Process for separation of tetrafluoroethylene from carbon dioxide using ionic liquids

Abstract

A process for separating tetrafluoroethylene from a mixture comprising tetrafluoroethylene and carbon dioxide by contacting the mixture with at least one ionic liquid.

1 . A process for separating tetrafluoroethylene from a mixture comprising tetrafluoroethylene and carbon dioxide, comprising contacting the mixture with at least one ionic liquid in which carbon dioxide is soluble to a greater extent than tetrafluoroethylene, and separating the tetrafluoroethylene from the mixture. 
     
     
         2 . The process of  claim 1  wherein an ionic liquid has a cation selected from the group consisting of the following eleven cations: 
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are independently selected from the group consisting of:
 (i) H 
 (ii) halogen 
 (iii) —CH 3 , —C 2 H 5 , or C 3  to C 2  straight-chain, branched or cyclic alkane or alkene, optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH 2  and SH; 
 (iv) —CH 3 , —C 2 H 5 , or C 3  to C 25  straight-chain, branched or cyclic alkane or alkene comprising one to three heteroatoms selected from the group consisting of O, N and S, and optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH 2  and SH; 
 (v) C 6  to C 20  unsubstituted aryl, or C 3  to C 25  unsubstituted heteroaryl having one to three heteroatoms independently selected from the group consisting of O, N and S; and 
 (vi) C 6  to C 25  substituted aryl, or C 3  to C 25  substituted heteroaryl having one to three heteroatoms independently selected from the group consisting of O, N and S; and wherein said substituted aryl or substituted heteroaryl has one to three substituents independently selected from the group consisting of:
 (1) —CH 3 , —C 2 H 5 , or C 3  to C 25  straight-chain, branched or cyclic alkane or alkene, optionally substituted with at least one member selected from the group consisting of Cl, Br, F I, OH, NH 2  and SH, 
 (2) OH, 
 (3) NH 2 , and 
 (4) SH; 
 
 
         R 7 , R 8 , R 9 , and R 10  are independently selected from the group consisting of:
 (vii) —CH 3 , —C 2 H 5 , or C 3  to C 25  straight-chain, branched or cyclic alkane or alkene, optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH 2  and SH; 
 (viii)-CH 3 , —C 2 H 5 , or C 3  to C 25  straight-chain, branched or cyclic alkane or alkene comprising one to three heteroatoms selected from the group consisting of O, N and S, and optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH 2  and SH; 
 (ix) C 6  to C 25  unsubstituted aryl, or C 3  to C 25  unsubstituted heteroaryl having one to three heteroatoms independently selected from the group consisting of O, N and S; and 
 (x) C 6  to C 25  substituted aryl, or C 3  to C 25  substituted heteroaryl having one to three heteroatoms independently selected from the group consisting of O, N and S; and wherein said substituted aryl or substituted heteroaryl has one to three substituents independently selected from the group consisting of:
 (1) —CH 3 , —C 2 H 5 , or C 3  to C 25  straight-chain, branched or cyclic alkane or alkene, optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH 2  and SH, 
 (2) OH, 
 (3) NH 2 , and 
 (4) SH; and 
 
 
         wherein optionally at least two of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10  can together form a cyclic or bicyclic alkanyl or alkenyl group. 
       
     
     
         3 . The process of  claim 1  wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , and R 10  comprises F − . 
     
     
         4 . The process of  claim 1  wherein an ionic liquid comprises an anion selected from the group consisting of [CH 3 CO 2 ] − , [HSO 4 ] − , [CH 3 OSO 3 ] − , [C 2 HSOSO 3 ] − , [AlCl 4 ] − , [CO 3 ] 2− , [HCO 3 ] − , [NO 2 ] − , [NO 3 ] − , [SO 4 ] 2− , [PO 4 ] 3− , [HPO 4 ] 2− , [H 2 PO 4 ] − , [HSO 3 ] − , [CuCl 2 ] − , Cl − , Br − , I − , SCN − , and any fluorinated anion. 
     
