E.i. Dupont De Nemours and Company

Klaus Guenter Wuttke

Mario Joseph Nappa

V N Rao

Jan J Lerou

Carl S Kellner

A process is disclosed for producing 1,1-difluoroethane (HFC-152a) in a liquid phase by contacting chloroethene and hydrogen fluoride in the presence of a tin tetrahalide catalyst. The ability to reduce tar formation and increase volumetric productivity is also disclosed.

Continuous manufacture of 1,1-difluoroethane

A process is disclosed for producing 1,1-difluoroethane (CH.sub.3 CHF.sub.2 or HFC-152a) in a two-step reaction in a manner that reduces formation of high boiling materials. The first step comprises adding at least one of HCl or HF to chloroethene (CH.sub.2 .dbd.CHCl) in order to obtain at least one of 1,1-dichloroethane (CH.sub.3 CHF.sub.2) or 1-chloro-1-fluoroethane (CH.sub.3 CHClF). The second step comprises converting 1,1-dichloroethane or 1-chloro-1-fluoroethane to 1,1-difluoroethane.

Two-step process for manufacturing 1,1-difluoroethane

This invention provides a process for the regeneration and/or activation of a noble catalyst comprising contacting said catalyst with an atmosphere comprising a fluorohalocarbon and/or a fluorohydrocarbon of the formula, C.sub.n H.sub.m F.sub.p X.sub.q, wherein X is chlorine and/or bromine; n is an integer from 1 to 6; m is an integer from 0 to 6, provided that m can be no more than the total n in the compound; p and q are integers from 1-13 when the compound is acyclic and integers from 1-11 when the compound is cyclic, provided that the fluorohalocarbon and/or fluorohalohydrocarbon always contains at least one chlorine or bromine atom and provided that m+p+q=2n+2 when the compound is acyclic and that m+p+q=2n when the compound is cyclic, at a temperature in excess of 200.degree. C.

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Wilmington, DE, United States of America

Klaus Guenter Wuttke