Device and method for synthesizing and separating alkoxy silane
By designing a device for TEOS synthesis and separation, including reactors and flash tanks, using nitrogen replacement and flash evaporation technology, the problems of many side reactions, complex products and difficult separation in traditional TEOS production methods are solved, efficient and pure alkoxysilane synthesis and separation are achieved, and industrial development is promoted.
Patent Information
- Application Number
- CN202510133522.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-06
- Publication Date
- 2025-04-22
AI Technical Summary
The traditional TEOS production method has problems such as many side reactions, complex product components, and difficulty in separation. Moreover, the direct reaction of silanol to synthesize alkoxysilanes is not yet mature, making it difficult to promote industrial development.
Design a device including a reactor and a flash silane, connect it through a gas pipe, replace air with nitrogen, control the pressure in the reactor, combine it with atomizer and screen plate in the flash silane to achieve efficient synthesis and separation of silanol and alkoxysilane, and avoid complex filtration and distillation operations.
The efficiency of silanol is achieved in the direct synthesis of alkoxysilanes, with very few by-products, and the product purity and yield of more than 95.7% and above 92.5%, avoiding the risk of hydrolysis of alkoxysilanes in contact with air, and simplifying the pilot and industrial production processes.
Smart Images
Figure CN119857459A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a device and a method for synthesizing and separating alkoxysilane, belonging to the technical field of chemical equipment. Background Art
[0002] When the hydrogen atoms in the Si-H bond of silane are replaced by alkoxy groups, they are called alkoxysilanes, such as methoxysilane (TMOS), ethoxysilane (TEOS), propoxysilane, butoxysilane, etc. Among them, TEOS is the most representative and is widely used in daily chemical products, functional materials, biomedicine and other fields. High-purity TEOS is also used in high-end application fields such as optical fibers and semiconductors. The traditional TEOS production method uses silicon tetrachloride and ethanol to undergo ester exchange reaction. However, this reaction route has many side reactions, the product components are complex, and there are various azeotropic components, making separation particularly difficult. The synthesis of TEOS by direct reaction of silanols has been a hot topic in recent years. Under specific catalyst conditions, silanols are directly reacted to obtain four ethoxy groups grafted on silicon atoms. By controlling the conditions, the selectivity of TEOS can reach more than 95%. Due to the solid-liquid reaction between silicon powder and ethanol, the post-reaction treatment requires complex purification operations such as filtration, filter pressing, centrifugation or distillation, which increases the probability of TEOS hydrolysis due to frequent contact with air. At present, the synthesis of alkoxysilanes by direct reaction of silanols mostly remains in the laboratory stage, and the pilot-scale expansion and industrial production of this process are still immature. A pilot-scale synthesis and separation device and method are needed to promote the technology towards industrial development. Summary of the invention
[0003] In order to solve the problems existing in the prior art, the present invention provides a device and method for the synthesis and separation of alkoxysilanes, which can efficiently carry out the reaction of synthesizing alkoxysilanes from silanols and separate the products, avoiding a series of complicated operations such as filtration, filter pressing, centrifugation, and distillation, and also avoiding the problem of hydrolysis of alkoxysilanes due to contact with air caused by frequent loading and unloading of materials.
[0004] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: A device for synthesizing and separating alkoxysilane, comprising a reaction kettle and a flash tank; The reactor is connected to the flash tank through an air guide pipe and extends to the interior of the flash tank.
[0005] Preferably, a feed pipe, a discharge pipe, an air inlet pipe, an exhaust pipe, an electromagnetic exhaust valve, and a safety valve are provided outside the reactor.
[0006] Preferably, the feed pipe, discharge pipe, air inlet pipe and exhaust pipe are connected to the interior of the reactor and are controlled by a manual valve; the electromagnetic exhaust valve is also connected to a pressure sensor, the other end of which is connected to the top of the reactor, and the pressure in the reactor is adjusted by feedback control.
[0007] Preferably, a reactor jacket is further provided on the outside of the reactor, a circulating heating medium pipeline 1 is provided at the bottom of the reactor jacket, and a circulating heating medium pipeline 2 is provided at the top of the reactor jacket.
[0008] Preferably, the end of the air guide pipe inside the flash tank is connected to an atomizer, and sieve plates are staggered inside the flash tank, and the sieve plates are filled with molecular sieves.
[0009] Preferably, the number of the atomizers is 3 to 6, the number of the sieve plates is 3 to 6, and the molecular sieve is 3A molecular sieve.