     
         5 . The process of  claim 2  wherein an ionic liquid comprises an anion selected from the group consisting of [CH 3 CO 2 ] − , [HSO 4 ] − , [CH 3 OSO 3 ] − , [C 2 H S OSO 3 ] − , [AlCl 4 ] − , [CO 3 ] 2− , [HCO 3 ] − , [NO 2 ] − , [NO 3 ] − , [SO 4 ] 2− , [PO 4 ] 3− , [HPO 4 ] 2− , [H 2 PO 4 ] − , [HSO 3 ] − , [CuCl 2 ] − , Cl − , Br − , I − , SCN − , and any fluorinated anion. 
     
     
         6 . The process of  claim 3  wherein an ionic liquid comprises an anion selected from the group consisting of [CH 3 CO 2 ] − , [HSO 4 ] − , [CH 3 OSO 3 ] − , [C 2 HSOSO 3 ] − , [AlCl 4 ] − , [CO 3 ] 2− , [HCO 3 ] − , [NO 2 ] − , [NO 3 ] − , [SO 4 ] 2− , [PO 4 ] 3− , [HPO 4 ] 2− , [H 2 PO 4 ] − , [HSO 3 ] − , [CuCl 2 ] − , Cl − , Br, I − , SCN − , and any fluorinated anion. 
     
     
         7 . The process of  claim 1  wherein an ionic liquid comprises an anion selected from the group consisting of [BF] − , [BF 3 CF 3 ] − , [BF 3 C 2 F 5 ] − , [PF 6 ] − , [PF 3 (C 2 F 5 ) 3 ] − , [SbF 6 ] − , [CF 3 SO 3 ] − , [HCF 2 CF 2 SO 3 ] − , [CF 3 HFCCF 2 SO 3 ] − , [HCClFCF 2 SO 3 ] − , [(CF 3 SO 2 ) 2 N] − , [(CF 3 CF 2 SO 2 ) 2 N] − , [(CF 3 SO 2 ) 3 C] − , [CF 3 CO 2 ] − , [CF 3 OCFHCF 2 SO 3 ] − , [CF 3 CF 2 OCFHCF 2 SO 3 ] − , [CF 3 CFHOCF 2 CF 2 SO 3 ] − , [CF 2 HCF 2 OCF 2 CF 2 SO 3 ] − , [CF 2 ICF 2 OCF 2 CF 2 SO 3 ] − , [CF 3 CF 2 OCF 2 CF 2 SO 3 ] − , [CF 2 HCF 2 SO 2 ) 2 N] − , [(CF 3 CFHCF 2 SO 2 ) 2 N] − , and F − . 
     
     
         8 . The process of  claim 2  wherein an ionic liquid comprises an anion selected from the group consisting of [BF] − , [BF 3 CF 3 ] − , [BF 3 C 2 F 5 ] − , [PF 6 ] − , [PF 3 (C 2 F 5 ) 3 ] − , [SbF 6 ] − , [CF 3 SO 3 ] − , [HCF 2 CF 2 SO 3 ] − , [CF 3 HFCCF 2 SO 3 ] − , [HCClFCF 2 SO 3 ] − , [(CF 3 SO 2 ) 2 N] − , [(CF 3 CF 2 SO 2 ) 2 N] − , [(CF 3 SO 2 ) 3 C] − , [CF 3 CO 2 ] − , [CF 3 OCFHCF 2 SO 3 ] − , [CF 3 CF 2 OCFHCF 2 SO 3 ] − , [CF 3 CFHOCF 2 CF 2 SO 3 ] − , [CF 2 HCF 2 OCF 2 CF 2 SO 3 ] − , [CF 2 ICF 2 OCF 2 CF 2 SO 3 ] − , [CF 3 CF 2 OCF 2 CF 2 SO 3 ] − , [(CF 2 HCF 2 SO 2 ) 2 N] − , [(CF 3 CFHCF 2 SO 2 ) 2 N] − , and F − . 
     
