Method for separating nitrogen from lng

Abstract

The invention relates to a method for separating a nitrogen-enriched fraction from a liquefied methane-rich, nitrogen-containing fraction, wherein—the liquefied methane-rich, nitrogen-containing fraction is subjected to a stripping process to which a methane-rich fraction is supplied as a stripping medium,—during the stripping process, a nitrogen-depleted, methane-rich liquid fraction and a nitrogen-enriched fraction are obtained,—the nitrogen-enriched fraction is condensed, cooled, and separated into a methane-rich liquid fraction and a nitrogen-rich gas fraction in a rectificatory double-column process, and—the methane-rich liquid fraction and the nitrogen-rich gas traction are used to cool the nitrogen-enriched fraction. According to the invention, at least one sub-stream of the re-evaporated methane-rich liquid fraction is supplied to the stripping process as the stripping medium.

Dependencies are inferred from the claim text.