E.i. Dupont De Nemours and Company

William H Gumprecht

Vinci Martinez Felix

Barry Asher Mahler

Leo E Manzer

V N Rao

Richard E Fernandez

Wesley Gerald Schindel

Kaplan, Ralph B

William Joel Huebner

John A Wehner

William J Steiner

A process is disclosed for treating used aluminum chlorofluoride catalyst either alone or mixed with organics. It involves forming a solution of the catalyst in water or an aqueous acid and then adjusting the pH and/or composition of the aqueous phase formed to precipitate compounds containing the aluminum and/or fluorine.

Recovery of aluminum and/or fluoride values from used aluminum

A process for the manufacture of a hydrochlorofluoropropane by halogen exchange using SbF.sub.5-y Cl.sub.y, where y=0 to 1, at 50.degree.-100.degree. C. to fluorinate a hydrochlorofluoropropane precursor characterized by the formula C.sub.3 HCl.sub.7-x F.sub.x, where x=2 to 5 and H is at a terminal carbon, wherein the degree of halogen exchange, p, and the number of moles, n, of SbF.sub.5-y Cl.sub.y per mole of precursor is such that (5-y)-(p/n) is at least 3. Such a process produces a more highly fluorinated hydrochlorofluoropropane substantially free of perhalogenated or carbon--carbon cleavage products.

Halogen exchange process for manufacture of hydrochlorofluoropropanes

An improved process for the manufacture of CF.sub.3 CHF.sub.2 by contacting CF.sub.3 CHCl.sub.2 or CF.sub.3 CHClF with HF in the presence of a Cr.sub.2 O.sub.3 catalyst prepared by pyrolysis of ammonium dichromate, the reaction being conducted under controlled conditions whereby the production of CF.sub.3 CHF.sub.2 is maximized, and the formation of chloropentafluoroethane (CF.sub.3 CClF.sub.2) and other perhalo derivatives is minimized. The subject hydrogen-containing compound is useful as a blowing agent, propellant, refrigerant, fire extinguishing agent, or sterilant carrier gas.

Process for the manufacture of pentafluoroethane

An improved process for the manufacture of CF.sub.3 CHF.sub.2 by contacting 1,2-dichloro-1,1,2-trifluoroethane (CClF.sub.2 CHClF) or 1-chloro-1,1,2,2-tetrafluoroethane (CHF.sub.2 CClF.sub.2) or mixtures of CF.sub.3 CHCl.sub.2 and CClF.sub.2 CHClF or mixtures of CF.sub.3 CHClF and CHF.sub.2 CClF.sub.2 with HF in the presence of a Cr.sub.2 O.sub.3 catalyst prepared by pyrolysis of ammonium dichromate, the reaction being conducted under controlled conditions whereby the production of CF.sub.3 CHF.sub.2 is maximized, and the formation of chloropentafluoroethane (CF.sub.3 CClF.sub.2) and other perhalo derivatives is minimized. The subject hydrogen-containing compound is useful as a blowing agent, propellant, refrigerant, fire extinguishing agent, or sterilant carrier gas.

A process for converting the isomers of HCFC-123 to HCFC-123 using TaF.sub.5 and/or Nb.sub.5 in the absence of HF.

Isomerization process

An improved process is disclosed for the manufacture of 1,1,1,2-tetrafluoroethane by the vapor-phase reaction of 2-chloro-1,1,1-trifluoroethane with hydrogen fluoride in the presence of an inorganic chromium (III) catalyst which includes co-feeding molecular chlorine to extend catalyst activity.

Process for manufacture of 1,1,1,2-tetrafluoroethane

An improved process for preparing 1,1-dichloro-1-fluoroethane by hydrogen fluoride addition, in the vapor phase, to 1,1-dichloroethylene in the presence of an aluminum fluoride catalyst.

Process for 1,1-dichloro-1-fluoroethane

A process for fluorination by contacting a haloolefin with molten alkali metal acid fluoride to provide a fluorinated saturated or unsaturated hydrocarbon having at least one more fluorine than the starting haloolefin.

Fluorination of haloolefins

A process for preparing hydrogen fluoride that involves treating anhydrous hydrogen fluoride containing primarily trivalent arsenic impurities with an iodine compound capable of providing iodide ions (e.g., HI) so as to precipitate the arsenic (i.e., as AsI.sub.3) following by separation and recovery (e.g., by distillation or filtration) or purified anhydrous hydrogen fluoride.

Process for purifying hydrogen fluoride

Process of the preparation of highly fluorinated alkanes by contacting halogenated alkenes or alkanes with at least the molar equivalent of HF in the presence of a catalyst selected from TaF.sub.5 and NbF.sub.5 in an amount of at least 0.25 molar equivalent at a temperature of 0.degree. C. to 175.degree. C.

Catalyzed hydrofluorination process

A process for preparing hydrogen fluoride that involves treating anhydrous hydrogen fluoride containing primarily trivalent arsenic impurities with a sulfur compound capable of providing sulfide ions (e.g., H.sub.2 S) so as to precipitate the arsenic (i.e., as As.sub.2 S.sub.3) followed by separation and recovery (e.g., by distillation or filtration) of purified anhydrous hydrogen fluoride.

A process is disclosed for dissolving and dispersing spent antimony halide catalysts by contact with methylene chloride.

Spent antimony halide catalysts treatment

A process is disclosed for the manufacture of 1,1,1,2-tetrafluoroethane, FC-134a, more particularly for its manufacture from 1,1,1-trifluoro-2-chloroethane, FC-133a, by reaction with a high fluoride content antimony pentahalide.

Liquid phase halogen exchange process for the manufacture of

An improved gas-phase process for the manufacture of 1,1,1-trifluorodichloroethane and/or 1,1,1,2-tetrafluorochloroethane by contacting a suitable tetrahaloethylene and/or pentahaloethane with hydrogen fluoride in the presence of Cr.sub.2 O.sub.3, prepared by pyrolysis of (NH.sub.4).sub.2 Cr.sub.2 O.sub.7, the reaction being conducted under controlled conditions whereby the production of pentafluoroethane is minimized.

Process for the manufacture of 1,1,1-trifluorodichloroethane and

2-Chloro- and 2-bromo-1,1,1-trifluoroethane react with potassium, cesium or rubidium fluoride in aqueous solution at elevated temperature under autogenous pressure to produce 1,1,1,2-tetrafluoroethane.

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Wilmington, DE, United States of America

William H Gumprecht