A dehydration catalyst, a method for producing a vinylbenzene compound

Abstract

The present application relates to a dehydration catalyst, a method for producing a vinylbenzene compound, and belongs to the field of chemical industry. The preparation method of the dehydration catalyst comprises the following steps: uniformly mixing an active ingredient, a surfactant and water, volatilizing and drying, calcining, mixing with a pore-forming agent and water, extruding through a screw, rolling into pills, drying, and secondly calcining to obtain a solid spherical catalyst; wherein the active ingredient is selected from at least two of SiO2, Al2O3, MgO, ZnO, AlPO4, TiO2, ZrO2, V2O5, Ga2O3, WO3, Nb2O5, CeO2, Fe2O3, Fe3O4, MoO3, NiO, CuO, SnO2, La2O3, CaO, Cr2O3, P2O5, Zr(HPO4)2, ZrSiO4 or Bi2O3; and the prepared dehydration catalyst can efficiently catalyze the reaction of synthesizing a vinylbenzene compound from aryl secondary alcohol compounds.

Description

Technical Field

[0001] This invention relates to the field of organic chemistry, and more specifically to a dehydration catalyst and a method for producing vinylbenzene compounds. Background Technology

[0002] 4-Acetoxystyrene is an important chemical and pharmaceutical intermediate. Removing the acetyl group from 4-acetoxystyrene yields 4-hydroxystyrene. This compound has wide applications in various polymer materials and pharmaceutical synthesis processes. For example, in emerging photoresist technology, positive chemical amplification resists generally use derivatives of 4-hydroxystyrene as acid-sensitive resins. The use of 4-hydroxystyrene-based polymeric photoresists has become a key technology for photolithography of 0.11μm linewidth chips.

[0003] In the existing technology, the most common method for preparing p-hydroxystyrene is to use 4-acetoxyphenylmethylmethanol as a starting material and carry out a dehydration reaction in the presence of a dehydrating agent to obtain p-acetoxystyrene.

[0004] Chinese patent document CN116102422A discloses a method for preparing 4-acetoxystyrene. Using 4-acetoxyacetophenone as a raw material, the method first involves catalytic hydrogenation of the carbonyl group to obtain 4-acetoxyphenyl-1-ethanol, followed by protection of the hydroxyl group with p-toluenesulfonyl chloride or methanesulfonyl chloride to obtain 4-{1-[(methanesulfonyl / p-toluenesulfonyl)oxy]ethyl}phenyl acetate. Finally, elimination is performed using potassium hydrogen sulfate, tert-butylcatechol, and trifluorotoluene to obtain 4-acetoxystyrene. The synthesis of 4-acetoxystyrene from 4-acetoxyphenyl-1-ethanol involves two steps and employs a jacketed reaction flask, filtration device, rotary evaporator, and vacuum distillation apparatus. This process requires numerous reagents, necessitates frequent adjustments to temperature and pressure, and reagent additions. It also involves multiple filtrations, vacuum concentrations, rotary evaporations, and vacuum distillations—intermittent operations that prevent continuous production and result in low efficiency. The yield of 4-acetoxystyrene from 4-acetoxyphenyl-1-ethanol is low (<78.6%).

[0005] Chinese patent document CN112694402A discloses a method for synthesizing p-acetoxystyrene, which involves dehydrating 4-acetoxyphenylmethylmethanol in an alkaline ionic liquid to obtain p-acetoxystyrene. This reaction requires the addition of polymerization inhibitors (including p-tert-butylcatechol, p-hydroxyanisole, phenothiazine, hydroquinone, N-oxygen (nitrooxide) polymerization inhibitors: 4-hydroxyTEMPO and 1,6-hexyl-di(N-formyl-N-(1-oxy-2,2,6,6,-tetramethylpiperidin)-4-yl)amine and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate nitroxide radicals). After the reaction, the alkaline ionic liquid needs to be recovered by toluene extraction, followed by intermittent operations such as organic phase washing, drying, vacuum concentration, and vacuum distillation purification to obtain p-acetoxystyrene. This method cannot achieve continuous production and has low production efficiency.

[0006] Both of the above methods use traditional batch reactors, and subsequent separation and purification require distillation. However, as an active substance, p-acetoxystyrene is prone to self-polymerization at high temperatures, which leads to a decrease in yield. Therefore, the above two methods have certain limitations in industrial production.

[0007] Chinese patent document CN1039411A discloses a method for the continuous production of p-acetoxystyrene. This method involves introducing KHSO4 (as a catalyst), a polymerization inhibitor, and 4-acetoxyphenylmethylmethanol into a glass thin-film evaporator with a short residence time (0.2–10 minutes) at a specific rate. A dehydration reaction occurs at 155 mmHg and 240°C. A distillation column is connected to the outlet of the evaporator, and the distillate from the top of the column is collected as a mixture containing p-acetoxystyrene. However, the p-acetoxystyrene content is less than 70%, indicating low purity, which is not conducive to practical applications. Summary of the Invention

[0008] [Technical Issues]

[0009] A method for preparing a dehydration catalyst is provided. The prepared dehydration catalyst can efficiently catalyze the reaction of synthesizing vinylbenzene compounds from aryl secondary alcohols, and the dehydration catalyst has a long lifespan and good stability.

[0010] [Technical Solution]

[0011] On the one hand, a method for preparing a dehydration catalyst is provided, comprising the following steps: mixing 100 parts by weight of active ingredient, 2-20 parts by weight of surfactant and 0-180 parts by weight of water, evaporating and drying, and calcining for the first time to obtain a catalyst precursor; wherein the active ingredient is selected from at least two of the following: SiO2, Al2O3, MgO, ZnO, AlPO4, TiO2, ZrO2, V2O5, Ga2O3, WO3, Nb2O5, CeO2, Fe2O3, Fe3O4, MoO3, NiO, CuO, SnO2, La2O3, CaO, Cr2O3, P2O5, Zr(HPO4)2, ZrSiO4 or Bi2O3; mixing the catalyst precursor, pore-forming agent and water, extruding by screw extrusion, pelletizing, drying, and calcining for the second time to obtain a solid spherical catalyst, which is the dehydration catalyst.

[0012] In some embodiments, the catalyst precursor is prepared by mixing 100 parts by weight of active ingredient, 5-18 parts by weight of surfactant and 50-180 parts by weight of water, evaporating and drying, and then calcining for the first time; preferably, it is prepared by mixing 100 parts by weight of active ingredient, 10-15 parts by weight of surfactant and 100-150 parts by weight of water, evaporating and drying, and then calcining for the first time.

[0013] In some embodiments, the surfactant is selected from any one or more of Tween 60, PEG-400, sodium dodecylbenzenesulfonate, PVA, CTAB, PVP, or Brij-56.

