Grading method and application of hydrotreating catalyst

Abstract

The invention discloses a grading method and application of a hydrotreating catalyst. The method comprises the following steps: arranging N hydrotreating catalysts along a material flow direction; the activity of the downstream hydrotreating catalyst is greater than that of the upstream hydrotreating catalyst adjacent to the downstream hydrotreating catalyst; the active metal of each hydrotreating catalyst comprises group VIB metal and group VIII metal; the weight ratio of the group VIB metal to the group VIII metal in the downstream hydrotreating catalyst is greater than the weight ratio of the group VIB metal to the group VIII metal in the adjacent upstream hydrotreating catalyst, and the active metal is calculated by oxide; in each hydrotreating catalyst, the weight ratio of the VIB group metal to the VIII group metal is 2-12 in terms of oxide. The grading method can improve the catalytic performance of a distillate oil hydrogenation reaction system. Especially, the hydrodenitrogenation performance is improved.

Description

Technical Field

[0001] The invention belongs to the field of hydroprocessing catalysts, and in particular relates to a grading method and application of a hydroprocessing catalyst. Background Art

[0002] Catalyst regeneration can be categorized as either in-situ or ex-situ. Due to its numerous drawbacks, in-situ regeneration is rarely used. Ex-situ regeneration requires a high-temperature carbonization step, leaving the metals in the catalyst mostly in an oxidized state. The catalyst's activity recovery after ex-situ regeneration depends on catalyst usage and regeneration level, typically reaching 75% to 95% of fresh catalyst activity.

[0003] Currently, the global petroleum and chemical industries generate 700,000 to 900,000 tons of spent catalysts annually, and this amount is constantly increasing. Hydroprocessing catalysts used in oil refining contain approximately 20% to 30% by weight of metals, such as molybdenum and nickel. Recycling these catalysts not only solves the problem of solid hazardous waste disposal, but also increases economic benefits and alleviates the shortage of metal mineral resources.

[0004] CN201180044418.7 provides a method for treating spent catalysts containing heavy metals, such as Group VIB and Group VIII metals. After deoiling the spent catalyst, the method treats the spent catalyst with an ammoniacal leach solution under conditions sufficient to dissolve the Group VIB and Group VIII metals in the ammoniacal leach solution, forming a leach slurry. After solid-liquid separation to recover the leach solution, the chemical precipitate and solids are re-slurried to produce an effluent stream containing ammonium sulfate (Amsul), ammonium sulfamate, Group VB metals, Group VIB metals, and Group VIII metals. Following sulfidation, the Group VIII metals are completely removed from the Amsul stream, while the Group VB and Group VI metals are partially removed. In a separate oxidative hydrolysis and iron precipitation step, an effective amount of ferric ions is added at a preselected pH to form insoluble complexes with the Group VB and Group VIB metals, which, through liquid-solid separation, produces an effluent ammonium sulfate stream containing less than 10 ppm of each Group VB and Group VIB metal.

[0005] Existing technologies often use strong acids and strong bases to treat deactivated hydroprocessing catalysts to recover the active metals therein. The post-processing steps are complex, energy-intensive, and polluting. The process is prone to produce toxic and harmful gases (such as carbon dioxide and hydrogen sulfide), and is highly destructive to the alumina support, thereby reducing the catalytic performance of the catalyst after reuse. Summary of the Invention

[0006] To address the shortcomings of the prior art, the present invention provides a grading method and application for hydroprocessing catalysts. The grading method improves the catalytic performance of distillate oil hydrogenation reaction systems, particularly the hydrodenitrogenation performance. Furthermore, the method allows the use of regenerated deactivated catalysts, eliminating the need for extensive treatment of the deactivated catalysts. This method offers the advantages of a simple, environmentally friendly process.

[0007] The first aspect of the present invention provides a grading method for the reuse of hydroprocessing catalysts. The grading method comprises: arranging N hydroprocessing catalysts along the direction of logistics; that is, the first hydroprocessing catalyst to the Nth hydroprocessing catalyst; wherein N ≥ 2, preferably N ≥ 3, and more preferably N is 3-5; the activity of the downstream hydroprocessing catalyst is greater than the activity of its adjacent upstream hydroprocessing catalyst. That is, the first hydroprocessing catalyst along the direction of logistics is the first hydroprocessing catalyst, and so on. The active metal of each hydroprocessing catalyst includes a Group VIB metal and / or a Group VIII metal; the weight ratio of the Group VIB metal to the Group VIII metal in the downstream hydroprocessing catalyst is greater than the weight ratio of the Group VIB metal to the Group VIII metal in the adjacent upstream hydroprocessing catalyst, and the active metal is calculated as oxide; in each hydroprocessing catalyst, the weight ratio of the Group VIB metal to the Group VIII metal, calculated as oxide, is 2-12.

[0008] According to the present invention, the activity of the hydroprocessing catalyst is adjusted by increasing or decreasing the mass content of the active metal as oxide. Furthermore, along the flow direction, the mass content of the active metal as oxide of two adjacent hydroprocessing catalysts differs by at least 1.5 percentage points, preferably by at least 1.5 to 20 percentage points, and more preferably by 1.5 to 15 percentage points.

[0009] According to the present invention, each hydroprocessing catalyst comprises a support and an active metal; the support is a porous refractory oxide. Preferably, the support comprises at least one of alumina and silica. The active metal comprises a Group VIB metal and / or a Group VIII metal; preferably, the active metal comprises at least one of W, Mo, Ni, and Co, with Mo and Ni being preferred.

[0010] According to the present invention, further, in each hydroprocessing catalyst, the weight ratio of the Group VIB metal to the Group VIII metal, calculated as oxide, is 2 to 12, preferably 2 to 8.

[0011] According to the present invention, the weight ratio of the Group VIB metal to the Group VIII metal in two adjacent hydroprocessing catalysts differs by 0.1 to 3, preferably by 0.3 to 2, in terms of active metal oxide.

