Hydrogenation catalyst, process for its preparation and use and process for the hydrofining of catalytic diesel

Abstract

This invention relates to the field of catalytic diesel hydrorefining, specifically to a hydrorefining catalyst, its preparation method, its application, and a method for catalytic diesel hydrorefining. The catalyst comprises a hydrorefining active component and a support, wherein the support contains an alkaline earth metal, and the hydrorefining active component contains Group VIII and Group VIB elements; the hydrorefining active component has a layered stacked structure. The catalyst of this invention, comprising a hydrorefining active component and a support, wherein the support contains an alkaline earth metal, can modulate the acidity of the support surface, reducing the interaction strength between the hydrorefining active metal and the support. Combined with the preparation method of this invention, the catalyst of this invention, with its layered stacked structure of the hydrorefining active component, achieves the technical effect of improving the dispersion of the active component.

Description

Technical Field

[0001] This invention relates to the field of catalytic diesel hydrorefining, specifically to a hydrorefining catalyst, its preparation method and application, and a method for catalytic diesel hydrorefining. Background Technology

[0002] Catalytic cracked diesel (also known as light cycle oil, catalytic diesel, or LCO) is a heavy diesel fraction produced from catalytic cracking (FCC) units. Its composition is complex, with aromatics content as high as 80%, of which naphthalene-based bicyclic aromatics account for approximately 70%, monocyclic and tricyclic aromatics each account for about 15%, and the remainder consists of small amounts of alkanes, cycloalkanes, and alkenes. LCO contains approximately 0.2–1.5 wt% sulfur, 100–1000 ppm nitrogen, and has a cetane number of 15–25, exhibiting poor ignition performance and making it unsuitable for direct use as automotive diesel. With the saturation of oil pools and the squeeze-out effect of declining diesel consumption, LCO utilization has become a serious problem for refineries, restricting the full-load operation of their units and the improvement of overall efficiency.

[0003] Currently, LCO processing typically employs hydrorefining and hydrocracking. Hydrorefining primarily functions to remove sulfur and nitrogen, and to saturate aromatics. While it improves color and stability, the increase in cetane number is relatively small, failing to meet the cetane number requirements for automotive diesel. Hydrocracking processes, such as UOP's Unicracking process, can yield gasoline, jet fuel, and diesel products, but when blended with excessively high proportions of secondary processed oils like LCO, qualified jet fuel cannot be obtained. To address the aromatic content of LCO and achieve high-value utilization, UOP developed the LCO-X process, a new process for producing xylene and benzene through hydroconversion-selective alkyl transfer. The process principle involves first hydrorefining LCO to remove sulfur and nitrogen impurities from the feedstock, and then selectively hydrogenating and saturating the polycyclic aromatic hydrocarbons before proceeding to a hydrocracking reactor for selective cracking. In the LCO-X process, the total yield of xylene and benzene is about 44%. In addition, some liquefied petroleum gas, light naphtha and ultra-low sulfur diesel components are also produced as byproducts. This process requires the construction of a series of reaction and separation units after the hydrocracking reaction. The process is long and the investment is high. There are no reports of industrial application.

[0004] Given the current challenges of oil product upgrading and gasoline / diesel pool saturation, chemical-based conversion has become an inevitable trend in LCO utilization. The most competitive chemical utilization route involves a two-stage reaction of LCO via hydrorefining and hydrocracking to produce light aromatics and low-carbon saturated hydrocarbons. The light aromatics can be directly fed into an aromatics complex, while the low-carbon saturated hydrocarbons can be used as feedstock for ethylene production via steam cracking, thus achieving high-value-added utilization of LCO. In the two-stage process, to achieve high aromatics yield, the first-stage hydrorefining process should possess the following characteristics: 1. High conversion rate of polycyclic aromatic hydrocarbons (PAHs) to maximize the production of monocyclic aromatic hydrocarbons (MAHs); 2. High selectivity for MAHs to avoid aromatics loss due to deep hydrorefining; 3. Deep desulfurization and denitrification performance to provide high-quality feedstock for the second-stage hydrocracking. Deep denitrification requires enhanced hydrorefining, while increasing aromatics content requires inhibiting deep hydrorefining. Therefore, simultaneously meeting these requirements presents a significant challenge to the development of hydrorefining catalysts.

[0005] CN105754646A This invention discloses a combined method for catalytic cracking diesel hydroconversion and catalytic gasoline hydrotreating.

[0006] CN1040610A discloses a hydrorefining catalyst supported on γ-Al₂O₃ containing TiO₂. The supported catalyst γ-Al₂O₃ contains 5-30% titanium oxide, with W, Mo, and Ni as active components. The performance of the hydrorefining catalyst supported on TiO₂-modified Al₂O₃ is improved to some extent. However, the support has a lower acidity, especially fewer moderately strong acid centers, which is unfavorable for the ring-opening and breaking of nitrogen heterocycles, resulting in a less significant denitrification effect.

[0007] The petroleum hydrocarbon hydrotreating method disclosed in USP4880524 employs a highly active hydrogenation catalyst. This catalyst is of the NiMo / Al₂O₃ type with a specific surface area greater than 300 m². 2 / g, with pore sizes smaller than 7nm exceeding 70%. This catalyst exhibits good hydrorefining activity for light distillate oils, but its hydrorefining effect on catalytic diesel fractions with relatively large molecular sizes is poor.

[0008] CN109777514A discloses a method for the hydroconversion of catalytic diesel to produce aromatics, which adopts a two-stage hydrorefining + hydrocracking process. The hydrorefining catalyst has high acid strength, the aromatic yield is low and the aromatic loss is large during the refining process. It can be used as a catalytic diesel product scheme, but it is not suitable for the chemical utilization of catalytic diesel. Summary of the Invention

[0009] The purpose of this invention is to overcome the problems of poor denitrification effect and low monocyclic aromatic hydrocarbon content in the existing technology of catalytic diesel hydrotreating, and to provide a hydrogenation catalyst, its preparation method and application, and a method for catalytic diesel hydrorefining. This catalyst has excellent denitrification effect and monocyclic aromatic hydrocarbon selectivity.