     
         9 . The process of  claim 3  wherein an ionic liquid comprises an anion selected from the group consisting of [BF] − , [BF 3 CF 3 ] − , [BF 3 C 2 F 5 ] − , [PF 6 ] − , [PF 3 (C 2 F 5 ) 3 ] − , [SbF 6 ] − , [CF 3 SO 3 ] − , [HCF 2 CF 2 SO 3 ] − , [CF 3 HFCCF 2 SO 3 ] − , [HCClFCF 2 SO 3 ] − , [(CF 3 SO 2 ) 2 N] − , [(CF 3 CF 2 SO 2 ) 2 N] − , [(CF 3 SO 2 ) 3 C] − , [CF 3 CO 2 ] − , [CF 3 OCFHCF 2 SO 3 ] − , [CF 3 CF 2 OCFHCF 2 SO 3 ] − , [CF 3 CFHOCF 2 CF 2 SO 3 ] − , [CF 2 HCF 2 OCF 2 CF 2 SO 3 ] − , [CF 2 ICF 2 OCF 2 CF 2 SO 3 ] − , [CF 3 CF 2 OCF 2 CF 2 SO 3 ] − , [(CF 2 HCF 2 SO 2 ) 2 N] − , [CF 3 CFHCF 2 SO 2 ) 2 N] − , and F − . 
     
     
         10 . The process of  claim 1  wherein an ionic liquid comprises imidazolium as the cation; and comprises an anion selected from the group consisting of [BF] − , [BF 3 CF 3 ] − , [BF 3 C 2 F 5 ] − , [PF 6 ] − , [PF 3 (C 2 F 5 ) 3 ] − , [SbF 6 ] − , [CF 3 SO 3 ] − , [HCF 2 CF 2 SO 3 ] − , [CF 3 HFCCF 2 SO 3 ] − , [HCClFCF 2 SO 3 ] − , [(CF 3 SO 2 ) 2 N] − , [(CF 3 CF 2 SO 2 ) 2 N] − , [(CF 3 SO 2 ) 3 C] − , [CF 3 CO 2 ] − , [CF 3 OCFHCF 2 SO 3 ] − , [CF 3 CF 2 OCFHCF 2 SO 3 ] − , [CF 3 CFHOCF 2 CF 2 SO 3 ] − , [CF 2 HCF 2 OCF 2 CF 2 SO 3 ] − , [CF 2 ICF 2 OCF 2 CF 2 SO 3 ] − , [CF 3 CF 2 OCF 2 CF 2 SO 3 ] − , [(CF 2 HCF 2 SO 2 ) 2 N] − , [(CF 3 CFHCF 2 SO 2 ) 2 N] − , and [CH 3 OSO 3 ] − . 
     
     
         11 . The process of  claim 1  wherein an ionic liquid comprises 1-butyl-3-methylimidazolium as the cation; and comprises an anion selected from the group consisting of [BF]—, [BF 3 CF 3 ]—, [BF 3 C 2 F 5 ]—, [PF 6 ]—, [PF 3 (C 2 F 5 ) 3 ]—, [SbF 6 ] − , [CF 3 SO 3 ] − , [HCF 2 CF 2 SO 3 ] − , [CF 3 HFCCF 2 SO 3 ] − , [HCClFCF 2 SO 3 ] − , [(CF 3 SO 2 ) 2 N] − , [(CF 3 CF 2 SO 2 ) 2 N] − , [CF 3 SO 2 ) 3 C] − , [CF 3 CO 2 ] − , [CF 3 OCFHCF 2 SO 3 ] − , [CF 3 CF 2 OCFHCF 2 SO 3 ] − , [CF 3 CFHOCF 2 CF 2 SO 3 ] − , [CF 2 HCF 2 OCF 2 CF 2 SO 3 ] − , [CF 2 ICF 2 OCF 2 CF 2 SO 3 ] − , [CF 3 CF 2 OCF 2 CF 2 SO 3 ] − , [(CF 2 HCF 2 SO 2 ) 2 N] − , [(CF 3 CFHCF 2 SO 2 ) 2 N] −  and [CH 3 OSO 3 ] − . 
     
