Process for the synthesis of diisopropyl naphthalenes catalyzed by modified usy molecular sieves and the products synthesized thereby
By modifying USY molecular sieves to support rare earth elements, the problems of catalyst stability and selectivity were solved, and high-purity diisopropylnaphthalene was synthesized efficiently, making it suitable for industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2024-12-17
- Publication Date
- 2026-06-19
AI Technical Summary
In existing technologies, catalysts have low processing capacity, poor activity and stability, low naphthalene conversion rate, and low DIPN selectivity, resulting in a low overall yield of diisopropylnaphthalene. Furthermore, the catalysts suffer from coking and excessive cracking problems during alkylation reactions.
Modified USY molecular sieves were used as catalysts. By loading rare earth elements such as Ce and La, the stability and catalytic performance of the molecular sieves were improved, and the synthesis of diisopropylnaphthalene from propylene and naphthalene was catalyzed. The reaction conditions were optimized to obtain high conversion and selectivity.
It achieves high-purity, high-yield production of diisopropylnaphthalene, reduces the purity requirements of raw materials, allows for catalyst reuse, provides stable catalytic performance, and is suitable for industrial production.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of fine chemical technology, specifically relating to a method for the catalytic synthesis of diisopropylnaphthalene using modified USY molecular sieves and the synthesized product. Background Technology
[0002] Diisopropylnaphthalene (DIPN) is an important chemical product, raw material, and intermediate, widely used in the synthesis of fine chemicals. Due to its numerous advantages such as being colorless and odorless, having a high boiling point, and strong dissolving power, the mixture of diisopropylnaphthalene is widely used as a solvent in industries such as printing, coatings and paints, and adhesives. It can also be used as a plant growth regulator in agricultural production. Furthermore, it is a high-performance high-temperature synthetic heat transfer oil and electrical insulating oil. In addition, the main isomer of diisopropylnaphthalene, 2,6-diisopropylnaphthalene (2,6-DIPN), is an important chemical raw material that can be used to prepare monomers for high-performance polyester fibers and thermotropic liquid crystal polymers.
[0003] Current research reports on DIPN synthesis mainly focus on the screening of alkylation reaction catalysts and the shape-selective catalytic preparation of 2,6-DIPN using molecular sieve catalysts. Catalyst research primarily focuses on solid acid catalysts. CN 112661587A discloses a method for preparing 2,6-dialkylnaphthalene, which includes: (1) under first alkylation reaction conditions and in the presence of a first solid acid catalyst, naphthalene is subjected to a first contact with an alkylating agent to obtain an alkylated product; (2) under isomerization reaction conditions and in the presence of a second solid acid catalyst, the alkylated product is subjected to a second contact to obtain an isomerized product; (3) under second alkylation reaction conditions and in the presence of a third solid acid catalyst, the isomerized product is subjected to a third contact with an alkylating agent to obtain 2,6-dialkylnaphthalene. The first and third solid acid catalysts are selected from at least one of MFI-type molecular sieves, MTT-type molecular sieves, MWW-type molecular sieves, and solid superacids; the second solid acid catalyst is selected from at least one of MTT-type molecular sieves, BEA-type molecular sieves, MWW-type molecular sieves, MFI-type molecular sieves, and solid superacids. The naphthalene obtained by the method provided by this invention has a conversion rate as high as 48%, a selectivity for 2,6-dialkylnaphthalene as high as 61%, and the content of heavy components (substances with a molecular weight ≥ trialkylnaphthalene) in the product is less than 0.8 wt%.
[0004] The liquid-phase alkylation reaction of naphthalene and propylene is a complex process involving a series of intricate chemical changes, including isomerization, alkyl transfer, and dealkylation. This inevitably results in a large number of monosubstituted and polysubstituted products, leading to a relatively low overall yield of DIPN. Furthermore, current solid acid catalysts for alkylation reactions generally suffer from drawbacks such as low catalyst processing capacity, poor activity and stability, low naphthalene conversion, and low DIPN selectivity.
[0005] Y-type molecular sieves are synthesized from HY molecular sieves through high-temperature hydrothermal dealumination. They possess regular, open three-dimensional channels, adjustable acid content, and good hydrothermal stability. USY is a modified Y-type molecular sieve, which increases the silicon-to-aluminum ratio in the molecular sieve framework by removing Al and replenishing Si, making the structure more stable. USY molecular sieves have wide industrial applications in catalytic cracking, olefin alkylation, alkyl transfer, and gas adsorption separation. With the trend towards low-lead or lead-free gasoline, ultra-stable USY molecular sieves have entered the catalytic cracking arena and have been rapidly promoted and applied. This is mainly because using this zeolite molecular sieve as a catalyst can reduce hydrogen transfer reactions, increase the olefin content and octane number in gasoline, reduce coke yield, and increase light oil yield and throughput. However, due to its still relatively low and difficult-to-control silicon-to-aluminum ratio, numerous lattice defects, and the fact that removed aluminum remains within the molecular sieve cage, the migration of aluminum from the sub-outer layer to the outer layer leads to uneven distribution of bulk aluminum and enrichment of amorphous aluminum surfaces, which in turn promotes coking and excessive cracking, affecting further improvement in selectivity. There are currently no reports on the use of USY molecular sieves in the catalytic synthesis of DIPN from naphthalene and propylene. Summary of the Invention
[0006] The purpose of this invention is to provide a method for the catalytic synthesis of diisopropylnaphthalene using modified USY molecular sieves and the synthesized product. The modified USY molecular sieve of this invention exhibits good stability and catalytic performance. The method of this invention achieves high naphthalene conversion and selectivity for diisopropylnaphthalene, yields a high-purity diisopropylnaphthalene product, and the catalyst is reusable with good reproducibility of catalytic effects. This method is suitable for industrial applications involving the reaction of low-purity naphthalene with propylene to synthesize high-purity, high-yield diisopropylnaphthalene.
