METHOD FOR PURIFICATION OF NITROGEN TRIFLUORIDE FROM TETRAFLUOROMETHAN Russian patent published in 2005 - IPC

FIELD: method for separation of fluorine-containing product mixture, in particular mixtures containing nitrogen trifluoride and tetrafluoromethan.

SUBSTANCE: purification of nitrogen trifluoride from tetrafluoromethan is carried out by nitrogen trifluoride absorption using as absorbent solvent inert to nitrogen trifluoride and wherein nitrogen trifluoride solubility is more than the same of tetrafluoromethan, under absorbent consumption and pressure sufficient to nitrogen trifluoride absorption, followed by nitrogen trifluoride desorption. As inert solution halogenated or perhalogenated compounds are used. Solution is fed into absorber under upper pressure, and absorption and following desorption steps are repeated. Part of purified nitrogen trifluoride, recovered on desorption step, is recycled into absorption step to dilute starting product contaminated with tetrafluoromethan.

EFFECT: nitrogen trifluoride of high purity with minimum losses of target product.

6 cl, 7 ex, 7 tbl, 3 dwg