     
         12 . The process of  claim 1  wherein an ionic liquid comprises 1-1-ethyl-3-methylimidazolium as the cation; and comprises an anion selected from the group consisting of [BF]—, [BF 3 CF 3 ]—, [BF 3 C 2 F 5 ]—, [PF 6 ]—, [PF 3 (C 2 F 5 ) 3 ]—, [SbF 6 ] − , [CF 3 SO 3 ] − , [HCF 2 CF 2 SO 3 ] − , [CF 3 HFCCF 2 SO 3 ] − , [HCClFCF 2 SO 3 ] − , [(CF 3 SO 2 ) 2 N] − , [(CF 3 CF 2 SO 2 ) 2 N] − , [(CF 3 SO 2 ) 3 C] − , [CF 3 CO 2 ] − , [CF 3 OCFHCF 2 SO 3 ] − , [CF 3 CF 2 OCFHCF 2 SO 3 ] − , [CF 3 CFHOCF 2 CF 2 SO 3 ] − , [CF 2 HCF 2 OCF 2 CF 2 SO 3 ] − , [CF 2 ICF 2 OCF 2 CF 2 SO 3 ] − , [CF 3 CF 2 OCF 2 CF 2 SO 3 ] − , [(CF 2 HCF 2 SO 2 ) 2 N] − , [(CF 3 CFHCF 2 SO 2 ) 2 N] −  and [CH 3 OSO 3 ] − . 
     
     
         13 . The process of  claim 1  wherein an ionic liquid comprises 1-ethyl-3-methylimidazolium as the cation, and comprises an anion selected from the group consisting of [(CF 3 CF 2 SO 2 ) 2 N] − , [PF 6 ] −  and [HCF 2 CF 2 SO 3 ] − . 
     
     
         14 . The process of  claim 1  wherein an ionic liquid comprises 1-1,3-dimethylimidazolium as the cation; and comprises an anion selected from the group consisting of [BF 4 ]—, [BF 3 CF 3 ]—, [BF 3 C 2 F 5 ]—, [PF 6 ]—, [PF 3 (C 2 F 5 ) 3 ]—, [SbF 6 ] − , [CF 3 SO 3 ] − , [HCF 2 CF 2 SO 3 ] − , [CF 3 HFCCF 2 SO 3 ] − , [HCClFCF 2 SO 3 ] − , [(CF 3 SO 2 ) 2 N] − , [(CF 3 CF 2 SO 2 ) 2 N] − , [CF 3 SO 2 ) 3 C] − , [CF 3 CO 2 ] − , [CF 3 OCFHCF 2 SO 3 ] − , [CF 3 CF 2 OCFHCF 2 SO 3 ] − , [CF 3 CFHOCF 2 CF 2 SO 3 ] − , [CF 2 HCF 2 OCF 2 CF 2 SO 3 ] − , [CF 2 ICF 2 OCF 2 CF 2 SO 3 ] − , [CF 3 CF 2 OCF 2 CF 2 SO 3 ] − , [(CF 2 HCF 2 SO 2 ) 2 N] − , [(CF 3 CFHCF 2 SO 2 ) 2 N] −  and [CH 3 OSO 3 ] − . 
     
     
         15 . The process of  claim 1  which is performed in a distillation or absorption column. 
     
     
         16 . The process of  claim 15  wherein the TFE is removed from the top of the column. 
     
     
         17 . The process of  claim 15  wherein an ionic liquid and CO 2  are removed together from the bottom of the column, the ionic liquid and CO 2  are separated outside the column, and the separated ionic liquid is returned to the column. 
     
     
         18 . A process according to  claim 1  further comprising the steps of recovering the TFE, and subjecting the TFE to a polymerization reaction to prepare a fluorinated polymer or copolymer. 
     
     
         19 - 22 . (canceled)