Abstract: A method and apparatus for continuously separating a volatile solvent from a solution of the solvent and a relatively non-volatile solute at a temperature substantially below the boiling point of the solvent. The apparatus includes opposed, slightly spaced, extended surfaces across which a temperature differential is established. In an exemplification of desalination, salt water is applied along an upper edge of the warmer surface and flows downwardly by gravity. Condensate of warm vapor from the warmed salt water is formed and collects on the cooler surface and flows downwardly for subsequent collection and removal. The cooler surface can be maintained cool by application of sea water, and the warmer surface can be maintained warm by the rays of the sun or by any heated discharge whose heat would ordinarily be wasted, such as coolant from an internal combustion engine or a nuclear power reactor.

Abstract: A method and apparatus for separating a volatile solvent from a solution of the solvent and a relatively non-volatile solute. A temperature gradient is provided across solvent-absorbing and gas-entraining matrix material infiltrated with the solution, resulting in concentration of the solution near the hotter matrix surface and dilution of the solution near the cooler matrix surface. The process lends itself to the desalination of sea water and to applications which require the recovery of either solute or solvent.