A hydrofining catalyst, a preparation method, a pre-sulfiding method and a start-up method thereof

Abstract

The application provides a hydrofining catalyst and a preparation method, a presulfurization method and a start-up method thereof. The preparation method comprises the following steps: before impregnating the active component, spraying the carrier with a potassium-containing spraying solution, and impregnating the sprayed carrier with a potassium-containing active component impregnation solution. The obtained catalyst has excellent hydrogenation performance while reducing the amount of sulfiding agent required for presulfurization treatment, can greatly reduce the emission of hydrogen sulfide during presulfurization, reduce environmental pollution, reduce production cost and operation safety risk.

Description

Technical Field

[0001] This invention belongs to the field of hydrorefining catalysts, specifically relating to a hydrorefining catalyst and its preparation method, presulfurization method, and start-up method. Background Technology

[0002] Hydrorefining technology is a primary means of improving the quality of petrochemical products, and its core lies in the hydrorefining catalyst. Hydrorefining catalysts are classified into supported and unsupported types, with supported catalysts currently being the main type used in industry. Supported hydrorefining catalysts are generally prepared by impregnating an active metal (Mo, W, Ni, Co, etc.) onto a support. The active component of the catalyst prepared by this impregnation method is distributed on the inner and outer surfaces of the catalyst support, including the inner surfaces of deep pores and voids. Numerous reports have been published on the preparation methods of hydrorefining catalysts, mainly focusing on preparation methods and processes, support modification, and the addition of auxiliary agents.

[0003] Conventional methods produce hydrorefining catalysts with active metals in an oxidized state, while the actual catalytically active substance is the sulfide state of the active component. Before use, the active metal in an oxidized catalyst must be converted to a sulfide state to achieve higher catalytic activity. Therefore, hydrorefining catalysts require sulfide activation before use, a process known as pre-sulfidation. Pre-sulfidation significantly impacts catalyst performance and is a crucial pretreatment step. Based on the sulfur loading method, pre-sulfidation methods can be categorized into in-vessel pre-sulfidation and external pre-sulfidation.

[0004] In-reactor pre-sulfurization technology involves loading the catalyst into the reactor before sulfidation. The hydrogen sulfide required for the reaction is usually produced by decomposing a sulfiding agent, and industrially, dimethyl disulfide (hereinafter referred to as DMDS) is commonly used. The main sulfidation steps are as follows: under hot hydrogen circulation (reactor inlet temperature reaches 180℃), DMDS is gradually injected into the system, then decomposes with hydrogen to release hydrogen sulfide gas, which then reacts with the oxidized catalyst in the reactor to finally obtain the sulfided catalyst. This method has three main problems: (1) the sulfiding agent used is toxic and harmful, and easily causes environmental pollution; (2) the equipment needs to be equipped with sulfidation facilities and supporting pipelines that are only used during operation; (3) the equipment poses safety and environmental hazards during the sulfidation process due to high temperature, high pressure, and high H2S concentration.

[0005] Therefore, the external pre-sulfurization method has emerged. The advantages of external pre-sulfurization technology are: (1) External pre-sulfurization technology improves the utilization rate of active metal components of hydrogenation catalyst and makes the catalyst more fully sulfided; (2) External pre-sulfurization technology can save start-up time and make the start-up process more convenient; (3) The start-up site of external pre-sulfurization catalyst avoids the use of toxic sulfides and does not require the installation of special sulfidation facilities.

[0006] CN112742487A discloses a start-up method for a pre-sulfurized hydrogenation catalyst, the method comprising: (1) mixing a sulfiding agent with an oxidized hydrogenation catalyst uniformly; (2) heat-treating the mixture from step (1); adding a phosphorus-containing substance after cooling; (3) drying the material obtained in step (2) to obtain a pre-sulfurized catalyst; and (4) loading the pre-sulfurized catalyst from step (3) into a reactor for wet activation start-up.

[0007] CN104646034A relates to a method for preparing a sulfide-type hydrorefining catalyst. The method involves impregnating a support with an impregnation solution, followed by in-situ crystallization and heat treatment to obtain the sulfide-type hydrorefining catalyst. The impregnation solution contains an active metal ammonium molybdate and / or ammonium tungstate, an inorganic salt precursor of Ni and / or Co, and also contains a sulfiding agent, an organic complexing agent, and a co-solvent.

[0008] CN109926101A discloses a start-up method for a sulfidation-type catalyst, which also includes a sulfidation method for an external pre-sulfidation hydrogenation catalyst. The sulfidation-type catalyst composition comprises: an oxidized hydrogenation catalyst, solid sulfur, auxiliary materials, an organic compound, and hydrazine hydrate. The sulfidation-type hydrogenation catalyst composition is loaded into a reactor, and a nitrogen gas seal is established. After the nitrogen gas seal is deemed secure, hydrogen is gradually introduced to establish a low-pressure hydrogen gas seal. After the low-pressure gas seal is deemed secure, the temperature and pressure are increased to establish a high-pressure gas seal. After the high-pressure gas seal is deemed secure, the pressure is adjusted to the reaction pressure until sulfidation is complete. Finally, the temperature is adjusted to the reaction temperature, and feedstock oil is introduced to begin the hydrogenation reaction.

[0009] ZL200810010245.7 discloses a method for pre-sulfurizing a hydrogenation catalyst and a start-up method for a hydrogenation process. During the catalyst pre-sulfurization process, the amount of sulfiding agent introduced into the pre-sulfurized portion of the catalyst is significantly higher than the theoretical sulfur requirement of the active hydrogenation metal in the catalyst. The pre-sulfurized hydrogenation catalyst is mixed with or layered with the un-sulfurized hydrogenation catalyst in the reactor. After start-up activation, all catalysts undergo effective sulfidation treatment. However, the active phase of this catalyst may exhibit uneven distribution.

[0010] CN103805235A relates to a wet start-up method for a hydrogenation unit, a low-energy hydrogenation process, and hydrogenation equipment. The hydrogenation unit's reaction zone is loaded with a sulfide-type hydrogenation catalyst. During start-up, starter oil is first passed through the catalyst bed to reach a certain temperature via heat exchange. The heat from heat exchange and activation is used to raise the catalyst bed temperature to 180±10℃ or higher. A portion of gas with a high olefin content is mixed into the circulating gas, and the heat from the olefin hydrogenation reaction is used to further raise the temperature to 230±5℃ for isothermal activation. When the temperature reaches 270±10℃ or higher, feedstock oil is introduced in stages. The heat from the hydrogenation reaction in the feedstock oil is used to further raise the temperature. Finally, the reaction temperature is adjusted by controlling the amount of cold hydrogen and the heat exchanger, and normal production begins. However, under high-temperature conditions, the high-olefin content feedstock oil may lead to carbon deposition during sulfide formation, competing for the site of sulfide-state active metals.

[0011] CN102051203A discloses a start-up method for an externally pre-sulfurized catalyst. The method includes: during the catalyst wetting stage, starter oil and hydrogen are introduced from the bottom of the reactor. After the starter oil fills the reaction system, the system is circulated in a closed loop, and the temperature is gradually increased for activation. Activation ends when the bed temperature reaches 280-320℃. In this invention, the catalyst wetting is achieved by introducing starter oil and hydrogen from the bottom of the reactor, resulting in more thorough and complete catalyst wetting. This effectively prevents the existence of "dry zones" in the catalyst bed, thus ensuring more complete catalyst activation. The start-up method of this invention is simple, convenient to operate, and provides a more ideal activation effect than conventional methods, thereby improving catalyst activity.

[0012] CN111321001A discloses a start-up method for a hydrotreating catalyst, which specifically includes the following steps: (1) introducing start-up diesel fuel into the sulfidated hydrotreating catalyst bed to wet the sulfidated hydrotreating catalyst, wherein the start-up diesel fuel contains phosphorus-containing organic matter; (2) after the start-up diesel fuel penetrates the catalyst bed, increasing the reactor temperature to 300-400℃ for 10-120 minutes; (3) switching the feedstock oil to produce qualified products.

[0013] CN200710012674.3 describes a start-up method for gasoline hydrorefining. This method involves pre-sulfurizing the hydrodesulfurization catalyst at a specific sulfidation temperature and time, then switching the feedstock, and directly adjusting the process parameters to conventional reaction conditions for selective hydrodesulfurization of gasoline. A drawback of this method is the long stabilization time after feedstock switching. In a specific embodiment of this patent, the stabilization time on a small evaluation device is as long as 100 hours, resulting in low efficiency in terms of experimental time. More importantly, it is well known that the poor product quality caused by unstable catalyst activity during the initial start-up of large industrial plants can bring significant economic pressure to enterprises.

