System device and method for preparing methyltrimethoxysilane through alcoholysis of methyl trichlorosilane

Abstract

The invention discloses a system device and method for preparing methyltrimethoxysilane through alcoholysis of methyl trichlorosilane. The system device comprises an alcohol raw material storage tank, a first delivery pump, an alcohol preheater, an alcohol vaporizer, a supergravity reactor, a stripping tower, a second delivery pump, a condenser, a hydrogen chloride purification tower, a third delivery pump, an alcohol separation tower and a fourth delivery pump. The stripping tower is combined with the supergravity reactor to complete the continuous production process design of the alcoholysis process, namely along the path from the top of the stripping tower to the supergravity reactor, the concentrations of methyl trichlorosilane and hydrogen chloride in the system are gradually reduced, and the concentrations of methanol steam and the product methyltrimethoxysilane are gradually increased; the concentration gradient distribution effectively inhibits the occurrence of side reactions, and is helpful for improving the reaction selectivity and the product quality.

Description

Technical Field

[0001] This invention relates to the field of methyltrimethoxysilane synthesis technology. Specifically, it relates to a system apparatus and method for preparing methyltrimethoxysilane by alcoholysis of methyltrichlorosilane. Background Technology

[0002] Methyltrimethoxysilane, as a key crosslinking agent for silicone rubber, is widely used in the production of dealcoholized vulcanized silicone rubber due to its low cost and rapid reaction. Alcohololysis is the main production method for methyltrimethoxysilane, using methyltrichlorosilane and alcohols (such as methanol) as raw materials, undergoing the reactions shown in equations (1)-(4). Equation (1) is the main reaction, while equations (2)-(4) are side reactions. This method, by controlling the reaction conditions, can reduce the occurrence of side reactions while achieving a high conversion rate, effectively generating high-purity methyltrimethoxysilane.

[0003]

[0004] CH3OH+HCl→CH3Cl+H2O formula (2)

[0005]

[0006] Traditional methyltrichlorosilane alcoholysis processes mostly employ intermittent production methods, which have limitations such as long reaction cycles, extensive manual intervention, and large fluctuations in product quality.

[0007] For example, Chinese patent application CN101210029A discloses "a method for the alcoholysis of methylchlorosilane." This method involves adding excess alcohol to the alcoholysis reaction system of methylchlorosilane and alcohol to ensure complete reaction. Simultaneously, the excess alcohol also serves as a solvent for the reaction byproduct HCl. The acid content in the system is reduced by discharging the excess acidic alcohol, and the discharged excess alcohol is then used as the base alcohol for the next batch of alcoholysis reaction. Furthermore, two alcoholysis reactors are used alternately for the reaction. While this patented intermittent alcoholysis process with alternating operation of two reactors achieves a certain degree of continuous operation, it still struggles to balance high-efficiency conversion with product consistency, resulting in problems such as low reaction efficiency, high material loss, and significant fluctuations in product quality.

[0008] Continuous production can effectively overcome the limitations of intermittent production and is more suitable for industrial production. For example, Chinese patent application CN102372733A discloses a "continuous preparation method of methyltrialkoxysilane," which includes the following steps: alcoholysis, in-depth alcoholysis, neutralization, and distillation separation. This continuous production method of methyltrialkoxysilane uses a tower-bottom coupled falling film reactor for continuous liquid-phase alcoholysis and improves the purity of the product methyltrimethoxysilane through staged temperature control and alkaline neutralization treatment. This not only achieves continuous production and improves efficiency but also features a simple process and low equipment investment. However, this technology still has the following drawbacks: the process system structure is complex, there are many operating steps, and the inorganic impurities introduced by the neutralizing agent pose a challenge to product purification, making it difficult to meet the comprehensive requirements of continuous, high-purity, and green production.

[0009] Consequently, those skilled in the art have made further improvements. For example, Chinese patent application CN113861233A discloses "A preparation process and apparatus for methyltrimethoxysilane." This patented technology further proposes a solvent-containing gas-liquid two-phase continuous alcoholysis process, in which liquid methyltrichlorosilane is mixed with liquid methanol at high speed to undergo a preliminary liquid-liquid reaction; subsequently, the mixture and methanol vapor enter a stripping tower together, completing the entire alcoholysis process under high-temperature gas-liquid conditions and achieving the discharge of the byproduct HCl. This process improves continuity, but its drawbacks include: uneven contact of raw materials and the ease of side reactions; furthermore, the selection of the solvent system is not yet perfect, posing a risk of secondary pollution and increased energy consumption.

