Gas conditioning process for the recovery of LPG/NGL (C₂₊) from LNG

摘要

Liquified petroleum gas or natural gas liquids may be recovered from liquified natural gas by receiving an input stream comprising substantially rich liquified natural gas, splitting the input stream into a direct stream and a bypass stream, heating the direct stream in a cross-exchanger to produce a stream of heat rich liquified natural gas, splitting the heated rich liquified natural gas into a primary column feed, an optional bypass stream and a secondary column feed.

主权项

1. A method for recovery of liquefied petroleum gas or natural gas liquids from liquefied natural gas and producing a desired mixture of conditioned lean liquefied natural gas and unconditioned rich liquefied natural gas, the method comprising:
receiving an input stream comprising substantially rich liquefied natural gas; splitting the input stream into a direct stream and a bypass stream; heating said direct stream in a cross-exchanger to produce a stream of heated rich liquefied natural gas; splitting said heated rich liquefied natural gas into a primary column feed and a secondary column feed; vaporizing feed from said secondary column feed in a vaporizer to produce a vaporized secondary column feed; fractionating a top feed, said primary column feed, and said vaporized secondary column feed in a fractionation unit to produce an overhead product stream and a bottom product stream; condensing feed from said overhead product stream by cooling said feed from said overhead product stream in said cross-exchanger to produce a condensed overhead product stream; pumping a reflux portion of said condensed overhead product stream to a top of said fractionation unit as said top feed; mixing said bypass stream with a balance portion of said condensed overhead product stream to produce an output stream; and vaporizing said output stream to produce a conditioned natural gas suitable for delivery to a pipeline or for commercial use, wherein said bypass stream provides a supply of rich liquefied natural gas to be blended with said condensed overhead product stream to provide said desired mixture of conditioned lean liquefied natural gas and unconditioned rich liquefied natural gas.