[0014] Specifically, PEG-400 is polyethylene glycol 400, PVA is polyvinyl alcohol, CTAB is hexadecyltrimethylammonium bromide, PVP is polyvinylpyrrolidone, and Brij-56 is polyethylene glycol hexadecyl ether.

[0015] In some embodiments, the temperature of the first firing is 500-700°C, and the temperature of the second firing is 500-700°C.

[0016] On the other hand, a dehydration catalyst is provided, which is prepared according to the aforementioned method, wherein the dehydration catalyst has a compressive strength greater than 50 N and a specific surface area greater than 100 m². 2 / g.

[0017] On the other hand, a method for producing vinylbenzene compounds is provided, involving the following reactions:

[0018]

[0019] In the above formula: each R is independently a C1-C6 alkyl, O-C1-C6 alkyl, OC(O)-C1-C6 alkyl, C(O)-C1-C6 alkyl, O-C6-C10 Aryl, OC(O)-C6-C 10 Aryl or C(O)-C6-C 10 Aryl; the C1-C6 alkyl, O-C1-C6 alkyl, OC(O)-C1-C6 alkyl, C(O)-C1-C6 alkyl, O-C6-C 10 Aryl, OC(O)-C6-C 10 Aryl and C(O)-C6-C 10 The aryl group is optionally surrounded by 1, 2 or 3 R groups. 1 replace;

[0020] The R 1 Independently, it is a C1-C6 alkyl group;

[0021] Alternatively, two adjacent Rs and the benzene rings attached to them together form a C8-C ring. 14 Aryl or C8-C 14 cycloalkyl; the C8-C 14 Aryl and C8-C 14 The cycloalkyl group is optionally surrounded by 1, 2 or 3 R's. 2 replace;

[0022] The R 2 It is independently C1-C6 alkyl, O-C1-C6 alkyl, OC(O)-C1-C6 alkyl or C(O)-C1-C6 alkyl;

[0023] n is 0, 1, 2, 3, 4 or 5;

[0024] Each R may be the same or different;

[0025] The method includes the following steps:

[0026] The material containing the vaporized compound 1 is passed into a reaction apparatus containing the aforementioned dehydration catalyst to react and obtain compound 2.

[0027] In some embodiments, each R is independently a C1-C6 alkyl, O-C1-C6 alkyl, or OC(O)-C1-C6 alkyl; the C1-C6 alkyl, O-C1-C6 alkyl, and OC(O)-C1-C6 alkyl are optionally represented by 1, 2, or 3 Rs. 1 replace;

[0028] The R 1 Independently, it is a C1-C6 alkyl group;

[0029] Alternatively, two adjacent Rs and the benzene rings attached to them together form a C8-C ring. 14 Aryl; the C8-C 14 The aryl group is optionally surrounded by 1, 2 or 3 R groups.2 replace;

[0030] The R 2 It is independently C1-C6 alkyl, O-C1-C6 alkyl, or OC(O)-C1-C6 alkyl;

[0031] n is 0, 1, or 2.

[0032] In some embodiments, R, R 1 and R 2 In this context, the C1-C6 alkyl group can be a C1-C4 alkyl group, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, or tert-butyl.

[0033] In some embodiments, R and R 2 In the O-C1-C6 alkyl group and the C1-C6 alkyl group of the OC(O)-C1-C6 alkyl group, the C1-C6 alkyl group can be C1-C4 alkyl groups, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl.

[0034] In some embodiments, the two adjacent R atoms together with the carbon atom they are attached to form C8-C. 14 C8-C in aryl 14 Aryl groups can be C8-C 10 Aryl, for example,

[0035] In some embodiments, each R is independently a C1-C4 alkyl, O-C1-C4 alkyl, or OC(O)-C1-C4 alkyl; the C1-C4 alkyl, O-C1-C4 alkyl, and OC(O)-C1-C4 alkyl are optionally represented by 1, 2, or 3 Rs. 1 replace;

[0036] The R 1 Independently C1-C4 alkyl;

[0037] Alternatively, two adjacent Rs and the benzene rings attached to them together form a C8-C ring. 10 Aryl; the C8-C 10 The aryl group is optionally surrounded by 1, 2 or 3 R groups. 2 replace;

[0038] The R 2 It is independently C1-C4 alkyl, O-C1-C4 alkyl, or OC(O)-C1-C4 alkyl;

[0039] n is 0, 1, or 2.

[0040] In some embodiments, compound 1 is selected from any of the following compounds:

[0041] In some embodiments, the material containing the vaporized compound 1 includes compound 1 and a dispersant for dispersing the compound 1, the dispersant having a boiling point of 30-190°C.

[0042] In some embodiments, the dispersant is any one or more of DMAc, DMF, or DMSO. Specifically, DMAc is N,N-dimethylacetamide, DMF is N,N-dimethylformamide, and DMSO is dimethyl sulfoxide.

[0043] In some embodiments, the reaction temperature is 160-200°C.

[0044] In another aspect, the present invention provides a dehydration reaction apparatus, comprising:

[0045] A gasification unit is used to at least gasify the reaction raw material to obtain gasified material, wherein the reaction raw material is compound 1;

[0046] A catalytic reaction unit, filled with a dehydration catalyst, is directly or indirectly connected to the gasification unit. It is used to receive the gasified material and to react the gasified material under the action of the dehydration catalyst to form the target product.

[0047] A product collection unit, connected to the catalytic reaction unit, is used to receive and collect the target product discharged from the catalytic reaction unit;

[0048] At least one vacuum supply unit is provided to supply negative pressure to the interior of the gasification unit, the catalytic reaction unit and the product collection unit;

[0049] The gasification unit includes:

[0050] A vaporization cylinder having at least one inlet and at least one outlet;

[0051] A vaporization bottle heating device is used to heat the vaporization bottle;

[0052] Several dispersing components are disposed inside the vaporization bottle to disperse the reaction raw materials entering the vaporization bottle;

[0053] A stirrer is disposed inside the vaporization bottle to drive the dispersant to move within the vaporization bottle.

[0054] In some embodiments, the dehydration reaction apparatus further includes:

[0055] The preheating unit, connected to the gasification unit, is used to preheat the reaction raw materials to a preheating temperature to form a preheated material, and then introduce the preheated material into the gasification unit.

[0056] The preheating unit includes:

[0057] Preheating flask, used to contain reaction raw materials;

[0058] A preheater is used to heat the preheating flask to preheat the reaction raw materials in the preheating flask;

[0059] The first pipe connects the preheating bottle to the vaporization unit;

[0060] A delivery pump is used to transport the reaction materials in the preheating flask to the gasification unit.

[0061] In some embodiments, the dehydration reaction apparatus further includes:

[0062] A secondary heating unit, located between the gasification unit and the catalytic reaction unit, is used to reheat the gasified material leaving the gasification unit.

