Process for purifying (hydro)halocarbon compositions

Abstract

A process for treating a composition comprising one or more desired (hydro)halocarbons and one or more undesired halogenated hydrocarbon containing impurities so as to reduce the concentration of at least one undesired halogenated hydrocarbon containing impurity, the process comprising contacting the composition with an adsorbent comprising a carbon molecular sieve.

We claim: 
     
         1 . A composition that is substantially free of undesired halogenated hydrocarbon impurities, said composition obtained by a process of contacting a composition including the undesired halogenated hydrocarbon impurities with an adsorbent comprising a carbon molecular sieve,
 wherein the undesired halogenated hydrocarbon containing impurities comprises one or more of a mono-, di- or tri-halomethane,   the desired (hydro)haloethanes are selected from
 (i) 1,1,1,2-tetrafluorethane, 1,1,1-trifluoroethane, 1,1-difluoroethane, perfluoroethane or other mono-, di-, tri- or tetra-fluoroethanes; 
 (ii) 1,2-dichloro-1,1,2,2-tetrafluoroethane, 1,1,1-trichloro-2,2,2-trifluoroethane, 1,1-dichloro-1-fluoroethane, 1-chloro-1,1-difluoroethane, 1,1,1-trifluoro-2-chloroethane, 2,2-dichloro-1,1,1-trifluoroethane (R-123), 2-chloro-1,1,1,2-tetrafluoroethane and/or other (hydro)chlorofluoroethanes; and/or 
 (iii) (hydro)chloroethanes, (hydro)bromoethanes and/or (hydro)iodomethanes. 
   
     
     
         2 . The composition according to  claim 1  comprising 1,1-difluoroethane (R-152a), 1,1,1,2-tetrafluoroethane (R-134a), or mixtures thereof that is substantially free of undesired mono-, di- or tri-halomethane impurities. 
     
     
         3 . The composition according to  claim 2  wherein the composition is substantially free of chloromethane. 
     
     
         4 . A composition comprising 1,1-difluoroethane as a major component that substantially free of chloromethane. 
     
     
         5 . The composition according to  claim 1  as a propellant, especially as a medical and/or pharmaceutical propellant. 
     
     
         6 . The composition according to  claim 5  as a medical and/or pharmaceutical propellant. 
     
     
         7 . The composition according to  claim 1  used as a refrigerant, as a foam blowing agent, as a solvent and/or as a fire extinguishing agent. 
     
     
         8 . An apparatus comprising a carbon molecular sieve and means to supply to said carbon molecular sieve a composition comprising one or more desired (hydro)halocarbons and one or more undesired halogenated hydrocarbon containing impurities so as to reduce the concentration of at least one undesired halogenated hydrocarbon containing impurity,
 wherein the undesired halogenated hydrocarbon containing impurities comprises one or more of a mono-, di- or tri-halomethane,   the desired (hydro)halocarbons are selected from   (i) 1,1,1,2-tetrafluorethane, 1,1,1-trifluoroethane, 1,1-difluoroethane, perfluoroethane or other mono-, di-, tri- or tetra-fluoroethanes;   (ii) 1,2-dichloro-1,1,2,2-tetrafluoroethane, 1,1,1-trichloro-2,2,2-trifluoroethane, 1,1-dichloro-1-fluoroethane, 1-chloro-1,1-difluoroethane, 1,1,1-trifluoro-2-chloroethane, 2,2-dichloro-1,1,1-trifluoroethane (R-123), 2-chloro-1,1,1,2-tetrafluoroethane and/or other (hydro)chlorofluoroethanes; and/or   (iii) (hydro)chloroethanes, (hydro)bromoethanes and/or (hydro)iodomethanes,   the apparatus being adapted and arranged to perform a process according to  claim 1 .   
     
     
         9 . A pharmaceutical delivery device containing one or more pharmaceutically active substances and/or compositions and a composition according to  claim 1 . 
     
     
         10 . The pharmaceutical delivery device according to  claim 9  further containing ethanol. 
     
     
         11 . A method of providing cooling or heating using a heat transfer fluid comprising:
 (i) 1,1,1,2-tetrafluorethane, 1,1,1-trifluoroethane, 1,1-difluoroethane, perfluoroethane or other mono-, di-, tri- or tetra-fluoroethanes;   (ii) 1,2-dichloro-1,1,2,2-tetrafluoroethane, 1,1,1-trichloro-2,2,2-trifluoroethane, 1,1-dichloro-1-fluoroethane, 1-chloro-1,1-difluoroethane, 1,1,1-trifluoro-2-chloroethane, 2,2-dichloro-1,1,1-trifluoroethane (R-123), 2-chloro-1,1,1,2-tetrafluoroethane and/or other (hydro)chlorofluoroethanes; and/or   (iii) (hydro)chloroethanes, (hydro)bromoethanes and/or (hydro) iodomethanes;   which method comprises a method of reducing or removing undesired halogenated hydrocarbon containing impurities comprising one or more of a mono-, di- or tri-halomethane, as defined in  claim 1 .   
     
     
         12 . The method according to  claim 11  wherein the method of providing cooling is performed in a mobile air conditioning system. 
     
     
         13 . A heat transfer device comprising a heat transfer fluid comprising
 (i) 1,1,1,2-tetrafluorethane, 1,1,1-trifluoroethane, 1,1-difluoroethane, perfluoroethane or other mono-, di-, tri- or tetra-fluoroethanes;   (ii) 1,2-dichloro-1,1,2,2-tetrafluoroethane, 1,1,1-trichloro-2,2,2-trifluoroethane, 1,1-dichloro-1-fluoroethane, 1-chloro-1,1-difluoroethane, 1,1,1-trifluoro-2-chloroethane, 2,2-dichloro-1,1,1-trifluoroethane (R-123), 2-chloro-1,1,1,2-tetrafluoroethane and/or other (hydro)chlorofluoroethanes, and/or   (iii) (hydro)chloroethanes, (hydro)bromoethanes and/or (hydro)iodomethanes;   
       and an absorbent comprising a carbon molecular sieve. 
     
     
         14 . The heat transfer device according to  claim 13  wherein the heat transfer device is a refrigeration system. 
     
     
         15 . A heat transfer composition comprising a composition according to  claim 1 .