Dehydration and purification method and system for industrial-grade dimethyl carbonate
By using sodium methoxide or sodium ethoxide as a dehydrating agent in combination with molecular sieves for separation in industrial-grade dimethyl carbonate, and combining it with distillation column separation, the problem of low separation efficiency of high-purity dimethyl carbonate in existing technologies has been solved, realizing the production of high-purity dimethyl carbonate with high efficiency and low cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI PAISHENG INFORMATION TECHNOLOGY CO LTD
- Filing Date
- 2026-01-15
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies struggle to efficiently and cost-effectively separate high-purity (above 99.99%) electronic-grade dimethyl carbonate from industrial-grade dimethyl carbonate, especially failing to meet the stringent requirements of water content ≤10ppm and purity ≥99.999%.
Sodium methoxide or sodium ethoxide is used as a dehydrating agent, and combined with type A molecular sieve, silica-alumino-phosphorus molecular sieve or KCC molecular sieve as an adsorbent. After mixing and reaction, the mixture is separated by distillation in a distillation column. This constructs a multi-process deep coupling system that combines catalytic reaction, adsorption dehydration and precision distillation, simplifies operation steps and reduces material loss and secondary pollution.
The production of electronic-grade dimethyl carbonate with a water content of ≤10ppm and a purity of ≥99.999% has been achieved, meeting the stringent requirements of high-end electronic chemicals and reducing energy consumption and costs.
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Figure CN122010736A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of dimethyl carbonate purification, specifically to a method and system for the dehydration and purification of industrial-grade dimethyl carbonate. Background Technology
[0002] Dimethyl carbonate (DMC) is widely used in lithium battery electrolyte solvents, electronic component cleaning, photolithography processes, environmentally friendly coatings and inks, pharmaceutical intermediate synthesis, and fuel additives. It combines environmental friendliness and high efficiency, and is a key raw material for promoting the development of new energy, semiconductors, and green chemicals.
[0003] As an indispensable organic solvent in the electronics and battery industries, DMC plays a crucial role in the production of lithium battery electrolytes. As the core material of lithium-ion batteries, the performance of electrolytes is highly dependent on the quality of solvents in the formulation, especially the water content, total alcohol content, and other impurity content of electronic-grade dimethyl carbonate. These factors directly affect the performance of the electrolyte, thereby influencing various battery indicators, making the market increasingly demanding on the quality of electronic-grade dimethyl carbonate.
[0004] Currently, industrial-grade DMC, a byproduct of the domestic coal-to-ethylene glycol industry, has great potential for preparing electronic-grade DMC. However, due to the variety of impurities and the complexity of the azeotropic system, traditional technologies struggle to separate high-purity (99.99%) products.
[0005] In the prior art, Chinese patent CN115228119A discloses a dimethyl carbonate purification system and method. The disclosed purification system includes an adsorption tower and a distillation unit, obtaining high-purity dimethyl carbonate through a combination of adsorption and distillation. Chinese patent CN113121346A discloses a purification method for electronic-grade dimethyl carbonate, employing a distillation-adsorption coupled process to purify industrial-grade dimethyl carbonate to a 99.99% electronic-grade dimethyl carbonate product. The existing technological processes are relatively complex, consume high energy during the production of high-purity products, and require a large amount of adsorbent. The purity of the obtained dimethyl carbonate product needs further improvement. Summary of the Invention
[0006] This invention aims to provide a method and system for the dehydration and purification of industrial-grade dimethyl carbonate (DMC). By constructing a multi-process deeply coupled system integrating reaction, adsorption, and distillation functions, this system can accurately meet the stringent requirements of electronic-grade DMC for water content and purity in industrial production scenarios, with a water content ≤10ppm and a purity ≥99.999%, providing a high-quality raw material guarantee for the electronic chemical industry.
[0007] To solve the above technical problems, the specific solution adopted by the present invention is as follows: a dehydration and purification method for industrial grade dimethyl carbonate, wherein industrial grade dimethyl carbonate, dehydrating agent and adsorbent are mixed and reacted in a mass ratio of 1:(0.05-0.07):(0.05-0.07), and the resulting reaction product is sent to a distillation column for distillation separation, and electronic grade dimethyl carbonate is obtained from the bottom of the distillation column; The dehydrating agent is one or a combination of sodium methoxide and sodium ethoxide; the adsorbent is one or a combination of more than two of type A molecular sieve, silica-alumino-phosphorus molecular sieve, and KCC type molecular sieve.
