Alkylene dehydrogenation catalyst, method for preparing and using the same, and method for preparing butadiene by butene oxidative dehydrogenation

Abstract

This invention relates to the field of catalytic dehydrogenation technology, specifically to an alkene dehydrogenation catalyst, its preparation method and application, and a method for the oxidative dehydrogenation of butene to butadiene. The catalyst has a structure comprising a spinel crystalline phase and an iron oxide crystalline phase, and contains auxiliary metal and non-metal components. The acid center density on the catalyst surface is 60–300 μmol / g. The catalyst provided by this invention has a structure comprising a spinel crystalline phase and an iron oxide crystalline phase, and contains auxiliary metal and non-metal components. By controlling the acid center density on the catalyst surface to 60–300 μmol / g, the catalyst exhibits excellent stability and activity.

Description

Technical Field

[0001] This invention relates to the field of catalytic dehydrogenation technology, specifically to an alkene dehydrogenation catalyst, its preparation method and application, and a method for the oxidative dehydrogenation of butene to butadiene. Background Technology

[0002] Mo-Bi, Sn-P-Li, and Feate systems can all be used for olefin oxidative dehydrogenation. Among them, iron-based catalysts have significant advantages: stable operation, relatively few oxidation byproducts, and a relatively low water-to-olefin ratio of 12–16, making them the most widely used catalysts for butene oxidative dehydrogenation. However, existing iron-based olefin oxidative dehydrogenation catalysts are susceptible to the properties of the reactants, such as olefin positional and geometric isomerism, leading to performance instability. Furthermore, the activity of existing olefin oxidative dehydrogenation catalysts needs further improvement.

[0003] Current technology uses oxidative dehydrogenation to produce butadiene. The upstream butene feedstock can come from refineries or methanol-to-olefins (MTO) plants. The content of butene-1 and butene-2 ​​isomers varies among different feedstock sources. These butene isomers with different structures exhibit significant differences in dehydrogenation activity on iron-based dehydrogenation catalysts, decreasing in the order of 1-butene > cis-2-butene > trans-2-butene under the same conditions. Therefore, a higher concentration of trans-2-butene in the feedstock composition will significantly impact the dehydrogenation performance of the catalyst. Summary of the Invention

[0004] To address the problems of low activity and poor stability of existing alkene dehydrogenation catalysts, this invention provides an alkene dehydrogenation catalyst, its preparation method and application, and a method for the oxidative dehydrogenation of butene to butadiene. This catalyst features high activity and good stability.

[0005] To achieve the above objectives, the first aspect of the present invention provides an alkene dehydrogenation catalyst, the catalyst having a structure comprising a spinel crystal phase and an iron oxide crystal phase, and the catalyst containing an auxiliary metal component and a non-metal component, wherein the acid center density on the catalyst surface is 60–300 μmol / g.

[0006] A second aspect of the present invention provides a method for preparing the catalyst described above, the method comprising:

[0007] (1) Prepare a solution by mixing inorganic salts required to form spinel structure, including iron salts, inorganic salts containing auxiliary metal components, inorganic salts containing non-metallic components and / or inorganic acids and high molecular weight organic matter, and then co-precipitate, age, filter and wash the solution with inorganic alkali to obtain slurry.

[0008] (2) Spray dry the slurry obtained in step (1) to obtain granular powder; press it to prepare granules of the required shape as needed;

[0009] (3) Roast the particles obtained in step (2).

[0010] A third aspect of the present invention provides the application of the catalyst described herein in olefin dehydrogenation.

[0011] A fourth aspect of the present invention provides a method for the oxidative dehydrogenation of butene to produce butadiene, the method comprising:

[0012] Using butene as a raw material, water as a diluent, and molecular oxygen as an oxidant, the reaction was carried out at a temperature of 280–600℃, a pressure of 0–0.4 MPa(a), and a butene volume hourly space velocity of 100–500 h⁻¹. -1 Under conditions where the volume ratio of H2O to butene is 1–20 and the volume ratio of O2 to butene is 0.4–1.0, the raw materials react with the catalyst to produce butadiene.

[0013] By adopting the above solution, the present invention has the following advantages:

[0014] The catalyst provided by this invention has a structure comprising a spinel crystal phase and an iron oxide crystal phase, and contains auxiliary metal and non-metal components. By controlling the acid center density on the catalyst surface to be 60–300 μmol / g, the catalyst exhibits excellent stability and activity.

[0015] Applying the catalyst provided by this invention to olefin dehydrogenation can significantly improve the conversion rate of olefins and the catalyst service life.

[0016] The catalyst of this invention is particularly suitable for the oxidative dehydrogenation of butene to butadiene, which can not only significantly improve the conversion rate of olefins and the catalyst service life, but also maintain a high product selectivity. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] The present invention provides an alkene dehydrogenation catalyst, the structure of which includes a spinel crystal phase and an iron oxide crystal phase, and the catalyst contains auxiliary metal components and non-metal components, and the acid center density on the catalyst surface is 60-300 μmol / g.

[0019] The catalyst provided by this invention has a structure comprising a spinel crystal phase and an iron oxide crystal phase, and contains auxiliary metal and non-metal components. By controlling the acid center density on the catalyst surface to be 60–300 μmol / g, the catalyst exhibits excellent stability and activity.

[0020] According to a preferred embodiment of the present invention, the acid center density on the catalyst surface is 100–200 μmol / g. By adopting the aforementioned preferred embodiment, the activity and stability of the catalyst can be further improved.

[0021] In this invention, as long as the objective of this invention can be achieved, the content of non-metallic components in the catalyst is not particularly limited. According to a preferred embodiment of this invention, the catalyst contains non-metallic components in an elemental weight of 0.01 to 1.0 wt%, preferably 0.1 to 0.8 wt%. By adopting the aforementioned preferred embodiment, the activity and stability of the catalyst can be further improved.

[0022] In this invention, as long as the objective of the invention can be achieved, the content of the auxiliary metal component in the catalyst is not particularly limited. According to a preferred embodiment of the invention, the catalyst contains an auxiliary metal component of 0.5 to 5.0 wt% by weight of oxide, preferably 1.0 to 3.0 wt%. By adopting the aforementioned preferred embodiment, the activity and stability of the catalyst can be further improved.

[0023] In this invention, the content of spinel phase in the catalyst is not particularly limited. According to a preferred embodiment of the invention, the percentage of spinel phase in the catalyst is 60-90 wt%, for example, it can be 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, or 90 wt%, preferably 70-80 wt%. By adopting the aforementioned preferred embodiment, the activity and stability of the catalyst can be further improved.

[0024] In this invention, the content of the iron oxide crystalline phase in the catalyst is not particularly limited. According to a preferred embodiment of the invention, the percentage of the iron oxide crystalline phase in the catalyst is 5-40 wt%, for example, it can be 5 wt%, 8 wt%, 10 wt%, 15 wt%, 18 wt%, 20 wt%, 30 wt%, or 40 wt%, preferably 8-20 wt%. By adopting the aforementioned preferred embodiment, the activity and stability of the catalyst can be further improved.

[0025] According to a preferred embodiment of the present invention, the pore volume of the catalyst is 0.2–6.0 ml / g, preferably 2.0–5.0 ml / g. For example, the pore volume of the catalyst of the present invention can be 0.2 ml / g, 0.5 ml / g, 1.0 ml / g, 1.5 ml / g, 2.0 ml / g, 3.0 ml / g, 4.0 ml / g, 5.0 ml / g, or 6.0 ml / g. By adopting the aforementioned preferred embodiment, the activity and stability of the catalyst can be further improved.

[0026] According to a preferred embodiment of the present invention, the catalyst has an average pore size of 400–900 nm, preferably 500–800 nm. By adopting the aforementioned preferred embodiment, the activity and stability of the catalyst can be further improved.

[0027] According to a preferred embodiment of the present invention, the catalyst has a specific surface area of ​​1 to 80 m². 2 / g, preferably 10-50m 2 / g. For example, the pore volume of the catalyst of the present invention can be 1m³. 2 / g、5m 2 / g, 10m 2 / g、20m 2 / g、30m 2 / g、40m 2 / g, 50m 2 / g、60m 2 / g、70m 2 / g、80m 2 / g. By adopting the aforementioned preferred scheme, the activity and stability of the catalyst can be further improved.

[0028] According to a preferred embodiment of the present invention, the non-metallic component element is selected from one or more of B, Cl, P, and S, preferably from one or two of Cl and P. By adopting the aforementioned preferred embodiment, the activity and stability of the catalyst can be further improved.

[0029] According to a preferred embodiment of the present invention, the auxiliary metal component element is selected from one or more of Cd, Al, Zr, Ce, Sn, Bi, and Mo. By adopting the aforementioned preferred embodiment, the activity and stability of the catalyst can be further improved.

[0030] According to a preferred embodiment of the present invention, the spinel structure satisfies the chemical formula: AB₂O₄, wherein A 2+ Selected from Ca 2+ Mn 2+ Co 2+ Ni 2+ Cu 2+ Zn 2+ Cd2+ Hg 2+ Mg 2+ Sn 2+ One or more of the following; B 3+ Selected from Al 3+ Co 3+ Bi 3 + Fe 3+ Ti 3+ V 3+ In 3+ One or more of the above-mentioned preferred embodiments can be used. By adopting the aforementioned preferred embodiments, the activity and stability of the catalyst can be further improved.

[0031] This invention provides a method for preparing the catalyst described above, the method comprising:

[0032] (1) Prepare a solution by mixing inorganic salts required to form spinel structure, including iron salts, inorganic salts containing auxiliary metal components, inorganic salts containing non-metallic components and / or inorganic acids and high molecular weight organic matter, and then co-precipitate, age, filter and wash the solution with inorganic alkali to obtain slurry.

[0033] (2) Spray dry the slurry obtained in step (1) to obtain granular powder; press it to prepare granules of the required shape as needed;

[0034] (3) Roast the particles obtained in step (2).

[0035] The catalyst preparation method provided by the present invention can obtain a catalyst with the aforementioned characteristics.

[0036] In this invention, the washing conditions can be conventionally chosen in the art. According to a preferred embodiment of the invention, the washing conditions include: washing the filtered material with a dilute aqueous solution of the inorganic salt containing the non-metallic component and / or a dilute inorganic acid at a temperature of 20–60°C for 10–60 minutes, and washing at least once. By adopting the aforementioned preferred scheme, the activity and stability of the prepared catalyst can be further improved.

[0037] According to a preferred embodiment of the present invention, the material obtained after washing is dispersed by slurrying with deionized water.

[0038] According to a preferred embodiment of the present invention, spray drying is performed at 110-120°C, and the spray drying yields particulate powder with a particle size of less than 200 μm.

[0039] In this invention, the calcination conditions can be conventionally chosen in the art. According to a preferred embodiment of the invention, the calcination conditions include: a temperature of 550–750°C, preferably 620–700°C; and a time of 4–18 hours. By adopting the aforementioned preferred scheme, the activity and stability of the prepared catalyst can be further improved.

[0040] According to a preferred embodiment of the present invention, the inorganic base is 10-20 wt% ammonia water.

[0041] In this invention, the aging conditions can be conventionally selected in the art. According to a preferred embodiment of the invention, the aging conditions include: a temperature of 10–50°C, a pH value of 8.0–11.0, preferably 8.5–9.8, and a time of 0.5–4 hours. By adopting the aforementioned preferred scheme, the activity and stability of the prepared catalyst can be further improved.

[0042] In this invention, the polymeric organic compound can be a conventional choice in the art. According to a preferred embodiment of the invention, the polymeric organic compound is at least one selected from polyethylene glycol, starch, sodium methyl cellulose, and sucrose. The content of the polymeric organic compound is 0.1 wt% to 6.0 wt% of the total mass of the mixture, preferably 0.6 to 4.0 wt%. By adopting the aforementioned preferred embodiment, the activity and stability of the prepared catalyst can be further improved.

[0043] According to a preferred embodiment of the present invention, the iron-containing salt is selected from at least one of ferric nitrate, basic ferric acetate, ferric chloride, and ferric ammonium sulfate. By adopting the aforementioned preferred embodiment, the activity and stability of the prepared catalyst can be further improved.

[0044] According to a preferred embodiment of the present invention, the inorganic salt containing the auxiliary metal component is selected from at least one of bismuth nitrate, zirconium nitrate, ammonium molybdate, tin tetrachloride, and cerium nitrate. By adopting the aforementioned preferred embodiment, the activity and stability of the prepared catalyst can be further improved.

[0045] According to a preferred embodiment of the present invention, the inorganic salt and / or inorganic acid containing non-metallic components are wherein the inorganic salt is selected from at least one of sodium chloride, ferric chloride, sodium hydrogen phosphate, and ammonium sulfide; and the inorganic acid is selected from one or two of phosphoric acid and boric acid. By adopting the aforementioned preferred embodiment, the activity and stability of the prepared catalyst can be further improved.

[0046] This invention provides an application of the catalyst described herein in olefin dehydrogenation.

[0047] Applying the catalyst provided by this invention to olefin dehydrogenation can significantly improve the conversion rate of olefins and the catalyst service life.

[0048] This invention provides a method for the oxidative dehydrogenation of butene to produce butadiene, the method comprising:

[0049] Using butene as a raw material, water as a diluent, and molecular oxygen as an oxidant, the reaction was carried out at a temperature of 280–600℃, a pressure of 0–0.4 MPa(a), and a butene volume hourly space velocity of 100–500 h⁻¹. -1 Under conditions where the volume ratio of H2O to butene is 1–20 and the volume ratio of O2 to butene is 0.4–1.0, the raw materials react with the catalyst to produce butadiene.

[0050] The method for producing butadiene not only significantly improves the conversion rate of olefins and the catalyst lifespan, but also maintains high product selectivity.

[0051] According to a preferred embodiment of the present invention, the conditions for the contact reaction include: a reaction temperature of 300–500°C; a reaction pressure of 0.1–0.2 MPa(a); and a butene volume hourly space velocity of 150–400 h⁻¹. -1 The volume ratio of H2O to butene is 6–11, and the volume ratio of O2 to butene is 0.5–0.8.

[0052] The present invention will be further illustrated below through examples.

[0053] The butene dehydrogenation reaction was carried out in a micro catalytic reactor in a continuous flow stainless steel reactor. Product analysis was performed using an HP-6820 gas chromatograph (TCD and FID dual detectors) to analyze the content of organic compounds such as olefins and dienes, as well as gases such as oxygen, carbon monoxide, and carbon dioxide in the dehydrogenation products, and to calculate the conversion rate, selectivity, and yield of the reaction.

[0054] Conversion rate = (Total butene feedstock - Residual butene in dehydrogenation products) / Total butene feedstock * 100%;

[0055] Yield = Amount of butadiene in dehydrogenation product / Theoretical yield of butadiene * 100%;

[0056] Selectivity = Yield / Conversion Rate;

[0057] The acid center density was measured using the NH3 desorption method: 0.15 g of sample was placed in a reaction tube with an inner diameter of 4 mm, and helium (He) was used as the carrier gas (flow rate 30 mL / min). The temperature was raised to 600 °C and kept at the in-situ constant temperature for 1 h. Then, the temperature was lowered to below 100 °C to absorb ammonia for 0.5 h. After purging with He for 1.5 h, the temperature was programmed to rise again (10 °C / min). The ammonia molecules desorbed from the sample were detected by a thermal conductivity cell and quantitative analysis was performed.

[0058] Example 1

[0059] 22.7g of ferric nitrate (Fe(NO3)3 9H2O), 477.5g of aluminum nitrate (Al(NO3)3 9H2O), 323.5g of manganese nitrate (Mn(NO3)2), 13.1g of bismuth nitrate (Bi(NO3)3 5H2O), 0.9g of sodium sulfide, and 14.8g of sodium methylcellulose were added to 1500ml of deionized water. The mixture was then co-precipitated at room temperature using 18wt% ammonia solution to control the pH at 9.5. After aging at room temperature for 3.0h, the mixture was filtered. The filtered material was then washed twice with 1500ml of dilute sodium sulfide solution for 30 minutes. Finally, it was dispersed into a slurry with 1000ml of deionized water. This slurry was spray-dried at 120℃ to obtain catalyst powder with a particle size below 200μm. The powder was pressed into cylindrical particles and calcined at 630℃ for 8 hours to obtain composite oxide catalyst A. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0060] Example 2

[0061] 213.8 g of basic ferric acetate (FeOH(CH3COO)2), 323.3 g of magnesium nitrate (Mg(NO3)2 6H2O), 14.1 g of zirconium nitrate (Zr(NO3)4 5H2O), 0.9 g of ammonium sulfide, and 24.8 g of sucrose were added to 1500 ml of deionized water. The mixture was then co-precipitated at room temperature using 15 wt% ammonia solution to control the pH at 9.0. After aging at room temperature for 2.0 h, the mixture was filtered. The filtered material was then washed twice with 1500 ml of dilute ammonium sulfide solution for 30 minutes each time. Finally, it was dispersed into a slurry with 1000 ml of deionized water and set aside. The slurry was spray-dried at 110 °C to obtain catalyst powder with a particle size below 200 μm. The powder was pressed into cylindrical particles and calcined at 660 °C for 6 hours to obtain composite oxide catalyst B. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0062] Example 3

[0063] 429.4g of ferric nitrate (Fe(NO3)3·9H2O), 297.6g of cobalt nitrate (Co(NO3)2·6H2O), 4.0g of ammonium molybdate ((NH4)6Mo7O4·4H2O), 0.8g of ammonium sulfide, and 34.9g of starch were added to 1500ml of deionized water. The mixture was then co-precipitated at room temperature using 17wt% ammonia solution to control the pH at 9.5. After aging at room temperature for 3.0h, the mixture was filtered. The filtered material was washed twice with 1000ml of dilute ammonium sulfide solution for 30 minutes, and then dispersed into a slurry with 1000ml of deionized water. This slurry was spray-dried at 120℃ to obtain catalyst powder with a particle size below 200μm. The powder was pressed into cylindrical particles and calcined at 650℃ for 8 hours to obtain composite oxide catalyst C. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0064] Example 4

[0065] 442.0 g of ferric nitrate (Fe(NO3)3·9H2O), 356.6 g of zinc nitrate (Zn(NO3)2·6H2O), 6.8 g of cerium nitrate (Ce(NO3)3·6H2O), 0.05 g of sodium chloride, and 20.8 g of sodium methylcellulose were added to 1200 ml of deionized water. The mixture was then co-precipitated at room temperature using 14 wt% ammonia solution to control the pH at 8.5. After aging at room temperature for 3.0 h, the mixture was filtered. The filtered material was washed twice with 1000 ml of dilute sodium chloride solution for 30 minutes each time. Finally, it was dispersed into a slurry with 800 ml of deionized water and set aside. The slurry was spray-dried at 110 °C to obtain catalyst powder with a particle size below 200 μm. The powder was pressed into cylindrical particles and calcined at 640 °C for 9 hours to obtain composite oxide catalyst D. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0066] Example 5

[0067] 434.7g of ferric nitrate (Fe(NO3)3 9H2O), 339.2g of zinc nitrate (Zn(NO3)2 6H2O), 2.8g of bismuth nitrate (Bi(NO3)3 5H2O), 1.7g of ammonium molybdate ((NH4)6Mo7O4·4H2O), 0.8g of sodium chloride, and 42.6g of sodium methylcellulose were added to 1200ml of deionized water. The mixture was then co-precipitated at room temperature using 14wt% ammonia solution to control the pH at 9.0. After aging at room temperature for 2.0h, the mixture was filtered. The filtered material was then washed twice with 1000ml of dilute sodium chloride solution for 30 minutes each time. Finally, it was dispersed into a slurry with 800ml of deionized water and set aside. The slurry was spray-dried at 110℃ to obtain catalyst powder with a particle size below 200μm. The powder was pressed into cylindrical particles and calcined at 670℃ for 6 hours to obtain composite oxide catalyst E. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0068] Example 6

[0069] 427.6 g of ferric nitrate (Fe(NO3)3 9H2O), 289.0 g of nickel nitrate (Ni(NO3)2 6H2O), 5.6 g of bismuth nitrate (Bi(NO3)3 5H2O), 1.1 g of phosphoric acid, and 28.0 g of sodium methylcellulose were added to 1000 ml of deionized water. The mixture was then co-precipitated at room temperature using 16 wt% ammonia solution to control the pH at 9.8. After aging at room temperature for 3.0 h, the mixture was filtered, and the filtered material was washed twice with 1000 ml of dilute phosphoric acid for 30 minutes. Finally, it was dispersed into a slurry with 800 ml of deionized water for later use. This slurry was spray-dried at 110 °C to obtain catalyst powder with a particle size below 200 μm. The powder was pressed into cylindrical particles and calcined at 650 °C for 8 hours to obtain composite oxide catalyst F. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0070] Example 7

[0071] 68.2g of ferric nitrate (Fe(NO3)3 9H2O), 411.5g of bismuth nitrate (Bi(NO3)3 5H2O), 299.5g of magnesium nitrate (Mg(NO3)2 6H2O), 5.9g of tin tetrachloride, 0.9g of phosphoric acid, and 12.5g of sodium methylcellulose were added to 1000ml of deionized water. The mixture was then co-precipitated at room temperature using 19wt% ammonia solution to maintain a pH of 9.8. After aging at room temperature for 3.0h, the mixture was filtered. The filtered material was washed twice with 1000ml of dilute phosphoric acid for 30 minutes, and then dispersed into a slurry with 800ml of deionized water. This slurry was spray-dried at 120℃ to obtain catalyst powder with a particle size below 200μm. The powder was pressed into cylindrical particles and calcined at 670℃ for 5 hours to obtain composite oxide catalyst G. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0072] Example 8

[0073] 79.5g of ferric nitrate (Fe(NO3)3 9H2O), 406.3g of bismuth nitrate (Bi(NO3)3 5H2O), 295.7g of magnesium nitrate (Mg(NO3)2 6H2O), 2.1g of tin tetrachloride, 0.12g of phosphoric acid, and 12.5g of sodium methylcellulose were added to 1000ml of deionized water. The mixture was then co-precipitated at room temperature using 19wt% ammonia solution to maintain a pH of 9.5. After aging at room temperature for 3.0h, the precipitated slurry was filtered and washed twice with 1000ml of dilute phosphoric acid for 30 minutes each time. The slurry was then dispersed in 800ml of deionized water and set aside. This slurry was spray-dried at 120℃ to obtain catalyst powder with a particle size below 200μm. The powder was pressed into cylindrical particles and calcined at 660℃ for 7 hours to obtain composite oxide catalyst H. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0074] Example 9

