and part of the alkaline precipitant solution, a precipitation reaction occurs. The temperature of the mixture is controlled at 20-80°C (i.e., the precipitation reaction temperature is 20-80°C), preferably 50-70°C, and the mixing time is 30-50 min, preferably 30-40 min. In step 1b, after adding the remaining alkaline precipitant solution and the modified metal salt solution to the system of step 1a, the alkaline precipitant and the modified metal salt will undergo a precipitation reaction. The temperature of the mixture is controlled at 20-80°C (i.e., the precipitation reaction temperature is 20-80°C), preferably 50-70°C, and the addition time is 3-15 min, preferably 3-10 min, more preferably 5-8 min. This ensures that the resulting alumina has uniform grain size.

[0048] In one embodiment, in step 2, the system obtained in step 1 is aged at a temperature of 60–100°C, preferably 60–70°C, for a time of 60–180 min, preferably 100–150 min. After aging, the system is filtered, and the resulting filter cake is dried directly without washing at a temperature of 120–180°C, preferably 120–150°C, for a time of 60–120 min, preferably 90–120 min, to obtain modified alumina dry gel.

[0049] After filtration, the filtrate obtained from the aging system of this invention can be recycled for the co-precipitation process in step 1. Specifically, the filtrate can be used as a solvent to form the aluminum precursor solution and the alkaline precipitant solution. Without washing the filter cake, the filtrate is recycled, using the solution obtained after filtration as a solvent to dissolve the aluminum precursor and the alkaline precipitant. Modified additives are dissolved in deionized water, and the pH value of the precipitant solution is adjusted to meet the pH environment required during precipitation. This achieves sufficient precipitation while solving the problem of the filtrate being unrecyclable due to the insolubility of metal additives during precipitation. Simultaneously, it achieves the environmentally friendly production goal of zero discharge of wastewater containing metal ions.

[0050] Step 3 is to prepare the obtained modified alumina dry gel into a support, and then load the active component to obtain the hydrogenation catalyst.

[0051] The present invention does not specifically limit the specific method of preparing the modified alumina dry adhesive into a carrier. In one embodiment, the modified alumina dry adhesive of the present invention is mixed with a binder, a pore expander and an extrusion aid, extruded into strips, and then dried and calcined to obtain the modified alumina carrier. In another embodiment, the binder is one or more of silica sol, nitric acid, acetic acid, and malic acid, preferably silica sol and acetic acid; the pore-expanding agent is one or more of citric acid, yeast, methylcellulose, and hydroxypropyl methylcellulose, wherein methylcellulose and hydroxypropyl methylcellulose have, for example, a viscosity of 200,000, preferably citric acid, yeast, and methylcellulose (200,000 viscosity); the extrusion aid is one or more of guar gum powder, starch, and citric acid; the dry weight ratio of the binder to the modified alumina dry adhesive is 0.02-0.05:1, preferably 0.03-0.05:1; the dry weight ratio of the pore-expanding agent to the modified alumina dry adhesive is 0.01-0.1:1, preferably 0.03-0.06:1; and the dry weight ratio of the extrusion aid to the modified alumina dry adhesive is 0.01-0.05:1, preferably 0.03-0.04:1. This invention does not particularly limit the drying temperature and calcination temperature during the preparation of the modified alumina carrier; conventional techniques in the art are sufficient.

[0052] In the carrier extrusion process of this invention, when the binder is silica sol, the silica sol acts as a modifying agent, thus simultaneously achieving the purpose of carrier extrusion and silica modification. By introducing silica, the acid distribution of the carrier is modulated, the Brønsted acid content is increased, and the desulfurization activity and selectivity of the catalyst are promoted.

[0053] This invention does not specifically limit the method of loading the active component onto the support, for example, by impregnation. In one embodiment, the active component is at least one of a Group VIII element and a Group VIB element. The precursor of the active component is dissolved in a complexing agent to prepare a stable active component complex solution, which is then impregnated onto the support prepared above, for example by equal-volume impregnation, followed by drying and calcination to obtain a hydrogenation catalyst.

[0054] In another embodiment, the complexing agent is one or more of phosphoric acid, tartaric acid, malic acid, oxalic acid, nitric acid, EDTA, and EDTP mixed with citric acid, preferably one or more of phosphoric acid, oxalic acid, and nitric acid mixed with citric acid, and the solution pH is 0.1-5.0, preferably 1.0-3.0.

