Separating the hydrocarbons and fluids from pure natural gas produces pipeline quality dry natural gas. The two principle techniques for removing Natural Gas Liquids (NGLs) are the absorption and the cryogenic expander method. The absorption method is very similar to that of dehydration except that an absorbing oil is used instead of glycol. Once NGLs have been removed from the natural gas stream, they must be separated out, or fractionated.
Level control in the absorption method is typically found in flash drums, separation towers and reflux systems. Level control in the cryogenic method is applied to the separator and dehydrator.