[0063] The secondary heating unit includes:

[0064] The secondary heating unit housing is internally connected to the outlet of the vaporization bottle and the interior of the catalytic reaction unit; preferably, the secondary heating unit housing is made of transparent material, more preferably, the secondary heating unit housing is made of transparent glass.

[0065] Several metal tubes are installed inside the outer shell of the secondary heating unit;

[0066] A high-frequency induction heater has a heating coil wound around the outside of the secondary heating unit housing for heating the metal tube.

[0067] In some embodiments, the secondary heating unit further includes:

[0068] The packing material is disposed at both ends of the metal tube to disperse and mix the gas passing through the metal tube; preferably, the packing material is spring glass packing.

[0069] In some embodiments, the gasification unit further includes:

[0070] A first inner liner gas guide tube is disposed at the outlet of the gasification bottle; preferably, the first inner liner gas guide tube is made of organic polymer material, more preferably, the first inner liner gas guide tube is made of polytetrafluoroethylene material.

[0071] An isolation net is installed on the side of the first liner gas guide pipe away from the gasification bottle to prevent the catalyst in the catalytic reaction unit from entering the gasification bottle.

[0072] In some embodiments, the catalytic reaction unit includes:

[0073] The catalytic reaction unit housing has at least one inlet and one outlet; preferably, the catalytic reaction unit housing is made of a transparent material, more preferably, the catalytic reaction unit housing is made of transparent glass.

[0074] Several catalyst sections are installed inside the outer shell of the catalytic reaction unit, with filler voids forming between adjacent catalyst sections.

[0075] Each of the catalyst units includes:

[0076] Tower connection;

[0077] A dehydration catalyst is positioned above the column inlet.

[0078] In some embodiments, the catalytic reaction unit further includes:

[0079] The second inner lining gas guide tube is disposed at the outlet of the outer shell of the catalytic reaction unit; preferably, the second inner lining gas guide tube is made of organic polymer material, more preferably, the second inner lining gas guide tube is made of polytetrafluoroethylene material.

[0080] In some embodiments, the product collection unit includes:

[0081] The distillation column head, installed at the top of the catalytic reaction unit, is used to condense the target product into a liquid target product;

[0082] The product collector is connected to the head of the distillation column via a product collection pipe and is used to collect the liquid target product.

[0083] In some embodiments, the dispersing element is a metal bead, preferably a steel bead, and more preferably a steel bead with a particle size of 1-5 mm.

[0084] In some embodiments, the vaporization bottle is made of a transparent material; preferably, the vaporization bottle is made of transparent glass.

[0085] Terminology definition:

[0086] The term "substitution" or "substituent" refers to the replacement of a hydrogen atom in a group with a specified group. Substitution can occur at any position unless the substitution site is specified, but it is only permitted if a stable or chemically viable compound is formed. Examples are given below: The structure indicates that the hydrogen atoms on the benzene ring are replaced by n R atoms.

[0087] When any variable (e.g., R) appears more than once in the composition or structure of a compound, its definition is independent in each case. Therefore, for example, if a group is substituted by one or more Rs, the group can optionally be substituted by at least one R, and R has independent options in each case. Furthermore, combinations of substituents are only permitted if such combinations produce a stable compound.

[0088] The term "alkyl" refers to a saturated straight-chain or branched monovalent hydrocarbon group. In this invention, "C1-C6 alkyl" in all terms containing "C1-C6 alkyl" is preferably C1-C4 alkyl, wherein C1-C4 alkyl refers to an alkyl group having 1-4 carbon atoms, specifically methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, or tert-butyl.

[0089] The term "aryl" refers to an all-carbon monocyclic or fused polycyclic (fused polycyclic) group with a conjugated π-electron system, preferably C8-C. 14 Aryl or C6-C 10 Aryl groups, such as phenyl, benzocyclobutenyl, or naphthyl.

[0090] The term "cycloalkyl" refers to a monovalent hydrocarbon group, preferably C8-C, that is saturated or partially unsaturated, either monocyclic or polycyclic (e.g., monocyclic or fused-ring). 14 Cycloalkyl.

[0091] The terms "optional" or "optionally" mean that the event or situation subsequently described may, but does not have to, occur; the description includes the circumstances under which the event or situation may or may not occur. For example, "optionally by R..." 1 "Replace" means R 1 It may be present, but is not mandatory; this description includes the group being R. 1 Replacement scenarios and not being R 1 The situation of substitution.

[0092] The term "raw material conversion rate" = peak area of ​​target product / (total peak area - solvent peak area).

[0093] [Beneficial Effects]

[0094] This invention provides a method for preparing a dehydration catalyst, using at least two of the following active ingredients: SiO2, Al2O3, MgO, ZnO, AlPO4, TiO2, ZrO2, V2O5, Ga2O3, WO3, Nb2O5, CeO2, Fe2O3, Fe3O4, MoO3, NiO, CuO, SnO2, La2O3, CaO, Cr2O3, P2O5, Zr(HPO4)2, ZrSiO4, or Bi2O3. The catalyst is prepared by mixing with a surfactant and water in a specific ratio, followed by volatilization and drying, a first calcination, then mixing with a pore-forming agent and water, screw extrusion, pelletizing, drying, and a second calcination. This successfully produces a catalyst with a compressive strength greater than 50 N and a specific surface area greater than 100 m². 2 The applicant unexpectedly discovered that such catalysts can dehydrate gaseous aryl secondary alcohols to form olefins with a high conversion rate.

[0095] The dehydration reaction apparatus provided by this invention utilizes a gasification unit comprising a gasification bottle, a gasification bottle heater, a dispersing element, and a stirrer. This effectively prevents coking of the raw materials during gasification, thereby reducing the loss of starting materials. Furthermore, because the gasification unit includes a dispersing element, the apparatus can better disperse the material, allowing for faster gasification. The friction between the dispersing elements also promotes thorough gasification and reduces coking. Moreover, the use of steel balls as the dispersing element provides better heat transfer compared to other materials, further facilitating smoother material gasification. Furthermore, the inclusion of a stirrer within the gasification unit drives the dispersing element to move continuously during operation, causing friction between the elements and removing ash from their surfaces. This ensures the dispersing element maintains excellent mass and heat transfer, ultimately achieving rapid material gasification.

[0096] The dehydration reaction device provided by the present invention also uses a first inner lining conduit and a second inner lining conduit to ensure that the connection between two adjacent units also has a good heat insulation effect, thereby avoiding material loss caused by condensation at the two units.

[0097] The dehydration reaction apparatus provided by this invention also uses a secondary heating unit, which can effectively prevent gaseous materials from cooling and liquefying after entering the catalytic reaction unit, thus preventing further blockage of the pipes due to caking. Furthermore, since the secondary heating unit uses high-frequency induction heating, compared with traditional electric heating wire heating, high-frequency induction heating can generate heat evenly from the inside, with a large heating area, fast heat transfer, small size, and short residence time.