[0055] In another embodiment, the Group VIII element is cobalt or nickel, and the Group VIB element is molybdenum; the precursor of cobalt is a cobalt salt, such as one or more of cobalt nitrate, basic carbonate, acetate or sulfate; the precursor of nickel is a nickel salt, such as one or more of nickel nitrate, basic carbonate, acetate or sulfate; and the precursor of molybdenum is a molybdenum salt, such as one or more of ammonium heptamolybdate, ammonium tetramolybdate, ammonium dimolybdate, and molybdenum oxide.

[0056] In one embodiment, the carrier of the present invention is impregnated with the active component, for example by vacuum impregnation, with an impregnation pressure of 0.05-0.1 MPa, preferably 0.07-0.09 MPa, for 4-8 hours, preferably 4-6 hours, followed by drying at 100-150°C for 3-6 hours, preferably 100-120°C for 3-6 hours, and calcination at 400-600°C for 3-6 hours.

[0057] In the hydrogenation catalyst of this invention, the active component, calculated as metal oxide, has a mass content of 9-20%. In one embodiment, the content of Mo, calculated as MoO3, is 8.0% to 16.0%, and the content of Co and / or Ni, calculated as oxide, is 1.0% to 4.0%.

[0058] In one embodiment, the catalyst support of the present invention is composed of silicon dioxide (e.g., derived from a binder) and modified alumina (wherein, modification includes modification of alumina by potassium oxide, and modification of alumina by at least one of zirconium oxide, lanthanum oxide, and copper oxide); the active component of the catalyst of the present invention is composed of oxides of Mo and oxides of Co and / or Ni. Based on 100% by mass of the catalyst, the catalyst comprises: MoO3 content of 8.0%–16.0%, preferably 10.0%–13.0%; CoO or NiO content of 1.0%–4.0%, preferably 2.5%–3.5%; silicon dioxide content of 0.1%–1.5%, preferably 0.5%–1.0%; potassium oxide content of 2%–4%, preferably 2.0%–3.5%; zirconium oxide content of 0.1%–2%, preferably 0.5%–1.5%; lanthanum oxide content of 0.1%–1%, preferably 0.3%–0.8%; copper oxide content of 0.1%–2%, preferably 0.3%–0.8%; and the balance being an alumina support.

[0059] The catalyst prepared by the method of the present invention has the following physical properties: bulk density of 0.5–0.8 g / ml, preferably 0.6–0.7 g / ml; pore volume of 0.3–0.8 ml / g, preferably 0.4–0.6 ml / g; and specific surface area of ​​150–300 m² / g. 2 / g, preferably 170-220m 2 / g, with an average pore size of 7-16nm, preferably 8-14nm, wherein the volume of pores with a diameter of 10-20nm accounts for 50-80% of the total pore volume, preferably 60-80%.

[0060] The hydrogenation catalyst prepared by this invention needs to be sulfided before use. In one embodiment, a programmed temperature sulfidation method can be used. The sulfidation method can be wet sulfidation or dry sulfidation. The sulfidation conditions are: heating rate 10-40℃ / h, residence time at 150℃ for 2h, residence time at 230℃ for 8h, residence time at 320℃ for 6h, and volume hourly space velocity 1-3h. -1 The hydrogen-to-oil ratio is 100:1-500:1, and the pressure is 1.0-3.0 MPa. For example, the process parameters for the hydrogenation catalyst are: hydrogen pressure 1.0-3.0 MPa, temperature 220-300℃, and space velocity 1.0-4.0 h⁻¹. -1 Hydrogen-to-oil ratio of 100:1-500:1, for example, used in desulfurization processes in petroleum processing.

[0061] In another embodiment, the vulcanization conditions are: a heating rate of 20-30°C / h, a residence time of 150°C for 2 hours, a residence time of 230°C for 8 hours, a residence time of 320°C for 6 hours, and a volume hourly space velocity of 1-3 h. -1 Hydrogen-to-oil ratio 200:1-400:1, pressure 1.0-3.0 MPa; Catalyst application process parameters: hydrogen pressure 1.0-3.0 MPa, temperature 220-300℃, space velocity 2.0-3.0 h⁻¹ -1 Hydrogen-to-oil ratio of 200:1-400:1, for example, used in desulfurization processes in petroleum processing.

[0062] The catalyst prepared by the method of this invention has a concentrated pore structure, with 60-80% of the pores being 10-20 nm in size. It achieves a desulfurization rate of ≥90% and a desulfurization selectivity of ≥70% for heavy gasoline. Compared with conventional catalyst preparation methods, this method achieves green and environmentally friendly production while providing a more concentrated pore structure and higher desulfurization rate and selectivity. It can meet the deep desulfurization requirements of China VI standard clean gasoline and results in less octane number loss.

