A catalyst for preparing acrylonitrile by propylene ammoxidation, and a preparation method and application thereof

Abstract

The application discloses a catalyst for preparing acrylonitrile through propylene ammoxidation and a preparation method and application thereof. An active component of the catalyst comprises La, Q and R, R is at least one of Ce, Pr, Nd, Sm and Eu elements, and Q is at least one of Zr, Ca, Ti and P elements; an atomic ratio of the La to the R is 0.05-0.45, and an atomic ratio of the Q / (La+R) is 0.01-0.25. When the catalyst is used for preparing acrylonitrile through propylene ammoxidation, the catalyst has the characteristics of high activity and low two-carbon yield in a long-period running process.

Description

Technical Field

[0001] This invention relates to an ammonia oxidation catalyst, specifically to a catalyst for the ammonia oxidation of propylene to acrylonitrile, its preparation method, and its application. Background Technology

[0002] Acrylonitrile is mainly used to produce acrylic fibers, ABS plastics, styrene plastics, acrylamide, etc., and is an important chemical raw material. Industrially, it is mainly produced from propylene using the fluidized bed ammoxidation process. Although the propylene ammoxidation to acrylonitrile technology has been successfully industrialized in acrylonitrile plants worldwide, the catalyst for propylene ammoxidation to acrylonitrile, which is one of the core technologies of this process, is still under continuous research and development in order to prepare catalysts with better overall performance in terms of activity, selectivity, and stability.

[0003] Currently, Mo-Bi catalysts have been widely used in industry. CN1600423A discloses a method for preparing a fluidized bed catalyst for the ammoxidation of olefins. The catalyst uses silica as a support, with the support accounting for 30-50 wt% of the total catalyst volume. The active component is composed of Mo (general formula). (12-g) Bi a Fe b Ni c X d Y e Z f Q g O x The expression indicates that X represents Mg, Co, Ca, etc.; Y represents La, Ce, Sm, etc.; Z represents Li, K, Rb, etc.; Q represents B, W, P, etc.; and a to f represent the atomic number of the corresponding element. The catalyst preparation method involves dissolving the starting materials of the metal elements to form a mixed salt solution, then co-precipitating it with the supporting starting materials to form a slurry. After aging the slurry, it is spray-dried, and the dried particles are calcined at high temperature to obtain the finished catalyst.

[0004] For catalysts used in the ammoxidation of propylene to acrylonitrile, developing Mo-Bi-based catalysts that simultaneously exhibit high activity and low yields of both carbon atoms has been a long-standing research goal in this field. Summary of the Invention

[0005] To address the problems of low catalyst activity and high two-carbon yield in the existing technology for the ammoxidation of propylene to acrylonitrile, this invention provides a catalyst for the ammoxidation of propylene to acrylonitrile, its preparation method, and its application. This catalyst for the ammoxidation of propylene to acrylonitrile exhibits both high activity and low two-carbon yield.

[0006] The first aspect of the present invention provides a catalyst for the ammoxidation of propylene to prepare acrylonitrile, wherein the active components of the catalyst include La, Q and R, wherein R is at least one of Ce, Pr, Nd, Sm and Eu, and Q is at least one of Zr, Ca, Ti and P; the atomic ratio of La / R is 0.05-0.45, and the atomic ratio of Q / (La+R) is 0.01-0.25.

[0007] Furthermore, the atomic ratio of La / R is 0.08-0.40, and the atomic ratio of Q / (La+R) is 0.01-0.20.

[0008] Furthermore, the active component is a composite oxide, and in addition to La, Q and R, the active component also includes Mo, Bi, Fe, alkali metal elements, alkaline earth metal elements and other elements A.

[0009] Furthermore, the catalyst also includes a support, preferably silica.

[0010] Furthermore, based on the weight of the catalyst, the content of the active component, calculated as oxide, is 30%-90%, and the content of the support is 10%-70%.

[0011] Furthermore, the alkali metal element is selected from at least one of Li, Na, K, Rb, and Cs; the alkaline earth metal element is selected from at least one of Be, Mg, Sr, and Ba; and the other element A is selected from at least one of W, V, Nb, Ni, Co, Cr, Mn, Tl, Au, Ag, Pt, Ru, Rh, Pd, Sb, In, Sn, Te, and In.

[0012] Furthermore, in the active components, the amount is based on the weight of the catalyst.

[0013] The Mo element, calculated as MoO3, has a weight content of 15%-55%, preferably 20%-45%.

[0014] The Bi element, calculated as Bi₂O₃, has a weight content of 0.5%-3.5%, preferably 1.0%-3.5%.

[0015] The Fe element, calculated as Fe2O3, has a weight content of 1%-12%, preferably 1.5%-11%.

[0016] The weight content of the La and R elements, calculated as their respective oxides, is 1.5%-8.5%, preferably 2.5%-5.0%.

[0017] The Q element, calculated as oxide, has a weight content of 0.01%-5.0%, preferably 0.01%-3.5%.

[0018] The alkali metal element, calculated as oxide, has a weight content of 0.01%-0.60%, preferably 0.05%-0.55%.

[0019] The alkaline earth metal, calculated as oxides, has a weight content of 0.01%-4.0%, preferably 0.5%-2.5%.

