Composite catalytic material, preparation method and application thereof

Abstract

The present application relates to a kind of composite catalytic materials and its preparation method and application, the composite catalytic material has the structure of hollow multistage hole ZSM-5 nanocrystalline material encapsulation copper-containing heating material;Wherein, the hollow multistage hole ZSM-5 nanocrystalline material has closed hollow structure, average grain size is 0.4-3.0 μm, the ratio of the ratio of surface silicon aluminum molar ratio and body phase silicon aluminum molar ratio is 1.0-1.2, total specific surface area is 340-400 m 2 / g, mesoporous specific surface area is 40-150 m 2 / g, N2 adsorption-desorption curve presents H4 type hysteresis loop.The composite catalytic material of the present application has good catalytic activity, and also has good heating performance and anti-carbon deposition performance.

Description

Technical Field

[0001] This invention relates to a composite catalytic material, its preparation method, and its application. Background Technology

[0002] Hollow materials possess unique internal microenvironments and spatial confinement effects, exhibiting excellent performance in heterogeneous catalysis, biomedicine, adsorption separation, and energy storage. Hollow ZSM-5 molecular sieves, with their nanoscale hierarchical porous shells and relatively closed internal structures, possess advantages such as strong acidity, excellent diffusion properties, and outstanding encapsulation capabilities, making them highly valuable and promising materials for industrial catalysis and adsorption separation. CN106082263B developed a porous nano-hollow ZSM-5 molecular sieve. Using tetraethyl orthosilicate, tetrapropylammonium hydroxide, aluminum nitrate, sodium hydroxide, and deionized water as raw materials, the solution underwent aging, crystallization, centrifugation, washing, drying, and calcination to obtain nano-ZSM-5 molecular sieves. The nano-ZSM-5 molecular sieves were then added to an inorganic alkaline aqueous solution, stirred for 10–50 h, separated, washed, and dried to obtain nano-ZSM-5 with a hollow structure. However, this preparation method uses relatively simple raw materials, and the resulting product has a size of 50–100 nm, with excessively large mesopores. Further improvements are needed in hydrothermal stability and mechanical strength.

[0003] Catalytic cracking units are core equipment in refineries' secondary processing, converting distillate or residue feedstock from atmospheric and vacuum distillation towers into fuels such as liquefied petroleum gas (LPG), gasoline, and diesel, or chemical feedstocks such as ethylene, propylene, butene, and BTX, under the action of catalysts and high temperatures. The catalyst is not only the reactive center of the catalytic cracking reaction but also the heat and mass transfer carrier in the catalytic cracking regeneration system. The catalyst enters the reactor from the high-temperature regenerator, bringing in a large amount of heat to promote the catalytic cracking reaction. The resulting coke is loaded onto the catalyst surface. Then, during the regeneration process, it burns with oxygen in the air, generating a large amount of heat, thus completing the heat transfer and generation process.

[0004] With the increasing use of heavier and lower-quality raw materials, and the requirement for oil refining units to transform into chemical-oriented operations, reaction conditions are becoming more stringent. However, the limited heat capacity of catalysts results in a limited amount of heat supplied to the reaction section, making it difficult to further increase the reaction temperature. At the same time, in order to transfer more heat, the catalyst-to-oil ratio also increases, leading to more side reactions.

[0005] In the field of catalytic cracking engineering design, the empirical formula used to calculate the catalyst heat capacity is: Cp(J / (k·g)) = 0.00233 × alumina% + 1.08. Generally, alumina content is 35-60%, meaning the heat capacity is between 1.16-1.22 J / (℃·g). Moreover, the alumina content in the catalyst is usually relatively stable with small fluctuations, limiting the extent to which the heat capacity can be increased.

[0006] Heating materials release heat through continuous oxidation-reduction reactions of metals and their oxides, primarily utilizing the following reactions:

[0007] 2Cu+O2→2CuO ΔH=-156KJ / mol=-1914J / g,

[0008] CuO+2H2→Cu+2H2O ΔH=-95KJ / mol=-1190J / g,

[0009] As can be seen from the above, the heating effect of the heating material is significant. However, the contact between the heating material and heavy oil hydrocarbon molecules can easily lead to a significant increase in coking. The problem of how to avoid or reduce the impact of the heating material on the reaction performance of the catalytic cracking catalyst needs to be solved urgently. Summary of the Invention

[0010] The purpose of this invention is to provide a composite catalytic material, its preparation method, and its application. The composite catalytic material has good catalytic activity and good heat generation effect, and can effectively inhibit the dehydrogenation and coking reaction of heavy oil hydrocarbon molecules on the catalyst surface.

