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, wherein the activity of a downstream hydrotreating catalyst is greater than that of an upstream hydrotreating catalyst adjacent to the downstream hydrotreating catalyst; the preparation method of each hydrotreating catalyst comprises the following steps: firstly, carrying out oxidation treatment on the inactivated hydrotreating catalyst, so that the mass content of a sulfur element in the treated inactivated hydrotreating catalyst is reduced by 20wt%-80wt% compared with the mass content of the sulfur element in the untreated inactivated hydrotreating catalyst; and then preparing the hydrotreating catalysts from the treated material through active metal leaching and active metal leaching and active metal dipping and loading methods respectively. According to the grading method, the regenerated deactivated catalyst is used, deep treatment on the deactivated catalyst is not needed, the grading method has the advantages of simple steps and green process, and meanwhile, the catalytic performance of a distillate oil hydrogenation reaction system can be 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] During use, the activity of hydroprocessing catalysts gradually decreases, a phenomenon known as catalyst deactivation. The causes can generally be categorized as coking deactivation (causing blockage of catalyst pores), poisoning deactivation (causing poisoning of the catalyst's acidic centers), and sintering deactivation (causing changes in the catalyst's crystal phase). The main causes of industrial hydrogenation catalyst deactivation are coke formation and metal clogging, migration or aggregation of active metal components, changes in phase composition, a decrease in the number of active centers, carrier sintering, and zeolite structural collapse. Deactivated catalysts caused by carbon deposition can be regenerated to restore their activity, but deactivated catalysts caused by metal deposition cannot be regenerated to restore their activity and must be discarded.

[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] CN105709853B discloses a method for recycling spent hydroprocessing catalysts. The spent hydroprocessing catalyst is degreased and ground into a powder. Calcium and iron deposits are washed away with hydrochloric acid. Chlorine and air are then introduced to react, producing chlorides or oxychlorides of metals such as molybdenum, nickel, cobalt, or vanadium. The metals are then volatilized to separate the gas and solid phases. The metals are condensed and recovered from the gas phase. The solid residue is washed with water or an acidic solution, dried, kneaded with an extrusion aid and a binder, and calcined in a nitrogen atmosphere to produce an alumina-carbon composite support.

[0005] 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.

[0006] 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

[0007] To address the shortcomings of existing technologies, the present invention provides a grading method and application for hydroprocessing catalysts. The grading method utilizes regenerated deactivated catalysts, eliminating the need for extensive treatment of the deactivated catalysts. This method offers the advantages of simple steps and a green process, while also improving the catalytic performance of distillate oil hydroprocessing systems.

[0008] The first aspect of the present invention provides a grading method for a hydroprocessing catalyst. 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 to 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 activity of the hydroprocessing catalyst is adjusted by increasing or decreasing the mass content of the active metal in terms of oxide. Preferably, along the direction of logistics, the mass content of the active metal in terms of oxide of two adjacent hydroprocessing catalysts differs by at least 3 percentage points, preferably by at least 3 to 20 percentage points, and preferably by 3 to 15 percentage points. 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%, preferably by 25wt% to 65wt%, and more preferably by 30wt% to 60wt% compared with the mass content of sulfur in the deactivated hydroprocessing catalyst before the treatment; and then the treated material is subjected to leaching of active metals and leaching of active metals and impregnation of loaded active metals to prepare each hydroprocessing catalyst.

[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, based on the mass of the catalyst, the mass content of molybdenum oxide is 5 wt% to 40 wt%, and the mass content of nickel oxide is 1 wt% to 10 wt%.

[0011] 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 5 wt% to 20 wt%, and the mass content of nickel oxide is 1 wt% to 4 wt%.

[0012] 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 3 percentage points, preferably 3 to 12 percentage points, and the mass content of nickel oxide differs by at least 0.5 percentage points, preferably 0.5 to 3 percentage points.

[0013] 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%.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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%.

[0020] 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:

[0021] (1) The deactivated hydrotreating catalyst is subjected to oxidation treatment;

[0022] (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;

[0023] The obtained solid material is used to prepare any one of the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst.