[0020] The other element A, calculated as oxides, has a weight content of 0.01%-15%, preferably 0.05%-14%.

[0021] Furthermore, in the active component, the atomic ratio of Bi / Mo is 0.008-0.25, preferably 0.01-0.20; examples, but not limited to, are: 0.02, 0.04, 0.05, 0.06, 0.07, 0.08, 0.10, 0.12, 0.14, 0.16, 0.18, 0.20, etc.

[0022] Furthermore, in the active component, the atomic ratio of Fe / Bi is 1.0-12.0, preferably 1.5-11.0; examples, but not limited to, include: 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, etc.

[0023] Furthermore, in the active component, the atomic ratio of (La+R+alkali metal element+alkaline earth metal element) / Mo is 0.05-0.4, preferably 0.10-0.35; examples, but not limited to: 0.10, 0.12, 0.14, 0.16, 0.18, 0.20, 0.22, 0.25, 0.28, 0.30, 0.32, 0.35, etc.

[0024] Furthermore, in the active component, the atomic ratio of A / Mo is 0.01-1.0, preferably 0.02-0.90; examples, but not limited to: 0.02, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, etc.

[0025] A second aspect of the present invention provides a method for preparing the catalyst for the ammoxidation of propylene to acrylonitrile described above, comprising the following steps:

[0026] (1) Mix the precursors of La, R, Q and some of Mo, and heat treat them to form a mixture I;

[0027] (2) Mix the precursors of the active components other than La, R, Q and Mo to form solution I;

[0028] (3) Mix the remaining Mo precursor and the carrier precursor to form a mixture II, add the mixture I and solution I, and perform heat treatment to form slurry I;

[0029] (4) Spray dry slurry I to obtain particulate matter;

[0030] (5) The particulate matter is calcined to obtain the catalyst.

[0031] Furthermore, the heating rate of the heat treatment in step (1) is controlled at 5-20℃ / min, the heat treatment temperature is controlled at 50-120℃, and the temperature is maintained at a constant temperature for 5-20min.

[0032] Furthermore, the heating rate of the heat treatment in step (3) is controlled at 8-20℃ / min, the heat treatment temperature is controlled at 100-150℃, and the temperature is kept constant for 5-20min.

[0033] Further, the carrier precursor in step (3) is a silicon dioxide precursor, preferably a silica sol, wherein the solid content of the silica sol is 20wt%-50wt% based on silicon dioxide, and the average particle size distribution is 10-35nm.

[0034] Furthermore, there are no particular limitations on the proportions or amounts of the La, R, Q, Mo, and other element precursors (Fe, alkali metal, alkaline earth metal, and other element A precursors) and the support precursor, as long as the content of each component in the final catalyst particles meets the requirements.

[0035] Further, in step (1), the Mo element introduced into the catalyst accounts for 40%-80% of the total MoO3 content in the catalyst, preferably 40%-70%.

[0036] Furthermore, there are no particular limitations on the Mo precursor; it can be an oxide of Mo or any substance that can generate such an oxide upon calcination. Examples include oxides, hydroxides, inorganic acid salts, organic acid salts, and oxyacid ammonium salts (including hydrates of these compounds). Water-soluble inorganic acid salts, water-soluble organic acid salts, and oxyacid ammonium salts of Mo are preferred, and oxyacid ammonium salts of Mo are more preferred, such as (NH4)6Mo7O. 24 Or its hydrates.

[0037] Furthermore, there are no particular limitations on the precursors of Bi, Fe, La, R, Q, alkali metals, alkaline earth metals, and other elements A. These precursors can be oxides of the corresponding elements or any substance that can generate an oxide upon calcination. Examples include oxides, hydroxides, inorganic acid salts, and organic acid salts (including hydrates of these compounds). Water-soluble inorganic acid salts and water-soluble organic acid salts are preferred, and halides, alkoxides, nitrates, and acetates are even more preferred, especially nitrates. These precursors can be used individually or in combination in any proportion.

[0038] Further, the conditions for spray drying in step (4) include: the drying heat source is air, the drying temperature is 250-350℃, preferably 300-350℃, the drying time is 0.1-2.0h, preferably 0.2-1.0h, and the average diameter of the spray droplets is 20-200μm, preferably 40-180μm.

[0039] Further, the roasting in step (5) is carried out in two stages. The first stage roasting conditions are: roasting temperature of 200-300℃, roasting time of 0.5-5h, and heating rate of 1-5℃ / min; the second stage roasting conditions are: roasting temperature of 500-750℃, roasting time of 0.5-5h, and heating rate of 8-20℃ / min. The roasting is carried out in an oxygen-containing atmosphere. In the oxygen-containing atmosphere, the volume content of oxygen is generally greater than 0% and less than 100%, preferably greater than 0% and less than 50%, relative to the total volume of the oxygen-containing atmosphere.

[0040] A third aspect of this invention provides a method for preparing acrylonitrile by ammoxidation of propylene, comprising: in the presence of the above-described catalyst or a catalyst prepared by the above-described method, propylene undergoes an ammoxidation reaction to generate acrylonitrile, wherein the reaction conditions are: a molar ratio of propylene:ammonia:air of 1:1.1-1.35:9.5-10, a reaction temperature of 420-440℃, a reaction pressure of 0.03-0.14 MPa (gauge pressure), and a weight hourly space velocity of 0.04-0.10 h⁻¹. 1 .

