Hydrodesulfurization agent and preparation method thereof

Abstract

The invention belongs to the technical field of petrochemical engineering catalysts, and particularly relates to a hydrodesulfurization agent and a preparation method thereof. According to the invention, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is adopted to modify the prepared mesoporous silica, so that the loading capacity of the mesoporous silica to the active component and the reaction activity of the surface of the channel of the mesoporous silica are improved, and the service life of the hydrodesulfurization agent is further prolonged; a phosphomolybdic acid molecular cluster is introduced into a carrier through electrostatic interaction, small-size and high-dispersion Mo2N is obtained through roasting, the catalytic specific surface area and catalytic active sites are effectively increased, obtained nickel is also loaded in the carrier through the reaction of reducing nickel chloride through lithium borohydride, and therefore the Ni-Mo2N composite catalyst is obtained. The catalytic activity of the hydrodesulfurization agent is effectively improved, and the catalytic hydrogenation capacity is favorably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of petrochemical catalysts, and in particular relates to a hydrodesulfurization agent and a preparation method thereof. Background Art

[0002] Sulfur compounds in gasoline will generate sulfur oxides SOx after combustion, which can poison the catalyst of the automobile exhaust conversion system, further affecting the effective conversion of NOx, CO, and CH. In addition, sulfur oxides discharged into the atmosphere will form acid rain to pollute the environment. As people pay more and more attention to environmental protection, environmental protection regulations are becoming increasingly stringent, and the global gasoline sulfur content index is becoming increasingly stringent. Similarly, my country's requirements for the sulfur content of petroleum products (gasoline, diesel, naphtha, solvent oil, etc.) are also getting higher and higher, which puts higher requirements on the desulfurization technology of my country's oil refining enterprises.

[0003] Hydrodesulfurization technology is one of the most effective means to improve oil quality, and the development of efficient hydrodesulfurization catalysts is the key to hydrodesulfurization technology. Traditional hydrodesulfurization catalysts are mainly composed of transition metals such as Mo and W as active components, Ni or Co as additives, and alumina, titanium oxide and zirconium oxide as carriers. In order to achieve the purpose of deep desulfurization, traditional hydrodesulfurization catalysts need to improve the reaction conditions, and the catalyst is easy to deactivate under such conditions, reducing the catalyst life. When alumina is used as a carrier, it has a strong interaction with the metal component and is easy to form spinel, which affects the activity of the catalyst.

[0004] A gasoline desulfurizer and its preparation method and application are disclosed in a Chinese patent application document with publication number CN106554803A. The desulfurizer is composed of illite, perillyl alcohol, salicylic acid and triethylene diamine. The preparation process is: crush the illite, add triethylene diamine solution, seal, heat and stir, then drop salicylic acid, ultrasonic treatment, then add perillyl alcohol solution, stir until dry, and calcine to obtain the desulfurizer. The desulfurizer prepared by this method has good selectivity for sulfur and high desulfurization depth. It can deeply remove sulfur-containing compounds in gasoline while avoiding octane loss caused by olefin hydrogenation saturation, and has a long service life. A catalyst for hydrogenation conversion of organic sulfur in coke oven gas and its preparation method are disclosed in a Chinese patent application document with publication number CN101642712A. The composition of the catalyst includes γ-Al2O3 as a carrier and active components such as molybdenum, iron, cobalt, and nickel loaded by impregnation method; the shape of the catalyst carrier can be spherical, cylindrical or strip-shaped. This type of organic sulfur hydrogenation conversion catalyst is produced by the impregnation method. The active components are evenly distributed, the product quality is stable, the activity (organic sulfur hydrogenation conversion rate) is high, the catalyst production links are few, the process is short, the production cost is low, and the operation is convenient. However, γ-Al2O3 as a carrier will affect the activity of the catalyst. Summary of the invention

