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U.S. Department of Energy
Office of Scientific and Technical Information

Process for extractive-stripping of lean hydrocarbon gas streams at high pressure with a preferential physical solvent

Patent ·
OSTI ID:5896777

This patent describes a process for selectively extracting hydrocarbons from a hydrocarbon gas feed stream with a preferential physical solvent which provides selective capability for extremely high recoveries according to any selected degree of a selected hydrocarbon component and heavier hydrocarbons within the group consisting of ethane, propane, butane, and pentane without the need simultaneously to recover hydrocarbons lighter than the selected hydrocarbon component from the hydrocarbon gas feed stream. The recoveries are: (a) ethane in amounts within the range of 2-100%, (b) propane in amounts within the range of 2-100%, (c) butane in amounts within the range of 2-100%, or (d) pentanes and higher molecular weight hydrocarbons in amounts ranging up to 100% by the following steps: (a) selectively extracting and stripping the hydrocarbon gas feed stream with the physical solvent to produce a residue hydrocarbon gas stream of pipeline specifications and a rich solvent stream containing ethane and heavier hydrocarbon components, (b) distilling the rich solvent to produce: (1) the selected hydrocarbon component and heavier hydrocarbons as overhead product. The improvement comprises the selective enrichment of the hydrocarbon gas feed stream with recycle of a selected portion of the overhead product to the extracting and stripping step, whereby the extremely high recoveries according to the any selected degree are feasible without the excessive solvent flow rates or the high reboiler temperatures.

Assignee:
Advanced Extraction Technologies, Inc., Houston, TX
Patent Number(s):
US 4695672
OSTI ID:
5896777
Country of Publication:
United States
Language:
English