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0042] 1. The inventors discovered through research that by controlling the ratio of La element to other rare earth elements R (Ce, Pr, Nd, Sm, Eu) and the ratio of Q to rare earth elements (La+R) in the catalyst for the ammoxidation of propylene to acrylonitrile, the formed rare earth molybdate phase can form a solid solution with the active phase, thereby stabilizing the existence of the active phase and preventing the formation of other phases, thus ensuring that the catalyst has high activity and low two-carbon yield.

[0043] 2. This invention employs a method of pre-mixing Q, rare earth (La and R), and a portion of Mo as raw materials during catalyst preparation. This facilitates the formation of a more stable phase between the rare earth molybdate and Q. Simultaneously, the heat treatment and calcination processes during catalyst preparation significantly reduce the yield of carbon and carbon and improve catalyst stability. This is likely due to the stable proportion of crystalline phases on the catalyst surface, which allows for sufficient active sites for the adsorption and reaction of reactant gases during the reaction process. This enables the reaction to proceed with high selectivity, stability, and appropriate levels, effectively controlling the problem of excessively high yields of carbon and carbon.

[0044] 3. When the catalyst of the present invention is used for the ammoxidation of propylene to acrylonitrile, it has a low two-carbon yield and can significantly improve the stability and activity of the catalyst. Detailed Implementation

[0045] In this invention, the two carbons refer to CO and CO2, and the yield of the two carbons (%) = (total moles of carbon monoxide and carbon dioxide generated in the reaction / moles of propylene feed in carbon moles) × 100%.

[0046] In this invention, propylene conversion and acrylonitrile selectivity are defined as follows:

[0047] Propylene conversion rate (%) = (moles of propylene consumed in the reaction / moles of propylene fed) × 100%,

[0048] Acrylonitrile selectivity (%) = (moles of acrylonitrile produced in the reaction / moles of acrylonitrile consumed in the reaction) × 100%.

[0049] The present invention will be further illustrated by the following examples.

[0050] Example 1

[0051] 521 grams of (NH4)6Mo7O 24 Dissolve 4H2O in water, add 2.21 g ZrO2, 77.2 g Pr(NO3)3·6H2O and 25.6 g La(NO3)3·6H2O to form mixed solution I, heat to 80℃ at a rate of 10℃ / min and hold at that temperature for 15 min; dissolve 3.64 g KOH, 798.9 g Fe(NO3)3·9H2O, 173.9 g Bi(NO3)3·5H2O, 526.6 g Ni(NO3)2·6H2O and 137.9 g Mg(NO3)2·6H2O in water to obtain solution I; add 306.0 g (NH4)6Mo7O 24• 4H₂O was dissolved in water, and 2750 g of silica sol with a weight concentration of 40% was added. After stirring for 30 min, mixture II was formed. Mixture I was added and stirred, followed by the addition of solution I and stirring. Then, the temperature was increased to 150 °C at a rate of 10 °C / min and held for 15 min to form slurry I. Slurry I was then subjected to microsphere forming in a spray dryer at 300 °C for 0.5 h, resulting in an average droplet diameter of 100 μm, thus obtaining particulate matter. Finally, the calcination was carried out in an air atmosphere, with the calcination temperature increased at a rate of 5 °C / min to 300 °C and held for 30 min. Then, the temperature was increased at a rate of 20 °C / min to 550 °C and held for 45 min. The composition of the catalyst obtained according to the above steps is expressed by the following formula:

[0052] 50% Zr 0.05 K 0.15 Fe 5.46 Ni 5.0 Mg 1.5 Pr 0.5 La 0.18 Bi 1.0 Mo 13 O x +50% SiO2

[0053] The reaction conditions for the ammoxidation of propylene to acrylonitrile using the above catalyst are as follows: In a millimeter-sized fluidized bed reactor, the catalyst particle size was 50 micrometers, the reaction temperature was 430℃, the reaction pressure was 0.084 MPa, the catalyst loading was 300 g, and the catalyst propylene loading (WWH) was 0.085 h. -1 Raw material ratio (molar): C3 ＝ / NH3 / air = 1 / 1.25 / 9.6. After running for 1000 hours, the reaction results are shown in Table 1.

