Solid acid alkylation catalyst and its preparation and use

Abstract

The present invention provides a solid acid alkylation catalyst and its preparation method and use, the preparation method includes the steps of: S1: mixing aluminum source, water, alkali source, template agent, silicon source and seed crystal to form gel, carrying out crystallization reaction to obtain MWW structure molecular sieve (wherein the template agent is composed of main template agent and sub-template agent with a molar ratio of 0.5-20:1); S2: calcining the MWW structure molecular sieve obtained in S1 to remove template agent, then carrying out ammonium exchange, and calcining again to obtain H type molecular sieve; S3: mixing the H type molecular sieve obtained in S2 with inorganic oxide and nitric acid solution, kneading and molding to obtain solid acid alkylation catalyst. The present invention uses the method of seed crystal and two kinds of template agents to cooperate in crystallization, directly synthesizing MWW structure molecular sieve without using hexamethyleneimine, piperidine, homopiperazine, and further obtaining solid acid alkylation catalyst.

Description

[Technical Field]

[0001] The present invention relates to a solid acid catalyst, and in particular to a solid acid alkylation catalyst and its method of preparation and use. [Background technology]

[0002] Alkylation is a very important reaction in the petrochemical industry, and the production of alkyl-substituted aromatic hydrocarbons by the alkylation of aromatic hydrocarbons with olefins is a particularly important reaction. Typical catalysts can be divided into L-acid catalysts and B-acid catalysts. L-acid catalysts, primarily represented by anhydrous AlCl3, have advantages such as low cost, high catalytic activity, and technological maturity. However, the production process generates large amounts of aluminum-containing wastewater and has numerous side reactions, making this catalyst largely obsolete. B-acid catalysts include HF, H2SO4, and H3PO4. However, reactions with long-carbon-chain olefins are prone to catalyst deactivation due to carbon buildup. Therefore, the use of liquid acids is currently focused primarily on the alkylation of long-chain olefins (carbon numbers > 8). However, the highly corrosive nature of HF and H2SO4 places high demands on equipment materials, and the production process involves the discharge of various waste products, which creates significant environmental costs. Therefore, the development of solid acid catalysts is urgently needed.

[0003] Although 12-membered ring macroporous molecular sieves have strong channel diffusion properties and are effective in alleviating the problem of rapid catalyst deactivation due to channel clogging, conventional 12-membered ring macroporous molecular sieves, such as octahedral zeolite and beta zeolite, are prone to deactivation due to large molecules blocking the channels inside the crystal. Conventional technologies use different types of 12-membered ring macroporous molecular sieves as the main active component of catalysts, and further improve the diffusion properties by modifying the molecular sieve, but still have problems such as complicated manufacturing costs, the inclusion of highly corrosive halogens, and reduced stability of the molecular sieve.

[0004] MWW molecular sieves have a typical two-dimensional sheet morphology. This sheet structure is composed of several basic monolayers stacked together, forming a unique channel structure consisting primarily of two-dimensional sinusoidal 10-membered ring channels in the ab-axis plane and 12-membered ring supercages and semi-supercages along the c-axis. The 10-membered ring channels have openings measuring 0.41 nm × 0.51 nm and are distributed outside the supercages. The 12-membered ring supercages have openings measuring 0.71 nm × 0.71 nm × 1.82 nm, and are connected to six identical supercages in the surrounding ab-axis plane via 10-membered rings. The semi-supercages distributed on the surface of the sheet layer have openings measuring 0.71 nm × 0.71 nm × 0.8 nm. The open 12-membered ring openings are highly favorable for reactant diffusion, providing excellent catalytic performance for large molecule reactions, making them widely applicable to alkylation and other reactions.

[0005] MWW molecular sieves can be subdivided into several varieties according to the lamination method of the basic monolayer, including MCM-22(P) molecular sieves, which are mainly hydrogen-bonded between monolayers, MCM-49 molecular sieves, which are oxygen-bridged between monolayers, MCM-36 molecular sieves, which form a columnar support structure between the layers, MCM-56 molecular sieves, which are randomly stacked between the layers, and ITQ-2 molecular sieves with a monolayer structure. Among them, MCM-22(P) molecular sieves are relatively unique. After calcining and dehydrating the silanol groups between the layers to form oxygen bridges, MCM-22 molecular sieves (which have the same crystalline structure as MCM-49 molecular sieves) can be obtained, which can then be used to produce MCM-36 molecular sieves through swelling and columnar support, and ITQ-2 molecular sieves through swelling and layer peeling. Therefore, MCM-22(P) molecular sieves have good modification potential.

[0006] Template agents for the direct synthesis of MWW molecular sieves generally include hexamethyleneimine, piperidine, and homopiperazine. Among these, hexamethyleneimine is the most commonly used, but it has the disadvantages of being highly volatile, flammable, and toxic. Piperidine is a chemical that easily produces toxic substances and is difficult to obtain. Homopiperazine is expensive and difficult to apply. Therefore, it is very important to develop an inexpensive and green method for synthesizing MWW molecular sieves.

