Grading method and application of regenerated catalyst

Abstract

The invention discloses a grading method and application of a regenerated 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 preparation method of the catalyst comprises the following steps: carrying out oxidation treatment on an inactivated hydrogenation catalyst, so that the mass content of a sulfur element in the treated inactivated hydrogenation catalyst is reduced by 20wt%-80wt% compared with the mass content of the sulfur element in the untreated inactivated hydrogenation catalyst; then, preparing hydrotreating catalysts from the treated material by a method of leaching active metal and a method of leaching the active metal and impregnating and loading the active metal respectively; in each hydrotreating catalyst, the content of molybdenum oxide is 5wt%-40wt%, the content of nickel oxide is 1wt%-10wt%, and the content of cobalt oxide is 0.5 wt%-5wt%. The method is used in a distillate oil hydrogenation reaction, and the catalytic performance, especially the hydrodesulfurization performance, of a hydrogenation reaction system 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 regenerated catalyst. Background Art

[0002] The increasing demand for engine fuels is encouraging petrochemical and coal chemical companies to use heavy residual oil or coal liquefaction products as starting materials. Given increasingly stringent environmental regulations on emissions, fuel quality requirements are rapidly shifting towards lower sulfur and nitrogen emissions and cleaner fuels. The demand for catalysts capable of deep desulfurization and denitrification continues to increase, while the disposal of deactivated catalysts has become a prominent issue. Direct disposal poses environmental risks due to the presence of water-soluble transition metal ions, and the catalyst itself is relatively expensive. Therefore, the regeneration of deactivated hydrogenation catalysts has attracted widespread attention from both industry and academia. Improving the activity of regenerated hydrogenation catalysts not only has significant social benefits but also brings significant economic benefits to refineries.

[0003] CN201610893952.X discloses a method for regenerating a deactivated catalyst for oil hydrogenation. The method uses steam to remove oil from the deactivated catalyst. The deactivated catalyst is then added to an acid solution, along with a flux. The volume ratio of acid to flux is 1:0.01-0.05, and the solid-to-liquid ratio is 1:1-2.5. Stirring is initiated and the solution is heated to 80-90°C for 2-4 hours. After the reaction, impurities are removed by filtration. The flux comprises one of polyoxyethylene alkyl alcohol ether and polyoxyethylene alkyl phenol ether. The solution is then adjusted to a pH of 2-4 with alkali solution, and residual impurities are removed by filtration to obtain a nickel solution. The prepared nickel solution and sodium carbonate solution are then added concurrently to a reactor for reaction. After neutralization, the solution is filtered and washed until free of acid ions, then dried, roasted, reduced, cooled, and solidified to form the catalyst. Under certain process conditions, the catalyst prepared by this method can hydrogenate palm oil from an initial iodine value of 42.8 to a value below 1.0.

[0004] CN201010514360.5 discloses a method for regenerating a deactivated hydroprocessing catalyst. The method comprises: pre-treating the deactivated hydroprocessing catalyst to remove oil, removing metal impurities deposited in the deactivated catalyst, and charring the deactivated catalyst. Removing the metal impurities deposited in the deactivated catalyst involves impregnating the deactivated catalyst with an alkaline solution, filtering, and then acid-washing. This method not only removes metal impurities such as nickel, vanadium, and iron deposited in the deactivated hydroprocessing catalyst, restoring the catalyst's pore structure and catalytic performance, but also features low investment, minimal pollution, a simple process, and ease of industrialization.

[0005] CN201180044418.7 discloses a method for treating spent catalysts containing heavy metals, such as Group VIB and Group VIII metals. After deoiling the spent catalyst, the spent catalyst is treated 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 the prior art, the present invention provides a catalyst grading method and application. The grading method utilizes regenerated deactivated catalyst, eliminating the need for extensive catalyst treatment. This method offers the advantages of simple steps and a green process. It can also improve the catalytic performance of distillate oil hydrogenation reaction systems, particularly hydrodesulfurization performance.

[0008] The first aspect of the present invention provides a grading method for regenerating a 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 preparation method of each hydroprocessing catalyst is: 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% compared with the mass content of sulfur in the deactivated hydroprocessing catalyst before treatment, preferably by 25wt% to 65wt%, and more preferably by 30wt% to 60wt%; then, each hydroprocessing catalyst is prepared by leaching active metals and leaching active metals and impregnating loaded active metals from the treated materials.

[0009] 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 between two adjacent hydroprocessing catalysts differs by at least 3 percentage points, preferably by at least 4 to 20 percentage points, and more preferably by 4 to 15 percentage points.