[0008] As a further optimization of the above technical solution: the temperature of the mixing reaction is 60-80ºC, and the reaction time is 2-4h.
[0009] As a further optimization of the above technical solution: the mixing reaction is accompanied by stirring, and the stirring rate is 150-250 r / min.
[0010] As a further optimization of the above technical solution: the obtained reaction product is heated to 70-85ºC and fed into a distillation column.
[0011] As a further optimization of the above technical solution: the top pressure of the distillation column is 0.95-0.1 MPa, the top temperature is 62-65ºC, and the top reflux ratio is 1-5.
[0012] As a further optimization of the above technical solution: the bottom temperature of the distillation column is 87-91ºC.
[0013] As a further optimization of the above technical solution: the dehydrating agent is sodium methoxide, the adsorbent is type A molecular sieve, the mixing reaction temperature is 60ºC, the reaction time is 2h, the mixing reaction is accompanied by stirring at a stirring rate of 150r / min, the obtained reaction product is heated to 80ºC and sent to a distillation column, the top pressure of the distillation column is 0.1MPa, the top temperature is 65ºC, the top reflux ratio is 2, and the bottom temperature is 90ºC.
[0014] As a further optimization of the above technical solution: the distillation column adopts one or a combination of two of the following: wire mesh corrugated packing and perforated plate corrugated packing.
[0015] An industrial-grade dimethyl carbonate dehydration and purification system, comprising a stirred reactor and a distillation column; The outlet of the stirred reactor is connected to the inlet of the distillation column via a reaction product delivery pipeline; The top of the distillation column is equipped with a top distillate conveying pipeline, and the end of the top distillate conveying pipeline is connected to a top condenser. The top condenser is connected to two material discharge pipelines, one of which is connected to the upper part of the distillation column, and the other material discharge pipeline is used to output the top product. The bottom of the distillation column is equipped with a bottom distillate conveying pipeline, which branches into two branches. One branch is connected to the lower part of the distillation column, and the other branch is used to output electronic grade dimethyl carbonate.
[0016] As a further optimization of the above technical solution: a first heat exchanger is installed on the reaction product conveying pipeline, a second heat exchanger is installed on the top distillate conveying pipeline, and a reboiler is installed on the branch pipeline connected to the lower part of the distillation column.
[0017] This invention utilizes a combination of dehydrating agent catalysis and molecular sieve adsorption for synergistic pretreatment, which is then combined with subsequent precision distillation to construct a multi-process deeply coupled system. This system organically integrates catalytic reaction, adsorption dehydration, and precision distillation into a continuous process flow, avoiding the transfer and storage of intermediate products, reducing material loss and the risk of secondary pollution, simplifying operation steps, and improving overall production efficiency.
[0018] Sodium methoxide, a dehydrating agent, can not only catalyze potential side reactions, but its combination with molecular sieve adsorbents can also effectively remove water and small amounts of light component impurities such as alcohols from the source, greatly reducing the separation load on subsequent distillation columns. This allows for the use of lower reflux ratios and fewer theoretical plates, thus optimizing costs.
[0019] The dehydration and purification method of this invention can efficiently remove key impurities such as alcohol and water from raw industrial-grade DMC, and can stably ensure that the water content in the electronic-grade DMC product in the bottom of the tower is no more than 10 ppm, which meets the stringent requirements of high-end electronic chemicals for trace moisture. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the system structure of the present invention; Attached reference numerals: 1. Feed line, 2. Stirred reactor, 3. Reaction product conveying line, 4. Conveyor pump, 5. First heat exchanger, 6. Distillation column, 7. Top distillate conveying line, 8. Second heat exchanger, 9. Top condenser, 10. Condenser material discharge line, 1001. Top reflux line, 1002. Top product output line, 11. Bottom distillate conveying line, 1101. Bottom reflux line, 1102. Bottom product output line, 12. Reboiler. Detailed Implementation
[0021] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. Parts not described or disclosed in detail in the following embodiments of the present invention should be understood as prior art known or should be known by those skilled in the art.
