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CN-120518477-B - Production process method of electronic grade diethyl carbonate

CN120518477BCN 120518477 BCN120518477 BCN 120518477BCN-120518477-B

Abstract

The invention relates to the technical field of fine chemical engineering, and particularly discloses a production process method of electronic grade diethyl carbonate. The method comprises the steps of carrying out transesterification reaction on ethylene carbonate and absolute ethyl alcohol in a microwave reaction kettle under the catalysis of a composite catalyst, obtaining an intermediate by adopting a continuous separation process of normal pressure and reduced pressure rectification coupling after phase separation treatment of reaction liquid, removing metal impurities and moisture through molecular sieve adsorption, and realizing ultra-clean purification by combining polytetrafluoroethylene membrane precise filtration, wherein the composite catalyst can obviously improve transesterification reaction efficiency and product selectivity. The technology realizes the efficient removal of moisture, metal impurities and nano-scale particles in a reaction system through the synergistic effect of reaction process reinforcement and a multi-stage purification technology, and the purity of the prepared electronic grade diethyl carbonate meets the severe requirements of the field of high-end electronic chemicals such as lithium battery electrolyte and the like, and has the technical advantages of short reaction period, thorough impurity removal, high product purity and the like.

Inventors

  • LAN Chen Shenghui
  • CHEN FANG
  • ZHOU ZHIWEI
  • KANG JIAN

Assignees

  • 安徽利安德新材料科技有限公司

Dates

Publication Date
20260505
Application Date
20250519

Claims (8)

  1. 1. The production process of electronic grade diethyl carbonate is characterized by comprising the following steps: S1, adding ethylene carbonate and absolute ethyl alcohol into a microwave reaction kettle, adding a composite catalyst, introducing inert gas to replace air, starting microwave heating, controlling the microwave frequency to be 2000-2500MHz, the power to be 200-400W, the reaction temperature to be 60-70 ℃ and the pressure to be 0.04-0.06MPa, and stirring and reacting for 25-35min to obtain a crude reaction solution containing diethyl carbonate, ethanol and ethylene glycol; s2, cooling the crude reaction liquid, adding sodium carbonate for phase separation, separating an upper organic phase, and sequentially pumping the organic phase into a normal pressure rectifying tower and a reduced pressure rectifying tower for continuous separation to obtain a diethyl carbonate intermediate; S3, adsorbing the diethyl carbonate intermediate through a fixed bed reactor filled with molecular sieve to remove water and metal impurities, and filtering by a polytetrafluoroethylene film to intercept particles with the particle size of 0.05-0.2 mu m to obtain electronic grade diethyl carbonate; The preparation steps of the composite catalyst in the step S1 are as follows: Dispersing hexagonal boron nitride in N-methylpyrrolidone, adding sodium dodecyl benzene sulfonate, carrying out ultrasonic stripping for 3-5h, centrifuging and drying to obtain boron nitride nano-sheets, dispersing the boron nitride nano-sheets and alumina nano-particles in absolute ethyl alcohol, carrying out ultrasonic dispersion for 30-40min, stirring and blending at 70-80 ℃ for 2-4h, centrifuging and drying to obtain a composite carrier; a2, dispersing the composite carrier in toluene, adding 3-aminopropyl trimethoxy silane, reacting for 4-6 hours at 80-100 ℃ under the protection of nitrogen, washing and drying to obtain an intermediate, dispersing the intermediate in toluene, adding 3-glycidol ether oxypropyl trimethoxy silane, reacting for 5-7 hours at 90-110 ℃ under the protection of nitrogen, washing and drying to obtain a modified composite carrier; a3, dispersing the modified composite carrier and the 1-butyl-3-methylimidazole glycolate into deionized water, adjusting the pH to 10-12, reacting for 6-8 hours at 50-70 ℃, then adding the 1-propylsulfonic group-3-methylimidazole bisulfate, continuously reacting for 7-9 hours at 60-80 ℃, and washing and drying to obtain the composite catalyst.
  2. 2. The process for producing electronic grade diethyl carbonate according to claim 1, wherein in step S1, 10-15 parts by weight of ethylene carbonate, 8-12 parts by weight of absolute ethyl alcohol and 0.4-0.8 part by weight of a composite catalyst are calculated.
  3. 3. The process for producing electronic grade diethyl carbonate according to claim 1, wherein in step S2, the temperature of the top of the atmospheric rectification column is 75-80 ℃, the temperature of the bottom of the column is 115-125 ℃, the vacuum degree of the vacuum rectification column is-0.08 to-0.1 MPa, the temperature of the top of the column is 80-90 ℃, and the temperature of the bottom of the column is 105-115 ℃.
  4. 4. The process for producing electronic grade diethyl carbonate according to claim 1, wherein in step S3, the adsorption temperature is 45-55 ℃ and the flow rate is 0.3-0.7BV/h.
  5. 5. The process for producing electronic grade diethyl carbonate according to claim 1, wherein the molecular sieve in the step S3 consists of 3A and 13X type molecular sieves with a mass ratio of 1-3:1, and the filling height of the mixed molecular sieve is 4-6 times of the diameter of the bed.
  6. 6. The process for producing electronic grade diethyl carbonate according to claim 1, wherein in the step A1, 10-15 parts by weight of hexagonal boron nitride, 80-90 parts by weight of N-methylpyrrolidone, 1-3 parts by weight of sodium dodecyl benzene sulfonate, 10-15 parts by weight of boron nitride nano-sheets, 5-8 parts by weight of alumina nano-particles and 70-80 parts by weight of absolute ethyl alcohol are calculated.
  7. 7. The process for producing electronic grade diethyl carbonate according to claim 1, wherein in step A2, 10-15 parts by weight of a composite carrier, 60-70 parts by weight of toluene and 2-5 parts by weight of 3-aminopropyl trimethoxysilane, and 10-15 parts by weight of an intermediate, 60-70 parts by weight of toluene and 3-6 parts by weight of 3-glycidoxypropyl trimethoxysilane are used.
  8. 8. The process for producing electronic grade diethyl carbonate according to claim 1, wherein in the step A3, 3-6 parts of modified composite carrier, 0.3-0.8 part of 1-butyl-3-methylimidazole glycolate, 30-40 parts of deionized water and 0.5-1 part of 1-propylsulfonic acid group-3-methylimidazole bisulfate are calculated according to parts by weight.

