MEMBRANE SEPARATION TECHNOLOGIES: CURRENT DEVELOPMENTS

Abstract

This article provides a brief overview of major developments in membrane separation technologies over the last six years until 1995. Progress in membrane separation processes, membrane separation techniques and membranes for given separation problems are of primary interest. The order of importance for membrane separation technologies is: already commercialized, being commercialized and having great potential based on laboratory performance. Separations involving liquid solutions, gaseous mixtures and particle removals have been covered. Notable recent developments in eight commercialized technologies namely, reverse osmosis, ultrafiltration, microfiltration, electrodialysis, dialysis, pervaporation, gas permeation, emulsion liquid membrane are illustrated first. New membrane-based equilibrium separation processes involving gas-liquid and liquid-liquid contacting, distillation and adsorption are then considered. The progress in new membrane-based rate-governed separation processes of vapor permeation and continuous deionization are treated next followed by a number of developing techniques, e.g., perstraction, facilitated transport, osmotic distillation, contained liquid membrane, supported liquid membrane and supported polymeric liquid membrane. Developments in hybrid separation processes where one of the techniques employs membranes are identified. The potential and current reality of membrane reactors is provided at the end.