Organic silicon monomer synthesis process and fluidized bed reactor

Abstract

The invention discloses an organic silicon monomer synthesis process and a fluidized bed reactor, an upper expansion section and a lower cone section are respectively arranged at the top and the bottom of a reaction zone barrel to form the fluidized bed reactor, and an organic silicon monomer is synthesized in the fluidized bed reactor. The method comprises the following synthesis steps: silicon powder is brought into a fluidized bed reactor by chloromethane through a chloromethane inlet at the bottom of the fluidized bed reactor, and meanwhile, part of chloromethane gas enters the fluidized bed reactor through a chloromethane auxiliary inlet; organic silicon gas generated by the reaction in the reactor enters a finished product refining section through a finished product gas outlet, and heat generated by the reaction is taken away by a cooling medium in the U-shaped heat exchange tube; according to the process, the conversion per pass of chloromethane is high, the product selectivity is high, and the defects of a traditional organic silicon synthesis process are overcome.

Description

Technical Field

[0001] The invention belongs to the field of chemical synthesis process and reactor equipment design and manufacturing, and specifically relates to an organosilicon monomer synthesis process and a fluidized bed reactor. Background Art

[0002] Organosilicon refers to the organosilicon monomer dimethyldichlorosilane and its by-products. It is directly synthesized from silicon powder and methyl chloride. The main reaction is as follows: However, the actual process is more complicated and is accompanied by the following series of side reactions: Side reactions such as thermal decomposition, disproportionation, hydrolysis of chlorosilane, and coking may also occur during the reaction, making the reaction products more complex.

[0003] The reaction for synthesizing organosilicon monomers has the following characteristics: ① This reaction is a gas-solid-solid catalytic reaction. Under the reaction conditions, solid silicon powder first undergoes a solid-solid reaction with the catalyst copper to form an active contact Cu3Si, which then reacts with chloromethane gas at the active center. ② This process is a highly exothermic reaction with a reaction heat of 291.8 kJ·mol -1 Moreover, the reactant silicon powder is a poor conductor of heat, and the product chlorosilane is easily decomposed to form high-boiling products at high temperatures. Therefore, timely heat exchange during the reaction process is the technical key to the synthesis of silicone monomers.

[0004] One of the key pieces of equipment for organosilicon monomer production is the synthesis fluidized bed reactor, where gaseous methyl chloride reacts with solid silicon powder to produce organosilicon monomer. Methyl chloride gas enters the reactor from the bottom and reacts with the silicon powder inside to form organosilicon monomer. Heat generated by the reaction is removed by heat exchange tubes mounted within the reactor, and the resulting organosilicon gas exits the reactor through the upper outlet and enters the next refining stage.

[0005] Theoretically, the synthesis of organosilicon monomers is related to the following factors: (1) the diameter of the heat exchange tube of the fluidized bed reactor; the smaller the diameter of the heat exchange tube of the gas-solid phase fluidized bed reactor, the higher the heat transfer efficiency; the smaller the diameter of the heat exchange tube, the smaller the tube spacing can be, which is more conducive to uniform radial temperature distribution in the bed; however, if the diameter of the heat exchange tube is too small, the stiffness of the heat exchange tube will decrease. In order to maintain the stiffness of the heat exchange tube, a certain number of grids need to be arranged in the axial direction of the heat exchange tube. The grid plays two roles: ensuring the stiffness of the heat exchange tube and facilitating equipment processing; however, the setting of the grid also has two disadvantages: it reduces the flow area of the gas in the bed and reduces the fluidization effect of the silicon powder, which is not conducive to the uniform reaction. ; (2) The reaction temperature of the fluidized bed reactor; the higher the reaction temperature, the faster the reaction speed and the higher the utilization efficiency of the equipment; however, if the temperature is too high, the probability of producing tar and by-products will increase; (3) The appropriate initial silicon powder filling amount; if the initial silicon powder filling amount is too large, the gas resistance will be large, which is not conducive to initial fluidization; but if the filling amount is too small, the silicon powder content in the mobile phase will be low, the single-pass conversion rate of chloromethane will be reduced, and the production efficiency will be indirectly reduced; (4) Reasonable gas velocity in the reactor; if the gas velocity is greater than the carry-out speed of the silicon powder particles, the residence time of the gas in the reaction zone must be greater than the reaction residence time of chloromethane and silicon powder to ensure that the silicon powder reacts completely.

