Gasoline hydrodesulfurization microspherical catalyst, its preparation method and application

Abstract

A gasoline hydrodesulfurization microsphere catalyst, its preparation method, and its application are disclosed. The preparation steps include: controlling the flow rates of acidic and alkaline aluminum salt solutions under stirring to maintain the pH of the gelling material in the mixed reaction at 7–10; filtering and washing; adding zinc- and nickel-containing compounds under stirring to achieve a Ni / (Ni+Zn+Al) molar ratio of 0.3–0.35 and a Zn / (Ni+Zn+Al) molar ratio of 0.5–0.52; adding 0.5 wt%–8 wt% (dry basis) of hierarchical porous shape-selective catalytic zeolite and 5 wt% of other components. A 100-400 mesh silica-containing filler of 15-15 wt% is ground in a stirred mill for 15-130 minutes, then spray-dried at a liquid / solid weight ratio of 2.5-4, with the exhaust gas temperature above 150°C. It is then spray-coated with an equal volume of a 3-4 wt% ammonium phosphate solution and dried. Finally, it is calcined at 250-600°C for 0.5-4 hours. The catalyst has an average particle size of 60-80 micrometers and a pore volume of 0.4-0.9 ml / g. In the hydrodesulfurization reaction of fluidized gasoline, it exhibits wear resistance, high desulfurization activity, long single-stage reaction cycle, and low liquid yield and octane number loss.

Description

Technical Field

[0001] This invention belongs to the field of petroleum refining technology, and particularly relates to a gasoline hydrodesulfurization microsphere catalyst, its preparation method, and its application. Background Technology

[0002] my country has long implemented the stringent National VI gasoline standard (S < 10 μg / g), and deep desulfurization of gasoline is an important technology in the oil refining industry. Hydrogenation technology is a commonly used method for desulfurizing fuel hydrocarbons, and there are relatively mature technologies for hydrodesulfurization of gasoline, which have been widely adopted. For example, Prim G of the French Petroleum and New Energy Research Institute (IFPEN) has... + The process can reduce the sulfur content of gasoline to 25 μg / g and the RON loss to 0.65 units. However, for catalytic cracking gasoline with high olefin content, reducing octane number loss while producing ultra-low sulfur clean gasoline with a sulfur content of less than 10 μg / g remains a challenging task.

[0003] ConocoPhillips' S-Zorb adsorption desulfurization technology can perform deep desulfurization of gasoline fractions to produce gasoline with a sulfur content of less than 10 μg / g, at 343–413℃, 0.7–2.1 MPa, and space velocity of 4–10 h⁻¹. -1 Under reaction conditions with a hydrogen purity of 70% to 99%, sulfur-containing compound molecules are adsorbed, removing sulfur atoms. This allows sulfur atoms in hydrocarbon molecules to remain on the adsorbent, while some of the catalytic cracked gasoline is released and returned to the gasoline.

[0004] The S-Zorb process employs a fluidized bed reactor, which circulates the desulfurization adsorption catalyst particles in the reactor, regeneration system, and reducer. The adsorbent is regenerated through an oxygen-enriched regeneration method. The adsorbent has zinc oxide and nickel oxide as the main active components, thus achieving continuous desulfurization of catalytic cracking gasoline and continuous regeneration of the catalyst, as disclosed in the company's patent document USP7182918B2.

[0005] Because the performance of catalysts has a significant impact on the application effect of process technology, the company has conducted extensive research on desulfurization adsorbents. For example, in the patent documents disclosed by the company in USP USP06150300, USP06254766, USP06346190, USP06350422, USP06428685, USP06429170, USP06482314, and USP06955752, a method for producing gasoline or diesel with a sulfur content of less than 30ug / g under hydrogen-containing conditions is used. This method employs a mixture of zinc oxide, silica, and alumina as a carrier, mixed with one or two components selected from reduced metals such as cobalt, nickel, iron, manganese, copper, molybdenum, tungsten, silver, tin, and vanadium, and then molded into an adsorbent. This method achieves desulfurization adsorption reactions with relatively low hydrogen consumption. However, the octane number of the product gasoline shows a significant loss, the sulfur capacity of the adsorbent during the reaction process is not large enough, and the single-stage reaction cycle is short.

[0006] In addition to its US patents, Philips has also applied for and been granted numerous patents in China for technology transfer and sales purposes, such as CN1151333A, CN1048418C, CN1130253C, CN1208124C, and CN1258396C. In its patent document CN01807982, the company details the preparation and application methods of an adsorption catalyst. This involves impregnating an adsorbent carrier containing zinc oxide, expanded perlite, and alumina with a promoter metal such as nickel and / or cobalt, followed by reduction of the valence of the promoter metal, to prepare an adsorbent composition for removing sulfur and sulfur compounds such as hydrogen sulfide, carbonyl sulfide, and mercaptans from cracked gasoline and diesel fuels. The adsorbent carrier is formed using ground expanded perlite, and adjusting the zinc oxide and binder content provides a wear-resistant adsorbent and extends its service life.

[0007] After acquiring the technology, domestic oil refining companies disclosed desulfurization methods and other technical details in patent documents such as CN1382201B, CN1627988B, CN100438970C, CN100560197C, CN1930271B, CN115926841A, and CN115960626A. They also continued their research on adsorption catalysts, as disclosed in patent documents such as CN101618313B, CN101619231B, CN101618314B, and CN107910993B. Other domestic entities also conducted research on adsorbents and devices, as shown in patents such as CN1326977C, CN103240117B, CN112908424A, and CN209568065U. Research on the hydrodesulfurization process of fluidized gasoline, especially the improvement of catalysts, has been ongoing and has received attention. Summary of the Invention

[0008] Based on a comprehensive analysis of the existing technologies, further improving the catalytic performance and wear resistance of microsphere hydrodesulfurization catalysts, while balancing gasoline liquid recovery, reducing octane number loss, increasing sulfur adsorption capacity, and extending the single-stage reaction cycle, has always been a key focus and challenge in technological improvement, and is also crucial for enhancing the efficiency of fluidized gasoline hydrodesulfurization processes. Therefore, the purpose of this invention is to overcome the shortcomings of existing technologies and provide a gasoline hydrodesulfurization microsphere catalyst, its preparation method, and its application method.

[0009] Unlike conventional catalysts used in hydrodesulfurization reactions, this invention provides a bifunctional adsorption catalyst with moderate hydrogenation activity and deep sulfur adsorption capacity for gasoline hydrodesulfurization reactions. This is done to reduce octane number loss due to olefin saturation during desulfurization and to avoid liquid octane reduction caused by cracking under high temperature conditions. Furthermore, the mechanical properties of the catalyst are improved to enhance wear resistance and extend its service life.

[0010] Most sulfides in gasoline are difficult to be directly adsorbed by adsorbents, but chemical adsorption occurs on the active metal sites on the catalyst surface, causing the CS bond to break. While releasing hydrocarbon molecules, metal sulfides are generated on the catalyst surface. The metal sulfides then undergo a reversible reaction with hydrogen to generate hydrogen sulfide and an active metal. The hydrogen sulfide is instantly captured by the chalcophilic metal oxide on the catalyst, promoting the shift of the chemical equilibrium reaction. This allows the sulfur element in the sulfides in gasoline to be adsorbed and fixed on the catalyst, achieving precise desulfurization of gasoline.

[0011] During the hydrosorption desulfurization process, the sulfur element in gasoline is captured and adsorbed by the catalyst, which shifts the chemical reaction equilibrium in a direction favorable to the conversion of sulfides. This effectively avoids the secondary reaction between hydrogen sulfide and other hydrocarbons, especially olefins, in the gasoline fraction to generate small amounts of sulfides, such as mercaptans, which occurs in conventional hydrotreating processes. As a result, deep desulfurization of gasoline is achieved, and the reduction and loss of olefins are reduced.