[0054] Example 2

[0055] 526.5 grams of (NH4)6Mo7O 24 Dissolve 4H2O in water, add 3.57 g Ca(NO3)2·6H2O, 78.7 g Nd(NO3)3·6H2O and 21.6 g La(NO3)3·6H2O to form mixed solution I, heat to 100℃ at a rate of 5℃ / min and hold at that temperature for 10 min; dissolve 3.68 g KOH, 807.4 g Fe(NO3)3·9H2O, 87.9 g Bi(NO3)3·5H2O, 527.2 g Co(NO3)2·6H2O, 128.4 g Mn(NO3)2, 139.3 g Mg(NO3)2·6H2O and 6.12 g AgNO3 in water to obtain solution I; add 309.2 g (NH4)6Mo7O 24• 4H₂O was dissolved in water, and 2750 g of silica sol with a weight concentration of 40% was added. After stirring for 30 min, mixture II was formed. Mixture I was added and stirred, followed by the addition of solution I and stirring. Then, the temperature was increased to 120°C at a rate of 10°C / min and held for 15 min to form slurry I. Slurry I was then subjected to microsphere forming in a spray dryer at a temperature of 300°C for 0.5 h, resulting in an average droplet diameter of 100 μm, thus obtaining particulate matter. Finally, the calcination was carried out in an air atmosphere, with the calcination temperature increased at a rate of 5°C / min to 300°C and held for 30 min. Then, the temperature was increased at a rate of 20°C / min to 550°C and held for 45 min. The composition of the catalyst obtained according to the above steps is expressed by the following formula:

[0056] 50% Ca 0.08 Ag 0.1 K 0.15 Fe 5.46 Co 5.0 Mn 1.0 Mg 1.5 Nd 0.5 La 0.15 Bi 0.5 Mo 13 O x +50% SiO2

[0057] The reaction conditions for the ammoxidation of propylene to acrylonitrile using the above catalyst are as follows: In a millimeter-sized fluidized bed reactor, the catalyst particle size was 50 micrometers, the reaction temperature was 430℃, the reaction pressure was 0.084 MPa, the catalyst loading was 300 g, and the catalyst propylene loading (WWH) was 0.085 h. -1 Raw material ratio (molar): C3 ＝ / NH3 / air = 1 / 1.25 / 9.6. After running for 1000 hours, the reaction results are shown in Table 1.

[0058] Example 3

[0059] 755.8 grams of (NH4)6Mo7O 24 Dissolve 4H2O in water, add 6.41 g ZrO2, 67.8 g Ce(NO3)3·6H2O and 24.8 g La(NO3)3·6H2O to form mixed solution I, heat to 120℃ at a rate of 10℃ / min, and hold at that temperature for 8 min; dissolve 11.5 g RbNO3, 1159 g Fe(NO3)3·9H2O, 126.1 g Bi(NO3)3·5H2O, 756.8 g Co(NO3)2·6H2O, 184.2 g Mg(NO3)2·6H2O, 5.25 g Cr2O3 and 4.4 g AgNO3 in water to obtain solution I; add 443.9 g (NH4)6Mo7O24 • 4H₂O was dissolved in water, and 1650 g of silica sol with a weight concentration of 40% was added. After stirring for 30 min, mixture II was formed. Mixture I was added and stirred, followed by the addition of solution I and stirring. Then, the temperature was increased to 100℃ at a rate of 10℃ / min and held for 15 min to form slurry I. Slurry I was then subjected to microsphere forming in a spray dryer at a drying temperature of 300℃ for 0.5 h, resulting in an average droplet diameter of 100 μm to obtain particulate matter. Finally, the calcination was carried out in an air atmosphere, with the calcination temperature increased at a rate of 5℃ / min to 300℃ and held for 30 min, followed by an increase at a rate of 20℃ / min to 550℃ and held for 45 min. The composition of the catalyst obtained according to the above steps is expressed by the following formula:

[0060] 70% Zr 0.10 Ag 0.05 Rb 0.15 Fe 5.46 Co 5.0 Cr 0.1 Mg 1.5 La 0.12 Ce 0.3 Bi 0.5 Mo 13 O x +30% SiO2

[0061] The reaction conditions for the ammoxidation of propylene to acrylonitrile using the above catalyst are as follows: In a millimeter-sized fluidized bed reactor, the catalyst particle size was 50 micrometers; the reaction temperature was 430℃; the reaction pressure was 0.084 MPa; the catalyst loading was 300 g; and the catalyst propylene loading (WWH) was 0.085 h⁻¹. 1 Raw material ratio (moles): C3 = NH3 / air = 1 / 1.25 / 9.6. After running for 1000 hours, the reaction results are shown in Table 1.

[0062] Example 4

[0063] 646.8 grams of (NH4)6Mo7O 24Dissolve 4H2O in water, add 1.65 g ZrO2, 38.8 g Sm(NO3)3·6H2O and 8.8 g La(NO3)3·6H2O to form mixed solution I, heat to 80℃ at a rate of 20℃ / min, and hold at that temperature for 15 min; dissolve 9.85 g RbNO3, 991.8 g Fe(NO3)3·9H2O, 108 g Bi(NO3)3·5H2O, 653.8 g Ni(NO3)2·6H2O, 171.2 g Mg(NO3)2·6H2O, 4.5 g Cr2O3 and 11.28 g AgNO3 in water to obtain solution I; add 379.9 g (NH4)6Mo7O 24 • 4H₂O was dissolved in water, and 2200 g of silica sol with a weight concentration of 40% was added. After stirring for 30 min, mixture II was formed. Mixture I was added and stirred, followed by the addition of solution I and stirring. Then, the temperature was increased to 150 °C at a rate of 20 °C / min and held for 15 min to form slurry I. Slurry I was then subjected to microsphere forming in a spray dryer at 300 °C for 0.5 h, resulting in an average droplet diameter of 100 μm, thus obtaining particulate matter. Finally, the calcination was carried out in an air atmosphere, with the calcination temperature increased at a rate of 5 °C / min to 300 °C and held for 20 min, followed by increasing the temperature at a rate of 20 °C / min to 550 °C and holding for 45 min. The composition of the catalyst obtained according to the above steps is expressed by the following formula:

