(19) TZZ Z¥__T (11) EP 2 054 361 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) Int Cl.: of the grant of the patent: C07C 17/38 (2006.01) C07C 17/383 (2006.01) 17.02.2016 Bulletin 2016/07 C07C 17/386 (2006.01) C01B 7/19 (2006.01) C07C 17/25 (2006.01) (21) Application number: 07811541.7 (86) International application number: (22) Date of filing: 24.08.2007 PCT/US2007/018837 (87) International publication number: WO 2008/024508 (28.02.2008 Gazette 2008/09) (54) PROCESSES FOR SEPARATION OF FLUOROOLEFINS FROM HYDROGEN FLUORIDE BY AZEOTROPIC DISTILLATION VERFAHREN ZUR TRENNUNG VON FLUOROLEFINEN VON WASSERSTOFFFLUORID DURCH AZEOTROPE DESTILLATION PROCÉDÉS DE SÉPARATION DE FLUOROOLÉFINES DU FLUORURE D’HYDROGÈNE PAR DISTILLATION AZÉOTROPIQUE (84) Designated Contracting States: • MAHLER, Barry, Asher DE ES FR GB IT PL Glen Mills, Pennsylvania 19342 (US) • TOTON, Donald, J. (30) Priority: 24.08.2006 US 839737 P New Castle, Delaware 19720 (US) (43) Date of publication of application: (74) Representative: Matthews, Derek Peter et al 06.05.2009 Bulletin 2009/19 Dehns St Bride’s House (60) Divisional application: 10 Salisbury Square 11174594.9 London EC4Y 8JD (GB) 11174764.8 / 2 433 921 (56) References cited: (73) Proprietor: E. I. du Pont de Nemours and Company WO-A-99/20585 WO-A-99/26907 Wilmington, DE 19898 (US) US-A1- 2006 116 538 US-B1- 6 303 838 (72) Inventors: Remarks: • KNAPP, Jeffrey, P. Thefile contains technical information submitted after Wilmington, Delaware 19808 (US) the application was filed and not included in this specification Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 2 054 361 B1 Printed by Jouve, 75001 PARIS (FR) EP 2 054 361 B1 Description CROSS REFERENCE(S) TO RELATED APPLICATION(S) 5 [0001] This application claims the priority benefit of U.S. Provisional Application No. 60/839,737, filed August 24, 2006. Attention is also directed to European divisional patent application no. 11174764.8 claiming the entrainer-based proc- esses disclosed herein. BACKGROUND INFORMATION 10 Field of the Disclosure [0002] This disclosure relates in general to processes for separating HF from fluoroolefins. 15 Description of the Related Art [0003] The chemical manufacture of fluoroolefins may produce mixtures of the desired fluoroolefins and hydrogen fluoride (HF). The separation of fluoroolefins and HF is not always easily accomplished. Existing methods of distillation and decantation are very often ineffective for separation of these compounds. Aqueous scrubbing may be effective, but 20 requires the use of large amounts of scrubbing solutions and produces excessive waste as well as wet product that must then be dried. Therefore, there is a need for new methods of separating HF from fluoroolefins. SUMMARY 25 [0004] The present disclosure provides a process for separating a mixture comprising HF and fluoroolefin, said process comprising: a) feeding the composition comprising HF and fluoroolefin to a first distillation column; b) removing an azeotrope composition comprising HF and fluoroolefin as a first distillate and either i) HF or ii) fluoroolefin as a first column bottoms composition; c) condensing the first distillate to form two liquid phases, being i) an HF-rich phase and ii) a fluoroolefin-rich phase; and d) recycling a first liquid phase enriched in the same compound that is removed as the 30 first column bottoms, said first liquid phase being either i) HF-rich phase or ii) fluoroolefin-rich phase, back to the first distillation column. [0005] Also disclosed is a process for separating a fluoroolefin from a mixture comprising hydrogen fluoride and said fluoroolefin, wherein said fluoroolefin is present in a concentration greater than the azeotrope concentration for hydrogen fluoride and said fluoroolefin, said process comprising: a) feeding said mixture comprising hydrogen fluoride and said 35 fluoroolefin to a first distillation column; b) removing an azeotrope composition comprising hydrogen fluoride and fluoroole- fin as a first distillate from the first distillation column; c) recovering fluoroolefin essentially free of hydrogen fluoride as a first bottoms composition from the first distillation column; d) condensing the first distillate to form two liquid phases, being i) a hydrogen fluoride-rich phase and ii) a fluoroolefin-rich phase; and e) recycling the fluoroolefin-rich phase to the first distillation column. 