Passivation method of sulfurized hydrogenation catalyst

Abstract

The invention provides a passivation method of a sulfuration-state hydrogenation catalyst. The passivation method comprises the following steps: step 1, sulfurizing an oxidation-state hydrogenation catalyst; step 2, preparing a saturated solution of the passivator, and controlling the temperature to be 30-45 DEG C; step 3, in an inert atmosphere, impregnating the sulfurized hydrogenation catalyst in the saturated solution of the passivator, cooling the impregnated hydrogenation catalyst to room temperature in the inert atmosphere, and covering the passivator separated out by crystallization on the surface of the hydrogenation catalyst; wherein the passivating agent can be decomposed into a non-oxidizing small molecule compound at the temperature of 50 to 100 DEG C. The specific passivator is adopted, the hydrogenation catalyst is impregnated in the saturated solution of the passivator at a certain temperature, then the hydrogenation catalyst is cooled to the room temperature, and the passivator is crystallized, separated out and covered on the surface and pore channels of the hydrogenation catalyst, so that the catalyst can be isolated from external oxygen, and the effect of preventing the sulfurized hydrogenation catalyst from being oxidized is achieved.

Description

Technical Field

[0001] This invention relates to the field of hydrogenation catalysis, and more specifically to a passivation method for a sulfide-state hydrogenation catalyst. Background Technology

[0002] With the trend towards heavier and lower-quality crude oil, the quality standards for clean oil products are becoming increasingly stringent, leading to a growing demand for hydrotreating technology in refineries. The core of hydrotreating technology lies in the hydrotreating catalyst. Hydrotreating catalysts are generally composed of oxides of Co(Ni)-Mo(W) metals as the active component. To obtain high hydrotreating activity, selectivity, and stability, these non-precious metal oxide catalysts must be sulfided before use. Therefore, the sulfidation effect of non-precious metal oxide catalysts is crucial for maintaining optimal hydrotreating activity and stability, improving catalyst selectivity, extending catalyst lifespan, and extending the operating cycle of the hydrotreating unit. Because high-surface-area sulfided catalysts generate SO2 and heat when exposed to air and encountering O2, they tend to self-heat or burn below 200°C. Therefore, externally sulfided catalysts pose safety risks during packaging, storage, and transportation, necessitating passivation of fully sulfided external catalysts.

[0003] Currently, publicly available passivation technologies are broadly classified into two types: gas-phase passivation and liquid-phase passivation. Gas-phase passivation primarily uses oxidizing gases to form an oxide film on the surface of the sulfide catalyst at an appropriate temperature, protecting the sulfide-state catalyst. In gas-phase passivation, after complete sulfidation of the oxidized catalyst, the sulfide-state catalyst undergoes trace oxygen passivation. Partial sulfur in the microcrystals of the active metal sulfide is replaced by oxygen, forming metal oxysulfides. These compounds are easily activated under hydrogen conditions and provide acidic active sites in addition to metal sites. Therefore, the oxygen-passivated catalyst has more acidic active sites than the sulfide-state catalyst, which explains the increased activity of the gas-phase passivated catalyst after reactivation. Liquid-phase passivation mainly employs methods such as spraying and impregnation to load organic oxygen-containing hydrocarbons onto the surface of the sulfide-state catalyst to form a protective film. Liquid-phase passivation involves uniformly spraying a liquefied protective liquid onto the surface of a solid catalyst at a temperature below the liquid's freezing point, allowing the protective liquid to crystallize and form a solid protective film. Alternatively, heavy hydrocarbons (such as vacuum distillate oil) can be used; spraying hot hydrocarbons onto a low-temperature catalyst surface increases their viscosity and slows their diffusion towards the particle center, effectively encapsulating the catalyst surface and isolating it from air. Another method is to dilute or emulsify the aforementioned passivating substances in a solvent to form a mixed solution, which is then sprayed onto the catalyst surface at a temperature above the solvent's boiling point. The solvent evaporates rapidly, and the passivating substance forms a protective film on the catalyst surface. When using liquid passivation, the amount of protective liquid sprayed must be strictly controlled. Too much protective substance makes it difficult to remove at the start of the reaction, thus affecting the catalyst's activity; conversely, too little protective substance fails to effectively prevent oxygen from penetrating the catalyst surface and pores.

[0004] Chinese patent CN111729690A describes a method for obtaining a nitrogen-supported catalyst by loading organic nitrogen compounds onto a sulfide-type hydrocracking catalyst in the presence of an organic solvent, followed by drying to obtain a passivated catalyst. This method results in the loss of some active sites in the catalyst, and requires maintaining an oxygen-free environment during the drying process, making the operation cumbersome.

[0005] Chinese patent CN106179522B discloses an external pre-sulfurization method for a hydrogenation catalyst. The passivating agent used contains component A and component B. Component A is one or more of ethylene glycol, propanolamine, propanol, and butanol, and component B is one or more of urea, glycerol, and acrylamide. This method results in a significant loss of hydrogenation catalyst activity after passivation.

[0006] Chinese patent CN109675643A discloses a method for preparing a sulfide catalyst, the sulfide catalyst itself, and its applications. This method involves passivation using distillate oil and oxygen-containing substances. However, this type of passivation leads to the permanent loss of some active sites on the catalyst, which cannot be recovered, thus affecting catalytic activity. Furthermore, the process is complex and not conducive to large-scale application.

[0007] Therefore, further research is needed in this field on the passivation of sulfide-state hydrogenation catalysts. Summary of the Invention

[0008] The main objective of this invention is to provide a passivation method for sulfide-state hydrogenation catalysts, so as to overcome the defects of existing passivation agents that have poor protective effect on sulfide-state hydrogenation catalysts or affect the activity of hydrogenation catalysts.

[0009] To achieve the above objectives, the present invention provides a passivation method for a sulfide-state hydrogenation catalyst, comprising the following steps:

[0010] Step 1: Sulfide the oxidized hydrogenation catalyst;

[0011] Step 2: Prepare a saturated solution of the passivating agent, controlling the temperature at 30-45℃;

[0012] Step 3: In an inert atmosphere, impregnate the sulfided hydrogenation catalyst with a saturated solution of passivating agent, and then lower the impregnated hydrogenation catalyst to room temperature in an inert atmosphere, so that the passivating agent crystallizes out and covers the surface of the hydrogenation catalyst.

[0013] The passivating agent can decompose into non-oxidizing small molecule compounds at 50-100℃.

[0014] In one embodiment of the passivation method for the sulfide-state hydrogenation catalyst of the present invention, the hydrogenation catalyst includes a support and an active metal supported on the support, wherein the active metal includes at least one metal element from Group VIB and Group VIII of the periodic table, and the support includes at least one from alumina, zirconium oxide, silicon oxide, activated carbon, diatomite, and zeolite.

[0015] In one embodiment of the passivation method for the sulfide-state hydrogenation catalyst of the present invention, the active metal is at least one of Co and Ni, and at least one of Mo and W.

[0016] In one embodiment of the passivation method for the sulfide-state hydrogenation catalyst described in this invention, the sulfidation conditions are: hydrogen sulfide concentration 3000-10000 ppm, hydrogen partial pressure 1.5-2.5 MPa, reaction temperature 200-350℃, and volume hourly space velocity 2.0-5.0 h⁻¹. -1 The vulcanization time is 5-20 hours.

[0017] In one embodiment of the passivation method for the sulfide-state hydrogenation catalyst of the present invention, the non-oxidizing small molecule gas is ammonia, carbon dioxide, or water.

[0018] In one embodiment of the passivation method for the sulfide-state hydrogenation catalyst described in this invention, the passivating agent does not undergo a decomposition reaction in a saturated solution of the passivating agent.

[0019] In one embodiment of the passivation method for the sulfide-state hydrogenation catalyst of the present invention, the passivating agent is at least one of ammonium bicarbonate and ammonium carbonate.

[0020] In one embodiment of the passivation method for the sulfide-state hydrogenation catalyst of the present invention, the impregnation in step 3 is an equal-volume impregnation.

[0021] In one embodiment of the passivation method for the sulfide-state hydrogenation catalyst of the present invention, the time for the passivating agent to crystallize and precipitate is 2-5 hours.

[0022] In one embodiment of the passivation method for the sulfide-state hydrogenation catalyst of the present invention, the inert atmosphere is a nitrogen atmosphere, an argon atmosphere, or a helium atmosphere.

[0023] The beneficial effects of this invention are:

[0024] This invention employs a specific passivating agent. A saturated solution of the passivating agent at a certain temperature is used to impregnate the hydrogenation catalyst. Then, the hydrogenation catalyst is cooled to room temperature, and the passivating agent crystallizes out and covers the surface and pores of the hydrogenation catalyst. This isolates the catalyst from external oxygen, thus preventing the sulfide-state hydrogenation catalyst from being oxidized.

[0025] In addition, during the catalyst packaging and loading process, the passivating agent can completely or partially isolate O2. Even if a small amount of oxygen comes into contact with the sulfide catalyst and releases a little heat, the surrounding passivating agent compound will decompose upon heating, releasing NH3 or inert gas, thus achieving the purpose of isolating the air again.

[0026] During the storage and transportation of the catalyst, the sulfide catalyst is stored in a sealed manner. The inert gas generated by the decomposition of some of the passivating agent will inhibit the further decomposition of the passivating agent, ensuring the stability of the passivating agent crystals, thereby ensuring the encapsulation of the sulfide catalyst by the passivating agent and achieving the purpose of isolating it from air.

[0027] When the catalyst is in use, as the temperature rises, the passivating agent wrapped around the catalyst gradually decomposes, releasing the sulfided catalyst and its active sites. The activity of the sulfided hydrogenation catalyst is not lost, thus fully achieving the goal of ensuring the safety of the packaging, storage, transportation and filling process of the sulfided catalyst and preventing the loss of catalyst activity. Detailed Implementation

[0028] The technical solution of the present invention will be described in detail below. The following embodiments are implemented under the premise of the technical solution of the present invention and a detailed implementation process is given. However, the protection scope of the present invention is not limited to the following embodiments. Structures or experimental methods that do not specify specific conditions in the following embodiments are generally performed under conventional conditions.

[0029] This invention provides a passivation method for a sulfide-state hydrogenation catalyst, comprising the following steps:

[0030] Step 1: Sulfide the oxidized hydrogenation catalyst;

[0031] Step 2: Prepare a saturated solution of the passivating agent, controlling the temperature at 30-45℃;

[0032] Step 3: In an inert atmosphere, impregnate the sulfided hydrogenation catalyst with a saturated solution of passivating agent, and then lower the impregnated hydrogenation catalyst to room temperature in an inert atmosphere, so that the passivating agent crystallizes out and covers the surface of the hydrogenation catalyst.

[0033] The passivating agent can decompose into non-oxidizing small molecule gas at 50-100℃.

[0034] In this invention, under an inert atmosphere, a saturated solution of a specific passivating agent is uniformly impregnated onto the surface of a sulfurized hydrogenation catalyst. After the catalyst is cooled to room temperature, the passivating agent precipitates out in a crystallizing manner, covering the surface and pores of the sulfurized hydrogenation catalyst, thereby obtaining a passivated sulfurized hydrogenation catalyst. During packaging and loading, the passivating agent completely or partially isolates O2. Even if a small amount of oxygen comes into contact with the sulfide catalyst and releases a little heat, the passivating agent decomposes below 100°C to produce NH3 or inert gas compounds. Therefore, the surrounding passivating agent will decompose upon heating, releasing NH3 or inert gas, thus achieving the purpose of isolating the catalyst from air again. During storage and transportation, the sulfide catalyst is stored in a sealed manner. The inert gas produced by the decomposition of some passivating agents will inhibit the further decomposition of the remaining passivating agents, ensuring the stability of the passivating agent coating layer. This ensures the encapsulation of the sulfide catalyst by the passivating agent, achieving the purpose of isolating the catalyst from air during the final loading process. After startup, as the temperature rises, the passivating agent wrapped around the catalyst gradually decomposes, releasing the sulfide catalyst and its active sites. The activity of the sulfide hydrogenation catalyst is not lost, thus fully achieving the goal of ensuring safety and no loss of catalyst activity during the packaging, storage, transportation, and loading processes of the sulfide catalyst.