[0010] Therefore, developing a more efficient and high-purity continuous green alcoholysis process is of great significance for improving the economic benefits and environmental friendliness of producing methyltrimethoxysilane from methyltrichlorosilane. Summary of the Invention

[0011] The first technical problem this invention aims to solve is to provide a system for the alcoholysis of methyltrichlorosilane to produce methyltrimethoxysilane. This invention employs a stripping tower combined with a high-gravity reactor to achieve a continuous production process for the alcoholysis, effectively improving production efficiency and product quality. This invention constructs a closed-loop system including hydrogen chloride purification and recovery, and methanol separation and reuse. The byproduct hydrogen chloride in the reaction tail gas is effectively purified and collected through condensation and purification towers, and the byproduct can be recycled as an industrial raw material. Simultaneously, unreacted methanol and the entrained mixture of methyltrichlorosilane, methylmethoxychlorosilane, and methyltrimethoxysilane can be separated in a methanol separation tower and returned to the system for recycling. The entire process has low material loss and minimal waste discharge, significantly improving resource utilization efficiency and meeting the current technical requirements of the organosilicon industry for environmental protection and sustainable development.

[0012] The second technical problem this invention aims to solve is to provide a method for preparing methyltrimethoxysilane by alcoholysis of methyltrichlorosilane using the aforementioned system. This invention, through integrated process design, organically couples pretreatment, reaction, separation, and recovery units, significantly reducing traditional steps such as alcohol washing and distillation, lowering methanol and energy consumption, shortening the process flow, and reducing equipment investment and operating costs, making it suitable for continuous industrial production.

[0013] To solve the first technical problem mentioned above, the present invention adopts the following technical solution:

[0014] A system apparatus for the alcoholysis of methyltrichlorosilane to methyltrimethoxysilane, comprising:

[0015] Alcohol raw material storage tank, first transfer pump, alcohol preheater, alcohol vaporizer, high gravity reactor, stripping tower, second transfer pump, condenser, hydrogen chloride purification tower, third transfer pump, alcohol separation tower and fourth transfer pump;

[0016] The bottom material outlet of the alcohol raw material storage tank is connected in sequence to the bottom inlet of the first conveying pump, the alcohol preheater, and the alcohol vaporizer via pipelines; the top material inlet of the alcohol raw material storage tank is connected to the raw material liquid alcohol.

[0017] The upper gas outlet of the alcohol vaporizer is connected to the gas inlet of the hypergravity reactor via a pipe.

[0018] The top gas outlet of the supergravity reactor is connected to the lower gas inlet of the stripping tower via a pipeline.

[0019] The bottom liquid outlet of the stripping tower is connected to the second transfer pump and the liquid inlet of the supergravity reactor in sequence via pipelines; the top gas outlet of the stripping tower is connected to the lower liquid inlet of the condenser and the hydrogen chloride purification tower in sequence via pipelines.

[0020] The bottom liquid outlet of the hydrogen chloride purification tower is connected in sequence to the third transfer pump and the liquid inlet of the middle section of the alcohol separation tower via pipelines.

[0021] The top gas outlet of the alcohol separation tower is connected to the gas inlet of the supergravity reactor via a pipeline; the bottom liquid outlet of the alcohol separation tower is connected to the fourth transfer pump and the liquid inlet of the middle section of the stripping tower via pipelines.

[0022] To solve the second technical problem mentioned above, the present invention adopts the following technical solution:

[0023] A method for preparing methyltrimethoxysilane by alcoholysis of methyltrichlorosilane using the above-mentioned system and apparatus includes the following steps:

[0024] 1) Alcohol vaporization:

[0025] Freshly fed liquid alcohols flow out of the alcohol raw material storage tank and are sequentially sent to the alcohol preheater and alcohol vaporizer by the first transfer pump for alcohol vaporization pretreatment.

