Catalyst and preparation method, preparation method of isopropyl naphthalene heat transfer oil and prepared isopropyl naphthalene heat transfer oil

Abstract

This invention discloses a catalyst and its preparation method, a method for preparing isopropylnaphthalene heat transfer oil, and the prepared isopropylnaphthalene heat transfer oil. The invention provides a catalyst comprising a support and a supported component. The support is a composite material containing ZrO2 and SiO2, and the supported component is SO4. 2‑ Based on the total mass of the catalyst, the content of ZrO2 in the catalyst is 50wt%–70wt%, the content of SiO2 is 50wt%–70wt%, and the content of SO4 is [missing information]. 2‑ The content of ZrO2 is 3wt% to 12wt%, and the catalyst has a large specific surface area and high acidic sites on its surface. This invention provides SO4 supported on a composite material of ZrO2 and SiO2. 2‑ The catalyst provided by this invention exhibits high conversion rates and selectivity for diisopropylnaphthalene in the isopropylation reaction of naphthalene and propylene. In the isopropylation reaction of naphthalene and propylene of this invention, the conversion rate of naphthalene can reach over 98%, and the selectivity for diisopropylnaphthalene can reach over 64%.

Description

Technical Field

[0001] This invention relates to the field of heat transfer oil preparation technology, specifically to catalysts and preparation methods, preparation methods of isopropylnaphthalene heat transfer oil, and the prepared isopropylnaphthalene heat transfer oil. Background Technology

[0002] With the continuous development of the petrochemical and energy industries, the demand for high-temperature heating is increasing due to the iterative upgrading of new technologies and processes. High-temperature synthetic heat transfer oils offer advantages such as high initial boiling point and narrow distillation range, less high-temperature cracking during the reaction, and good high-temperature thermal stability. However, they also have high production costs, high prices, high technological content, low volatility, recyclability, and a service life of 5-10 years. As the advantages of high-temperature synthetic heat transfer oils are recognized and unit production costs decrease, they will gradually replace mineral-based heat transfer oils as the mainstream product in the market. Among them, isopropylnaphthalene (diisopropylnaphthalene, triisopropylnaphthalene) is an excellent heat transfer oil.

[0003] Diisopropylnaphthalene, a high-temperature synthetic heat transfer oil made from naphthalene and propylene / isopropanol, possesses advantages such as being odorless, non-corrosive to metals, having good thermal stability, excellent low-temperature performance, and being recyclable. Its good thermal stability allows it to operate continuously at high temperatures of 320–330°C. With its low pour point, non-corrosive nature, and lack of unpleasant odor, it is easy to use and a high-performance high-temperature synthetic heat transfer oil. Therefore, it can be widely used in industries such as petrochemicals, automotive transportation, power and electrical engineering, textile printing and dyeing, and energy.

[0004] Currently, the synthesis of diisopropylnaphthalene generally employs a liquid-phase alkylation method using naphthalene and propylene / isopropanol. However, the isopropylation of naphthalene often utilizes batch reactors or fixed-bed reactors, where the catalyst is highly susceptible to deactivation during the reaction (Journal of Catalysis 220(2003)265-272), making continuous preparation of diisopropylnaphthalene difficult.

[0005] In existing processes for preparing isopropyl naphthalene, the catalysts exhibit low reactivity and low selectivity for diisopropyl naphthalene. Therefore, it is crucial to develop high-performance supported catalysts to synthesize isopropyl naphthalene-based heat transfer oils with low viscosity, low pour point, and good thermal stability through the isopropylation reaction of naphthalene and propylene. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention proposes a catalyst and its preparation method, a method for preparing isopropylnaphthalene heat-conducting oil, and the prepared isopropylnaphthalene heat-conducting oil.

[0007] In a first aspect, the present invention provides a catalyst comprising a support and a supported component, wherein the support is a composite material containing ZrO2 and SiO2, and the supported component is SO4. 2-Based on the total mass of the catalyst, the content of ZrO2 in the catalyst is 50wt%–70wt%, the content of SiO2 is 20wt%–40wt%, and the content of SO4 is [missing information]. 2- The content is 3wt% to 12wt%.