[0098] The catalytic reaction unit of the dehydration reaction device provided by the present invention has multiple catalytic sections and there are packing voids between two adjacent catalytic sections. Therefore, during the reaction, the catalyst in each catalytic section can be blown by the airflow, thereby achieving a technical effect similar to that of a fluidized bed. This not only improves the heat and mass transfer effect of the catalyst, but also significantly improves the catalyst life and product conversion rate.

[0099] This invention also provides a method for producing vinylbenzene compounds. Using the above-mentioned dehydration catalyst and dehydration reaction apparatus, the continuous production of vinylbenzene compounds from aryl secondary alcohols is successfully realized. Compared with the prior art, the operation steps are greatly simplified, the controllability of the reaction is improved, the production efficiency is increased, and the yield and purity of the target product vinylbenzene compounds are also improved, the catalytic stability of the dehydration catalyst is enhanced, and the service life of the dehydration catalyst is extended. Attached Figure Description

[0100] Figure 1 This is a schematic diagram of a dehydration reaction device provided in Embodiment 1 of the present invention.

[0101] Figure 2 This is a schematic diagram of the secondary heating unit provided in Embodiment 1 of the present invention.

[0102] Figure 3 This is a schematic diagram of the structure of the secondary heating unit without filler provided in Embodiment 1 of the present invention.

[0103] In the diagram: 1. Preheater; 2. Preheating bottle; 3. First pipeline; 4. Transfer pump; 5. Vaporization bottle heater; 6. Vaporization bottle; 7. First inner liner conduit; 8. High-frequency inductor; 9. Metal pipe; 10. Secondary heating unit shell; 11. Tower connection; 12. Catalyst; 13. Packing voids; 14. Distillation column head; 15. Dispersant; 16. Sampler; 17. Product collection pipe; 18. First vacuum tube; 19. Vacuum unit; 201. First vacuum gauge; 202. Second vacuum gauge; 21. 221. Air valve; 222. First thermometer; 223. Second thermometer; 224. Third thermometer; 225. Fourth thermometer; 26. Electric heating tape; 27. Catalytic reaction unit shell; 28. Catalytic section; 29. ​​Second inner liner gas guide tube; 20. Product collector; 21. Second vacuum tube; 226. Packing material; 30. Barbs; 100. Preheating unit; 21. Vaporization unit; 227. Secondary heating unit; 228. Catalytic reaction unit; 229. Product collection unit; 220. Vacuum supply unit. Detailed Implementation

[0104] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0105] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0106] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and connections within two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0107] Example 1

[0108] A dehydration reaction device

[0109] Please refer to Figure 1 , Figure 2 and Figure 3 This embodiment provides a dehydration reaction device, including: a preheating unit 100, a gasification unit 200, a secondary heating unit 300, a catalytic reaction unit 400, a product collection unit 500, and a vacuum supply unit 600.

[0110] The preheating unit 100 includes: a preheater 1, a preheating bottle 2, a first pipeline 3, and a delivery pump 4.

[0111] Preheater 1 can be any device with heating function. Preferably, it can be a heating device with mechanical or electromagnetic stirring function, such as a constant-temperature heating magnetic stirrer. In this embodiment, the preheater 1 uses a Yuhua heat-collecting constant-temperature heating magnetic stirrer 3L model DF-101SH, and the heating temperature is set to 60°C during the reaction.

[0112] Preheating flask 2, placed within preheater 1, contains the starting material. In this embodiment, a magnetic stirrer can be placed inside preheating flask 2 to stir the mixture under the drive of preheater 1, ensuring that the starting material inside the flask is always in a uniformly mixed state. In this embodiment, the starting material is a mixed solution of 4-acetoxyphenyl-1-ethanol and DMAc (dimethylacetamide) in a mass ratio of 2:1. Since this device is a continuous reaction apparatus, when needed, the same mixed solution can be added to preheating flask 2 as the starting material when the initial starting material is about to be completely consumed, thereby maintaining the reaction.

[0113] The first pipe 3 connects the preheating bottle 2 and the vaporization unit 200.

[0114] A transfer pump 4, installed on the first pipeline 3, is used to transport the starting material in the preheating bottle 2 to the gasification unit 200. Preferably, in this embodiment, the transfer pump 4 is a Reaver peristaltic pump, and the flow rate is preferably 0.5-2.0 mL / min.

[0115] The gasification unit 200 includes: a gasification bottle heater 5, a gasification bottle 6, a dispersing component 15, a stirrer (not shown in the figure), a first inner liner gas guide pipe 7, and an isolation net (not shown in the figure).

[0116] The vaporization bottle heater 5 can be any device with a heating function. Preferably, it can be a heating device with mechanical or electromagnetic stirring functions, such as a constant-temperature heating magnetic stirrer. In this embodiment, the vaporization bottle heater 5 uses a Yuhua thermal collector constant-temperature heating magnetic stirrer 3L model DF-101SH. During the reaction, the heating temperature of the vaporization bottle heater 5 is set to 160°C.

[0117] A vaporization bottle 6, placed within a vaporization bottle heater 5, has at least two ports: one port connects to the first pipe 3 to receive the starting material delivered by the transfer pump 4, and the other port connects to the interior of the secondary heating unit 300. The vaporization bottle 6 contains a dispersing element 15 and a stirrer. The starting material vaporizes within the vaporization bottle 6, changing from a liquid to a gaseous state, forming a gaseous starting material. Preferably, the vaporization bottle 6 may also have an additional port for mounting a first thermometer 221 to detect the internal temperature of the vaporization bottle 6. In this embodiment, a 500mL three-necked bottle is used as the vaporization bottle 6. In one embodiment, the vaporization bottle 6 may also be equipped with a first vacuum gauge 201 to detect the negative pressure inside the vaporization bottle 6.

[0118] The dispersant 15 can be any number of any particulate matter that will not chemically react with the starting material, such as silica particles, steel balls, glass beads, etc. The dispersant 15 is disposed inside the vaporization bottle 6 and is driven by a stirrer during the vaporization process, moving within the vaporization bottle 6. The total volume of the dispersant 15 is 0.2%-0.5% of the internal volume of the vaporization bottle. In this embodiment, the dispersant 15 consists of 100 steel balls with a particle size of 3mm (0.2826% of the volume).

[0119] A stir bar, located inside the vaporization bottle 6, is used to rotate under the influence of an external magnetic field, thereby driving the dispersing component 15 to move. In some embodiments, when the vaporization bottle heater 5 has a mechanical stirring function, the stir bar is not necessary, and the mechanical stirring component in the vaporization bottle heater 5 can replace the relevant functions of the stir bar.