[0035] This invention does not specifically limit the hydrogenation catalyst; any hydrogenation catalyst in the art is acceptable. In one embodiment, the hydrogenation catalyst comprises a support and an active metal supported on the support. The active metal comprises at least one metallic element from Group VIB and Group VIII of the periodic table. The support comprises at least one of alumina, zirconium oxide, silicon dioxide, activated carbon, diatomaceous earth, and zeolite. In another embodiment, the active metal is at least one of Co and Ni, and at least one of Mo and W.

[0036] In this invention, the oxidized hydrogenation catalyst is, for example, a hydrogenation catalyst prepared by conventional methods and then calcined. The oxidized hydrogenation catalyst is then subjected to sulfidation treatment to obtain a sulfidated hydrogenation catalyst. This invention does not particularly limit the conditions for sulfidation treatment; for example, the sulfidation conditions are: hydrogen sulfide concentration 3000-10000 ppm, hydrogen partial pressure 1.5-2.5 MPa, reaction temperature 200-350 °C, and volume hourly space velocity 2.0-5.0 h⁻¹. -1 The vulcanization time is 5-20 hours.

[0037] In this invention, as the temperature decreases, the solubility of the passivating agent decreases, therefore, the saturated solution of the passivating agent crystallizes and precipitates as the temperature decreases. Furthermore, the passivating agent of this invention can decompose into non-oxidizing small molecule compounds, such as small molecule gases, water, etc., more specifically, for example, ammonia, carbon dioxide, water, etc., leaving no residue on the catalyst surface and not affecting the active sites of the catalyst. In one embodiment, the passivating agent of this invention is at least one of ammonium bicarbonate and ammonium carbonate. Here, "non-oxidizing" means that it will not oxidize the active sites of the sulfide-state hydrogenation catalyst.

[0038] In this invention, the temperature of the saturated solution of the passivating agent is controlled between 30-45°C. At this temperature, the passivating agent in the solution will not undergo a decomposition reaction. Here, "saturated solution" can refer to a solution in a saturated state or a supersaturated state.

[0039] Then, under an inert atmosphere, the sulfided hydrogenation catalyst is impregnated with a saturated solution of passivating agent at that temperature, and the impregnated hydrogenation catalyst is cooled to room temperature under an inert atmosphere, and the passivating agent that crystallizes out covers the surface of the hydrogenation catalyst.

[0040] This invention does not specifically limit the inert atmosphere, such as a nitrogen atmosphere, argon atmosphere, or helium atmosphere. In one embodiment, the impregnation method of this invention is equal-volume impregnation. After impregnation, the catalyst is cooled to room temperature (e.g., 20°C) under an inert atmosphere, with or without solid-liquid separation, and the passivating agent crystallizes and precipitates, covering the surface of the hydrogenation catalyst. In another embodiment, the passivating agent crystallizes and precipitates within 2-5 hours.

[0041] The passivation method of this invention is simple to operate, has a simple process route, and uses inexpensive and readily available passivating agents. Compared with other passivation methods for sulfurized hydrogenation catalysts, it has a significant cost advantage and is very suitable for industrial applications.

[0042] In addition, the present invention ensures that the catalyst is isolated from O2 by covering the surface of the sulfide catalyst with passivating agent crystals and covering the catalyst surface with NH3 or inert gas generated by the decomposition of the passivating agent. This ensures safety during packaging, storage, transportation and filling. After start-up, the compound is completely decomposed, leaving no residue on the catalyst surface, and the active sites of the catalyst are completely released, ensuring zero loss of catalyst activity.

