FIELD: chemistry.
SUBSTANCE: invention relates to a method of separating C2+-hydrocarbons from a starting fraction primarily containing nitrogen and hydrocarbons. The disclosed method includes: a) the starting fraction is partially condensed and fractionally divided into C2+-hydrocarbon impoverished and rich fractions; b) the C2+-hydrocarbon impoverished fraction is partially condensed and divided into a liquid fraction which forms at least a partially reverse stream for fractional separation, and a C2+-hydrocarbon impoverished gaseous fraction; c) the C2+-hydrocarbon impoverished gaseous fraction is divided in a double-column process into a nitrogen-rich and a methane-rich fraction. The liquid fraction obtained at step (b) is also at least partially fed into the double-column process and divided therein into a nitrogen-rich and a methane-rich fraction.
EFFECT: invention is aimed at improving the efficiency of separating C2+-hydrocarbons.
4 cl, 3 dwg