[0120] The first inner lining conduit 7 is disposed at the mouth of the vaporization bottle 6 connected to the secondary heating unit 300. Preferably, the first inner lining conduit 7 is made of a polymer material. In this embodiment, the diameter of the first inner lining conduit 7 is adapted to the diameter of the mouth of the vaporization bottle 6 connected to the secondary heating unit 300, so that the first inner lining conduit 7 can be precisely positioned at the mouth of the bottle. In this embodiment, the first inner lining conduit 7 is a 10cm long polytetrafluoroethylene tube, which has better heat insulation properties than glass, thereby preventing the vaporized starting material from re-liquefying at the outlet of the vaporization bottle 6.

[0121] An isolation mesh, installed on top of the first inner liner conduit 7, covers the entire upper port of the first inner liner conduit 7 and is used to prevent the catalyst in the catalytic reaction unit 400 from entering the gasification bottle 6. The pore size of the isolation mesh can be determined according to the pore size of the actual catalyst used, preferably preventing the catalyst from passing through the isolation mesh smoothly. In this embodiment, the pore size of the isolation mesh is 0.5 mm.

[0122] The secondary heating unit 300 includes: a secondary heating unit housing 10, a metal tube 9, a high-frequency inductor 8, and a filler 29.

[0123] The secondary heating unit housing 10 is connected at one end to the vaporization bottle 6 and at the other end to the catalytic reaction unit 400. It can be integrally formed with the vaporization bottle 6 or the catalytic reaction unit 400, or it can be connected to the vaporization bottle 6 and the catalytic reaction unit 400 via other means that will not cause the vaporized starting material to overflow from the interface, such as by clips or by threads. In this embodiment, the secondary heating unit housing 10 is made of transparent glass. Several inwardly extending barbs 30 are formed at the same height inside the secondary heating unit housing 10; these barbs 30 are used to support the metal tube 9.

[0124] Metal tubes 9 are inserted inside the secondary heating unit housing 10, with their length direction aligned with the extension direction of the secondary heating unit housing 10. Generally, the number of metal tubes 9 is not limited. In this embodiment, there are seven identical copper tubes 9, each with an outer diameter of 8mm, an inner diameter of 6mm, and a length of 10cm. The arrangement of the seven metal tubes 9 is not particularly limited; generally, they can be arranged in a specific pattern. Figure 2 The metal tubes 9 are arranged in the manner described above. When using multiple metal tubes 9, they can be bound together with ropes or spot-welded between adjacent metal tubes 9 to achieve a fixed connection. In this embodiment, seven metal tubes 9 are bound together with ropes.

[0125] The high-frequency inductor 8 has its induction coil sleeved on the outside of the secondary heating unit housing 10 and is activated after the reaction begins. In this embodiment, the high-frequency inductor 8 is a Shanghai Hanggong Electric ZDBT-6-T type high-frequency induction heater with a power of 3kW.

[0126] The packing material 29 is respectively filled at both ends of the metal tube 9. On the one hand, it is used to better fix the metal tube 9, and on the other hand, it can make the gas entering and leaving the secondary heating unit 200 mix evenly. In this embodiment, the packing material selected is glass spring packing. The glass spring packing has a size of 4mm×20mm, and the filling thickness at both ends is 40mm. The upper end is filled above the metal tube 9, and the lower end is filled above the isolation net.

[0127] The catalytic reaction unit 400 includes: a catalytic reaction unit housing 24, a catalytic unit 25, a temperature control unit, and a second inner liner gas guide pipe 26.

[0128] The catalytic reaction unit housing 24 is fitted onto the top of the secondary heating unit housing 10 and is integrally formed with the secondary heating unit housing 10. In this embodiment, the catalytic reaction unit housing 24 is a transparent double-layered glass.

[0129] The catalyst section 25 includes a catalyst 12 and a conduit 11. The number of catalyst sections 25 can be adjusted according to actual needs; for example, one or more catalyst sections 25 can be used. When multiple catalyst sections 25 are used, a packing void 13 is formed between two adjacent catalyst sections. In this embodiment, three identical catalyst sections 25 are used, and the length of the packing void 13 between two adjacent catalyst sections 25 is 4 cm. When the gaseous starting material passes through the catalyst section 25, it reacts under the action of the catalyst 12 to form gaseous products.

[0130] The connector 11 is installed inside the outer shell 24 of the catalytic reaction unit. In this embodiment, the connector 11 is a thick-walled polytetrafluoroethylene tube with a length of 20 mm, an inner diameter of 25 mm, and an outer diameter of 29 mm. Its bottom is tightly wrapped with a 0.1 mm aperture steel wire mesh, and the outer side is wrapped with PTFE tape to form a suitable outer diameter sealing side.

[0131] Catalyst 12 is packed onto tower section 11 to a height of 100-200 mm, which is 120 mm in this embodiment. Catalyst 12 can be any solid catalyst, including but not limited to spherical catalysts and columnar catalysts, depending on actual needs. In this embodiment, solid spherical catalysts with a particle size of 0.4-6 mm are selected for catalyst 12, and the packing is performed using fluidized bed packing or fixed packing.

[0132] The temperature control unit includes an electric heating tape 23 and a controller connected thereto, the controller being used to control the heating power of the electric heating tape 23.

[0133] The heating tape 23 is wound around the outer shell 24 of the catalytic reaction unit. In this embodiment, since the outer shell 24 of the catalytic reaction unit is a double-layer structure, the heating tape 23 is preferably wound around the outer side of the inner layer of the catalytic reaction unit outer shell. In this embodiment, the heating tape 23 is wound around the outer side of the entire inner layer of the catalytic reaction unit outer shell 24. In some embodiments, at least one thermometer may be installed between the inner and outer layers of the catalytic reaction unit outer shell 24. Preferably, a second thermometer 222 is installed at the lower part between the inner and outer layers of the catalytic reaction unit outer shell 24 to detect the temperature at the lower part of the catalytic reaction unit outer shell 24; a third thermometer 223 is installed at the upper part between the inner and outer layers of the catalytic reaction unit outer shell 24 to detect the temperature at the upper part of the catalytic reaction unit outer shell 24.

[0134] The second inner liner conduit 26 is disposed at the top outlet of the catalytic reaction unit housing 24. Preferably, the second inner liner conduit 26 is made of a polymer material. In this embodiment, the diameter of the second inner liner conduit 26 is adapted to the diameter of the top outlet of the catalytic reaction unit housing 24, so that the second inner liner conduit 26 can be precisely positioned at the outlet. In this embodiment, the second inner liner conduit 26 is a 10cm long polytetrafluoroethylene tube, which has better heat insulation properties than the glass material of the catalytic reaction unit housing 24, thereby preventing the vaporized reaction products from re-liquefying.