[0011] To achieve the above objectives, the first aspect of the present invention provides a composite catalytic material having a structure in which a copper-containing heating material is encapsulated in a hollow hierarchical porous ZSM-5 nanocrystalline material.

[0012] The hollow hierarchical porous ZSM-5 nanocrystalline material has a closed hollow structure, an average grain size of 0.4-3.0 μm, a bulk silicon-aluminum molar ratio to surface silicon-aluminum molar ratio of 1.0-1.2, and a total specific surface area of ​​340-400 m². 2 / g, mesoporous specific surface area is 40-150m² 2 / g, the N2 adsorption-desorption curves show an H4-type hysteresis loop.

[0013] Optionally, the molar ratio of the hollow hierarchical porous ZSM-5 nanocrystalline material to the copper-containing heating material in the composite catalytic material is 1:(0.01-0.1), wherein the hollow hierarchical porous ZSM-5 nanocrystalline material is calculated as SiO2 and the copper-containing heating material is calculated as CuO.

[0014] Optionally, the copper-containing heating material contains cuprous oxide and / or copper oxide.

[0015] Optionally, the hollow hierarchical porous ZSM-5 nanocrystalline material has an average grain size of 0.4-2.5 μm, a bulk silicon-aluminum molar ratio to a surface silicon-aluminum molar ratio of 1-1.1, and a total specific surface area of ​​360-400 m². 2 / g, mesoporous specific surface area is 50-140m² 2 / g.

[0016] A second aspect of the present invention provides a method for preparing the composite catalytic material provided in the first aspect of the present invention, the method comprising:

[0017] S1. After mixing and reacting the silicon source, the first copper source, and the first solvent at 30-50°C for 0.5-5 hours, the temperature is then raised to 70-100°C and stirred for 2-10 hours. The resulting mixed liquid is then mixed with the template agent at 20-30°C for 0.5-3.0 hours to obtain the first mixed product.

[0018] S2. Mix alkali metal hydroxide (calculated as alkali metal oxide), second solvent, and aluminum source (calculated as Al2O3) in a molar ratio of (1.5-5):(60-350):1 at 20-80℃ for 0.5-2 hours to obtain a second mixed product.

[0019] S3. The first mixed product and the second mixed product are mixed and then dynamically crystallized. The resulting solid is taken out and subjected to a first calcination to obtain the first solid product.

[0020] S4. The first solid product is mixed with an alkaline solution, and the temperature is increased to the reaction temperature at a rate of 1-5℃ / min. The mixture is then reacted at the reaction temperature for 10-90 min to obtain the second solid product. The reaction temperature is 60-90℃, and the alkaline content in the alkaline solution is 0.45-2 mol / L.

[0021] S5. The second solid product is subjected to ammonium exchange, and the solid product obtained by ammonium exchange is subjected to a second calcination to obtain a composite catalyst material.

[0022] Optionally, the molar ratio of the total amount of the first copper source, the template agent, the first solvent and the second solvent, the alkali metal hydroxide and the silicon source is (0.01-0.1):(0.06-0.55):(10-100):(0.02-1.5):1, and the molar ratio of the silicon source to the aluminum source is (20-500):1; wherein the first copper source is calculated as CuO, the silicon source is calculated as SiO2, the alkali metal hydroxide is calculated as alkali metal oxide, and the aluminum source is calculated as Al2O3.

[0023] Optionally, in step S2, the molar ratio of the alkali metal hydroxide (calculated as alkali metal oxide), the second solvent, and the aluminum source (calculated as Al2O3) is (2-4.5):(80-350):1.

[0024] Optionally, in step S4, the molar ratio of the first solid product to the amount of the alkaline solution is 1:(2-10), preferably 1:(4-8, and the first solid product is calculated as SiO2;

[0025] The ratio of the bulk silicon-aluminum molar ratio to the surface silicon-aluminum molar ratio of the first solid product is 1.2-5.0.

[0026] Optionally, step S5 further includes: reducing the solid obtained by the second calcination in a reducing atmosphere to obtain the composite catalyst material;

[0027] The conditions for the reduction treatment include: a temperature of 600-750℃ and a time of 0.5-5 min.

[0028] Optionally, in step S5, the ammonium exchange of the second solid product includes: mixing the second solid product, the ammonium source, and the third solvent in a weight ratio of 1:(0.5-1.0):(8-10), and then reacting the resulting mixture at 70-90°C for 0.5-2 hours; wherein the ammonium source is selected from one or more of ammonium chloride, ammonium sulfate, and ammonium nitrate.