[0007] In "Synthesis and Application Research of MCM-22 Molecular Sieves [D]. Dalian. Dalian Institute of Chemical Physics, Chinese Academy of Sciences. 2006," the synthesis of MCM-22 molecular sieves was achieved using hexamethyleneimine and cyclohexylamine as double template agents, effectively reducing the amount of hexamethyleneimine used. CN02145233.4 discloses a method for synthesizing MCM-22 molecular sieves using pentamethyleneimine, hexamethyleneimine, or heptamethyleneimine as template agents and recycling the mother liquor, effectively reducing the amount of template agent used. CN201310538868.2 discloses a method for synthesizing MCM-22 molecular sieves using hexamethyleneimine and cyclohexylamine as double template agents. CN201110216909.7 discloses a method for synthesizing MCM-22 family molecular sieves using acidified hexamethyleneimine templating agent and refluxing the templating agent. [Microporous and Mesoporous Materials. 2019, 276:192-200.] demonstrated the induced synthesis of MCM-49 molecular sieves using seed crystals and cyclohexylamine. However, due to the unique nature of MWW molecular sieves, direct synthesis using seed crystals was not possible. Adding seed crystals and then cyclohexylamine resulted in the construction of complete MCM-49 molecular sieves with 10-membered ring channels, but the hydrogen bond spacing between the basic layers was not achieved. Previously, there had been no prior experience with synthesizing MCM-22 molecular sieves without the use of hexamethyleneimine, piperidine, or homopiperazine, which inevitably led to problems with the templating agent during MCM-22 preparation. Summary of the Invention

[0008] In order to solve the above technical problems, the present invention provides a solid acid alkylation catalyst and its preparation method and use, which directly synthesizes MWW molecular sieves and obtains a solid acid alkylation catalyst by using a seed crystal and two template agents in combination to assist crystallization, without using hexamethyleneimine, piperidine, or homopiperazine. S1: mixing an aluminum source, water, an alkali source, a template agent, a silicon source, and seed crystals to form a gel, followed by crystallization to obtain an MWW molecular sieve; S2: The MWW molecular sieve obtained in S1 is calcined to remove the template, and then ammonium-exchanged and calcined again to obtain H-type molecular sieve; S3: Mixing the H-type molecular sieve obtained in S2 with an inorganic oxide and an inorganic acid solution, kneading and shaping, drying and calcining to obtain a solid acid alkylation catalyst; A method for producing a solid acid alkylation catalyst, comprising: The template agent is composed of a main template agent and a subtemplate agent in a molar ratio of 0.5-20:1, and the main template agent is cyclohexylamine. The subtemplate agent is diisopropylamine, di-n-butylamine, diisobutylamine, 1,4-diazabicyclo[2.2.2]octane, 1,6-hexanediamine, N,N,N,N-tetramethyl-1,6-hexanediamine (CAS No. 111-18-2, molecular formula C 10 H 24 The present invention provides a method for preparing a solid acid alkylation catalyst comprising at least one of:

[0009] In the production method of the present invention, both the main template agent and the sub-template agent are low-toxicity and inexpensive organic amines. Here, the main template agent can cooperate with the seed crystal to realize the construction of the molecular sieve base layer structure, and the sub-template agent can be used to form a molecular sieve in which the N atom is sp 3 Hybrid aliphatic amines are used, and the nitrogen atom sp 3The hybrid orbitals form interlayer hydrogen bonds with the silanol groups on the surface of the single-layer structure via vacant orbital holes, and the process of forming hydrogen bonds does not affect the overall crystallization effect of the molecular sieve. Therefore, in some embodiments, the MWW molecular sieve obtained by the above preparation method has interlayer hydrogen bonds formed between the silanol groups and the subtemplate agent.

[0010] The production method of the present invention enables the synthesis of molecular sieves having an MWW structure with interlayer hydrogen bonds without using hexamethyleneimine, piperidine, or homopiperazine, due to the synergistic effects of the main template agent, subtemplate agent, and seed crystals.

[0011] In the method for producing the solid acid alkylation catalyst, preferably, in the gel S1, the molar ratio of the silicon source as SiO, the aluminum source as AlO, the alkali source as an alkali metal oxide, and the template agent is 1:0.005-0.05:0.03-0.50:0.1-0.75; The mass ratio of seed crystals to silicon source as SiO2 on a dry basis is 0.01-0.25:1.

[0012] In the above-mentioned method for preparing a solid acid alkylation catalyst, preferably, in step S1, the seed crystal is a molecular sieve having an MWW topology structure.

[0013] In the above-mentioned method for producing a solid acid alkylation catalyst, preferably, in step S1, the seed crystals comprise MCM-22 molecular sieves or MCM-49 molecular sieves from which a template agent has not been removed. The seed crystals preferably comprise MCM-22 molecular sieves from which a template agent has not been removed, and the molecular sieves have interlayer hydrogen bonds. Using the seed crystals in the above-mentioned production process is advantageous for obtaining molecular sieves with interlayer hydrogen bonds and an MWW structure similar to that of MCM-22 molecular sieves.

[0014] In the above-mentioned method for producing a solid acid alkylation catalyst, preferably, in S1, the silicon source includes at least one of silica sol, solid silica gel, white carbon, and water glass.

[0015] In the above-mentioned method for producing a solid acid alkylation catalyst, preferably, in S1, the alkali source includes sodium hydroxide and / or potassium hydroxide.

[0016] In the above-mentioned method for producing a solid acid alkylation catalyst, preferably, in S1, the aluminum source includes at least one of sodium metaaluminate, aluminum sulfate, aluminum oxide, and pseudoboehmite.

[0017] In the above-mentioned method for preparing a solid acid alkylation catalyst, preferably, in step S1, the crystallization reaction is carried out at a temperature of 120-170° C. for a reaction time of 12-120 hours.

[0018] In the above-mentioned method for preparing a solid acid alkylation catalyst, step S1 preferably includes the steps of: mixing an aluminum source, water, an alkali source, a main template agent, and a sub-template agent to obtain an intermediate solution; slowly adding a silicon source to the intermediate solution and mixing uniformly; then adding seed crystals and mixing to form a gel; and then conducting a crystallization reaction to obtain the MWW molecular sieve. The above synthesis sequence is advantageous for uniform dispersion of each raw material and accelerating the crystallization reaction. The main template agent and sub-template agent are added after the aluminum source, which contributes to the complete dissolution and uniform dispersion of the aluminum source in the solution. Adding the seed crystals after slowly adding the silicon source improves the uniformity and stability of the reaction system and avoids the problem of colloid formation with the aluminum source after rapid addition of the silicon source, resulting in non-uniform dispersion in the reaction system.