[0012] To address the competitive adsorption of olefins by π electrons on metal active sites against sulfide molecules, the adsorption and hydrogenation of olefins can be thermodynamically suppressed by appropriately increasing the temperature. This results in less olefin saturation and reduced loss of gasoline octane number during the reaction. Since the reaction temperature is higher than that of general hydrogenation reactions, the liquid yield loss caused by side reactions such as cracking can be reduced by modulating the acidity and cracking activity of the catalyst.

[0013] Specifically, the method for preparing a gasoline hydrodesulfurization microsphere catalyst provided by the present invention includes the following steps:

[0014] (1) The flow rates of acidic aluminum salt solution and alkaline aluminum salt solution are controlled separately under stirring so that the pH value of the gelling material of the mixed reaction is controlled within the range of 7 to 10. The slurry is filtered and washed with deionized water 1 to 3 times.

[0015] (2) Add zinc-containing compounds and nickel-containing compounds under stirring to make the Ni / (Ni+Zn+Al) molar ratio 0.3-0.35 and the Zn / (Ni+Zn+Al) molar ratio 0.5-0.52;

[0016] (3) Add 0.5wt% to 8wt% of hierarchical porous shape-selective catalytic zeolite on a dry basis, and 5wt% to 15wt% of 100 to 400 mesh silica-containing fine powder filler. After grinding with a stirring mill for 15 to 130 minutes, the slurry is spray-dried at a liquid / solid weight ratio of 2.5 to 4 and the tail gas temperature is >150℃.

[0017] (4) Spray and impregnate with an equal volume of solution containing 3wt% to 4wt% ammonium phosphate compound, then dry; calcine at 250 to 600°C for 0.5 to 4 hours;

[0018] The microsphere catalyst has an average particle size of 40–80 micrometers and a pore volume of 0.4–0.9 ml / g.

[0019] In the method for preparing a gasoline hydrodesulfurization microsphere catalyst provided by the present invention, the preferred embodiment is that the pH value of the mixed gelling material is controlled at 8.5-9.5; the Ni / (Ni+Zn+Al) molar ratio when adding zinc-containing compounds and nickel-containing compounds is 0.33 and the Zn / (Ni+Zn+Al) molar ratio is 0.5; 1 wt%-5 wt% of hierarchical porous shape-selective catalytic zeolite and 9 wt%-11 wt% of 150-250 mesh silica-containing fine powder filler are added on a dry basis, and the mixture is ground for 30-60 minutes; calcined at 380-500℃ for 1-3 hours; and the average particle size of the microspheres is 60-75 micrometers.

[0020] The method for preparing a gasoline hydrodesulfurization microsphere catalyst provided by the present invention is characterized in that the hierarchical porous shape-selective catalytic zeolite is selected from hierarchical porous ZSM-5 zeolite, hierarchical porous Silicate-1 zeolite, hierarchical porous ZSM-35 zeolite, hierarchical porous ZSM-22 zeolite, hierarchical porous ZSM-23 zeolite, and hierarchical porous mordenite; the preferred shape-selective catalytic zeolite is hierarchical porous ZSM-5 zeolite.

[0021] The method for preparing a gasoline hydrodesulfurization microsphere catalyst provided by the present invention is characterized in that the silicon-containing fine powder filler is selected from kaolin, halloysite, diatomite, bentonite, montmorillonite, leucite, sepiolite, palygorskite, soapstone, perlite, and macroporous silica; the preferred filler is kaolin.

[0022] The method for preparing a gasoline hydrodesulfurization microsphere catalyst provided by the present invention is characterized in that the acidic aluminum salt is selected from aluminum nitrate, aluminum chloride, aluminum sulfate, aluminum oxalate, and aluminum acetate; the preferred acidic aluminum salt is aluminum sulfate.

[0023] The method for preparing a gasoline hydrodesulfurization microsphere catalyst provided by the present invention is characterized in that the basic aluminum salt is sodium aluminate and / or potassium aluminate, and the preferred basic aluminum salt is sodium aluminate.

[0024] The method for preparing a gasoline hydrodesulfurization microsphere catalyst provided by the present invention is characterized in that the nickel-containing compound is selected from nickel nitrate, nickel chloride, nickel sulfate, nickel fluoride, and nickel tetracarbonyl, with nickel nitrate being the preferred nickel-containing compound.

[0025] The method for preparing a gasoline hydrodesulfurization microsphere catalyst provided by the present invention is characterized in that the zinc-containing compound is selected from zinc dihydroxycarbonate, zinc oxide, zinc chloride, zinc nitrate, zinc sulfate, zinc carbonate, zinc acetate, and zinc oxalate, with zinc dihydroxycarbonate being the preferred zinc-containing compound.

[0026] The method for preparing a gasoline hydrodesulfurization microsphere catalyst provided by the present invention is characterized in that the ammonium phosphate compound is selected from ammonium phosphate, diammonium hydrogen phosphate, and ammonium dihydrogen phosphate.

[0027] The reagents and chemical raw materials used to prepare gasoline hydrodesulfurization microsphere catalysts are conventional raw materials used in chemical experiments and production, and can be easily obtained through commercial purchase.

[0028] This invention provides a gasoline hydrodesulfurization microsphere catalyst prepared by the above-described preparation steps, contents, and methods. Besides differing from the prior art disclosed in patent documents in terms of raw materials, preparation contents, synthesis methods, and operating steps, the prepared catalyst also differs from the disclosed prior art in its physicochemical properties, pore structure, and especially its catalytic reaction performance.

[0029] In addition to providing a gasoline hydrodesulfurization microsphere catalyst and its preparation method, this invention also provides a gasoline desulfurization method, comprising reacting sulfur-containing gasoline with the catalyst obtained in the above preparation process at a weight hourly space velocity (WHSV) of 2–8 h⁻¹. -1 The sulfur in gasoline is removed by contacting it at 380–450℃, 0.5–2.8 MPa and a hydrogen / oil molar ratio of 0.1–0.8 under hydrogen-exposed conditions, thereby obtaining low-sulfur gasoline, or even ultra-low sulfur gasoline (S≤10μg / g).

[0030] During the deep desulfurization reaction of gasoline, the thiophilic oxides on the catalyst gradually become saturated with sulfur after adsorbing sulfur elements, and the adsorption and desulfurization capacity decreases. The catalyst needs to be regenerated and reduced to restore its desulfurization activity.

[0031] The gasoline desulfurization method provided by the present invention further includes a catalyst regeneration and reduction process. The regeneration conditions are: air regeneration at 400-600°C and 0.1-1 MPa for 1-4 hours; and the catalyst reduction conditions are: hydrogen reduction at 350-500°C and 0.1-3 MPa for 1-4 hours.

[0032] The preparation method of gasoline hydrodesulfurization microsphere catalyst and the gasoline desulfurization method provided by this invention involve chemical operations in the catalyst preparation and gasoline hydrodesulfurization process that are well known to those skilled in the art and are used in daily scientific experiments and oil refining and chemical production processes.

[0033] The present invention provides a gasoline hydrodesulfurization microsphere catalyst, its preparation method, and its application. The positive benefits are as follows: the prepared catalyst possesses strong sulfur adsorption performance, moderate hydrogenation activity, and a certain shape-selective catalytic ability; the three active components with catalytic functions are evenly distributed, effectively synergistically enhancing catalytic reaction efficiency; it has a stepped pore structure conducive to sulfur adsorption and diffusion, resulting in high desulfurization reaction activity, large sulfur adsorption capacity, and a long single-stage desulfurization reaction cycle; it achieves deep and precise desulfurization, reducing sulfur in gasoline to below 10 μg / g, meeting the stringent China VI gasoline emission standards; simultaneously, through acid regulation, it exhibits low product octane number loss, minimal liquid recovery loss, low requirements for hydrogen purity, and very low hydrogen consumption; the dense layer improves wear resistance and extends service life; and the catalyst preparation process is simple and low-cost. Detailed Implementation

[0034] The following embodiments will further illustrate the present invention, but are not intended to limit the invention.

