Hydrogenation dearsenification catalyst, its preparation method and application

Abstract

The present invention discloses a hydrodesulfurization catalyst, a preparation method thereof and an application thereof. The preparation method comprises: (1) mixing a carrier precursor with sesbania powder, pore-expanding aid I and a binder, molding the mixture, and then performing first drying and first calcination to obtain a porous carrier; (2) performing a first reaction on a promoter active component precursor, an organic complexing agent, pore-expanding aid II and deionized water to obtain a pre-impregnation solution; performing a second reaction on the pre-impregnation solution and a main active component precursor to obtain a first impregnation solution; performing a first impregnation on the porous carrier with the first impregnation solution, and then performing second drying and second calcination to obtain a catalyst precursor; (3) preparing a second impregnation solution from pore-expanding aid III, an activation aid and deionized water; performing a second impregnation on the catalyst precursor with the second impregnation solution, and then performing third drying and third calcination to obtain the catalyst. The present invention improves the dispersion and effective utilization rate of arsenic poisoning sites on the surface and in the pores, and thus improves the arsenic capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and particularly to a hydrodesulfurization catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] Hydrogenation technology is one of the main methods for cleaning the quality of oil products in China. In the refining field, hydrogenation technology is commonly used to reduce the contents of impurities such as sulfur, nitrogen, and aromatics in oil products to improve the quality of oil products. Arsenides in the raw materials are poisons in the hydrogenation process. Especially for the noble metal catalyst used in the reforming unit, a very small amount of arsenides will cause the catalyst to be permanently poisoned and inactivated, shortening the long-term operation of the unit and bringing losses to the economic benefits of the refinery. Therefore, arsenides need to be pre-treated for arsenic removal to ensure the stable operation of subsequent units. Different production links have different requirements for the arsenic content of the raw materials. For units filled with noble metal catalysts such as reforming, the raw materials need to have a long-term stable arsenic content <1 ppb. Therefore, higher requirements are put forward for the high arsenic removal activity and long-term stability of the arsenic remover.

[0003] Common methods for removing arsenic from oil products include: adsorption arsenic removal method, oxidation method, and hydrogenation method. The hydrogenation method for arsenic removal has a large arsenic capacity, good arsenic removal effect, and long operation cycle, and is more suitable for production conditions with high arsenic content in raw materials, low arsenic content in products, and long device operation cycle requirements. The hydrodesulfurization process is different from the desulfurization process. The hydrodesulfurization process is a permanent poisoning process of arsenic and is non-renewable. The principle of hydrodesulfurization is that the outermost lone pair of 4s electrons of trace organic arsenides is easily combined with the d orbitals of Group VIII metals on the surface of conventional hydrogenation catalysts to form coordination bonds (since nickel has a face-centered cubic structure and is more likely to combine with arsenic to form arsenides with a hexagonal crystal system, the common main active metal for arsenic removal is generally nickel). As the temperature rises, the arsenic atoms on the surface will migrate a large amount into the catalyst interior to form a stable arsenic alloy, ultimately causing the permanent inactivation of the active poisoning sites. Unlike the hydrogenation desulfurization reaction, the hydrodesulfurization process does not have a sulfur desorption process. The arsenic removal process is a process of permanently sacrificing a large number of arsenic poisoning sites, and the used arsenic poisoning sites cannot be used again. Therefore, it is particularly important to improve the utilization rate of arsenic poisoning sites. On the one hand, the hydrodesulfurization catalyst needs to provide enough arsenic active poisoning sites, and on the other hand, it needs to provide enough pore structures to ensure that arsenides will fully contact and combine with these poisoning sites and react. However, although the current arsenic removal catalyst has a high metal content, the arsenic capacity of the catalyst is not high, and there is often a phenomenon that the catalyst is penetrated in the later stage of the device operation. The reason is that on the one hand, the dispersion degree of the arsenic poisoning sites of the catalyst is not enough, and the dispersion on the surface and inside the pores of the catalyst is uneven, resulting in the stacking of poisoning sites and not facilitating the rapid adsorption process of arsenic; on the other hand, since the catalyst pores cannot provide a suitable diffusion space for macromolecular arsenides, the arsenic poisoning sites in the catalyst pores are not fully utilized, resulting in a waste of arsenic poisoning sites.

[0004] CN108246242A proposes a hydrogenation arsenic removal catalyst for catalytic gasoline and its application. This technology modifies the TiO2-Al2O3 composite support by hydrothermal treatment, and uses a single nickel system to prepare the hydrogenation arsenic removal catalyst. The catalyst has good arsenic removal selectivity. When treating raw materials with an arsenic content of about 200 ppb, the arsenic removal selectivity can reach more than 99%. However, due to the limited arsenic removal ability of the single nickel system, there will be problems of insufficient arsenic removal ability and stability when treating high-arsenic raw materials (>300 ppb) for a long period to ensure that the product is less than 1 ppb.

[0005] CN108246302A proposes a hydrogenation arsenic removal catalyst for catalytic gasoline and its application. This technology uses a bimetallic system arsenic removal catalyst that modifies the TiO2-Al2O3 composite support by hydrothermal method, which can reduce the arsenic content of the raw material from 200 ppb to less than 20 ppb. Compared with the single nickel system, the arsenic capacity and arsenic removal activity of the bimetallic system are improved. However, the invention does not involve the working condition where the product index is less than 1 ppb in long-term treatment, and at the same time, it does not involve the utilization rate of arsenic poisoning sites in the metal pores after pore expansion.

