A method and apparatus for synthesizing phenyltrichlorosilane by an alpha-elimination mechanism of trichlorosilane

Abstract

This invention discloses a method and apparatus for synthesizing phenyltrichlorosilane via a trichlorosilane α-elimination mechanism in the field of organosilicon chemistry. Using silica-supported nickel, copper, or other metals as catalysts, chlorobenzene and trichlorosilane are mixed and subjected to a gas-phase thermal condensation reaction. Through the synergistic effect of the catalyst and initiator, the α-elimination of trichlorosilane is promoted to generate a dichlorosilane carbene intermediate, improving reaction efficiency. In this invention, the single-pass yield of phenyltrichlorosilane is increased from 65% in the traditional process to over 85%, reaching a maximum of 92%. The reaction temperature is reduced to 450-550℃, significantly reducing energy consumption. Carbon deposition is suppressed, extending the operating cycle of the apparatus. The raw material cost is low, and existing production lines can be directly modified, making it highly valuable for industrialization.

Description

Technical Field

[0001] This invention relates to the field of organosilicon chemistry, specifically to a method and apparatus for synthesizing phenyltrichlorosilanes with a trichlorosilane α-elimination mechanism. Background Technology

[0002] Phenylacetyltrichlorosilane (PTCS) is an important organosilicon compound. It can be used to synthesize various silane coupling agents and organosilicon polymers. Its importance and usage are second only to methylchlorosilane, making it one of the priority functional silicon monomers for development in my country. Compared to methylchlorosilane, due to the influence of the benzene ring, polymers synthesized from PTCS generally exhibit superior heat resistance, chemical stability, radiation resistance, and refractive index, giving them unique application value in multiple fields such as chemical engineering, electronics, aerospace, and coatings.

[0003] The synthesis technology of PTCS is a key research direction in the field of organosilicon chemistry, and improving the synthesis efficiency and product quality of PTCS is of great significance for its industrial application. Currently reported industrially feasible synthesis methods include: Grignard reagent method, direct method, and vapor-phase thermal shrinkage method.

[0004] The Grignard reagent method first prepares a phenyl magnesium chloride solution from chlorobenzene and magnesium, which then reacts with silicon tetrachloride to generate PTCS. Although this method has the advantages of high yield and mild reaction conditions, industrial production still faces challenges due to the difficulty in controlling the Grignard reaction and its potential hazards. The direct method, similar to the production of methylchlorosilane, involves directly passing chlorobenzene, HCl, and silicon powder through a copper or silver catalyst bed at 280-350°C to obtain the target product. The disadvantages of this method include the formation of a byproduct, diphenyldichlorosilane, with a boiling point close to that of PTCS, which is difficult to completely fractionate using conventional distillation methods, resulting in a PTCS purity of less than 97%. Furthermore, this method also produces polychlorinated biphenyls (PCBs), which are potent carcinogens, posing a significant environmental burden. The gas-phase thermal shrinkage method involves reacting chlorobenzene with trichlorosilane (HSiCl3) in a high-temperature reaction tube at 500-600°C in the presence of a catalyst or initiator to generate PTCS. Compared to the direct method, this method has simpler reactants and equipment, is easier to implement for continuous production, and the products are easier to separate, readily yielding PTCS products with a purity of 99%. It is currently the main industrial production process abroad. This process was introduced to my country twenty years ago, but because this product involves a cutting-edge field, relevant information is scarce, and the key technologies for its industrial production are controlled by a few foreign organosilicon companies such as Dow Corning, resulting in a low PTCS yield during production (approximately 65%, based on HSiCl3). This application aims to develop a method and apparatus for the synergistic promotion of phenyltrichlorosilane synthesis using a supported metal catalyst and initiator.

[0005] Chinese patent CN102443021A discloses a method for preparing phenyltrichlorosilane (PTCS) by gas-phase thermal condensation of chlorobenzene and trichlorosilane (HSiCl3): chlorobenzene and HSiCl3 are used as raw materials, reacted at 300-600℃ and 0.2-0.8 MPa to generate PTCS-containing syngas. To improve the PTCS yield, one of chloroform, potassium persulfate, azobisisobutyronitrile (AIBN), or benzoyl peroxide (BPO) is added to the reaction system as an initiator, with the initiator amounting to 0.1-2 wt% of the total materials. Although this method can enhance the reaction activity through the initiator, it still suffers from problems such as high reaction temperature, a wide range of initiator system choices with unclear mechanisms of action, easy induction of side reactions leading to carbon buildup and equipment scaling / clogging, and insufficient safety and scale-up stability of different initiators in high-temperature chlorine-containing systems. These limitations restrict further improvement in PTCS selectivity and long-term stable operation.