[0064] 60% Zr 0.03 Ag 0.15 Rb 0.15 Fe 5.46 Ni 5.0 Cr 0.1 Mg 1.5 Sm 0.5 La 0。05 Bi 0.5 Mo 13 O x +40% SiO2

[0065] The reaction conditions for the ammoxidation of propylene to acrylonitrile using the above catalyst are as follows: In a millimeter-sized fluidized bed reactor, the catalyst particle size was 50 micrometers, the reaction temperature was 430℃, the reaction pressure was 0.084 MPa, the catalyst loading was 300 g, and the catalyst propylene loading (WWH) was 0.085 h. -1 Raw material ratio (moles): C3 = NH3 / air = 1 / 1.25 / 9.6. After running for 1000 hours, the reaction results are shown in Table 1.

[0066] Example 5

[0067] 646.0 grams of (NH4)6Mo7O 24Dissolve 4H2O in water, add 2.74 g ZrO2, 38.8 g Sm(NO3)3·6H2O and 21.2 g La(NO3)3·6H2O to form mixed solution I, heat to 80℃ at a rate of 10℃ / min and hold at that temperature for 15 min; dissolve 9.83 g RbNO3, 990.7 g Fe(NO3)3·9H2O, 107.8 g Bi(NO3)3·5H2O, 653 g Ni(NO3)2·6H2O, 171 g Mg(NO3)2·6H2O, 4.49 g Cr2O3 and 6.65 g In(NO3)3 in water to obtain solution I; add 379.4 g (NH4)6Mo7O 24 • 4H₂O was dissolved in water, and 2200 g of silica sol with a weight concentration of 40% was added. After stirring for 30 min, mixture II was formed. Mixture I was added and stirred, followed by the addition of solution I and stirring. Then, the temperature was increased to 120°C at a rate of 20°C / min and held for 15 min to form slurry I. Slurry I was then subjected to microsphere forming in a spray dryer at 300°C for 0.5 h, resulting in an average droplet diameter of 100 μm, thus obtaining particulate matter. Finally, the calcination was carried out in an air atmosphere, with the calcination temperature increased at a rate of 5°C / min to 300°C and held for 10 min, followed by increasing the temperature at a rate of 20°C / min to 550°C and holding for 45 min. The composition of the catalyst obtained according to the above steps is expressed by the following formula:

[0068] 60% Zr 0.05 In 0.05 Rb 0.15 Fe 5.46 Ni 5.0 Cr 0.1 Mg 1.5 Sm 0.5 La 0。12 Bi 0.5 Mo 13 O x +40% SiO2

[0069] The reaction conditions for the ammoxidation of propylene to acrylonitrile using the above catalyst are as follows: In a millimeter-sized fluidized bed reactor, the catalyst particle size was 50 micrometers, the reaction temperature was 430℃, the reaction pressure was 0.084 MPa, the catalyst loading was 300 g, and the catalyst propylene loading (WWH) was 0.085 h. -1 Raw material ratio (moles): C3 = NH3 / air = 1 / 1.25 / 9.6. After running for 1000 hours, the reaction results are shown in Table 1.

[0070] Example 6

[0071] 642.9 grams of (NH4)6Mo7O24 Dissolve 4H2O in water, add 2.73 g ZrO2, 95.3 g Pr(NO3)3·6H2O and 14.1 g La(NO3)3·6H2O to form mixed solution I, heat to 80℃ at a rate of 10℃ / min and hold at that temperature for 15 min; dissolve 6.52 g RbNO3, 985.9 g Fe(NO3)3·9H2O, 107.3 g Bi(NO3)3·5H2O, 649.9 g Ni(NO3)2·6H2O, 156.7 g Mg(NO3)2·6H2O, 4.47 g CrO3 and 13.24 g In(NO3)3 in water to obtain solution I; add 377.6 g (NH4)6Mo7O 24 • 4H₂O was dissolved in water, and 2200 g of silica sol with a weight concentration of 40% was added. After stirring for 30 min, mixture II was formed. Mixture I was added and stirred, followed by the addition of solution I and stirring. Then, the temperature was increased to 100℃ at a rate of 20℃ / min and held for 15 min to form slurry I. Slurry I was then subjected to microsphere forming in a spray dryer at a drying temperature of 300℃ for 0.5 h, resulting in an average droplet diameter of 100 μm to obtain particulate matter. Finally, the particulate matter was calcined in an air atmosphere, with the calcination temperature increased at a rate of 5℃ / min to 300℃ and held for 20 min, followed by increasing the temperature at a rate of 20℃ / min to 550℃ and holding for 45 min. The composition of the catalyst obtained according to the above steps is expressed by the following formula:

[0072] 60% Zr 0.05 In 0.1 Rb 0.10 Fe 5.46 Ni 5.0 Cr 0.1 Mg 1.5 Pr 0.5 La 0.08 Bi 0.5 Mo 13 O x +40% SiO2

[0073] The reaction conditions for the ammoxidation of propylene to acrylonitrile using the above catalyst are as follows: In a millimeter-sized fluidized bed reactor, the catalyst particle size was 50 micrometers; the reaction temperature was 430℃; the reaction pressure was 0.084 MPa; the catalyst loading was 300 g; and the catalyst propylene loading (WWH) was 0.085 h⁻¹. 1 Raw material ratio (moles): C3 = NH3 / air = 1 / 1.25 / 9.6. After running for 1000 hours, the reaction results are shown in Table 1.

