Patent ID: 7608188

Claim:
A liquid extraction system comprising: a feed source configured to supply a feed stream having a first pressure and comprising a solvent; a permeate source comprising an inlet and a fluid at a second pressure and configured to supply a permeate stream; a flow cell comprising a feed inlet, a feed outlet, a permeate inlet, a permeate outlet, and a membrane, the flow cell coupled to the feed source and the permeate source such that the membrane is intermediate, and may be placed in contact with, the feed and permeate streams; a flow pump in communication with the feed source, whereby the flow pump causes the feed stream to flow on the membrane; a vacuum pump operatively coupled to the permeate outlet of the flow cell and to the inlet of the permeate source, whereby the vacuum pump draws a vacuum on the permeate stream and the permeate side of the flow cell, causing permeate to flow from the permeate source, though the permeate inlet of the flow cell into the flow cell, and from the permeate outlet of the flow cell back into the permeate source; whereby a partial vapor pressure differential is induced across the membrane by a temperature differential between the feed and permeate streams and a differential between the first and second pressures, causing solvent to evaporate from the feed stream, pass through the membrane, and condense in the permeate stream flowing through the flow cell.