METHOD FOR INTEGRATED PRODUCTION OF FLUOROCARBONS Russian patent published in 2000 - IPC

FIELD: industrial organic synthesis. SUBSTANCE: method includes pyrolysis of difluorochloromethane in presence of water steam and 1,12,2- tetrafluorochloroethane followed by hardening of pyrolysis products. Secondarily formed hydrogen chloride is bound into aqueous solution. Multistep rectification allows isolation of tetrafluoroethylene fraction and fractions containing difluorochloromethane/hexafluoropropylene and 1,1,2,2-tetrafluorochloroethane/octafluorocyclobutane azeotropic mixtures, which are then separated by absorption with water to give hexafluoropropylene and octafluorocyclobutane. Above-mentioned azeotropic mixtures are run off successively. The first one is distilled at pressure 3-8 atm within boiling range from 42 to 38 C (on conversion to atmospheric pressure) and the second at pressure 2-7 atm within boiling range from 15 to 0 C. EFFECT: reduced consumption of difluorochloromethane due to its integrated use and improved environmental condition due to optimum operation conditions and to goal utilization of high-toxicity hexafluoropropylene and octafluorocyclobutane. 23 cl, 3 ex