[0006] Therefore, the design of the synthesis process parameters for organosilicon monomers and the fluidized bed reactor requires a comprehensive balance among factors such as the heat exchange tube diameter, tube spacing, the presence of a grid, the initial charge of silicon powder, and gas flow rate. This balance requires complex modeling and optimization calculations across heat transfer, fluid mechanics, reaction kinetics, structural mechanics, and material mechanics to determine the final reaction temperature and pressure, gas flow rate, heat exchange tube diameter, the presence of a grid, tube spacing, and other equipment parameters.

[0007] Under certain organosilicon monomer synthesis process conditions and reactor equipment structure, if the single-pass conversion rate of chloromethane is high, the content of dimethyldichlorosilane in the product is high, the amount of silicon powder carried out at the reactor outlet is small, and the tar content is low, such process conditions and equipment structure are better process conditions and equipment.

[0008] At present, the shortcomings of the domestic organosilicon monomer synthesis process are as follows: the single-pass conversion rate of methyl chloride is low, usually between 30-45%, the dipotassium content in the product is generally around 86%, the amount of silicon powder carried out at the reactor outlet is large, the subsequent product separation load is high, and more energy is required.

[0009] The main reasons for the above shortcomings are: (1) The diameter of silicon powder particles is large, usually with an average particle size of about 80 microns. The silicon powder is carried out of the reactor by the gas before it is completely reacted; (2) Limited by the traditional fluidization theory, the gas velocity in the reactor is low, and the reactants and products stay in the reactor for too long, causing the raw materials and products to coke and decompose; (3) The initial silicon powder filling amount in the reactor is too large, the local fluidization effect in the reactor is poor, and the local temperature in the reactor is overheated; (4) In order to pursue heat exchange efficiency, the diameter of the selected heat exchange tube is too small, and the heat exchange tube is not stiff enough. It is necessary to set one or even multiple layers of grids to ensure the stiffness of the heat exchange tube, which reduces the fluidization effect in the reactor and even causes silicon powder blockage between the heat exchange tube and the grid, causing local overheating and coking; (5) The reaction temperature is relatively low, generally not exceeding 300°C, and the reaction speed is relatively slow. Summary of the Invention

[0010] The present invention aims to provide a process for synthesizing an organosilicon monomer and a fluidized bed reactor, which have better process parameters, a reasonable reactor structure, high heat transfer efficiency, a fast reaction speed, a short residence time, a uniform temperature distribution in the bed, a high single-pass conversion rate of methyl chloride, and a high selectivity for dimethyldichlorosilane, thereby overcoming the shortcomings of conventional organosilicon synthesis processes, improving the production efficiency of organosilicon, and reducing production costs.

[0011] The technical solution of the present invention is: a process for synthesizing an organosilicon monomer in a fluidized bed reactor. The synthesis steps are as follows: silicon powder is introduced into the fluidized bed reactor by methyl chloride through a methyl chloride inlet at the bottom of the fluidized bed reactor, and simultaneously, a portion of methyl chloride gas enters the fluidized bed reactor through a methyl chloride auxiliary inlet; methyl chloride reacts with silicon powder in the reactor, and the generated organosilicon gas is transported to a finished product refining section through a finished product gas outlet, while the heat generated by the reaction is removed by a cooling medium in a U-tube heat exchange tube; the synthesis conditions are: the reaction temperature in the fluidized bed reactor is controlled between 320-330°C, the reaction pressure is between 0.3-0.35 MPa, the average diameter of the silicon powder particles is between 20-30 microns, and the average gas velocity in the fluidized bed reaction zone is between 0.30 m / s and 0.65 m / s.

[0012] The synthesis of the organosilicon monomer is carried out in a fluidized bed reactor, which includes a reaction zone cylinder, an upper expansion section and a lower cone section. The upper expansion section and the lower cone section are respectively installed at the top and bottom of the reaction zone cylinder. A U-tube heat exchange tube is installed in the reaction zone cylinder. A finished gas outlet is provided at the top of the expansion section, a cooling medium inlet and outlet are provided on the side of the expansion section, a chloromethane inlet is provided at the bottom of the lower cone section, and a plurality of chloromethane gas auxiliary inlets are provided on the side of the lower cone section.