[0008] Preferred, SO4 2- The content is 3wt% to 10wt%.

[0009] In a second aspect, the present invention provides a method for preparing the catalyst provided in the first aspect of the present invention, which involves mixing, soaking, filtering, drying and calcining a ZrO2 and SiO2 composite material with a sulfuric acid solution.

[0010] In a specific embodiment of the present invention, the concentration of the sulfuric acid solution is 0.5 to 2 mol / L.

[0011] As a specific embodiment of the present invention, the solid-liquid ratio of the ZrO2 and SiO2 composite material to the sulfuric acid solution is 1g:3-20mL.

[0012] In a specific embodiment of the present invention, the soaking time is 2 to 8 hours.

[0013] As a specific embodiment of the present invention, the calcination conditions include: a temperature of 450–700°C and a time of 2–6 hours.

[0014] As a specific embodiment of the present invention, the preparation method of ZrO2 and SiO2 composite material includes the following steps:

[0015] (1) Mix tetraethyl orthosilicate, water and ethanol to hydrolyze tetraethyl orthosilicate (TEOS) to obtain hydrolyzed tetraethyl orthosilicate;

[0016] (2) The hydrolyzed tetraethyl orthosilicate was mixed with ZrO(NO3)2·2H2O solution to obtain a mixture. The mixture was stirred to obtain a gel solution.

[0017] (3) The adhesive solution is aged and centrifuged to obtain a solid product;

[0018] (4) The solid product was dried to obtain a ZrO2 and SiO2 composite material.

[0019] In a specific embodiment of the present invention, the sum of the concentrations of ZrO(NO3)2 and tetraethyl orthosilicate in the mixture is 0.1 to 0.6 mol / L, and the molar ratio of Zr to Si is 1:0.5 to 2.

[0020] In a specific embodiment of the present invention, the solvent in the ZrO(NO3)2·2H2O solution is alcohol and water.

[0021] In a specific embodiment of the present invention, the ratio of alcohol to water in the mixture is 2 to 7:1.

[0022] As a specific embodiment of the present invention, the hydrolysis conditions include: a temperature of 60–90°C and a time of 6–18 h.

[0023] As a specific embodiment of the present invention, the aging conditions include: a temperature of 60-90°C and a time of 16-48 hours.

[0024] In a specific embodiment of the present invention, anhydrous ethanol is used to centrifuge the adhesive solution, thereby replacing the water in the adhesive solution.

[0025] As a specific embodiment of the present invention, the drying conditions include: using spray drying, and the spray drying temperature is 80-120°C.

[0026] Thirdly, the present invention provides a method for preparing isopropylnaphthalene heat-conducting oil, wherein a raw material containing naphthalene source and propylene is reacted to prepare isopropylnaphthalene heat-conducting oil in the presence of the catalyst provided in the first aspect of the present invention or the catalyst prepared by the preparation method provided in the second aspect of the present invention.

[0027] In a specific embodiment of the present invention, the molar ratio of naphthalene source to propylene is 1:1 to 1:6, preferably 1:1 to 1:5.

[0028] In a specific embodiment of the present invention, the naphthalene source is naphthalene or 2-isopropylnaphthalene.

[0029] As a specific embodiment of the present invention, the amount of catalyst used is 0.2% to 20% of the mass of the naphthalene source, preferably 0.5% to 10%.

[0030] In a specific embodiment of the present invention, naphthalene source and propylene are reacted in a reactor to prepare heat transfer oil.

[0031] Specifically, the reactor is one of the following: a batch reactor (reaction vessel), a fixed-bed reactor, or a slurry-bed reactor.

[0032] As a specific embodiment of the present invention, the reaction conditions between naphthalene source and propylene include: a temperature of 150-300°C, preferably 170-270°C; a reaction time of 1-10 h, preferably 3-8 h; and a reaction pressure of 0.5-5 MPa, preferably 1-3 MPa.

[0033] In a specific embodiment of the present invention, the conversion rate of the naphthalene source in the preparation method is 98% to 99.8%, and the selectivity of diisopropylnaphthalene is 63% to 70%.

[0034] Fourthly, the present invention provides an isopropylnaphthalene heat-conducting oil, which is prepared using the preparation method provided in the third aspect of the present invention.

[0035] Preferably, the kinematic viscosity of the isopropylnaphthalene heat transfer oil at 100°C is 1.8–2.7 mm. 2 / s, pour point is -42 to -49℃.

[0036] Compared with the prior art, the present invention has the following beneficial effects.

[0037] This invention provides SO4 supported by a composite material of ZrO2 and SiO2. 2- The catalyst provided by this invention has a large specific surface area and a high number of acidic sites on its surface. The catalyst exhibits high conversion rate and selectivity for diisopropylnaphthalene in the isopropylation reaction of naphthalene and propylene. In the isopropylation reaction of naphthalene and propylene of this invention, the conversion rate of naphthalene can reach over 98%, and the selectivity for diisopropylnaphthalene can reach over 64%.

[0038] The isopropyl naphthalene heat transfer oil prepared by this invention has low color, low viscosity, low pour point and good thermal stability. It can operate at a temperature of 320-330℃ for a long time and has very good application prospects. Detailed Implementation

[0039] The present invention will be further described below with reference to specific embodiments, but this does not constitute any limitation on the present invention.

[0040] The raw materials used in the various embodiments of this invention are commercially available, wherein:

[0041] Ethyl orthosilicate was purchased from Sinopharm Reagent Company, CAS No.: 78-10-4;

[0042] Ethanol was purchased from Sinopharm Reagent Company, AR, CAS No.: 64-17-5;

[0043] Zirconium oxynitrate was purchased from Beijing Wokai Biotechnology Co., Ltd., with a purity of 99.5% and CAS number: 14985-18-3.

[0044] Sulfuric acid was purchased from Sinopharm Reagent Company, with a purity of 95.0 wt% to 98.0 wt%, CAS No.: 7664-93-9;

[0045] Naphthalene was purchased from Sinopharm Reagent, with a purity of ≥98.0 wt%, CAS No.: 91-20-3;

[0046] Hβ molecular sieve and MOR molecular sieve were both purchased from Zhuoran Environmental Protection Technology Co., Ltd.

[0047] The propylene was sourced from Sinopec Maoming Branch, with a purity of ≥98.0 wt%.

[0048] The analytical method and the calculation of conversion rate and selectivity described in this invention are as follows:

[0049] Qualitative and quantitative analysis of the products was performed offline using a Shimadzu GC-2030 gas chromatograph, with separation using an HP-INNOWAX column and detection using a flame ionization detector.

[0050] Conversion rate of naphthalene = (Number of moles of naphthalene converted / Total number of moles of naphthalene) × 100%

[0051] Diisopropylnaphthalene selectivity = (number of moles of diisopropylnaphthalene in the product / total number of moles of the product) × 100%

[0052] Selectivity for tri- and polysubstituted isopropyl naphthalene = (Moles of tri- and polysubstituted isopropyl naphthalene in the product) / (Total moles of the product) × 100%

[0053] Example 1

[0054] ZrO2 and SiO2 composite material loaded with SO4 2- Preparation of catalyst and performance testing in the isopropylation reaction of naphthalene and propylene

[0055] (1) A certain amount of tetraethyl orthosilicate was dissolved in anhydrous ethanol. An appropriate amount of deionized water was added according to the alcohol-to-water volume ratio of 3. After mixing, the mixture was placed in a constant temperature water bath at 60℃ and stirred for 12 hours for hydrolysis. Then, a calculated amount of ZrO(NO3)2·2H2O alcohol-water solution (the volume ratio of alcohol to water in the ZrO(NO3)2·2H2O alcohol-water solution was 3:1) was added to obtain a mixed solution. (The sum of the concentrations of ZrO(NO3)2 and TEOS in the mixed solution was 0.2 mol / L, the molar ratio of Zr to Si was 1:2, and the volume ratio of alcohol to water in the ZrO(NO3)2·2H2O alcohol-water solution was 3:1). After stirring the mixed solution for 10 hours to form a gel, it was aged for 24 hours. Then, the alcohol-water exchange was performed by centrifugation with anhydrous ethanol. The ZrO2 and SiO2 composite material was obtained by spray drying at 100℃.