[0010] To achieve the above objectives, the first aspect of the present invention provides a hydrogenation catalyst comprising a hydrogenation active component and a support, wherein the support comprises an alkaline earth metal, and the hydrogenation active component comprises a Group VIII element and a Group VIB element; the hydrogenation active component is in a layered stacked structure.

[0011] A second aspect of the present invention provides a method for preparing the hydrogenation catalyst described in the first aspect, the method comprising:

[0012] a. The carrier, alkaline earth metal, first additive and optional organic acid are first mixed in a first solvent, first dried and first calcined to obtain an intermediate product;

[0013] b. The intermediate product is mixed with the hydrogenation active component precursor and the second additive in a second solvent, then dried and calcined to obtain the hydrogenation catalyst.

[0014] The first additive is a nonionic surfactant; the second additive is a polybasic inorganic acid or a polybasic organic acid.

[0015] A third aspect of the present invention provides an application of the hydrogenation catalyst described in the first aspect.

[0016] A fourth aspect of the present invention provides a method for hydrorefining catalytic diesel, the method comprising contacting catalytic diesel with hydrogen in the presence of a catalyst to carry out a hydrogenation reaction; wherein the catalyst is a pre-sulfurized hydrogenation catalyst of the first aspect.

[0017] Through the above technical solution, the present invention has the following advantages:

[0018] The catalyst of this invention comprises a hydrogenation active component and a support. The support contains an alkaline earth metal, which can modulate the acid properties of the support surface and reduce the interaction strength between the hydrogenation active metal and the support. In conjunction with the preparation method of this invention, the hydrogenation active component is obtained in a layered stacked structure, thereby improving the dispersion of the active component.

[0019] When the catalyst of this invention is applied to the catalytic hydrorefining of diesel, it exhibits excellent denitrification effect and monocyclic aromatic hydrocarbon selectivity. Attached Figure Description

[0020] Figure 1 This is a transmission electron microscope (TEM) image of the catalyst in Example 1;

[0021] Figure 2 This is the ammonia temperature-programmed desorption (NH3-TPD) curve of the catalyst in Example 1;

[0022] Figure 3 This is a TEM image of the catalyst from Example 2;

[0023] Figure 4 This is a TEM image of the catalyst in Comparative Example 1. Detailed Implementation

[0024] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0025] The present invention provides a hydrogenation catalyst comprising a hydrogenation active component and a support, wherein the support comprises an alkaline earth metal, and the hydrogenation active component comprises Group VIII and Group VIB elements; the hydrogenation active component is in a layered stacked structure.

[0026] The catalyst of this invention comprises a hydrogenation active component consisting of Group VIII and Group VIB elements and a support. The support contains an alkaline earth metal, which can modulate the acid properties of the support surface and reduce the interaction strength between the hydrogenation active metal and the support. In conjunction with the preparation method of this invention, the catalyst of this invention has a layered stacked structure of the hydrogenation active component, thereby improving the dispersion of the active component.

[0027] According to a preferred embodiment of the present invention, the active components of the hydrogenation catalyst have a 3-10 layered stacked structure, and preferably, the active components of the hydrogenation catalyst have a 3-7 layered stacked structure.

[0028] According to a preferred embodiment of the present invention, the stacking length of each layer in the active component stacking structure of the hydrogenation catalyst is 3-25 nm, for example, it can be 3-7 nm, 3-15 nm, 5-15 nm, 5-25 nm, 6-12 nm, 6-18 nm, or 6-25 nm; preferably, the stacking length of each layer is 3-7 nm.

[0029] In this invention, the range of types of carriers is relatively wide. According to a preferred embodiment of this invention, the carrier is selected from at least one of silica-alumina molecular sieve, phosphorus-alumina molecular sieve, silicon dioxide, zirconium dioxide, titanium dioxide, and aluminum oxide.

[0030] According to a preferred embodiment of the present invention, the carrier contains 0.1-1.0 wt% alkaline earth metal.

[0031] In this invention, alkaline earth metals are all applicable. According to a preferred embodiment of the invention, the alkaline earth metal is selected from at least one of Mg, Ca, Sr, and Ba, more preferably Ca. By adopting the aforementioned preferred embodiment, the hydrogenation performance of the equilibrium catalyst can be further improved, as can the denitrification effect and the selectivity for monocyclic aromatic hydrocarbons be improved.

[0032] According to a preferred embodiment of the present invention, the specific surface area of ​​the hydrogenation catalyst is 150-300 m². 2 / g, preferably 180-300m 2 / g.

[0033] According to a preferred embodiment of the present invention, the average pore size of the hydrogenation catalyst is 10-20 nm, preferably 10-15 nm.

[0034] According to a preferred embodiment of the present invention, the pore volume of the hydrogenation catalyst is 0.7-1.3 ml / g, preferably 0.85-1.2 ml / g.

[0035] According to a preferred embodiment of the present invention, the surface of the hydrogenation catalyst has suitable acid properties, with a density ratio of weak acid sites to moderately strong acid sites of about 2-4:1.

[0036] In this invention, there are no particular limitations on the content of each component in the hydrogenation catalyst. According to a preferred embodiment of the invention, by weight percentage, the support content in the hydrogenation catalyst is 50-85%, preferably 75-85%; the content of the hydrogenation active component, calculated as metal oxide, is 15-50%, preferably 15-25%. By adopting the aforementioned preferred scheme, the hydrogenation performance of the equilibrium catalyst can be further improved, as well as the denitrification effect and the selectivity of monocyclic aromatic hydrocarbons.

[0037] In this invention, as long as the objective of the invention can be achieved, there is no particular limitation on the mass ratio of Group VIII and Group VIB elements in the hydrogenation active component. According to a preferred embodiment of the invention, the mass ratio of Group VIII and Group VIB elements in the hydrogenation active component, measured in metal oxides, is 0.1-0.5. By adopting the aforementioned preferred scheme, the hydrogenation performance of the equilibrium catalyst can be further improved, as can the denitrification effect and the selectivity of monocyclic aromatic hydrocarbons.