[0007] The objective of this invention is achieved through the following technical solution:
[0008] In a first aspect, the present invention provides a method for the catalytic synthesis of diisopropylnaphthalene using modified USY molecular sieve, the method comprising using modified USY molecular sieve as a catalyst to catalyze the synthesis of diisopropylnaphthalene from propylene and naphthalene in the raw materials, wherein the modified USY molecular sieve is a USY molecular sieve loaded with rare earth elements.
[0009] In some embodiments of the present invention, the modified USY molecular sieve is added to the synthesis reaction in an amount of 1 to 16 wt% of the total mass of the raw materials, preferably 3 to 8 wt%. The total amount of the raw materials is the sum of propylene and naphthalene.
[0010] In some embodiments of the present invention, the amount of modified USY molecular sieve added in the synthesis reaction is 1 to 16 wt% of the total mass of the raw materials, which means that the amount of modified USY molecular sieve added can be selected from any value of the following mass fractions or any value between any two of them: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 wt%.
[0011] In some embodiments of the present invention, the molar ratio of naphthalene to propylene in the synthesis reaction is 1:(1 to 10).
[0012] In some embodiments of the present invention, the molar ratio of naphthalene to propylene in the synthesis reaction is 1:(1 to 10), which means that the molar ratio of naphthalene to propylene can be selected from any of the following molar ratios or any value between any two of them: 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10.
[0013] In some embodiments of the present invention, the loading of the rare earth elements on the USY molecular sieve is 1 to 22 wt% based on the total amount of the modified USY molecular sieve, preferably 3 to 17 wt%.
[0014] In some embodiments of the present invention, the loading of rare earth elements on the USY molecular sieve, calculated as the total amount of modified USY molecular sieve, is 1 to 22 wt%, meaning that the loading can be selected from any of the following mass percentages or any value between any two of them: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 wt%.
[0015] In some embodiments of the present invention, the specific surface area of the modified USY molecular sieve is ≥400 m². 2 / g, preferably 400-650m 2 / g, more preferably 500-620m 2 / g.
[0016] In some embodiments of the present invention, the pore volume of the modified USY molecular sieve is 0.10–0.26 cm³. 3 / g, preferably 0.12~0.23cm 3 / g.
[0017] In some embodiments of the present invention, the rare earth element includes at least one of Ce and La.
[0018] In some embodiments of the present invention, when the rare earth element is Ce, the loading of Ce on the USY molecular sieve is 1 to 22 wt% based on the total amount of modified USY molecular sieve, preferably 5 to 14 wt%.
[0019] In some embodiments of the present invention, the Ce loading on the USY molecular sieve, which is 1 to 22 wt% based on the total amount of modified USY molecular sieve, means that the loading can be selected from any of the following mass percentages or any value between any two of them: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 wt%.
[0020] In some embodiments of the present invention, when the rare earth element is La, the loading of La on the USY molecular sieve is 1 to 20 wt% based on the total amount of modified USY molecular sieve, preferably 3 to 17 wt%.
[0021] In some embodiments of the present invention, the loading of La on the USY molecular sieve, which is 1 to 20 wt% based on the total amount of modified USY molecular sieve, means that the loading can be selected from any of the following mass percentages or any value between any two of them: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 wt%.
[0022] In some embodiments of the present invention, the USY molecular sieve comprises a hydrogen-form USY molecular sieve.
[0023] In some embodiments of the present invention, the purity of the propylene is ≥65%, preferably 65% to 70%.
[0024] In some embodiments of the present invention, the purity of the naphthalene is ≥90%, preferably ≥95%, and more preferably 95% to 99%.
[0025] In some embodiments of the present invention, the conditions for the synthesis reaction include: a temperature of 160–260°C, a pressure of 1.2–5.0 MPa, and a time of 1–11 h.
[0026] In some embodiments of the present invention, the modified USY molecular sieve is prepared by a method comprising the following steps:
[0027] 1) Dissolve water-soluble salts of rare earth elements in water to prepare a solution;
[0028] 2) Mix the USY molecular sieve with the solution obtained in step 1), and then react at 85-95℃ for 2-6 hours;
[0029] 3) Recover the solid obtained after the reaction in step 2), and dry and calcine it to obtain the final product.
[0030] In some embodiments of the present invention, the water-soluble salt of the rare earth element in step 1) is selected from at least one of the rare earth element nitrates, chlorides, and sulfates, preferably including at least one of Ce(NO3)3·6H2O, CeCl3·7H2O, La(NO3)3·6H2O, and LaCl3·7H2O.
[0031] In some embodiments of the present invention, in step 1), the mass percentage of water-soluble salts of rare earth elements in the solution is 1%-99%.
[0032] In some embodiments of the present invention, in step 2), the solid-liquid ratio of the mixture is 1g:(1~22)mL.
[0033] In some embodiments of the present invention, in step 2), the USY molecular sieve mixed with the solution obtained in step 1) comprises a hydrogen-type USY molecular sieve.
[0034] In some embodiments of the present invention, the USY molecular sieve mixed with the solution obtained in step 1) in step 2) is obtained by hydrothermal ultrastabilization treatment of NH4Y molecular sieve; preferably, the hydrothermal ultrastabilization treatment of NH4Y molecular sieve includes: placing NH4Y molecular sieve in a hydrothermal reactor at a temperature of 500 to 700°C and calcining it in a water vapor atmosphere of 90 to 100% volume for 2 to 5 hours.