[0063] The technical solution of the present invention will be described in detail below through specific embodiments, but the technical solution of the present invention is not limited to the following embodiments.

[0064] Example 1

[0065] (1) Preparation of aluminum hydroxide dry adhesive

[0066] Weigh 374g of aluminum nitrate nonahydrate and dissolve it in the filtrate after precipitation and aging, then dilute to 1L, with a solution concentration of Al2O3 51g / L; weigh 706g of potassium carbonate and dissolve it in the filtrate after precipitation and aging, add 26.8g of urea, and dilute to 4L with the filtrate, with a solution concentration of K2O 125g / L and a solution pH of 8, to serve as a precipitant; weigh 2.3g of zirconium nitrate, 0.97g of lanthanum nitrate, and 1.1g of copper nitrate and dissolve them in 60g of deionized water to prepare a modifying agent solution. First, add the filtrate to the reactor and preheat it to 60°C. While stirring, add 1L of aluminum nitrate solution and 1.62L of potassium carbonate solution in a parallel flow, adjusting the flow rate to maintain the pH of the slurry in the reactor at 7, with a feeding time of 40 minutes. After the addition is complete, continue adding a mixed modification agent solution of zirconium nitrate and lanthanum nitrate, along with 165ml of potassium carbonate solution, while stirring. Adjust the flow rate to maintain the pH of the slurry in the reactor at 7, with a feeding time of 5 minutes. After the addition is complete, allow the mixture to stand and age for 120 minutes at this temperature and pH. After aging, filter the slurry, and dry the resulting filter cake at 150°C for 120 minutes to obtain aluminum hydroxide dry gel. The filtrate is recycled as a solution for dissolving aluminum salts and potassium carbonate.

[0067] (2) Carrier preparation

[0068] Weigh 100g of aluminum hydroxide dry adhesive (71% dry basis), 2.1g of guar gum powder, and 1.4g of methylcellulose (200,000 viscosity) and add them to a kneader, kneading for 10 minutes. Then, add 2.5g of silica sol, 2.1g of acetic acid, and 1.4g of citric acid to 61g of deionized water and stir until dissolved. Slowly add the resulting solution to the kneader and knead for 30 minutes. The mixed material is then extruded, dried at 120℃, and calcined at 550℃ for 4 hours to obtain carrier Z1.

[0069] (3) Catalyst preparation

[0070] Weigh 8.0g ammonium heptamolybdate, 2.0g citric acid, and 1.0g nitric acid, dissolve them in deionized water, stir until a clear solution is obtained, add 6.9g cobalt nitrate and stir until dissolved, then bring the volume to 41ml with deionized water, and adjust the pH to 2.0-3.0; weigh 50g of support Z1 and impregnate it with an equal volume under vacuum pressure of 0.08MPa, let it stand for 6 hours, dry it at 120℃ for 4 hours, and calcine it at 500℃ for 4 hours to obtain catalyst A1.

[0071] Example 2

[0072] (1) Preparation of aluminum hydroxide dry adhesive

[0073] Weigh 374g of aluminum nitrate nonahydrate and dissolve it in the filtrate after precipitation and aging, then dilute to 1L, resulting in a solution concentration of Al2O3 51g / L. Weigh 706g of potassium carbonate and dissolve it in the filtrate after precipitation and aging, add 41.7g of urea, and dilute to 4L with the filtrate, resulting in a solution concentration of K2O 125g / L and a solution pH of 9.5, which serves as the precipitant. Weigh 2.3g of zirconium nitrate, 0.97g of lanthanum nitrate, and 1.1g of copper nitrate and dissolve them in 61g of deionized water to prepare a modifying agent solution. Control the pH of the slurry in the reactor to 8, and follow the same steps as in Example 1.

[0074] (2) Carrier preparation

[0075] The preparation method of carrier Z2 is the same as that of carrier Z1. The only difference is that 2.5g of silica sol, 2.3g of acetic acid and 1.4g of citric acid are added to 63g of deionized water in sequence, and then the mixture is kneaded, extruded, dried and calcined.

[0076] (3) Catalyst preparation

[0077] The metal impregnation method for catalyst A2 is the same as that for A1, except that deionized water is brought to a final volume of 40 ml before impregnation, drying, and calcination.