[0005] In order to solve the technical problems of catalyst deactivation, short catalyst life and the like existing in the related art, the object of the present invention is to provide a hydrodesulfurization agent and a preparation method thereof.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows: A method for preparing a hydrodesulfurization agent comprises the following steps: S1: dispersing the carrier in deionized water, adding phosphomolybdic acid solution dropwise under stirring, filtering after sufficient stirring, washing, drying, roasting, and cooling to obtain powder material I; S2: Mix nickel chloride and hydrogen chloride solution, add powder material I obtained in step S1, stir, add sodium hydroxide solution to adjust the pH value to 10.5-11, continue to add lithium borohydride aqueous solution, stir the reaction in an ice-water bath, filter, wash, and dry to obtain a hydrodesulfurization agent.

[0007] The present invention adopts a coupled molecule anchoring method to modify molecules with functional groups on a carrier, then utilizes electrostatic interaction to introduce phosphomolybdic acid molecular clusters into the carrier, and obtains small-sized, highly dispersed Mo2N through calcination, effectively increasing the catalytic specific surface area and catalytic active sites, and then uses lithium borohydride to reduce nickel chloride so that the obtained nickel is also loaded on the carrier, thereby obtaining a Ni-Mo2N composite catalyst, effectively improving the catalytic activity of the hydrodesulfurization agent, and being beneficial to improving the catalytic hydrogenation capacity.

[0008] Furthermore, the mass fractions of the components in step S1 of the preparation method of the hydrodesulfurization agent are: 30-40 parts of the carrier, 60-70 parts of deionized water, and 20-25 parts of the molybdenum phosphate solution; the mass percentage of the molybdenum phosphate solution is 15%-20%.

[0009] Furthermore, the specific process of calcination in step S1 of the preparation method of the hydrodesulfurization agent is: first calcination at 320-350°C in an air atmosphere for 3.5-4h, with a heating rate of 5-7°C / min; then calcination at 560-600°C in an ammonia atmosphere for 3.5-4h, with a heating rate of 2-5°C / min.

[0010] During the research process, the inventors found that the calcination process after the carrier is loaded with phosphomolybdic acid has a great influence on the performance of the hydrodesulfurization agent. When the calcination temperature or the heating rate is too high, the performance of the obtained hydrodesulfurization agent is reduced. This is because high temperature or a high heating rate will cause the generated catalyst active nanoparticles to agglomerate, resulting in a reduction in active sites.

[0011] Furthermore, the mass fractions of the components in step S2 of the preparation method of the hydrodesulfurization agent are: 5-10 parts of nickel chloride, 15-20 parts of hydrogen chloride solution, 5-10 parts of powder material I, and 15-20 parts of lithium borohydride aqueous solution; the mass percentage of the hydrogen chloride solution is 12%-15%; the concentration of the sodium hydroxide is 0.8-1 mol / L; the concentration of the lithium borohydride aqueous solution is 0.3-0.5 mol / L.

[0012] Furthermore, in the step S2 of the preparation method of the hydrodesulfurization agent, the stirring time is 15-20 hours; the stirring reaction time in the ice-water bath is 5-7 hours; the drying temperature is 65-70° C., and the drying time is 12-15 hours.

[0013] Furthermore, the preparation method of the carrier is as follows: (1) dissolving hexadecyltrimethylammonium bromide in a mixed solution of amyl alcohol and cyclohexane to obtain solution I; mixing urea and deionized water evenly to obtain solution II; adding solution II to solution I under stirring, stirring, continuing to add tetraethyl orthosilicate, stirring, heating to 110-120° C., keeping warm for reaction, centrifuging and drying the lower precipitate and then calcining to obtain a powdery material; (2) mixing N-(2-aminoethyl)-3-aminopropyltrimethoxysilane with the powdery material, performing reflux extraction with toluene as solvent, suction filtering, washing, and vacuum drying to obtain a carrier.

