PROCESS FOR INTEGRATED PRODUCTION OF FLUOROCARBONS Russian patent published in 2002 - IPC

FIELD: industrial organic synthesis. SUBSTANCE: production of industrially important fluorocarbons, in particular tetrafluoroethylene, hexafluoropropylene, and oectafluorocyclobutane, is accomplished via pyrolysis of difluorochloromethane with water steam and tetrafluorochloroethane. Pyrolyzate is subjected to tempering, fried of HCl (to use for production of hydrochloric acid), neutralized, compressed, and condensed in three-step process receiving polymerization inhibitor before the first and second condensation steps. From the second-step condensate, low-boiling substances are removed by rectification and tetrafluoroethylene is recovered. Still fraction is combined with first-step condensate and resulting mixture is subjected to multistep rectification to yield fractions of difluorochloromethane/hexafluoropropylene and tetrafluorochloroethane/oectafluorocyclobutane azeotropes, from which hexafluoropropylene and oectafluorocyclobutane are isolated. In the third condensation step, difluorochloromethane or indicated azeotropes are additionally introduced. Third-step condensate is added to still fraction/first-step condensate mixture and, from combined mixture before isolation of above-indicated azeotropes, first tetrafluoroethylene-containing gases (which are transferred into pyrolyzate compression stage) and then, optionally, trifluoroethylene are rectified into light fraction. Tetrafluoroethylene concentration in the third-step condensate is advantageously maintained between 10 and 30%. EFFECT: increased yield of valuable products (to 99%) due to reduced loss of tetrafluoroethylene and using trifluoroethylene. 5 cl, 5 ex