| 摘要 |
A process and apparatus for reducing the nitrogen content of a liquefied, normally gaseous feed comprising predominantly methane with a significant amount of nitrogen and having an elevated pressure in which the feed is separated into a first vapor phase portion, containing a major portion of nitrogen, and an unvaporized first liquid phase portion, the first vapor phase portion is cooled, the cooled first vapor phase portion is further separated into a second vapor phase portion, further enriched in nitrogen, and an unvaporized second liquid phase portion, the unvaporized first and second liquid phase portions are combined, an expanded body of fluids is formed from the combined unvaporized first and second liquid phase portions, at least part of the cooling of the first vapor phase portion is carried out by passing the same in indirect heat exchange with the expanded body of fluids formed from the unvaporized first and second liquid phase portions and the expanded body of fluids formed from the unvaporized first and second liquid phase portions is separated into a third vapor phase portion and an unvaporized third liquid phase portion.
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