[0056] The dried ZrO2 and SiO2 composite material was ground, then soaked in 1 mol / L sulfuric acid solution at a solid-liquid ratio of 1 g: 5 mL for 3 h. After filtration, the solid sample was collected, dried at 120 °C for 12 h, and then calcined in a muffle furnace at 600 °C for 4 h in air atmosphere to obtain the ZrO2 and SiO2 composite material loaded with SO4. 2- Catalyst.

[0057] (2) The catalyst prepared above was used to evaluate the isopropylation reaction of naphthalene and propylene in a reactor. 8g of catalyst and 80g of solid naphthalene were placed in the reactor, sealed, and purged with nitrogen. Nitrogen was then introduced into the reactor until the pressure reached 0.3MPa. The reactor was heated to 150℃, and 52.5g of gaseous propylene was introduced. The reaction temperature was controlled at 210℃, the reaction pressure at 2.5MPa, and the reaction time at 6 hours. The catalyst was removed by filtration, and the filtrate was then separated by distillation to obtain isopropyl naphthalene heat transfer oil. The kinematic viscosity of the isopropyl naphthalene heat transfer oil at 100℃ was 1.8 mm. 2 The reaction proceeds at a rate of 1 / s, with a pour point of -49℃. The conversion rate and product selectivity are shown in Table 1.

[0058] Example 2

[0059] ZrO2 and SiO2 composite material loaded with SO4 2- Preparation of catalyst and performance testing in the isopropylation reaction of naphthalene and propylene

[0060] (1) A certain amount of tetraethyl orthosilicate was dissolved in anhydrous ethanol. An appropriate amount of deionized water was added according to the alcohol-to-water volume ratio of 3. After mixing, the mixture was placed in a constant temperature water bath at 60℃ and stirred for 12 hours for hydrolysis. Then, a calculated amount of ZrO(NO3)2·2H2O alcohol-water solution (the volume ratio of alcohol to water in the ZrO(NO3)2·2H2O alcohol-water solution was 3:1) was added to obtain a mixed solution. (The sum of the concentrations of ZrO(NO3)2 and TEOS in the mixed solution was 0.5 mol / L, the molar ratio of Zr to Si was 1:2, and the volume ratio of alcohol to water in the ZrO(NO3)2·2H2O alcohol-water solution was 3:1). After stirring the mixed solution for 12 hours to form a gel, it was aged for 24 hours. Then, the alcohol and water were exchanged by centrifugation with anhydrous ethanol. The ZrO2 and SiO2 composite material was obtained by spray drying at 110℃.

[0061] The dried ZrO2 and SiO2 composite material was ground, and then soaked in 0.5 mol / L sulfuric acid solution at a solid-liquid ratio of 1 g: 20 mL for 6 h. After filtration, the solid sample was collected, dried at 100 °C for 12 h, and then calcined in a muffle furnace at 650 °C for 3 h in air atmosphere to obtain a ZrO2 and SiO2 composite material loaded with SO4. 2- Catalyst.

[0062] (2) The catalyst prepared above was used to evaluate the isopropylation reaction of naphthalene and propylene in a reactor. 5g of catalyst and 100g of naphthalene were placed in the reactor, sealed, and purged with nitrogen. Nitrogen was then introduced into the reactor until the pressure reached 0.3MPa. The reactor was heated to 150℃, and 65.6g of gaseous propylene was introduced. The reaction temperature was controlled at 230℃, the reaction pressure at 3MPa, and the reaction time at 5 hours. The catalyst was removed by filtration, and the filtrate was then separated by distillation to obtain isopropylnaphthalene heat transfer oil. The kinematic viscosity of the isopropylnaphthalene heat transfer oil at 100℃ was 2.0 mm. 2 The reaction proceeds at a rate of 1 / s, with a pour point of -46℃. The naphthalene conversion and product selectivity are shown in Table 1. The catalyst prepared in Example 2 was reused ten times according to the heat transfer oil preparation method in Example 2 to test its reusability. The catalyst reusability is shown in Table 2.

[0063] Example 3

[0064] ZrO2 and SiO2 composite material loaded with SO4 2- Preparation of catalyst and performance testing in the isopropylation reaction of naphthalene and propylene

[0065] (1) A certain amount of tetraethyl orthosilicate was dissolved in anhydrous ethanol. An appropriate amount of deionized water was added according to the alcohol-to-water volume ratio of 5. After mixing, the mixture was placed in a constant temperature water bath at 60℃ and stirred for pre-hydrolysis for 12h. Then, a calculated amount of ZrO(NO3)2·2H2O alcohol-water solution (the volume ratio of alcohol to water in the ZrO(NO3)2·2H2O alcohol-water solution was 5:1) was added to obtain a mixed solution. (The sum of the concentrations of ZrO(NO3)2 and TEOS in the mixed solution was 0.2mol / L, the molar ratio of Zr to Si was 1:1, and the volume ratio of alcohol to water in the ZrO(NO3)2·2H2O alcohol-water solution was 5:1). After stirring the mixed solution for 8h to form a gel, it was aged for 24h. Then, the alcohol-water exchange was performed by centrifugation with anhydrous ethanol. The ZrO2 and SiO2 composite material was obtained by spray drying at 120℃.

[0066] The dried ZrO2 and SiO2 composite material was ground, and then soaked in 1 mol / L sulfuric acid solution at a solid-liquid ratio of 1 g:10 mL for 6 h. After filtration, the solid sample was collected, dried at 100 °C for 12 h, and then calcined in a muffle furnace at 650 °C for 3 h in air atmosphere to obtain the ZrO2 and SiO2 composite material loaded with SO4. 2- Catalyst.

[0067] (2) The catalyst prepared above was used to evaluate the isopropylation reaction of naphthalene and propylene in a reactor. 2g of catalyst and 80g of naphthalene were placed in the reactor, sealed, and purged with nitrogen. Nitrogen was then introduced into the reactor until the pressure reached 0.3MPa. The reactor was heated to 150℃, and 78.8g of gaseous propylene was introduced. The reaction temperature was controlled at 250℃, the reaction pressure at 2MPa, and the reaction time at 4 hours. The catalyst was removed by filtration, and the filtrate was then separated by distillation to obtain isopropylnaphthalene heat transfer oil. The kinematic viscosity of the isopropylnaphthalene heat transfer oil at 100℃ was 2.6 mm. 2 The reaction proceeded at a rate of 1 / s, with a pour point of -42℃. The naphthalene conversion and product selectivity are shown in Table 1.

[0068] Example 4

[0069] ZrO2 and SiO2 composite material loaded with SO4 2- Preparation of catalysts and performance testing for isopropylation of naphthalene and propylene

[0070] (1) A certain amount of tetraethyl orthosilicate was dissolved in anhydrous ethanol. An appropriate amount of deionized water was added according to the alcohol-to-water volume ratio of 3. After mixing, the mixture was placed in an 80℃ constant temperature water bath and stirred for pre-hydrolysis for 8 hours. Then, a calculated amount of ZrO(NO3)2·2H2O alcohol-water solution (the volume ratio of alcohol to water in the ZrO(NO3)2·2H2O alcohol-water solution was 3:1) was added to obtain a mixed solution. (The sum of the concentrations of ZrO(NO3)2 and TEOS in the mixed solution was 0.2 mol / L, the molar ratio of Zr to Si was 1:1.5, and the volume ratio of alcohol to water in the ZrO(NO3)2·2H2O alcohol-water solution was 3:1). After stirring the mixed solution for 14 hours to form a gel, it was aged for 18 hours. Then, the alcohol-water exchange was performed by centrifugation with anhydrous ethanol. The ZrO2 and SiO2 composite material was obtained by spray drying at 90℃.