[0012] According to the present invention, further, in each hydroprocessing catalyst, based on the mass of the catalyst, the mass content of molybdenum oxide is 3 wt% to 40 wt%, and the mass content of nickel oxide is 1 wt% to 10 wt%.

[0013] According to the present invention, further, in the first hydroprocessing catalyst, based on the mass of the catalyst, the mass content of molybdenum oxide is 3 wt% to 20 wt%, and the mass content of nickel oxide is 1 wt% to 4 wt%.

[0014] According to the present invention, further, in two adjacent hydroprocessing catalysts, the mass content of active metals, calculated as oxides, of molybdenum oxide differs by at least 1.5 percentage points, preferably 1.5 to 12 percentage points, and the mass content of nickel oxide differs by at least 0.2 percentage points, preferably 0.3 to 3 percentage points.

[0015] According to the present invention, each hydroprocessing catalyst further contains carbon; based on the mass of the catalyst, the carbon mass content is 1 wt% to 9 wt%.

[0016] According to the present invention, the preparation method of each hydroprocessing catalyst is as follows: the deactivated hydroprocessing catalyst is first subjected to an oxidation treatment, so that the mass content of sulfur in the deactivated hydroprocessing catalyst after treatment is reduced by 20wt% to 80wt%, preferably by 25wt% to 65wt%, and more preferably by 30wt% to 60wt% compared to the mass content of sulfur in the deactivated hydroprocessing catalyst before treatment; then, the treated material is subjected to the methods of leaching active metals and leaching active metals and impregnating loaded active metals to prepare each hydroprocessing catalyst. When leaching active metals, the leaching liquid is an acidic solution and / or an alkaline solution, which is used to reduce the amount of active metals on the deactivated hydroprocessing catalyst after treatment. When impregnating loaded active metals, the leaching liquid is an leaching liquid containing active metals, preferably a liquid phase material containing active metals obtained after leaching active metals, which is used to increase the amount of active metals on the deactivated hydroprocessing catalyst after treatment. In the grading method, the requirements for active metal content in each level of hydroprocessing catalyst are different, and the amount of leached active metal or the amount of leached active metal and the amount of impregnated loaded active metal can be used to adjust the amount of hydroprocessing catalyst to obtain each level.

[0017] According to the present invention, in the preparation method, the oxidation treatment can be a conventional oxidation treatment method in the prior art, and the oxidant used can be one or more of oxygen, air, humid air, a gas mixture containing oxygen, hydrogen peroxide, and sodium chlorate, preferably air or a gas mixture containing oxygen.

[0018] According to the present invention, in the preparation method, the oxidation treatment is a low-temperature heat treatment in an oxygen-containing atmosphere, the treatment temperature is 150-400°C, preferably 150-350°C, and more preferably 200-320°C; the treatment time is 0.5-10h, preferably 1-8h, and more preferably 2-5h.

[0019] According to the present invention, in the preparation method, the sulfur content in the deactivated hydrogenation catalyst before treatment is 4wt% to 16wt%, preferably 6wt% to 13wt%; the carbon content in the deactivated hydrogenation catalyst before treatment is 1wt% to 10wt%, preferably 1wt% to 6wt%, wherein the sulfur content is calculated by sulfur mass, and the carbon content is calculated by carbon mass, based on the weight of the deactivated hydrogenation catalyst.

[0020] According to the present invention, in the preparation method, the deactivated hydrogenation catalyst before treatment or the deactivated hydrogenation catalyst after treatment uses alumina as a carrier and contains a Group VIB metal and a Group VIII metal as active components, the Group VIB metal is at least molybdenum, and the Group VIII metal is at least nickel.

[0021] According to the present invention, in the preparation method, based on the weight of the deactivated hydrogenation catalyst before treatment, the mass content of molybdenum calculated as molybdenum oxide is 3wt% to 40wt%, preferably 15wt% to 30wt%; the mass content of nickel calculated as nickel oxide is 1wt% to 10wt%, preferably 2wt% to 7wt%.

[0022] According to the present invention, the first to N-1 hydroprocessing catalysts can be prepared as needed by controlling the amount of leaching active metals, specifically comprising the following steps:

[0023] (1) The deactivated hydrotreating catalyst is subjected to oxidation treatment;

[0024] (2) using an acidic solution and / or an alkaline solution as a leaching liquid to leach the deactivated hydroprocessing catalyst after the oxidation treatment in step (1); separating the leached material to obtain a liquid material and a solid material; then impregnating the solid material with a solution containing Ni, and using the solid material to prepare any hydroprocessing catalyst from the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst.

[0025] According to the present invention, preferably, the Nth hydroprocessing catalyst is prepared by a method of leaching active metals and impregnating loaded active metals, specifically comprising the following steps:

[0026] (1) The deactivated hydrotreating catalyst is subjected to oxidation treatment;

[0027] (2) using an acidic solution and / or an alkaline solution as a leaching solution to leach the deactivated hydroprocessing catalyst after the oxidation treatment in step (1); separating the leached material to obtain a liquid material and a solid material;

[0028] (3) The liquid material of step (2) is concentrated to obtain an impregnation liquid, and the dried solid material obtained in step (2) and / or any one of the first hydroprocessing catalyst to the N-1 hydroprocessing catalyst is used as a precursor, and the precursor is impregnated with the impregnation liquid to obtain the Nth hydroprocessing catalyst.

[0029] According to the present invention, preferably, the preparation method of the first hydroprocessing catalyst to the Nth hydroprocessing catalyst comprises the following steps:

[0030] (1) The deactivated hydrotreating catalyst is first subjected to oxidation treatment;

[0031] (2) using an acidic solution and / or an alkaline solution as a leaching liquid to leach the deactivated hydroprocessing catalyst after the oxidation treatment in step (1); the leaching is performed at least once; the material after each leaching treatment is separated to obtain a liquid material and a solid material; wherein, a portion of the solid material obtained after each leaching treatment is impregnated with a solution containing Ni and used to prepare the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst, and the other portion is used as a raw material for further leaching and / or a precursor raw material for step (3);

[0032] (3) Concentrating at least a portion of the liquid material obtained in each leaching step (2) to form an impregnation liquid, and using a dried product of any solid material obtained in step (2) and / or any hydroprocessing catalyst from the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst as a precursor, and impregnating the precursor with the impregnation liquid to obtain the Nth hydroprocessing catalyst.