[0074] Comparative Example 1

[0075] Dissolve 2.21 g ZrO2, 77.2 g Pr(NO3)3·6H2O, 25.6 g La(NO3)3·6H2O, 3.64 g KOH, 798.9 g Fe(NO3)3·9H2O, 173.9 g Bi(NO3)3·5H2O, 526.6 g Ni(NO3)2·6H2O, and 137.9 g Mg(NO3)2·6H2O in water to obtain solution I; dissolve 827.0 g (NH4)6Mo7O 24 • 4H₂O was dissolved in water, and 2750 g of silica sol with a weight concentration of 40% was added. After stirring for 30 min, a mixture I was formed. Solution I was added and stirred, and then the temperature was increased to 150 °C at a rate of 10 °C / min and held for 15 min to form slurry I. The prepared slurry I was then subjected to microsphere forming in a spray dryer at a drying temperature of 300 °C for 0.5 h, with an average droplet diameter of 100 μm, to obtain particulate matter. Finally, the particulate matter was calcined in an air atmosphere, with the calcination temperature increased at a rate of 5 °C / min to 300 °C and held for 30 min, and then increased at a rate of 20 °C / min to 550 °C and held for 45 min. The composition of the catalyst obtained according to the above steps is expressed by the following formula:

[0076] 50% Zr 0.05 K 0.15 Fe 5.46 Ni 5.0 Mg 1.5 Pr 0.5 La 0.18 Bi 1.0 Mo 13 O x +50% SiO2

[0077] The reaction conditions for the ammoxidation of propylene to acrylonitrile using the above catalyst are as follows: In a millimeter-sized fluidized bed reactor, the catalyst particle size was 50 micrometers; the reaction temperature was 430℃; the reaction pressure was 0.084 MPa; the catalyst loading was 300 g; and the catalyst propylene loading (WWH) was 0.085 h⁻¹. 1 Raw material ratio (moles): C3 = NH3 / air = 1 / 1.25 / 9.6. After running for 1000 hours, the reaction results are shown in Table 1.

[0078] Comparative Example 2

[0079] 521 grams of (NH4)6Mo7O 24Dissolve 4H2O in water, add 2.22 g ZrO2 and 77.8 g Pr(NO3)3·6H2O to form mixed solution I, heat to 80℃ at a rate of 10℃ / min, and hold at that temperature for 15 min; dissolve 3.67 g KOH, 804.6 g Fe(NO3)3·9H2O, 175.1 g Bi(NO3)3·5H2O, 530.4 g Ni(NO3)2·6H2O, and 138.9 g Mg(NO3)2·6H2O in water to obtain solution I; add 306.0 g (NH4)6Mo7O 24 • 4H₂O was dissolved in water, and 2750 g of silica sol with a weight concentration of 40% was added. After stirring for 30 min, mixture II was formed. Mixture I was added and stirred, followed by the addition of solution I and stirring. Then, the temperature was increased to 150 °C at a rate of 10 °C / min and held for 15 min to form slurry I. Slurry I was then subjected to microsphere forming in a spray dryer at a drying temperature of 300 °C for 0.5 h, resulting in an average droplet diameter of 100 μm to obtain particulate matter. Finally, the calcination was carried out in an air atmosphere, with the calcination temperature increased at a rate of 5 °C / min to 300 °C and held for 30 min. Then, the temperature was increased at a rate of 20 °C / min to 550 °C and held for 45 min. The composition of the catalyst obtained according to the above steps is expressed by the following formula:

[0080] 50% Zr0 .05 K 0.15 Fe 5.46 Ni 5.0 Mg 1.5 Pr 0.5 Bi 1.0 Mo 13 O x +50% SiO2

[0081] The reaction conditions for the ammoxidation of propylene to acrylonitrile using the above catalyst are as follows: In a millimeter-sized fluidized bed reactor, the catalyst particle size was 50 micrometers; the reaction temperature was 430℃; the reaction pressure was 0.084 MPa; the catalyst loading was 300 g; and the catalyst propylene loading (WWH) was 0.085 h⁻¹. 1 Raw material ratio (moles): C3 = NH3 / air = 1 / 1.25 / 9.6. After running for 1000 hours, the reaction results are shown in Table 1.