40 [0006] Also provided is a process for separating hydrogen fluoride from a mixture comprising hydrogen fluoride and a fluoroolefin, wherein hydrogen fluoride is present in a concentration greater than the azeotrope concentration for hydrogen fluoride and said fluoroolefin, said process comprising: a) feeding said mixture comprising hydrogen fluoride and fluoroolefin to a first distillation column; b) removing an azeotrope or azeotrope-like composition comprising fluoroole- fin and HF as a first distillate from the first distillation column; c) recovering hydrogen fluoride essentially free of fluoro olefin 45 as a first bottoms composition from the first distillation column; d) condensing the first distillate to form two liquid phases , being a fluoroolefin-rich phase and a hydrogen fluoride-rich phase; and e) recycling the HF-rich phase to the first distillatio n column. [0007] The foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as defined in the appended claims. 50 [0008] The entrainer-based processes described below are not claimed herein.and are instead claimed, as noted above, in European divisional patent application no. 11174764.8 BRIEF DESCRIPTION OF THE DRAWINGS 55 [0009] Embodiments are illustrated in the accompanying figures to improve understanding of concepts as presented herein. FIG. 1 is an illustration of one embodiment of an azeotropic distillation for the separation of HF and a fluoroolefin 2 EP 2 054 361 B1 with no added entrainer. FIG. 2 is an illustration of one embodiment of an azeotropic distillation for the separation of HF and a fluoroolefin with an added entrainer. FIG. 3 is an illustration of one embodiment of a process to separate at least one of HFC-236ea and HFC-236cb 5 from a mixture comprising HFC-1225ye, HF and said at least one of HFC-236ea and HFC-236cb via azeotropic distillation wherein HFC-1225ye acts as an entrainer followed by a process in which HFC-1225ye and HF are separated from a mixture comprising HFC-1225ye and HF, but now substantially free of HFC-236ea and/or HFC- 236cb, by azeotropic distillation without the addition of another chemical compound to function as an entrainer. FIG. 4 is an illustration of one embodiment of a process to separate HFC-1225ye and at least one of HFC-236ea 10 and HFC-236cb from a mixture comprising HFC-1225ye, HF and said at least one of HFC-236ea and HFC-236cb via azeotropic distillation wherein a supplemental entrainer is fed to the distillation. FIG 5 is an illustration of one embodiment of a process to separate at least one of HFC-236ea and HFC-236cb from a mixture comprising HFC-1225ye, HF and said at least one of HFC-236ea and HFC-236cb via azeotropic distillation wherein HFC-1225ye acts as an entrainer followed by a process in which HFC-1225ye and HF are separated from 15 amixture comprising HFC-1225ye and HF,but nowsubstantially free ofHFC-236ea and/or HFC-236cb,by azeotropic distillation with an added entrainer. FIG 6 illustrates another embodiment of the process shown in Figure 3 wherein the two-phase mixture leaving the condenser of the first column is decanted and separated into HFC-1225ye-rich and HF-rich streams which are fed to the HFC-1225ye and HF columns, respectively. 20 FIG 7 illustrates another embodiment of the process shown in Figure 5 wherein the two-phase mixture leaving the condenser of the first column is decanted and separated into HFC-1225ye-rich and HF-rich streams which are fed to the HFC-1225ye and HF columns, respectively. FIG 8 illustrates another embodiment of the process shown in FIG 6, wherein the three columns, 20, 110, and 220, share one decanter. 25 [0010] Skilled artisans appreciate that objects in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the objects in the figures may be exaggerated relative to other objects to help to improve understanding of embodiments. 30 DETAILED DESCRIPTION [0011] Many aspects and embodiments have been described above and are merely exemplary and not limiting. After reading this specification, skilled artisans appreciate that other aspects and embodiments are possible without departing from the scope of the invention. 35 [0012] Other features and benefits of any one or more of the embodiments will be apparent from the following detailed description, and from the claims. 1. Definitions and Clarification of Terms 40 [0013] Before addressing details of embodiments described below, some terms are defined or clarified. [0014] By azeotropic or azeotrope composition is meant a constant-boiling mixture of two or more substances that boils at a constant composition and thus behaves as a single substance. Constant-boiling compositions are characterized as azeotropic because they exhibit either a maximum or minimum boiling point, when compared with the boiling points of the individual components. Azeotropic compositions are also characterized by a minimum or a maximum in the vapor 45 pressure measurements relative to the vapor pressure of the neat components in a PTx cell as a function of composition at a constant temperature.