Ni-modified microporous-mesoporous molecular sieve, preparation method and application thereof
By using Ni-modified microporous-mesoporous molecular sieve catalysts, the problem of the difficult decomposition of acetal heavy components in the production of 2-ethylhexanal was solved, the product yield was improved and the raw material consumption and waste liquid treatment costs were reduced, thus achieving efficient utilization of resources.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WANHUA CHEM GRP CO LTD
- Filing Date
- 2023-11-27
- Publication Date
- 2026-05-19
AI Technical Summary
In the existing technology for the production of 2-ethylhexanal, acetal-type heavy components are difficult to decompose effectively, resulting in low product yield, high raw material consumption, and increased waste liquid treatment costs.
Ni-modified microporous-mesoporous molecular sieve catalysts were synthesized in an alkaline environment using a preparation method to provide acidic centers and macromolecular reaction channels for the catalytic decomposition of acetal-type heavy components.
It improved the product yield of 2-ethylhexanal, reduced raw material consumption and waste liquid treatment costs, simplified the process flow, and achieved efficient decomposition of acetal heavy components and recycling of raw materials.
Smart Images
Figure BDA0004571553810000101
Abstract
Description
Technical Field
[0001] This invention relates to a modified molecular sieve, and more particularly to a Ni-modified microporous-mesoporous molecular sieve, its preparation method, and its application. Background Technology
[0002] 2-Ethylhexanal (isooctanal) is produced by reacting 2-ethylhexenal with hydrogen in the presence of a catalyst, and is an intermediate in the production of 2-ethylhexanoic acid, an important chemical. Existing technologies have been extensively studied for the production methods of 2-ethylhexanal, such as:
[0003] Patent US3903171A reports the catalytic preparation of 2-ethylhexanal from 2-ethylhexenal using platinum, palladium, or ruthenium (containing 0.03-0.3% of the catalyst) at 80-160°C and 1-25 MPa. During feeding, the product 2-ethylhexanal is used as a solvent, and the amount of 2-ethylhexanal is 2-10 times that of 2-ethylhexenal. The composition of the discharged reaction mixture is: 2-ethylhexanal: 94.6%, 2-ethylhexenal: 0.8%.
[0004] Patent US4273945A reports a method for preparing saturated aliphatic aldehydes by liquid-phase hydrogenation of olefinic unsaturated aldehydes under palladium catalysis. The active component of the catalyst consists of 2-90% palladium and 10-98% rare earth metal oxides or salts, with an Al₂O₃ content greater than 90%. Specifically, at a reaction pressure of 1-3.5 MPa and a temperature of 80-150 °C, the conversion rate of 2-ethylhexenal is greater than 95%, and the selectivity of 2-ethylhexenal is greater than 94%.
[0005] Patent CN109809973 reports a two-stage hydrogenation and two-stage recycling process for preparing 2-ethylhexanal using 2-ethylhexenal as a raw material. The first-stage catalyst contains Pd, Pt, Cu, and Ni, which exhibits good decomposition effects on aldehyde polymers. The second-stage catalyst contains Pd, Co, and Ag, further enhancing the hydrogenation conversion rate and aldehyde polymer decomposition. However, this process uses precious metal catalysts, resulting in complex catalyst preparation, high costs, and a long process flow. Furthermore, the catalyst lifespan is not mentioned, potentially hindering industrial feasibility.
[0006] Patent CN116237054A discloses a catalyst supported on a group VIB metal using a g-C3N4 modified mesoporous alumina composite material and its application in the selective hydrogenation of isooctaldehyde. The catalyst support is a g-nitrogen carbide modified mesoporous alumina composite material, with one or both of Ni and Co as the main active component and one or both of Mo and W as the secondary active component. This catalyst support contains a large number of nitrogen-containing groups, which can effectively stabilize metal nanoparticles. Simultaneously, using SBA-15 as a template agent results in a larger specific surface area, a more regular pore structure, a suitable acid-base distribution, and dual active centers, which can improve the selectivity of isooctaldehyde. However, its decomposition effect on the trimer and tetramer components of butyraldehyde in the hydrogenation feedstock is weak, only able to decompose 2.4% of the butyraldehyde polymer in the feedstock to about 1-2.2%, with a decomposition rate of only 8-58%. Furthermore, the decomposition product of the butyraldehyde polymer is not isooctaldehyde, failing to achieve the goal of improving the isooctaldehyde yield. The patent also does not mention the decomposition effect on C8 dimers.
[0007] As can be seen from the above reports, although known technologies have made various improvements to hydrogenation catalysts, a certain amount of acetal or hemiacetal heavy components, such as 2-ethylhexanal dimers or trimers, 2-ethylhexenal dimers or trimers, and 2-ethylhexanal and 2-ethylhexenal dimers or trimers, are still generated during the reaction, preventing further improvement in the yield of 2-ethylhexanal. Furthermore, the heavy components accumulated at the bottom of the reactor after distillation and purification of the hydrogenation reaction liquid are generally incinerated as waste liquid, resulting in increased raw material consumption, product loss, and increased waste liquid treatment costs. If the heavy components can be decomposed during the distillation and purification of the hydrogenation reaction liquid, the product yield will be further improved and the raw material consumption will be reduced. This invention relates to a novel catalyst that facilitates the decomposition of acetal heavy components in the hydrogenation reaction liquid to generate 2-ethylhexanal. Summary of the Invention
[0008] To address the above technical problems, this invention proposes a Ni-modified microporous-mesoporous molecular sieve, its preparation method, and its application.
[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0010] A method for preparing Ni-modified microporous-mesoporous molecular sieves includes the following steps:
[0011] a. A microporous molecular sieve precursor is prepared by mixing silicon source, aluminum source, microporous directing agent and nickel source in water under alkaline environment and room temperature, stirring and then crystallizing.
[0012] b. At room temperature, a mesoporous directing agent is added to the microporous molecular sieve precursor, and after thorough stirring, crystallization, filtration, washing, and calcination are carried out to obtain a microporous-mesoporous molecular sieve.
[0013] The Ni-modified microporous-mesoporous molecular sieve is a novel composite catalyst material. Its microporous structure can provide acidic centers for catalytic action, while its larger mesoporous structure can provide channels for macromolecular reactions. Continuous research has found that it has good effects in catalyzing the decomposition reaction of acetal-type heavy components.
[0014] In a preferred embodiment of the present invention, in step a, the ratio of the silicon source, aluminum source, microporous guide agent, and nickel source, calculated as the molar ratio of SiO2:Al:microporous guide agent:Ni, is 1:(0.01-0.5):(0.01-0.3):(0.03-0.2).
[0015] In a preferred embodiment of the present invention, the silicon source is one or more of silica sol, fumed silica, silicotungstic acid, di-tert-butylsilane, and triisobutylsilane;
[0016] Preferably, the aluminum source is one or more of aluminum isopropoxide, boehmite, aluminum sulfate, and aluminum hydroxide;
[0017] Preferably, the nickel source is one or more of nickel nitrate, nickel sulfate, and nickel chloride;
[0018] Preferably, the microporous guiding agent is one or more of benzyl dimethyl (2-hydroxyethyl) ammonium chloride, benzyl trimethyl ammonium chloride, N,N,N-trimethyl-1-adamantyl ammonium hydroxide, and benzyl trimethyl ammonium hydroxide.
[0019] In a preferred embodiment of the present invention, in step a, the crystallization conditions are 100-200℃ and the crystallization time is 5-50h.
[0020] Preferably, the alkaline environment is provided by an inorganic base such as NaOH, so that the pH of the mixed solution is 11-14.
[0021] In a preferred embodiment of the present invention, the mesoporous guiding agent is one or more of bis(tetradecyldimethylammonium bromide), decadecyltrimethylammonium bromide, bis(decyldimethylammonium bromide), and hexadecyltrimethylammonium hydroxide.
[0022] In a preferred embodiment of the present invention, in step b, the amount of the mesoporous guiding agent is 0.01-0.5 times the amount of silicon source added in step a, based on the molar amount of SiO2.
[0023] In a preferred embodiment of the present invention, in step b, the crystallization conditions are 120-200℃ and the crystallization time is 20-100h.
[0024] Preferably, the calcination temperature in step b is 400-600℃.
[0025] This invention uses a precursor assembly method to synthesize molecular sieves. First, a microporous precursor with acid centers is synthesized, and Ni is loaded to further enhance its activity in catalyzing the cracking of acetal polymers. Based on the microporous precursor, a mesoporous structure is generated through crystallization, which can provide channels for the cracking reaction of heavy components of acetal polymers. Moreover, this molecular sieve has good hydrothermal stability because of the crystallized microporous structure in the mesopore.
