A method and system for the dehydrogenative synthesis of tert-butylstyrene

Abstract

The present application belongs to the field of chemical synthesis, and particularly relates to a tert-butyl styrene dehydrogenation synthesis method, which comprises the following steps: carrying out catalytic dehydrogenation reaction on a mixed system containing tert-butyl ethylbenzene, an auxiliary agent, water and an iron-based catalyst at a temperature of 500-600 DEG C, and then separating to obtain tert-butyl styrene; the auxiliary agent is at least one of cyclohexane, cyclohexyl ethane and methylcyclohexane. The process and conditions of the present application can synergistically reduce the isopropyl styrene side reaction in the dehydrogenation process, and help to improve the yield and purity of the tert-butyl styrene.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis, specifically to the field of catalytic dehydrogenation of tert-butylethylbenzene to prepare tert-butylstyrene. Background Technology

[0002] Among industrially produced plastics, polystyrene ranks among the top in terms of output and performance. However, with the rapid development of my country's economy, its application areas are constantly expanding, demand is increasing, and quality requirements are also rising. In today's era of rapid technological advancement, higher demands are being placed on certain special properties of polymers, making research on polymer modification particularly important.

[0003] Styrene is easily modified due to the presence of its benzene ring, resulting in a wide variety of types. Furthermore, styrene is highly volatile, posing a certain degree of environmental harm. Introducing relatively large groups into the benzene ring is an effective method to reduce its volatility. Tert-butylstyrene is a derivative of styrene. Due to the greater steric hindrance of the tert-butyl group, the degree of freedom of molecular thermal motion in the polymer chain is reduced, significantly increasing the glass transition temperature of its homopolymer, which is approximately 42°C higher than that of polystyrene. Additionally, the increased alkyl chain length improves its solubility in aliphatic hydrocarbons, making it soluble in various aromatic solvents. The excellent physicochemical properties of tert-butylstyrene make it a promising candidate for developing novel materials in various fields, including synthetic rubber and synthetic resins.

[0004] Currently, there are two main routes for the synthesis of tert-butylstyrene: (1) tert-butylbenzene, ethylene and oxygen react with oxygen under catalytic conditions to produce tert-butylstyrene; (2) tert-butylethylbenzene undergoes a dehydrogenation reaction under dehydrogenation catalyst conditions to prepare it.

[0005] US3932549 discloses a method for synthesizing tert-butylethylbenzene from tert-butylbenzene, ethylene, and oxygen using a palladium catalyst. This method uses a palladium catalyst, which is expensive and increases production costs; furthermore, the reaction pressure reaches 100 kg / cm². 2 The requirements for the reaction equipment are too high, and the excessive pressure makes the operation process unsafe.

[0006] US3631213 discloses the use of an iron-based catalyst to catalytically dehydrogenate tert-butylethylbenzene to produce tert-butylstyrene at a reaction temperature of 540℃~700℃. Due to the high reaction temperature, a large number of byproducts of the dehydrogenation reaction are generated. The reactants are prone to cracking at high temperatures, resulting in a high content of isopropyl styrene impurities in the dehydrogenation products. This substance has similar properties to tert-butylstyrene, making it difficult to completely separate them using ordinary vacuum distillation. When the isopropyl styrene impurity content in the tert-butylstyrene product exceeds 100 ppm, it will hinder its polymerization reaction. GB2163773 reports the use of sulfolane as a solvent for extractive distillation to separate impurities, and US4982034 discloses a method using activated carbon adsorption to remove isopropyl styrene generated during dehydrogenation. Both of these methods are relatively complex and increase reaction energy consumption; therefore, the content of the isopropyl styrene impurity must be strictly controlled during the synthesis of tert-butylstyrene.

[0007] US4363748, GB2068767, US4291184, US4363748, and US4393263 utilize different phosphate catalysts to prepare tert-butylstyrene via an oxidative dehydrogenation reaction with oxygen. While these disclosed methods all involve relatively low reaction temperatures (350℃–600℃) and exhibit high selectivity for tert-butylstyrene with minimal formation of isopropenylated styrene impurities, the presence of oxygen in the reaction results in a low safety profile, which is detrimental to industrial production. Summary of the Invention

[0008] To address the problems of unsatisfactory yield and purity of the target product due to the side reaction of isopropylene styrene during the dehydrogenation of tert-butylethylbenzene to tert-butylstyrene, the primary objective of this invention is to provide a dehydrogenation synthesis method for tert-butylstyrene, which aims to effectively suppress the isopropylene styrene side reaction and improve the yield and purity of the target product.