[0038] According to a preferred embodiment of the present invention, the group VIII element is selected from at least one of Fe, Co, and Ni, preferably Ni and / or Co.

[0039] According to a preferred embodiment of the present invention, the group VIB element is selected from at least one of Cr, Mo, and W, preferably Mo and / or W.

[0040] This invention provides a method for preparing the hydrogenation catalyst according to the present invention, the method comprising:

[0041] a. The carrier, alkaline earth metal, first additive and optional organic acid are first mixed in a first solvent, first dried and first calcined to obtain an intermediate product;

[0042] b. The intermediate product is mixed with the hydrogenation active component precursor and the second additive in a second solvent, then dried and calcined to obtain the hydrogenation catalyst.

[0043] The first additive is a nonionic surfactant; the second additive is a polybasic inorganic acid or a polybasic organic acid.

[0044] By employing the aforementioned preparation method, a catalyst with the characteristics of this invention can be prepared.

[0045] According to a preferred embodiment of the present invention, the first additive is selected from polyethylene glycol and / or Tween; the second additive is a polybasic inorganic acid.

[0046] According to a preferred embodiment of the present invention, the first additive is polyethylene glycol 200; the second additive is phosphoric acid.

[0047] According to a preferred embodiment of the present invention, the first mixing and the second mixing are each independently selected from equal volume impregnation and / or excessive impregnation, preferably equal volume impregnation.

[0048] According to a preferred embodiment of the present invention, the hydrogenation active component precursor is a compound corresponding to a Group VIII element and / or a Group VIB element, preferably a corresponding salt.

[0049] In this invention, the preparation of the support can be carried out using conventional methods in the art. According to a preferred embodiment of the invention, the preparation method of the support includes: mixing and molding a support precursor, an extrusion aid, and a pectinic acid to obtain the support. By adopting the aforementioned preferred scheme, the hydrogenation performance of the equilibrium catalyst can be further improved, as well as the denitrification effect and the selectivity for monocyclic aromatic hydrocarbons can be improved.

[0050] According to a preferred embodiment of the present invention, the carrier is obtained by drying and calcining after molding, preferably by drying at 100-120°C for 4-8 hours and then calcining at 600-800°C for 4-8 hours.

[0051] According to a preferred embodiment of the present invention, the extrusion aid is selected from at least one of guar gum powder, polyvinyl alcohol, and hydroxymethyl cellulose.

[0052] According to a preferred embodiment of the present invention, the extrusion aid is polyvinyl alcohol, and preferably the mass concentration of the polyvinyl alcohol solution is 1-10%.

[0053] According to a preferred embodiment of the present invention, the pectinic acid is selected from one or more of phosphoric acid, nitric acid, and acetic acid, preferably a mixed solution of nitric acid and phosphoric acid, and more preferably the volume ratio of nitric acid to phosphoric acid in the mixed solution is 1-2:2-1.

[0054] According to a preferred embodiment of the present invention, the molding includes forming into a clover strip shape, a cylindrical strip shape, or a sphere shape, preferably a clover strip shape.

[0055] In this invention, as long as the objective of the invention can be achieved, there are no particular limitations on the weight ratio of the support, alkaline earth metal, first additive, and organic acid in step a. According to a preferred embodiment of the invention, in step a, the weight ratio of the support, alkaline earth metal (calculated as oxide), first additive, and organic acid is 1:0.01-0.04:0.02-0.05:0.05-0.15. By adopting the aforementioned preferred scheme, the hydrogenation performance of the equilibrium catalyst can be further improved, as well as the denitrification effect and the selectivity of monocyclic aromatic hydrocarbons.

[0056] According to a preferred embodiment of the present invention, the organic acid is selected from at least one of citric acid, tartaric acid, and oxalic acid.

[0057] According to a preferred embodiment of the present invention, the first solvent is selected from at least one of deionized water, ethanol, and acetic acid / sodium acetate buffer solution.

[0058] According to a preferred embodiment of the present invention, the second solvent is selected from at least one of deionized water, ethanol, and acetic acid / sodium acetate buffer solution.

[0059] According to a preferred embodiment of the present invention, the conditions for the first drying include: a drying temperature of 60°C-150°C and a drying time of 2h-24h.

[0060] According to a preferred embodiment of the present invention, the conditions for the first calcination include: a calcination temperature of 250℃-750℃ and a calcination time of 2h-12h.

[0061] According to a preferred embodiment of the present invention, the conditions for the second drying include: a drying temperature of 60°C-150°C and a drying time of 2h-24h.

[0062] According to a preferred embodiment of the present invention, the conditions for the second calcination include: a calcination temperature of 250°C-750°C and a calcination time of 2h-12h.

[0063] This invention provides an application of the catalyst described herein in the catalytic hydrorefining of diesel fuel.

[0064] When the catalyst of this invention is applied to the catalytic hydrorefining of diesel, it exhibits excellent denitrification effect and monocyclic aromatic hydrocarbon selectivity.

[0065] This invention provides a method for hydrorefining catalytic diesel fuel, the method comprising contacting catalytic diesel fuel with hydrogen in the presence of a catalyst to carry out a hydrogenation reaction, wherein the catalyst is a pre-sulfurized hydrogenation catalyst as described in this invention.

[0066] By employing the method of this invention for catalytic diesel hydrorefining, the refined product exhibits high denitrification rate and high selectivity for monocyclic aromatic hydrocarbons.

[0067] According to a preferred embodiment of the present invention, the catalytic diesel oil has a distillation range of 200-370°C, preferably 200-330°C. By adopting the aforementioned preferred embodiment, the denitrification rate and monocyclic aromatic hydrocarbon selectivity of the refined product can be further improved.

[0068] According to a preferred embodiment of the present invention, the density of the catalytic diesel oil is 0.90 g / ml or higher, preferably 0.93 g / ml or higher. By adopting the aforementioned preferred embodiment, the denitrification rate and monocyclic aromatic hydrocarbon selectivity of the refined product can be further improved.