[0024] 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:

[0025] (1) The deactivated hydrotreating catalyst is subjected to oxidation treatment;

[0026] (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;

[0027] (3) The liquid material of step (2) is concentrated to obtain an impregnation liquid, and then the dried solid material obtained in step (2) and / or any one of the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst is impregnated to obtain the Nth hydroprocessing catalyst.

[0028] According to the present invention, preferably, the preparation method of the first hydroprocessing catalyst to the Nth hydroprocessing catalyst comprises the following steps:

[0029] (1) The deactivated hydrotreating catalyst is first subjected to oxidation treatment;

[0030] (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, and 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 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);

[0031] (3) Concentrating at least a portion of the liquid material obtained in each leaching in step (2) to prepare an Nth hydroprocessing catalyst, and then impregnating the dried solid material obtained in step (2) and / or any hydroprocessing catalyst from the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst.

[0032] 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.

[0033] 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).

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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, and then impregnate the above precursor with the impregnation solution described in step (3) to obtain the Nth hydroprocessing catalyst.

[0043] 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.

[0044] According to the present invention, further, 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.

[0045] 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 an air atmosphere, an inert atmosphere (such as nitrogen, a rare gas), a reducing atmosphere (such as hydrogen), a water vapor atmosphere, and a vacuum atmosphere. The roasting atmosphere is preferably an inert atmosphere (such as nitrogen, a rare gas). Preferably, when the Nth hydroprocessing catalyst is impregnated multiple times during preparation, drying and / or roasting are performed after the last impregnation.

[0046] 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.

[0047] The second aspect of the present invention provides the application of the catalyst grading method in distillate oil hydroprocessing reaction.

[0048] 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.

[0049] 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%.

[0050] 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.

[0051] Compared with the prior art, the main advantages of the present invention are:

[0052] 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.

[0053] 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.

[0054] 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 of distillate oil hydrogenation reaction systems, particularly their denitrification and desulfurization performance. DETAILED DESCRIPTION

[0055] The preparation effects of the present invention are further illustrated below by way of 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.

[0056] In the present invention, % refers to mass percentage unless otherwise specified.

[0057] 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.

[0058] 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.

[0059] Table 1 Composition of deactivated hydrotreating catalyst

[0060] <![CDATA[Mo, calculated as MoO3, wt%]]> Ni is calculated as NiO, wt% C, wt% S, wt% 20.8 3.7 5.37 9.12

[0061] 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:

[0062]

[0063]

[0064] 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.

[0065] 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.

[0066] Example 1

[0067] (1) The sample obtained after the deactivated hydroprocessing catalyst was oxidized was recorded as CZ; the oxidation treatment was a low-temperature heat treatment in an air atmosphere at a temperature of 230° C. for 3 h, and the mass content of sulfur was reduced by 35%.

[0068] (2) A mixed solution containing 0.03 mol / L phosphoric acid and 0.02 mol / L citric acid was used as the leaching solution to immerse the CZ sample. The weight of the CZ sample was 1 g / 3 mL of the leaching solution. 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.

[0069] (3) After leaching, the catalyst precursor was filtered and designated CZ1, and the filtrate was designated CY1. A portion of CZ1 was dried at 120°C for 3 h, resulting in a sample designated CZ1-1. This was then calcined at 420°C for 2 h to obtain a second hydroprocessing catalyst designated C1. Both calcination and drying were performed in a nitrogen atmosphere.

[0070] (4) Take part of CZ1 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 CZ1 to the volume of the leaching solution is 1g / 3mL. 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 CZ2 and the filtrate is recorded as CY2. CZ2 is dried at 120℃ for 3h and calcined at 420℃ for 2h to obtain the first hydroprocessing catalyst recorded as C2. The calcination and drying atmospheres are both nitrogen atmospheres.

[0071] (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 33.5 g / 100 mL and the nickel oxide metal content was 5.1 g / 100 mL, was used as an impregnation solution for impregnation of CZ1-1 in equal volumes. The impregnation sample was dried at 130° C. for 3 h and calcined at 450° C. for 2 h to obtain a third hydroprocessing catalyst, designated C3. The calcination and drying atmospheres were both nitrogen atmospheres.