[0006] CN106833731B proposes a hydrodesulfurization catalyst for naphtha and its application method. The catalyst support is prepared by non-constant pH alternate titration to obtain a zinc-aluminum spinel-containing zinc oxide layered structure. The preparation process is complex and the industrial production cost is high, which is difficult to achieve in actual production. At the same time, it does not involve the dispersion and utilization of active metals in the pores. Summary of the Invention

[0007] The purpose of the present invention is to overcome the problems existing in the prior art, such as insufficient dispersion of arsenic poisoning sites and insufficient utilization of arsenic poisoning sites, and to provide a hydrogenation arsenic removal catalyst, its preparation method and application. During the preparation process of the hydrogenation arsenic removal catalyst, the pore channels are improved multiple times to improve the dispersion of active metals in the pore channels, ensure that the active metals enter the pore channels for high-dispersion loading while the pores are expanded, increase the available arsenic poisoning sites of the catalyst, ensure that the active metals in the pore channels can be fully utilized, and thus improve the arsenic capacity of the catalyst and the utilization rate of catalyst metals, and reduce the investment cost of refineries.

[0008] In order to achieve the above object, the first aspect of the present invention provides a preparation method of a hydrogenation arsenic removal catalyst, and the preparation method includes:

[0009] (1) After mixing the carrier precursor with sesbania powder, pore-expanding aid I and binder and molding, perform the first drying and the first calcination to obtain a porous carrier;

[0010] (2) React the promoter precursor, organic complexing agent, pore-expanding aid II, and deionized water in a first reaction to obtain a pre-impregnation solution; react the pre-impregnation solution with the main active component precursor in a second reaction to obtain a first impregnation solution; impregnate the porous support with the first impregnation solution for the first time, and then perform second drying and second calcination to obtain a catalyst precursor;

[0011] (3) Prepare a second impregnation solution from pore-expanding aid III, activation aid, and deionized water; impregnate the catalyst precursor with the second impregnation solution for the second time, and then perform third drying and third calcination to obtain the hydrodesulfurization catalyst.

[0012] The second aspect of the present invention provides a hydrodesulfurization catalyst prepared by the aforementioned preparation method.

[0013] The third aspect of the present invention provides the application of the aforementioned hydrodesulfurization catalyst in oil product hydrodesulfurization.

[0014] Through the above technical solutions, the beneficial technical effects obtained by the present invention are as follows:

[0015] 1) In the first impregnation process of the method of the present invention, a pre-dispersion impregnation form is adopted, in which the dispersion aid and pore-expanding components are uniformly complexed and then complexed with the main active metal, ensuring the uniform dispersion of the pore-expanding components and the main metal promoter, improving the dispersion degree of the active metal during the catalyst loading process, and increasing the number of arsenic poisoning sites.

[0016] 2) The pore-expanding components of the present invention are pre-dispersed and then complexed with the active metal to form a bond. During the calcination process, the active metal can be uniformly loaded while expanding the pores, not only improving the fluidity of macromolecular arsenides, but also improving the dispersion and number of effective arsenic poisoning sites in the expanded pores.

[0017] 3) In the preparation process of the catalyst support of the present invention, pore-expanding aid I is added for primary pore-expanding treatment to adjust the pore structure distribution of the original support; in the first impregnation process, pore-expanding aid II (the molecular weight of pore-expanding aid II is less than that of pore-expanding aid I) is added, which can ensure that the active metal enters the pore channels of the support during pore expansion without destroying the original pore structure and is highly dispersed and loaded; in the second impregnation and activation process, pore-expanding aid III (the molecular weight of pore-expanding aid III is less than that of pore-expanding aid II) is further added to improve the hydroxyl distribution in the pore channels and further improve the pore structure. The method of the present invention ensures the fluidity of arsenides in the pore channels and the metal dispersion by means of stepwise improvement of the pore structure.

[0018] 4) Through post-treatment means, the active metal is redispersed in the present invention, which can ensure that the secondary activation impregnating solution enters the pores, prevent metal agglomeration caused by heating during the calcination process after metal impregnation, further improve the dispersion and effective utilization rate of arsenic poisoning sites on the surface and in the pores, and increase the arsenic capacity. The increase in arsenic capacity can extend the service life of the catalyst, ensure ultra-deep and stable arsenic removal in a long cycle, ensure the stable operation of the long-cycle device in the refinery, and save investment costs. Detailed implementation mode

[0019] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0020] The first aspect of the present invention provides a preparation method of a hydrodesulfurization catalyst, and the preparation method includes the following steps:

[0021] (1) After mixing the carrier precursor with sesbania powder, pore-expanding aid I, and binder and molding, first drying and first calcination are carried out to obtain a porous carrier;

[0022] (2) Carry out a first reaction on the promoter precursor, organic complexing agent, pore-expanding aid II, and deionized water to obtain a pre-impregnating solution; carry out a second reaction on the pre-impregnating solution and the main active component precursor to obtain a first impregnating solution; use the first impregnating solution to carry out a first impregnation on the porous carrier, and then carry out second drying and second calcination to obtain a catalyst precursor;

[0023] (3) Prepare a second impregnating solution from pore-expanding aid III, activation aid, and deionized water; use the second impregnating solution to carry out a second impregnation on the catalyst precursor, and then carry out third drying and third calcination to obtain the hydrodesulfurization catalyst.

[0024] According to the present invention, during the first impregnation process, in the form of pre-dispersed impregnation, the dispersion aid and pore-expanding components are uniformly complexed and then complexed with the main active metal, ensuring the uniform dispersion of the pore-expanding components and the main metal promoter, improving the dispersion degree of the active metal during the catalyst loading process, and increasing the number of arsenic poisoning sites.

[0025] The pore-expanding aid II of the present invention is pre-dispersed and then complexed with the active metal to form a bond. During the calcination process, it can uniformly load the active metal while expanding the pores, not only improving the fluidity of large-molecular arsenic compounds, but also improving the dispersion and quantity of effective arsenic poisoning sites in the expanded pores.

[0026] In some embodiments of the present invention, the molecular weight of the pore-expanding aid II is less than that of the pore-expanding aid I.

[0027] In some embodiments of the present invention, the molecular weight of the pore-expanding aid III is less than that of the pore-expanding aid II.

[0028] By the method of the present invention, a hydrogenation arsenic-removing catalyst with stepped pore expansion can be obtained. During the preparation process of the catalyst support, the pore-expanding aid I is added for primary pore-expanding treatment to adjust the pore structure distribution of the original support; during the first impregnation process, the pore-expanding aid II (the molecular weight of the pore-expanding aid II is less than that of the pore-expanding aid I) is added, which can ensure that the active metal enters the pores of the support during pore expansion without destroying the original pore structure and is highly dispersed and loaded; during the second impregnation process, the pore-expanding aid III (the molecular weight of the pore-expanding aid III is less than that of the pore-expanding aid II) is further added to improve the hydroxyl distribution in the pores and further improve the pore structure. The method of the present invention ensures the fluidity of arsenic compounds in the pores and the metal dispersion by means of stepped improvement of the pore structure.

[0029] In the present invention, the active metal is secondarily dispersed and activated by post-treatment means, which can ensure that the secondary activation impregnation solution enters the pores, prevent metal agglomeration caused by heating during the calcination process after metal impregnation, further improve the dispersion and effective utilization rate of arsenic poisoning sites on the surface and in the pores, and improve the arsenic capacity. The improvement of the arsenic capacity can extend the service life of the catalyst, ensure ultra-deep and stable arsenic removal in a long cycle, ensure the stable operation of the long-cycle device in the refinery, and save investment costs.

[0030] In some embodiments of the present invention, in step (1), the support precursor is selected from one or more of an alumina precursor, a titanium oxide precursor, a silica precursor, and a magnesia precursor; the support precursor is preferably an alumina precursor.

[0031] In the present invention, the alumina precursor, the titanium oxide precursor, the silica precursor, and the magnesia precursor are substances that can be converted into porous alumina, titanium oxide, silica, and magnesia supports respectively after the first calcination; taking the alumina precursor as an example, the alumina precursor can be selected from the following substances: Si-containing pseudo-boehmite, Ti, Si-containing pseudo-boehmite, P-containing pseudo-boehmite, or F, B-containing pseudo-boehmite, which is converted into alumina after the first calcination.

[0032] In some embodiments of the present invention, in step (1), the binder is selected from one or more of organic acids and inorganic acids, preferably selected from one or more of acetic acid, citric acid, nitric acid, hydrochloric acid, and phosphoric acid.

[0033] In some embodiments of the present invention, the addition amount of the binder is 1-7 wt% of the mass of the carrier precursor, such as 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt% and any value within the range composed of any two numerical values, and preferably 2-5 wt%.

[0034] In some embodiments of the present invention, in step (1), the pore-expanding aid I is selected from one or more of polyethylene glycol, polyvinyl alcohol, polypropylene alcohol, sodium stearate, methyl cellulose and soluble starch.

[0035] In some preferred embodiments of the present invention, the pore-expanding aid I is selected from one or more of polyethylene glycol, methyl cellulose and soluble starch.

[0036] In some preferred embodiments of the present invention, the molecular weight of the pore-expanding aid I is 60-20000 g / mol; such as 100 g / mol, 500 g / mol, 800 g / mol, 1000 g / mol, 1200 g / mol, 1500 g / mol, 2000 g / mol, 3000 g / mol, 5000 g / mol, 8000 g / mol, 10000 g / mol, 12000 g / mol, 15000 g / mol, 18000 g / mol, 20000 g / mol and any value within the range composed of any two numerical values, and preferably 500-15000 g / mol.

[0037] In some preferred embodiments of the present invention, the addition amount of the pore-expanding aid I is 2-15 wt% of the mass of the carrier precursor, such as 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 12 wt%, 15 wt% and any value within the range composed of any two numerical values, and preferably 3-10 wt%.

[0038] In the present invention, the function of the pore-expanding aid I is to adjust and improve the pore structure of the carrier during the carrier forming process.

[0039] In some embodiments of the present invention, in step (2), the co-active component precursor is selected from salts, acids or oxides of Group VIB metals; preferably, the Group VIB metals are molybdenum and / or tungsten.

[0040] In some preferred embodiments of the present invention, the co-active component precursor is selected from one or more of molybdenum oxide, molybdic acid, molybdates, tungsten oxide, tungstic acid, metatungstic acid, tungstates and metatungstates; more preferably one or more of molybdenum trioxide and molybdates.

[0041] In some embodiments of the present invention, in step (2), the organic complexing agent is ammonia water or hydroxy acid compounds; preferably, the hydroxy acid compounds are selected from one or more of glycolic acid, glyceric acid, malic acid, citric acid, tartaric acid, gluconic acid, and lactic acid.

[0042] In some preferred embodiments of the present invention, the organic complexing agent is ammonia water or citric acid.

[0043] In the present invention, the organic complexing agent bonds with the main active component during the solution preparation process to form a stable complex, which is beneficial to improving the dispersion degree of the main active component.

[0044] In some embodiments of the present invention, in step (2), the pore-expanding aid II is an alcohol or a soluble pore-expanding agent.

[0045] In some embodiments of the present invention, the pore-expanding aid II is selected from one or more of glycerol, propylene glycol, 1,4-butanediol, pentaerythritol, ethylene glycol, polyethylene glycol, diethylene glycol, polyvinyl alcohol, sodium stearate, carboxymethyl cellulose, and soluble starch.

[0046] In some preferred embodiments of the present invention, the pore-expanding aid II is selected from one or more of glycerol, ethylene glycol, polyethylene glycol, sodium carboxymethyl cellulose, and soluble starch.

