Method for separating an organic phase from an electrolyte-containing aqueous and organic phase

Abstract

A method for separating electrolyte-containing water from an organic phase by means of permeation on a hydrophobic separating means. The permeated organic solution is substantially depleted in water and the retained water is enriched with electrolytes.

1 . Method for separating an organic phase from a mixture of an organic phase comprising an organic solution and an aqueous phase comprising an electrolyte-containing water, wherein the mixture to be separated is passed over a hydrophobic porous separating means selected from the group consisting of (a) a flat textile structure without hydrophobic or organophilic coatings or further modification, (b) a flat textile structure with a hydrophobic coating of a hydrophobic and/or organophilic material wherein the coating is produced by applying a smooth hydrophobic coating onto a previously roughened surface of the separating means or by applying a rough hydrophobic coating to the surface of the separating means, (c) an organophilic membrane having a coating of hydrophobic material, said coating being produced by applying a rough hydrophobic coating to the surface of the separating means, (d) an organophilic membrane without coating, at least a part of the organic phase of the mixture permeating through the separating means while the electrolyte-containing aqueous phase is at least partially retained together with the remainder, if any, of the organic phase. 
     
     
         2 . Method according to  claim 1 , wherein said hydrophobic porous separating means is a flat textile structure of metal or plastic with a hydrophobic coating or hydrophobic surface. 
     
     
         3 . Method according to  claim 1 , wherein said flat textile structure is a woven or knitted fabric or a felt of polypropylene, polytetraflouoroethylene, polyinylidine fluoride or of a combination of such polymeric materials, without hydrophobic or organoophilic coatings. 
     
     
         4 . Method according to  claim 2  wherein said flat textile structure is a mesh of stainless steel. 
     
     
         5 . Method according to  claim 2 , wherein said hydrophobic porous separating means is a woven metal mesh with a hydrophobic coating said coating being a coating of a hydrophobic and/or organophilic material. 
     
     
         6 . Method according to  claim 5 , wherein said coating is formed of or by a material selected from the group consisting of Teflon® AF PTEF, PTFE dispersion, isocyanates, organic polymers, organic latex, fluoro polymers, fluoro latex, hybrid copolymers, and in particular diblock copolymers of a polysilsesquioxan block, preferably poly(methylsilsesquioxan) or poly(stearylsilsesquioxan) and a hydrophobic polymer block selected from the series comprising polystyrene, polymethyl acrylate, polyethyl hexyl acrylate, polymethyl methacrylate, polydecyl methacrylate, fatty acids, silanes, lacquers, silicones, silicone oils and polysilsesquioxans, or organic and/or fluoro deposits applied from a plasma process, and mixtures of any two or more thereof. 
     
     
         7 . Method according to  claim 1 , wherein said separating means is a hydrophobic woven metal mesh without further surface modification. 
     
     
         8 . Method according to  claim 5 , wherein the woven metal mesh has a mesh width <500 μm. 
     
     
         9 . Method according to  claim 8 , wherein said mesh width is <5 μm. 
     
     
         10 . Method according to  claim 1 , wherein the mixture to be separated is an emulsion or dispersion of a water-immiscible aromatic or aliphatic organic solvent or polymer and water and electrolyte. 
     
     
         11 . Method according to  claim 1 , wherein the mixture to be separated is an emulsion or dispersion of polycarbonate dissolved in organic solvent and water and electrolyte. 
     
     
         12 . Method according to  claim 1 , wherein the mixture to be separated is a mixture of polyether polyol and water and electrolyte. 
     
     
         13 . Method according to  claim 5 , wherein the hydrophobic coating is produced by applying a smooth hydrophobic coating onto a previously roughened surface of the separating means. 
     
     
         15 . Method according to  claim 5 , wherein the hydrophobic coating is produced by applying a rough hydrophobic coating to the surface of the separating means.