[0010] Preferably, a saturated steam discharge pipe is provided at the top of the flash tank, and a saturated liquid discharge pipe is provided at the bottom of the flash tank; a flash tank jacket is also provided outside the flash tank, a circulating water pipeline 1 is provided at the bottom of the flash tank jacket, and a circulating heating medium pipeline 2 is provided at the top of the flash tank jacket.
[0011] A method for synthesizing and separating alkoxysilane using the device for synthesizing and separating alkoxysilane comprises the following steps: S1, the silanol mixed raw material enters the reactor through the reactor feed pipe; S2, nitrogen is filled into the reactor from the air inlet pipe to replace the air in the reactor, and the air is discharged from the exhaust pipe of the reactor; S3. After the reaction is completed, open the air pipe to pass the high-pressure saturated liquid into the flash tank; S4. Saturated steam is obtained from the low-boiling discharge pipe, and saturated liquid is obtained from the high-boiling discharge pipe.
[0012] Compared with the prior art, the advantages and positive effects of the present invention are: silanol directly synthesizes alkoxysilane, there are very few by-products in the product, the main impurities in the product after the reaction are unreacted alcohol, the saturated liquid formed by alkoxysilane and alcohol is sprayed out through an atomizer under pressure, and the unreacted solid impurities are discharged from the discharge pipe at the bottom of the reactor, so as to achieve the effect of solid-liquid separation. The saturated liquid entering the flash tank is affected by the environmental pressure change, and the low-boiling alcohol is rapidly vaporized to form saturated steam and discharged from the top of the flash tank. The atomizer arranged in the flash tank further reduces the particle size of the saturated steam. The saturated steam with a smaller particle size can better carry out mass transfer and heat transfer processes, so that the high-boiling alkoxysilane can be rapidly liquefied to form a saturated liquid, while the low-boiling alcohol is still separated from the product in the form of saturated steam. During the falling process of silane, the sieve plate filled with 3A molecular sieve is passed to filter out the water that has not yet vaporized, so as to avoid hydrolysis of alkoxysilane. At the same time, the bottom of the flash tank maintains a certain temperature, so that the silane can be further distilled and impurized. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 A schematic diagram of an apparatus for synthesizing and separating alkoxysilanes provided by the present invention.
[0014] Explanation of markings in the figure: 1. Reactor; 2. Flash tank; 3. Air guide pipe; 4. Reactor feed pipe; 5. Reactor discharge pipe; 6. Reactor air inlet pipe; 7. Reactor exhaust pipe; 8. Solenoid valve; 9. Pressure sensor; 10. Safety valve; 11. Reactor jacket circulating heating medium pipeline 1; 12. Reactor jacket circulating heating medium pipeline 2; 13. Saturated steam discharge pipe; 14. Saturated liquid discharge pipe; 15. Atomizer; 16. Sieve plate; 17. Flash tank jacket circulating water pipeline 1; 18. Flash tank jacket circulating water pipeline 2.
[0015] The present invention is further described below in conjunction with the accompanying drawings and specific implementation modes, but the protection scope of the present invention is not limited to the following implementation modes. DETAILED DESCRIPTION
[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0017] Example 1 like Figure 1As shown, the device for synthesizing and separating alkoxysilane comprises a reactor 1 and a flash tank 2. The reactor 1 is connected to the flash tank 2 through an air guide pipe 3 and extends to the inside of the flash tank. A feed pipe 4, a discharge pipe 5, an air inlet pipe 6, an exhaust pipe 7, an electromagnetic exhaust valve 8, and a safety valve 10 are arranged outside the reactor 1. The electromagnetic exhaust valve 8 is also connected to a pressure sensor 9. The other end of the pressure sensor is connected to the top of the reactor. The pressure in the reactor is adjusted by feedback control. A reactor jacket is also arranged outside the reactor. The bottom of the reactor jacket is A ring heating medium pipeline 11 is provided, a circulating heating medium pipeline 2 12 is provided on the upper part of the reactor jacket, three atomizers 15 are connected to the end of the air guide pipe 3 inside the flash tank 2, three sieve plates 16 are also staggered in the flash tank, and 3A molecular sieves are filled in the sieve plates, a saturated steam discharge pipe 13 is provided on the top of the flash tank 3, a saturated liquid discharge pipe 14 is provided at the bottom of the flash tank, a flash tank jacket is also provided outside the flash tank 3, a circulating water pipeline 17 is provided at the bottom of the flash tank jacket, and a circulating heating medium pipeline 2 18 is provided on the upper part of the flash tank jacket.