[0006] German patent DE10349286A1 discloses a gas-phase thermal condensation of HSiCl3 and chlorobenzene in a steel tubular reactor under conditions of 300-600℃, atmospheric pressure, and residence time of 3-30s. It also discloses the selection of 1,2-diphenylethane, 2,3-diphenyl-2,3-dimethylbutane, 1,1,2,2-tetraphenylethane, 3,4-dimethyl-3,4-diphenylethane, dicycloethyldiazene, and di-tert-butyldiazene as initiating systems to achieve a high PTCS yield with relatively few byproducts and low carbonization and corrosion of the reactor. The limitations of this method are: the reaction still relies on a short residence window at temperatures above 300°C, and it is extremely sensitive to the uniformity of feed mixing, heat transfer, and residence time distribution; the various organic azo / polyphenyl ethane initiators used are costly, and the supply chain and impurity control requirements are stringent; at the same time, in systems containing HCl and high-temperature chlorosilane, there may still be engineering risks such as complex initiator cracking pathways, yield fluctuations due to batch differences, and carbon deposition caused by local overheating after scale-up.

[0007] Krasnova's team studied the thermal decomposition behavior of HSiCl3 in the presence of different amounts of chloroform at 350-600℃, with a residence time of approximately 30 s, in a hollow quartz tube (28 mm inner diameter, 400 mm reaction zone length). The results showed that approximately 1 mol% chloroform can promote the formation of dichlorosilene (:SiCl2), thereby promoting PTCS formation. Chloroform is also commonly used as an initiator in existing industrial chlorobenzene gas-phase thermal shrinkage methods, achieving PTCS yields of approximately 65%. However, chloroform initiation systems typically suffer from a narrow effective dosage window: excessive chloroform can easily trigger deep decomposition and carbon-containing side reactions, leading to carbon deposition, increased post-processing burden, and decreased long-term stability of the equipment.

[0008] In summary, existing PTCS gas-phase thermal condensation processes generally face problems such as high reaction temperatures, difficulty in completely suppressing side reactions of initiators (especially chloroform / azo systems) in high-temperature chlorine-containing environments, and resulting carbon deposition, corrosion, and yield fluctuations. The fundamental reason lies in the fact that the reaction involves both the key active intermediate "dichlorosilene (:SiCl2) pathway," which is beneficial to PTCS formation, and the potential parallel occurrence of multiple free radical chain reactions and carbon-containing cracking condensation processes. If the α-elimination efficiency of HSiCl3 cannot be directionally improved and non-selective free radical side reactions cannot be suppressed, it is difficult to simultaneously achieve high yield, high selectivity, and low carbon deposition. Summary of the Invention

[0009] This invention addresses the technical challenges of existing gas-phase thermal shrinkage processes for producing phenyltrichlorosilane, including high reaction temperatures, low trichlorosilane conversion, low single-pass yield, and reactor clogging due to carbon buildup. It provides a method for synthesizing phenyltrichlorosilane based on the α-elimination mechanism of trichlorosilane. This method introduces a specific silica-supported transition metal catalyst system, coupled with a specific free radical initiator, particularly utilizing the synergistic effect of nickel and toluene. This significantly reduces the activation energy of the α-elimination reaction of trichlorosilane to form the active dichlorosilane carbene intermediate, thereby greatly improving the yield and selectivity of the target product under milder reaction conditions and effectively inhibiting carbon buildup.

[0010] A method for synthesizing phenyltrichlorosilane based on the α-elimination mechanism of trichlorosilane, characterized in that the method is carried out in a tubular furnace reactor and includes the following steps: Step 1: Preparation of Supported Catalyst Silica, which has a large specific surface area and good thermal stability, was selected as the carrier, and one of nickel, copper, cobalt, and iron was selected as the active metal component.

[0011] (1) The silica carrier is pretreated at high temperature to remove surface adsorbed water and impurities; (2) Using the equal volume impregnation method, an aqueous solution containing active metal nitrates is uniformly impregnated onto the pretreated silica carrier; (3) Allow the impregnated carrier to stand and age, and then dry it. (4) The dried precursor is roasted in an air atmosphere to decompose the metal salt into metal oxide. (5) Finally, the metal catalyst supported on silica is obtained by reduction treatment under a hydrogen or nitrogen-hydrogen mixed atmosphere.

[0012] The loading of active metal components in the total mass of the catalyst is 1wt%-10wt%.

[0013] Step 2: Preparation of reaction raw materials The molar ratio of the main raw materials chlorobenzene and trichlorosilane is controlled at 1:1-3:1. After the two raw materials are mixed, an initiator is added, with the amount of initiator being 1wt%-10wt% of the sum of the mass of trichlorosilane and chlorobenzene.

[0014] The initiator is selected from one or a combination of several of toluene, chloroform, azobisisobutyronitrile, and benzoyl peroxide.

[0015] Step 3: Gas-phase thermal condensation reaction The catalyst prepared in step one is loaded into the isothermal section of the tubular furnace reactor. The mixed feed liquid prepared in step two is fed into the vaporizer through a high-pressure metering pump, and after complete vaporization at 200-300℃, it enters the tubular furnace reactor.

[0016] Under reaction conditions of 450-620 ℃ and 0.2-0.4 MPa, the raw material gas undergoes a gas-phase condensation reaction in a tubular reactor.

[0017] Step 4: Product Collection The mixed gas after the reaction flows out of the reactor and is condensed into a liquid product by the condenser.

[0018] As a preferred technical solution of the present invention: The optimal catalyst and initiator combination is as follows: the active metal component is preferably nickel; the initiator is preferably toluene. This represents a synergistic system of a silica-supported nickel catalyst and a toluene initiator.

[0019] Preferred reaction conditions: When using the above combination of nickel and toluene, the preferred reaction temperature is 530°C; the preferred reaction pressure is 0.3 MPa; the optimal molar ratio of raw materials chlorobenzene and trichlorosilane is 2:1; and the preferred mass fraction of toluene added as initiator is 3 wt%.

[0020] Mechanism Explanation: The preferred combination of toluene and nickel is due to the fact that nickel's active sites effectively activate the silicon-hydrogen bonds of trichlorosilane, promoting its α-elimination reaction to generate dichlorosilane carbene and hydrogen chloride. Meanwhile, toluene readily loses a hydrogen atom at high temperatures to form a stable benzyl radical. This radical acts as a chain transfer agent, inducing the reaction system to generate more active radicals, accelerating the breaking of the C-Cl bond in chlorobenzene and the insertion of the carbene. The synergistic effect of these two components allows the reaction to achieve extremely high conversion efficiency at relatively low temperatures.

[0021] Compared with the prior art, the present invention has the following significant advantages: (1) Significantly improved yield: This invention utilizes the synergistic effect of silica-supported metal catalysts and initiators, especially the combination of toluene and nickel, to greatly promote the α-elimination process of trichlorosilane. Experimental data show that under optimal conditions, the single-pass yield of phenyltrichlorosilane can be increased from about 65% in the traditional process to more than 85%, or even up to 92%, which significantly reduces the material recycling volume and production cost.

[0022] (2) Lower reaction temperature and lower energy consumption: Traditional processes usually require temperatures above 650℃, while this invention lowers the optimal reaction temperature to 450-550℃ through catalytic activation. This not only significantly reduces production energy consumption, but also reduces the stringent requirements on high-temperature corrosion-resistant equipment.

[0023] (3) Suppress carbon buildup and extend cycle: The preferred toluene initiator has excellent thermal stability and can suppress deep cracking and dehydrogenation condensation reactions at high temperatures through free radical transfer mechanism; combined with the high specific surface area dispersion effect of silica support, it effectively reduces the formation of carbon buildup on the catalyst surface and extends the continuous operation cycle of the device.

[0024] (4) Raw materials are cheap and readily available: The silica carrier and active metal components such as nickel and iron used in this invention are inexpensive; the initiator toluene is also a bulk chemical raw material. Compared with the use of precious metal palladium or expensive special initiators, this invention has extremely high industrial application value and economic benefits.

[0025] (5) Strong process adaptability: The device and method proposed in this invention can be directly modified and implemented on existing gas phase condensation production lines without replacing the main reaction equipment, which facilitates the technical upgrade of old equipment. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a diagram of the experimental apparatus for the gas-phase condensation synthesis of phenyltrichlorosilane according to the present invention.

[0028] The attached diagram lists the components represented by each number as follows: BV-1 Back pressure valve; C-1 Condenser; FI-1 Filter; M-1 Liquid mixer; NV-1 Needle valve; PR-1 Preheater; R-1 Tubular furnace reactor; S-1 Reaction liquid storage tank; SP-1, SP-2 High-pressure injection pumps; TV-1, TV-2, TV-3 Three-way ball valves Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0030] This invention proposes a "composite initiation / regulation system for directionally promoting the α-elimination of HSiCl3 to generate :SiCl2" for the preparation of PTCS from chlorobenzene and HSiCl3. By rapidly and gently generating and maintaining an appropriate concentration of :SiCl2 at the front end of the reaction, the reaction is made more inclined towards the main pathway of ":SiCl2 chlorination → trichlorosilane group formation → coupling with aryl species to generate PTCS". At the same time, by synergistically controlling the initiator structure / addition amount and the residence time in the reaction zone, the risk of carbon deposition and corrosion caused by deep decomposition of the initiator at high temperatures is reduced. This achieves: improved PTCS selectivity and yield within a wider operating window, reduced by-product formation, reduced reactor coking tendency, and improved long-term operational stability of the unit.

[0031] I. Catalyst Support Carrier 3 is selected from spherical silica gel (SiO2) with a particle size of 20-40 mesh and a specific surface area of ​​300-400 m². 2 / g, with a pore volume of 0.8-1.2cm / g.

[0032] 2. Raw material specifications Chlorobenzene (purity >99.5%), trichlorosilane (purity >99%), toluene, and other initiators were all analytical grade reagents.

[0033] 3. Evaluation Indicators and Calculation Methods The reaction results were evaluated primarily by the yield of phenyltrichlorosilane (PhSiCl3), which was calculated based on the amount of trichlorosilane (HSiCl3) introduced. II. Catalyst Preparation Example A: Preparation of Ni / SiO2 catalyst 100 g of SiO2 support dried at 120 °C for 4 h was weighed. 60 mL of an aqueous solution containing 24.8 g of nickel nitrate hexahydrate (target loading 5 wt%) was prepared. The nickel nitrate solution was uniformly sprayed onto the support surface using an equal-volume impregnation method, and the mixture was continuously stirred until complete adsorption. The impregnated sample was aged at room temperature for 12 h, followed by drying at 120 °C for 12 h. The dried solid was placed in a muffle furnace and calcined at 500 °C for 4 h in air to decompose nitrates; after cooling, it was transferred to a tube furnace and reduced at 400 °C for 4 h in H2 atmosphere to obtain a 5 wt% Ni / SiO2 catalyst.

[0034] Examples B, C, and D: Preparation of other metal catalysts Following the steps in Example A, Cu / SiO2, Co / SiO2, and Fe / SiO2 catalysts were prepared by replacing nickel nitrate hexahydrate with equimolar amounts of copper nitrate trihydrate, cobalt nitrate hexahydrate, and ferric nitrate nonahydrate, respectively; their metal loadings, converted to molar basis, were consistent with those of Ni / SiO2.

[0035] III. Synthesis and Evaluation of Phenylacetic Trichlorosilane First, the prepared catalyst and conventional initiators were screened. Based on the PhSiCl3 yield results, a suitable catalyst-initiator combination system was selected.

[0036] The following are examples of catalyst and initiator screening. Example 1: Toluene + Ni / SiO2 system (optimal solution) Filling: 50 mL of Ni / SiO2 catalyst is filled into the constant temperature zone of the stainless steel tubular furnace bed reactor.

[0037] Feeding: Prepare a mixed feed solution with a molar ratio of chlorobenzene to HSiCl3 of 2:1; add toluene as an initiator, with the amount of toluene added being 3 wt% of the total mass of the raw materials chlorobenzene and HSiCl3.

[0038] Reaction: After the catalyst bed temperature stabilizes at 530℃, a high-pressure metering pump is used to feed the material at a rate of 1.5 mL / min. The raw material is vaporized in a 260℃ vaporizer before entering the reactor; the reaction pressure is controlled at 0.3 MPa.