[0047] In some embodiments of the present invention, the molecular weight of the pore-expanding aid II is 50 - 15000 g / mol, such as 100 g / mol, 500 g / mol, 800 g / mol, 1000 g / mol, 1200 g / mol, 1500 g / mol, 2000 g / mol, 3000 g / mol, 5000 g / mol, 8000 g / mol, 10000 g / mol, 12000 g / mol, 15000 g / mol, and any value within the range composed of any two of these values, preferably 200 - 12000 g / mol.

[0048] In some preferred embodiments of the present invention, the addition amount of the pore-expanding aid II is 1 - 20 wt% of the mass of the porous carrier, such as 1 wt%, 2 wt%, 3 wt%, 5 wt%, 8 wt%, 9 wt%, 10 wt%, 12 wt%, 15 wt%, 16 wt%, 18 wt%, 20 wt%, and any value within the range composed of any two of these values, more preferably 2 - 15 wt%.

[0049] In the present invention, during the first impregnation process, by adding pore-expanding aid II (the molecular weight of pore-expanding aid II is less than that of pore-expanding aid I), it is possible to ensure that the active metal enters the carrier pores during pore expansion without damaging the original pore structure, and perform highly dispersed loading of the main active metal.

[0050] In some embodiments of the present invention, in step (2), the main active component precursor is selected from Group VIII metal salts, preferably nickel salts.

[0051] In some preferred embodiments of the present invention, the nickel salt is selected from one or more of nickel nitrate, nickel acetate, nickel sulfate, and nickel basic carbonate; more preferably nickel nitrate or nickel basic carbonate.

[0052] In some embodiments of the present invention, in step (3), the pore-expanding aid III is an alcohol, preferably selected from one or more of ethanol, glycerol, ethylene glycol, and polyethylene glycol.

[0053] In some preferred embodiments of the present invention, the molecular weight of the pore-expanding aid III is 20 - 10000 g / mol, such as 50 g / mol, 100 g / mol, 500 g / mol, 800 g / mol, 1000 g / mol, 1200 g / mol, 1500 g / mol, 2000 g / mol, 3000 g / mol, 5000 g / mol, 8000 g / mol, 10000 g / mol, and any value within the range composed of any two of these values, preferably 100 - 8000 g / mol.

[0054] In some preferred embodiments of the present invention, the addition amount of the pore-expanding aid III is 0.5 - 15 wt% of the mass of the catalyst precursor, such as 1 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 12 wt%, 15 wt%, and any value within the range composed of any two of these values, more preferably 1 - 10 wt%.

[0055] In the present invention, during the second impregnation process, by adding pore-expanding aid III (the molecular weight of pore-expanding aid III is less than that of pore-expanding aid II), the hydroxyl distribution in the pores is improved, and the pore structure is further improved.

[0056] In some embodiments of the present invention, in step (3), the activation aid is selected from one or more of phosphoric acid, phosphates, and boric acid.

[0057] In some embodiments of the present invention, the addition amount of the activation assistant is 2% - 10% of the mass of the catalyst precursor, such as 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, and any value within the range composed of any two numerical values, and more preferably 3% - 8%.

[0058] In the present invention, an activation assistant with a pore channel improvement function is used in the second impregnation process to further improve the flow performance of the pore channels and, to a certain extent, improve the acidity of the catalyst. When used in combination with the pore enlarging assistant III, it further prevents metal agglomeration caused by heating during the calcination process after metal impregnation, which is beneficial to improving the dispersion and effective utilization rate of arsenic poisoning sites on the surface and in the pore channels, and improving the arsenic capacity.

[0059] In some embodiments of the present invention, in step (1), the temperature of the first drying is 50 - 120°C, preferably 80 - 120°C; the temperature of the first calcination is 500°C - 1000°C, preferably 500°C - 900°C.

[0060] In some embodiments of the present invention, in step (2), the temperature of the first reaction is 10 - 100°C, and the time is 10 - 120 min; preferably, the temperature of the first reaction does not exceed the boiling point of the pore enlarging assistant II.

[0061] In some embodiments of the present invention, in step (2), the temperature of the second reaction is 10 - 100°C, and the time is 10 - 120 min; preferably, the temperature of the second reaction does not exceed the boiling point of the pore enlarging assistant II.

[0062] In some embodiments of the present invention, in step (2), the first impregnation is saturated impregnation or supersaturated impregnation; after the first impregnation is completed, it is left to stand for 1 - 7 h before the second drying and the second calcination; preferably, after the first impregnation is completed, the standing time is 1 - 6 h.

[0063] In some embodiments of the present invention, in step (2), the temperature of the second drying is 50 - 150°C, and the time is 3 - 6 h; the temperature of the second calcination is 300°C - 600°C, and the time is 3 - 6 h; preferably, in step (2), the temperature of the second drying is 50 - 120°C.

[0064] In some embodiments of the present invention, in step (3), the second impregnation is saturated impregnation or supersaturated impregnation; after the second impregnation is completed, it is left to stand for 1 - 7 h before the third drying and the third calcination; preferably, after the second impregnation is completed, the standing time is 1 - 6 h.

[0065] In some embodiments of the present invention, in step (3), the temperature of the third drying is 50 - 150 °C, and the time is 3 - 6 h; the temperature of the third calcination is 300 °C - 600 °C, preferably 50 - 120 °C; the time is 3 - 6 h, preferably 4 - 5 h.

[0066] The second aspect of the present invention provides a hydrodesulfurization catalyst prepared by the aforementioned preparation method.

[0067] In some embodiments of the present invention, the hydrodesulfurization catalyst comprises: 6 - 25 wt% of NiO, 1 - 22 wt% of MoO3 and / or WO3, and 53 - 93 wt% of a porous support.

[0068] In the present invention, based on the total weight of the hydrodesulfurization catalyst, the content of NiO can be 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt%, and any value within the range composed of any two of these values; the content of MoO3 and / or WO3 can be 1 wt%, 2 wt%, 5 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, 22 wt%, and any value within the range composed of any two of these values; the remainder is the porous support, such as 53 wt%, 55 wt%, 60 wt%, 65 wt%, 69 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, 91 wt%, 93 wt%, and any value within the range composed of any two of these values.

