Method for removing mercaptans from lng

摘要

Method for separating mercaptans from a natural gas feed stream to be liquified, comprises (a) introducing the feed stream to a refluxed scrub column to form an overhead methane stream and a liquid bottoms stream rich in ethane and heavier hydrocarbons; (b) fractionating the bottoms stream from step (a) to form a natural gas liquids stream consisting of pentane and heavier hydrocarbons, and on or more overhead streams consisting primarily of ethane, propane and butane; (c) removing mercaptans from at least one of the overhead streams from step (b) to form a mercaptan-lean stream; (d) partially condensing and separating the overhead stream from step (a) to form vapour and liquid streams; (e) recycling at least a portion of the liquid stream from step (d) as at least a portion of the reflux to the scrub column in step (a); and (f) cooling the vapour stream from step (d) to form a liquified natural gas stream.