[0029] Optionally, the conditions for dynamic crystallization include: a temperature of 160-180°C and a time of 12-60 hours;

[0030] The conditions for the first and second roastings are each independent of each other: a temperature of 400-600℃ and a time of 2-6 hours.

[0031] Optionally, the template agent is selected from one or more of tetrapropylammonium bromide, tetrapropylammonium hydroxide, n-butylamine, and hexamethylenediamine;

[0032] The silicon source is methyl orthosilicate and / or ethyl orthosilicate;

[0033] The first copper source is selected from one or more of copper sulfate, copper chloride, copper nitrate, and copper carbonate;

[0034] The aluminum source is selected from one or more of sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum isopropoxide, and aluminum sol;

[0035] The alkali metal hydroxide is selected from one or more of lithium hydroxide, sodium hydroxide, and potassium hydroxide;

[0036] The first solvent and the second solvent are each independently water.

[0037] The third aspect of this invention provides the application of the composite catalytic material provided in the first aspect of this invention in the catalytic cracking reaction of heavy hydrocarbon oil.

[0038] Through the above technical solution, the composite catalytic material of the present invention has good catalytic activity and good heat generation effect, and can effectively inhibit the dehydrogenation and coking reaction of heavy oil hydrocarbon molecules on the catalyst surface, thereby improving the yield of low carbon olefins.

[0039] Other features and advantages of the present invention will be described in detail in the following detailed description section. Detailed Implementation

[0040] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0041] The first aspect of this invention provides a composite catalytic material having a structure in which a copper-containing heating material is encapsulated by a hollow hierarchical porous ZSM-5 nanocrystalline material.

[0042] The hollow hierarchical porous ZSM-5 nanocrystalline material has a closed hollow structure, an average grain size of 0.4-3.0 μm, a bulk silicon-aluminum molar ratio to surface silicon-aluminum molar ratio of 1.0-1.2, and a total specific surface area of ​​340-400 m². 2 / g, mesoporous specific surface area is 40-150m² 2 / g, the N2 adsorption-desorption curves show an H4-type hysteresis loop.

[0043] In this invention, "hollow hierarchical porous ZSM-5 nanocrystalline material encapsulating copper-containing heating material" refers to a hollow structure within the ZSM-5 nanocrystalline material containing a copper-containing heating material. The outer surface of the copper-containing heating material can be connected to or not connected to the inner surface of the ZSM-5 nanocrystalline material. When connected, the composite catalytic material can also be described as having a core-shell structure. In this invention, the hollow hierarchical porous ZSM-5 nanocrystalline material filters hydrocarbon molecules entering the surface of the internal copper-containing heating material, preventing the copper-containing heating material from directly contacting heavy oil hydrocarbon molecules as a dehydrogenation center, thus avoiding increased coking. This reduces the impact of the copper-containing heating material on the catalytic cracking catalyst's reaction performance, while simultaneously ensuring both the heating effect and good catalytic activity of the composite catalytic material, thereby improving the yield of low-carbon olefins.

[0044] In one specific embodiment of the present invention, based on the dry weight of the composite catalytic material, the content of the copper-containing exothermic material is 1-50% by weight, preferably 1-30% by weight. In this invention, the content of the copper-containing exothermic material in the composite catalytic material is measured using the XRF method. The catalyst with the above composition not only has good catalytic activity but also superior exothermic performance.

[0045] According to the present invention, the molar ratio of the hollow hierarchical porous ZSM-5 nanocrystalline material to the copper-containing heating material contained in the composite catalytic material can vary within a large range, for example, it can be 1:(0.01-0.1), wherein the hollow hierarchical porous ZSM-5 nanocrystalline material is calculated as SiO2 and the copper-containing heating material is calculated as CuO.

[0046] In one specific embodiment of the present invention, the copper-containing heating material contains cuprous oxide and / or copper oxide. The valence state of copper can be detected using the XPS method in this invention.

[0047] In one specific embodiment of the present invention, the average grain size of the hollow hierarchical porous ZSM-5 nanocrystalline material is 0.4-2.5 μm. In the present invention, grain size refers to the size of the widest part of the grain, which can be obtained by measuring the size of the widest part of the grain projection plane in the SEM or TEM image of the sample. The average grain size is obtained by selecting any 10 molecular sieves in the SEM or TEM image and calculating their average value.