[0033] According to the present invention, further, the deactivated hydroprocessing catalyst described in step (1) is a hydroprocessing catalyst that has been unloaded by gas stripping. If the gas stripping time is long or the temperature is high before unloading, the pretreatment temperature can be appropriately lowered; at the same time, when the oxidation treatment temperature is high, the treatment time can be appropriately shortened.

[0034] According to the present invention, further, the oxidation treatment in step (1) is a heat treatment of the deactivated hydroprocessing catalyst in a flowing, oxygen-containing atmosphere (preferably air).

[0035] According to the present invention, further, the acidic solution or alkaline solution in step (2) contains at least one of phosphate and organic acid radicals. The phosphate-containing substances include, but are not limited to, one or more of phosphoric acid, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, and hydroxyphosphoric acid; the organic acid-containing substances include, but are not limited to, one or more of oxalic acid, citric acid, tartaric acid, malic acid, ascorbic acid, ammonium oxalate, and ammonium citrate. The solute in the acidic solution or alkaline solution is preferably at least one of phosphoric acid, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, oxalic acid, citric acid, tartaric acid, and malic acid. Furthermore, aqueous ammonia can also be added to the leaching solution.

[0036] According to the present invention, further, in step (2), the concentration of phosphate in the acidic solution or alkaline solution is 0.002 to 0.2 mol / L, preferably 0.005 to 0.1 mol / L; the concentration of organic acid radical is 0.005 to 0.5 mol / L, preferably 0.01 to 0.2 mol / L.

[0037] According to the present invention, further, in step (2), the volume ratio of the amount (mass) of the deactivated hydroprocessing catalyst to the leaching liquid is 1 g / (2-20) ml, preferably 1 g / (2-10) ml; the leaching temperature is 60-120° C., preferably 90-110° C.; and the leaching time is 30-150 min, preferably 60-120 min.

[0038] According to the present invention, further, in the step (2), the leaching times are 1 to 6 times, preferably 1 to 3 times, and the leaching liquid, operating conditions, etc. used in each leaching can be the same or different.

[0039] According to the present invention, further, the separation in step (2) is carried out by filtration, and the filtration can be carried out at an appropriate temperature, for example, at an extraction temperature of 60 to 120°C, preferably 80 to 100°C.

[0040] According to the present invention, in step (2), preferably, the solid material obtained by the first leaching of active metals is partially used to prepare the N-1 hydroprocessing catalyst, and then the solid material obtained by the first leaching of active metals is subjected to a second leaching of active metals using an acidic solution and / or an alkaline solution as the leaching liquid. The solid material obtained by the second leaching of active metals is partially used to prepare the N-2 hydroprocessing catalyst. Similarly, the preparation of the upstream catalyst along the logistics direction in the grading method can be prepared by using the solid material used in the preparation of the adjacent downstream catalyst as a precursor and further leaching using an acidic solution and / or an alkaline solution as the leaching liquid.

[0041] According to the present invention, in step (2), when the solid material obtained after leaching the active metal is used to prepare the first hydroprocessing catalyst to the N-1 hydroprocessing catalyst, the solid material is dried and calcined to obtain the corresponding hydroprocessing catalyst. The calcination temperature is 300-650°C, preferably 400-500°C, and the time is 0.5-8h, preferably 1-4h. The drying temperature is 60-200°C, preferably 100-160°C, and the time is 0.5-10h, preferably 1-4h. The drying and calcination atmosphere is one or more of air atmosphere, inert atmosphere (such as nitrogen, rare gas), reducing atmosphere (such as hydrogen), water vapor atmosphere and vacuum atmosphere. The calcination atmosphere is preferably an inert atmosphere (such as nitrogen, rare gas). Preferably, when the active metal is leached multiple times during the preparation process of the hydroprocessing catalyst, the solid material obtained by the last leaching of the active metal is dried and calcined.

[0042] According to the present invention, in step (2), the nickel-containing solution has a nickel oxide content of 0.5 to 5 g / 100 mL, calculated as oxide. The nickel-containing solution impregnation process can be a single impregnation or multiple impregnations, preferably a single impregnation; and can be an excess impregnation or an equal volume impregnation, preferably an equal volume impregnation.

[0043] According to the present invention, the impregnation liquid for preparing the Nth hydroprocessing catalyst in step (3) can be a liquid material containing active metals obtained by leaching active metals in the process of preparing any hydroprocessing catalyst from the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst in step (2), or can be a liquid material obtained by mixing liquid materials containing active metals obtained by leaching active metals in the process of preparing multiple hydroprocessing catalysts from the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst.

[0044] According to the present invention, in step (3), when preparing the Nth hydroprocessing catalyst, it is preferred to use the N-1th hydroprocessing catalyst as a precursor, or to use the dried solid material of the N-1th hydroprocessing catalyst before calcination as a precursor. The precursor is then impregnated with the impregnation solution described in step (3) to produce the Nth hydroprocessing catalyst.

[0045] According to the present invention, the concentration process in step (3) can be carried out by evaporation or the like. The evaporation can be natural evaporation. To improve efficiency and save energy, an MVR multi-effect evaporator or a permeable membrane can also be used for concentration.

[0046] According to the present invention, the concentrated active metal leachate in step (3) further comprises a Group VIB metal content of 10 g to 80 g / 100 mL, preferably 10 g to 60 g / 100 mL, and a Group VIII metal content of 1 g to 15 g / 100 mL, preferably 2 g to 10 g / 100 mL. The metal concentration in the leachate of step (3) can also be adjusted by additionally adding Ni.

