Patent ID: 7565815

Claim:
In a process for liquefying a natural gas stream containing methane and heavier hydrocarbon components wherein (a) said natural gas stream is cooled under pressure to condense at least a portion of it and form a condensed stream; and (b) said condensed stream is expanded to lower pressure to form said liquefied natural gas stream; the improvement wherein (1) said natural gas stream is treated in one or more cooling steps; (2) said cooled natural gas stream is expanded to an intermediate pressure and thereafter directed into a contacting device, thereby forming a volatile residue gas fraction containing a major portion of said methane and lighter components and a first liquid stream; (3) said first liquid stream is directed into a distillation column wherein said stream is separated into a more volatile vapor distillation stream and a relatively less volatile fraction containing a major portion of said heavier hydrocarbon components; (4) said more volatile vapor distillation stream is cooled sufficiently to condense at least a part of it, thereby forming a second liquid stream; (5) at least a portion of said expanded cooled natural gas stream is intimately contacted with at least part of said second liquid stream in said contacting device; and (6) said volatile residue gas fraction is cooled under pressure to condense at least a portion of it and form thereby said condensed stream.