Process for producing 2,3,3,3-tetrafluoropropene

Abstract

The invention relates to a process to prepare 2-chloro-3,3,3-trifluoropropene (HCO-1233xf) or 2-chloro-1,1,12-tetrafluoropropane (HCFC-244bb) using dichloro-trifluoropropanes and/or trichloro-difluoropropanes, and to prepare 2-chloro-3,3,3-trifluoropropene (HCO-1233xf) using various 242 and 243 isomers.

What is claimed is: 
     
         1 . A process to prepare 2-chloro-1,1,12-tetrafluoropropane (HCFC-244bb) comprising contacting a compound selected from the group consisting of a dichloro-trifluoropropane, a trichloro-difluoropropane, and combinations thereof, with anhydrous hydrogen fluoride (HF) under conditions effective to produce HCFC-244bb. 
     
     
         2 . The process of  claim 1  wherein the dichloro-trifluoropropane is selected from the group consisting of 2,2-dichloro-1,1,1-trifluoropropane (HCFC-243ab), 1,2-dichloro-1,1,2-trifluoropropane (HCFC-243bc), 2,3-dichloro-1,1,1-trifluoropropane (HCFC-243 db) and combinations thereof. 
     
     
         3 . The process of  claim 1  wherein the trichloro-difluoropropane is selected from the group consisting of 1,2,2-trichloro-1,1-difluoropropane (HCFC-242ac), 1,1,2-trichloro-1,2-difluoropropane (HCFC-242bc), 1,2,3-trichloro-1,1-difluoropropane (HCFC-242dc) and combinations thereof. 
     
     
         4 . The process of  claim 1  wherein the process occurs in a vapor phase. 
     
     
         5 . The process of  claim 1  wherein the contacting occurs in the presence of a catalyst. 
     
     
         6 . The process of  claim 5  wherein the catalyst is selected from the group consisting of Cr 2 O 3 , FeCl 3 /C, Cr 2 O 3 /Al 2 O 3 , Cr 2 O 3 /AlF 3 , Cr 2 O 3 /carbon, CoCl 2 /Cr 2 O 3 /Al 2 O 3 , NiCl 2 /Cr 2 O 3 /Al 2 O 3 , CoCl 2 /AlF 3 , NiCl 2 /AlF 3  and combinations thereof. 
     
     
         7 . The process of  claim 1  wherein the contacting occurs at a temperature between about 150° C. and about 500° C. 
     
     
         8 . The process of  claim 1  wherein the contacting occurs at a pressure of between about 20 psig and about 200 psig. 
     
     
         9 . A process to prepare 2-chloro-3,3,3-trifluoropropene (HCO-1233xf) and 2-chloro-1,1,1,2-tetrafluoropropane (244bb) comprising a contacting step comprising contacting at least one compound of Formulae (I), (II), (III)
   CX 2 ═CCl—CH 2 X  (I)
     CX 3 —CCl═CH 2   (II)
     CX 3 —CHCl—CH 2 X  (III)
   wherein X is independently selected from F, Cl, Br, and I, provided that at least one X is not fluorine, with anhydrous hydrogen fluoride (HF) in the presence of a catalyst under conditions effective to form a composition comprising HCO-1233xf and a by-product selected from the group consisting of a dichloro-trifluoropropane, a trichloro-difluoropropane and combinations thereof;   recovering the by-product from the composition;   recycling the by-product to the contacting step wherein the by-product is converted to 2-chloro-1,1,1,2-tetrafluoropropane (244bb).   
     
     
         10 . The process of  claim 9  wherein the recovering step comprises phase separation and distillation. 
     
     
         11 . The process of  claim 9  wherein the catalyst is selected from the group consisting of Cr 2 O 3 , FeCl 3 /C, Cr 2 O 3 /Al 2 O 3 , Cr 2 O 3 /AlF 3 , Cr 2 O 3 /carbon, CoCl 2 /Cr 2 O 3 /Al 2 O 3 , NiCl 2 /Cr 2 O 3 /Al 2 O 3 , CoCl 2 /AlF 3 , NiCl 2 /AlF 3  and combinations thereof. 
     
     
         12 . The process of  claim 9  wherein the dichloro-trifluoropropane is selected from the group consisting of 2,2-dichloro-1,1,1-trifluoropropane (HCFC-243ab), 1,2-dichloro-1,1,2-trifluoropropane (HCFC-243bc), and combinations thereof. 
     
     
         13 . The process of  claim 9  wherein the trichloro-difluoropropane is selected from the group consisting of 1,2,2-trichloro-1,1-difluoropropane (HCFC-242ac), 1,1,2-trichloro-1,2-difluoropropane (HCFC-242bc), and combinations thereof. 
     
     
         14 . A process to prepare 2-chloro-3,3,3-trifluoropropene (HCO-1233xf) comprising contacting 1,1,1-trifluoro-2,2-dichloropropane (243ab) with a dehydrochlorination catalyst under conditions effective to form 1233xf. 
     
     
         15 . The process of  claim 14  wherein the dehydrochlorination catalyst is selected from the group consisting of carbon solids, metal halides, halogenated metal oxides, zero metals and combinations thereof. 
     
     
         16 . A process to prepare 2-chloro-1,1,1,2-tetrafluorpropane (244bb) comprising contacting 2-chloro-3,3,3-trifluoropropene (HCO-1233xf) with HF in a reaction zone under conditions effective to form a composition comprising 244bb and 1,1,1-trifluoro-2,2-dichloropropane (243ab); contacting the 243ab with a dehydrochlorination catalyst selected from the group consisting of carbon solids, metal halides, halogenated metal oxides, zero metals and combinations thereof under conditions effective to form 1233xf; and recycling the formed 1233xf to the reaction zone. 
     
     
         17 . A process to prepare 2-chloro-3,3,3-trifluoropropene (HCO-1233xf) comprising contacting at least one compound selected from the group consisting of 2,2-dichloro-1,1,1-trifluoropropane (HCFC-243ab), 1,2-dichloro-1,1,2-trifluoropropane (HCFC-243bc), 1,2,2-trichloro-1,1-difluoropropane (HCFC-242ac), and 1,2-dichloro-1,1,2-trifluoropropane (HCFC-243bc) in the presence of HF under conditions effective to form (HCO-1233xf). 
     
     
         18 . The process of  claim 17  wherein the conditions effective include the presence of a catalyst selected from the group consisting of Cr 2 O 3 , FeCl 3 /C, Cr 2 O 3 /Al 2 O 3 , Cr 2 O 3 /AlF 3 , Cr 2 O 3 /carbon, CoCl 2 /Cr 2 O 3 /Al 2 O 3 , NiCl 2 /Cr 2 O 3 /Al 2 O 3 , CoCl 2 /AlF 3 , NiCl 2 /AlF 3  and combinations thereof.