[0069] According to a preferred embodiment of the present invention, the catalytic diesel fuel is derived from DCC and / or MIP processes.

[0070] According to a preferred embodiment of the present invention, the catalytic diesel oil contains, by weight percentage, 15-25% monocyclic aromatics, 50-60% dicyclic aromatics, and 2-8% tricyclic aromatics; and 7%-33% other components, preferably including saturated hydrocarbons such as alkanes and cycloalkanes. By adopting the aforementioned preferred embodiment, the denitrification rate and monocyclic aromatics selectivity of the refined product can be further improved.

[0071] According to a preferred embodiment of the present invention, the conditions for the hydrogenation reaction include: a reaction temperature of 260-320°C, preferably 270-300°C; a reaction pressure of 5.0-8.0 MPa, preferably 6.0-7.0 MPa; and a volume hourly space velocity of 0.6-1.0 h⁻¹. -1 Preferably 0.7-0.8h -1 The hydrogen-to-oil volume ratio is 1000-2000, preferably 1200-1500. By adopting the aforementioned preferred scheme, the denitrification rate and monocyclic aromatic hydrocarbon selectivity of the refined product can be further improved.

[0072] According to a preferred embodiment of the present invention, the pre-sulfurization conditions include: a hydrogen partial pressure of 4-6 MPa and a hydrogen sulfide concentration of 5000-15000 ppm in the circulating hydrogen, followed by programmed temperature increases at 210-250℃ for 12-20 h, 260-300℃ for 12-20 h, and 310-340℃ for 12-20 h; the total sulfurization time is 36-60 h.

[0073] The present invention will be described in detail below through embodiments.

[0074] In the following embodiments:

[0075] Bicyclic aromatic hydrocarbon conversion rate (%) = (Bicyclic aromatic hydrocarbon content in raw material and bicyclic aromatic hydrocarbon content in product) / Bicyclic aromatic hydrocarbon content in raw material × 100%;

[0076] Tricyclic aromatic hydrocarbon conversion rate (%) = (Tricyclic aromatic hydrocarbon content in raw material / Tricyclic aromatic hydrocarbon content in product) / Tricyclic aromatic hydrocarbon content in raw material × 100%;

[0077] Monocyclic aromatic hydrocarbon selectivity (%) = (Monocyclic aromatic hydrocarbon content in product / Monocyclic aromatic hydrocarbon content in raw material) / (Polycyclic aromatic hydrocarbon content in raw material / Polycyclic aromatic hydrocarbon content in product) × 100%;

[0078] Denitrification rate (%) = (Nitrogen compound content in raw materials - Nitrogen compound content in product) / Nitrogen compound content in raw materials × 100%.

[0079] Example 1

[0080] 1. Catalyst Preparation

[0081] Weigh out 20 grams of boehmite (equivalent to 130 grams of alumina), 8 grams of guar gum powder, mix them, then add 20 grams of a 5% polyvinyl alcohol solution, 2.4 grams of 85% phosphoric acid, 3.2 grams of 67% nitric acid, and 200 ml of water, and extrude it into a paste. A support was prepared by drying millimeter-thick clover strips at 110°C for 6 hours and then calcining them at 700°C for 6 hours. 50 grams of the calcined sample were impregnated with an equal-volume aqueous solution containing 4.8 grams of calcium nitrate, 2.5 grams of polyethylene glycol 200, and 4.5 grams of citric acid. After drying at 110°C for 4 hours, the mixture was calcined at 450°C for 6 hours to obtain a hydrorefining catalyst support.

[0082] The above-mentioned support was mixed with a mixed solution containing phosphoric acid, nickel acetate and ammonium molybdate (equivalent to containing 3.2g NiO, 13.4g MoO3 and 2g phosphoric acid) by an equal volume impregnation method, dried at 110℃ for 6 hours and calcined at 450℃ for 4 hours to obtain catalyst CAT-1.

[0083] The surface characteristics of catalyst CAT-1 include a specific surface area of ​​285 m². 2 / g, with an average pore size of 13.5nm and a pore volume of 0.85ml / g; the surface of the hydrogenation catalyst has weak acid sites and medium-strong acid sites, and has suitable surface acid properties, with a density ratio of weak acid sites to medium-strong acid sites of about 3.2:1.

[0084] Figure 1 The transmission electron microscope image of CAT-1 shows that the active components of CAT-1 have a layered stacked structure with 3-7 layers and a stack length of 3-8 nm, exhibiting very good dispersibility. Figure 2 The ammonia temperature programmed desorption (NH3-TPD) diagram of CAT-1 shows that there are two types of acidic sites on the catalyst surface: weak acidic sites and medium-strong acidic sites. The ratio of weak acidic sites to medium-strong acidic sites is appropriate, which ensures the high dispersion of the metal active components.

[0085] 2. The above catalyst needs to be pre-sulfurized before use. The sulfidation conditions are as follows: maintain low nitrogen oil circulation in the sulfidated oil, DMDS concentration in the sulfidated oil of 7000 mg / kg, and hydrogen partial pressure of 5.0 MPa. Sulfurize at 230℃ for 16 h, 280℃ for 16 h, and 320℃ for 16 h respectively, according to the programmed temperature rise. The total sulfidation time is 48 h.

[0086] 3. Hydrorefining reaction: The pre-sulfurized catalyst and catalytic diesel (from the MIP process, containing 15-25% monocyclic aromatics, 50-60% bicyclic aromatics, and 2-8% tricyclic aromatics) are contacted with hydrogen to carry out a hydrogenation reaction.

[0087] The conditions were: reaction inlet temperature 280℃, reaction pressure 6.0 MPa, and volume hourly space velocity (VHSV) 1.0 h⁻¹. -1 The hydrogen-to-oil volume ratio was 1500, and the reaction results are shown in Table 1.