[0014] In the present invention, a mesoporous silica material with radial pores is prepared by a sol-gel method, which has a large specific surface area and pore volume, can improve the dispersion of active components, and lays a foundation for increasing the loading amount of active components. However, there are fewer active sites in the pores of mesoporous silica, which is not conducive to the adsorption and loading of active components. Therefore, in the preparation process of the mesoporous silica material in the present invention, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is added to modify the mesoporous silica, and -NH2 is introduced into the pores of the mesoporous silica. Through the coordination effect of the amino functional group on the metal ions, the loading amount of the mesoporous silica on the active components and the reaction activity of the surface of the mesoporous silica pores are increased, thereby improving the life of the hydrodesulfurization agent.

[0015] Furthermore, the weight percentages of the components in step (1) of the carrier preparation method are: 20-25 parts of hexadecyltrimethylammonium bromide, 15-20 parts of amyl alcohol, 50-60 parts of cyclohexane, 6-10 parts of urea, 100-120 parts of deionized water, and 35-40 parts of tetraethyl orthosilicate.

[0016] Furthermore, in the step (1) of the preparation method of the carrier, the stirring time is 1-1.5 h, the heat preservation reaction time is 17-20 h, the calcination temperature is 700-750° C., and the calcination time is 3.5-4 h.

[0017] Furthermore, the mass fractions of the components in step (2) of the carrier preparation method are: 15-20 parts of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and 40-45 parts of powdered material.

[0018] Furthermore, in the step (2) of the carrier preparation method, the reflux extraction temperature is 130-140°C, the reflux extraction time is 24-28h, and the vacuum drying temperature is 100-120°C.

[0019] The present invention also provides a hydrodesulfurization agent prepared by using the preparation method of the hydrodesulfurization agent.

[0020] Compared with the prior art, the hydrodesulfurization agent and preparation method thereof provided by the present invention have the following technical advantages: (1) The present invention adopts a coupled molecular anchoring method to modify molecules with functional groups on the carrier, and then introduces phosphomolybdic acid molecular clusters into the carrier to obtain small-sized, highly dispersed Mo2N through a nitridation reaction, thereby effectively increasing the catalytic specific surface area and catalytic active sites; (2) In the present invention, the nickel obtained by reducing nickel chloride with lithium borohydride is also loaded on the carrier, and synergistically acts with Mo2N to effectively improve the catalytic activity of the hydrodesulfurization agent; (3) In the present invention, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is used to modify the prepared mesoporous silica, thereby increasing the loading amount of the mesoporous silica for the active components and the reaction activity of the mesoporous silica pore surface, thereby increasing the life of the hydrodesulfurization agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a micro fixed bed reaction device for organic sulfur hydrogenation. DETAILED DESCRIPTION

[0022] The technical scheme of the present invention is clearly and completely described below in conjunction with specific embodiments. The specific embodiments described are only partial embodiments of the present invention, rather than limitations of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present invention.

[0023] Example 1 A method for preparing a hydrodesulfurization agent comprises the following steps: S1: 30 parts of the carrier were dispersed in 70 parts of deionized water, and 20 parts of a 15% by mass phosphomolybdic acid solution were added dropwise under stirring. After being fully stirred for 4 hours, the mixture was filtered, and the filter residue was washed twice with anhydrous ethanol and deionized water, respectively. The residue was dried at 65°C for 14 hours, and then calcined at 320°C (air atmosphere, heating rate of 5°C / min) for 4 hours, and then calcined at 560°C (ammonia atmosphere, heating rate of 2°C / min) for 4 hours. The mixture was cooled to obtain powder material I; S2: Mix 5 parts of nickel chloride with 15 parts of 12% by mass hydrogen chloride solution, add 5 parts of powder material I obtained in step S1, stir for 15 hours, add 0.8 mol / L sodium hydroxide solution to adjust the pH value to 10.5, continue to add 15 parts of 0.3 mol / L lithium borohydride aqueous solution to reduce nickel, stir in an ice-water bath for 5 hours, filter, wash the filter residue twice with countless ethanol and deionized water respectively, and dry in vacuum at 65°C for 15 hours to obtain a hydrodesulfurization agent.

