Method for preparing 1,1,1,3,3-pentafluoropropane

Abstract

A process for the production of C2-C4 hydrofluorocarbon, such as 1,1,1,3,3-pentafluoropropane, by contacting a non-fluorinated hydrochlorocarbon with a fluorinating agent, such as hydrogen fluoride, in a liquid catalyst system preferably comprising fluorinated superacid catalyst prepared from SbF 5 , NbF 5 , TaF 5 or TaF 5 /SnF 4 and HF.

1 . A method of producing 1,1,1,3,3-pentafluoropropane comprising: 
 (a) providing a catalytic solution comprising a fluorination catalyst at least partially dissolved in an azeotrope-like mixture of 1,1,1,3,3-pentafluoropropane and hydrogen fluoride; and    (b) adding to said catalytic solution at least one non-fluorinated hydrochlorocarbon under conditions effective to convert at least a portion of said non-fluorinated hydrochlorocarbon to 1,1,1,3,3-pentafluoropropane.    
   
   
       2 . The method of  claim 1  wherein said non-fluorinated hydrochlorocarbons is selected from the group consisting of 1,1,1,3,3-pentachloropropane, 1,3,3,3-tetrachloropropene and combinations thereof.  
   
   
       3 . The method of  claim 2  wherein said non-fluorinated hydrochlorocarbons comprises 1,1,1,3,3-pentachloropropane.  
   
   
       4 . The method of  claim 2  wherein said non-fluorinated hydrochlorocarbons comprises 1,3,3,3-tetrachloropropene.  
   
   
       5 . The method of  claim 1  wherein said fluorination catalyst is selected from the group consisting of SbF 5 , NbF 5 , TaF 5 , a mixture of TaF 5  and SnF5 and combinations of two or more of these.  
   
   
       6 . The method of  claim 5  wherein said fluorination catalyst comprises SbF 5 .  
   
   
       7 . The method of  claim 1  wherein at least a portion of said conversion step comprises conducting a reaction at a temperature of from about 60° C. to about 120° C.  
   
   
       8 . The method of  claim 1  wherein said effective conditions comprise maintaining said hydrogen fluoride and said non-fluorinated hydrochlorocarbons in a reaction mixture in a mole ratio of at least about 10:1  
   
   
       9 . The method of  claim 8  wherein said hydrogen fluoride and said 1,1,1,3,3-pentafluoropropane in said reaction mixture are present in a mole ratio of not more than about 12:1  
   
   
       10 . The method of  claim 8  wherein said hydrogen fluoride and said fluorination catalyst are present in a molar ratio of at least about 10:1.  
   
   
       11 . The method of  claim 1  wherein said method is a continuous process.  
   
   
       12 . The method of  claim 11  further comprising adding hydrogen fluoride to said catalytic solution as a component of a first feed stream and said non-fluorinated hydrochlorocarbon is added to said solution as a component of a second feed stream.  
   
   
       13 . The method of  claim 12  further comprising the step of recycling at least a portion of at least one of unreacted hydrochlorocarbons, hydrogen fluoride, and partially fluorinated organic intermediates from said liquid reaction system back into said solution as a recycle stream.  
   
   
       14 . The method of  claim 13  wherein said first and second feed streams and said recycle stream comprise a net molar feed ratio of hydrogen fluoride to hydrochlorocarbons of at least about 5:1.  
   
   
       15 . The method of  claim 12  further comprising the step of neutralizing at least a portion of water introduced into said reaction system via said first feed stream, second feed stream, or said catalytic solution, by contacting said water with a dehydrating agent selected from the group consisting of COCl 2 , COF 2 , and SOCl 2 .  
   
   
       16 . A method of producing a C2-C4 hydrofluorocarbon comprising: 
 (a) providing a catalytic solution comprising C2-C4 hydrofluorocarbon, fluorinating agent, and a fluorination catalyst at least partially dissolved in said C2-C4 hydrofluorocarbon; and    (b) adding to said catalytic solution at least one non-fluorinated hydrochlorocarbon under conditions effective to produce C2-C4 hydrofluorocarbon.    
   
   
       17 . The method of  claim 16  wherein said C2-C4 hydrofluorocarbon comprises 1,1,1,3,3-pentafluoropropane.  
   
   
       18 . The method of  claim 16  wherein said non-fluorinated hydrochlorocarbons is selected from the group consisting of 1,1,1,3,3-pentachloropropane, 1,3,3,3-tetrachloropropene, and mixtures thereof.  
   
   
       19 . The method of  claim 16  wherein said fluorination catalyst is selected from the group consisting of SbF 5 , NbF 5 , TaF 5 , a mixture of TaF 5  and SnF 5 , and combinations thereof.  
   
   
       20 . The method of  claim 16  wherein said fluorinating agent comprises HF.  
   
   
       21 . The method of  claim 16  wherein said effective conditions comprise contacting said catalytic solution with said at least one non-fluorinated hydrochlorocarbon at a temperature of from about 60° C. to about 120° C.