[0047] According to the present invention, in step (3), when preparing the Nth hydroprocessing catalyst, it is necessary to dry and / or roast it after impregnation. The temperature of the roasting is 300-650°C, preferably 400-500°C, and the time is 0.5-8h, preferably 1-4h. The temperature of the drying is 60-200°C, preferably 100-160°C, and the time is 0.5-10h, preferably 1-4h. The drying and roasting atmosphere is one or more of air atmosphere, inert atmosphere (such as nitrogen, rare gas), reducing atmosphere (such as hydrogen), water vapor atmosphere and vacuum atmosphere. The roasting atmosphere is preferably an inert atmosphere (such as nitrogen, rare gas). Preferably, when the Nth hydrogenation catalyst is impregnated multiple times during preparation, drying and / or roasting are performed after the last impregnation.

[0048] According to the present invention, further, in the step (3), the impregnation process can be a single impregnation or multiple impregnations, preferably a single impregnation; it can be an excess impregnation or an equal volume impregnation, preferably an equal volume impregnation.

[0049] The second aspect of the present invention provides the application of the catalyst grading method in distillate oil hydroprocessing reaction.

[0050] According to the present invention, the feedstock oil is sequentially contacted with the catalysts loaded according to the above-mentioned grading method to carry out a hydroprocessing reaction.

[0051] According to the present invention, the application method can process a variety of distillate oil feedstocks. The feedstock oil for the reaction includes at least one of diesel, VGO, CGO, and DAO. The main properties of the feedstock oil are as follows: an initial boiling point greater than or equal to 180°C, preferably 180-320°C, a final boiling point less than or equal to 750°C, preferably 500-700°C; a density of 0.8100-0.9600 / g·cm -3 (20℃); nitrogen content is 100~5000μg·g -1 ; The sulfur mass content is 0.05wt% to 4.0wt%.

[0052] According to the present invention, the reaction conditions are as follows: the reaction pressure is 3MPa to 20MPa, preferably 8MPa to 17MPa, the liquid hourly volume space velocity is 0.2h -1 ~4.0h -1 , preferably 0.8h-1 ~2.0h -1 The reaction temperature is 260°C to 430°C, preferably 300°C to 400°C. The hydrogen to oil volume ratio is 200 to 2000.

[0053] Compared with the prior art, the main advantages of the present invention are:

[0054] In the grading method of the present invention, the weight ratio of Group VIB and Group VIII metals in the upper reactor bed is greater than that in the lower bed, which can enhance the hydrogenation saturation capacity of the upper bed and is more conducive to improving the hydrogenation and denitrification capacity of the entire reaction system.

[0055] Due to the high chemical and thermal stability of MoS2 in deactivated hydroprocessing catalysts, the prior art generally employs high-temperature calcination in an oxygen-containing atmosphere or oxidation with a strong oxidant to completely oxidize the active metals, including MoS2, before leaching and recycling the active metals. Through in-depth research, the inventors of the present invention have discovered that after partial oxidation of the deactivated hydroprocessing catalyst (partially oxidizing the sulfide metals in the deactivated hydroprocessing catalyst), the active metals, including Mo, can be dissolved in the catalyst at a suitable temperature and in a leaching solution containing phosphate and organic acid radicals.

[0056] Further analysis shows that although pure MoS2 is difficult to leach, the hydroprocessing catalyst still contains a certain proportion of Ni and / or Co. The Ni and / or Co in the deactivated hydroprocessing catalyst may enter the MoS2 lattice, increasing the solubility of MoS2; at the same time, after partial oxidation treatment, the metal sulfide is partially oxidized, destroying the original sulfide structure, resulting in lattice distortion and defects; under the strong complexation of phosphate ions and / or organic acid ions, most of the active metals including molybdenum in the deactivated catalyst can be leached without the need for high-temperature calcination or the addition of oxidants such as hydrogen peroxide for complete oxidation.

[0057] Compared with existing technologies, this invention eliminates the need for extensive treatment of deactivated catalysts, offers simple steps, a green process, and achieves recycling of metals and carriers. During the leaching of active metals from deactivated catalysts, the introduction of multiple leaching aids not only facilitates metal leaching but also redisperses the active metals, improving catalyst performance. The resulting high-metal-content catalyst exhibits higher activity, making it more suitable for use in high-temperature zones and enhancing reaction system performance. The grading method of this invention can improve the catalytic performance, particularly denitrification performance, of distillate oil hydrogenation reaction systems. DETAILED DESCRIPTION

[0058] The preparation effects of the present invention are further illustrated below through examples and comparative examples. It should be understood that the specific embodiments described are only intended to illustrate and explain the present invention and are not intended to limit the present invention.

[0059] In the present invention, % refers to mass percentage unless otherwise specified.

[0060] In the present invention and the following examples and comparative examples, the deactivated hydroprocessing catalyst was obtained from a hydrocracking pretreatment unit at a refinery. Mo and Ni contents were determined by spectrophotometry according to Q / SH 361 925. Sulfur and carbon contents in the deactivated catalyst were determined using high-frequency combustion infrared absorption method according to HG / T 5594-2019.

[0061] In the present invention, the deactivated hydroprocessing catalyst in each example uses alumina as a support. The composition excluding the support is shown in Table 1.

[0062] Table 1 Composition of deactivated hydrotreating catalyst

[0063] <![CDATA[Mo, calculated as MoO3, wt%]]> Ni is calculated as NiO, wt% C, wt% S, wt% 20.5 3.6 5.25 8.83

[0064] In the present invention, the hydrodesulfurization and hydrodenitrogenation activities of each catalyst are expressed as the hydrodesulfurization and hydrodenitrogenation activities relative to the reference agent (Comparative Example 1), respectively. The relative hydrodesulfurization activity (RVA(S)) and relative hydrodenitrogenation activity (RVA(N)) of the catalyst are calculated according to formula (1) and formula (2), respectively:

[0065]

[0066]

[0067] In formula (1) and formula (2), k(S) and k(N) represent the hydrodesulfurization and hydrodenitrogenation activities of the catalyst, respectively; k(DS) and k(DN) represent the hydrodesulfurization and hydrodenitrogenation activities of the reference agent (Comparative Example 1), respectively.