[0022] This invention discloses a method for dehydrating and purifying industrial-grade dimethyl carbonate. Industrial-grade dimethyl carbonate, a dehydrating agent, and an adsorbent are mixed and reacted in a mass ratio of 1:(0.05-0.07):(0.05-0.07). The reaction temperature is 60-80ºC, the reaction time is 2-4h, and the reaction is accompanied by stirring at a stirring rate of 150-250r / min.
[0023] The resulting reaction product is heated to 70-85ºC and then fed into a distillation column for fractionation. Electronic-grade dimethyl carbonate is obtained from the bottom of the distillation column. The dehydrating agent is one or a combination of sodium methoxide and sodium ethoxide; the adsorbent is one or a combination of more than two of type A molecular sieves, silica-alumina-phosphorus molecular sieves, and KCC molecular sieves; the top pressure of the distillation column is 0.95-0.1 MPa, the top temperature is 62-65ºC, and the top reflux ratio is 1-5. The bottom temperature of the distillation column is 87-91ºC.
[0024] Preferably, the dehydrating agent is sodium methoxide, the adsorbent is type A molecular sieve, the mixing reaction temperature is 60ºC, the reaction time is 2h, the mixing reaction is accompanied by stirring at a stirring rate of 150r / min, the obtained reaction product is heated to 80ºC and sent to a distillation column, the top pressure of the distillation column is 0.1MPa, the top temperature is 65ºC, the top reflux ratio is 2, and the bottom temperature is 90ºC.
[0025] The obtained electronic-grade DMC can precisely meet the stringent requirements for water content and purity, with a water content of ≤10ppm and a purity of ≥99.999%, providing a high-quality raw material guarantee for the electronic chemical industry.
[0026] like Figure 1 As shown, the present invention also discloses an industrial-grade dimethyl carbonate dehydration and purification system, comprising a stirred reaction vessel 2 and a distillation column 6 connected by a reaction product conveying pipeline 3.
[0027] The stirred reactor 2 has a feed inlet and a discharge outlet. The feed inlet is connected to a feed pipeline to allow industrial-grade dimethyl carbonate, dehydrating agent, and adsorbent to enter the stirred reactor 2. The discharge outlet of the stirred reactor 2 is connected to the feed inlet of the distillation column 6 through the reaction product conveying pipeline 3, so as to send the reaction products after reaction in the stirred reactor 2 into the distillation column 3.
[0028] The reaction product conveying pipeline 3 is equipped with a conveying pump 4 and a first heat exchanger 5. The reaction product in the stirred reactor 2 is first heated to the target temperature by the first heat exchanger 5 and then sent to the distillation column 3.
[0029] The top of the distillation column 6 is equipped with a top distillate delivery pipeline 7, on which a second heat exchanger 8 is installed. The end of the top distillate delivery pipeline 7 is connected to a top condenser 9. The top product after heat exchange in the second heat exchanger 8 is sent to the top condenser 9 for condensation. The top condenser 9 is connected to a condenser material discharge pipeline 10, which is divided into two discharge pipelines. One discharge pipeline is a top reflux pipeline 1001 connected to the upper part of the distillation column 6, and the other discharge pipeline is a top product output pipeline 1002 used to output the top product.
[0030] The bottom of the distillation column 6 is provided with a bottom distillate conveying pipeline 11. The bottom distillate conveying pipeline 11 is divided into two branch pipelines. One branch pipeline is a bottom reflux pipeline 1101 connected to the lower part of the distillation column 6. The bottom reflux pipeline 1101 is provided with a reboiler 12. The other branch pipeline is a bottom product output pipeline 1102 used to output electronic grade dimethyl carbonate.
[0031] It should be noted that the composition of the material returned to the bottom of the distillation column 6 and the electronic-grade dimethyl carbonate output is the same. The purpose of setting up the reboiler 12 is to partially vaporize the dimethyl carbonate after heating in the reboiler and return it to the bottom of the column to provide rising steam, thereby promoting the separation of the raw materials.
[0032] Example 1 This embodiment provides a method for dehydrating and purifying industrial-grade dimethyl carbonate, including reaction, adsorption, and distillation units.
[0033] The reaction and adsorption of industrial-grade DMC were carried out in a stirred reactor. Sodium methoxide was used as the dehydrating agent and type A molecular sieve was used as the adsorbent. The mass ratio of DMC, sodium methoxide and molecular sieve was 1:0.05:0.05. The reaction temperature was 60ºC, the reaction time was 2h, and the stirring rate was 150r / min.
[0034] The product from the stirred reactor is transported to the first heat exchanger via a transfer pump, where the reaction product is heated to 80ºC.
[0035] The reaction products after heat exchange enter a distillation column for product separation. The distillation column is a high-efficiency packed distillation column with structured wire mesh packing. The top reflux ratio is 2, the top pressure is 0.1 MPa, the top temperature is 65ºC, and the bottom temperature is 91ºC, resulting in a heavy component product (electronic grade DMC) in the bottom. The water content in the electronic grade DMC in the bottom is measured.
[0036] Example 2 This embodiment provides a method for dehydrating and purifying industrial-grade dimethyl carbonate, including reaction, adsorption, and distillation units.
[0037] The reaction and adsorption of industrial-grade DMC were carried out in a stirred reactor. Sodium methoxide was used as the dehydrating agent and type A molecular sieve was used as the adsorbent. The mass ratio of DMC, sodium methoxide and molecular sieve was 1:0.07:0.05. The reaction temperature was 60ºC, the reaction time was 2h, and the stirring rate was 150r / min.
[0038] The product from the stirred reactor is transported to the first heat exchanger via a transfer pump, where the reaction product is heated to 80ºC.
[0039] The reaction products after heat exchange enter a distillation column for product separation. The distillation column is a high-efficiency packed distillation column with structured wire mesh packing. The top reflux ratio is 2, the top pressure is 0.1 MPa, the top temperature is 65ºC, and the bottom temperature is 91ºC, resulting in a heavy component product (electronic grade DMC) in the bottom. The water content in the electronic grade DMC in the bottom is measured.
[0040] Example 3 This embodiment provides a method for dehydrating and purifying industrial-grade dimethyl carbonate, including reaction, adsorption, and distillation units.
[0041] The reaction and adsorption of industrial-grade DMC were carried out in a stirred reactor. Sodium methoxide was used as the dehydrating agent and type A molecular sieve was used as the adsorbent. The mass ratio of DMC, sodium methoxide and molecular sieve was 1:0.05:0.07. The reaction temperature was 60ºC, the reaction time was 2h, and the stirring rate was 150r / min.
[0042] The product from the stirred reactor is transported to the first heat exchanger via a transfer pump, where the reaction product is heated to 80ºC.
[0043] The reaction products after heat exchange enter a distillation column for product separation. The distillation column is a high-efficiency packed distillation column with structured wire mesh packing. The top reflux ratio is 2, the top pressure is 0.1 MPa, the top temperature is 65ºC, and the bottom temperature is 91ºC, resulting in a heavy component product (electronic grade DMC) in the bottom. The water content in the electronic grade DMC in the bottom is measured.
[0044] Comparative Example 1 This comparative example provides a method for dehydrating and purifying industrial-grade dimethyl carbonate, including reaction and distillation units.
[0045] The reaction and adsorption of industrial-grade DMC were carried out in a stirred reactor, with sodium methoxide as the dehydrating agent. The mass ratio of DMC to sodium methoxide was 1:0.05. The reaction temperature was 60ºC, the reaction time was 2h, and the stirring rate was 150r / min.
[0046] The products from the stirred reactor are pumped to a heat exchanger to bring the reaction products to 80ºC.
[0047] The heat-exchanged product enters a high-efficiency packed distillation column (structured wire mesh packing) for product separation. The top reflux ratio is 2, the top pressure is 0.1 MPa, the top temperature is 65ºC, and the bottom temperature is 91ºC, resulting in a heavy component product (electronic grade DMC) in the bottom column. The water content in the electronic grade DMC in the bottom column is measured.
[0048] Comparative Example 2 This comparative example provides a method for dehydrating and purifying industrial-grade dimethyl carbonate, including adsorption and distillation units.
[0049] The reaction and adsorption of industrial-grade DMC were carried out in a stirred reactor, with type A molecular sieve as the adsorbent, a mass ratio of DMC to molecular sieve of 1:0.05, an adsorption temperature of 60ºC, an adsorption time of 2 h, and a stirring rate of 150 r / min.
[0050] The products from the reactor are pumped to a heat exchanger, where they are heated to 80ºC.