[0035] In some embodiments of the present invention, the NH4Y molecular sieve is obtained by ion exchange after mixing NaY molecular sieve with an aqueous NH4Cl solution; preferably, the concentration of NH4Cl in the aqueous NH4Cl solution is 0.5-1.5 mol / L, and the mass ratio of NaY molecular sieve to NH4Cl is 100:(50-100); more preferably, the ion exchange conditions include a temperature of 75-85°C and a time of 1-5 h.
[0036] In some embodiments of the present invention, step 2) further includes stirring the reactants during the reaction. The purpose of stirring is to ensure that the USY molecular sieve and rare earth elements are in more sufficient contact, and that the rare earth elements are more fully and uniformly loaded on the USY molecular sieve. There is no specific limitation on the stirring speed.
[0037] In some embodiments of the present invention, the drying conditions in step 3) include: a temperature of 80–120°C, preferably 90–110°C; and a time of 8–16 h, preferably 10–14 h.
[0038] In some embodiments of the present invention, the calcination conditions in step 3) include: a temperature of 400–600°C, preferably 450–550°C; and a time of 3–7 h, preferably 4–6 h.
[0039] In some embodiments of the present invention, step 3) further includes washing the recovered solid to a neutral pH value before drying and calcining, preferably with water.
[0040] In some embodiments of the present invention, the recovery of solids in step 3) is carried out by filtering to remove the filtrate.
[0041] In some embodiments of the present invention, the method includes feeding naphthalene, propylene and modified USY molecular sieve into a reactor at a molar ratio of naphthalene to propylene of 1:(1-10), adding 1-16 wt% of the total mass of the raw materials, and reacting the raw materials at 160-260°C and 1.2-5.0 MPa for 1-11 h.
[0042] In some embodiments of the present invention, the reactor is any one of a batch reactor, a fixed bed reactor, a slurry bed reactor, a microchannel reactor, etc.
[0043] In some embodiments of the present invention, when using reactors such as batch reactors, fixed-bed reactors, and slurry-bed reactors for discontinuous production, the method includes the following steps:
[0044] (1) The modified USY molecular sieve is added at a rate of 1 to 16 wt% of the total mass of the raw materials and the molar ratio of naphthalene to propylene is 1:(1 to 10). Naphthalene and modified USY molecular sieve are loaded into the reactor.
[0045] (2) Heat the reactor until the temperature reaches 160°C. Then, introduce gaseous or liquid propylene into the reactor at a molar ratio of naphthalene to propylene of 1:(1~10). Keep the reactor temperature at 160~260°C and the pressure at 1.2~5.0 MPa, so that the raw materials react in the reactor for 1~11 hours.
[0046] In some embodiments of the present invention, the propylene flow rate in step (2) is 10 to 40 mL / h.
[0047] In some embodiments of the present invention, when continuous production is carried out using a reactor such as a microchannel reactor, the method for synthesizing 2,6-diisopropylnaphthalene includes the following steps:
[0048] (a) The modified USY molecular sieve is added at a rate of 1 to 16 wt% of the total mass of the raw materials and the molar ratio of naphthalene to propylene is 1:(1 to 10). Naphthalene and modified USY molecular sieve are first mixed and heated to form a fluid. Then the fluid and liquid propylene are simultaneously fed into the reactor.
[0049] (b) Control the temperature inside the reactor to 160–260°C and the pressure to 1.2–5.0 MPa, so that the residence time of the fluid and liquid propylene inside the reactor is 1–10 h.
[0050] In some embodiments of the present invention, the temperature of the fluid in step (a) is 70–110°C.
[0051] In some embodiments of the present invention, the rate at which the fluid is introduced into the reactor in step (a) is 5 to 12 mL / min, measured by the volumetric flow rate of the naphthalene source.
[0052] In some embodiments of the present invention, the method further includes subjecting the crude diisopropylnaphthalene product obtained from the reaction to vacuum distillation; preferably, the conditions for vacuum distillation include: a temperature of 75-85°C and a pressure of 900-2000 Pa.
[0053] In some embodiments of the present invention, the method further includes distilling the product containing diisopropylnaphthalene obtained by vacuum distillation; preferably, the distillation includes collecting monoisopropylnaphthalene at 70–110°C and collecting diisopropylnaphthalene at 120–260°C.
[0054] In some embodiments of the present invention, the method further includes recovering and regenerating the catalyst and then reloading it into the reactor for the synthesis of diisopropylnaphthalene; preferably, the regeneration includes washing the catalyst with ethyl acetate and then drying it; more preferably, the drying is performed at 90-100°C for 12-16 hours.
[0055] Secondly, the present invention provides the application of the method described in the first aspect in the industrial production of diisopropylnaphthalene.
[0056] Thirdly, the present invention provides a diisopropylnaphthalene synthesized by the method described in the first aspect.
[0057] In some embodiments of the present invention, the purity of the diisopropylnaphthalene is ≥99.9%, more preferably ≥99.99%.
[0058] In some embodiments of the present invention, the flash point (opening) of the diisopropylnaphthalene is 135–145°C.
[0059] In some embodiments of the present invention, the density (20°C) of the diisopropylnaphthalene is 0.92–0.94 g / cm³. 3 .
[0060] In some embodiments of the present invention, the kinematic viscosity of the diisopropylnaphthalene at 40°C is 4–5 mm. 2 / s.
[0061] In some embodiments of the present invention, the kinematic viscosity of the diisopropylnaphthalene at 100°C is 1.6–2.0 mm. 2 / s.