[0068] In formula (1) and formula (2), Ssp is the sulfur content in the reaction product of the evaluation catalyst used; Ssf is the sulfur content in the reaction raw material used; Sdp is the sulfur content in the reaction product of the reference agent; Nsp is the nitrogen content in the reaction product of the evaluation catalyst used; Nsf is the nitrogen content in the reaction raw material used; Ndp is the nitrogen content in the reaction product of the reference agent, where the sulfur content and nitrogen content are expressed in mass fraction.

[0069] Example 1

[0070] (1) The sample obtained after the deactivated hydroprocessing catalyst was oxidized was recorded as CA; the oxidation treatment was a low-temperature heat treatment in an air atmosphere, the treatment temperature was 230°C, the treatment time was 3 hours, and the mass content of sulfur element was reduced by 36%.

[0071] (2) A mixed solution containing 0.02 mol / L phosphoric acid and 0.03 mol / L citric acid was used as the leaching solution to immerse the CA sample. The weight of the CA leached was 1 g / 4 mL. The leaching temperature was 100°C, and the leaching time was 60 min. The solution was stirred to maintain a fluid state during the leaching process.

[0072] (3) After leaching, the catalyst precursor was filtered and designated CA1, and the filtrate was designated CY1. A portion of CA1 was dried at 120°C for 3 h. The resulting sample was designated CA1-1. A solution containing 1.1 g / 100 mL of nickel nitrate was prepared. This solution was used as the impregnation solution for an equal volume of CA1-1. The solution was dried at 130°C for 3 h and calcined at 430°C for 2 h to obtain a second hydroprocessing catalyst designated C1. The calcination and drying atmospheres were both nitrogen.

[0073] (4) Take part of CA1 for leaching. The composition of the leaching solution is the same as that of the leaching solution in step (2). The weight ratio of the impregnated CA1 to the volume of the leaching solution is 1g / 4mL. The leaching temperature is 100℃, the leaching time is 120min, and the solution is kept in a flowing state by stirring during the leaching process. After the leaching is completed, the solution is filtered and the obtained catalyst precursor is recorded as CA2 and the filtrate is recorded as CY2. CA2 is dried at 120℃ for 3h to obtain a sample recorded as CA2-1. A solution is prepared with nickel nitrate, with a nickel oxide content of 1.7g / 100mL. This solution is used as the leaching solution to immerse CA2-1 in equal volume, dried at 130℃ for 3h, and roasted at 480℃ for 2h to obtain the first hydroprocessing catalyst recorded as C2. The roasting and drying atmospheres are both nitrogen atmospheres.

[0074] (5) The filtrate CY1 from step (3) and the filtrate CY2 from step (4) were mixed and evaporated to remove excess water. The resulting concentrated active metal solution, wherein the molybdenum oxide metal content was 35.5 g / 100 mL and the nickel oxide metal content was 5.2 g / 100 mL, was used as an impregnation solution for impregnation of CA1-1 in equal volumes. After impregnation, the sample was dried at 130° C. for 3 h and calcined at 400° C. for 2 h to obtain a third hydroprocessing catalyst, designated C3. The calcination and drying atmospheres were both nitrogen.

[0075] The catalyst composition and loading scheme of this example are shown in Table 2.

[0076] Table 2 Catalyst composition and loading scheme

[0077]

[0078] Example 2

[0079] (1) The sample obtained after the deactivated hydroprocessing catalyst was oxidized was recorded as CB; the oxidation treatment was a low-temperature heat treatment in an air atmosphere at a temperature of 270° C. for 3 h, and the mass content of sulfur was reduced by 50%.

[0080] (2) A mixed solution containing 0.05 mol / L diammonium hydrogen phosphate and 0.15 mol / L oxalic acid was used as the leaching solution to immerse the sample CB. The weight of the CB to the volume of the leaching solution was 1 g / 3 mL. The leaching temperature was 90°C and the leaching time was 90 min. The solution was stirred to maintain a fluid state during the leaching process.

[0081] (3) After leaching, the catalyst precursor was filtered and designated as CB1, and the filtrate was designated as CY3. A portion of CB1 was dried at 120°C for 3 h. The resulting sample was designated as CB1-1. A solution containing 1.1 g / 100 mL of nickel nitrate was prepared. CB1-1 was impregnated with an equal volume of this solution. The solution was dried at 130°C for 3 h and calcined at 420°C for 2 h to obtain a second hydroprocessing catalyst designated as C4. The calcination and drying atmospheres were both nitrogen.

[0082] (4) Take part of CB1 and leach it. The composition of the leachate is the same as that of the leachate in step (2). The weight ratio of the impregnated CB1 to the volume of the leachate is 1g / 3mL. The leachate temperature is 90℃, the leachate time is 120min, and the solution is kept in a flowing state by stirring during the leachate process. After the leachate is completed, the solution is filtered and the obtained catalyst precursor is recorded as CB2 and the filtrate is recorded as CY4. CB2 is dried at 120℃ for 3h to obtain a sample recorded as CB2-1. A solution is prepared with nickel nitrate, with a nickel oxide content of 1.0g / 100mL. CB2-1 is impregnated with an equal volume of this solution as the leachate, dried at 130℃ for 3h, and roasted at 460℃ for 2h to obtain the first hydroprocessing catalyst recorded as C5. The roasting and drying atmospheres are both nitrogen atmospheres.

[0083] (5) The filtrate CY3 from step (3) and the filtrate CY4 from step (4) were mixed and evaporated to remove excess water. The resulting concentrated active metal solution, wherein the molybdenum oxide metal content was 27.7 g / 100 mL and the nickel oxide metal content was 4.1 g / 100 mL, was used as the impregnation solution to impregnate an equal volume of CB1-1. The leached sample was dried at 120° C. for 3 h and calcined at 400° C. for 2 h to obtain a third catalyst, designated C6. The calcination and drying atmospheres were both nitrogen.

