METHOD AND APPARATUS FOR REMOVING NITROGEN FROM A CRYOGENIC HYDROCARBON COMPOSITION

摘要

Nitrogen is removed from a cryogenic hydrocarbon composition. The cryogenic hydrocarbon composition is split into a first portion and a second portion having the same composition and phase as the first portion. The first portion is fed to a nitrogen stripper column, operating at a stripping pressure, from which a nitrogenstripped liquid is drawn. The second portion is fed into the nitrogen-stripped liquid or in a liquid hydrocarbon product stream or in a process vapour which are produced from the nitrogen-stripped liquid involving at least a step of depressurizing the nitrogen-stripped liquid to a flash pressure that is lower than the stripping pressure. The second portion bypasses the nitrogen stripper column between the stream splitting and the feeding of the second portion into the nitrogen-stripped liquid or the liquid hydrocarbon product stream or the process vapour.