[0075] 41.7g of ferric nitrate (Fe(NO3)3 9H2O), 432.3g of bismuth nitrate (Bi(NO3)3 5H2O), 314.7g of magnesium nitrate (Mg(NO3)2 6H2O), 11.9g of tin tetrachloride, 1.35g of phosphoric acid, and 12.6g of sodium methylcellulose were added to 1000ml of deionized water. The mixture was then co-precipitated at room temperature using 19wt% ammonia solution to control the pH at 8.5, followed by aging at room temperature for 3.0h. After filtration, the material was washed twice with 1000ml of dilute phosphoric acid for 30 minutes each time. Finally, it was dispersed into a slurry with 800ml of deionized water for later use. This slurry was spray-dried at 120℃ to obtain catalyst powder with a particle size below 200μm. The powder was pressed into cylindrical particles and calcined at 660℃ for 7 hours to obtain composite oxide catalyst I. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0076] Example 10

[0077] 434.9g of ferric nitrate (Fe(NO3)3 9H2O), 339.6g of zinc nitrate (Zn(NO3)2 6H2O), 2.8g of bismuth nitrate (Bi(NO3)3 5H2O), 1.7g of ammonium molybdate ((NH4)6Mo7O4·4H2O), 0.8g of ammonium sulfide, and 42.6g of sodium methylcellulose were added to 1200ml of deionized water. The mixture was then co-precipitated at room temperature using 14wt% ammonia solution to control the pH at 9.0. After aging at room temperature for 2.0h, the mixture was filtered, and the filtered material was slurried and washed twice with 1000ml of dilute sodium dihydrogen phosphate solution for 30 minutes. Finally, it was dispersed into a slurry with 800ml of deionized water and set aside. This slurry was then spray-dried at 110℃ to obtain catalyst powder with a particle size below 200μm. The powder was pressed into cylindrical particles and then calcined at 670℃ for 6 hours to obtain composite oxide catalyst J. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0078] Example 11

[0079] 442.0 g of ferric nitrate (Fe(NO3)3 9H2O), 356.6 g of zinc nitrate (Zn(NO3)2 6H2O), 2.8 g of bismuth nitrate (Bi(NO3)3 5H2O), 1.7 g of ammonium molybdate ((NH4)6Mo7O4·4H2O), 0.8 g of sodium chloride, and 43.9 g of sodium methylcellulose were added to 1200 ml of deionized water. The mixture was then co-precipitated at room temperature using 14 wt% ammonia solution to control the pH at 9.0. After aging at room temperature for 2.0 h, the mixture was filtered. The filtered material was washed twice with 1000 ml of dilute sodium chloride solution for 30 minutes each time. Finally, it was dispersed into a slurry with 800 ml of deionized water and set aside. The slurry was spray-dried at 110 °C to obtain catalyst powder with a particle size below 200 μm. The powder was pressed into cylindrical particles and calcined at 670 °C for 6 hours to obtain composite oxide catalyst K. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0080] Example 12

[0081] 434.6 g of ferric nitrate (Fe(NO3)3 9H2O), 339.3 g of zinc nitrate (Zn(NO3)2 6H2O), 2.8 g of bismuth nitrate (Bi(NO3)3 5H2O), 1.7 g of ammonium molybdate ((NH4)6Mo7O4·4H2O), 1.4 g of sodium chloride, and 42.6 g of sodium methylcellulose were added to 1200 ml of deionized water. The mixture was then co-precipitated at room temperature using 14 wt% ammonia solution to control the pH at 9.0. After aging at room temperature for 2.0 h, the mixture was filtered. The filtered material was then washed twice with 1000 ml of dilute sodium chloride solution for 30 minutes each time. Finally, it was dispersed into a slurry with 800 ml of deionized water and set aside. The slurry was spray-dried at 110 °C to obtain catalyst powder with a particle size of less than 200 μm. The powder was pressed into cylindrical particles and calcined at 670 °C for 6 hours to obtain composite oxide catalyst L. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0082] Example 13