[0043] Therefore, this invention solves the problem of permanent loss of catalyst active sites caused by passivation methods of other sulfurized hydrogenation catalysts, thus more effectively extending catalyst life and ensuring long-term operation of the hydrogenation unit.

[0044] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0045] The oxidized hydrogenation catalyst used in the examples has an alumina support and molybdenum trioxide as the active component, with an active component content of 10 wt%.

[0046] Example 1

[0047] 100 ml of oxidized hydrogenation catalyst was used at a hydrogen sulfide concentration of 5000 ppm, a hydrogen partial pressure of 2.0 MPa, and a volume hourly space velocity of 3.5 h⁻¹. -1 A sulfurized hydrogenation catalyst was obtained by sulfiding at a sulfidation temperature of 300℃ for 10 hours. Under a N2 atmosphere, an equal volume of saturated ammonium bicarbonate solution prepared at 40℃ was impregnated onto the sulfurized hydrogenation catalyst. After standing for 5 hours, the catalyst was passedivated and the passivated sulfurized hydrogenation catalyst C1 was obtained after the temperature dropped to room temperature and ammonium bicarbonate crystallized out and completely covered the catalyst surface.

[0048] Example 2

[0049] 100 ml of oxidized hydrogenation catalyst was used at a hydrogen sulfide concentration of 6000 ppm, a hydrogen partial pressure of 2.5 MPa, and a volume hourly space velocity of 4.5 h⁻¹. -1 A sulfurized hydrogenation catalyst was obtained by sulfiding at a sulfidation temperature of 280℃ for 10 hours. Under a N2 atmosphere, an equal volume of supersaturated ammonium bicarbonate solution prepared at 45℃ was impregnated onto the sulfurized hydrogenation catalyst. After standing for 5 hours, the catalyst was passedivated and the passivated sulfurized hydrogenation catalyst C2 was obtained after the temperature dropped to room temperature and ammonium bicarbonate crystallized out and completely covered the catalyst surface.

[0050] Example 3

[0051] 100 ml of oxidized hydrogenation catalyst was used at a hydrogen sulfide concentration of 7000 ppm, a hydrogen partial pressure of 2.2 MPa, and a volume hourly space velocity of 5 h⁻¹. -1 A sulfurized hydrogenation catalyst was obtained by sulfiding at a sulfidation temperature of 300℃ for 10 hours. Under a N2 atmosphere, an equal volume of saturated ammonium bicarbonate solution prepared at 40℃ was impregnated onto the sulfurized hydrogenation catalyst. After standing for 4 hours, the catalyst was passedivated and the passivated sulfurized hydrogenation catalyst C3 was obtained after the temperature dropped to room temperature and ammonium bicarbonate crystallized out and completely covered the catalyst surface.

[0052] Example 4

[0053] 100 ml of oxidized hydrogenation catalyst was used at a hydrogen sulfide concentration of 5000 ppm, a hydrogen partial pressure of 2.5 MPa, and a volume hourly space velocity of 4.0 h⁻¹. -1 A sulfurized hydrogenation catalyst was obtained by sulfiding at a sulfidation temperature of 300℃ for 10 hours. Under a N2 atmosphere, an equal volume of saturated ammonium bicarbonate solution prepared at 40℃ was impregnated onto the sulfurized hydrogenation catalyst. After standing for 5 hours, the catalyst was passedivated and the passivated sulfurized hydrogenation catalyst C4 was obtained after the temperature dropped to room temperature and ammonium bicarbonate crystallized out and completely covered the catalyst surface.