[0019] The MWW molecular sieve obtained in the present invention S1 has interlayer hydrogen bonds and a structure similar to that of uncalcined MCM-22 molecular sieves (i.e., without template removal). Therefore, it can be considered a precursor to MCM-22 molecular sieves (referred to as MCM-22(P) molecular sieves). The MWW molecular sieve of the present invention has good modification potential. For example, it can be used to produce MCM-36 molecular sieves through swelling and column support, and ITQ-2 molecular sieves through swelling and exfoliation. Research conducted by the present inventors has revealed that MCM-49 molecular sieves lack interlayer hydrogen bonds and cannot be swollen or exfoliated. However, both the MCM-22 molecular sieve prepared using a conventional template (hexamethyleneimine) and the MWW molecular sieve provided by the present invention possess interlayer hydrogen bonds, and therefore, both of these molecular sieves are capable of swelling and exfoliation. Compared with the MCM-22 molecular sieve prepared using a conventional template (hexamethyleneimine), the MWW molecular sieve provided by the present invention is less difficult to exfoliate. Specifically, the pH of the alkaline environment required for exfoliation is closer to neutral, indicating that the interlayer hydrogen bond strength of the MWW molecular sieve provided by the present invention is more appropriate than that of the MCM-22 molecular sieve. When the molecular sieve is subjected to column support or exfoliation modification, it is more advantageous to maintain the integrity of the molecular sieve's sheet crystal structure, improve the stability of the molecular sieve, and reduce the loss of catalytically active sites, thereby improving the catalytic activity and stability when the molecular sieve is applied to reactions such as alkylation, isomerization, and cracking.

[0020] In the method for preparing the solid acid alkylation catalyst, preferably, in step S2, the two calcinations are each carried out in an air atmosphere, the calcination temperature is independently 490-590° C., and the calcination time is independently 0.5-72 hours.

[0021] In the above-mentioned method for preparing a solid acid alkylation catalyst, preferably, in step S2, the ammonium exchange is carried out in an ammonium nitrate solution, the concentration of the ammonium nitrate solution is 0.1-10 mol / L, the ammonium exchange temperature is 30-120°C, and the ammonium exchange time is 0.5-72 hours.

[0022] In the above-mentioned method for producing a solid acid alkylation catalyst, preferably, in S3, the mass ratio of the H-type molecular sieve to the inorganic oxide is 10-95:5-90.

[0023] In the above-mentioned method for producing a solid acid alkylation catalyst, preferably, in S3, the inorganic oxide includes at least one of aluminum oxide, pseudoboehmite, boehmite, and aluminum hydroxide.

[0024] In the above-mentioned method for producing a solid acid alkylation catalyst, preferably, in step S3, the inorganic acid solution contains at least one of a nitric acid solution, a phosphoric acid solution, a hydrochloric acid solution, and a sulfuric acid solution. In the present invention, the inorganic acid solution is used to emulsify an inorganic oxide to form a binder.

[0025] In the above-mentioned method for preparing a solid acid alkylation catalyst, preferably, in step S3, the calcination is carried out in an air atmosphere, the calcination temperature is 490-590° C., and the calcination time is 0.5-72 hours.

[0026] The present invention also provides a solid acid alkylation catalyst obtained by the above-mentioned method for producing a solid acid alkylation catalyst.

[0027] The present invention also provides use of the solid acid alkylation catalyst obtained by the above-mentioned method for producing a solid acid alkylation catalyst in the alkylation reaction of an aromatic hydrocarbon with an olefin.

[0028] In the above use, the aromatic hydrocarbon is preferably at least one selected from benzene, alkylbenzene, naphthalene, alkylnaphthalene, anthracene, and alkylanthracene, and more preferably at least one selected from benzene, alkylbenzene, naphthalene, and anthracene.

[0029] In the above use, the olefin is preferably selected from olefins having 2 to 20 carbon atoms, more preferably from olefins having 2 to 15 carbon atoms.

[0030] In the above use, the alkylation reaction conditions are preferably a reaction temperature of 100-385°C, a reaction pressure of 0.5-7 MPa, and a mass space velocity of 0.1-12 h -1 More preferably, the alkylation reaction conditions are a reaction temperature of 120-350°C, a reaction pressure of 0.5-5 MPa, and a mass space velocity of 0.5-10 h -1 This includes being.

[0031] In the above use, the molar ratio of the aromatic hydrocarbon to the olefin is preferably 0.05-200.

[0032] The technical solution provided in the present invention has the following beneficial effects:

[0033] (1) In the solid acid alkylation catalyst provided by the present invention, the catalytically active component, H-type molecular sieve, is prepared from MWW molecular sieve by ammonium exchange. The MWW molecular sieve realizes the construction of a basic layer structure by the seed crystal and the main template agent, and realizes the construction of interlayer hydrogen bonds by the subtemplate agent, and has properties similar to MCM-22(P) molecular sieve. (2) The primary and secondary template agents used in the present invention are both low-toxicity, readily available organic amines, which are inexpensive and do not require highly toxic template agents such as hexamethyleneimine, piperidine, or homopiperazine, which are prone to producing toxic substances. This reduces the pollution and cost involved in the preparation of the solid acid alkylation catalyst, and the resulting solid acid alkylation catalyst has high alkylation catalytic activity and product selectivity. This significantly improves the operability of the production of MWW molecular sieves, which is of great practical significance. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is an XRD pattern of a seed crystal. [Figure 2] This is an SEM image of a seed crystal. [Figure 3] 1 is an XRD pattern of the MWW molecular sieve synthesized in Example 1. [Figure 4] 1 is an SEM image of the MWW molecular sieve synthesized in Example 1. [Figure 5] 1 is an XRD pattern of the MWW molecular sieve synthesized in Example 2. [Figure 6] 1 is an SEM image of the MWW molecular sieve synthesized in Example 2. [Figure 7] 1 is an XRD pattern of the molecular sieve synthesized in Comparative Example 1. [Figure 8] 1 is an SEM image of the molecular sieve synthesized in Comparative Example 1. [Figure 9] 1 is an XRD pattern of the molecular sieve synthesized in Comparative Example 3. [Figure 10] 1 is an SEM image of the molecular sieve synthesized in Comparative Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0035] In order to make the technical requirements, objectives and beneficial effects of the present invention more clearly understood, the technical solutions of the present invention are described in detail below, but should not be understood as limiting the possible scope of the present invention.

