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CN-122006807-A - Catalyst for preparing vinylene carbonate, preparation method and method for preparing vinylene carbonate by using catalyst

CN122006807ACN 122006807 ACN122006807 ACN 122006807ACN-122006807-A

Abstract

The invention discloses a catalyst for preparing vinylene carbonate, a preparation method and a method for preparing vinylene carbonate, which comprises the steps of taking chloroethylene carbonate as a raw material, and carrying out catalytic reaction in a fixed bed to generate gas-phase vinylene carbonate. The method for preparing the vinylene carbonate can directly obtain the vinylene carbonate crude product with the purity of more than 98 percent by one-step reaction, and can directly carry out melt crystallization purification without rectification purification to obtain the vinylene carbonate product with the purity of more than 99.995 percent. The method for preparing the vinylene carbonate disclosed by the invention has the advantages of simple process, simple equipment, simple catalyst preparation and low cost, can realize large-scale production, and has wide application prospect.

Inventors

  • TIAN BO
  • DING YULONG
  • WANG JIE
  • LIN ZENGHUI

Assignees

  • 万华化学集团股份有限公司

Dates

Publication Date
20260512
Application Date
20241112

Claims (10)

  1. 1. A catalyst for preparing vinylene carbonate is characterized by comprising a carrier and an active component, wherein the carrier is a mixture of the vinylene carbonate and the polyvinyl carbonate, and the active component is chloride or oxide of calcium, barium, nickel, magnesium and copper.
  2. 2. The catalyst according to claim 1, characterized in that the mass ratio of the polyvinyl carbonate to the polyvinyl carbonate is 1:5-1:100, preferably 1:10-1:50; Preferably, the addition mass of the active component is 0.5% -10%, preferably 2% -8% of the total mass of the poly (ethylene carbonate) and the poly (ethylene carbonate).
  3. 3. A method for preparing the catalyst for preparing vinylene carbonate according to claim 1 or 2, comprising the steps of: 1) Mixing vinylene carbonate, ethylene carbonate and triethylamine, and heating at T1; 2) Heating to T2, adding one or more active components into the mixed solution, adding triethylamine hydrochloride, and stirring thoroughly; 3) Heating to T3, introducing nitrogen preheated to T3 into the mixed liquid, and coking the mixed liquid to generate solid precipitate; 4) Calcining the generated solid to obtain the catalyst.
  4. 4. The method according to claim 3, wherein the mass ratio of vinylene carbonate to ethylene carbonate in the step 1) is 1:5-1:100, preferably 1:10-1:50, and the mass ratio of vinylene carbonate to triethylamine is 1:0.005-1:0.2, preferably 1:0.02-1:0.1.
  5. 5. The process according to claim 3 or 4, wherein the temperature T1 in step 1) is 50-80 ℃, preferably 65-75 ℃.
  6. 6. A process according to claim 3, wherein the T2 temperature in step 2) is 60-100 ℃, preferably 80-90 ℃.
  7. 7. The preparation method according to claim 3 or 6, wherein the active component in the step 2) is selected from one or more of calcium chloride, barium chloride, nickel chloride, magnesium chloride, copper chloride, cuprous chloride, calcium oxide, barium oxide, nickel oxide, magnesium oxide, copper oxide, and cuprous oxide, preferably one or more of calcium chloride, barium chloride, nickel chloride, magnesium chloride, copper chloride, and cuprous chloride; preferably, the addition mass of the active component is 0.5% -10% of the total mass of vinylene carbonate and ethylene carbonate, preferably 2% -8%; More preferably, the mass ratio of the added triethylamine hydrochloride to the vinylene carbonate is 0.01:1-0.2:1, preferably 0.03:1-0.1:1.
  8. 8. A process according to claim 3, wherein the T3 temperature in step 3) is 120-200 ℃, preferably 150-180 ℃, and/or Calcining in the step 4) for 5-30h in a nitrogen atmosphere at 300-500 ℃.
  9. 9. A process for preparing vinylene carbonate using the catalyst of claim 1 or 2 or the catalyst prepared by the preparation process of any of claims 3-8, characterized by comprising the steps of: A) Preheating liquid-phase chloroethylene carbonate, and introducing the preheated liquid-phase chloroethylene carbonate into a fixed bed filled with a catalyst for dehydrochlorination reaction; B) The product after the reaction is subjected to gas-liquid separation, wherein the liquid phase is unreacted chloroethylene carbonate, and the gas phase is vinylene carbonate and hydrogen chloride; C) Condensing the gaseous phase to obtain liquid phase of vinylene carbonate, and feeding the gaseous phase hydrogen chloride into an alkali absorption device.
  10. 10. The process according to claim 9, wherein in step a), after loading the prepared catalyst into a fixed bed, ammonia is introduced at 400-600 ℃ for 2-10 hours, preferably at 450-550 ℃ for 5-8 hours; Preferably, the preheating temperature of the chloroethylene carbonate in the step A) is 80-120 ℃, preferably 90-110 ℃, and the feeding space velocity of the chloroethylene carbonate is 0.1-10m/s, preferably 2-7m/s; preferably, the reaction temperature in step A) is 70-130 ℃, preferably 80-115 ℃, and the pressure is 50PaA-1000PaA, preferably 100PaA-500PaA; Preferably, the condensation temperature in step C) is between 10 and 25 ℃, preferably between 14 and 20 ℃.