[0088] Example 2

[0089] Weigh out 20 grams of boehmite (equivalent to 130 grams of alumina), 8 grams of guar gum powder, mix them, then add 20 grams of a 5% polyvinyl alcohol solution, 2.4 grams of 85% phosphoric acid, 3.2 grams of 67% nitric acid, and 200 ml of water, and extrude it into a paste. A support was prepared by drying millimeter-thick clover strips at 110°C for 6 hours and then calcining at 700°C for 6 hours. 50 grams of the calcined sample was impregnated with an equal-volume aqueous solution containing 2.4 grams of calcium nitrate, 2.5 grams of polyethylene glycol 200, and 4.5 grams of citric acid. After drying at 110°C for 4 hours, the mixture was calcined at 450°C for 6 hours to obtain a hydrorefining catalyst support.

[0090] 50 g of the above-mentioned support was mixed with an equal-volume impregnation method using a mixed aqueous solution containing phosphoric acid, nickel acetate, and ammonium molybdate (containing 3.2 g NiO, 13.4 g MoO, and 2 g phosphoric acid). The mixture was dried at 110 °C for 6 hours and calcined at 450 °C for 4 hours to obtain catalyst CAT-2. The dispersibility characteristics of catalyst CAT-2 are as follows: specific surface area is 283 m². 2 / g, with an average pore size of 13.5nm and a pore volume of 0.85ml / g; the surface of the hydrogenation catalyst has weak acid sites and medium-strong acid sites, with a density ratio of weak acid sites to medium-strong acid sites of approximately 2.4:1. Figure 3 The transmission electron microscope image of CAT-1 shows that the active components on the catalyst surface have a layered stacked structure with 3-7 layers and a stacking length of 6-12 nm.

[0091] The reaction conditions for the hydrorefining catalyst and the presulfurization conditions for the catalyst were the same as in Example 1. The reaction results are shown in Table 1.

[0092] Example 3

[0093] Weigh out 20 grams of boehmite (equivalent to 130 grams of alumina), 8 grams of guar gum powder, mix them, then add 20 grams of a 5% polyvinyl alcohol solution, 2.4 grams of 85% phosphoric acid, 3.2 grams of 67% nitric acid, and 200 ml of water, and extrude it into a paste. A support was prepared by drying millimeter-thick clover strips at 110°C for 6 hours and then calcining them at 700°C for 6 hours. 50 grams of the calcined sample were impregnated with an equal-volume aqueous solution containing 4.8 grams of calcium nitrate, 2.5 grams of polyethylene glycol 200, and 2.0 grams of citric acid. After drying at 110°C for 4 hours, the mixture was calcined at 450°C for 6 hours to obtain a hydrorefining catalyst support.

[0094] 50 g of the above-mentioned support was mixed with an equal-volume impregnation method using a mixed aqueous solution containing phosphoric acid, nickel acetate, and ammonium molybdate (containing 3.2 g NiO, 13.4 g MoO3, and 2 g phosphoric acid). The mixture was dried at 110 °C for 6 hours and calcined at 450 °C for 4 hours to obtain catalyst CAT-3. The dispersibility characteristics of catalyst CAT-3 are as follows: specific surface area is 282 m². 2 The catalyst has an average pore size of 13.4 nm and a pore volume of 0.86 ml / g. The surface of the hydrogenation catalyst contains both weakly acidic and moderately strong acidic sites, with a density ratio of approximately 3.2:1. The active components on the catalyst surface exhibit a layered stacked structure, with 3-10 layers and a stack length of 6-18 nm, further reducing its dispersibility.

[0095] The reaction conditions for the hydrorefining catalyst and the presulfurization conditions for the catalyst were the same as in Example 1. The reaction results are shown in Table 1.

[0096] Example 4

[0097] Weigh out 20 grams of boehmite (equivalent to 130 grams of alumina), 8 grams of guar gum powder, mix them, then add 20 grams of a 5% polyvinyl alcohol solution, 2.4 grams of 85% phosphoric acid, 3.2 grams of 67% nitric acid, and 200 ml of water, and extrude it into a paste. A support was prepared by drying millimeter-thick clover strips at 110°C for 6 hours and then calcining them at 700°C for 6 hours. 50 grams of the calcined sample were impregnated with an equal-volume aqueous solution containing 4.8 grams of calcium nitrate, 2.5 grams of Tween, and 4.5 grams of citric acid. After drying at 110°C for 4 hours, the mixture was calcined at 450°C for 6 hours to obtain a hydrorefining catalyst support.

[0098] 50 g of the above-mentioned support was mixed with an equal-volume impregnation method using a mixed aqueous solution containing phosphoric acid, nickel acetate, and ammonium molybdate (containing 3.2 g NiO, 13.4 g MoO3, and 2 g phosphoric acid). The mixture was dried at 110 °C for 6 hours and calcined at 450 °C for 4 hours to obtain catalyst CAT-4. The dispersibility characteristics of catalyst CAT-4 are as follows: specific surface area is 284 m². 2 The catalyst has an average pore size of 13.5 nm and a pore volume of 0.84 ml / g; the density ratio of weakly acidic sites to moderately strong acidic sites on the surface of the hydrogenation catalyst is approximately 3.0:1. The active components on the catalyst surface exhibit a layered stacked structure with 3-10 layers and a stack length of 3-15 nm.

[0099] The reaction conditions for the hydrorefining catalyst and the presulfurization conditions for the catalyst were the same as in Example 1. The reaction results are shown in Table 1.

[0100] Example 5

[0101] Weigh out 20 grams of boehmite (equivalent to 130 grams of alumina), 8 grams of guar gum powder, mix them, then add 20 grams of a 5% polyvinyl alcohol solution, 2.4 grams of 85% phosphoric acid, 3.2 grams of 67% nitric acid, and 200 ml of water, and extrude it into a paste. A support was prepared by drying millimeter-thick clover strips at 110°C for 6 hours and then calcining at 700°C for 6 hours. 50 grams of the calcined sample was impregnated with an equal-volume aqueous solution containing 5.2 grams of magnesium nitrate, 2.5 grams of polyethylene glycol 200, and 4.5 grams of citric acid. After drying at 110°C for 4 hours, the mixture was calcined at 450°C for 6 hours to obtain a hydrorefining catalyst support.