[0013] Furthermore, U-tube heat exchange tubes are installed in the reaction zone cylinder. The U-tubes are divided into several groups. Each group of U-tubes includes several straight tubes and U-shaped elbows. The cooling medium in the U-tubes is heat transfer oil.

[0014] Furthermore, no fixed grid is provided in the axial direction of the U-shaped tube.

[0015] Going a step further, a coating is designed on the U-bend.

[0016] The present invention has the following advantages: (1) a high single-pass conversion rate of methyl chloride, reaching more than 58%; (2) a high content of dimethyldichlorosilane in the product, exceeding 87%; (3) a small diameter of silicon powder particles, a multiplied specific surface area, and a significant increase in reaction speed; (4) an appropriate increase in the reaction temperature on the basis of the traditional fluidized bed reaction temperature, raising the average reaction temperature from 300°C to 325°C, and the reaction temperature exceeding the traditional reaction temperature by more than 20°C, further increasing the reaction speed, which will increase the reaction speed by at least 2 times; (5) a reasonable selection of the diameter and wall thickness of the U-shaped tube to ensure the rigidity of the U-shaped tube, and removing the fixed grid of the heat exchange tube to avoid silicon powder blockage between the heat exchange tube and the grid, causing local overheating. (6) Due to the increased reaction rate, the gas flow rate in the bed is high, which is greater than the silicon powder carry-out rate, and the residence time of the reactants and products is short, which reduces the probability of coking and side reactions. (7) The diameter of the silicon powder particles is reduced from the traditional 80 microns to 20 microns, so that the specific surface area of the particles will increase by 16 times. By reducing the particle diameter, the reaction rate will be increased by 32 times. (8) Several auxiliary inlets for chloromethane gas are set on the side of the lower vertebral segment. These auxiliary inlets ensure that the chloromethane gas has a better uniform distribution in the radial direction of the fluidized bed, thereby improving the one-way conversion rate of chloromethane. (9) A coating is designed on the U-shaped elbow to enhance the wear resistance of the heat exchange tube and extend the service life of the elbow. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the fluidized bed reactor of the present invention.

[0018] In the figure: 1 reaction zone cylinder, 2 cooling medium inlet, 3 cooling medium outlet, 4 upper expansion section, 5 finished gas outlet, 6 U-tube heat exchange tube, 7 U-shaped elbow, 8 lower cone section, 9 chloromethane auxiliary inlet, 10 chloromethane inlet. DETAILED DESCRIPTION

[0019] Below in conjunction with specific embodiment, the present invention is described in further detail.Should be understood that these embodiments are only for illustrating the present invention, but not for limiting the scope of the invention in any way.In order to highlight the innovation of the present invention and narrate simply, general general technology is omitted in this embodiment, as necessary valve on pipeline, instrument interface, audition port, manhole, support etc. on equipment are not explained, those of ordinary skill in the industry can carry out necessary design according to common sense, also can make many variations and improvements, for example, change feed metering mode, adjust, increase or decrease the mouth of the pipe of reactor, all these variations, adjustments, improvements should be considered as protection scope of the present invention.

[0020] The design and calculation of a fluidized bed involves the iterative solution of a complex set of nonlinear equations. Currently, designing entirely according to the modeling and joint solution method presents mathematical difficulties. However, with years of design and production experience, we can provide good initial values, simplify the calculation method, and perform rapid design calculations.

