US 2014/0275646 A1 · METHOD FOR MITIGATING HFC-245CB FORMATION DURING HCFO-1233XF HYDROFLUORINATION TO HCFC-244BB

Abstract

The present process relates to a method for minimizing the formation of 1,1,1,2,2-pentafluoropropane in a liquid phase reaction of 2-chloro-3,3,3-trifluoropropene and HF in the presence of a hydrofluorination catalyst comprising: (a) reacting HF with sufficient amount of 2-chloro-3,3,3-trifluoropropene in the presence of a hydrofluorination catalyst under conditions effective to form 2-chloro-1,1,1,2-tetrafluoropropane, the hydrofluorination catalyst being present in sufficient amounts to catalyze said reaction and the 2-chloro-1,1,1,2-tetrafluoropropane being formed with both a conversion of greater than 80% and a 1,1,1,2,2-pentafluoropropane selectivity lower than 20%; and (b) maintaining the 2-chloro-1,1,1,2-tetrafluoropropane being formed with both a conversion of about 80% or more and a 1,1,1,2,2-pentafluoropropane selectivity of about 20% or less by adding said hydrofluorination catalyst to the reactor in small increments.

Claims32

Dependent claims

A method for minimizing the formation of 1,1,1,2,2-pentafluoropropane in a liquid phase reaction of 2-chloro-3,3,3-trifluoropropene and HF in the presence of a hydrofluorination catalyst in a reactor comprising:

(a) reacting HF with sufficient amount of 2-chloro-3,3,3-trifluoropropene in the presence of a hydrofluorination catalyst under conditions effective to form 2-chloro-1,1,1,2-tetrafluoropropane, the hydrofluorination catalyst being present in sufficient amounts to catalyze said reaction and 2-chloro-1,1,1,2-tetrafluoropropane being formed with both a conversion of about 80% or more and 1,1,1,2,2-pentafluoropropane selectivity of about 20% or less;
and
(b) maintaining the 2-chloro-1,1,1,2-tetrafluoropropane being formed with both a conversion of about 80% or more and a 1,1,1,2,2-pentafluoropropane selectivity of about 20% or less by adding said hydrofluorination catalyst continuously or periodically to the reactor in small increments.

A method for preparing 2,3,3,3-tetrafluoroprop-1-ene comprising:

(a) providing a starting composition comprising at least one compound having a structure selected from Formulas I, II and III:
CX2═CCl−CH2X Formula I
CX3—CCl═CH2 Formula II
CX3—CHCl—CH2X Formula III
wherein X is independently selected from F, Cl, Br and I, provided that at least one X is not fluorine:
(b) contacting said starting composition with a first hydrofluorinating agent to produce a first intermediate composition comprising 2-chloro-3,3,3-trifluoropropene;
(c) reacting HF with sufficient amount of 2-chloro-3,3,3-trifluoropropene in the presence of a second hydrofluorination catalyst under conditions effective to form 2-chloro-1,1,1,2-tetrafluoropropane, the second hydrofluorination catalyst being present in sufficient amounts to catalyze said reaction and 2-chloro-1,1,1,2-tetrafluoropropane being formed with both a conversion of at least 80% and 1,1,1,2,2-pentafluoropropane selectivity of at most 20%;
and
(d) maintaining the 2-chloro-1,1,1,2-tetrafluoropropane being formed with both a conversion of about 80% or more and a 1,1,1,2,2-pentafluoropropane selectivity of about 20% or less by adding said second hydrofluorination catalyst to the reactor periodically or continuously in small increments;
and
(e) dehydrochlorinating 2-chloro-1,1,1,2-tetrafluoropropane to produce a reaction product comprising 2,3,3,3-tetrafluoroprop-1-ene.

8 more elements

Dependencies are inferred from the claim text.

Method for mitigating hfc-245cb formation during hcfo-1233xf hydrofluorination to hcfc-244bb

Life of this patent

Method for mitigating hfc-245cb formation during hcfo-1233xf hydrofluorination to hcfc-244bb

Life of this patent

Abstract

Claims32