[0102] 50 g of the above-mentioned support was mixed with an equal-volume impregnation method using a mixed aqueous solution containing phosphoric acid, nickel acetate, and ammonium molybdate (containing 3.2 g NiO, 13.4 g MoO, and 2 g phosphoric acid). The mixture was dried at 110 °C for 6 hours and calcined at 450 °C for 4 hours to obtain catalyst CAT-5. The dispersibility characteristics of catalyst CAT-5 are as follows: specific surface area is 285 m² / g. 2 The catalyst has an average pore size of 13.4 nm and a pore volume of 0.84 ml / g; the density ratio of weakly acidic sites to moderately strong acidic sites on the surface of the hydrogenation catalyst is approximately 2.7:1. The active components on the catalyst surface exhibit a layered stacked structure with 3-10 layers and a stacking length of 5-15 nm.

[0103] The reaction conditions for the hydrorefining catalyst and the presulfurization conditions for the catalyst were the same as in Example 1. The reaction results are shown in Table 1.

[0104] Example 6

[0105] Weigh the purchased goods 150 g of clover-shaped γ-alumina was dried at 110 °C for 6 hours and then calcined at 700 °C for 6 hours. 50 g of the calcined sample was impregnated with an equal-volume aqueous solution containing 4.8 g of calcium nitrate, 2.5 g of polyethylene glycol 200, and 4.5 g of citric acid. After drying at 110 °C for 4 hours, the mixture was calcined at 450 °C for 6 hours to obtain a hydrorefining catalyst support.

[0106] 50 g of the above-mentioned support was mixed with an equal-volume impregnation method using a mixed aqueous solution containing phosphoric acid, nickel acetate, and ammonium molybdate (containing 3.2 g NiO, 13.4 g MoO, and 2 g phosphoric acid). The mixture was dried at 110 °C for 6 hours and calcined at 450 °C for 4 hours to obtain catalyst CAT-7. The dispersibility characteristics of catalyst CAT-7 are as follows: specific surface area is 207 m². 2 / g, with an average pore size of 8.4nm, a pore volume of 0.7ml / g, and a surface weak acid site to strong acid site density ratio of 1:1.2; the active components on the catalyst surface have a layered stacked structure with 3-10 layers and a stacking length of 6-25nm.

[0107] The reaction conditions for the hydrorefining catalyst and the presulfurization conditions for the catalyst were the same as in Example 1. The reaction results are shown in Table 1.

[0108] Example 7

[0109] Weigh out 20 grams of boehmite (equivalent to 130 grams of alumina), 8 grams of guar gum powder, mix them, then add 20 grams of a 5% polyvinyl alcohol solution, 2.4 grams of 85% phosphoric acid, 3.2 grams of 67% nitric acid, and 200 ml of water, and extrude it into a paste. A support was prepared by drying clover strips (mm) at 110°C for 6 hours and then calcining them at 700°C for 6 hours. 50 g of the calcined sample was impregnated with an aqueous solution containing 4.8 g of calcium nitrate using an equal-volume impregnation method. After drying at 110°C for 4 hours, the mixture was calcined at 450°C for 6 hours to obtain a hydrorefining catalyst support.

[0110] 50 g of the above-mentioned support was mixed with an equal-volume impregnation method using a mixed aqueous solution containing phosphoric acid, nickel acetate, and ammonium molybdate (containing 3.2 g NiO, 13.4 g MoO, and 2 g phosphoric acid). The mixture was dried at 110 °C for 6 hours and calcined at 450 °C for 4 hours to obtain catalyst CAT-9. The dispersibility characteristics of catalyst CAT-9 are as follows: specific surface area is 284 m². 2 The catalyst has an average pore size of 13.5 nm and a pore volume of 0.85 ml / g; the density ratio of weakly acidic sites to moderately strong acidic sites on the surface of the hydrogenation catalyst is approximately 3.2:1. The active components on the catalyst surface exhibit a layered stacked structure with 3-10 layers and a stack length of 5-25 nm.

[0111] The reaction conditions for the hydrorefining catalyst and the presulfurization conditions for the catalyst were the same as in Example 1. The reaction results are shown in Table 1.

[0112] Comparative Example 1

[0113] Weigh out 20 grams of boehmite (equivalent to 130 grams of alumina), 8 grams of guar gum powder, mix them, then add 20 grams of a 5% polyvinyl alcohol solution, 2.4 grams of 85% phosphoric acid, 3.2 grams of 67% nitric acid, and 200 ml of water, and extrude it into a paste. A millimeter-long clover strip was dried at 110°C for 6 hours and then calcined at 700°C for 6 hours to obtain a hydrorefining catalyst support.

[0114] 50 g of the above-mentioned support was mixed with an equal-volume impregnation method using a mixed aqueous solution containing phosphoric acid, nickel acetate, and ammonium molybdate (containing 3.2 g NiO, 13.4 g MoO, and 2 g phosphoric acid). The mixture was dried at 110 °C for 6 hours and calcined at 450 °C for 4 hours to obtain catalyst CAT-D1. The dispersibility characteristics of catalyst CAT-D1 are as follows: specific surface area is 280 m². 2 / g, with an average pore size of 13.5nm and a pore volume of 0.84ml / g; the density ratio of weak acidic sites to moderately strong acidic sites on the surface of the hydrogenation catalyst is approximately 2.1:1. Figure 4 The image is a transmission electron microscope image of CAT-1, which does not show a clear layered stacking structure.

[0115] The reaction conditions for the hydrorefining catalyst and the presulfurization conditions for the catalyst were the same as in Example 1. The reaction results are shown in Table 1.