[0078] Example 3

[0079] (1) Preparation of aluminum hydroxide dry adhesive

[0080] 374g of aluminum nitrate nonahydrate was dissolved in the filtrate after precipitation and aging, and the volume was adjusted to 1L, resulting in a solution concentration of Al₂O₃ 51g / L. 706g of potassium carbonate was dissolved in the filtrate after precipitation and aging, and 41.1g of urea and 15.6g of ammonia were added. The volume was adjusted to 4L with the filtrate, resulting in a solution concentration of K₂O 125g / L and a pH of 11, serving as the precipitant. 2.3g of zirconium nitrate, 0.97g of lanthanum nitrate, and 1.1g of copper nitrate were dissolved in 60g of deionized water to prepare a modifying agent solution. The pH of the slurry in the reactor was controlled to 9, and other steps were the same as in Example 1.

[0081] (2) Carrier preparation

[0082] The preparation method of carrier Z3 is the same as that of carrier Z1. The only difference is that 2.5g of silica sol, 2.4g of acetic acid and 1.5g of citric acid are added to 62g of deionized water in sequence, and then the mixture is kneaded, extruded, dried and calcined.

[0083] (3) Catalyst preparation

[0084] The metal impregnation method for catalyst A3 is the same as that for A1, except that deionized water is brought to a final volume of 38 ml before impregnation, drying, and calcination.

[0085] Example 4

[0086] (1) Preparation of aluminum hydroxide dry adhesive

[0087] The preparation method of aluminum hydroxide dry adhesive is the same as in Example 2. The only difference is that the filtrate is added to the reaction vessel first, preheated to 20°C, and the feeding time of aluminum nitrate solution and potassium carbonate solution is 50 min. The filter cake obtained by filtering the slurry is dried at 120°C for 120 min to obtain aluminum hydroxide dry adhesive.

[0088] (2) Carrier preparation

[0089] The preparation method of carrier Z4 is the same as that of carrier Z2. The only difference is that 2.5g of silica sol, 2.7g of acetic acid and 1.5g of citric acid are added to 63g of deionized water in sequence, and then the mixture is kneaded, extruded, dried and calcined.

[0090] (3) Catalyst preparation

[0091] The metal impregnation method for catalyst A4 is the same as that for A2.

[0092] Example 5

[0093] (1) Preparation of aluminum hydroxide dry adhesive

[0094] The preparation method of aluminum hydroxide dry adhesive is the same as in Example 2. The only difference is that the filtrate is added to the reaction vessel first, preheated to 80°C, and the feeding time of aluminum nitrate solution and potassium carbonate solution is 30 min. The filter cake obtained by filtering the slurry is dried at 180°C for 60 min to obtain aluminum hydroxide dry adhesive.

[0095] (2) Carrier preparation

[0096] The preparation method of carrier Z5 is the same as that of carrier Z2. The only difference is that 2.5g of silica sol, 2.5g of acetic acid and 1.5g of citric acid are added to 63g of deionized water in sequence, and then the mixture is kneaded, extruded, dried and calcined.

[0097] (3) Catalyst preparation

[0098] The metal impregnation method for catalyst A5 is the same as that for A2.

[0099] Example 6

[0100] (1) Preparation of aluminum hydroxide dry adhesive

[0101] The preparation method of aluminum hydroxide dry adhesive is the same as that in Example 2, except that the aging temperature of the slurry in the reactor is 100°C and the aging time is 60 min.

[0102] (2) Carrier preparation

[0103] The preparation method of carrier Z6 is the same as that of carrier Z2. The only difference is that 2.5g of silica sol, 2.5g of acetic acid and 1.5g of citric acid are added to 63g of deionized water in sequence, and then the mixture is kneaded, extruded, dried and calcined.

[0104] (3) Catalyst preparation

[0105] The metal impregnation method for catalyst A6 is the same as that for A2.

[0106] Example 7

[0107] (1) Preparation of aluminum hydroxide dry adhesive

[0108] The preparation method of aluminum hydroxide dry adhesive is the same as that in Example 2, except that the aging temperature of the slurry in the reactor is 100°C and the aging time is 60 min.

[0109] (2) Carrier preparation

[0110] The preparation method of carrier Z7 is the same as that of carrier Z2. The only difference is that 2.5g of silica sol, 2.4g of acetic acid and 1.5g of citric acid are added to 63g of deionized water in sequence, and then the mixture is kneaded, extruded, dried and calcined.