[0009] A second objective of this invention is to provide a synergy for implementing the aforementioned dehydrogenation synthesis method.

[0010] Unlike conventional ethylbenzene dehydrogenation, tert-butylethylbenzene, due to the structural characteristics of its substituents, is prone to producing isopropyl styrene as a byproduct during the dehydrogenation process, affecting the yield and purity of the product. To address this issue, this invention provides the following solution:

[0011] A method for the dehydrogenation synthesis of tert-butylstyrene involves carrying out a catalytic dehydrogenation reaction of a mixed system containing tert-butylethylbenzene, an auxiliary agent, water, and an iron-based catalyst at a temperature of 500°C to 600°C, followed by separation to obtain tert-butylstyrene.

[0012] The auxiliary agent is at least one of cyclohexane, cyclohexylethane, and methylcyclohexane.

[0013] This invention demonstrates that the innovative use of an iron-based catalyst, combined with the aforementioned auxiliary agent and the joint control of the catalytic dehydrogenation temperature, can achieve synergistic effects, effectively suppressing side reactions such as isopropyl styrene, and improving the yield and purity of tert-butylstyrene.

[0014] In this invention, the tert-butylethylbenzene is at least one of p-tert-butylethylbenzene and m-tert-butylethylbenzene.

[0015] In this invention, the iron-based catalyst, the auxiliary agent, and the temperature combination are key to synergistically resolving the isopropylene styrene side reaction in the dehydrogenation stage of tert-butyl ethylbenzene, and improving the yield and purity of tert-butyl styrene products.

[0016] In this invention, the use of the additive, in combination with the catalyst and temperature, can unexpectedly achieve synergy, effectively reducing the side reactions of isopropyl styrene. In addition, since it does not undergo dehydrogenation, it helps to significantly improve the selectivity and efficiency of tert-butyl styrene conversion.

[0017] In this invention, the weight ratio of tert-butylethylbenzene, additives, and water is 1-4:1:3-7.

[0018] In this invention, the iron-based catalyst comprises Fe2O3, K2O, Ce2O3, MoO3, CaO, and MgO.

[0019] In this invention, the iron-based catalyst comprises, by weight percentage, K2O4-9%; Ce2O36-11%; MoO31-5%; CaO0.5-5%; MgO0.5-5%; with the balance being Fe2O3 (e.g., 66-79%).

[0020] In this invention, the dehydrogenation reaction can be intermittent or continuous. For example, it can be carried out continuously using a conventional gas-solid reaction apparatus.

[0021] Preferably, in the preparation method, tert-butylethylbenzene, additives, and water are preheated and vaporized, and then the vaporized mixture is contacted with an iron-based catalyst to carry out a catalytic dehydrogenation reaction at the specified temperature.

[0022] Preferably, in the preparation method, the gasified mixture is passed through a dehydrogenation reactor packed with an iron-based catalyst to carry out a catalytic dehydrogenation reaction.

[0023] Preferably, the space velocity of the gasification mixture is 0.5 h⁻¹ during the catalytic dehydrogenation reaction stage. -1 ~2.0h -1 (Preferred time: 0.8–1.5 h) -1 The catalytic dehydrogenation reaction pressure is 10–100 kPa.

[0024] In this invention, after the catalytic reaction is completed, the isopropylstyrene product can be obtained using existing methods. For example, after the catalytic dehydrogenation reaction, dehydration is performed, followed by distillation to obtain tert-butylstyrene.

[0025] The present invention also provides a system for implementing the dehydrogenation synthesis method, comprising a preheater, a dehydrogenation reactor, an oil-water separator, a separation tower, a tert-butylstyrene light component removal tower, a tert-butylstyrene heavy component removal tower, an additive recovery tower, and a tert-butylethylbenzene recovery tower;

[0026] The inlet of the preheater is connected to the inlet of tert-butylethylbenzene, additives, and water, and the outlet is connected to the inlet of the dehydrogenation reactor loaded with iron-based catalyst. The outlet of the dehydrogenation reactor is connected to an oil-water separator.

[0027] The oil phase outlet of the oil-water separator is connected to the inlet of the separation tower, the light material outlet of the separation tower is connected to the inlet of the additive recovery tower, and the outlet of the additive recovery tower is connected to the inlet of the tert-butylethylbenzene recovery tower.