[0010] 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, Ni, and Co being preferred.

[0011] According to the present invention, further, in each hydroprocessing catalyst, based on the mass of the catalyst, the mass content of molybdenum oxide is 5wt% to 40wt%, the mass content of nickel oxide is 1wt% to 10wt%, and the mass content of cobalt oxide is 0.5wt% to 5wt%.

[0012] 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 8wt% to 30wt%, the mass content of nickel oxide is 1wt% to 6wt%, and the mass content of cobalt oxide is 0.5wt% to 4wt%.

[0013] According to the present invention, further, in two adjacent hydroprocessing catalysts, the active metals are calculated as oxides, the mass content of molybdenum oxide differs by at least 3 percentage points, preferably 3 to 12 percentage points, the mass content of nickel oxide differs by at least 0.5 percentage points, preferably 0.5 to 3 percentage points, and the mass content of cobalt oxide differs by at least 0.4 percentage points, preferably 0.4 to 2 percentage points.

[0014] 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%.

[0015] 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 leaching of active metals and leaching of active metals and impregnation loading of active metals to prepare each hydroprocessing catalyst. When leaching the active metals, the leaching liquid is an acidic solution and / or an alkaline solution, which is used to reduce the amount of active metal on the deactivated hydroprocessing catalyst after treatment. When impregnating the loaded active metals, the leaching liquid is an leaching liquid containing active metals, preferably a liquid phase material containing active metals obtained after leaching the active metals, which is used to increase the amount of active metal 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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%.

[0021] 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:

[0022] (1) The deactivated hydrotreating catalyst is subjected to oxidation treatment;

[0023] (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 material after the leaching treatment to obtain a liquid material and a solid material; and loading the obtained solid material with Co element 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 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;

[0027] (3) The liquid material of step (2) is concentrated and then a Co source is introduced 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 impregnation liquid is used to impregnate the precursor 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; 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 loaded with Co element and used to prepare the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst, and the other portion is used as the raw material for re-leaching and / or the precursor raw material of step (3);

[0031] (3) Concentrating at least a portion of the liquid material obtained in each leaching step (2) and then introducing a Co source as 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.

[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 and / or 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 Co in step (2) comes from a soluble Co salt. In step (2), the method for loading the Co element can be an impregnation method. That is, the solid material is impregnated with a Co source solution. In the Co source solution, the content of cobalt oxide is 1 to 20 g / 100 mL, preferably 2 to 10 g / 100 mL, calculated as oxide. The impregnation 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.

[0042] According to the present invention, the Co source in step (3) is a soluble Co salt.

[0043] According to the present invention, the impregnation liquid for preparing the Nth hydroprocessing catalyst in step (3) can be a liquid phase 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) (with a Co source added as needed), or can be a liquid phase material obtained by mixing liquid phase 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 (with a Co source added as needed).

[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, further, in the impregnation solution after the Co source is introduced in step (3), the content of molybdenum oxide is 10g~80g / 100mL, the content of nickel oxide is 1g~15g / 100mL, and the content of cobalt oxide is 1g~20g / 100mL.

[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] 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.

[0055] 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.

[0056] 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 Co-containing 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 desulfurization performance, of distillate oil hydrogenation reaction systems. DETAILED DESCRIPTION

[0057] 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.

[0058] In the present invention, % refers to mass percentage unless otherwise specified.

[0059] 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.

[0060] 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.

[0061] Table 1 Composition of deactivated hydrotreating catalyst

[0062] <![CDATA[Mo, calculated as MoO3, wt%]]> Ni is calculated as NiO, wt% C, wt% S, wt% 21.3 3.8 4.48 9.42

[0063] 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:

[0064]

[0065]

[0066] 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.

[0067] 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.

[0068] Example 1

[0069] (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 240°C, the treatment time was 3 hours, and the mass content of sulfur element was reduced by 38%.

[0070] (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 / 4.5 mL. The leaching temperature was 85°C, and the leaching time was 60 min. The solution was stirred to maintain a fluid state during the leaching process.

[0071] (3) After leaching, the catalyst precursor was filtered and designated as CA1, and the filtrate was designated as CL1. A portion of CA1 was dried at 120°C for 3 h. The resulting sample was designated as CA1-1. A solution containing 4.0 g / 100 mL of cobalt nitrate was prepared. This solution was used as the impregnation solution to impregnate CA1-1 in equal volumes. The solution was dried at 130°C for 3 h and calcined at 450°C for 2 h to obtain a second hydroprocessing catalyst designated as C1. The calcination and drying atmospheres were both nitrogen.