[0135] The product collection unit 500 includes: a distillation column head 14, a product collection pipe 17, a product collector 27, and a sampler 16.

[0136] The distillation column head 14 is installed on the top side of the catalytic reaction unit shell 24 and is connected to the second inner lining gas guide pipe 26. It is used to receive gaseous products and condense them to form liquid products.

[0137] Product collection pipe 17 connects the distillation column head 14 and product collector 27, and is used to introduce liquid products into product collector 27.

[0138] Sampler 16 may be mounted on product collection tube 17 for sampling and testing. In some embodiments, sampler 16 is not required.

[0139] Product collector 27 is installed at the outlet of product collection pipe 17 and is used to collect liquid products.

[0140] In some embodiments, the distillation column head 14 is equipped with a fourth thermometer 224 for detecting its internal temperature.

[0141] The vacuum supply unit 600 includes: a vacuum unit 19, a vacuum valve 21, a second vacuum gauge 202, a first vacuum tube 18, and a second vacuum tube 28.

[0142] The vacuum unit 19 is used to generate negative pressure and provide a certain negative pressure to the vaporization unit 200, the secondary heating unit 300, the catalytic reaction unit 400 and the product collection unit 500.

[0143] The second vacuum tube 28 is connected at one end to the vacuum unit 19 and at the other end to the product collection tube 17, and is used to provide negative pressure to the product collection tube 17 and the various units connected to the product collection tube 17.

[0144] One end of the first vacuum tube 18 is connected to the second vacuum tube 28, and the other end extends into the product collector 27 to provide negative pressure to the product collector 27. By setting the first vacuum tube 18, the internal pressure of the product collection tube 17 and the internal pressure of the product collector 27 can be basically the same, so that the liquid product can flow out smoothly from the product collection tube 17.

[0145] The second vacuum gauge 202 is installed on the second vacuum tube 28 and is used to detect the negative pressure inside the second vacuum tube 28.

[0146] Vacuum valve 21 is installed on the second vacuum tube 28 and is used to control the opening and closing of the second vacuum tube 28.

[0147] Example 2

[0148] A dehydration reaction device

[0149] This embodiment provides a dehydration reaction device with a structure that is basically the same as the dehydration reaction device in Embodiment 1. The only difference is that the gasification unit 200 is different. In this embodiment, the gasification unit 200 is a commercially available steel pipe gasifier.

[0150] Example 3

[0151] A dehydration reaction device

[0152] This embodiment provides a dehydration reaction device with a structure that is basically the same as the dehydration reaction device in Embodiment 1, except that no dispersing component is provided in its gasification bottle 6.

[0153] Example 4

[0154] A dehydration reaction device

[0155] This embodiment provides a dehydration reaction device with a structure that is basically the same as the dehydration reaction device in Example 1. The only difference is that 50 mL of zeolite with a particle size of 3-4 mm is used instead of steel balls as the dispersing element in Example 1.

[0156] Example 5

[0157] A dehydration reaction device

[0158] This embodiment provides a dehydration reaction device with a structure that is basically the same as the dehydration reaction device in Embodiment 1. The only difference is that no stir bar is used in the gasification unit 200.

[0159] Example 6

[0160] A dehydration reaction device

[0161] This embodiment provides a dehydration reaction device with a structure that is basically the same as the dehydration reaction device in Embodiment 1. The only difference is that the gasification unit 200 does not have a first inner liner conduit 7.

[0162] Example 7

[0163] A dehydration reaction device

[0164] This embodiment provides a dehydration reaction device with a structure that is basically the same as the dehydration reaction device in Embodiment 1. The only difference is that there is no secondary heating unit 300, and the catalytic reaction unit 400 is directly connected to the gasification unit 200.

[0165] Example 8

[0166] A dehydration reaction device

[0167] This embodiment provides a dehydration reaction device with a structure that is basically the same as the dehydration reaction device in Embodiment 1. The only difference is that an electric heater is used to replace the high-frequency inductor 8, and the heating wire of the electric heater is wound around the outside of the secondary heating unit housing 10.

[0168] Example 9

[0169] A dehydration reaction device

[0170] This embodiment provides a dehydration reaction device with a structure that is basically the same as the dehydration reaction device in Embodiment 1. The only difference is the number of catalyst sections 25. In this embodiment, only one set of catalyst sections 25 is used, but the total amount of catalyst 12 is the same as in Embodiment 1.

[0171] Example 10

[0172] Dehydration catalyst

[0173] This embodiment provides a method for preparing a dehydration catalyst, the specific steps of which are as follows:

[0174] 1000g of active ingredient, 150g of surfactant, and 1000g of water were mixed and heated to 80℃ for solvent evaporation. After complete solvent evaporation, the mixture was calcined at 600℃ for 8 hours to obtain a catalyst precursor. The catalyst precursor was pulverized, and 250g of sodium methylcellulose and 800g of water were added. The mixture was then extruded using a screw extruder (screw length-to-diameter ratio of 9), pelletized, dried at room temperature, and calcined at 550℃ for 3 hours to obtain a solid spherical catalyst. The composition of the active ingredient and surfactant, as well as the average particle size of the obtained solid spherical catalyst, are shown in Table 1.

[0175] Various dehydration catalysts were prepared using the above methods, as shown in Table 1:

[0176] Table 1

[0177]

[0178]

[0179] All dehydration catalysts listed in the table above have a compressive strength greater than 50 N and a specific surface area greater than 100 m². 2 / g, wherein the compressive strength is tested in accordance with GB3635-1983, and the specific surface area is tested using the BET test method.

[0180] Example 11

[0181] Preparation method of 4-acetoxystyrene

[0182] This embodiment provides a method for preparing 4-acetoxystyrene, and the reaction formula is as follows:

[0183]

[0184] The reaction steps are as follows:

[0185] The reaction is carried out in the dehydration reaction apparatus as described in the examples.

[0186] The catalyst used was prepared according to catalyst A1 in Example 10.

[0187] Step 1: Activate the vacuum supply unit 600, setting the second vacuum gauge 202 reading to -350 Pa and the first vacuum gauge 201 reading to 0.098 MPa. Activate the vaporization bottle heater 5 in the vaporization unit 200, setting the first thermometer 221 reading to 160°C and simultaneously initiating the stirring of the steel balls. Activate the high-frequency induction heater 8 in the secondary heating unit 300, setting the internal temperature of the secondary heating unit casing 10 to 185°C.

[0188] Step 2: Compound 1a and solvent DMAc are mixed at a mass ratio of 2:1 and added to preheating bottle 2. The power of preheater 1 is adjusted to raise the temperature of the material in preheating bottle 2 to 60°C. The transfer pump 4 is started to transfer the material in preheating bottle 2 to vaporization bottle 6 at a rate of 0.5-5 mL / min (1.5 mL / min in this embodiment). The material is rapidly vaporized. The vaporized material enters catalytic reaction unit 400 through secondary heating unit 300 to undergo dehydration reaction and form gaseous product. The gaseous product enters product collection unit 500, is condensed to form liquid product, and enters product collector 27.