[0082] Comparative Example 3

[0083] 521 grams of (NH4)6Mo7O 24Dissolve 4H2O in water, add 77.2 g of Pr(NO3)3·6H2O and 25.6 g of La(NO3)3·6H2O to form mixed solution I, heat to 80℃ at a rate of 10℃ / min, and hold at that temperature for 15 min; dissolve 3.64 g of KOH, 798.9 g of Fe(NO3)3·9H2O, 173.9 g of Bi(NO3)3·5H2O, 526.6 g of Ni(NO3)2·6H2O, and 137.9 g of Mg(NO3)2·6H2O in water to obtain solution I; add 306.0 g of (NH4)6Mo7O 24 • 4H₂O was dissolved in water, and 2750 g of silica sol with a weight concentration of 40% was added. After stirring for 30 min, mixture II was formed. Mixture I was added and stirred, followed by the addition of solution I and stirring. Then, the temperature was increased to 150 °C at a rate of 10 °C / min and held for 15 min to form slurry I. Slurry I was then subjected to microsphere forming in a spray dryer at a drying temperature of 300 °C for 0.5 h, resulting in an average droplet diameter of 100 μm to obtain particulate matter. Finally, the calcination was carried out in an air atmosphere, with the calcination temperature increased at a rate of 5 °C / min to 300 °C and held for 30 min. Then, the temperature was increased at a rate of 20 °C / min to 550 °C and held for 45 min. The composition of the catalyst obtained according to the above steps is expressed by the following formula:

[0084] 50% K 0.15 Fe 5.46 Ni 5.0 Mg 1.5 Pr 0.5 La 0.18 Bi 1.0 Mo 13 O x +50% SiO2

[0085] The reaction conditions for the ammoxidation of propylene to acrylonitrile using the above catalyst are as follows: In a millimeter-sized fluidized bed reactor, the catalyst particle size was 50 micrometers; the reaction temperature was 430℃; the reaction pressure was 0.084 MPa; the catalyst loading was 300 g; and the catalyst propylene loading (WWH) was 0.085 h⁻¹. 1 Raw material ratio (moles): C3 = NH3 / air = 1 / 1.25 / 9.6. After running for 1000 hours, the reaction results are shown in Table 1.

[0086] Comparative Example 4

[0087] 521 grams of (NH4)6Mo7O 24Dissolve 4H2O in water, add 2.21 g ZrO2, 77.2 g Pr(NO3)3·6H2O and 25.6 g La(NO3)3·6H2O to form mixed solution I, heat to 80℃ at a rate of 10℃ / min and hold at that temperature for 15 min; dissolve 3.64 g KOH, 798.9 g Fe(NO3)3·9H2O, 173.9 g Bi(NO3)3·5H2O, 526.6 g Ni(NO3)2·6H2O and 137.9 g Mg(NO3)2·6H2O in water to obtain solution I; add 306.0 g (NH4)6Mo7O 24 • 4H₂O was dissolved in water, and 2750 g of silica sol with a weight concentration of 40% was added. After stirring for 30 min, mixture II was formed. Mixture I was added and stirred, followed by the addition of solution I and stirring. Then, the temperature was increased to 150 °C at a rate of 10 °C / min and held for 15 min to form slurry I. Slurry I was then subjected to microsphere forming in a spray dryer at 300 °C for 0.5 h, resulting in an average droplet diameter of 100 μm, yielding particulate matter. Finally, the slurry was calcined in air at 550 °C for 45 min. The composition of the catalyst obtained according to the above steps is shown in the following formula:

[0088] 50% Zr 0.05 K 0.15 Fe 5.46 Ni 5.0 Mg 1.5 Pr 0.5 La 0.18 Bi 1.0 Mo 13 O x +50% SiO2

[0089] The reaction conditions for the ammoxidation of propylene to acrylonitrile using the above catalyst are as follows: In a millimeter-sized fluidized bed reactor, the catalyst particle size was 50 micrometers, the reaction temperature was 430℃, the reaction pressure was 0.084 MPa, the catalyst loading was 300 g, and the catalyst propylene loading (WWH) was 0.085 h. -1 Raw material ratio (molar): C3 ＝ / NH3 / air = 1 / 1.25 / 9.6. After running for 1000 hours, the reaction results are shown in Table 1.

[0090] Table 1

[0091]

[0092]

[0093] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A catalyst for the ammoxidation of propylene to acrylonitrile, characterized in that, The active components of the catalyst include Mo, Bi, Fe, alkali metal elements, alkaline earth metal elements, other elements A, as well as La, Q, and R. R is at least one of Ce, Pr, Nd, Sm, and Eu. Q is at least one of Zr, Ca, Ti, and P. A is selected from at least one of W, V, Nb, Ni, Co, Cr, Mn, Tl, Au, Ag, Pt, Ru, Rh, Pd, Sb, In, Sn, Te, and In. The atomic ratio of La to R is 0.05-0.45, and the atomic ratio of Q / (La+R) is 0.01-0.

25.

2. The catalyst according to claim 1, characterized in that, The atomic ratio of La to R is 0.08-0.40, and the atomic ratio of Q / (La+R) is 0.01-0.

20.

3. The catalyst according to claim 1, characterized in that, The catalyst also includes a support, which is silicon dioxide.

4. The catalyst according to claim 1, characterized in that, The alkali metal element is selected from at least one of Li, Na, K, Rb and Cs; and / or, the alkaline earth metal element is selected from at least one of Be, Mg, Sr and Ba.

