Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C17/00—Preparation of halogenated hydrocarbons
  • C07C17/093—Preparation of halogenated hydrocarbons by replacement by halogens
  • C07C17/20—Preparation of halogenated hydrocarbons by replacement by halogens of halogen atoms by other halogen atoms
  • C07C17/21—Preparation of halogenated hydrocarbons by replacement by halogens of halogen atoms by other halogen atoms with simultaneous increase of the number of halogen atoms
• • 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
  • C07C17/383—Separation; Purification; Stabilisation; Use of additives by distillation
  • C07C17/386—Separation; Purification; Stabilisation; Use of additives by distillation with auxiliary compounds
• • 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

Definitions

• This invention relates to compositions of 1,1 ,1-trifluor ⁇ ethane (HFC-
• reaction by-products among which is 1-chloro-2,2,2-trifluoroethane (R-133a). It is highly desirable to be able to remove such reaction by-products in order to achieve purer 1 ,1 ,1-trifiuoroethane or a 1 ,1 1-trifluoroethane compositions having a boiling point within a relatively small range.
• the present inventors have discovered azeotropic or azeotropic-iike compositions of effective amounts of 1 ,1 ,1-trifluoroethane (HFC-143a) and 1-chloro- 2,2,2-trifluoroethane (R-133a).
• HFC-143a 1 ,1 ,1-trifluoroethane
• R-133a 1-chloro- 2,2,2-trifluoroethane
• the discovery of the azeotropic or azeotropic-like compositions of HFC-143a and R-133a permits such azeotropic or azetrop ⁇ c-like compositions to be distilled off from a composition containing both HFC-143a and R- 133a in a distillation coiumn whereby the concentration of R-133a at the top of the column is greater than the concentration of R-133a in the bottom of the coiumn.
• This distillation process has particular applicability in purifying HFC-143a when it is produced from the reaction of vinyi ⁇ dene chloride with HF since the azeotropic or azeotropic-like compositions of HFC-143a and R-133a can be distilled from the products of thai reaction in craer to purify the HFC-143a produced.
• tne azeoiropie or azeotropic-iike compositions of HFC-143a and R-133a permits such azeotropic or azeotropic-iike compositions to be distiliecf off from a composftion containing both HFC-143a and R-133a in a distillation column whereby the concentration of R-133a at the top of the column is greater than the concentration of R-133a in the bottom of the column.
• This distiilation process has particular applicability In purifying HFC-143a when it is produced from the reaction of vinylidene chloride with HF since the azeotropic or azeotropic-iike compositions of HFC-143a and R-133a can be distilled from the products of that reaction in order to purify the HFC-143a produced.
• the azeotropic or azeotropic-iike composition of HFC-143a and R-133a from the top of the coiumn can be recycled or sent back to IJ 16 reactor for conversion of R-133a to HFC-143a.
• tnat HFC-143a and R-133a form azeotropic or azeotropic-llke compositions naving a boiiing pomt with a relatively small range of -46.5 ⁇ 2 °C at atmospheric pressure (14.42 psia).
• the azeotropic or azeotropic-llke compositions have a boiiing point of from about -46.6 to about -47.2 °C. !n a still further embodiment, the azeotropic or azeotropfc-like compositions have a boiling point of from about -46.8 °C to about - 47.2 0 C.
• the azeotropic or azeotropic-iike compositions have a boiling point of from about -47 °C to abcut -47.2 °C. in another still further embodiment, the azeotropic or azeofropic-iike compositions have a boiling point of about -47.2 °C.
• Such azeotropfc or azeotropic-ike compositions generally are mixtures of HFC-143a and R-133a wherein the composition comprises, and preferably consists essentially of: from about 70% by weight up tc an amount just less than about 100% by weight of HFC-i43a. and from about 30% Dy weight down to an amount just more than 0% by weight of R-133a. wherein the vveight percentages are based en tne lota! weight of the composition.
• the azeotropic or azeotropic- jike compositions generally are mixtures of HFC-143a and R-133a wherein the composition comprises, and preferably consists essentially of; from about 75% by weight up to aoou ⁇ 99.9% by weight of HFC-143a, and from about 0,1% by weight to about 25% by weight of R-133a, wherein the weight percentages are based on the total weight of the composition.
• the azeotropic or azeotropic-iike composition of HFC-143a and R-133a from the top of the coiumn can be recycled or sent back to the reactor for conversion of R-133a to HFC-143a.
• the azeotropic or azeotropic-like compositions generally are mixtures of HFC-143a and R-133a wherein the composition comprises, and preferably consists essentially of: from about 90% by weight up to about 99.9% by weight of HFC-143a, and from about 0.1 % by weight to about 10% by weight R- 133a, wherein the weight percentages are based on the total weight of the composition.
• the azeotropic or azeotropic-like composition of HFC-143a and R-133a from the top of the coiumn can be recycled or sent back to the reactor for conversion of R-133a to HFC-143a.
• the inventors have also discovered that during a distillation process involving 143a and 133a mixtures, the 133a will tend to accumulate in the upper, coofer part of the coiumn, up to the azeotropic composition, instead of the bottom warmer part of the coiumn