[0036] The raw materials used in the examples of the present invention are as follows.

[0037] Silicon source: silica sol (SiO2 content 40%), solid silica gel (SiO2 content 95%), white carbon black (SiO2 content 93%), ethyl orthosilicate (purity 98%), Aluminum source: sodium metaaluminate (Al2O3 content 41%), aluminum sulfate (Al2O3 content 15%), aluminum oxide (95%), pseudoboehmite (Al2O3 content 70%), Alkaline source: Sodium hydroxide (purity 99%), potassium hydroxide (purity 99%), Main template agent: cyclohexylamine (purity 99%) Subtemplate agent: diisopropylamine (purity 99%), di-n-butylamine (purity 99%), diisobutylamine (purity 99%), 1,4-diazabicyclo[2.2.2]octane (purity 99%), 1,6-hexanediamine (purity 99%), N,N,N,N-tetramethyl-1,6-hexanediamine (purity 99%), Seed crystal: MCM-22 molecular sieve manufactured by Mobil Corp. The molecular sieve was not calcined to remove the template, and the XRD pattern and SEM image of the surface were shown in Figures 1 and 2, respectively.

[0038] Other: Deionized water.

[0039] The present invention will now be described with reference to specific embodiments and drawings.

[0040] Example 1 This embodiment provides a MWW molecular sieve, the preparation method of which is as follows:

[0041] 1.87 g of sodium hydroxide was added to 120 g of deionized water and stirred to dissolve. 2.15 g of sodium metaaluminate was added and stirred to dissolve. Stirring was continued vigorously for 1 hour. 9.50 g of cyclohexylamine was slowly added and stirred vigorously for 0.5 hours. 6.50 g of diisopropylamine was slowly added and stirred vigorously for 0.5 hours. 80 g of silica sol was slowly added and stirred vigorously for 3 hours. Seed crystals were added in an amount equivalent to 3% of the effective SiO2 mass of the silica sol, and stirring was continued vigorously for 1 hour to prepare a crystallized gel. The crystallized gel was crystallized at 140 °C for 60 hours. After crystallization, the temperature was lowered to room temperature. The product was washed with deionized water, filtered, and dried at 120 °C for 4 hours to obtain MWW molecular sieve.

[0042] The MWW molecular sieve obtained in this example was analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). As shown in Figures 3 and 4, the XRD pattern and SEM image of the MWW molecular sieve showed typical MWW structural peaks, and the molecular sieve morphology was a flower cluster of nanosheets.

[0043] The MWW molecular sieve obtained in this example was calcined in an air atmosphere at 540°C, and then subjected to BET analysis and evaluation of the specific surface area and pore size. The BET test results are shown in Table 1. In Table 1, S BET is the specific surface area, S mic is the micropore surface area, S ext is the mesopore surface area, V pore is the pore volume, V mic is the micropore volume.

[0044] Example 2 This embodiment provides a MWW molecular sieve, the preparation method of which is as follows:

[0045] 1.87 g of sodium hydroxide was added to 120 g of deionized water and stirred to dissolve. 2.50 g of sodium metaaluminate was added and stirred to dissolve. Stirring was continued vigorously for 1 hour. 9.00 g of cyclohexylamine was slowly added and stirred vigorously for 0.5 hours. 8.00 g of 1,6-hexadiamine was slowly added and stirred vigorously for 0.5 hours. 80 g of silica sol was slowly added and stirred vigorously for 3 hours. Seed crystals were added in an amount equivalent to 5% of the available SiO2 mass in the silica sol, and stirring was continued vigorously for 1 hour to prepare a crystallized gel. The crystallized gel was crystallized at 145°C for 72 hours. After crystallization, the temperature was lowered to room temperature. The product was washed with deionized water, filtered, and dried at 120°C for 4 hours to obtain MWW molecular sieve.

[0046] The MWW molecular sieve obtained in this example was analyzed by XRD and SEM. The XRD pattern and SEM image are shown in Figures 5 and 6, respectively. The MWW molecular sieve had typical MWW structural characteristic peaks, and the molecular sieve morphology was a flower cluster of nanosheets.

[0047] The MWW molecular sieve obtained in this example was calcined in an air atmosphere at 540° C., and then subjected to BET analysis evaluation. The BET test results are shown in Table 1.

[0048] Example 3 This embodiment provides a MWW molecular sieve, the preparation method of which is as follows:

[0049] 1.95 g of sodium hydroxide was added to 130 g of deionized water and stirred to dissolve. 2.33 g of sodium metaaluminate was added and stirred to dissolve. Stirring was continued vigorously for 1 hour. 9.00 g of cyclohexylamine was slowly added and stirred vigorously for 0.5 hours. 9.00 g of 1,4-diazabicyclo[2.2.2]octane was slowly added and stirred vigorously for 0.5 hours. 80 g of silica sol was slowly added and stirred vigorously for 3 hours. Seed crystals were added in an amount equivalent to 5% of the available SiO2 mass in the silica sol, and stirring was continued vigorously for 1 hour to prepare a crystallized gel. The crystallized gel was crystallized at 140 °C for 72 hours. After crystallization, the temperature was lowered to room temperature. The product was washed with deionized water, filtered, and dried in the shade for 48 hours to obtain MWW molecular sieves.