[0021] The design and selection of the organosilicon monomer synthesis process and fluidized bed reactor of the present invention follow the following rapid simulation design steps: based on many years of design and production experience, initial values such as silicon powder particle diameter, fluidized bed diameter, heat exchange tube specifications, heat exchange tube length, reaction temperature, and pressure are selected according to the production scale; the gas flow rate inside the fluidized bed reactor is calculated; the minimum fluidization velocity and carry-out velocity are calculated; the residence time of the gas in the reaction zone is calculated, requiring the gas residence time to be greater than the residence time of the silicon powder reaction; the theoretical heat exchange area is calculated, requiring the actual heat exchange area to be greater than the theoretical heat exchange area; the fluid resistance on the heat transfer oil side is calculated, requiring the fluid resistance on the heat transfer oil side to be less than the head of the hot oil delivery pump; the stiffness of the heat exchange tube is calculated, and if the stiffness is insufficient, the diameter or wall thickness of the heat exchange tube is increased; and the above calculation steps are repeated until all constraints are met.

[0022] like Figure 1 As shown, the synthesis of the organosilicon monomer is carried out in a fluidized bed reactor, which includes a reaction zone cylinder 1, an upper expansion section 4 and a lower cone section 8. The upper expansion section 4 and the lower cone section 8 are respectively installed at the top and bottom of the reaction zone cylinder 1, a U-tube heat exchange tube 6 is installed in the reaction zone cylinder 1, a finished gas outlet 5 is provided at the top of the upper expansion section 4, a cooling medium inlet 2 and a cooling medium outlet 3 are provided on the side of the upper expansion section 4, a chloromethane inlet 10 is provided at the bottom of the lower cone section 8, and a plurality of chloromethane gas auxiliary inlets 9 are provided on the side of the lower cone section 8.

[0023] Furthermore, U-tube heat exchange tubes 6 are installed in the reaction zone cylinder 1 and are divided into several groups. Each group of U-tubes includes several straight tubes and U-shaped elbows 7. The cooling medium in the U-tubes is heat transfer oil.

[0024] Furthermore, no fixed grid is provided in the axial direction of the U-shaped tube.

[0025] Furthermore, a coating is designed on the U-bend 7 .

[0026] Example 1: 300,000 tons / year organosilicon monomer synthesis process and fluidized bed reactor The simulation design process of the 300,000 tons / year organic silicon monomer synthesis process and fluidized bed reactor is as follows: (1) Design initial values: average pressure in the fluidized bed reactor is 0.3 MPa, average reaction temperature is 325℃, methyl chloride feed rate is 63750 kg / h, average silicon powder particle size is 20 μm, inlet and outlet temperatures of thermal oil are 250℃ and 285℃, thermal oil flow rate is 1800 m3 / h, thermal oil pump head is 140 m; the diameter of the reaction zone cylinder is 4 m, the diameter of the upper expansion section cylinder is 5.6 m, the specification of the U-tube heat exchange tube is Φ89×7.5, the length of the straight section of the U-tube is 12 m, the number of U-tubes is 414, divided into 23 groups, the center distance of the U-tube is 0.171 m, and no fixed grid is set along the axial direction of the U-tube.

[0027] (2) Calculate the gas velocity in the fluidized bed reactor: upper reaction zone: 0.39 m / s, lower reaction zone: 0.557 m / s, expansion section: 0.182 m / s.

[0028] (3) Calculation of minimum fluidization velocity and carry-out velocity: When the average particle diameter of silicon powder is 80 μm, the minimum fluidization velocity is 0.0051 m / s and the carry-out velocity is 0.259 m / s. The average particle diameter of silicon powder actually selected is 20 μm, and its minimum fluidization velocity and carry-out velocity must be less than the above calculated values.

[0029] (4) Calculate the residence time of the gas in the reaction zone: the length of the reaction zone (i.e. the length of the straight section of the U-tube): 12 meters; calculate the residence time of the gas based on the gas velocity at the bottom of the reaction zone, 12 / 0.557=21.5 seconds, the gas residence time is greater than the silicon powder reaction residence time, that is, under the set gas operating conditions, the goal of complete reaction of the silicon powder in the reaction zone is met.

[0030] (5) Calculate the theoretical heat exchange area of the fluidized bed reactor: According to the operating conditions, the calculated theoretical heat exchange area is 1000.5 square meters; according to the actual number and specifications of the heat exchange tubes, the calculated actual heat exchange area is 1388.1 square meters; the actual heat exchange area is larger than the theoretically calculated heat exchange area, that is, the heat exchange area is sufficient to ensure that the reaction heat is removed from the fluidized bed reactor in a timely manner.