[0018] The above device is used to carry out the reaction, and the specific process is as follows: Open the stop valve of the reactor feed pipe 4, pass the silanol raw material into the reactor 1, open the stop valves of the reactor air inlet pipe 6 and the exhaust pipe 7, continue to pass nitrogen to replace the air in the reactor 1, after the replacement is completed, close all stop valves and pressurize the reactor to 0.5MPa, open the reactor jacket circulating heating medium pipeline 1 11 and pipeline 2 12, pass 200℃ heat transfer oil to heat the reactor, turn on the stirring device, as the reaction proceeds, the pressure in the reactor 1 rises rapidly, when the pressure rises to 8MPa, the pressure sensor 9 controls the electromagnetic exhaust valve 8 to release the pressure and stabilize the pressure at 8MPa, after the reaction is completed, open the circulating water pipeline 1 17 and pipeline 2 18 of the flash tank 3, pass 60℃ The flash tank is heated by circulating water, the stop valves of the air guide pipe 3 and the reactor air inlet pipe 6 are opened, and nitrogen is introduced to maintain a pressure difference of 6MPa. Under the action of the pressure difference, the saturated liquid in the reactor 1 enters the flash tank 2 through the air guide pipe 3, and is evenly dispersed by the atomizer 15 to form droplets with a particle size of 5μm. The low-boiling alcohol is quickly vaporized to form saturated steam and discharged from the saturated steam discharge pipe 13. The high-boiling alkoxysilane falls in the form of saturated liquid and is distributed on the sieve plate 16. The 3A molecular sieve on the sieve plate 16 can absorb the water entrained in the high-boiling alkoxysilane. The low-boiling alkoxysilane that is not vaporized in time continues to be heated and vaporized and rises. The falling high-boiling alkoxysilane finally gathers at the bottom of the flash tank 2 and is finally discharged through the bottom saturated liquid discharge pipe 14. The yield of the obtained silane is 92.5%, and the purity is 95.7%.
[0019] Example 2 Using the device of Example 1, open the stop valve of the reactor feed pipe 4, pass the silanol raw material into the reactor 1, open the stop valves of the reactor air inlet pipe 6 and the exhaust pipe 7, continue to pass nitrogen to replace the air in the reactor 1, close all stop valves after the replacement is completed, and pressurize the reactor to 0.5MPa, open the reactor jacket circulating heating medium pipeline 1 11 and pipeline 2 12, pass 200°C heat transfer oil to heat the reactor, turn on the stirring device, as the reaction proceeds, the pressure in the reactor 1 rises rapidly, when the pressure rises to 9MPa, the pressure sensor 9 controls the electromagnetic exhaust valve 8 to release the pressure and stabilize the pressure at 9MPa, after the reaction is completed, open the circulating water pipeline 1 17 and pipeline 2 18 of the flash tank 3, Circulating water at 60°C is introduced to heat the flash tank, the stop valves of the air duct 3 and the reactor air inlet pipe 6 are opened, and nitrogen is introduced to maintain a pressure difference of 7MPa. Under the action of the pressure difference, the saturated liquid in the reactor 1 enters the flash tank 2 through the air duct 3, and is evenly dispersed through the atomizer 15 to form droplets with a particle size of 3μm. The low-boiling alcohol is quickly vaporized to form saturated steam and discharged from the saturated steam discharge pipe 13. The high-boiling alkoxysilane falls in the form of saturated liquid and is distributed on the sieve plate 16. The 3A molecular sieve on the sieve plate 16 can absorb the moisture entrained in the high-boiling alkoxysilane. The low-boiling alkoxysilane that is not vaporized in time continues to be heated and vaporized and rises. The falling high-boiling alkoxysilane finally gathers at the bottom of the flash tank 2 and is finally discharged through the bottom saturated liquid discharge pipe 14. The yield of the obtained silane is 90.8%, and the purity is 97.3%.