[0071] The dried ZrO2 and SiO2 composite material was ground, and then soaked in 1 mol / L sulfuric acid solution at a solid-liquid ratio of 1 g:10 mL for 6 h. After filtration, the solid sample was collected, dried at 100 °C for 12 h, and then calcined in a muffle furnace at 550 °C for 6 h in air atmosphere to obtain the ZrO2 and SiO2 composite material loaded with SO4. 2- Catalyst.

[0072] (2) The catalyst prepared above was used to evaluate the isopropylation reaction of naphthalene and propylene in a reactor. 4.8 g of catalyst and 80 g of naphthalene were placed in the reactor, sealed, and purged with nitrogen. Nitrogen was then introduced into the reactor until the pressure reached 0.3 MPa. The reactor was heated to 150°C, and 65.6 g of gaseous propylene was introduced. The reaction temperature was controlled at 210°C, the reaction pressure at 1.5 MPa, and the reaction time at 5 hours. The catalyst was removed by filtration, and the filtrate was then separated by distillation to obtain isopropyl naphthalene heat transfer oil. The kinematic viscosity of the isopropyl naphthalene heat transfer oil at 100°C was 2.4 mm⁻¹. 2 The reaction proceeds at a rate of 1 / s, with a pour point of -44℃. The naphthalene conversion and product selectivity are shown in Table 1. The physicochemical properties of the isopropylnaphthalene heat transfer oil are shown in Table 3.

[0073] Comparative Example 1

[0074] SiO2 loaded SO4 2- Preparation of catalysts and performance testing in the isopropylation reaction of naphthalene and propylene

[0075] Tetraethyl orthosilicate was dissolved in anhydrous ethanol, and an appropriate amount of deionized water was added at an alcohol-to-water volume ratio of 3 to obtain a tetraethyl orthosilicate solution (the concentration of tetraethyl orthosilicate in the tetraethyl orthosilicate solution was 0.12 mol / L). The tetraethyl orthosilicate solution was placed in an 80℃ constant temperature water bath for pre-hydrolysis by stirring for 8 h, then stirred for 18 h, and then centrifuged with anhydrous ethanol to exchange alcohol and water. SiO2 was obtained by spray drying at 90℃.

[0076] The dried SiO2 was ground, then soaked in 1 mol / L sulfuric acid solution at a solid-liquid ratio of 1 g:10 mL for 6 h. After filtration, the solid sample was collected, dried at 100 °C for 12 h, and then calcined in a muffle furnace at 550 °C for 6 h in air atmosphere to obtain SiO2-loaded SO4. 2- Catalyst.

[0077] The catalyst was used for isopropylation performance testing of naphthalene and propylene using the same procedures as in Example 4. The naphthalene conversion and product selectivity of the reaction are shown in Table 1.

[0078] Comparative Example 2

[0079] ZrO2 loaded SO4 2- Preparation of catalysts and performance testing in the isopropylation reaction of naphthalene and propylene

[0080] Take ZrO(NO3)2·2H2O alcohol-water solution (ZrO(NO3)2 solution concentration is 0.1mol / L, the volume ratio of alcohol to water in the solution is 3:1), place it in a constant temperature water bath at 60℃ and stir for 8h to form a gel, then age for 24h, then centrifuge with anhydrous ethanol to exchange alcohol and water, and spray dry at 120℃ to obtain ZrO2.

[0081] The dried ZrO2 was ground, then soaked in 1 mol / L sulfuric acid solution at a solid-liquid ratio of 1 g:10 mL for 6 h. After filtration, the solid sample was collected, dried at 100 °C for 12 h, and then calcined in a muffle furnace at 650 °C for 3 h in air atmosphere to obtain ZrO2-supported SO4. 2- Catalyst.

[0082] The catalyst was used for isopropylation performance testing of naphthalene and propylene using the same procedures as in Example 3. The naphthalene conversion and product selectivity of the reaction are shown in Table 1.

