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CN-122010700-A - Continuous production process of perfluoro-pentanone

CN122010700ACN 122010700 ACN122010700 ACN 122010700ACN-122010700-A

Abstract

The invention belongs to the technical field of preparation of perfluoro-pentanone, and particularly relates to a continuous production process of perfluoro-pentanone. The continuous production process of the perfluoro-pentanone comprises the following steps of filling a fluorination catalyst into a reaction tube, blowing nitrogen, introducing mixed and preheated hexafluoropropylene and trifluoro-acetyl fluoride gas into the reaction tube for continuous reaction, partially condensing the reacted gas to obtain the target product perfluoro-pentanone, and circularly returning the other part to the mixed and preheated stage. According to the continuous production process of the perfluoropentanone, hexafluoropropylene and trifluoroacetyl fluoride are used as raw materials, the perfluoropentanone is rapidly synthesized by adopting a one-step gas phase continuous flow under the action of a MgF 2 -based fluorination catalyst, a solvent is not required to be introduced, the raw material trifluoroacetyl fluoride is taken from byproducts for preparing hexafluoropropylene oxide, the raw materials are easy to obtain, the process route is simple, the conversion rate is high, the selectivity is high, and the industrial mass production is easy.

Inventors

  • YU KEBO
  • YANG ZEWEI
  • WU HAIPENG
  • QI XIANGDONG
  • JING BIN
  • CUI HUAILEI
  • LIU ZHIQIANG

Assignees

  • 山东齐氟新材料有限公司
  • 山东中柔新材料有限公司

Dates

Publication Date
20260512
Application Date
20260414

Claims (9)

  1. 1. A continuous production process of perfluoro pentanone, characterized in that it is carried out in a tubular reactor, comprising the following steps: filling a fluorination catalyst into a reaction tube, after nitrogen purging, introducing mixed gas of hexafluoropropylene and trifluoroacetyl fluoride after mixed preheating into the reaction tube for continuous reaction, and partially condensing the reacted gas to obtain a target product of perfluoropentanone, wherein the other part is circularly returned to the mixed preheating stage; The fluorination catalyst is MgF 2 -based fluorination catalyst, and is prepared by taking anhydrous MgCl 2 , anhydrous Fe (NO 3 ) 3 、La 2 O 3 、NH 4 HF 2 and graphite powder as effective components through solid-phase grinding, forming, roasting, fluorination and activation treatment.
  2. 2. The continuous process for producing perfluoropentanone according to claim 1, wherein the bulk density of the fluorination catalyst in the tubular reactor is 0.25-0.80g/cm 3 .
  3. 3. The continuous production process of perfluoropentanone according to claim 1, wherein the pressure of the continuous reaction is 0.05-0.1MPa and the reaction temperature is 200-300 ℃.
  4. 4. The continuous production process of perfluoro pentanone according to claim 1, wherein the molar ratio of hexafluoropropylene to trifluoroacetyl fluoride is 1 (1-2), and the inflow rate of the mixed gas is 100-500mL/min.
  5. 5. The continuous production process of perfluoro pentanone according to claim 1, wherein said MgF 2 -based fluorination catalyst preparation method comprises the steps of: (1) Mixing anhydrous MgCl 2 , anhydrous Fe (NO 3 ) 3 、La 2 O 3 、NH 4 HF 2 and graphite powder) as effective components, grinding for 4-5h at room temperature, and performing compression molding by adopting a mold with the aperture of 1-3mm to obtain cylindrical wet particles; (2) Placing wet particles in a muffle furnace, roasting under nitrogen atmosphere, absorbing roasting tail gas by adopting an alkaline absorbent, and naturally cooling to obtain catalyst particles; (3) Before use, the catalyst particles are transferred into a fixed bed reactor, mixed gas of HF/N 2 is introduced, and the finished MgF 2 -based fluorination catalyst is obtained after activation treatment.
  6. 6. The continuous production process of perfluoro pentanone according to claim 5, wherein in the step (1), the mass ratio of anhydrous MgCl 2 , anhydrous Fe (NO 3 ) 3 、La 2 O 3 、NH 4 HF 2 and graphite powder) is (8-10): (0.8-0.9): (0.3-0.5): (7-9): (0.7-0.9).
  7. 7. The continuous production process of perfluoro pentanone according to claim 5, wherein in the step (2), the roasting procedure is that in the first stage, the temperature is raised to 200-250 ℃ at a temperature raising rate of 2-5 ℃ per minute, and the temperature is kept for 1-2 hours, and in the second stage, the temperature is raised to 400-500 ℃ at a temperature raising rate of 2-5 ℃ per minute, and the temperature is kept for 6-8 hours.
  8. 8. The continuous process for producing perfluoropentanone according to claim 5, wherein in said step (2), the alkaline absorbent is an aqueous sodium hydroxide solution having a concentration of 10 to 15 wt.%.
  9. 9. The continuous production process of perfluoro pentanone according to claim 5, wherein in the step (3), the volume fraction of HF in the mixed gas of HF/N 2 is 5-8%, the inlet flow rate of the mixed gas of HF/N 2 is 30-60mL/min, the activation treatment temperature is 250-300 ℃, and the activation time is 2-4 hours.