[0026] This invention also proposes a Ni-modified microporous-mesoporous molecular sieve prepared according to the method described above. This molecular sieve catalyst can decompose acetal heavy components in the hydrogenation reaction solution of 2-ethylhexenal into 2-ethylhexanal and 2-ethylhexenal, thereby improving product yield and realizing the recovery and utilization of raw materials.
[0027] The present invention also provides the application of Ni-modified microporous-mesoporous molecular sieve prepared according to the method described above in the treatment of 2-ethylhexenal hydrogenation reaction solution.
[0028] The present invention preferably employs a catalytic reactive distillation process, which couples the decomposition of acetal heavy components in the hydrogenation reaction solution of 2-ethylhexenal and the purification of 2-ethylhexenal in a single distillation column, thereby simplifying the process flow.
[0029] One application method as described above involves feeding the 2-ethylhexenal hydrogenation reaction solution into a distillation column packed with the Ni-modified microporous-mesoporous molecular sieve for reactive distillation. The top of the column yields 2-ethylhexenal with a purity >99%, while the bottom yields a heavy component rich in 2-ethylhexenal. Preferably, the heavy component from the bottom is recycled to the hydrogenation process or the reactive distillation process.
[0030] Preferably, the composition of the 2-ethylhexenal hydrogenation reaction solution includes: 60-96% 2-ethylhexenal, 3-30% heavy components, and 1-10% other impurities, based on 100% of the total mass of the reaction solution; the heavy components include 2-ethylhexenal dimer and / or trimer, 2-ethylhexenal dimer and / or trimer, 2-ethylhexenal and 2-ethylhexenal dimer and / or trimer, and other substances with boiling points higher than 2-ethylhexenal;
[0031] Preferably, the reactive distillation conditions are: column pressure 1-50 kPaA, reflux ratio (1-10):1; feed space velocity of the hydrogenation reaction liquid (calculated based on the volume of the packed molecular sieve catalyst) 0.001-0.02 h⁻¹. -1 .
[0032] According to the distillation column described above, its general composition includes a rectification section, a reaction section, and a stripping section from top to bottom. The Ni-modified microporous-mesoporous molecular sieve is packed in the reaction section. The theoretical number of plates in the rectification section is 15-30, the theoretical number of plates in the reaction section is 10-30, and the theoretical number of plates in the stripping section is 10-20.
[0033] It is understood that the application of Ni-modified microporous-mesoporous molecular sieves in the treatment of 2-ethylhexenal hydrogenation reaction solution in this invention is not limited to the above-mentioned application methods. Based on its catalytic mechanism, it is also applicable to conventional process flows. After the 2-ethylhexenal hydrogenation reaction solution is distilled, the heavy components enriched in the bottom of the column are decomposed. It is conventionally thought that such high-concentration heavy components should be diluted with solvents before treatment, preferably with soluble solvents, and then decomposed to prepare 2-ethylhexenal under the action of Ni-modified microporous-mesoporous molecular sieves in this invention.
[0034] This invention proposes a Ni-modified microporous-mesoporous molecular sieve, which is applied to the reactive distillation of 2-ethylhexenal hydrogenation reaction solution. It can decompose acetal heavy components while purifying the product, thereby improving the yield of 2-ethylhexenal. Moreover, the bottom product is rich in 2-ethylhexenal and can be reused in the hydrogenation process to improve the utilization rate of raw materials. Detailed Implementation
[0035] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.
[0036] Unless otherwise specified, the raw materials and catalysts used in the embodiments of this application were all purchased commercially.
[0037] 2-Ethylhexenal hydrogenation reaction solution A: 2-Ethylhexenal content 62%, 2-Ethylhexenal dimer 9%, 2-Ethylhexenal trimer 6%, 2-Ethylhexenal and 2-Ethylhexenal dimer 11%, and other impurities 12%.
[0038] 2-Ethylhexenal hydrogenation reaction solution B: 2-Ethylhexenal content 94%, 2-Ethylhexenal trimer 1%, 2-Ethylhexenal dimer 1%, 2-Ethylhexenal and 2-Ethylhexenal trimer 1%, and other impurities 3%.