[0062] The beneficial effects of this invention are as follows:
[0063] This invention proposes a method for synthesizing diisopropylnaphthalene from propylene and naphthalene using USY molecular sieves loaded with rare earth elements as a catalyst. The USY molecular sieve exhibits good stability and catalytic performance. Using it to synthesize diisopropylnaphthalene from propylene and naphthalene simultaneously achieves high naphthalene conversion and selectivity. Furthermore, the method of this invention has lower purity requirements for the catalyst, allowing for the synthesis of diisopropylnaphthalene from low-purity naphthalene and low-purity propylene while maintaining high naphthalene conversion and selectivity. This facilitates the direct use of industrially produced low-purity naphthalene and low-purity propylene to synthesize high-value diisopropylnaphthalene, thereby reducing the cost of purifying the raw materials and ultimately lowering the production cost of diisopropylnaphthalene. Additionally, the catalyst in this method exhibits high activity stability, is reusable, and demonstrates good reproducibility of its effects.
[0064] The method of the present invention can also achieve catalyst recycling by filtering and separating the solid catalyst and liquid reaction products from the reactants obtained after the reaction. In addition, unreacted naphthalene can be removed by vacuum distillation, and monoisopropylnaphthalene and diisopropylnaphthalene can be separated by distillation to obtain high-purity diisopropylnaphthalene products.
[0065] The method of this invention is applicable to the industrial production of high-purity, high-yield diisopropylnaphthalene directly from low-purity naphthalene and low-purity propylene as raw materials, showing promising prospects for industrial application. Furthermore, the diisopropylnaphthalene product obtained by the method of this invention has high purity, meeting market demand for high-purity diisopropylnaphthalene. Detailed Implementation
[0066] The following embodiments further illustrate the technology of the present invention. It should be noted that the specific embodiments below are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the terms used herein are descriptive and explanatory, not limiting. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications having the same function.
[0067] The endpoints and any values of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.
[0068] The raw materials and detection methods used in the preparation examples, comparative preparation examples, embodiments, and comparative examples of this invention are as follows:
[0069] NaY molecular sieves were purchased from the catalyst factory of Nankai University, CAS number 1318-02-1.
[0070] Nitric acid, purity ≥90%, purchased from Alorich Chemistry, CAS No. 7697-37-2.
[0071] Ammonium chloride (NH4Cl), purity ≥90%, purchased from Alorich Chemistry, CAS No. 12125-02-9.
[0072] Cerium nitrate (Ce(NO3)3·6HO) was purchased from Sinopharm Chemical Reagent Co., Ltd., CAS No. 10294-41-4.
[0073] Lanthanum nitrate (La(NO3)3·6HO) was purchased from Sinopharm Chemical Reagent Co., Ltd., CAS No. 10277-43-7.
[0074] The deionized water was made by the inventor himself.
[0075] The propylene with a purity of approximately 68% was sourced from the refining and chemical unit of Sinopec Maoming Petrochemical Company. Impurities included ethylene, butene, propane, butane, oxygen, nitrogen, and water.
[0076] The 90% pure propylene was obtained by purifying and quantitatively measuring propylene from the refining and chemical unit of Sinopec Maoming Petrochemical Company. Impurities included ethylene, butene, propane, butane, oxygen, nitrogen, and water.
[0077] The naphthalene with a purity of 95% was obtained quantitatively from naphthalene sourced from the refining and chemical unit of Sinopec Maoming Petrochemical Company. Impurities included indene and nitrile substances.
[0078] The naphthalene with a purity of 90% was obtained quantitatively from naphthalene sourced from the refining and chemical unit of Sinopec Maoming Petrochemical Company. Impurities included indene and nitrile substances.
[0079] The conversion rate of propylene and the selectivity of diisopropylnaphthalene and monoisopropylnaphthalene were determined by gas chromatography. The instrument was a Shanghai Kechuang Chromatography Co., Ltd. 900A with an FID detector. The carrier gas was nitrogen, the injection volume was 2 μL, the split ratio was 50:1, and the column was a 60m AC-10 capillary column (Australia). The chromatographic program was set as follows: stabilize at 140℃ for 5 min, increase to 170℃ at 3℃ / min and stabilize for 14 min, increase to 210℃ at 4℃ / min and stabilize for 7 min, and finally increase to 230℃ at 8℃ / min and stabilize for 10 min.
[0080] Conversion rate of naphthalene = (number of moles of naphthalene converted / total number of moles of naphthalene) * 100%;
[0081] DIPN selectivity = (number of moles of DIPN in the product / total number of moles of the product) * 100%;
[0082] 2,6-DIPN selectivity = (number of moles of 2,6-DIPN in the product / total number of moles of disubstituted products) * 100%.
[0083] The substances corresponding to the spectral peaks were identified together using a Finnigan MD800 chromatograph-mass spectrometer from the Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.
[0084] The flash point (open cup) performance test shall be performed in accordance with the test method of GB / T3536-2008 "Determination of flash point and fire point of petroleum products".
[0085] The pour point performance test shall be performed in accordance with the test method of GB / T3535-2006 "Petroleum Pour Point Determination".
[0086] The acid value test shall be performed in accordance with GB / T4945-2002 "Determination of Acid and Base Values of Petroleum Products and Lubricants (Color Indication Method)".
[0087] Density testing shall be performed in accordance with GB / T1884-2000 "Determination of Density of Petroleum Products" and GB / T 1885-1998 "Petroleum Measurement Tables".
[0088] The kinematic viscosity shall be tested in accordance with the method specified in GB / T265-1988 "Determination of Kinematic Viscosity of Petroleum Products".
[0089] The catalysts used in the embodiments and comparative examples of the present invention were prepared by the following preparation examples or comparative preparation examples.
