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US 4,792,643 AGranted
Catalyst and process for 1,1,1,2-tetrafluoroethane by vapor phase reaction
AssigneeKaiser Aluminum & Chemical Corporation
InventorIgor Sobolev
Life of this patent
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Abstract
A novel catalyst is prepared by codepositing hexavalent chromium oxide and a transition metal compound, preferably titanium trichloride, on alumina, followed by fluorinating the resulting combination. The catalyst is useful in the fluorination of a haloethylene of the formula CX.sub.2 .dbd.CHX (where the X's are chlorine or bromine or a combination of the two) in the vapor phase to form 1,1,1,2-tetrafluoroethane.
Claims24
A process for the manufacture of 1,1,1,2-tetrafluoroethane which comprises:
- (a) contacting a haloethylene of the formula CX.sub.2 .dbd.CHX in which the X's are chlorine or bromine or a combination thereof, with hydrogen fluoride in a vapor phase reaction at elevated temperature in the presence of a catalyst prepared by:
- (i) codepositing hexavalent chromium oxide and a compound of a transition metal selected from the group consisting of titanium, zirconium, vanadium, molybdenum and manganese on alumina;
- and
- (ii) contacting the product of step (i) with hydrogen fluoride to fluorinate at least a substantial portion thereof;
- to form a product mixture;
- and
- (b) recovering from said product mixture 1,1,1,2-tetrafluoroethane.
4 more elements
A process for the manufacture of 1,1,1,2-tetrafluoroethane which comprises:
- (a) contacting CCl.sub.2 .dbd.CHCl with hydrogen fluoride in the vapor phase at a temperature ranging from about 350.degree. C. to about 550.degree. C. and a residence time of about 30 seconds to about 300 seconds, in the presence of a catalyst prepared by:
- (i) codepositing hexavalent chromium oxide and titanium trichloride at a chromium:titanium atomic ratio of about 1:1 to about 3:1 on solid porous alumina particles having a surface area of at least about 100 m.sub.2 /g to produce impregnated alumina particles of which said hexavalent chromium oxide and said titanium trichloride together comprise from about 5 to about 20 weight percent;
- and
- (ii) contacting the product of step (i) with hydrogen fluoride gas for about 3 to about 20 hours at a temperature of about 300.degree. C. to about 500.degree. C.;
- to form a gaseous product mixture;
- and
- (b) recovering from said gaseous product mixture 1,1,1,2-tetrafluoroethane.
4 more elements
Dependencies are inferred from the claim text.