[0039] 2-Ethylhexenal hydrogenation reaction solution C: 2-Ethylhexenal content 79%, 2-Ethylhexenal dimer and trimer 4%, 2-Ethylhexenal dimer and trimer 6%, 2-Ethylhexenal and 2-Ethylhexenal dimer and trimer 5%, and other impurities 6%.
[0040] The main testing methods involved in this invention are as follows:
[0041] (1) Organic matter content analysis
[0042] Analytical instrument: Agilent 7820A, capillary column (J&W 122-5532:3569.41079 DB-5ms, 325℃: 30m×320m×0.5μm)
[0043] Gas chromatography analysis method: area normalization method
[0044] Gas chromatography analysis conditions: Injector heater 270℃, pressure 11.724psi, total flow rate 32.366mL / min, septum purge flow rate 1.3661mL / min, split ratio 30:1, split flow rate 30mL / min; column temperature programmed: initial temperature 60℃, hold for 1 min; ramp to 80℃ at a rate of 10℃ / min, hold for 1 min, then ramp to 270℃ at a rate of 15℃ / min, hold for 7 min, run time 23.66 minutes. Detector: FID detector, heater 280℃, carrier gas: high-purity N2; air flow rate 400mL / min, hydrogen flow rate 30mL / min, make-up gas flow rate 25mL / min, injection volume 0.2μL.
[0045] (2) Formula for calculating the decomposition rate of heavy components: Decomposition rate of heavy components = (mass of heavy components entering the reactive distillation column - mass of heavy components in the material collected from the reactive distillation column) / (mass of heavy components entering the reactive distillation column), where the mass of heavy components = mass of the material * peak area of heavy components in gas chromatography analysis.
[0046] (3) 2-Ethylhexanol yield = Mass of 2-ethylhexanol collected from the side stream of the reactive distillation column / (Mass of 2-ethylhexenol before hydrogenation / 126 * 128 * 2-ethylhexenol conversion rate after hydrogenation).
[0047] (3) Raw material utilization rate = (mass of 2-ethylhexenal in the material before hydrogenation - total mass of heavy components in the stream collected from the reactive distillation column) / mass of 2-ethylhexenal in the material before hydrogenation. Heavy components refer to 2-ethylhexenal dimer and trimer, 2-ethylhexenal dimer and trimer, 2-ethylhexenal and 2-ethylhexenal dimer and trimer, and other substances with boiling points higher than 2-ethylhexenal.
[0048] The following Examples 1-3 and Comparative Examples 1-3 were used to prepare different molecular sieve catalysts:
[0049] Example 1
[0050] Weigh out silica sol, aluminum isopropoxide, benzyl dimethyl (2-hydroxyethyl) ammonium chloride, nickel nitrate hexahydrate, and 50 times the molar amount of water in a SiO2:Al:microporous directing agent:Ni molar ratio of 1:0.1:0.05:0.08. First, add water to a stirred tank, then add NaOH to adjust the pH to 12. At room temperature, add aluminum isopropoxide and benzyl dimethyl (2-hydroxyethyl) ammonium chloride to the stirred tank. While stirring, add silica sol and nickel nitrate hexahydrate. After thorough mixing, transfer to a stainless steel crystallization tank and crystallize at 150℃ for 20 hours to obtain the microporous molecular sieve precursor. At room temperature, ditetradecyl dimethyl ammonium bromide was added to the microporous molecular sieve precursor at a molar ratio of mesoporous directing agent to SiO2 of 0.1:1. After thorough stirring, the mixture was crystallized at 150℃ for 50 h. The reaction slurry was filtered through a sintered funnel, and the filter cake was washed twice with deionized water until the filtrate was neutral or slightly alkaline. The filter cake was then dried at 180℃ for 4 h. The dried filter cake was then spread out evenly and calcined at 400℃ for 20 h to obtain Ni-SSZ-MCM-1 molecular sieve.