[0028] The heavy material outlet of the separation tower is connected to the inlet of the tert-butylstyrene light material removal tower, and the outlet of the tert-butylstyrene light material removal tower is connected to the inlet of the tert-butylstyrene heavy material removal tower.

[0029] The p-tert-butylethylbenzene raw material, additives, and steam are mixed and fed into a preheater. After preheating, the mixture enters a dehydrogenation reactor to obtain a reaction gas containing p-tert-butylstyrene. This dehydrogenation reaction gas is then condensed in a condenser. The p-tert-butylstyrene, reaction byproducts, unreacted p-tert-butylethylbenzene, additives, and water are condensed into a liquid and then enter an oil-water separator. Non-condensable hydrogen gas exits from the top of the oil-water separator. The dehydrogenated liquid obtained after dehydration in the oil-water separator enters a separation tower. Simultaneously, the polymerization inhibitor p-tert-butylcatechol is added to the separation tower at a dosage of 10–100 ppm relative to the p-tert-butylstyrene content. The crude p-tert-butylstyrene product discharged from the bottom of the separation tower sequentially enters a tert-butylstyrene light component removal tower and a tert-butylstyrene heavy component removal tower to separate the light and heavy components, yielding a high-purity p-tert-butylstyrene product. The tert-butylethylbenzene catalytic dehydrogenation process has the following parameters: preheater temperature 250–350°C, dehydrogenation reactor temperature 500–600°C, and tert-butylethylbenzene liquid hourly space velocity (LHSV) of 0.5 h⁻¹. -1 ~2.0h -1 The mass ratio of water to tert-butylethylbenzene is 3–7, and the dehydrogenation reaction pressure is 10–100 kPa. The light components discharged from the top of the separation tower are successively passed through the auxiliary agent recovery tower and the tert-butylethylbenzene recovery tower to recover the auxiliary agent and the tert-butylethylbenzene, which are then returned to the dehydrogenation reactor for reuse.

[0030] Beneficial effects

[0031] This invention innovatively employs an iron-based catalyst, combined with the aforementioned additives and temperature control, which can effectively suppress byproducts such as isopropylene and styrene during the dehydrogenation stage of tert-butylethylbenzene, thereby helping to improve the raw material conversion rate, product yield, and purity.

[0032] The production process of this invention is oxygen-free, ensuring good production safety. At the same time, this process requires a low temperature, has high selectivity for tert-butylstyrene, and does not generate isopropylstyrene impurities during the production process. High-purity p-tert-butylstyrene products can be obtained directly through vacuum distillation.

[0033] This invention designs a reasonable process flow, using modified iron-based catalysts and additives. Under the above conditions, the selectivity for tert-butylstyrene is greater than 94%, the purity is greater than 97%, and the mass content of isopropyl styrene produced is less than 0.001%. This process has low production cost and good production safety, and can be used for the industrial production of tert-butylstyrene. Attached Figure Description

[0034] Figure 1 Here is the process flow diagram of this invention:

[0035] In the diagram: 1-Preheater; 2-Dehydrogenation reactor; 3-Oil-water separator; 4-Separation tower; 5-T-tert-butylstyrene light component removal tower; 6-T-tert-butylstyrene heavy component removal tower; 7-Auxiliary agent recovery tower; 8-T-tert-butylethylbenzene recovery tower Detailed Implementation

[0036] The tert-butyl ethylbenzene raw material and additives are mixed with water vapor in a certain proportion and heated in a preheater 1 (the temperature is such that the raw material is vaporized, for example, 250-350℃) before entering the dehydrogenation reactor 2 for dehydrogenation reaction. The dehydrogenation product and raw material are condensed and then enter an oil-water separator 3. The dehydrogenated liquid obtained by dehydration in the oil-water separator enters a separation tower 4. The crude tert-butyl styrene product discharged from the bottom of the separation tower 4 enters the tert-butyl styrene light component removal tower 5 and the tert-butyl styrene heavy component removal tower 6 in sequence to separate the light component and the heavy component, and obtain 97% tert-butyl styrene.

[0037] The light components discharged from the top of the separation tower 4 are successively passed through the additive recovery tower 7 and the tert-butyl ethylbenzene recovery tower 8 to recover the additives and tert-butyl ethylbenzene, which are then returned to the dehydrogenation reactor 2 for reuse.

[0038] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited thereto.

