FIELD: chemistry.
SUBSTANCE: invention relates to method and device to remove nitrogen from cryogenic hydrocarbon compositions, nitrogen-containing and methane-containing liquid phase. By-product vapour from cryogenic hydrocarbon composition, at low pressure of 0.1 to 0.2 MPa, is compressed to separation pressure in range from 0.2 to 1.5 MPa. Said compressed vapour is partially liquefied by heat exchange of compressed vapour with auxiliary flow of coolant and, thus, inflow of heat from compressed vapour into stream of auxiliary coolant into cooling mode. Condensed fraction of partially liquefied compressed vapour is subjected to pressure release and at least a portion thereof is re-fed into cryogenic hydrocarbon composition. Exhaust gas, consisting of non-condensed vapour fraction of partially liquefied compressed vapour, is removed from first gas-liquid separator. Cooling mode is corrected to adjust calorific capacity removed vapour fraction.
EFFECT: technical result is enabling adjustment of calorific capacity of removed vapour fraction.
17 cl, 4 dwg, 5 tbl
