Method for producing 1-chloro-2,2-difluoroethane
First Claim
1. A process for producing 1-chloro-2,2-difluoroethane from 1,1,2-trichloroethane, comprising:
- (i) at least one step comprising reacting the 1,1,2-trichloroethane with hydrofluoric acid in the gas phase, in the presence or absence of a fluorination catalyst, so as to give a stream comprising 1-chloro-2,2-difluoroethane, hydrochloric acid, hydrofluoric acid, unreacted 1,1,2-trichloroethane and at least one compound A selected from the group consisting of 1,2-dichloroethylenes (cis and trans), 1-chloro-2-fluoroethylenes (cis and trans), and 1,2-dichloro-2-fluoroethane;
(ii) at least one step comprising separating the compounds resulting from the reaction step, so as to give a first stream comprising hydrochloric acid and a second stream comprising hydrofluoric acid, 1-chloro-2,2-difluoroethane, at least a portion of the at least one compound A and unreacted 1,1,2-trichloroethane;
(iii) at least one step comprising separating the second stream, so as to give an organic phase comprising the 1-chloro-2,2-difluoroethane, at least a portion of the at least one compound A, HF and unreacted 1,1,2-trichloroethane and a nonorganic phase comprising HF; and
(iv) at least one step comprising separating the 1-chloro-2,2-difluoroethane from the organic phase obtained in (iii);
wherein step (iv) comprises;
a) purifying the organic phase obtained in step (iii) so as to form a first stream comprising 1-chloro-2,2-difluoroethane, at least a portion of the at least one compound A and hydrofluoric acid and a second stream comprising 1,1,2-trichloroethane;
b) eliminating the hydrofluoric acid from said first stream so as to form a third stream comprising 1-chloro-2,2-difluoroethane and at least a portion of the at least one compound A; and
c) purifying said third stream comprising 1-chloro-2,2-difluoroethane.
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Abstract
The invention relates to a method for producing 1-chloro-2,2-difluoroethane from 1,1,2-trichloroethane, comprising at least one step of separating 1-chloro-2,2-difluoroethane from the organic phase produced during the method; said step comprising a) purification of the organic phase obtained in step (iii) so as to form a first stream comprising 1-chloro-difluoroethane and hydrofluoric acid and a second stream comprising 1,1,2-trichloroethane; b) the elimination of the hydrofluoric acid from said first stream in order to form a third stream comprising 1-chloro-difluoroethane; and c) a purification of said third stream comprising 1-chloro-difluoroethane.
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10 Claims
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1. A process for producing 1-chloro-2,2-difluoroethane from 1,1,2-trichloroethane, comprising:
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(i) at least one step comprising reacting the 1,1,2-trichloroethane with hydrofluoric acid in the gas phase, in the presence or absence of a fluorination catalyst, so as to give a stream comprising 1-chloro-2,2-difluoroethane, hydrochloric acid, hydrofluoric acid, unreacted 1,1,2-trichloroethane and at least one compound A selected from the group consisting of 1,2-dichloroethylenes (cis and trans), 1-chloro-2-fluoroethylenes (cis and trans), and 1,2-dichloro-2-fluoroethane; (ii) at least one step comprising separating the compounds resulting from the reaction step, so as to give a first stream comprising hydrochloric acid and a second stream comprising hydrofluoric acid, 1-chloro-2,2-difluoroethane, at least a portion of the at least one compound A and unreacted 1,1,2-trichloroethane; (iii) at least one step comprising separating the second stream, so as to give an organic phase comprising the 1-chloro-2,2-difluoroethane, at least a portion of the at least one compound A, HF and unreacted 1,1,2-trichloroethane and a nonorganic phase comprising HF; and (iv) at least one step comprising separating the 1-chloro-2,2-difluoroethane from the organic phase obtained in (iii);
wherein step (iv) comprises;a) purifying the organic phase obtained in step (iii) so as to form a first stream comprising 1-chloro-2,2-difluoroethane, at least a portion of the at least one compound A and hydrofluoric acid and a second stream comprising 1,1,2-trichloroethane; b) eliminating the hydrofluoric acid from said first stream so as to form a third stream comprising 1-chloro-2,2-difluoroethane and at least a portion of the at least one compound A; and c) purifying said third stream comprising 1-chloro-2,2-difluoroethane. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification