METHOD OF SEPARATION OF CARBON ISOTOPES Russian patent published in 2001 - IPC

FIELD: extraction of carbon isotopes from industrial waste, monitoring of environment, recovery of radioactive ¹⁴C isotope from radioactive waste. SUBSTANCE: mixture of carbon isotopes containing 1.104 at % of ¹³C isotope is purified by cryogenic rectification, is separated in cascade of rectification packing columns. The resulting semiproduct is hydrogenated with hydrogen to methane. Hydrogenation uses burnt gas resulting from production of deuterium by rectification of liquid hydrogen containing 0.0015 at % of deuterium. Hydrogenation product is subjected to drying and fed into continuously operating counterflow adsorption column filled with zeolite NaX, NaA, CaA at bottom when, heated to 470 K, at tip methane is absorbed with zeolite when cooled to 200 K. Pressure in column is maintained at level of 10⁵ Pa. Concentration of ¹³C isotope is at least 99.95 wt.%, separation coefficient is at least 1.02; enrichment coefficient exceeds identical characteristic for the well known method by 6 times. EFFECT: more efficient separation method. 4 cl, 4 ex, 3 tbl