Patent ID: 8429932
Filing Date: 2013-04-30
Classification: C10L,F25J,Y02C

Abstract:
1. A method for selective extraction of natural gas liquids from “rich” natural gas, comprising the steps of: positioning a storage vessel for liquid natural gas (LNG) at a straddle plant facility that has a series of separators operating at different selected hydrocarbon dew points in order to condense different natural gas liquids (NGLs); mixing a rich natural gas stream entering a first of the separators with a stream of LNG from the storage vessel by direct mixing to lower a temperature of the rich natural gas stream to a selected hydrocarbon dew point for a selected natural gas liquid in order to condense the selected natural gas liquid in the rich natural gas stream, the entire rich natural gas stream after LNG addition entering the first separator, a remainder of the rich natural gas stream exiting the first separator, after removal of the selected natural gas liquid, passing to a subsequent one of the series of separators; and mixing the remainder of the rich natural gas stream sequentially entering each of the separators after removal of the selected natural gas liquid with a stream of LNG from the storage vessel by direct mixing to lower a temperature of the remainder of the rich natural gas stream to the selected hydrocarbon dew point in order to condense a next selected natural gas liquid in the remainder of the rich natural gas stream, the entire remainder of the rich natural gas stream after LNG addition entering each separator, the temperature of the rich natural gas stream being controlled by controlling addition of LNG to the rich natural gas stream, separation taking place sequentially with natural gas liquids having progressively lower hydrocarbon dew points.