[0051] Example 2
[0052] Weigh out silicotungstic acid, boehmite, benzyltrimethylammonium chloride, nickel nitrate hexahydrate, and 30 times the molar amount of water in a SiO2:Al:microporous directing agent:Ni molar ratio of 1:0.05:0.1:0.03. First, add water to a stirred tank, then add NaOH to adjust the pH to 13. At room temperature, add boehmite and benzyltrimethylammonium chloride to the stirred tank. While stirring, add silicotungstic acid and nickel nitrate hexahydrate. After thorough mixing, transfer to a stainless steel crystallization tank and crystallize at 120℃ for 30 hours to obtain the microporous molecular sieve precursor. At room temperature, decaalkyltrimethylammonium bromide was added to the microporous molecular sieve precursor at a molar ratio of mesoporous directing agent to SiO2 of 0.05:1. After thorough stirring, the mixture was crystallized at 160℃ for 40 h. The reaction slurry was filtered through a sintered funnel, and the filter cake was washed twice with deionized water until the filtrate was neutral or slightly alkaline. The filter cake was then dried at 180℃ for 4 h. The dried filter cake was then spread out evenly and calcined at 500℃ for 12 h to obtain Ni-SSZ-MCM-2 molecular sieve.
[0053] Example 3
[0054] Weigh out di-tert-butylsilane, aluminum hydroxide, N,N,N-trimethyl-1-adamantyl ammonium hydroxide, nickel sulfate hexahydrate, and water at a molar ratio of SiO2:Al:microporous directing agent:Ni of 1:0.3:0.3:0.2. First, add water to a stirred tank, then add NaOH to adjust the pH to 11. At room temperature, add aluminum hydroxide and N,N,N-trimethyl-1-adamantyl ammonium hydroxide to the stirred tank. While stirring, add di-tert-butylsilane and nickel sulfate hexahydrate. After thorough mixing, transfer to a stainless steel crystallization tank and crystallize at 170℃ for 15 hours to obtain the microporous molecular sieve precursor. At room temperature, decaalkyltrimethylammonium bromide was added to the microporous molecular sieve precursor at a molar ratio of mesoporous directing agent to SiO2 of 0.02:1. After thorough stirring, the mixture was crystallized at 120℃ for 80 h. The reaction slurry was filtered through a sintered funnel, and the filter cake was washed twice with deionized water until the filtrate was neutral or slightly alkaline. The filter cake was then dried at 180℃ for 4 h. The dried filter cake was then spread out evenly and calcined at 600℃ for 15 h to obtain Ni-SSZ-MCM-3 molecular sieve.
[0055] Comparative Example 1
[0056] Molecular sieves were prepared using essentially the same method as in Example 1, except that nickel nitrate hexahydrate was not added to the raw materials when preparing the microporous molecular sieve precursor. The resulting molecular sieve was designated as SSZ-MCM-4 molecular sieve.
[0057] Comparative Example 2
[0058] Molecular sieves were prepared using a method essentially the same as in Example 1, except that the microporous molecular sieve precursor was filtered through a sand core funnel, the filter cake was washed twice with deionized water until the filtrate was neutral or slightly alkaline, and then the filter cake was dried at 180°C for 4 hours. The dried filter cake was then spread out evenly and calcined at 400°C for 20 hours. The resulting molecular sieve was designated as Ni-SSZ-5 molecular sieve.
[0059] Comparative Example 3
[0060] Weigh out silica sol, aluminum isopropoxide, ditetradecyl dimethyl ammonium bromide, nickel nitrate hexahydrate, and 50 times the molar weight of SiO2, in a molar ratio of SiO2:Al2O3:mesoporous directing agent:Ni of 1:0.1:0.05:0.08. First, add water to a stirred tank, then add NaOH to adjust the pH to 12. At room temperature, add aluminum isopropoxide and ditetradecyl dimethyl ammonium bromide to the stirred tank. While stirring, add silica sol and nickel nitrate hexahydrate. After thorough mixing, transfer to a stainless steel crystallization tank and crystallize at 150℃ for 20 hours. Filter the reaction slurry through a sintered sand funnel. Wash the filter cake twice with deionized water until the filtrate is neutral or slightly alkaline. Then, dry the filter cake at 180℃ for 4 hours. Spread the dried filter cake evenly and calcine at 400℃ for 20 hours. The resulting molecular sieve is designated as Ni-MCM-6 molecular sieve.
[0061] [Application Example 1-3, Comparison with Application Example 1-3]
[0062] According to the reactive distillation process conditions shown in Table 1 below, the molecular sieves prepared in Examples 1-3 and Comparative Examples 1-3 were used as catalysts in the distillation column to distill the hydrogenation reaction solution of 2-ethylhexenal. The composition of the reaction solution before and after reactive distillation was analyzed, and the calculation results are shown in Table 2.