[0054] Example 5

[0055] 100 ml of oxidized hydrogenation catalyst was subjected to an oxidation state of 9000 ppm hydrogen sulfide concentration, 2.3 MPa hydrogen partial pressure, and 3.5 h⁻¹ volume hourly space velocity (VHSV). -1 A sulfurized hydrogenation catalyst was obtained by sulfiding at a sulfidation temperature of 290℃ for 10 hours. Under a N2 atmosphere, an equal volume of supersaturated ammonium bicarbonate solution prepared at 40℃ was impregnated onto the sulfurized hydrogenation catalyst. After standing for 5 hours, the catalyst was passedivated and the passivated sulfurized hydrogenation catalyst C5 was obtained after cooling to room temperature and the ammonium bicarbonate crystallized out and completely covered the catalyst surface.

[0056] Example 6

[0057] 100 ml of oxidized hydrogenation catalyst was used at a hydrogen sulfide concentration of 5000 ppm, a hydrogen partial pressure of 2.5 MPa, and a volume hourly space velocity of 3.5 h⁻¹. -1 A sulfurized hydrogenation catalyst was obtained by sulfiding at a sulfidation temperature of 290℃ for 10 hours. Under a N2 atmosphere, an equal volume of saturated ammonium bicarbonate solution prepared at 30℃ was impregnated onto the sulfurized hydrogenation catalyst. After standing for 5 hours, the catalyst was passedivated and the passivated sulfurized hydrogenation catalyst C6 was obtained after the temperature dropped to room temperature and ammonium bicarbonate crystallized out and completely covered the catalyst surface.

[0058] Example 7

[0059] 100 ml of oxidized hydrogenation catalyst was subjected to an oxidation state of 10,000 ppm hydrogen sulfide concentration, 2.0 MPa hydrogen partial pressure, and 3.5 h⁻¹ volume hourly space velocity (VHSV). -1 A sulfurized hydrogenation catalyst was obtained by sulfiding at a sulfidation temperature of 300℃ for 10 hours. Under a N2 atmosphere, an equal volume of saturated ammonium bicarbonate solution prepared at 40℃ was impregnated onto the sulfurized hydrogenation catalyst. After standing for 5 hours, the catalyst was passedivated and the passivated sulfurized hydrogenation catalyst C7 was obtained after the temperature dropped to room temperature and ammonium bicarbonate crystallized out and completely covered the catalyst surface.

[0060] Example 8

[0061] 100 ml of oxidized hydrogenation catalyst was subjected to an oxidation state of 7000 ppm hydrogen sulfide concentration, 2.4 MPa hydrogen partial pressure, and 3.3 h⁻¹ volume hourly space velocity (VHSV). -1 A sulfurized hydrogenation catalyst was obtained by sulfiding at a sulfidation temperature of 300℃ for 10 hours. Under a N2 atmosphere, an equal volume of saturated ammonium bicarbonate solution prepared at 40℃ was impregnated onto the sulfurized hydrogenation catalyst. After standing for 3 hours, the catalyst was passedivated and the passivated sulfurized hydrogenation catalyst C8 was obtained after the temperature dropped to room temperature and ammonium bicarbonate crystallized out and completely covered the catalyst surface.

[0062] Example 9

[0063] 100 ml of oxidized hydrogenation catalyst was subjected to an oxidation state of 7000 ppm hydrogen sulfide concentration, 2.4 MPa hydrogen partial pressure, and 3.3 h⁻¹ volume hourly space velocity (VHSV).-1 A sulfurized hydrogenation catalyst was obtained by sulfiding at a sulfidation temperature of 300℃ for 10 hours. Under a N2 atmosphere, an equal volume of saturated ammonium carbonate solution prepared at 40℃ was impregnated onto the sulfurized hydrogenation catalyst. After standing for 3 hours, the catalyst was passedivated and the passivated sulfurized hydrogenation catalyst C9 was obtained after the temperature dropped to room temperature and the ammonium carbonate crystallized out and completely covered the catalyst surface.

[0064] Comparative Example 1

[0065] The preparation of the sulfide catalyst was the same as in Example 8. After the sulfide catalyst was prepared in this comparative example, it was cooled to room temperature in a N2 atmosphere without passivation treatment. This catalyst was named D1.