[0083] Comparative Example 3

[0084] Hβ molecular sieve loaded with SO4 2- Preparation of catalysts and performance testing in the isopropylation reaction of naphthalene and propylene

[0085] Take 10g of Hβ molecular sieve and soak it in 1mol / L sulfuric acid solution at a solid-liquid ratio of 1g:10mL for 6h. Then filter the solution, collect the solid sample, dry it at 100℃ for 12h, and calcine it in a muffle furnace at 550℃ for 6h in air atmosphere to obtain Hβ molecular sieve loaded with SO4. 2- Catalyst.

[0086] The catalyst was used for isopropylation performance testing of naphthalene and propylene using the same procedures as in Example 4. The naphthalene conversion and product selectivity of the reaction are shown in Table 1.

[0087] Comparative Example 4

[0088] MOR molecular sieve loaded with SO4 2- Preparation of catalysts and performance testing in the isopropylation reaction of naphthalene and propylene

[0089] Take 10g of MOR molecular sieve and soak it in 1mol / L sulfuric acid solution at a solid-liquid ratio of 1g:10mL for 6h. Then filter the solution, collect the solid sample, dry it at 100℃ for 12h, and calcine it in a muffle furnace at 550℃ for 6h in air atmosphere to obtain SO4-loaded MOR molecular sieve. 2- Catalyst.

[0090] The catalyst was used for isopropylation performance testing of naphthalene and propylene using the same procedures as in Example 4. The naphthalene conversion and product selectivity of the reaction are shown in Table 1.

[0091] Comparative Example 5

[0092] A certain amount of tetraethyl orthosilicate was dissolved in anhydrous ethanol. An appropriate amount of deionized water was added at an alcohol-to-water volume ratio of 3. After mixing, the mixture was placed in an 80℃ constant temperature water bath and stirred for pre-hydrolysis for 8 hours. Then, a calculated amount of ZrO(NO3)2·2H2O alcohol-water solution (the volume ratio of alcohol to water in the ZrO(NO3)2·2H2O alcohol-water solution was 3:1) was added to obtain a mixed solution. (The sum of the ZrO(NO3)2 concentration and the TEOS concentration in the mixed solution was 0.2 mol / L, the molar ratio of Zr to Si was 1:1.5, and the volume ratio of alcohol to water in the ZrO(NO3)2·2H2O alcohol-water solution was 3:1). After stirring the mixture for 14 hours to form a gel, it was aged for 18 hours. Then, the alcohol and water were exchanged by centrifugation with anhydrous ethanol, and the ZrO2 and SiO2 composite material was obtained by spray drying at 90℃. This composite material was used as a catalyst.

[0093] The catalyst was used for isopropylation performance testing of naphthalene and propylene using the same procedures as in Example 4. The naphthalene conversion and product selectivity of the reaction are shown in Table 1.

[0094] Table 1. Activity and selectivity of catalysts for the isopropylation of naphthalene and propylene

[0095]

[0096] Table 2. Performance evaluation of the reusability of the catalyst prepared in Example 2

[0097]

[0098]

[0099] Table 3. Physicochemical properties of the heat transfer oil prepared in Example 4

[0100]

[0101] As shown in Table 1, the methods for preparing diisopropylnaphthalene via the isopropylation reaction of naphthalene and propylene in all embodiments of the present invention achieve high naphthalene conversion rates and selectivity, with naphthalene conversion rates exceeding 98%. Table 2 shows that the catalyst prepared in this invention exhibits good reusability; after 10 uses, the naphthalene source conversion rate can still reach over 98%. Table 3 shows that the viscosity of diisopropylnaphthalene at 40°C is 2.4 mm. 2The closed-cup flash point is 154℃, indicating that this lubricating oil has high safety standards for storage, transportation, and operation. The pour point of diisopropylnaphthalene is -44℃, indicating excellent low-temperature fluidity, which is beneficial for use in low-temperature environments. A 720-hour thermal stability test at 320℃ revealed a degradation rate of only 1.8%, demonstrating excellent thermal stability.