[0050] The product obtained in this example was analyzed by XRD, SEM, and BET (after calcination at 540°C in air) and found to have typical MWW structure peaks and a molecular sieve morphology consisting of nanosheets and flower clusters. The BET test results are shown in Table 1.

[0051] Example 4 This embodiment provides a MWW molecular sieve, the preparation method of which is as follows:

[0052] 1.93 g of sodium hydroxide was added to 150 g of deionized water and stirred to dissolve. 1.50 g of sodium metaaluminate was added and stirred to dissolve. Stirring was continued vigorously for 1 hour. 12.25 g of cyclohexylamine was slowly added and stirred vigorously for 0.5 hours. 8.50 g of N,N,N,N-tetramethyl-1,6-hexanediamine was slowly added and stirred vigorously for 0.5 hours. 80 g of silica sol was slowly added and stirred vigorously for 3 hours. Seed crystals were added in an amount equivalent to 10% of the available SiO2 mass in the silica sol, and stirring was continued vigorously for 1 hour to prepare a crystallized gel. The crystallized gel was crystallized at 140 °C for 100 hours. After crystallization, the temperature was lowered to room temperature. The product was washed with deionized water, filtered, and dried at 120 °C for 4 hours to obtain MWW molecular sieve.

[0053] The product obtained in this example was analyzed by XRD, SEM, and BET (after calcination in air at 540°C), and it was found to have typical MWW structural characteristic peaks and the molecular sieve morphology was a flower cluster of deposited nanosheets.

[0054] Example 5 This embodiment provides a MWW molecular sieve, the preparation method of which is as follows:

[0055] 2.21 g of sodium hydroxide was added to 175 g of deionized water and stirred to dissolve. 1.25 g of sodium metaaluminate was added and stirred to dissolve. Stirring was continued vigorously for 1 hour. 7.55 g of cyclohexylamine was slowly added and stirred vigorously for 0.5 hours. 10.50 g of diisobutylamine was slowly added and stirred vigorously for 0.5 hours. 80 g of silica sol was slowly added and stirred vigorously for 3 hours. Seed crystals were added in an amount equivalent to 15% of the available SiO2 mass in the silica sol, and stirring was continued vigorously for 1 hour to prepare a crystallized gel. The crystallized gel was crystallized at 140°C for 120 hours. After crystallization was completed, the temperature was lowered to room temperature. The product was washed with deionized water, filtered, and dried in the shade for 48 hours to obtain an MWW molecular sieve.

[0056] The product obtained in this example was analyzed by XRD, SEM, and BET (after calcination at 540°C in air) and found to have typical MWW structure peaks and a molecular sieve morphology consisting of nanosheets and flower clusters. The BET test results are shown in Table 1.

[0057] Example 6 This example provides a solid acid alkylation catalyst, the preparation method of which is as follows:

[0058] The MWW molecular sieve product of Example 1 was taken and calcined at 540°C for 5 hours in an air atmosphere to remove the template, and then ammonium-exchanged in a 1 mol / L ammonium nitrate solution at 80°C for 2 hours, and then calcined again at 540°C for 4 hours in an air atmosphere to obtain an H-type molecular sieve. 90 g of the H-type molecular sieve and 15 g of pseudoboehmite were mixed uniformly, and 55 g of nitric acid solution was slowly added while kneading. The mixture was band extruded into a φ2.0 mm cylindrical catalyst, which was then cut into a 2.5 mm cylindrical catalyst. The catalyst was dried at room temperature for 24 hours and then calcined at 550 °C for 6 hours to obtain the final solid acid alkylation catalyst.

[0059] The solid acid alkylation catalyst obtained in this example was applied to the catalytic action of the alkylation reaction of aromatic hydrocarbons with olefins, specifically as follows.

[0060] 2 g of the above solid acid alkylation catalyst was placed in a fixed-bed reactor and a mixture of benzene and ethylene was introduced. The alkylation reaction conditions were: benzene to ethylene molar ratio 5, reaction temperature 330°C, reaction pressure 1.4 MPa, mass hourly space velocity 2.0 h -1 It was.

[0061] As a result of the reaction, after 500 hours of reaction, the ethylene conversion was 99.99% and the ethylbenzene selectivity was 96.21%.

[0062] Example 7 This example provides a solid acid alkylation catalyst, the preparation method of which is as follows:

[0063] The MWW molecular sieve product of Example 2 was taken and calcined at 540°C for 5 hours in an air atmosphere to remove the template, and then ammonium-exchanged in a 1 mol / L ammonium nitrate solution at 80°C for 2 hours, and then calcined again at 540°C for 4 hours in an air atmosphere to obtain an H-type molecular sieve.

[0064] 90 g of the H-type molecular sieve and 15 g of pseudoboehmite were mixed uniformly, and 55 g of nitric acid solution was slowly added while kneading. The mixture was band extruded into a φ2.0 mm cylindrical catalyst, which was then cut into a 2.5 mm cylindrical catalyst. The catalyst was dried at room temperature for 24 hours and then calcined at 550 °C for 6 hours to obtain the final solid acid alkylation catalyst.

[0065] The solid acid alkylation catalyst obtained in this example was applied to the catalytic action of the alkylation reaction of aromatic hydrocarbons with olefins, specifically as follows.

[0066] 2 g of the above solid acid alkylation catalyst was placed in a fixed-bed reactor and a mixture of benzene and propylene was introduced. The reaction conditions were: benzene to propylene molar ratio 4, reaction temperature 150°C, reaction pressure 2.5 MPa, mass hourly space velocity 3.0 h -1 It was.