[0066] Comparative Example 2

[0067] The preparation of the sulfide-state catalyst was the same as in Example 8, with 100 ml of oxidized hydrogenation catalyst added at a hydrogen sulfide concentration of 7000 ppm, a hydrogen partial pressure of 2.4 MPa, and a volume hourly space velocity of 3.3 h⁻¹. -1 A sulfurized hydrogenation catalyst was obtained by sulfidation at 300℃ for 10 hours. An equal volume of a saturated sodium carbonate solution prepared at 40℃ was then impregnated onto the sulfurized hydrogenation catalyst under a N2 atmosphere. After standing for 3 hours, the catalyst was allowed to cool to room temperature and sodium carbonate crystals precipitated and completely covered the catalyst surface, resulting in a passivated sulfurized hydrogenation catalyst. In this comparative example, ammonium bicarbonate was replaced with sodium carbonate, which is less prone to decomposition, and this catalyst was named D2.

[0068] Comparative Example 3

[0069] The preparation of the sulfide-state catalyst was the same as in Example 8, with 100 ml of oxidized hydrogenation catalyst added at a hydrogen sulfide concentration of 7000 ppm, a hydrogen partial pressure of 2.4 MPa, and a volume hourly space velocity of 3.3 h⁻¹. -1 A sulfurized hydrogenation catalyst was obtained by sulfidation at 300℃ for 10 hours. Under N2 atmosphere, 40g of ammonium bicarbonate solid powder was mixed uniformly with the sulfurized hydrogenation catalyst to obtain a passivated sulfurized hydrogenation catalyst. In this comparative example, instead of impregnating the catalyst surface with an equal volume of saturated solution, ammonium bicarbonate solid powder was directly mixed uniformly with the catalyst. This catalyst was named D3.

[0070] Comparative Example 4

[0071] 100 ml of oxidized hydrogenation catalyst was sulfided in a hydrogenation evaluation apparatus at a hydrogen sulfide concentration of 7000 ppm, a hydrogen partial pressure of 2.4 MPa, and a volume hourly space velocity of 3.3 h⁻¹. -1 A sulfurized hydrogenation catalyst was obtained by sulfurization at 300℃ for 10 hours. This catalyst was directly retained in the hydrogenation evaluation unit and can be started for evaluation immediately. The comparative example used a conventional in-unit sulfurization catalyst, which was named D4.

[0072] The temperature changes of the catalysts in the above embodiments and comparative examples when exposed to air are shown in Table 1.

[0073] Table 1. Temperature Changes of Sulfated Catalysts Exposed to Air

[0074]

[0075] As shown in Table 1, the passivated sulfide-state catalysts C1-C9 and the comparative catalysts D1, D2, and D3 were simultaneously exposed to air, and the temperature changes on the catalyst surface were measured after different time periods. In the examples, the passivated sulfide-state hydrogenation catalysts exposed to air did not show a significant temperature increase over time. However, in the comparative examples, both the unpassivated catalyst D1 and the catalyst D2, which was passivated with non-decomposable sodium carbonate, experienced significant temperature increases. This indicates that the sulfide-state hydrogenation catalysts passivated with ammonium bicarbonate have very high stability. The catalysts obtained by mixing ammonium bicarbonate solid powder with the catalyst also showed a sharp temperature increase, indicating that this method cannot achieve the desired passivation effect for the sulfide-state catalysts.

[0076] Catalyst evaluation: The reaction performance of the passivated sulfurized gasoline hydrogenation catalyst was evaluated using a UN-QYJQ-20ML fixed-bed reactor with a catalyst loading of 20mL.

[0077] Raw material: Full-range catalytic cracked gasoline, sulfur content 269 ppm, olefin content 36%.

[0078] The reaction conditions were: temperature 240℃, hydrogen / gasoline volume ratio (H / O) 350, pressure 2.0 MPa, and space velocity 2.5 h⁻¹. -1 After stabilizing for 24 hours, samples were taken to determine the desulfurization rate and olefin saturation rate of the product, as shown in Table 2.