[0026] 2) Steam stripping alcoholysis:

[0027] Fresh alcohol vapors that have completed vaporization pretreatment are combined with circulating alcohol gas from the top of the alcohol separation tower and fed into a centrifugal reactor. There, they come into contact with the initial alcoholysis products from the stripping tower. The two phases are rapidly and thoroughly mixed to carry out the second-stage alcoholysis reaction. The product flows out of the liquid outlet of the centrifugal reactor, while the unreacted alcohol and hydrogen chloride mixture is fed from the gas outlet of the centrifugal reactor to the bottom gas inlet of the stripping tower. In the stripping tower, the gaseous feed from the bottom gas inlet comes into countercurrent contact with the two liquid feeds coming from the top to complete the initial alcoholysis reaction. The first of the two liquid feed streams is fresh liquid methyltrichlorosilane fed into the stripper from the liquid inlet at the top. The second stream is a mixture of methyltrichlorosilane, methylmethoxychlorosilane, and methyltrimethoxysilane carried by unreacted alcohols and hydrogen chloride byproducts from the gas outlet at the top of the stripper. This mixture is then sequentially fed into the condenser, hydrogen chloride purification tower, third transfer pump, alcohol separation tower, and fourth transfer pump before being recycled back to the liquid feed in the middle section of the stripper. The initial alcoholysis products from the stripper exit from the liquid outlet at the bottom of the stripper and are finally fed into the high gravity reactor.

[0028] 3) Hydrogen chloride purification and recovery:

[0029] The mixture after condensation by the condenser is fed into the hydrogen chloride purification tower for purification and recovery of hydrogen chloride. The by-product hydrogen chloride gas leaves from the top of the purification tower. The separated alcohol, methyltrichlorosilane, methylmethoxychlorosilane and methyltrimethoxysilane mixture liquid is sent into the alcohol separation tower by the third transfer pump.

[0030] 4) Alcohol separation and recycling:

[0031] The mixed liquid from the hydrogen chloride purification tower enters the alcohol separation tower from the middle section for distillation separation of alcohols with a mixture of methyltrichlorosilane, methylmethoxychlorosilane, and methyltrimethoxysilane. Gaseous alcohols leave from the top of the tower and merge with fresh alcohol vapors into the high gravity reactor. The mixture of methyltrichlorosilane, methylmethoxychlorosilane, and methyltrimethoxysilane leaves from the bottom of the tower and is fed into the middle section of the stripping tower via the fourth transfer pump, completing the material circulation.

[0032] Preferably, in step 1), the preheating temperature of the alcohol preheater is 50-60°C.

[0033] Preferably, in step 1), the heating temperature inside the alcohol vaporizer is 70-90°C.

[0034] Preferably, in step 2), the molar ratio of the fresh feed methyltrichlorosilane to methanol is 1:3-1:3.5, more preferably 1:3.1-1:3.3.

[0035] Preferably, in step 2), the rotational speed of the hypergravity reactor is 1500-2500 rpm; the temperature is 90℃-110℃, preferably 90℃-100℃.

[0036] Preferably, in step 2), the stripping tower adopts a packed tower, a rotating packed tower, or a falling film reaction tower structure.

[0037] Preferably, in step 2), the reaction temperature inside the stripping tower is 65-90℃.

[0038] Preferably, in step 3), the condensation temperature of the condenser is 40-50℃.

[0039] Any range described in this invention includes the endpoint, any value between the endpoints, and any subrange consisting of the endpoint or any value between the endpoints.

[0040] Unless otherwise specified, all raw materials used in this invention can be obtained commercially, and the equipment used in this invention can be conventional equipment in the relevant field or refer to existing technology in the relevant field.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1) Enhanced reaction and high product purity. This invention employs a two-stage stripping alcoholysis system constructed by connecting a stripping tower and a centrifugal reactor in series. The initial alcoholysis is rapidly completed through countercurrent contact between the raw material and steam in the stripping tower, while the centrifugal reactor provides a highly efficient mass transfer environment for further refining the initial alcoholysis products. Along the path from the top of the stripping tower to the centrifugal reactor, the concentrations of methyltrichlorosilane and hydrogen chloride gradually decrease, while the concentrations of methanol vapor and the product methyltrimethoxysilane gradually increase. This concentration gradient effectively suppresses side reactions, contributing to improved reaction selectivity and product quality. The entire reaction system possesses the combined advantages of rapid reaction rate, high conversion efficiency, and high product purity, making it suitable for high-quality continuous production.

[0043] 2) Closed-loop process with high resource utilization. This invention constructs a closed-loop system that includes hydrogen chloride purification and recovery, and methanol separation and reuse. The by-product hydrogen chloride in the reaction tail gas is effectively purified and collected through condensation and purification towers, and the by-product can be recycled as an industrial raw material. At the same time, the unreacted methanol and the mixture of entrained methyltrichlorosilane, methylmethoxychlorosilane, and methyltrimethoxysilane can be separated in a methanol separation tower and returned to the system for recycling. The entire process has low material loss and low waste liquid discharge, significantly improving resource utilization efficiency and meeting the current technical requirements of the organosilicon industry for environmental protection and sustainable development.