[0090] Preparation Example 1
[0091] 1) Mix 100g of NaY molecular sieve with 1000mL of 1mol / L NH4Cl solution, stir at 80℃ for 1h, then filter the mixture to recover the solid, and wash the solid with deionized water until the pH value is neutral.
[0092] 2) Mix 100g of the solid obtained in step 1) with 1000mL of NH4Cl solution with a concentration of 1mol / L, stir at 80℃ for 1h, then filter the mixture to recover the solid, and wash the solid with deionized water until the pH value is neutral.
[0093] 3) Mix 100g of the solid obtained in step 2) with 1000mL of 1mol / L NH4Cl solution, stir at 80℃ for 1h, then filter the mixture to recover the solid, and wash the solid with deionized water until the pH is neutral. Then dry the obtained solid in an oven at 120℃ for 12h to obtain NH4Y molecular sieve.
[0094] 4) Place the NH4Y molecular sieve obtained in step 3) in a tube furnace, heat it to 600°C, and calcine it for 3 hours in a 100% volume water vapor atmosphere; cool the calcined material to room temperature and then place it back in the tube furnace, heat it to 600°C, and calcine it for 3 hours in a 100% volume water vapor atmosphere; thus obtaining the USY molecular sieve.
[0095] 5) Dissolve Ce(NO3)3·6H2O in deionized water to prepare a solution with a Ce mass fraction of 5 wt%.
[0096] 6) Mix the USY molecular sieve obtained in step 4) with the solution obtained in step 5) at a solid-liquid ratio of 1:10, and then react in a water bath at 90°C for 4 hours.
[0097] 7) The reactants obtained after step 6) were filtered to recover the solid. The solid was then washed with deionized water until the pH was neutral. The solid was then dried in an oven at 100°C for 12 hours under normal pressure. The dried solid was then ground and passed through a 300-mesh sieve. The powder passing through the sieve was calcined at 500°C for 5 hours. The resulting catalyst was labeled as 5wt% Ce-USY. The specific surface area of this 5wt% Ce-USY molecular sieve catalyst was determined to be 640 m². 2 / g, pore volume 0.22cm3 / g.
[0098] Preparation Example 2
[0099] Similar to Preparation Example 1, except that in step 5), a solution with a Ce mass fraction of 10% was prepared; and in step 7), the catalyst obtained was labeled as 10 wt% Ce-USY. The specific surface area of this 10 wt% Ce-USY molecular sieve catalyst was determined to be 600 m². 2 / g, pore volume 0.20cm 3 / g.
[0100] Preparation Example 3
[0101] Similar to Preparation Example 1, except that in step 5), a solution with a Ce mass fraction of 15% was prepared; and in step 7), the catalyst obtained was labeled as 15 wt% Ce-USY. The specific surface area of this 15 wt% Ce-USY molecular sieve catalyst was determined to be 510 m². 2 / g, pore volume 0.15cm 3 / g.
[0102] Preparation Example 4
[0103] Similar to Preparation Example 1, except that step 5) involves dissolving La(NO3)3·6H2O in deionized water to prepare a solution with a La mass fraction of 4%; the catalyst obtained in step 7) is labeled as 4wt%La-USY. The specific surface area of this 4wt%La-USY molecular sieve catalyst was determined to be 612 m². 2 / g, pore volume is 0.23cm 3 / g.
[0104] Preparation Example 5
[0105] Similar to Preparation Example 4, except that in step 5), a solution with a mass fraction of 6% La was prepared; and in step 7), the catalyst obtained was labeled as 6wt% La-USY.
[0106] Preparation Example 6
[0107] Similar to Preparation Example 4, except that in step 5), a solution with a La mass fraction of 9% was prepared; and in step 7), the catalyst obtained was labeled as 9 wt% La-USY. The specific surface area of this 9 wt% La-USY molecular sieve catalyst was determined to be 597 m². 2 / g, pore volume is 0.18cm 3 / g.
[0108] Preparation Example 7
[0109] Similar to Preparation Example 4, except that in step 5), a solution with a La mass fraction of 16% was prepared; and in step 7), the catalyst obtained was labeled as 16 wt% La-USY. The specific surface area of this 16 wt% La-USY molecular sieve catalyst was determined to be 498 m². 2 / g, pore volume is 0.13cm 3 / g.
[0110] Comparative Preparation Example 1
[0111] 1) Mix 100g of NaY molecular sieve with 1000mL of 1mol / L NH4Cl solution, stir at 80℃ for 1h, then filter the mixture to recover the solid, and wash the solid with deionized water until the pH value is neutral.
[0112] 2) Mix 100g of the solid obtained in step 1) with 1000mL of NH4Cl solution with a concentration of 1mol / L, stir at 80℃ for 1h, then filter the mixture to recover the solid, and wash the solid with deionized water until the pH value is neutral.
[0113] 3) Mix 100g of the solid obtained in step 2) with 1000mL of 1mol / L NH4Cl solution, stir at 80℃ for 1h, then filter the mixture to recover the solid, and wash the solid with deionized water until the pH is neutral. Then dry the obtained solid in an oven at 120℃ for 12h to obtain NH4Y molecular sieve.
[0114] 4) The NH4Y molecular sieve obtained in step 3) was placed in a tube furnace and heated to 600°C, then calcined for 3 hours in a 100% volumetric water vapor atmosphere. The calcined material was cooled to room temperature and then placed back into the tube furnace, heated to 600°C, and calcined for 3 hours in a 100% volumetric water vapor atmosphere to obtain the USY molecular sieve. The specific surface area of this USY molecular sieve catalyst was determined to be 700 m². 2 / g, pore volume is 0.28cm 3 / g.