[0067] As a result of the reaction, after 300 hours of reaction, the propylene conversion was 99.97% and the selectivity to isopropylbenzene was 99.20%.

[0068] Example 8 This example provides a solid acid alkylation catalyst, the preparation method of which is as follows:

[0069] The MWW molecular sieve product of Example 3 was taken and calcined at 540°C for 5 hours in an air atmosphere to remove the template, and then ammonium-exchanged in a 1 mol / L ammonium nitrate solution at 80°C for 2 hours, and then calcined again at 540°C for 4 hours in an air atmosphere to obtain an H-type molecular sieve.

[0070] 90 g of the H-type molecular sieve and 15 g of pseudoboehmite were mixed uniformly, and 55 g of nitric acid solution was slowly added while kneading. The mixture was band extruded into a φ2.0 mm cylindrical catalyst, which was then cut into 2.5 mm cylindrical catalyst pieces. The cylindrical catalyst was dried at room temperature for 24 hours and then calcined at 550°C for 6 hours to obtain the final solid acid alkylation catalyst.

[0071] The solid acid alkylation catalyst obtained in this example was applied to the catalytic action of the alkylation reaction of aromatic hydrocarbons with olefins, specifically as follows.

[0072] 2 g of the above solid acid alkylation catalyst was placed in a fixed-bed reactor and a mixture of benzene and n-dodecene was introduced. The reaction conditions were: benzene to n-dodecene molar ratio 15, reaction temperature 150°C, reaction pressure 3.0 MPa, mass hourly space velocity 2.0 h -1 It was.

[0073] As a result of the reaction, after 300 hours of reaction, the n-dodecene conversion was 99.97% and the 2-alkylbenzene selectivity was 42.01%.

[0074] Comparative Example 1 This comparative example provides a molecular sieve, the manufacturing method of which is as follows:

[0075] 1.95 g of sodium hydroxide was added to 130 g of deionized water and stirred to dissolve. 2.33 g of sodium metaaluminate was added and stirred to dissolve. Stirring was continued vigorously for 1 hour. 9.00 g of cyclohexylamine was slowly added and stirred vigorously for 0.5 hours. 80 g of silica sol was slowly added and stirred vigorously for 3 hours. Seed crystals were added in an amount equivalent to 5% of the available SiO2 mass in the silica sol, and stirring was continued vigorously for 1 hour. A crystallized gel was prepared. The crystallized gel was crystallized at 140°C for 72 hours. After crystallization, the temperature was lowered to room temperature. The product was washed with deionized water, filtered, and dried in the shade for 48 hours to obtain a molecular sieve.

[0076] The molecular sieve obtained in this comparative example was subjected to XRD and SEM analysis. As shown in Figures 7 and 8, the XRD pattern and SEM image of the molecular sieve showed the characteristic peaks of a typical MWW structure, and the molecular sieve could be subdivided into MCM-49 molecular sieves. The molecular sieve had the morphology of a regular stack of nanosheets.

[0077] The molecular sieve obtained in this comparative example was calcined in an air atmosphere at 540° C., and then subjected to BET analysis evaluation. The BET test results are shown in Table 1.

[0078] Based on the test results, comparing Comparative Example 1 with Example 3, when seed crystals and cyclohexylamine are used as template agents, a highly crystalline and pure MWW molecular sieve can be directly synthesized, and can be subdivided into MCM-49 molecular sieves. However, since cyclohexylamine cannot form interlayer hydrogen bonds, this method is only applicable to the synthesis of MAM-49 molecular sieves and cannot synthesize other types of MWW molecular sieves. [Table 1]

[0079] On the other hand, in Example 1, diisopropylamine was added, so the nitrogen atom sp 3 The hybridized electron holes and the hydrogen in the interlayer silanol groups formed hydrogen bonds, which made the molecular sieve product more similar to the properties of MCM-22(P) molecular sieve, reduced the number of deposited base layers, reduced the thickness of the molecular sieve sheet layer, increased the total surface area and external surface area, and changed the deposition morphology of the molecular sieve.

[0080] Comparative Example 2 This comparative example provides a catalyst made from the molecular sieve of Comparative Example 1, and its preparation method is as follows:

[0081] The molecular sieve of Comparative Example 1 was calcined at 540°C for 5 hours in an air atmosphere to remove the template, and then ammonium-exchanged in a 1 mol / L ammonium nitrate solution at 80°C for 2 hours. Then, it was calcined again at 540°C for 4 hours in an air atmosphere to obtain an H-type molecular sieve.

[0082] 90 g of the H-type molecular sieve and 15 g of pseudo-boehmite were uniformly mixed, and 55 g of nitric acid solution was slowly added while kneading. The mixture was band extruded into a φ2.0 mm cylindrical catalyst, which was then cut into a 2.5 mm cylindrical catalyst. The cylindrical catalyst was dried at room temperature for 24 hours and then calcined at 550 °C for 6 hours to obtain the finished catalyst.

[0083] The solid acid alkylation catalyst obtained in this comparative example was applied to the alkylation reaction of aromatic hydrocarbons with olefins, as follows.

[0084] 2 g of the above catalyst was placed in a fixed-bed reactor and a mixture of benzene and n-dodecene was introduced. The reaction conditions were: benzene to n-dodecene molar ratio 15, reaction temperature 150°C, reaction pressure 3.0 MPa, mass space velocity 2.0 h -1 As a result of the reaction, after 100 hours of reaction, the olefin conversion was 76.32% and the 2-alkylbenzene selectivity was 45.03%.

[0085] Comparing Comparative Example 2 with Example 8, when the MCM-49 molecular sieve was used to prepare an alkylation catalyst for the reaction of benzene with n-dodecane, the thickness of the molecular sieve was greater than that of the MCM-22 molecular sieve, and therefore the number of exposed surface catalytic active sites per unit mass of catalyst was reduced, leading to faster blockage and deactivation during the reaction, and shortening the catalyst life.