[0039] In the following examples, the water-oil mass ratio refers to the weight ratio of water to p-tert-butylethylbenzene.

[0040] Example 1

[0041] Preparation of catalyst for the dehydrogenation reaction of p-tert-butylethylbenzene:

[0042] 75 parts Fe2O3, 5 parts K2O, 6 parts Ce2O3, 4 parts MoO3, 5 parts CaO and 5 parts MgO are mechanically mixed and then extruded into shape.

[0043] p-tert-butylethylbenzene, water, and additives are preheated and vaporized in a preheater, and then fed into tubular reactor 2 for catalytic dehydrogenation. A modified iron-based catalyst is loaded into a Φ25mm reactor with a catalyst bed height of 1.5m. The catalyst is filled with quartz sand at both ends. The mass ratio of p-tert-butylethylbenzene feedstock to cyclohexylethane additive is 3:1, the reaction temperature is 550℃, the water-to-oil mass ratio is 3:1, and the space velocity is 0.8h⁻¹. -1 The reaction pressure was 100 kPa. The dehydrogenation reaction of tert-butylethylbenzene was carried out under these conditions. Online gas chromatography analysis of the dehydrogenation products showed a selectivity of 95.32% for tert-butylstyrene and a mass content of <0.001% for isopropyl styrene. The crude reaction product was condensed and drained through oil-water separator 3. The oil phase entered separation tower 4. The crude tert-butylstyrene discharged from the bottom of separation tower 4 successively entered tert-butylstyrene light phase removal tower 5 and tert-butylstyrene heavy phase removal tower 6. 97.8% p-tert-butylstyrene was obtained at the top of tert-butylstyrene heavy phase removal tower 6.

[0044] Example 2

[0045] Preparation of catalyst for the dehydrogenation reaction of p-tert-butylethylbenzene:

[0046] 70 parts Fe2O3, 8 parts K2O, 10 parts Ce2O3, 5 parts MoO3, 4 parts CaO and 3 parts MgO are mechanically mixed and then extruded.

[0047] The tert-butylethylbenzene, water, and additives are preheated and vaporized in a preheater, and then fed into a tubular reactor 2 for catalytic dehydrogenation. A modified iron-based catalyst is loaded into the Φ25mm reactor, with a catalyst bed height of 1.5m. The catalyst is filled with quartz sand at both ends. The mass ratio of tert-butylethylbenzene feedstock to cyclohexylethane additive is 1:1. The reaction temperature is 580℃, the water-to-oil mass ratio is 6:1, and the space velocity is 1.5h⁻¹. -1 The reaction pressure was 50 kPa. The dehydrogenation reaction of tert-butylethylbenzene was carried out under these conditions. Online gas chromatography analysis of the dehydrogenation products showed a selectivity of 94.65% for tert-butylstyrene and a mass content of <0.001% for isopropyl styrene. The crude reaction product was condensed and drained through oil-water separator 3. The oil phase entered separation tower 4. The crude tert-butylstyrene discharged from the bottom of separation tower 4 successively entered tert-butylstyrene light phase removal tower 5 and tert-butylstyrene heavy phase removal tower 6. 97.5% p-tert-butylstyrene was obtained at the top of tert-butylstyrene heavy phase removal tower 6.

[0048] Example 3

[0049] Preparation of catalyst for the dehydrogenation reaction of p-tert-butylethylbenzene:

[0050] 75 parts Fe2O3, 9 parts K2O, 8 parts Ce2O3, 2 parts MoO3, 3 parts CaO and 3 parts MgO are mechanically mixed and then extruded.

[0051] The tert-butylethylbenzene, water, and additives are preheated and vaporized in a preheater, and then fed into a tubular reactor 2 for catalytic dehydrogenation. A modified iron-based catalyst is loaded into the Φ25mm reactor, with a catalyst bed height of 1.5m. The catalyst is filled with quartz sand at both ends. The mass ratio of tert-butylethylbenzene feedstock to cyclohexylethane additive is 1:1. The reaction temperature is 500℃, the water-to-oil mass ratio is 7:1, and the space velocity is 1.0 h⁻¹. -1 The reaction pressure was 10 kPa. The dehydrogenation reaction of tert-butylethylbenzene was carried out under the above conditions. Online gas chromatography analysis of the dehydrogenation products showed a selectivity of 97.32% for tert-butylstyrene and a mass content of <0.001% for isopropyl styrene. The crude reaction product was condensed and drained through oil-water separator 3. The oil phase entered separation tower 4. The crude tert-butylstyrene discharged from the bottom of separation tower 4 successively entered tert-butylstyrene light phase removal tower 5 and tert-butylstyrene heavy phase removal tower 6. 98.0% p-tert-butylstyrene was obtained at the top of tert-butylstyrene heavy phase removal tower 6.