5. The catalyst according to any one of claims 1-4, characterized in that, Based on the weight of the catalyst, the content of the active component, calculated as oxide, is 30%-90%, and the content of the support is 10%-70%.

6. The catalyst according to claim 3 or 4, characterized in that, Of the active components, the amount is based on the weight of the catalyst. The Mo element, calculated as MoO3, has a weight content of 15%-55%. The weight content of Bi element, calculated as Bi₂O₃, is 0.5%-3.5%. The Fe element, calculated as Fe2O3, has a weight content of 1%-12%. The weight content of the La and R elements, calculated as their respective oxides, is 1.5%-8.5%. The weight content of element Q, calculated as oxides, is 0.01%-5.0%. The alkali metal element, calculated as oxides, has a weight content of 0.01%-0.60%. The alkaline earth metal, calculated as oxides, has a weight content of 0.01%-4.0%. The other element A, calculated as oxides, has a weight content of 0.01%-15%.

7. The catalyst according to claim 6, characterized in that, Of the active components, the amount is based on the weight of the catalyst. The Mo element, calculated as MoO3, has a weight content of 20%-45%. The Bi element, calculated as Bi₂O₃, has a weight content of 1.0%-3.5%. The Fe element, calculated as Fe2O3, has a weight content of 1.5%-11%. The weight content of the La and R elements, calculated as their respective oxides, is 2.5%-5.0%. The weight content of element Q, calculated as oxides, is 0.01%-3.5%. The alkali metal element, calculated as oxides, has a weight content of 0.05%-0.55%. The alkaline earth metal, calculated as oxides, has a weight content of 0.5%-2.5%. The other element A, calculated as oxides, has a weight content of 0.05%-14%.

8. The catalyst according to claim 1, characterized in that, In the active components, the atomic ratio of Bi / Mo is 0.008-0.25; the atomic ratio of Fe / Bi is 1.0-12.0; the atomic ratio of (La+R+alkali metal element+alkaline earth metal element) / Mo is 0.05-0.4; and the atomic ratio of A / Mo is 0.01-1.

0.

9. The catalyst according to claim 8, characterized in that, In the active components, the atomic ratio of Bi / Mo is 0.01-0.20; the atomic ratio of Fe / Bi is 1.5-11.0; the atomic ratio of (La+R+alkali metal element+alkaline earth metal element) / Mo is 0.10-0.35; and the atomic ratio of A / Mo is 0.02-0.

90.

10. A method for preparing the catalyst according to any one of claims 1-9, comprising the following steps: (1) Mix the precursors of La, R, Q and some of Mo, and heat treat them to form a mixture I; (2) Mix the precursors of the active components other than La, R, Q and Mo to form solution I; (3) Mix the remaining Mo and the carrier precursor to form mixture II, add mixture I and solution I, and perform heat treatment to form slurry I; (4) Spray dry slurry I to obtain particulate matter; (5) The particulate matter is calcined to obtain the catalyst particles.

11. The preparation method according to claim 10, characterized in that, The heating rate of the heat treatment in step (1) is controlled at 5-20℃ / min, the heat treatment temperature is controlled at 50-120℃, and the temperature is kept constant for 5-20min. And / or, the heating rate of the heat treatment in step (3) is controlled at 8-20℃ / min, the heat treatment temperature is controlled at 100-150℃, and the temperature is kept constant for 5-20min.

12. The preparation method according to claim 10, characterized in that, The carrier precursor mentioned in step (3) is a silicon dioxide precursor.

13. The preparation method according to claim 12, characterized in that, The carrier precursor in step (3) is silica sol, the solid content of which is 20wt%-50wt% based on silicon dioxide, and the average particle size distribution is 10-35nm.

14. The preparation method according to claim 10, characterized in that, The conditions for spray drying in step (4) include: air as the heat source, 250-350℃ as the drying temperature, 0.1-2.0h as the drying time, and an average droplet diameter of 20-200μm; and / or, the calcination in step (5) is carried out in two stages. The first stage calcination conditions are: calcination temperature of 200-300℃, calcination time of 0.5-5h, and heating rate of 1-5℃ / min; the second stage calcination conditions are: calcination temperature of 500-750℃, calcination time of 0.5-5h, and heating rate of 8-20℃ / min; the calcination is carried out in an oxygen-containing atmosphere.

15. The preparation method according to claim 14, characterized in that, The conditions for spray drying in step (4) include: drying temperature of 300-350℃, drying time of 0.2-1.0h, and average diameter of spray droplets of 40-180μm.

16. A method for producing acrylonitrile by ammoxidation of propylene, comprising: In the presence of the propylene ammoxidation catalyst for acrylonitrile production according to any one of claims 1-9 or the propylene ammoxidation catalyst particles prepared according to any one of claims 10-15, propylene undergoes an ammoxidation reaction to produce acrylonitrile.

17. The method according to claim 16, characterized in that, The reaction conditions for the ammoxidation of propylene to acrylonitrile include: a molar ratio of propylene / ammonia / air of 1:1.1-1.35:9.5-10, a reaction temperature of 420-440℃, a reaction pressure of 0.03-0.14 MPa (gauge pressure), and a weight hourly space velocity of 0.04-0.10 h⁻¹. -1 .

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