[0024] The preparation method of the carrier is as follows: (1) dissolving 20 parts of hexadecyltrimethylammonium bromide in a mixed solution of 15 parts of amyl alcohol and 50 parts of cyclohexane to obtain solution I; mixing 6 parts of urea and 120 parts of deionized water to obtain solution II; adding solution II to solution I under stirring, stirring for 1 hour, continuing to add 35 parts of tetraethyl orthosilicate, stirring for 1 hour, heating to 110°C, keeping the temperature for reaction for 17 hours, centrifuging and drying the lower layer of precipitate, and calcining at 700°C for 3.5 hours to obtain a powdery material; (2) mixing 15 parts of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane with 40 parts of the powdery material, reflux extracting at 130°C for 24 hours with toluene as solvent, filtering, washing, and vacuum drying at 100°C to obtain a carrier.

[0025] Example 2 A method for preparing a hydrodesulfurization agent comprises the following steps: S1: 40 parts of the carrier were dispersed in 60 parts of deionized water, and 25 parts of a 20% by mass phosphomolybdic acid solution were added dropwise under stirring. After being fully stirred for 6 hours, the mixture was filtered, and the filter residue was washed twice with anhydrous ethanol and deionized water, respectively. The residue was dried at 70°C for 12 hours, and then calcined at 350°C (air atmosphere, heating rate of 7°C / min) for 3.5 hours, and then calcined at 600°C (ammonia atmosphere, heating rate of 5°C / min) for 3.5 hours. The mixture was cooled to obtain powder material I; S2: 10 parts of nickel chloride were mixed with 20 parts of 15% by mass hydrogen chloride solution, 10 parts of powder material I prepared in step S1 were added, and the mixture was stirred for 20 hours. A 1 mol / L sodium hydroxide solution was added to adjust the pH value to 11, and 20 parts of a 0.5 mol / L lithium borohydride aqueous solution were added to reduce the nickel. The mixture was stirred in an ice-water bath for 7 hours, and the mixture was filtered. The residue was washed twice with countless ethanol and deionized water, respectively, and vacuum dried at 70°C for 12 hours to obtain a hydrodesulfurization agent.

[0026] The preparation method of the carrier is as follows: (1) dissolving 25 parts of hexadecyltrimethylammonium bromide in a mixed solution of 20 parts of amyl alcohol and 60 parts of cyclohexane to obtain solution I; mixing 10 parts of urea and 100 parts of deionized water to obtain solution II; adding solution II to solution I under stirring, stirring for 1.5 hours, continuing to add 40 parts of tetraethyl orthosilicate, stirring for 1.5 hours, heating to 120°C, keeping the temperature for reaction for 20 hours, centrifuging and drying the lower layer of precipitate, and calcining at 750°C for 4 hours to obtain a powdery material; (2) mixing 20 parts of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane with 45 parts of the powdery material, reflux extracting at 140°C for 28 hours with toluene as solvent, filtering, washing, and vacuum drying at 120°C to obtain a carrier.

[0027] Example 3 A method for preparing a hydrodesulfurization agent comprises the following steps: S1: 33 parts of the carrier were dispersed in 65 parts of deionized water, and 22 parts of a 17% by mass phosphomolybdic acid solution were added dropwise under stirring. After sufficient stirring for 4.8 hours, the mixture was filtered, and the filter residue was washed twice with anhydrous ethanol and deionized water, respectively. The residue was dried at 67°C for 13 hours, and then calcined at 340°C (air atmosphere, heating rate of 6°C / min) for 3.8 hours, and then calcined at 580°C (ammonia atmosphere, heating rate of 4°C / min) for 3.8 hours. The mixture was cooled to obtain powder material I; S2: 8 parts of nickel chloride were mixed with 18 parts of 14% by mass hydrogen chloride solution, 8 parts of powder material I prepared in step S1 were added, and the mixture was stirred for 18 hours. A 0.9 mol / L sodium hydroxide solution was added to adjust the pH value to 10.7, and 17 parts of a 0.4 mol / L lithium borohydride aqueous solution were added to reduce nickel. The mixture was stirred in an ice-water bath for 6 hours, and the residue was washed twice with countless ethanol and deionized water, respectively, and vacuum dried at 67°C for 13 hours to obtain a hydrodesulfurization agent.