[0189] During the reaction, the time when liquid product begins to be collected by product collector 27 is defined as 0h. Samples of the product are taken at regular intervals for HPLC analysis. The results are shown in Table 2.

[0190] Table 2

[0191]

[0192]

[0193] Testing showed that the product collected from 0-8 hours, without further purification, had a purity of 93% according to HPLC. After distillation purification, the product collected from 0-8 hours yielded the target product with a purity of 99.5% in 90.5% yield.

[0194] Test Example 1

[0195] Performance testing of dehydration reaction device

[0196] This test example tested the performance of the dehydration reaction apparatus provided in Examples 1-9. The test method is as follows:

[0197] Step 1: Activate the vacuum supply unit 600, making the second vacuum gauge 202 read -350 Pa and the first vacuum gauge 201 read 0.098 MPa. Activate the vaporization bottle heater 5 in the vaporization unit 200, making the first thermometer 221 read 160°C and simultaneously starting the stir bar to agitate the steel balls. Activate the high-frequency induction heater 8 in the secondary heating unit 300 (this step is unnecessary if there is no secondary heating unit 300), making the internal temperature of the secondary heating unit casing 10 reach 185°C.

[0198] Step 2: Compound 1a and solvent DMAc are mixed at a mass ratio of 2:1 and added to preheating bottle 2. The power of preheater 1 is adjusted to raise the temperature of the material in preheating bottle 2 to 60°C. The transfer pump 4 is started to transfer the material in preheating bottle 2 to vaporization bottle 6 at a rate of 1-5 mL / min (1.5 mL / min in this test example). The material is rapidly vaporized. The vaporized material enters the catalytic reaction unit 400 through the secondary heating unit 300 to undergo a dehydration reaction and form a gaseous product. The gaseous product enters the product collection unit 500, is condensed to form a liquid product, and enters the product collector 27.

[0199] During the reaction, the time when the product collector 27 begins to collect liquid product is designated as 0h. The product is sampled every 2 hours and analyzed by HPLC. When the reaction conversion rate is less than 50%, this time is taken as the longest usable time for a single dehydration reaction device.

[0200] In the above test method, the catalyst used in the catalytic reaction unit 400 is catalyst A1 provided in Example 10.

[0201] The test results are shown in Table 3.

[0202] Table 3

[0203]

[0204]

[0205] Test Example 2

[0206] Catalyst performance testing

[0207] In this test example, various performance tests were conducted on the 12 catalysts provided in Example 10. The test methods are as follows:

[0208] Optimal conversion rate: The catalyst was loaded into the reaction apparatus of Example 1, and the reaction was carried out using the method of Example 11. Samples were taken every 2 hours during the reaction process, and the highest conversion rate detected during this process was the optimal conversion rate.

[0209] Single lifetime: The catalyst was loaded into the reaction apparatus of Example 1 and the reaction was carried out using the method of Example 11. Samples were taken every 2 hours during the reaction. When the conversion rate was less than 60% at the nth test, the single lifetime of the catalyst was recorded as (2n-2)h.

[0210] Maximum number of regenerations: The catalyst is loaded into the reaction apparatus of Example 1 and the reaction is carried out using the method of Example 11. Samples are taken every 2 hours during the reaction. When the conversion rate is lower than 60%, the reaction is stopped and the catalyst is regenerated. The above process is repeated after regeneration. When the single lifetime of the catalyst is less than 8 hours after the mth regeneration, the maximum number of regenerations of the catalyst is recorded as (m-1) times.

[0211] Total lifespan: The catalyst lifespan during initial use is denoted as t0, and the catalyst lifespan after the (m-1)th regeneration is t. m-1 Then the total lifetime of the catalyst is denoted as t0 + t1 + ... + t m-1 , where m-1 is the maximum number of regenerations for the catalyst.

[0212] Catalyst regeneration method: Add 200 mL of DMAc to the vaporization bottle, heat to 160 °C, and set the negative pressure inside the vaporization bottle to 0.098 MPa to allow the DMAc to reflux within the catalytic reaction unit for 2 hours.

[0213] The test results are shown in Table 4.

[0214] Table 4

[0215]

[0216]

[0217] Test Example 3

[0218] Substrate Expansion

[0219] The substrate was extended using the method of Example 11. In this test example, all the components were the same as in Example 11 except for the starting materials.

[0220] The test results are shown in Table 5.

[0221] Table 5

[0222]

[0223] The method for producing vinylbenzene compounds disclosed in this invention employs a self-developed dehydration reaction device. The raw material is vaporized and then passed into a reaction device filled with a specific dehydration catalyst for dehydration reaction. Therefore, the method for producing vinylbenzene compounds provided by this invention can not only improve the conversion rate of the product, but also enable continuous production. The solvent and product are directly separated after the reaction, avoiding the risk of self-polymerization of the product during subsequent purification.

[0224] According to the dehydration catalysts involved in this invention, a variety of catalysts containing metal oxides or metal phosphates are provided. The applicant unexpectedly discovered that such catalysts can cause gaseous aryl secondary alcohols to undergo dehydration reactions to form olefins with a high conversion rate.

[0225] The dehydration reaction apparatus according to the present invention, because it uses a gasification unit containing a gasification bottle, a gasification bottle heater, a dispersing element, and a stirrer, can effectively prevent coking of raw materials during the gasification process, thereby reducing the loss of starting materials.

[0226] Furthermore, since the gasification unit includes a dispersing element, the device can better disperse the material so that it can be gasified more quickly, and the friction between the dispersing elements helps the material to be completely gasified and reduces the occurrence of coking.

[0227] Furthermore, because steel balls are used in the dispersion component, it has a better heat transfer effect compared to dispersion components made of other materials, which is more conducive to the smooth gasification of materials.

[0228] Furthermore, since the gasification unit includes a stirrer, it can not only drive the dispersing components to move continuously during the operation of the device, causing friction between the dispersing components to remove the ash formed on their own surfaces, but also ensure that the dispersing components always maintain good mass and heat transfer effects, thereby achieving the technical effect of rapid gasification of materials.

[0229] According to the dehydration reaction apparatus of the present invention, since the apparatus also uses a first inner lining conduit and a second inner lining conduit, it ensures that the connection between two adjacent units also has a good heat insulation effect, thereby avoiding material loss caused by condensation at the two units.

[0230] The dehydration reaction apparatus according to the present invention also uses a secondary heating unit, which can effectively prevent gaseous materials from cooling and liquefying due to heat dissipation after entering the catalytic reaction unit, thus preventing further blockage of the pipes by caking.

