A purification method and purification device suitable for high-purity tetramethylsilane preparation

Abstract

The application discloses a purification method and a purification device suitable for preparation of high-purity tetramethylsilane, and the purification device comprises a raw material feeding system, a filtering and adsorbing system, a rectification and purification system and a discharge recovery system. The filtering and adsorbing system is divided into two parts. The first part is arranged behind the raw material feeding system and in front of the rectification and purification system, and comprises a solid-liquid separation device and a hydrolysis separation device. The second part is arranged in the rectification and purification system, behind a first rectification kettle and in front of a second rectification kettle, and is a low-boiling-point impurity adsorption separation device. In addition, the purification device is additionally provided with a circulating water device which is connected with an overflow heat area of the hydrolysis separation device and the rectification and purification system through an outer surrounding stainless steel circulating pipeline. The purification device has the characteristics of high-efficiency separation of low-boiling-point substances, low energy consumption, less circulation times and energy recycling.

Description

Technical Field

[0001] This invention relates to the field of semiconductor materials technology, and in particular to a purification method and apparatus suitable for the preparation of high-purity tetramethylsilane. Background Technology

[0002] Tetramethylsilane (4MS) is an important organosilicon material with wide applications in medicine, aerospace, construction, and machinery. 4MS is non-polar, chemically stable, and has a low boiling point at room pressure, ranging from 26.5℃ to 28℃. Ultra-high purity 4MS (over 99.99% by mass) can be used in the electronics industry as a precursor for chemical vapor deposition (CVD) or plasma-enhanced chemical vapor deposition (PECVD) to prepare high-quality silicon carbide thin films. Furthermore, 4MS can be used to prepare semiconductor silicon materials, low-dielectric-constant materials, plasma-polymerized organosilicon films, waterproof materials, and as a raw material for fumed silica.

[0003] Currently, there are two main methods for preparing 4MS: one is the organosilicon conversion method, and the other is the organosilicon low-boiling separation method. These two methods have several problems: 1. Separation and purification of low-boiling-point substances, especially those with boiling points close to 4MS, is difficult, with high energy consumption, many cycles, and complicated processes. 2. Temperature control is difficult to be precise, and the impurities after purification are complex. 3. It has high energy consumption and serious waste, which is not conducive to energy conservation, emission reduction and sustainable development. At the same time, the purification cost is also very high.

[0004] Therefore, there is an urgent need in the market for a purification method and purification device suitable for the preparation of high-purity tetramethylsilane that is efficient in separating low-boiling-point substances, has low energy consumption, requires fewer cycles, and allows for energy recovery and utilization. Summary of the Invention

