Multi-stage continuous esterification reaction treatment equipment

Abstract

Multi-stage continuous esterification reaction treatment equipment is used for producing methyltrimethoxysilane by taking methyl trichlorosilane and methanol as raw materials, and comprises a first esterification kettle, a second esterification kettle, a third esterification kettle, a neutralization reaction kettle, a centrifugal separation device and a rectification purification device which are communicated in sequence. The equipment has the advantages of simple reaction condition control, low equipment investment and maintenance cost, high flexibility and the like.

Description

Technical Field

[0001] The present invention relates to a multi-stage continuous esterification reaction treatment device, and specifically to a continuous esterification reaction treatment device for producing methyltrimethoxysilane using methyltrichlorosilane and methanol as raw materials, belonging to the technical field of methyltrimethoxysilane production equipment. Background Art

[0002] Existing equipment for producing methyltrimethoxysilane using methyltrichlorosilane and methanol as raw materials, as shown in the Chinese invention patent application "Publication No.: CN18873958A; Publication Date: November 1, 2024; Title: A Methyltrimethoxysilane Production Device and Production Method", the esterification reaction of methyltrichlorosilane and methanol is carried out in a single reactor (reactive distillation column), and only one reactive distillation column is used to achieve the main reaction. There are defects such as high reaction control difficulty (parameters such as temperature, pressure, and residence time need to be precisely controlled), high equipment investment and maintenance costs (the structure of the reactive distillation column is complex, the cost is high, and the operation and maintenance costs are high), and lack of flexibility (once the process parameters and equipment specifications are determined, it is difficult to change, which may not be flexible enough for enterprises that need to frequently adjust the production process or production scale). Summary of the Invention

[0003] The purpose of the present invention is to address the above technical defects of the existing methyltrimethoxysilane production equipment, and provide a multi-stage continuous esterification reaction treatment device for producing methyltrimethoxysilane using methyltrichlorosilane and methanol as raw materials, which has the advantages of simple reaction condition control, low equipment investment and maintenance costs, and high flexibility.

[0004] The above technical objective of the present invention is achieved through the following technical solutions:

[0005] A multi-stage continuous esterification reaction treatment device for producing methyltrimethoxysilane using methyltrichlorosilane and methanol as raw materials, comprising a first esterification kettle, a second esterification kettle, a third esterification kettle, a neutralization reaction kettle, a centrifugal separation device, and a rectification and purification device connected in sequence.

[0006] By adopting the above technical solutions, a multi-stage continuous esterification reaction treatment device for producing methyltrimethoxysilane using methyltrichlorosilane and methanol as raw materials is provided, which has the advantages of simple reaction condition control, low equipment investment and maintenance costs, and high flexibility.

[0007] The further setting of the present invention is that the first esterification kettle, the second esterification kettle, and the third esterification kettle are all esterification kettles with adjustable temperature and internal stirring structures.

[0008] By adopting the above technical solution, the specific functions of the three esterification reactors are defined. The temperatures of the three esterification reactors are adjustable, enabling precise control of the temperatures of the three esterification reactors; the stirring structures provided in the three esterification reactors can not only accelerate the uniform mixing of raw materials, but also loosen the accumulated methyltrimethoxysilane during discharging, assisting in smooth discharging.

[0009] A further setting of the present invention is that during the continuous esterification reaction, the temperature in the first esterification reactor is maintained at 25°C - 40°C, the temperature in the second esterification reactor is maintained at 40°C - 60°C, and the temperature in the third esterification reactor is maintained at 60°C - 70°C.

[0010] By adopting the above technical solution, the temperatures in the three esterification reactors are defined. The low temperature in the first esterification reactor can avoid methanol gasification or side reactions (such as hydrolysis to produce silanol) caused by high temperature at the initial stage of the esterification reaction; the medium temperature in the second esterification reactor can increase the reaction rate, promote the further conversion of unreacted methyltrichlorosilane, and shorten the residence time; the high temperature in the third esterification reactor is close to the boiling point of methanol, which can ensure to the greatest extent that methanol reacts with methyltrichlorosilane rather than overflows due to high-temperature gasification. This solution effectively avoids the occurrence of side reactions during the reaction process and effectively improves the conversion rate of the reaction by reasonably controlling the reaction temperatures of the three esterification reactors.

[0011] A further setting of the present invention is that the tops of the first esterification reactor, the second esterification reactor, and the third esterification reactor are sequentially connected to a methanol condensation recovery device and a hydrogen chloride recovery device through exhaust gas pipes. The exhaust gas pipes at the tops of the first esterification reactor, the second esterification reactor, and the third esterification reactor can be respectively equipped with independent methanol condensation recovery devices and hydrogen chloride recovery devices, or can be equipped with unified methanol condensation recovery devices and hydrogen chloride recovery devices.

