FIELD: chemistry.
SUBSTANCE: invention relates to method and device for removing nitrogen from cryogenic hydrocarbon composition. At least a first portion of a cryogenic hydrocarbon composition is fed to a nitrogen stripper column as a first nitrogen stripper feed stream. Nitrogen-stripped liquid is drawn from nitrogen stripper column. Liquid hydrocarbon product stream and process vapour are produced comprising at least a step of depressurising nitrogen-stripped liquid to a flash pressure. Process vapour is compressed, and selectively split into a stripping portion and a non-stripping portion. Stripping vapour stream comprising at least stripping portion is passed into nitrogen stripper column. Vapour fraction is discharged as off gas, comprising a discharge fraction of overhead vapour from nitrogen stripper column and comprising at least bypass portion from non-stripping portion of compressed vapour, which bypasses a stripping section positioned in nitrogen stripper column.
EFFECT: technical result is prevention of imbalance in nitrogen stripper column and reduced loss of vapour.
17 cl, 2 dwg, 3 tbl