[0031] (6) Calculate the fluid resistance on the heat transfer oil side: In the fluidized bed, each group of U-tubes has 18 straight tubes with a total length of 216 meters, 17 180-degree elbows, and 2 inlet and outlet tees. Considering that the heat transfer oil will be used for a long time, it is assumed that the relative roughness of the U-tube heat exchange tube is 0.2 mm and the heat transfer oil is in a turbulent state. The calculated resistance on the heat transfer oil side is 96 meters of water column and the head of the heat transfer oil pump is 140 meters, which is sufficient to ensure that the heat transfer oil overcomes the resistance in the fluidized bed.

[0032] (7) Calculate the stiffness of the heat exchange tube: Calculate the stiffness based on the operating temperature, gas flow rate, length and specifications of the U-tube heat exchange tube. If the stiffness meets the requirements, there is no need to set a grid.

[0033] Through simulation design, the parameters of the 300,000 tons / year organic silicon monomer synthesis process and fluidized bed reactor are as follows: the fluidized bed reactor includes a reaction zone cylinder, an upper expansion section and a lower cone section. The diameter of the reaction zone cylinder is 4 meters and the diameter of the upper expansion section is 5.6 meters. U-tube heat exchange tubes are installed in the reaction zone cylinder. The U-tube heat exchange tubes are divided into 23 groups. Each group of U-tube heat exchange tubes contains 18 straight tubes. The specification of the U-tube heat exchange tubes is Φ89×7.5. The length of the straight tube section of the U-tube heat exchange tube is 12 meters. The center distance of the U-tube heat exchange tubes is 0.17 1 meter, and no fixed grid is set along the axial direction of the U-tube heat exchange tube; wherein, the reaction temperature in the fluidized bed reactor is controlled at 325℃, and the reaction pressure is 0.3MPa; the average particle size of the silicon powder is 20 microns; the gas flow rate in the upper reaction zone of the fluidized bed is 0.39 m / s, the gas flow rate in the lower reaction zone is 0.557 m / s, and the gas flow rate in the expansion section is 0.182 m / s; wherein, the chloromethane feed rate is 63750 kg / h, the inlet and outlet temperatures of the thermal oil are 250℃ and 285℃, the thermal oil flow rate is 1800 cubic meters / h, and the thermal oil pump head is 140m.

[0034] During production, silicon powder is brought into the fluidized bed reactor by methyl chloride through the methyl chloride inlet at the bottom of the lower cone section. At the same time, part of the methyl chloride gas enters the fluidized bed reactor through the methyl chloride auxiliary inlet. In the fluidized bed reactor, methyl chloride reacts with silicon powder, and the organic silicon gas generated by the reaction is sent to the finished product refining section through the finished product gas outlet. The heat generated by the reaction is carried away by the cooling medium of the U-tube heat exchange tube.

[0035] The operating results of the 300,000 tons / year organosilicon monomer synthesis process and fluidized bed reactor are as follows: the single-pass conversion rate of methyl chloride is 60%; the product composition is 89% dimethyldichlorosilane, 5% monomethyltrichlorosilane, 2.5% trimethylmonochlorosilane, 1% monomethyldichlorosilane, 0.4% dimethylmonochlorosilane, 0.1% tetramethylsilane, and 2% high-boiling substances.

[0036] Example 2: 200,000 tons / year organosilicon monomer synthesis process and fluidized bed reactor The simulation design process of the 200,000 tons / year organosilicon monomer synthesis process and fluidized bed reactor is as follows: (1) Initial design values: average pressure in the fluidized bed reactor is 0.32 MPa, average reaction temperature is 323°C, methyl chloride feed rate is 42,500 kg / h, average silicon powder particle size is 20 μm, inlet and outlet temperatures of thermal oil are 250°C and 285°C, thermal oil flow rate is 1,200 m3 / h, and thermal oil pump head is 140 m; the diameter of the reaction zone cylinder is 3.4 m, the diameter of the upper expansion section cylinder is 4.2 m, the specification of the U-tube heat exchange tube is Φ89×7.5, the length of the straight section of the U-tube heat exchange tube is 12.3 m, the number of U-tube heat exchange tubes is 280, divided into 20 groups, the center distance of the U-tube heat exchange tube is 0.172 m, and no fixed grid is set along the axial direction of the U-tube heat exchange tube.