[0052] Example 4

[0053] Preparation of catalyst for the dehydrogenation reaction of p-tert-butylethylbenzene:

[0054] 70 parts Fe2O3, 5 parts K2O, 10 parts Ce2O3, 5 parts MoO3, 5 parts CaO and 5 parts MgO are mechanically mixed and then extruded.

[0055] The tert-butylethylbenzene, water, and additives are preheated and vaporized in a preheater, and then fed into a tubular reactor 2 for catalytic dehydrogenation. A modified iron-based catalyst is loaded into the Φ25mm reactor, with a catalyst bed height of 1.5m. The catalyst is filled with quartz sand at both ends. The mass ratio of tert-butylethylbenzene feedstock to cyclohexane additive is 2:1. The reaction temperature is 550℃, the water-to-oil mass ratio is 6:1, and the space velocity is 0.8h⁻¹. -1 The reaction pressure was 50 kPa. The dehydrogenation reaction of tert-butylethylbenzene was carried out under these conditions. Online gas chromatography analysis of the dehydrogenation products showed a selectivity of 97.58% for tert-butylstyrene and a mass content of <0.001% for isopropyl styrene. The crude reaction product was condensed and drained through oil-water separator 3. The oil phase entered separation tower 4. The crude tert-butylstyrene discharged from the bottom of separation tower 4 successively entered tert-butylstyrene light phase removal tower 5 and tert-butylstyrene heavy phase removal tower 6. 98.2% p-tert-butylstyrene was obtained at the top of tert-butylstyrene heavy phase removal tower 6.

[0056] Example 5

[0057] Preparation of catalyst for the dehydrogenation reaction of p-tert-butylethylbenzene:

[0058] 75 parts Fe2O3, 5 parts K2O, 6 parts Ce2O3, 4 parts MoO3, 5 parts CaO and 5 parts MgO are mechanically mixed and then extruded into shape.

[0059] The tert-butylethylbenzene, water, and additives are preheated and vaporized in a preheater, and then fed into a tubular reactor 2 for catalytic dehydrogenation. A modified iron-based catalyst is loaded into the Φ25mm reactor, with a catalyst bed height of 1.5m. The catalyst is filled with quartz sand at both ends. The mass ratio of tert-butylethylbenzene feedstock to methylcyclohexane additive is 4:1. The reaction temperature is 580℃, the water-to-oil mass ratio is 4:1, and the space velocity is 0.8h⁻¹. -1 The reaction pressure was 100 kPa. The dehydrogenation reaction of tert-butylethylbenzene was carried out under these conditions. Online gas chromatography analysis of the dehydrogenation products showed a selectivity of 96.98% for tert-butylstyrene and a mass content of <0.001% for isopropyl styrene. The crude reaction product was condensed and drained through oil-water separator 3. The oil phase entered separation tower 4. The crude tert-butylstyrene discharged from the bottom of separation tower 4 successively entered tert-butylstyrene light phase removal tower 5 and tert-butylstyrene heavy phase removal tower 6. 97.4% tert-butylstyrene was obtained at the top of tert-butylstyrene heavy phase removal tower 6.

[0060] Example 6

[0061] Preparation of catalyst for the dehydrogenation reaction of p-tert-butylethylbenzene:

[0062] 70 parts Fe2O3, 8 parts K2O, 10 parts Ce2O3, 5 parts MoO3, 4 parts CaO and 3 parts MgO are mechanically mixed and then extruded.

