Method for prolonging a catalyst's life during hydrofluorination

Abstract

The invention provides an improved process to manufacture 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) by reacting 2-chloro-3,3,3,-trifluoropropene (HCFO-1233xf) with hydrogen fluoride, in the presence of a fluorination catalyst, where by using 2-chloro-3,3,3,-trifluoropropene (HCFO-1233xf) of high purity, the need to add an oxidizing agent (typically chlorine) to keep the catalyst active can be avoided. The HCFC-244bb is then used as an intermediate in the production of 2,3,3,3-tetrafluoropropene-1 (HFO-1234yf).

We claim: 
     
         1 ) A process for producing 2-chloro-1,1,1,2-tetrafluoropropane comprising reacting a feed comprising a substantially pure organic component of 2-chloro-3,3,3,-trifluoropropene with hydrogen fluoride and a fluorination catalyst in the absence of an oxidizing agent. 
     
     
         2 ) The process of  claim 1  wherein the substantially pure organic component of 2-chloro-3,3,3,-trifluoropropene comprises at least 99% of 2-chloro-3,3,3-trifluoropropene. 3) The process of  claim 1  wherein the substantially pure organic component of 2-chloro-3,3,3,-trifluoropropene is produced by a process comprising fluorinating 1,1,2,3,-tetrachloropropene and/or 1,1,1,2,3-tetrachloropropane and separating 2-chloro-3,3,3-trifluoropropene from an intermediate stream. 
     
     
         4 ) The process of claim  3  wherein the intermediate stream comprises 2-chloro-3,3,3,-trifluoropropene and one or more reaction impurities. 
     
     
         5 ) The process of  claim 4  wherein at least one impurity is 2,3-dichloro-3,3-trifluoropropene. 
     
     
         6 ) The process of claim  3  wherein the step of separating 2-chloro-3,3,3-trifluoropropene from one or more impurities is performed by distillation. 
     
     
         7 ) The process of  claim 1  wherein the reaction is conducted in a liquid phase or a vapor phase. 
     
     
         8 ) The process of  claim 1  wherein the reaction is conducted continuously or batch-wise. 
     
     
         9 ) The process of  claim 1  wherein the mole ratio of hydrogen fluoride to the substantially pure organic component of 2-chloro-3,3,3-trifluoropropene that is fed to the reaction ranges from at least 1:1 to about 50:1. 
     
     
         10 ) The process of  claim 1  wherein fluorination catalyst is a liquid phase catalyst selected from the group consisting of antimony halide, a tin halide, a tantalum halide, a titanium halide, a niobium halide, and molybdenum halide, an iron halide, a fluorinated chrome halide, a fluorinated chrome oxide, SbCl 5 , SbCl 3 , SbF 5 , SnCl 4 , TaCl 5 , TiCl 4 , NbCl 5 , MoCl 6 , FeCl 3 , CrF 3 , Cr 2 O 3 , a fluorinated species of SbCl 5 , a fluorinated species of SbCl 3 , a fluorinated species of SnCl 4 , a fluorinated species of TaCl 5 , a fluorinated species of TiCl 4 , a fluorinated species of NbCl 5 , a fluorinated species of MoCl 6 , a fluorinated species of FeCl 3 , a fluorinated species of Cr 2 O 3 , and combinations thereof. 
     
     
         11 ) The process of  claim 1  wherein fluorination catalyst is a vapor phase catalyst selected from the group consisting of SbCl 5  impregnated on carbon, SbCl 5  is impregnated on Al 2 O 3  and combinations thereof. 
     
     
         12 ) The process of  claim 1  wherein the reacting is conducted at a temperature of from about 30° C. to about 200° C. 
     
     
         13 ) The process of  claim 1  wherein the reacting is conducted at a pressure of from about 5 psia to about 200 psia. 
     
     
         14 ) A process for the production of 2,3,3,3-tetrafluoropropene comprising:
 (i) reacting a feed comprising a substantially pure organic component of 2-chloro-3,3,3,-trifluoropropene with hydrogen fluoride and a fluorination catalyst in the absence of an oxidizing agent to produce 2-chloro-1,1,1,2-tetrafluoropropane; and   (ii) dehydrohalogenating the 2-chloro-1,1,1,2-tetrafluoropropane under conditions effective to produce 2,3,3,3-tetrafluoropropene.   
     
     
         15 ) The process of  claim 14  wherein the substantially pure organic component of 2-chloro-3,3,3,-trifluoropropene comprises at least 99% of 2-chloro-3,3,3-trifluoropropene. 
     
     
         16 ) The process of  claim 14  wherein the substantially pure organic component of 2-chloro-3,3,3,-trifluoropropene is produced by a process comprising fluorinating 1,1,2,3,-tetrachloropropene and/or 1,1,1,2,3-tetrachloropropane and separating 2-chloro-3,3,3-trifluoropropene from an intermediate stream comprising 2-chloro-3,3,3-trifluoropropene and on or more impurities 
     
     
         17 ) The process of  claim 16  wherein at least one impurity is 2,3-dichloro-3,3-trifluoropropene. 
     
     
         18 ) The process of  claim 16  wherein the step of separating 2-chloro-3,3,3-trifluoropropene from one or more impurities is performed by distillation. 
     
     
         19 ) A process for producing 2,3,3,3-tetrafluoropropene comprising
 (i) fluorinating 1,1,2,3,-tetrachloropropene and/or 1,1,1,2,3-tetrachloropropane to produce an intermediate stream comprising 2-chloro-3,3,3-trifluoropropene and one or more impurities;   (ii) separating 2-chloro-3,3,3-trifluoropropene from an intermediate stream to form substantially pure 2-chloro-3,3,3-trifluoropropene;   (iii) reacting a feed comprising a substantially pure organic component of 2-chloro-3,3,3,-trifluoropropene with hydrogen fluoride and a fluorination catalyst in the absence of an oxidizing agent to produce 2-chloro-1,1,1,2-tetrafluoropropane; and   (iv) dehydrohalogenating the 2-chloro-1,1,1,2-tetrafluoropropane under conditions effective to produce 2,3,3,3-tetrafluoropropene.