[0012] By adopting the above technical solution, the exhaust gas pipes of the three esterification reactors are connected to a methanol condensation recovery device and a hydrogen chloride recovery device to realize the recovery and treatment of the discharged gases from the three esterification reactors.

[0013] A further setting of the present invention is that a liquid methyltrichlorosilane inlet pipe is provided at the top of the first esterification reactor, and a liquid methanol inlet pipe is provided at the upper section of the side wall of the first esterification reactor; the top of the second esterification reactor is connected to the bottom of the first esterification reactor through a first transfer pipe with a pump, the bottom of the second esterification reactor is connected to the top of the third esterification reactor through a second transfer pipe with a pump, and gaseous methanol inlet pipes are provided at the lower sections of the side walls of the second esterification reactor and the third esterification reactor.

[0014] By adopting the above technical solution, the inlet and outlet methods of raw materials and various materials after the reaction in the three esterification reactors are defined.

[0015] A further setting of the present invention is that nitrogen inlet pipes are provided in the middle of the first esterification kettle, the second esterification kettle and the third esterification kettle, and the air outlet of the nitrogen inlet pipe is located above the liquid level in the corresponding esterification kettle.

[0016] By adopting the above technical solution, nitrogen inlet pipes are provided for all three esterification kettles. The charging of nitrogen can promptly push out the hydrogen chloride gas after the reaction from the reaction kettle, effectively avoiding the occurrence of side reactions and improving the conversion rate of methyltrimethoxysilane.

[0017] A further setting of the present invention is that the rectification and purification device includes a first rectification tower and a second rectification tower that are connected to each other. The gas outlet pipe at the top of the first rectification tower is connected to the methanol condensation and recovery device, and the gas outlet pipe at the top of the second rectification tower is connected to the methyltrimethoxysilane condensation and recovery device.

[0018] By adopting the above technical solution, the rectification and purification device is defined. Two rectification towers are used to separately extract methanol and methyltrimethoxysilane, which has the advantages of simple purification control and good purification effect.

[0019] A further setting of the present invention is that the first esterification kettle includes a tank body. Inside the tank body, a countercurrent contact part and a stirring reaction part are sequentially arranged from top to bottom. A heating device is arranged on the outer side wall of the stirring reaction part. The lower end of the tank body is provided with a discharge port connected to the first conveying pipe. The countercurrent contact part includes a spiral flow channel attached to the inner wall of the tank body. The liquid outlet of the liquid methanol inlet pipe is provided with a methanol nozzle for the spiral flow channel. The methanol nozzle corresponds to the upper section of the spiral flow channel, and the methanol nozzle sprays liquid methanol obliquely upward against the spiral flow channel evenly.

[0020] By adopting the above technical solution, a countercurrent contact part and a stirring reaction part are sequentially arranged from top to bottom in the first esterification kettle. The matching of the spiral flow channel of the countercurrent contact part and the methanol nozzle can effectively extend the flow distance after the mixing of methyltrichlorosilane and methanol, and effectively achieve the uniform mixing of the two.

[0021] A further setting of the present invention is that a stirring motor is arranged at the top of the tank body. The output shaft of the stirring motor extends downward through the middle channel inside the spiral flow channel to the stirring reaction part at the bottom of the tank body, and a stirring structure is arranged at the lower end of the output shaft.

[0022] A further setting of the present invention is that the middle channel inside the spiral flow channel is the axial inner hole of a cylinder. The outer wall of the cylinder is hermetically connected to the spiral flow channel. The lower end of the cylinder is located above the liquid level of the stirring reaction part. The upper end of the cylinder is connected to the waste gas discharge pipe. A nitrogen inlet pipe corresponding to the spiral flow channel is arranged at the top of the first esterification kettle.

[0023] By adopting the above technical solution, the channel between the spiral flow channel and the output shaft of the stirring structure is creatively utilized to connect the stirring reaction part and the exhaust gas pipe outside the tank body. At the same time, a nitrogen inlet pipe corresponding to the spiral flow channel is arranged at the top of the tank body. This series of designs can not only ensure that the hydrogen chloride gas in the stirring reaction part is discharged in time, but also effectively prevent the hydrogen chloride gas in the stirring reaction part from contacting the raw materials on the spiral flow channel and causing side reactions. This solution can effectively avoid the occurrence of side reactions and further improve the conversion rate of methyltrimethoxysilane.