[0116] Comparative Example 2

[0117] Weigh out 20 grams of boehmite (equivalent to 130 grams of alumina), 8 grams of guar gum powder, mix them, then add 20 grams of a 5% polyvinyl alcohol solution, 2.4 grams of 85% phosphoric acid, 3.2 grams of 67% nitric acid, and 200 ml of water, and extrude it into a paste. A support was prepared by drying millimeter-thick clover strips at 110°C for 6 hours and then calcining them at 700°C for 6 hours. 50 grams of the calcined sample was impregnated with an equal-volume aqueous solution containing 2.5 grams of polyethylene glycol 200 and 4.5 grams of citric acid using an impregnation method. After drying at 110°C for 4 hours, the mixture was calcined at 450°C for 6 hours to obtain a hydrorefining catalyst support.

[0118] 50 g of the above-mentioned support was mixed with an equal-volume impregnation method using a mixed aqueous solution containing phosphoric acid, nickel acetate, and ammonium molybdate (containing 3.2 g NiO, 13.4 g MoO3, and 2 g phosphoric acid). The mixture was dried at 110 °C for 6 hours and calcined at 450 °C for 4 hours to obtain catalyst CAT-D2. The dispersibility characteristics of catalyst CAT-D2 are as follows: specific surface area is 283 m². 2 The catalyst has an average pore size of 13.4 nm and a pore volume of 0.85 ml / g; the density ratio of weakly acidic sites to moderately strong acidic sites on the surface of the hydrogenation catalyst is approximately 2.1:1. The catalyst has no stacking structure.

[0119] The reaction conditions for the hydrorefining catalyst and the presulfurization conditions for the catalyst were the same as in Example 1. The reaction results are shown in Table 1.

[0120] Comparative Example 3

[0121] Weigh out 20 grams of boehmite (equivalent to 130 grams of alumina), 8 grams of guar gum powder, mix them, then add 20 grams of a 5% polyvinyl alcohol solution, 2.4 grams of 85% phosphoric acid, 3.2 grams of 67% nitric acid, and 200 ml of water, and extrude it into a paste. A support was prepared by drying clover strips (mm in diameter) at 110°C for 6 hours and then calcining them at 700°C for 6 hours. 50 g of the calcined sample was impregnated with an equal-volume aqueous solution containing 4.8 g of calcium nitrate, 2.5 g of polyethylene glycol 200, and 3.0 g of hydrochloric acid (36.5%). After drying at 110°C for 4 hours, the mixture was calcined at 450°C for 6 hours to obtain a hydrorefining catalyst support.

[0122] 50 g of the above-mentioned support was mixed with an equal-volume impregnation method using a mixed aqueous solution containing phosphoric acid, nickel acetate, and ammonium molybdate (containing 3.2 g NiO, 13.4 g MoO, and 2 g phosphoric acid). The mixture was dried at 110 °C for 6 hours and calcined at 450 °C for 4 hours to obtain catalyst CAT-D3. The dispersibility characteristics of catalyst CAT-D3 are as follows: specific surface area is 257 m². 2The catalyst has an average pore size of 14.2 nm and a pore volume of 0.88 ml / g; the density ratio of weakly acidic sites to moderately strong acidic sites on the surface of the hydrogenation catalyst is approximately 1:1.3. The active components on the catalyst surface exhibit a layered aggregate structure.

[0123] The reaction conditions for the hydrorefining catalyst and the presulfurization conditions for the catalyst were the same as in Example 1. The reaction results are shown in Table 1.

[0124] Comparative Example 4

[0125] Weigh out 20 grams of boehmite (equivalent to 130 grams of alumina), 8 grams of guar gum powder, mix them, then add 20 grams of a 5% polyvinyl alcohol solution, 2.4 grams of 85% phosphoric acid, 3.2 grams of 67% nitric acid, and 200 ml of water, and extrude it into a paste. A support was prepared by drying millimeter-thick clover strips at 110°C for 6 hours and then calcining them at 700°C for 6 hours. 50 grams of the calcined sample were impregnated with an equal-volume aqueous solution containing 4.8 grams of calcium nitrate, 2.5 grams of polyethylene glycol 200, and 4.5 grams of citric acid. After drying at 110°C for 4 hours, the mixture was calcined at 450°C for 6 hours to obtain a hydrorefining catalyst support.

[0126] 50 g of the above-mentioned support was mixed with a solution containing nickel acetate (containing 3.2 g of NiO) using an equal-volume impregnation method, dried at 110 °C for 6 hours, and calcined at 450 °C for 4 hours to obtain catalyst CAT-6. The dispersibility characteristics of catalyst CAT-6 are as follows: specific surface area is 285 m². 2 The catalyst has an average pore size of 13.5 nm and a pore volume of 0.85 ml / g; the density ratio of weakly acidic sites to moderately strong acidic sites on the surface of the hydrogenation catalyst is approximately 3.2:1. The active components on the catalyst surface have a plate-like structure with a length of 10-15 nm.

[0127] The reaction conditions for the hydrorefining catalyst and the presulfurization conditions for the catalyst were the same as in Example 1. The reaction results are shown in Table 1.

[0128] Table 1

[0129]

[0130]

[0131] 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 inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A hydrogenation catalyst, characterized in that, The catalyst comprises a hydrogenation active component and a support, wherein the support comprises an alkaline earth metal, and the hydrogenation active component comprises Group VIII and Group VIB elements; the hydrogenation active component has a layered stacked structure; the density ratio of weak acidic sites to moderately strong acidic sites on the surface of the hydrogenation catalyst is 2-4:1; the active component of the hydrogenation catalyst has a 3-10 layered stacked structure, and / or the length of each stacked layer is 3-25 nm.

2. The hydrogenation catalyst according to claim 1, wherein, The active components of the hydrogenation catalyst have a 3-7 layered stacked structure, and / or each stacked layer has a length of 3-7 nm; and / or The carrier is selected from at least one of silica-alumina molecular sieve, phosphorus-alumina molecular sieve, silica, zirconium dioxide, titanium dioxide, and aluminum oxide; and / or The carrier contains 0.1-1.0 wt% alkaline earth metal; and / or The specific surface area of ​​the hydrogenation catalyst is 150-300 m². 2 / g; and / or The hydrogenation catalyst has an average pore size of 10-20 nm; and / or The hydrogenation catalyst has a pore volume of 0.7-1.3 ml / g; and / or By weight percentage, the hydrogenation catalyst contains 50-85% support and 15-50% active hydrogenation component, calculated as metal oxide.

