Dehydrofluorination of pentafluoroalkanes to form tetrafluoroolefins
AssigneeArkema Inc.
InventorsMaher Y. Elsheikh, Philippe Bonnet, Olga C. N. Keeley, Benjamin Bin Chen
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Abstract
A method for producing a tetrafluoroolefin, such as 2,3,3,3-tetrafluoropropene (HFO-1234yf), comprises dehydrofluorinating a pentafluoroalkane in a gas phase in the presence of a catalyst comprising chromium oxyfluoride. In a preferred embodiment, 2,3,3,3-tetrafluoropropene (HFO-1234yf) is produced by forming a catalyst comprising chromium oxyfluoride by calcining CrF3.xH2O, where x is 1-10, in the presence of a flowing gas comprising nitrogen to form a calcined chromium oxyfluoride, and dehydrofluorinating 1,1,1,2,2-pentafluoropropane (HFC-245cb) in a gas phase in the presence of the catalyst to form the 2,3,3,3-tetrafluoropropene (HFO-1234yf).
Claims14
A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) comprising dehydrofluorinating a pentafluoroalkane selected from the group consisting of 1,1,1,2,2-pentafluoropropane (HFC-245cb), 1,1,1,2,3-pentafluoropropane (HFC-245eb), and mixtures thereof in a gas phase in the presence of air and/or oxygen and a calcined chromium oxyfluoride catalyst, containing 1-20 weight % of a co-catalyst selected from the group consisting of Zn, Co, Mn, and Mg, wherein said catalyst is support or unsupported and wherein said catalyst is not activated with hydrogen fluoride and wherein said 2,3,3,3-tetrafluoropropene (HFO-1234yf) is produced directly from said pentafluoroalkane in a single step.
A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) comprising:
- (a) forming a catalyst comprising calcined chromium oxyfluoride containing 1-20 weight % a co-catalyst selected from the group consisting of Zn, Co, Mn, and Mg, wherein said catalyst is not activated with hydrogen fluoride;
- and
- (b) dehydrofluorinating 1,1,1,2,2-pentafluoropropane (HFC-245cb), in a gas phase in the presence of air and/or oxygen and said calcined chromium oxyfluoride catalyst to form, directly, in a single step, 2,3,3,3-tetrafluoropropene (HFO-1234yf).
Dependencies are inferred from the claim text.