[0024] The main beneficial effects of the present invention are as follows:

[0025] 1. The present invention adopts a three-stage continuous esterification reactor to realize the staged esterification reaction of methyltrichlorosilane and methanol as raw materials, which has the advantages of simple reaction condition control, low equipment investment and maintenance cost, and high flexibility.

[0026] 2. The temperatures in the three esterification reactors of the present invention are all limited. The low temperature in the first esterification reactor can avoid the gasification of methanol or side reactions (such as hydrolysis to produce silanol) caused by high temperature at the initial stage of the esterification reaction; the medium temperature in the second esterification reactor can increase the reaction rate, promote the further conversion of unreacted methyltrichlorosilane, and shorten the residence time; the high temperature in the third esterification reactor is close to the boiling point of methanol, which can ensure to the greatest extent that methanol reacts with methyltrichlorosilane rather than overflows due to high temperature gasification. By reasonably controlling the reaction temperatures of the three esterification reactors, the occurrence of side reactions during the reaction is effectively avoided, and the conversion rate of the reaction is effectively improved.

[0027] 3. In the first esterification reactor of the present invention, a countercurrent contact part and a stirring reaction part are sequentially arranged from top to bottom. The arrangement of the spiral flow channel of the countercurrent contact part and the methanol nozzle effectively prolongs the flow distance after the mixing of methyltrichlorosilane and methanol, and can effectively realize the uniform mixing of the two.

[0028] 4. By adopting the above technical solution, the channel between the spiral flow channel and the output shaft of the stirring structure is creatively utilized to connect the stirring reaction part and the exhaust gas pipe outside the tank body. At the same time, a nitrogen inlet pipe corresponding to the spiral flow channel is arranged at the top of the tank body. This series of designs can not only ensure that the hydrogen chloride gas in the stirring reaction part is discharged in time, but also effectively prevent the hydrogen chloride gas in the stirring reaction part from contacting the raw materials on the spiral flow channel and causing side reactions. This solution can effectively avoid the occurrence of side reactions and further improve the conversion rate of methyltrimethoxysilane. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 is the schematic diagram of the present invention;

[0031] Figure 2 is the structural schematic diagram inside the first esterification kettle in the present invention.

[0032] In the figure, 1 is the first esterification kettle; 11 is the tank body; 12 is the heating device; 131 is the stirring structure; 132 is the output shaft; 133 is the stirring motor; 14 is the spiral flow channel; 15 is the cylinder; 16 is the middle channel; 2 is the second esterification kettle; 3 is the third esterification kettle; 4 is the neutralization reaction kettle; 5 is the centrifugal separation device; 61 is the first rectification tower; 62 is the second rectification tower. Specific Embodiments

[0033] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0034] Embodiment 1:

[0035] As Figures 1 to 2 shown, a multi-stage continuous esterification reaction treatment device is used to produce methyltrimethoxysilane from methyltrichlorosilane and methanol as raw materials, and includes a first esterification kettle 1, a second esterification kettle 2, a third esterification kettle 3, a neutralization reaction kettle 4, a centrifugal separation device 5 and a rectification and purification device connected in sequence. The rectification and purification device includes a first rectification tower 61 and a second rectification tower 62 that are connected to each other. The gas outlet pipe at the top of the first rectification tower 61 is connected to the methanol condensation recovery device, and the gas outlet pipe at the top of the second rectification tower 62 is connected to the methyltrimethoxysilane condensation recovery device.

[0036] The first esterification kettle 1, the second esterification kettle 2, and the third esterification kettle 3 are all esterification kettles with adjustable temperature and internal stirring structures. The tops of the first esterification kettle 1, the second esterification kettle 2, and the third esterification kettle 3 are all connected in sequence to a methanol condensation recovery device and a hydrogen chloride recovery device through exhaust gas pipes. The exhaust gas pipes at the tops of the first esterification kettle 1, the second esterification kettle 2, and the third esterification kettle 3 can be respectively equipped with independent methanol condensation recovery devices and hydrogen chloride recovery devices, or can be equipped with unified methanol condensation recovery devices and hydrogen chloride recovery devices. A liquid methyltrichlorosilane inlet pipe is arranged at the top of the first esterification kettle 1, and a liquid methanol inlet pipe is arranged at the upper section of the side wall of the first esterification kettle 1; the top of the second esterification kettle 2 is connected to the bottom of the first esterification kettle 1 through a first delivery pipe with a pump 7, and the bottom of the second esterification kettle 2 is connected to the top of the third esterification kettle 3 through a second delivery pipe with a pump 7. Gas-phase methanol inlet pipes are arranged at the lower sections of the side walls of the second esterification kettle 2 and the third esterification kettle 3. Nitrogen inlet pipes are arranged in the middle of the first esterification kettle 1, the second esterification kettle 2, and the third esterification kettle 3, and the air outlet of the nitrogen inlet pipe is located above the liquid level in the corresponding esterification kettle. During the continuous esterification reaction process, the temperature in the first esterification kettle 1 is maintained at 25°C - 40°C, the temperature in the second esterification kettle 2 is maintained at 40°C - 60°C, and the temperature in the third esterification kettle 3 is maintained at 60°C - 70°C.

