A method for preparing a hydroprocessing catalyst

Abstract

The application provides a preparation method of a hydrogen pretreatment catalyst, comprising the following steps: (1) preparing a first impregnation solution, wherein the first impregnation solution contains fluorine, an active metal component and gelatin; (2) unsaturatedly impregnating an alumina carrier with the first impregnation solution obtained in the step (1), and then performing a cooling solidification treatment to obtain a hydrogen pretreatment catalyst precursor; (3) preparing a second impregnation solution, wherein the second impregnation solution contains the active metal component; (4) impregnating the hydrogen pretreatment catalyst precursor obtained in the step (2) with the second impregnation solution obtained in the step (3), and then performing a growth maintenance, drying and calcination to obtain the hydrogen pretreatment catalyst. The catalyst prepared by the preparation method has high activity, and is particularly suitable for a hydrogen pretreatment process of heavy raw materials, such as naphthenic base wax oil, coking wax oil and the like.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical technology, specifically, it relates to a method for preparing a hydrogenation pretreatment catalyst. Background Technology

[0002] The increasing weight and quality of crude oil poses a significant challenge to the petrochemical industry, leading to a decline in the quality of heavy oil. For example, secondary processed oils such as intermediate naphthenic or naphthenic wax oils obtained from atmospheric and vacuum distillation, as well as coking wax oils, have high contents of cyclic hydrocarbons with two or more rings and low contents of alkanes. When these heavy oils are used as feedstock for hydrocracking units, higher requirements are placed on the hydrotreating performance of the hydrotreating catalysts.

[0003] Studies have shown that fluorine modification of hydrotreating catalysts can increase catalyst acidity and improve catalyst performance. CN1166455C discloses a fluorinated alumina support and its preparation method. The composition of the support (based on the mass of the catalyst) is: fluorine 0.5-15 m%, additive M 1.0-30 m%, and the remainder alumina. The fluorine and additive M are added by kneading during the alumina support molding process. The composition of fluorine and additive M and the F / M ratio in the support prepared by this method can be adjusted within a certain range, and the physicochemical properties of the support can also be adjusted within a certain range. This makes it suitable as a support for various hydrotreating catalysts, and its characteristic is that fluorine is not easily lost from the support.

[0004] CN1169336A discloses a catalyst for the hydrorefining of distillate oils. This catalyst primarily utilizes a mixture of alumina powders with different pore sizes, followed by modification with a fluorine-containing substance, and then impregnation with a tungsten-nickel metal solution. This catalyst is particularly suitable for the hydrorefining of low-quality distillate oils with high sulfur content and a distillation range of 80–550℃.

[0005] When the aforementioned patent modifies the catalyst with fluorine, it introduces fluorine-containing compounds into the catalyst in a non-selective and non-targeted manner. Its effect on modifying the acid properties of the catalyst is limited, so the catalyst activity needs to be improved when the above-mentioned catalyst is used in the heavy oil hydrotreating process. Summary of the Invention

[0006] During their research, the inventors discovered that the distribution of acidic sites within the catalyst pores has a significant impact on the performance, especially the activity, of the hydrotreating catalyst. Further research revealed that by adjusting the introduction location of fluorine elements during the preparation of the hydrotreating catalyst to modify the distribution of acidic sites within the catalyst pores, the catalyst's activity in the heavy oil hydrotreating process can be improved.

[0007] Based on the above research results, the present invention provides a method for preparing a hydrotreating catalyst. The catalyst obtained by the preparation method has high activity and is particularly suitable for the hydrotreating process of heavy feedstocks, such as naphthenic wax oil and coking wax oil.

[0008] According to a first aspect of the present invention, a method for preparing a hydrogenation pretreatment catalyst is provided, comprising the following steps:

[0009] (1) Prepare a first impregnation solution, wherein the first impregnation solution contains fluorine, active metal components, and gelatin;

[0010] (2) The alumina support is impregnated with the first impregnation liquid obtained in step (1) and then subjected to cooling and curing treatment to obtain the hydrogenation pretreatment catalyst precursor.