[0069] In some preferred embodiments of the present invention, the hydrodesulfurization catalyst comprises: 7 - 20 wt% of NiO, 2 - 15 wt% of MoO3 and / or WO3, and 65 - 91 wt% of a porous support.

[0070] The hydrodesulfurization catalyst prepared by the preparation method of the present invention has a stepped distribution of pores due to multiple pore improvements during the catalyst preparation process. The stepped addition of the pore-expanding aid and the pre-dispersion treatment method help to improve the dispersion of the active metal in the pores, ensuring that the active metal enters the pores for high-dispersion loading while expanding the pores, increasing the available arsenic poisoning sites of the catalyst. The present invention enables the pores of the hydrodesulfurization catalyst to have a stepped distribution and a high utilization rate of arsenic poisoning sites in the pores.

[0071] The third aspect of the present invention provides the application of the aforementioned hydrodesulfurization catalyst in the hydrodesulfurization of oil products.

[0072] In some embodiments of the present invention, the catalyst is used in a sulfided form.

[0073] In some embodiments of the present invention, the use conditions of the hydrodesulfurization catalyst include: the temperature is 200 - 350 °C, and the space velocity is 2 - 25 h -1 .

[0074] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited to the following description.

[0075] For those not specifying specific conditions in the following examples and comparative examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For reagents or instruments not indicating the manufacturer, they are all conventional products that can be obtained through commercial channels.

[0076] In the following examples, the arsenic content analysis was performed using Agilent ICP - MS 7850. The analysis of the group composition of the oil product was determined using Agilent pona chromatography analysis.

[0077] Example 1

[0078] (1) Take 600 g of pseudoboehmite, add 12 g of sesbania powder and mix. Then add a solution composed of 15 g of citric acid, 20 ml of glacial acetic acid, 48 g of polyethylene glycol - 4000 and 630 g of water. After preparing D3.0 clover - shaped wet strips with a conventional laboratory extrusion machine, dry at 120 °C and then calcine at 900 °C for 6 hours to obtain carrier L1;

[0079] (2) Dissolve 5 g of polyethylene glycol - 2000, 7.3 g of ammonium molybdate and 4 g of citric acid in deionized water. After mixing at 25 °C for 40 min to form a homogeneous and clear solution, add 14 g of nickel nitrate and make up the volume to 42 ml. Mix for 30 min to form a homogeneous and clear solution. Weigh 50 g of carrier L1 for equal - volume impregnation, then let it stand for 6 hours, dry at 120 °C and then calcine at 500 °C to obtain catalyst precursor A1 - 1;

[0080] (3) Dissolve 2.5 g of polyethylene glycol - 1000 and 2.5 g of phosphoric acid in deionized water and make up the volume. Perform equal - volume impregnation on 50 g of catalyst precursor A1 - 1, let it stand for 6 hours, dry at 120 °C and then calcine at 550 °C to obtain catalyst A1.

[0081] Example 2

[0082] (1) Take 600 g of pseudoboehmite, add 15 g of sesbania powder and mix. Then add a solution composed of 15 g of citric acid, 25 ml of glacial acetic acid, 30 g of polyethylene glycol - 2000 and 625 g of water. After preparing D3.0 clover - shaped wet strips with a conventional laboratory extrusion machine, dry at 110 °C and then calcine at 850 °C for 6 hours to obtain carrier L2;

[0083] (2) Dissolve 3.5 g of polyethylene glycol - 500, 3 g of phosphoric acid, 1.3 g of molybdenum oxide, and 3 g of citric acid in deionized water, mix at 90 °C, and after 60 min to a homogeneous and clear solution, add 21.5 g of nickel basic carbonate, reflux at 90 °C for 120 min, make up the volume to 41 ml, mix for 10 min to a homogeneous and clear solution, weigh 50 g of support L2 for equal - volume impregnation, then let it stand for 6 hours, dry at 120 °C and then calcine at 450 °C to obtain catalyst precursor A2 - 1;

[0084] (3) Dissolve 2.5 g of glycerol and 5 g of phosphoric acid in deionized water and make up the volume, perform equal - volume impregnation on 50 g of catalyst precursor A2 - 1, let it stand for 6 hours, dry at 50 °C and then calcine at 600 °C to obtain catalyst A2.

[0085] Example 3

[0086] (1) Take 600 g of pseudoboehmite, add 12 g of carboxymethyl cellulose and mix. Then add a solution composed of 15 g of citric acid, 30 ml of glacial acetic acid, 18 g of soluble starch, and 640 g of water. Use a conventional laboratory extrusion machine to prepare D3.0 clover - shaped wet strips, dry at 110 °C, and then calcine at 750 °C for 6 hours to obtain support L3;

[0087] (2) Dissolve 1 g of ethylene glycol, 15.7 g of ammonium molybdate, and 3 g of citric acid in deionized water, mix at 30 °C for 30 min to a homogeneous and clear solution, then add 5 g of nickel nitrate and make up the volume to 41 ml, mix for 25 min to a homogeneous and clear solution, weigh 50 g of support L3 for equal - volume impregnation, let it stand for 5 hours, dry at 90 °C and then calcine at 350 °C to obtain catalyst precursor A3 - 1;

[0088] (3) Dissolve 0.5 g of ethanol and 1.5 g of ammonium dihydrogen phosphate in deionized water and make up the volume, perform equal - volume impregnation on 50 g of catalyst precursor A3 - 1, let it stand for 5 hours, dry at 80 °C and then calcine at 300 °C to obtain catalyst A3.