[0084] The catalyst composition and loading scheme of this example are shown in Table 3.

[0085] Table 3 Catalyst composition and loading scheme

[0086]

[0087]

[0088] Example 3

[0089] (1) The sample obtained after the deactivated hydroprocessing catalyst was oxidized was recorded as CC; the oxidation treatment was a low-temperature heat treatment in an air atmosphere at a temperature of 280° C. for 2 h, and the mass content of sulfur was reduced by 43%.

[0090] (2) Sample CC was impregnated with a mixed solution containing 0.04 mol / L ammonium dihydrogen phosphate and 0.05 mol / L tartaric acid. The weight of the impregnated CC and the volume of the leaching solution were 1 g / 5 mL. The leaching temperature was 95°C and the leaching time was 60 min. The solution was stirred to maintain a fluid state during the leaching process.

[0091] (3) After leaching, the catalyst precursor was filtered and designated CC1, and the filtrate was designated CY5. A portion of CC1 was dried at 120°C for 3 h. The resulting sample was designated CC1-1. A solution containing 1.1 g / 100 mL of nickel nitrate was prepared. This solution was used as the impregnation solution for an equal volume of CB1-1. The solution was dried at 130°C for 3 h and calcined at 420°C for 2 h to obtain a second hydroprocessing catalyst designated C7. The calcination and drying atmospheres were both nitrogen.

[0092] (4) Take part of CC1 and leach the metal. A mixed solution containing 0.02 mol / L phosphoric acid and 0.03 mol / L malic acid is used as the leachate. The weight of the impregnated CC1 and the volume ratio of the leachate are 1 g / 5 mL. The leachate temperature is 95 ° C, the leachate time is 120 min, and the solution is kept in a flowing state by stirring during the leachate process. After the leachate is completed, the catalyst precursor is recorded as CC2 and the filtrate is recorded as CY6. CC2 is dried at 120 ° C for 3 h, and the obtained sample is recorded as CC2-1. A solution is prepared with nickel nitrate, with a nickel oxide content of 1.6 g / 100 mL. CC2-1 is impregnated with an equal volume of this solution as the leachate, dried at 130 ° C for 3 h, and calcined at 450 ° C for 2 h to obtain a third hydroprocessing catalyst recorded as C8. The calcination and drying atmospheres are both nitrogen atmospheres.

[0093] (5) The filtrate CY5 from step (3) and the filtrate CY6 from step (4) were mixed and evaporated to remove excess water. The resulting concentrated active metal solution, wherein the molybdenum oxide metal content was 30.4 g / 100 mL and the nickel oxide metal content was 4.8 g / 100 mL, was used as an impregnation solution to impregnate CC1-1 in equal volumes. The impregnation sample was dried at 120° C. for 3 h and calcined at 400° C. for 2 h to obtain a third hydroprocessing catalyst, designated C9. The calcination and drying atmospheres were both nitrogen atmospheres.

[0094] The catalyst composition and loading scheme of this example are shown in Table 4.

[0095] Table 4 Catalyst composition and loading scheme

[0096]

[0097] Example 4

[0098] (1) The sample obtained after the deactivated hydroprocessing catalyst was oxidized was recorded as CD; the oxidation treatment was a low-temperature heat treatment in an air atmosphere at a temperature of 230°C for 3 hours, and the mass content of sulfur was reduced by 36%.

[0099] (2) A mixed solution containing 0.02 mol / L phosphoric acid and 0.02 mol / L citric acid was used as the leaching solution to immerse the CD sample. The weight of the CD sample to the volume of the leaching solution was 1 g / 4 mL. The leaching temperature was 100°C and the leaching time was 60 min. The solution was stirred to maintain a fluid state during the leaching process.

[0100] (3) After leaching, the catalyst precursor was filtered and designated CD1, and the filtrate was designated CY7. A portion of CD1 was dried at 120°C for 3 h. The resulting sample was designated CD1-1. A solution containing 1.1 g / 100 mL of nickel nitrate was prepared. This solution was used as the impregnation solution to impregnate CD1-1 in equal volumes. The solution was dried at 130°C for 3 h and calcined at 430°C for 2 h to obtain a third hydroprocessing catalyst designated C10. Both calcination and drying were performed in a nitrogen atmosphere.

[0101] (4) Take part of CD1 for leaching. The composition of the leaching solution is the same as that of the leaching solution in step (2). The weight ratio of the impregnated CD1 to the volume of the leaching solution is 1g / 4mL. The leaching temperature is 100℃, the leaching time is 120min, and the solution is kept in a flowing state by stirring during the leaching process. After the leaching is completed, the solution is filtered and the obtained catalyst precursor is recorded as CD2 and the filtrate is recorded as CY8. CD2 is dried at 120℃ for 3h to obtain a sample recorded as CD2-1. A solution is prepared with nickel nitrate, with a nickel oxide content of 1.7g / 100mL. This solution is used as the leaching solution to immerse CD2-1 in equal volume, dried at 130℃ for 3h, and calcined at 480℃ for 2h to obtain a second hydroprocessing catalyst recorded as C11. The calcination and drying atmospheres are both nitrogen atmospheres.

[0102] (5) A portion of CD2 was leached. A mixed solution containing 0.06 mol / L phosphoric acid and 0.1 mol / L oxalic acid was used as the leaching solution. The weight of CD2 to be leached and the volume ratio of the leaching solution were 1 g / 3 mL. The leaching temperature was 100°C and the leaching time was 120 min. The solution was stirred to maintain a fluid state during the leaching process. After the leaching was completed, the solution was filtered. The obtained catalyst precursor was recorded as CD3 and the filtrate was recorded as CY9.

