Patent ID: 8499581
Filing Date: 2013-08-06
Classification: F25J

Abstract:
1. A method for recovery of liquefied petroleum gas or natural gas liquids from liquefied natural gas, the method comprising: splitting an input stream comprising substantially rich liquefied natural gas into a direct stream and a bypass stream; heating said direct stream in a cross-exchanger to produce a heated rich liquefied natural gas stream; splitting said heated rich liquefied natural gas into a primary column feed and a secondary column feed; vaporizing at least a major portion of said secondary column feed in a vaporizer to produce a vaporized secondary column feed; expanding said vaporized secondary column feed in an expander to produce a vaporized and expanded secondary column feed; fractionating a top feed, said primary column feed, and said vaporized and expanded secondary column feed in a fractionation unit to produce an overhead product stream and a bottom product stream; compressing said overhead product stream in a compressor which is coupled to said expander to produce a compressed overhead product stream; condensing at least a major portion of said compressed overhead product stream by cooling said compressed overhead product stream in said cross-exchanger to produce a compressed and condensed overhead product stream; directing a reflux stream comprising a part of both of said compressed and condensed overhead product stream and an output stream to a top of said fractionation unit as said top feed; mixing said bypass stream with a balance stream of said compressed and condensed overhead product stream to produce said output stream; and vaporizing said output stream to produce a conditioned natural gas suitable for delivery to a pipeline or for commercial use.