[0039] Results: Samples were taken for analysis after 10 hours of continuous operation. Gas chromatography results showed that the conversion rate of HSiCl3 was 94.5%, the selectivity of PhSiCl3 was 96.2%, and the single-pass yield of PhSiCl3 was 90.9%. No obvious carbon deposition was observed on the reaction tube wall or the catalyst surface.

[0040] Example 2: Toluene + Cu / SiO2 system The catalyst Ni / SiO2 in Example 1 was replaced with Cu / SiO2, and the other conditions were the same as in Example 1.

[0041] Results: The conversion rate of HSiCl3 was 85.3%, and the yield of PhSiCl3 was 81.5%. This indicates that Cu's activation ability for Si-H bonds is weaker than that of Ni.

[0042] Example 3: Toluene + Co / SiO2 system The catalyst Ni / SiO2 in Example 1 was replaced with Co / SiO2, and the other conditions were the same as in Example 1.

[0043] Results: The conversion rate of HSiCl3 was 82.0%, and the yield of PhSiCl3 was 78.4%.

[0044] Example 4: Toluene + Fe / SiO2 system Except for replacing the catalyst Ni / SiO2 in Example 1 with Fe / SiO2, all other conditions are the same as in Example 1.

[0045] Results: The conversion rate of HSiCl3 was 79.5%, and the yield of PhSiCl3 was 75.2%.

[0046] Example 5: Chloroform + Ni / SiO2 system The initiator toluene in Example 1 was replaced with chloroform, and the other conditions were the same as in Example 1.

[0047] Results: Chloroform can act as a free radical initiator, but it decomposes too rapidly at 530℃, leading to an increase in the byproduct SiCl4. The yield of PhSiCl3 was 64.6%. The pressure drop increased slightly after 5 hours of operation, indicating the presence of a small amount of carbon deposits.

[0048] Example 6: AIBN+Ni / SiO2 system The initiator toluene in Example 1 was replaced with azobisisobutyronitrile (AIBN), and the other conditions were the same as in Example 1.

[0049] Results: Due to the short half-life of AIBN, it decomposes in large quantities during the vaporization stage and fails to play an effective role in the bed. The yield of PhSiCl3 was 72.3%.

[0050] Example 7: Benzoyl peroxide + Ni / SiO2 system The initiator toluene in Example 1 was replaced with benzoyl peroxide, and the other conditions were the same as in Example 1.

[0051] Results: Benzoyl peroxide can act as a free radical initiator, but it decomposes too rapidly at 550℃, leading to an increase in the byproduct SiCl4. The yield of PhSiCl3 was 78.6%. The pressure drop increased slightly after 8 h of operation, indicating the presence of a small amount of carbon deposits.

[0052] Example 8: Initiator-free + Ni / SiO2 system (synergistic effect verification) Except for the absence of an initiator, the other conditions are the same as in Example 1.

[0053] Results: The yield of PhSiCl3 was 50.5% when relying solely on Ni / SiO2. This indicates that Ni can catalyze the reaction, but the lack of free radical chain transfer promoting effect provided by toluene reduces the overall efficiency.

[0054] Example 9: Toluene + Pure SiO2 Support (Verification of Metal Interaction) The catalyst Ni / SiO2 in Example 1 was replaced with a SiO2 support without metal loading, and the other conditions were the same as in Example 1 (i.e., only toluene initiation, no metal catalysis).

[0055] Results: The yield of PhSiCl3 was 42.8%. This indicates that toluene initiation alone is insufficient to effectively reduce the activation energy of α-elimination in HSiCl3.

[0056] Example 10: Traditional heat shrinkage process (blank control) The reactor was an empty tube (without catalyst), and no initiator was added to the feedstock; the thermal condensation reaction was carried out directly. To obtain an acceptable conversion rate, the reaction temperature was increased to 620°C, with other conditions the same as in Example 1.

[0057] Results: At 620℃, the yield of PhSiCl3 was only 23.4%, and the byproduct diphenyldichlorosilane increased significantly. The unit was forced to shut down after 24 hours of continuous operation due to severe carbon buildup and blockage.

[0058] The effects on the yield of the gas-phase thermal condensation reaction were further optimized by adjusting the raw material molar ratio, the mass fraction of the added toluene initiator, the reaction temperature, and the reaction pressure. Specific examples are shown below.