[0037] (2) Calculate the gas velocity in the fluidized bed reactor: upper reaction zone: 0.327 m / s, lower reaction zone: 0.466 m / s, expansion section: 0.222 m / s.

[0038] (3) Calculation of minimum fluidization velocity and carry-out velocity: When the average particle diameter of silicon powder is 80 μm, the results are: minimum fluidization velocity 0.0051 m / s, carry-out velocity 0.257 m / s; the actual average diameter of silicon powder particles selected is 20 μm, and its minimum fluidization velocity and carry-out velocity must be less than the above calculated values.

[0039] (4) Calculate the residence time of the gas in the reaction zone: The length of the reaction zone (i.e., the length of the straight section of the U-tube heat exchange tube (6)) is 12.3 meters. The gas residence time is calculated based on the gas velocity at the bottom of the reaction zone, 12.3 / 0.466=26.4 seconds. The gas residence time is greater than the silicon powder reaction residence time. In other words, under the set gas operating conditions, the goal of complete reaction of the silicon powder in the reaction zone is met.

[0040] (5) Calculation of the theoretical heat exchange area of the fluidized bed reactor: Based on the operating conditions, the calculated theoretical heat exchange area is 739.3 square meters; based on the actual number and specifications of the heat exchange tubes, the calculated actual heat exchange area is 962.4 square meters; the actual heat exchange area is larger than the theoretically calculated heat exchange area, that is, the heat exchange area is sufficient to ensure that the reaction heat is removed from the fluidized bed reactor in a timely manner.

[0041] (6) Calculate the fluid resistance on the heat transfer oil side: In the fluidized bed, each group of U-tube heat exchange tubes has 14 straight tubes with a total length of 172.2 meters, 13 180-degree elbows, and 2 inlet and outlet tees. Considering that the heat transfer oil will be used for a long time, it is assumed that the relative roughness of the U-tube heat exchange tube is 0.2 mm and the heat transfer oil is in a turbulent state. The calculated resistance on the heat transfer oil side is 39 meters of water column and the head of the heat transfer oil pump is 140 meters, which is sufficient to ensure that the heat transfer oil overcomes the resistance in the fluidized bed.

[0042] (7) Calculate the stiffness of the heat exchange tube: Calculate the stiffness based on the operating temperature, gas flow rate, length and specifications of the U-tube heat exchange tube. If the stiffness meets the requirements, there is no need to set a grid.

[0043] Through simulation design, the parameters of the 200,000 tons / year organic silicon monomer synthesis process and fluidized bed reactor are as follows: the organic silicon fluidized bed reactor includes a reaction zone cylinder, an upper expansion section and a lower cone section. The diameter of the reaction zone cylinder is 3.4 meters and the diameter of the upper expansion section is 4.2 meters. U-tube heat exchange tubes are installed in the reaction zone cylinder. The U-tube heat exchange tubes are divided into 20 groups. Each group of U-tube heat exchange tubes contains 14 straight tubes. The cooling medium in the U-tube heat exchange tubes is heat transfer oil. The specifications of the U-tube heat exchange tubes are Φ89×7.5. The length of the straight tube section of the U-tube heat exchange tube is 12.3 meters. The center distance between the U-tube heat exchange tubes is 0.172 meters, and no fixed grid is set along the axial direction of the U-tube heat exchange tubes; the reaction temperature in the fluidized bed reactor is controlled at 323°C, and the reaction pressure is 0.32MPa; the average particle size of the silicon powder is 20 microns; the gas flow rate in the upper reaction zone of the fluidized bed is 0.327 m / s, the gas flow rate in the lower reaction zone is 0.466 m / s, and the gas flow rate in the expansion section is 0.222 m / s; the chloromethane feed rate is 42,500 kg / h, the inlet and outlet temperatures of the thermal oil are 250°C and 285°C, the thermal oil flow rate is 1,200 cubic meters / h, and the thermal oil pump head is 140m.