[0115] Comparative Preparation Example 2
[0116] Using AlOOH as the aluminum source, phosphoric acid as the phosphorus source, tetraethyl orthosilicate as the silicon source, triethylamine(R) as the film-forming agent, and deionized water as the solvent, the amounts of each substance are specified in molar ratios.
[0117] The following steps are used to prepare SAPO-5 molecular sieves: 0.6Al₂O₃:1.00P₂O₅:1SiO₂:1.00R:60H₂O is weighed out.
[0118] 1) Place AlOOH in a three-necked flask and add deionized water and stir. Then dissolve phosphoric acid in deionized water and add it to the three-necked flask and stir continuously for 2 hours.
[0119] 2) Add tetraethyl orthosilicate to the mixture obtained in step 1) and continue stirring for 2 hours. Then add triethylamine and stir thoroughly to form a gel. Then, pack the gel into a high-pressure reactor lined with polytetrafluoroethylene and seal it. Crystallize at a crystallization temperature of 200°C for 24 hours and separate the solid.
[0120] 3) The solid obtained in step 2) was first dried in an oven at 120℃ for 4 hours, and then calcined in air at 600℃ for 6 hours to remove the template agent, finally obtaining SAPO-5 molecular sieve. The specific surface area of SAPO-5 molecular sieve was determined to be 246 m². 2 / g, pore volume is 0.13cm 3 / g.
[0121] Comparative preparation example 3
[0122] 1) SAPO-5 molecular sieve was prepared by the method of Comparative Preparation Example 2.
[0123] 2) Dissolve Ce(NO3)3·6H2O in deionized water to prepare a solution with a Ce mass fraction of 5 wt%.
[0124] 3) Mix the SAPO-5 molecular sieve obtained in step 1) with the solution obtained in step 2) at a solid-liquid ratio of 1:10, and then react in a 90℃ water bath for 4 hours.
[0125] 4) The reactants obtained after step 3) were filtered to recover the solid. The solid was then washed with deionized water until the pH was neutral. The solid was then dried in an oven at 100°C for 12 hours under normal pressure. The dried solid was then ground and passed through a 300-mesh sieve. The powder passing through the sieve was calcined at 500°C for 5 hours. The resulting catalyst was labeled as 5wt% Ce-SAPO-5. The specific surface area of this 5wt% Ce-SAPO-5 molecular sieve catalyst was determined to be 187 m². 2 / g, pore volume 0.08cm 3 / g.
[0126] Example 1
[0127] A method for synthesizing diisopropylnaphthalene using modified USY molecular sieve catalysis includes the following steps:
[0128] (1) The catalyst (5wt% Ce-USY) obtained in Preparation Example 1 was loaded into a high-pressure reactor at a catalyst addition amount of 5wt% of the total mass of the raw materials. At the same time, naphthalene with a purity of 95% was added into the high-pressure reactor at a molar ratio of naphthalene to propylene of 1:5. Then, liquid propylene with a purity of about 68% was introduced at a feed flow rate of 25 mL / h.
[0129] (2) Set the temperature of the high-pressure reactor to 210℃ and the pressure to 3.0 MPa. In addition, set the underpressure compensation in the high-pressure reactor to 3.0 MPa and the overpressure protection to 6.0 MPa. At the same time, set the stirring speed in the high-pressure reactor to 800 rpm. Let the raw materials react in the high-pressure reactor under the above-set conditions for 8 hours.
[0130] (3) After the synthesis reaction is completed, the reaction solution is filtered and the filtrate is taken to obtain the crude diisopropylnaphthalene product. The crude diisopropylnaphthalene product is then subjected to vacuum distillation at 80℃ and 900Pa for 3 hours to separate the unreacted naphthalene. The remaining liquid phase after vacuum distillation is then subjected to distillation. The gas phase is first distilled at 80℃ and collected to obtain monoisopropylnaphthalene, and then distilled at 180℃ and collected to obtain diisopropylnaphthalene.
[0131] (4) After the synthesis reaction is completed, the reaction solution is filtered to recover the filter residue, and the filter residue is washed twice with ethyl acetate and then dried at 100℃ for 12h.
[0132] (5) Using the catalyst obtained in step (4) as the catalyst for the synthesis of diisopropylnaphthalene, diisopropylnaphthalene was produced according to the methods in steps (1), (2), and (3). Then, the catalyst was recovered according to the method in step (4) and continued to be used as the catalyst for the synthesis of diisopropylnaphthalene according to the methods in steps (1), (2), and (3). The catalyst was used repeatedly as the catalyst for the synthesis of diisopropylnaphthalene 10 times. After each synthesis reaction, the conversion rate of propylene and the selectivity of diisopropylnaphthalene and monoisopropylnaphthalene were determined by gas chromatography. The results are shown in Table 1. In addition, the properties of the mixture of diisopropylnaphthalene obtained from the 10 productions are shown in Table 4.
[0133] Example 2
[0134] Similar to Example 1, except that in step (1), the catalyst (10 wt% Ce-USY) obtained in Preparation Example 2 was loaded into a high-pressure reactor.
[0135] Example 3
[0136] Similar to Example 1, except that in step (1), the catalyst (15 wt% Ce-USY) obtained in Preparation Example 3 was loaded into a high-pressure reactor.
[0137] Example 4
[0138] Similar to Example 2, except that naphthalene with a purity of 90% is introduced in step (1).
[0139] Example 5
[0140] Similar to Example 2, except that in step (1), liquid propylene with a purity of 90% is introduced.
[0141] Example 6
[0142] Same as Example 2, except that the amount of catalyst used is 3 wt% of the total mass of naphthalene and liquid propylene.
[0143] Example 7
[0144] Same as Example 2, except that the amount of catalyst used is 10 wt% of the total mass of naphthalene and liquid propylene.