[0014] Introducing promoters into catalysts is one of the most common methods to improve the activity of hydrogenation catalysts. Commonly used promoters for hydrorefining catalysts include primary promoters such as metals like cobalt and nickel, and secondary promoters such as non-metals like phosphorus and boron. Meanwhile, chelating agents, such as citric acid, phosphoric acid, ethylenediamine, ethylenediaminetetraacetic acid, and ethylene glycol, which are used as complexing components in the preparation of active component solutions, have also achieved good results in the preparation of hydrorefining catalysts.

[0015] CN110479300A discloses a hydrogenation catalyst, its preparation method and application, and a method for hydrogenation purification. The catalyst includes a support and an active metal component A, an active metal component B, and an organic chelating agent supported on the support. Part of the active metal component B exists in the form of a trisulfide, and the remaining part of the active metal component B exists in the form of a trioxide. The atomic ratio of sulfur to active metal component B is 2.1-2.9, and the degree of sulfidation of the catalyst is 40-85%. The preparation method of the catalyst includes: (1) impregnating the support with a solution C containing a Group VIII metal compound, a Group VIB metal compound, and an organic chelating agent, and drying to obtain solid A; (2) contacting solid A with a solution D containing an organic sulfur source, and then drying.

[0016] CN201110321357 discloses a method for sulfiding a hydrorefining catalyst. This method introduces hydrogen sulfide and injects a sulfiding agent into the system at a relatively high temperature, avoiding the low-temperature sulfidation of Co and / or Ni alone. Thus, under the conditions of higher temperature and the presence of hydrogen sulfide, Mo and / or W simultaneously sulfidate with Co and / or Ni to form a highly active Mo(W)-Co(Ni)-S phase.

[0017] Patent ZL201510700293.9 relates to a hydrogenation catalyst and its preparation method. The preparation method includes: (1) loading a water-soluble salt of a hydrogenation metal active component and an organic complexing agent onto a support using an impregnation method, followed by drying and calcination to obtain a semi-finished catalyst. The calcination conditions are such that, based on the total amount of the semi-finished catalyst, the carbon content in the semi-finished catalyst is 0.03-0.5% by weight; (2) impregnating the semi-finished catalyst obtained in step (1) with a solution containing an organic complexing agent as an impregnation liquid, followed by drying without calcination; (3) loading a metal element as an auxiliary agent onto the support. Step (3) is performed before, during, and after step (1) and before step (2). This patent uses a three-step impregnation method to prepare the catalyst, which consumes a large amount of manpower and resources, resulting in a significant increase in the cost of catalyst preparation.

[0018] ZL91110935.8 discloses a method for preparing a cobalt-molybdenum hydrogenation refining catalyst. This method involves dissolving cobalt acetate in water and then adding ethylenediamine at a molar ratio of 1:1.5-3 to form a cobalt-ethylenediamine mixed solution. Concentrated ammonia is added to the solution to adjust the pH to 12-14, followed by the addition of ammonium molybdate for complete dissolution, resulting in a co-impregnation solution containing cobalt and molybdenum metals. A porous support is then impregnated with this solution to prepare the catalyst. A drawback of this method is that calcination in an oxygen-free or micro-oxygen atmosphere is required to obtain the catalyst product.

[0019] US4409131 discloses a method for preparing a CoMo / NiMo catalyst, which is prepared by impregnating a support with a solution containing an active component and ammonia in one step. The method details the preparation process of the impregnation solution for the active component. During the preparation of the impregnation solution, the mixture needs to be heated to promote the dissolution of the active component.

[0020] US6013598 discloses a method for preparing a selective hydrodesulfurization catalyst. The catalyst consists of active components cobalt and molybdenum and a support alumina. It is prepared by impregnating the support with an equal volume of an aqueous solution containing the active components and citric acid. The catalyst obtained by this method can only reach a maximum molybdenum oxide content of 10 wt%.

[0021] ZL00130284.1 relates to a catalyst for the two-stage hydrorefining of cracked gasoline and its preparation method. The method uses alumina precursor, adding a polymer and a Group IV sub-metal during its molding process. After drying and calcination, a support containing the Group IV sub-metal is obtained. This support is then impregnated with an ammonia co-leaching solution containing molybdenum, cobalt, and nickel active components, followed by drying and calcination to obtain the catalyst. The addition of the Group IV sub-metal adjusts the acidity / basicity of the support and inhibits the rate of coking and deactivation of the catalyst.

[0022] ZL99113281.5 relates to a catalyst for hydrorefining distillate oil and its preparation method. The catalyst uses alumina or silica-containing alumina as a support, adds phosphorus additives, and uses W, Mo, and Ni as active components. It adopts a segmented co-impregnation technique, in which the prepared W, Mo, Ni, and P co-impregnation solution is impregnated multiple times to finally obtain the catalyst.

[0023] ZL00122922.2 discloses a catalyst for hydrodesulfurization of distillate oil and its preparation method. The catalyst uses alumina or silica-containing alumina as a support, Mo-Ni as the active component, and adds phosphorus additives. The catalyst is prepared by staged co-impregnation of the support with an alkaline Mo-Ni-P co-impregnation solution, followed by stepwise co-impregnation of the support. This patent uses two or more steps to prepare the catalyst.

[0024] The literature “Preparation of Co-Mo-Ni-W / γ-Al2O3 diesel hydrorefining catalyst (Yao Yuanyuan, Zhang Kongyuan et al., Industrial Catalysis, 2008(02):18-22.)” investigated the effects of pore expander and calcination temperature on the physicochemical properties of the support and the effects of impregnation solution preparation method on its stability. The impregnation solution preparation method disclosed there are two main methods: (1) Low temperature method: ① Heat deionized water and phosphoric acid and add basic nickel carbonate (or basic cobalt carbonate) and molybdenum trioxide, continue heating and stirring until dissolved, and cool to room temperature for later use; ② Add ammonium metatungstate and cobalt acetate (or nickel nitrate) to slightly heated deionized water, stir to dissolve, and cool to room temperature for later use; ③ Mix the cooled ammonium metatungstate and cobalt acetate (or nickel nitrate) solution with the nickel (cobalt) molybdenum phosphorus solution prepared in ①, stir evenly and make up to volume for later use. (2) High-temperature preparation: Dissolve molybdenum trioxide, phosphoric acid, and basic nickel carbonate (or basic cobalt carbonate) in deionized water, heat and stir until completely dissolved, then add ammonium metatungstate and cobalt acetate (or nickel nitrate), continue heating and stirring until completely dissolved into a clear solution, and then make up to volume for later use. Heating and the addition of inorganic acid are required in the preparation of the impregnation solution.

[0025] CN94114194.2 discloses a hydrocarbon hydrodesulfurization catalyst and its preparation method. The catalyst uses zinc oxide-modified γ-Al₂O₃ as a support and cobalt and molybdenum as active components, prepared by a single impregnation with a co-impregnation solution of cobalt and molybdenum. The resulting catalyst has the following composition: CoO 1-10wt%, MoO₃ 5-18wt%, ZnO 1-15wt%, with the balance being γ-Al₂O₃. However, the long-term stability of the catalyst requires further investigation.

[0026] Supported catalysts, especially those with high active component content, often struggle to form a monolayer dispersion or reach a dispersion threshold on the support surface. The suitability of the interaction between the active component and the support is a major factor influencing the effective loading of the catalyst. Generally, higher dispersion of the active component on the support results in a greater number of effective active sites, leading to higher catalyst activity. However, long-term stability must also be considered. Therefore, improving the interaction between the active component and the support to increase the effective loading of the active component on the support is a key focus in the development of hydrorefining catalysts. Simultaneously, during the pre-sulfurization process, the sulfur content loaded in the catalyst is generally determined based on the theoretical sulfur requirement of the active metal in the catalyst. The amount of sulfiding agent introduced into the catalyst is typically 90-150% of the theoretical sulfur requirement for all oxidized hydrogenation catalysts. During start-up, a direct heating operation is employed. Summary of the Invention

[0027] To address the aforementioned problems, the present invention aims to provide a hydrorefining catalyst and its preparation method, pre-sulfurization method, and start-up method. This catalyst exhibits excellent hydrogenation performance while reducing the amount of sulfiding agent required for pre-sulfurization treatment. During start-up, it significantly reduces hydrogen sulfide emissions, minimizes environmental pollution, and lowers production costs and operational safety risks.

[0028] To achieve the above objectives, the present invention provides a method for preparing a hydrorefining catalyst, wherein the preparation method includes: spraying a support with a potassium-containing spray solution before impregnating the active component, and impregnating the sprayed support with a potassium-containing active component impregnation solution.

[0029] In the above-mentioned method for preparing the hydrorefining catalyst, preferably, the spraying time is 1 min to 20 min, more preferably 3 min to 10 min. The spraying process can be carried out using conventional spraying equipment, such as an agricultural high-pressure electric sprayer.

[0030] In the above-mentioned method for preparing the hydrorefining catalyst, preferably, the potassium-containing spray solution is prepared by dissolving a potassium-containing compound (such as an inorganic salt of potassium, potassium hydroxide, etc.) in deionized water.