[0005] The present invention aims to provide a purification method and apparatus suitable for the preparation of high-purity tetramethylsilane, which is efficient in separating low-boiling-point substances, has low energy consumption, requires fewer cycles, and allows for energy recovery and utilization.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a purification device suitable for the preparation of high-purity tetramethylsilane, the purification device comprising a raw material feeding system, a filtration and adsorption system, a distillation and purification system, and an emission recovery system. The filtration and adsorption system is divided into two parts. The first part is located after the raw material feeding system and before the distillation and purification system, and includes a solid-liquid separation device and a hydrolysis separation device. The second part is located in the distillation and purification system, after the first distillation vessel and before the second distillation vessel, and is a low-boiling-point impurity adsorption and separation device. In addition, the purification device is also equipped with a circulating water device that connects the hydrolysis separation device and the heat overflow area of ​​the distillation and purification system through an outer stainless steel circulating pipe. A method for manufacturing the above-mentioned apparatus and using it to purify high-purity tetramethylsilane includes the following stages: S1: Raw Material Preparation ① Raw material preparation: Prepare sufficient DMF, formic acid, methanol, zirconium oxychloride octahydrate, fumaric acid, microporous filter membrane with pore size of 0.20-0.25, molecular sieve with pore size of 0.55nm±0.02nm, hydrochloric acid aqueous solution with solute mass fraction of 10%, vacuum sealed container, and quartz container with double outer wall. S2: Hydrolysis Separation Device ① Fix the titration apparatus inside the quartz container and inject a 10% hydrochloric acid aqueous solution into the titration apparatus; ② Deionized water is injected into the double-walled quartz container and connected to a constant temperature circulating water device. The heat source of the constant temperature circulating water device comes from the heat overflow from the distillation kettle in the distillation purification system and the heat recovered by condensation. ③A heating device is installed at the bottom of the quartz container to obtain the required hydrolysis separation device; S3: Low-boiling-point impurity adsorption and separation device ① Mix DMF, zirconium dichloride octahydrate, fumaric acid, and formic acid in a mass ratio of 80:(9-10):(3.1-3.3):(32-34) and stir until homogeneous. Then place the mixture in a sealed environment under nitrogen protection and heat it to 135℃-140℃ for 4-5 hours to obtain a solid-liquid mixture containing a white solid. ② The solid-liquid mixture obtained in step ① is subjected to solid-liquid separation using the microporous filter membrane prepared in step ① of stage S1. The solid part is the solid product A to be processed. ③ The solid product A obtained in step ② is soaked in DMF and methanol until its mass no longer changes, then taken out and placed in a vacuum environment and heated to 135℃-145℃ until it is completely dried to obtain functional solid A; ④ The molecular sieve is placed in the first vacuum sealed container, and the part that does not pass through the sieve is connected to the bottom of the second vacuum sealed container. The second vacuum sealed container is filled with functional solid A and a discharge port is set at the bottom. The first vacuum sealed container and the second vacuum sealed container are connected in series to obtain a low boiling point impurity adsorption and separation device. S4: Assembly and Use ① The solid-liquid separation device is set after the raw material feeding system to separate solids and liquids, and the liquid portion is passed into the hydrolysis separation device; ② Connect the feed end of the hydrolysis separation device to the liquid part discharge end of the solid-liquid separation device. After the hydrolysis separation device is filled with liquid, hydrochloric acid aqueous solution is added dropwise and a water bath is heated to carry out the hydrolysis reaction of the liquid part. Then, the part with a boiling point below 30℃ is heated and distilled. After the distillation process is completed, the undistilled part is passed into the emission recovery system. Then, the distilled part is passed into the first distillation vessel of the rectification purification system. After one rectification, the fraction with a boiling point of 26.5℃-28℃ is collected. Then, the fraction is passed into the low boiling point impurity adsorption separation device. ③ The inlet of the low-boiling-point impurity adsorption and separation device is connected to the outlet of the first distillation kettle, and the outlet is connected to the feed of the second distillation kettle. The adsorption and separation products are then fed into the emission recovery system.

[0007] Compared with the prior art, the present invention, by adopting the above technical solutions, has the following advantages: (1) This invention, through solid-liquid separation, hydrolysis for impurity removal, molecular sieve adsorption and filtration for impurity removal, and targeted impurity removal with functional solid A, combined with conventional distillation purification technology, comprehensively and energy-efficiently removes impurities that are difficult to remove using conventional techniques. Among these methods, solid-liquid separation removes solid impurities, hydrolysis mainly removes compounds containing Si-Cl bonds and low-boiling-point impurities, molecular sieve adsorption and filtration mainly screens out small molecule impurities such as metal salt impurities, and targeted impurity removal with functional solid A mainly adsorbs substances such as isopentane that are extremely difficult to separate and have boiling points very close to tetramethylsilane and similar polarities, differing only in molecular structure. These impurity removal techniques do not require high energy; only hydrolysis requires heating to tens of degrees Celsius, which is very low compared to the cost of distillation.

[0008] (2) The series circulating water device of the present invention collects the heat generated by the distillation kettle and the recovery device and feeds back to the components in the reaction system that need to be heated or kept warm, so that the energy recovery and utilization rate of the whole system is significantly improved compared with the prior art, while ensuring the stability of the whole reaction system.

[0009] (3) Because each of the various impurity removal technologies has its own specific application, the impurity removal effect is more thorough and the energy consumption is lower. In the entire purification process, tetramethylsilane products with a purity of 7N grade (99.99999%) or higher can be obtained after 2-3 distillations, which is economical and efficient.