[0072] (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 of the impregnated CA1 and the volume ratio of the leaching solution is 1g / 4.5mL. 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 CL2. CA2 is dried at 120℃ for 3h to obtain a sample recorded as CA2-1. A solution is prepared with cobalt nitrate, and the cobalt oxide content is 2.5g / 100mL. This solution is used as the leaching solution to immerse CA2-1 in equal volume, dried at 130℃ for 3h, and roasted at 450℃ for 2h to obtain the first hydroprocessing catalyst recorded as C2. The roasting and drying atmospheres are both nitrogen atmospheres.

[0073] (5) The filtrate CL1 from step (3) and the filtrate CL2 from step (4) were mixed, and excess water was evaporated to obtain a concentrated active metal solution. Cobalt nitrate was further added to the solution to obtain a Co-containing impregnation solution having a molybdenum oxide metal content of 25.3 g / 100 mL, a nickel oxide metal content of 4.5 g / 100 mL, and a cobalt oxide content of 6.3 g / 100 mL. This solution was used as the impregnation solution to impregnate CA1-1 in equal volumes. After impregnation, the 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.

[0074] The catalyst composition and loading scheme of this example are shown in Table 2.

[0075] Table 2 Catalyst composition and loading scheme

[0076]

[0077] Example 2

[0078] (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 290° C. for 3 h, and the mass content of sulfur was reduced by 60%.

[0079] (2) A mixed solution containing 0.02 mol / L phosphoric acid and 0.02 mol / L ammonium citrate was used as the leaching solution to immerse the sample CB. The weight of the CB leached was 1 g / 4 mL. The leaching temperature was 90°C and the leaching time was 120 min. The solution was stirred to maintain a fluid state during the leaching process.

[0080] (3) After leaching, the catalyst precursor was filtered and recorded as CB1, and the filtrate was recorded as CL3. A portion of CB1 was dried at 120°C for 3 hours and further calcined at 420°C for 2 hours. The obtained sample was recorded as CB1-1. A cobalt-containing aqueous solution was prepared with cobalt nitrate, with a cobalt oxide content of 3.7 g / 100 mL. This solution was used as the impregnation solution to impregnate CB1-1 in equal volume. The obtained sample was dried at 120°C for 3 hours and calcined at 460°C for 2 hours to obtain the second hydroprocessing catalyst recorded as C4. The calcination and drying atmospheres were both nitrogen atmospheres.

[0081] (4) Take part of CB1 and leach the metal. The composition of the leachate is the same as that of the leachate in step (2). The weight of the impregnated CB1 and the volume ratio of the leachate is 1g / 4mL. The leaching temperature is 95℃, 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 CB2 and the filtrate is recorded as CL4. Take part of CB2 and dry it at 120℃ for 3h and roast it at 450℃ for 2h. The obtained sample is recorded as CB2-1. Cobalt nitrate is used to prepare a cobalt-containing aqueous solution with a cobalt oxide content of 2.2g / 100mL. This solution is used as the leachate to impregnate CB2-1 in equal volume. The obtained sample is dried at 120℃ 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.

[0082] (5) The filtrate CL3 from step (3) and the filtrate CL4 from step (4) were mixed and evaporated to remove excess water. The resulting concentrated active metal solution was then further added with cobalt nitrate to obtain a Co-containing impregnation solution containing 22.4 g / 100 mL of molybdenum oxide, 3.8 g / 100 mL of nickel oxide, and 5.3 g / 100 mL of cobalt oxide. This solution was used as the impregnation solution to impregnate CB1-1 in equal volumes. The impregnation sample was dried at 120° C. for 3 h to obtain a third treated catalyst, designated C6. The drying atmosphere was nitrogen.

[0083] The catalyst composition and loading scheme of this example are shown in Table 3.

[0084] Table 3 Catalyst composition and loading scheme

[0085]

[0086] Example 3

[0087] (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 3 hours, and the mass content of sulfur was reduced by 55%.

[0088] (2) Sample CC was impregnated in a mixture of 0.1 mol / L phosphoric acid and 0.2 mol / L malic acid. The ratio of CC weight to leaching solution volume was 1 g / 4.5 mL. The leaching temperature was 90°C and the leaching time was 80 min. The solution was stirred to maintain fluidity during the leaching process.

[0089] (3) After leaching, the catalyst precursor was filtered and designated CC1, and the filtrate was designated CL5. A portion of CC1 was dried at 120°C for 3 h. The resulting sample was designated CC1-1. A solution containing 4.1 g / 100 mL of cobalt oxide was prepared using cobalt nitrate. This solution was used as the impregnation solution for an equal volume of CC1-1. The solution was dried at 130°C for 3 h and calcined at 400°C for 2 h to obtain a second hydroprocessing catalyst designated C7. The calcination and drying atmospheres were both nitrogen.