[0072] The catalyst composition and loading scheme of this example are shown in Table 2.

[0073] Table 2 Catalyst composition and loading scheme

[0074]

[0075] Example 2

[0076] (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 280°C, the treatment time was 3 hours, and the mass content of sulfur element was reduced by 55%.

[0077] (2) A mixed solution containing 0.01 mol / L diammonium hydrogen phosphate and 0.1 mol / L oxalic acid was used as the leaching solution to immerse the CA sample. The weight of the CA leached was 1 g / 3.5 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.

[0078] (3) After leaching, the catalyst precursor was filtered and designated CA1, and the filtrate was designated CY3. A portion of CA1 was dried at 120°C for 3 h, resulting in a sample designated CA1-1. This sample was then calcined at 420°C for 2 h to obtain a second hydroprocessing catalyst designated C4. Both the calcination and drying atmospheres were nitrogen.

[0079] (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 / 3mL. The leaching temperature is 95℃, the leaching time is 100min, 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 CY4. CA2 is dried at 120℃ for 3h and calcined at 450℃ for 2h to obtain the first hydroprocessing catalyst recorded as C5. The calcination and drying atmospheres are both nitrogen atmospheres.

[0080] (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, containing 32.5 g / 100 mL of molybdenum oxide and 4.9 g / 100 mL of nickel oxide, was used as the impregnation solution for impregnation of CA1-1 in equal volumes. The impregnation sample was dried at 120°C for 3 h to obtain a third hydroprocessing catalyst designated C6. The drying atmosphere was nitrogen.

[0081] The catalyst composition and loading scheme of this example are shown in Table 3.

[0082] Table 3 Catalyst composition and loading scheme

[0083]

[0084] Example 3

[0085] (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 280° C. for 2 h, and the mass content of sulfur was reduced by 45%.

[0086] (2) A mixed solution containing 0.01 mol / L ammonium dihydrogen phosphate and 0.05 mol / L tartaric acid was used as the leaching solution to immerse the sample CB. The weight of the CB leached was 1 g / 5 mL. The leaching temperature was 90°C and the leaching time was 70 min. The solution was stirred to maintain a fluid state during the leaching process.

[0087] (3) After leaching, the catalyst precursor was filtered and designated CB1, and the filtrate was designated CY5. A portion of CB1 was dried at 120°C for 3 h, resulting in a sample designated CB1-1. This was then calcined at 400°C for 2 h to obtain a second hydroprocessing catalyst designated C7. Both the calcination and drying atmospheres were nitrogen.

[0088] (4) Take part of CB1 and perform leaching. A mixed solution containing 0.05 mol / L phosphoric acid and 0.02 mol / L malic acid is used as the leaching solution. The weight of the impregnated CB1 and the volume ratio of the leaching solution is 1 g / 5 mL. The leaching temperature is 100 ° C, the leaching time is 100 min, 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 CB2 and the filtrate is recorded as CY6. CB2 is dried at 120 ° C for 3 h and calcined at 460 ° C for 2 h to obtain the first hydrotreatment catalyst recorded as C8. The calcination and drying atmospheres are both nitrogen atmospheres.

[0089] (5) Filtrate CY5 from step (3) and filtrate CY6 from step (4) were mixed and evaporated to remove excess water. The resulting concentrated active metal solution, containing 29.3 g / 100 mL of molybdenum oxide and 4.4 g / 100 mL of nickel oxide, was used as the impregnation solution for an equal volume of CB1-1. The impregnation sample was dried at 120°C for 3 h. The resulting third hydroprocessing catalyst was designated C9. The drying atmosphere was nitrogen.

[0090] The catalyst composition and loading scheme of this example are shown in Table 4.

[0091] Table 4 Catalyst composition and loading scheme

[0092]

[0093] Example 4

[0094] (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 4 hours, and the mass content of sulfur was reduced by 60%.