[0083] 434.5g of ferric nitrate (Fe(NO3)3 9H2O), 339.3g of zinc nitrate (Zn(NO3)2 6H2O), 2.8g of bismuth nitrate (Bi(NO3)3 5H2O), 1.7g of ammonium molybdate ((NH4)6Mo7O4·4H2O), 0.8g of sodium chloride, and 42.6g of sodium methylcellulose were added to 1200ml of deionized water. The mixture was then co-precipitated at room temperature using 14wt% ammonia solution to control the pH at 9.0. After aging at room temperature for 2.0h, the precipitated slurry was filtered and washed with 1000ml of dilute sodium chloride solution. The filtered material was then washed five times over 30 minutes. Finally, it was dispersed in 800ml of deionized water to form a slurry for later use. This slurry was then spray-dried at 110℃ to obtain catalyst powder with a particle size below 200μm. After the powder was pressed into cylindrical particles, it was calcined at 670℃ for 6 hours to obtain the composite oxide catalyst M. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0084] Table 1 Catalyst composition

[0085]

[0086] Table 2 Physical properties of catalysts

[0087] Pore ​​volume (ml / g) Average pore size (nm) <![CDATA[Specific surface area (m 2 / g)]]> Acid center density (μmol / g)* A 4.8 446 12.5 80 B 2.1 687 37.3 132 C 3.3 590 29.8 115 D 2.3 782 56.0 130 E 2.9 680 28.2 167 F 3.2 621 35.3 157 G 3.5 725 37.9 186 H 2.9 571 59.3 83 I 4.8 643 60.1 238 J 2.8 668 27.7 148 K 2.6 659 26.8 161 L 3.0 682 28.5 278 M 2.7 673 8.5 153 Comparative Example 1 3.8 726 35.6 11 Comparative Example 2 3.7 732 36.2 26 Comparative Example 3 3.9 723 37.1 31 Comparative Example 4 2.7 683 28.7 431

[0088] Comparative Example 1

[0089] The catalyst was prepared according to Example 7, except that tin tetrachloride and phosphoric acid were not added.

[0090] Comparative Example 2

[0091] The catalyst was prepared according to Example 7, except that phosphoric acid was not added.

[0092] Comparative Example 3

[0093] The catalyst composition was prepared according to Example 7, except that tin tetrachloride was not added.

[0094] Comparative Example 4

[0095] 434.5g of ferric nitrate (Fe(NO3)3 9H2O), 339.3g of zinc nitrate (Zn(NO3)2 6H2O), 2.8g of bismuth nitrate (Bi(NO3)3 5H2O), 1.7g of ammonium molybdate ((NH4)6Mo7O4·4H2O), 2.6g of sodium chloride, and 42.6g of sodium methylcellulose were added to 1200ml of deionized water. The mixture was then co-precipitated at room temperature using 14wt% ammonia solution to control the pH at 9.0. After aging at room temperature for 2.0h, the mixture was filtered. The filtered material was washed twice with 1000ml of dilute sodium chloride solution for 30 minutes, and then dispersed into a slurry with 800ml of deionized water. This slurry was spray-dried at 110℃ to obtain catalyst powder with a particle size below 200μm. The powder was pressed into cylindrical particles and calcined at 670℃ for 6 hours to obtain a composite oxide catalyst. The weight percentage composition of the obtained catalyst is shown in Table 1, and the physical properties of the catalyst are shown in Table 2.

[0096] Example 14

[0097] Catalyst A to Comparative Example 3 were prepared at 380 °C using a mixed feedstock of 25% 1-butene, 25% cis-2-butene, and 50% trans-2-butene (volume content), with a total butene volume hourly space velocity (VHSV) of 400 h⁻¹. -1 The performance was evaluated under the conditions of O2 / C4H8 volume ratio of 0.7 and water-olefin volume ratio of 6-12. The results are shown in Table 3.

[0098] Table 3

[0099]

[0100]

[0101] Example 13

[0102] Catalyst G (Example 7), Catalyst I (Example 9), and Comparative Example 1 were evaluated under the conditions of Example 10. The stability of the two catalysts was compared, and the performance of the catalysts after 500 hours is shown in Table 4.

[0103] Table 4

[0104]

[0105] In summary, the catalyst of the present invention has high activity and good stability, and can significantly improve the conversion rate of olefins and the product selectivity.