[0044] 3) Simple process, high efficiency and low consumption. This invention integrates pretreatment, reaction, separation and recovery units through process integration design, which significantly reduces traditional steps such as alcohol washing and distillation, reduces methanol and energy consumption, shortens the process flow, reduces equipment investment and operating costs, and is suitable for industrial continuous production. Attached Figure Description

[0045] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0046] Figure 1 This is a schematic diagram of the system apparatus for the alcoholysis of methyltrichlorosilane to produce methyltrimethoxysilane according to the present invention. Detailed Implementation

[0047] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0048] For ease of description, the use of terms such as "first," "second," etc., in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, such a combination should be considered non-existent and not within the scope of protection claimed by this invention.

[0049] As one aspect of the present invention, a system apparatus for the alcoholysis of methyltrichlorosilane to produce methyltrimethoxysilane is provided, comprising:

[0050] Alcohol raw material storage tank 1, first transfer pump 2, alcohol preheater 3, alcohol vaporizer 4, high gravity reactor 5, stripping tower 6, second transfer pump 7, condenser 8, hydrogen chloride purification tower 9, third transfer pump 10, alcohol separation tower 11 and fourth transfer pump 12;

[0051] The bottom material outlet of the alcohol raw material storage tank 1 is connected in sequence to the bottom inlet of the first conveying pump 2, the alcohol preheater 3 and the alcohol vaporizer 4 via pipelines; the top material inlet of the alcohol raw material storage tank 1 is connected to the raw material liquid alcohol.

[0052] The upper gas outlet of the alcohol vaporizer 4 is connected to the gas inlet of the hypergravity reactor 5 via a pipe.

[0053] The top gas outlet of the supergravity reactor 5 is connected to the lower gas inlet of the stripping tower 6 via a pipeline.

[0054] The bottom liquid outlet of the stripping tower 6 is connected to the second transfer pump 7 and the liquid inlet of the supergravity reactor 5 in sequence via pipelines; the top gas outlet of the stripping tower 6 is connected to the lower liquid inlet of the condenser 8 and the hydrogen chloride purification tower 9 in sequence via pipelines.

[0055] The bottom liquid outlet of the hydrogen chloride purification tower 9 is connected in sequence to the third transfer pump 10 and the middle section liquid inlet of the alcohol separation tower 11 via pipelines; its top gas outlet is the by-product hydrogen chloride gas outlet.

[0056] The top gas outlet of the alcohol separation tower 11 is connected to the gas inlet of the supergravity reactor 5 via a pipeline; the bottom liquid outlet of the alcohol separation tower 11 is connected to the fourth transfer pump 12 and the liquid inlet of the middle section of the stripping tower 6 via pipelines.

[0057] As another aspect of the present invention, a method for preparing methyltrimethoxysilane by alcoholysis of methyltrichlorosilane using the above-described system apparatus includes the following steps:

[0058] 1) Alcohol vaporization:

[0059] Freshly fed liquid alcohols flow out of the alcohol raw material storage tank and are sequentially sent to the alcohol preheater and alcohol vaporizer by the first transfer pump for alcohol vaporization pretreatment.

[0060] 2) Steam stripping alcoholysis:

[0061] The stripping tower and the centrifugal reactor together constitute a two-stage stripping alcoholysis reaction unit. Fresh alcohol vapors, after completing the vaporization pretreatment, are combined with circulating alcohol gas from the top of the alcohol separation tower and introduced into the centrifugal reactor. There, they contact the initial alcoholysis products from the stripping tower, and the two phases are rapidly and thoroughly mixed for the second-stage alcoholysis reaction. The high-purity alcohol vapors effectively ensure the selectivity and conversion rate of methyltrimethoxysilane. The product flows out from the liquid outlet of the centrifugal reactor, while the unreacted alcohol and hydrogen chloride mixture is introduced from the gas outlet of the centrifugal reactor to the bottom gas inlet of the stripping tower. In the process, the gaseous feed from the bottom gas inlet comes into countercurrent contact with two streams of liquid feed from top to bottom to complete the initial alcoholysis reaction; the first stream of the two liquid feeds is fresh liquid methyltrichlorosilane fed into the liquid inlet at the top of the stripper, and the other stream is a mixture of methyltrichlorosilane, methylmethoxychlorosilane, and methyltrimethoxysilane carried out by unreacted alcohols and byproduct hydrogen chloride from the gas outlet at the top of the stripper. It is then passed sequentially through the condenser, the hydrogen chloride purification tower, the third transfer pump, the alcohol separation tower, and the fourth transfer pump before being recycled back to the liquid feed in the middle section of the stripper.