[0059] Example 11 50 mL of Ni / SiO2 catalyst was packed into the isothermal zone of a stainless steel tubular furnace reactor. A feed solution of chlorobenzene and HSiCl3 at a molar ratio of 1:1 was mixed, and 2 wt% toluene initiator was added. After the catalyst bed temperature stabilized at 450 °C, the feed was introduced at a rate of 1.5 mL / min using a high-pressure metering pump. The feed was vaporized in a vaporizer at 260 °C before entering the reactor; the reaction pressure was controlled at 0.2 MPa. After 10 hours of continuous operation, samples were taken for GC analysis, and the yield of the product PTCS was calculated.

[0060] Examples 12-20 While keeping the type of initiator unchanged, the raw material molar ratio, the mass fraction of toluene initiator, the reaction temperature, and the reaction pressure in Example 11 were changed sequentially.

[0061] Comparing Examples 11-15, the yield of PTCS showed a trend of first increasing and then slowly decreasing as the raw material molar ratio increased. Considering the raw material cost, the preferred raw material molar ratio is 2:1.

[0062] Comparative Examples 15-20, as the mass fraction of toluene added as the initiator increases, the yield of PTCS first increases and then remains stable. Considering the actual production cost, the preferred mass fraction of toluene added as the initiator is 3 wt%.

[0063] Comparing Examples 14-19, the yield of PTCS gradually increases with increasing reaction pressure. When the reaction pressure is 0.3 MPa, the yield of PTCS is 90.7%. From the perspective of production safety and production cycle, a reaction pressure of 0.3 MPa is preferred.

[0064] Comparing Examples 11-20, higher temperatures resulted in faster reaction rates and shorter reaction times, while the PTCS yield also gradually increased. However, when the reaction temperature exceeded 550°C, severe carbonization of the raw materials led to severe blockage of the reaction apparatus, and the PTCS yield decreased drastically. Considering production safety and energy costs, the preferred reaction temperature was 530°C.

[0065] Based on previous investigations, the highest PTCS yield was 90.9% in Example 1. The preferred raw material molar ratio was 2:1; the preferred initiator toluene mass fraction was 3 wt%; the preferred reaction temperature was 530°C; and the preferred reaction pressure was 0.3 MPa.

[0066] IV. Summary of Experimental Conclusions Tables 1 and 2 summarize the key data of the above embodiments and comparative examples, respectively: Table 1. Screening data for catalysts and initiators in the gas-phase thermal condensation reaction of chlorobenzene and trichlorosilane. Table 2 Optimization data of gas-phase thermal condensation reaction conditions of chlorobenzene and trichlorosilane Note: The catalyst used was a 5 wt% Ni / SiO2 catalyst, and the amount of toluene added was calculated based on the total mass of the raw materials chlorobenzene and HSiCl3.

[0067] This application also proposes another experimental apparatus for the gas-phase condensation synthesis of phenyltrichlorosilane, mainly comprising a feed system, a reaction system, and a post-processing system. First, the pipeline is purged for 30 min with 99.999% nitrogen as the carrier gas at a flow rate of 10 mL / min. After removing air and moisture from the pipeline, chlorobenzene and trichlorosilane feed solutions are prepared separately, and then high-pressure injection pumps (SP-1 and SP-2) are used to deliver these two streams according to the volumetric flow ratio between the feeds. When an initiator or homogeneous catalyst needs to be added during the reaction, instead of setting a separate stream, these additives are pre-dissolved in a certain proportion in the HSiCl3 stream or the chlorobenzene stream before being fed into the reactor.

[0068] The reaction is carried out in a tubular furnace at a temperature of 450-620℃. The two raw materials are first mixed in mixer M-1, then vaporized in a preheater (PR-1) at a constant temperature of 260℃, and then enter the tubular furnace (R-1) to start the reaction. The pressure of the reaction system is regulated by a back pressure valve (BV-1).

[0069] After the reaction is complete, the tubular furnace heating is turned off. The gas stream after the reaction is cooled by the condenser (C-1) and then collects in the reaction liquid storage tank (S-1). There is a non-condensable gas outlet at the upper end of the storage tank, which is connected to an alkaline water washing bottle through a long hose for tail gas treatment or gas phase sampling and analysis. The lower end of the storage tank is connected to a needle valve (NV-1) for liquid product collection and gas phase sampling and analysis.