[0031] In the above-mentioned method for preparing the hydrorefining catalyst, preferably, the potassium-containing spray solution is a potassium hydroxide solution.

[0032] In the above-mentioned method for preparing the hydrorefining catalyst, preferably, the concentration of the potassium-containing spray solution is 0.1%-5%, more preferably 0.5%-1%.

[0033] In the above-mentioned method for preparing the hydrorefining catalyst, preferably, the volume of the potassium-containing spray liquid accounts for 1%-20% of the total volume of the potassium-containing spray liquid and the potassium-containing active component impregnation liquid, more preferably 5%-10%.

[0034] In the above-mentioned method for preparing the hydrorefining catalyst, preferably, the pH value of the potassium-containing spray solution is 12.2-13.5.

[0035] According to a specific embodiment of the present invention, preferably, the preparation method of the above-mentioned hydrorefining catalyst may include the following steps: spraying the support, primary aging, impregnation, secondary aging, drying, and calcination to obtain the catalyst in an oxidized state.

[0036] The catalyst prepared by this invention contains potassium. Part of the potassium is introduced by pre-spraying the carrier, and another part is introduced by impregnating the carrier with a potassium-containing active component impregnation solution. After spraying, the carrier needs to be aged before impregnation. That is, the preparation method also includes an aging step after spraying. Preferably, the aging time is 5-30 minutes, more preferably 10-20 minutes.

[0037] According to a specific embodiment of the present invention, preferably, no drying and calcination are performed between the step of spraying the carrier with a potassium-containing spray solution and the step of impregnating the sprayed carrier with a potassium-containing active component impregnation solution; that is, the sprayed carrier (after aging for an appropriate time) is directly used for the subsequent preparation of catalysts without drying and calcination.

[0038] This invention does not impose any particular limitation on the catalyst support. According to a specific embodiment of the invention, preferably, the support is a high-temperature resistant inorganic oxide, such as one or more combinations of alumina, silicon oxide, titanium oxide, and zirconium oxide, more preferably alumina.

[0039] According to a specific embodiment of the present invention, preferably, the water absorption rate of the carrier is 80%-120%, more preferably 85%-110%.

[0040] Through experimental research, the inventors discovered that supported catalyst supports release a large amount of adsorption heat during the impregnation process of the active component impregnation solution, affecting the dispersion state of the active component and the physicochemical properties of the catalyst in the later stage. By pre-spraying the support with a potassium-containing spray solution (such as potassium hydroxide solution) and then impregnating the supported active component with the active component impregnation solution, not only can the hydrogenation performance of the catalyst be improved, but the catalyst lifetime can also be effectively extended. The reasons may be as follows: Firstly, the potassium-containing spray solution pre-releases some of the adsorption heat of the support, allowing some of the adsorption heat of the catalyst support to be released in advance during the impregnation process of the active component. Secondly, the potassium-containing spray solution pre-sprays changes the number and arrangement of hydroxyl groups on the surface of the catalyst support, improving the dispersibility of the active component during the subsequent impregnation process. At the same time, the potassium-containing spray solution pre-occupies the relatively deep pores of the support due to the capillary effect, forming a gradient distribution during the subsequent impregnation and loading of the catalyst active component, resulting in more efficient and uniform dispersion of the active component. In addition, the alkali metal potassium in the potassium-containing spray solution can interact with the support, thereby reducing the acidity of the support surface.

[0041] In the above-mentioned method for preparing the hydrorefining catalyst, preferably, the volume of the potassium-containing active component impregnation solution is 1.05×(1-V)×X×T-1.25×(1-V)×X×T, more preferably 1.10×(1-V)×X×T-1.20×(1-V)×X×T, where V is the volume fraction of the potassium-containing spray solution to the total volume of the potassium-containing active component impregnation solution and the potassium-containing spray solution, X is the water absorption rate of the carrier, T is the mass of the carrier in grams, and the volume of the potassium-containing active component impregnation solution is in mL.

[0042] In the above-mentioned method for preparing the hydrorefining catalyst, preferably, the potassium-containing active component impregnation solution is prepared by the following steps: mixing ammonia, a polyamine complexing agent, and water to prepare a composite solvent; adding the active component and potassium hydroxide to the composite solvent in a certain order to obtain the potassium-containing active component impregnation solution. The solvent used to dissolve the active component in this invention is ammonia with added polyamine complexing agent. Using this composite solvent can, on the one hand, improve the solubility of the active component in ammonia and reduce the amount of ammonia used; on the other hand, the addition of the polyamine complexing agent can significantly improve the dispersion of the catalyst's active component; furthermore, potassium hydroxide enhances the alkalinity of the impregnation solution, thereby allowing the metal active component to better complex with the polyamine complexing agent, improving the stability of the impregnation solution, and also adjusting the catalyst's acidity to improve the catalyst's hydrorefining performance.

[0043] The present invention does not impose a particular limitation on the concentration of ammonia water used in preparing potassium-containing active component impregnation solution. The concentration is determined according to the amount of active component added, as long as each active component is completely dissolved. At this point, the active component forms a relatively stable complex with the polyamine complexing agent.

[0044] According to a specific embodiment of the present invention, the potassium-containing active component impregnation solution used in the present invention is an alkaline impregnation solution, and the prepared impregnation solution is clear, stable, and has low surface tension and viscosity.

[0045] According to a specific embodiment of the present invention, preferably, the polyamine complexing agent is one or more of C2-C7 amine compounds, such as one or more of ethylenediaminetetraacetic acid, ethylenediamine, primary amine, secondary amine and tertiary amine, more preferably ethylenediamine.

[0046] The amount of polyamine complexing agent added varies depending on the amount of active component added. This invention does not impose any particular limitation. If the amount of polyamine complexing agent added is too high, it will easily cause a large amount of organic matter to decompose during the calcination process. If the amount added is too low, it will not be able to achieve the effect of promoting the dissolution of active component and improving the dispersion of active component.

[0047] The potassium-containing active component impregnation solution of the present invention can be prepared at room temperature (generally defined as 10℃-30℃, preferably 15℃-25℃) without the need for heating. The present invention is particularly suitable for the preparation of catalysts with multiple active components and high active component content, especially the catalyst preparation method that uses one-step impregnation to load the active component onto a support. This method enables the active component to be highly dispersed on the catalyst and effectively eliminates Brønsted acid sites and weakens strong Lewis acid sites on the catalyst.

[0048] After spraying and impregnation with the active component solution using the method of this invention, the catalyst is obtained through aging, drying, calcination, and activation. Before impregnating the active component, spraying the catalyst support with a certain concentration of potassium hydroxide solution is exothermic and also modifies the support. Aging, drying, and calcination can all be carried out according to conventional methods in the art, and this invention has no special requirements. The final catalyst has a potassium oxide content of 0.3%-5%, preferably 0.5%-2.5%.

[0049] According to specific embodiments of the present invention, the active component of the catalyst is not particularly limited and can be determined according to the hydrogenation application, etc. Preferably, the active component is one or a combination of two or more of molybdenum, tungsten, cobalt, and nickel.

[0050] According to a specific embodiment of the present invention, preferably, the mass fraction of the active component is greater than or equal to 20% based on the total mass of the carrier being 100%, wherein the active component is calculated as an oxide of the active component metal element, for example, molybdenum is calculated as molybdenum trioxide, tungsten as tungsten trioxide, cobalt as cobalt oxide, and nickel as nickel oxide.

[0051] According to a specific embodiment of the present invention, molybdenum is preferably added in the form of ammonium molybdate, and tungsten is added in the form of one or more of ammonium metatungstate, tungstic acid and other basic tungstates, preferably ammonium metatungstate; cobalt and nickel are added in the form of one or more of their sulfates, halides, nitrates and acetates, preferably nitrates and / or acetates, as nitrates and acetates have good solubility, which is beneficial to the distribution of active components on the carrier.

[0052] The present invention also provides a hydrorefining catalyst, which is prepared by the above-described preparation method.

[0053] According to a specific embodiment of the present invention, the distribution of the active component in the hydrorefining catalyst exhibits a certain gradient.

[0054] This invention also provides a presulfurization method for the above-mentioned hydrorefining catalyst, wherein the amount of sulfiding agent introduced during the presulfurization process is 20-70% of the theoretical sulfur requirement of the hydrorefining catalyst, preferably 25-50%. The theoretical sulfur requirement of the catalyst is the amount of sulfur required for the active metal components on the oxidized hydrorefining catalyst to be completely converted into sulfides (Co9S8, MoS2, Ni3S2, WS2, etc.), expressed as elemental sulfur.

[0055] According to a specific embodiment of the present invention, preferably, the vulcanizing agent used in the pre-vulcanization method described above is elemental sulfur and / or sulfur-containing compounds.