[0103] A portion of CD3 was dried at 120°C for 3 hours. The resulting sample was designated CD3-1. A nickel nitrate solution with a nickel oxide content of 1.7 g / 100 mL was used as the impregnation solution for CD3-1. The solution was then dried at 130°C for 3 hours. The resulting sample was then dried at 120°C for 3 hours and calcined at 480°C for 2 hours to obtain the first catalyst, designated C12. Both the calcination and drying atmospheres were nitrogen.

[0104] (6) The filtrate CY7 from step (3), the filtrate CY8 from step (4), and the filtrate CY9 from step (5) were mixed and evaporated to remove excess water. The resulting concentrated active metal solution, wherein the molybdenum oxide metal content was 33.2 g / 100 mL and the nickel oxide metal content was 4.6 g / 100 mL, was used as an impregnation solution to impregnate CD1-1 in equal volumes, dried at 150° C. for 3 h, and calcined at 410° C. for 2 h to obtain a fourth hydroprocessing catalyst, designated C13. The calcination and drying atmospheres were both nitrogen atmospheres.

[0105] The catalyst composition and loading scheme of this example are shown in Table 5.

[0106] Table 5 Catalyst composition and loading scheme

[0107]

[0108] Comparative Example 1

[0109] In an air atmosphere, the deactivated catalyst in Table 1 was heated at 200°C for 1.5 hours, 320°C for 3 hours, and 410°C for 3 hours to obtain the charred regenerated catalyst ZS. Its properties are shown in Table 6. An impregnation solution containing 1.1 g of nickel oxide per 100 mL was prepared using nickel nitrate and used to impregnate ZS. The resulting sample was dried at 120°C for 3 hours and calcined at 430°C for 2 hours. The resulting catalyst is designated ZS-1. The catalyst composition and loading scheme for this example are shown in Table 6.

[0110] Table 6 Catalyst composition and loading scheme

[0111]

[0112] Comparative Example 2

[0113] The difference from Example 1 is that the deactivated hydroprocessing catalyst (same as Example 1, properties see Table 1) was subjected to oxidation treatment. The oxidation treatment was performed at a high temperature of 490°C for 3 hours in an air atmosphere, reducing the sulfur content by 95%. The remaining treatment conditions were the same as in Example 1. Three catalysts were prepared: C2-1, C1-1, and C3-1.

[0114] The catalyst composition and loading scheme of this example are shown in Table 7.

[0115] Table 7 Catalyst composition and loading scheme

[0116]

[0117] Test Case

[0118] The catalyst activity evaluation experiment was carried out on a small hydrogenation unit, and the catalyst was pre-sulfurized before the activity evaluation. The catalyst evaluation conditions were a total reaction pressure of 14.0 MPa and a liquid hourly space velocity of 1.0 h -1 The hydrogen-to-oil volume ratio was 900:1. In Examples 1, 2, 3, Comparative Examples 1, and 2, the temperature of bed 1 was 350°C, the temperature of bed 2 was 370°C, and the temperature of bed 3 was 390°C. In Example 4, the temperature of bed 1 was 350°C, the temperature of bed 2 was 350°C, the temperature of bed 3 was 370°C, and the temperature of bed 4 was 390°C. The properties of the feedstock oil used in the activity evaluation experiments are shown in Table 8, and the activity evaluation results are shown in Table 9.

[0119] Table 8 Properties of crude oil

[0120] crude oil <![CDATA[Density (20 °C), g / cm 3 > 0.9185 Sulfur content, wt% 1.95 Nitrogen content, μg / g 1382 Distillation range, ℃ IBP / EBP 301 / 597

[0121] Table 9 Catalyst activity evaluation results

[0122]

[0123] The evaluation results in Table 9 show that compared with Comparative Examples 1 and 2, the hydrodesulfurization and hydrodenitrogenation activities of the examples of the present invention were significantly improved, particularly the hydrodenitrogenation activity. Furthermore, the total metal content of the catalyst systems of the examples of the present invention was lower than that of the comparative examples (comparing Example 1 with Comparative Example 2), resulting in a higher utilization efficiency of active metals. This demonstrates that the catalyst grading method of the present invention is beneficial for improving the application effect of the entire catalyst system.

Claims

1. A grading method for a hydroprocessing catalyst, comprising: N hydroprocessing catalysts are arranged along the direction of the logistics; That is, the first hydroprocessing catalyst to the Nth hydroprocessing catalyst; wherein N ≥ 2, preferably N ≥ 3, and more preferably N is 3-5; the activity of the downstream hydroprocessing catalyst is greater than the activity of its adjacent upstream hydroprocessing catalyst; the active metals of each hydroprocessing catalyst include a Group VIB metal and a Group VIII metal; the weight ratio of the Group VIB metal to the Group VIII metal in the downstream hydroprocessing catalyst is greater than the weight ratio of the Group VIB metal to the Group VIII metal in the adjacent upstream hydroprocessing catalyst, the active metals being calculated as oxides; and the weight ratio of the Group VIB metal to the Group VIII metal in each hydroprocessing catalyst, calculated as oxides, is 2-12.

2. The method according to claim 1, characterized in that The active metals are calculated as oxides, and the weight ratio of the Group VIB metal to the Group VIII metal in two adjacent hydroprocessing catalysts differs by 0.1 to 3, preferably by 0.3 to 2.

3. The method according to claim 1, characterized in that The active metal includes at least one of W, Mo, Ni, and Co, preferably Mo and Ni; Further preferably, in each hydroprocessing catalyst, based on the mass of the catalyst, the mass content of molybdenum oxide is 3wt% to 40wt%, and the mass content of nickel oxide is 1wt% to 10wt%; More preferably, in the first hydroprocessing catalyst, based on the mass of the catalyst, the mass content of molybdenum oxide is 3 wt% to 20 wt%, and the mass content of nickel oxide is 1 wt% to 4 wt%.

4. The method according to claim 3, characterized in that For two adjacent hydroprocessing catalysts, the mass content of active metals, calculated as oxides, of molybdenum oxide differs by at least 1.5 percentage points, preferably 1.5 to 12 percentage points, and the mass content of nickel oxide differs by at least 0.2 percentage points, preferably 0.3 to 3 percentage points.