[0070] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for synthesizing phenyltrichlorosilane based on the α-elimination mechanism of trichlorosilane, characterized in that, Includes the following steps: Step 1: Preparation of the supported catalyst: Silica was selected as the support, and one of nickel, copper, cobalt, or iron was selected as the active metal component. The silica support was pretreated at high temperature to remove surface adsorbed water and impurities. An aqueous solution containing the active metal nitrate was uniformly impregnated onto the pretreated silica support using an equal-volume impregnation method. The impregnated silica support was allowed to stand and age, followed by drying. The dried precursor was calcined in an air atmosphere to decompose the metal salt into metal oxides. Finally, a reduction treatment was performed under a hydrogen or nitrogen-hydrogen mixed atmosphere to obtain the silica-supported metal catalyst. Step 2: Preparation of reaction raw materials: The molar ratio of the main raw materials chlorobenzene and trichlorosilane is controlled at 1:1-3:

1. After mixing the two raw materials, an initiator is added. The amount of initiator added is 1wt%-10wt% of the sum of the mass of trichlorosilane and chlorobenzene. Step 3, gas-phase thermal condensation reaction: The metal catalyst prepared in step 1 is filled into the isothermal section of the tubular furnace reactor. The mixed raw material liquid prepared in step 2 is sent into the vaporizer through a high-pressure metering pump. After being completely vaporized at 200-300℃, it enters the tubular furnace reactor to undergo a gas-phase condensation reaction. Step 4: Product Collection. The mixed gas after the reaction flows out of the reactor and is condensed into a liquid product by a condenser.

2. The method of synthesis of phenyltrichlorosilane based on the mechanism of alpha-elimination of trichlorosilane according to claim 1, characterized by the fact that: In step one, the silica carrier is selected as spherical silica gel with a particle size of 20-40 mesh, a specific surface area of ​​300-400 m² / g, and a pore volume of 0.8-1.2 cm³. 3 / g.

3. The method of synthesis of phenyltrichlorosilane based on the mechanism of alpha-elimination of trichlorosilane according to claim 1, characterized by the fact that: In step one, the loading of the active metal component in the total mass of the catalyst is 1wt%-10wt%.

4. The method for synthesizing phenyltrichlorosilane based on the α-elimination mechanism of trichlorosilane according to claim 1, characterized in that: In step one, the active metal component is nickel, and the initiator is toluene, forming a synergistic system of Ni / SiO2 catalyst and toluene.

5. The method for synthesizing phenyltrichlorosilane based on the α-elimination mechanism of trichlorosilane according to claim 1, characterized in that: In step two, the initiator is selected from one or a combination of several of toluene, chloroform, azobisisobutyronitrile, and benzoyl peroxide.

6. The method for synthesizing phenyltrichlorosilane based on the α-elimination mechanism of trichlorosilane according to claim 1, characterized in that: In step three, the reaction temperature in the tubular furnace reactor is 450-620℃ and the reaction pressure is 0.2-0.4MPa.

7. An apparatus for use in the method of any one of claims 1-6, characterized by This includes the feeding system, reaction system, and post-processing system; The feeding system includes two liquid feed lines and one gas purging line. The liquid feed lines use a micro-volume high-pressure injection pump to transport chlorobenzene and trichlorosilane raw material liquids. The reaction system includes a liquid mixer, a preheater, and a tubular furnace reactor. The liquid mixer is used to mix the two raw material liquids, and the preheater is used to vaporize the raw materials before they enter the tubular furnace to start the reaction. The pressure of the reaction system is regulated by a back pressure valve. After the reaction, the gas stream is cooled by a condenser and then collects in the reaction liquid storage tank. The upper end of the storage tank has a non-condensable gas outlet, which is connected to an alkaline water washing bottle through a long hose for tail gas treatment or gas phase sampling and analysis. The lower end of the storage tank is connected to a needle valve for liquid product collection and gas phase sampling and analysis.

8. The apparatus of claim 7, wherein: When an initiator or homogeneous catalyst is required in the reaction, instead of setting up a separate stream, these additives are dissolved in a certain proportion in the HSiCl3 stream or chlorobenzene stream before being fed into the reactor.

9. The apparatus of claim 7, wherein: The gas purging pipeline uses 99.999% nitrogen as the carrier gas, the purging flow rate is 10 mL / min, and the purging time is 30 min.

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