[0035] In each embodiment, the average particle size of the microsphere catalyst was measured using a laser particle size analyzer, and the composition was determined using an X-ray fluorescence spectrometer; the catalyst wear resistance was measured using a catalyst wear index analyzer; the pore volume was measured using a low-temperature nitrogen adsorption method; and the sulfur capacity was determined using dynamic hydrogen sulfide adsorption. The detection methods can also refer to (National Standard for Test Methods of Petroleum and Petroleum Products, China Standards Press, 1989) and (Analytical Methods for Petrochemical Products (RIPP Test Methods), Science Press, 1990), as well as standard methods in the chemical industry.

[0036] Example 1

[0037] According to the preparation steps and methods in the embodiments of the inventor's authorized patents CN107010639B and CN108178164B, and by controlling the silicon-to-aluminum ratio of the feed to make the silicon-to-aluminum atomic ratio of the product greater than 50, ZSM-5 zeolite with a hierarchical porous structure was prepared, with a crystallinity of 91% and a Si / Al ratio of 5:4; the volume of the 0.5 nm ten-membered ring micropores was 0.17 mL / g, and the volume of the 5–15 nm mesopores was 0.1 mL / g; the zeolite was washed with ammonium nitrate solution at 90 °C, with Na2O < 0.1 wt%, and dried at 120 °C for 1 hour.

[0038] Weigh out the calculated amount of aluminum sulfate reagent (chemically pure, Beijing Chemical Reagent Company) to prepare an Al2O3 solution of 90 g / L. Similarly, prepare an Al2O3 solution of 90 g / L using sodium aluminate reagent (chemically pure, Beijing Chemical Reagent Company). While stirring, control the flow rates of the aluminum nitrate solution and sodium aluminate solution separately to keep the pH value of the gelling material mixed in the gelling kettle within the range of 8.6 to 9.4. After the reaction is complete, filter the slurry, wash it twice with deionized water, ensuring that Na2O < 0.1 wt%, and then put it into the gelling kettle.

[0039] Add the calculated amount of zinc dihydroxy dizinc carbonate (chemically pure, Beijing Chemical Reagent Company) and the nickel solution prepared with nickel nitrate hexahydrate (chemically pure, Beijing Chemical Reagent Company) while stirring, so that the molar ratio of Ni / (Ni+Zn+Al) in the mixture is 0.33 and the molar ratio of Zn / (Ni+Zn+Al) is 0.5.

[0040] Weigh and add the aforementioned ZSM-5 zeolite with a multi-level porous structure and 200-mesh kaolin powder (industrial grade, Suzhou Kaolin Company) according to the calculated amount, accounting for 2wt% and 8wt% of the total amount respectively on a dry basis. Add deionized water to make the liquid / solid weight ratio of the slurry 3. After stirring and mixing evenly, grind it with a stirring mill for 60 minutes. Spray dry it in a small spray drying tower in the laboratory at an exhaust gas temperature of 155℃ to form the slurry.

[0041] A 3.5 wt% dilute solution was prepared using diammonium hydrogen phosphate (chemically pure, Beijing Chemical Reagent Company) and deionized water. An equal volume of this solution as the catalyst was measured, sprayed and impregnated onto a ball-rolling machine, and then dried at 110°C for 3 hours. The resulting microsphere catalyst for gasoline hydrodesulfurization, as described in Example 1, contained 51.3 wt% zinc oxide and 29.8 wt% nickel oxide on a dry basis, with a pore volume of 0.51 mL / g and an average particle size of 65 μm for the catalyst microspheres.

[0042] Example 2

[0043] Weigh out industrial-grade aluminum sulfate solution (industrial grade, Shandong Aluminum Plant, Al2O3 90 g / L) and sodium aluminate solution (industrial grade, Shandong Aluminum Plant, Al2O3 100 g / L) according to the calculated amounts. While stirring, control the flow rates of the aluminum sulfate solution and sodium aluminate solution separately to keep the pH value of the gelling material mixed in the gelling kettle within the range of 8.5 to 9.5. After the reaction is completed, filter the slurry, wash it three times with deionized water, and ensure that Na2O < 0.1 wt%. Then put it into the gelling kettle.

[0044] Following the same nickel, zinc, and aluminum molar ratio as in Example 1, a calculated amount of alkaline zinc carbonate (industrial grade, Shaanxi Nonferrous Metals Mining Company, Zn≥57%) and a solution prepared with nickel sulfate (industrial grade, Jinan Jiewei Chemical Technology Co., Ltd.) were added under stirring.

[0045] Following the same preparation steps as in Example 1, but controlling the silicon-to-aluminum ratio, a hierarchical porous high-silica ZSM-5 zeolite with a silicon-to-aluminum ratio greater than 300 was prepared, making its catalytic performance close to that of hierarchical silicate-1 (all-silica ZSM-5 type zeolite), with a crystallinity of 90%, a pore size of 0.5 nm, a ten-membered ring micropore volume of 0.16 mL / g, and a pore size of 5–15 nm mesopore volume of 0.08 mL / g. Sodium ions were removed by washing with ammonium sulfate solution, and Na2O < 0.1 wt% was weighed out on a dry basis and added to the above mixture.

[0046] Weigh out 6 wt% of the total dry weight of diatomaceous earth (industrial grade, Qingdao Shengtai Company) that has been ground to 250 mesh. Add deionized water to make the liquid / solid weight ratio of the slurry 2.5. After stirring and mixing evenly, grind it for 90 minutes with a stirring mill. Spray dry it in a small spray drying tower in the laboratory at an exhaust gas temperature of 160℃ to form the slurry.

[0047] A 4 wt% dilute solution of ammonium dihydrogen phosphate (chemically pure, Beijing Chemical Reagent Company) and deionized water was prepared. An equal volume of this solution as the catalyst was measured, sprayed and impregnated on a ball-rolling machine, and then dried at 120°C for 2 hours. The resulting microsphere catalyst for gasoline hydrodesulfurization, as described in Example 2, was then calcined at 420°C for 4 hours. The catalyst of Example 2, on a dry basis, contained 50.2 wt% zinc oxide, 30.1 wt% nickel oxide, had a pore volume of 0.63 mL / g, and an average particle size of 67 μm.

[0048] Example 3

[0049] Weigh out aluminum chloride (chemically pure, Beijing Chemical Reagent Company) according to the calculated amount to prepare an Al2O3 solution of 80 g / L, and potassium aluminate (chemically pure, Beijing Chemical Reagent Company) to prepare an Al2O3 solution of 80 g / L. While stirring, control the flow rates of the aluminum chloride solution and potassium aluminate solution respectively to keep the pH value of the gelling material mixed in the gelling kettle within the range of 8.7 to 9.3. After the reaction is completed, filter the slurry, wash it twice with deionized water, and after Na2O < 0.1 wt%, put it into the gelling kettle.

[0050] Following the same nickel, zinc, and aluminum molar ratio as in Example 1, add the calculated amount of zinc dihydroxy dizinc carbonate (industrial grade, Xiangtan Hongyan Chemical Co., Ltd.) and a solution prepared with nickel chloride (chemically pure, Beijing Chemical Reagent Co., Ltd.) while stirring.

[0051] Following the same preparation steps as in Example 1, but controlling the silicon-to-aluminum ratio, a hierarchical porous ZSM-5 zeolite with a silicon-to-aluminum ratio of 25 was prepared, with a crystallinity of 95%, a pore size of 0.5 nm, a ten-membered ring micropore volume of 0.18 mL / g, and a mesopore volume of 5–15 nm. Sodium ions were removed by washing with ammonium chloride solution, and Na2O < 0.1 wt% was weighed out on a dry basis and added to the above mixture.

[0052] Weigh out 10 wt% of halloysite (industrial grade, Shijiazhuang Borui Building Materials Co., Ltd.) on a dry basis, grind it to 150 mesh, and add it to the above mixture. Add deionized water to make the liquid / solid weight ratio of the slurry 2.2. After stirring and mixing evenly, grind it for 45 minutes with a stirring mill. Spray dry it in a small spray drying tower in the laboratory at an exhaust gas temperature of 165℃ to form the slurry.

[0053] A 3wt% dilute solution was prepared using ammonium phosphate (chemically pure, Beijing Chemical Reagent Company) and deionized water. The same volume of the solution as the catalyst was measured and sprayed onto a ball milling machine for impregnation. The solution was then dried at 110°C for 4 hours and calcined in a muffle furnace at 410°C for 6 hours. The catalyst contained 50.1wt% zinc oxide and 30.2wt% nickel oxide on a dry basis. The catalyst microspheres had an average radius of 67 μm and a pore volume of 0.58 mL / g.

[0054] Comparative Example 1

[0055] A commercially available microsphere desulfurization adsorbent with a chemical composition similar to that of Example 2 was used as a reference for comparison.

[0056] Example 4

[0057] The implementation effect of the present invention is illustrated by comparing the results of the hydrodesulfurization reaction of gasoline, and a method for applying the catalyst is provided, using catalytic cracked gasoline as the evaluation feedstock, the properties of which are shown in Table 1.

[0058] Referring to the principle of CN201821237862.6, a medium-sized fluidized bed reactor for laboratory use was modified into a gasoline hydrodesulfurization test and evaluation facility for evaluating the reaction-regeneration performance of gasoline hydrodesulfurization microsphere catalysts.

[0059] Table 1. Evaluation of the properties of gasoline used as raw material:

[0060]

[0061] The catalysts in the examples and comparative examples were pre-reduced with hydrogen to a zero valence state for nickel. The desulfurization evaluation reaction was conducted at 420°C, a hydrogen pressure of 0.7 MPa, a hydrogen / oil molar ratio of 0.3, and a weight hourly space velocity (WHSV) of 6 h⁻¹. -1 The breakthrough sulfur capacity, single-stage reaction cycle and product liquid yield of the catalyst were measured and are shown in Table 2.

[0062] Table 2. Breakthrough sulfur capacity and single-stage reaction cycle of catalysts in Examples 1-3 and Comparative Example 1.

[0063] <![CDATA[Maximum sulfur content of product gasoline / μg·g -1 > <10 <10 <10 <10 Single-stage reaction-regeneration cycle / hour 33.1 33.7 32.9 15.1 Desulfurization reaction product liquid yield / wt% 98.7 99.4 98.2 98.1

[0064] In Table 2, "through" refers to the period from the start of the desulfurization reaction until the sulfur content of the gasoline in the outlet product exceeds 10 μg / g. "Through-through sulfur capacity" refers to the total amount of sulfur adsorbed and stored on the desulfurization catalyst before breakthrough. "Single-stage reaction cycle" refers to the reaction time before the sulfur adsorption breakthrough. This property directly affects the cycle of gasoline desulfurization reaction-regeneration, and thus affects the reaction and regeneration process of the entire desulfurization process.

[0065] Table 3 compares the composition of the desulfurization adsorption reaction products of the catalyst in Example 1 and the catalyst in Comparative Example 1, as well as the octane number loss of the gasoline products. The data in Table 3 show that the desulfurization effect of the catalyst of the present invention is better than that of the catalyst in the comparative example.

[0066] Table 3. Comparison of the composition of adsorption reaction product families

[0067] Example 1 51.1 33.2 15.7 5.0 0.8 Comparative Example 1 52.3 32.1 15.6 6.1 1.0

[0068] In the deep desulfurization reaction of gasoline, after the sulfur adsorption on the catalyst is saturated, the catalyst needs to be regenerated by burning sulfur with air to restore the catalyst's adsorption desulfurization performance. After the coke burning regeneration is completed, hydrogen is also used to reduce the nickel metal active component on the catalyst to restore the catalyst's hydrodesulfurization activity. Table 4 also gives the process conditions for recycling and the physicochemical properties of the catalyst during the reaction process.