[0010] Therefore, the present invention has the characteristics of efficient separation of low-boiling-point substances, low energy consumption, few cycles, and energy recovery and utilization. Detailed Implementation Example 1

[0011] A purification apparatus suitable for the preparation of high-purity tetramethylsilane is disclosed. The apparatus includes a raw material feeding system, a filtration and adsorption system, a distillation and purification system, and an emission recovery system. The filtration and adsorption system is divided into two parts. The first part, located after the raw material feeding system and before the distillation and purification system, includes a solid-liquid separation device and a hydrolysis separation device. The second part, located after the first distillation vessel and before the second distillation vessel in the distillation and purification system, is a low-boiling-point impurity adsorption and separation device. Additionally, the purification apparatus includes a circulating water system that connects the hydrolysis separation device and the heat overflow area of ​​the distillation and purification system via an external stainless steel circulating pipe. A method for manufacturing the above-mentioned apparatus and using it to purify high-purity tetramethylsilane includes the following stages: S1: Raw Material Preparation ① Raw material preparation: Prepare sufficient DMF, formic acid, methanol, zirconium oxychloride octahydrate, fumaric acid, microporous filter membrane with pore size of 0.20-0.25, molecular sieve with pore size of 0.55nm±0.02nm, hydrochloric acid aqueous solution with solute mass fraction of 10%, vacuum sealed container, and quartz container with double outer wall. S2: Hydrolysis Separation Device ① Fix the titration apparatus inside the quartz container and inject a 10% hydrochloric acid aqueous solution into the titration apparatus; ② Deionized water is injected into the double-walled quartz container and connected to a constant temperature circulating water device. The heat source of the constant temperature circulating water device comes from the heat overflow from the distillation kettle in the distillation purification system and the heat recovered by condensation. ③A heating device is installed at the bottom of the quartz container to obtain the required hydrolysis separation device; S3: Low-boiling-point impurity adsorption and separation device ① Mix DMF, zirconium dichloride octahydrate, fumaric acid, and formic acid in a mass ratio of 80:(9-10):(3.1-3.3):(32-34) and stir until homogeneous. Then place the mixture in a sealed environment under nitrogen protection and heat it to 135℃-140℃ for 4-5 hours to obtain a solid-liquid mixture containing a white solid. ② The solid-liquid mixture obtained in step ① is subjected to solid-liquid separation using the microporous filter membrane prepared in step ① of stage S1. The solid part is the solid product A to be processed. ③ The solid product A obtained in step ② is soaked in DMF and methanol until its mass no longer changes, then taken out and placed in a vacuum environment and heated to 135℃-145℃ until it is completely dried to obtain functional solid A; ④ The molecular sieve is placed in the first vacuum sealed container, and the part that does not pass through the sieve is connected to the bottom of the second vacuum sealed container. The second vacuum sealed container is filled with functional solid A and a discharge port is set at the bottom. The first vacuum sealed container and the second vacuum sealed container are connected in series to obtain a low boiling point impurity adsorption and separation device. S4: Assembly and Use ① The solid-liquid separation device is set after the raw material feeding system to separate solids and liquids, and the liquid portion is passed into the hydrolysis separation device; ② Connect the feed end of the hydrolysis separation device to the liquid part discharge end of the solid-liquid separation device. After the hydrolysis separation device is filled with liquid, hydrochloric acid aqueous solution is added dropwise and a water bath is heated to carry out the hydrolysis reaction of the liquid part. Then, the part with a boiling point below 30℃ is heated and distilled. After the distillation process is completed, the undistilled part is passed into the emission recovery system. Then, the distilled part is passed into the first distillation vessel of the rectification purification system. After one rectification, the fraction with a boiling point of 26.5℃-28℃ is collected. Then, the fraction is passed into the low boiling point impurity adsorption separation device. ③ The inlet of the low-boiling-point impurity adsorption and separation device is connected to the outlet of the first distillation kettle, and the outlet is connected to the feed of the second distillation kettle. The adsorption and separation products are then fed into the emission recovery system.