[0062] The initial alcoholysis product of the stripping tower leaves from the bottom liquid outlet of the stripping tower and is finally fed into the supergravity reactor. Along the path from the top of the stripping tower to the supergravity reactor, the concentrations of methyltrichlorosilane and hydrogen chloride in the system gradually decrease, while the concentrations of alcohol vapor and product methyltrimethoxysilane gradually increase, forming a concentration gradient distribution, which can effectively suppress the occurrence of side reactions and improve product purity.

[0063] 3) Hydrogen chloride purification and recovery:

[0064] The mixture after condensation by the condenser is fed into the hydrogen chloride purification tower for purification and recovery of hydrogen chloride. The by-product hydrogen chloride gas leaves from the top of the purification tower. The separated alcohol, methyltrichlorosilane, methylmethoxychlorosilane and methyltrimethoxysilane mixture liquid is sent into the alcohol separation tower by the third transfer pump.

[0065] 4) Alcohol separation and recycling:

[0066] The mixed liquid from the hydrogen chloride purification tower enters the alcohol separation tower from the middle section for distillation separation of alcohols with a mixture of methyltrichlorosilane, methylmethoxychlorosilane, and methyltrimethoxysilane. Gaseous alcohols leave from the top of the tower and merge with fresh alcohol vapors before being fed into the high gravity reactor. The mixture of methyltrichlorosilane, methylmethoxychlorosilane, and methyltrimethoxysilane leaves from the bottom of the tower and is fed into the middle section of the stripping tower via the fourth transfer pump, completing the material circulation and effectively avoiding raw material loss.

[0067] In some embodiments of the present invention, in step 1), the preheating temperature of the alcohol preheater is 50-60°C.

[0068] In some embodiments of the present invention, in step 1), the heating temperature inside the alcohol vaporizer is 70-90°C.

[0069] In some embodiments of the present invention, in step 2), the molar ratio of the fresh feed methyltrichlorosilane to methanol is 1:3-1:3.5, preferably 1:3.1-1:3.3.

[0070] In some embodiments of the present invention, in step 2), the rotational speed of the hypergravity reactor is 1500-2500 rpm; the temperature is 90℃-110℃, preferably 90℃-100℃.

[0071] In some embodiments of the present invention, in step 2), the stripping tower adopts a packed tower, a rotating packed tower, or a falling film reaction tower structure.

[0072] In some embodiments of the present invention, in step 2), the reaction temperature inside the stripping tower is 65-90°C.

[0073] In some embodiments of the present invention, in step 3), the condensation temperature of the condenser is 40-50°C.

[0074] Example 1

[0075] The method for preparing methyltrimethoxysilane by alcoholysis of methyltrichlorosilane according to the present invention, using the above-described system apparatus, involves adding methyltrichlorosilane and methanol to the system at a molar ratio of 1:3.2. After the system stabilizes, the following operating conditions are adopted:

[0076] The outlet temperature of the methanol preheater is controlled at 50℃~60℃;

[0077] The methanol vaporizer temperature is controlled at 75℃;

[0078] The temperature of the stripping tower is controlled between 65℃ and 90℃;

[0079] The temperature of the hypergravity reactor was controlled at 95℃.

[0080] The temperature of the gas condenser at the top of the stripping tower is controlled at 40℃~50℃.

[0081] After the system reached steady-state operation, a continuous product of methyltrimethoxysilane was obtained. Analysis showed that the product purity was 99.3%, with residual Cl... - The content is 23 ppm.

[0082] Comparative Example 2

[0083] Example 1 was repeated, except that the supergravity reactor was omitted and only a stripping tower was used as the alcoholysis reaction unit.

