Mexichem Amanco Holding S.a. De C.v.

Imperial Chemical Industries Limited

Mexichem Amanco Holdings S.a. De C.v.

Andrew M Taylor

Andrew Paul Sharratt

John W Smith

Claire McGuinness

Claire McGuiness

Stephen John Adams

Robert W Wheelhouse

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.

Process for the preparation of 2,3,3,3-tetrafluoropropene

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 1225 ye 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).

Process for the preparation of 2, 3, 3, 3-tetrafluoropropene

A method for separating HFA 134a from an HFA 134a-rich mixture thereof with HF and/or CFC 1122 which comprises feeding the mixture to a distillation column to separate an azeotrope or near-azeotrope of HFA 134a and HF and/or CFC 1122 from a residue comprising substantially pure HFA 134a. Starting from an HF-rich mixture of HFA 134a such as a typical product stream in HFA 134a production, the method includes a first distillation step to separate HF from the initial mixture and produce an azeotrope or near azeotrope of HFA 134a and HF which is an HFA 134a-rich mixture.

Process for separating HFA 134a

A product stream containing, inter alia, HCl, HF and fluorocarbons which form close boiling point azeotropes with HF is subjected to distillation using sidestream rectification in order to effect energy efficient separation of selected fluorocarbon/HF azeotropes from one another.

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Chester, United Kingdom

Andrew M Taylor