[0056] According to a specific embodiment of the present invention, preferably, the sulfur-containing compound is one or a combination of two of inorganic sulfur-containing compounds and organic sulfur-containing compounds; the inorganic sulfur-containing compound is one or a combination of two of carbon disulfide and ammonium sulfide; the organic sulfur-containing compound is one or a combination of one or two of monosulfide and polysulfide compounds, preferably one or a combination of more than two of dimethyl disulfide, tert-butyl polysulfide, tert-nonyl polysulfide, thiourea, SZ-54 (manufactured by Lubrizol), thiols, thiophenols, and thioethers.

[0057] According to a specific embodiment of the present invention, preferably, the pre-sulfurization further includes the step of adding a sulfidation accelerator. Adding a sulfidation accelerator during the pre-sulfurization process facilitates uniform mixing of the sulfidation agent and the oxidized hydrogenation catalyst.

[0058] According to a specific embodiment of the present invention, preferably, the vulcanizing aid is an organic solvent.

[0059] According to a specific embodiment of the present invention, preferably, the vulcanizing aid is one or a combination of two of hydrocarbon oil and organic carboxylic acid esters; the hydrocarbon oil is one or a combination of more than two of gasoline, kerosene, diesel, kerosene, white oil, industrial soybean oil, and lubricating oil base oil, preferably a hydrocarbon oil obtained through secondary processing, wherein the processing is one or a combination of two of catalytic cracking and thermal cracking processes; the organic carboxylic acid ester is an organic carboxylic acid ester containing 6-60 carbon atoms, preferably one or a combination of more than two of fatty acid glycerides, animal oil, rapeseed oil, peanut oil, soybean oil, and cottonseed oil.

[0060] According to a specific embodiment of the present invention, preferably, the amount of the sulfidation aid is 0.5%-40% of the weight of the hydrorefining catalyst (i.e., the oxidized catalyst before pre-sulfidation), more preferably 3%-25%.

[0061] The present invention also provides an external presulfurization hydrogenation refining catalyst, which is prepared by the above-mentioned presulfurization method.

[0062] According to a specific embodiment of the present invention, preferably, the sulfur content in the above-mentioned external presulfurization hydrogenation refining catalyst is 3.5-10 wt% of the mass of the external presulfurization hydrogenation refining catalyst, more preferably 4-7 wt%.

[0063] The present invention also provides a start-up method for the above-mentioned external presulfurization hydrogenation refining catalyst, which includes the following steps:

[0064] (1) The pre-sulfurized hydrogenation refining catalyst from outside the reactor is loaded into the reactor;

[0065] (2) The reactor is sealed with nitrogen, replaced with hydrogen, and sealed with hydrogen.

[0066] (3) Under hydrogen circulation, the temperature is increased at a rate of 15-25℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 150-160℃, it is kept at a constant temperature for 3-5 hours; when the catalyst bed temperature reaches 180-220℃, it is kept at a constant temperature for 2-10 hours; when the catalyst bed temperature reaches 260-320℃, it is kept at a constant temperature for 2-10 hours (preferably 2-8 hours), and the catalyst sulfidation is completed.

[0067] (4) Adjust the system process conditions to the reaction conditions, switch the feed oil for operation, and complete the start-up.

[0068] The pre-sulfurized hydrorefining catalyst provided by this invention can reduce the amount of sulfiding agent used in the external pre-sulfurization process, ensuring a safe and stable start-up process and exhibiting excellent catalyst performance. This is likely because sulfidation plays a crucial role in catalyst performance, and the preparation method of the hydrorefining catalyst of this invention helps to form highly active phase II active centers, resulting in more appropriate stacking layers and lamellar lengths in the active phase lamellae after sulfidation.

[0069] The preparation method of the hydrorefining catalyst of this invention overcomes the impregnation effect and active component clustering caused by conventional impregnation methods, improves the loading effect of active metal components, and forms a certain gradient of active components in the prepared hydrorefining catalyst. This improves the dispersibility of active metals on the support surface and regulates the interaction between active metals and the support, thereby improving the hydrodesulfurization activity and stability of the catalyst. The partially sulfided catalyst maintains its excellent hydrorefining performance while unexpectedly reducing the amount of sulfiding agent required in the external pre-sulfidation process. During the use of the catalyst, the sulfides contained in the oil cause the catalyst performance to be released slowly. Attached Figure Description

[0070] Figure 1 The image shows the SEM-EDS characterization results of the catalyst in Example 3.

[0071] Figure 2This is an HRTEM compositional diagram of potassium in the catalyst of Example 3. Detailed Implementation

[0072] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0073] Example 1

[0074] This embodiment provides a hydrorefining catalyst and its preparation method, presulfurization method, and start-up method, specifically including:

[0075] Catalyst preparation:

[0076] The carrier used in the experiment was a clover-shaped γ-Al₂O₃ carrier with a specific surface area of ​​289 m². 2 / g, pore volume 0.63cm 3 / g, strength 154N / cm, water absorption rate 115%.

[0077] (1) First, prepare a potassium hydroxide aqueous solution for pre-spraying treatment: prepare 497 ml of 0.25% potassium hydroxide solution to obtain the spray solution;

[0078] (2) Weigh 10 kg of alumina carrier and add it to a rotary impregnation pot. Use the prepared potassium hydroxide spray solution to spray the carrier with atomized solution for 2.5 min. After spraying, the storage time for the first aging is 5 min to obtain the pre-sprayed carrier.

[0079] (3) Prepare a mixed solution of 5100ml ammonia water and 390ml triethylenetetramine, add ammonium molybdate and stir to dissolve, then add nickel nitrate, ammonium metatungstate and potassium hydroxide in sequence, add deionized water to adjust the solution volume to 11930ml, impregnate it on the pre-sprayed carrier obtained in step (2), age it for 4 hours, dry it at 110℃ for 3 hours, and calcine it at 450℃ for 4 hours to obtain catalyst C1.

[0080] Catalyst pre-sulfurization:

[0081] (1) Mix the sulfiding agent (SZ-54, the amount of which is 30% of the theoretical sulfur required by catalyst C1) and the sulfidation aid (a mixture of gasoline and soybean oil in a weight ratio of 2:1, the amount of which is 20% of the weight of catalyst C1) evenly to obtain the pre-sulfidation raw material.

[0082] (2) The catalyst C1 is placed in a rotary impregnation pot. The pre-sulfurization raw material is mixed with the catalyst C1 by spraying. After standing for 1 hour, it is treated at 120℃ for 2 hours to obtain the pre-sulfurization catalyst Cs1 outside the pot.

[0083] Start-up method for external pre-sulfurized catalysts:

[0084] (1) The pre-sulfurized catalyst Cs1 from outside the reactor is loaded into the reactor;

[0085] (2) The reactor device was tested for nitrogen gas tightness, hydrogen replacement and hydrogen gas tightness, and the gas tightness was qualified;

[0086] (3) Under hydrogen circulation, the temperature is increased at a rate of 20℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 150℃, it is kept at a constant temperature for 5 hours; when the catalyst bed temperature reaches 185℃, it is kept at a constant temperature for 4 hours; when the catalyst bed temperature reaches 280℃, it is kept at a constant temperature for 3 hours, and the catalyst sulfidation ends.

[0087] (4) Adjust the system process conditions to the reaction conditions and switch the feed oil for normal operation.

[0088] Example 2

[0089] This embodiment provides a hydrorefining catalyst and its preparation method, presulfurization method, and start-up method, specifically including:

[0090] Catalyst preparation:

[0091] The carrier used in the experiment was a clover-shaped γ-Al₂O₃ carrier with a specific surface area of ​​281 m². 2 / g, pore volume 0.62cm 3 / g, strength 177N / cm, water absorption rate 110%.

[0092] (1) First, prepare a potassium hydroxide aqueous solution for pre-spraying treatment: prepare 726 ml of 0.5% potassium hydroxide solution to obtain the spray solution;

[0093] (2) Weigh 10 kg of alumina carrier and add it to a rotary impregnation pot. Use the prepared potassium hydroxide spray solution to spray the carrier with atomized spray for 12 min. After spraying, the storage time for the first aging is 7 min to obtain the pre-sprayed carrier.

[0094] (3) Prepare a mixed solution of 5200ml ammonia water and 435g ethylenediaminetetraacetic acid. Add nickel nitrate and stir to dissolve. Then add ammonium molybdate, cobalt nitrate and potassium hydroxide in sequence. Add deionized water to adjust the solution volume to 11380ml. Impregnate the solution on the pre-sprayed carrier obtained in step (2). Aging for 4.5h, drying at 100℃ for 4h, and calcining at 480℃ for 4h to obtain catalyst C2.