[0079] Table 2 Gasoline Product Quality Table

[0080] catalyst Desulfurization rate / % Olefin saturation rate / % C1 97.3 49.5 C2 97.2 48.9 C3 96.9 49.1 C4 97.4 48.5 C5 96.9 48.8 C6 97.2 49.2 C7 97.1 48.7 C8 97.3 48.6 C9 96.8 48.9 D1 40.5 19.3 D2 51.3 22.4 D3 41.3 19.6 In-cell sulfurized catalyst D4 97.0 48.9

[0081] As shown in Table 2, the hydrodesulfurization rates of the C1-C9 sulfurized catalysts in Examples C1-C9 remained above 96.9%, while the olefin saturation remained above 48.6%, comparable to the activity of conventional sulfurized catalysts, and avoiding the time-consuming problems caused by sulfidation during the process. In contrast, the hydrodesulfurization rates of the comparative examples D1, D2, and D3 sulfurized catalysts remained below 52%, while the olefin saturation remained below 23%. This demonstrates that the Examples effectively passivated the sulfurized gasoline hydrodesulfurization catalysts, effectively preserving their catalytic activity, while the activity of unpassivated sulfurized catalysts or those using unsuitable passivating agents decreased significantly.

[0082] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A passivation method for a sulfide-state hydrogenation catalyst, characterized in that, Includes the following steps: Step 1: Sulfide the oxidized hydrogenation catalyst; Step 2: Prepare a saturated solution of the passivating agent, controlling the temperature at 30-45℃; Step 3: In an inert atmosphere, impregnate the sulfided hydrogenation catalyst with a saturated solution of passivating agent, and then lower the impregnated hydrogenation catalyst to room temperature in an inert atmosphere, so that the passivating agent crystallizes out and covers the surface of the hydrogenation catalyst. The passivating agent can decompose into non-oxidizing small molecule compounds at 50-100℃.

2. The passivation method for the sulfide-state hydrogenation catalyst according to claim 1, characterized in that, The hydrogenation catalyst includes a support and an active metal supported on the support, wherein the active metal includes at least one metal element from Group VIB and Group VIII, and the support includes at least one from alumina, zirconium oxide, silicon oxide, activated carbon, diatomaceous earth, and zeolite.

3. The passivation method for the sulfide-state hydrogenation catalyst according to claim 1, characterized in that, The active metal is at least one of Co and Ni, and at least one of Mo and W.

4. The passivation method for the sulfide-state hydrogenation catalyst according to claim 1, characterized in that, The sulfidation conditions were: hydrogen sulfide concentration 3000-10000 ppm, hydrogen partial pressure 1.5-2.5 MPa, reaction temperature 200-350℃, and volume hourly space velocity 2.0-5.0 h⁻¹. -1 The vulcanization time is 5-20 hours.

5. The passivation method for the sulfide-state hydrogenation catalyst according to claim 1, characterized in that, The non-oxidizing small molecule gases are ammonia, carbon dioxide, and water.

6. The passivation method for the sulfide-state hydrogenation catalyst according to claim 1, characterized in that, In a saturated solution of the passivating agent, the passivating agent does not undergo a decomposition reaction.

7. The passivation method for the sulfide-state hydrogenation catalyst according to claim 1, characterized in that, The passivating agent is at least one of ammonium bicarbonate and ammonium carbonate.

8. The passivation method for the sulfide-state hydrogenation catalyst according to claim 1, characterized in that, In step 3, the impregnation is an equal-volume impregnation.

9. The passivation method for the sulfide-state hydrogenation catalyst according to claim 1, characterized in that, The passivating agent crystallizes and precipitates in 2-5 hours.

10. The passivation method for the sulfide-state hydrogenation catalyst according to claim 1, characterized in that, The inert atmosphere is a nitrogen atmosphere, an argon atmosphere, or a helium atmosphere.

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