[0048] In one specific embodiment of the present invention, the ratio of the bulk silicon-aluminum molar ratio to the surface silicon-aluminum molar ratio of the hollow hierarchical porous ZSM-5 nanocrystalline material is 1-1.1, and the total specific surface area is 360-400 m². 2 / g, mesoporous specific surface area is 50-140m² 2 / g. The bulk silicon-aluminum molar ratio refers to the overall silicon-aluminum molar ratio of the hollow hierarchical porous ZSM-5 nanocrystalline material. The bulk silicon-aluminum molar ratio was determined by XRF, and the surface silicon-aluminum molar ratio was determined by XPS. The specific testing methods are well known to those skilled in the art and will not be elaborated here. In this invention, the total specific surface area and mesoporous specific surface area were obtained using BET analysis.

[0049] In one specific embodiment of the present invention, the relative crystallinity of the hollow hierarchical porous ZSM-5 nanocrystalline material is 75-95%. In the present invention, the relative crystallinity of the molecular sieve is based on the XRD standard ZSM-5 molecular sieve sample from the China Petroleum and Chemical Research Institute, and the crystallinity of the standard sample is considered as 100%.

[0050] The second aspect of this invention provides a method for preparing the composite catalytic material provided in the first aspect of this invention. The method includes: S1, mixing a silicon source, a first copper source, and a first solvent at 30-50°C for 0.5-5 hours, then heating to 70-100°C and stirring for 2-10 hours; mixing the resulting mixed liquid with a template agent at 20-30°C for 0.5-3.0 hours to obtain a first mixed product; S2, mixing an alkali metal hydroxide (calculated as an alkali metal oxide), a second solvent, and an aluminum source (calculated as Al2O3) at a molar ratio of (1.5-5):(60-350):1 at 20-80°C for 0.5-2 hours to obtain a second... S3. The first mixed product and the second mixed product are mixed and then subjected to dynamic crystallization. The resulting solid is taken out and subjected to a first calcination to obtain a first solid product. S4. The first solid product is mixed with an alkaline solution, and the temperature is raised to the reaction temperature at a heating rate of 1-5℃ / min. The reaction is carried out at the reaction temperature for 10-90 min to obtain a second solid product. The reaction temperature is 60-90℃, and the alkaline content in the alkaline solution is 0.45-2 mol / L. S5. The second solid product is subjected to ammonium exchange, and the solid product obtained by ammonium exchange is subjected to a second calcination to obtain a composite catalytic material.

[0051] According to the present invention, the molar ratio of the total amount of the first copper source, the template agent, the first solvent and the second solvent, the alkali metal hydroxide and the silicon source is (0.01-0.1):(0.06-0.55):(10-100):(0.02-1.5):1, preferably (0.02-0.08):(0.1-0.50):(15-85):(0.03-1.2):1, and the molar ratio of the silicon source to the aluminum source is (20-500):1, preferably (30-450):1; wherein the first copper source is calculated as CuO, the silicon source is calculated as SiO2, the alkali metal hydroxide is calculated as alkali metal oxide (for example, when the alkali metal hydroxide is sodium hydroxide, the alkali metal hydroxide is calculated as Na2O), and the aluminum source is calculated as Al2O3.

[0052] In one specific embodiment of the present invention, in step S2, the molar ratio of the alkali metal hydroxide (calculated as alkali metal oxide), the second solvent, and the aluminum source (calculated as Al2O3) is (2.0-4.5):(80-450):1, for example (2.2-4.2):(85-330):1.

[0053] In one specific embodiment of the present invention, in step S3, dynamic crystallization is well known to those skilled in the art, and the conditions for dynamic crystallization may include: a temperature of 80-200°C and a time of 4-80 hours; preferably, a temperature of 160-180°C and a time of 12-60 hours.

[0054] In one specific embodiment of the present invention, in step S4, the molar ratio of the first solid product to the amount of the alkali-containing solution is 1:(2-10), preferably 1:(4-8), the first solid product is calculated as SiO2, and the ratio of the bulk silicon-aluminum molar ratio to the surface silicon-aluminum molar ratio of the first solid product is 1.2-5.0.

[0055] In one specific embodiment of the present invention, step S5 further includes: reducing the solid obtained by the second calcination in a reducing atmosphere to obtain the composite catalytic material; the conditions for the reduction treatment include: a temperature of 600-750°C and a time of 0.5-5 min. The composite catalytic material obtained by the above method contains copper mainly in low valence states (+1 and / or 0 valence), which can further improve the thermal performance of the composite catalytic material and more effectively avoid the problem of coking of the composite catalytic material.