5. The method according to claim 1, characterized in that: Each hydroprocessing catalyst also contains carbon; based on the mass of the catalyst, the carbon mass content is 1wt% to 9wt%.

6. The method according to claim 1, characterized in that The preparation method of each hydroprocessing catalyst is as follows: the deactivated hydroprocessing catalyst is first subjected to an oxidation treatment so that the mass content of sulfur in the deactivated hydroprocessing catalyst after the treatment is reduced by 20wt% to 80wt% compared with the mass content of sulfur in the deactivated hydroprocessing catalyst before the treatment; then, the treated material is subjected to the methods of leaching active metals and leaching active metals and impregnation loading active metals to prepare each hydroprocessing catalyst.

7. The method according to claim 6, characterized in that The oxidant used in the oxidation treatment is one or more of oxygen, air, moist air, a gas mixture containing oxygen, hydrogen peroxide, and sodium chlorate, preferably air or a gas mixture containing oxygen.

8. The method according to claim 1, 6 or 7, characterized in that: The oxidation treatment is a low-temperature heat treatment in an oxygen-containing atmosphere, the treatment temperature is 150-400°C, preferably 150-350°C, more preferably 200-320°C; the treatment time is 0.5-10h, preferably 1-8h, more preferably 2-5h.

9. The method according to claim 6, characterized in that: Based on the weight of the deactivated hydrogenation catalyst before treatment, the mass content of molybdenum calculated as molybdenum oxide is 3wt% to 40wt%, preferably 15wt% to 30wt%; the mass content of nickel calculated as nickel oxide is 1wt% to 10wt%, preferably 2wt% to 7wt%.

10. The method according to claim 1 or 6, characterized in that: The preparation method of the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst comprises the following steps: (1) The deactivated hydrotreating catalyst is subjected to oxidation treatment; (2) using an acidic solution and / or an alkaline solution as a leaching liquid to leach the deactivated hydroprocessing catalyst after the oxidation treatment in step (1); separating the leached material to obtain a liquid material and a solid material; then impregnating the solid material with a solution containing Ni, and using the solid material to prepare any one of the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst; And / or, a method for preparing an Nth hydroprocessing catalyst, comprising the following steps: (1) The deactivated hydrotreating catalyst is subjected to oxidation treatment; (2) using an acidic solution and / or an alkaline solution as a leaching solution to leach the deactivated hydroprocessing catalyst after the oxidation treatment in step (1); separating the leached material to obtain a liquid material and a solid material; (3) The liquid material of step (2) is concentrated to obtain an impregnation liquid, and the dried solid material obtained in step (2) and / or any one of the first hydroprocessing catalyst to the N-1 hydroprocessing catalyst is used as a precursor, and the precursor is impregnated with the impregnation liquid to obtain the Nth hydroprocessing catalyst.

11. The method according to claim 6 or 10, characterized in that: Preferably, the preparation method of the first to Nth hydroprocessing catalysts comprises the following steps: (1) The deactivated hydrotreating catalyst is first subjected to oxidation treatment; (2) using an acidic solution and / or an alkaline solution as a leaching solution to leach the deactivated hydroprocessing catalyst after the oxidation treatment in step (1); the leaching is performed at least once; the material after each leaching treatment is separated to obtain a liquid material and a solid material; wherein, a portion of the solid material obtained after each leaching treatment is immersed in a solution containing Ni and used to prepare the first hydroprocessing catalyst to the N-1 hydroprocessing catalyst, and the other portion is used as a raw material for further leaching and / or a precursor raw material for step (3); (3) Concentrating at least a portion of the liquid material obtained in each leaching step (2) to form an impregnation liquid, and using a dried product of any solid material obtained in step (2) and / or any hydroprocessing catalyst from the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst as a precursor, and impregnating the precursor with the impregnation liquid to obtain the Nth hydroprocessing catalyst.

12. The method according to claim 10 or 11, characterized in that: The acidic solution or alkaline solution in step (2) contains at least one of phosphate and organic acid radical; Further preferably, the concentration of phosphate in the acidic solution or alkaline solution in step (2) is 0.02 to 1 mol / L, preferably 0.05 to 0.5 mol / L; the concentration of organic acid radical is 0.01 to 1 mol / L, preferably 0.01 to 0.3 mol / L; Further preferably, in step (2), the volume ratio of the amount (mass) of the deactivated hydroprocessing catalyst to the leaching liquid is 1 g / (2-20) ml, preferably 1 g / (2-10) ml; the leaching temperature is 60-120° C., preferably 90-110° C.; the leaching time is 30-150 min, preferably 60-120 min; More preferably, in step (2), the leaching times are 1 to 6 times, preferably 1 to 3 times; More preferably, in the step (2), the content of nickel oxide in the solution containing Ni is 0.5 to 5 g / 100 mL, calculated as oxide.

13. The method according to claim 10 or 11, characterized in that: The active metal leachate after concentration in step (3) has a Group VIB metal content of 10 g to 80 g / 100 mL, preferably 10 g to 60 g / 100 mL; and a Group VIII metal content of 1 g to 15 g / 100 mL, preferably 2 g to 10 g / 100 mL; and / or, in step (3), when preparing the Nth hydroprocessing catalyst, drying and / or calcination is required after impregnation; Furthermore, the calcination temperature is 300-650°C, preferably 400-500°C, and the calcination time is 0.5-8h, preferably 1-4h; Furthermore, the drying temperature is 60-200° C., preferably 100-160° C., and the drying time is 0.5-10 h, preferably 1-4 h; Furthermore, the drying and calcining atmosphere is one or more of air atmosphere, inert atmosphere, reducing atmosphere, water vapor atmosphere and vacuum atmosphere.

14. Use of the catalyst grading method according to any one of claims 1 to 13 in distillate oil hydroprocessing reactions.

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