[0012] The apparatus manufactured according to the method of this embodiment can obtain tetramethylsilane products with a purity of 7N grade (99.99999%) or higher through 2-3 distillations during the purification process of tetramethylsilane, which is economical and efficient.

[0013] The above description of the disclosed embodiments is merely intended to enable those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A purification apparatus suitable for the preparation of high-purity tetramethylsilane, the purification apparatus comprising a raw material feeding system, a filtration and adsorption system, a distillation and purification system, and an emission recovery system, characterized in that: The filtration and adsorption system is divided into two parts. The first part is located after the raw material feeding system and before the distillation and purification system, and includes a solid-liquid separation device and a hydrolysis separation device. The second part is located in the distillation and purification system, after the first distillation vessel and before the second distillation vessel, and is a low-boiling-point impurity adsorption and separation device. In addition, the purification device is also equipped with a circulating water device that connects the hydrolysis separation device and the heat overflow area of ​​the distillation and purification system through an outer stainless steel circulating pipe. A method for manufacturing the above-mentioned apparatus and using it to purify high-purity tetramethylsilane includes the following stages: S1: Raw Material Preparation ① Raw material preparation: Prepare sufficient DMF, formic acid, methanol, zirconium oxychloride octahydrate, fumaric acid, microporous filter membrane with pore size of 0.20-0.25, molecular sieve with pore size of 0.55nm±0.02nm, hydrochloric acid aqueous solution with solute mass fraction of 10%, vacuum sealed container, and quartz container with double outer wall. S2: Hydrolysis Separation Device ① Fix the titration apparatus inside the quartz container and inject a 10% hydrochloric acid aqueous solution into the titration apparatus; ② Deionized water is injected into the double-walled quartz container and connected to a constant temperature circulating water device. The heat source of the constant temperature circulating water device comes from the heat overflow from the distillation kettle in the distillation purification system and the heat recovered by condensation. ③A heating device is installed at the bottom of the quartz container to obtain the required hydrolysis separation device; S3: Low-boiling-point impurity adsorption and separation device ① Mix DMF, zirconium dichloride octahydrate, fumaric acid, and formic acid in a mass ratio of 80:(9-10):(3.1-3.3):(32-34) and stir until homogeneous. Then place the mixture in a sealed environment under nitrogen protection and heat it to 135℃-140℃ for 4-5 hours to obtain a solid-liquid mixture containing a white solid. ② The solid-liquid mixture obtained in step ① is subjected to solid-liquid separation using the microporous filter membrane prepared in step ① of stage S1. The solid part is the solid product A to be processed. ③ The solid product A obtained in step ② is soaked in DMF and methanol until its mass no longer changes, then taken out and placed in a vacuum environment and heated to 135℃-145℃ until it is completely dried to obtain functional solid A; ④ The molecular sieve is placed in the first vacuum sealed container, and the part that does not pass through the sieve is connected to the bottom of the second vacuum sealed container. The second vacuum sealed container is filled with functional solid A and a discharge port is set at the bottom. The first vacuum sealed container and the second vacuum sealed container are connected in series to obtain a low boiling point impurity adsorption and separation device. S4: Assembly and Use ① The solid-liquid separation device is set after the raw material feeding system to separate solids and liquids, and the liquid portion is passed into the hydrolysis separation device; ② Connect the feed end of the hydrolysis separation device to the liquid part discharge end of the solid-liquid separation device. After the hydrolysis separation device is filled with liquid, hydrochloric acid aqueous solution is added dropwise and a water bath is heated to carry out the hydrolysis reaction of the liquid part. Then, the part with a boiling point below 30℃ is heated and distilled. After the distillation process is completed, the undistilled part is passed into the emission recovery system. Then, the distilled part is passed into the first distillation vessel of the rectification purification system. After one rectification, the fraction with a boiling point of 26.5℃-28℃ is collected. Then, the fraction is passed into the low boiling point impurity adsorption separation device. ③ The inlet of the low-boiling-point impurity adsorption and separation device is connected to the outlet of the first distillation vessel, and the outlet is connected to the feed of the second distillation vessel. The adsorption and separation products are then fed into the emission recovery system.