[0095] Catalyst pre-sulfurization:

[0096] (1) Mix the sulfiding agent (elemental sulfur, the amount of which is 35% of the theoretical sulfur required for catalyst C2) and the sulfidation aid (kerosene, the amount of which is 15% of the weight of catalyst C2) evenly to obtain the pre-sulfided raw material.

[0097] (2) The catalyst C2 is placed in a rotary impregnation pot. The pre-sulfurization raw material is mixed evenly with the catalyst C2 by spraying. After standing for 0.5 hours, it is treated at 100°C for 2.5 hours to obtain the pre-sulfurization catalyst Cs2 outside the vessel.

[0098] Start-up method for external pre-sulfurized catalysts:

[0099] (1) The pre-sulfurized catalyst Cs2 from outside the reactor is loaded into the reactor;

[0100] (2) The reactor device was tested for nitrogen gas tightness, hydrogen replacement and hydrogen gas tightness, and the gas tightness was qualified;

[0101] (3) Under hydrogen circulation, the temperature is increased at a rate of 25℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 150℃, it is kept at a constant temperature for 5 hours; when the catalyst bed temperature reaches 180℃, it is kept at a constant temperature for 3 hours; when the catalyst bed temperature reaches 285℃, it is kept at a constant temperature for 4 hours, and the catalyst sulfidation ends.

[0102] (4) Adjust the system process conditions to the reaction conditions and switch the feed oil for normal operation.

[0103] Example 3

[0104] This embodiment provides a hydrorefining catalyst and its preparation method, presulfurization method, and start-up method, specifically including:

[0105] Catalyst preparation:

[0106] The carrier used in the experiment was a clover-shaped γ-Al₂O₃ carrier with a specific surface area of ​​275 m². 2 / g, pore volume 0.62cm 3 / g, strength 156N / cm, water absorption rate 105%.

[0107] (1) First, prepare a potassium hydroxide aqueous solution for pre-spraying treatment: prepare 588 ml of 0.3% potassium hydroxide solution to obtain the spray solution;

[0108] (2) Weigh 10 kg of alumina carrier and add it to a rotary impregnation pot. Use the prepared potassium hydroxide spray solution to spray the carrier with atomized solution for 3.5 min. After spraying, the storage time for the first aging is 9 min to obtain the pre-sprayed carrier.

[0109] (3) Prepare a mixed solution of 5400ml ammonia water and 600ml ethylenediamine, add ammonium molybdate and stir to dissolve, then add cobalt acetate, nickel nitrate and potassium hydroxide in sequence, add deionized water to adjust the solution volume to 11170ml, impregnate it on the pre-sprayed carrier obtained in step (2), age it for 5 hours, dry it at 120℃ for 3 hours, and calcine it at 500℃ for 4 hours to obtain catalyst C3.

[0110] Catalyst pre-sulfurization:

[0111] (1) Mix the sulfiding agent (SZ-54, the amount of which is 40% of the theoretical sulfur required by catalyst C3) and the sulfidation aid (white oil, the amount of which is 18% of the weight of catalyst C3) evenly to obtain the pre-sulfided raw material.

[0112] (2) The catalyst C3 is placed in a rotary impregnation pot. The pre-sulfurization raw material is mixed evenly with the catalyst C3 by spraying. After standing for 1.5 hours, it is treated at 90°C for 3 hours to obtain the pre-sulfurization catalyst Cs3 outside the vessel.

[0113] Start-up method for external pre-sulfurized catalysts:

[0114] (1) The pre-sulfurized catalyst Cs3 from outside the reactor is loaded into the reactor;

[0115] (2) The reactor device was tested for nitrogen gas tightness, hydrogen replacement and hydrogen gas tightness, and the gas tightness was qualified;

[0116] (3) Under hydrogen circulation, the temperature is increased at a rate of 15℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 150℃, it is kept at a constant temperature for 4 hours; when the catalyst bed temperature reaches 185℃, it is kept at a constant temperature for 6 hours; when the catalyst bed temperature reaches 290℃, it is kept at a constant temperature for 2 hours, and the catalyst sulfidation ends.

[0117] (4) Adjust the system process conditions to the reaction conditions and switch the feed oil for normal operation.

[0118] Example 4

[0119] This embodiment provides a hydrorefining catalyst and its preparation method, presulfurization method, and start-up method, specifically including:

[0120] Catalyst preparation:

[0121] The carrier used in the experiment was a clover-shaped γ-Al₂O₃ carrier with a specific surface area of ​​266 m². 2 / g, pore volume 0.61cm 3 / g, strength 169N / cm, water absorption 100%.

[0122] (1) First, prepare a potassium hydroxide aqueous solution for pre-spraying treatment: prepare 805 ml of 2% potassium hydroxide solution to obtain the spray solution;

[0123] (2) Weigh 10 kg of alumina carrier and add it to a rotary impregnation pot. Use the prepared potassium hydroxide spray solution to spray the carrier with atomized spray for 4 min. After spraying, the storage time for the first aging is 12 min to obtain the pre-sprayed carrier.

[0124] (3) Prepare a mixed solution of 5500ml ammonia water and 420g ethylenediaminetetraacetic acid. Add cobalt acetate and stir to dissolve. Then add ammonium molybdate, nickel nitrate and potassium hydroxide in sequence. Add deionized water to adjust the solution volume to 10700ml. Impregnate the solution on the pre-sprayed carrier obtained in step (2). Aging for 3 hours, drying at 100℃ for 5 hours, and calcining at 420℃ for 6 hours to obtain catalyst C4.

[0125] Catalyst pre-sulfurization:

[0126] (1) Mix the sulfiding agent (tert-butyl polysulfide and SZ-54, with a sulfur mass ratio of 1:2 and a dosage of 50% of the theoretical sulfur required for catalyst C4) and the sulfidation aid (diesel, with a dosage of 12% of the weight of catalyst C4) evenly to obtain the pre-sulfided raw material.

[0127] (2) Place the catalyst C4 into a rotary impregnation pot, and mix the pre-sulfurization raw material with the catalyst C4 by spraying. After standing for 1 hour, treat at 80°C for 4 hours to obtain the pre-sulfurization catalyst Cs4 outside the pot.

[0128] Start-up method for external pre-sulfurized catalysts:

[0129] (1) The pre-sulfurized catalyst Cs4 from outside the reactor is loaded into the reactor;

[0130] (2) The reactor device was tested for nitrogen gas tightness, hydrogen replacement and hydrogen gas tightness, and the gas tightness was qualified;

[0131] (3) Under hydrogen circulation, the temperature is increased at a rate of 15℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 155℃, it is kept at a constant temperature for 3 hours; when the catalyst bed temperature reaches 190℃, it is kept at a constant temperature for 4 hours; when the catalyst bed temperature reaches 300℃, it is kept at a constant temperature for 4 hours, and the catalyst sulfidation ends.

[0132] (4) Adjust the system process conditions to the reaction conditions and switch the feed oil for normal operation.

[0133] Example 5

[0134] This embodiment provides a hydrorefining catalyst and its preparation method, presulfurization method, and start-up method, specifically including:

[0135] Catalyst preparation:

[0136] The carrier used in the experiment was a clover-shaped γ-Al₂O₃ carrier with a specific surface area of ​​254 m². 2 / g, pore volume 0.61cm 3 / g, strength 135N / cm, water absorption rate 95%.

[0137] (1) First, prepare a potassium hydroxide aqueous solution for pre-spraying treatment: prepare 890 ml of 0.8% potassium hydroxide solution to obtain the spray solution;

[0138] (2) Weigh 10 kg of alumina carrier and add it to a rotary impregnation pot. Use the prepared potassium hydroxide spray solution to spray the carrier with atomized spray for 3 min. After spraying, the storage time for the first aging is 15 min to obtain the pre-sprayed carrier.

[0139] (3) Prepare a mixed solution of 5600ml ammonia water and 560g ethylenediamine, add ammonium molybdate and stir to dissolve, then add cobalt nitrate, nickel nitrate and potassium hydroxide in sequence, add deionized water to adjust the solution volume to 10230ml, impregnate it on the pre-sprayed carrier obtained in step (2), age it for 3.5h, dry it at 110℃ for 4h, and calcine it at 520℃ for 5h to obtain catalyst C5.

[0140] Catalyst pre-sulfurization:

[0141] (1) Mix the sulfiding agent (sulfide and SZ-54, with a sulfur mass ratio of 1:2, and the amount used is 45% of the theoretical sulfur required by catalyst C5) and the sulfidation aid (diesel, with the amount used is 10% of the weight of catalyst C5) evenly to obtain the pre-sulfided raw material.

[0142] (2) Place the catalyst C5 into a rotary impregnation pot, and mix the pre-sulfurization raw material with the catalyst C5 by spraying. After standing for 2 hours, treat at 85°C for 4 hours to obtain the pre-sulfurization catalyst Cs5 outside the pot.