[0095] (2) Sample CC was impregnated in a mixture of 0.01 mol / L phosphoric acid and 0.1 mol / L oxalic acid. The weight of the impregnated CC and the volume of the leaching solution were 1 g / 4 mL. The leaching temperature was 80°C and the leaching time was 60 min. The solution was stirred to maintain fluidity during the leaching process.

[0096] (3) After leaching, the catalyst precursor was filtered and designated CC1, and the filtrate was designated CY7. A portion of CC1 was dried at 120°C for 3 h, resulting in a sample designated CC1-1. This was then calcined at 430°C for 2 h to obtain a third hydroprocessing catalyst designated C10. Both the calcination and drying atmospheres were nitrogen.

[0097] (4) Take part of CC1 and perform 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 CC1 to the volume of the leaching solution is 1g / 4mL. The leaching temperature is 90℃, the leaching time is 80min, 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 CC2 and the filtrate is recorded as CY8. CC2 is dried at 120℃ for 3h and calcined at 450℃ for 2h to obtain a second hydroprocessing catalyst recorded as C11. The calcination and drying atmospheres are both nitrogen atmospheres.

[0098] (5) Take part of CC2 and perform 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 CC2 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 CC3 and the filtrate is recorded as CY9. CC3 is dried at 120℃ for 3h and calcined at 450℃ for 2h to obtain the first hydroprocessing catalyst recorded as C12. The calcination and drying atmospheres are both nitrogen atmospheres.

[0099] (6) Filtrate CY7 from step (3), filtrate CY8 from step (4), and 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 30.5 g / 100 mL and the nickel oxide metal content was 4.5 g / 100 mL, was used as the impregnation solution to impregnate CC1-1 in equal volumes. The impregnation sample was dried at 150° C. for 3 h. The resulting fourth hydroprocessing catalyst was designated C13. The drying atmosphere was nitrogen.

[0100] The catalyst composition and loading scheme of this example are shown in Table 5.

[0101] Table 5 Catalyst composition and loading scheme

[0102]

[0103] Comparative Example 1

[0104] 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. The catalyst composition and loading scheme for this example are shown in Table 6.

[0105] Table 6 Catalyst composition and loading scheme

[0106]

[0107] Comparative Example 2

[0108] The difference from Example 1 is that the deactivated hydroprocessing catalyst (same as Example 1, properties shown in Table 1) was subjected to oxidation treatment. The oxidation treatment was performed at a high temperature of 500°C and for 3 hours in an air atmosphere, resulting in a 96% reduction in the mass content of elemental sulfur. Other treatment conditions were the same as in Example 1.

[0109] The catalyst composition and loading scheme of this example are shown in Table 7.

[0110] Table 7 Catalyst composition and loading scheme

[0111]

[0112] Test Case

[0113] 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 15.0 MPa and a liquid hourly space velocity of 1.2 h -1 The hydrogen-to-oil volume ratio was 1000:1. 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.

[0114] Table 8 Properties of crude oil

[0115] crude oil <![CDATA[Density (20 °C), g / cm 3 > 0.9262 Sulfur content, wt% 1.81 Nitrogen content, μg / g 1563 Distillation range, ℃ IBP / EBP 305 / 589

[0116] Table 9 Catalyst activity evaluation results

[0117]

[0118] The evaluation results in Table 9 show that the hydrodesulfurization and hydrodenitrogenation activities of the examples of the present invention were significantly improved compared to those of Comparative Examples 1 and 2. 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 the 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 flow, i.e., the first hydroprocessing catalyst to the Nth hydroprocessing catalyst; wherein N ≥ 2, preferably N ≥ 3, and more preferably N is 3 to 5; the activity of the downstream hydroprocessing catalyst is greater than the activity of its adjacent upstream hydroprocessing catalyst; preferably, along the direction of the flow, the mass content of active metals in terms of oxides of two adjacent hydroprocessing catalysts differs by at least 3 percentage points; 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; and then the treated material is subjected to leaching of active metals and leaching of active metals and impregnation of loaded active metals to prepare each hydroprocessing catalyst.

2. The method according to claim 1, characterized in that The mass content of sulfur in the treated deactivated hydrogenation catalyst is reduced by 25 wt% to 65 wt% compared to the mass content of sulfur in the deactivated hydrogenation catalyst before treatment, and preferably reduced by 30 wt% to 60 wt%.