[0145] Example 8
[0146] Similar to Example 1, except that in step (1), the catalyst (4 wt% La-USY) obtained in Preparation Example 4 was loaded into the high-pressure reactor, and in step (5), the catalyst was used repeatedly as a catalyst for the synthesis of diisopropylnaphthalene 10 times. After each synthesis reaction, the conversion rate of propylene and the selectivity of diisopropylnaphthalene and monoisopropylnaphthalene were determined by gas chromatography. The results are shown in Table 2. In addition, the properties of the mixture of diisopropylnaphthalene obtained from the 10 productions are shown in Table 4.
[0147] Example 9
[0148] Similar to Example 8, except that in step (1), the catalyst (6 wt% La-USY) obtained in Preparation Example 5 was loaded into a high-pressure reactor.
[0149] Example 10
[0150] Similar to Example 8, except that in step (1), the catalyst (9 wt% La-USY) obtained in Preparation Example 6 was loaded into a high-pressure reactor.
[0151] Example 11
[0152] Similar to Example 8, except that in step (1), the catalyst (16 wt% La-USY) obtained in Preparation Example 7 was loaded into a high-pressure reactor.
[0153] Example 12
[0154] Similar to Example 10, except that naphthalene with a purity of 90% is introduced in step (1).
[0155] Comparative Example 1
[0156] Similar to Example 1, except that in step (1), the catalyst (USY molecular sieve) obtained in Comparative Preparation Example 1 was loaded into the high-pressure reactor. In step (5), the catalyst was used repeatedly as a catalyst for the synthesis of diisopropylnaphthalene 10 times. After each synthesis reaction, the conversion rate of propylene and the selectivity of diisopropylnaphthalene and monoisopropylnaphthalene were determined by gas chromatography. The results are shown in Table 2. In addition, the properties of the mixture of diisopropylnaphthalene obtained from the 10 productions are shown in Table 4.
[0157] Comparative Example 2
[0158] Similar to Example 1, except that in step (1), the catalyst (SAPO-5 molecular sieve) obtained in Comparative Preparation Example 2 was loaded into the high-pressure reactor. In step (5), the catalyst was used repeatedly as a catalyst for the synthesis of diisopropylnaphthalene 10 times. After each synthesis reaction, the conversion rate of propylene and the selectivity of diisopropylnaphthalene and monoisopropylnaphthalene were determined by gas chromatography. The results are shown in Table 3. In addition, the properties of the mixture of diisopropylnaphthalene obtained from the 10 productions are shown in Table 4.
[0159] Comparative Example 3
[0160] Similar to Example 1, except that in step (1), the catalyst (SAPO-5 molecular sieve) obtained in Comparative Preparation Example 2 was loaded into the high-pressure reactor, and 90% pure liquid propylene was introduced in step (1). In step (5), the catalyst was used repeatedly as a catalyst for the synthesis of diisopropylnaphthalene 10 times. After each synthesis reaction, the conversion rate of propylene and the selectivity of diisopropylnaphthalene and monoisopropylnaphthalene were determined by gas chromatography. The results are shown in Table 3. In addition, the properties of the mixture of diisopropylnaphthalene obtained from the 10 productions are shown in Table 4.
[0161] Comparative Example 4
[0162] Similar to Example 1, except that in step (1), the catalyst (SAPO-5 molecular sieve) obtained in Comparative Preparation Example 2 was loaded into the high-pressure reactor, and naphthalene with a purity of 90% was introduced in step (1). In step (5), the catalyst was used repeatedly as a catalyst for the synthesis of diisopropylnaphthalene 10 times. After each synthesis reaction, the conversion rate of propylene and the selectivity of diisopropylnaphthalene and monoisopropylnaphthalene were determined by gas chromatography. The results are shown in Table 3. In addition, the properties of the mixture of diisopropylnaphthalene obtained from the 10 productions are shown in Table 4.
[0163] Comparative Example 5
[0164] Similar to Example 1, except that in step (1), the catalyst (5 wt% Ce-SAPO-5) obtained in Comparative Preparation Example 3 was loaded into the high-pressure reactor. In step (5), the catalyst was used repeatedly as a catalyst for the synthesis of diisopropylnaphthalene 10 times. After each synthesis reaction, the conversion rate of propylene and the selectivity of diisopropylnaphthalene and monoisopropylnaphthalene were determined by gas chromatography. The results are shown in Table 3. In addition, the properties of the mixture of diisopropylnaphthalene obtained from the 10 productions are shown in Table 4.
[0165] Comparative Example 6
[0166] Similar to Example 1, except that in step (1), the catalyst (SAPO-5 molecular sieve) obtained in Comparative Preparation Example 2 was loaded into the high-pressure reactor, and in step (1), 90% pure liquid propylene and 90% pure naphthalene were introduced. In step (5), the catalyst was used repeatedly as a catalyst for the synthesis of diisopropylnaphthalene 10 times. After each synthesis reaction, the conversion rate of propylene and the selectivity of diisopropylnaphthalene and monoisopropylnaphthalene were determined by gas chromatography. The results are shown in Table 3. In addition, the properties of the mixture of diisopropylnaphthalene obtained from the 10 productions are shown in Table 4.
[0167] Comparative Example 7
[0168] Similar to Example 1, except that in step (1), the catalyst (5 wt% Ce-SAPO-5) obtained in Comparative Preparation Example 3 was loaded into a high-pressure reactor, and in step (1), 90% pure liquid propylene and 90% pure naphthalene were introduced. In step (5), the catalyst was used repeatedly as a catalyst for the synthesis of diisopropylnaphthalene 10 times. After each synthesis reaction, the conversion rate of propylene and the selectivity of diisopropylnaphthalene and monoisopropylnaphthalene were determined by gas chromatography. The results are shown in Table 3. In addition, the properties of the mixture of diisopropylnaphthalene obtained from the 10 productions are shown in Table 4.