• This property may be used ic remove the 133a, the undesirable component, from the mixture, as the pure 143a having a boiiing point higher than of the azeoirope, wil ⁇ tend to accumulate in the bottom of the column, from wnere it can be extracted.
• a distillation process of this invention wiii comprise distilling an azeoiropic cr azeotro ⁇ c- ⁇ e HFC-143a/HCFC-133a composition and as a result of the distillation the 133a concentration on the top of the column is higher than the 133a concentration in the composition in the bottom of the column.
• the azetropic or azetropic-like compositions being distiJied are azeotropic or azeotropic-Nke compositions cf effective amounts of 1,1,1-trifiuoroethane (HFC-143a) and 1-chloro- 2,2,2-trifluoroethane (R-133a).
• HFC-143a and R- 133a form azeotropic or azeotroplc-iike compositions being distilled may have a boiiing point with a relatively small range of -46.5+2 °C at atmospheric pressure (14.42 psia).
• the azeotropic or azeoiropic-Hke compositions being distilled have a boiling point of from about -46.6 to about -47.2 °C. in a still further emoodiment, the azeotropic or azeotropic-iike comp ⁇ sftions being distilled have a boiiing point of from about -46.8 °C to about -47.2 °C.
• the azeotropic or azeotropic-like compositions being distilled have a boiling point cf from about -47 °C to about -47.2 °C.
• the azeotropic or azeotropsc-iike compositions being distilled have a boiling point of aboui -47.2 °C.
• the azeotropic or azeotropic-like compositions generally are mixtures of HFC-143a and R-133a wherein the composition comprises, and preferably consists essentially of: from about 70% by weight up to an amount just iess than about 100% by weight Of HFC-143a, and from about 30% by weight down to an amount just more than 0% by weight of
• the azeotropic or azeotropic-like compositions generally are mixtures of HFC-143a and R-133a wherein tne composition comprises, and preferably consists essentially of: from about 75% by weight up to about 99.9% by weight of HFC-143a, and from about 0.1 % by weight to about 25% by weight of R-133a, wherein the weight percentages are based on the total weight o f the composition.
• the azeotropic or azeotropic-iike compositions generally are mixtures of HFC-i43a and R-133a wherein the composition comprises, and preferably consists essentially of: from about 90% by weight up to about 99.9% by weight of HFC-143a. and from about 0.1% by weight to about 10% by weight of R-133a, wherein the weight percentages are based on the tota! weight o? the composition.
• the invention wiii be partic ⁇ iariy useful when HFC-143a is produced by the reaction of vinyiidene chloride with HF and the reaction product contains HFC- 143 a and FM 33a since the afore-mentioned distillation process may be conducted on the products of that reaction to distil! off from the products of that reaction any of the azeotropic or azeotropic-like compositions as described herein before in order to purify the HFC-143a product produced.
• This invention provides azeoptropic or azeoptropic-iike compositions of
• Such azeotropic or azeotropic-like compositions generally are mixtures of HFO143a and R-133a wherein the composition comprises, and preferably consists essentially of: from about 70% by weight up to an amount just less than about 100% by weight of H FC- 143a, and from about 30% by weight down to an amouni just more than 0% by weight R-133a, wherein the weight percentages are based on the iota! weight of the composition.
• compositions will have a boiling Doini at atmospheric pressure (14.42 psia) within the relatively smali range of ⁇ 46, ⁇ 2 C C
• Preferred compositions of this invention are those consisting essentially of about 75% to about 99% by weight of HFC-143a and from about 1% to about 25% by weight of R-133a and having a boiling point at atmospheric pressure of about -46.5x2 °C. More preferred compositions of this invention are those consisting essentially of about 90% to about 99% by weight of HFC-143a and from about 1 % to about 10% by weight of R-133a and having a boiling point at atmospheric pressure of about -46.5+2 °C,
• a further aspect of this invention is a process for removing 1-chloro-
• R-133a 2,2,2-trifluoroethane (R-133a; impurity from a mixture 1 1 , 1 -trifluoroethane (HFC- 143a) and R-133a impurity comprising forming an azeotropic or azeotrope- ⁇ ke composition of the HFC-143a and R-133a, as described herein before, and thereafter separating the azeotropic or azeotrope- ⁇ ke composition from the mixture.
• HFC- 143a 2,2,2-trifluoroethane
• R-133a impurity from a mixture 1 1 , 1 -trifluoroethane (HFC- 143a) and R-133a impurity comprising forming an azeotropic or azeotrope- ⁇ ke composition of the HFC-143a and R-133a, as described herein before, and thereafter separating the azeotropic or azeotrope- ⁇ ke composition from the mixture.
• azeotropic or azeotropic-like ccmpositions of this invention are illustrated by. but not limited to. the following examples in Table 1 of composiiions having a boiling point within the range of - 46.5 ⁇ 2 °C.

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

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• 2006
  • 2006-08-17 US US11/506,129 patent/US7608574B2/en active Active
• 2007
  • 2007-08-15 EP EP07840964A patent/EP2051954B1/en not_active Not-in-force
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