[0069] Table 4. Comparison of process conditions and effects during recycling

[0070]

[0071] The data in Table 4 show that, during the reaction-regeneration process, the stable sulfur adsorption capacity and wear intensity of the catalyst of the present invention are better than those of the comparative catalyst, which is crucial for the practical application of the catalyst.

[0072] Finally, the above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features. It should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept; for example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for desulfurizing gasoline, characterized in that, This includes using gasoline hydrodesulfurization microsphere catalysts at weight space velocities of 2–8 h⁻¹. -1 The sulfur in the gasoline is removed by contacting it under hydrogen-exposed conditions of 380–450℃, 0.5–2.8 MPa and a hydrogen / oil molar ratio of 0.1–0.8 to obtain low-sulfur gasoline. The method for preparing the gasoline hydrodesulfurization microsphere catalyst includes the following steps: (1) The flow rates of acidic aluminum salt solution and alkaline aluminum salt solution are controlled separately under stirring so that the pH value of the gelling material of the mixed reaction is controlled within the range of 7 to 10. The slurry is filtered and washed with deionized water 1 to 3 times. (2) Add zinc-containing compounds and nickel-containing compounds under stirring to make the Ni / (Ni+Zn+Al) molar ratio 0.3-0.35 and the Zn / (Ni+Zn+Al) molar ratio 0.5-0.52; (3) Add 0.5wt% to 8wt% of hierarchical porous shape-selective catalytic zeolite and 5wt% to 15wt% of 100-400 mesh silica-containing fine powder filler on a dry basis. After grinding with a stirring mill for 15 to 130 minutes, spray dry the slurry at a liquid / solid weight ratio of 2.5 to 4, with the exhaust gas temperature >150℃. (4) Spray and impregnate with an equal volume of solution containing 3wt% to 4wt% ammonium phosphate compound, then dry; calcine at 250 to 600°C for 0.5 to 4 hours; The microsphere catalyst has an average particle size of 40–80 micrometers and a pore volume of 0.4–0.9 mL / g; the acidic aluminum salt is aluminum sulfate; the basic aluminum salt is sodium aluminate; the nickel-containing compound is nickel nitrate; and the zinc-containing compound is zinc dihydroxycarbonate. The hierarchical porous shape-selective catalytic zeolite is selected from hierarchical porous ZSM-5 zeolite; crystallinity 91%, Si / Al 54; pore size 0.5 nm ten-membered ring micropore volume 0.17 mL / g, pore size 5–15 nm mesopore volume 0.1 mL / g.

2. The method according to claim 1, characterized in that, The pH value of the mixed gelling material is controlled at 8.5~9.5; the Ni / (Ni+Zn+Al) molar ratio is 0.33 and the Zn / (Ni+Zn+Al) molar ratio is 0.5 when zinc-containing and nickel-containing compounds are added; 1wt%~5wt% of hierarchical porous shape-selective catalytic zeolite and 9wt%~11wt% of 150~250 mesh silica-containing fine powder filler are added on a dry basis, and the mixture is ground for 30~60 minutes; the calcination conditions are 380~500℃ for 1~3 hours; the average particle size of the microspheres is 60~75 micrometers.

3. The method according to claim 1, characterized in that, The silica-containing fine powder filler is selected from kaolin, halloysite, diatomite, bentonite, montmorillonite, leucite, sepiolite, palygorskite, soapstone, perlite, and macroporous silica.

4. The method according to claim 3, characterized in that, The silicon-containing fine powder filler is kaolin.

5. The method according to claim 1, characterized in that, The regeneration conditions for the deactivated catalyst recycled to the regenerator are: 400–600℃, 0.1–1MPa, and air regeneration for 1–4 hours; the reduction conditions for the catalyst are: 350–500℃, 0.1–3MPa, and hydrogen reduction for 1–4 hours.

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