[0106] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An olefin dehydrogenation catalyst, characterized in that, The catalyst has a structure comprising a spinel crystal phase and an iron oxide crystal phase, and contains auxiliary metal and non-metal components. The density of acid centers on the catalyst surface is 60~300 μmol / g. The non-metallic component elements are selected from one or more of B, Cl, P and S; The auxiliary metal component element is selected from one or more of Cd, Al, Zr, Ce, Sn, Bi, and Mo; The catalyst contains non-metallic components at a weight of 0.01~1.0 wt%; The catalyst contains an auxiliary metal component in the form of oxides at a weight of 0.5~5.0 wt%; The percentage of spinel phase in the catalyst is 60-90 wt%. The percentage of iron oxide crystalline phase in the catalyst is 5-40 wt%. The spinel structure satisfies the chemical formula: AB₂O₄, where A 2+ Selected from Ca 2+ Mn 2+ Co 2+ Ni 2+ Cu 2+ Zn 2+ Cd 2+ Hg 2 + Mg 2+ Sn 2+ One or more of the following; B 3+ Selected from Al 3+ Co 3+ Bi 3+ Fe 3+ Ti 3+ V 3+ In 3+ One or more of them.

2. The catalyst according to claim 1, wherein, The density of acid centers on the catalyst surface is 100~200 μmol / g.

3. The catalyst according to claim 1, wherein, The catalyst contains non-metallic components at a weight of 0.1-0.8 wt%; and / or The catalyst contains an auxiliary metal component in an amount of 1.0 to 3.0 wt% by weight of oxide.

4. The catalyst according to any one of claims 1-3, wherein, The catalyst has a pore volume of 2.0~6.0 ml / g; and / or The catalyst has an average pore size of 400~900 nm; and / or The catalyst has a specific surface area of ​​1~80m². 2 / g.

5. The catalyst according to claim 4, wherein, The catalyst contains 70-80 wt% spinel phase; and / or The catalyst contains 8-20 wt% iron oxide crystalline phase; and / or The catalyst has a pore volume of 2.5~5.0 ml / g; and / or The catalyst has an average pore size of 500~800 nm; and / or The catalyst has a specific surface area of ​​10~50m². 2 / g.

6. The catalyst according to claim 1, wherein, The non-metallic component element is selected from one or two of Cl and P.

7. A method for preparing the catalyst according to any one of claims 1-6, characterized in that, The method includes: (1) Prepare a solution by mixing inorganic salts, iron salts, inorganic salts containing auxiliary metal components, inorganic salts containing non-metal components and / or inorganic acids, and high molecular weight organic matter required to form spinel structure, and then co-precipitate, age, filter and wash to obtain slurry; (2) Spray dry the slurry obtained in step (1) to obtain granular powder; press it to prepare granules of the required shape as needed; (3) Roast the particles obtained in step (2).

8. The preparation method according to claim 7, wherein, The roasting conditions include a temperature of 550~750°C. o C; Time is 4~18 hours; and / or Aging conditions include: a temperature of 10~50°C. o C, pH value 8.0~11.0; time 0.5~4 hours.

9. The preparation method according to claim 8, wherein, The roasting conditions include a temperature of 620~700°C. o C; and / or The aging conditions include a pH value of 8.5 to 9.

8.

10. The preparation method according to claim 7, wherein, The high molecular weight organic compound is at least one of polyethylene glycol and starch, and the content of the high molecular weight organic compound is 0.1 wt% to 6.0 wt% of the total mass of the mixture; and / or The iron-containing salt is selected from at least one of ferric nitrate, basic ferric acetate, ferric chloride, and ferric ammonium sulfate; and / or The inorganic salt containing the auxiliary metal component is selected from at least one of bismuth nitrate, zirconium nitrate, ammonium molybdate, tin tetrachloride, and cerium nitrate; and / or The inorganic salt and / or inorganic acid containing non-metallic components, wherein the inorganic salt is selected from at least one of sodium chloride, ferric chloride, sodium hydrogen phosphate, and ammonium sulfide; and the inorganic acid is selected from one or two of phosphoric acid and boric acid.

11. The preparation method according to claim 10, wherein, The content of the high molecular weight organic matter is 0.6 to 4.0 wt% of the total mass of the mixture.

12. The use of the catalyst according to any one of claims 1-6 in olefin dehydrogenation.

13. A method for the oxidative dehydrogenation of butene to produce butadiene, characterized in that, The method includes: Using butene as a raw material, water as a diluent, and molecular oxygen as an oxidant, the reaction was carried out at a temperature of 280–600 °C, a pressure of 0–0.4 MPa, and a butene volume hourly space velocity of 100–500 h⁻¹. -1 Under the conditions that the volume ratio of H2O / butene is 1~20 and the volume ratio of O2 / butene is 0.4~1.0, the raw materials react with the catalyst described in any one of claims 1-6 to produce butadiene.

14. The method according to claim 13, wherein, The reaction temperature is 300~500℃; the reaction pressure is 0.1~0.2MPa; and the butene volume hourly space velocity is 150~400 h⁻¹. -1 The volume ratio of H2O to butene is 6~11, and the volume ratio of O2 to butene is 0.5~0.8.

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