[0037] The first esterification kettle 1 includes a tank body 11. Inside the tank body 11, a countercurrent contact part and a stirring reaction part are sequentially arranged from top to bottom. A heating device 12 is arranged on the outer side wall of the stirring reaction part. The lower end of the tank body 11 is provided with a discharge port connected to the first delivery pipe. The countercurrent contact part includes a spiral flow channel 14 attached to the inner wall of the tank body 11. The liquid outlet of the liquid methanol inlet pipe is provided with a methanol nozzle for the spiral flow channel 14. The methanol nozzle corresponds to the upper section of the spiral flow channel 14, and the methanol nozzle sprays liquid methanol obliquely upward against the spiral flow channel 14 evenly. A stirring motor 133 is arranged at the top of the tank body 11. The output shaft 132 of the stirring motor 133 extends downward through the middle channel 16 inside the spiral flow channel 14 to the stirring reaction part at the bottom of the tank body 11. A stirring structure 131 is arranged at the lower end of the output shaft 132. The middle channel 16 inside the spiral flow channel 14 is the axial inner hole of a cylinder 15. The outer wall of the cylinder is hermetically connected to the spiral flow channel 14. The lower end of the cylinder 15 is located above the liquid level of the stirring reaction part, and the upper end of the cylinder 15 is connected to the exhaust gas pipe. A nitrogen inlet pipe corresponding to the spiral flow channel 14 is arranged at the top of the first esterification kettle 1.

[0038] Principle of use:

[0039] In the first esterification kettle 1, liquid methyltrichlorosilane and liquid methanol come into reverse contact in the upper section of the spiral flow channel 14 and flow along the spiral flow channel 14 into the stirring reaction part for a preliminary stirring esterification reaction. During the reaction process, the temperature in the first esterification kettle 1 is maintained at 25°C - 40°C. Nitrogen is introduced into the top of the first esterification kettle 1. The nitrogen moves downward through the spiral flow channel 14 and turns back when reaching the liquid level of the stirring reaction part, and will push the waste gas (mainly hydrogen chloride gas) generated by the esterification reaction from the axial inner hole of the cylinder 15 (i.e., the middle channel 16) to the waste gas discharge pipe at the top of the first esterification kettle 1, discharging the hydrogen chloride gas in time, which can effectively avoid the occurrence of side reactions;

[0040] The second esterification kettle 2 receives the mixed liquid after the reaction in the first esterification kettle 1. The mixed liquid that is not completely reacted in the first esterification kettle 1 further reacts in the second esterification kettle 2. During this reaction process, gaseous methanol is appropriately supplemented into the second esterification kettle 2. The gaseous methanol is introduced below the liquid level in the second esterification kettle 2, and the temperature in the second esterification kettle 2 is maintained at 40°C - 60°C to accelerate the esterification reaction;

[0041] The third esterification kettle 3 receives the mixed liquid after the reaction in the second esterification kettle 2. The mixed liquid that is not completely reacted in the second esterification kettle 2 undergoes a final reaction in the third esterification kettle 3. During this reaction process, gaseous methanol is appropriately supplemented into the third esterification kettle 3. The gaseous methanol is introduced below the liquid level in the third esterification kettle 3, and the temperature in the third esterification kettle 2 is maintained at 60°C - 70°C to ensure the complete reaction of methyltrichlorosilane.

[0042] The waste gases generated after the reactions in the first esterification kettle 1, the second esterification kettle 2, and the third esterification kettle 3 are respectively treated by a methanol condensation recovery device and a hydrogen chloride recovery device and then discharged.

[0043] The mixed liquid after the reaction in the third esterification kettle 3 is first adjusted to a neutral pH value with a 29% sodium methoxide solution in the neutralization reaction kettle 4, and then sodium chloride is separated under the action of the centrifugal separation device 5. The liquid from which sodium chloride has been separated is finally distilled and purified for methanol and methyltrimethoxysilane respectively through the first distillation column 61 and the second distillation column 62. The obtained methanol can be reused, and the obtained methyltrimethoxysilane is a high-purity product.