[0086] Comparative Example 3 This comparative example provides a molecular sieve, the manufacturing method of which is as follows:

[0087] 1.87 g of sodium hydroxide was added to 120 g of deionized water and stirred to dissolve. 2.15 g of sodium metaaluminate was added and stirred to dissolve. Stirring was continued vigorously for 1 hour. 19.0 g of hexamethyleneimine was slowly added and stirring was continued vigorously for 0.5 hours to obtain an intermediate solution.

[0088] 80 g of silica sol was slowly added to the intermediate solution and stirred vigorously for 3 hours to prepare a crystallized gel. The crystallized gel was crystallized at 155°C for 60 hours. After crystallization was complete, the temperature was lowered to room temperature. The product was washed with deionized water, filtered, and dried at 120°C for 4 hours to obtain the molecular sieve product.

[0089] The molecular sieve obtained in this comparative example was analyzed by XRD and SEM. The XRD pattern and SEM image are shown in Figures 9 and 10, respectively. The molecular sieve product had a typical MWW structure characteristic peak and could be subdivided into MCM-22 molecular sieves, and the molecular sieve morphology was a nanosheet stack.

[0090] The hexamethyleneimine used in this comparative example is a typical template agent for preparing MCM-22 molecular sieves. This method can produce pure MCM-22 molecular sieves, but requires a large amount of template agent, which is expensive and highly toxic.

[0091] Comparing the XRD results of the molecular sieve products of Examples 1-5 with those of Comparative Example 3, it was found that the molecular sieves of Examples 1-5 had structures similar to that of MCM-22 molecular sieve, further demonstrating that the molecular sieves prepared by the present invention S1 have interlayer hydrogen bonds. <Additional Notes> The present disclosure includes the following aspects. <Section 1> S1: mixing an aluminum source, water, an alkali source, a template agent, a silicon source, and seed crystals to form a gel, followed by crystallization to obtain an MWW molecular sieve; S2: The MWW molecular sieve obtained in S1 is calcined to remove the template, and then ammonium-exchanged and calcined again to obtain H-type molecular sieve; S3: Mixing the H-type molecular sieve obtained in S2 with an inorganic oxide and an inorganic acid solution, kneading and shaping, drying and calcining to obtain a solid acid alkylation catalyst; A method for producing a solid acid alkylation catalyst, comprising: The method for producing a solid acid alkylation catalyst includes a main template agent and a sub-template agent in a molar ratio of 0.5 to 20:1, the main template agent being cyclohexylamine, and the sub-template agent including at least one of diisopropylamine, di-n-butylamine, diisobutylamine, 1,4-diazabicyclo[2.2.2]octane, 1,6-hexanediamine, and N,N,N,N-tetramethyl-1,6-hexanediamine. <Section 2> In the gel of S1, SiO 2 and Al as a silicon source. 2 O 3 the molar ratio of the aluminum source as an alkali metal oxide to the template agent is 1:0.005-0.05:0.03-0.50:0.1-0.75; Seed crystals on a dry basis and SiO 2 The method for producing a solid acid alkylation catalyst according to <Item 1>, wherein the mass ratio of the silicon source to the catalyst is 0.01-0.25:1. <Section 3> In S1, the seed crystal is a molecular sieve having an MWW topology structure. <Section 4> In S1, the seed crystals comprise a template-unremoved MCM-22 molecular sieve or an MCM-49 molecular sieve, preferably a template-unremoved MCM-22 molecular sieve. <Section 5> In S1, the silicon source comprises at least one of silica sol, solid silica gel, white carbon, and water glass. <Section 6> In S1, the alkali source includes sodium hydroxide and / or potassium hydroxide. <Section 7> In S1, the aluminum source includes at least one of sodium metaaluminate, aluminum sulfate, aluminum oxide, and pseudoboehmite. <Section 8> In S1, the crystallization reaction is carried out at a temperature of 120-170°C for 12-120 hours. <Section 9> In S2, the two calcinations are each carried out in an air atmosphere, the calcination temperature is independently 490-590°C, and the calcination time is independently 0.5-72 hours. <Section 10> In S2, the ammonium exchange is carried out in an ammonium nitrate solution, the concentration of the ammonium nitrate solution is 0.1-10 mol / L, the ammonium exchange temperature is 30-120°C, and the ammonium exchange time is 0.5-72 hours. <Section 11> Item 1. The method for producing a solid acid alkylation catalyst according to <Item 1>, wherein in S3, the mass ratio of the H-type molecular sieve to the inorganic oxide is 10-95:5-90. <Section 12> In S3, the inorganic oxide includes at least one of aluminum oxide, pseudoboehmite, boehmite, and aluminum hydroxide; Preferably, the inorganic acid solution contains at least one of a nitric acid solution, a phosphoric acid solution, a hydrochloric acid solution, and a sulfuric acid solution. <Section 13> In step S3, the calcination is carried out in an air atmosphere, the calcination temperature is 490-590°C, and the calcination time is 0.5-72 hours. <Section 14> A solid acid alkylation catalyst obtained by the method for producing a solid acid alkylation catalyst according to any one of <Item 1> to <Item 13>. <Section 15> Use of a solid acid alkylation catalyst obtained by the method for producing a solid acid alkylation catalyst according to any one of <Item 1> to <Item 13> in an alkylation reaction of an aromatic hydrocarbon with an olefin. <Section 16> The use according to <Item 15>, wherein the aromatic hydrocarbon is at least one selected from benzene, alkylbenzene, naphthalene, alkylnaphthalene, anthracene, and alkylanthracene, and preferably at least one of benzene, alkylbenzene, naphthalene, and anthracene. <Section 17> The use according to <Item 15>, wherein the olefin is selected from olefins having 2 to 20 carbon atoms, preferably from olefins having 2 to 15 carbon atoms. <Section 18> The alkylation reaction conditions are: reaction temperature 100-385°C, reaction pressure 0.5-7MPa, mass space velocity 0.1-12h -1 The use according to <Item 15>, including: <Section 19> The alkylation reaction conditions are: reaction temperature 120-350°C, reaction pressure 0.5-5MPa, mass space velocity 0.5-10h -1 The use according to <Item 18>, including: <Section 20> The use according to <Item 15>, wherein the molar ratio of aromatic hydrocarbon to olefin is 0.05-200.

