Integrated process for the manufacture of fluorinated olefins
AssigneeHoneywell International Inc.
InventorsSelma Bektesevic, Hsueh Sung Tung, Haluk Kopkalli
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Abstract
The instant invention relates, at least in part, to a method increasing the cost efficiency for dehydrohalogenation production of a fluorinated olefin by recovering and recycling spent dehydrohalogenation agent. In one aspect, the present invention relates to dehydrohalogenating a fluorinated alkane (e.g. pentafluoropropane and/or hexafluoropropane) in the presence of a dehydrohalogenating agent to produce a fluorinated olefin (e.g. tetrafluoropropenes and/or pentafluoropropenes). Removal of spent dehydrohalogenating agent from the reactor allows for facile separation of organic and dehydrohalogenating agent, the latter of which is recycled.
Claims46
A method for producing at least one fluorinated olefin comprising:
- a. hydrogenating a starting material stream comprising at least one alkene according to Formula (I):
- (CXnY3-n)(CR1aR2b)zCX═CHmX2−m (I)
- by contacting said starting material with a reducing agent to produce an intermediate product stream comprising at least one alkane according to Formula (II):
- (CXnY3−n)(CR1aR2b)zCHXCHm+1X2−m (II)
- where:
- each X is independently Cl, F, I or Br, provided that at least two Xs are F;
- each Y is independently H, Cl, F, I or Br;
- each R1 is independently H, Cl, F, I, Br or unsubstituted or halogen substituted methyl or ethyl radical;
- each R2 is independently H, Cl, F, I, Br or unsubstituted or halogen substituted methyl or ethyl radical;
- n is 1, 2 or 3;
- a and b are each 0, 1 or 2, provided that a+b=2;
- m is 0, 1 or 2;
- and
- z is 0, 1, 2 or 3;
- b. optionally, separating said intermediate product stream into a plurality of intermediate product streams, said plurality of intermediate product streams comprising two or more streams selected from the group consisting of a first stream rich in at least a first alkane according to Formula II, a seconds stream rich in at least a second alkane according to Formula II, and an alkane recycle stream;
- c. dehydrofluorinating, in the presence of a dehydrohalogenating agent, at least a portion of said intermediate process stream from step (a) or said plurality of intermediate process streams of step (b) to produce an alkene product stream comprising 1,1,1,2,3-pentafluoropropene and at least one additional alkene having a lower degree of fluorine substitution compared to the degree of fluorination of the compound of formula (I);
- and
- d. withdrawing from a dehydrofluorinated product stream a product reaction stream comprising spent dehydrohalogenating agent;
- and
- e. recovering spent dehydrohalogenating agent.
A method for producing 2,3,3,3-tetrafluoropropene comprising:
- a. hydrogenating a starting material stream comprising hexafluoropropylene by contacting said starting material stream with a reducing agent in a hydrogenation reactor to produce an intermediate stream comprising 1,1,1,2,3-pentafluoropropane or 1,1,1,2,3,3-hexafluoropropane;
- b. dehydrofluorinating, in the presence of a dehydrohalogenating agent, said 1,1,1,2,3-pentafluoropropane or said 1,1,1,2,3,3-hexafluoropropane in a dehydrofluorination reactor to produce a product stream comprising 2,3,3,3-tetrafluoropropene or 1,2,3,3,3-pentafluoropropene;
- c. withdrawing from the product stream a second product stream comprising spent dehydrohalogenating agent;
- and
- d. recovering spent dehydrohalogenating agent.
A process for the manufacture of a fluoroolefin comprising:
- (a) dehydrohalogenating a haloalkane in the presence of KOH to produce a haloalkene;
- (b) withdrawing a reaction stream comprising spent KOH;
- and
- (c) recovering spent KOH.
A process for the manufacture of a fluoroolefin comprising:
- (a) dehydrohalogenating 1,1,1,2,3,3-hexafluoropropane (HFC-236ea) or 1,1,1,2,3-pentafluoropropane (HFC-245eb) in the presence of KOH to produce 2,3,3,3-tetrafluoropropene (HFO-1234yf) or 1,2,3,3,3-pentafluoropropene (HFO-1225ye);
- (b) withdrawing a reaction stream comprising spent KOH;
- and
- (c) recovering spent KOH.
Dependencies are inferred from the claim text.