[0063] The tert-butylethylbenzene, water, and additives are preheated and vaporized in a preheater, and then fed into a tubular reactor 2 for catalytic dehydrogenation. A modified iron-based catalyst is loaded into a Φ25mm reactor with a catalyst bed height of 1.5m. The catalyst is filled with quartz sand at both ends. The mass ratio of the tert-butylethylbenzene feedstock to the mixed solution of methylcyclohexane and cyclohexane additives is 3:1. The reaction temperature is 550℃, the water-to-oil mass ratio is 6:1, and the space velocity is 1.5h⁻¹. -1The reaction pressure was 100 kPa. The dehydrogenation reaction of tert-butylethylbenzene was carried out under these conditions. Online gas chromatography analysis of the dehydrogenation products showed a selectivity of 94.98% for tert-butylstyrene and a mass content of <0.001% for isopropyl styrene. The crude reaction product was condensed and drained through oil-water separator 3. The oil phase entered separation tower 4. The crude tert-butylstyrene discharged from the bottom of separation tower 4 successively entered tert-butylstyrene light phase removal tower 5 and tert-butylstyrene heavy phase removal tower 6. 97.3% p-tert-butylstyrene was obtained at the top of tert-butylstyrene heavy phase removal tower 6.

[0064] Comparative Example 1

[0065] The other conditions are the same as in Example 1, except that no additives are added to the raw materials.

[0066] Under these conditions, the selectivity of tert-butylstyrene is 83.34%, and the content of isopropyl styrene is 0.012%. After the crude product from the reaction is condensed and drained through oil-water separator 3, the oil phase enters separation tower 4. The crude tert-butylstyrene product discharged from the bottom of separation tower 4 enters tert-butylstyrene light product removal tower 5 and tert-butylstyrene heavy product removal tower 6 in sequence. 95.4% p-tert-butylstyrene is obtained at the top of tert-butylstyrene heavy product removal tower 6.

[0067] Comparative Example 2

[0068] Other conditions were the same as in Comparative Example 1, except that the reaction temperature was 620℃. Under these conditions, the selectivity for tert-butylstyrene was 93.28%, and the content of isopropylstyrene was 1.256%. After the crude product was condensed and drained through oil-water separator 3, the oil phase entered separation tower 4. The crude tert-butylstyrene product discharged from the bottom of separation tower 4 successively entered tert-butylstyrene light phase removal tower 5 and tert-butylstyrene heavy phase removal tower 6. 94.8% p-tert-butylstyrene was obtained at the top of tert-butylstyrene heavy phase removal tower 6.

Claims

1. A method for the dehydrogenation synthesis of tert-butylstyrene, characterized in that, A mixed system containing tert-butylethylbenzene, additives, water, and an iron-based catalyst was subjected to a catalytic dehydrogenation reaction at a temperature of 500℃~600℃, and then tert-butylstyrene was obtained by separation. The auxiliary agent is at least one of cyclohexane, cyclohexylethane, and methylcyclohexane.

2. The method for dehydrogenation synthesis of tert-butylstyrene as described in claim 1, characterized in that, The tert-butylethylbenzene mentioned is at least one of p-tert-butylethylbenzene and m-tert-butylethylbenzene.

3. The method for dehydrogenation synthesis of tert-butylstyrene as described in claim 1, characterized in that, The weight ratio of tert-butylethylbenzene, additives, and water is 1~4:1:3~7.

4. The method for dehydrogenation synthesis of tert-butylstyrene as described in claim 1, characterized in that, The iron-based catalyst comprises Fe2O3, K2O, Ce2O3, MoO3, CaO and MgO.

5. The method for dehydrogenation synthesis of tert-butylstyrene as described in claim 4, characterized in that, The iron-based catalyst, by weight percentage, contains 4-9% K₂O, 6-11% Ce₂O₃, 1-5% MoO₃, 0.5-5% CaO, 0.5-5% MgO, and the balance is Fe₂O₃.

6. The method for dehydrogenation synthesis of tert-butylstyrene according to any one of claims 1 to 5, characterized in that, The tert-butylethylbenzene, additives, and water are preheated and vaporized. The vaporized mixture is then contacted with an iron-based catalyst to carry out a catalytic dehydrogenation reaction at the stated temperature.

7. The method for dehydrogenation synthesis of tert-butylstyrene as described in claim 6, characterized in that, The gasified mixture is passed through a dehydrogenation reactor packed with an iron-based catalyst to carry out a catalytic dehydrogenation reaction.

8. The method for dehydrogenation synthesis of tert-butylstyrene as described in claim 6, characterized in that, During the catalytic dehydrogenation reaction stage, the space velocity of the gasification mixture is 0.5 h⁻¹. -1 ~2.0h -1 The catalytic dehydrogenation reaction pressure is 10~100 kPa.

9. The method for dehydrogenation synthesis of tert-butylstyrene as described in claim 1, characterized in that, After catalytic dehydrogenation, the product undergoes dehydration treatment, followed by distillation to obtain tert-butylstyrene.

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