[0044] During production, silicon powder is brought into the fluidized bed reactor by methyl chloride through the methyl chloride inlet at the bottom of the lower cone section. At the same time, part of the methyl chloride gas enters the fluidized bed reactor through the methyl chloride auxiliary inlet. In the fluidized bed reactor, methyl chloride reacts with silicon powder, and the organic silicon gas generated by the reaction is sent to the finished product refining section through the finished product gas outlet. The heat generated by the reaction is carried away by the cooling medium of the U-tube heat exchange tube.

[0045] The operating results of the 200,000 tons / year organosilicon monomer synthesis process and fluidized bed reactor are as follows: single-pass conversion rate of methyl chloride is 59.5%; product composition: dimethyldichlorosilane 87.23%, monomethyltrichlorosilane 5.27%, trimethylmonochlorosilane 3.38%, monomethyldichlorosilane 0.98%, dimethylmonochlorosilane 0.38%, tetramethylsilane 0.10%, and high-boiling substances 2.00%.

[0046] As can be seen from Examples 1 and 2, the organosilicon monomer is synthesized in a fluidized bed reactor. The synthesis steps are as follows: silicon powder is introduced into the fluidized bed reactor by methyl chloride through the methyl chloride inlet at the bottom of the fluidized bed reactor. Simultaneously, a portion of methyl chloride gas enters the fluidized bed reactor through an auxiliary methyl chloride inlet; within the reactor, the methyl chloride reacts with the silicon powder, and the generated organosilicon gas is transported to the finished product refining section through the finished product gas outlet. The heat generated by the reaction is removed by the cooling medium in the U-tube heat exchange tube. The synthesis conditions are as follows: the reaction temperature in the fluidized bed reactor is controlled between 320-330°C, the reaction pressure is between 0.3-0.35 MPa, the average diameter of the silicon powder particles is between 20-30 microns, and the average gas velocity in the fluidized bed reaction zone is between 0.30 m / s and 0.65 m / s.

Claims

1. A process for synthesizing an organosilicon monomer in a fluidized bed reactor, characterized in that Its synthesis steps are as follows: silicon powder is brought into the fluidized bed reactor by methyl chloride through the methyl chloride inlet at the bottom of the fluidized bed reactor, and at the same time, part of the methyl chloride gas enters the fluidized bed reactor through the methyl chloride auxiliary inlet; in the reactor, the methyl chloride reacts with the silicon powder, and the organic silicon gas generated by the reaction is sent to the finished product refining section through the finished product gas outlet, and the heat generated by the reaction is carried away by the cooling medium in the U-tube heat exchange tube.

2. The process for synthesizing an organosilicon monomer according to claim 1, wherein Its synthesis conditions are: the reaction temperature in the fluidized bed reactor is controlled between 320-330°C, the reaction pressure is between 0.3-0.35 MPa; the average diameter of the silicon powder particles is between 20-30 microns; in the fluidized bed reaction zone, the average gas flow rate in the bed is between 0.30 m / s and 0.65 m / s.

3. A fluidized bed reactor for synthesizing organosilicon monomers, characterized by: The fluidized bed reactor includes a reaction zone cylinder, an upper expansion section and a lower cone section. The upper expansion section and the lower cone section are respectively installed at the top and bottom of the reaction zone cylinder. A U-tube heat exchange tube is installed in the reaction zone cylinder. A finished gas outlet is set at the top of the expansion section, a cooling medium inlet and outlet are set on the side of the expansion section, a chloromethane inlet is set at the bottom of the lower cone section, and a plurality of chloromethane gas auxiliary inlets are set on the side of the lower cone section.

4. The fluidized bed reactor for synthesizing organosilicon monomers according to claim 3, characterized in that: U-shaped heat exchange tubes are installed in the reaction zone cylinder. The U-shaped tubes are divided into several groups. Each group of U-shaped tubes contains several straight tubes and U-shaped elbows. The cooling medium in the U-shaped tubes is heat transfer oil.

5. The fluidized bed reactor for synthesizing organosilicon monomers according to claim 4, characterized in that: No fixed grid is provided in the axial direction of the U-shaped tube.

6. The fluidized bed reactor for synthesizing organosilicon monomers according to claim 4, characterized in that: Design coating on U-bend.

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