[0056] In one specific embodiment of the present invention, step S5, wherein the ammonium exchange of the second solid product comprises: mixing the second solid product, an ammonium source, and a third solvent in a weight ratio of 1:(0.5-1.0):(8-10), and reacting the resulting mixture at 70-90°C for 0.5-2 hours; wherein the ammonium source is selected from one or more of ammonium chloride, ammonium sulfate, and ammonium nitrate.

[0057] In one specific embodiment of the present invention, roasting is a technical means conventionally used by those skilled in the art, and roasting can be carried out in a muffle furnace, tube furnace, etc. In one embodiment, the conditions for the first roasting and the second roasting each independently include: a temperature of 400-600°C and a time of 2-6 hours, preferably, a temperature of 450-580°C and a time of 3-5 hours.

[0058] In one specific embodiment of the present invention, compared with the first solid product, the composite catalytic material has a 100-500% increase in mesoporous specific surface area, a 150-600% increase in mesoporous volume, and a 50-250% increase in total acidity. In this invention, the mesoporous volume can be obtained by BET testing, and the total acidity can be detected by the NH3-TPD method.

[0059] In one specific embodiment of the present invention, the template agent is selected from one or more of tetrapropylammonium bromide, tetrapropylammonium hydroxide, n-butylamine, and hexamethylenediamine; the silicon source is methyl orthosilicate and / or tetraethyl orthosilicate; the first copper source is selected from one or more of copper sulfate, copper chloride, copper nitrate, and copper carbonate; the aluminum source is selected from one or more of sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum isopropoxide, and aluminum sol; the alkali metal hydroxide is selected from one or more of lithium hydroxide, sodium hydroxide, and potassium hydroxide; and the first solvent and the second solvent are each independently water.

[0060] The third aspect of this invention provides the application of the composite catalytic material provided in the first aspect of this invention in the catalytic cracking and catalytic pyrolysis of feedstock oils, especially in the catalytic cracking reaction of heavy hydrocarbon oils.

[0061] The composite catalytic material of this invention, used in catalytic cracking and catalytic pyrolysis reactions, has the advantages of increasing reaction temperature and improving the yield of low-carbon olefins (e.g., ethylene, propylene). In one specific embodiment of this invention, the feedstock oil is contacted with the composite catalytic material to carry out the catalytic cracking or catalytic pyrolysis reaction. Preferably, the composite catalytic material is a composite catalytic material that has undergone enhanced reduction.

[0062] In one embodiment, the enhanced reduction composite catalytic material is obtained by a method comprising the following steps: subjecting the catalytic cracking promoter to a reduction reaction at 600-750°C for 0.5-3 min in a reducing atmosphere. According to the present invention, the reducing atmosphere contains dry gas and / or hydrogen, preferably, the dry gas originating from dry gas generated by the catalytic cracking unit.

[0063] The present invention will be further illustrated by the following examples, but the present invention is not limited thereto.

[0064] Unless otherwise specified, all raw materials used in the following examples and comparative examples were commercially available. The catalytic cracking equilibrium catalyst ECAT was purchased from Sinopec Catalyst Company Qilu Branch COKC-1 industrial catalyst. The copper nitrate trihydrate used in Comparative Example 4 was purchased from Sigma-Aldrich, and the ZSM-5 molecular sieve used was purchased from Sinopec Catalyst Company Qilu Branch.

[0065] In the examples and comparative examples, the crystal size of the molecular sieve was measured by SEM. Ten crystal sizes were randomly measured, and the average value was taken to obtain the average crystal size of the molecular sieve sample.

[0066] The bulk silica-alumina molar ratio of the sample was determined by XRF using a ZSX Primus II (Rigaku) ​​X-ray fluorescence spectrometer. Test conditions included an excitation voltage of 50 kV, an excitation current of 50 mA, and rhodium and palladium. The elemental composition of the molecular sieve was analyzed by measuring the peak intensity of each element using a scintillation counter and a proportional counter.

[0067] The surface silicon-to-aluminum molar ratio of the samples was determined by XPS using a Thermo Fisher ESCALab 250 X-ray photoelectron spectrometer. The testing conditions were: monochromatic Al Kα X-rays as the excitation source, excitation energy 1496.6 eV, and power 150 W. The electron binding energy was corrected using the C1s peak (284.8 eV) of the contaminating carbon.