[0063] Table 1. Reactive Distillation Process Conditions
[0064]
[0065] Table 2. Reaction Results
[0066] Recombination decomposition rate Raw material utilization rate 2-Ethylhexanol yield Application Example 1 96.3％ 97.2％ 98.5％ Application Example 2 90.9％ 92.3％ 96.6％ Application Example 3 94.4％ 95.7％ 97.3％ Comparative Application Example 1 80.2％ 89.2％ 87.5％ Comparative Application Example 2 46.5％ 78.9％ 77.8％ Comparative Application Example 3 82.1％ 85.4％ 84.2％
[0067] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.
Claims
1. The application of a Ni-modified microporous-mesoporous molecular sieve in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, The preparation method of the Ni-modified microporous-mesoporous molecular sieve includes the following steps: a. A microporous molecular sieve precursor is prepared by mixing silicon source, aluminum source, microporous directing agent and nickel source in water under alkaline environment and room temperature, stirring and then crystallizing. b. At room temperature, a mesoporous directing agent is added to the microporous molecular sieve precursor, and after thorough stirring, crystallization, filtration, washing, and calcination are carried out to obtain a microporous-mesoporous molecular sieve.
2. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 1 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, In step a, the ratio of silicon source, aluminum source, microporous guide agent, and nickel source is 1:(0.01-0.5):(0.01-0.3):(0.03-0.2), calculated as the molar ratio of SiO2:Al:microporous guide agent:Ni.
3. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 1 or 2 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, The silicon source is one or more of the following: silica sol, fumed silica, silicotungstic acid, di-tert-butylsilane, and triisobutylsilane.
4. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 3 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, The aluminum source is one or more of aluminum isopropoxide, boehmite, aluminum sulfate, and aluminum hydroxide.
5. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 3 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, The nickel source is one or more of nickel nitrate, nickel sulfate, and nickel chloride.
6. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 3 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, The microporous directing agent is one or more of benzyl dimethyl (2-hydroxyethyl) ammonium chloride, benzyl trimethyl ammonium chloride, N,N,N-trimethyl-1-adamantyl ammonium hydroxide, and benzyl trimethyl ammonium hydroxide.
7. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 1 or 2 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, In step a, the crystallization conditions are 100-200℃ and the crystallization time is 5-50h.
8. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 7 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, The alkaline environment is provided by an inorganic base, making the pH of the mixed solution 11-14.
9. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 1 or 2 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, The mesoporous directing agent is one or more of bis(tetradecyl dimethyl ammonium bromide), decyltrimethyl ammonium bromide, bis(decyl dimethyl ammonium bromide), and hexadecyltrimethyl ammonium hydroxide.
10. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 9 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, In step b, the amount of the mesoporous guiding agent is 0.01-0.5 times the amount of silicon source added in step a, based on the molar amount of SiO2.
11. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 1 or 2 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, In step b, the crystallization conditions are 120-200℃ and the crystallization time is 20-100h.
12. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 11 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, The roasting temperature in step b is 400-600℃.
13. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 1 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, The hydrogenation reaction solution of 2-ethylhexenal is fed into a distillation column packed with the Ni-modified microporous-mesoporous molecular sieve for reactive distillation. 2-ethylhexenal with a purity >99% is collected from the top of the column, and heavy components rich in 2-ethylhexenal are collected from the bottom of the column.
14. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 13 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, The reclaimed components from the column bottom are reused in the hydrogenation or reactive distillation processes.
15. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 13 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, The composition of the 2-ethylhexenal hydrogenation reaction solution includes: 60-96% 2-ethylhexenal, 3-30% heavy components, and 1-10% other impurities, based on 100% of the total mass of the reaction solution; the heavy components include 2-ethylhexenal dimer and / or trimer, 2-ethylhexenal dimer and / or trimer, 2-ethylhexenal and 2-ethylhexenal dimer and / or trimer, and other substances with boiling points higher than 2-ethylhexenal.
16. The application of the Ni-modified microporous-mesoporous molecular sieve according to claim 13 in the treatment of 2-ethylhexenal hydrogenation reaction solution, characterized in that, The conditions for reactive distillation are: column pressure 1-50 kPaA, reflux ratio (1-10):1; feed space velocity of the hydrogenation reaction liquid 0.001-0.02 h⁻¹. -1 .