Application: Natural gas liquids (NGL) separation from liquefied natural gas (LNG) for Btu control of LNG and for enhanced product value. Primary application is for LNG import terminals.
Product: NGL stream containing ethane and heavier hydrocarbons. Can be used to produce light (ethane plus), medium (propane plus) or heavy (butane plus) product stream as desired for a specific project.
LNG is fed from storage to the process unit. Liquid feed pressure is increased with the feed pump (1) to proper pressure. Feed is then warmed in the main exchanger (2) against cold gas. The warmed feed stream is flashed (3) to separate the liquid and vapor. Liquid is pumped (4) to a demethanizer (5) where the NGL is separated. The vapor from this demethanizer joins the flash vapor which has been compressed (6). This stream is recondensed (2) to become LNG product which is pumped to sales pressure and sent to LNG vaporizers.
Internal operating parameter adjustments in the process unit allows the NGL stream recovery to fit a given application. Varying these parameters allows production of light or heavy NGL streams. A wide range of LNG feedstocks can be fed to a process unit and have the NGL successfully removed. Ethane recoveries of 90% are possible as well as near complete ethane rejection back into the LNG product.
Licensor: Black & Veatch Pritchard Inc.