Method and apparatus for removing nitrogen from a cryogenic hydrocarbon composition

摘要

Nitrogen is removed from a cryogenic hydrocarbon composition. A least a first portion of the cryogenic hydrocarbon composition is fed to a nitrogen stripper column as a first nitrogen stripper feed stream. A nitrogen-stripped liquid is drawn from the nitrogen stripper column. A liquid hydrocarbon product stream and a process vapour are produced comprising at least a step of depressurizing the nitrogen-stripped liquid to a flash pressure. The process vapour is compressed, and selectively split into a stripping portion and a non-stripping portion. A stripping vapour stream comprising at least the stripping portion is passed into the nitrogen stripper column. A vapour fraction is discharged as off gas, comprising a discharge fraction of overhead vapour from the nitrogen stripper column and comprising at least the bypass portion from the non-stripping portion of the compressed vapour, which bypasses a stripping section positioned in the nitrogen stripper column.