[0028] The preparation method of the carrier is as follows: (1) dissolving 22 parts of hexadecyltrimethylammonium bromide in a mixed solution of 17 parts of amyl alcohol and 56 parts of cyclohexane to obtain solution I; mixing 8 parts of urea and 110 parts of deionized water to obtain solution II; adding solution II to solution I under stirring, stirring for 1.2 hours, continuing to add 38 parts of tetraethyl orthosilicate, stirring for 1.2 hours, heating to 114°C, keeping the temperature for reaction for 18 hours, centrifuging and drying the lower layer of precipitate, and calcining at 720°C for 3.8 hours to obtain a powdery material; (2) mixing 18 parts of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane with 42 parts of the powdery material, reflux extracting at 135°C for 26 hours with toluene as solvent, filtering, washing, and vacuum drying at 110°C to obtain a carrier.

[0029] Example 4 A method for preparing a hydrodesulfurization agent comprises the following steps: S1: 37 parts of the carrier were dispersed in 69 parts of deionized water, and 21 parts of a 19% by mass phosphomolybdic acid solution were added dropwise under stirring. After being fully stirred for 5.5 hours, the mixture was filtered, and the filter residue was washed twice with anhydrous ethanol and deionized water, respectively. The residue was dried at 68°C for 13 hours, and then calcined at 340°C (air atmosphere, heating rate of 7°C / min) for 3.8 hours, and then calcined at 590°C (ammonia atmosphere, heating rate of 4°C / min) for 3.7 hours. The mixture was cooled to obtain powder material I; S2: 9 parts of nickel chloride were mixed with 17 parts of 14% by mass hydrogen chloride solution, 9 parts of powder material I prepared in step S1 were added, and the mixture was stirred for 18 hours. A 0.9 mol / L sodium hydroxide solution was added to adjust the pH value to 10.8, and 19 parts of a 0.4 mol / L lithium borohydride aqueous solution were added to reduce nickel. The mixture was stirred in an ice-water bath for 6 hours, and the mixture was filtered. The residue was washed twice with countless ethanol and deionized water, respectively, and vacuum dried at 69°C for 14 hours to obtain a hydrodesulfurization agent.

[0030] The preparation method of the carrier is as follows: (1) dissolving 23 parts of hexadecyltrimethylammonium bromide in a mixed solution of 18 parts of amyl alcohol and 57 parts of cyclohexane to obtain solution I; mixing 9 parts of urea and 115 parts of deionized water to obtain solution II; adding solution II to solution I under stirring, stirring for 1.3 hours, continuing to add 38 parts of tetraethyl orthosilicate, stirring for 1.3 hours, heating to 117°C, keeping the temperature for reaction for 19 hours, centrifuging and drying the lower layer of precipitate, and calcining at 735°C for 3.8 hours to obtain a powdery material; (2) mixing 19 parts of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane with 43 parts of the powdery material, reflux extracting at 136°C for 26 hours with toluene as solvent, filtering, washing, and vacuum drying at 115°C to obtain a carrier.

[0031] Comparative Example 1 The preparation method of the hydrodesulfurization agent in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is that an equal amount of palladium chloride is used instead of nickel chloride in step S2 of the preparation method of the hydrodesulfurization agent in this comparative example.

[0032] Comparative Example 2 The preparation method of the hydrodesulfurization agent in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is that an equal amount of sodium borohydride is used instead of lithium borohydride in step S2 of the preparation method of the hydrodesulfurization agent in this comparative example.