[0089] Example 4

[0090] (1) Take 600 g of pseudoboehmite, add 12 g of carboxymethyl cellulose and mix. Then add a solution composed of 15 g of citric acid, 25 ml of glacial acetic acid, 90 g of methyl cellulose, and 650 g of water. Use a conventional laboratory extrusion machine to prepare D3.0 clover - shaped wet strips, dry at 100 °C, and then calcine at 500 °C for 6 hours to obtain support L4;

[0091] (2) Dissolve 10 g of sodium carboxymethyl cellulose and 25.5 g of ammonium molybdate in 25 mL of 25% ammonia water. After mixing for 20 min at 20 °C until a homogeneous and clear solution is obtained, add 78.6 g of nickel acetate and make up the volume to 42 ml. Mix for 20 min until a homogeneous and clear solution is obtained. Weigh 50 g of support L4, perform equal-volume impregnation, then let it stand for 4 hours, dry at 80 °C, and calcine at 350 °C to obtain catalyst precursor A4-1;

[0092] (3) Dissolve 7.5 g of ethylene glycol and 5 g of ammonium dihydrogen phosphate in deionized water and make up the volume. Perform equal-volume impregnation on 50 g of catalyst precursor A4-1, let it stand for 4 hours, dry at 80 °C, and calcine at 300 °C to obtain catalyst A4.

[0093] Example 5

[0094] (1) Take 600 g of pseudoboehmite, add 12 g of carboxymethyl cellulose and mix. Then add a solution composed of 15 g of citric acid, 28 ml of glacial acetic acid, 12 g of glycerol and 635 g of water. Use a conventional laboratory extrusion machine to prepare D3.0 clover-shaped wet strips. After drying at 100 °C, calcine at 700 °C for 6 hours to obtain support L5;

[0095] (2) Dissolve 0.5 g of ethylene glycol, 2.5 g of phosphoric acid, 0.54 g of molybdenum oxide and 2.7 g of citric acid in deionized water. Mix at 90 °C for 60 min until a homogeneous and clear solution is obtained. Then add 5.4 g of basic nickel carbonate, reflux at 90 °C for 120 min, make up the volume to 41 ml, mix for 10 min until a homogeneous and clear solution is obtained. Weigh 50 g of support L5, perform equal-volume impregnation, then let it stand for 3 hours, dry at 120 °C, and calcine at 450 °C to obtain catalyst precursor A5-1;

[0096] (3) Dissolve 0.25 g of ethanol and 1 g of boric acid in deionized water and make up the volume. Perform equal-volume impregnation on 50 g of catalyst precursor A5-1, let it stand for 3 hours, dry at 50 °C, and calcine at 500 °C to obtain catalyst A5.

[0097] Example 6

[0098] (1) Take 600 g of pseudoboehmite, add 12 g of carboxymethyl cellulose and mix. Then add a solution composed of 15 g of citric acid, 28 ml of glacial acetic acid, 12 g of ethylene glycol and 635 g of water. Use a conventional laboratory extrusion machine to prepare D3.0 clover-shaped wet strips. After drying at 100 °C, calcine at 700 °C for 6 hours to obtain support L6;

[0099] (2) Dissolve 0.5 g of ethylene glycol, 2.5 g of phosphoric acid, 0.54 g of molybdenum oxide, and 2.7 g of citric acid in deionized water, mix at 90 °C, and after 60 min to a homogeneous and clear solution, add 5.4 g of nickel basic carbonate, reflux at 90 °C for 120 min, make up the volume to 41 ml, mix for 10 min to a homogeneous and clear solution, weigh 50 g of support L6 for equal-volume impregnation, then let it stand for 3 hours, dry at 120 °C and calcine at 450 °C to obtain catalyst precursor A6-1;

[0100] (3) Dissolve 0.25 g of ethylene glycol and 1 g of boric acid in deionized water to make up the volume, perform equal-volume impregnation on 50 g of catalyst precursor A6-1, let it stand for 3 hours, dry at 50 °C and calcine at 500 °C to obtain catalyst A6.

[0101] Comparative Example 1

[0102] (1) Take 600 g of pseudoboehmite, add 12 g of sesbania powder and mix, then add a solution composed of 15 g of citric acid, 28 ml of glacial acetic acid, 12 g of glycerol and 635 g of water. After preparing D3.0 clover-shaped wet strips with a conventional laboratory extrusion machine, dry at 100 °C and calcine at 700 °C for 6 hours to obtain support DL1;

[0103] (2) Dissolve 0.5 g of ethylene glycol, 2.5 g of phosphoric acid, 0.54 g of molybdenum oxide, 2.7 g of citric acid, and 5.4 g of nickel basic carbonate in deionized water, mix at 90 °C, and after 60 min to a homogeneous and clear solution, reflux for 120 min, make up the volume to 41 ml, mix for 10 min to a homogeneous and clear solution, weigh 50 g of support DL1 for equal-volume impregnation, then let it stand for 3 hours, dry at 120 °C and calcine at 450 °C to obtain catalyst precursor D1-1;

[0104] (3) Dissolve 0.25 g of ethanol and 1 g of boric acid in deionized water to make up the volume, perform equal-volume impregnation on 50 g of catalyst precursor D1-1, let it stand for 3 hours, dry at 50 °C and calcine at 500 °C to obtain catalyst D1.

[0105] Comparative Example 2

[0106] (1) Take 600 g of pseudoboehmite, add 12 g of sesbania powder and mix, then add a solution composed of 15 g of citric acid, 28 ml of glacial acetic acid and 635 g of water. After preparing D3.0 clover-shaped wet strips with a conventional laboratory extrusion machine, dry at 100 °C and calcine at 700 °C for 6 hours to obtain support DL2;

[0107] (2) Dissolve 2.5 g of phosphoric acid, 0.54 g of molybdenum oxide, and 2.7 g of citric acid in deionized water, mix them at 90 °C, and after 60 min to a homogeneous and clear solution, add 5.4 g of nickel basic carbonate, reflux at 90 °C for 120 min, make up the volume to 41 ml, mix for 10 min to a homogeneous and clear solution, weigh 50 g of the support DL2 for equal-volume impregnation, then let it stand for 3 hours, dry at 120 °C and calcine at 450 °C to obtain the catalyst precursor D2-1;

[0108] (3) Dissolve 1 g of boric acid in deionized water to make up the volume, perform equal-volume impregnation on 50 g of the catalyst precursor D2-1, let it stand for 3 hours, dry at 50 °C and calcine at 500 °C to obtain the catalyst D2.

