A process is disclosed to remove a high-volatility component, such as
nitrogen, from a feed stream rich in methane to produce a product
substantially free of the high-volatility component. The feed stream is
expanded and fed to a phase separator which produces a vapor stream and a
liquid stream. The vapor stream is enriched in the volatile component. The
liquid stream, which is lean in the volatile component and rich in
methane, is pumped to a higher pressure and heated to produce a
pressurized liquefied product stream having a pressure sufficient for the
product stream to be at or below its bubble point and having a temperature
above about -112.degree. C. (-170.degree. F.).