Imperial Chemical Industries Limited

Stephen John Adams

Ralph J Doy

Charles Brian Blake

Rowland J Brierley

Brian Schofield

James Malcolm Forsyth

Jane Andrea Roberts

Ann San Liow

Neil David Shilling

Andrew M Taylor

Water present in a hot gaseous product stream from a reactor system A.B (FIG. 1) containing hydrogen fluoride is separated from the stream in order to eliminate a potentially corrosive combination of water and HF. The water is removed by contacting the gaseous product stream with liquid HF in a distillation column so as to obtain a bottoms product containing liquid HF and water and a top product containing dry HF and the product to be recovered. The invention encompasses the separation process, a vessel for carrying out the process (FIGS. 2 to 4), a control system for the liquid HF supply to the distillation column (FIGS. 5 and 6) and a recovery system for recovering HF employed during operation of the reactor system in different regimes employing HF as a fluorination agent, as a diluent during catalyst regeneration and/or catalyst prefluorination (FIG. 7).

Water separation process

Water present in a hot gaseous product stream from a reactor system A,B (FIG. 1 ) containing hydrogen fluoride is separated from the stream in order to eliminate a potentially corrosive combination of water and HF. The water is removed by contacting the gaseous product stream with liquid HF in a distillation column so as to obtain a bottoms product containing liquid HF and water and a top product containing dry HF and the product to be recovered. The invention encompasses the separation process, a vessel for carrying out the process (FIGS. 2 to 4), a control system for the liquid HF supply to the distillation column (FIGS. 5 and 6) and a recovery system for recovering HF employed during operation of the reactor system in different regimes employing HF as a fluorination agent, as a diluent during catalyst regeneration and/or catalyst prefluorination (FIG. 7 ).

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.

Separation process

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Warrington, United Kingdom

Stephen John Adams