[0109] Application Example

[0110] This example relates to the evaluation method of the catalysts prepared in Examples 1-6 and Comparative Examples 1-2.

[0111] The evaluation of the catalysts in the above examples and comparative examples was carried out in a 30 ml micro-reactor evaluation device. Wet sulfidation was used, and carbon disulfide was used as the sulfiding agent with an addition amount of 3 wt%. The sulfiding oil was refined naphtha, and hydrogen passed through once. The sulfiding conditions were sulfiding at 230 °C and 320 °C for 8 h respectively, the sulfiding pressure was 2.0 MPa, and the hydrogen-oil ratio was 300:1. After the sulfidation was completed, the feedstock oil was introduced. The properties of the feedstock oil are shown in Table 1, and the reaction process parameters and products of each example are shown in Table 2.

[0112] The arsenic content analysis was carried out using Agilent ICP-MS 7850. The analysis of the group composition of the oil product was determined using Agilent pona chromatography.

[0113] The arsenic capacity experiment was carried out using the arsenic-containing feedstock in Table 1. The arsenic-containing feedstock was prepared by adding triethylarsine (20 ppm) to the catalytic gasoline product oil. The dearsenification reaction was carried out under the reaction conditions of a temperature of 260 °C, a pressure of 2 MPa, a space velocity of 11 h -1 , and a hydrogen / oil ratio of 300. When the dearsenification rate of the product < 90%, the arsenic capacity experiment was stopped, and the As2O3 content was measured on an X-ray diffraction spectrometer (XRF analysis), and then the arsenic capacity of the catalyst was obtained.

[0114] Table 1 Properties of the feedstock oil

[0115]

[0116] Table 2 Summary table of evaluation results

[0117]

[0118] It can be seen from the evaluation results in Table 2 that among Examples 1 to 5 of the catalyst prepared by the preparation method of the present invention, on the premise of ensuring that the arsenic removal product meets the index of <1 ppb, a higher arsenic capacity is achieved in the arsenic capacity experiment. Since the arsenic capacity is an important index for the long-term stability of the catalyst, it can be shown that the catalysts in Examples 1 to 5 exhibit better long-term stability. In addition, the catalyst prepared by this method can also meet the requirement that the arsenic content of the product is less than 1 ppb under the condition of a large space velocity.

[0119] The results show that due to the improvement of the hierarchical pore channels in the catalyst prepared by the present invention, the fluidity of macromolecular arsenic compounds is improved, the depth of the arsenic removal reaction of the catalyst is increased, and the fast reaction characteristics of the catalyst under the condition of a large space velocity are enhanced. At the same time, due to the improvement of the dispersion of arsenic poisoning sites in the pore channels of the catalyst prepared by this method, the utilization rate of arsenic poisoning sites is increased, thereby increasing the arsenic capacity of the catalyst. Therefore, it can be shown that the catalyst prepared by the present invention has higher long-term stability and arsenic removal activity under the same conditions.

[0120] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A preparation method of a hydrodesulfurization catalyst, characterized in that, The preparation method includes: (1) After mixing a carrier precursor, sesbania powder, pore-expanding aid I, and a binder and forming them, perform first drying and first calcination to obtain a porous carrier; wherein, the carrier precursor is selected from one or more of an alumina precursor, a titanium oxide precursor, a silica precursor, and a magnesia precursor; the pore-expanding aid I is selected from one or more of polyethylene glycol, polyvinyl alcohol, polypropylene alcohol, sodium stearate, methyl cellulose, and soluble starch; (2) Perform a first reaction on a co-active component precursor, a complexing agent, pore-expanding aid II, and deionized water to obtain a pre-impregnation solution; perform a second reaction on the pre-impregnation solution and a main active component precursor to obtain a first impregnation solution; use the first impregnation solution to perform a first impregnation on the porous carrier, and then perform second drying and second calcination to obtain a catalyst precursor; wherein, the co-active component precursor is selected from salts, acids, or oxides of Group VI B metals; the complexing agent is ammonia water or a hydroxy acid compound; the pore-expanding aid II is an alcohol or a soluble pore-expanding agent; the main active component precursor is selected from Group VIII metal salts; (3) Prepare a second impregnation solution from pore-expanding aid III, an activation aid, and deionized water; use the second impregnation solution to perform a second impregnation on the catalyst precursor, and then perform third drying and third calcination to obtain the hydrodesulfurization catalyst; wherein, the pore-expanding aid III is an alcohol; the activation aid is selected from one or more of phosphoric acid, phosphates, and boric acid; Wherein, the molecular weight of the pore-expanding aid II is less than the molecular weight of the pore-expanding aid I; the molecular weight of the pore-expanding aid III is less than the molecular weight of the pore-expanding aid II.

2. The preparation method according to claim 1, wherein, In step (1), the carrier precursor is selected from an alumina precursor; and / or, the binder is selected from one or more of organic acids and inorganic acids; and / or, the addition amount of the binder is 1-7 wt% of the mass of the carrier precursor.

3. The preparation method according to claim 2, wherein The binder is selected from one or more of acetic acid, citric acid, nitric acid, hydrochloric acid, and phosphoric acid.

4. The preparation method according to claim 1, wherein, In step (1), the pore-expanding aid I is selected from one or more of polyethylene glycol, methyl cellulose, and soluble starch; and / or, the molecular weight of the pore-expanding aid I is 60-20000 g / mol; and / or, the addition amount of the pore-expanding aid I is 2-15 wt% of the mass of the carrier precursor.

5. The preparation method according to claim 4, wherein, The addition amount of the pore-expanding aid I is 3-10 wt% of the mass of the carrier precursor.

6. The preparation method according to claim 1, wherein, The Group VI B metal is molybdenum and / or tungsten.

7. The preparation method according to claim 6, wherein The co-active component precursor is selected from one or more of molybdenum oxide, molybdic acid, molybdates, tungsten oxide, tungstic acid, metatungstic acid, tungstates, and metatungstates.

8. The preparation method according to claim 7, wherein, The co-active component precursor is one or more of molybdenum trioxide and molybdates.

9. The preparation method according to claim 1, wherein, The hydroxy acid compound is selected from one or more of glycolic acid, glyceric acid, malic acid, citric acid, tartaric acid, gluconic acid, and lactic acid.

10. The preparation method according to claim 9, wherein, The complexing agent is ammonia water or citric acid.

11. According to the preparation method described in claim 1, wherein, The pore-expanding aid II is selected from one or more of glycerol, propylene glycol, 1,4-butanediol, pentaerythritol, ethylene glycol, polyethylene glycol, diethylene glycol, polyvinyl alcohol, sodium stearate, carboxymethyl cellulose, and soluble starch; and / or, the molecular weight of the pore-expanding aid II is 50 - 15000 g / mol; and / or, the addition amount of the pore-expanding aid II is 1 - 20 wt% of the mass of the porous support.

12. The preparation method according to claim 11, wherein, The pore-expanding aid II is selected from one or more of glycerol, ethylene glycol, polyethylene glycol, sodium carboxymethyl cellulose, and soluble starch; and / or, the addition amount of the pore-expanding aid II is 2 - 15 wt% of the mass of the porous support.

13. The preparation method according to claim 1, wherein, In step (2), the main active component precursor is selected from nickel salts.

14. The preparation method according to claim 13, wherein, The nickel salts are selected from one or more of nickel nitrate, nickel acetate, nickel sulfate, and basic nickel carbonate.

15. The preparation method according to claim 14, wherein The nickel salt is nickel nitrate or basic nickel carbonate.

16. The preparation method according to claim 1, wherein In step (3), the pore-expanding aid III is selected from one or more of ethanol, glycerol, ethylene glycol, and polyethylene glycol; and / or, the molecular weight of the pore-expanding aid III is 20 - 10000 g / mol; and / or, the addition amount of the pore-expanding aid III is 0.5 - 15 wt% of the mass of the catalyst precursor.

17. The preparation method according to claim 16, wherein, The addition amount of the pore-expanding aid III is 1 - 10 wt% of the mass of the catalyst precursor.

18. The preparation method according to claim 1, wherein, The addition amount of the activation aid is 2% - 10% of the mass of the catalyst precursor.

19. The preparation method according to claim 18, wherein, The addition amount of the activation aid is 3% - 8% of the mass of the catalyst precursor.

20. The preparation method according to claim 1, wherein, In step (1), the temperature of the first drying is 50 - 120 °C, and the temperature of the first calcination is 500 °C - 1000 °C.

21. The preparation method according to claim 20, wherein, The temperature of the first drying is 80 - 120 °C, and the temperature of the first calcination is 500 °C - 900 °C.

22. The preparation method according to claim 1, wherein, In step (2), the temperature of the first reaction is 10 - 100 °C, and the time is 10 - 120 min; and / or, the temperature of the first reaction does not exceed the boiling point of the pore-expanding aid II; and / or, in step (2), the temperature of the second reaction is 10 - 100 °C, and the time is 10 - 120 min; and / or, the temperature of the second reaction does not exceed the boiling point of the pore-expanding aid II; and / or, in step (2), the first impregnation is saturated impregnation or supersaturated impregnation; after the first impregnation ends, let it stand for 1 - 7 h before performing the second drying and the second calcination; and / or, after the first impregnation ends, the standing time is 1 - 6 h; and / or, in step (2), the temperature of the second drying is 50 - 150 °C, and the time is 3 - 6 h; the temperature of the second calcination is 300 °C - 600 °C, and the time is 3 - 6 h.

23. The preparation method according to claim 22, wherein, The temperature of the second calcination is 50 - 120 °C, and the time is 4 - 5 h.

24. The preparation method according to claim 1, wherein In step (3), the second impregnation is saturated impregnation or supersaturated impregnation; after the second impregnation ends, let it stand for 1 - 7 h before performing the third drying and the third calcination; and / or, after the second impregnation ends, the standing time is 1 - 6 h; And / or, in step (3), the temperature of the third drying is 50 - 150 °C and the time is 3 - 6 h; the temperature of the third calcination is 300 °C - 600 °C and the time is 3 - 6 h.

25. A hydrodesulfurization catalyst prepared by the preparation method according to any one of claims 1 - 24.

26. The hydrodesulfurization catalyst according to claim 25, wherein, The hydrodesulfurization catalyst comprises: 6 - 25 wt% of NiO, 1 - 22 wt% of MoO3 and / or WO3, and 53 - 93 wt% of a porous support.

27. The hydrodesulfurization catalyst according to claim 26, wherein, The hydrodesulfurization catalyst comprises: 7 - 20 wt% of NiO, 2 - 15 wt% of MoO3 and / or WO3, and 65 - 91 wt% of a porous support.

28. Use of the hydrodesulfurization catalyst according to any one of claims 25 - 27 in hydrodesulfurization of oil products.

29. According to the use of claim 28, the hydrodesulfurization catalyst is in a sulfided form when in use.

30. The application according to claim 28 or 29, wherein, The use conditions of the hydrodesulfurization catalyst include: temperature of 200-350 °C and space velocity of 2-25 h -1 .

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