Conversion of fluorocarbons

Abstract

A process is disclosed for the conversion of fluorocarbons into fluorinated unsaturated compounds useful as monomers or other chemical precursors, such as C 2 H 2 F 2 . The process comprises reacting a hydrocarbon feed ( 20 ) and a fluorocarbon feed ( 10 ) in a high temperature reactor ( 26 ), at sufficiently high temperature and sufficiently short resident time to form a reaction product mixture ( 28 ) having the fluorinated unsaturated compound as the major reaction product, and cooling ( 18 ) to a temperature sufficiently low to inhibit polymerisation of the unsaturated compound. The reaction product may then be processed by removal of higher molecular weight compounds ( 35 ) and acids ( 32 ) and optionally separated ( 44 ) into product components.

1 . A process for production of fluorinated C 2  or higher unsaturated compounds from reaction of a hydrocarbon with a fluorocarbon feed, including the steps of: 
 (a) reacting a hydrocarbon or hydrocarbon mixture with a fluorocarbon feed under non-oxidative conditions in a high temperature reactor, at sufficiently high temperature and sufficiently short residence time to form a reaction product mixture having a fluorinated unsaturated compound as the major reaction component thereof,    (b) rapidly cooling said reaction product mixture to a temperature sufficiently low to substantially inhibit polymerisation of said fluorinated unsaturated compound.    
   
   
       2 . A process according to  claim 1 , further including the step of: 
 (c) condensing higher boiling point compounds from said cooled reaction product mixture.    
   
   
       3 . A process according to  claim 1 , further including the step of: 
 (d) removing hydrogen halide acids from the reaction product mixture.    
   
   
       4 . A process according to  claim 1 , further including the step of: 
 (e) separating said fluorinated unsaturated C 2  or higher compound from said reaction product mixture, and optionally    (f) recycling at least a portion of the remainder of said reaction product mixture from step (e) to said reactor.    
   
   
       5 . A process according to  claim 1 , wherein said fluorocarbon is selected from the group consisting of hydrofluorocarbons, halofluorocarbons and hydrohalofluorocarbons.  
   
   
       6 . A process according to  claim 1 , wherein said fluorocarbon is selected from the group consisting of CCl 2 F 2 , CFCl 2 Br, CF 3 Br, CF 3 H, CHClF 2 , C 4 F 10 , CH 2 F 2 , CF 3 H, C 3 F 8  and C 3 F 8 O.  
   
   
       7 . A process according to  claim 6  wherein said fluorocarbon is selected from the group consisting of CF 3 Br and CF 2 ClBr.  
   
   
       8 . A process according to  claim 1 , wherein said fluorinated unsaturated C 2  or higher reaction compound is selected from the group consisting of CF 2 CFH, C 2 H 3 F and C 2 H 2 F 2 .  
   
   
       9 . A process according to  claim 8 , wherein said fluorinated unsaturated C 2  or higher reaction compound is C 2 H 2 F 2 .  
   
   
       10 . A process according to  claim 1 , wherein said fluorocarbon feed is at least 30% concentrated.  
   
   
       11 . A process according to  claim 10 , wherein said fluorocarbon feed is at least 50% concentrated.  
   
   
       12 . A process according to  claim 11 , wherein said fluorocarbon feed is at least 90% concentrated.  
   
   
       13 . A process according to  claim 1 , wherein said reaction is conducted at a temperature of about 950-1300K.  
   
   
       14 . A process according to  claim 13 , wherein said reaction is conducted at a temperature of about 1050-1200K.  
   
   
       15 . A process according to  claim 14 , wherein said reaction is conducted at a temperature of from 1050-1150K.  
   
   
       16 . A process according to  claim 1 , wherein said reaction residence time of said fluorocarbon feed is less than 0.5 s.  
   
   
       17 . A process according to  claim 16 , wherein said reaction residence time is from 0.01 s to 0.5 s.  
   
   
       18 . A process according to  claim 17 , wherein said reaction residence time is from 0.02-0.15 s.  
   
   
       19 . A process according to  claim 18 , wherein said reaction residence time is under about 0.1 s.  
   
   
       20 . A process according to  claim 1 , wherein said hydrocarbon is provided to said reactor in excess of an amount required to react completely with said fluorocarbon feed.  
   
   
       21 . A process according to  claim 20 , wherein a hydrocarbon to fluorocarbon molar feed ratio is less than 2 to 1.  
   
   
       22 . A process according to  claim 21 , wherein said hydrocarbon to fluorocarbon molar feed ratio is less than 1.5 to 1.  
   
   
       23 . A process according to  claim 22 , wherein said hydrocarbon to fluorocarbon molar feed ratio is about 1.3 to 1.