3. The method according to claim 1, characterized in that Along the logistics direction, the mass content of active metals in two adjacent hydroprocessing catalysts calculated as oxides differs by at least 3 to 20 percentage points, preferably by 3 to 15 percentage points.

4. The method according to claim 1, 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.

5. The method according to claim 1, 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.

6. The method according to claim 1, characterized in that The sulfur content of the deactivated hydrogenation catalyst before treatment is 4wt% to 16wt%, preferably 6wt% to 13wt%; the carbon content of 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.

7. The method according to claim 1, characterized in that: In the grading method, the active metal of each hydroprocessing catalyst includes a Group VIB metal and / or a Group VIII metal; preferably, the active metal includes at least one of W, Mo, Ni, and Co, preferably Mo and Ni; More preferably, based on the mass of the catalyst, the mass content of molybdenum oxide is 5wt% to 40wt%, and the mass content of nickel oxide is 1wt% to 10wt%; Further preferably, in the first hydroprocessing catalyst, based on the mass of the catalyst, the mass content of molybdenum oxide is 5wt% to 20wt%, and the mass content of nickel oxide is 1wt% to 4wt%; Further preferably, each hydroprocessing catalyst further contains carbon; based on the mass of the catalyst, the carbon mass content is 1 wt% to 9 wt%; It is further preferred that, along the logistics direction, the mass content of active metals in two adjacent hydroprocessing catalysts, calculated as oxides, differ by at least 3 percentage points, preferably 3 to 12 percentage points, in molybdenum oxide, and by at least 0.5 percentage points, preferably 0.5 to 3 percentage points, in nickel oxide.

8. The method according to claim 1, 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%.

9. The method according to claim 1 or 7, 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; and using the obtained 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 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 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; the dried solid material obtained in step (2) and / or any one of the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst is used as a precursor, and the precursor is impregnated with the impregnation liquid to obtain the Nth hydroprocessing catalyst.

10. The method according to claim 9, characterized in that: The preparation method of the first hydroprocessing catalyst to the Nth hydroprocessing catalyst 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 liquid to leach the deactivated hydroprocessing catalyst after the oxidation treatment in step (1), the leaching is performed at least once, and 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 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); (3) Concentrating at least a portion of the liquid material obtained in each leaching in step (2) to form an impregnation liquid, 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; preferably, using a dried product of the solid material obtained after the first leaching treatment and / or the N-1th hydroprocessing catalyst as a precursor.

11. The method according to claim 9 or 10, characterized in that: The acidic solution or alkaline solution contains at least one of phosphate and organic acid radicals; the phosphate-containing substance is selected from one or more of phosphoric acid, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, and hydroxyphosphoric acid; the organic acid radical-containing substance is selected from one or more of oxalic acid, citric acid, tartaric acid, malic acid, ascorbic acid, ammonium oxalate, and ammonium citrate.

12. The method according to any one of claims 1, 9 and 10, characterized in that: When preparing any of the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst from the solid material obtained after the leaching treatment, 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 calcination time is 0.5-8h, preferably 1-4h; The drying temperature is 60-200°C, preferably 100-160°C, and the drying time is 0.5-10h, preferably 1-4h; The drying and calcining atmosphere is one or more of air atmosphere, inert atmosphere, reducing atmosphere, water vapor atmosphere and vacuum atmosphere; the calcining atmosphere is preferably inert atmosphere.

13. The method according to claim 9, characterized in that: The active metal impregnation solution 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.

14. The method according to any one of claims 1, 9 and 13, characterized in that: When preparing the Nth hydroprocessing catalyst, the impregnation is followed by drying and / or calcination; 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 drying time is 0.5-10h, preferably 1-4h; The drying and calcining atmosphere is one or more of air atmosphere, inert atmosphere, reducing atmosphere, water vapor atmosphere and vacuum atmosphere; the calcining atmosphere is preferably inert atmosphere.

15. Use of the method according to any one of claims 1 to 14 in distillate oil hydrotreating reaction.

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