[0111] (3) Catalyst preparation

[0112] The metal impregnation method for catalyst A7 is the same as that for A2.

[0113] Example 8

[0114] (1) Preparation of aluminum hydroxide dry adhesive

[0115] The preparation method of aluminum hydroxide dry adhesive is the same as in Example 2.

[0116] (2) Carrier preparation

[0117] The preparation method of carrier Z8 is the same as that of carrier Z2. The only difference is that 0.3g of silica sol, 3.3g of acetic acid and 1.6g of citric acid are added to 63g of deionized water in sequence, and then the mixture is kneaded, extruded, dried and calcined.

[0118] (3) Catalyst preparation

[0119] The metal impregnation method for catalyst A8 is the same as that for A2, except that deionized water is brought to a final volume of 40 ml before impregnation, drying, and calcination.

[0120] Example 9

[0121] (1) Preparation of aluminum hydroxide dry adhesive

[0122] The preparation method of aluminum hydroxide dry adhesive is the same as in Example 2.

[0123] (2) Carrier preparation

[0124] The preparation method of carrier Z9 is the same as that of carrier Z2. The only difference is that 4.2g of silica sol, 1.3g of acetic acid and 1.2g of citric acid are added to 63g of deionized water in sequence, and then the mixture is kneaded, extruded, dried and calcined.

[0125] (3) Catalyst preparation

[0126] The metal impregnation method for catalyst A9 is the same as that for A2, except that deionized water is brought to a final volume of 40 ml before impregnation, drying, and calcination.

[0127] Example 10

[0128] (1) Preparation of aluminum hydroxide dry adhesive

[0129] Weigh 374g of aluminum nitrate nonahydrate and dissolve it in the filtrate after precipitation and aging, then dilute to 1L, resulting in a solution concentration of Al2O3 51g / L. Weigh 706g of potassium carbonate and dissolve it in the filtrate after precipitation and aging, add 41.7g of urea, and dilute to 4L with the filtrate, resulting in a solution concentration of K2O 125g / L and a solution pH of 9.5, which serves as the precipitant. Weigh 0.5g of zirconium nitrate, 0.2g of lanthanum nitrate, and 0.2g of copper nitrate and dissolve them in 60g of deionized water to prepare a modifying agent solution. Other steps are the same as in Example 2.

[0130] (2) Carrier preparation

[0131] The preparation method of carrier Z10 is the same as that of carrier Z2. The only difference is that 2.5g of silica sol, 1.9g of acetic acid and 1.4g of citric acid are added to 60g of deionized water in sequence, and then the mixture is kneaded, extruded, dried and calcined.

[0132] (3) Catalyst preparation

[0133] The metal impregnation method for catalyst A10 is the same as that for A2, except that deionized water is brought to a final volume of 41 ml before impregnation, drying, and calcination.

[0134] Example 11

[0135] (1) Preparation of aluminum hydroxide dry adhesive

[0136] Weigh 374g of aluminum nitrate nonahydrate and dissolve it in the filtrate after precipitation and aging, then dilute to 1L, resulting in a solution concentration of Al2O3 51g / L. Weigh 706g of potassium carbonate and dissolve it in the filtrate after precipitation and aging, add 41.7g of urea, and dilute to 4L with the filtrate, resulting in a solution concentration of K2O 125g / L and a solution pH of 9.5, which serves as the precipitant. Weigh 4.7g of zirconium nitrate, 1.9g of lanthanum nitrate, and 4.4g of copper nitrate and dissolve them in 100g of deionized water to prepare a modifying agent solution. Other steps are the same as in Example 2.

[0137] (2) Carrier preparation

[0138] The preparation method of carrier Z11 is the same as that of carrier Z2 in Example 2. The only difference is that 2.5g of silica sol, 2.5g of acetic acid and 1.4g of citric acid are added to 63g of deionized water in sequence, and then the mixture is kneaded, extruded, dried and calcined.

[0139] (3) Catalyst preparation

[0140] The metal impregnation method for catalyst A11 is the same as that for catalyst A2 in Example 2, except that the volume of deionized water is adjusted to 38 ml before impregnation, drying, and calcination.

[0141] Example 12

[0142] (1) Preparation of aluminum hydroxide dry adhesive

[0143] The preparation method of aluminum hydroxide dry adhesive is the same as in Example 2.

[0144] (2) Carrier preparation

[0145] The preparation method of carrier Z12 is the same as that of carrier Z2 in Example 2.

