Process for the preparation of 2,3,3,3-tetrafluoropropene
AssigneeMexichem Amanco Holdings S.A. De C.V.
InventorsJohn W. Smith, Claire McGuinness, Andrew P. Sharratt, Andrew Taylor
Life of this patent
Estimating the term…
Abstract
The invention provides a process for the preparation of 1234yf comprising (a) contacting 1,1,2,3,3,3-hexafluoropropene (1216) with hydrogen in the presence of a hydrogenation catalyst to produce 1,1,2,3,3,3-hexafluoropropane (236ea); (b) dehydrofluorinating 236ea to produce 1,2,3,3,3-pentafluoropropene (1225ye); (c) contacting 1225ye with hydrogen in the presence of a hydrogenation catalyst to produce 1,2,3,3,3-pentafluoropropane (245eb); and (d) dehydrofluorinating 245eb to produce 1234yf.
Claims21
1-20. (canceled)
A process for the preparation of 1,2,3,3,3-pentafluoropropene (1225ye), the process comprising:
- (a) contacting 1,1,2,3,3,3-hexafluoropropene (1216) with hydrogen in the presence of a hydrogenation catalyst to produce 1,1,2,3,3,3-hexafluoropropane (236ea);
- and
- (b) dehydrofluorinating 236ea to produce 1,2,3,3,3-pentafluoropropene (1225ye);
- wherein step (a) is carried out with a diluent gas stream that comprises a molar excess of about 42% to 380% of feedstock 1216.
A process for the preparation of 1,2,3,3,3-pentafluoropropene (1225ye), the process comprising:
- (a) contacting 1,1,2,3,3,3-hexafluoropropene (1216) with hydrogen in the presence of a hydrogenation catalyst to produce 1,1,2,3,3,3-hexafluoropropane (236a);
- and
- (b) dehydrofluorinating 236a to produce 1,2,3,3,3-pentafluoropropene (1225ye);
- wherein a product from step (a) and/or (b) is subjected to a purification step;
- wherein step (b) is carried out in the presence of a base selected from sodium hydroxide and potassium hydroxide;
- and
- wherein step (b) is carried out in the presence of water as a solvent.
A process for the preparation of 1,2,3,3,3-pentafluoropropene (1225ye), the process comprising:
- (a) contacting 1,1,2,3,3,3-hexafluoropropene (1216) with hydrogen in the presence of a hydrogenation catalyst to produce 1,1,2,3,3,3-hexafluoropropane (236a);
- and
- (b) dehydrofluorinating 236a to produce 1,2,3,3,3-pentafluoropropene (1225ye);
- wherein step (a) is carried out at a temperature of from about 0 to about 250° C.;
- wherein a product from step (a) and/or (b) is subjected to one or more purification steps;
- wherein the one or more purification steps for step (b) comprises scrubbing with water or aqueous base, and a drying step;
- wherein the purification step for step (a) comprises a distillation step;
- and
- wherein steps (a) and (b) are carried out in the vapor phase.
Dependencies are inferred from the claim text.