Description

Catalyst for preparing vinylene carbonate, preparation method and method for preparing vinylene carbonate by using catalyst Technical Field The invention belongs to the technical field of chemical synthesis, and relates to a catalyst for preparing vinylene carbonate, a preparation method and a method for preparing vinylene carbonate by using the catalyst. Background Vinylene Carbonate (VC) is a core additive of lithium battery electrolyte, and can promote formation of a solid electrolyte interface film (SEI film) in initial charge and discharge of a lithium battery. The membrane has stable electrochemical performance, and can effectively inhibit solvent molecule intercalation, thereby avoiding the reduction of performances such as battery cycle life and the like. At present, only one industrialized mature method for preparing VC is to take chloroethylene carbonate (CEC) as a raw material, add a certain amount of CEC, solvent and polymerization inhibitor into a reaction kettle, then drop triethylamine at a certain temperature, perform acid-binding elimination reaction on the triethylamine and CEC to generate VC and triethylamine hydrochloride, perform solid-liquid separation after the reaction, obtain a VC crude product with purity of more than or equal to 97% after separation procedures of desolventizing, decoking, light removal and rectification, and the VC crude product enters a melting crystallization procedure to obtain a qualified VC product after crystallization, and the triethylamine hydrochloride enters a triethylamine recovery procedure to recover triethylamine. The traditional production method is intermittent production, the production batch time is long, the production efficiency is low, because solid triethylamine hydrochloride is generated in the reaction process, the solubility of the hydrochloride in solvents and products is poor, if a continuous process is adopted, engineering problems such as pipeline blockage and the like are difficult to avoid, in addition, because VC has thermosensitive property, the generated VC cannot leave a reaction system in the long-time reaction process, polymerization side reaction occurs, the reaction selectivity is less than 75%, VC products can be obtained by separating the reacted VC through a plurality of processes, and the yield is further reduced because of the further polymerization side reaction of the thermosensitive property in the separation process. In summary, the traditional process for preparing VC has the advantages of high raw material energy consumption, more three wastes, high treatment cost, long flow, complex working procedure and high equipment investment. Therefore, the production efficiency is improved, the selectivity of VC is improved, and the VC preparation process is simplified, so that the VC preparation method is a main optimization direction. CN114797957A provides a solid catalyst which can be used in the reaction of preparing vinylene carbonate by liquid phase catalytic removal of hydrogen chloride from chloroethylene carbonate, and can effectively improve the conversion rate of chloroethylene carbonate and the selectivity of vinylene carbonate, wherein the catalyst comprises a carrier and an active component, the carrier is a molecular sieve, the active component is hydroxide, carbonate and bicarbonate of IA main groups and IIA main groups, and the molecular sieve is at least one of Y, beta, MOR, ZSM and magnesium aluminum hydrotalcite. The reaction is liquid phase reaction, the products after the reaction are VC and a large amount of unreacted CEC, and the VC is inevitably caused to undergo thermosensitive polymerization in the subsequent separation process due to the higher boiling point of CEC, so that the yield loss is caused. Introducing nitrogen and fluoroethylene carbonate into a fixed bed reactor in the presence of a catalyst in CN115043812A to react to obtain vinylene carbonate, wherein the catalyst is an acidic catalyst, and the acidic catalyst is activated carbon, aluminum fluoride, chromium fluoride, magnesium fluoride, aluminum oxyfluoride, chromium oxyfluoride, magnesium oxyfluoride, aluminum fluochloride, chromium fluochloride or magnesium fluochloride. The method does not generate liquid waste and solid waste, the synthesis process is environment-friendly and simple, but the raw material fluoroethylene carbonate is difficult to obtain, the price of the fluoroethylene carbonate is close to that of the vinylene carbonate in the market at present, and the synthesis cost is high. CN117402134A provides a solvent-free method for preparing vinylene carbonate, which comprises the following specific operation steps of mixing chloroethylene carbonate with a catalyst, heating to a reaction temperature, introducing protective gas, and performing dechlorination reaction, wherein the catalyst is a supported Schiff base metal complex catalyst, and comprises an A1 2O3 carrier and an active component supported on the carrier, and