[0011] (3) Prepare a second impregnation solution containing an active metal component;

[0012] (4) Impregnate the hydrogenation pretreatment catalyst precursor obtained in step (2) with the second impregnation solution obtained in step (3), and obtain the hydrogenation pretreatment catalyst after conditioning, drying and calcination.

[0013] In step (1) of the above method, the fluorine is derived from one or more water-soluble fluorine-containing compounds such as ammonium fluoride, ammonium fluorosilicate, hydrogen fluoride, ammonium hydrogen fluoride, calcium fluoride, and sodium fluoride, preferably ammonium fluorosilicate and / or ammonium fluoride; the amount of the water-soluble fluorine-containing compound (calculated as an element) added accounts for 0.3wt% to 1.5wt% of the weight of the alumina carrier (on a dry basis), preferably 0.4wt% to 0.8wt%.

[0014] In step (1) of the above method, the active metal component comprises at least one metal selected from Group VIII and at least one metal selected from Group VIB. Preferably, the active metal component comprises Ni and W; wherein Ni is derived from one or more of nickel nitrate, basic nickel carbonate, nickel oxalate, nickel chloride, and nickel acetate, and W is derived from one or more of ammonium metatungstate and ammonium tetrathiotungstate. Based on the weight of the final hydrogenation pretreatment catalyst, the content of the active metal component Ni, calculated as oxide, is 1 wt% to 5 wt%, preferably 2 wt% to 4 wt%; the content of the active metal component W, calculated as oxide, is 5 wt% to 18 wt%, preferably 8 wt% to 15 wt%.

[0015] In step (1) of the above method, the gelatin is one or more of marine gelatin, pig gelatin, bovine gelatin and chicken gelatin, and the purity level is industrial grade or food grade; the molecular weight of the gelatin is 10,000 to 70,000, preferably 20,000 to 50,000; based on the weight of the first impregnation solution, the gelatin concentration in the first impregnation solution is 4 wt% to 10 wt%.

[0016] In step (1) of the above method, the temperature of the first impregnation liquid is 40-70°C, preferably 50-60°C.

[0017] In step (2) of the above method, the properties of the alumina support are generally required to be as follows: pore volume of 0.3–1.5 mL / g and specific surface area of ​​150–450 m². 2 / g; Preferably, the alumina support has bimodal channels, with pores having a diameter of 0-15 nm accounting for 40-80% of the total pore volume, preferably 50-70%; and pores having a diameter >15 nm accounting for 20-60% of the total pore volume, preferably 30-50%.

[0018] In step (2) of the above method, the alumina carrier also contains an additive, which is selected from one or more of silicon dioxide, magnesium oxide, zirconium oxide, boron oxide and titanium dioxide, and the content of the additive (calculated as oxide) in the alumina carrier is less than 30 wt%.

[0019] In step (2) of the above method, the amount of the alumina carrier impregnated by the first impregnation solution is 30-60 wt% of the saturated water absorption capacity of the alumina carrier, preferably 40-50 wt%.

[0020] In step (2) of the above method, the impregnation temperature of the first impregnation solution for unsaturated impregnation of the alumina carrier is 40-70°C, preferably 50-60°C.

[0021] In step (2) of the above method, the first impregnation solution can be used to impregnate the alumina carrier in any of the existing technologies that can achieve unsaturated impregnation, such as spray impregnation, and the temperature of the impregnation solution is 40-70°C, preferably 50-60°C.

[0022] In step (2) of the above method, the cooling and curing treatment involves placing the alumina carrier impregnated with the first impregnation solution in an environment of 2–25°C, preferably 5–20°C, for 1–30 hours, preferably 3–20 hours. This cooling and curing treatment allows the first impregnation solution adsorbed in the alumina carrier to be converted into a gel state, and the gel-state first impregnation solution can be largely concentrated within the macropores of the alumina carrier.

[0023] In step (3) of the above method, the active metal component comprises at least one metal selected from Group VIII and at least one metal selected from Group VIB. Preferably, the active metal component comprises Ni and Mo. The active metal component Ni is derived from one or more of nickel nitrate, basic nickel carbonate, nickel oxalate, nickel chloride, and nickel acetate, and the Mo is derived from one or more of molybdenum oxide, ammonium molybdate, ammonium tetrathiomolybdate, and ammonium secondary molybdate. Based on the weight of the final hydrogenation pretreatment catalyst, the content of the active metal component Ni, calculated as oxide, is 2wt% to 6wt%, preferably 3wt% to 5wt%; the content of the active metal component Mo, calculated as oxide, is 10wt% to 22wt%, preferably 12wt% to 20wt%.

[0024] In step (4) of the above method, the impregnation of the hydrogenation pretreatment catalyst precursor by the second impregnation liquid is carried out by unsaturated impregnation method, and the impregnation amount is the difference between the water absorption rate of the support and the solution volume of the first impregnation liquid; the impregnation temperature is 1 to 30°C, preferably 15 to 25°C.

[0025] In step (4) of the above method, the operating conditions for health preservation are as follows: the health preservation time is 1 to 30 hours, preferably 5 to 20 hours; the health preservation temperature is 0 to 30°C, preferably 5 to 25°C.

[0026] In step (4) of the above method, the drying and calcination conditions are as follows: the drying time is generally 2h to 15h, preferably 3h to 10h, the drying temperature is 80℃ to 160℃, preferably 100℃ to 130℃; the calcination temperature is 80℃ to 650℃, preferably 100℃ to 500℃, and the calcination time is 1 to 10h, preferably 2 to 6h.

[0027] According to a second aspect of the present invention, a hydrogenation pretreatment catalyst prepared by the above method is provided.

[0028] According to a third aspect of the present invention, an application of the above-described hydrogenation pretreatment catalyst in the hydrogenation pretreatment process of heavy feedstock is provided.

[0029] In the above applications, the heavy feedstock is naphthenic wax oil and / or secondary processed oil, and the secondary processed oil is one or more of coking wax oil and catalytic diesel oil.

[0030] In the above applications, the operating conditions for the heavy feedstock hydrogenation pretreatment process are as follows: reaction temperature 330–430℃, preferably 350–410℃; reaction pressure 4–18 MPa, preferably 6–16 MPa; hydrogen-to-oil ratio 400:1–1500:1, preferably 600:1–1200:1; and volume hourly space velocity (VHSV) 0.5–4.0 h⁻¹. -1 Preferably, it is 0.5 to 2.0 h. -1 .

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] 1. In the preparation method of the hydrotreating catalyst provided by this invention, an alumina support is unsaturatedly impregnated with a first impregnation solution containing fluorine, an active metal component, and gelatin. Then, utilizing the low-temperature solidification property of gelatin, the first impregnation solution adsorbed in the alumina support is converted into a gel state through a cooling and solidification treatment. The gel-state first impregnation solution can be largely enriched within the macropores of the alumina support, thereby ensuring that the fluorine and active metal components contained therein are mostly loaded within the macropores of the alumina support. Subsequently, a second impregnation solution containing the active metal component but not fluorine is used for impregnation. This second impregnation solution is an aqueous solution and is immiscible with the gel-state first impregnation solution, making it difficult for the fluorine to enter the positions occupied by the gel-state first impregnation solution. Instead, the active metal component is loaded into other pores. This operation can introduce the majority of the fluorine element into the macropores of the alumina support, thereby modulating the distribution of acidic sites within the pores. When applied to the heavy oil hydrotreating process, the catalyst exhibits good activity.

[0033] 2. In the preparation method of the hydrogenation pretreatment catalyst provided by the present invention, the first impregnation liquid and the second impregnation liquid may contain different active metal components respectively. By introducing Ni-W and Mo-Ni active metal components into different positions of the alumina support through the first impregnation liquid and the second impregnation liquid respectively, the distribution of active metal in the pores is regulated, and the activity of the catalyst in the hydrogenation pretreatment process of heavy feedstock is further improved. Detailed Implementation

[0034] The present invention will be described in detail below through embodiments, but the present invention is not limited to the following embodiments. Furthermore, unless otherwise specified, all percentages in the present invention refer to weight percentages.