Claims

1. S1: mixing an aluminum source, water, an alkali source, a template agent, a silicon source, and seed crystals to form a gel, followed by crystallization to obtain an MWW-structure molecular sieve; S2: calcining the MWW molecular sieve obtained in S1 to remove the template, then ammonium-exchange the resulting molecular sieve, and calcining it again to obtain an H-type molecular sieve; S3: Mixing the H-type molecular sieve obtained in S2 with an inorganic oxide and an inorganic acid solution, kneading and shaping the mixture, drying, and calcining the mixture to obtain a solid acid alkylation catalyst; A method for producing a solid acid alkylation catalyst, comprising: the template agent comprises a main template agent and a sub-template agent in a molar ratio of 0.5-20:1, the main template agent being cyclohexylamine, and the sub-template agent comprising at least one of diisopropylamine, di-n-butylamine, diisobutylamine, 1,4-diazabicyclo[2.2.2]octane, 1,6-hexanediamine, and N,N,N,N-tetramethyl-1,6-hexanediamine; the molar ratio of the silicon source as SiO2, the aluminum source as Al2O3, the alkali source as an alkali metal oxide, and the template agent in the gel S1 is 1:0.005-0.05:0.03-0.50:0.1-0.75; and the mass ratio of the seed crystals to the silicon source as SiO2 on a dry basis is 0.01-0.25:

1.

2. 2. The method for producing a solid acid alkylation catalyst according to claim 1, wherein in S1, the seed crystal is a molecular sieve having an MWW topology structure.

3. 2. The method for producing a solid acid alkylation catalyst according to claim 1, wherein in step S1, the seed crystals comprise MCM-22 molecular sieve or MCM-49 molecular sieve from which a template agent has not been removed.

4. The method for producing a solid acid alkylation catalyst according to claim 1, wherein in step S1, the seed crystals comprise MCM-22 molecular sieves from which the template agent has not been removed.

5. 2. The method for producing a solid acid alkylation catalyst according to claim 1, wherein in step S1, the silicon source comprises at least one of silica sol, solid silica gel, white carbon, and water glass.

6. 2. The method for producing a solid acid alkylation catalyst according to claim 1, wherein in step S1, the alkali source comprises sodium hydroxide and / or potassium hydroxide.

7. 2. The method for producing a solid acid alkylation catalyst according to claim 1, wherein in step S1, the aluminum source comprises at least one of sodium metaaluminate, aluminum sulfate, aluminum oxide, and pseudoboehmite.

8. 2. The method for producing a solid acid alkylation catalyst according to claim 1, wherein in step S1, the crystallization reaction is carried out at a temperature of 120-170°C for a reaction time of 12-120 hours.

9. 2. The method for producing a solid acid alkylation catalyst according to claim 1, wherein in step S2, the two calcinations are each carried out in an air atmosphere, the calcination temperature is independently 490-590°C, and the calcination time is independently 0.5-72 hours.

10. 2. The method for preparing a solid acid alkylation catalyst according to claim 1, wherein in step S2, the ammonium exchange is carried out in an ammonium nitrate solution, the concentration of the ammonium nitrate solution is 0.1-10 mol / L, the ammonium exchange temperature is 30-120°C, and the ammonium exchange time is 0.5-72 hours.

11. 2. The method for producing a solid acid alkylation catalyst according to claim 1, wherein in step S3, the mass ratio of the H-type molecular sieve to the inorganic oxide is 10-95:5-90.

12. 2. The method for producing a solid acid alkylation catalyst according to claim 1, wherein in S3, the inorganic oxide comprises at least one of aluminum oxide, pseudoboehmite, boehmite, and aluminum hydroxide.

13. 2. The method for producing a solid acid alkylation catalyst according to claim 1, wherein in step S3, the inorganic acid solution comprises at least one of a nitric acid solution, a phosphoric acid solution, a hydrochloric acid solution, and a sulfuric acid solution.

14. 2. The method for producing a solid acid alkylation catalyst according to claim 1, wherein in step S3, the calcination is carried out in an air atmosphere, the calcination temperature is 490-590°C, and the calcination time is 0.5-72 hours.

15. Use of the solid acid alkylation catalyst obtained by the method for producing a solid acid alkylation catalyst according to claim 1 in the alkylation reaction of an aromatic hydrocarbon with an olefin.

16. The use according to claim 15, wherein the aromatic hydrocarbon is at least one selected from benzene, alkylbenzene, naphthalene, alkylnaphthalene, anthracene, and alkylanthracene.

17. 16. The use according to claim 15, wherein the olefin is selected from olefins having 2 to 20 carbon atoms.

18. 18. The use according to claim 17, wherein the olefin is selected from olefins having 2 to 15 carbon atoms.

19. The alkylation reaction conditions are: reaction temperature 100-385°C, reaction pressure 0.5-7 MPa, mass space velocity 0.1-12 h -１ The use according to claim 15, comprising:

20. The alkylation reaction conditions are: reaction temperature 120-350°C, reaction pressure 0.5-5 MPa, mass space velocity 0.5-10 h -１ 20. The use according to claim 19, comprising:

21. The use according to claim 15, wherein the ratio of the number of moles of aromatic hydrocarbon fed to the number of moles of olefin fed is 0.05-200.

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