3. The hydrogenation catalyst according to claim 2, wherein, The active components of the hydrogenation catalyst have a 3-7 layered stacked structure, and / or each stacked layer has a length of 3-7 nm; and / or The alkaline earth metal is selected from at least one of Mg, Ca, Sr, and Ba; and / or The specific surface area of ​​the hydrogenation catalyst is 180-300 m². 2 / g; and / or The hydrogenation catalyst has an average pore size of 10-15 nm; and / or The hydrogenation catalyst has a pore volume of 0.85-1.2 ml / g; and / or By weight percentage, the hydrogenation catalyst contains 75-85% support and 15-25% active hydrogenation component, calculated as metal oxide.

4. The hydrogenation catalyst according to claim 3, wherein, The alkaline earth metal is Ca.

5. The hydrogenation catalyst according to claim 1, wherein, The mass ratio of Group VIII and Group VIB elements in the hydrogenation active component, measured as metal oxides, is 0.1-0.

5.

6. The hydrogenation catalyst according to claim 5, wherein, The group VIII element is selected from at least one of Fe, Co, and Ni; The group VIB element is selected from at least one of Cr, Mo, and W.

7. The hydrogenation catalyst according to claim 6, wherein, The Group VIII element is Ni and / or Co; The group VIB elements are Mo and / or W.

8. A method for preparing the hydrogenation catalyst according to any one of claims 1-7, characterized in that, The preparation method includes: a. The carrier, alkaline earth metal, and first additive are first mixed in a first solvent, first dried, and first calcined to obtain an intermediate product; b. The intermediate product is mixed with the hydrogenation active component precursor and the second additive in a second solvent, then dried and calcined to obtain the hydrogenation catalyst. The first additive is a nonionic surfactant; the second additive is a polybasic inorganic acid or a polybasic organic acid.

9. The preparation method according to claim 8, wherein, In step a, the carrier, alkaline earth metal, first additive and organic acid are first mixed in a first solvent, first dried and first calcined to obtain an intermediate product.

10. The preparation method according to claim 8, wherein, The first additive is selected from polyethylene glycol and / or Tween; the second additive is a polybasic inorganic acid.

11. The preparation method according to claim 10, wherein, The first additive is polyethylene glycol 200; the second additive is phosphoric acid.

12. The preparation method according to claim 8, wherein, The method for preparing the carrier includes: mixing and molding a carrier precursor, an extrusion aid, and a pectinic acid to obtain the carrier.

13. The preparation method according to claim 12, wherein, The extrusion aid is selected from at least one of guar gum powder, polyvinyl alcohol, and hydroxymethyl cellulose; and / or The colloidal acid is selected from at least one of phosphoric acid, nitric acid, and acetic acid.

14. The preparation method according to claim 13, wherein, The colloidal acid is a mixed solution of nitric acid and phosphoric acid.

15. The preparation method according to claim 8, wherein, In step a, the weight ratio of the carrier, alkaline earth metal (calculated as oxide), first additive, and organic acid is 1:0.01-0.04:0.02-0.05:0.05-0.15; and / or The organic acid is selected from at least one of citric acid, tartaric acid, and oxalic acid; and / or The first solvent is selected from at least one of deionized water, ethanol, and acetic acid / sodium acetate buffer solution; and / or The second solvent is selected from at least one of deionized water, ethanol, and acetic acid / sodium acetate buffer solution.

16. The preparation method according to claim 8, wherein, The first drying conditions include: a drying temperature of 60℃-150℃, and a drying time of 2h-24h; and / or The conditions for the first calcination include: a calcination temperature of 250℃-750℃ and a calcination time of 2h-12h; and / or The second drying conditions include: a drying temperature of 60℃-150℃ and a drying time of 2h-24h; and / or The conditions for the second roasting include: a roasting temperature of 250℃-750℃ and a roasting time of 2h-12h.

17. The use of the catalyst according to any one of claims 1-7 in the catalytic hydrorefining of diesel fuel.

18. A method for catalytic hydrorefining of diesel fuel, characterized in that, This method involves a hydrogenation reaction in which catalytic diesel fuel is contacted with hydrogen in the presence of a catalyst. The catalyst is a pre-sulfurized hydrogenation catalyst according to any one of claims 1-7.

19. The method according to claim 18, wherein, The catalytic diesel oil has a distillation range of 200-370°C; and / or The density of the catalytic diesel oil is above 0.90 g / ml; and / or The catalytic diesel fuel is derived from DCC and / or MIP processes; and / or The conditions for the hydrogenation reaction include: a reaction temperature of 260-320℃; a reaction pressure of 5.0-8.0 MPa; and a volume hourly space velocity of 0.6-1.0 h⁻¹. -1 Hydrogen-to-oil volume ratio 1000-2000; and / or The pre-sulfurization conditions include: a hydrogen partial pressure of 4-6 MPa and a hydrogen sulfide concentration of 5000-15000 ppm in the circulating hydrogen, followed by programmed temperature increases at 210-250℃ for 12-20 h, 260-300℃ for 12-20 h, and 310-340℃ for 12-20 h; the total sulfurization time is 36-60 h.

20. The method according to claim 19, wherein, The catalytic diesel oil has a distillation range of 200-330℃; and / or The density of the catalytic diesel fuel is above 0.93 g / ml; and / or The catalytic diesel fuel contains, by weight percentage, 15-25% monocyclic aromatic hydrocarbons, 50-60% dicyclic aromatic hydrocarbons, and 2-8% tricyclic aromatic hydrocarbons; and / or The conditions for the hydrogenation reaction include: a reaction temperature of 270-300℃; a reaction pressure of 6.0-7.0 MPa; and a volume hourly space velocity of 0.7-0.8 h⁻¹. -1 The hydrogen-to-oil volume ratio is 1200-1500.

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