[0068] The total specific surface area and mesoporous specific surface area of ​​the samples were determined using the BET method. Instrument: Micromeritics ASAP 2420 adsorption analyzer (USA). Test conditions: The samples were degassed under vacuum at 100℃ and 300℃ for 0.5h and 6h, respectively, and then N2 adsorption-desorption tests were conducted at 77.4K. The adsorption and desorption amounts of nitrogen by the purified samples under different specific pressures were measured, and N2 adsorption-desorption isotherms were obtained. The BET specific surface area was calculated using the BET formula, the micropore area was calculated using t-plot, and the pore size distribution was calculated using the BJH method.

[0069] The oxidation state of copper and the content of copper in different oxidation states in the copper-containing heating materials in the samples were determined by XPS method.

[0070] The molar amounts of hollow hierarchical porous ZSM-5 nanocrystalline material (calculated as SiO2) and the molar amounts of the copper-containing heating material (calculated as CuO) in the sample were determined by XRF method.

[0071] Example 1

[0072] S1. Weigh 4.88 g of copper chloride and 91.2 g of tetraethyl orthosilicate, then add 639.14 g of deionized water. Stir and heat in a water bath at 40 °C for 2 h, then raise the water bath temperature to 70 °C and stir and heat for 4 h to remove the ethanol produced by the hydrolysis of the silicon source. During this process, intermittently replenish the system with water that evaporates along with the ethanol. Mix the resulting liquid with 111.65 g of tetrapropylammonium hydroxide solution (tetrapropylammonium hydroxide weight fraction is 25.0 wt%) at 25 °C for 1 h to obtain the first mixed product.

[0073] S2. Add 3.44 g of sodium hydroxide granules to 60.8 g of deionized water to completely dissolve the sodium hydroxide, then add 8.16 g of aluminum nitrate nonahydrate and stir at room temperature for 1.0 h to obtain the second mixed product (i.e., aluminum source solution).

[0074] S3. The second mixed product is slowly added to the first mixed product and mixed evenly. The mixture is stirred at room temperature for 4.0 h. The resulting precursor liquid is transferred to a synthesis vessel and dynamically crystallized at 170 °C for 48 h. After crystallization, the resulting mixture is centrifuged, filtered, washed, and dried. It is then calcined at 550 °C for 4 h to obtain the first solid product (denoted as molecular sieve C-M1).

[0075] S4. Mix the first solid product with a sodium hydroxide solution with a concentration of 0.65 mol / L. The weight ratio of molecular sieve to alkaline solution is 1:10. Heat the solution to 80°C at a heating rate of 2°C / min, and then heat and stir at this temperature for 30 min. Filter, wash, and dry to obtain the second solid product (denoted as molecular sieve C-S1-Na).

[0076] S5. The second solid product, ammonium chloride, and deionized water are mixed evenly at a weight ratio of 1:1:10. The mixture is stirred and heated in an 80°C water bath for 30 minutes, then filtered, washed, and dried. The mixture is then mixed again at a weight ratio of 1:0.5:10 for a second ammonium exchange, filtered, washed, and dried. Finally, it is calcined at 550°C for 2 hours to obtain the composite catalyst (denoted as C-S1-H). The composition of the catalyst is shown in Table 1.

[0077] Example 2

[0078] The composite catalyst C-S2-H was prepared using the same method as in Example 1, except that in step S1, 9.77 g of copper chloride and 91.2 g of tetraethyl orthosilicate were weighed, and 639.14 g of deionized water was added. The mixture was stirred and heated in a water bath at 40°C for 2 h, and then the water bath temperature was increased to 70°C and stirred and heated for 4 h to remove the ethanol produced by the hydrolysis of the silicon source. During this process, water that evaporated along with the ethanol was intermittently added to the system. The resulting mixed liquid was mixed and stirred with 111.65 g of tetrapropylammonium hydroxide solution (tetrapropylammonium hydroxide weight fraction of 25.0 wt%) at 25°C for 1 h to obtain the first mixed product.

[0079] Comparative Example 1

[0080] Catalyst D-S1-H was prepared using the same method as in Example 1, except that copper chloride was not added in step S1.

[0081] Comparative Example 2

[0082] Kaolin carrier, alumina sol and copper chloride were mixed in a weight ratio of kaolin: binder: copper chloride of 50:40:10 to prepare a slurry. The slurry was spray-dried and the product obtained by spray drying was calcined at 550℃ for 3 hours to obtain copper oxide-containing additive Z-1.