[0084] Methyltrichlorosilane and methanol are added to the system at a molar ratio of 1:3.2. The liquid methyltrichlorosilane and methanol vapor undergo an alcoholysis reaction in a stripping tower in a countercurrent manner. After the system stabilizes, the following operating conditions are adopted:

[0085] The outlet temperature of the methanol preheater is controlled at 50℃~60℃;

[0086] The methanol vaporizer temperature is controlled at 75℃;

[0087] The temperature of the stripping tower is controlled between 65℃ and 95℃;

[0088] The temperature of the gas condenser at the top of the stripping tower is controlled at 40℃~50℃.

[0089] After the system reached steady-state operation, a continuous product of methyltrimethoxysilane was obtained. Analysis showed that the product purity was 94.4%, and the residual Cl... - The content is 262 ppm.

[0090] Examples 3-7

[0091] The process flow and steps are the same as in Example 1, but the parameters of the relevant processes have been adjusted, as shown in Table 1 below:

[0092] Table 1

[0093]

[0094] From the above, we can see that:

[0095] 1) In the above embodiments, Example 1 is within the process parameter range claimed by the present invention. The results of the example show that the product purity is high and the residual Cl... - It has a low content, low system energy consumption, and excellent overall performance.

[0096] 2) In the above examples, Comparative Example 2 maintained the alcoholysis reaction temperature within the optimal range of 65℃~95℃, omitting the hypergravity reactor and using only a stripping tower as the alcoholysis reaction unit. The results of the comparative example show that without the hypergravity reactor for mass transfer enhancement in the two-stage alcoholysis reaction, the product purity is significantly reduced, and the residual Cl... - The content increased significantly, which had a noticeable impact on product quality.

[0097] 3) In the above embodiments, the process operating parameters of Embodiments 3, 5, and 7 are not within the optimal range. The results from these embodiments show that increasing the methanol input leads to improvements in product purity and residual Cl. - The effect of reducing the content is limited, while increasing the system's recovery burden. Meanwhile, the increase in methanol vaporizer temperature and the slight increase in centrifugal reactor temperature have limited impact on product quality, but will have a greater impact on system energy consumption.

[0098] 4) In the above embodiments, the process operating parameters of Examples 4 and 6 are outside the range of process parameters claimed in this invention. The results from these examples show that when the methanol input is reduced to below the stoichiometric ratio, some methyltrichlorosilane is not alcoholyzed, and a larger amount of side reactions are prone to occur, significantly affecting product purity and residual Cl. - Content. Meanwhile, excessive increases in the temperature of the hypergravity reactor can easily trigger side reactions, leading to increased product impurities, decreased purity, and elevated acid value. Deviations from the process operating parameters claimed in this invention will significantly affect product quality.

[0099] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. In particular, the system embodiments are largely similar to the method embodiments, so the descriptions are relatively simple; relevant parts can be found in the descriptions of the method embodiments.

[0100] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments described in this specification. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0101] Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples, without contradiction. The above descriptions are merely embodiments of the embodiments described in this specification and are not intended to limit the embodiments of this specification. Various modifications and variations can be made to the embodiments described in this specification by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the embodiments described in this specification should be included within the scope of the claims of the embodiments described in this specification.

Claims

1. A system apparatus for the alcoholysis of methyltrichlorosilane to produce methyltrimethoxysilane, characterized in that, include: Alcohol raw material storage tank, first transfer pump, alcohol preheater, alcohol vaporizer, high gravity reactor, stripping tower, second transfer pump, condenser, hydrogen chloride purification tower, third transfer pump, alcohol separation tower and fourth transfer pump; The bottom material outlet of the alcohol raw material storage tank is connected in sequence to the bottom inlet of the first conveying pump, the alcohol preheater, and the alcohol vaporizer via pipelines; the top material inlet of the alcohol raw material storage tank is connected to the raw material liquid alcohol. The upper gas outlet of the alcohol vaporizer is connected to the gas inlet of the hypergravity reactor via a pipe. The top gas outlet of the supergravity reactor is connected to the lower gas inlet of the stripping tower via a pipeline. The bottom liquid outlet of the stripping tower is connected to the second transfer pump and the liquid inlet of the supergravity reactor in sequence via pipelines; the top gas outlet of the stripping tower is connected to the lower liquid inlet of the condenser and the hydrogen chloride purification tower in sequence via pipelines. The bottom liquid outlet of the hydrogen chloride purification tower is connected in sequence to the third transfer pump and the liquid inlet of the middle section of the alcohol separation tower via pipelines. The top gas outlet of the alcohol separation tower is connected to the gas inlet of the supergravity reactor via a pipeline; the bottom liquid outlet of the alcohol separation tower is connected to the fourth transfer pump and the liquid inlet of the middle section of the stripping tower via pipelines.