[0146] (3) Catalyst preparation

[0147] Weigh 5.5g ammonium heptamolybdate, 1.7g citric acid, and 1.0g nitric acid, dissolve them in deionized water, stir until a clear solution is obtained, add 2.2g cobalt nitrate and stir until dissolved, then bring the volume to 40ml with deionized water, and adjust the pH to 2.0-3.0; weigh 50g of support Z6 and impregnate it with an equal volume under vacuum pressure of 0.08MPa, let it stand for 6 hours, dry it at 120℃ for 4 hours, and calcine it at 500℃ for 4 hours to obtain catalyst A12.

[0148] Example 13

[0149] (1) Preparation of aluminum hydroxide dry adhesive

[0150] The preparation method of aluminum hydroxide dry adhesive is the same as in Example 2.

[0151] (2) Carrier preparation

[0152] The preparation method of carrier Z13 is the same as that of carrier Z2 in Example 2.

[0153] (3) Catalyst preparation

[0154] A two-step impregnation method was adopted: First, 7.2g of ammonium heptamolybdate, 1.8g of citric acid, and 1.0g of aminotriacetic acid were weighed and dissolved in deionized water. After stirring until a clear solution was obtained, 6.8g of cobalt nitrate was added and stirred until dissolved. The solution was then diluted to 40ml with deionized water, and the pH value was 2.0-3.0. 50g of support Z7 was weighed and impregnated in an equal volume under vacuum pressure of 0.08MPa. The solution was allowed to stand for 6 hours, dried at 120℃ for 4 hours, and calcined at 500℃ for 4 hours to obtain a one-step impregnated catalyst. Weigh 4.0g ammonium heptamolybdate, 1.4g citric acid, and 0.8g aminotriacetic acid, dissolve them in deionized water, stir until a clear solution is obtained, add 2.1g cobalt nitrate and stir until dissolved, then bring the volume to 32ml with deionized water, and adjust the pH to 2.0-3.0; weigh 50g of one-step impregnation carrier and impregnate it with an equal volume under vacuum pressure of 0.08MPa, let it stand for 6 hours, dry it at 120℃ for 4 hours, and calcine it at 500℃ for 4 hours to obtain catalyst A13.

[0155] Example 14

[0156] (1) Preparation of aluminum hydroxide dry adhesive

[0157] The preparation method of aluminum hydroxide dry adhesive is similar to that of Example 2, except that aluminum nitrate solution, potassium carbonate solution and modified additive solution are added in parallel for co-precipitation. The rest is the same as in Example 2, and aluminum hydroxide dry adhesive is obtained.

[0158] (2) Carrier preparation

[0159] The method for carrier Z14 is the same as that for carrier Z2 in Example 2.

[0160] (3) Catalyst preparation

[0161] The metal impregnation method for catalyst A14 is the same as that for catalyst A2 in Example 2.

[0162] Example 15

[0163] (1) Preparation of aluminum hydroxide dry adhesive

[0164] The preparation method of aluminum hydroxide dry gel is the same as in Example 2, except that 574g of potassium hydroxide is weighed and dissolved in the filtrate after precipitation and aging, 12.9g of urea is added, and the volume is adjusted to 4L with the filtrate. The pH value of the solution is 9.5, which serves as the precipitant. The other steps are the same as in Example 2.

[0165] (2) Carrier preparation

[0166] The preparation method of carrier Z15 is the same as that of carrier Z2. The only difference is that 2.5g of silica sol, 2.0g of acetic acid and 1.5g of citric acid are added to 62g of deionized water in sequence, and then the mixture is kneaded, extruded, dried and calcined.

[0167] (3) Catalyst preparation

[0168] The metal impregnation method for catalyst A15 is the same as that for A2.

[0169] Example 16

[0170] (1) Preparation of aluminum hydroxide dry adhesive

[0171] The preparation method of aluminum hydroxide dry gel is the same as in Example 2, except that 1023g of potassium bicarbonate is weighed and dissolved in the filtrate after precipitation and aging, 54.9g of urea is added, and the volume is adjusted to 4L with the filtrate. The pH value of the solution is 9.5, which serves as the precipitant. Other steps are the same as in Example 2.

[0172] (2) Carrier preparation

[0173] The preparation method of carrier Z16 is the same as that of carrier Z2. The only difference is that 2.5g of silica sol, 2.2g of acetic acid and 1.5g of citric acid are added to 62g of deionized water in sequence, and then the mixture is kneaded, extruded, dried and calcined.

[0174] (3) Catalyst preparation

[0175] The metal impregnation method for catalyst A16 is the same as that for A2.

