METHOD OF REMOVING TETRAFLUOROETHYLENE FROM GAS MIXTURE Russian patent published in 2000 - IPC

FIELD: gas treatment. SUBSTANCE: invention is intended for use in production of tetrafluoroethylene for removing the latter from by-product fractions formed during the pyrolysis of difluorochloromethane, especially in the presence of steam. Gas mixture is treated with liquid difluorochloromethane in countercurrent mode at temperature from -40 to 0 C and pressure 5-10 atm observing molar ratio of difluorochloromethane to tetrafluoroethylene (1-10): 1. Sorption solution is then rectified to produce gaseous head fraction, which is brought into contact with hydrogen on Pd/alpha-alumina catalyst at 80-200 C, space velocity 50 to 1000 h^-1, and tetrafluoroethylene-to-hydrogen molar ratio 0.9-1.2. Contact product is 1,1,2,2-tetrafluoroethane serving as ozone- safe chladone. Removal of tetrafluoroethylene from by-product fraction reaches 97%. EFFECT: increased tetrafluoroethylene recovery. 3 cl, 1 tbl, 2 ex