Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C19/00—Acyclic saturated compounds containing halogen atoms
  • C07C19/08—Acyclic saturated compounds containing halogen atoms containing fluorine
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C17/00—Preparation of halogenated hydrocarbons
  • C07C17/07—Preparation of halogenated hydrocarbons by addition of hydrogen halides
  • C07C17/087—Preparation of halogenated hydrocarbons by addition of hydrogen halides to unsaturated halogenated hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C17/00—Preparation of halogenated hydrocarbons
  • C07C17/38—Separation; Purification; Stabilisation; Use of additives

Definitions

• the present invention relates to a process for the production of 1,1,1,2,3,3,3-heptafluoropropane from hexafluoropropene and to a process for the separation of mixtures comprising 1,1,1,2,3,3,3-heptafluoropropane and hydrogen fluoride.
• reaction product phase-separates in the liquid phase to afford an organic-rich phase, which comprises HFC 227ea and HFP, and a hydrogen fluoride-rich phase.
• the mole fraction of HF to 227ea in the reaction product may be from about 0.1 to 0.9.
• the reaction mixture charged to the liquid-phase separator in Step (A) comprises an HFC 227ea/HF azeotrope, or azeotrope-like mixture, and optionally an HFP/HF azeotrope, or azeotrope-like mixture.
• the reaction mixture charged to the liquid-phase separator in Step A may be the mixture arising directly from the reactor in which HFP is reacted with hydrogen fluoride (direct mixture). It is often preferred, however, that the mixture charged to the liquid-phase separator is essentially an HFC 227ea/hydrogen fluoride azeotrope, for example obtained from distillation of the direct mixture.
• reaction of HFP with hydrogen fluoride in the process according to the first aspect of the present invention may be carried out in the liquid phase or in the vapour phase.
• Step A is preferably carried out at below ambient temperature, typically at below 30°C.
• Bottoms line (9) from the liquid-phase separator (7) is in fluid-flow communication with a second distillation column (10), which is for example a packed column.
• Distillation column (10) is typically operated at a pressure of around 12 bars with a tops temperature of 37°C and a bottoms temperature of around 60°C.
• Distillation column (10) is provided with an exit pipe for product (11) and a tops pipe (12).
• a stream comprising HFP and essentially all the hydrogen fluoride content of the stream entering distillation column (10) via line (9) is removed from the top of distillation column (1Q) via line (12) and the product stream HFC 227ea is removed from the bottom of column (10) via exit pipe (11).
• feed pipe (1) leads to a reactor (2), which optionally contains a fluorination catalyst.
• Line (14) from reactor (2) is provided with a feed line (13) and is in fluid-flow communication with a liquid-phase separator (7).
• Tops line (8) from the liquid-phase separator (7) is in fluid- flow communication with feed-pipe (1).
• Bottoms line (9) from the liquid-phase separator (7) is in fluid-flow communication with a distillation column (10), which is for example a packed column.
• Distillation column (10) is typically operated at a pressure of around 12 bars with a tops temperature of 37°C and a bottoms temperature of around 60°C.
• Distillation column (10) is provided with an exit pipe for product (11) and a tops pipe (12) which is in fluid flow communication with line (14) to liquid-phase separator (7).
• the organics-rich phase flows via bottoms line (9) to distillation column (10).
• a stream comprising HFP and essentially all the hydrogen fluoride content of the stream entering distillation column (10) via line (9) is removed from the top of distillation column (10) via line (12) and returned to the liquid phase separator (7) via line (14).
• the product stream HFC 227ea is removed from the bottom of column (10) via exit pipe (11).
• compositions in the area of the figure designated A phase-separate namely compositions comprising 0.4-0.6 mole % HF, greater than 0.4 mole % HFP and less than 0.6 mole % HFC 227ea.
• a phase-separate namely compositions comprising 0.4-0.6 mole % HF, greater than 0.4 mole % HFP and less than 0.6 mole % HFC 227ea.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)

Applications Claiming Priority (5)

Publications (1)

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Family Cites Families (3)

• 2000
  • 2000-05-15 EP EP00927586A patent/EP1178950A1/en not_active Withdrawn
  • 2000-05-15 JP JP2000618218A patent/JP2002544248A/ja active Pending
  • 2000-05-15 WO PCT/GB2000/001861 patent/WO2000069797A1/en active IP Right Grant
  • 2000-05-15 CA CA002373437A patent/CA2373437A1/en not_active Abandoned
  • 2000-05-15 AU AU45977/00A patent/AU769137B2/en not_active Ceased

Non-Patent Citations (1)

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