[0143] Start-up method for external pre-sulfurized catalysts:

[0144] (1) Load the pre-sulfurized catalyst Cs5 from outside the reactor into the reactor;

[0145] (2) The reactor device was tested for nitrogen gas tightness, hydrogen replacement and hydrogen gas tightness, and the gas tightness was qualified;

[0146] (3) Under hydrogen circulation, the temperature is increased at a rate of 20℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 160℃, it is kept at a constant temperature for 4 hours; when the catalyst bed temperature reaches 200℃, it is kept at a constant temperature for 5 hours; when the catalyst bed temperature reaches 310℃, it is kept at a constant temperature for 5 hours, and the catalyst sulfidation ends.

[0147] (4) Adjust the system process conditions to the reaction conditions and switch the feed oil for normal operation.

[0148] Example 6

[0149] This embodiment provides a hydrorefining catalyst and its preparation method, presulfurization method, and start-up method, specifically including:

[0150] Catalyst preparation:

[0151] The carrier used in the experiment was a clover-shaped γ-Al₂O₃ carrier with a specific surface area of ​​239 m². 2 / g, pore volume 0.6cm 3 / g, strength 189N / cm, water absorption rate 89%.

[0152] (1) First, prepare a potassium hydroxide aqueous solution for pre-spraying treatment: prepare 1270 ml of 0.6% potassium hydroxide solution to obtain the spray solution;

[0153] (2) Weigh 10 kg of alumina carrier and add it to a rotary impregnation pot. Use the prepared potassium hydroxide spray solution to spray the carrier with atomized solution for 5.5 min. After spraying, the storage time for the first aging is 18 min to obtain the pre-sprayed carrier.

[0154] (3) Prepare a mixed solution of 5800ml ammonia water and 450g ethylenediamine, add ammonium molybdate and stir to dissolve, then add cobalt acetate, nickel nitrate and potassium hydroxide in sequence, add deionized water to adjust the solution volume to 9320ml, impregnate it on the pre-sprayed carrier obtained in step (2), age it for 2.5h, dry it at 100℃ for 5h, and calcine it at 470℃ for 5h to obtain catalyst C6.

[0155] Catalyst pre-sulfurization:

[0156] (1) Mix the sulfiding agent (thiophenol and SZ-54, with a sulfur mass ratio of 1:2, and the amount is 55% of the theoretical sulfur required for catalyst C6) and the sulfidation aid (diesel, with the amount being 25% of the weight of catalyst C6) evenly to obtain the pre-sulfided raw material.

[0157] (2) The catalyst C6 is placed in a rotary impregnation pot. The pre-sulfurization raw material is mixed evenly with the catalyst C6 by spraying. After standing for 2 hours, it is treated at 90°C for 3 hours to obtain the pre-sulfurization catalyst Cs6 outside the pot.

[0158] Start-up method for external pre-sulfurized catalysts:

[0159] (1) The pre-sulfurized catalyst Cs6 is loaded into the reactor;

[0160] (2) The reactor device was tested for nitrogen gas tightness, hydrogen replacement and hydrogen gas tightness, and the gas tightness was qualified;

[0161] (3) Under hydrogen circulation, the temperature is increased at a rate of 25℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 155℃, it is kept at a constant temperature for 4 hours; when the catalyst bed temperature reaches 210℃, it is kept at a constant temperature for 4 hours; when the catalyst bed temperature reaches 320℃, it is kept at a constant temperature for 6 hours, and the catalyst sulfidation ends.

[0162] (4) Adjust the system process conditions to the reaction conditions and switch the feed oil for normal operation.

[0163] Example 7

[0164] This embodiment provides a hydrorefining catalyst and its preparation method, presulfurization method, and start-up method, specifically including:

[0165] Catalyst preparation:

[0166] The carrier used in the experiment was a clover-shaped γ-Al₂O₃ carrier with a specific surface area of ​​223 m². 2 / g, pore volume 0.59cm 3 / g, strength 141N / cm, water absorption rate 84%.

[0167] (1) First, prepare a potassium hydroxide aqueous solution for pre-spraying treatment: prepare 1030 ml of 0.4% potassium hydroxide solution to obtain the spray solution;

[0168] (2) Weigh 10 kg of alumina carrier and add it to a rotary impregnation pot. Use the prepared potassium hydroxide spray solution to spray the carrier with atomized solution for 7.5 min. After spraying, the storage time for the first aging is 22 min to obtain the pre-sprayed carrier.

[0169] (3) Prepare a mixed solution of 6000ml ammonia water and 590ml triethylenetetramine, add ammonium metatungstate and stir to dissolve, then add nickel nitrate, cobalt nitrate and potassium hydroxide in sequence, add deionized water to adjust the solution volume to 9200ml, impregnate it on the pre-sprayed carrier obtained in step (2), age it for 2 hours, dry it at 110℃ for 4 hours, and calcine it at 500℃ for 5 hours to obtain catalyst C7.

[0170] Catalyst pre-sulfurization:

[0171] (1) Mix the sulfiding agent (elemental sulfur and ammonium sulfide, with a sulfur mass ratio of 2:1 and an amount of 20% of the theoretical sulfur required for catalyst C7) and the sulfidation aid (soybean oil, with an amount of 3% of the weight of catalyst C7) evenly to obtain the pre-sulfided raw material.

[0172] (2) Place the catalyst C7 into a rotary impregnation pot, mix the pre-sulfurization raw material with the catalyst C7 by spraying, let it stand for 1 hour, and then treat it at 100°C for 2 hours to obtain the pre-sulfurization catalyst Cs7 outside the pot.

[0173] Start-up method for external pre-sulfurized catalysts:

[0174] (1) Load the pre-sulfurized catalyst Cs7 from outside the reactor into the reactor;

[0175] (2) The reactor device was tested for nitrogen gas tightness, hydrogen replacement and hydrogen gas tightness, and the gas tightness was qualified;

[0176] (3) Under hydrogen circulation, the temperature is increased at a rate of 15℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 160℃, it is kept at a constant temperature for 4 hours; when the catalyst bed temperature reaches 220℃, it is kept at a constant temperature for 8 hours; when the catalyst bed temperature reaches 290℃, it is kept at a constant temperature for 3 hours, and the catalyst sulfidation ends.

[0177] (4) Adjust the system process conditions to the reaction conditions and switch the feed oil for normal operation.

[0178] Comparative Example 1

[0179] This comparative example provides a hydrorefining catalyst and its preparation method, presulfurization method, and start-up method, specifically including:

[0180] Catalyst preparation:

[0181] The carrier used in the experiment was a clover-shaped γ-Al₂O₃ carrier with a specific surface area of ​​289 m². 2 / g, pore volume 0.63cm 3 / g, strength 154N / cm, water absorption rate 115%.

[0182] A mixed solution of 5100 ml ammonia and 390 ml triethylenetetramine was prepared. Ammonium molybdate was added and stirred to dissolve. Nickel nitrate, ammonium metatungstate, and potassium hydroxide were added in sequence. Deionized water was added to adjust the solution volume to 11930 ml. The solution was then impregnated on a 10 kg carrier, aged for 4 h, dried at 110 °C for 3 h, and calcined at 450 °C for 4 h to obtain catalyst D1.

[0183] Catalyst pre-sulfurization:

[0184] (1) Mix the sulfiding agent (SZ-54, the amount of which is 30% of the theoretical sulfur required by catalyst D1) and the sulfidation aid (a mixture of gasoline and soybean oil in a weight ratio of 2:1, the amount of which is 20% of the weight of catalyst D1) evenly to obtain the pre-sulfided raw material.

[0185] (2) Place catalyst D1 into a rotary impregnation pot, mix the pre-sulfurization raw material with catalyst D1 by spraying, let it stand for 1 hour, and then treat it at 120℃ for 2 hours to obtain the pre-sulfurization catalyst Ds1 outside the pot.

[0186] Start-up method for external pre-sulfurized catalysts:

[0187] (1) Load the pre-sulfurized catalyst Ds1 from outside the reactor into the reactor;

[0188] (2) The reactor device was tested for nitrogen gas tightness, hydrogen replacement and hydrogen gas tightness, and the gas tightness was qualified;

[0189] (3) Under hydrogen circulation, the temperature is increased at a rate of 20℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 150℃, it is kept at a constant temperature for 5 hours; when the catalyst bed temperature reaches 185℃, it is kept at a constant temperature for 4 hours; when the catalyst bed temperature reaches 280℃, it is kept at a constant temperature for 3 hours, and the catalyst sulfidation ends.

[0190] (4) Adjust the system process conditions to the reaction conditions and switch the feed oil for normal operation.

[0191] Comparative Example 2

[0192] This comparative example provides a hydrorefining catalyst and its preparation method, presulfurization method, and start-up method, specifically including:

[0193] Catalyst preparation:

[0194] The carrier used in the experiment was a clover-shaped γ-Al₂O₃ carrier with a specific surface area of ​​275 m². 2 / g, pore volume 0.62cm 3 / g, strength 156N / cm, water absorption rate 105%.