[0176] Comparative Example 1

[0177] (1) Preparation of aluminum hydroxide dry adhesive

[0178] The preparation method of aluminum hydroxide dry gel is similar to that in Example 1, the only difference being that the slurry is filtered after aging, and the filter cake is washed multiple times with deionized water to remove the precipitant metal cation K. + Wash until the filtrate is neutral, then dry the filter cake at 150℃ for 120 minutes to obtain aluminum hydroxide dry gel.

[0179] (2) Carrier preparation

[0180] The preparation method of carrier D1 is the same as that of carrier Z1.

[0181] (3) Catalyst preparation

[0182] The metal impregnation method for catalyst D1 is the same as that for catalyst A1 in Example 1.

[0183] The physicochemical properties of the catalysts obtained in the above embodiments and comparative examples are shown in Table 1.

[0184] The catalysts prepared in the above embodiments and comparative examples were respectively loaded into a 100ml hydrogenation evaluation device for performance evaluation. The catalysts were subjected to wet sulfidation, with carbon disulfide as the sulfiding agent and refined naphtha as the sulfiding oil. Hydrogen was passed through once. The sulfidation conditions were as follows: sulfiding oil was introduced at 150°C and held for 2 hours; the temperature was increased to 230°C at a rate of 20-30°C / h and held for 8 hours; the temperature was further increased to 320°C at a rate of 20-30°C / h and held for 6 hours; the volume hourly space velocity was 2 h⁻¹. -1 The hydrogen-to-oil ratio is 200:1, and the pressure is 2.0 MPa. After sulfidation, the temperature is lowered to 230°C, and then catalytic heavy gasoline feedstock is introduced.

[0185] Hydrogenation reaction conditions: reaction temperature 260℃, reaction pressure 2.0 MPa, hydrogen-to-oil volume ratio 300:1, volume hourly space velocity 2.5 h⁻¹ -1 The properties of heavy gasoline feedstock and hydrogenation products are shown in Table 2.

[0186]

[0187]

[0188] As shown in Table 2, the hydrotreating catalyst prepared by the method of this invention exhibits significantly better desulfurization activity and selectivity than the catalyst prepared in the comparative example during selective desulfurization. It meets the China VI standard for high-selectivity deep desulfurization of clean gasoline while reducing octane number loss. Specifically, Examples 1-3 achieved K content modulation and pore structure modification by adjusting the pH value of the precipitant and the precipitation reaction. With increasing pH, the K content on the catalyst gradually increased, and the percentage of 10-20 nm pore volume in the total pore volume showed a trend of first increasing and then decreasing. Examples 2, 4, 6, and 7 modified the catalyst pore structure by adjusting the precipitation temperature and time, slurry aging temperature, and drying temperature. Examples 2, 8, and 9 increased the catalyst surface acidity by adjusting the amount of silica sol added. With increasing silica content, the catalyst desulfurization activity gradually increased, while the desulfurization selectivity first increased and then decreased. Examples 2, 10, and 11 modified the pore structure and regulated the metal-support interaction by adjusting the content of the modifying agent. Examples 2, 12, and 13 regulated the active phase structure by adjusting the content of the metal active component. Compared with Example 1, Comparative Example 1 involved adding multiple washing of the filter cake to remove potassium during the preparation of aluminum hydroxide dry gel. +In addition to the environmental drawbacks of generating a large amount of waste liquid, the catalyst produced also suffers from a low proportion of 10-20nm pores due to the lack of modification by the modifier K, resulting in a significant decrease in both desulfurization activity and selectivity. In Example 14, compared to Example 2, the aluminum hydroxide dry gel preparation process involves the simultaneous co-precipitation of aluminum nitrate solution, potassium carbonate solution, and modifier solution. Due to the competition for precipitation between the aluminum source and the modifier, the modified additive tends to clog the alumina pores after precipitation, leading to a decrease in the proportion of 10-20nm pores. This is not conducive to the effective utilization of active components and results in a relative decrease in both desulfurization activity and selectivity of the catalyst.

[0189] This invention utilizes a method in the preparation of boehmite, employing potassium salts as both a precipitant and a precursor for a modified metal additive. Through in-situ modification with potassium, the metal additive is facilitated to enter the alumina channels, resulting in a catalyst with a concentrated pore structure (60-80% of pores are 10-20 nm). Simultaneously, it eliminates the need for multiple washing of the filter cake to remove potassium. + The steps simplify the production process; in addition, the method of recycling the filtrate is adopted, and the solution obtained after filtration is used as a solvent to dissolve aluminum salts and alkaline precipitants. By adjusting the pH value of the precipitant solution, the required pH environment for precipitation is achieved, so as to achieve full precipitation and solve the environmental protection production problem of zero discharge of waste liquid containing metal ions. The catalyst exhibits excellent desulfurization activity and selectivity.