[0020] Example 3 Using the device of Example 1, open the stop valve of the reactor feed pipe 4, pass the silanol raw material into the reactor 1, open the stop valves of the reactor air inlet pipe 6 and the exhaust pipe 7, continue to pass nitrogen to replace the air in the reactor 1, close all stop valves after the replacement is completed, and pressurize the reactor to 0.5MPa, open the reactor jacket circulating heating medium pipeline 1 11 and pipeline 2 12, pass 200°C heat transfer oil to heat the reactor, turn on the stirring device, as the reaction proceeds, the pressure in the reactor 1 rises rapidly, when the pressure rises to 10MPa, the pressure sensor 9 controls the electromagnetic exhaust valve 8 to release the pressure and stabilize the pressure at 10MPa, after the reaction is completed, open the circulating water pipeline 1 17 and pipeline 2 18 of the flash tank 3 , circulating water at 60°C is introduced to heat the flash tank, the stop valves of the air duct 3 and the reactor air inlet pipe 6 are opened, and nitrogen is introduced to maintain a pressure difference of 8MPa. Under the action of the pressure difference, the saturated liquid in the reactor 1 enters the flash tank 2 through the air duct 3, and is evenly dispersed through the atomizer 15 to form droplets with a particle size of 1μm. The low-boiling alcohol is quickly vaporized to form saturated steam and discharged from the saturated steam discharge pipe 13. The high-boiling alkoxysilane falls in the form of saturated liquid and is distributed on the sieve plate 16. The 3A molecular sieve on the sieve plate 16 can absorb the moisture entrained in the high-boiling. The low-boiling that is not vaporized in time continues to be heated and vaporized and rises. The falling high-boiling finally gathers at the bottom of the flash tank 2 and is finally discharged through the bottom saturated liquid discharge pipe 14. The obtained silane yield is 95.5% and the purity is 99.8%.
[0021] The above description is only an embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the application scope of the present invention shall be included in the protection scope of the present invention.
Claims
1. A device for synthesizing and separating alkoxysilanes, characterized in that: Including reactor and flash tank; The reactor is connected to the flash tank via an air guide pipe, which extends into the interior of the flash tank.
2. The device for synthesizing and separating alkoxysilane according to claim 1, characterized in that: The outside of the reactor is provided with a feed pipe, a discharge pipe, an air inlet pipe, an exhaust pipe, an electromagnetic exhaust valve and a safety valve.
3. The device for synthesizing and separating alkoxysilane according to claim 2, characterized in that: The feed pipe, discharge pipe, air inlet pipe and exhaust pipe are connected to the interior of the reactor and are controlled by a manual valve; the electromagnetic exhaust valve is also connected to a pressure sensor, the other end of which is connected to the top of the reactor, and the pressure in the reactor is adjusted by feedback control.
4. The device for synthesizing and separating alkoxysilane according to claim 1, characterized in that: A reactor jacket is also provided outside the reactor, a circulating heating medium pipeline 1 is provided at the bottom of the reactor jacket, and a circulating heating medium pipeline 2 is provided at the top of the reactor jacket.
5. The device for synthesizing and separating alkoxysilane according to claim 1, characterized in that: The end of the air guide pipe inside the flash tank is connected to an atomizer, and sieve plates are alternately arranged on both sides of the flash tank, and the sieve plates are filled with molecular sieves.
6. The device for synthesizing and separating alkoxysilane according to claim 5, characterized in that: The number of the atomizers is 3 to 6, the number of the sieve plates is 3 to 6, and the molecular sieve includes 3A molecular sieve.
7. The device for synthesizing and separating alkoxysilane according to claim 1, characterized in that: A saturated steam discharge pipe is provided on the top of the flash tank, and a saturated liquid discharge pipe is provided on the bottom of the flash tank; a flash tank jacket is also provided on the outside of the flash tank, a circulating water pipeline 1 is provided at the bottom of the flash tank jacket, and a circulating heating medium pipeline 2 is provided on the top of the flash tank jacket.
8. A method for synthesizing and separating alkoxysilane using the device for synthesizing and separating alkoxysilane according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, silanol mixed raw material enters the reactor through the reactor feed pipe; S2, nitrogen is filled into the reactor from the air inlet pipe to replace the air in the reactor, and the air is discharged from the exhaust pipe of the reactor; S3. After the reaction is completed, open the air pipe to pass the high-pressure saturated liquid in the reactor into the flash tank; S4. Saturated steam is obtained from the low-boiling discharge pipe, and saturated liquid is obtained from the high-boiling discharge pipe, thereby realizing the synthesis and separation of alkoxysilane.
9. The method according to claim 8, characterized in that The temperature in the reactor is 150~200℃. Before the reaction, the pressure in the reactor is controlled to be 0.5~2MPa after nitrogen is introduced to replace the air in the reactor. During the reaction, the pressure in the reactor is maintained at 8~12MPa by an electromagnetic exhaust valve. After the reaction, when the material is passed into the flash tank, the pressure in the reactor is maintained at 6~8MPa by nitrogen pressurization.
10. The method according to claim 8, characterized in that The temperature of the flash tank is 50~70℃, the pressure is normal pressure or micro pressure, the aperture of the atomizer inside the flash tank is 1~5mm, and the atomized particle size is 1~5μm through the pressure difference.