[0195] A mixed solution of 5400 ml ammonia and 600 ml ethylenediamine was prepared. Ammonium molybdate was added and stirred to dissolve. Cobalt acetate, nickel nitrate, and potassium hydroxide were added in sequence. Deionized water was added to adjust the solution volume to 11170 ml. The solution was then impregnated on a 10 kg carrier, aged for 5 h, dried at 120 °C for 3 h, and calcined at 500 °C for 4 h to obtain catalyst D2.

[0196] Catalyst pre-sulfurization:

[0197] (1) Mix the sulfiding agent (SZ-54, the amount of which is 40% of the theoretical sulfur required by catalyst D2) and the sulfidation aid (white oil, the amount of which is 18% of the weight of catalyst D2) evenly to obtain the pre-sulfided raw material.

[0198] (2) Place catalyst D2 into a rotary impregnation pot, mix the pre-sulfurization raw material with catalyst D2 by spraying, place for 1.5h, and then treat at 90℃ for 3h to obtain pre-sulfurization catalyst Ds2 outside the pot.

[0199] Start-up method for external pre-sulfurized catalysts:

[0200] (1) Load the pre-sulfurized catalyst Ds2 from outside the reactor into the reactor;

[0201] (2) The reactor device was tested for nitrogen gas tightness, hydrogen replacement and hydrogen gas tightness, and the gas tightness was qualified;

[0202] (3) Under hydrogen circulation, the temperature is increased at a rate of 15℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 150℃, it is kept at a constant temperature for 4 hours; when the catalyst bed temperature reaches 185℃, it is kept at a constant temperature for 6 hours; when the catalyst bed temperature reaches 290℃, it is kept at a constant temperature for 2 hours, and the catalyst sulfidation ends.

[0203] (4) Adjust the system process conditions to the reaction conditions and switch the feed oil for normal operation.

[0204] Comparative Example 3

[0205] This comparative example provides a hydrorefining catalyst and its preparation method, presulfurization method, and start-up method, specifically including:

[0206] Catalyst preparation:

[0207] The carrier used in the experiment was a clover-shaped γ-Al₂O₃ carrier with a specific surface area of ​​254 m². 2 / g, pore volume 0.61cm 3 / g, strength 135N / cm, water absorption rate 95%.

[0208] A mixed solution of 5600 ml ammonia and 560 g ethylenediamine was prepared. Ammonium molybdate was added and stirred to dissolve. Cobalt nitrate, nickel nitrate, and potassium hydroxide were added in sequence. Deionized water was added to adjust the solution volume to 10230 ml. The solution was then impregnated on a 10 kg carrier and aged for 3.5 h. The solution was dried at 110 °C for 4 h and calcined at 520 °C for 5 h to obtain catalyst D3.

[0209] Catalyst pre-sulfurization:

[0210] (1) Mix the sulfiding agent (sulfide and SZ-54, with a sulfur mass ratio of 1:2, and the amount is 45% of the theoretical sulfur required by catalyst D3) and the sulfidation aid (diesel, with the amount being 10% of the weight of catalyst D3) evenly to obtain the pre-sulfided raw material.

[0211] (2) Place catalyst D3 into a rotary impregnation pot, mix the pre-sulfurization raw material with catalyst D3 by spraying, place for 2 hours, and then treat at 85°C for 4 hours to obtain pre-sulfurization catalyst Ds3 outside the pot.

[0212] Start-up method for external pre-sulfurized catalysts:

[0213] (1) Load the pre-sulfurized catalyst Ds3 from outside the reactor into the reactor;

[0214] (2) The reactor device was tested for nitrogen gas tightness, hydrogen replacement and hydrogen gas tightness, and the gas tightness was qualified;

[0215] (3) Under hydrogen circulation, the temperature is increased at a rate of 20℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 160℃, it is kept at a constant temperature for 4 hours; when the catalyst bed temperature reaches 200℃, it is kept at a constant temperature for 5 hours; when the catalyst bed temperature reaches 310℃, it is kept at a constant temperature for 5 hours, and the catalyst sulfidation ends.

[0216] (4) Adjust the system process conditions to the reaction conditions and switch the feed oil for normal operation.

[0217] Comparative Example 4

[0218] This comparative example provides a hydrorefining catalyst and its preparation method, presulfurization method, and start-up method, specifically including:

[0219] Catalyst preparation:

[0220] The carrier used in the experiment was a clover-shaped γ-Al₂O₃ carrier with a specific surface area of ​​223 m². 2 / g, pore volume 0.59cm 3 / g, strength 141N / cm, water absorption rate 84%.

[0221] A mixed solution of 6000 ml ammonia and 590 ml triethylenetetramine was prepared. Ammonium metatungstate was added and stirred to dissolve. Nickel nitrate, cobalt nitrate, and potassium hydroxide were added in sequence. Deionized water was added to adjust the solution volume to 9200 ml. The solution was then impregnated on a 10 kg carrier and aged for 2 hours. The solution was then dried at 110 °C for 4 hours and calcined at 500 °C for 5 hours to obtain catalyst D4.

[0222] Catalyst pre-sulfurization:

[0223] (1) Mix the sulfiding agent (elemental sulfur and ammonium sulfide, with a sulfur mass ratio of 2:1 and an amount of 20% of the theoretical sulfur required by catalyst D4) and the sulfidation aid (soybean oil, with an amount of 3% of the weight of catalyst D4) evenly to obtain the pre-sulfided raw material.

[0224] (2) Place catalyst D4 into a rotary impregnation pot, mix the pre-sulfurization raw material with catalyst D4 by spraying, let it stand for 1 hour, and then treat it at 100℃ for 2 hours to obtain the pre-sulfurization catalyst Ds4 outside the pot.

[0225] Start-up method for external pre-sulfurized catalysts:

[0226] (1) Load the pre-sulfurized catalyst Ds4 from outside the reactor into the reactor;

[0227] (2) The reactor device was tested for nitrogen gas tightness, hydrogen replacement and hydrogen gas tightness, and the gas tightness was qualified;

[0228] (3) Under hydrogen circulation, the temperature is increased at a rate of 15℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 160℃, it is kept at a constant temperature for 4 hours; when the catalyst bed temperature reaches 220℃, it is kept at a constant temperature for 8 hours; when the catalyst bed temperature reaches 290℃, it is kept at a constant temperature for 3 hours, and the catalyst sulfidation ends.

[0229] (4) Adjust the system process conditions to the reaction conditions and switch the feed oil for normal operation.

[0230] Table 1 lists the mass content of each component in the catalysts obtained in Examples 1-7 and Comparative Examples 1-4.

[0231] Table 1. Mass content of each component in the catalyst

[0232]

[0233]

[0234] The catalyst was characterized by elemental distribution analysis and the distribution of active components on the catalyst was investigated using SEM-EDS. The contents of active components at different locations in the catalyst are shown in Table 2 below. The SEM-EDS characterization results of catalyst Cs3 in Example 3 are shown below. Figure 1 As shown, the catalyst contains Ni, Mo, Co, and K elements, and also contains small amounts of Si and P; the HRTEM composition distribution of potassium element in catalyst Cs3 in Example 3 is shown in Figure 3. Figure 2 As shown, the K element can be observed and is relatively evenly distributed.

[0235] Table 2. Percentage (%) of metal content of active components at different locations in the catalyst to the total content of active components.

[0236]

[0237] As can be seen from the characterization results in Table 2, the concentration distribution of the active component prepared by the hydrogenation catalyst of the present invention is more reasonable.

[0238] Catalyst evaluation:

[0239] The feedstock was the C6-C8 fraction of cracked gasoline, processed using a single-stage hydrogenation process. The reaction conditions were: reaction pressure 2.8 MPa, liquid hourly space velocity 2.0 h⁻¹. -1 The reaction temperature was 240℃, and the hydrogen-to-oil volume ratio was 250:1.

[0240] The catalysts Cs3 and Ds2 prepared above were evaluated after 300 hours, using products from the first stage of cracked gasoline hydrogenation as feedstock. The properties of the feedstock are shown in Table 3. The catalyst evaluation was conducted on a 250 ml adiabatic bed hydrogenation reactor, with the catalysts using a bottom-two-stage loading method, with a loading volume of 150 ml. Samples were taken every 12 hours to analyze the bromine value and sulfur content of the products. The average data from the 300-hour catalyst evaluation are shown in Table 4.

[0241] Table 3 Hydrogenation Feedstock Indicators

[0242]

[0243] Table 4. Average data of catalysts Cs3 and Ds2 after 300 hours of evaluation.

