Process for the manufacture of 1,1,1,3,3-pentafluoropropene, 2-chloro-pentafluoropropene and compositions comprising saturated derivatives thereof

#This invention relates to fluorine-substituted hydrocarbons, and more particularly to processes for producing CF3CH═CF2, CF3CCl═CF2 and saturated derivatives thereof such as CF3CH2CF3, CF3CH2CHF2 and CF3CHFCF3, and to compositions comprising the saturated derivatives (e.g., azeotropes of said saturated derivatives with HF and uses of said azeotropes).

#A number of chlorine-containing halocarbons are considered to be detrimental toward the Earth's ozone layer. There is a world-wide effort to develop materials having lower ozone depletion potential that can serve as effective replacements. For example, the hydrofluorocarbon, 1,1,1,2-tetrafluoro-ethane (HFC-134a) is being used as a replacement for dichlorodifluoromethane (CFC-12) in refrigeration systems. The production of hydrofluorocarbons (i.e., compounds containing only carbon, hydrogen and fluorine), has been the subject of considerable interest to provide environmentally desirable products for use as solvents, blowing agents, refrigerants, cleaning agents, aerosol propellants, heat transfer media, dielectrics, fire extinguishants and power cycle working fluids (see, e.g., PCT International Publication No. WO 93/02150).

#A process is provided in accordance with this invention for producing pentafluoropropenes of the formula CF3CX═CF2, where X is H or Cl. The process comprises hydrodehalogenating CF3CCl2CF3 with hydrogen at an elevated temperature in the vapor phase over a catalyst comprising at least one component selected from the group consisting of elemental metals, metal oxides, metal halides and metal oxyhalides; wherein the metal of said hydrodehalogenation catalyst component is selected from copper, nickel, chromium and mixtures thereof and the halogen of said halides and said oxyhalides is selected from fluorine, chlorine and mixtures thereof.

#Aqueous calcium nitrate (2.7 moles) is mixed with aqueous potassium fluoride (5.4 moles), heated and stirred briefly at 100° C. to form a slurry of CaF2. To this slurry is added copper nitrate (1 mole), nickel nitrate (1 mole) and chromium nitrate (1 mole) as solids. The slurry is stirred at 70 to 80° C. until the salts, other than CaF2, dissolve. This is followed by adding 0.1 mole of aqueous potassium hydroxide over 1 hour and boiling the mixture briefly. The slurry is cooled to 40 to 50° C. and filtered. The solid is washed exhaustively to reduce the potassium content to an undetectable level. After drying, potassium hydroxide is added as a solution in quantities sufficient to provide a catalyst containing 9 weight % potassium. After drying again, the catalyst is calcined at 600° C. for 8 to 16 hours, then granulated and screened to 1 to 2 mm particles. The catalyst is mixed with 1 to 5 wt % “Sterotex” powdered lubricant (registered trademark of Capital City Products Co., Columbus Ohio, division of Stokely-Van Camp, for its edible hydrogenated vegetable oil) to give ⅛″×⅛″ (3.2 mm ×3.2 mm) cylindrical pellets from a Stokes tablet machine.

#The products leaving the reactor were analyzed on line using a gas chromatograph. The column consisted of a 20′ (6.1 m) ×⅛″ (3.2 mm) stainless steel tube containing Krytox™ perfluorinated polyether on an inert support. Helium was used as the carrier gas. The product analyses are reported in mole %.

#Legend: