Imperial Chemical Industries Limited

Rachel A Steven

John David Scott

A method of producing 1,1,1,2-tetrafluoroethane in two separation reaction zones involving (1) reaction of trichloroethylene and hydrogen fluoride to produce l,l,l-trifluoro-2-chloroethane and (2) reaction of the 1,1,1-trifluoro-2-chloroethane and hydrogen fluoride to produce 1,1,1,2-tetrafluoroethane wherein both reactions are carried out at superatmospheric pressure, reaction (2) is carried out at a temperature in the range of 250.degree.-450.degree. C., reaction (1) is carried out at a temperature in the range of 200.degree.-400.degree. C. but below that used in reaction (2) and unconverted 1,1,1-trifluoro-2-chloroethane is recycled for further reaction with hydrogen fluoride.

Chemical process

A method of producing 1,1,1,2-tetrafluoroethane in two separation reaction zones involving (1) reaction of trichloroethylene and hydrogen fluoride to produce 1,1,1-trifluoro-2-chloroethane and (2) reaction of the 1,1,1- trifluoro-2-chloroethane and hydrogen fluoride to produce 1,1,1,2-tetrafluoroethane wherein both reactions are carried out at superatmospheric pressure, reaction (2) is carried out at a temperature in the range of 250.degree.-450.degree. C., reaction (1) is carried out at a temperature in the range of 200.degree.-400.degree. C. but below that used in reaction (2) and unconverted 1,1,1-trifluoro-2-chloroethane is recycled for further reaction with hydrogen fluoride.

Process for the manufacture of 1,1,1,2-tetrafluoroethane

1,1,1,2-tetrafluoroethane (HFA 134a) is manufactured from trichloroethylene by a two-stage process comprising reacting trichloroethylene with hydrogen fluoride under superatmospheric pressure in a first reaction zone to form 1,1,1-trifluoro-2-chloroethane (133a) and reacting the 1,1,1-trifluoro-2-chloroethane with hydrogen fluoride in a second reaction zone to form 1,1,1,2-tetrafluoroethane; the entire product stream from the 133a reaction zone together with additional HF of required is fed through the 134a reaction zone. The two reaction zones may be provided within a single reaction vessel.

1,1,1,2-tetrafluoroethane (HFA 134a) is manufactured from trichloroethylene by a two-stage process comprising reacting trichloroethylene with hydrogen fluoride in one reactor to form 1,1,1-trifluoro-2-chloroethane (133a) and reacting the 1,1,1-trifluoro-2-chloroethane with hydrogen fluoride in another reactor to form 1,1,1,2-tetrafluoroethane. The invention is characterized by reversing the reactor sequence and passing the entire product stream from the HFA 134a reactor together with trichloroethylene through the 133a reactor and separating 134a and hydrogen chloride from the recycle stream between the 133a reactor and the 134a reactor.

Chemical process for the manufacture of 1,1,1,2-tetrafluoroethane

1,1,1,2-tetrafluoroethane (HFA 134a) is manufactured from trichloroethylene by a two-stage process comprising reacting trichloroethylene with hydrogen fluoride in one reactor to form 1,1,1-trifluoro-2-chloroethane (133a) and reacting the 1,1,1-trifluoro-2-chloroethane with hydrogen fluoride in another reactor to form 1,1,1,2-tetrafluoroethane. The invention is characterised by reversing the reactor sequence and passing the entire product stream from the HFA 134a reactor together with trichloroethylene through the 133a reactor and separating 134a and hydrogen chloride from the recycle stream between the 133a reactor and the 134a reactor.

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Manley, United Kingdom

Rachel A Steven