[0035] In this invention, the gelatin used in the examples and comparative examples was purchased from Maclean's, CAS: 9000-70-8. The molecular weight of the gelatin was 10,000 to 50,000.

[0036] In this invention, the properties of the alumina support in the examples and comparative examples are as follows: pore volume of 0.79 mL / g and specific surface area of ​​228 m². 2 / g.

[0037] In this invention, the preparation process of the first impregnation solution in the examples and comparative examples is as follows: (1) Gelatin is added to deionized water at 20°C, stirred at 50 r / min, and treated at 70°C until completely dissolved, finally obtaining a gelatin solution; (2) An aqueous solution containing fluorine and active metal components is prepared using ammonium fluoride and a salt / oxide containing active metal components; (3) The gelatin solution and the aqueous solution containing fluorine and active metal components are mixed to obtain the first impregnation solution. The temperature of the first impregnation solution is 70°C.

[0038] In this invention, in the embodiments and comparative examples, Ni is derived from basic nickel carbonate, W is derived from ammonium metatungstate, and Mo is derived from molybdenum oxide.

[0039] Example 1

[0040] (1) Prepare 50 mL of the first impregnation solution, the active metal components being Ni and W. Specifically, based on the mass of the first impregnation solution, the gelatin concentration is 5 wt%; the amount of ammonium fluoride added, calculated as elemental fluorine, is 0.4 wt% of the weight of the alumina support (on a dry basis); based on the weight of the final hydrogenation pretreatment catalyst, the active metal content, calculated as oxides, is 5 wt% W and 1 wt% Ni.

[0041] (2) Impregnate 100g of alumina support with a water absorption rate of 100% with the first impregnation liquid obtained in step (1) at 50°C, and then cool and solidify at 10°C for 5h to obtain hydrogenation pretreatment catalyst precursor.

[0042] (3) Prepare 50 mL of the second impregnation solution. The active metal components are Mo and Ni. The nickel oxide content is 4 wt% and the molybdenum oxide content is 20 wt% based on the weight of the catalyst.

[0043] (4) The hydrogenation pretreatment catalyst precursor obtained in step (2) is impregnated with the second impregnation liquid obtained in step (3) at 15°C, cured at room temperature (20°C) for 6 hours, dried at 120°C for 6 hours, and calcined at 420°C for 3 hours to obtain the final hydrogenation pretreatment catalyst Cat-1.

[0044] Example 2

[0045] (1) Prepare 40 mL of the first impregnation solution, with Ni and W as the active metal components. The gelatin concentration is 10 wt% based on the mass of the first impregnation solution; the amount of ammonium fluoride added is 0.8 wt% of the weight of the alumina support (dry basis) based on elemental fluorine; and the active metal content is 15 wt% W and 3 wt% Ni based on the weight of the final hydrogenation pretreatment catalyst.

[0046] (2) Impregnate 100g of alumina support with a water absorption rate of 100% with the first impregnation liquid obtained in step (1) at 40°C, and then cool and solidify at 15°C for 3h to obtain hydrogenation pretreatment catalyst precursor.

[0047] (3) Prepare 60 mL of the second impregnation solution. The active metals are Mo and Ni. The nickel oxide content is 2 wt% and the molybdenum oxide content is 10 wt% based on the weight of the catalyst.

[0048] (4) The hydrogenation pretreatment catalyst precursor obtained in step (2) is impregnated with the second impregnation liquid obtained in step (3) at 20°C, cured at room temperature (20°C) for 6 hours, dried at 120°C for 8 hours, and calcined at 420°C for 3 hours to obtain the final hydrogenation pretreatment catalyst Cat-2.

[0049] Example 3

[0050] (1) Prepare 60 mL of the first impregnation solution, with Ni and W as the active metal components. The gelatin concentration is 4 wt% based on the mass of the first impregnation solution; the amount of ammonium fluoride added is 0.6 wt% of the weight of the alumina support (on a dry basis) based on elemental fluorine; and the active metal content is 12 wt% W and 2.4 wt% Ni based on the weight of the final hydrogenation pretreatment catalyst.

[0051] (2) Impregnate 100g of alumina support with a water absorption rate of 100% with the first impregnation liquid obtained in step (1) at 40°C, and then cool and solidify at 10°C for 3h to obtain hydrogenation pretreatment catalyst precursor.

[0052] (3) Prepare 40 mL of the second impregnation solution. The active metals are Mo and Ni. The nickel oxide content is 2.6 wt% and the molybdenum oxide content is 13 wt% by weight of the catalyst.

[0053] (4) The hydrogenation pretreatment catalyst precursor obtained in step (2) is impregnated with the second impregnation liquid obtained in step (3) at 15°C, cured at room temperature (20°C) for 6 hours, dried at 120°C for 10 hours, and calcined at 420°C for 3 hours to obtain the final hydrogenation pretreatment catalyst Cat-3.

[0054] Example 4

[0055] (1) Prepare 50 mL of the first impregnation solution, with active metal components of Ni and W. The gelatin concentration is 8 wt% based on the mass of the first impregnation solution; the amount of ammonium fluoride added is 0.6 wt% of the alumina support weight (dry basis) based on elemental fluorine; and the active metal content (based on the weight of the final hydrogenation pretreatment catalyst) is 10 wt% W and 2 wt% Ni (based on oxides).

[0056] (2) Impregnate 100g of alumina support with a water absorption rate of 100% with the first impregnation liquid obtained in step (1) at 50°C, and then cool and solidify at 10°C for 3h to obtain hydrogenation pretreatment catalyst precursor.

[0057] (3) Prepare 50 mL of the second impregnation solution. The active metals are Mo and Ni. By weight of catalyst, the content of nickel oxide is 3 wt% and the content of molybdenum oxide is 15 wt%.

[0058] (4) The hydrogenation pretreatment catalyst precursor obtained in step (2) is impregnated with the second impregnation liquid obtained in step (3) at 20°C, cured at room temperature (20°C) for 6 hours, dried at 120°C for 6 hours, and calcined at 420°C for 3 hours to obtain the final hydrogenation pretreatment catalyst Cat-4.

[0059] Example 5

[0060] Compared with Example 1, the difference is that the active metal components contained in the first impregnation solution in step (1) are Mo and Ni, as detailed below:

[0061] (1) Prepare 50 mL of the first impregnation solution, with Ni and Mo as the active metal components. The gelatin concentration is 5 wt% based on the mass of the first impregnation solution; the amount of ammonium fluoride added is 0.4 wt% of the weight of the alumina support (dry basis) based on elemental fluorine; and the active metal content is 5 wt% Mo and 1 wt% Ni based on the weight of the final hydrogenation pretreatment catalyst.

[0062] Comparative Example 1

[0063] (1) Prepare 100 mL of impregnation solution containing fluorine and active metal components. The amount of ammonium fluoride added is 0.6 wt% of the weight of the alumina carrier (on a dry basis) based on the amount of elemental fluorine. Based on the weight of the catalyst, it contains 5 wt% nickel oxide, 12 wt% tungsten oxide and 13 wt% molybdenum oxide.

[0064] (2) Impregnate 100g of alumina support with a water absorption rate of 100% with the above impregnation solution, cure at room temperature of 20℃ for 6h, dry at 120℃ for 6h, and calcine at 420℃ for 3h to obtain the final hydrogenation pretreatment catalyst DC-1.

[0065] Comparative Example 2

[0066] Compared to Example 3, the first impregnation solution in step (1) does not contain gelatin. The specific operation process is as follows.

[0067] (1) Prepare a first impregnation solution of 60 mL containing fluorine and active metals, the active metal components being Ni and W. The amount of ammonium fluoride added is 0.6 wt% of the weight of the alumina support (on a dry basis) based on elemental fluorine; based on the weight of the final hydrogenation pretreatment catalyst, the active metal W content (based on oxides) is 12 wt%, and the Ni content (based on oxides) is 2.4 wt%.

[0068] (2) Impregnate 100g of alumina support with a water absorption rate of 100% with the first impregnation liquid obtained in step (1) at 40°C, and then cool and solidify at 10°C for 3h to obtain hydrogenation pretreatment catalyst precursor.

[0069] (3) Prepare 40 mL of the second impregnation solution, with the active metals being Mo and Ni, based on the weight of the final hydrogenation pretreatment catalyst: the nickel oxide content is 2.6 wt% and the molybdenum oxide content is 13 wt%.

[0070] (4) The hydrogenation pretreatment catalyst precursor obtained in step (2) is impregnated with the second impregnation liquid obtained in step (3) at 15°C, cured at room temperature (20°C) for 6 hours, dried at 120°C for 10 hours, and calcined at 420°C for 3 hours to obtain the final hydrogenation pretreatment catalyst DC-2.

[0071] Comparative Example 3

[0072] Compared with Example 3, gelatin is not used in the first impregnation solution in step (1), but rather nitrotriacetic acid (NTA). The specific operation process is as follows.

[0073] (1) Prepare 60 mL of a first impregnation solution containing fluorine, an active metal, and nitrotriacetic acid (NTA). The active metal components are Ni and W. The amount of ammonium fluoride added is 0.6 wt% of the weight of the alumina support (on a dry basis) based on elemental fluorine. Based on the weight of the final hydrogenation pretreatment catalyst, the active metal W content (based on oxides) is 12 wt%, the Ni content (based on oxides) is 2.4 wt%, and the NTA concentration is 4 wt% based on the mass of the first impregnation solution.

[0074] (2) The alumina support with a water absorption rate of 100% was impregnated with the first impregnation solution obtained in step (1) at 40°C and cured at 10°C for 3 hours to obtain the hydrogenation pretreatment catalyst precursor.

[0075] (3) Prepare 40 mL of the second impregnation solution, with the active metals being Mo and Ni, based on the weight of the final hydrogenation pretreatment catalyst: the nickel oxide content is 2.6 wt% and the molybdenum oxide content is 13 wt%.

[0076] (4) The hydrogenation pretreatment catalyst precursor obtained in step (2) is impregnated with the second impregnation liquid obtained in step (3) at 15°C, cured at room temperature (20°C) for 6 hours, dried at 120°C for 10 hours, and calcined at 420°C for 3 hours to obtain the final hydrogenation pretreatment catalyst DC-3.

[0077] Example 6

[0078] Catalytic performance evaluation test of hydrotreating catalyst: Before evaluation, CS2 cyclohexane solution was used as sulfidation solution to treat the hydrotreating catalyst. The concentration of CS2 in the CS2 cyclohexane solution was 4wt%, the sulfidation temperature was 270℃, the sulfidation pressure was 14.2MPa, the sulfidation time was 6h, and the corresponding volume ratio of hydrogen to sulfidation solution was 550:1.

[0079] A mixture of straight-run paraffinic wax oil, coking wax oil, and straight-run naphthenic wax oil was used as feedstock. The properties of the feedstock oils are shown in Table 3. The catalyst activity was evaluated in a small-scale hydrogenation unit with a catalyst loading of 100 mL, at a reaction temperature of 380 °C, a reaction pressure of 14.2 MPa, and a volume hourly space velocity of 1.0 h⁻¹. -1 The hydrogen-to-oil volume ratio was 800. The evaluation results of the catalysts prepared in the examples and comparative examples are shown in Table 4.

[0080] Table 3 Properties of Feed Oil

[0081] <![CDATA[Density (20℃), g·cm -3 > 0.8793 Distillation range, °C 343-461 <![CDATA[S,μg·g -1 ]]> 1240 <![CDATA[N,μg·g -1 ]]> 915

[0082] Table 4 Evaluation Results

[0083]

[0084] *Relative activity is based on comparative DC-1.

[0085] As can be seen from Table 3, compared with the comparative catalyst, the hydrogenation pretreatment catalyst prepared in this invention has higher activity and is particularly suitable for the hydrogenation pretreatment of inferior raw materials, such as cycloalkyl and secondary processed raw materials.

Claims

1. A method for preparing a hydrogenation pretreatment catalyst, characterized in that: Includes the following steps: (1) Prepare a first impregnation solution containing fluorine, an active metal component and gelatin; (2) The alumina support is impregnated with the first impregnation liquid obtained in step (1) and then subjected to cooling and curing treatment to obtain the hydrogenation pretreatment catalyst precursor. (3) Prepare a second impregnation solution containing an active metal component; (4) Impregnate the hydrogenation pretreatment catalyst precursor obtained in step (2) with the second impregnation solution obtained in step (3), and obtain the hydrogenation pretreatment catalyst after conditioning, drying and calcination. In step (2), the impregnation temperature of the first impregnation solution for unsaturated impregnation of the alumina carrier is 40~70℃; In step (2), the cooling and curing process involves placing the alumina carrier impregnated with the first impregnation solution in an environment of 2~25℃ for 1~30 h. In step (4), the second impregnation solution impregnates the hydrogenation pretreatment catalyst precursor using an unsaturated impregnation method, and the impregnation amount is the difference between the water absorption rate of the support and the solution volume of the first impregnation solution; the impregnation temperature is 1~30℃. In step (1), the active metal component comprises at least one metal selected from Group VIII and at least one metal selected from Group VIB; In step (3), the active metal component comprises at least one metal selected from Group VIII and at least one metal selected from Group VIB.

2. The preparation method according to claim 1, characterized in that: In step (1), the fluorine is derived from one or more fluorine-containing compounds selected from ammonium fluoride, ammonium fluorosilicate, hydrogen fluoride, ammonium hydrogen fluoride, calcium fluoride, and sodium fluoride; the amount of the fluorine-containing compound added, based on the elemental content, is 0.3wt% to 1.5wt% of the dry weight of the alumina carrier.

3. The preparation method according to claim 2, characterized in that: In step (1), the fluorine is derived from ammonium fluorosilicate and / or ammonium fluoride; the amount of the fluorine-containing compound added, based on the elemental content, is 0.4 wt% to 0.8 wt% of the dry weight of the alumina carrier.

4. The preparation method according to claim 1, characterized in that: In step (1), the active metal component comprises Ni and W; based on the weight of the final hydrogenation pretreatment catalyst, the content of the active metal component Ni, calculated as oxide, is 1 wt% to 5 wt%; the content of the active metal component W, calculated as oxide, is 5 wt% to 18 wt%.

5. The preparation method according to claim 4, characterized in that: In step (1), based on the weight of the final hydrogenation pretreatment catalyst, the content of active metal component Ni as oxide is 2wt%~4wt%; the content of active metal component W as oxide is 8wt%~15wt%.

6. The preparation method according to claim 1, characterized in that: In step (1), the gelatin is one or more of marine gelatin, pig gelatin, bovine gelatin and chicken gelatin, and the purity level is industrial grade or food grade; the molecular weight of the gelatin is 10,000 to 70,000; based on the weight of the first impregnation solution, the gelatin concentration in the first impregnation solution is 4 wt% to 10 wt%.

7. The preparation method according to claim 6, characterized in that: In step (1), the molecular weight of the gelatin is 20,000 to 50,000.

8. The preparation method according to claim 1, characterized in that: In step (1), the temperature of the first impregnation solution is 40~70℃.

9. The preparation method according to claim 8, characterized in that: In step (1), the temperature of the first impregnation solution is 50~60℃.

10. The preparation method according to claim 1, characterized in that: In step (2), the alumina support has the following properties: pore volume of 0.3~1.5 mL / g and specific surface area of ​​150~450 m². 2 / g.

11. The preparation method according to claim 10, characterized in that: In step (2), the alumina support has bimodal pores, with pores having a diameter of 0~15nm accounting for 40~80% of the total pore volume; and pores having a diameter >15nm accounting for 20~60% of the total pore volume.

12. The preparation method according to claim 11, characterized in that: In step (2), the alumina carrier has bimodal pores, with pores having a diameter of 0~15nm accounting for 50~70% of the total pore volume; and pores having a diameter >15nm accounting for 30~50% of the total pore volume.

13. The preparation method according to claim 1, characterized in that: In step (2), the alumina carrier also contains an additive, which is selected from one or more of silicon dioxide, magnesium oxide, zirconium oxide, boron oxide and titanium dioxide, and the content of the additive in the alumina carrier as an oxide is less than 30 wt%.