Description

Continuous production process of perfluoro-pentanone Technical Field The invention belongs to the technical field of preparation of perfluoro-pentanone, and particularly relates to a continuous production process of perfluoro-pentanone. Background The perfluoro-pentanone is also called perfluoro-3-methyl-2-butanone, is a novel perfluoro-ketone compound, is colorless, odorless and nonflammable and easy to liquefy gas/liquid at normal temperature, has the characteristics of low GWP, short atmospheric life, high dielectric strength, low toxicity, good compatibility with materials and the like, is an important environment-friendly medium for replacing high GWP greenhouse gases, and has wide application prospect in the fields of electric insulation, clean fire extinguishment, electronic cleaning and the like. The synthesis of perfluoro pentanone is mainly prepared by taking perfluoro olefin and acyl fluoride/perfluoro epoxy intermediate as raw materials through liquid phase addition or gas-solid phase reaction, and the synthesis technology of perfluoro pentanone is subjected to a plurality of development stages, namely electrochemical fluorination and direct fluorination in an early laboratory stage, and has the inherent defects of poor fluoro selectivity, frequent side reaction, low product yield, serious corrosion to production equipment and the like, so that the industrial application cannot be realized all the time. The prior synthesis technology is mainly concentrated on liquid phase addition or gas-solid phase reaction preparation, CN109704935A discloses a method for preparing perfluoro-3-methyl-2-butanone, hexafluoropropylene and trifluoroacetyl fluoride are used as raw materials, and the raw materials react under the action of a liquid phase composite catalyst of main catalyst metal fluoride/fluorohydride, auxiliary catalyst C6-C9 perfluoroolefin, auxiliary agent crown ether/crown ether-like and polar aprotic solvent, so that the reaction speed is high and the product yield is high, but the liquid phase batch method has the problems of complex catalyst system and non-regenerability, and simultaneously, an organic solvent is required to be used, so that the post-treatment is complicated. CN109896936a discloses a perfluoro pentanone and its preparation method, hexafluoropropylene and trifluoroacetyl fluoride are used as raw materials, aprotic solvent is added, and the perfluoro pentanone is prepared by reaction under the action of alkali metal fluoride KF and/or NaF, the method adopts one-pot synthesis, the intermediate product is not required to be treated step by step, the process links and equipment investment are reduced, the operation flow is simpler, the catalyst cannot be recovered and regenerated by KF homogeneous catalysis, the organic solvent acetonitrile is required, the post-treatment is complicated, and the energy consumption is high; the reaction is intermittent high-pressure operation, the period is long, and unreacted raw materials are difficult to recycle. CN116037118A discloses a preparation method of perfluoro-3-methyl-2-butanone, CXY=CH 2 and 2, 2-dichloro-1, 3-hexafluoropropane are used as starting materials, and target products of perfluoro through multi-step reactions such as telomerization, fluorine-chlorine exchange, isomerization, oxidation and the like, and finally through ethylene oxide isomerization3Methyl group2Butanone adopts a gas phase reaction mode, is favorable for realizing continuous production, designs three special catalytic systems of an initiator, a fluorination catalyst and an isomerization catalyst, respectively adapts to different reaction stages of telomerization, fluorine-chlorine exchange, isomerization and the like, has high catalytic selectivity, and is favorable for ensuring the purity of a target product, but the method relates to a multi-step reaction route, has long steps, and the related raw materials have complex structures, and realizes continuous reaction, but the industrial continuous control difficulty is large. In view of the above, the prior art has developed routes such as a liquid phase one-step method, a one-pot method and a multi-step gas phase method for synthesizing perfluoropentanone, and has made a certain progress in the aspects of raw material suitability, catalytic activity or process simplification, but still has the problems of excessively relying on aprotic solvents, low catalyst selectivity and difficulty in realizing continuous production. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a continuous production process of perfluoro pentanone, which takes hexafluoropropylene and trifluoro acetyl fluoride as raw materials, adopts a one-step method for gas phase continuous flow to rapidly synthesize perfluoro pentanone under the action of MgF 2 -based fluorination catalyst, does not need to introduce a solvent, and takes the trifluoro acetyl fluoride as the raw material to be taken from by