2. A method for preparing methyltrimethoxysilane by alcoholysis of methyltrichlorosilane using the system apparatus of claim 1, characterized in that, Includes the following steps: 1) Alcohol vaporization: Freshly fed liquid alcohols flow out of the alcohol raw material storage tank and are sequentially sent to the alcohol preheater and alcohol vaporizer by the first transfer pump for alcohol vaporization pretreatment. 2) Steam stripping alcoholysis: Fresh alcohol vapors that have completed vaporization pretreatment are combined with circulating alcohol gas from the top of the alcohol separation tower and fed into a centrifugal reactor. There, they come into contact with the initial alcoholysis products from the stripping tower. The two phases are rapidly and thoroughly mixed to carry out the second-stage alcoholysis reaction. The product flows out of the liquid outlet of the centrifugal reactor, while the unreacted alcohol and hydrogen chloride mixture is fed from the gas outlet of the centrifugal reactor to the bottom gas inlet of the stripping tower. In the stripping tower, the gaseous feed from the bottom gas inlet comes into countercurrent contact with the two liquid feeds coming from the top to complete the initial alcoholysis reaction. The first of the two liquid feed streams is fresh liquid methyltrichlorosilane fed into the stripper from the liquid inlet at the top. The second stream is a mixture of methyltrichlorosilane, methylmethoxychlorosilane, and methyltrimethoxysilane carried by unreacted alcohols and hydrogen chloride byproducts from the gas outlet at the top of the stripper. This mixture is then sequentially fed into the condenser, hydrogen chloride purification tower, third transfer pump, alcohol separation tower, and fourth transfer pump before being recycled back to the liquid feed in the middle section of the stripper. The initial alcoholysis products from the stripper exit from the liquid outlet at the bottom of the stripper and are finally fed into the high gravity reactor. 3) Hydrogen chloride purification and recovery: The mixture after condensation by the condenser is fed into the hydrogen chloride purification tower for purification and recovery of hydrogen chloride. The by-product hydrogen chloride gas leaves from the top of the purification tower. The separated alcohol, methyltrichlorosilane, methylmethoxychlorosilane and methyltrimethoxysilane mixture liquid is sent into the alcohol separation tower by the third transfer pump. 4) Alcohol separation and recycling: The mixed liquid from the hydrogen chloride purification tower enters the alcohol separation tower from the middle section for distillation separation of alcohols with a mixture of methyltrichlorosilane, methylmethoxychlorosilane, and methyltrimethoxysilane; gaseous alcohols leave from the top of the tower and merge with fresh alcohol vapors into the high gravity reactor; the mixture of methyltrichlorosilane, methylmethoxychlorosilane, and methyltrimethoxysilane leaves from the bottom of the tower and is fed into the middle section of the stripping tower via the fourth transfer pump, completing the material circulation.

3. The method for preparing methyltrimethoxysilane by alcoholysis according to claim 2, characterized in that: In step 1), the preheating temperature of the alcohol preheater is 50-60℃.

4. The method for preparing methyltrimethoxysilane by alcoholysis according to claim 2, characterized in that: In step 1), the heating temperature inside the alcohol vaporizer is 70-90℃.

5. The method for preparing methyltrimethoxysilane by alcoholysis according to claim 2, characterized in that: In step 2), the molar ratio of the fresh feed methyltrichlorosilane to methanol is 1:3-1:3.5, preferably 1:3.1-1:3.

3.

6. The method for preparing methyltrimethoxysilane by alcoholysis according to claim 2, characterized in that: In step 2), the rotational speed of the hypergravity reactor is 1500-2500 rpm; the temperature is 90℃-110℃, preferably 90℃-100℃.

7. The method for preparing methyltrimethoxysilane by alcoholysis according to claim 2, characterized in that: In step 2), the stripping tower adopts a packed tower, a rotating packed tower, or a falling film reaction tower structure.

8. The method for preparing methyltrimethoxysilane by alcoholysis according to claim 2, characterized in that: In step 2), the reaction temperature inside the stripping tower is 65-90℃.

9. The method for preparing methyltrimethoxysilane by alcoholysis according to claim 2, characterized in that: In step 3), the condensation temperature of the condenser is 40-50℃.

Images