[0231] Furthermore, since the secondary heating unit uses high-frequency induction heating, compared with traditional electric heating wire heating, high-frequency induction heating can generate heat evenly from the inside, with a large heating area, fast heat transfer, small size, and short residence time.

[0232] According to the dehydration reaction apparatus of the present invention, since the catalytic reaction unit has multiple catalytic sections and there are packing voids between two adjacent catalytic sections, the catalyst in each catalytic section can be blown by the airflow during the reaction, thereby achieving a technical effect similar to that of a fluidized bed. This not only improves the heat and mass transfer effect of the catalyst, but also significantly enhances the catalyst life and product conversion rate.

[0233] According to the dehydration reaction apparatus of the present invention, since the vaporization bottle, the outer shell of the catalytic reaction unit, and the outer shell of the secondary heating unit are all made of transparent glass, the user can directly see the internal situation of the apparatus during operation and can directly monitor the operating status of the apparatus.

[0234] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for preparing a dehydration catalyst, characterized in that, Includes the following steps: Mix 100 parts by weight of active ingredient, 2-20 parts by weight of surfactant and 0-180 parts by weight, evaporate and dry, and calcine for the first time to obtain catalyst precursor; The catalyst precursor, pore-forming agent, and water are mixed, extruded using a screw extruder, pelletized, dried, and then calcined a second time to obtain a solid spherical catalyst, which is the dehydration catalyst. The active ingredients are silicon dioxide and gallium trioxide in a mass ratio of 2:3, and the surfactant is PEG-400. Alternatively, the active ingredients are silicon dioxide and gallium trioxide in a mass ratio of 2:3, and the surfactant is Brij-56; Alternatively, the active ingredients are aluminum oxide and tungsten dioxide in a mass ratio of 1:1, and the surfactant is PEG-400; Alternatively, the active ingredients are magnesium oxide and cerium dioxide in a mass ratio of 1:1, and the surfactant is PEG-400; Alternatively, the active ingredients are zinc oxide and iron oxide in a mass ratio of 1:1, and the surfactant is PEG-400; Alternatively, the active ingredients are aluminum phosphate and molybdenum oxide in a mass ratio of 1:1, and the surfactant is PEG-400; Alternatively, the active ingredients are titanium dioxide and nickel oxide in a mass ratio of 1:1, and the surfactant is Tween 60; Alternatively, the active ingredients are silicon dioxide, zirconium oxide, and copper oxide in a mass ratio of 1:4.5:4.5, and the surfactant is sodium dodecyl sulfonate.

2. The method according to claim 1, characterized in that, in, The temperature of the first roasting is 500-700℃, and the temperature of the second roasting is 500-700℃.

3. A dehydration catalyst, characterized in that, Prepared by the method according to any one of claims 1 to 2.

4. A method for producing vinylbenzene compounds, characterized in that, The reactions involved are as follows: In the above formula: Each R is independently C1-C6 alkyl, O-C1-C6 alkyl, OC(O)-C1-C6 alkyl, C(O)-C1-C6 alkyl, O-C6-C 10 Aryl, OC(O)-C6-C 10 Aryl or C(O)-C6-C 10 Aryl; the C1-C6 alkyl, the O-C1-C6 alkyl, the OC(O)-C1-C6 alkyl, the C(O)-C1-C6 alkyl, the O-C6-C 10 Aryl, the aforementioned OC(O)-C6-C 10 Aryl and the aforementioned C(O)-C6-C 10 The aryl group is optionally surrounded by 1, 2 or 3 R groups. 1 replace; The R 1 Independently, it is a C1-C6 alkyl group; Alternatively, two adjacent Rs and the benzene rings attached to them together form a C8-C ring. 14 Aryl or C8-C 14 cycloalkyl; the C8-C 14 Aryl and the C8-C 14 The cycloalkyl group is optionally surrounded by 1, 2 or 3 R's. 2 replace; The R 2 It is independently C1-C6 alkyl, O-C1-C6 alkyl, OC(O)-C1-C6 alkyl or C(O)-C1-C6 alkyl; n is 0, 1, 2, 3, 4 or 5; Each R may be the same or different; The method includes the following steps: The material containing the vaporized compound 1 is reacted with the dehydration catalyst described in claim 3 to obtain compound 2.

5. The method for producing vinylbenzene compounds according to claim 4, characterized in that: in, The material containing the vaporized compound 1 includes compound 1 and a dispersant for dispersing the compound 1, the dispersant having a boiling point of 30-190 °C.

6. The method for producing vinylbenzene compounds according to claim 5, characterized in that: in, The dispersant is any one or more of DMAc, DMF, or DMSO.

7. The method for producing vinylbenzene compounds according to claim 4, characterized in that: in, The reaction temperature is 160-200 ℃.

8. The method for producing vinylbenzene compounds according to claim 4, characterized in that, The dehydration reaction is carried out in a dehydration reaction apparatus; the dehydration reaction apparatus includes: A gasification unit is used to at least gasify the reaction raw material to obtain gasified material, wherein the reaction raw material is compound 1; A catalytic reaction unit, filled with the dehydration catalyst, is directly or indirectly connected to the gasification unit. It is used to receive the gasified material and to react the gasified material under the action of the dehydration catalyst to form the target product. A product collection unit, connected to the catalytic reaction unit, is used to receive and collect the target product discharged from the catalytic reaction unit; At least one vacuum supply unit is provided to supply negative pressure to the interior of the gasification unit, the catalytic reaction unit and the product collection unit; The gasification unit includes: A vaporization cylinder having at least one inlet and at least one outlet; A vaporization bottle heating device is used to heat the vaporization bottle; Several dispersing components are disposed inside the vaporization bottle to disperse the reaction raw materials entering the vaporization bottle; A stirrer is disposed inside the vaporization bottle to drive the dispersing component to move within the vaporization bottle; The catalytic reaction unit includes: The outer shell of the catalytic reaction unit has at least one inlet and one outlet; Multiple catalytic units are installed inside the outer shell of the catalytic reaction unit. A packing void is formed between two adjacent catalytic units. During the reaction, the dehydration catalyst in each catalytic unit can be blown by the airflow.

9. The method for producing vinylbenzene compounds according to claim 8, characterized in that, The dehydration reaction apparatus further includes: A secondary heating unit, located between the gasification unit and the catalytic reaction unit, is used to reheat the gasified material leaving the gasification unit. The secondary heating unit includes: The outer shell of the secondary heating unit is connected to the outlet of the gasification bottle and the interior of the catalytic reaction unit. Several metal tubes are installed inside the outer shell of the secondary heating unit; A high-frequency induction heater has a heating coil wound around the outside of the secondary heating unit housing for heating the metal tube.

10. The method for producing vinylbenzene compounds according to claim 4, characterized in that, Compound 1 is .

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