Flüssigmembran‐Technik — ein zukunftweisender Extraktionsprozeß

Abstract

Abstract The liquid‐membrane technique – a promising extraction process . The liquid‐membrane technique is the name given to a simultaneous extraction/stripping process by means of a selective liquid phase (liquid membrane) separating two other miscible liquids (solvent, extract phase). This review attempts to summarize the present applications of the liquid‐membrane technique, pointing out the scope and limitations of this membrane process. No industrial application of the liquidmembrane technique is yet known. Nevertheless some applications have been suggested or claimed as patents, for example the removal of weak acids such as phenol from waste water, the separation of ethylene and methane, the concentration of ions with the aid of carriers in the liquid membrane and catalytic gas/liquid oxidations (oxidation of ethylene to acetaldehyde). Further proposed applications are in the field of medical technology (artificial systems for organ assistance or replacement). The summary of applications of the liquid‐membrane technique is preceded by a general discussion of the physical properties of liquid membranes and the relevant mass transfer mechanisms for a better understanding of this novel technology.