[0169] Table 1
[0170]
[0171] Table 2
[0172]
[0173]
[0174] Table 3
[0175]
[0176] Table 4
[0177]
[0178]
[0179] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to embodiments, but it should be understood that the terms used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications having the same function.
Claims
1. A method for synthesizing diisopropylnaphthalene using modified USY molecular sieve catalysis, characterized in that, The method includes using a modified USY molecular sieve as a catalyst to synthesize diisopropylnaphthalene from propylene and naphthalene in the raw materials. The modified USY molecular sieve is a USY molecular sieve loaded with rare earth elements.
2. The method according to claim 1, characterized in that, The amount of the modified USY molecular sieve added in the synthesis reaction is 1 to 16 wt% of the total mass of the raw materials, preferably 3 to 8 wt%. And / or, the molar ratio of naphthalene to propylene in the raw material is 1:(1 to 10).
3. The method according to claim 1 or 2, characterized in that, The loading of rare earth elements on the USY molecular sieve is 1 to 22 wt% based on the total amount of modified USY molecular sieve, preferably 3 to 17 wt%. And / or, the specific surface area of the modified USY molecular sieve is ≥400 m². 2 / g, preferably 400-650m 2 / g, more preferably 500-620m 2 / g; And / or, the pore volume of the modified USY molecular sieve is 0.10–0.26 cm³. 3 / g, preferably 0.12~0.23cm 3 / g; And / or, the rare earth element includes at least one of Ce and La; preferably, when the rare earth element is Ce, the loading of Ce on the USY molecular sieve is 1 to 22 wt% based on the total amount of modified USY molecular sieve, preferably 5 to 14 wt%; when the rare earth element is La, the loading of La on the USY molecular sieve is 1 to 20 wt% based on the total amount of modified USY molecular sieve, preferably 3 to 17 wt%. And / or, the USY molecular sieve includes the hydrogen form of the USY molecular sieve.
4. The method according to any one of claims 1 to 3, characterized in that, The purity of the propylene is ≥65%, preferably 65% to 70%; And / or, the purity of the naphthalene is ≥90%, preferably ≥95%, more preferably 95% to 99%; And / or, the conditions for the synthesis reaction include: a temperature of 160–260 °C, a pressure of 1.2–5.0 MPa, and a time of 1–11 h.
5. The method according to any one of claims 1 to 4, characterized in that, The modified USY molecular sieve is prepared by a method comprising the following steps: 1) Dissolve water-soluble salts of rare earth elements in water to prepare a solution; 2) Mix the USY molecular sieve with the solution obtained in step 1), and then react at 85-95℃ for 2-6 hours; 3) Recover the solid obtained after the reaction in step 2), and dry and calcine it to obtain the final product.
6. The method according to claim 5, characterized in that, In step 1), the water-soluble salt of rare earth element is selected from at least one of rare earth element nitrate, chloride and sulfate, preferably including at least one of Ce(NO3)3·6H2O, CeCl3·7H2O, La(NO3)3·6H2O and LaCl3·7H2O. And / or, in step 1), the mass percentage of water-soluble salts of rare earth elements in the solution is 1% to 99%; And / or, in step 2), the solid-liquid ratio of the mixture is 1g:(1~22)mL; And / or, in step 2), the USY molecular sieve mixed with the solution obtained in step 1) includes the hydrogen-type USY molecular sieve. And / or, the drying conditions in step 3) include: a temperature of 80–120°C, preferably 90–110°C; and a time of 8–16 h, preferably 10–14 h. And / or, the calcination conditions in step 3) include: a temperature of 400–600°C, preferably 450–550°C; and a time of 3–7 h, preferably 4–6 h. And / or, step 3) further includes washing the recovered solids to a neutral pH value before drying and calcination, preferably with water; And / or, in step 3), the recovery of solids is carried out by removing the filtrate through filtration.
7. The method according to any one of claims 1 to 6, characterized in that, The method includes feeding naphthalene, propylene, and modified USY molecular sieve into a reactor at a molar ratio of naphthalene to propylene of 1:(1-10), with the modified USY molecular sieve added at an amount of 1-16 wt% of the total mass of the raw materials, and reacting the raw materials at 160-260°C and 1.2-5.0 MPa for 1-11 hours; preferably, the reactor is any one of a batch reactor, a fixed-bed reactor, a slurry-bed reactor, or a microchannel reactor.
8. The method according to claim 7, characterized in that, The method further includes subjecting the crude diisopropylnaphthalene product obtained from the reaction to vacuum distillation; preferably, The conditions for vacuum distillation include: a temperature of 75–85°C and a pressure of 900–2000 Pa. And / or, the method further includes distilling the product containing diisopropylnaphthalene obtained by vacuum distillation; preferably, the distillation includes collecting monoisopropylnaphthalene at 70–110°C and collecting diisopropylnaphthalene at 120–260°C.
9. The method according to claim 7 or 8, characterized in that, The method further includes recovering and regenerating the catalyst and then reloading it into the reactor for the synthesis of diisopropylnaphthalene; preferably, the regeneration includes washing the catalyst with ethyl acetate and then drying it; more preferably, the drying is performed at 90-100°C for 12-16 hours.
10. A diisopropylnaphthalene synthesized by the method of any one of claims 1 to 9; preferably, the diisopropylnaphthalene has a purity of ≥99.9%, more preferably ≥99.99%.