Patent ID: 8445736

Claim:
A process for preparing 1,1,1,2-tetrafluoropropene, comprising contacting, 1,1,2,3-tetrachloropropene with hydrogen fluoride in gas phase in the presence of a chromium fluorination catalyst, and an oxygen containing oxidizing agent, under conditions sufficient to directly produce, in a single reaction step, a reaction mixture comprising 1,1,1,2-tetrafluoropropene and at least one compound of formula CF 3 R, where R is selected from —CCl═CH 2 , —CF 2 —CH 3 , —CFClCH 3 and CHF—CH 2 F; removing HCl from said reaction mixture; separating 1,1,1,2-tetrafluoropropene from said reaction mixture; and recycling to the reactor hydrogen fluoride, at least one compound of formula CF 3 R, where R is selected from —CCl═CH 2 , —CF 2 —CH 3 , —CFClCH 3 and —CHF CH 2 F wherein said fluorination catalyst is activated with hydrogen fluoride at a pressure above about 150 psi.