[0083] Comparative Example 3

[0084] S1. Weigh 4.88 g of copper chloride and 91.2 g of tetraethyl orthosilicate, then add 639.14 g of deionized water. Stir and heat in a water bath at 40 °C for 2 h, then raise the water bath temperature to 70 °C and stir and heat for 4 h to remove the ethanol produced by the hydrolysis of the silicon source. During this process, intermittently replenish the system with water that evaporates along with the ethanol. Mix the resulting liquid with 111.65 g of tetrapropylammonium hydroxide solution (tetrapropylammonium hydroxide weight fraction is 25.0 wt%) at 25 °C for 1 h to obtain the first mixed product.

[0085] S2. Add 3.44 g of sodium hydroxide granules to 60.8 g of deionized water to completely dissolve the sodium hydroxide, then add 8.16 g of aluminum nitrate nonahydrate and stir at room temperature for 1.0 h to obtain the second mixed product (i.e., aluminum source solution).

[0086] S3. The second mixed product is slowly added to the first mixed product and mixed evenly. The mixture is stirred at room temperature for 4.0 h. The resulting precursor liquid is transferred to a synthesis vessel and subjected to dynamic crystallization at 120 °C for 24 h. After crystallization, the resulting mixture is centrifuged, filtered, washed, and dried. It is then calcined at 550 °C for 4 h to obtain the first solid product (denoted as molecular sieve D-M3).

[0087] S4. Mix the first solid product with a sodium hydroxide solution with a concentration of 0.65 mol / L. The weight ratio of molecular sieve to alkaline solution is 1:10. Heat the solution to 80°C at a heating rate of 2°C / min, and then heat and stir at this temperature for 30 min. Filter, wash, and dry to obtain the second solid product (denoted as molecular sieve D-S3-Na).

[0088] S5. The second solid product, ammonium chloride, and deionized water are mixed evenly at a weight ratio of 1:1:10. The mixture is stirred and heated in an 80°C water bath for 30 minutes. After filtration, washing, and drying, the mixture is then mixed evenly again at a weight ratio of 1:0.5:10 for a second ammonium exchange. After filtration, washing, and drying, the mixture is calcined at 550°C for 2 hours to obtain the composite catalyst material (denoted as D-S3-H). The composition of the catalyst is shown in Table 1.

[0089] Comparative Example 4

[0090] 3.8 g of copper nitrate trihydrate was completely dissolved in 3.7 g of deionized water. Then, the copper nitrate trihydrate dissolved in deionized water was added dropwise to 15 g of slightly crushed ZSM-5 molecular sieve while stirring. The resulting solid was dried in an oven at 110 °C for 4 hours, and then calcined in air at 650 °C for 4 hours to prepare the catalyst Z-2.

[0091] Test case

[0092] The catalytic materials prepared in the above examples and comparative examples were subjected to ACE evaluation at a ratio of 10 wt% (C-S1-H or C-S2-H or D-S1-H or Z-1 or D-S3-H or Z-2) + 90 wt% catalytic cracking equilibrium catalyst (ECAT). The reaction temperature was set at 530℃ and the catalyst-to-oil mass ratio was 8. The exothermic effect was observed by recording the changes in reaction temperature. The results are shown in Tables 2 and 3.

[0093] Table 1

[0094]

[0095]

[0096]

[0097]

[0098]

[0099] In the composite catalytic material, CuO / SiO2 refers to the molar ratio of the copper-containing heating material to the hollow hierarchical porous ZSM-5 nanocrystalline material contained in the composite catalytic material.

[0100] Table 2

[0101]

[0102]

[0103] Table 3

[0104]

[0105] As shown in Tables 2 and 3, the composite catalytic material of the present invention has both good reactivity and heat dissipation properties, which can improve the yield of low-carbon olefins.

[0106] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0107] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0108] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A composite catalytic material having a structure in which a copper-containing heating material is encapsulated by a hollow hierarchical porous ZSM-5 nanocrystalline material; in, The hollow hierarchical porous ZSM-5 nanocrystalline material has a closed hollow structure, an average grain size of 0.4-3.0 μm, a bulk silicon-aluminum molar ratio to surface silicon-aluminum molar ratio of 1.0-1.2, and a total specific surface area of ​​340-400 m². 2 / g, mesoporous specific surface area is 40-150m² 2 / g, the N2 adsorption-desorption curves show an H4-type hysteresis loop; The composite catalytic material contains a hollow hierarchical porous ZSM-5 nanocrystalline material with a molar ratio of 1:(0.01-0.1) to the copper-containing heating material, wherein the hollow hierarchical porous ZSM-5 nanocrystalline material is calculated as SiO2 and the copper-containing heating material is calculated as CuO.

2. The composite catalytic material according to claim 1, wherein, The copper-containing heating material contains cuprous oxide and / or copper oxide.

3. The composite catalytic material according to claim 1, wherein, The hollow hierarchical porous ZSM-5 nanocrystalline material has an average grain size of 0.4-2.5 μm, a bulk silicon-aluminum molar ratio to a surface silicon-aluminum molar ratio of 1-1.1, and a total specific surface area of ​​360-400 m². 2 / g, mesoporous specific surface area is 50-140m² 2 / g.

4. A method for preparing the composite catalytic material according to any one of claims 1-3, the method comprising: S1. After mixing and reacting the silicon source, the first copper source, and the first solvent at 30-50°C for 0.5-5 hours, the temperature is then raised to 70-100°C and stirred for 2-10 hours. The resulting mixed liquid is then mixed with the template agent at 20-30°C for 0.5-3.0 hours to obtain the first mixed product. S2. Mix alkali metal hydroxide (calculated as alkali metal oxide), second solvent, and aluminum source (calculated as Al2O3) in a molar ratio of (1.5-5):(60-350):1 at 20-80℃ for 0.5-2 hours to obtain a second mixed product. S3. The first mixed product and the second mixed product are mixed and then dynamically crystallized. The resulting solid is taken out and subjected to a first calcination to obtain the first solid product. S4. The first solid product is mixed with an alkaline solution, and the temperature is increased to the reaction temperature at a rate of 1-5℃ / min. The mixture is then reacted at the reaction temperature for 10-90 min to obtain the second solid product. The reaction temperature is 60-90℃, and the alkaline content in the alkaline solution is 0.45-2 mol / L. S5. The second solid product is subjected to ammonium exchange, and the solid product obtained by ammonium exchange is subjected to a second calcination to obtain a composite catalyst material.

5. The method according to claim 4, wherein, The molar ratio of the total amount of the first copper source, the template agent, the first solvent and the second solvent, the alkali metal hydroxide and the silicon source is (0.01-0.1):(0.06-0.55):(10-100):(0.02-1.5):1, and the molar ratio of the silicon source to the aluminum source is (20-500):1; wherein the first copper source is calculated as CuO, the silicon source is calculated as SiO2, the alkali metal hydroxide is calculated as alkali metal oxide, and the aluminum source is calculated as Al2O3.

6. The method according to claim 4, wherein, In step S2, the molar ratio of the alkali metal hydroxide (calculated as alkali metal oxide), the second solvent, and the aluminum source (calculated as Al2O3) is (2-4.5):(80-350):

1.

7. The method according to claim 4, wherein, In step S4, the molar ratio of the first solid product to the alkaline solution is 1:(2-10), and the first solid product is calculated as SiO2. The ratio of the bulk silicon-aluminum molar ratio to the surface silicon-aluminum molar ratio of the first solid product is 1.2-5.

0.

8. The method according to claim 7, wherein, In step S4, the molar ratio of the first solid product to the alkaline solution is 1:(4-8), and the first solid product is calculated as SiO2.

9. The method according to claim 4, wherein, Step S5 further includes: reducing the solid obtained by the second calcination in a reducing atmosphere to obtain the composite catalyst material; The conditions for the reduction treatment include: a temperature of 600-750℃ and a time of 0.5-5 min.

10. The method according to claim 4, wherein, In step S5, the ammonium exchange of the second solid product includes: mixing the second solid product, the ammonium source, and the third solvent in a weight ratio of 1:(0.5-1.0):(8-10), and then reacting the resulting mixture at 70-90°C for 0.5-2 hours; the ammonium source is selected from one or more of ammonium chloride, ammonium sulfate, and ammonium nitrate.

11. The method according to claim 4, wherein, The conditions for dynamic crystallization include: a temperature of 160-180℃ and a time of 12-60 hours; The conditions for the first and second roastings are each independent of each other: a temperature of 400-600℃ and a time of 2-6 hours.

12. The method according to claim 4, wherein, The template agent is selected from one or more of tetrapropylammonium bromide, tetrapropylammonium hydroxide, n-butylamine, and hexamethylenediamine; The silicon source is methyl orthosilicate and / or ethyl orthosilicate; The first copper source is selected from one or more of copper sulfate, copper chloride, copper nitrate, and copper carbonate; The aluminum source is selected from one or more of sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum isopropoxide, and aluminum sol; The alkali metal hydroxide is selected from one or more of lithium hydroxide, sodium hydroxide, and potassium hydroxide; The first solvent and the second solvent are each independently water.

13. The application of the composite catalytic material according to any one of claims 1-3 in the catalytic cracking reaction of heavy hydrocarbon oil.

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