[0244]

[0245] As can be seen from the characterization results in Table 2, the concentration distribution of the active components of the catalyst prepared by the present invention is more reasonable. As can be seen from the evaluation results in Table 4, under the same evaluation process conditions, the hydrogenation product of the catalyst prepared by the present invention has relatively lower bromine value and total sulfur, which fully demonstrates that the catalyst of the present invention has better hydrogenation activity.

[0246] 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 method for preparing an external presulfurization hydrogenation refining catalyst, comprising the following steps: The hydrorefining catalyst is pre-sulfurized, and the amount of sulfiding agent introduced during the pre-sulfurization process is 20-70% of the theoretical sulfur requirement of the hydrorefining catalyst. The hydrorefining catalyst is prepared by the following steps: The steps include spraying the carrier with a potassium-containing spray solution before impregnating the active component, aging after spraying, and impregnating the sprayed carrier with a potassium-containing active component impregnation solution. No drying or calcination occurs between the steps of spraying the carrier with a potassium-containing spray solution and impregnating the sprayed carrier with a potassium-containing active component impregnation solution. The potassium-containing spray solution is a potassium hydroxide solution; The volume of the potassium-containing active component impregnation solution is 1.05×(1-V)×X×T - 1.25×(1-V)×X×T; Wherein, V is the volume fraction of the potassium-containing spray solution to the total volume of the potassium-containing active component impregnation solution and the potassium-containing spray solution, X is the water absorption rate of the carrier, and T is the mass of the carrier in grams. The volume of the potassium-containing active component impregnation solution is measured in mL.

2. The preparation method according to claim 1, wherein, The amount of sulfurizing agent introduced during the pre-sulfurization process is 25-50% of the theoretical sulfur requirement of the hydrorefining catalyst.

3. The preparation method according to claim 1, wherein, The spraying time is 1 min to 20 min.

4. The preparation method according to claim 1, wherein, The spraying time is 3-10 minutes.

5. The preparation method according to claim 1, wherein, The concentration of the potassium-containing spray solution is 0.1%-5%.

6. The preparation method according to claim 1, wherein, The concentration of the potassium-containing spray solution is 0.5%-1%.

7. The preparation method according to claim 1, wherein, The volume of the potassium-containing spray solution accounts for 1%-20% of the total volume of the potassium-containing spray solution and the potassium-containing active component impregnation solution.

8. The preparation method according to claim 1, wherein, The volume of the potassium-containing spray solution accounts for 5%-10% of the total volume of the potassium-containing spray solution and the potassium-containing active component impregnation solution.

9. The preparation method according to claim 1, wherein, The pH value of the potassium-containing spray solution is 12.2-13.

5.

10. The preparation method according to claim 1, wherein, The aging time is 5 min to 30 min.

11. The preparation method according to claim 1, wherein, The aging time is 10-20 minutes.

12. The preparation method according to claim 1, wherein, The water absorption rate of the carrier is 80%-120%.

13. The preparation method according to claim 1, wherein, The water absorption rate of the carrier is 85%-110%.

14. The preparation method according to claim 1, wherein, The carrier is a high-temperature resistant inorganic oxide.

15. The preparation method according to claim 1, wherein, The carrier is one or a combination of two or more of alumina, silicon oxide, titanium oxide, and zirconium oxide.

16. The preparation method according to claim 1, wherein, The carrier is an alumina carrier.

17. The preparation method according to claim 1, wherein, The volume of the potassium-containing active component impregnation solution is 1.10×(1-V)×X×T - 1.20×(1-V)×X×T.

18. The preparation method according to claim 1, wherein, The potassium-containing active component impregnation solution is prepared by the following steps: mixing ammonia, polyamine complexing agent and water to prepare a composite solvent, adding the active component and potassium hydroxide to the composite solvent to obtain the potassium-containing active component impregnation solution.

19. The preparation method according to claim 18, wherein, The polyamine complexing agent is one or a combination of two or more C2-C7 amine compounds.

20. The preparation method according to claim 18, wherein, The polyamine complexing agent is one or a combination of two or more of ethylenediaminetetraacetic acid, ethylenediamine, primary amine, secondary amine and tertiary amine.

21. The preparation method according to claim 18, wherein, The polyamine complexing agent is ethylenediamine.

22. The preparation method according to claim 18, wherein, The active component is one or a combination of two or more of molybdenum, tungsten, cobalt and nickel.

23. The preparation method according to claim 22, wherein, With the total mass of the carrier as 100%, the mass fraction of the active component is greater than or equal to 20%, wherein the molybdenum is calculated as molybdenum trioxide, the tungsten as tungsten trioxide, the cobalt as cobalt oxide, and the nickel as nickel oxide.

24. The preparation method according to claim 22, wherein, The molybdenum is added in the form of ammonium molybdate.

25. The preparation method according to claim 22, wherein, The tungsten is added in the form of one or more combinations of ammonium metatungstate, tungstic acid, and basic tungstate.

26. The preparation method according to claim 22, wherein, The tungsten is added in the form of ammonium metatungstate.

27. The preparation method according to claim 22, wherein, The cobalt and nickel are added in the form of one or more combinations of their sulfates, halides, nitrates and acetates.

28. The preparation method according to claim 22, wherein, The cobalt and nickel are added in the form of their nitrates and / or acetates.

29. The preparation method according to claim 1, wherein, The potassium oxide content of the hydrorefining catalyst is 0.3wt%-5wt%.

30. The preparation method according to claim 1, wherein, The potassium oxide content of the hydrorefining catalyst is 0.5wt%-2.5wt%.

31. The preparation method according to claim 1, wherein, The pre-vulcanizing agent used is elemental sulfur and / or sulfur-containing compounds.

32. The preparation method according to claim 31, wherein, The sulfur-containing compound is one or a combination of two of inorganic sulfur-containing compounds and organic sulfur-containing compounds; the inorganic sulfur-containing compound is one or a combination of two of carbon disulfide and ammonium sulfide; and the organic sulfur-containing compound is one or a combination of two of monosulfide and polysulfide compounds.

33. The preparation method according to claim 31, wherein, The sulfur-containing compound is one or a combination of two or more of the following: dimethyl disulfide, tert-butyl polysulfide, tert-nonyl polysulfide, thiourea, SZ-54, thiols, thiophenols, and thioethers.

34. The preparation method according to claim 1, wherein, The pre-vulcanization also includes the step of adding vulcanization aids.

35. The preparation method according to claim 34, wherein, The vulcanization aid is an organic solvent.

36. The preparation method according to claim 34, wherein, The vulcanization aid is one or a combination of two of hydrocarbon oils and organic carboxylic acid esters, wherein the hydrocarbon oil is one or a combination of two or more of gasoline, kerosene, diesel, kerosene, white oil, industrial soybean oil, and lubricating oil base oil.

37. The preparation method according to claim 36, wherein, The hydrocarbon oil is a hydrocarbon oil obtained through secondary processing, wherein the processing is one or a combination of two of the following processes: catalytic cracking and thermal cracking; the organic carboxylic acid ester is an organic carboxylic acid ester containing 6-60 carbon atoms.

38. The preparation method according to claim 36, wherein, The organic carboxylic acid ester is one or a combination of two or more of the following: fatty acid glycerides, animal oils, rapeseed oil, peanut oil, soybean oil, and cottonseed oil.

39. The preparation method according to claim 34, wherein, The amount of the sulfidation aid is 0.5%-40% of the weight of the hydrorefining catalyst.

40. The preparation method according to claim 34, wherein, The amount of the sulfidation aid is 3%-25% of the weight of the hydrorefining catalyst.

41. An external presulfurization hydrogenation refining catalyst, which is prepared by the preparation method according to any one of claims 1-40.

42. The external pre-sulfurization hydrogenation refining catalyst according to claim 41, wherein, In this external presulfurization catalyst, the sulfur content is 3.5-10 wt% of the mass of the external presulfurization hydrogenation refining catalyst.

43. The external pre-sulfurization hydrogenation refining catalyst according to claim 41, wherein, In this external presulfurization catalyst, the sulfur content is 4-7 wt% of the mass of the external presulfurization hydrogenation refining catalyst.

44. The start-up method of the external presulfurization hydrorefining catalyst according to any one of claims 41-43, comprising the following steps: (1) The pre-sulfurized hydrogenation refining catalyst is loaded into the reactor; (2) The reactor is sealed with nitrogen, replaced with hydrogen, and sealed with hydrogen. (3) Under hydrogen circulation, the temperature is increased at a rate of 15-25℃ / hour at the reactor inlet temperature. When the catalyst bed temperature reaches 150-160℃, it is kept at a constant temperature for 3-5 hours; when the catalyst bed temperature reaches 180-220℃, it is kept at a constant temperature for 2-10 hours; when the catalyst bed temperature reaches 260-320℃, it is kept at a constant temperature for 2-10 hours, and the catalyst sulfidation is completed. (4) Adjust the system process conditions to the reaction conditions, switch the feed oil for operation, and complete the start-up.

Images