[0090] (4) Take part of CC1 and leach it, using a mixed solution containing 0.2 mol / L ammonium dihydrogen phosphate and 0.1 mol / L tartaric acid as the leachate. The weight of the impregnated CC1 and the volume ratio of the leachate are 1 g / 4.5 mL. The leachate temperature is 100 ° C, the leachate time is 110 min, and the solution is kept in a flowing state by stirring during the leachate process. After the leachate is completed, it is filtered and the obtained catalyst precursor is recorded as CC2, and the filtrate is recorded as CL6. CC2 is dried at 120 ° C for 3 h, and the obtained sample is recorded as CC2-1. A solution is prepared with cobalt nitrate, and the cobalt oxide content is 2.4 g / 100 mL. This solution is used as the leachate to impregnate CC2-1 in equal volume, dried at 130 ° C for 3 h, and calcined at 460 ° C for 2 h to obtain the third hydroprocessing catalyst recorded as C8. The calcination and drying atmospheres are both nitrogen atmospheres.

[0091] (5) The filtrate CL5 from step (3) and the filtrate CL6 from step (4) were mixed, and excess water was evaporated to remove the concentrated active metal solution. Cobalt nitrate was further added to the solution to obtain a Co-containing impregnation solution having a molybdenum oxide metal content of 23.8 g / 100 mL, a nickel oxide metal content of 3.9 g / 100 mL, and a cobalt oxide content of 6.0 g / 100 mL. This solution was used as the impregnation solution to impregnate CC1-1 in equal volumes. The impregnation sample was dried at 120° C. for 3 h to obtain a third hydroprocessing catalyst, designated C9. The drying atmosphere was air.

[0092] The catalyst composition and loading scheme of this example are shown in Table 4.

[0093] Table 4 Catalyst composition and loading scheme

[0094]

[0095] Example 4

[0096] (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, the treatment temperature was 240°C, the treatment time was 3 hours, and the mass content of sulfur element was reduced by 38%.

[0097] (2) A mixed solution containing 0.01 mol / L phosphoric acid and 0.03 mol / L citric acid was used as the leaching solution to immerse the CD sample. The ratio of the CD weight to the leaching solution volume was 1 g / 4.5 mL. The leaching temperature was 85°C and the leaching time was 60 min. The solution was stirred to maintain a fluid state during the leaching process.

[0098] (3) After leaching, the catalyst precursor was filtered and designated CD1, and the filtrate was designated CL7. A portion of CD1 was dried at 120°C for 3 h. The resulting sample was designated CD1-1. A solution containing 4.0 g / 100 mL of cobalt nitrate was prepared. This solution was used as the impregnation solution to impregnate CD1-1 in equal volumes. The solution was then dried at 130°C for 3 h and calcined at 450°C for 2 h to obtain a third hydroprocessing catalyst designated C10. Both the calcination and drying atmospheres were nitrogen.

[0099] (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 / 4.5mL. 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 CL8. CD2 is dried at 120℃ for 3h to obtain a sample recorded as CD2-1. A solution is prepared with cobalt nitrate, with a cobalt oxide content of 2.5g / 100mL. This solution is used as the leaching solution to immerse CD2-1 in equal volume, dried at 130℃ 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.

[0100] (5) Take CD2 in the example for leaching. A mixed solution containing 0.05 mol / L phosphoric acid and 0.1 mol / L oxalic acid is used as the leaching solution. The weight of the impregnated CD2 and the volume ratio of the leaching solution is 1 g / 4 mL. The leaching temperature is 100 ° C, the leaching time is 110 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 CD3 and the filtrate is recorded as CL9. Take part of CD3 and dry it at 120 ° C for 3 hours. The obtained sample is recorded as CD3-1. Cobalt nitrate is used to prepare a cobalt-containing aqueous solution with a cobalt oxide content of 1.8 g / 100 mL. CD3-1 is impregnated with equal volume. The obtained sample is dried at 120 ° C for 3 hours and calcined at 450 ° C for 2 hours to obtain the first hydroprocessing catalyst recorded as C12. The calcination and drying atmospheres are both nitrogen atmospheres.