[0051] The heat-exchanged product enters a high-efficiency packed distillation column (structured wire mesh packing) for product separation. The top reflux ratio is 2, the top pressure is 0.1 MPa, the top temperature is 65ºC, and the bottom temperature is 91ºC, resulting in a heavy component product (electronic grade DMC) in the bottom column. The water content in the electronic grade DMC in the bottom column is measured.
[0052] Comparative Example 3 This embodiment provides a method for dehydrating and purifying industrial-grade dimethyl carbonate, including reaction, adsorption, and distillation units.
[0053] The reaction and adsorption of industrial-grade DMC were carried out in a stirred reactor. Sodium methoxide was used as the dehydrating agent and type A molecular sieve was used as the adsorbent. The mass ratio of DMC, sodium methoxide and molecular sieve was 1:0.01:0.05. The reaction temperature was 60ºC, the reaction time was 2h, and the stirring rate was 150r / min.
[0054] The product from the stirred reactor is transported to the first heat exchanger via a transfer pump, where the reaction product is heated to 80ºC.
[0055] The reaction products after heat exchange enter a distillation column for product separation. The distillation column is a high-efficiency packed distillation column with structured wire mesh packing. The top reflux ratio is 2, the top pressure is 0.1 MPa, the top temperature is 65ºC, and the bottom temperature is 91ºC, resulting in a heavy component product (electronic grade DMC) in the bottom. The water content in the electronic grade DMC in the bottom is measured.
[0056] Comparative Example 4 This embodiment provides a method for dehydrating and purifying industrial-grade dimethyl carbonate, including reaction, adsorption, and distillation units.
[0057] The reaction and adsorption of industrial-grade DMC were carried out in a stirred reactor. Sodium methoxide was used as the dehydrating agent and type A molecular sieve was used as the adsorbent. The mass ratio of DMC, sodium methoxide and molecular sieve was 1:0.03:0.05. The reaction temperature was 60ºC, the reaction time was 2h, and the stirring rate was 150r / min.
[0058] The product from the stirred reactor is transported to the first heat exchanger via a transfer pump, where the reaction product is heated to 80ºC.
[0059] The reaction products after heat exchange enter a distillation column for product separation. The distillation column is a high-efficiency packed distillation column with structured wire mesh packing. The top reflux ratio is 2, the top pressure is 0.1 MPa, the top temperature is 65ºC, and the bottom temperature is 91ºC, resulting in a heavy component product (electronic grade DMC) in the bottom. The water content in the electronic grade DMC in the bottom is measured.
[0060] Comparative Example 5 This embodiment provides a method for dehydrating and purifying industrial-grade dimethyl carbonate, including reaction, adsorption, and distillation units.
[0061] The reaction and adsorption of industrial-grade DMC were carried out in a stirred reactor. Sodium methoxide was used as the dehydrating agent and type A molecular sieve was used as the adsorbent. The mass ratio of DMC, sodium methoxide and molecular sieve was 1:0.05:0.03. The reaction temperature was 60ºC, the reaction time was 2h, and the stirring rate was 150r / min.
[0062] The product from the stirred reactor is transported to the first heat exchanger via a transfer pump, where the reaction product is heated to 80ºC.
[0063] The reaction products after heat exchange enter a distillation column for product separation. The distillation column is a high-efficiency packed distillation column with structured wire mesh packing. The top reflux ratio is 2, the top pressure is 0.1 MPa, the top temperature is 65ºC, and the bottom temperature is 91ºC, resulting in a heavy component product (electronic grade DMC) in the bottom. The water content in the electronic grade DMC in the bottom is measured.
[0064] Table 1. Water content and DMC purity of the products obtained in Examples 1-3 and Comparative Examples 1-6 Serial Number Water content (ppm) DMC purity (%) raw material 1317 99.869 Example 1 10 99.999 Example 2 8 99.999 Example 3 8 99.999 Comparative Example 1 305 99.969 Comparative Example 2 875 99.913 Comparative Example 3 622 99.948 Comparative Example 4 373 99.963 Comparative Example 5 86 99.992 Analysis results: The water content and purity results of the bottom products of Examples 1-3 and Comparative Examples 1-6 are listed in Table 1. As can be seen from Table 1, the process of the present invention can effectively reduce the water content in DMC and increase its concentration. The electronic-grade DMC obtained in Examples 1-3 has a water content of ≤10ppm and a purity of ≥99.999%, which meets the stringent requirements for water content and purity of electronic-grade DMC.
[0065] Comparative Examples 1-3 and 3-5 show that the water content in the product is related to the mass of sodium methoxide dehydrating agent and type A molecular sieve adsorbent added. When the mass of sodium methoxide dehydrating agent and type A molecular sieve adsorbent added is low, the water content in the product is high and the DMC purity is low. When the mass of sodium methoxide dehydrating agent and type A molecular sieve adsorbent increases, the water content in the product decreases and the DMC purity increases.
[0066] Comparing Example 1, Comparative Example 1, and Comparative Example 2, it can be seen that sodium methoxide dehydrating agent, type A molecular sieve adsorbent, and distillation unit all play a certain role in the dehydration and purification of DMC, and the three complement each other.
[0067] The above description of the disclosed embodiments enables 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 method for dehydrating and purifying industrial-grade dimethyl carbonate, characterized in that: Industrial grade dimethyl carbonate, dehydrating agent and adsorbent are mixed and reacted in a mass ratio of 1:(0.05-0.07):(0.05-0.07). The reaction product is sent to a distillation column for distillation separation. Electronic grade dimethyl carbonate is obtained from the bottom of the distillation column. The dehydrating agent is one or a combination of sodium methoxide and sodium ethoxide; the adsorbent is one or a combination of more than two of type A molecular sieve, silica-alumino-phosphorus molecular sieve, and KCC type molecular sieve.
2. The method for dehydrating and purifying industrial-grade dimethyl carbonate according to claim 1, characterized in that: The temperature for the mixed reaction is 60-80ºC, and the reaction time is 2-4h.
3. The method for dehydrating and purifying industrial-grade dimethyl carbonate according to claim 1, characterized in that: The mixing reaction is accompanied by stirring at a rate of 150-250 r / min.
4. The method for dehydrating and purifying industrial-grade dimethyl carbonate according to claim 1, characterized in that: The resulting reaction product is heated to 70-85ºC and fed into a distillation column.
5. The method for dehydrating and purifying industrial-grade dimethyl carbonate according to claim 1, characterized in that: The top pressure of the distillation column is 0.95-0.1 MPa, the top temperature is 62-65ºC, and the top reflux ratio is 1-5.
6. The method for dehydrating and purifying industrial-grade dimethyl carbonate according to claim 1, characterized in that: The bottom temperature of the distillation column is 87-91ºC.
7. The method for dehydrating and purifying industrial-grade dimethyl carbonate according to claim 1, characterized in that: The dehydrating agent is sodium methoxide, the adsorbent is type A molecular sieve, the mixing reaction temperature is 60ºC, the reaction time is 2h, and the mixing reaction is accompanied by stirring at a stirring rate of 150r / min. The obtained reaction product is heated to 80ºC and sent to a distillation column. The top pressure of the distillation column is 0.1MPa, the top temperature is 65ºC, the top reflux ratio is 2, and the bottom temperature is 90ºC.
8. The method for dehydrating and purifying industrial-grade dimethyl carbonate according to claim 1, characterized in that: The distillation column uses one or a combination of two of the following: wire mesh corrugated packing and perforated plate corrugated packing.
9. A dehydration and purification system for industrial-grade dimethyl carbonate, characterized in that, Includes a stirred reactor (2) and a distillation column (6); The outlet of the stirred reactor (2) is connected to the inlet of the distillation column (6) through the reaction product conveying pipeline (3); The top of the distillation column (6) is provided with a top distillate conveying pipeline (7), and the end of the top distillate conveying pipeline (7) is connected to a top condenser (9). The top condenser (9) is connected to two material discharge pipelines, one of which is connected to the upper part of the distillation column (6), and the other is used to output the top product. The bottom of the distillation column (6) is provided with a bottom distillate conveying pipeline (11). The bottom distillate conveying pipeline (11) is divided into two branch pipelines. One branch pipeline is connected to the lower part of the distillation column (6), and the other branch pipeline is used to output electronic grade dimethyl carbonate.
10. The industrial-grade dimethyl carbonate dehydration and purification system according to claim 9, characterized in that, A first heat exchanger (5) is installed on the reaction product conveying pipeline (3), a second heat exchanger (8) is installed on the top distillate conveying pipeline (7), and a reboiler (12) is installed on the branch pipeline connected to the lower part of the distillation column (6).