[0102] 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 typical embodiments, but it should be understood that the words 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 with the same function.

Claims

1. A catalyst, characterized in that, It includes a support and a loading component, wherein the support is a composite material containing ZrO2 and SiO2, and the loading component is SO4. 2- Based on the total mass of the catalyst, the catalyst contains 50wt%–70wt% ZrO2, 20wt%–40wt% SiO2, and SO42-20wt% ... 2- The content is 3wt% to 12wt%.

2. A method for preparing a catalyst, characterized in that, The catalyst is prepared by mixing, soaking, filtering, drying, and calcining a ZrO2 and SiO2 composite material with a sulfuric acid solution.

3. The method for preparing the catalyst according to claim 2, characterized in that, The concentration of the sulfuric acid solution is 0.5–2 mol / L; And / or, the solid-liquid ratio of the ZrO2 and SiO2 composite material to the sulfuric acid solution is 1g:3-20mL; And / or, the soaking time is 2 to 8 hours; And / or, the calcination conditions include: a temperature of 450–700°C and a time of 2–6 hours.

4. The method for preparing the catalyst according to claim 2 or 3, characterized in that, The preparation method of the ZrO2 and SiO2 composite material includes the following steps: (1) Mix tetraethyl orthosilicate, water and ethanol to hydrolyze tetraethyl orthosilicate to obtain hydrolyzed tetraethyl orthosilicate; (2) The hydrolyzed tetraethyl orthosilicate is mixed with ZrO(NO3)2·2H2O solution to obtain a mixture. The mixture is stirred to obtain a gel solution. (3) The adhesive solution is aged and centrifuged to obtain a solid product; (4) The solid product is dried to obtain the ZrO2 and SiO2 composite material.

5. The method for preparing the catalyst according to claim 4, characterized in that, In the mixture, the sum of the concentrations of ZrO(NO3)2 and tetraethyl orthosilicate is 0.1–0.6 mol / L, and the molar ratio of Zr to Si is 1:0.5–2. And / or, the solvent in the ZrO(NO3)2·2H2O solution is alcohol and water. And / or, the ratio of alcohol to water in the mixture is 2 to 7:1; And / or, the conditions for hydrolysis include: a temperature of 60–90°C and a time of 6–18 h; And / or, aging conditions include: a temperature of 60–90°C and a time of 16–48 hours; And / or, centrifuge the adhesive solution with anhydrous ethanol; And / or, the drying conditions include: using spray drying at a temperature of 80–120°C.

6. A method for preparing isopropylnaphthalene heat-conducting oil, characterized in that, In the presence of the catalyst described in claim 1 or the catalyst prepared by the preparation method described in any one of claims 2 to 5, a raw material containing naphthalene source and propylene is reacted to prepare isopropylnaphthalene heat transfer oil.

7. The method for preparing the heat transfer oil according to claim 6, characterized in that, The molar ratio of naphthalene source to propylene is 1:1 to 1:6, preferably 1:1 to 1:5; And / or, the naphthalene source is naphthalene or 2-isopropylnaphthalene.

8. The method for preparing the heat transfer oil according to claim 7, characterized in that, The amount of catalyst used is 0.2% to 20% of the mass of the naphthalene source, preferably 0.5% to 10%.

9. The method for preparing the heat transfer oil according to any one of claims 6 to 8, characterized in that, The reaction conditions include a temperature of 150–300°C, preferably 170–270°C; The reaction time is 1 to 10 hours, preferably 3 to 8 hours; The reaction pressure is 0.5–5 MPa, preferably 1–3 MPa; And / or, in the preparation method, the conversion rate of the naphthalene source is 98% to 99.8%, and the selectivity of diisopropylnaphthalene is 63% to 70%.

10. An isopropylnaphthalene heat transfer oil, characterized in that, Prepared using the preparation method according to any one of claims 6 to 9; preferably, the isopropylnaphthalene heat transfer oil has a kinematic viscosity of 1.8 to 2.7 mm at 100°C. 2 / s, pour point is -42 to -49℃.

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