[0101] (6) The filtrate CL7 of step (3) and the filtrate CL8 of step (4) were mixed with the filtrate CL9 of step (3). After evaporation to remove excess water, the concentrated active metal solution was further added with cobalt nitrate to obtain a Co-containing impregnation solution, wherein the molybdenum oxide metal content was 25.0 g / 100 mL, the nickel oxide metal content was 3.8 g / 100 mL, and the cobalt oxide content was 5.8 g / 100 mL. This solution was used as the impregnation solution to impregnate CD1-1 in equal volumes. The obtained sample was dried at 150° C. for 3 h and calcined at 450° C. for 2 h to obtain a fourth hydroprocessing catalyst, designated C13. The calcination and drying atmospheres were both nitrogen atmospheres.

[0102] The catalyst composition and loading scheme of this example are shown in Table 5.

[0103] Table 5 Catalyst composition and loading scheme

[0104]

[0105] Comparative Example 1

[0106] 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 5.1 g of cobalt oxide per 100 mL was prepared using cobalt nitrate. ZS was then impregnated with the resulting sample, which was then dried at 120°C for 3 hours and calcined at 410°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.

[0107] Table 6 Catalyst composition and loading scheme

[0108]

[0109] Comparative Example 2

[0110] 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.

[0111] The catalyst composition and loading scheme of this example are shown in Table 7.

[0112] Table 7 Catalyst composition and loading scheme

[0113]

[0114] Test Case

[0115] 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 1.3 h -1 , with a hydrogen-to-oil volume ratio of 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 temperatures of beds 1 and 2 were 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.

[0116] Table 8 Properties of crude oil

[0117] crude oil <![CDATA[Density (20 °C), g / cm 3 > 0.9221 Sulfur content, wt% 1.96 Nitrogen content, μg / g 1455 Distillation range, ℃ IBP / EBP 302 / 595

[0118] Table 9 Catalyst activity evaluation results

[0119]

[0120]

[0121] 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 hydrodesulfurization 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 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 regenerating a 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, 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; 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 leaching of active metals and leaching of active metals and impregnation of loaded active metals to prepare each hydroprocessing catalyst; In each hydroprocessing catalyst, based on the mass of the catalyst, the mass content of molybdenum oxide is 5wt% to 40wt%, the mass content of nickel oxide is 1wt% to 10wt%, and the mass content of cobalt oxide is 0.5wt% to 5wt%.

2. The method according to claim 1, characterized in that In the first hydroprocessing catalyst, based on the mass of the catalyst, the mass content of molybdenum oxide is 8wt% to 30wt%, the mass content of nickel oxide is 1wt% to 6wt%, and the mass content of cobalt oxide is 0.5wt% to 4wt%.

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 percentage points, preferably by at least 4 to 20 percentage points, preferably by 4 to 15 percentage points; Furthermore, 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; the mass content of nickel oxide differs by at least 0.5 percentage points, preferably 0.5 to 3 percentage points; and the mass content of cobalt oxide differs by at least 0.4 percentage points, preferably 0.4 to 2 percentage points.

4. The method according to claim 1, characterized in that In each hydroprocessing catalyst, based on the mass of the catalyst, the mass content of molybdenum oxide is 5wt% to 40wt%, the mass content of nickel oxide is 1wt% to 10wt%, and the mass content of cobalt oxide is 0.5wt% to 5wt%.

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 oxidant for 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; And / or, 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.

7. 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%.

8. The method according to claim 1 or 3, 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 material after the leaching treatment to obtain a liquid material and a solid material; and loading the obtained solid material with Co element 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 and then a Co source is introduced 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 impregnation liquid is used to impregnate the precursor to obtain the Nth hydroprocessing catalyst.

9. The method according to claim 8, 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; 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 loaded with Co element and used to prepare the first hydroprocessing catalyst to the N-1th hydroprocessing catalyst, and the other portion is used as the raw material for re-leaching and / or the precursor raw material of step (3); (3) Concentrating at least a portion of the liquid material obtained in each leaching in step (2) and then introducing a Co source as 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.

10. The method according to claim 8 or 9, characterized in that: The acidic solution or alkaline solution in step (2) contains at least one of phosphate and organic acid radical; Furthermore, in step (2), the concentration of phosphate in the acidic solution or alkaline solution 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; Furthermore, 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. Furthermore, in step (2), the leaching times are 1 to 6 times, preferably 1 to 3 times.

11. The method according to claim 8, characterized in that: In the impregnation solution after the Co source is introduced in step (3), the content of molybdenum oxide is 10g to 80g / 100mL, the content of nickel oxide is 1g to 15g / 100mL, and the content of cobalt oxide is 1g to 20g / 100mL.

12. Use of the catalyst grading method according to any one of claims 1 to 11 in distillate oil hydroprocessing reaction.

Images