14. The preparation method according to claim 1, characterized in that: In step (2), the amount of the first impregnation solution used to impregnate the alumina carrier is 30 to 60 wt% of the saturated water absorption capacity of the alumina carrier.

15. The preparation method according to claim 14, characterized in that: In step (2), the amount of the first impregnation solution used to impregnate the alumina carrier is 40-50 wt% of the saturated water absorption capacity of the alumina carrier.

16. The preparation method according to claim 1, characterized in that: In step (2), the impregnation temperature of the first impregnation solution for unsaturated impregnation of the alumina carrier is 50~60℃.

17. The preparation method according to claim 1, characterized in that: In step (2), the first impregnation solution is used to impregnate the alumina carrier by spraying, and the temperature of the impregnation solution is 40~70℃.

18. The preparation method according to claim 17, characterized in that: In step (2), the first impregnation solution is used to impregnate the alumina carrier by spraying, and the temperature of the impregnation solution is 50~60℃.

19. The preparation method according to claim 1, characterized in that: In step (2), the cooling and curing process involves placing the alumina carrier that has been impregnated with the first impregnation liquid in an environment of 5~20℃ for 3~20 h.

20. The preparation method according to claim 1, characterized in that: In step (3), the active metal component includes Ni and Mo; based on the weight of the final hydrogenation pretreatment catalyst, the content of active metal component Ni as oxide is 2wt%~6wt%; the content of active metal component Mo as oxide is 10wt%~22wt%.

21. The preparation method according to claim 20, characterized in that: In step (3), the active metal component includes Ni and Mo; based on the weight of the final hydrogenation pretreatment catalyst, the content of active metal component Ni as oxide is 3wt%~5wt%; the content of active metal component Mo as oxide is 12wt%~20wt%.

22. The preparation method according to claim 1, characterized in that: In step (4), the hydrogenation pretreatment catalyst precursor is impregnated with the second impregnation liquid using an unsaturated impregnation method, and the impregnation amount is the difference between the water absorption rate of the support and the solution volume of the first impregnation liquid; the impregnation temperature is 15~25℃.

23. The preparation method according to claim 1, characterized in that: In step (4), the operating conditions for health preservation are as follows: the health preservation time is 1~30h; the health preservation temperature is 0~30℃.

24. The preparation method according to claim 23, characterized in that: In step (4), the operating conditions for health preservation are as follows: the health preservation time is 5~20h; the health preservation temperature is 5~25℃.

25. The preparation method according to claim 1, characterized in that: In step (4), the drying and calcination conditions are as follows: drying time is 2h~15h, drying temperature is 80℃~160℃; calcination temperature is 80℃~650℃, and calcination time is 1~10h.

26. The preparation method according to claim 25, characterized in that: In step (4), the drying and calcination conditions are as follows: drying time is 3h~10h, drying temperature is 100℃~130℃; calcination temperature is 100℃~500℃, and calcination time is 2~6h.

27. The hydrogenation pretreatment catalyst prepared by any one of claims 1-26.

28. The application of the hydrotreating catalyst according to claim 27 in the hydrotreating process of heavy feedstock.

29. The application according to claim 28, characterized in that: The heavy feedstock is naphthenic wax oil and / or secondary processed oil, wherein the secondary processed oil is one or more of coking wax oil and catalytic diesel oil.

30. The application according to claim 28, characterized in that: The operating conditions for the heavy feedstock hydrogenation pretreatment process are as follows: reaction temperature 330~430℃, reaction pressure 4~18MPa, hydrogen-to-oil ratio 400:1~1500:1, and volumetric hourly space velocity 0.5~4.0h⁻¹. -1 .

31. The application according to claim 30, characterized in that: The operating conditions for the heavy feedstock hydrogenation pretreatment process are as follows: reaction temperature 350~410℃, reaction pressure 6~16MPa, hydrogen-to-oil ratio 600:1~1200:1, and volumetric hourly space velocity 0.5~2.0 h⁻¹. -1 .

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