[0190] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a hydrogenation catalyst, characterized in that, Includes the following steps: Step 1 includes: Step 1a: Mix the solution of aluminum precursor and part of the alkaline precipitant solution, and control the pH value of the system at 7.0~9.0 by controlling the mixing rate; Step 1b: Add the remaining alkaline precipitant solution and the modified metal salt solution to the system of step 1a, and control the pH value of the system at 7.0~9.0 by controlling the addition rate; wherein, the alkaline precipitant is one or more of potassium carbonate, potassium hydroxide, and potassium bicarbonate. Step 2: Aging and filtering the system obtained in Step 1, and then drying the resulting filter cake to obtain modified alumina dry gel. Step 3: Prepare the modified alumina dry gel as a support, and then load the active component to obtain the hydrogenation catalyst; The amount of alkaline precipitant added, including a portion and the remainder, is such that the mass content of K in the resulting hydrogenation catalyst, calculated as potassium oxide, is 2% to 4%. The filtrate obtained from step 2 is recycled for the preparation of solutions of aluminum precursor and alkaline precipitant. The modified metal salt is at least one of zirconium salt, lanthanum salt, and copper salt.

2. The method for preparing the hydrogenation catalyst according to claim 1, characterized in that, The aluminum precursor is a soluble aluminum salt; the amount of modified metal salt added is such that the mass content of the modified metal in the resulting hydrogenation catalyst, calculated as modified metal oxide, is 0.1%-5%.

3. The method for preparing the hydrogenation catalyst according to claim 1, characterized in that, The aluminum precursor is at least one of aluminum nitrate and aluminum sulfate; the modified metal salt is at least one of zirconium nitrate, lanthanum nitrate, copper nitrate, zirconium acetate, lanthanum acetate, and copper acetate.

4. The method for preparing the hydrogenation catalyst according to claim 1, characterized in that, In step 1a, the mixing temperature of the aluminum precursor solution and the partial alkaline precipitant solution is 20-80℃, and the mixing time is 30-50 min.

5. The method for preparing the hydrogenation catalyst according to claim 1, characterized in that, The remaining alkaline precipitant solution and the modified metal salt solution were added at a time of 5-15 minutes, and the temperature of the system was controlled at 20-80℃.

6. The method for preparing the hydrogenation catalyst according to claim 1, characterized in that, The aging temperature is 60~100℃ and the aging time is 60~180min; the filter cake is dried at a temperature of 120-180℃ and the drying time is 60~120min.

7. The method for preparing the hydrogenation catalyst according to claim 1, characterized in that, The steps for preparing the carrier from the modified alumina dry adhesive are as follows: the modified alumina dry adhesive is mixed with a binder, a pore-expanding agent, and an extrusion aid, extruded into strips, and then dried and calcined to obtain the carrier; the binder is one or more of silica sol, nitric acid, acetic acid, and malic acid; the pore-expanding agent is one or more of citric acid, yeast, methylcellulose, and hydroxypropyl methylcellulose; the extrusion aid is one or more of guar gum powder, starch, and citric acid; the dry basis mass ratio of the binder to the modified alumina dry adhesive is 0.02-0.05:1, the dry basis mass ratio of the pore-expanding agent to the modified alumina dry adhesive is 0.01-0.1:1, and the dry basis mass ratio of the extrusion aid to the modified alumina dry adhesive is 0.01-0.05:

1.

8. The method for preparing the hydrogenation catalyst according to claim 1, characterized in that, The active component is at least one of Group VIII and Group VIB elements; in the hydrogenation catalyst, the active component has a mass content of 9%-20% based on metal oxides.

9. The method for preparing the hydrogenation catalyst according to claim 1, characterized in that, The active component is Mo, and at least one of Co and Ni; in the hydrogenation catalyst, the mass content of Mo, calculated as MoO3, is 8.0% to 16.0%, and the mass content of Co and / or Ni, calculated as oxides, is 1.0% to 4.0%.

10. The application of the hydrogenation catalyst obtained by the preparation method according to any one of claims 1-9 in the hydrodesulfurization of distillate oil.

Images