Description

Production process method of electronic grade diethyl carbonate Technical Field The invention relates to the technical field of fine chemical engineering, in particular to a production process method of electronic grade diethyl carbonate. Background Diethyl carbonate is used as an important lipid compound, and becomes a key component of high-end electronic chemicals such as lithium ion battery electrolyte, semiconductor photoresist and the like due to good chemical stability and solubility. The electronic grade diethyl carbonate has extremely high purity requirement, moisture, metal ions and nano-grade particle impurities are required to be strictly controlled, and the preparation technology is characterized in that the efficient transesterification reaction control and precise purification process design are adopted. At present, the industrial preparation of diethyl carbonate mainly adopts an ester exchange method, takes ethylene carbonate or propylene carbonate and ethanol as raw materials, and is generated through ester exchange reaction under the action of a catalyst. However, these conventional processes have disadvantages in that, on the one hand, dimethyl carbonate produced by the reaction forms an azeotrope with methanol or ethanol, resulting in difficulty in separating the product from the raw materials, and affecting the yield and purity of diethyl carbonate. On the other hand, the traditional catalyst usually adopts a homogeneous phase or solid catalyst, and has the problems of difficult catalyst separation, low selectivity, easy occurrence of side reaction and the like, so that the yield and purity of the target product are limited, the reaction condition is more severe, high temperature and high pressure are usually required, the energy consumption is high, and the production efficiency is low. Therefore, the invention provides a production process method of electronic grade diethyl carbonate, which aims to solve the technical problems. Disclosure of Invention The invention aims to provide a production process method of electronic grade diethyl carbonate, which realizes the efficient removal of moisture, metal impurities and nano-grade particles in a reaction system through the synergistic effect of reaction process reinforcement and a multi-stage purification technology, and the purity of the prepared electronic grade diethyl carbonate meets the severe requirements of the field of high-end electronic chemicals such as lithium battery electrolyte and the like, and has the technical advantages of short reaction period, thorough impurity removal, high product purity and the like. The production process of electronic grade diethyl carbonate includes the following steps: S1, adding ethylene carbonate and absolute ethyl alcohol into a microwave reaction kettle, adding a composite catalyst, introducing inert gas to replace air, starting microwave heating, controlling microwave heating conditions, reaction temperature and pressure, and stirring for reaction to obtain a crude reaction solution containing diethyl carbonate, ethanol and ethylene glycol; S2, cooling the crude reaction liquid to 20-30 ℃, adding sodium carbonate for phase separation, separating an upper organic phase, and sequentially pumping the organic phase into a normal pressure rectifying tower and a reduced pressure rectifying tower for continuous separation to obtain a diethyl carbonate intermediate; S3, adsorbing the diethyl carbonate intermediate through a fixed bed reactor filled with molecular sieve to remove water and metal impurities, and filtering by a polytetrafluoroethylene film to intercept particles with the particle size of more than 0.05-0.2 mu m to obtain the electronic grade diethyl carbonate. Preferably, in step S1, 10-15 parts by weight of ethylene carbonate, 8-12 parts by weight of absolute ethyl alcohol and 0.4-0.8 part by weight of a composite catalyst are calculated. Preferably, in the step S1, the microwave frequency is 2000-2500MHz, the power is 200-400W, the reaction temperature is 60-70 ℃, the pressure is 0.04-0.06MPa, and the stirring reaction time is 25-35min. Preferably, the process for producing electronic grade diethyl carbonate according to claim 1 in step S2 is characterized in that the temperature at the top of the atmospheric rectification column in step S2 is 75-80 ℃, the temperature at the bottom of the atmospheric rectification column is 115-125 ℃, the vacuum degree of the vacuum rectification column is-0.08-0.1 MPa, the temperature at the top of the atmospheric rectification column is 80-90 ℃, and the temperature at the bottom of the atmospheric rectification column is 105-115 ℃. Preferably, in the step S3, the adsorption temperature is 45-55 ℃ and the flow rate is 0.3-0.7BV/h. Preferably, the molecular sieve in the step S3 consists of 3A and 13X type molecular sieves with the mass ratio of 1-3:1, and the filling height of the mixed molecular sieve is 4-6 times of the diameter of the bed layer. P