Claims

1. A multi-stage continuous esterification reaction treatment device, which is used to produce methyltrimethoxysilane with methyltrichlorosilane and methanol as raw materials, and is characterized in that: It includes a first esterification kettle (1), a second esterification kettle (2), a third esterification kettle (3), a neutralization reaction kettle (4), a centrifugal separation device (5) and a rectification and purification device that are connected in sequence.

2. The multi-stage continuous esterification reaction treatment equipment according to claim 1, characterized in that: The first esterification kettle (1), the second esterification kettle (2) and the third esterification kettle (3) are all esterification kettles with adjustable temperature and internal stirring structures.

3. A multi-stage continuous esterification reaction treatment device according to claim 2, characterized in that: During the continuous esterification reaction process, the temperature in the first esterification kettle (1) is maintained at 25°C - 40°C, the temperature in the second esterification kettle (2) is maintained at 40°C - 60°C, and the temperature in the third esterification kettle (3) is maintained at 60°C - 70°C.

4. A multi-stage continuous esterification reaction treatment device according to claim 3, characterized in that: The tops of the first esterification kettle (1), the second esterification kettle (2) and the third esterification kettle (3) are all connected in sequence to a methanol condensation recovery device and a hydrogen chloride recovery device through exhaust gas pipes. The exhaust gas pipes at the tops of the first esterification kettle (1), the second esterification kettle (2) and the third esterification kettle (3) can be respectively equipped with independent methanol condensation recovery devices and hydrogen chloride recovery devices, or can be equipped with a unified methanol condensation recovery device and hydrogen chloride recovery device.

5. A multi-stage continuous esterification reaction treatment device according to claim 4, characterized in that: A liquid methyltrichlorosilane inlet pipe is arranged at the top of the first esterification kettle (1), and a liquid methanol inlet pipe is arranged at the upper section of the side wall of the first esterification kettle (1); the top of the second esterification kettle (2) is connected to the bottom of the first esterification kettle (1) through a first delivery pipe with a pump (7), the bottom of the second esterification kettle (2) is connected to the top of the third esterification kettle (3) through a second delivery pipe with a pump (7), and gaseous methanol inlet pipes are arranged at the lower sections of the side walls of the second esterification kettle (2) and the third esterification kettle (3).

6. A multi-stage continuous esterification reaction treatment device according to claim 5, characterized in that: Nitrogen inlet pipes are arranged in the middle parts of the first esterification kettle (1), the second esterification kettle (2) and the third esterification kettle (3), and the air outlet of the nitrogen inlet pipe is located above the liquid level in the corresponding esterification kettle.

7. The multi-stage continuous esterification reaction treatment equipment according to claim 6, characterized in that: The rectification and purification device includes a first rectification tower (61) and a second rectification tower (62) that are connected to each other. The gas outlet pipe at the top of the first rectification tower (61) is connected to the methanol condensation recovery device, and the gas outlet pipe at the top of the second rectification tower (62) is connected to the methyltrimethoxysilane condensation recovery device.

8. A multi-stage continuous esterification reaction treatment device according to claim 5, characterized in that: The first esterification kettle (1) includes a tank body (11). Inside the tank body (11), a countercurrent contact part and a stirring reaction part are arranged in sequence from top to bottom. A heating device (12) is arranged on the outer side wall of the stirring reaction part. The lower end of the tank body (11) is provided with a discharge port connected to the first delivery pipe. The countercurrent contact part includes a spiral flow channel (14) attached to the inner wall of the tank body (11). The liquid outlet of the liquid methanol inlet pipe is provided with a methanol nozzle aiming at the spiral flow channel (14). The methanol nozzle corresponds to the upper section of the spiral flow channel (14), and the methanol nozzle sprays liquid methanol obliquely upward against the spiral flow channel (14) evenly.

9. A multi-stage continuous esterification reaction treatment device according to claim 8, characterized in that: A stirring motor (133) is arranged at the top of the tank body (11). The output shaft (132) of the stirring motor (133) extends downward through the middle channel (16) inside the spiral flow channel (14) to the stirring reaction part at the bottom of the tank body (11), and a stirring structure (131) is arranged at the lower end of the output shaft (132).

10. A multi-stage continuous esterification reaction treatment device according to claim 9, characterized in that: The middle channel (16) inside the spiral channel (14) is the axial inner hole of the cylinder (15). The outer wall of the cylinder (15) is sealingly connected to the spiral channel (14). The lower end of the cylinder (15) is located above the liquid level of the stirring reaction part. The upper end of the cylinder (15) is connected to the exhaust gas pipe. A nitrogen inlet pipe corresponding to the spiral channel (14) is arranged at the top of the first esterification kettle (1).

Images