摘要 |
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. |