[0033] Comparative Example 3 The preparation method of the hydrodesulfurization agent in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is that in step S1 of the preparation method of the hydrodesulfurization agent in this comparative example, after drying, the mixture is calcined at 580° C. for 7.6 h in a nitrogen atmosphere with a heating rate of 4° C. / min.

[0034] Comparative Example 4 The preparation method of the hydrodesulfurization agent in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is as follows: in the preparation method of the hydrodesulfurization agent in this comparative example, after drying in step S1, it is first calcined at 340°C (air atmosphere, heating rate of 20°C / min) for 3.8h, and then calcined at 580°C (ammonia atmosphere, heating rate of 20°C / min) for 3.8h.

[0035] Comparative Example 5 The preparation method of the hydrodesulfurization agent in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is that an equal amount of 3-aminopropyltrimethoxysilane is used instead of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane in the preparation method of the carrier in this comparative example.

[0036] Comparative Example 6 The preparation method of the hydrodesulfurization agent in this comparative example is similar to that in Example 3. The difference between this comparative example and Example 3 is that an equal amount of γ-(methacryloyloxy)propyltrimethoxysilane is used instead of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane in the preparation method of the carrier in this comparative example.

[0037] Test example In this test example, an organic sulfur hydrogenation micro fixed bed reactor is used to evaluate the hydrodesulfurization agent. Figure 1 shown.

[0038] In this test example, industrial catalytic cracking gasoline with a sulfur content of 500ug / g is used as the test raw material, the catalyst loading amount is 30g, and the industrial catalytic cracking gasoline is contacted with the hydrodesulfurization agent prepared in Example 1-Example 4 and Comparative Example 1-Comparative Example 6 under the conditions of reaction temperature of 350℃, reaction pressure of 5MPa, weight hourly space velocity of 8h-1, and hydrogen-oil volume ratio of 400. After 100h of reaction, sampling and analysis are performed. The sulfur content in the oil sample is determined by wavelength dispersive X-ray fluorescence spectrometry (GB / T 11140-2008); the calculation formula of sulfur removal rate is: η=(1-c2 / c1)×100%, where c1 is the sulfur content in the industrial catalytic cracking gasoline raw material, and c2 is the sulfur content in the gasoline after the reaction.

[0039] The test results are shown in Table 1.

[0040] Table 1 Desulfurization test results

[0041] As shown in Table 1, the desulfurization rate of the hydrodesulfurizer provided by the present invention is 97.6%-99.4%, and it has good desulfurization activity. Among them, the desulfurization rate of the hydrodesulfurizer prepared in Example 3 is the highest, which is the best embodiment of the present invention.

[0042] Compared with Example 3, in Comparative Example 1, an equal amount of palladium chloride is used instead of nickel chloride, and in Comparative Example 2, an equal amount of sodium borohydride is used instead of lithium borohydride, but the desulfurization rate of the obtained hydrodesulfurization agent is slightly reduced, which indicates that the desulfurization effect of the metal palladium loaded in the carrier is worse than that of the metal nickel loaded in the carrier, and the reduction effect of sodium borohydride is worse than that of lithium borohydride; in the preparation method of the hydrodesulfurization agent in Comparative Example 3, temperature segmented calcination is not performed during drying in step S1, and the heating rate during calcination is increased in Comparative Example 4, but the obtained hydrodesulfurization agent is The desulfurization rate of the sulfur agent is significantly reduced, which indicates that the calcination process after the carrier is loaded with molybdenum phosphate is the key to affecting the desulfurization rate. A higher calcination temperature or too fast a heating rate will cause the catalyst active nanoparticles to agglomerate, thereby reducing the desulfurization effect. In Comparative Examples 5 and 6, a common silane coupling agent is used instead of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, but the desulfurization rate of the obtained hydrodesulfurization agent is reduced, which indicates that not all silane coupling agents can play the role of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

[0043] The above embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any person skilled in the art shall not modify the above embodiments without violating the spirit and scope of the present invention. Therefore, any modification, equivalent substitution and improvement made by those skilled in the art under the technical concept of the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for preparing a hydrodesulfurization agent, characterized in that: The following steps are involved: S1: dispersing the carrier in deionized water, adding phosphomolybdic acid solution dropwise under stirring, filtering after sufficient stirring, washing, drying, roasting, and cooling to obtain powder material I; S2: Mix nickel chloride and hydrogen chloride solution, add powder material I obtained in step S1, stir, add sodium hydroxide solution to adjust the pH value to 10.5-11, continue to add lithium borohydride aqueous solution, stir the reaction in an ice-water bath, filter, wash, and dry to obtain a hydrodesulfurization agent.

2. The method for preparing a hydrodesulfurization agent according to claim 1, characterized in that: The mass fractions of the components in step S1 are: 30-40 parts of the carrier, 60-70 parts of deionized water, and 20-25 parts of the molybdenum phosphate solution; the mass percentage of the molybdenum phosphate solution is 15%-20%.

3. The method for preparing a hydrodesulfurization agent according to claim 1, characterized in that: The specific process of calcination in step S1 is: first calcination at 320-350°C in air atmosphere for 3.5-4h, with a heating rate of 5-7°C / min; then calcination at 560-600°C in ammonia atmosphere for 3.5-4h, with a heating rate of 2-5°C / min.

4. The method for preparing a hydrodesulfurization agent according to claim 1, characterized in that: The mass fractions of the components in step S2 are: 5-10 parts of nickel chloride, 15-20 parts of hydrogen chloride solution, 5-10 parts of powder material I, and 15-20 parts of lithium borohydride aqueous solution; The mass percentage of the hydrogen chloride solution is 12%-15%; the concentration of the sodium hydroxide is 0.8-1 mol / L; and the concentration of the lithium borohydride aqueous solution is 0.3-0.5 mol / L.

5. The method for preparing a hydrodesulfurization agent according to claim 1, characterized in that: The stirring time in step S2 is 15-20 hours; the stirring reaction time in the ice-water bath is 5-7 hours; the drying temperature is 65-70° C., and the drying time is 12-15 hours.

6. The method for preparing a hydrodesulfurization agent according to claim 1, characterized in that: The preparation method of the carrier is as follows: (1) dissolving hexadecyltrimethylammonium bromide in a mixed solution of amyl alcohol and cyclohexane to obtain solution I; uniformly mixing urea and deionized water to obtain solution II; adding solution II to solution I under stirring, stirring, continuing to add tetraethyl orthosilicate, stirring, heating to 110-120° C., keeping the temperature for reaction, centrifuging and drying the lower precipitate and then calcining to obtain a powdery material; (2) mixing N-(2-aminoethyl)-3-aminopropyltrimethoxysilane with the powdery material, performing reflux extraction with toluene as solvent, suction filtering, washing, and vacuum drying to obtain the carrier.

7. The method for preparing a hydrodesulfurizing agent according to claim 6, characterized in that: The weight percentages of the components in step (1) of the carrier preparation method are: 20-25 parts of hexadecyltrimethylammonium bromide, 15-20 parts of amyl alcohol, 50-60 parts of cyclohexane, 6-10 parts of urea, 100-120 parts of deionized water, and 35-40 parts of tetraethyl orthosilicate.

8. The method for preparing a hydrodesulfurization agent according to claim 6, characterized in that: In the step (1) of the preparation method of the carrier, the stirring time is 1-1.5 hours, the heat preservation reaction time is 17-20 hours, the calcination temperature is 700-750° C., and the calcination time is 3.5-4 hours.

9. The method for preparing a hydrodesulfurization agent according to claim 6, characterized in that: The mass fractions of the components in step (2) of the carrier preparation method are: 15-20 parts of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and 40-45 parts of powdered material; the reflux extraction temperature is 130-140°C, the reflux extraction time is 24-28h, and the vacuum drying temperature is 100-120°C.

10. A hydrodesulfurization agent prepared according to the method for preparing a hydrodesulfurization agent according to any one of claims 1 to 9.

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